Note: Descriptions are shown in the official language in which they were submitted.
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MICROWAVE REACTIVATION SYSTEM FOR STANDARD AND EXPLOSION-
PROOF DEHUMIDIFICATION
RELATED APPLICATIONS
This application claims priority to U.S. Application Serial No. 13/116,910,
filed May 25,
2011 which is a continuation of Application Serial No. 12/801,292 filed June
2, 2010.
BACKGROUND OF THE INVENTION
Dehumidification and the control of moisture / humidity are of extreme
importance and of
crucial interest in numerous industrial sectors, such as; offshore, onshore,
marine and
military. Several processes and techniques have been designed and developed to
address this
serious problem. Some of these HVAC (Heating Ventilation and Air-Conditioning)
hybrid
systems which perform humidity control within specific spaces, do so primarily
by using
temperature; heating and expanding the air's capability to absorb and retain
moisture, thus
lowering the relative humidity and then by cooling the air temperature below
its dew point,
condensing and extracting the moisture / water vapors. Conventional systems,
such as the
basic cooling systems are comprised of cooling coils, a condenser coil,
ventilation fan and a
compressor unit.
While these systems are widely used and may operate effectively in various
conditions, their
main function and design purpose is to climatise and provide heating and
cooling of a
specific area, with dehumidification as a byproduct result. These type systems
are generally
used in various sites and conventional as well as hazardous industrial
location applications.
The primary advantage of using these type systems is that they do not generate
hot airstreams
or operate within high temperatures which could potentially ignite or spark
flammable vapors
and or even volatile gases found within the ambient air.
These cooling systems are generally very efficient while operating in warmer
humid climatic
conditions mostly found in the southern hemisphere but are found to be
inefficient and non-
compatible when operating in colder, damp climatic conditions located in
hazardous, volatile
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environments found in northern regions. The desiccant dehumidification system
operates on a
completely different premise, which is that of differential vapor pressures
and water vapor
depression. The greater the dampness and humidity in the air, the greater the
water vapor
concentration and pressure.
In comparison, a dry desiccant rotor found in a desiccant based
dehumidification system has
a very low water vapor pressure. When damp humid high vapor pressure air
molecules come
in contact with the desiccant rotor's surface low vapor pressure, the
molecules move from
high to low in an attempt to achieve equilibrium. As the wet damp airstream
passes through
the rotor, the molecules are retained by the desiccant material and the
resulting discharge air
is delivered dry. Given that the desiccant dehumidification system does not
utilize liquid
condensate or gases, it allows this system the capability to effectively
continue to operate and
remove water vapors / moisture even when the dew point air temperature drops
below
freezing. Therefore, the desiccant dehumidification performance actually
improves in colder
temperatures and is not affected by the same deficiencies / drawbacks usually
found in
conventional cooling-based and or hybrid systems which utilize combinations of
heating and
cooling stages during operation.
The desiccant dehumidification systems are equipped with a desiccant rotor
which is pierced
and impregnated with a desiccant type material. The system includes two
operational yet
segregated sections; a process section and a reactivation section. During
regular operation, an
ambient airstream flows through the process section and subsequently the
desiccant rotor,
where the moisture is collected and removed from the airstream. The resultant
is dry air
discharge which is then delivered into the area or enclosure to be
dehumidified.
Simultaneously, another airstream passes through the desiccant dehumidifier
and flows in the
opposite direction through the segregated reactivation section and
subsequently through the
rotor's desiccant material. This air stream passing through the reactivation
section is heated
approximately 200 to 250 degrees F., prior to coming in contact with the
rotors' surface. Heat
has the effect of deactivating the desiccant material in the rotor, which in
turn allows the
material to release the water vapor molecules into the discharge airstream and
to the outside
atmosphere.
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During the operating process, the desiccant rotor rotates slowly (approx. 8-10
rotations per
minute) about its longitudinal axis. It has been established that desiccant
dehumidification
systems are highly effective in greatly reducing and controlling moisture and
humidity in the
air they are treating. Unfortunately, sometimes the energy required to operate
such a system
may be limited or not readily available, especially in the case of marine,
offshore or remote
mobile sites where these systems are required to operate.
This problem is caused by the fact that a high (heat) temperature rise in the
airflow is
absolutely required in the reactivation section in order to dry out the rotor
desiccant material
which usually translates into high energy requirements. The generating of heat
is generally
accomplished with the use of but not limited to the following systems;
electric heating banks
or elements, flame gas burners or submersible heater immersed in a fluid
running through
coils located in the airflow pathway that act in a way to radiate and transfer
heat onto the
reactivation airflow.
These methods are generally the most commonly used means to heat the desiccant
dehumidification reactivation inlet airflow, so that the air temperature rises
to a degree set
point, before coming in contact with the rotor desiccant material. On the
other hand, in the
case of a typical mechanical dehumidification system where heating and or
cooling processes
are utilized separately or in combination such as a hybrid system, the role of
the heating
element is to generate heat to expand and raise the temperature of the air
volume lowering the
relative humidity. This airflow then goes through the refrigerant coils which
rapidly cool
down the airflow temperature enabling the extraction of moisture as
condensate. This new
"Microwave Reactivation System" is designed and intended to be installed in
standard and
explosion-proof dehumidification systems for operation as a high heat
generating source. In
the preferred embodiment, this microwave reactivation system is installed in
the reactivation
section of either a standard or explosion-proof desiccant dehumidification
system.
This microwave reactivation system produces heat by generating electromagnetic
waves
which passes through materials and fluids, causing the molecules within to
rapidly oscillate
in excitation and in turn generating heat.
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In the preferred embodiment, the medium used to store and transmit this heat
is a fluid. This
fluid is moved by means of supply and return pumps, flowing through a first
parallel series of
glass ceramic coils which is part of a closed-loop circuit, passing through
the microwave
heating chamber where the fluid molecules are treated and exposed to
electromagnetic waves
causing excitation and generating high heat. This super heated fluid then
flows through a
second parallel series of metallic coils located in the lower reactivation
section, in the direct
path of the airflow. This heat transfer from the fluid to the coils
substantially raises the
temperature of the airflow as it comes in contact and passes across the
surface of the coils.
This heated airflow is then used to deactivate the perforated desiccant
material which is
impregnated within the desiccant wheel / rotor, as it passes through it. This
heat laden
airstream has a demagnetizing effect on the desiccant material enabling it to
release the
retained accumulated moisture and thus greatly lowering the vapor pressure in
the desiccant
material for reuse in the dehumidification process section. In an alternative
embodiment, the
microwave reactivation system can also be adopted and installed in any
mechanical heating /
cooling hybrid or refrigerant type dehumidification system that must generate
a heat source
in order to successfully accomplish the dehumidification process.
In the above types of dehumidification systems which are included but not
limited to, a heat
source is required in order to raise the intake ambient airflow temperature,
expand air volume
and then allow the refrigerant cooling coils to rapidly cool down the
processed airflow as it
passes through, so that the suspended moisture can be extracted through
condensation.
Essentially, the microwave reactivation system can replace other conventional
heat
generating sources as previously mentioned but not limited to, such as;
electric heating banks
and elements, flame gas burner or submersible heating element immersed in a
fluid which
raises the temperature producing heat. The installation and operation of this
microwave
reactivation system will enable the capability to achieve the heat generating
requirements
which are essential for operational efficiency and optimum output of the
mechanical hybrid,
refrigerant and particularly the desiccant dehumidification type processes.
Simultaneously,
due to its highly effective ratio of low energy requirement versus high heat
generating
capabilities, the microwave reactivation heating system will substantially
diminish the
electrical power demand and consumption without compromising on performance.
It is
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essential for these industrial dehumidification systems and in particular for
the desiccant
dehumidification system whether standard or explosion-proof rated, to develop
proper BTU
heat generation for optimum dehumidification and peak operational performance.
The
microwave reactivation heating system enables to safely and effectively
achieve and surpass
5 all of the above requirements.
BRIEF SUMMARY OF THE INVENTION
According to the broad aspect of an embodiment of the present invention, there
is provided a
Microwave Reactivation System which has the function of heat generation for
the
reactivation section of a desiccant type dehumidification system or a
mechanical
dehumidification system which combines both heating and cooling. The
mechanical heating /
cooling hybrid, refrigerant or desiccant dehumidification systems are used for
the purpose of
dehumidifying and drying materials and or an air volume within an enclosed
area or space.
In the preferred embodiment, the Microwave Reactivation System is designed for
use in the
desiccant dehumidification type system. The desiccant dehumidification system
is comprised
of two operating sections; the process and the reactivation sections. The
desiccant
dehumidification system has a desiccant rotor / wheel assembly which is
mounted and rotates
within a cabinet made up of two separate isolated sections. The desiccant
rotor / wheels'
perforated core is impregnated with a desiccant type material which has the
capability of
capturing and retaining water vapors found in ambient air. The process section
is intended as
the collection and retention of the moisture / water vapors found in the
ambient airflow. A
blower located in the process section is provided to propel at high velocity
this airflow
through the rotor, where the desiccant material retains the moisture and the
airflow which is
discharged through the process outlet is delivered dry to the enclosure.
Simultaneously, another blower located in the reactivation section propels the
airflow which
passes through the reactivation section. This airflow comes in contact and is
heated by a
series of hollow serpentine coils which have an internal heated fluid which
flows through it.
The high heat radiated off the coils is transferred through the coils and onto
the airflow
substantially raising the temperature as it comes in contact with the rotor
surface. As the hot
airflow passes through the perforated rotor, this process deactivates the
desiccant material
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enabling it to release the moisture into the airflow transporting the damp air
through a
discharge outlet to the ambient atmosphere.
This perpetual process allows the rotor's core desiccant material to release
the moisture build-
up as it rotates through the reactivation section and then rotating back into
the process section
where it resumes the removal of water vapor / moisture in the process airflow.
The Microwave Reactivation System is comprised of two separate sections
working together.
The microwave section is made up of an explosion-proof outer cabinet with an
inner casing
which includes a cavity with inner surfaces thereof forming a microwave
heating chamber. A
shielding plate forming a compartment located above the microwave heating
chamber is to
provide housing for the microwave power transformation components therein,
such as;
magnetron, high voltage transformer, diode, capacitor and other operational
components.
In the preferred embodiment, the Microwave Reactivation System is comprised of
two
separate coil assemblies combined as part of a single closed-loop system. They
are mounted
and firmly secured in place by using a series of shock resistant mounting
brackets. There is a
glass-ceramic coil assembly which is mounted in the microwave heating chamber
and linked
at two points to a metallic coil assembly which is mounted in the reactivation
section. These
coil assemblies are firmly linked at two opposite points by means of fittings
and seals which
are securely connected to separate pumps, one for supply and the other for
return. The pumps
ensure a steady and continuous heater fluid flow from the microwave section to
the
reactivation section and back again. These pumps are oppositely located in a
shielding plate
forming a compartment in between the microwave heating chamber and the
reactivation
section. This closed-loop circuit passes through both the microwave heating
chamber in the
microwave section and the reactivation section of the dehumidification system.
The hollow
coil is constructed of one length and designed as a closed loop line, in which
flows a heat
transfer fluid, such as a; thermal oil or heater liquid, used to carry thermal
energy. The fluid
is continuously heated within the microwave section as it is pumped and
circulates through
the heating chamber and transferring the accumulated thermal energy / heat to
the coils which
radiate onto the airflow as it passes through the reactivation section. The
fluid uninterrupted
movement is ensured by the installation and operation of one or several
explosion- proof
pumps within the assembly. This ensures the circulation of the heated fluid
from the heating
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chamber located in the microwave section onto the reactivation section and
back again in a
continuous process.
This Microwave Reactivation System therefore generates the heat source and
airflow
temperature rise which is required to properly deactivate the desiccant
material found in the
rotor core, so that it can release the accumulated moisture / water vapors
into the airstream
being discharged to the ambient atmosphere.
The enormous benefits of the Microwave Reactivation System is that it performs
its primary
function of providing a reactivation heat source, while greatly reducing the
energy
requirement for heat generation and overall power consumption of the desiccant
dehumidification system. This important energy savings allow for the
dehumidification
systems to be more widely accessible and available in standard and critical
hazardous
applications which would have been previously unserviceable due to power
supply
limitations. The high energy requirements usually associated with the use of
standard
dehumidification units is eliminated with the adaption of this microwave
reactivation system.
Present sources of heat generation utilized in reactivation sections such as;
electric heating
elements, account for the major share of operating energy of a desiccant or
mechanical
dehumidification system. Because of the greatly reduced electrical power
requirements
needed to operate the microwave reactivation system, it therefore allows the
dehumidification
technology to be operated at optimum performance in environments and
applications found
onshore, offshore, marine and military, where power availability may be
limited and or
utilized for other critical operational requirements.
The explosion-proof cabinet construction of the heating chamber part of the
Microwave
Reactivation System can be constructed and installed in an existing explosion-
proof
dehumidification system ref.: USPTO Patent No. 7,308,798 B2, for use and
operation in
hazardous locations.
The Microwave Reactivation System can be also incorporated and adapted to
standard non-
explosion-proof dehumidification systems such as; desiccant units requiring
heat for reactivation
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and HVAC units which use a combination of heating and cooling in the
dehumidification process.
Thus, the system may include one or more of a compressor, a condenser and an
evaporator coil.
According to an aspect, there is provided a Heating, Ventilation and Air
Conditioning
(HVAC) system comprising: a cabinet including an airway path; a microwave
heating section
comprised of: a microwave unit for producing and housing microwaves therein; a
first coil
assembly containing thermal heating fluid therein, where the first coil
assembly includes a
first hollow serpentine coil section through which the thermal heating fluid
passes, where the
hollow serpentine coil section of the first coil assembly is positioned at
least partially within
the microwave unit; and a second coil assembly including a second hollow
serpentine coil
section through which the thermal heating fluid passes, wherein the second
hollow serpentine
coil section of the second coil assembly is positioned at least partially
within the airway path,
the first and second coil assemblies being linked to form a closed loop
system; and a blower
for drawing an airflow of ambient air into the cabinet airway path, across at
least one of the
first and second coil assemblies thereby heating the airflow, and out of the
cabinet.
According to another aspect, there is provided a method of treating ambient
air via an HVAC
unit, the method comprising: heating a thermal fluid within a first hollow
serpentine coil
section of a first coil assembly by exposing at least a part of the first
hollow serpentine coil
section and the thermal fluid contained therein to microwaves within a
microwave unit;
drawing ambient air as an airflow into an airway path within a cabinet via a
blower; pumping
the heated thermal fluid into a second coil assembly, where at least a second
hollow
serpentine coil section of the second coil assembly is positioned at least
partially within the
airway path; heating the airflow by drawing the airflow across the second
hollow serpentine
coil section of the second coil assembly; and expelling the heated airflow
from the cabinet.
According to another aspect, there is provided a system for dehumidifying air
in an enclosed
space or area comprising a desiccant rotor/wheel assembly, the desiccant
rotor/wheel
assembly comprising: a. a cabinet; b. a desiccant rotor/wheel assembly
rotatively mounted
within the casing or cabinet and having the core impregnated with a desiccant
material and a
metallic outer shell construction surrounding the desiccant core material,
wherein the
desiccant rotor/wheel assembly simultaneously rotates through a process
section and a
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microwave reactivation section; c. means for driving the rotation of the
desiccant rotor/wheel
assembly within the cabinet; d. a first high static blower to provide means
for drawing a
supply airflow from the enclosed area or space and through the process section
wherein
moisture in the process inlet airflow is removed by the desiccant rotor/wheel
assembly core
material; e. a process dry air outlet located downstream of the process
section is utilized for
discharging dry air supply from the desiccant rotor/wheel assembly into the
enclosed space or
area to be treated, dehumidified and controlled; f. a microwave reactivation
section including
a microwave heating chamber which is enclosed in an explosion-proof casing or
cabinet
including explosion-proof rated system components for purpose of raising the
temperature of
a thermal fluid within coils assemblies which come in contact and heating
incoming
reactivation airflow; g. a second high static blower to provide means for
drawing in the
incoming reactivation airflow from outside the enclosed space or area and
siphoning it
through the reactivation section to heat the airflow into a super-heated
reactivation airflow,
urging the reactivation airflow through the reactivation heating coils
assembly part of the
microwave reactivation section and through the desiccant rotor/wheel assembly
core
material; h. wherein the super heated reactivation airflow has a
demagnetizing effect
which deactivates the desiccant core material, wherein the moisture retained
within the
desiccant core material is immediately released into the reactivation airflow
to create a
reactivation hot wet airflow discharge; i. a reactivation air outlet which is
located
downstream of the reactivation section, exhausts the reactivation hot wet
airflow discharge
externally into ambient atmosphere outside of the enclosed space or area which
is being
treated and dehumidified.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The embodiments of the present invention shall be more clearly understood by
making
reference to the following detailed description of the embodiments of the
invention taken in
conjunction with the following accompanying drawings which are described as
follows;
FIG.1 is the schematic diagram elevation and prospective views of the
dehumidification
system according to the preferred embodiment of the invention. These
corresponding views
are enlarged and shown on FIGS.3, 4, 5, 8, 9 and 10.
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FIG.2 is a schematic diagram sectional view of the desiccant rotor / wheel
assembly
depicting the typical air flow movement drawn by the suction blowers
simultaneously across
the microwave reactivation and process sections and through the desiccant
rotor or wheel
core material during operation of the dehumidification system along with the
electric drive
5 motor for driving and rotating the desiccant rotor / wheel assembly (not
to scale);
FIG.3 is a schematic diagram elevation view of the dehumidification system
shown also in
unit view 1 FIG.1;
FIG.4 is a schematic diagram which combines a full sectional and elevation
view of the
dehumidification system 31 shown also in FIGS.1, 3 with the various
dehumidification
10 operational exposed sections; process section, microwave reactivation /
regeneration section,
microwave heating chamber also shown in FIGS.6 and 7 (not to scale);
FIG.5 is a schematic elevation end view of the dehumidification system shown
also in unit
view 2 FIG.1 with the exposed closed-loop inter-linked coil assemblies shown
also in
FIGS.4, 5, 6, 7 located jointly in the microwave heating chamber and the
microwave
reactivation / regeneration section. The airflow process inlet and
reactivation outlet side
including the high static blower, shown in FIG.4 (not to scale);
FIG.6 is a schematic diagram sectional view of the inner construction of the
closed- looped
coils assemblies part of the Microwave Reactivation System. The microwave
heating
chamber coils assembly is connected to the reactivation section coils assembly
shown also
exposed in FIGS.4, 5 and 7. Included are the major operational components such
as;
capacitor, diode, high voltage transformer, heater fluid circulation pumps,
magnetron, stirrer
blade and wave guide (not to scale);
FIG.7 is a schematic diagram with a perspective and sectional view of the
Microwave
Reactivation System as shown also in FIGS.4, 5 and 6 (not to scale);
FIG.8 is a schematic diagram elevation side view of the airflow process inlet
and reactivation
outlet including the high static reactivation discharge blower, shown in unit
view 2 FIG.1 and
FIGS.2, 4 and 5;
FIG.9 is a schematic diagram sectional and perspective view shown in unit view
3 FIG.1,
which illustrates the cabinet's inner operational sections such as the process
and microwave
_________________________________________________ reactivation, including the
desiccant rotor / wheel assembly compal tiiient;
FIG.10 is a schematic diagram perspective view shown in unit view 4 FIG.1;
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DETAILED DESCRIPTION OF THE INVENTION
The description which follows and the embodiments described therein are
provided by way
of illustration of an example, or examples of particular embodiments of
principles and
aspects of the present invention. These examples are provided for the purpose
of explanation
and not of limitation, of those principles of the invention.
In the description that follows, like parts are marked throughout the
specification and the
drawings with the same respective reference numerals. With regards to the
nomenclature, the
term "explosion-proof' as it is used throughout the specification in
connection with the
Microwave Reactivation System FIGS.3, 4, 5, 6, 7 herein and or any electrical
components,
parts or modules as part of the microwave reactivation system 33, means that
the enclosure
thereof is capable of withstanding the pressure of an explosion or of an
explosive mixture
exploding inside the enclosure without rupture and capable of preventing the
propagation of
an explosion inside the enclosure to the atmosphere surrounding the enclosure.
Referring to
FIGS.3, 4, 5, 6 and 7, the Microwave Reactivation System as shown will be
identified
throughout the description by the numeral 33. Referring to FIGS. 1, 3, 4, 5,
8, 9 and 10, there
is shown a dehumidification system identified throughout the description as
numeral 31 and
illustrated on FIG.1 unit views 1, 2, 3 and 4.
As will be explained in greater detail below, that the dehumidification system
31 is operable
to remove moisture / humidity from the air in a specific enclosed space (not
shown). The
dehumidification system 31 FIGS.1, 3, 4, 5, 8, 9 and 10 can be installed
inside or outside of
an enclosed space and the dry air distributed by using duct work tubing. By
using the
microwave reactivation system 33 FIGS.4, 5, 6, 7 in an explosion-proof
designed casing 34
FIGS.3 and 4 as part of an overall explosion-proof dehumidification system 31
which can be
used near or within an enclosure located in a hazardous environment. A perfect
example is a
location identified as Class. 1 ¨ Division / Zone 2 as defined in the 2002
edition of the
Canadian Electrical Code, Part 1, Section 18 entitled "Hazardous Locations",
published by
the CSA Canadian Standards Association, Toronto, Ontario. In such a location,
flammable
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gas or vapors may be present in the air in quantities sufficient to produce an
explosive or
ignitable mixture.
However, while this hazard does not normally exist, it may occur under
abnormal conditions.
Examples of such hazardous locations include offshore installations and
drilling platforms,
nuclear plants, petrochemical / chemical plants, oil refineries, military live
installations and
armament storage facilities, etc... As it will be explained below in greater
detail, that an
explosion-proof dehumidification system 31 FIGS.1, 3, 4, 5, 8, 9 and 10 is
designed with a
microwave reactivation system 33 FIGS.4, 5, 6, 7 in an explosion-proof casing
34 FIGS.3
and 4 would be well-suited for a safe deployment in such hazardous and
volatile locations.
The dehumidification system 31 unit views 1, 2, 3, 4, FIG.1 is supported and
mounted inside
a rectangular box-like, rigid steel frame 16 FIG.3. This frame 16 FIG.3 is
constructed from
several structural members assembled from top to bottom as; longitudinal beams
17a, b, base
longitudinal beams 17c, d FIG.3, transversal beams 22a, b, c with 22d, e,
supporting the
electrical box 30 and (PLC) programmable logistic controller panel 29.
Vertical posts 18a, b,
c, d, e, f FIG.3 with 18g, h, supporting the PLC panel 29 and plug-in power
cable connector
panel 28 and diagonal brace members 19a, b, c, d, e, f, g, h, FIG.3. There is
also a u-shaped
beam 23 comprised of a small longitudinal beam and two small transversal beams
which
surrounds and supports the PLC panel 29 and plug-in power cable connector
panel 28 and
attaches to the vertical posts 18c, e, providing support and sturdiness. There
are three
additional small longitudinal beams 24, 25, 26 located behind the PLC panel
and plug-in
power cable connector panel which are attached to the vertical posts 18g and
18h also
providing support and sturdiness to this framework surrounding the control and
electrical
panels of the dehumidification system 31. The frame 16 FIG.3 also includes two
base feet
20a and 20b FIG.3 located at both ends for positioning on a structural support
surface as well
as two sleeve channels 21a, b, FIG.3 located in the base center for fork
lifting and four corner
lifting points 27a, b, c, d FIG.3 located at the top corners of the frame, for
inserting the hooks
of a sling assembly to enable manipulation and displacement on a roof, floor
or platform.
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In the preferred embodiment, the dehumidification unit frame 16 is constructed
of stainless
steel and the cabinet 32 / casing 34 is constructed of stainless steel or
aluminum in order to
prevent rust accumulation, corrosion and deterioration even when used in
abrasive
environments, such as offshore marine applications. In an alternate
embodiment, an epoxy
coated resistant steel frame 16 and cabinet 32 type construction may also be
used.
Therefore, the dehumidification system 31 FIGS. 1, 3, 4, 5, 8, 9 and 10 is
well supported by
this frame structure 16 and benefits from enhanced and secured portability in
all
environments and locations. It can be transported and deployed with ease to
various
temporary or permanent work sites and facilities. As shown in FIGS. 1, 3, 4,
5, 8, 9 and 10
the frame 16 FIG.3 is open to thereby facilitate and enable access to the
overall
dehumidification system 31 FIGS.1 and 3 cabinet 32 FIGS.1 and 3 in order to
verify the
components and perform routine maintenance and repairs. However it must be
understood
that in an alternative embodiment, the frame 16 could be constructed with an
outer shell,
panels or walls which would encapsulate and form a structural enclosure which
would house
the dehumidification system 31 FIGS.1 and 3 as well as its operating
components including
the Microwave Reactivation System as described in 33 FIGS.4, 5, 6 and 7. The
construction
of such an enclosed structure would definitely provide additional enhanced
environmental
protection for the dehumidification system 31 FIG.1 and the microwave
reactivation system
33 FIGS.4, 5, 6 and 7.
The overall design can be explained in an exemplary application, where an
explosion-proof
dehumidification system 31 which is designed and equipped with the Microwave
Reactivation System 33 FIGS.4, 5, 6, 7 is encased in an explosion-proof casing
34 FIG.3 that
can be deployed on a work site which is categorized as a hazardous environment
or location.
On the other hand the same Microwave Reactivation System 33 FIGS.4, 5, 6, 7
could be
incorporated in a standard desiccant dehumidification or HVAC system as heat
generating
source, in order to greatly reduce power requirements and electrical
consumption while
enabling heat generation in these systems in order for them to perform
efficiently. The
control of negative effects such as corrosion and failures on materials,
systems and
components created by high humidity, moisture on work sites such as; offshore,
marine, etc...
are of crucial and extreme importance. In addition, coupled with the hazardous
locations and
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volatile environments which may potentially exist, adds a major concern for
the coating,
blasting and resurfacing work of metal surfaces to remove protective coatings
thereby
exposing the underlying metal surfaces to the ambient air. Maintenance
procedures and work
which must be performed on mechanical systems, electrical / electronic
equipment and
components are also seriously affected and compromised by these high humidity
conditions.
If the level of humidity in contact with these substances is left unchecked or
uncontrolled, the
exposed metal surfaces will corrode, deteriorate and or fail before the new
protective coating
can be applied. Mechanical systems, electrical equipment and electronic
components are also
at risk of corrosion, deterioration and operational failure if exposed to
these same
uncontrolled damp and humid conditions.
Deployment of the dehumidification system 31 FIGS.1, 3, 4 on the work site
will
substantially reduce the moisture concentration within an enclosure or area
and therefore,
mitigate and greatly reduce the risk of corrosion, deterioration and
subsequently system
failure. In addition, by incorporating the Microwave Reactivation System 33
FIGS.4, 5, 6 and
7 in the dehumidification system 31 FIGS. 1, 3, 4 this will enable to achieve
important
reductions in electrical power requirement and consumption without
compromising and
delivering optimum system performance. This highly important benefit acquired
when using
the Microwave Reactivation System 33 FIGS.4, 5, 6 and 7 will enable the
capacity to achieve
substantial energy savings without compromising on the advantages of the
dehumidification
system and technology 31. The inclusion of the microwave reactivation system
33 into the
dehumidification system 31 will enable highly effective dehumidification and
the capability
to operate in areas, applications and sites with limitations on energy and
electrical power
supply availability. Given the portability of the dehumidification system 31
FIGS.1, 3, 4
which is designed and equipped with the Microwave Reactivation System 33
FIGS.4, 5, 6
and 7 this allows for rapid movement to another application or work site
within the facility
once the various work projects such as corrosion maintenance or resurfacing
and recoating
have been completed. In reference to the construction, FIGS.2, 4 demonstrate
the components
of the dehumidification system 31 FIGS.1, 3, 4 which includes; a desiccant
rotor / wheel
assembly 5 FIGS.2, 4 with a process section 35 FIGS.2, 4, 5, 6, 7, 8, 9 and a
microwave
heating chamber 36 FIGS.4, 5, 6, 7 as part of the reactivation or regeneration
section 38
FIGS.2, 4, 5, 6, 7 and 9.
CA 02835570 2015-08-03
The process airflow 13 FIGS.2 and 4 is drawn through the process section 35
FIGS.2, 4, 6
and the perforated desiccant rotor / wheel assembly 5 core material 6 FIGS.2,
4, 6, 7 by
means of a high static suction blower 14 with motor assembly FIGS.2, 4, 9
which draws
through and propels the dry process airflow 13 and discharging it to the
enclosed space or
5 zone to be dehumidified and treated. The Microwave Reactivation System 33
FIGS.4, 5, 6, 7
includes the microwave heating chamber 36 FIGS.4, 5, 6, 7 which incorporates
the glass
ceramic coils assembly 39 and the reactivation section 38 which incorporates
the reactivation
metallic coils assembly 9. The Microwave Reactivation System 33 is used for
heating of the
reactivation airflow 15 FIGS.2, 4, 6, 7 prior to it coming in contact with the
desiccant core
10 material 6 in the desiccant rotor / wheel assembly 5 FIGS.2, 4, 6 and 7.
A second high static suction blower 8 FIGS.2, 3, 4, 8 draws the reactivation
airflow 15 which
has been heated as it flows through the reactivation metallic coils assembly 9
and perforated
desiccant rotor / wheel assembly 5 core material 6 FIGS.2, 4, 6 and 7. This
heated
15 reactivation airflow 15 has a deactivating effect on the desiccant core
material's 6 retention
properties which enables the desiccant core material 6 to release the trapped
moisture vapors
into the reactivation airflow 15 FIGS.2, 4, 6 and 7. This hot and moisture
laden reactivation
airflow 15 is drawn downstream and discharged outside into the ambient
environment away
from the dehumidified and treated space or enclosure.
A (PLC) programmable logistical controller panel 29 FIGS.3, 4, 5, 8, 9, 10 is
responsible for
governing the various ongoing operations of the systems and components of the
dehumidification system 31 and particularly the actuation of the Microwave
Reactivation
System 33 FIGS.4, 5, 6, 7 which includes the thermal fluid (not shown), the
circulation
pumps (supply pump 80 and return pump 81) FIGS.4 and 6 and the microwave
reactivation
system 33 high voltage part 40 and components FIG.6 such as; magnetron 41, HV
transformer 42, capacitor 43, diode 44, electrical conduit 45, wave guide 46
and stirrer blades
and motor assembly 47. The PLC controller panel 29 FIGS.3, 4, 5, 8, 9, 10 also
governs the
reactivation and process high static blowers 8 and 14 FIGS.2 and 4, the
desiccant rotor /
wheel assembly 5 rotation motor assembly 11 FIGS.2, 4, 5, 8, and controls the
operation of
the dehumidification system 31. The PLC controller panel 29 is assisted by
input received
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from various temperature and/or airflow sensors 48, 49, 50 FIG.6 located in
the microwave
heating chamber 36, the reactivation section 38 down flow and aft of the glass
ceramic coils
assembly 39 and the process section 35 down flow and aft of the desiccant
rotor / wheel
assembly 5. The electrical box 30 with bolted lid, the (PLC) programmable
logistic controller
29 and plug-in power cable connector panel 28 FIGS.3, 4, 5, 8, 9, 10 are
housed in a
generally square or rectangular design protective type enclosures. The PLC
controller panel
29 has a hinged lid and screw type fasteners 70 FIGS.3 and 4 and angles at
various points for
attachment and tight sealing of the lid. The electrical box 30, PLC controller
panel 29 and the
plug-in power cable connector panel 28 protective type enclosures can be
designed as
standard or explosion-proof rated enclosures.
In the preferred design, the electrical box 30, PLC controller panel 29 and
plug-in power
cable connector panel 28 protective enclosures are constructed of either
stainless steel or of
aluminum. Referring to FIGS.2, 4 and 5, the desiccant rotor / wheel assembly 5
FIGS.2, 4, 5,
6, 7, 8 is housed in a rectangular shaped cabinet 32 FIGS.1, 3, 4, 5, 8, 9, 10
supported on
cross members 20a, b FIGS. 1 and 3 of the unit frame 16.
In the preferred embodiment, the cabinet 32 FIGS.1, 3 is constructed from
stainless or from
welded aluminum, coated with a durable resistant enamel or air-dry
polyurethane corrosion
resistant paint steel in order to resist corrosion. The cabinet 16 FIGS.1, 3,
4, 5, 8, 9 and 10
includes top and bottom walls, front and rear spaced walls and opposed side
walls as shown.
As shown in unit view 2 FIG.1 and FIGS.5 and 8 adjacent the bottom wall, the
front wall has
the process inlet 51 and the reactivation outlet 54. The process inlet 51 is
to allow airflow to
pass into the process section 35 FIGS.2 and 4 through the desiccant rotor /
wheel assembly 5.
Mounted at the process inlet 51 FIGS.2, 3, 4 there could be installed an
intake filter (not
shown) for removing airborne contaminants or dust particles found in the
ingested process
airflow 13 prior to it entering the process section 35 and through the
desiccant rotor / wheel
assembly 5 and core material 6. The intake filter (not shown) installation in
some
applications tends to prevent the dust particles from accumulating within the
process section
FIGS.2 and 4 and clogging the desiccant rotor / wheel assembly 5 core material
6
30 channels 7 which will affect the performance of the desiccant rotor /
wheel 5 and the overall
operating dehumidification system 31 FIG.1.
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17
In the preferred embodiment, the intake filter (not shown) would be located at
the process
inlet 51 and is constructed as a metallic mesh filter which is washable and
can be removed
for cleaning and rinsing of dust and particles. As also shown in unit view 2
FIG.1 and FIGS.
2, 4, 5, 8 the front wall also has a reactivation outlet 54 wet air discharge
which permits the
reactivation airflow 15 to flow through the desiccant rotor / wheel assembly 5
core material
6, out from the reactivation section 38 and expelled through the reactivation
outlet 54 for the
evacuation of the wet air discharge into the atmosphere. In an alternate
embodiment, there
could be installed in reactivation outlet 54 a manually operated damper
assembly (not shown)
including at least (1) one or more rotating louvers for selectively
restricting the airflow out of
the reactivation outlet 54. The use of this feature can increase the heat
retention within the
reactivation section 38 which will in turn increase the efficiency of the
desiccant rotor /
wheel assembly 5 core material 6 by accelerating the deactivation and
drastically affecting
the retention capabilities of the desiccant core material 6, which in turn
speeds up the drying
out of the desiccant core material 6 within the desiccant rotor / wheel
assembly 5 as it rotates
back into the process section 35 to resume its sorption (adsorption) operating
cycle. In the
preferred embodiment, there are (2) two explosion-proof rated high static
suction blowers (8
and 14) with motor assemblies; one is a forward, curved, high static suction
blower 14 with
direct drive motor assembly located in the process section 35, and the other
is an axial type
high static suction blower 8 with direct drive motor assembly located in the
reactivation
section 38 FIG.2 and 4.
In both the process section 35 and the reactivation section 38 the blowers and
direct drive
motor assemblies housings 55 and 56 FIGS.2 and 4 are secured within and to the
cabinet 32
compartment bases, sides and upper walls by means of reinforced L and C shaped
brackets
and clamps (not shown) with bolt and nut assemblies (not shown). As viewed in
FIGS.2 and
4, the process outlet 52 allows for the discharge of the dry process airflow
13 which is drawn
through the desiccant rotor / wheel assembly 5 core material 6 channels 7 in
the process
section 35 by the forward curved high static suction blower 14 driven by an
electric direct
drive motor (not shown) and through the process outlet 52 directly into the
enclosure to be
dehumidified. In an alternative embodiment, mounted in the process outlet 52
(dry air
supply) there could be a manually operated damper assembly (not shown)
including at least
CA 02835570 2015-08-03
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(1) one or more rotating louvers for selectively restricting the dry process
airflow 13 out of
the process outlet 52 (dry air supply) to increase the air pressure when
required to the
dehumidified area or enclosure. The second high static suction blower 8 with
motor assembly
FIGS.2 and 4 is located in the reactivation section 38 outlet 54 and is a high
static axial type
high static suction blower 8 with direct drive motor assembly installed and
secured within
and to the cabinet 32 compartment. As viewed in FIGS.2 and 4, this axial type
high static
suction blower 8 discharges out of the reactivation outlet 54 the hot moisture
laden
reactivation airflow 15 which is drawn into the reactivation inlet 53, through
the Microwave
Reactivation System 33 heating reactivation metallic coils assembly 9 and
flowing through
the perforated desiccant rotor / wheel assembly 5 core material 6. This high
static suction
blower 8 is driven by an electric direct drive motor (not shown).
In an alternative embodiment, mounted in the reactivation outlet 54 (wet air
discharge) there
could be a manually operated damper assembly (not shown) including at least
(1) one or
more rotating louvers for selectively restricting the reactivation airflow 15
out of the
reactivation outlet 54. This restriction of the reactivation airflow 15
induces the temperature
within the reactivation section 38 to rise, which has the effect of further
deactivating the
desiccant rotor / wheel 5 core material 6 retention capabilities. This
restriction induces the
core material 6 to release into the reactivation airflow 15 greater quantities
and more rapidly
its accumulated moisture. This damper assembly is only utilized as required.
In the preferred
embodiment, as viewed in FIGS.2 and 4 both of the electric direct drive motors
(not shown)
used for driving the high static suction blowers 14 and 8 in the process
section 35 and
reactivation section 38 are completely enclosed and designed to be explosion-
proof or
intrinsically safe for use in hazardous environments. However it will be
appreciated and
understood that the electric direct drive motors which drive the process
section 35 and
reactivation section 38 high static suction blowers 14 and 8 need not be
electric motors.
In alternative embodiments, there may be installed either hydraulic, pneumatic
or steam
driven motors designed and approved with hazardous location classification,
which could be
utilized to accomplish the same task of driving the process section 35 high
static suction
blower 14 and reactivation section 38 high static suction blower 8. As shown
in unit view 1
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and 3 FIG.1 and FIGS.3, 4, 9 adjacent the bottom wall, the rear wall has the
process outlet 52
and the reactivation inlet 53.
The process outlet 52 allows for the discharge of the dry process airflow 13
which is drawn
through the desiccant rotor / wheel assembly 5 core material 6 in the process
section 35 by
the forward curved high static suction blower 14. This high static suction
blower 14 is located
at the process outlet 52 installed and secured firmly within the cabinet 32
compal Intent. The
forward curved high static suction blower 14 is driven by an electric direct
drive explosion-
proof motor (not shown). The dry process airflow 13 is in turn discharged and
propelled at
high velocity through the process outlet 52 directly into the enclosure or
area to be
dehumidified and treated. As also shown in unit views 1 and 3 FIG.1 and
FIGS.3, 4, 9 the
rear wall also has a reactivation inlet 53 which permits the ambient air to
flow into the
reactivation section 38. In an alternate embodiment, mounted at the intake of
the reactivation
inlet 53 there could be installed an intake filter (not shown) for removing
airborne
contaminants or dust particles found in the incoming airflow entering the
reactivation section.
Installation of these intake filters in some applications tends to prevent the
dust particles from
accumulating within the reactivation section 38 or process section 35 FIGS.2
and 4
eventually clogging the desiccant rotor / wheel assembly 5 core material 6
channels 7 which
will affect the performance of the desiccant rotor / wheel 5 core material 6
and the overall
operating system.
The type intake filters will now be explained in detail. In the preferred
embodiment, there are
installed two (2) industrial type metallic mesh filters (not shown) to avoid
ingestion of dust
particles and or foreign objects.
As shown in unit views 2 and 4 FIGS.1, 3, 4, one of these filters (not shown)
is located at the
intake of the process inlet 51 and the other at the intake of the reactivation
inlet 53. The
filters (not shown) are constructed of metallic mesh which is washable and can
be removed
for cleaning and rinsing of dust and particles.
The invention; Microwave Reactivation System 33 for Standard and Explosion-
Proof
Dehumidification System will now be explained in greater detail. As viewed in
FIGS.2, 4, 6
and 7, the reactivation airflow 15 is drawn into the reactivation inlet 53 of
the reactivation
CA 02835570 2015-08-03
section 38, flowing through the microwave reactivation system super heated
reactivation
metallic coils assembly 9. The reactivation airflow 15 air temperature is
rapidly raised to a set
point (approx. 200 to 250 degrees F.) prior to coming in contact with the
desiccant rotor /
wheel assembly 5 core material 6. The super heated reactivation airflow 15
passing through
5 the desiccant core material 6 demagnetizes the core material 6 channels 7
which are
impregnated with a desiccant coating. This high heat within the reactivation
airflow 15
creates a deactivating effect on the retention properties of the core material
6 which in turn
allows for in some cases greater release of moisture vapors / water droplets
into the
reactivation airflow 15 and discharged through the reactivation outlet 54 to
ambient.
10 Mounted in the reactivation outlet is a manually operated damper
assembly (not shown)
including at least (1) one or more rotating louvers for selectively
restricting the air flow out
of the reactivation outlet 54.
As previously mentioned, the use of this feature in some applications may be
recommended
15 in order to increase the heat retention within the reactivation section
38 which will in turn
deactivate the retention capabilities of the desiccant core material 6
inducing a greater and
more rapid release of moisture vapors embedded in the desiccant rotor / wheel
assembly 5
core material 6.
20 Therefore, the inducing of increased temperature within the reactivation
section 38, will in
some operational cases promote a faster drying out of the desiccant core
material 6 so that it
can resume its moisture retention capabilities as it rotates back into the
process section 35
also known as the sorption (adsorption) cycle. As viewed in unit views 1, 2, 3
FIG.1 and
FIGS.3, 4, 5, 8 and 9, both of the process inlet 51 and process outlet 52
ports as well as the
reactivation inlet 53 and reactivation outlet 54 ports are designed and
adapted to receive
flexible or rigid ducting for air recirculation and distribution. Given the
enclosed tubular
design, ducting is also used to maintain airflow pressure enabling the
delivery and
distribution of dry air to specific target areas to be dehumidified that are
not in proximity to
the dehumidification unit 31. As shown in FIG.3 that the side wall has outer
access panels
56a to 56h with latch assemblies (not shown) which lock and unlock to allow
for easy access
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during servicing and maintenance. These panels 56a to 56h (except 56b) FIG.4
enable quick
access to all the dehumidification unit 31 operational systems and major
components.
These operational components include; desiccant rotor / wheel assembly 5 and
rotation motor
assembly 11 FIGS.2, 4, microwave reactivation system 33 FIGS.4, 6, 7 which
includes the
high voltage part 40 and components 41 to 47, the microwave heating chamber 36
which
houses the glass-ceramic coils assembly 39, the reactivation section 38 which
incorporates
the reactivation metallic coils assembly 9 and the thermal fluid circulation
pumps (supply
pump 80 and return pump 81). Other accessible components within the process
section 35
and reactivation section 38 are the high static suction blowers 8 and 14 with
direct drive
motor assemblies. All of these access panels 56a to 56h (except 56b) FIG.4 may
be designed
and provided with a small window (not shown) in order to allow for visual
inspection of the
various components including more specifically the desiccant rotor / wheel
assembly 5 and
rotation motor assembly 11, the high static suction blowers 8 and 14 with
motor assemblies
and particularly the Microwave Reactivation System 33 and its various
components. The
other cabinet 32 side wall access panel 56b FIG.4 allows for access to the
compartment used
during shipment of the dehumidification system's 31 for storage of the quick
disconnect
electrical supply cables (not shown) and flexible ducting sleeves (not shown)
used for air
distribution. With reference to the desiccant rotor / wheel assembly 5 FIGS.2,
4, 5, 6 and 8 it
is mounted upright and perpendicular to the base within the cabinet 32
accessed through
panel 56f between two interior walls thereof as shown on FIG.4 which are
located fwd and
aft of the desiccant rotor / wheel assembly 5. The desiccant rotor / wheel
assembly 5 is
supported on two (2) sets of roller bearings 58 FIGS.2, 4, 5, 8 permanently
affixed at the base
at the 5 and 7 o'clock positions.
The desiccant rotor / wheel assembly 5 outer metallic shell 57 rests on these
(2) two sets of
roller bearings 58 providing not only support but allowing for rotational
movement of the
desiccant rotor / wheel assembly 5 about its longitudinal axis as it operates
within the process
section and reactivation section which incorporates the Microwave Reactivation
System 33.
In the preferred embodiment, there is an explosion-proof, electric drive,
rotation motor
assembly 11 FIGS.2, 4, 5, 8, which provides for driving rotation of the
desiccant rotor /
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wheel assembly 5 along its longitudinal axis. In the case where a standard non-
explosion-
proof motor is installed, in order to mitigate and avoid the hazard of
explosion caused by
sparking from brush contacts within the electric motor, the electric drive
rotation motor
assembly 11 can also be encapsulated within a housing (not shown) classified
with an
explosion-proof rating. In an alternative embodiment and design adapted for
some
applications, the electric drive rotation motor assembly 11 may include an
internal ventilation
fan for cooling the electric drive rotation motor assembly 11. Alternatively,
the electric drive
rotation motor assembly 11 may be designed and fitted with an air bleed /
purging device (not
shown). This air bleed / purging device can build up a positive pressure of
air within the
casing in order to decrease any build-up of flammable gases or volatile vapors
and maintain
conditions within tolerable and acceptable levels. This device prevents and
avoids explosive
volatile gases and vapor accumulation and expanding into the electrical
sources which could
cause high risk of sparking and igniting.
Though the preferred embodiment demonstrates the use of an electric drive
rotation motor
assembly 11, it must be appreciated that in other alternative embodiments, the
motor could be
powered and driven pneumatically or hydraulically in order to perform the same
function. As
shown in FIGS.2, 4, 5, 8 the electric drive rotation motor assembly 11 is
connected to the
desiccant rotor! wheel assembly 5 by way of a gearbox (not shown) which in
turn drives a
self-tension drive belt 12 FIGS.2, 4, 5, 6, 8. The gearbox (not shown)
provides for drive
rotation motor assembly 11 speed to be reduced allowing for the specified
desiccant rotor /
wheel assembly 5 rotations to be achieved.
In the preferred embodiment, the desiccant rotor / wheel assembly 5 is driven
to complete
one full rotation every 8 to 10 minutes. The rotations could vary according to
the diameter
and thickness of the desiccant rotor / wheel assembly 5 as well as the
specific applications
and operational environment where it may be utilized. The electric drive
rotation motor
assembly 11 is connected to a junction box (not shown) designed and rated
explosion-proof
The electric drive rotation motor assembly 11 is connected to the (PLC)
programmable logic
controller panel 29 FIGS.3, 4, 5, 8, 10 rated explosion-proof for hazardous
location, through
an electrical conduit system (not shown) assembled within the dehumidification
system
frame 16 FIGS.3, 4, 5, 8, 9, 10 for protection from the external environment
and elements.
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23
This electrical conduit system (not shown) is internally comprised of
electrical lines (not
shown) which are encapsulated within the conduit in a sealed metal tubing (not
shown) and
connected to the junction box. (not shown).
In an alternative embodiment, it must be appreciated that the electrical
conduit system which
houses the electrical lines / wiring which are linked to the junction box may
be designed and
housed externally on the unit. As best demonstrated in FIGS.2, 4, 6 the
desiccant rotor /
wheel assembly 5 includes an electrically conductive outer metallic shell 57
and a monolithic
core which is the desiccant core material 6. In the preferred embodiment, the
outer metallic
shell 57 is made of aluminum. However, it will be appreciated that in
alternative
embodiments, other type of electrically conductive alloys or metals could also
be used in the
fabrication of the desiccant rotor / wheel assembly 5 outer metallic shell 57.
The core of the
desiccant material 6 as shown in FIG. 2 is perforated and has a matrix made up
of small
uniformed tunnels or channels 7 with honeycomb, circular or square like shaped
walls. These
small uniformed channels 7 run parallel to the axis of the airflow (both the
process section 35
and reactivation section 38). The desiccant core material 6 tunnel walls are
constructed of a
non- metallic, non-corrosive inert composite. The walls are made of extruded
fiberglass paper
fibers with an opening measuring at least 5 microns in diameter and are coated
/ impregnated
with a solid desiccant type material which could preferably be, but is not
limited to; silica gel,
titanium silica gel, molecular sieve or lithium chloride, including other
types of desiccant
materials which can withstand repeated temperature fluctuations and moisture
cycling. The
desiccant material is evenly spread throughout the core material 6 FIG.2 of
the desiccant
rotor / wheel assembly 5.
When the desiccant core material 6 is cool and dry, it extracts the moisture
from the process
airflow 13 (called sorption) because of its low vapor concentration and
pressure in
comparison to the incoming airflow which usually has a higher vapor
concentration.
Conversely, the desiccant core material 6 will release moisture as it is
induced by the heated
reactivation airflow 15 (called desorption) because under these conditions the
desiccant
material will tend to have a high vapor concentration and pressure which is
released by the
introduction of heat. The desiccant rotor / wheel assembly 5 FIGS.2 and 4 is
considered to be
an active desiccant rotor / wheel because it performs its tasks of sorption
and desorption by
CA 02835570 2015-08-03
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continuously rotating about its longitudinal axis, passing through the process
section 35 and
reactivation section 38 cycles and back for reuse in a perpetual process. This
alternating cycle
from high to low vapor pressures FIGS. 2 and 4 enables the sorption of
moisture from the
process section 35 airflow and desorption, releasing moisture into the
reactivation section 38
airflow.
In the preferred embodiment, as shown on FIGS.2, 4, 6 and 7 the desiccant
dehumidification
system 31 uses reactivation airflow 15 which is heated by the microwave
reactivation system
33 metallic coils assembly 9 located within the reactivation section 38. This
heated
reactivation airflow 15 has a demagnetizing effect as it passes through the
channels 7 of the
desiccant core material 6 within the desiccant rotor / wheel assembly 5 which
in turn releases
the moisture back into the reactivation airflow 15 which is discharged to
ambient.
Because the moisture removal in the desiccant rotor / wheel assembly 5 core
material 6
occurs in the vapor phase, there is no liquid condensate. Therefore, the
desiccant
dehumidification system 31 can continue to extract moisture from the process
airflow 13
even when the dewpoint of the process airflow 13 is below freezing.
Consequently, in
comparison to the conventional heating cooling hybrid or refrigerant based
dehumidification
systems, the desiccant dehumidification system 31 tends to be extremely more
versatile in
various climatic conditions and certainly better suited to operate in regions
having cold and
humid climates.
In the preferred embodiment, the desiccant rotor / wheel assembly 5 is
installed and utilized
within the standard or explosion-proof desiccant dehumidification system 31
and can be
supplied by any approved desiccant rotor / wheel manufacturer which meets the
industry
standards and approved equipment specifications.
In the preferred embodiment, the portion of the core material 6 of the
desiccant rotor / wheel
assembly 5 which is reactivated or regenerated FIG.2 is sectioned off by a V-
shaped partition
member 59 FIG.2 which is mounted in the cabinet 32 and which isolates and
segregates a
pie-shaped section approximately 1/4 (one-quarter) of the desiccant rotor /
wheel assembly 5
CA 02835570 2015-08-03
core material 6 from the remaining portion of the core material 6 thereof,
which defines the
reactivation section 38 of the desiccant rotor / wheel assembly 5.
The remaining portion approximately 3/4 (three-quarters) of the desiccant
rotor / wheel
assembly 5 core material 6 FIG.2 defines the process section 35 of the
desiccant rotor / wheel
5 assembly 5. The reactivation portion of the desiccant rotor / wheel
assembly 5 core material 6
may cover between one-quarter to one third of the surface core material 6 area
of the
desiccant rotor / wheel assembly 5. In the preferred embodiment, the
reactivation portion of
the desiccant rotor / wheel assembly 5 core material 6 covers one-quarter of
the surface core
area. As shown in FIGS.2, 4, 5, 8, during the operation of the
dehumidification system 31,
10 the portions of the desiccant rotor / wheel assembly 5 core material 6
which define the
process section 35 and the reactivation section 38 are constantly changing as
a result of the
rotation of the desiccant rotor / wheel assembly 5 by the electric drive
rotation motor
assembly 11 which are linked by a rotation belt 12. Accordingly, as the
portion of the
desiccant rotor / wheel assembly 5 core material 6 that is exposed to the
process airflow 13
15 defines the process section 35, likewise the portion of the desiccant
rotor / wheel assembly 5
core material 6 that is exposed to the reactivation airflow 15 defines the
reactivation section
38. Passing through three-quarters (75%) portion FIGS.2, 4, 5, 8 of the
desiccant rotor /
wheel assembly 5 core material 6 surface, the process airflow 13 is drawn by
means of a high
static suction blower 14 FIGS.2 and 4 into the process inlet 51 through the
process section 35
20 and propelled by the high static suction blower 14 through the process
outlet 52.
Simultaneously, the reactivation airflow 15 travelling in the direction
opposite to that of the
process airflow 13 is drawn into the reactivation inlet 53 by means of an
axial type high static
suction blower 8 through a series of parallel super heated reactivation
metallic coils assembly
25 9 part of the microwave reactivation system 33 within the reactivation
section 38. The
reactivation airflow 15 continues its path through the V-shaped one-quarter
(25%) portion of
the desiccant rotor / wheel assembly 5 core material 6 surface. The
reactivation airflow 15
which is saturated with moisture vapors is then expelled by the axial type
high static suction
blower 8 and discharged through the reactivation outlet 54 to ambient. As
shown in FIGS.2,
4, 5, 8, it will thus be understood that as it rotates, the desiccant rotor /
wheel assembly 5
processes two completely separate, counter-flowing or opposing airflows within
its two
CA 02835570 2015-08-03
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sections; the process section 35 and the reactivation section 38. Two (2)
pressure seals 60
FIGS.2, 4, 6 mounted fore and aft of the desiccant rotor / wheel assembly 5 at
the extremities
of the outer shell rim and at the edges of V-shaped partition member 59 FIG.2
are provided in
order to separate and completely isolate the process airflow 13 from the
reactivation airflow
15 and eliminate any possible air leakage or moisture crossover within the two
operating
sections located in the dehumidification system 31 cabinet 32.
In the preferred embodiment, the frame 16 FIGS.1, 3, 4, 5, 8, 9, 10 will serve
as ground, but
it will be appreciated that in other embodiments, an alternative ground system
including an
electrical ground could be utilized.
With reference to FIGS.4, 5, 6, and 7 the Microwave Reactivation System 33
will now be
described in greater detail. The Microwave Reactivation System 33 can be
installed in either
a standard or explosion-proof rated desiccant dehumidification system 31.
In the preferred embodiment, the microwave heating chamber 36 part of the
Microwave
Reactivation System 33 is encapsulated in an explosion-proof type construction
casing 34
including the microwave electrical and electronic high voltage part 40 and
components 41 to
47 for use in hazardous locations and volatile environments.
This Microwave Reactivation System 33 FIGS.4, 5, 6, 7 rapidly produces intense
heat by
generating electromagnetic RF waves which pass through materials and fluids,
causing the
molecules within to move rapidly in excitation, causing atomic motion which
generates heat.
In the preferred embodiment, the medium used to store and transmit this heat
is a synthetic
thermal fluid (not shown) located in the hollow coils assemblies (reactivation
metal coils
assembly 9 and glass ceramic coils assembly 39) of the closed-loop circuit. As
illustrated in
FIGS.2, 4, 6, 7 this thermal fluid is moved by means of supply pump 80 and
return pump 81,
flowing through a first parallel series of glass ceramic coils assembly 39
located in the
microwave heating chamber 36 where the fluid molecules are treated and exposed
to
electromagnetic waves causing excitation, high temperature rise and heat
generation within
the fluid. This super heated thermal fluid (not shown) is then pumped and
flows through a
second parallel series of metallic coils assembly 9 located in the compartment
below called
CA 02835570 2015-08-03
27
the reactivation section 38 coming in direct contact and in the path of the
reactivation airflow
15.
The heat transfer from the super heated thermal fluid (not shown) within the
reactivation
metallic coils assembly 9 in the reactivation section 38 substantially raises
the temperature of
the reactivation airflow 15 as it comes in contact and passes across the
surface of the
reactivation metallic coils assembly 9. This heated reactivation airflow 15 is
then used to
deactivate the perforated desiccant core material 6 within the desiccant rotor
/ wheel
assembly 5 as it flows through it. This heated airflow has a demagnetizing
effect on the
desiccant core material 6 enabling it to release the retained accumulated
moisture, exhausting
it through the reactivation outlet 54 to ambient. This heat generating
reactivation process of
reactivation section 38 removes the moisture vapors from the desiccant core
material 6
greatly lowering its moisture vapor concentration and pressure enabling the
desiccant core
material 6 to be re-energized for reuse in the air dehumidification process
section 35. In an
alternative embodiment, the microwave reactivation system 33 is designed and
can be
utilized as a heat generating system and also installed not only in desiccant
dehumidification
system 31 but also in any mechanical heating / cooling hybrid or refrigerant
type
dehumidification system (not shown) that must generate and incorporate a heat
source in
order to successfully accomplish the dehumidification process.
In the above mentioned types of dehumidification systems which are included, a
heat source
is required in order to raise the ambient intake airflow temperature,
expanding the air volume
and then allowing the refrigerant cooling coils to rapidly cool down the
processed airflow as
it passes through.
This enables the extraction of the suspended moisture vapors suspended within
the airflow
through condensation. Therefore, the Microwave Reactivation System 33 can also
be a
modular system that can be adapted to retrofit any conventional air treatment
and
conditioning, mechanical power or heat generating systems to provide a highly
effective and
cost efficient super heat generating source.
The Microwave Reactivation System 33 FIGS.4, 5, 6, 7 power generation is
divided into two
parts, the control part (PLC panel 29) and the highvoltage part 40. In the
preferred
embodiment, the control part is actually comprised of the programmable logic
controller also
CA 02835570 2015-08-03
28
referred to as PLC panel 29 and of which the casing is explosion-proof in
design. The PLC
panel 29 controls and governs the power output and desired operational
settings, monitors the
various system functions, interlock protections and safety devices. Also in
the preferred
embodiment, the components in the high-voltage part 40 FIG.6 are also
explosion-proof rated
and or encapsulated in an explosion-proof rated housing (not shown). Referring
to FIG.6,
these components serve to step up the voltage to a much higher voltage which
is then
converted into microwave energy in the microwave heating chamber 36.
Generally, the
control part includes either an electromechanical relay or an electronic
switch called a triac
(not illustrated). Once the system is turned on, sensing that all systems are
"go," the control
circuit in the PLC controller panel 29 generates a signal that causes the
relay or triac to
activate, thereby producing a voltage path to the high-voltage transformer 42.
By adjusting the on-off ratio of this activation signal, the control part
governs the flow of
voltage to the high-voltage transformer 42 thereby controlling the on-off
ratio of the
magnetron tube 41 and the output power to the microwave heating chamber 36. In
the high-
voltage part 40 FIG.6, the high-voltage transformer 42 along with a special
diode 44 and
capacitor 43 arrangement serve to increase the voltage to an extreme high
voltage for the
magnetron 41. The magnetron 41 dynamically converts the high voltage it
receives into
undulating waves of electromagnetic energy. This microwave energy is then
transmitted into
a metal rectangular channel identified as a waveguide 46 which directs the
microwave energy
or waves into the microwave heating chamber 36. The effective and even
distribution of the
electromagnetic energy or waves within the entire microwave heating chamber 36
is achieved
by the revolving metal stirrer blades and motor assembly 47. In the preferred
embodiment,
FIGS.6 and 7, high tensile and heat resistant glass ceramic hollow tubing
capable of
withstanding wide temperature variations is used in the construction of the
glass ceramic
coils assembly 39 located in the microwave heating chamber 36. The
electromagnetic energy
or waves produced by the magnetron 41 are dispersed by the metal stirrer
blades and motor
assembly 47 and come in contact with the entire glass ceramic coils assembly
39 located
within the microwave heating chamber 36.
The thermal fluid (not shown) flowing in these hollow coils is then
simultaneously treated
and exposed to this electromagnetic energy causing molecular excitation,
atomic motion,
high temperature rise between 250 ¨ 300 degrees Fahrenheit and heat
generation.
CA 02835570 2015-08-03
29
This super heated thermal fluid is simultaneously siphoned and propelled by
means of a
supply pump 80 flowing into and through the reactivation metallic coils
assembly 9 located
in the compartment below called the reactivation section 38.
In the preferred embodiment, as demonstrated in FIGS.4, 5, 6, 7 the hollow
tubing of the
reactivation metallic coils assembly 9 located in the reactivation section 38
is constructed of
steel, aluminum or other high tensile and heat resistant metal which is
adaptable to extreme
temperature variances and which can effectively retain and radiate heat. It is
important to
note that the diameter of the tubing of the reactivation metallic coils
assembly 9 in the
reactivation section 38 may be either smaller or of the same size in
comparison to the
diameter of the glass-ceramic coils assembly 39 in the microwave heating
chamber 36. Also
in the preferred embodiment, the distance between the coils of the
reactivation metallic coils
assembly 9 in the reactivation section 38 is narrower and the number of actual
coils is 1.5
times greater but in an alternate design may be up to 2 times greater in
number comparatively
to the glass-ceramic coils assembly 39 located in the microwave heating
chamber 36. This
construction allows for a greater temperature rise and a more efficient heat
transfer and
distribution to the reactivation airflow 15 as it comes in contact passing
across the surface
and through the reactivation metallic coils assembly 9 in the reactivation
section 38. As
shown in FIGS.6 and 7 the tightly spaced coil design of the reactivation
metallic coils
assembly 9 allows for a more effective and substantial heat transfer radiated
from the heated
thermal fluid onto the metal coils / tubing and radiated to the reactivation
airflow 15.
A temperature rise of the reactivation airflow 15 of 170-200 degrees is
achieved as it passes
through the reactivation metallic coils assembly 9 in the reactivation section
38. This
temperature rise in the reactivation airflow 15 and induction of high heat has
an
demagnetizing effect on the desiccant impregnated core material 6 within the
desiccant rotor
/ wheel assembly 5. This super heated reactivation airflow 15 induces the
desiccant
impregnated core material 6 to rapidly release its retained accumulated
moisture vapors back
into the reactivation airflow 15 discharging through the reactivation outlet
54 to ambient and
outside of the enclosure or area which is being dehumidified. The desiccant
core material 6 is
then ready for reuse, as the desiccant rotor / wheel assembly 5 rotates about
it longitudinal
axis and back into the air dehumidification process section 35. The heated
thermal fluid (not
CA 02835570 2015-08-03
shown) is simultaneously propelled and siphoned as it continues to transfer
and radiate its
heat as it flows through the metallic coils assembly 9 in the reactivation
section 38. As
viewed on FIG.4 and 6, the continuous and simultaneous siphoning and
propelling of the
heated thermal fluid (not shown) is duplicated by means of a second pump which
is the return
5 pump 81. This return pump 81 draws the thermal fluid back into the glass-
ceramic coils
assembly 39 in the microwave heating chamber 36 as part of a coils assemblies
(reactivation
metallic coils assembly 9 and glass ceramic coils assembly 39) closed-loop
circuit. Therefore,
in a perpetual cycle, the thermal fluid (not shown) undergoes repeated
exposure to the
microwave electromagnetic energy causing molecular excitation, atomic motion,
high
10 temperature rise between 250 ¨ 300 degrees Fahrenheit and heat
generation.
Consequently, the thermal fluid is the medium which moves back and forth
passing through
the microwave heating chamber 36 where it rapidly absorbs intense heat and
onto the
reactivation section 38 where it then releases this intense heat by
dissipation and radiation as
15 part of the Microwave Reactivation System 33. In the preferred
embodiment, in FIG.6, the
thermal fluid circulation pumps (supply pump 80 and return pump 81) are of
explosion-proof
construction and rating, but alternate non-explosion-proof type can be
installed. The
modulation and cycling of the power to the high voltage part 40 is governed by
the PLC
controller panel 29 with data feed provided from temperature and airflow
sensors located
20 within the dehumidification system 31. As viewed on FIG.6, there are two
(2) thermocouple
type temperature sensors 48 and 49, one located in the microwave heating
chamber 36 and
the other in the reactivation section 38. The temperature sensor 49 located in
the reactivation
section 38 has a secondary function which is that of an airflow sensor. A
third sensor 50
functioning as an airflow sensor is located in the reactivation section 38.
All sensors 48, 49
25 and 50 are mounted in place by a support bracket and interconnected by
cable installed in a
system of electrical metallic conduits (not shown) to the control part and
circuit in the (PLC)
programmable logic controller panel 29.
These sensors enable the detection of temperature and air pressure variations
in the
microwave heating chamber 36, the reactivation section 38 and the process
section 35, then
30 relay this information data to PLC controller panel 29 which in turn
governs the high voltage
part 40 to direct output power to the microwave heating chamber 36.
Consequently, in FIG.6
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31
the thermocouple type temperature sensor 48 located in the microwave heating
chamber 36
ensures that the Microwave Reactivation System 33 operates and modulates as
required in
order to automatically generate the microwave energy needed to achieve and
maintain the
desired high temperature settings. These temperature settings within the
microwave heating
chamber 36 are required in order to ensure proper heat transfer to the thermal
fluid as it flows
through the glass ceramic coils assembly 39 in the microwave heating chamber
36 and into
the reactivation metallic coils assembly 9 in the reactivation section 38.
This thermocouple
type temperature sensor 48 detects the temperature within the microwave
heating chamber 36
as it is emitted off of the glass-ceramic coils assembly 39 which contains the
heat thermal
fluid. As shown in FIGS.4, 5, 6, 7 this interaction between the temperature
sensor 48 in the
microwave heating chamber 36, the temperature and airflow sensor 49 in the
reactivation
section 38, the airflow sensor 50 in the process section 35 provide real time
data /
information to the PLC controller panel 29. In acquiring this information, the
PLC controller
panel 29 governs the high voltage part 40 part of the Microwave Reactivation
System 33,
ensuring that the specified reactivation airflow 15 temperature is achieved
and maintained for
an effective reactivation / regeneration of the desiccant rotor / wheel
assembly 5 core material
6 within the air dehumidification system 31. In turn, the airflow sensors 49
and 50 in both the
reactivation section 38 and process section 35 ensure that proper airflow
static pressure is
consistently maintained. These sensors are also safety devices during
operation which will
identify and signal an alarm on the PLC controller panel 29 screen if there is
a malfunction
such as low reactivation temperature or drop in airflow pressure.
These sensors will also shut down the unit by signaling the control circuit in
the PLC
controller panel 29 in the case where the temperature exceeds the prescribed
high
temperature limit or when there is a substantial drop or loss of airflow
through the system due
to blockage of the inlet or outlet ports.
In the preferred embodiment, the electrical connections of these components to
each other
and the control part or PLC controller panel 29 is achieved by way of several
electrical
conduit systems (not shown) which are constructed and connected in part to the
dehumidification system frame 16, yet accessible for maintenance and
verification. In the
preferred embodiment, all of the electrical conduits and wiring in the
dehumidification
CA 02835570 2015-08-03
32
system 31 are designed and rated for use in hazardous and volatile
environments. It will be
understood that in alternative embodiments, the Microwave Reactivation System
33 will
incorporate design modifications which will allow for variations in
performance capabilities.
The modifications will determine size, output capacity and operational ranges
in order to
adapt to any dehumidification system 31 requirements whether it is a standard
desiccant
dehumidification, HVAC or explosion-proof dehumidification system.
The following is a resume of the operation of the Microwave Reactivation
System 33 within
a dehumidification system 31. As shown in FIGS.2 and 4, upon deployment of the
dehumidification system 31, the desiccant rotor / wheel assembly 5 is driven
to rotate by
means of a rotation motor assembly 11 and belt assembly 12.
Consequently, both the process section 35 and reactivation section 38 high
static suction
blowers 8 and 14 are activated and operating. The process section 35 high
static suction
blower 14 draws through the process inlet 51 and filter (not shown) the
process airflow 13
from either the ambient air or from an enclosed space, defined in FIG.2. As
the process
airflow 13 passes through the desiccant rotor / wheel assembly 5 core material
6 it is stripped
of its moisture vapors which are retained by the inner channels 7 impregnated
with a
desiccant material which acts as a moisture magnet. The resultant is dry air
which exits the
desiccant rotor / wheel assembly 5 and is exhausted by means of a high static
suction blower
14 from the process section 35 through the process outlet 52 into the
enclosure or space that
must be treated and humidity controlled. The process outlet 52 dry air supply
high static
suction blower 14 will maintain a recommended airflow static pressure for
various flow rates
(cubic feet per minute - CFM) of at least 2.5 to 3.0 + inches of water column
(WC) to provide
effective dry air distribution within the space or enclosure to be treated and
dehumidified.
This process section 35 dry process airflow 13 supply has extremely low
moisture content or
greatly reduced to a predetermined or desired moisture level. Simultaneously,
the reactivation
section 38 high static suction blower 8 draws the reactivation airflow 15 from
the ambient air
and through the reactivation inlet 53 and filter (not shown) defined in FIG.2.
In the preferred embodiment, the reactivation airflow 15 rate will be
maintained at least 15
cubic meters per minute / 530 cubic feet per minute. As the reactivation
airflow 15 passes
CA 02835570 2015-08-03
33
through the reactivation section 38 its temperature immediately increases as a
result of an
intense heat transfer radiated from the heated thermal fluid (not shown)
within the
reactivation metallic coils assembly 9 part of the Microwave Reactivation
System 33.
Though there could be acceptable variations in the reactivation airflow 15
temperature, the
recommended operating temperature of the reactivation airflow 15 should reach
between
degrees; 120 C to 150 C / 250 F to 300 F. Subsequently, the super heated
reactivation airflow
flows through the desiccant rotor / wheel assembly 5 core material 6 which is
saturated
with moisture vapors.
10 This super heated reactivation airflow 15 serves to regenerate the "V"
shaped partition
member 59 of the desiccant rotor / wheel assembly 5 core material 6. The high
heat has a
demagnetizing effect on the inner channels 7 of the perforated desiccant core
material 6
causing the desiccant core material 6 to release the moisture vapors back into
the reactivation
airflow 15 previously collected and retained within the desiccant rotor /
wheel assembly 5
15 core material 6 from exposure to the process section 35 process airflow
13. The moisture
laden reactivation airflow 15 is then discharged by means of the high static
suction blower 8
through the reactivation outlet 54 into ambient and away from the space or
enclosure to be
treated and dehumidified.
It is recommended to ensure that the reactivation section 38 discharge
temperature leaving
the reactivation outlet 54 does not exceed degrees; 50 C / 122 F. During the
rotation of the
desiccant rotor / wheel assembly 5, prior to re-entering the process section
35, the desiccant
core material 6 is cooled down in order to greatly reduce the vapor pressure
of the desiccant
core material 6, enhancing its tremendously effective adsorbing properties.
The slow
rotational speed of the desiccant rotor / wheel assembly 5; full rotation once
every 8 to 10
minutes, is required to enable the cooling down of the desiccant core material
6.
Although the foregoing description and accompanying drawings relate to
specific preferred
embodiments of the present invention and specific methods of reactivation and
heat
generation for dehumidification systems as presently contemplated by the
inventor, it will be
understood that various modifications, changes and adaptations, may be made
without
departing in any way from the scope of the invention.
