Note: Descriptions are shown in the official language in which they were submitted.
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-1_
METHOD AND APPARATUS FOR
INCREASING PERFORMANCE OF ION WIND DEVICES
1 O FIELD OF THE INVENTION
[0001] The present invention relates generally to devices that produce- an
electro-
kinetic flow of air from Which pas~ticulate matter is substantially removed.
BACKGROUND OF THE INVENTION
[0002] The use of an electric motor to rotate a fan blade to create an airflow
has long
been known in the aa-t. Unfortunately, such fans produce substantial noise,
and can
present a hazard to children who may be tempted to poke a finger or a pencil
into the
moving fan blade. Although such fans can produce substantial airflow (e.g.,
1,000
ft3/minute or more), substantial electrical power is required to operate the
motor, and
essentially no conditioning of the flowing air occurs.
[0003] It is known to provide such fans with ~. HEPA-compliant filter element
to
remove particulate matter larger than perhaps 0.3 ~,m. Unfortunately, the
resistance to
airflow presented by the filter element may require doubling the electric
motor size to
maintain a desired level of airflow. Further, HEPA-compliant filter elements
are
expensive, and can represent a substantial portion of the sale price of a HEPA-
° compliant filter-fan unit. While such filter-fan units can condition
the air by removing
large particles, particulate matter small enough to pass through the filter
element is not
removed, including bacteria, for example.
[0004] It is also known in the art to produce an airflow using electro-kinetic
techniques, by which electrical power is converted into a flow of air without
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-2-
mechanically moving components. One such system is described in U.S. Patent
No.
4,789,801 to Lee (1988), depicted herein in simplified form as FIGS. lA and 1B
and
which patent is incorporated herein by reference. System 10 includes an array
of first
("emitter") electrodes or conductive surfaces 20 that are spaced-apart
symmetrically
from an array of second ("collector") electrodes or conductive surfaces 30.
The
positive terminal of a generator such as, for example, pulse generator 40 that
outputs a
train of high voltage pulses (e.g., 0 to perhaps + 5 ITV) is coupled to the
first array,
and the negative pulse generator terminal is coupled to the second array in
this
example. It is to be understood that the arrays depicted include multiple
electrodes,
I O but that an array can include or be replaced by a single electrode.
[0005] The high voltage pulses ionize the air between the arrays, and create
an
airflow 50 from the first array toward the second array, without requiring any
moving
parts. Particulate matter 60 in the air is entrained within the airflow 50 and
also moves
towards the second electrodes 30. Much of the particulate matter is
electrostatically
attracted to the surfaces of the second electrodes, where it remains, thus
conditioning
the flow of air exiting system 10. Further, the high voltage field present
between the
electrode arrays can release ozone into the ambient environment, which can
eliminate
odors that are entrained in the airflow.
[0006] In the particular embodiment of FIG. lA, first electrodes 20 are
circular in
cross-section, having a diameter of about 0.003" (0.08 mm), whereas the second
electrodes 30 are substantially larger in area and define a "teardrop" shape
in cross-
section. The ratio of cross-sectional radii of curvature between the bulbous
front nose
of the second electrode and the first electrodes exceeds 10:1. As shown in
FIG. IA,
the bulbous front surfaces of the second electrodes face the first electrodes,
and the
somewhat "sharp" trailing edges face the exit direction of the airflow. The
"sharp"
trailing edges on the second electrodes promote good electrostatic attachment
of
particulate matter entrained in the airflow.
[0007] In another particular embodiment shown herein as FIG. 1B, second
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-3-
electrodes 30 are symmetrical and elongated in cross-section. The elongated
trailing
edges on the second electrodes provide increased area upon which particulate
matter
entrained in the airflow can attach.
[4008] While the electrostatic techniques disclosed by the '801 patent are
advantageous over conventional electric fan-filter units, further increased
air
transport-conditioning efficiency would be advantageous.
[0009] Ion wind devices such as those described in U.S. Patent No. 4,789,801
provide accelerated gas ions generated by the use of differential high voltage
electric
fields between an array of one or more emitters and a plurality of collectors
(accelerators). The ions are entrained in the ambient bulk gases, causing the
gases to
flow. Gas velocities can reach as high as eight hundred feet per minute.
However, the
high voltage electric fields used to generate the gas ions and provide the
force
necessary for gas acceleration are also responsible for creating molecular
disassociation reactions, the most common of which include ozone generated
from
oxygen when such devices are operating in a breathable atmosphere. The U.S.
Food
and Drug Administration has determined that indoor, airborne ozone in
concentrations
above 50 ppb (parts per billion) may be hazardous to humans. NIOSH (National
Institute of Occupational Safety and Health) has ruled that indoor
concentrations of
ozone above 100 ppb may be hazardous to humans. Devices which utilize high
voltage electric fields to generate atmospheric plasma, corona discharge and
air ions,
axe all susceptible to generating this allotropic of oxygen, ozone. There
exists a linear
relationship between the level of the high voltage fields and current and the
level of
ozone concentration in most direct current operated ion wind systems. Also, a
linear
relationship exists between the acceleration velocity and intensity of the
electric fields.
Typically, the higher the voltage the higher the acceleration. Since it is
desired to
have maximum acceleration, methods must be employed to reduce ozone production
or convert unwanted ozone back to oxygen before it is expelled into the
breathable
atmosphere. It is an object of this invention to provide methods to convert
generated
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-4-
ozone back to oxygen in such devices.
[0010] Ion wind devices that have been specifically designed as air cleaners
have
also been inherently limited in their airflow and in the amount of particle
contamination they can remove. Unlike electrostatic air cleaners that rely
upon a
motor driven fan to propel air into an ionizing field, the ion wind device
utilizes a
structured ionizing field as the primary air movement force. This requires
molecular
ionization levels at many orders of magnitude greater than are used in
electrostatic
precipitator devices. Consequently, like-charged particles and matter
clustered in the
air stream inhibit some airflow and precipitation ability of ion wind devices.
It is a
further object of this invention to teach a method and apparatus for de-
ionizing a large
portion of the charged molecules responsible for the resisting forces in the
air stream
and to improve precipitation efficiency of the charged contaminant particles
by
accelerating them towards an oppositely charged collector plate array.
1 S SUMMARY OF THE INVENTION
[0011) The present invention provides such an apparatus.
[0012] One aspect of the present invention is to provide an electro-kinetic
air
transporter-conditioner that produces an enhanced airflow velocity, enhanced
particle
collection, and an appropriate amount of ozone production.
[0013] An embodiment includes one or more focus or leading electrodes. Each
focus or leading electrode may be located upstream to, or even with, each
first
electrode. The focus or leading electrodes assists in controlling the flow of
ionized
particles within the airflow. The focus or leading electrode shapes the
electrostatic
field generated by each first electrode within the electrode assembly.
[0014] Another embodiment includes one or more trailing electrodes. Each
trailing
electrode can be located downstream of a second electrode. The trailing
electrode can
assist in neutralizing the amount of ions exiting this embodiment of the
invention, and
can further assist in collecting ionized particles. The trailing electrode can
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-5-
alternatively enhance the flow of negative ions from the transporter-
conditioner.
Additionally, the trailing electrodes can improve the laminar flow properties
of the
airflow exiting the air transporter-conditioner.
[0015] Another embodiment of the invention includes at least one interstitial
electrode located between two second electrodes. The interstitial electrode
can also
assist in the collection of particulate matter by the second electrodes.
[0016] In yet another embodiment of the invention, one or more of the second
electrodes are formed to have an enhanced protective end or trailing surface
which
assists in the operation and cleaning of the embodiment.
(0017j In still a further embodiment of the invention, one or more first
electrode are
of enhanced length in order to increase the emissivity of the first electrode.
[0018] Other objects, aspects, features and advantages of the invention will
appear
from the following description in which the preferred embodiments have been
set
forth in detail, in conjunction with the accompanying drawings and also from
the
following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
(0019] FIGS. lA-1B; FIG. lA is a plan, cross-sectional view, of a first
embodiment
of an electro-kinetic air transporter-conditioner system according to the
prior art; FIG.
1B is a plan, cross-sectional view, of a second embodiment of an electro-
kinetic air
transporter-conditioner system according to the prior art;
[0020] FIGS. 2A-2B; FIG. 2A is a perspective view of a typical embodiment of
the
housing of an electro-kinetic air transporter-conditioner; FIG. 2B is a
perspective view
of the embodiment shown in FIG. 2A illustrating the removable second
electrodes;
[0021] FIG. 3 is an electrical block diagram of the present invention;
[0022] FIGS. 4A-4F; FIG. 4A is a perspective view showing an embodiment of an
electrode assembly according to the present invention; FIG. 4B is a plan view
of the
embodiment illustrated in FIG. 4A; FIG. 4C is a perspective view showing
another
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-6-
embodiment of an electrode assembly according to the present invention; FIG.
4D is a
plan view illustrating a modified version of the embodiment of FIG. 4C; FIG.
4E is a
perspective view showing yet another embodiment of an electrode assembly
according
to the present invention; FIG. 4F is a plan view of the embodiment of FIG. 4E;
[0023] FTGS. SA-SB; FIG. SA is a perspective view of still another embodiment
of
the present invention illustrating the leading or focus electrode added to the
embodiment shown in FIG. 4A; FIG. SB is a plan view of a modified embodiment
of
the present invention similar to that shown in FIG. SA illustrating a
protective end on
each second electrode;
[0024] FTGS. 6A-6D; FIG. 6A is a perspective view of a further embodiment of
the
present invention, illustrating a leading or focus electrode added to the
embodiment
shown in FIG. 4C; FIG. 6B is a perspective view of a modified embodiment of
the
present invention as shown in FIG. 6A; FIG. 6C is a perspective view of a
modified
embodiment of the present invention as shown in FIG. 6B; FIG. 6D is a modified
~ embodiment of the present invention, illustrating a leading or focus
electrode added to
the embodiment in FIG. 4D;
[0025] FIGS. 7A-7C; FIG. 7A is a perspective view of another embodiment of the
present invention, illustrating a leading or focus electrode added to the
embodiment
shown in FTG. 4E; FIG. 7B is a perspective view of an embodiment modified from
that shown in FIG. 7A; FIG. 7C is a perspective view of an embodiment modified
from that shown in FIG. 7B;
[0026] FIGS. 8A-8C; FIG. 8A is a perspective view of still a further
embodiment of
the present invention, illustrating another embodiment of the leading or focus
electrode; FIG. 8B is a perspective view of an embodiment modified from that
shown
in FIG. SA; FIG. 8C is a perspective view of yet another embodiment;
[0027] FIGS. 9A-9C; FIG. 9A is perspective view of a further embodiment of the
present invention; FIG. 9B is a partial view of an embodiment modified from
that
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
shown in FIG. 1 OA; FIG. 9C is another embodiment modified from that shown in
FIG. 9A;
[0028] FTGS. 1 OA-l OD; FIG. l0A is a perspective view of another embodiment
of
the present invention, illustrating a trailing electrode added to the
embodiment in FTG.
7A; FIG. l OB is a plan view of the embodiment shown in FIG. 10A; FTG. l OC is
a
plan view of a further embodiment of the present invention; FTG. 10D is a plan
view
of another embodiment of the present invention similar to FTG. 1 OC.
[0029] FIGS. 11A-11F; FIG. 1 IA is a plan view of still another embodiment of
the
present invention; FIG. 11B is a plan view of an embodiment modified from that
shown in FIG. 11A; FIG. 11C is a plan view of a further embodiment of the
present
invention; FIG. 11D is a plan view of an embodiment modified from that shovcm
in
FIG. 11C; FIG. 1 lE is a plan view of a fiu-ther embodiment of the present
invention;
FIG. 11F is a plan view of an embodiment modified from that shown in FIG. 11F;
and
[0030] FIGS. 12A-12C; FIG. 12A is a perspective view of still another
embodiment
of the present invention; FIG. 12B is a perspective view of a further
embodiment of
the present invention; FIG. 12C is a perspective view of yet another
embodiment of
the present invention;
[0031] FIG. 13 is a schematic view of an ion wind device of this invention
illustrating the use of one ox more interstitial electrodes to reduce the
discharge of
ozone;
[0032] FIG. 14 is a schematic view of an ion wind device of this invention
illustrating the use of one or more interstitial electrodes to increase
airflow by de-
ionizing charged molecules responsible for resisting forces in the airstream;
[0033] FIG. 15 is a schematic view of an ion wind device of this invention
illustrating the use of one or more interstitial electrodes to increase
airflow by
improving the precipitation efficiency of charged particles;
[0034] FIG. 16 is a schematic view of a high voltage power source for ion wind
devices of this invention; and
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
_g_
[0035j FIG. 17 is a schematic view of an alternate wiring option for an
interstitial
electrode of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Overall Air Transporter-Conditioner System Configuration:
[0036] FIGS. 2A and 2B depict an electro-kinetic air transporter-conditioner
system
100 whose housing 102 includes preferably rear-located intake vents or louvers
104
and preferably front located exhaust vents 106, and a base pedestal 108. If
desired a
single vent can provide and be used as both an air intake and an air exhaust
with an air
inlet channel and an air exhaust channel communicating with the vent and the
electrodes. Preferably the housing is freestanding and/or upstandingly
vertical and/or
elongated. Internal to the transporter housing is an ion generating unit 160,
preferably
powered by an AC:DC power supply that is energizable or excitable using switch
S1.
S l, which along with the other below described user operated switches are
conveniently located at the top 103 of the unit 100. Ion generating unit 160
is self
contained in that other ambient air, nothing is required from beyond the
transporter
housing, save external operating potential, for operation of the present
invention.
[0037] The upper surface of housing 102 includes a user-liftable handle member
112
to which is affixed a second array 240 of collector electrodes 242 within an
electrode
assembly 220. Electrode assembly 220 also comprises a first array of emitter
electrodes 230, or a single frst electrode shov~m here as a single wire or
wire-shaped
electrode 232. (The terms "wire" and "wire-shaped" shall be used
interchangeably
herein to mean an electrode either made from a wire or, if thicker or stiffer
than a
wire, having the appearance of a wire.) In the embodiment shown, lifting
member
1 I2 Iifts second array electrodes 240 upward, causing the second electrode to
telescope out of the top of the housing and, if desired, out of mit I 00 for
cleaning,
while the first electrode array 230 remains witlun unit 100. As is evident
from the
figure, the second array of electrode can be lifted vertically out from the
top 103 of
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-9-
unit 100 along the longitudinal axis or direction of the elongated housing
I02. This
arrangement with the second electrodes removable from the top 103 of the unit
100,
makes it easy for the user to pull the second electrodes out for cleaning. In
FIG. 2B,
the bottom ends of second electrodes 242 are connected to a member 113, to
which is
attached a mechanism 500, which includes a flexible member and a slot for
capturing
and cleaning the first electrode 232, whenever handle member 112 is moved
upward
or downward by a user.
[0038] The first and second arrays of electrodes are coupled to the output
terminals
of ion generating unit 160, as best seen in FIG. 3.
[0039] The general shape of the embodiment of the invention shown in FIGS. 2A
and 2B is that of a figure eight in cross-section, although other shapes are
within the
spirit and scope of the invention. The top-to-bottom height of the preferred
embodiment is in one preferred embodiment, 1 m, with a left-to-right width of
preferably 15 cm, and a front-to-back depth of perhaps 10 cm, although other
dimensions and shapes can of course be used. A louvered construction provides
ample
inlet and outlet venting in an economical housing configuration. There need be
no
real distinction between vents 104 and 106, except their location relative to
the second
electrodes. These vents serve to ensure that an adequate flow of ambient air
can be
drawn into or made available to the unit 100, and that an adequate flow of
ionized air
that includes appropriate amounts of 03 flows out from unit 100.
[0040] As will be described, when unit 100 is energized with S 1, high voltage
or
high potential output by ion generator 160 produces ions at the first
electrode, which
ions are attracted to the second electrodes. The movement of the ions in an
"IN" to
"OUT" direction carries with the ions air molecules, thus electro-kinetically
producing
an outflow of ionized air. The "IN" notation in FIGS. 2A and 2B denote the
intake of
ambient air with particulate matter 60. The "OUT" notation in the figures
denotes the
outflow of cleaned air substantially devoid of the particulate matter, which
particulate
matter adheres electrostatically to the surface of the second electrodes. In
the process
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-10-
of generating the ionized airflow appropriate amounts of ozone (03) are
beneficially
produced. It may be desired to provide the inner surface of housing 102 with
an
electrostatic shield to reduces detectable electromagnetic radiation. For
example, a
metal shield could be disposed within the housing, or portions of the interior
of the
housing can be coated with a metallic paint to reduce such radiation.
[0041] The housing preferably has a substantially oval-shaped or-elliptically
shaped
cross-section with dimpled side grooves. Thus, as indicated above, the cross-
section
looks somewhat like a figure eight. It is within the scope of the present
invention for
the housing to have a different shaped cross-section such as, but not limited
to, a
rectangular shape, an egg shape, a tear-drop shape, or circular shape. The
housing
preferably has a tall, thin configuration. As will become apparent later, the
housing is
preferably functionally shaped to contain the electrode assembly.
[0042] As mentioned above, the housing has an inlet and an outlet. Both the
inlet
and the outlet are covered by fins or louvers. Each fin is a thin ridge spaced-
apart
from the next fin, so that each fin creates minimal resistance as air flows
through the
housing. The fins are horizontal and are directed across the elongated
vertical
upstanding housing of the unit. Thus, the fins are substantially perpendicular
in this
preferred embodiment to the electrodes. The inlet and outlet fins are aligned
to give
the unit a "see through" appearance. Thus, a user can "see through" the unit
from the
inlet to the outlet. The user will see no moving parts within the housing, but
just a
quiet unit that cleans the air passing therethrough. Alternatively the fins
can be
parallel with the electrodes in another preferred embodiment. Other
orientations of
fins and electrodes are possible in other embodiments.
[0043] As best seen in FIG. 3, ion generating unit 160 includes a high voltage
generator unit 170 and circuitry 180 for converting raw alternating voltage
(e.g., 117
VAC) into direct current ("DC") voltage. Circuitry 180 preferably includes
circuitry
controlling the shape and/or duty cycle of the generator unit output voltage
(which
control is altered with user switch S2). Circuitry 180 preferably also
includes a pulse
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-11-
mode component, coupled to switch S3, to temporarily provide a burst of
increased
output ozone. Circuitry 180 can also include a timer circuit and a visual
indicator
such as a light emitting diode ("LED"). The LED or other indicator (including,
if
desired, an audible indicator) signals when ion generation quits occurring.
The timer
can automatically halt generation of ions and/or ozone after some
predetermined time,
e.g., 30 minutes.
[0044] The high voltage generator unit 170 preferably comprises a Iow voltage
oscillator circuit 190 of perhaps 20 KHz frequency, that outputs low voltage
pulses to
an electronic switch 200, e.g., a thyristor or the like. Switch 200 switchably
couples
the low voltage pulses to the input winding of a step-up transformer T1. The
secondary winding of T1 is coupled to a high voltage multiplier circuit 210
that
outputs high voltage pulses. Preferably the circuitry and components
comprising high
voltage pulse generator 170 and circuit I 80 are fabricated on a printed
circuit board
that is mounted within housing 102. If desired, external audio input (e.g.,
from a
stereo tuner) could be suitably coupled to oscillator 190 to acoustically
modulate the
kinetic airflow produced by unit 160. The result would be an electrostatic
loudspeaker, whose output airflow is audible to the human ear in accordance
with the
audio input signal. Further, the output air stream would still include ions
and ozone.
(0045] Output pulses from high voltage generator 170 preferably are at Ieast
10 ITV
peak-to-peak with an effective DC offset of, for example, half the peak-to-
peak
voltage, and have a frequency of, for example, 20 I~Hz. Frequency of
oscillation can
include other values, but frequency of at least about 20KHz is preferred as
being
inaudible to humans. If pets will be in the same room as the unit 100, it may
be
desired to utilize and even higher operating frequency, to prevent pet
discomfort
and/or howling by the pet. The pulse train output preferably has a duty cycle
of for
example 10%, which will promote battery lifetime if live current is not used.
Of
course, different peak-peak amplitudes, DC offsets, pulse train wave shapes,
duty
cycle, and/or repetition frequencies can be used instead. Indeed, a 100% pulse
train
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-12-
(e.g., an essentially DC high voltage) may be used, albeit with shorter
battery lifetime.
Thus, generator unit 170 for this embodiment can be referred to as a high
voltage
pulse generator. Unit 170 functions as a DC:DC lugh voltage generator, and
could be
implemented using other circuitry and/or techniques to output high voltage
pulses that
are input to electrode assembly 220.
[0046] As noted, outflow (OUT) preferably includes appropriate amounts of
ozone
that can remove odors and preferably destroy or at least substantially alter
bacteria,
germs, and other living (or quasi-living) matter subjected to the outflow.
Thus, when
switch S I is closed and the generator 170 has sufficient operating potential,
pulses
from high voltage pulse generator unit 170 create an outflow (OUT) of ionized
air and
ozone. When S 1 is closed, LED will visually signal when ionization is
occurring.
[0047] Preferably operating parameters of unit 100 are set during manufacture
and
are generally not user-adjustable. For example, with respect to operating
parameters,
increasing the peak-to-peak output voltage and/or duty cycle in the high
voltage pulses
generated by unit 170 can increase the airflow rate, ion content, and ozone
content.
These parameters can be set by the user by adjusting switch S2 as disclosed
below. In
the preferred embodiment, output flow rate is about 200 feet/minute, ion
content is
about 2,000,000/cc and ozone content is about 40 ppb (over ambient) to perhaps
2,000
ppb (over ambient). Decreasing the ratio of the radius of the nose of the
second
electrodes to the radius of the first electrode or decreasing the ratio of the
cross-
sectioned area of the second electrode to the first electrode below about 20:1
will
decrease flow rate, as will decreasing the peak-to-peak voltage and/or duty
cycle of
the high voltage pulses coupled between the first and second electrode arrays.
[0048] In practice, unit I00 is placed in a room and connected to an
appropriate
source of operating potential, typically 117 VAC. With S1 energizing
ionization unit
160, systems 100 emits ionized air and preferably some ozone via outlet vents
106.
The airflow, coupled with the ions and ozone freshens the air in the room, and
the
ozone can beneficially destroy or at least diminish the undesired effects of
certain
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-13-
odors, bacteria, germs, and the like. The airflow is indeed electro-
lcinetically
produced, in that there are no intentionally moving parts within unit 100.
(Some
mechanical vibration may occur within the electrodes.).
[0049] Having described various aspects of this embodiment of the invention in
general, preferred embodiments of electrode assembly 220 are now described. In
the
various embodiments, electrode assembly 220 comprises a first array 230 of at
least
one electrode or conductive surface 232, and further comprises a second array
240 of
preferably at least one electrode or conductive surface 242. Understandably
materials) for electrodes 232 and 242 should conduct electricity, be resistant
to
corrosive effects from the application of high voltage, yet be strong enough
to be
cleaned.
[0050] In the various electrode assemblies to be described herein, electrodes)
232 in
the first electrode array 230 are preferably fabricated from tungsten.
Tungsten is
sufficiently robust in order to withstand cleaning, has a high melting point
to retard
breakdown due to ionization, and has a rough exterior surface that seems to
promote
efficient ionization. On the other hand, electrodes) 242 preferably have a
highly
polished exterior surface to minimize unwanted point-to-point radiation. As
such,
electrodes) 242 preferably are fabricated from stainless steel and/or brass,
among
other materials. The polished surface of electrodes) 232 also promotes ease of
electrode cleaning.
[0051] In contrast to the prior art electrodes disclosed by the '801 patent,
electrodes
232 and 242, are light weight, easy to fabricate, and lend themselves to mass
production. Further, electrodes 232 and 242 described herein promote more
efficient
generation of ionized air, and appropriate amounts of ozone, (indicated in
several of
the figures as 03).
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-14-
Electrode Assembly with First and Second Electrodes:
FIGS. 4A-4F
[0052] FIGS. 4A-4F illustrate various configurations of the electrode assembly
220.
The output from high voltage pulse generator unit 170 is coupled to an
electrode
assembly 220 that comprises a first electrode array 230 and a second electrode
array
240. Again, instead of arrays, single electrodes or single conductive surfaces
can be
substituted for one or both array 230 and array 240.
[0053] The positive output terminal of unit 170 is coupled to first electrode
array
230, and the negative output terminal is coupled to second electrode array
240. It is
believed that with this arrangement the net polarity of the emitted ions is
positive, e.g.,
more positive ions than negative ions are emitted. This coupling polarity has
been
found to work well, including minimizing unwanted audible electrode vibration
or
hum. However, while generation of positive ions is conducive to a relatively
silent
airflow, from a health standpoint, it is desired that the output airflow be
richer in
negative ions, not positive ions. It is noted that in some embodiments, one
port
(preferably the negative port) of the high voltage pulse generator can in fact
be the
ambient air. Thus, electrodes in the second array need not be connected to the
high
voltage pulse generator using a wire. Nonetheless, there will be an "effective
connection" between the second array electrodes and one output port of the
high
voltage pulse generator, in this instance, via ambient air. Alternatively the
negative
output terminal of unit I70 can be connected to the first electrode array 230
and the
positive output terminal can be connected to the second electrode axray 240.
[0054] With this arrangement an electrostatic flow of air is created, going
from the
first electrode array towards the second electrode array. (This flow is
denoted "OUT"
in the figures.) Accordingly electrode assembly 220 is mounted within
transporter
system 100 such that second electrode array 240 is closer to the OUT vents and
first
electrode array 230 is closer to the IN vents.
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-15-
[0055] When voltage or pulses from high voltage pulse generator 170 are
coupled
across first and second electrode arrays 230 and 240, a plasma-like field is
created
surrounding electrodes 232 in first aiTay 230. This electric field ionizes the
ambient
air between the first and second electrode arrays and establishes an "OUT"
airflow
that moves towards the second array. It is understood that the IN flow enters
via
vents) 104, and that the OUT flow exits via vents) 106.
[0056] Ozone and ions axe generated simultaneously by the first array
electrodes
232, essentially as a function of the potential from generator 170 coupled to
the first
array of electrodes or conductive surfaces. Ozone generation can be increased
or
decreased by increasing or decreasing the potential at the first array.
Coupling an
opposite polarity potential to the second array electrodes 242 essentially
accelerates
the motion of ions generated at the first array, producing the airflow denoted
as
"OUT" in the figures. As the ions and ionized particulate move toward the
second
array, the ions and ionized particles push or move air molecules toward the
second
array. The relative velocity of this motion may be increased, by way of
example, by
decreasing the potential at the second array relative to the potential at the
first array.
[0057] For example, if +10 KV were applied to the first array electrode(s),
and no
potential were applied to the second array electrode(s), a cloud of ions
(whose net
charge is positive) would form adjacent the first electrode array. Further,
the
relatively high 10 KV potential would generate substantial ozone. By coupling
a
relatively negative potential to the second array electrode(s), the velocity
of the air
mass moved by the net emitted ions increases.
[0058] On the other hand, if it were desired to maintain the same effective
outflow
(OUT) velocity, but to generate less ozone, the exemplary 10 KV potential
could be
divided between the electrode arrays. For example, generator 170 could provide
+4
KV (or some other fraction) to the first array electrodes and -6 KV (or some
other
fraction) to the second array electrodes. In this example, it is understood
that the +4
KV and the -6 KV are measured relative to ground. Understandably it is desired
that
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-16-
the unit 100 operates to output appropriate amounts of ozone. Accordingly, the
high
voltage is preferably fractionalized with about +4 KV applied to the first
array
electrodes and about -6 KV applied to the second array electrodes.
[0059] In the embodiments of FIGS. 4A and 4B, electrode assembly 220 comprises
a frst array 230 of wire-shaped electrodes 232, and a second array 240 of
generally
"U"-shaped electrodes 242. In preferred embodiments, the number N1 of
electrodes
comprising the first array can preferably differ by one relative to the number
N2 of
electrodes comprising the second array 240. In many of the embodiments shown,
N2>N1. However, if desired, additional first electrodes 232 could be added at
the
outer ends of array 230 such that N1>N2, e.g., five first electrodes 232
compared to
four second electrodes 242.
[0060] As previously indicated first or emitter electrodes 232 are preferably
lengths
of tungsten wire, whereas electrodes 242 are formed from sheet metal,
preferably
stainless steel, although brass or other sheet metal could be used. The sheet
metal is
readily configured to define side regions 244 and bulbous nose region 246,
forming
the hollow, elongated "U"-shaped electrodes 242. While FIG. 4A depicts four
electrodes 242 in second array 240 and three electrodes 232 in first array
230, as noted
previously, other numbers of electrodes in each array could be used,
preferably
retaining a symmetrically staggered configuration as shown. It is seen in FIG.
4A that
while particulate matter 60 is present in the incoming (IN) air, the outflow
(OUT) air
is substantially devoid of particulate matter, which adheres to the preferably
large
surface area provided by the side regions 244 of the second array electrodes
242.
(0061] FTG. 4B illustrates that the spaced-apart configuration between the
first and
second arrays 230, 240 is staggered. Preferably, each first array electrode
232 is
substantially equidistant from two second array electrodes 242. This
symmetrical
staggering has been found to be an efficient electrode placement. Preferably,
in this
embodiment, the staggering geometry is symmetrical in that adjacent electrodes
232 or
adjacent electrodes 242 are spaced-apart a constant distance, Y1 and Y2
respectively.
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-17-
However, a non-symmetrical configuration could also be used. Also, it is
understood
that the number of electrodes 232 and 242 may differ from what is shown.
[0062] In the embodiment of FIGS. 4A, typically dimensions are as follows:
diameter of electrodes 232, RI, is about 0.08 mm, distances Yl and Y2 are each
about
S 16 mm, distance Xl is about I6 mm, distance L is about 20 mm, and electrode
heights
Z1 and Z2 are each about 1 m. The width W of electrodes 242 is preferably
about 4
mm, and the thicleness of the material from which electrodes 242 are formed is
about
O.S mm. Of course other dimensions and shapes could be used. For example,
preferred dimensions for distance X1 may vary between 12-30mm, and the
distance
Y2 may vary between 1 S-30mm. It is preferred that electrodes 232 have a small
diameter. A wire having a small diameter, such as R1, generates a high voltage
field
and has a high emissivity. Both characteristics are beneficial for generating
ions. At
the same time, it is desired that electrodes 232 (as well as electrodes 242)
be
sufficiently robust to withstand occasional cleaning.
1S [0063] Electrodes 232 in first array 230 are coupled by a conductor 234 to
a first
(preferably positive) output port of high voltage pulse generator 170.
Electrodes 242
in second array 240 are coupled by a conductor 249 to a second (preferably
negative)
output port of high voltage generator 170. The electrodes may be electrically
connected to the conductors 234 ox 249 at various locations. By way of example
only,
FIG. 4B depicts conductor 249 making connection with some electrodes 242
internal
to bulbous end 246, while other electrodes 242 make electrical connection to
conductor 249 elsewhere on the electrode 242. Electrical connection to the
various
electrodes 242 could also be made on the electrode external surface, provided
no
substantial impairment of the outflow airstream results; however it has been
found to
2S be preferable that the connection is made internally.
[0064] In this and the other embodiments to be described herein, ionization
appears
to occur at the electrodes 232 in the first electrode array 230, with ozone
production
occurring as a function of high voltage arcing. For example, increasing the
peals-to-
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-18-
peak voltage amplitude and/or duty cycle of the pulses from the high voltage
pulse
generator 170 can increase ozone content in the output flow of ionized air. If
desired,
user-control S2 can be used to somewhat vary ozone content by varying
amplitude
and/or duty cycle. Specific cixcuitry for achieving such control is known lIl
the art and
need not be described in detail herein.
[0065] Note the inclusion in FIGS. 4A and 4B of at least one output
controlling
electrodes 243, preferably electrically coupled to the same potential as the
second
array electrodes 242. Electrode 243 preferably defines a pointed shape in side
profile,
e.g., a triangle. The sharp point on electrodes 243 causes generation of
substantial
negative ions (since the electrode is coupled to relatively negative high
potential).
These negative ions neutralize excess positive ions otherwise present in the
output
airflow, such that the OUT flow has a net negative charge. Electrodes 243 is
preferably stainless steel, copper, or other conductor material, and is
perhaps 20 mm
high and about 12 mm wide at the base. The inclusion of one electrode 243 has
been
found sufficient to provide a sufficient number of output negative ions, but
more such
electrodes may be included.
[0066] In the embodiments of FIGS. 4A, 4B and 4C, each "U"-shaped electrode
242
has two trailing surface or sides 244 that promote efficient kinetic transport
of the
outflow of ionized air and ozone. For the embodiment of FIG. 4C, there is the
inclusion on at least one portion of a txailing edge of a pointed electrode
region 243'.
Electrode region 243' helps promote output of negative ions, in the same
fashion that
was previously described with respect to electrodes 243, as shown in FIGS. 4A
and
4B.
[0067] In FIG. 4C and the figures to follow, the particulate matter is omitted
for ease
of illustration. However, from what was shown in FIGS. 4A-4B, particulate
matter
will be present in the incoming air, and will be substantially absent from the
outgoing
air. As has been described, particulate matter 60 typically will be
electrostatically
precipitated upon the surface area of electrodes 242.
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-19-
[0068] As discussed above and as depicted by FIG. 4C, it is relatively
unimportant
where on an electrode array electrical connection is made. Thus, first array
electrodes
232 are shown electrically cormected together at their bottom regions by
conductor
234, whereas second array electrodes 242 are shown electrically connected
together in
their middle regions by the conductor 249. Both arrays may be connected
together in
more than one region, e.g., at the top and at the bottom. It is preferred that
the wire or
strips or other inter-connecting mechanisms be at the top, bottom, or
periphery of the
second array electrodes 242, so as to minimize obstructing stream air movement
through the housing 210.
[0069] It is noted that the embodiments of FIGS. 4C and 4D depict somewhat
truncated versions of the second electrodes 242. Whereas dimension L in the
embodiment of FIGS. 4A and 4B was about 20 mm, in FIGS. 4C and 4D, L has been
shortened to about 8 mm. Other dimensions in FIG. 4C preferably are similar to
those
stated for FIGS. 4A and 4B. It will be appreciated that the configuration of
second
electrode array 240 in FIG. 4C can be more robust than the configuration of
FIGS. 4A
and 4B, by virtue of the shorter trailing edge geometry. As noted earlier, a
symmetrical staggered geometry for the first and second electrode arrays is
preferred
for the configuration of FIG. 4C.
[0070] In the embodiment of FIG. 4D, the outermost second electrodes, denoted
242-1 and 242-4, have substantially no outermost trailing edges. Dimension L
in FIG.
4D is preferably about 3 mm, and other dimensions may be as stated for the
configuration of FIGS. 4A and 4B. Again, the ratio of the radius or surface
areas
between the first electrode 232 and the second electrodes 242 for the
embodiment of
FIG. 4D preferably exceeds about 20:1.
[0071] FIGS. 4E and 4F depict another embodiment of electrode assembly 220, in
which the first electrode array 230 comprises a single wire electrode 232, and
the
second electrode array 240 comprises a single pair of curved "L"-shaped
electrodes
242, in cross-section. Typical dimensions, where different than what has been
stated
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-20-
for earlier-described embodiments, are X1 ~ 12 mm, Y2 ~ S mm, and L1 ~ 3 mm.
The effective surface area or radius ratio is again greater than about 20:1.
The fewer
electrodes comprising assembly 220 in FIGS. 4E and 4F promote economy of
construction, aild ease of cleaning, although more than one electrode 232, and
moxe
S than two electrodes 242 could of course be employed. This pa.uticular
embodiment
incorporates the staggered symmetry described earlier, in which electrode 232
is
equidistant from two electrodes 242. Other geometric arrangements, which may
not
be equidistant, are within the spirit and scope of the invention.
Electrode Assembly With an Upstream Focus Electrode:
FIGS. SA-SB
[0072] The embodiments illustrated in FIGS. SA-SB are somewhat similar to the
previously described embodiments in FIGS. 4A-4B. The electrode assembly 220
includes a first array of electrodes 230 and a second array of electrodes 240.
Again,
1 S for this and the other embodiments, the term "array of electrodes" may
refer to a
single electrode or a plurality of electrodes. Preferably, the number of
electrodes 232
in the first array of electrodes 230 will differ by one relative to the number
of
electrodes 242 in the second array of electrodes 240. The distances L, X1, Y1,
Y2, Zl
and Z2 for this embodiment are similar to those previously described in FIG.
4A.
[0073] As shown in FIG. SA, the electrode assembly 220 preferably adds a
third, or
leading, or focus, or directional electrode 224a, 224b, 224c (generally
referred to as
"electrode 224") upstream of each first electrode 232-1, 232-2, 232-3. The
focus
electrode 224 produces an enhanced airflow velocity exiting the devices 100 or
200.
In general, the third focus electrode 224 directs the airflow, and ions
generated by the
2S first electrode 232, towards the second electrodes 242. Each third focus
electrode 224
is a distance XZ upstream from at Least one of the first electrodes 232. The
distance
X2 is preferably S-6 mm, or four to five diameters of the focus electrode 224.
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-21 -
However, the third focus electrode 224 can be fuxther from or closer to the
first
electrode 232.
[0074] The third focus electrode 224 illustrated in FIG. SA is a rod-shaped
electrode. The third focus electrode 224 can also comprise other shapes that
preferably do not contain any sharp edges. The third focus electrode 224 is
preferably
manufactured from material that will not erode or oxidize, such as stainless
steel. The
diameter of the third focus electrode 224, in a preferred embodiment, is at
least fifteen
times greater than the diameter of the first electrode 232. The diameter of
the third
focus electrode 224 can be larger or smaller. The diameter of the third focus
electrode
224 is preferably Iarge enough so that third focus electrode 224 does not
function as
an ion emitting surface when electrically connected with the first electrode
232. The
maximum diameter of the third focus electrode 224 is somewhat constrained. As
the
diameter increases, the third focus electrode 224 will begin to noticeably
impair the
airflow rate of the units 100 or 200. Therefore, the diameter of the third
electrode 224
I S is balanced between the need to form a non-ion emitting surface and
airflow
properties of the unit 100 or 200.
[0075] In a preferred embodiment, each third focus electrodes 224a, 224b, 224c
are
electrically connected with the first array 230 and the high voltage generator
170 by
the conductor 234. As shown in FIG. SA, the third focus electrodes 224 are
electrically connected to the same positive outlet of the high voltage
generator 170 as
the first array 230. Accordingly, the first electrode 232 and the third focus
electrode
224 generate a positive electrical field. Since the electrical fields
generated by the
third focus electrode 224 and the first electrode 232 axe both positive, the
positive
field generated by the third focus electrode 224 can push, or repel, or
direct, the
positive field generated by the first electrode 232 towards the second array
240. For
example, the positive field generated by the third focus electrode 224a will
push, or
repel, or direct, the positive field generated by the first electrode 232-I
towards the
second array 240. In general, the third focus electrode 224 shapes the
electrical field
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-22-
generated by each electrode 232 in the first array 230. This shaping effect is
believe
to decrease the amount of ozone generated by the electrode assembly 220 and
increases the airflow of the units 100 and 200.
[0076] The particles within the airflow are positively charged by the ions
generated
by the first electrode 232. As previously mentioned, the positively charged
particles
are collected by the negatively charged second electrodes 242. The third focus
electrode 224 also directs the airflow towards the second electrodes 242 by
guiding
the charged particles towards the trailing sides 244 of each second electrode
242. It is
believed that the airflow will travel around the third focus electrode 224,
partially
focusing the airflow towards the trailing sides 244, improving the collection
rate of
the electrode assembly 220.
[0077] The third focus electrode 224 may be located at various positions
upstream
of each first electrode 232. By way of example only, a third focus electrode
224b is
located directly upstream of the first electrode 232-2 so that the center of
tile third
focus electrode 224b is in-line and symmetrically aligned with the first
electrode 232-
2, as shown by extension line B. Extension line B is located midway between
the
second electrode 242-2 and the second electrode 242-3.
[0078] Alternatively, a third focus electrode 224 can also be located at an
angle
relative to the first electrode 232. For example, a third focus electrode 224a
can be
located upstream of the first electrode 232-1 along a line extending from the
middle of
the nose 246 of the second electrode 242-2 through the center of the first
electrode
232-1, as shown by extension line A. The third focus electrode 224a is in-line
and
symmetrically aligned with the first electrode 232-1 along extension line A.
Similarly, the third electrode 224c is located upstream to the first electrode
232-3
along a line extending from the middle of the nose 246 of the second electrode
242-3
through the first electrode 232-3, as shown by extension line C. The third
focus
electrode 224c is in-line and symmetrically aligned with the first electrode
232-3
along extension line C. It is within the scope of the present invention for
the electrode
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-23-
assembly 220 to include third focus electrodes 224 that are both directly
upstream and
at an angle to the first electrodes 232, as depicted in FIG. SA. Thus the
focus
electrodes fan out relating to the first electrodes.
[0079] FIG. SB illustrates that an electrode assembly 220 may contain multiple
third
focus electrodes 224 upstream of each first electrode 232. By way of example
only,
the third focus electrode 224a2 is in-line and synunetrically aligned with the
third
focus electrode 224a1, as shown by extension line A. In a preferred
embodiment, only
the third focus electrodes 224aI, 224b1, 224cI are electrically connected to
the high
voltage generator 170 by conductor 234. Accordingly, not all of the third
electrodes
224 are at the same operating potential. In the embodiment shown in FIG. SB,
the
third focus electxodes 224a1, 224b1, 224c1 are at the same electrical
potential as the
first electrodes 232, while the thixd focus electrodes 224a2, 224b2, 224c2 axe
floating.
Alternatively, the thixd focus electrodes 224a2, 224b2 and 224c2 may be
electrically
connected to the high voltage generator 170 by the conductor 234.
[0080] FIG. SB illustrates that each second electrode 242 may also have a
protective
end 241. In the previous embodiments, each "U"-shaped second electrode 242 has
an
open end. Typically, the end of each trailing side or side wall 244 contains
sharp
edges. The gap between the trailing sides or side walls 244, and the sharp
edges at the
end of the trailing sides ox side walls 244, generate unwanted eddy curxents.
The eddy
currents create a "back draft," or aixflow traveling from the outlet towards
the inlet,
which slow down the airflow rate of the units 100 ox 200.
[0081] In a preferred embodiment, the protective end 241 is created by
shaping, or
rolling, the trailing sides or side walls 244 inward and pressing them
together, forming
a rounded txailing end with no gap between the trailing sides or side walls of
each
second electrode 242. Accordingly the side walls have outer surfaces, and the
outer
surface of end of the side walls are bent back adjacent to the trailing ends
of the side
walls so that the outer surface of the side walls are adjacent to, or face, or
touch each
othex. Accordingly a smooth trailing edge is integrally formed on the second
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
- 24. -
electrode. If desired, it is within the scope of the invention to spot weld
the rounded
ends together along the length of the second electrode 242. It is also within
the scope
of the present invention to form the protective end 241 by other methods such
as, but
not limited to, placing a strap of plastic across each end of the trailing
sides 244 for
the full length of the second electrode 242. The rounded or capped end is an
improvement over the previous electrodes 242 without a protective end 241.
Eliminating the gap between the trailing sides 244 also reduces or eliminates
the eddy
currents typically generated by the second electrode 242. The rounded
protective end
also provides a smooth surface for purpose of cleaning the second electrode.
Accordingly in this embodiment the collector electrode is a one-piece,
integrally
formed, electrode with a protection end.
FIGS. 6A-6D
[0082] FIG. 6A illustrates an electrode assembly 220 including a first array
of
electrodes 230 having three wire-shaped first electrodes 232-1, 232-2, 232-3
(generally referred to as "electrode 232") and a second array of electrodes
240 having
four "U"-shaped second electrodes 242-1, 242-2, 242-3, 242-4 (generally
referred to
as "electrode 242"). Each first electrode 232 is electrically connected to the
high
voltage generator 170 at the bottom region, whereas each second electrode 242
is
electrically connected to the high-voltage generator 170 in the middle to
illustrate that
the first and second electrodes 232, 242 can be electrically connected in a
variety of
locations.
[0083] The second electrode 242 in FIG. 6A is a similar version of the second
electrode 242 shown in FIG. 4C. The distance L has been shortened to about
8mm,
while the other dimensions Xl, Y1, Y2, Z1, Z2 are similar to those shown in
FIG. 4A.
[0084] A third leading or focus electrode 224 is located upstream of each
first
electrode 232. The innermost third focus electrode 224b is located directly
upstream
of the first electrode 232-2, as shown by extension line B. Extension line B
is located
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
- 25 -
midway between the second electrodes 242-2, 242-3. The third focus electrodes
224a,
224c are at an angle with respect to the first electrodes 232-1, 232-3. For
example, the
third focus electrode 224a is upstream to the first electrode 232-1 along a
line
extending from the middle of the nose 246 of the second electrode 242-2
extending
through the center of the first electrode 232-1, as shown by extension line A.
The
third electrode 224c is located upstream of the first electrode 232-3 along a
line
extending from the center of the nose 246 of the second electrode 242-3
through the
center of the first electrode 232-3, as shown by extension line C. Accordingly
and
preferably the focus electrodes fan out relative to the first electrodes as an
aid for
directing the flow of ions and charged particles. FIG. 6B illustrates that the
third
focus electrodes 224 and the first electrode 232 may be electrically connected
to the
high voltage generator 170 by conductor 234.
[0085] FIG. 6C illustrates that a pair of third focus electrodes 224 may be
located
upstream of each first electrode 232. Preferably, the multiple third focus
electrodes
224 are in-line and symmetrically aligned with each other. Fox example, the
third
focus electrode 224a2 is in-line and symmetrically aligned with the third
focus
electrode 224a1, along extension line A. As previously mentioned, preferably
only
third focus electrodes 224a1, 224b1, 224c1 are electrically connected with the
first
electrodes 232 by conductor 234. It is also within the scope of the present
invention
to have none or all of the third focus electrodes 224 electrically connected
to the high
voltage generator 170.
[0086] FIG. 6D illustrates third focus electrodes 224 added to the electrode
assembly 220 shown in FIG. 4D. Preferably, a third focus electrode 224 is
located
upstream of each first electrode 232. For example, the third focus electrode
224b is
in-line and symmetrically aligned with the first electrode 232-2, as shown by
extension line B. Extension Line B is located midway between the second
electrodes
242-2, 242-3. The third focus electrode 224a is in-line and symmetrically
aligned
with the first electrode 232-1, as shov~m by extension line A. Similarly, the
third
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-26-
electrode 224c is in-Iine and symmetrically aligned with the first electrode
232-3, as
shown by extension line C. Extension lines A-C extend from the middle of the
nose
246 of the "U"-shaped second electrodes 242-2, 242-3 through the first
electrodes
232-1, 232-3, respectively. In a preferred embodiment, the third electrodes
224a,
S 224b, 224c with the high voltage generator 170 by the conductor 234. This
embodiment can also include a pair of third focus electrodes 224 upstream of
each
first electrode 232 as is depicted in FIG. 6C.
FIGS. 7A-7C
[0087] FIGS. 7A-7C illustrate that the electrode assembly 220 shown in FIG. 4E
can
include a third focus electrode upstream of the first array of electrodes 230
comprising
a single wire electrode 232. Preferably, the center of the third focus
electrode 224 is
in-line and symmetrically aligned with the center of the first electrode 232,
as shown
by extension line B. Extension line B is located midway between the second
IS electrodes 242. The distances Xl, X2, YI, Y2, ZI and Z2 are similar to the
embodiments previously described. The first electrode 232 and the second
electrode
242 may be electrically connected to the high-voltage generator 170 by
conductor 234,
249 respectively. It is within the scope of the present invention to connect
the first
and second electrodes to opposite ends of the high voltage generator 170
(e.g., the first
electrode 232 may be negatively charged and the second electrode 242 may be
positively charged). In a preferred embodiment the third focus electrode 224
is also
electrically connected to the high voltage generator I70.
[0088] FIG. 7B illustrates that a pair of third focus electrodes 224a, 224b
may be
located upstream of the first electrode 232. The third focus electrodes 224a,
224b are
2S in-line and symmetrically aligned with the first electrode 232, as shown by
extension
line B. Extension line B is located midway between the second electrodes 242.
Preferably, the third focus electrode 224b is upstream of third focus
electrode 224a a
distance equal to the diameter of a third focus electrode 224. In a preferred
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
_2'j_
embodiment, only the third focus electrode 224a is electrically connected to
the high
voltage generator 170. It is within the scope of the present invention to
electrically
connect both third focus electrodes 224a, 224b to the high voltage generator
170.
[0089] FIG. 7C illustrates that each third focus electrode 224 can be located
at an
angle with respect to the first electrode 232. Similar to the previous
embodiments, the
third focus electrode 224a1 and 224b1 is located a distance X2 upstream from
the first
electrode 232. By way of example only, the third focus electrodes 224a1, 224a2
are
located along a line extending from the middle of the second electrode 242-2
through
the center of the first electrode 232, as shown by extension line A.
Similarly, the third
focus electrodes 224b1, 224b2 are along a line extending from the middle of
the
second electrode 242-1 through the middle of the first electrode 232, as shown
by
extension line B. The third focus electrode 224a2 is in-line and symmetrically
aligned
with the third focus electrode 224a1 along extension line A. Similarly, the
third focus
electrode 224b2 is in line and symmetrically aligned with the third focus
electrode
224b1 along extension line B. The third focus electrodes 224 are fanned out
and form
a "V" pattern upstream of first electrode 232. In a preferred embodiment, only
the
third focus electrodes 224a1 and 224b1 are electrically connected to the high-
voltage
generator 170 by conductor 234. It is within the scope of the invention to
electrically
connect the third focus electrodes 224a and 224b2 to the high voltage
generator 170.
FIGS. 8A-8B
[0090] The previously described embodiments of the electrode assembly 220
disclose a rod- shaped third focus electrode 224 upstream of each first
electrode 232.
FIG. 8A illustrates an alternative configuration for the third focus electrode
224. By
way of example only, the electrode assembly 220 may include a "U"-shaped or
possibly "C"-shaped third focus electrode 224 upstream of each first electrode
232.
Further the third focus electrode 224 can have other curved configurations
such as, but
not limited to, circular-shaped, elliptical-shaped, and parabolically-shaped
other
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-28-
concave shapes facing the first electrode 232, In a preferred embodiment, the
third
focus electrode 224 has holes 225 extending through, forming a perforated
surface to
minimize the resistance of the third focus electrode 224 on the airflow rate.
[0091] In a preferred embodiment, the third focus electrode 224 is
electrically
connected to the high voltage generator 170 by conductor 234. The third focus
electrode 224 in FIG. 8A is preferably not an ion emitting surface. Similar to
previous
embodiments, the third focus electrode 224 generates a positive electric field
and
pushes or repels the electric field generated by the first electrode 232
towards the
second array 240.
[0092] FIG. 8B illustrates that a perforated "U"-shaped or "C"-shaped third
focus
electrode 224 can be incorporated into the electrode assembly 220 shown in
FIG. 4A.
Even though only two configurations of the electrode assembly 220 are shown
with
the perforated "U"-shaped third focus electrode 224, all the embodiments
described
in FIGS. SA-12C may incorporate the perforated "U"-shaped third focus
electrode
224. It is also within the scope of the invention to have multiple perforated
"U"-
shaped third focus electrodes 224 upstream of each first electrode 232.
Further in
other embodiment the "U"-shaped third focus electrode 224 can be made of a
screen
or a mesh.
[0093] FIG. 8C illustrates third focus electrodes 224 similar to those
depicted in
FIG. 8B, except that the third focus electrodes 224 are rotated by 180°
to preset a
convex surface facing to the first electrodes 232 in order to focus and direct
the field
of ions and airflow from the first electrode 232 toward the second electrode
242.
These thixd focus electrodes 224 shown in FIGS. 8A-8C are located along
extension
lines A, B, C similar to previously described embodiments.
FIGS. 9A-9C
[0094] FIG. 9A illustrates a pin-ring conf guration of the electrode assembly
220.
The electrode assembly 220 contains a cone-shaped or triangular-shaped first
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-29-
electrode 232, a ring-shaped second electrode 242 downstream of the first
electrode
232, and a third focus electrode 250 upstream of the first electrode 232. The
third
focus electrodes 250 may be electrically connected to the high voltage
generator 170.
Preferably the focus electrode 250 is spaced from the first electrode 232 a
distance
that is in accordance with the other embodiments described herein.
Alternatively, the
third focus electrode 250 can have a floating potential. As indicated by
phantom
elements 232', 242', the electrode assembly 220 can comprise a plurality of
such pin-
like and ring-Iike elements. The plurality of pin-ring configurations as
depicted in
FIG. 9A can be positioned one above the other along the elongated housing of
the
invention. Such a plurality of pin-ring configurations can of course operate
in another
embodiment without the third focus electrode. It is understood that this
plurality of
pin-ring configurations can be upstanding and elongated along the elongated
direction
of said housing and can replace the first and second electrodes shown, for
example, in
FIG. 2B and be removable much as the second electrode in Fig 2B is removable.
Preferably, the first electrode 232 is tungsten, and the second electrode 242
is stainless
steel. Typical dimensions for the embodiment of FIG. 9A are L 1 ~ 10
millimeters,
X 1 ~ 9. 5 millimeters, T ~ 0.5 millimeters and the diameter of the opening
246 ~ 12millimeters.
[0095] The electrical properties and characteristics of the third focus
electrode 250
is similar to the third focus electrode 224 described in previous embodiments.
In
contrast to the rod-shaped physical characteristic of the previous
embodiments, the
shape the third focus electrode 250 is a concave disc, with the concave
surface
preferably facing toward the second electrodes 242. The third focus electrode
250
preferably has holes extending therethxough to minimize the disruption in
airflow. It
is within the scope of the present invention for the third focus electrode 250
to
comprise other shapes such as, but not limited to, a convex disc a parabolic
disc, a
spherical disc, or other convex or concave shapes or a rectangle, ox other
planar
surface and be within the spirit and scope of the invention. The diameter of
the third
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-30-
focus electrode 250 is preferably at least fifteen times greater than the
diameter of the
first electrode 232. The focus electrode 250 can also be made of a screen or a
mesh.
[0096] The second electrode 242 has an opening 246. The opening 246 is
preferably
circular in this embodiment. It is within the scope of the present invention
that the
opening 246 can comprise other shapes such as, but not limited to,
rectangular,
hexagonal or octagonal. The second electrode 242 has a collar 247 (see FIG.
9B)
surrounding the opening 246. The collar 247 attracts the dust contained within
the
airstream passing through the opening 246. As seen in the FIGS. 9B and 9C the
collar
247 includes a downstream extending tubular portion 248 which can collect paz-
ticles.
As a result, the airstream emitted by the electrode assembly 220 has a reduced
dust
content.
[0097] Other similar pin-ring embodiments axe shown in FIGS. 9B-9C. For
example, the first electrode 232 can comprise a rod-shaped electrode having a
tapered
end. In FIG. 9B, a detailed cross-sectional view of the central portion of the
second
electrode 242 in FIG. 9A is shown. Preferably, the collar 247 is positioned in
relation
to the first electrode 232, such that the ionization paths from the distal tip
of the first
electrode 232 to the collar 247 have substantially equal path lengths. Thus,
while the
distal tip (or emitting tip) of the first electrode 232 is advantageously
small to
concentrate the electric field, the adjacent regions of the second electrode
242
preferably provide many equidistant inter-electrode paths. The lines drawn in
phantom in FIGS. 9B and 9C depict theoretical electric force field lines
emanating
from the first electrode 232 and terminating on the curved surface of the
second
electrode 242. Preferably, the bulk of the field emanates within about 45
degrees of
coaxial axis between the first electrode 232 and the second electrode 242.
[0098] In FIG. 9C, one or more first electrodes 232 are replaced by a
conductive
block 232" of carbon fibers, the block having a distal surface in which
projecting
fibers 233-1,...233-N take on the appearance of a "bed of nails." The
projecting fibers
can each act as an emitter electrode and provide a plurality of emitting
surfaces. Over
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-31 -
a period of time, some or all of the electrodes will literally be consumed,
where upon
the blocl~ 232" may be replaced. Materials other than graphite may be used for
block
232" providing that the material has a surface with projecting conductive
fibers such
as 233-N.
Electrode Assembly With a Downstream Trailing Electrode:
FIGS. l0A-lOD
[0099] FIGS. l0A-l OC illustrate an electrode assembly 220 having an array of
trailing electrodes 245 added to an electrode assembly 220 similar to that
shown in
FIG. 7A. It is understood that an alternative embodiment similar to FIG. l0A
can
include a trailing electrode or electrodes without any focus electrodes and be
within
the spirit and scope of the inventions. Referring now to FIGS. l0A-1 OB, each
trailing
electrode 245 is located downstream of the second array of electrodes 240.
Preferably, the trailing electrodes are located downstream from the second
electrodes
242 by at least three times the radius R2 (see FIG. l OB). Further, the
trailing
electrodes 245 are preferably directly downstream of each second electrode 242
so as
not to interfere with the flow of air. Also, the trailing electrode 245 is
aerodynamically smooth, for example, circular, elliptical, or teardrops shaped
in cross-
section so as not to unduly interfere with the smoothness of the airflow
thereby. In a
preferred embodiment, the trailing electrodes 245 are electrically connected
to the
same outlet of the high voltage generator 170 as the second array of
electrodes 240.
As shown in FIG. 10A, the second electrodes 242 and the trailing electrodes
245 have
a negative electrical charge. This arrangement can introduce more negative
charges
into the air stream. Alternatively, the trailing electrodes 245 can have a
floating
potential if they are not electrically connected. The trailing electrodes 245
can also be
grounded in other embodiments. Further alternatively, as shown in FIG. 10D,
the
trailing electrode 245 can be formed with the second electrode out of a sheet
of metal
formed in the shape of the second electrode and then extending to the position
of the
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-32-
trailing electrode and formed as a hollow trailing electrode with a peripheral
wall that
is about the shape of the outer surface of the trailing electrode 245 depicted
in FIG.
10C.
[0100] When the trailing electrodes 245 are electrically connected to the high
voltage generator 170, the positively charged particles within the airflow are
also
attracted to and collect on, the trailing electrodes. In a typical electrode
assembly with
no trailing electrode 245, most of the particles will collect on the surface
area of the
second electrodes 242. However, some particles will pass through the unit 200
,
without being collected by the second electrodes 242. Thus, the trailing
electrodes
245 serve as a second surface area to collect the positively charged
particles. The
trailing electrodes 245 also can deflect charged particles toward the second
electrodes.
[0101] The trailing electrodes 245 preferably also emit a small amount of
negative
ions into the airflow. These negative ions will neutralize the positive ions
emitted by
the first electrodes 232. If the positive ions emitted by the first electrodes
232 are not
neutralized before the airflow reaches the outlet 260, the outlet fns 212 can
become
electrically charged and particles within the airflow may tend to stick to the
fins 212.
If this occurs, eventually the amount of particles collected by the fins 212
will block
or minimize the airflow exiting the unit 200.
[0102] FIG. 1 OC illustrates another embodiment of the electrode assembly 200,
having trailing electrodes 245 added to an embodiment similar to that shown in
FIG.
7C. The trailing electrodes 245 are located downstream of the second axray 240
similar to the previously described embodiments above. It is within the scope
of the
present invention to electrically connect the trailing electrodes 245 to the
high voltage
generator I70. As shown in FIG. l OC, all of the third focus electrodes 224
are
electrically connected to the high voltage generator 170. In a preferred
embodiment,
only the third focus electrodes 224a1, 224b1 are electrically connected to the
high
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-33-
voltage generator 170. The third focus electrodes 224a2, 224b2 have a floating
potential.
Electrode Assemblies With Various Combinations of Focus Electrodes, Trailing
Electrodes and Enhanced Second Electrodes With Protective Ends:
FIGS. 11 A-11 D
[0103] FIG. 11A illustrates an electrode assembly 220 that includes a first
array of
electrodes 230 having two wire-shaped electrodes 232-1, 232-2 (generally
referred to
as "electrode 232") and a second array of electrodes 240 having three "U"-
shaped
electrodes 242-1, 242-2, 242-3 (generally referred to as "electrode 242").
This
configuration is in contrast to, for example, the configurations of FIG. 9A,
wherein
there are three first emitter electrodes 232 and four second collector
electrodes 242.
[0104] Upstream from each first electrode 232, at a distance X2, is a third
focus
electrode 224. Each third focus electrode 224a, 224b is at an angle with
respect to a
first electrode 232. For example, the third focus electrode 224a is preferably
along a
line extending from the middle of the nose 246 of the second electrode 242-2
through
the center of the first electrode 232-1, as shown by extension Line A. The
third focus
electrode 224a is in-line and symmetrically aligned with the first electrode
232-1
along extension line A. Similarly, the third focus electrode 224b is located
along a
line extending from middle of the nose 246 of the second electrode 242-2
through the
center of the first electrode 232-2, as shown by extension line B. The third
focus
electrode 224b is in-line and symmetrically aligned with the first electrode
232-2
along extension line B. As previously described, the diameter of each third
focus
electrode 224 is preferably at Least fifteen times greater than the diameter
of the first
electrode 232.
[0105] As shown in FIG. 11A, and similar to the embodiment shown in FIG. SB,
each second electrode preferably has a protective end 241. In a preferred
embodiment,
the third focus electrodes 224 are electrically connected to the high voltage
generator
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-34-
170 (not shown). It is within the spirit and scope of the invention to not
electrically
connect the third focus electrodes 224.
[0106] FIG. 11B illustrates that multiple third focus electrodes 224 may be
located
upstream of each first emitter electrode 232. For example, the third focus
electrode
224a2 is in-line and symmetrically aligned with the third focus electrode
224a1 along
extension line A. Similarly, the third focus electrode 224b2 is in-line and
symmetrically aligned with the third focus electrode 242b1 along extension
line B. It
is within the scope of the present invention to electrically connect all, or
none of, the
third focus electrodes 224 to the high-voltage generator 170. In a preferred
embodiment, only the third focus electrodes 224a1, 224b1 are electrically
connected
to the high voltage generator 170, with the third focus electrodes 224a2,
224b2 having
a floating potential.
[0107] FIG. 11C illustrates that the electrode assembly 220 shown in FIG. 11A
may
also include a trailing electrode 245 downstream of each second electrode 242.
Each
trailing electrode 245 is in-line with the second electrode so as not to
interfere with
airflow past the second electrode 242. Each trailing electrode 245 is
preferably
located a distance downstream of each second electrode 242 equal to at least
three
times the width W of the second electrode 242. It is within the scope of the
present
invention fox the trailing electrode to by located at other distances
downstream. The
diameter of the trailing anode 245 is preferably no greater than the width W
of the
second electrode 242 to limit the interference of the airflow coming off the
second
electrode 242.
[0108] One aspect of the trailing electrode 245 is to direct the air trailing
off the
second electrode 242 and provide a more laminar flow of air exiting the outlet
260.
Another aspect of the trailing electrode 245 is to neutralize the positive
ions generated
by the first array 230 and collect particles within the airflow. As shown in
FIG. 11C,
each trailing electrode 245 is electrically connected to a second electrode
242 by a
conductor 248. Thus, the trailing electrode 245 is negatively charged, and
serves as a
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-35-
collecting surface, similar to the second electrode 242, attracts the
positively charged
particles in the airflow. As previously described, the electrically connected
trailing
electrode 245 also emits negative ions to neutralize the positive ions emitted
by the
first electrodes 232.
[0109] FIG. 11D illustrates that a pair of third focus electrodes 224 may be
located
upstream of each first electrode 232. For example, the third focus electrode
224a2 is
upstream of the third focus electrode 224a1 so that the third focus electrodes
224a1,
224a2 are in-Line and symmetrically aligned with each other along extension
line A.
Similarly, the third focus electrode 224b2 is in line and symmetrically
aligned with the
third focus electrode 224b1 along extension line B. As previously described,
preferably only the third focus electrodes 224a1, 224b1 are electrically
connected to
the high voltage generator 170, while the third focus electrodes 224a2, 224b2
have a
floating potential. It is within the spirit and scope of the present invention
to
electrically connect all, or none, of the third focus electrodes to the high
voltage
generator 170.
Electrode Assemblies With Second Collector Electrodes Having Interstitial
Electrodes: FIGS. 11E-11F
[0110] FIG. 11E illustrates another embodiment of the electrode assembly 220
with
an interstitial electrode 246. In this embodiment, the interstitial electrode
246 is
located midway between the second electrodes 242. For example, the
interstitial
electrode 246a is located midway between the second electrodes 242-I, 242-2,
while
the interstitial electrode 246b is Located midway between second electrodes
242-2,
242-3. Preferably, the interstitial electrode 246a, 246b are electrically
connected to
the first electrodes 232, and generate an electrical field with the same
positive or
negative charge as the first electrodes 232. The interstitial electrode 246
and the first
electrode 232 then have the same polarity. Accordingly, particles traveling
toward the
interstitial electrode 246 will be repelled by the interstitial electrode 246
towards the
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-36-
second electrodes 242. Alternatively, the interstitial electrodes can have a
floating
potential or be grounded.
[0111] It is to be understood that interstitial electrodes 246a, 246b may also
be
closer to one second collector electrode than to the other. Also, the
interstitial
electrodes 246a, 246b are preferably located substantially near or at the
protective end
241 or ends of the trailing sides 244, as depicted in FIG. 1 lE. Still further
the
interstitial electrode can be substantially located along a line between the
two trailing
portions or ends of the second electrodes. These rear positions are preferred
as the
interstitial electrodes can cause the positively charged particle to deflect
towards the
trailing sides 244 along the entire length of the negatively charged second
collector
electrode 242, in order for the second collector electrode 242 to collect more
particles
from the airflow.
[0112] Still further, the interstitial electrodes 246a, 246b can be located
upstream
along the trailing side 244 of the second collector electrodes 244. However,
the closer
the interstitial electrodes 246a, 246b get to the nose 246 of the second
electrode 242,
generally the less effective interstitial electrodes 246a, 246b are in urging
positively
charged particles toward the entire length the second electrodes 242.
Preferably, the
interstitial electrodes 246a, 246b are wire-shaped and smaller or
substantially smaller
in diameter than the width "W" of the second collector electrodes 242. For
example,
the interstitial electrodes can have a diameter of, the same as, or on the
order, of the
diameter of the first electrodes. Fox example, the interstitial electrodes can
have a
diameter of one-sixteenth of an inch. Also, the diameter of the interstitial
electrodes
246a, 246b is substantially less than the distance between second collector
electrodes,
as indicated by Y2. Further the interstitial electrode can have a length or
diameter in
the downstream direction that is substantially less than the length of the
second
electrode in the downstream direction. The reason for this size of the
interstitial
electrodes 246a, 246b is so that the interstitial electrodes 246a, 246b have a
minimal
effect on the airflow rate exiting the device 100 or 200.
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-37-
[0113] FIG. 11F illustrates that the electrode assembly 220 in FIG. 11E can
include
a pair of third electrodes 224 upstream of each first electrode 232. As
previously
described, the pair of third electrodes 224 are preferably in-line and
symmetrically
aligned with each other. For example, the third electrode 224a2 is in-line and
symmetrically aligned with the third electrode 224a1 along extension line A.
Extension line A preferably extends from the middle of the nose 246 of the
second
electrode 242-2 through the center of the first electrode 232-1. As previously
disclosed, in a preferred embodiment, only the third electrodes 224a1, 224b1
are
electrically connected to the high voltage generator 170. In FIG. 11F, a
plurality of
interstitial electrode 296a and 246b are located between the second electrodes
242.
Preferably these interstitial electrodes axe in-line and have a potential
gradient with an
increasing voltage potential on each successive interstitial electrode in the
downstream direction in order to urge particles towaxd the second electrodes.
In this
situation the voltage on the interstitial electrodes would have the same sign
as the
voltage of the first electrode 232.
Electrode Assembly_With an Enhanced First Emitter Electrode Beina Slack:
FIGS. 12A-12C
[0114] The previously described embodiments of the electrode assembly 220
include a first array of electrodes 230 having at least one wire-shaped
electrode 232.
It is within the scope of the present invention for the first array of
electrodes 230 to
contain electrodes consisting of other shapes and configurations.
[0115] FIG. 12A illustrates that the first array of electrodes 230 may include
curved
wire-shaped electrodes 252. The curved wire-shaped electrode 252 is an ion
emitting
surface and generates an electric field similar to the previously described
wire-shaped
electrodes 232. Also similar to previous embodiments, each second electrode
242 is
"downstream," and each third focus electrode 224 is "upstream," to the curved
wire-
shaped electrodes 252. The electrical properties and characteristics of the
second
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-38-
electrode 242 and the third focus electrode 224 are similar to the previously
described
embodiment shown in FIG. SA. It is to be understood that an alternative
embodiment
of FIG. 12A can exclude the focus electrodes and be within the spirit and
scope of the
invention.
[0116] As shown in FIG. 12A, positive ions are generated and emitted by the
first
electrode 252. In general, the quantity of negative ions generated and emitted
by the
first electrode is proportional to the surface area of the first electrode.
The height Z1
of the first electrode 252 is equal to the height Z1 of the previously
disclosed wire-
shaped electrode 232. However, the total length of the electrode 252 is
greater than
the total length of the electrode 232. By way of example only, and in a
preferred
embodiment, if the electrode 252 was straightened out the curved or slack wire
electrode 252 is 15-30% longer than a rod or wire-shaped electrode 232. The
electrode 252 is allowed to be slack to achieve the shorter height Z1. When a
wire is
held slack, the wire may form a curved shape similax to the first electrode
252 shown
in FIG. 12A. The greater total length of the electrode 252 translates to a
larger surface
area than the wire-shaped electrode 232. Thus, the electrode 252 will generate
and
emit more ions than the electrode 232. Ions emitted by the first electrode
array attach
to the particulate matter within the airflow. The charged particulate matter
is
attracted to, and collected by, the oppositely charged second collector
electrodes 242.
Since the electrodes 252 generate and emit more ions than the previously
described
electrodes 232, more particulate matter will be removed from the airflow.
[0117] FIG. 12B illustrates that the first array of electrodes 230 may include
flat coil
wire-shaped electrodes 254. Each flat coil wire-shaped electrode 254 also has
a larger
surface area than the previously disclosed wire-shaped electrode 232. By way
of
example only, if the electrode 254 was straightened out, the electrode 254
will have a
total length that is preferably 10% longer than the electrode 232. Since the
height of
the electrode 254 remains at Z1, the electrode 254 has a "kinked"
configuration as
shown in FIG. 12B. This greater length translates to a larger surface area of
the
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-39-
electrode 254 than the surface area of the electrode 232. Accordingly, the
electrode
254 will generate and emit a greater number of ions than electrode 232. It is
to be
understood that an alternative embodiment of FIG. 12B can exclude the focus
electrodes and be within the spirit and scope of the invention.
[0118] FIG. 12C illustrates that the first array of electrodes 230 may also
include
coiled wire-shaped electrodes 256. Again, the height Z1 of the electrodes 256
is
similar to the height Zl of the previously described electrodes 232. However,
the total
length of the electrodes 256 is greater than the total length of the
electrodes 232. In a
preferred embodiment, if the coiled electrode 256 was straightened out the
electrodes
256 will have a total length two to three times longer than the wire-shaped
electrodes
232. Thus, the electrodes 256 have a laxger surface area than the electrodes
232, and
generate and emit more ions than the first electrodes 232. The diameter of the
wire
that is coiled to produce the electrode 256 is similar to the diameter of the
electrode
232. The diameter of the electrode 256 itself is preferably 1-3mm, but can be
smaller
in accordance with the diameter of first emitter electrode 232. The diameter
of the
electrode 256 shall remain small enough so that the electrode 256 has a high
emissivity and is an ion emitting surface. It is to be understood that an
alternative
embodiment of FIG. 12C can exclude the focus electrodes and be within the
spirit and
scope of the invention.
[0119] The electrodes 252, 254 and 256 shown in FIGS. 12A-12C may be
incorporated into any of the electrode assembly 220 configurations previously
disclosed in this application.
[0120] As described supra, the use of one or more interstitial electrodes
improves
the overall performance of ion wind devices by increasing charged particle
precipitation. These uniquely positioned and energized electrodes may also
reduce the
discharge of ozone and increase airflow in ion wind devices.
[0121] FIG. 13 is a schematic view of an ion wind device of this invention
illustrating the use of one or more interstitial electrodes to reduce the
discharge of
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-40-
ozone. Ion wind device 300 includes one or more emitters 302, collectors 304,
and
high voltage power source 306, all as discussed in more detail supra. Ozone
cations
(03~) are formed at the positively charged emitter element 302 (302 ~ 203 ).
Nitrogen (N2~) cations and oxygen (OZ+) cations are also produced at the
positively
charged emitter element 302. When the molecules of 03, NZ, and OZ gain or lose
valence electrons from their outer shell, their respective sizes change also.
For
example, non-ionized (neutral) nitrogen has an atomic radius of 0.71 angstroms
and
oxygen has a radius of 0.66 angstroms. When they gain electrons (become
anionic),
they increase in size to 1.71 angstrom units for nitrogen and 1.40 angstrom
units for
oxygen. In the case of an 03+ ozone ion, if it is abruptly converted to 03 or
O3- by
adding electrons to its L (2p) shell using a high voltage potential it will
radically
increase in size, become even more unstable, and convert back to oxygen (2 03+
-~ 3
Oi ). Placing a charged interstitial electrode 308 downstream in the ion wind
apparatus accelerates the ozone cations toward the negatively charged
collector
electrode 304 where the cations will receive one or more valence electrons to
abruptly
convert them to a balanced ion or to an anion. Some of the ozone cations will
contact
the leading edge and surface area of the collector electrode 304 and convert
to oxygen
without the need for acceleration. However, very few will actually make
contact with
the negatively charged collector. The down line electrodes) 308 may be charged
with
any positive pulsed or DC voltage with respect to the collector from +00 volts
to
+10,000 volts depending upon the physical configuration of the array and the
specific
emitter and collector voltages in use. A grounded or negatively charged plate
will also
act as a direct contact breakdown source to the ozone cation. However, like
the
random contact made by the ozone cation upon the collector plates, there is
the same
likelihood that only minimal and random contact is made with the down line
electrodes. The more positive the voltage potential applied to the down line
electrodes without corona occurring, the more effective the rate of chemical
conversion to oxygen becomes. Also, a great deal of the nitrogen cation Nz* is
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-41 -
balanced or converted to an anion N2'. This is desirable in most ion wind
devices to
minimize the output of breathable cations, which are typically nitrogen
molecules that
make up almost 80% of the atmosphere.
[0122] The down line electrode 308 may be in the form of either one or more
conductive rods or a thin plate material. The differential voltage between the
down
line electrode should not be high enough to create high voltage break over or
corona
current since this may create additional ozone as well as damage high voltage
circuitry. Each electrode is preferably equipped with a high voltage series
resistor 310
(e.g., between one and ten megohms) to limit peak current and inhibit break
over. The
higher the series resistance the less likelihood of voltage break over and
incidence of
corona current. However, higher resistance also will inhibit electron transfer
between
voltage source and flee ions. An optimum series resistance is dependent upon
selected applied voltages, electrode spacing and desired effect. Typically a
one
megohm emitter series resistor 312, ten megohm collector series resistor 314
and a 4
megohm down line electrode series resistor 3 I O are desirable when using
+BKV, -
8KV and +4KV respectively in a 1" X 1" X ~/a" array.
[0123] The down line electrode 308 is preferably positioned equidistantly from
and
between the collector plates 304. The position of the electrode from the rear
(air
discharge) point of the collector plates toward the emitter element is voltage
dependent. The down line electrode should not be positioned and/or charged in
such a
manner as to distort (bend) the primary voltage gradient. Typically, a charged
interstitial electrode configuration should not exceed +4,000 volts DC and
extend
beyond the halfway distance from the end of the collector plates 304 toward
the
emitter element 302. Deeper upstream penetration toward the emitter element is
possible at reduced electrode voltage. However, positioning of any electrode,
charged
or not, too close to the leading edge of the collector plates will alter
primary balanced
lines of force with the result of reduced airflow. Utilizing a poorly filtered
DC voltage
source for the collector and down line electrode is also desirable. The ripple
voltage
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-42-
acts to further excite the accelerated movement of the ozone cation resulting
in
additional molecular disassociation.
[0124] FIG. 14 is a schematic view of an ion wind device of this invention
illustrating the use of one or more interstitial electrodes to increase
airflow by de-
S ionizing charged molecules responsible for resisting forces in the
airstream. Ion wind
devices do not rely upon a motorized fan to force charged airflow through a
collector
array. Instead, airflow is achieved by charging air molecules, NZ and O~ , and
repelling the air ions within a balanced voltage gradient, while
simultaneously
attracting some of them to an oppositely charged element (collector).
Therefore, the
existence of a heavily populated cationic field of molecules downstream from
the
source of cation production inhibits unrestricted airflow. The down line
electrode 308
reduces the like-charge effect by accelerating a large amount of the nitrogen
cations
toward a negatively charged field and collector element 304 where their
valence may
be balanced or reversed. The acceleration of atmospheric ions toward an
oppositely
1 S charged collector 304 is far more effective than random contacts with a
grounded or
negatively charged electrode.
[0125] FIG. 1 S' is a schematic view of an ion wind device of this invention
illustrating the use of one or more interstitial electrodes to increase
airflow by
improving the precipitation efficiency of charged particles. As air is drawn
into the
emitter area of the ion wind device, so too are small particles P of pollen,
airborne
viruses, spores, miscellaneous air pollution, etc. These materials,
particularly in the
size range of .1 micron to 10 microns, are also either directly ionized or are
attached to
the charged oxygen and nitrogen. By virtue of their relatively large mass and
momentum induced by acceleration from transverse electric fields many are
collected
2S upon the surface of the oppositely charged collector plates 304 before they
can exit the
array. To increase the number of collected charged particles, various schemes
have
been proposed. Principally, increasing collector surface area, increasing
collector
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
- 43 -
surface voltage level, and reducing air velocity have been the most common
methods
used by ion wind devices.
[0126] The addition of a positively charged down line electrode 309 exerts a
repelling force upon the positively charged particles P. A positive high
voltage field
accelerates a positively charged particle, or particle cluster, toward the
negatively
charged plate 304. Typically, a collector plate area A must be squared (AZ )
to double
particle precipitation efficiently. The addition of a down line +4KV plate
electrode or
rod 309 having an area of less than A/2 will also double particle
precipitation
efficiency. As the air stream is evacuated more quickly of charged particles,
gaseous
ions are allowed to flow with less opposition. The result is increased
airflow.
[0127] FIG. 16 is a schematic view of a typical high voltage power source for
the
present invention. Power source 306 includes a dual positive and negative half
wave
voltage multiplier 316 operating with an input frequency of 20,OOOHz or above.
Typical output voltages are +BKV, -8KV and +4KV (which is derived from the
first
stage 318 of the two-stage positive voltage multiplier). Multiplier
capacitance values
are typically between 220pf and 470pf at l OKV or greater depending upon the
desired
voltage and ripple effect.
[0128] FIG. 17 is a schematic view of an alternate wiring option for an
interstitial
electrode. A down line electrode plate or rod element which is isolated from
ground
or a voltage source will accumulate a surface charge proportional to air
stream ion
polarity and density. Also, a down line electrode which is connected to ground
via a
high voltage capacitor will accumulate a large surface charge proportional to
air
stream ion polarity and density. This may be achieved by the direct connection
of one
or more interstitial electrodes 308 to a 470 pf HV capacitor 320 in series
with a 20M
ohm resistor 322 to ground. Instead of using a direct ground or an active
voltage
source to the additional electrodes, this configuration permits the electrodes
to float to
a positive voltage level and behave the same as if a direct DC bias were
applied to
CA 02480878 2004-09-30
WO 03/084658 PCT/US03/09977
-44-
them. This serves to increase precipitation efficiency and airflow, while
simultaneously reducing ozone and power consumption.
[0129] Finally, reversing the polarity of emitter, collector and down line
electrodes
will have similar benefits as described herein. However, using a negative high
voltage emitter source generally increases the production of ozone and
irregular
plasma envelope emissivity at the primary emitter element.
[0130] The foregoing description of the preferred embodiments of the present
invention has been provided for the purposes of illustration and description.
It is not
intended to be exhaustive or to limit the invention to the precise forms
disclosed.
Many modifications and variations will be apparent to the practitioner skilled
in the
art. Modifications and variations may be made to the disclosed embodiments
without
departing from the subject and spirit of the invention as defined by the
following
claims. Embodiments were chosen and described in order to best describe the
principles of the invention and its practical application, thereby enabling
others skilled
in the art to understand the invention, the various embodiments and with
various
modifications that are suited to the particular use contemplated. It is
intended that the
scope of the invention be defined by the following claims and their
equivalents.
