Note: Descriptions are shown in the official language in which they were submitted.
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AIR FILTRATION SYSTEM, AIR FILTRATION DEVICE, AND AIR FILTRATION
MODULE FOR USE THEREWITH
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Design Patent Application
No. 29/737,110,
filed June 5, 2020, entitled "AIR FILTRATION SYSTEM," U.S. Design Patent
Application No.
29/737,141, filed June 5, 2020, entitled "AIR FILTRATION STAND," U.S. Design
Patent
Application No. 29/737,148, filed June 5, 2020, entitled "AIR FILTRATION
MODULE," U.S.
Design Patent Application No. 29/737,150, filed June 5, 2020, entitled "AIR
FILTRATION
MODULE," and U.S. Design Patent Application No. 29/737,154, filed June 5,
2020, entitled "AIR
FILTRATION DEVICE," the entire contents of which are incorporated herein by
reference in their
entireties for all purposes.
TECHNICAL FIELD
[0002] This disclosure relates to air filtration, and more particularly to
an air filtration system,
an air filtration device, and an air filtration module.
BACKGROUND OF THE INVENTION
[0003] Currently, high efficiency air filtration is typically achieved by
moving ambient air
through either a high efficiency particulate air (HEPA) or an ultra-low
penetration air (ULPA)
filtration system. HEPA and ULPA filtration are capable of achieving
relatively low particulate
levels, but require a substantial system pressure drop to transport air
through the large, dense filters
necessary for effective particulate collection. Additionally, current HEPA and
ULPA filtration
systems generally do not remove volatile organic compounds (VOCs), oxides or
odors.
[0004] There remains a need in the art for air filtration systems and
methods capable of
achieving high efficiency air filtration, together with removal of other
contaminants such as VOCs.
SUMMARY OF THE INVENTION
[0005] In one aspect, the present disclosure generally relates to an air
filtration system, an air
filtration device, and an air filtration module for removing ultra-fine
particles (UFPs), pathogens
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(e.g., viruses, bacteria, etc.), volatile organic compounds (VOCs), oxides or
odors. The systems,
devices, and filter modules of the disclosure perform at enhanced filter and
power efficiencies.
[0006] In certain aspects, an air filtration system is provided that
includes a docking base for
receiving a removable, portable air filtration device in fluid communication
with the docking base.
In certain embodiments, the air filtration system further includes the
removable, portable air
filtration device. The portable air filtration device may optionally include
an air filtration module.
[0007] In certain aspects, the air filtration system generally comprises a
docking base including
a docking opening for receiving a portable air filtration device in fluid
communication with the
docking base; one or more unfiltered air inlets for directing unfiltered air
to a portable air filtration
device when docked in the docking opening; an air outlet for directing air
into a portable air
filtration device when docked in the docking opening; a removable secondary
media retention
feature; and one or more sound dampening features to reduce air flow noise
and/or vibrational
noise during use.
[0008] In certain aspects, a portable air filtration device is provided,
which may be used alone
or which may be interfaced with the docking base. The portable air filtration
device may include
a device housing including an external air intake for directing unfiltered air
into the device; a filter
module disposed within the housing; a fan plenum assembly including at least
one fan to draw
input air into the device and to generate a positive pressure air flow through
the device; wherein
the fan plenum assembly is located upstream of the filter module such that
input air flow is directed
from the fan plenum assembly into an input, turbulent air flow region of the
filter module during
use.
[0009] In some embodiments, the fan plenum assembly may comprise a fan air
intake side, a
fan air outlet side, and a fan plenum seal on the fan air outlet side of the
fan plenum assembly
interfaced with the fan plenum attachment seat of the filter module to form an
air tight seal between
the fan plenum assembly and the filter module.
[0010] In yet other aspects, a filter module is provided, which may be used
in connection with
the portable air filtration device or air filtration systems of the
disclosure. The filter module may
comprise an external housing having a filtered air outlet for directing
filtered air from the device;
an internal chassis having a face plate including an input air inlet for
directing input air into the
filter module and a fan plenum attachment seat for securing the filter module
to a fan plenum
assembly; at least two primary filter media, wherein the at least two primary
filter media are
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secured to the internal chassis in a spaced apart orientation in a parallel
air flow configuration;
wherein the internal chassis is positioned substantially within the external
housing with the face
plate sealed to the perimeter of a surface of the external housing so as to
form the exterior of the
filter module, with the at least two primary filter media located within the
filter module so as to
separate an input air flow region from a filtered air flow region within the
filter module; and
wherein an input, turbulent air flow region is created within the filter
module in a space between
the spaced apart primary filter media during use.
[0011] In certain embodiments, the primary filter media may be pleated
composite primary
filter media that are over-molded into a structural frame, and the structural
frame is secured to the
internal chassis.
[0012] In yet other embodiments, the internal chassis further comprises an
input air flow path
seal opposite the input air inlet, and opposed side walls, each having one or
more filter media
retention features that secure the at least two primary filter media to the
side walls of the internal
chassis; and wherein the input, turbulent air flow region is created within
the filter module in a
space between the chassis input air inlet, the chassis input air flow path
seal, the chassis opposed
side walls, and the spaced apart primary filter media during use.
[0013] These and other aspects of the invention are evident in the drawings
and in the
description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates a perspective view of an exemplary air filtration
system with a
portable air filtration device inserted into a docking base, in accordance
with embodiments of the
disclosure.
[0015] FIG. 2 illustrates a perspective view of an exemplary air filtration
system with a
portable air filtration device removed from a docking base, in accordance with
embodiments of
the disclosure.
[0016] FIG. 3 illustrates a perspective view of an exemplary air filtration
system having a
docking base with no portable air filtration system docked, in accordance with
embodiments of
the disclosure.
[0017] FIG. 4 illustrates an exploded view of an exemplary air filtration
system, in accordance
with embodiments of the disclosure.
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[0018] FIG. 5 illustrates a perspective view of an exemplary air filtration
system having a
docking base with no portable air filtration system docked and the secondary
media retention
feature and secondary media removed, in accordance with embodiments of the
disclosure.
[0019] FIG. 6 illustrates an exploded perspective view of an interior frame
of a docking base,
in accordance with embodiments of the disclosure.
[0020] FIGS. 7A-7D illustrate exemplary secondary media, in accordance with
embodiments
of the disclosure. FIG. 7A shows a perspective top view of an exemplary
secondary media. FIG.
7B shows a perspective bottom view of an exemplary media. FIG. 7C shows a
cross section of
the exemplary secondary media of FIGS. 7A-7B, and FIG. 7D shows a detail of
the exemplary
secondary media.
[0021] FIG. 8 illustrates a perspective view of an exemplary portable air
filtration device with
a filter module inserted, in accordance with embodiments of the disclosure.
[0022] FIG. 9 illustrates a bottom perspective view of the portable air
filtration device of FIG.
8, in accordance with embodiments of the disclosure.
[0023] FIG. 10 illustrates a perspective view of an exemplary portable air
filtration device
with a filter module released from the housing of the device, in accordance
with embodiments of
the disclosure.
[0024] FIG. 11 illustrates a perspective view of an exemplary portable air
filtration device
with a filter module removed from the housing of the device, in accordance
with embodiments of
the disclosure.
[0025] FIG. 12 illustrates a top perspective view of an exemplary portable
air filtration device
without a filter module in the housing of the device, in accordance with
embodiments of the
disclosure.
[0026] FIG. 13A-13B illustrates a fan plenum assembly, in accordance with
embodiments of
the disclosure. FIG. 13A shows a front view of a fan plenum assembly, while
FIG. 13B shows a
cross section of a fan plenum seal of the fan plenum assembly of FIG. 13A.
[0027] FIG. 14 illustrates a perspective view of fan plenum assembly sealed
in an air tight
configuration to a filter module, in accordance with embodiments of the
disclosure.
[0028] FIG. 15 illustrates cross section of an exemplary portable air
filtration device without
a filter module in the housing of the device, in accordance with embodiments
of the disclosure.
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[0029] FIG. 16 illustrates a fan plenum assembly with an air flow path
diffuser, in accordance
with embodiments of the disclosure.
[0030] FIGS. 17A-17B illustrate an exemplary pre-filter media, in
accordance with
embodiments of the disclosure. FIG. 17A shows a perspective view of a pre-
filter media, while
FIG. 17B shows a detail cross-section of the pre-filter media.
[0031] FIG. 18 illustrates a perspective view of a filter module, in
accordance with
embodiments of the disclosure.
[0032] FIG. 19 illustrates a cross-section of a filter module, in
accordance with embodiments
of the disclosure.
[0033] FIG. 20 illustrates a perspective view of an alternative embodiment
of a filter module,
in accordance with embodiments of the disclosure.
[0034] FIG. 21A-21B illustrates top (FIG. 21A) and bottom (FIG. 21B) view
of a filter
module, in accordance with embodiments of the disclosure.
[0035] FIG. 22 illustrates a bottom perspective view of a filter module, in
accordance with
embodiments of the disclosure.
[0036] FIG. 23 illustrates a front perspective view of an internal chassis
of a filter module, in
accordance with embodiments of the disclosure.
[0037] FIG. 24 illustrates a back perspective view of an internal chassis
of a filter module, in
accordance with embodiments of the disclosure.
[0038] FIG. 25 illustrates a detail perspective view of an internal chassis
of a filter module
secured to primary filter media, in accordance with embodiments of the
disclosure.
[0039] FIG. 26A-26B illustrate an internal chassis of a filter module
secured to primary filter
media, in accordance with embodiments of the disclosure. FIG. 26A shows a
cross section of the
internal chassis secured to primary filter media, while FIG. 26B shows a
detail cross-section of an
exemplary seal between the primary filter media and the internal chassis.
[0040] FIG. 27 illustrates a perspective cross-section of a filter module
including to an internal
chassis secured to primary filter media, in accordance with embodiments of the
disclosure.
[0041] FIG. 28 illustrates an exploded perspective view of a filter module,
in accordance with
embodiments of the disclosure.
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[0042] FIG. 29 illustrates a perspective view of the insertion of an
internal chassis secured to
primary filter media into the external housing of a filter module, in
accordance with embodiments
of the disclosure.
[0043] FIG. 30A-30D illustrate an exemplary primary filter media, in
accordance with
embodiments of the disclosure. FIG. 30A shows a top view of a primary filter
media, FIG. 30B
shows a cross-section of the filter media along the direction of the filter
media pleating, FIG. 30C
shows a cross-section of the primary filter media across the direction of the
filter media pleating,
and FIG. 30D shows a detail cross-section of the primary filter media.
[0044] FIG. 31 depicts a block diagram of example components of a
filtration device, in
accordance with an embodiment of the disclosure.
[0045] FIG. 32 shows an example controller of a filtration device, in
accordance with an
embodiment of the disclosure.
[0046] FIG. 33 is an example computing system that may implement various
systems and
methods discussed herein.
[0047] FIG. 34 illustrates particle size removal efficiency of an exemplary
air filtration
system, in accordance with embodiments of the disclosure.
[0048] FIG. 35 illustrates concentration change for various challenge
chemicals during testing
using an exemplary air filtration system, in accordance with embodiments of
the disclosure.
[0049] FIG. 36 illustrates for various challenge chemicals during testing
using an exemplary
air filtration system, in accordance with embodiments of the disclosure.
DETAILED DESCRIPTION
[0050] The present disclosure generally relates to an air filtration
system, an air filtration
device, and an air filtration module for removing ultra-fine particles (UFPs),
pathogens (e.g.,
viruses, bacteria, etc.), volatile organic compounds (VOCs), oxides or odors.
The systems,
devices, and filter modules of the disclosure perform at enhanced filter and
power efficiencies.
Without intending to be limited by theory, the systems and devices described
herein generally
utilize a low face velocity of less than or equal to 5 cm/s at the surface of
the filtration media (i.e.,
particle velocity at the surface of the filtration media) to achieve desired
filtration efficiencies.
[0051] In certain embodiments, the devices and systems of the disclosure
provide a particle
velocity at the surface of a primary filter component(s) (face velocity) less
than or equal to 5 cm/s,
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4 cm/s, 3 cm/s, 2 cm/s, or 1 cm/s. In certain aspects, at such face
velocities, with the filtration
module described herein, the collection efficiency for the filtration media of
the filtration module
is greater than 99.99%, 99.999%, 99.999%, 99.9999%, or 99.99999%, which
greatly out performs
HEPA filters known in the art. Further, in certain embodiments, using a face
velocity less than or
equal to 5 cm/s, 4 cm/s, 3 cm/s, 2 cm/s, or 1 cm/s, also produces a lower
pressure drop across the
filtration module, as compared to using a higher face velocity, e.g., greater
than 5 cm/s, which is
beneficial for overall system efficiency (e.g., less demanding for the
blower/fan(s)).
[0052] Aspects of the present disclosure generally relate to an air
filtration system for
removing ultra-fine particles (UFPs), pathogens (e.g., viruses, bacteria,
etc.), volatile organic
compounds (VOCs), oxides or odors. With reference to FIG. 1, in one
embodiment, an air
filtration system 100 of the disclosure includes a docking base 104 for
receiving a removable,
portable air filtration device 102 in fluid communication with the docking
base 104. In certain
embodiments, the air filtration system 100 further includes the removable,
portable air filtration
device 102. The portable air filtration device 102 may optionally include an
air filtration module
106 of the disclosure. In this regard, FIG. 2 illustrates a portable air
filtration device 102 removed
from docking base 104, and FIG. 3 illustrates docking base 104 without
portable air filtration
device 102. During use, a portable air filtration device 102 may be removably
docked in the
docking base 104, and the air filtration device 102 may operate to generate a
positive pressure air
flow through the docking base 104, into the air filtration device 102, and
through a filter module
106 housed within the air filtration device 102. In one implementation, the
filtration device 102
achieves extremely high filter efficiencies of at least 99.9999% at low face
velocities less than or
equal to 5 cm/s. At such face velocities, the filtration device 102 has a
filter efficiency of
99.99999% for particles below 300 nm, as well as pathogens of similar size.
[0053] With reference to FIG. 4, in certain embodiments, the docking base
104 includes a
docking opening 120 for receiving a removable, portable air filtration device
102; one or more
unfiltered air inlets 122 for directing unfiltered air to a removable,
portable air filtration device
102 when docked in the docking opening 120; an air outlet 124 for directing
air into a removable,
portable air filtration device 102 when docked in the docking opening; a
removable, secondary
media retention feature 126; and one or more sound dampening features (not
shown) to reduce air
flow noise and/or vibrational noise during use. The docking base may further
include a power
charging port (not shown) in electrical communication with a portable air
filtration device 102
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when docked, and an air entry mesh 128 at each of the one or more unfiltered
air inlets 122 to
remove large particulates from unfiltered air drawn into the docking base 104
during use. FIG. 5
illustrates the secondary media retention 126 with secondary filter media 108
removed from the
docking base 104.
[0054] In certain embodiments, air enters into the docking base 104
initially through the air
entry mesh 128 at each of the unfiltered air inlets 122. Although illustrated
with the air entry mesh
128 at each of the unfiltered air inlets 122 disposed at each side of the
docking base 104, the
disclosure is not so limited and alternative configuration and orientations
are within the scope of
the disclosure. For instance, unfiltered air inlets 122 and related air entry
mesh 128 may be
configured at the front and back or along the side walls of the docking base
104. In one
implementation, air entry meshes 128 are separate components which are
attached to the docking
base 104. In another implementation, air entry meshes 128 are integrated into
the docking base
104 as a unitary component. Air entry meshes 128 may be constructed from a
light-weight, durable
material.
[0055] Air entry meshes 128 serve as an initial entry port for input air to
enter the docking
base 104 and thereby the air filtration system 100, and is therefore also a
region of large particle
filtration. The openings of the air entry mesh 128 are sized and spaced such
that each of the
openings are large enough to reduce resistance to air being drawn into the
docking base 104 and
small enough to prevent very large particles from entering the docking base
104. In one
implementation, the openings in the air entry mesh 128 are generally slat
shaped openings of a
finite width and length arranged in parallel. The parallel arrangement of the
openings allows for
a linear reduction in flow resistance that is directly related to the number
of openings without
sacrificing the minimum opening dimension, which in turn governs the size of
particles that are
allowed to pass through the openings.
[0056] With reference to FIG. 6, in certain embodiments, the docking base
102 may be
configured to form one or more air flow paths between the unfiltered air
inlets and the air outlet.
By way of example, the docking base 102 may be configured to include an
interior docking frame
130 that includes the one or more air flow paths located between the docking
opening 120 for
receiving a portable air filtration device 102 and the exterior of the docking
base 104. The air flow
paths may be formed between one more baffles 132 or similar flow direction
surfaces. The interior
docking frame 130 may also be configured to include one or more openings 134,
136 to
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accommodate the portable air filtration device, the secondary filter retention
feature, respectively.
The air flow paths may direct air from the unfiltered air inlet inlets into
the docking base, under
the secondary filter media (if present) and into the portable air filtration
device. In certain
embodiments, the one or more air flow paths may form non-turbulent air flow
paths (e.g.,
transitional or laminar air flow paths). In certain embodiments, the sound
dampening features (not
shown) may be located along or adjacent to the air flow paths, at the bottom
of the docking base,
or a combination thereof.
[0057] In certain embodiments, the removable, secondary media retention
feature 126 may be
located in the air flow path between the unfiltered air inlets 122 and the air
outlet 124. By way of
example, the removable, secondary media retention feature 126 may be
configured in any suitable
manner, e.g., as a clip-on frame, a slide-in frame, etc. In certain aspects,
the docking base 104
may further comprises a secondary media 108 housed in the removable secondary
media retention
feature 126. The secondary media retention feature 126 and secondary media 108
may be
configured to provide a desired air flow residence time through the secondary
media 108 during
use, e.g., so as to maximize filtering efficiency of the secondary media 108.
[0058] In certain embodiments, the secondary media 108 may comprise an
activated carbon
media to remove volatile organic compound (VOCs), oxides, odors, and
combinations thereof. By
way of example, the activated carbon media be comprised of at least two
electrostatically charged
scrim layers enclosing granulated activated carbon. In certain embodiments,
between 150 grams
to about 175 grams, preferably about 160 grams of the granulated activated
carbon is enclosed
within the electrostatically charged scrim layers of the activated carbon
media. By way of
example, the granulated activated carbon may be a 12 x 40 standard sieve size
coconut shell
activated carbon, a 6 x 12 standard sieve size coconut shell activated carbon,
or a 4 x 8 standard
sieve size coconut shell activated carbon. In other embodiments, the secondary
media 108 may
comprise a pleated composite primary filter media that is over-molded into a
structural frame.
[0059] With reference to FIGS. 7A-7D, an exemplary embodiment of a
secondary media filter
700 is illustrated, with FIG. 7A showing a top view, FIG. 7B showing a bottom
view, and FIG.
7C showing a cross-section of the secondary media filter 700. The secondary
media filter 700
includes a bottom container 702 and a lid 704. With reference to FIG. 7D, a
detail of the interface
between the top lid 704 and the bottom container 704 is illustrated, showing
the top lid 704 and
bottom container 702 being bonded together at connection features 708 to form
an internal media
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enclosure 706. Any suitable method for bonding the top lid 704 to the bottom
container 702 may
be used, including, e.g., ultrasonic welding, thermal bonding, adhesives, etc.
Each of the bottom
container 702 and top lid 704 comprise multiple air flow openings 702a, 704a,
respectively, to
allow air flow through an internal media enclosure 706. As illustrated, the
top lid 704 includes
four air flow openings 704a, and the bottom container 702 includes eight air
flow openings 702a.
However, the disclosure is not so limited, and any suitable air flow opening
configuration, e.g.,
having more or fewer air flow openings, sufficient to provide desired airflow
and filter media
residence time may be utilized. By way of example, in the embodiment
exemplified, each air flow
opening is covered with a scrim layer 710 that allows for air flow through the
opening. In certain
embodiments, the scrim layer is an electrostatically charged scrim layer,
e.g., nonwoven scrim
substrate. The internal media enclosure comprises activated carbon filtration
media 712.
[0060] In certain embodiments, the air filtration system 100 optionally
includes a user control
device 112. The user device 112 is in communication with the portable
filtration device 102 for
controlling the operations of the filtration device 102. The user device 112
is generally any form
of computing device, such as remote control, a mobile device, tablet, personal
computer,
multimedia console, set top box, or the like, capable of interacting with the
filtration device 102.
The user device 112 may communicate with the filtration device 102 via a wired
(e.g., Universal
Serial Bus (USB) cable) and/or wireless (e.g., Bluetooth or WiFi) connection.
In addition to
controlling the operation of the filtration device 102, the user device 112
may be used to monitor
the performance of the filtration device 102, including filter and collection
efficiency, power
consumption, system pressure, air flow rates, and the like. The user device
112 further provides
real time information on power level, fan speed, filter life, and pressure
alarm.
[0061] Docking base 104 may be constructed from a light-weight, durable
material. By way
of non-limiting example, suitable materials for construction of docking
base104 may include
anodized aluminum, titanium, titanium alloys, aluminum alloys, fibrecore
stainless steel, carbon
fiber, KevlarTM, polycarbonate, acrylonitrile-butadiene- styrene (ABS),
polyurethane, or any
combination of the mentioned materials. The sound dampening features may be
formed from any
suitable materials known in the art for such purposes, e.g., polyurethane
foam, silicone, cotton
fiber, etc.
[0062] In other aspects, the present disclosure relates to a portable air
filtration device 102,
which may be used independently or in connection with the air filtration
system 100 disclosed
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herein. In certain embodiments, the portable air filtration device 102 may be
configured to
interface in fluid communication with the docking stand 104 of the air
filtration system 100
disclosed herein. Alternatively, the portable air filtration device 102 may
operate in a "stand-
alone" configuration without the docking stand of the air filtration system.
In yet other
embodiment, the portable air filtration device 102 may interface with
alternative docking stands
(not shown). In yet other embodiments, the portable air filtration device 102
may interface in fluid
communication with face masks, air-flow hoses, or breathing tubes of power-
assisted air purifying
(PAAP) respirators, continuous positive airway pressure (CPAP) machines, bi-
level positive
airway pressure (BiPAP) machines, and/or ventilators (not shown).
[0063] With reference to FIGS. 4 and 8, in certain embodiments, the
portable air filtration
device 102 includes a device housing 200 including an external air intake 216
for directing input
air into the filtration device 102. The filtration device 102 also includes a
fan plenum assembly
218 disposed within the device housing 200 and including at least one fan 220
to draw input air
into the filtration device 102 and to generate a positive pressure air flow
through the filtration
device 102 (see FIG. 15). As described herein, the filtration device 102 may
also include a filter
module 106 disposed within the device housing 200. The filter module 106 may
include an
external filter module housing 300 having a filtered air outlet 302 for
directing filtered air from
the filtration device 102, an internal chassis 304 for securing at least two
primary filter media 306,
and a fan plenum attachment seat 308 for securing the filter module 106 to the
fan plenum
assembly 218 (see FIG. 19). In certain embodiments, the fan plenum assembly
218 is located
upstream of the filter module 106 within the device housing 200 such that
input air flow is directed
from the fan plenum assembly 218 into the filter module 106 during use.
[0064] In certain embodiments, the filtration device 102 includes a device
housing 200 to
enclose the internal components of the filtration device 102. In one
implementation, device
housing 200 includes a removable cover 202 which, when attached or affixed to
the housing
encases the internal components of the filtration device 102. For instance,
removable cover 202
may be used to access compartments holding internal components such as pre-
filter 210, one or
more power source(s) 208, etc. It will be appreciated, however, that more or
fewer covers may be
included for accessing a variety of different internal components. While the
removable cover 202
as illustrated extends the entire length of one side of housing 200, the
disclosure is not so limited.
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[0065] Device housing 200 may also include a user control interface 204 for
providing
operation of the device. In certain embodiments, the housing 200 may also
include one or more
filtration module releasable securing features 206, for releasably securing
the filtration module to
the filtration device housing. By way of non-limiting example, such releasable
securing features
may be configured as a clip, snap, slide, set screw, or similar releasable
fixing element. In certain
embodiments, the external filter module housing 300 may include one or more
housing retention
features 330 that may be sized and shaped so as to interface with filtration
module releasable
securing features 206.
[0066] With reference to FIG. 9, a perspective bottom view of the
filtration device 102 is
shown. In certain embodiments, air enters into the filtration device 102
initially through the air
entry mesh 212 attached or integrated at the bottom of the housing 200. In
some embodiments,
the bottom of housing 200 includes an opening or other type of access port to
allow for
attachment/integration of an air entry mesh 212. Although illustrated with the
air entry mesh 212
disposed at the bottom of the housing 200, the disclosure is not so limited
and alternative
configuration and orientations are within the scope of the disclosure. For
instance, the air entry
mesh 212 may be configured on any of the other walls of housing 200. In one
implementation,
the air entry mesh 212 is a separate component which is attached to the
housing 200. In another
implementation, the air entry mesh 212 is integrated into the housing 200 as a
unitary component.
The air entry mesh 212 may be constructed from a light-weight, durable
material.
[0067] The air entry mesh 212 serves as an initial entry port for input air
to enter the filtration
device 102 and is therefore also a region of large particle filtration. The
openings of the air entry
mesh 212 are sized and spaced such that each of the openings are large enough
to reduce resistance
to air being drawn into the filtration device 102 and small enough to prevent
very large particles
from entering the filtration device 102. In one implementation, the openings
in the air entry mesh
212 are generally openings having a defined shape (e.g., cylinders, pentagons,
hexagons, octagons,
etc.) of a finite thickness and diameter arranged in parallel. The parallel
arrangement of the
openings allows for a linear reduction in flow resistance that is directly
related to the number of
openings without sacrificing the minimum opening dimension, which in turn
governs the size of
particles that are allowed to pass through the openings.
[0068] In particular embodiments, the openings have a diameter ranging from
approximately
1.1 mm to approximately 2.2 mm, preferably from approximately 1.3 mm to
approximately 1.6
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mm, e.g., approximately 1.4 mm, approximately 1.5 mm, etc.. In certain
embodiments, the
openings have a pitch between holes of approximately 2.2 mm to approximately
2.6 mm,
preferably approximately 2.25 mm to approximately 2.4 mm. It will be
appreciated that these
dimensions are exemplary only and the openings may include larger or smaller
dimensions.
[0069] As described herein, in addition to superior filtration efficiency,
the filtration device
102 achieves reduced power consumption. Without intending to be limited by
theory, generally,
the functionality of a filter over time has a direct effect on the performance
and efficiency of a
power source 208. For instance, as a filter is loaded with particles the
overall resistance of the
filter is increased. When the filter resistance increases, it requires more
energy output from the
power source 208 to drive the fans 220 at the flow rate/face velocity set in
the unloaded state. As
such, in some embodiments, the air filtration system 100 and/or filtration
device 102 includes
secondary filters 108 and/or pre-filters 210 to extend the life of the filter
module 106 and to reduce
power consumption.
[0070] The power source 208 may utilize, without limitation, direct current
(DC), alternating
current (AC), solar power, battery power, and/or the like. In one particular
implementation, the
power source 208 includes one or more lithium ion batteries that are
rechargeable with a DC 15V
power adapter. In certain embodiments, the docking base 104 may include a
charging port and
electrical communication to facilitate charging of the power source 208, the
filtration device 102
may including a charging port and electrical communication to facilitate
charging of the power
source 208, or any combination thereof. In certain embodiments, the batteries
of the power source
208 are hot swappable during operation of the filtration device 102. For
example, during use, if
one or more of the batteries are low, the batteries may be can replaced
individually without ever
turning the filtration device 102 off.
[0071] In certain embodiments, the controller manages the power consumption
of the filtration
device 102 by controlling the charging and discharging of the one or more
power sources 208. In
certain aspects, the controller may receive an input from the user device 112
and/or controls on
the filtration device 102 and in response, may activate the one or more fans
220 to provide airflow
through the filtration device 102 at various flow rates. In one embodiment,
the user device 112
communicates with the filtration device 102 via a wired connection or wireless
connection. The
controller may also alter the speed of the fans 220 according to the charge
level of the power
sources 208 and may convert a provided input power through a power connector
to an appropriate
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charging voltage and current for the power sources 208. The controller further
manages other
operations of the filtration device 102. For example, the controller may
manage status light
emitting diodes (LEDs) that indicate the current operational mode of the
filtration device 102, the
operation of one or more sensors, and the like. The LEDs may indicate when the
filters and/or
other components need replacing.
[0072] With reference to FIG. 10 and FIG. 11, in some embodiments, device
housing 200
may be configured with opening 214 or other type of access port to allow for
insertion of filter
module 106, to allow for fluid communication between the fan plenum assembly
and fan(s) (not
shown), and to allow for air flow out of the filtration device 102, as
described herein. FIG. 12
illustrates a perspective top view of the filtration device 102 with the
filter module 106 removed
to show the fan air outlet side 224 and fan plenum seal 226 of the fan plenum
assembly 218, which
provides for air tight securement of the fan plenum assembly 218 (and thereby
the device housing
200) to the filter module 106 when the filter module 106 is inserted in
opening 214 and interfaced
with the fan plenum seal 226.
[0073] In certain embodiments, the filter module 106 may be removed for
replacement through
the opening 214 using one or more filtration module releasable securing
features 206. More
specifically, the filter module 106 may be spring loaded into the filtration
device 102 and may be
removed by pushing the filtration module releasable securing features 206 in
and slightly pushing
down on the filter module 106 to release the filter module 106 (FIG. 10), and
the filtration module
106 may be removed from the filtration device 102 (FIG. 11).
[0074] The device housing 200 may be a variety of shapes and sizes. For
example, in one
particular implementation, the overall dimensions of the housing 200 range
from approximately
10" x 3" x 8" to approximately 16" x 7" x 12". It will be appreciated that
these dimensions are
exemplary only and the housing 200 may be modified to accommodate larger or
smaller
dimensions. For example, by keeping the same proportions, the filtration
device 102 can function
properly by being reduced by a percentage between 0 and 60% of these
dimensions.
[0075] The device housing 200 may be constructed from a light-weight,
durable material. By
way of non-limiting example, suitable materials for construction of the
housing 200 include
anodized aluminum, titanium, titanium alloys, aluminum alloys, fibrecore
stainless steel, carbon
fiber, KevlarTM, polycarbonate, acrylonitrile-butadiene- styrene (ABS),
polyurethane, or any
combination of the mentioned materials.
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[0076] In certain aspects of the disclosure, during operation, the at least
one fan 220 pulls input
air through the air entry mesh 212 and into the filtration device 102 through
a fan air outlet side
224. If the filtration device 102 is docked in the docking base 104, the at
least one fan 220 pulls
input air through the air entry mesh 128 of the docking base 104, through air
flow paths of the
docking base 104 (and optionally secondary filters 108), and then through the
air entry mesh 212
of the filtration device 102. After entering the filtration device 102 through
the air entry mesh 212,
input air is drawn through optional pre-filters 210 (as described herein).
Optional pre-filters 210
filter large particles that may potentially build up on and/or damage the fans
220 and/or a filter
module 106.
[0077] With reference to FIG. 13A, in certain embodiments, the fan plenum
assembly 218
includes a fan air intake side 222; a fan air outlet side 224; and a fan
plenum seal 226 on the fan
air outlet side 224 of the fan plenum assembly 218, which may be interfaced
with a fan plenum
attachment seat of the filter module to thereby form an air tight seal between
the fan plenum
assembly 218 and the filter module. The fan plenum assembly 218 may also
include a fan chamber
220c, to house the one or more fans (not shown, and a pre-filter retention
feature 240, sized and
shaped so as to accommodate an optional pre-filter (not shown). FIG. 13B
illustrates a cross-
section of the fan plenum seal 226 comprising an accordion style gasket.
However, the disclosure
is not so limited, and any suitable sealing configuration may be utilized to
form an air tight seal
between the fan plenum assembly 218 and the filter module 106, e.g., 0-rings,
silicone gaskets,
etc.
[0078] With reference to FIG. 14, an exemplary embodiment is shown
illustrating a filter
module 106 secured in an air tight configuration to a fan plenum assembly 218.
In certain
embodiments, the at least one fan may comprise a plurality of serially
stacked, axial fans 220a,
220b within a fan chamber 220c. Without intending to be limited by theory, as
opposed to a
parallel configuration (i.e., both fans disposed beside each other), the
series (stacked) configuration
allows the pressure output to be additive, whereas a parallel configuration
results in an increase in
overall flow. The fan plenum assembly may also include a pre-filter retention
area in the fan air
intake side 222 to secure a pre-filter 210. An air tight seal may be formed
between the filter module
106 and the fan plenum assembly 218 via a fan plenum assembly seat 308 located
on the internal
chassis 304 of the filter module 106 and a fan plenum seal (not shown) located
on the fan air outlet
side 224 of the fan plenum assembly 218. The fan assembly seat 308 may be
configured to
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structurally mate with the fan plenum seal so as to form an air tight seal
between the filter module
106 and the fan plenum assembly 218.
[0079] With reference to FIG. 15, an air filtration device 102 is
illustrated including opening
214 for insertion of a filtration module (not shown) during use so as to form
an air tight seal to a
fan plenum assembly 218. The air filtration device 102 may further include a
controller (not
shown) in electronic communication with a power source 208 (e.g., comprised of
one or more
batteries), the controller configured to provide power from the power source
208 to drive the at
least one fan 220a, 220b during use, and an optional user control device (not
shown) in
communication with the controller to operate the at least one fan 220a, 220b.
The device housing
200 may also comprise an air entry mesh 214 to remove large particulates from
input air drawn
into the filtration device 102 during use.
[0080] In one implementation, the one or more fans 220a, 220b operate at
high hydrostatic
pressures (e.g., 3-5 inches of water) and generate high flow rates up to 300
SLM. In certain
implementations, to achieve high efficiency for the filter module 106, the
fans 220a, 220b operate
between approximately 50 and 300 SLM. The fans 220a, 220b may operate at
various speeds, for
example, low (100 SLM), medium (130 SLM), and high (180 SLM). There may
optionally be
sound dampening material around the fans. The material may be, without
limitation, polyurethane
foam, silicone, cotton fiber, etc.
[0081] Any suitable fan design and configuration may be utilized in
connection with present
disclosure. For example, in addition to fan power and output, fan
configurations may be selected
based on fan blade size, shape, number, orientation, surface area, and the
like. Pressure is
proportional to the square of the rotations per minute (RPM). An increase in
RPM will result in a
power increase proportional to the cube of the RPM. Higher RPM means higher
pressure, lower
RPM means lower pressure, thereby requiring more blades. In one
implementation, the number
of fan blades is of less concern than total blade surface area. Blade surface
area is the single
blade's surface area times the number of blades. Orientation may also be taken
into consideration.
For instance, if fan blades are too close together, there may not be
sufficient air between the blades
to have adequate performance. In one implementation, the fans 220 comprise fan
blades that are
narrow on the tip to decrease air resistance and will widen toward the hub.
The angle of the fan
blades may be minimized at the tip and generally increase toward the hub. In
this regard, in one
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implementation, the transition from the angle at the tip to the angle at the
hub may be gradual
and/or smooth to prevent back flow.
[0082] The static pressure of the filtration device 102 may be increased by
including a plurality
of fans 220a, 220b in a stacked configuration having contra-rotating two stage
axial impellers. In
one implementation, two or more stacked fans 220a, 220b are provided, as
described above, which
rotate in opposite directions with the upstream fan having a pitch angle that
is approximately 8-10
degrees higher than the fan further downstream.
[0083] With reference to FIG. 16, the one or more fans 220 may direct air
flow into the filter
module 106 using a flow transitional diffuser 228 disposed downstream of the
fans 220. The
diffuser 228 includes one or more surfaces 230 that spread the airflow evenly
across the primary
filter media 306 of the filter module 106, ensuring that particles collected
by the primary filters
306 are not concentrated in any one region, thereby increasing the overall
lifetime of the primary
filters 306 and consequently the power sources 208.
[0084] In some embodiments, the portable air filtration device 102 may
include at least one
pre-filter retention feature 240 that may house a pre-filter 210 to remove
large particles from the
positive pressure air flow. The at least one pre-filter 210 may be located
upstream of the fan
plenum assembly 218 and/or the filter module 106. The pre-filter 210 may have
any suitable filter
pore size and may be formed in pleated or non-pleated configurations. For
example, the pore sizes
of the pre-filter 210 can range from approximately 0.1 micron-900 microns.
Such pore sizes, and
pleating/non-pleating configuration generally produce very low pressure drop.
[0085] The pre-filter 210 may be formed from any suitable filter materials
and may have any
suitable pore size. Further, the pre-filter 210 may be formed in pleated or
non-pleated
configurations. For instance, in certain embodiments, the pore sizes of the
pre-filter material can
range from 0.1 micron-900 microns. Such pore sizes, and pleating/non-pleating
configuration
generally produce very low pressure drop. By way of non-limiting example, the
pre-filter 210 may
be formed from a variety of suitable filter materials used in high-efficiency
particulate air (HEPA)
class filters. For instance, the pre-filter 210 may be formed from spunbonded
polyester nonwoven
fabric materials, polytetrafluoroethylene (PTFE), polyethylene terephthalate
(PET), activated
carbon, impregnated activated carbon, or any combination of the listed
materials. These materials
may also be, optionally, electrostatically charged. In other embodiments, the
pre-filter may include
one or more hydrophobic layers, e.g., to minimize intrusion of moisture/water
into the device. In
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one implementation, the pre-filter 210 is a single pleated or sheet of
material. In another
implementation, the pre-filter is co-pleated or laminated with other desired
materials for combined
benefits. In other embodiments, the pre-filter 210 is a carbon filter that may
comprise at least two
electrostatically charged scrim layers enclosing granulated activated carbon.
[0086] With reference to FIGS. 17A-17B, an exemplary embodiment of a pre-
filter 800 is
illustrated. The pre-filter 800 may comprise a pleated composite pre-filter
media 802 that is over-
molded 806 into a structural frame 804. In certain embodiments, the pleated
composite pre-filter
media 802 includes one or more structural pleat support features 810.
[0087] In yet other aspects, the present disclosure provides a filter
module which may be used
alone or in connection with the portable air filtration device and/or air
filtration systems described
herein. With reference to FIG. 18, in certain embodiments, the air filtration
module 106 may
include an external filter module housing 300 having a filtered air outlet 302
for directing filtered
air from the module 106, device 102 or system 100. In certain embodiments, the
external filter
module housing 300 may include one or more housing retention features 330 that
may be sized
and shaped so as to interface with filtration module releasable securing
features. In certain
embodiments, the filtered air outlet 302 may be configured at a grate or grill
312. With reference
to FIG. 19, the air filtration module 106 is shown in cross section. As shown,
the air filtration
module 106 may include an internal chassis 304 having a face plate 310
including an input air inlet
310a for directing input air into the filter module 106; at least two filter
media 306a, 306b, secured
to the internal chassis 304 in a spaced apart orientation in a parallel air
flow configuration during
use. In other embodiments, with reference to FIG. 20, the filtered air outlet
302 may be configured
at as cylinder or tube 314. However, the disclosure is not so limited, and any
configuration of the
air outlet may be used.
[0088] FIG. 21A illustrates a top view of the filter module 106, and FIG.
21B illustrates a
bottom view of filter module 106. FIG. 22 illustrates a perspective bottom
view of filter module
106. As shown, in certain embodiments, internal chassis 304 includes a fan
plenum attachment
seat 308 for securing the filter module 106 to a fan plenum assembly (not
shown) in an air tight
seal configuration. By way of example, as shown in FIG. 21B, FIG. 22, and FIG.
23, the fan
plenum attachment seat 308 may be configured as a recessed portion 308a of the
face plate 310 of
internal chassis 304 sized and shaped so as to structurally mate with the edge
of the fan plenum
seal (e.g., the accordion style gasket).
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[0089] With reference to FIG. 23 and FIG. 24, a front and back perspective
view of an internal
chassis 304 of the disclosure is illustrated. In certain embodiments, the
internal chassis 304
includes a fan plenum attachment seat 308 for securing the filter module 106
to a fan plenum
assembly (not shown) in an air tight seal configuration, an input air flow
path seal 316 opposite
the face plate 310 including the input air inlet 310a, and opposed side walls
318, each having one
or more filter media retention features 318a that secure the primary filter
media (not shown) to the
internal chassis side walls 318.
[0090] With reference to FIG. 25, in certain embodiments, the spaced apart
primary filter
media 306a, 306b may be secured, at least in part, to the side wall 318 of the
chassis via the filter
media retention features 318a to form an air tight seal between the primary
filter media 306 and
the internal chassis 304. In certain embodiments, the filter media retention
features 318a of the
side walls of the internal chassis 304 are selected from clips, grooves,
snaps, and combinations
thereof. With reference to FIG. 26A and FIG. 26B, in some embodiments, in
addition to the
securement along the side walls, the primary filter media 306a, 306b may be
further secured to the
internal chassis 304 at the input air flow path seal 316, and/or the face
plate 310 including the input
air flow inlet 310a using a bonding feature 318b, e.g., thermal bonding,
ultrasonic welding, or
adhesives.
[0091] With reference to FIG. 19 and FIG. 27, in some embodiments, the
spaced apart
primary filter media 306a, 306b may be located within the filter module 106 so
as to separate an
input air flow region 322 from a filtered air flow region 324 within the
filter module 106. In certain
embodiments, the input air flow region 324 is created within the filter module
106 in a space
between the face plate 310, the chassis input air flow path seal 316, the
chassis opposed side walls
(not shown), and the spaced apart primary filter media 306a, 306b during use.
In accordance with
the disclosure, the filter air flow region 324 is in filtered isolation from
input air flow region 322,
i.e., air flow is sealed via the air tight seal between the filter media 306a,
306b and the internal
chassis 304and only available through the filter media). In certain
embodiments, the input air flow
region 322 may be configured so as to provide turbulent air flow within the
input air flow region
322 during use.
[0092] As illustrated, in certain embodiments, the primary filter media
306a, 306b are arranged
in a spaced apart orientation in intersecting planes so as to provide for
parallel air flow between
the filters during use (i.e., as opposed to serial air flow through one filter
and then the other, air
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flow through one filter or the other in parallel). In some embodiments, the
primary filter media
306a, 306b are arranged in a spaced apart orientation in planes that converge
towards each other.
In yet other embodiments, the primary filter media 306a, 306b are arranged in
a spaced apart
orientation in planes that converge towards each other proximate the filtered
air outlet 302.
[0093] In one embodiment, the spaced apart orientation of the primary
filter media inside the
filter module may be such that the filters be angled relative to one another
so as to reduce the size
of the device. When the angle is equal to 0 degrees, the filters are perfectly
parallel. Conversely,
when the angle is equal to 90 degrees the filters are perfectly perpendicular.
As the angle increases,
the loading of the filter becomes increasingly unevenly distributed along the
filter. By way of
example, an angle of 60 degrees allows for minimization of the effects of
uneven loading of the
primary filter media during use yet provides for size reduction.
[0094] With reference to FIG. 28 and FIG. 29, primary filter media 306a,
306b may be
secured to internal chassis 304, and internal chassis 304 with secured primary
filter media 306 may
be positioned into an opening 300a in the external housing 300 of the filer
module. An interior
perimeter of face plate 310 of internal chassis 340 may be sealed to an
external perimeter of a
surface 320 of the external filter module housing 300, so as to form a sealed
exterior of filter
module 106. Any suitable sealing method may be used, e.g., ultrasonic welding,
thermal bonding,
adhesives, etc. Once assembled, the internal chassis 304 may be located
substantially within the
external housing 300 of filter module 106.
[0095] As illustrated, in certain embodiments, the internal chassis 304 of
the filter module 106
is positioned substantially within the external filter module housing 300 with
an interior perimeter
of face plate 310 of the internal chassis 304 sealed to an exterior perimeter
of a surface 320 of the
external filter module housing 300 so as to form sealed exterior of the filter
module 106. Without
intending the be limited, the entirety of the internal chassis may be within
the external filter module
housing, the face plate of the filter module housing may be flush with an the
surface of an opening
of the housing, portions of the internal chassis (e.g., portions of the face
plate) may protrude from
the housing, etc. However, in general, the internal chassis is positioned
within the external housing
such that the internal chassis may be sealed to the housing so as to form an
air tight seal between
the internal chassis and the housing to thereby form the filer module. In
certain embodiments, the
face plate 310 of the internal chassis 304 is sealed to a surface 320 of the
external filter module
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housing 300 using thermal bonding, ultrasonic welding, or adhesives so as to
form an air tight seal
between the internal chassis 304 and the external filter module housing 300.
[0096] In certain embodiments, the primary filter media 306 may be formed
in any suitable
manner to achieve the desired filtering efficiency. With reference to FIGS.
30A-30D, by way of
example, the primary filter media 306 may be comprised of a pleated composite
primary filter
media 400 that are over-molded 402 into a structural frame 404. FIG. 30A
illustrates a top view
of an exemplary primary filter media, while FIG. 30B illustrates a cross-
section side view in line
with the filter pleat, while FIG. 30C illustrates a cross-section side view
across the filter pleat.
FIG. 30D illustrates a detail view of the over-molding of the composite
primary filter media into
the structural frame. The structural frame 404 may then be secured to the
internal chassis (not
shown) utilizing, e.g., securement tabs 406 in connection with various filter
media retention
features or bonding elements (not shown). In certain embodiments, the
structural frame 404 may
be formed from a material selected from polypropylene or acrylonitrile
butadiene styrene (ABS).
In certain embodiments, the pleated composite primary filter media 400 may be
over-molded 402
into the structural frame 404 along the entire perimeter of the structural
frame 404.
[0097] In certain embodiments, with reference to FIG. 30A, structural frame
404 may
comprise an outside frame perimeter 410 and one or more inner support dividers
412 to form
multiple filter frame sections 414. Each filter frame section 414 may then
comprise a pleated
composite primary filter media 400 over-molded 402 into the filter frame
section 414. Although
illustrated with two dividers 412 and three filter frame sections 414, the
disclosure is not so limited,
and any suitable configuration may be used, including more or fewer dividers,
e.g., zero dividers
so as to have a unitary filter frame section, one divider so as to have two
filter frame sections, two
dividers so as to have three filter frame sections, three dividers so as to
have four filter frame
sections, etc. Suitable configurations may be selected based on filter
structural integrity and air
flow considerations, among other factors.
[0098] Any suitable method may be used to achieve the desired over-molding
of the pleated
filter into the structural frame. For instance, pleat support frames may be
used during injection
processing of the filter into the structural frame. Injection temperatures
between, e.g., 300 to 500 F
and pressures of 600-12,000 psi may be used. However, the disclosure is not so
limited.
[0099] For instance, by way of non-limiting example, the primary media 306
may include any
HEPA type membrane material, e.g., with a 0.1 micron ¨ 0.3 micron pore size
made from an inert
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material such as polytetrafluoroethylene (PTFE), polyethylene terephthalate
(PET), activated
carbon, impregnated activated carbon, or any combination of the listed
materials. These materials
may also be, optionally, electrostatically charged. In certain embodiments,
the primary filter media
306 may be a single pleated or sheet of material. In some embodiments, the
primary filter media
306 media may be co-pleated or laminated with other desired materials for
combined benefits. By
way of non-limited example, the primary filter media 306 may be a composite
material including
more than one layer of filter materials co-pleated using a thermal procedure
(adhesiveless), or
adhesive-based bonding to attach one or more additional layer(s) of filter
material, load bearing
material, activated carbon for added system protection, impregnated activated
carbon, and/or the
like. In one embodiment, adhesive-based bonding may be used, employing
adhesives having low
or no outgassing. Stated differently, the primary filter media 306 may be
formed by bonding, co-
pleating, laminating or otherwise attaching additional layers to suitable
filter materials.
[00100] In one particular embodiment, the primary filter media 306 may include
a layer of ultra-
high-molecular-weight polyethylene (UHMWPE) in a composite filter stack to
increase the filter
efficiency. The layers of the primary filter media 306 may be affixed/bonded
in any suitable
manner, e.g., by thermal bonding, crimping, adhesive, etc. In certain
implementations, the layers
of the primary filter media 306 may be bonded by crimping the edges and
pleating together by
loading into a collator. In other embodiments, adhesive with a thickness range
between
approximately 0.5 oz per square yard to 3 oz per square yard, e.g., 1 oz per
square yard may be
used. Without intending to be limited by theory, the adhesive may add
resistance to the primary
filter media 306, which may create and add pressure drop to the system.
Alternatively, or in
addition, any adhesive may be reduced or removed to decrease pressure drop and
to reduce
outgassing and VOCs emitted therefrom. If desired, activated carbon may also
be added to remove
VOCs (odors and chemical fumes).
[00101] In another embodiment, the primary filter media 306 may include a
plurality of
thermally attached layers, including a first PE/PET layer, an activated carbon
layer, a first PTFE
membrane layer, a second PE/PET layer, a second PTFE membrane layer, a third
PE/PET layer, a
second activated carbon layer, and a fourth PE/PET layer.
[00102] By way of non-limiting example, the primary filter media 306 may
comprise a pleated
composite primary filter media that includes at least three layers in the
composite media, at least
five layers in the composite media, at least seven layers in the composite
media, etc. The layers
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of the composite media may include scrim layers, membrane layers, activated
carbon layers, etc.
In certain embodiments, the pleated composite primary filter media may
comprise at least three
scrim layers and at least two membrane layers. In certain embodiments, the
pleated composite
primary filter media may have a filter pleating pitch between 4 pleats to 30
pleats per inch, between
6 pleats to 24 pleats per inch, preferably between 10 pleats to 18 pleats per
inch, more preferably12
pleats per inch. By way of example, the pleated composite primary filter media
may have a filter
pleat count of between 50 pleats to 100 pleats, preferably between 55 pleats
to 75 pleats, more
preferably between 60 pleats to 65 pleats, more preferably 62 pleats.
[00103] By way of example, the size of the primary filter media may range
between 1.38 ft2 ¨
4.13 ft2 for maximum flow rates (flow rate for highest setting) between, e.g.,
100 SLM ¨ 300 SLM.
The size of the filter may be determined based on design requirements. By way
of non-limiting
example, for a pollution application, a desired airflow face velocity may be
selected to not exceed
1.3 cm/s. The following equation is used to determine the filter face velocity
as a function of filter
surface area:
v = QA,
where v is the filter face velocity, Q is the volumetric flow rate of the air
stream entering
the filter, and As, is the surface area of the filter.
[00104] As discussed above, in certain embodiments, the systems, device, and
filter modules of
the disclosure are designed to keep the particle velocity at the surface of
the filter (face velocity)
less than or equal to 5 cm/s, 4 cm/s, 3 cm/s, 2 cm/s, or 1 cm/s. In certain
aspects, this low face
velocity may be achieved, at least in part, by increasing the surface area of
the primary filter
component(s), e.g., by pleating the primary filter component(s), using more
than one primary filter
component, etc.
[00105] Without being limited by theory, the face velocity is directly
proportional to the
volumetric flow rate (Q) and inversely proportional to the surface area (As)
of the filter as shown
in the equation below
Q
v =
As
[00106] In certain aspects, the surface area (As) of a filter may be greatly
increased by pleating.
The surface area of a pleated filter can be calculated using the following
expression (for 1 filter):
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A = 2 *L*W*d*# pleats
s
inch
where L is the length of the pleated filter, W is the width of the pleated
filter, d is the pleat
depth, and #pleats/inch represents the pleat density. The equation shows that
the surface area is
directly related to the number of pleats present on the surface so increasing
the amount of pleats
allows for the increase in the overall surface area and a corresponding
decrease in the face velocity.
[00107] In certain embodiments, when coupled in a parallel air flow
configuration with another
filter component of the same dimensions, such a configuration will generally
generate a face
velocity of less than or equal to 1 cm/s under normal operating flow rates of
80-200 SLM.
Exemplary dimensional measurements are illustrated. However, the disclosure is
not so limited,
and alternative dimensional configurations are envisioned as within the scope
of the disclosure.
[00108] As can be understood from FIG. 31, the filtration device 102 includes
a variety of
electrical components for controlling the operation of the air filtration
system 100. In one
implementation, the filtration device 102 includes the controller 1240, one or
more input devices
1202, one or more output devices 1204, a power source 1200, such as the power
source 242
described herein, and one or more fans 220, such as the stacked serial axis
fans described herein.
[00109] The controller 1240 receives power from the power source 1200 and
manages the
distribution of the power to the various other components in the filtration
device 102. In one
implementation, the controller 1240 provides power to the fans 220 and a
signal indicating a status
of the operations to the output device 1204 according to user input. The
controller 1240 accepts
the user input via the input device 1202 and dictates the operation of the
filtration device 102.
Specifically, a user may manipulate the input device 1202 to cause the
controller 1240 to vary the
speed of the fans 220 and consequently the flow of filtered air.
[00110] In one implementation, the input device 1202 is configured to allow a
user to
manipulate the operation of the filtration device 102. The input device 1202
may include
electromechanical devices such as switches or buttons or may include
electronic devices such as a
touch screen. The input device 1202 may be directly connected to the
controller 1240 using a
wired or wireless connection. In one implementation, the input device 1202
includes the user
device 112 and/or the filtration device 102. For example, the input device
1202 may include a
single button protruding outward from a side of the filtration device 102 that
can be found by touch
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without actually having to see the button. The button is triggered by
squeezing and may include a
contoured shape so that a finger naturally comes to rest on the center of the
button.
[00111] The input device 1202 may further be running an application executed
by a process to
generate a graphical user interface (GUI) that accepts user inputs via a
touchscreen or other input
method, as described herein. In one implementation, the input device 1202 may
be used to turn
the filtration device 102 on and off, select a desired fan speed, change the
aesthetics of the filtration
device 102 (e.g., using LEDs or one or more displays configured to display
designs, colors, and/or
graphics).
[00112] In one example, the filtration device 102 is configured to operate at
low, medium, and
high settings for the fans 220. The input device 1202 provides a medium for
the user to select the
fan speed. In one implementation, the input device 1202 is a button that when
depressed, provides
the controller 1240 with a signal. The controller 1240 receives the signal and
is configured to
cycle through the various modes of operation.
[00113] The output device 1204 may include any device capable of providing
visual, audible,
and/or tactile feedback to the user to indicate a state or status of the
filtration device 102. The
output device 1204 and the input device 1202 may be the user device 112. In
one implementation,
the output device 1204 receives a signal indicative of a status from the
filtration device 102 and
provides an output for the user. The signal provided by the controller 1240
may include an analog
or digital signal for conveying the state or status.
[00114] In one implementation, the output device 1204 includes one or more
alerts configured
to indicate whether the filtration device 102 has been activated, a current
state of the power supply
1200, a change filter indicator, a current fan speed of the filtration device
102, and/or any other
relevant status. In this example, the controller 1240 may provide analog
voltage signals to cause
LEDs corresponding to the status to become illuminated. For example, the LEDs
may be
configured to include a power charge indication, a power on indication, a fan
speed indication and
a change filter indication. The power on LED may include a single white or
other colored LED
that indicates when the filtration device 102 is powered on.
[00115] The power charge indication may include a group of five single color
LEDs used to
indicate the current charge level of the power source 1200. When the power
source 1200 is near
100% charge, all five LEDs are illuminated. Four LEDs are illuminated when the
power source
1200 drops to 80% charge, three LEDs are illuminated when the power source
1200 drops to 60%
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charge, two LEDs are illuminated when the power source 1200 drops to 40%
charge, and one LED
is illuminated when the power source 1200 drops to 20% charge.
[00116] The fan speed indication may include three single color LEDs. A single
LED is
illuminated when the fan speed is set to low, two LEDs are illuminated when
the fan speed is set
to medium, and three LEDs are illuminated when the fan speed is set to high.
The change filter
indicator may include a bi-color LED that is off when the filters are in
acceptable condition, amber
or yellow when the pre-filter 210 needs to be replaced and red when the
primary filter 306 needs
to be replaced.
[00117] In another implementation, the output device 1204 includes a display,
such as a liquid
crystal display (LCD) screen that displays text and other graphical indicators
for the output. In
this case, the controller 1240 would provide an appropriate digital signal for
displaying a status on
the display. In some cases, the LCD may be on the user device 112 or other
remote device.
[00118] As described herein, when the user device 112 or other computing
device is utilized,
the computing device may serve as both the input device 1202 and the output
device 1204. As
described above, the output device 1204 may include computing devices such as
smart phones,
tablet computer, and personal computers running applications configured to
receive inputs from
the user and display the current status to the user. In one implementation,
the user device 112
generates a GUI that allows the user to both control the operation of the
filtration device 102 and
display a current status of the filtration device 102. In this example, the
output device 1204 may
be connected to the controller 1240 via a wired or wireless connection.
[00119] The output device 1204 may further include a speaker capable of
producing audible
tones for indicating the status. In this example, the controller 1240 is
configured to provide the
output device 1204 with an analog signal that causes a desired sound or series
of sounds to be
played by the speaker. In another example, the output device 1204 may include
a vibration device
capable that is provided with a signal for producing different vibration
patterns depending on the
status.
[00120] In one implementation, the controller 1240 is configured to manage the
operation of
the fans 220 that draw air through the filters and provide a user with clean
air. The controller 1240
is configured to draw power from the power source 1200, receive an input from
the input device
1202, provide power to the fans 220, and drive an output on the output device
1204. The controller
1240 may be implemented using a variety of computing devices. For example, the
controller 1240
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may be implemented using a general purpose computer or using smaller embedded
systems such
as systems utilizing a microcontroller, microcomputer, field-programmable gate
array (FPGA), or
other integrated circuit or combination of circuits.
[00121] Turning to FIG. 32, a more detailed description of the controller 1240
is provided. In
one implementation, the controller 1240 includes a battery manager 1208 for
controlling the
charging and discharging of one or more batteries included in the power source
1200, at least one
switch input 1214 for receiving a signal or other communications for the input
device 1202, at
least one output for indicating or sending a status of the filtration device
102 (e.g., a LED driver
1216), and a power output device for each of the fans 220, such as pulse width
modulators (PWMs)
1210 for supplying each of the fans 220 with a power signal.
[00122] The PWMs 1210 may be configured to output a power signal at a
frequency within the
frequency range used by the fans 220. For example, the fans 220 may operate
with a peak
performance when supplied with a 25 kHz power input. Thus, the controller 1240
may operate
the PWMs 1210 at a frequency of 25 kHz. Furthermore, the speed of the fans 220
may be varied
by altering the duty cycle of the PWMs 1210. For example, a low setting may be
set at a 10% duty
cycle, a medium setting may be set at a 50% duty cycle, and a high setting may
be set at a 100%
duty cycle.
[00123] The output of the PWMs 1210 is dictated according to the user input
and/or the batter
manager 1208. In one example, beginning when the filtration device 102 is
turned off, a button
connected to an input on the controller 1240 may be pressed to activate the
filtration device 102.
Various fan speeds may be cycled through by additional button presses. For
example, an additional
press of the button may cause the controller 1240 to activate the PWMs 1210 at
the example 10%
duty cycle thereby driving the fan(s) 220 at the low speed. An additional
press of the button may
cause the controller 1240 to up the duty cycle to 50% and thereby drive the
fan(s) 220 at medium
speed, and yet another press of the button may cause the duty cycle to be
increased to 100% and
the fans 220 to be driven at the high speed. Additional button presses may
continue the cycling
through the various fan speeds. In one example, each press of the button
causes the fan speed to
cycle from low, to medium, to high, to medium, and back to low. In this
example, the filtration
device 102 may be deactivated at any time by pressing and holding the button
for a preset time,
such as several seconds. In another example, each press of the button causes
the fan speed to cycle
from low, to medium, to high, to turning the filtration device 102 off. The
controller 1240 may
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also automatically reduce the duty cycle of the PWMs 1210 according to the
current status of the
power source 1200, as monitored by the battery manager 1208, to prolong
operation.
[00124] In one implementation, the battery manager 1208 determines battery
charge levels,
predicts battery life, and manages the charging of the battery when filtration
device 102 is
connected to a power source using the AC/DC converter. The battery manager
1208 may be
configured to override a user selected fan speed and decrease the fan speed
according to a current
battery life or availability of other power sources. For example, if the
battery life drops below a
threshold and the fan speed is set to high, the controller 1240 may
automatically drop the fan speed
to medium once the charge threshold is reached. Similarly, if the fan speed is
set to medium and
the battery charge falls below a second threshold, the controller 1240 may
automatically reduce
the fan speed to low.
[00125] In one implementation, the battery manager 1208 includes a charger and
is configured
to connect the controller to one or more batteries. The charger supports the
simultaneous charging
and discharging of the batteries. In one example, the charger includes a
single charger stage
connected to the batteries via a charge MUX. The charge MUX is configured to
allow for the
charge current to be shared between each of the batteries while preventing
charge transfer between
the batteries. When charging a single battery, the battery manager 1208
adjusts the total current
supplied by the charger to match the current required to properly charge the
battery. When there
is more than one battery being charged, the battery manager 1208 compares the
desired charge
currents for charging each battery. The minimum charge current is then
provided via the charge
MUX to each of the batteries. In this example, the battery manager 1208 does
not allow the charge
current to exceed the current required by any battery. Charging operates
independent from the
remainder of the operation, allowing for the batteries to be charged
regardless of whether the
filtration device 102 is turned on or off, so long as the filtration device
102 is attached to an external
power supply.
[00126] The controller 1240 may also be configured to monitor the status of
the filter and
provide feedback to the user. In one implementation, the controller 1240 logs
when a filter is
changed and tracks filter usage by logging the amount of time that the
filtration device 102 has
been used. An alert may then be generated when the filter usage is close to or
has exceeded the
projected lifespan of the filter. The filter usage data may also be adjusted
by logging the amount
of time at each speed that the filter has operated. Once the filter usage
limit is reached, an indicator
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to change the filter may be activated. For example, an LED may be lit to
indicate that the filter
needs to be changed. In another example, a tri-color LED may be used to
indicate that a filter is
good, needs to be changed soon, or needs to be changed immediately. The
indicator may also be
triggered on the user device 112 or other remote device.
[00127] In particular implementation, the filtration device 102 has four
operational modes
dictated by the controller 1240. The modes include an off mode, an on mode
with LEDs
illuminated mode, an on mode without the LEDs illuminated, and a warning mode.
In this
example, the off mode is a very low power mode similar to a standby mode. The
filtration device
102 only consumes a small amount of power when in the off mode and operations
are limited to
recognizing an input being received from the input device 1202 and turning on.
Once the input is
received the filtration device 102 goes into the power on with LEDs
illuminated mode. In this
mode, the filtration device 102 will accept fan speed setting changes and a
command for powering
off. The LEDs will be illuminated to relay the state of the filtration device
102, for example,
indicating the fan speed, battery charge, and whether the filter needs to be
replaced. In the power
on with no LEDs illuminated mode, the fan 220 is kept at its current speed and
the only command
that the controller 1240 will recognize is to power off. The warning mode is
triggered when the
filtration device 102 is engaged in one of the on modes and a problem emerges.
For example, the
warning mode may be activated when battery is running low. In this case, a low
battery LED may
be illuminated or begin flashing. Similarly, when the filter needs to be
changed an LED may be
illuminated.
[00128] In one particular implementation, the controller 1240 includes a DC
power input and a
protection circuit configured to protect against a reverse polarity power
input. When connected to
an external DC power supply, the controller 1240 controls both the operation
of the filtration
device 102 and the charging of the batteries. To charge the batteries, the
controller 1240 measures
the voltage of each battery and controls a charging current using a series of
MOSFETs or other
switches. Once the DC power supply has been disconnected, the controller 1240
switches to
drawing power from the batteries. In this example, the controller 1240
includes two
microcontroller units operating in a master/slave configuration. The slave
microcontroller is
configured to control the output devices 1204, in this case by supplying the
LED driver 1216 with
a signal for lighting a plurality of LEDs to indicate current operational
state. The slave
microcontroller unit is also configured to receive input from the input device
1202, in this case the
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switch 1214. The master microcontroller unit is configured to manage the
charging of the battery
and includes PWM outputs for supplying the appropriate power to the fans.
[00129] In various implementations, the components of the controller 1240 are
divided between
multiple circuit boards. For example, a main board may include a
microcontroller, pressure sensor,
a speaker, and various other components, such as a voltage regulator, several
choke coils for
preventing excessive current, an on/off controller, a battery charger,
including the battery manager
1208 and charge circuitry. A second controller board may include user
interface circuitry, such as
a microcontroller, LEDS, a speaker, and a diagnostic port interface. It will
be appreciated that
these components are exemplary only and other configurations and components
are contemplated.
[00130] Referring to FIG. 33, a detailed description of an example computing
system 1700
having one or more computing units that may implement various systems and
methods discussed
herein is provided. The computing system 1700 may be applicable to the user
device 112, the
filtration device 102, or other computing devices. It will be appreciated that
specific
implementations of these devices may be of differing possible specific
computing architectures
not all of which are specifically discussed herein but will be understood by
those of ordinary skill
in the art.
[00131] The computer system 1700 may be a general computing system is capable
of executing
a computer program product to execute a computer process. Data and program
files may be input
to the computer system 1700, which reads the files and executes the programs
therein. Some of
the elements of a general purpose computer system 1700 are shown in Figure 29
wherein a
processor 1702 is shown having an input/output (I/O) section 1704, a Central
Processing Unit
(CPU) 1706, and memory 1708. There may be one or more processors 1702, such
that the
processor 1702 of the computer system 1700 comprises a single central-
processing unit 1706, or a
plurality of processing units, commonly referred to as a parallel processing
environment. The
computer system 1700 may be a conventional computer, a distributed computer,
or any other type
of computer, such as one or more external computers made available via a cloud
computing or
other network architecture. The presently described technology is optionally
implemented in
software devices loaded in memory 1708, stored on a configured DVD/CD-ROM 1710
or storage
unit 1712, and/or communicated via a wired or wireless network link 1714,
thereby transforming
the computer system 1700 in FIG. 33 to a special purpose machine for
implementing the described
operations.
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[00132] The I/O section 1704 is connected to one or more user-interface
devices (e.g., a
keyboard 1716 and a display unit 1718), the storage unit 1712, and/or a disc
drive unit 1720. In
the case of a tablet or smart phone device, there may not be a physical
keyboard but rather a touch
screen with a computer generated touch screen keyboard. Generally, the disc
drive unit 1720 is a
DVD/CD-ROM drive unit capable of reading the DVD/CD-ROM 1710, which typically
contains
programs and data 1722. Computer program products containing mechanisms to
effectuate the
systems and methods in accordance with the presently described technology may
reside in the
memory section 1704, on the disc storage unit 1712, on the DVD/CD-ROM 1710 of
the computer
system 1700, or on external storage devices with such computer program
products, including one
or more database management products, web server products, application server
products, and/or
other additional software components. Alternatively, the disc drive unit 1720
may be replaced or
supplemented by an optical drive unit, a flash drive unit, magnetic drive
unit, or other storage
medium drive unit. Similarly, the disc drive unit 1720 may be replaced or
supplemented with
random access memory (RAM), magnetic memory, optical memory, and/or various
other possible
forms of semiconductor based memories commonly found in smart phones and
tablets.
[00133] The network adapter 1724 is capable of connecting the computer system
1700 to a
network via the network link 1714, through which the computer system can
receive instructions
and data and/or issue file system operation requests. Examples of such systems
include personal
computers, Intel or PowerPC-based computing systems, AMD-based computing
systems and other
systems running a Windows-based, a UNIX-based, or other operating system. It
should be
understood that computing systems may also embody devices such as terminals,
workstations,
mobile phones, tablets or slates, multimedia consoles, gaming consoles, set
top boxes, etc.
[00134] When used in a LAN-networking environment, the computer system 1700 is
connected
(by wired connection or wirelessly) to a local network through the network
interface or
adapter 1724, which is one type of communications device. When used in a WAN-
networking
environment, the computer system 1700 typically includes a modem, a network
adapter, or any
other type of communications device for establishing communications over the
wide area network.
In a networked environment, program modules depicted relative to the computer
system 1700 or
portions thereof, may be stored in a remote memory storage device. It is
appreciated that the
network connections shown are examples of communications devices for and other
means of
establishing a communications link between the computers may be used.
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[00135] In an example implementation, filtration system control software and
other modules
and services may be embodied by instructions stored on such storage systems
and executed by the
processor 1702. Some or all of the operations described herein may be
performed by the processor
1702. Further, local computing systems, remote data sources and/or services,
and other associated
logic represent firmware, hardware, and/or software configured to control
filtration system
operation. Such services may be implemented using a general purpose computer
and specialized
software (such as a server executing service software), a special purpose
computing system and
specialized software (such as a mobile device or network appliance executing
service software),
or other computing configurations. In addition, one or more functionalities of
the systems and
methods disclosed herein may be generated by the processor 1702 and a user may
interact with a
Graphical User Interface (GUI) using one or more user-interface devices (e.g.,
the keyboard 1716,
the display unit 1718, and the user devices 112) with some of the data in use
directly coming from
online sources and data stores. The system set forth in Figure 29 is but one
possible example of a
computer system that may employ or be configured in accordance with aspects of
the present
disclosure.
[00136] While not limiting the scope of the disclosure, the following examples
demonstrate
efficiency of exemplary embodiments of the disclosure through, e.g., pressure
integrity, flow
momentum, superior power efficiency, etc.
EXAMPLES
Example I: Particulate Filtration Performance Testink
[00137] The purpose of this testing is to determine the filtration performance
of exemplary
filtration modules of the disclosure. The EN1822-5 test standard is used to
evaluate the filter
modules, and to demonstrate that the filter modules have no input air "by-
pass" such that seal
integrity is maintained so that the air coming out of the filter module is
completely filtered and
achieves the filtration specification of the system.
[00138] The EN1822-5 test standard evaluates a filters' particle removal
efficiency in a size
range between 20 nm-300 nm. The reported efficiency from the EN1822-5 testing
procedure is
given at the lowest measured efficiency value recorded during the challenge.
Test conditions and
test results are provided in the tables below.
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Ckjleg
Aer AmnoiiZ,,M
300 daffier: it I Si DU diCtountet
T COn=Z,16',MS
'knt: Air ernmi e::k 75,2
c,t).: 4,4
SaMtMtlk:
f 033:
M U2t)*::
Test rt#ttlitS
MFP %),WM8.414
Projedid Rating OA inJategmt for ele64.514): Ul 7
[00139] With reference to FIG. 34, test results showed that filter modules
according to the
disclosure achieve 99.99999% efficiency at the lowest performing particle size
region (MPPS) of
the filter in the ultrafine particle size range. This result far exceeds (3000
times better) the standard
HEPA filtration performance of 99.97% at 300 nm.
[00140] A modified Clean Air Delivery Rate (CADR) test was also performed
using an
exemplary air filtration system (air filtration system including filter module
docked in docking
base) of the disclosure, comparing the level of ultrafine particles a test
chamber room before and
after filtration with the standard procedure of the test facility versus
filtration with a system of the
disclosure. The standard procedure of the test facility consisted of a large
HEPA filter combined
with a high powered fan that when powered on had a much higher CADR than the
system of the
disclosure. The results showed that after 90 minutes of runtime, the system of
the disclosure
removed ultrafine particles at an efficiency greater than 99% over the entire
range of particles
challenged in the room. In contrast, the standard cleaning procedure only
removed up to 85%, and
form many particle sizes less than 65%.
Example 2: VOC Testink
[00141] The purpose of this testing is to determine the efficacy of air
filtration system (air
filtration system including filter module docked in docking base) of the
disclosure to remove
challenge VOCs. VOC removal testing was performed referencing NRCC-54013
(April 2011):
Method for Testing Portable Air Cleaners sections 3.2 and 5.1.2. Testing was
conducted for a total
of 8 hours.
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[00142] Natural system decay for the challenge chemicals is performed prior to
the test. The air
filtration system of the disclosure was placed in the center of a chamber,
which was then sealed
and flushed with clean air for a minimum of one night. An additional enclosure
fan was operated
to ensure air mixing. The challenge chemicals (formaldehyde and toluene) were
injected and
allowed to circulate for 30 minutes during which an air sample was taken. Each
challenge
chemical was performed using a fresh filter. The air filtration system was
then turned on using the
highest fan speed beginning the test timing.
[00143] VOC samples were collected at 5, 10, 15, 20, 25, 30, 45, 60, 90, 120,
180, 240, 300,
360, 420, and 480 minutes after starting the system. Samples analyzed for
toluene were collected
on multi-sorbent tubes containing Tenax TA. These VOC samples were analyzed by
thermal
desorption-gas chromatography/mass- spectro scopy, TD-GC/MS.
Samples analyzed for
formaldehyde were collected on cartridges treated with 2,4-di-
nitrophenylhydrazine (DNPH) and
were analyzed using high performance liquid chromatography, HPLC. Individual
VOCs were
calculated using calibration curves based on pure standards.
TEST PARAMETERS:
Table 1: Chamber conditions during test period
PARAMETER SYMBOL VALUE UNITS
Chamber Volume V 30 .3
Testing Duration t 8 h
Average Temperature
: (Range) T 23.6 (23.5-23.8) C
2
Average Humidity
c) (Range) RH 49.2 (48.9-49.9) % RH
TEST RESULTS:
Table 2: Concentration of challenge chemical decay through test.
Time (min) Formaldehyde (pg/m3) Toluene (pg/m3)
D-Limonene (pg/m3)
0 180 835 695
171 792 671
163 705 595
161 675 578
153 650 552
151 616 528
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30 148 605 519
45 140 488 415
60 129 431 370
90 118 301 257
120 108 210 177
180 90 103 85
240 83 52 41
300 73 23 18
360 67 9 <8
420 59 <8 <8
480 51 <8 <8
[00144] The clean air delivery rate (CADR) is calculated according to equation
1:
(L) k, E. 1.
ke I '
where:
4 chemical conc.entration at time t (t.igirrf')
Co chemical concentration at time to kvgim3)
V: volume of the test chamber (PI3)
time (I
CADR: Clean Air Delivery Rate (m3/h}:
km;. first order decay consta:nt with PAC turned off
[00145] The single pass efficiency (SPE) is calculated according to equation
2:
sp=,;
where:
Ce purif1er. flow rate (21
Table 3: Purifier efficiency ¨ calculation of clean air delivery rate and
single pass
efficiency.
VOC CAS No. CADR (m3/h) SPE
(%)
Formaldehyde 50-00-0 5.6 21
Toluene 108-88-3 18.8 69
D-Limonene 5989-27-5 18.5 68
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As shown in FIGS. 35 and 36, after 8 hours of testing, the air filtration
system of the disclosure
removed 99% of toluene, 99% of D-limonene, and 71% of formaldehyde.
Example 3: Virus and Bacterial Removal Efficiency
[00146] The purpose of this testing is to determine the efficacy of air
filtration system (air
filtration system including filter module docked in docking base) of the
disclosure to remove
viruses and bacteria.
[00147] Viral Filtration Efficiency (VFE) at an Increased Challenge Level
[00148] This test procedure was performed to evaluate the VFE of a filtration
system of the
disclosure at an increased challenge level. A suspension of OX174
bacteriophage was delivered to
the test system at a challenge level of greater than 107 plaque-forming units
(PFU) to determine
the filtration efficiency. The challenge was aerosolized using a nebulizer and
delivered to the test
system at a fixed air pressure and flow rate of 150 liters per minute (LPM).
The aerosol droplets
were generated in a glass aerosol chamber and drawn through the test system
into all glass
impingers (AGIs) for collection. The challenge was delivered for a 10 minute
interval and
sampling through the AGIs was conducted for 11 minutes to clear the aerosol
chamber. The mean
particle size (MPS) control was performed at a flow rate of 28.3 LPM using a
six-stage, viable
particle, Andersen sampler for collection. The VFE at an Increased Challenge
Level test procedure
was adapted from ASTM F2101.
[00149] Challenge Procedure: The viral culture suspension was aerosolized
using a nebulizer
and delivered to the test article at a constant flow rate and fixed air
pressure. The aerosol droplets
were generated in a glass aerosol chamber and drawn through the test system
into AGIs.
Approximately one third of the effluent air was collected for quantification
during testing;
therefore, the plate count results for the controls and test articles were
multiplied by three in order
to reflect the entire quantity of air passing through the test article. The
challenge was delivered
for a 10 minute interval and the vacuum and air pressure were allowed to run
for an additional
minute in order to clear the aerosol chamber. Positive control runs were
performed (no filter
medium in the air stream) prior to the first test system run, after every 5-7
test system runs, and
after the last test system run to determine the average number of viable
particles being delivered
to each test system. The MPS of the challenge aerosol was determined using a
six-stage Andersen
sampler.
36
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[00150] Plaque Assay Procedure: The titer of the AGI assay fluid was
determined using
standard plaque assay techniques. Approximately 2.5 mL of molten top agar was
dispensed into
sterile test tubes and held at 45 2 C in a waterbath. An aliquot of the
assay fluid from the test
article was added to the sterile test tubes along with approximately 0.1 mL of
an Escherichia coli
culture. The contents were mixed and poured over the surface of bottom agar
plates. The agar was
allowed to solidify on a level surface and the plates were incubated at 37 2
C for 12-24 hours
[00151] Results:
Teo 4ftw Tow pru RiN,..vamro Fatatior) Entit=Itty
04)
vFE 1 2:7, ;it) =r)91,1:1 TB
112.Vfi ti.tt .49 .t,-3,4(441$
Th.re
03vFE,073 k, = P .,?Kgc:?i
,p,,ere .. d agues oh of the essay plates this teat artide.
[00152] The filtration efficiency percentages were calculated using the
following equation:
e.: T C C1',11allenge Uwe!
ilc:1=17E, , x 100
T
recQvered dOwnStfearl of the test article
[00153] Test Method Acceptance Criteria: The average VFE positive control
challenge level
shall be > 1 x 106 PFU when the flow rate is > 30 LPM. The average MPS of the
challenge aerosol
at 1 cubic foot per minute (CFM) (28.3 LPM) must be maintained at 3.0 0.3
p.m.
[00154] Bacterial Filtration Efficiency (BFE) at an Increased Challenge Level
GLP Report
[00155] This test procedure was performed to evaluate the BFE of test articles
at an increased
challenge level. A suspension of Staphylococcus aureus, ATCC #6538, was
delivered to the test
system at a challenge level of greater than 106 colony forming units (CFU).
The challenge was
aerosolized using a nebulizer and delivered to the test article at a fixed air
pressure and flow rate
of 150 liters per minute (LPM). The aerosol droplets were generated in a glass
aerosol chamber
and drawn through the test article into all glass impingers (AGIs) for
collection. The challenge
was delivered for a 10 minute interval and sampling through the AGIs was
conducted for 11
minutes to clear the aerosol chamber. The mean particle size (MPS) control was
performed at a
flow rate of 28.3 LPM using a six-stage, viable particle, Andersen sampler for
collection. This
method was adapted from ASTM F2101.
37
CA 03178150 2022-09-29
WO 2021/247044 PCT/US2020/036576
[00156] Culture Preparation: Approximately 100 mL of soybean casein digest
broth
(SCDB) was inoculated with S aureus, ATCC #6538, and incubated with mild
shaking for 24
4 hours at 37 2 C. To determine the MPS of the challenge aerosol, the
culture was diluted
in peptone water (PEPW) to an appropriate concentration in order to yield
counts within the
limits of the Andersen sampler.
[00157] AGI Preparation: In a laminar flow hood, a 30 mL aliquot of PEPW was
dispensed
into each AGI.
[00158] Challenge Procedure: The bacterial culture suspension was aerosolized
using a
nebulizer and delivered to the test article at a constant flow rate and fixed
air pressure. The
aerosol droplets were generated in a glass aerosol chamber and drawn through
the test article
into AGIs. Approximately one third of the effluent air was collected for
quantification during
testing; therefore, the plate count results for the controls and test articles
were multiplied by
three in order to reflect the entire quantity of air passing through the test
article. The challenge
was delivered for a 10 minute interval and the vacuum and air pressure were
allowed to run
for an additional minute in order to clear the aerosol chamber. Positive
control runs were
performed (no filter medium in the air stream) prior to the first test system
run, after every 5-
7 test system runs, and after the last test system run to determine the
average number of viable
particles being delivered to each test system. The MPS of the challenge
aerosol was
determined using a six-stage Andersen sampler.
[00159] Assay Procedure: The titer of the AGI assay fluid was determined using
standard
spread plate and/or membrane filtration techniques.
[00160] Spread Plating: An aliquot of the test article assay fluid was
dispensed onto a Tryptic
soy agar (TSA) plate and spread using a sterile rod.
[00161] Membrane Filtration: A sterile filter funnel was placed on a manifold.
A sterile
0.45 p.m membrane was aseptically removed from the packaging and centered over
the base of
the funnel. An appropriate volume of the test article assay fluid was
transferred into the sterile
filter funnel. The vacuum was applied in order for the assay fluid to be
filtered under light
suction. The membrane was then rinsed to ensure that all organisms were
impinged onto the
membrane. The membrane was removed from the filter funnel and placed onto the
surface of
a TSA plate.
[00162] All plates were incubated at 37 2 C for 48 4 hours prior to
counting.
38
CA 03178150 2022-09-29
WO 2021/247044 PCT/US2020/036576
[00163] Results:
uka Recovervd Patat,,.1tEnmemyeA)
oiRcl 54 t.;
akel
CQf3:;:E01.9
8 There wtz-e .e,t..,,.icted colonies on any of the
plates for ttm teat arttle.
[00164] The filtration efficiency percentages were calculated using the
following equation:
C Chancle
100
T Toai GFU 'e:.c)vered downstream ot tna=teSt wide
[00165] Test Method Acceptance Criteria: The average BFE positive control
challenge
level shall be > 106 CFU when the flow rate is > 30 LPM. The average MPS of
the challenge
aerosol at 1 cubic foot per minute (CFM) (28.3 LPM) shall be maintained at 3.0
0.3 pm.
[00166] Conclusion
[00167] When testing for virus efficiency performance our filtration systems
were challenged
with OX174 bacteriophage which is one off the smallest known viruses (25 nm -
27 nm) in size.
The virus was aerosolized into airborne droplets and filtered through an
exemplary filtration
system of the disclosure as a challenge. The result was that the systems of
the disclosure can filter
out over 99.99999% of the aerosolized viral load. The test for the bacteria
filtration efficiency
(BFE) was conducted in a similar fashion using an aerosolized challenge of
Staphylococcus
aureus. As with the VFE test, the BFE test showed that filtration systems of
the disclosure can
remove over 99.99999% of the challenged bacterial aerosol.
[00168] In the present disclosure, the methods disclosed may be implemented as
sets of
instructions or software readable by a device. Further, it is understood that
the specific order or
hierarchy of steps in the methods disclosed are instances of example
approaches. Based upon
design preferences, it is understood that the specific order or hierarchy of
steps in the method can
be rearranged while remaining within the disclosed subject matter. The
accompanying method
claims present elements of the various steps in a sample order, and are not
necessarily meant to be
limited to the specific order or hierarchy presented. Some or all of the steps
may be executed in
parallel, or may be omitted or repeated.
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[00169] The described disclosure may be provided as a computer program
product, or software,
that may include a non-transitory machine-readable medium having stored
thereon instructions,
which may be used to program a computer system (or other electronic devices)
to perform a
process according to the present disclosure. A machine-readable medium
includes any mechanism
for storing information in a form (e.g., software, processing application)
readable by a machine
(e.g., a computer). The machine-readable medium may include, but is not
limited to, magnetic
storage medium, optical storage medium; magneto-optical storage medium, read
only memory
(ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM
and
EEPROM); flash memory; or other types of medium suitable for storing
electronic instructions.
[00170] The description above includes example systems, methods, techniques,
instruction
sequences, and/or computer program products that embody techniques of the
present disclosure.
However, it is understood that the described disclosure may be practiced
without these specific
details.
[00171] It is believed that the present disclosure and many of its attendant
advantages will be
understood by the foregoing description, and it will be apparent that various
changes may be made
in the form, construction and arrangement of the components without departing
from the disclosed
subject matter or without sacrificing all of its material advantages. The form
described is merely
explanatory, and it is the intention of the following claims to encompass and
include such changes.
[00172] Although the foregoing describes various embodiments by way of
illustration and
example, the skilled artisan will appreciate that various changes and
modifications may be
practiced within the spirit and scope of the present disclosure.
