U.S. patent application number 17/063453 was filed with the patent office on 2021-08-26 for scrubber for hvac system.
This patent application is currently assigned to enVerid Systems, Inc.. The applicant listed for this patent is enVerid Systems, Inc.. Invention is credited to Israel BIRAN, Udi MEIRAV.
Application Number | 20210260519 17/063453 |
Document ID | / |
Family ID | 1000005570311 |
Filed Date | 2021-08-26 |
United States Patent
Application |
20210260519 |
Kind Code |
A1 |
MEIRAV; Udi ; et
al. |
August 26, 2021 |
SCRUBBER FOR HVAC SYSTEM
Abstract
In some embodiments, there is provided a scrubber system for
cleaning return air in an HVAC unit, where the scrubber system
attaches directly to an inlet of the return-air side of the HVAC
unit, for example, by the mating of a flange on the system with a
matching flange on the HVAC unit. The bolt-on scrubber system may
comprise one or more sorbent materials, a fan for circulating
return air through the sorbent, a damper-controlled inlet and a
damper-controlled outlet to the attached return air side of the
HVAC unit. Further, an additional air flow channel and a damper may
be included in the system to control the flow of outside air into
the HVAC unit. In some embodiments, the sorbents may be contained
in removable inserts.
Inventors: |
MEIRAV; Udi; (Newton,
MA) ; BIRAN; Israel; (Avihayil, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
enVerid Systems, Inc. |
Westwood |
MA |
US |
|
|
Assignee: |
enVerid Systems, Inc.
Westwood
MA
|
Family ID: |
1000005570311 |
Appl. No.: |
17/063453 |
Filed: |
October 5, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15754917 |
Feb 23, 2018 |
10792608 |
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PCT/US2016/048439 |
Aug 24, 2016 |
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17063453 |
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62208822 |
Aug 24, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 53/0415 20130101;
B01D 2253/108 20130101; B01D 2253/204 20130101; F24F 8/10 20210101;
B01D 53/0446 20130101; B01D 2253/202 20130101; B01D 2257/302
20130101; B01D 53/0462 20130101; B01D 2253/102 20130101; F24F 3/16
20130101; B01D 2253/104 20130101; Y02C 20/40 20200801; F24F 8/90
20210101; F24F 7/08 20130101; B01D 2253/11 20130101; B01D 2257/502
20130101; B01D 53/0454 20130101; B01D 2259/4508 20130101; B01D
2253/106 20130101; B01D 2257/708 20130101; F24F 8/15 20210101; B01D
2257/404 20130101; B01D 2257/504 20130101; B01D 53/0438 20130101;
B01D 2253/1124 20130101; F24F 8/158 20210101; B01D 2257/10
20130101; F24F 3/044 20130101 |
International
Class: |
B01D 53/04 20060101
B01D053/04; F24F 7/08 20060101 F24F007/08; F24F 3/044 20060101
F24F003/044; F24F 3/16 20060101 F24F003/16; F24F 8/10 20060101
F24F008/10 |
Claims
1. A scrubber assembly for scrubbing air from an enclosed
environment, comprising: a housing; an interface arranged on an
exterior of the housing and including a return air inlet (RAI) and
a treated air outlet (TAO), and an adsorbent material configured to
treat air received from the RAI, wherein: the first interface is
configured to mate with or otherwise couple to an external air
inlet (EAI) of a heating, ventilation and air conditioning (HVAC)
system, the EAI opens to a chamber of the HVAC system, through
which air returned from an interior space (return air) traverses,
the RAI is configured to receive at least a portion of the return
air flowing via an EAI, the adsorbent material is configured to
treat the at least a portion of the return air received via the RAI
by adsorbing at least one contaminant contained therein, and the
treated air is expelled from the scrubber assembly back to the HVAC
system via the EAI.
2. The assembly of claim 1, further comprising one or more outside
air inlets configured to receive outside air.
3. The assembly of claim 1, wherein: the HVAC system includes one
or more of an air handling unit (AHU) and a rooftop unit (RTU), the
adsorbent is regenerable, the return air from the chamber flows
directly into the scrubber assembly via the RAI without use of a
conduit, and/or the treated airflow flows directly into the chamber
via the TAO without use of a conduit.
4. (canceled)
5. The assembly of claim 1, where the adsorbent is configured to be
regenerated in-situ.
6. The assembly of claim 2, wherein the one or more outside air
inlets are further configured to receive at least a portion of the
return air for use as a purging air for regenerating the
regenerable adsorbent material.
7. The assembly of claim 1, further comprising one or more air
outlets for expelling air from the scrubber assembly.
8. The assembly of claim 7, wherein the one or more air outlets
comprise one or more purging air outlets configured to expel air
used to regenerate the absorbent material.
9-10. (canceled)
11. The assembly of claim 1, wherein the coupling of the interface
to the EAI is facilitated via a mating of a flange of the scrubber
assembly with a matching flange of the HVAC unit.
12. The assembly of claim 1, wherein the coupling of the interface
to the EAI covers the EAI entirely, and wherein the scrubber
assembly further comprises a pathway configured to allow flow of
outside air into the chamber of the HVAC unit.
13. The assembly of claim 1, wherein the coupling of the interface
to the EAI covers the EAI partially, and wherein the system further
comprises a separate channel configured to allow a flow of outside
air into the chamber via an unobstructed portion of the EAI.
14. The assembly of claim 1, wherein the coupling of the interface
to the EAI is configured to minimize a re-entrance of expelled,
treated air into the scrubber assembly.
15. The assembly of claim 1, wherein the coupling of the interface
to the EAI supports at least a substantial portion of a weight of
the assembly.
16. The assembly of claim 1, wherein the scrubber assembly is
configured as a portable unit configured for removable attachment
to the HVAC system.
17. The assembly of claim 1, further comprising a fan for
circulating the return air through the adsorbent material.
18. The assembly of claim 1, wherein the flow of the return air
through the RAI, and/or the flow of the treated air through the TAO
is/are controlled by a damper.
19. The assembly of claim 1, further comprising a heat source for
heating at least one of a purging gas and the adsorbent material,
the heat source selected from the group consisting of: a heat pump,
a furnace, solar heat, an electrical coil and hot water.
20. The assembly of claim 19, further comprising a bypass damper
configured to facilitate circulation of the heated air in the
assembly through and/or over the adsorbent.
21. The assembly of claim 1, further comprising one or more sensors
configured to measure an amount of a contaminant in the at least a
portion of the return air received via the RAI and/or the treated
air expelled via the EAI.
22. The assembly of claim 21, wherein the measurements are used to
control an activation and/or deactivation of the assembly.
23. The assembly of claim 1, wherein the adsorbent material is
contained within a removable insert or cartridge.
24-27. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 62/208,822, filed Aug. 24, 2015, entitled "Bolt-On
HVAC Scrubber," which is incorporated by reference herein in its
entirety.
FIELD OF THE DISCLOSURE
[0002] The present application generally relates to HVAC systems
and particularly to indoor air treatment and contaminant removal
therefrom.
BACKGROUND
[0003] Removal of contaminants from indoor air may be used as a
means to achieving improved indoor air quality and improved
economics of heating, ventilation and air conditioning (HVAC).
Energy savings may be achieved as an indirect result of the
contaminant removal, which enables reduced rate of air replacement.
Scrubbers are a general category of air cleaning devices. Certain
scrubbers utilize sorbent materials which effectuate air cleaning
by selectively adsorbing certain gas species from air that comes
into contact with the sorbent material. The use of regenerable
sorbents in a scrubber incorporated into an air management system
allows for long term operation, as a relative small amount of
sorbent can be used repeatedly through a two-phase of adsorption
and regeneration.
SUMMARY OF SOME OF THE EMBODIMENTS
[0004] Some embodiments of the current disclosure include a
scrubber assembly for scrubbing air from an enclosed environment,
comprising: a housing; an interface arranged on an exterior of the
housing and including a return air inlet (RAI) and a treated air
outlet (TAO), and an adsorbent material configured to treat air
received from the RAI. In some embodiments, the first interface is
configured to mate with or otherwise couple to an external air
inlet (EAI) of a heating, ventilation and air conditioning (HVAC)
system; the EAI opens to a chamber of the HVAC system, through
Which air returned from an interior space (return air) traverses;
the RAI is configured to receive at least a portion of the return
air flowing via an EAI; the adsorbent material is configured to
treat the at least a portion of the return air received via the RAI
by adsorbing at least one contaminant contained therein, and the
treated air is expelled from the scrubber assembly back to the HVAC
system via the EAI.
[0005] In some embodiments, the adsorbent is regenerable, and may
be configured to be regenerated in-situ. In some embodiments, the
adsorbent material may be contained within a removable insert or
cartridge. The assembly may further comprise one or more outside
air inlets configured to receive outside air, wherein the one or
more outside air inlets are further configured to receive at least
a portion of the return air for use as a purging air for
regenerating the regenerable adsorbent material. In some
embodiments, the HVAC system includes one or more of an air
handling unit (AHU) and a rooftop unit (RTU).
[0006] In some embodiments, the assembly further comprises one or
more air outlets for expelling air from the scrubber assembly,
wherein the one or more air outlets comprise one or more purging
air outlets configured to expel air used to regenerate the
absorbent material. In some embodiments, the return air from the
chamber can flow directly into the scrubber assembly via the RAI
without use of a conduit, and further the treated airflow may flow
directly into the chamber via the TAO without us of a conduit. In
some embodiments, the coupling of the interface to the EAI is
facilitated via a mating of a flange of the scrubber assembly with
a matching flange of the HVAC unit.
[0007] In some embodiments, the coupling of the interface to the
EAI covers the EAI entirely, and wherein the scrubber assembly
further comprises a pathway configured to allow flow of outside air
into the chamber of the HVAC unit. In some embodiments, wherein the
coupling of the interface to the EAI covers the EAI partially, the
system may further comprise a separate channel configured to allow
a flow of outside air into the chamber via an unobstructed portion
of the EAI. In some embodiments, the coupling of the interface to
the EAI may be configured to minimize a re-entrance of expelled,
treated air into the scrubber assembly. In some embodiments, the
coupling of the interface to the EAI can support at least a
substantial portion of a weight of the assembly.
[0008] In some embodiments, the scrubber assembly can be configured
as a portable unit configured for removable attachment to the HVAC
system. It may further comprise a fan for circulating the return
air through the adsorbent material in some embodiments, the flow of
the return air through the RAI, and/or the flow of the treated air
through the TAO may be controlled by a damper. In some embodiments,
the assembly may further comprise a heat source for heating at
least one of a purging gas and the adsorbent material, the heat
source selected from the group consisting of a heat pump, a
furnace, solar heat, an electrical coil and hot water. In addition,
the assembly may contain a bypass damper configured to facilitate
circulation of the heated air in the assembly through and/or over
the adsorbent.
[0009] In some embodiments, the scrubber assembly may comprise one
or more sensors configured to measure an amount of a contaminant in
the at least a portion of the return air received via the RAI
and/or the treated air expelled via the EAI. In some embodiments,
the measurements can be used to control an activation and/or
deactivation of the assembly.
[0010] Some embodiments of the current disclosure further include a
system for cleaning air from an enclosed environment, comprising:
an air handling unit (AHU) including an external air inlet (EAI),
and a mixing chamber for allowing a mixing of air returned from an
interior space (return air) of the enclosed environment with air
entering via the EAI; and a fastened-on scrubber (BOS) assembly,
the BOS assembly comprising a housing; an interface arranged on an
exterior of the housing and including a return air inlet (RAI) and
a treated air outlet (TAO), and an adsorbent material configured to
treat air received from the RAI. In some embodiments, the interface
is configured to mate with or otherwise couple to the EAI; the RAI
is configured to receive the return air via the EAI, the return air
having traversed through the mixing chamber, the adsorbent material
is configured to treat the return air received via the RAI by
adsorbing at least one contaminant contained therein, and the
treated air is expelled from the scrubber assembly back to the AHU
via the EAI.
[0011] In some embodiments, the coupling of the interface to the
EAI may facilitate a direct flow of the mixed air into the BOS
assembly. Further, the coupling of the interface to the EAI may
also facilitate a direct flow of the treated into the mixing
chamber of the AHU. In addition, the coupling of the interface to
the EAI can support at least a portion of a weight of the BOS
assembly.
[0012] It should be appreciated that all combinations of the
foregoing concepts and additional concepts discussed in greater
detail below (provided such concepts are not mutually inconsistent)
are contemplated as being part of the inventive subject matter
disclosed herein. In particular, all combinations of claimed
subject matter appearing at the end of this disclosure are
contemplated as being part of the inventive subject matter
disclosed herein. It should also be appreciated that terminology
explicitly employed herein that also may appear in any disclosure
incorporated by reference should be accorded a meaning most
consistent with the particular concepts disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The skilled artisan will understand that the drawings
primarily are for illustrative purposes and are not intended to
limit the scope of the inventive subject matter described herein.
The drawings are not necessarily to scale; in some instances,
various aspects of the inventive subject matter disclosed herein
may be shown exaggerated or enlarged in the drawings to facilitate
an understanding of different features. In the drawings, like
reference characters generally refer to like features (e.g.,
functionally similar and/or structurally similar elements).
[0014] FIG. 1 shows a schematic illustration of a rooftop unit
(RTU) with a bolt-on scrubber (BOS) attached to the RTU's external
air inlet (EAI), according to some embodiments.
DETAILED DESCRIPTION OF SOME OF THE EMBODIMENTS
[0015] In some embodiments, heating, ventilation and air
conditioning (HVAC) systems may be used to treat and/or condition
indoor air of an enclosed environment such as a building. For
example, a HVAC system may comprise a roof-top unit (RTU), also
known as a unitary system or a packaged unit. Such systems or units
are usually placed outside a building, such as but not limited to
the roof and the sides of the building. An RTU can refer to a
complete "packaged unit" including an air handling unit (AHU) and a
chiller, and/or an air handling unit receiving cold or hot fluid
from a separate chiller or boiler. Throughout this disclosure, the
terms "HVAC" and "RTU" may be used interchangeably to refer to a
system for treating and/or conditioning air (including an AHU).
[0016] In buildings with HVAC systems in general and RTUs in
particular, a scrubber may be added to the air circulation system.
In some embodiments, the location of the scrubber and its interface
with the indoor air circulation system can be an important
determinant of the cost and performance of the added scrubber.
Scrubbers run be integrated into a HVAC system, or they may be
separate from but operationally coupled to the HVAC system. In
buildings where the HVAC systems include outdoor RTUs, the physical
installation and mechanical support of an outdoor scrubber to
accompany the RTUs may be mechanically and structurally
challenging, besides being cost-ineffective. For example, ducts may
have to be used to connect scrubbers to RTU systems. Further, the
installation and maintenance of the HVAC systems including the
scrubbers may affect the structural integrity of the roof on which
the HVAC system is located.
[0017] The present disclosure introduces a counter-intuitive and
yet convenient and practical way to incorporate scrubbers into
buildings with RTUs, by operationally coupling the scrubber (e.g.,
physically attaching the scrubber) to an external inlet (EAI) of
the RTU. In some embodiments, the EAI may be a pre-existing outside
air inlet. In some embodiments, the EAI may be an inlet of the RTU
(or in general HVAC system) configured to specifically couple to
the disclosed scrubber. That is, the EAI may be configured to
couple to a scrubber so that the EAI provides the scrubber access
to a mixing chamber of the HVAC or RTU where entering outside air
and air returning from. an enclosed environment mix. In such
embodiments, the EAI may be the inlet that allows the outside air
to enter into the mixing chamber. For example, a flange on the
scrubber can be designed to mate with a flange around the EAI, and
the connection may serve to support the weight and stability of the
scrubber on the roof or the ground, as well as sealing the air flow
pathways between the scrubber and the rooftop unit. Such a scrubber
may be referred to as a bolt-on scrubber (BOS). Attaching a
scrubber directly to an EI is counterintuitive because scrubbers
are mainly used to treat or scrub return air (RA) returning from an
enclosed environment such as a building. For example, the RA may be
indoor air from a building and may contain unwanted substance that
may have originated from occupants of the enclosed space, building
materials, food, consumer products (e.g., cleaning products, etc.),
and/or the like. Examples of such air contaminants include
inorganic compounds, organic vapors, micro-organisms such as but
not limited to bacteria, viruses, mold, fungi, airborne particles,
etc., gases such as but not limited to carbon dioxide, carbon
monoxide, sulfur oxide, nitrous oxide, radon, etc., and/or the
like. Outside air (OA), which usually has less or no concentration
of such contaminants, is usually not the subject of scrubbing
systems. The inventors of the present disclosure have discovered
that operationally coupling a BOS to an OA of a RTU provides a
practical and effective system to scrub indoor air containing
contaminants with little or no effect on the structural integrity
of a roof.
[0018] In some embodiments, an RTU may include a mixing chamber
operationally coupled to a return air inlet and an EAI of the RTU,
which are configured to allow into the mixing chamber return air
and outside air, respectively. In the mixing chamber, the RA may
mix with the OA, in some cases diluting the concentration of the
contaminants in the RA. In some embodiments, the RA inlet and/or
the EAI may include dampers, valves, shutters, etc. to control the
amount of OA to be mixed with the RA. The EAI may be protected by a
louver or a rain cover.
[0019] In some embodiments, the coupling of the BOS to the RTU, or
in general to a HVAC unit, may be in the form of a direct
attachment between the BOS and the HVAC. For example, the BOS may
include an interface that is configured to align with the EAI of
the HVAC. In some embodiments, the 105 may include a housing and an
interface arranged on an exterior surface of the housing. The
interface may include a return air inlet (RAI) and a treated air
outlet (TAO), and the interface may be configured to mate with or
otherwise couple to an external air inlet (EAI) of the HVAC. In
some embodiments, the EAI may be arranged adjacent a chamber of the
HVAC system through which air returned from an interior space
(return air) traverses. Further, the RAI may be configured to
receive return air via the EOA, and once the return air is treated
by the BOS (e.g., by an adsorbent material of the BOS, as will be
discussed below), the treated air may be expelled from the TAO back
to the HVAC system via the EAI.
[0020] In some embodiments, the BOS may be coupled to the EAI of
the RTU such that a channel separate from the BOS may form and
serve as an inlet for outside air. For example, the BOS may cover
some fraction of the surface area of the RTU's EAI such that OA
enters the RTU through the unobstructed portion of the RTU's EAI.
The fraction may range from about 1.0% to almost about 1.00%,
including values and subranges there between. In some embodiments,
the BOS may cover the entire EAI of the RTU With the addition of
the bolt-on scrubber to the RTU, in some embodiments, a pathway may
be used to allow OA into the mixing chamber. The OA may be utilized
to maintain positive pressure in the enclosed environment that is
being air-conditioned, for example, to compensate for intentional
or unintentional air escaping from the building, including exhaust
from bathrooms, etc. Furthermore, when outdoor temperature and
humidity conditions are favorable, it may be energetically
preferable to increase the amount of outside air so as to reduce
the conditioning (cooling, heating, etc.) of the air to be supplied
to the enclosed environment. In such embodiments, the BOS may
include a pathway or channel that facilitates the introduction of
OA into the RTU (via the BOS, for example). There may also be an
additional separate channel (in addition to the pathway through the
BOS) that facilitates the flow of OA into the RTU. The bolt on
scrubber may entirely cover the EAI, and it can address the
changing need for OA by having a controlled pathway for outdoor air
to flow directly into the mixing chamber. The flow of OA through
the unobstructed portion and/or the BOS pathway may be controlled
via any suitable means such as but not limited to dampers,
shutters, fans, blowers, and/or the like. For example, the amount
of OA flowing through the noted pathway can be controlled by one or
more dampers, and may be further assisted by a booster fan,
although in general the RTU inlet has a lower pressure that the
outside air.
[0021] In some embodiments, the coupling of the BOS to the EAI may
be configured to facilitate the streaming of air into the BOS from
the RTU. For example, the BOS may be positioned on the EAI in such
a manner as to allow the BOS to receive a stream of air from the
mixing chamber of the RTU. For example, the BOS may be directly
attached to the EAI (e.g., an interface of the BOS including the
RAI and the TAO may be directly attached or "mated" with the EAI of
the HVAC or RTU). The air from the mixing chamber may be mixed air
containing both OA and RA. In some embodiments, the BOS and/or the
BOS's coupling to the RTU may be configured such that the mixed air
that flows into the BOS contains a desired proportion of RA to OA.
For example, the BOS may be coupled to the RTU such that a RA inlet
of the BOS may be positioned so as to intercept a desired amount
(at least approximately) of RA entering the mixing chamber. In some
embodiments, the amount of RA flowing into the BOS may comprise
between about 75% to about 100%, between about 85% to about 100%,
between about 90% to about 100%, about 95%, etc. including values
and subranges there between, of the total amount of mixed air
entering the BOS. In some embodiments, ducts may be used to couple
the inlets/outlets of the BOS those of the RTU. For example, the
BOS RA inlet and TAO may be coupled to the EAI of the RTU via
ducts. In some embodiments, however, the couplings may be direct
connections without the aid of ducts or similar equipment. For
example. the DOS RA inlet and treated air outlet may be directly
attached to the RTU's EAI. As will be discussed below, such
coupling or mechanical attachment may also facilitate the secure
placement of the BOS to that of the RTU.
[0022] In some embodiments, the BOS may also be equipped with air
flow aids such as a fan, blower, etc., to urge air to flow from the
mixing chamber to the BOS. The RTU may also contain a flow aid to
assist in the flow of mixed air from the mixing chamber of the RTU
into the BOS. In some embodiments, the RTU and/or the DOS may also
be equipped with a diverter that directs the incoming (into the
mixing chamber) RA to flow towards the BOS such that the mixed air
entering the BOS contains a higher amount of RA (e.g., compared to
OA).
[0023] In some embodiments, the coupling or mechanical attachment
of the BOS to the EAI of the RTU is configured to securely place
the BOS relative to the RTU and prevent its movement without
separately securing it to the roof or the ground. Such a
configuration is in particular useful to securely incorporate the
BOS to the RTU with little or no adverse effect to the structural
integrity of the roof. For example, the attachment may support some
or all of the BOS's weight, thereby reducing or even eliminating
the need to provide separate structural support between the BOS and
the roof or ground. Further, the coupling of the BOS to the RTU's
EAI can provide a direct connection to the RA stream, from which
one may draw RA (which may flow into the BOS as part or a mixed RA
and OA stream) to treat (e.g., filter, scrub, etc.) and reinject
the treated air back into circulation. The secure coupling or
mechanical physical attachment of the BOS to the RTU allows for the
formation of a single module that may be convenient for universal
installation procedures of field retrofits, and less dependent on
building specifics. Such modules make the retrofitting or
installation procedures easier to accomplish, and also to easier
teach to and train installation technicians.
[0024] In some embodiments, the BOS may comprise a BOS inlet to
receive mixed RA and OA from the mixing chamber of the RTU, and a
BOS treated air outlet to release air treated by the RTU back into
the mixing chamber. The BOS may also include an additional purge
gas inlet for receiving purge gas for use in the regeneration of
the sorbent of the BOS, and an exhaust outlet for releasing exhaust
purge gas containing some or all of the contaminants desorbed from
the sorbent of the scrubber during regeneration. In some
embodiments, the purge gas may be outside air, and/or RA diverted
away from the mixing chamber. For example, there may be certain
situations where one may not wish to use outside air as a purge air
(e.g., when OA itself contains a high level of pollution). In such
cases, some or all of the RA may be diverted towards the BOS (e.g.,
through the purge gas inlet) to regenerate a sorbent that may have
been saturated with contaminants. In some embodiments, a
combination of OA and RA may be used as purge air to regenerate the
adsorbent, and the OA inlet and/or the RA inlet of the BOS can be
used as an inlet to receive the purge air into the BOS.
[0025] I some embodiments, the BOS may include a heat source to
heat the purge gas OA and/or RA, for example) so as to enhance the
desorption of the sorbent during the regeneration phase. In some
cases, the purge air may be at the requisite temperature (e.g.,
when the purge air is an outside air in the summer when
temperatures are elevated), and the purge air may be used to
regenerate with sorbent of the scrubber without further heating.
The heat source may also be used to directly heat the adsorbents.
Examples of a heat source that can be used to heat the purge gas
and/or the adsorbent directly include an electrical coil, a
radiator, a heat pump, a solar heater, a furnace, hot water, gas or
other fuel, and/or the like.
[0026] In some embodiments, as mentioned above, a source of heat
for heating a purging gas and/or adsorbent materials of the BOS may
be a heat pump. The heat pump may use fluids and compressors in a
closed chiller loop of condensation and evaporation, also referred
to as a "condenser-evaporator loop", so as to move heat opposite
its usual direction, namely removing heat from a lower temperature
evaporator region and adding heal to a higher temperature condenser
region. in this way, a heat pump can act to continuously cool the
ambient environment in a cold region (i.e. the evaporator side or
cold side) while heating the ambient in a warmer region (the
condenser side or warm side). Viewed as a refrigerator or chiller,
it facilitates the cooling of air below its surrounding
temperature; viewed as a heater, it delivers heat where needed. In
some embodiments, the heat pump may be configured to remove heat
from RA and concurrently heat the purge gas (e.g., OA).
[0027] In some embodiments, the BOS may also comprise filters
configured to capture contaminants contained in air entering the
BOS. For example, one or more filters may be used to remove
unwanted substances from the mixed air coming in from the mixing
chamber and/or the purge air (outside air and/or returning air). In
some cases, the filter may not remove all the unwanted substances
in the air being filtered (e.g., very small sized particles). The
scrubbing of the mixed air may be accomplished via a sorbent
configured to remove some or all of the contaminants or unwanted
substances contained in the mixed air. For example, the sorbent may
include an adsorbent material or a scrubber configured to capture
and adsorb the contaminants in the incoming mixed air. The sorbent
material may be distributed in the path of the air flowing through
the scrubber, or it may be held in one or more locations in
replaceable and/or removable inserts or cartridges, to facilitate
sorbent replacement when needed. As discussed above the mixed air
flowing through the scrubber may at least partially be cleaned by
the process of filtration by the one or more filters. Further, the
air may be scrubbed of some or all of its remaining contaminants
via the adsorption of the contaminants onto the sorbent materials.
The cleaned air may then flow back into the mixing chamber via the
BOS outlet, from where it can be returned back into the building as
a supply air (SA) after being air conditioned through the cooling
(or heating) coils of the RTU. In some embodiments, some of this
clean air may be returned back into the BOS as part of the mixed
air flowing into the BOS. In most embodiments, this portion of
cleaned air that returns back into the BOS from the mixing chamber
may constitute a small proportion of the total mixed air entering
into the BOS. For example, the portion may be less than about 10%,
less than about 8%, less than about 5%, less than about 3%, less
than about 1%, of the total mixed air, including values and
subranges there between. In some embodiments, the portion of
cleaned air that may be immediately returned back into the BOS from
the mixing chamber may be minimized by judicious use of fans,
valves, blowers, etc. and favorable placements of the BOS inlet and
outlet (e.g., so as to direct the cleaned air away from the BOS
inlet and towards the air-conditioning units of the RTU).
[0028] In some embodiments, the scrubber may comprise a regenerable
adsorbent material that is configured to adsorb at least one
gaseous contaminant contained in the mixed airflow of OA and RA
during the adsorption mode of the operation of the scrubber. During
the regeneration mode, the regenerable adsorbent material is
configured to release contaminants adsorbed onto the adsorbent.
Regeneration may be achieved under appropriate conditions where the
contaminants that have been captured by the adsorbent material are
released and purged, allowing the adsorbent material to regain some
or all of its adsorptive properties. For example, regeneration may
take place during a temperature-swing cycle where the adsorbent
material is heated directly by a heat source (e.g., heater) and/or
by a heated purging gas, followed by the purging of the
contaminants by the purging gas to be exhausted through an exhaust
outlet of the scrubber. The combination of the effects of the heat
and the purging air may remove sonic or all of the contaminants via
temperature swing regeneration of the sorbents, Examples of
adsorbent materials that can be used as scrubber in the SOS include
clays, molecular sieves, zeolites, various forms of silica and
alumina, porous silica, porous alumina, various forms of carbon,
activated carbon, carbon fibers, carbon particles, titanium oxide,
porous polymers, polymer fibers and metal organic frameworks,
and/or the like. One or more of these adsorbent materials may be
used to scrub contaminants from the mixed air, the contaminants
including but not limited to carbon dioxide, volatile organic
compounds, sulfur oxides, radon, nitrous oxides and carbon
monoxide, and/or the like.
[0029] In some embodiments, the BOS may have the capability to
perform automatic regeneration of the sorbent material from time to
time. In other words, the BOS may be designed to switch
automatically between the adsorption mode where contaminants are
captured by the adsorbent to the regeneration mode where the
adsorbent is regenerated (e.g., via temperature swing
regeneration). The determination to switch between the modes may be
made based on measurements of the concentration of contaminants in
the air being treated (mixed RA and OA, for example) and/or the
concentration of adsorbed contaminants on the adsorbents. For
example, the BOS may comprise one or more sensors and a controller
where the one or more sensors are configured to generate a signal
corresponding to the concentration of the at least one gaseous
contaminant and/or the presence of the at least one gaseous
contaminant, and transmit the signal to the controller system. Upon
processing the data from the signal, in some embodiments, the
controller (e.g., an electromechanical control system) may instruct
the regeneration accessories to initiate the regeneration process.
For instance, the controller system may instruct the dampers of the
BOS's RAI to not let in any more mixed air into the BOS, while
allowing the damper of the SOS's OA inlet to receive outside air
that can serve as a purging air. The switching between adsorption
and regeneration may take place automatically as well as
repeatedly.
[0030] In some embodiments, regeneration can be accomplished by
heating the sorbent and subsequently purging the sorbent with a
stream of air that is exhausted externally. For example, the BOS
may be equipped with an exhaust outlet, as well as with a damper
that can open and close the outlet, i.e., control flow of the
exhaust through the outlet. In some embodiments, one may wish to
recycle the purging gas before exhausting the gas out the exhaust
outlet. In such embodiments, the DOS may include a closed loop
return path that may return used purge gas back to flow through and
or over the adsorbent in the DOS so as to regenerate it repeatedly.
In some embodiments, whether to recycle a purging gas or not may be
determined by the controller based on purging gas airflow
contaminant level measurements obtained front the one or more
sensors of the BOS. For example, if the gaseous contaminant level
in the exhausted purging gas is below some threshold level, then
the exhausted purging gas may be recycled and reused as purging gas
airflow by returning it to the adsorbent is the closed loop return
path. In some embodiments, the recycled purging gas may also be
combined with fresh purging gas (e.g., fresh OA and/or RA). In some
embodiments, the closed loop return path may be provided with
dampers to control the flow of the exhausted purge gas airflow into
and out of the closed loop. For example, one or more dampers within
the BOS may be opened so as to facilitate the circulation of a
purging gas within the BOS while other dampers (such as those
located at DOS inlets and outlets) are closed off to prevent entry
and/or escape of the purging gas before the regeneration is
complete.
[0031] In some embodiments, the BOS can be operably coupled to a
heat exchanger that is configured to facilitate thermal
communication between the exhaust purge gas and gas coming into the
DBS to be used as a fresh purge gas. For example, the heat
exchanger may facilitate thermal communication between an exhaust
purge gas and OA, RA, and/or a combination thereof. The thermal
communication may elevate the temperature of the incoming fresh
purge gas, aiding in the regeneration of the adsorbents with little
or no heating of the purge gas with additional heating source
(hence conserving energy, for example). In some embodiments, the
heat exchanger may facilitate thermal communication between the
exhaust purge gas and the mixed air in the mixing chamber (for
example, the mixed air drawn into the BOS for treatment).
[0032] Thermal communication may include any type of heat transfer,
such as by contact, convention or conduction, etc. For example, the
heat exchanger may comprise a shell and tube configuration, an air
coil configuration, a plate configuration, a fin configuration or a
counter-flow configuration. In some embodiments, the heat exchange
may be facilitated by having conduits carrying the incoming air
(e.g., OA, RA, combination thereof, etc.) and the exhaust purge air
to run in parallel and in close thermal communication over an
extended length of these conduits. Thermal communication can be
assisted by increasing a shared surface area of the parallel
conduits. In some embodiments, the two conduits may be arranged so
that the incoming gas and the exhaust purge gas flow in opposite
directions, substantially increasing the heat exchange rate. In
some embodiments, the purge gas may be recycled until the
efficiency of thermal communication falls below a desired threshold
(e.g., the temperature of the exhaust purge gas becomes too low to
heat the incoming purge gas in any substantial manner).
[0033] FIG. 1 is a schematic illustration of a rooftop unit (RTU)
200 with a bolt-on scrubber (BOS) 100 attached to the RTU's EAI
210. The RTU may comprise a mixing chamber 220 into which return
air (RA) returning front the enclosed environment and outside air
(OA) entering from outside the enclosed environment may flow. OA
may enter the RTU via a pathway through the BOS (for example, if
the BOS covers the entire EAI 210 of the RTU) or the OA may enter
into the mixing chamber through a separate channel 300. Without the
disclosed BOS, a mixture of the RA and the OA may proceed to and be
filtered by filter 240 before being conditioned (e.g., heated
and/or cooled) by an air conditioning unit 250 cooling/treating
coils). The treated air may then be supplied back into the enclosed
environment as a supply air (SA).
[0034] In the presence of the BOS, the RA, the OA or a mixture
thereof may flow into the BOS return air inlet (RAI) 110 for
scrubbing by the sorbents 160. The flow of the air into the BOS 100
may be facilitated by a suitable means such as a fan 150 that draws
the air into the BOS 100 via the BOS RA inlet 110. The air is then
scrubbed of some or all of its contaminants by a scrubber
containing inserts or cartridges of sorbents 160 before being
released back into the mixing chamber via the BOS treated air
outlet 120. The BOS may include such sorbent inserts and cartridges
along the flow path of the air to be treated (e.g., OA and RA
mixture) between the RA inlet 110 and treated air outlet 120 of the
BOS. In some embodiments, the air may also be filtered by a filter
190 in the BOS. In some embodiments, the BOS RAI 110 and the TAO
120 face the mixing chamber 220 of the RTU, and are securely
attached or otherwise coupled to the RTU EAI 210. In some
embodiments, the BOS 100 may not cover the entire RTU EAI 210,
leaving a portion of the inlet to be used as a separate channel 300
for allowing in outside air. In some embodiments, there may be a
separate channel 300 in addition to an OA pathway through the BOS
100 configured to allow OA flow into the RTU 200. Dampers 310 may
be used to control flow of OA into the mixing chamber 220.
[0035] In some embodiments, the adsorbent 160 may be regenerated so
as to desorb and remove the contaminants captured by the adsorbent
160. The adsorbent may be in the form of inserts or cartridges, and
in some cases it may be removable (i.e., replaceable). During
regeneration, the adsorbent 160 may be heated directly or
indirectly by a heating source 180. In some embodiments, air
circulates inside the scrubber in a closed loop, by opening a
bypass damper 170, carrying heat from the heating source 180 to the
sorbent 160. Accordingly, the adsorbent 160 may be heated so as to
facilitate the removal of the contaminants adsorbed onto the
adsorbent 160. Upon the heating of the adsorbent 160. In some
embodiments, a purge air in the form of OA incoming through the OA
inlet 130 may flow through/over the adsorbent 160 and purge or
remove the contaminants. In some embodiments, the purge gas may be
recycled by opening the bypass damper 170 and closing most or all
other dampers in the BOS. In some embodiments, the purge air
itself, containing OA and/or RA, may be heated by the heating
source 180, and the heated purge air may then heat the adsorbent so
as to facilitate the removal of the adsorbed contaminants, i.e.,
the heated purge air may heat the adsorbent and concurrently purge
away the contaminants. Examples of a heating source include an
electrical coil, a radiator, a heat pump (using fluids and
compressors in a closed chiller loop of condensation and
evaporation, for example), a solar heater, a furnace, hot water,
gas or other fuel, and/or the like.
[0036] The switch between the adsorption mode, where mixed air of
OA and RA flows through the adsorbent 160 so that the adsorbent 160
captures contaminants contained within the mixed air, and the
regeneration mode, where some or all of the adsorbed contaminants
are removed from the adsorbents 160, may be determined based on the
measurements of one or more sensors 115 located in the BOS 100
and/or the RTU 200. The sensors may measure, for example, the
concentration of contaminants adsorbed onto the adsorbent 160
and/or the amount of contaminants in the mixed air, and transmit
(wirelessly or wired, for example) the measurements to controller
(not shown) (e.g., microprocessor). The controller may then make a
determination and initiate the appropriate mode for the BOS 100.
For example, if the contaminant concentration of the RA or mixed
air exceeds a certain threshold amount, the controller may activate
the dampers of inlets and outlets of the BOS and the RTU to allow
the air flow into the BOS 100 and be scrubbed. Similarly, damper
310 may be activated to allow OA into the mixing chamber 220. The
controller may accomplish such tasks by transmitting signals
wirelessly, for example. Once the adsorbents are regenerated, the
exhaust purge gas may be discarded into the outside environment via
a BOS exhaust outlet 140. In some embodiments, the exhaust purge
gas may be reused for more cycles based on the amount of
contaminant concentration contained within (for example, as
measured by a sensor) or based on the temperature of the exhaust
purge gas (if the temperature of the exhaust purge gas is still
high enough to heat up the adsorbent, for example). The recycling
of the purge gas may be accomplished via a closed loop return path.
An example of such a closed loop return path occurs when dampers
located at 110, 120, 130 and 140 are closed and damper 170 is open,
facilitating the formation of a closed loop path where purging gas
circulates in the BOS using the closed path via the opening through
damper 170 and the passageway proximate to exhaust outlet 140. In
this manner, a purging gas may be recycled and used again to
regenerate the adsorbent in the BOS.
[0037] While various inventive embodiments have been described and
illustrated herein, those of ordinary skill in the art will readily
envision a variety of other means and/or structures for performing
the function and/or obtaining the results and/or one or more of the
advantages described herein, and each of such variations and/or
modifications is deemed to be within the scope of the inventive
embodiments described herein. More generally, those skilled in the
art will readily appreciate that all parameters, dimensions,
materials, and configurations described herein are meant to be an
example and that the actual parameters, dimensions, materials,
and/or configurations will depend upon the specific application or
applications for which the inventive teachings is/are used. Those
skilled in the art will recognize, or be able to ascertain using no
more than routine experimentation, many equivalents to the specific
inventive embodiments described herein. It is, therefore, to be
understood that the foregoing embodiments are presented by way of
example only and that, within the scope oldie appended claims and
equivalents thereto, inventive embodiments may be practiced
otherwise than as specifically described and claimed. Inventive
embodiments of the present disclosure are directed to each
individual feature, system, article, material, kit, and/or method
described herein. In addition, any combination of two or more such
features, systems, articles, materials, kits, and/or methods, if
such features, systems, articles, materials, kits, and/or methods
are not mutually inconsistent, is included within the inventive
scope of the present disclosure. Some embodiments may be
distinguishable from the prior art for specifically lacking one or
more features/elements/functionality (i.e., claims directed to such
embodiments may include negative limitations).
[0038] Also, various inventive concepts may be embodied as one or
more methods, of which an example has been provided. The acts
performed as part of the method may be ordered in any suitable way.
Accordingly, embodiments may be constructed in which acts are
performed in an order different than illustrated, which may include
performing some acts simultaneously, even though shown as
sequential acts in illustrative embodiments.
[0039] Any and all references to publications or other documents,
including but not limited to, patents, patent applications,
articles, webpages, books, etc., presented anywhere in the present
application, are herein incorporated by reference in their
entirety. Moreover, all definitions, as defined and used herein,
should be understood to control over dictionary definitions,
definitions in documents incorporated by reference, and/or ordinary
meanings of the defined terms.
[0040] The indefinite articles "a" and "an," as used herein in the
specification and in the claims, unless clearly indicated to the
contrary, should be understood to mean "at least one."
[0041] The phrase "and/or," as used herein in the specification and
in the claims, should be understood to mean "either or both" of the
elements so conjoined, i.e., elements that are conjunctively
present in some cases and disjunctively present in other cases.
Multiple elements listed with "and/or" should be construed in the
same fashion, i.e., "one or more" of the elements so conjoined.
Other elements may optionally be present other than the elements
specifically identified by the "and/or" clause, whether related or
unrelated to those elements specifically identified. Thus, as a
non-limiting example, a reference to "A and/or B", when used in
conjunction with open-ended language such as "comprising" can
refer, in one embodiment, to A only (optionally including elements
other than B); in another embodiment, to B only (optionally
including elements other than A) in et another embodiment, to both
A and B (optionally including other elements); etc.
[0042] As used herein in the specification and in the claims, "or"
should be understood to have the same meaning as "and/or" as
defined above. For example, when separating items in a list, "or"
or "and/or" shall be interpreted as being inclusive, i.e., the
inclusion of at least one, but also including more than one, of a
number or list of elements, and, optionally, additional unlisted
items. Only terms clearly indicated to the contrary, such as "only
one of" or "exactly one of" or, when used in the claims,
"consisting of" will refer to the inclusion of exactly one element
of a number or list of elements. In general, the term "or" as used
herein shall only be interpreted as indicating exclusive
alternatives (i.e. "one or the other but not both") when preceded
by terms of exclusivity, such as "either," "one of," "only one of,"
or "exactly one of." "Consisting essentially of," when used in the
claims, shall have its ordinary meaning as used in the field of
patent law.
[0043] As used herein in the specification and in the claims, the
phrase "at least one," in reference to a list of one or more
elements, should be understood to mean at least one element
selected from any one or more of the elements in the list of
elements, but not necessarily including at least one of each and
every element specifically listed within the list of elements and
not excluding any combinations of elements in the list of elements.
This definition also allows that elements may optionally be present
other than the elements specifically identified within the list of
elements to which the phrase "at least one" refers, whether related
or unrelated to those elements specifically identified. Thus, as a
non-limiting example, "at least one of A and B" (or, equivalently,
"at least one of A, or B," or, equivalently "at least one of A
and/or B") can refer, in one embodiment, to at least one,
optionally including more than one, A, with no B present (and
optionally including elements other than B); in another embodiment,
to at least one, optionally including more than one, B, with no A
present (and optionally including elements other than A); in yet
another embodiment, to at least one, optionally including more than
one, A, and at least one, optionally including more than one, B
(and optionally including other elements); etc.
[0044] In the claims, as well as in the specification above, all
transitional phrases such as "comprising,"' "including,"
"carrying," "having," "containing," "involving," "holding,"
"composed of," and the like are to be understood to be open-ended,
i.e., to mean including but not limited to. Only the transitional
phrases "consisting of" and "consisting essentially of" shall be
dosed or semi-closed transitional phrases, respectively, as set
forth in the United States Patent Office Manual of Patent Examining
Procedures, Section 2111.03.
* * * * *