US20130153170A1 - Precooler/Chiller/Reheater Heat Exchanger System - Google Patents
Precooler/Chiller/Reheater Heat Exchanger System Download PDFInfo
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- US20130153170A1 US20130153170A1 US13/767,179 US201313767179A US2013153170A1 US 20130153170 A1 US20130153170 A1 US 20130153170A1 US 201313767179 A US201313767179 A US 201313767179A US 2013153170 A1 US2013153170 A1 US 2013153170A1
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- Prior art keywords
- heat exchanger
- core
- air
- removal section
- moisture removal
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B29/00—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/26—Drying gases or vapours
- B01D53/265—Drying gases or vapours by refrigeration (condensation)
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
- F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
- F24F3/14—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification
- F24F3/153—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification with subsequent heating, i.e. with the air, given the required humidity in the central station, passing a heating element to achieve the required temperature
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D9/0093—Multi-circuit heat-exchangers, e.g. integrating different heat exchange sections in the same unit or heat-exchangers for more than two fluids
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F17/00—Removing ice or water from heat-exchange apparatus
- F28F17/005—Means for draining condensates from heat exchangers, e.g. from evaporators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
- F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
- F28F3/025—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being corrugated, plate-like elements
- F28F3/027—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being corrugated, plate-like elements with openings, e.g. louvered corrugated fins; Assemblies of corrugated strips
Definitions
- the present invention relates to the art of heat transfer; more particularly, to heat exchangers for use in refrigerated air drying; and most particularly to a precooler/chiller/reheater (“PCR”) system with a demister core.
- PCR precooler/chiller/reheater
- Refrigerated air dryers are known in the art of compressed air.
- warm, moist air such as from the interior of a factory, and which typically is compressed, is cooled and dried and then conveyed to a location where it is used.
- This is known in the prior art to be accomplished by using air- or water-cooled aftercoolers, moisture separators, and air dryers.
- Air dryers are available in many different types, and the present invention is illustrated with a non-cycling direct expansion refrigerated air dryer wherein the refrigerant compressor operates continuously.
- This type of air dryer effectively reduces water content in compressed air by physically chilling the compressed air directly with a refrigeration circuit and thus reducing the capacity of the compressed air to hold water vapor.
- Water vapor in the chilled compressed air condenses as liquid droplets as the temperature of the compressed air is lowered to a desired dew point, typically about 40 degrees Fahrenheit (F).
- the combination of chilled air and water droplets flows through a moisture separator that mechanically removes the droplets from the air stream.
- U.S. Pat. Nos. 5,845,505 and 6,085,529 disclose a system including a mesh pad inserted next to the chiller to capture and coalesce much of the condensed water leaving the chiller. Also, the return manifold is used to reduce the vertical upward velocity of the air flow and allow gravity to separate out any remaining droplets leaving the mesh pad. The manifold must be large enough to accommodate the mesh pad and also to reduce the upward air velocity sufficiently to prevent carryover of water into the reheater. Because the air within the PCR is compressed typically to 100 psig or more, the manifold, being of irregular shape not optimized for burst resistance, must be formed with very thick, heavy walls reinforced by internal bars.
- U.S. Pat. No. 7,121,102 discloses a large moisture separator section disposed between the precooler/reheater core and the chiller core. All dehumidified air passing through the chiller core exits the lower end thereof and then must travel upward the entire length of the separator section.
- the separator section includes a large number of plates having a large surface area for collection of the moisture.
- the system relies on marginally efficient low velocity and gravity settling of droplets in an oversized separator section of the heat exchanger core.
- the oversized section results in many extra passages with heavy fins for structural support that add considerable weight to the system.
- the present invention provides an improved precooler/chiller/reheater system having a precooler/reheater core and a chiller core.
- Warm, moist air enters the precooler/reheater core at a first end and exits through a crossover manifold.
- the crossover manifold conveys the precooled air to a first end of the chiller core.
- precooled air and condensate formed in the precooler enters the chiller core and exits at a second end, which preferably is at or near a low point in the system.
- a refrigerant source provides liquefied refrigerant to the chiller core. Moisture is condensed from the air in the chiller core and flows therefrom by gravity into a drain. Water flow is assisted by the downward passage of the air through the chiller.
- the components include a refrigeration system, a moisture separator, and two air heat exchangers.
- the first of these heat exchangers is a precooler/reheater. It precools warm saturated compressed air from an air compressor aftercooler by transferring heat to chilled air that is being returned from the moisture separator.
- This heat exchanger One benefit of this heat exchanger is that it reduces some of the cooling load that the refrigeration system would otherwise have to handle in subsequent dehumidification of the air. The refrigeration system becomes smaller, requiring less power for thriftier operation.
- Another benefit offered by this first heat exchanger is that it reheats the chilled air coming from the moisture separator, as described below. As noted above, reheating the chilled air reduces the chances that low ambient conditions can cause condensation in the air line downstream of the dryer and also reduces the likelihood of pipeline condensation or “sweating” that can occur on chilled surfaces in humid use conditions downstream of the PCR system.
- the second heat exchanger is an air-to-refrigerant chiller that takes the precooled air from the first heat exchanger and chills it to the desired dewpoint temperature by transferring heat from the air into a cold refrigerant on the other side of the heat exchanger, thereby causing condensation of water from the air. After being thus chilled, the air enters a moisture separator to remove any remaining condensed water, and then the air is returned to the cold side of the first heat exchanger for reheating and exit from the PCR.
- the improved precooler/chiller/reheater system includes a manifold to convey air from the chiller core into a moisture removal section wherein the air passes upward. Entrained water droplets are coalesced and stripped from the airflow and flow downward into the drain.
- the moisture removal section has a demister core extending from the bottom wall to the top wall of the section such that all of the air passes through it before returning to the precooler/reheater core.
- the demister core comprises a plurality of fins configured to create an undulating flow through the demister core in order to separate water from compressed air.
- the demister core forms a structure that can be oriented at an angle inside the moisture removal section in order to provide an enlarged entrance area and an enlarged exit area in the moisture removal section.
- the chilled and dried air passes out of the top of the moisture removal section into a third manifold wherein the air is conveyed to an entrance to the second side of the precooler/reheater core.
- the chilled, dry air passes through the precooler/reheater core, preferably in a downward direction from top to bottom in counterflow to the direction of the warm, moist air entering the system on the first side of the heat exchanger, and exits the system ready for use as tempered, dried air. All fluid flows in the system are parallel to such that fluid flows through the heat exchangers are counter-flow.
- FIG. 1 is a front perspective view of a PCR system of the present invention
- FIG. 2 is is a cross-sectional view of the PCR system of the present invention taken along lines 2 - 2 of FIG. 1 ;
- FIG. 3 is a rear perspective view of the PCR system of FIG. 1 ;
- FIG. 4 is an end perspective view of the PCR taken from the left side of FIG. 1 ;
- FIG. 5 illustrates a demister core of one embodiment of the present invention.
- FIG. 6 is an enlarged sectional view of the demister core taken along the line 6 - 6 of FIG. 5 .
- a PCR system 10 includes a precooler/reheater core 12 disposed adjacent to a chiller core 14 .
- the cores are configured like conventional heat exchangers of alternately connectable plates 16 , 18 and may be formed of aluminum as known to those of ordinary skill in the art. Materials passing through the cores on opposite sides thereof travel in opposite directions, i.e., in counter-flow.
- a moisture separator section 20 with a drain 21 located at the bottom of the section 20 , is disposed adjacent to the chiller core 14 .
- Warm moist air for example, from the discharge of an air compressor aftercooler, enters core 12 of PCR system 10 through an inlet fitting 22 and a manifold 24 in the direction of arrow 23 .
- the input air is obtained from a compressor 25 connected to fitting 22 via a conduit 26 .
- Coolant or refrigerant from a source 28 is supplied to chiller core 14 from conduit 29 via a distributor 30 and a manifold 32 in the direction of arrows 33 ( FIG. 2 ).
- Refrigerant is returned from chiller core 14 via a collector 34 and outlet fitting 36 to the source 28 in the direction of arrows 37 ( FIG. 2 ).
- the system also includes a precooler-to-chiller air manifold 38 (best shown in FIG. 3 ), a moisture separator-reheater manifold 40 , and an air outlet manifold 41 connected to air outlet fitting 44 .
- the chiller core 14 is in communication with the moisture separator section 20 by means of a manifold 47 .
- warm, moist air enters system 10 and is distributed into precooler/reheater heat exchanger 12 via manifold 24 .
- the partially-cooled air is conveyed by manifold 38 to a side entrance 54 in chiller core 14 .
- the air is then turned by another mitered section (not visible) to flow downwards in the direction of arrows 53 through core 14 to an exit 56 into manifold 47 .
- a demister core 150 is provided in moisture removal section 20 to promote surface turbulence and increased surface/air contact within section 20 .
- the term “demister core” herein refers to an apparatus that provides a large surface area to volume ratio that is well suited to provide a contact surface for water droplets to contact and coalesce on.
- An example of the structure of a brazed demister core is disclosed in U.S. Patent Publication No. 2011/0100594 entitled “Water Separator and System,” which is incorporated herein by reference.
- the demister core 150 in this embodiment may be easily and inexpensively manufactured by aluminum bar and plate brazing technology.
- fins are located where no heat transfer is occurring, i.e., there are no heat transfer/alternating coolant passages in the demister core.
- the brazed demister core 150 is placed downstream of the heat exchanging chiller core where it removes droplets from already cooled compressed air. In this aspect, the demister core operates as a separator only.
- the brazed demister core 150 separates moisture by causing the saturated air laden with entrained water particles e.g. 159 A, 159 B, 159 C to move at a reduced horizontal velocity and pass through the offset fins e.g. 154 D, 154 E, 154 F of the stacked aluminum sheets in an undulating and/or uneven path as shown by example direction arrows 156 A, 156 B, 156 C.
- the slower moving condensate impinges on the fins and causes coalescence of the suspended droplets into larger water particles e.g. 158 A, 158 B, 158 C.
- tie bars 90 a - e hold the demister core 150 in place within the moisture removal section 20 .
- the demister core 150 is positioned at an angle 152 inside the moisture removal section 20 .
- the moisture removal section 20 is bordered by sidewalls 200 , 202 and bottom wall 204 .
- the demister core 150 is supported by the bottom wall 204 at a first end 206 .
- a second end 209 of the demister core 150 is disposed in contact with the side wall 202 .
- the demister core 150 divides the moisture separator section 20 into two generally triangular shaped spaces.
- the space 210 is wider at the bottom and narrows toward the top where the demister core 150 contacts sidewall 202 .
- the triangular shaped spaces create an enlarged entrance area 95 near the bottom wall 204 .
- the triangular shaped space 213 creates an enlarged exit area 98 near the outlet 91 of the moisture removal section 20 .
- the angled positioning of the demister core 150 provides many advantages.
- the enlarged entrance area 95 reduces the vertical velocity in the moisture separator section 20 as much as possible to prevent re-entrainment of the coalesced water droplets.
- the droplets that coalesce inside the moisture separator section 20 must be free to fall toward the drain 21 without getting picked up again and carried over the demister core 150 . Carry-over defeats the purpose of the air dryer. Also, the lower velocity created by the enlarged entrance area 95 gives lower pressure drop which is always advantageous in this type of application. Because the demister core 150 is constructed from sheets of rigid material it can easily be arranged at an angle inside the moisture removal section 20 by means of the tie bars 90 a - e. The tie bars 90 a - e also serve as tension members to give the assembly the required mechanical strength for the desired pressure rating.
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Abstract
A system for drying and tempering flowing air that has been compressed to a super atmospheric level prior to treatment by the system. The system includes a precooler and reheater core and a chiller core disposed in adjacent relation for receiving flowing air serially therethrough. A moisture removal section is disposed adjacent to the chiller core for removing entrained moisture from the flowing air. The moisture removal section is defined by sidewalls. The moisture removal section has a demister core disposed therein. The demister core comprises a plurality of fins configured to create an undulating flow through the demister core. The demister core is disposed at an angle with respect to at least one of the sidewalls to create an enlarged entrance area and an enlarged exit area.
Description
- The present application is a continuation-in-part of U.S. patent application Ser. No. 13/001,904 filed on Dec. 29, 2010, which is a 371 of International Application No. PCT/US09/66975 filed on Dec. 7, 2009, which claims priority of U.S. Provisional Patent Application No. 61/176,071 filed on May 6, 2009, which are all incorporated by reference.
- The present invention relates to the art of heat transfer; more particularly, to heat exchangers for use in refrigerated air drying; and most particularly to a precooler/chiller/reheater (“PCR”) system with a demister core.
- Refrigerated air dryers are known in the art of compressed air. In a refrigerated air dryer system, warm, moist air such as from the interior of a factory, and which typically is compressed, is cooled and dried and then conveyed to a location where it is used. In such a compressed air system, it is important to reduce the water content of the compressed air before delivering the compressed air to the points of use to avoid condensation of moisture upon adiabatic decompression. This is known in the prior art to be accomplished by using air- or water-cooled aftercoolers, moisture separators, and air dryers. Air dryers are available in many different types, and the present invention is illustrated with a non-cycling direct expansion refrigerated air dryer wherein the refrigerant compressor operates continuously. This type of air dryer effectively reduces water content in compressed air by physically chilling the compressed air directly with a refrigeration circuit and thus reducing the capacity of the compressed air to hold water vapor. Water vapor in the chilled compressed air condenses as liquid droplets as the temperature of the compressed air is lowered to a desired dew point, typically about 40 degrees Fahrenheit (F). The combination of chilled air and water droplets flows through a moisture separator that mechanically removes the droplets from the air stream.
- Reheating or “tempering” the dried air lowers the relative humidity and prevents formation of condensation at the use point, and also prevents or reduces atmospheric condensation on compressed air piping within the factory, as might occur if the chilled dried air were piped directly without insulation.
- U.S. Pat. Nos. 5,845,505; 6,085,529 and 7,121,102 disclose PCRs, and the disclosures of these patents are hereby incorporated by reference.
- Such prior art PCRs, although functionally effective, have various drawbacks including large manifolds or and/or large moisture separator sections. These features add weight and size to the PCR and manufacturing complexity that add to the cost of manufacture.
- Due to its layout, the prior art PCR design of U.S. Pat. Nos. 5,845,505 and 6,085,529 requires a large and complex return manifold to direct the compressed air flow from the moisture separation section to the reheater section. This manifold is typically constructed from an aluminum casting, the size of which cannot be readily altered to accommodate larger or smaller capacity heat exchangers as may be desired for various end-use applications.
- The prior art PCR systems disclose different means for moisture separation. U.S. Pat. Nos. 5,845,505 and 6,085,529, disclose a system including a mesh pad inserted next to the chiller to capture and coalesce much of the condensed water leaving the chiller. Also, the return manifold is used to reduce the vertical upward velocity of the air flow and allow gravity to separate out any remaining droplets leaving the mesh pad. The manifold must be large enough to accommodate the mesh pad and also to reduce the upward air velocity sufficiently to prevent carryover of water into the reheater. Because the air within the PCR is compressed typically to 100 psig or more, the manifold, being of irregular shape not optimized for burst resistance, must be formed with very thick, heavy walls reinforced by internal bars.
- U.S. Pat. No. 7,121,102 discloses a large moisture separator section disposed between the precooler/reheater core and the chiller core. All dehumidified air passing through the chiller core exits the lower end thereof and then must travel upward the entire length of the separator section. The separator section includes a large number of plates having a large surface area for collection of the moisture. The system relies on marginally efficient low velocity and gravity settling of droplets in an oversized separator section of the heat exchanger core. The oversized section results in many extra passages with heavy fins for structural support that add considerable weight to the system.
- In one aspect, the present invention provides an improved precooler/chiller/reheater system having a precooler/reheater core and a chiller core. Warm, moist air enters the precooler/reheater core at a first end and exits through a crossover manifold. The crossover manifold conveys the precooled air to a first end of the chiller core. In another aspect, precooled air and condensate formed in the precooler enters the chiller core and exits at a second end, which preferably is at or near a low point in the system. A refrigerant source provides liquefied refrigerant to the chiller core. Moisture is condensed from the air in the chiller core and flows therefrom by gravity into a drain. Water flow is assisted by the downward passage of the air through the chiller.
- The components include a refrigeration system, a moisture separator, and two air heat exchangers. The first of these heat exchangers is a precooler/reheater. It precools warm saturated compressed air from an air compressor aftercooler by transferring heat to chilled air that is being returned from the moisture separator. One benefit of this heat exchanger is that it reduces some of the cooling load that the refrigeration system would otherwise have to handle in subsequent dehumidification of the air. The refrigeration system becomes smaller, requiring less power for thriftier operation. Another benefit offered by this first heat exchanger is that it reheats the chilled air coming from the moisture separator, as described below. As noted above, reheating the chilled air reduces the chances that low ambient conditions can cause condensation in the air line downstream of the dryer and also reduces the likelihood of pipeline condensation or “sweating” that can occur on chilled surfaces in humid use conditions downstream of the PCR system.
- The second heat exchanger is an air-to-refrigerant chiller that takes the precooled air from the first heat exchanger and chills it to the desired dewpoint temperature by transferring heat from the air into a cold refrigerant on the other side of the heat exchanger, thereby causing condensation of water from the air. After being thus chilled, the air enters a moisture separator to remove any remaining condensed water, and then the air is returned to the cold side of the first heat exchanger for reheating and exit from the PCR.
- In another aspect, the improved precooler/chiller/reheater system includes a manifold to convey air from the chiller core into a moisture removal section wherein the air passes upward. Entrained water droplets are coalesced and stripped from the airflow and flow downward into the drain. The moisture removal section has a demister core extending from the bottom wall to the top wall of the section such that all of the air passes through it before returning to the precooler/reheater core. In one aspect, the demister core comprises a plurality of fins configured to create an undulating flow through the demister core in order to separate water from compressed air. In yet another aspect, the demister core forms a structure that can be oriented at an angle inside the moisture removal section in order to provide an enlarged entrance area and an enlarged exit area in the moisture removal section.
- In another aspect of the improved precooler/chiller/reheater system, the chilled and dried air passes out of the top of the moisture removal section into a third manifold wherein the air is conveyed to an entrance to the second side of the precooler/reheater core. The chilled, dry air passes through the precooler/reheater core, preferably in a downward direction from top to bottom in counterflow to the direction of the warm, moist air entering the system on the first side of the heat exchanger, and exits the system ready for use as tempered, dried air. All fluid flows in the system are parallel to such that fluid flows through the heat exchangers are counter-flow.
- The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
-
FIG. 1 is a front perspective view of a PCR system of the present invention; -
FIG. 2 is is a cross-sectional view of the PCR system of the present invention taken along lines 2-2 ofFIG. 1 ; -
FIG. 3 is a rear perspective view of the PCR system ofFIG. 1 ; -
FIG. 4 is an end perspective view of the PCR taken from the left side ofFIG. 1 ; -
FIG. 5 illustrates a demister core of one embodiment of the present invention; and, -
FIG. 6 is an enlarged sectional view of the demister core taken along the line 6-6 ofFIG. 5 . - Referring to
FIGS. 1-4 , aPCR system 10 includes a precooler/reheater core 12 disposed adjacent to achiller core 14. The cores are configured like conventional heat exchangers of alternatelyconnectable plates moisture separator section 20, with adrain 21 located at the bottom of thesection 20, is disposed adjacent to thechiller core 14. Warm moist air, for example, from the discharge of an air compressor aftercooler, enterscore 12 ofPCR system 10 through an inlet fitting 22 and a manifold 24 in the direction ofarrow 23. Typically the input air is obtained from acompressor 25 connected to fitting 22 via aconduit 26. Coolant or refrigerant from asource 28 is supplied tochiller core 14 fromconduit 29 via adistributor 30 and a manifold 32 in the direction of arrows 33 (FIG. 2 ). Refrigerant is returned fromchiller core 14 via acollector 34 and outlet fitting 36 to thesource 28 in the direction of arrows 37 (FIG. 2 ). The system also includes a precooler-to-chiller air manifold 38 (best shown inFIG. 3 ), a moisture separator-reheater manifold 40, and anair outlet manifold 41 connected to air outlet fitting 44. Thechiller core 14 is in communication with themoisture separator section 20 by means of a manifold 47. - Referring to
FIG. 2 , in operation warm, moist air enterssystem 10 and is distributed into precooler/reheater heat exchanger 12 viamanifold 24. Air flows upward throughcore 12 in the direction ofarrows 23 and is turned via a mitered section (not visible) in anupper portion 13 ofcore 12 such that air flow is directed sideways fromcore 12 through acore exit 52 intomanifold 38. The partially-cooled air is conveyed bymanifold 38 to aside entrance 54 inchiller core 14. The air is then turned by another mitered section (not visible) to flow downwards in the direction ofarrows 53 throughcore 14 to anexit 56 intomanifold 47. - A vapor/liquid mixture of refrigerant is supplied from a source 28 (
FIG. 1 ) intodistributor 30 at the lower end ofcore 14. The flow rate and thermal load are adjusted to provide a dew point of about 40 degrees Fahrenheit (F) in the driedair exiting core 14. Air flowing downward in the direction ofarrows 53 incore 14 is cooled by heat exchange throughplates 18. The cool vapor/liquid mixture flows upwards in the direction ofarrows core 14 in counterflow to air flowing downward in the direction ofarrows 53 through thechiller core 14. - Dried air is then directed upwards in the direction of
arrow 57 from the bottom ofchiller core 14 through moisture-removal section 20 wherein any residual moisture droplets are coalesced and returned by gravity to drain 21. Ademister core 150 is provided inmoisture removal section 20 to promote surface turbulence and increased surface/air contact withinsection 20. The term “demister core” herein refers to an apparatus that provides a large surface area to volume ratio that is well suited to provide a contact surface for water droplets to contact and coalesce on. An example of the structure of a brazed demister core is disclosed in U.S. Patent Publication No. 2011/0100594 entitled “Water Separator and System,” which is incorporated herein by reference. Thedemister core 150 shown in the embodiment ofFIG. 5 is made of individual sheets e.g., 152A, 152B, 152C of stamped aluminum, forming aluminum fins e.g., 154A, 154B, 154C. Then when properly oriented, the individual sheets are brazed intointegral demister core 150 using the same production methods as those used for brazed aluminum bar and plate heat exchangers, such as air cooled oil coolers and compressed air aftercoolers, and other methods known to those of ordinary skill in the art. Thedemister core 150 in this embodiment may be easily and inexpensively manufactured by aluminum bar and plate brazing technology. In this embodiment, fins are located where no heat transfer is occurring, i.e., there are no heat transfer/alternating coolant passages in the demister core. The brazeddemister core 150 is placed downstream of the heat exchanging chiller core where it removes droplets from already cooled compressed air. In this aspect, the demister core operates as a separator only. - As shown in
FIG. 6 , and with reference toFIG. 5 , the brazeddemister core 150 separates moisture by causing the saturated air laden with entrained water particles e.g. 159A, 159B, 159C to move at a reduced horizontal velocity and pass through the offset fins e.g. 154D, 154E, 154F of the stacked aluminum sheets in an undulating and/or uneven path as shown byexample direction arrows - Returning to
FIG. 2 , tie bars 90 a-e hold thedemister core 150 in place within themoisture removal section 20. Thedemister core 150 is positioned at anangle 152 inside themoisture removal section 20. Themoisture removal section 20 is bordered by sidewalls 200, 202 andbottom wall 204. Thedemister core 150 is supported by thebottom wall 204 at afirst end 206. Asecond end 209 of thedemister core 150 is disposed in contact with theside wall 202. With respect to the orientation ofFIG. 2 , thedemister core 150 divides themoisture separator section 20 into two generally triangular shaped spaces. On the right side of thedemister core 150, thespace 210 is wider at the bottom and narrows toward the top where thedemister core 150 contacts sidewall 202. The triangular shaped spaces create anenlarged entrance area 95 near thebottom wall 204. On the opposite or left hand side of thedemister core 150, the triangular shapedspace 213 creates anenlarged exit area 98 near the outlet 91 of themoisture removal section 20. The angled positioning of thedemister core 150 provides many advantages. Theenlarged entrance area 95 reduces the vertical velocity in themoisture separator section 20 as much as possible to prevent re-entrainment of the coalesced water droplets. The droplets that coalesce inside themoisture separator section 20 must be free to fall toward thedrain 21 without getting picked up again and carried over thedemister core 150. Carry-over defeats the purpose of the air dryer. Also, the lower velocity created by theenlarged entrance area 95 gives lower pressure drop which is always advantageous in this type of application. Because thedemister core 150 is constructed from sheets of rigid material it can easily be arranged at an angle inside themoisture removal section 20 by means of the tie bars 90 a-e. The tie bars 90 a-e also serve as tension members to give the assembly the required mechanical strength for the desired pressure rating. The tie bars 90 a-e span the entire width of the of theseparator section 20 and protrude out from each side where they may be welded to the outer wall of themoisture separation section 20. Chilled, driedair exits section 20 through outlet 91 in the direction ofarrows 93 intomanifold 40 wherein it is conveyed tocore 12. - Air passes downward in the direction of
arrows 103 incore 12 in counterflow to the moist incoming warm air and is warmed by heat exchange therewith through the walls ofplates 16. Warmed, dried air is collected bymanifold 41 and is discharged fromsystem 10 throughoutlet 44 for use. The system may also be provided with asensor port 99. - While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
Claims (19)
1. A system for drying and tempering flowing air, comprising:
a housing;
a precooler and reheater core and a chiller core disposed in adjacent relation in the housing for receiving the flowing air serially therethrough;
a moisture removal section disposed in the housing adjacent to the chiller core for removing entrained moisture from the flowing air, the moisture removal section defined by sidewalls, the moisture removal section having a demister core disposed therein, the demister core comprising a plurality of fins configured to create an undulating flow through the demister core; and,
means for providing refrigerant to a second side of the chiller core.
2. The system of claim 1 , wherein the demister core is disposed at an angle with respect to at least one of the sidewalls to form an enlarged entrance area in the moisture removal section.
3. The system of claim 1 , wherein the demister core is angled to create a generally triangular shaped space in the moisture removal section.
4. The system of claim 1 , further comprising a first crossover manifold for conveying air from the precooler and reheater core to a first side of the chiller core.
5. The system of claim 4 , wherein the first crossover manifold is disposed in an upper portion of the precooler and reheater core.
6. The system of claim 1 , further comprising a second crossover manifold for conveying air from said moisture removal section to a second side of the precooler and reheater core.
7. The system of claim 6 , wherein the second crossover manifold is disposed inside the housing across the top of the moisture removal section, chiller core, and precooler and reheater core.
8. The system of claim 1 , further comprising an inlet manifold for conveying warm, moist air to the first side of the precooler and reheater core.
9. The system of claim 1 , further comprising an outlet manifold for conveying dried reheated air from the second side of the precooler and reheater core.
10. The system of claim 1 , wherein the demister core is formed from a plurality of stamped sheets arranged to form a matrix of offset rectangular fins.
11. A system for drying and tempering flowing air, comprising:
a first heat exchanger for precooling and subsequently reheating the flowing air;
a second heat exchanger for chilling the flowing air below the incoming dew point thereof to remove moisture therefrom, the second heat exchanger disposed adjacent to the first heat exchanger such that the flowing air passes serially therethrough;
a moisture removal section having an inlet and an outlet, the moisture removal section disposed adjacent to the second heat exchanger for removing entrained moisture from the air after it exits the second heat exchanger, the moisture removal section defined by sidewalls, the moisture removal section having a demister core disposed therein, the demister core disposed at an angle relative to at least one of the sidewalls to define an enlarged entrance area adjacent to the inlet and an enlarged exit area disposed adjacent to the outlet;
means for providing refrigerant to the second heat exchanger including a distributor in fluid communication with the second heat exchanger for providing refrigerant to a second side of the second heat exchanger and a collector in fluid communication with the second heat exchanger for collecting spent refrigerant from the second side of the second heat exchanger;
wherein said flowing air is compressed to a super atmospheric pressure prior to treatment by the system.
12. The system of claim 11 , further comprising refrigerating means for receiving the spent refrigerant, recompressing the refrigerant, and providing compressed refrigerant to the distributor.
13. The system of claim 11 , further comprising a first crossover manifold for conveying air from the first heat exchanger to a first side of the second heat exchanger.
14. The system of claim 13 , wherein the first crossover manifold is disposed in an upper portion of the first heat exchanger.
15. The system of claim 14 , further comprising a second crossover manifold for conveying air from said moisture removal section to a second side of the first heat exchanger.
16. The system of claim 15 , wherein the second crossover manifold is disposed across the top of the moisture removal section, the second heat exchanger, and the first heat exchanger.
17. The system of claim 11 , further comprising an inlet manifold for conveying warm, moist air to the first side of the first heat exchanger.
18. The system of claim 11 , further comprising an outlet manifold for conveying dried reheated air from the second side of the first heat exchanger.
19. A system for drying and tempering flowing air, comprising:
a first heat exchanger for precooling and subsequently reheating the flowing air;
a second heat exchanger for chilling the flowing air below the incoming dew point thereof to remove moisture therefrom, the second heat exchanger disposed adjacent to the first heat exchanger such that flowing air passes serially therethrough;
a moisture removal section having an inlet and an outlet, the moisture removal section disposed adjacent to the second heat exchanger for removing entrained moisture from the air after it exits the second heat exchanger, the moisture removal section defined by sidewalls, the moisture removal section having a demister core disposed therein, the demister core disposed at an angle relative to at least one of the sidewalls to define an enlarged entrance area adjacent to the inlet and an enlarged exit area disposed adjacent to the outlet;
means for providing refrigerant to a second side of the second heat exchanger;
a first crossover manifold for conveying air from the first heat exchanger to a first side of the second heat exchanger;
a second crossover manifold for conveying air from said moisture removal section to a second side of the first heat exchanger;
an inlet manifold for conveying warm, moist air to the first side of the first heat exchanger;
an outlet manifold for conveying dried reheated air from the second side of the first heat exchanger
wherein said flowing air is compressed to a super atmospheric pressure prior to treatment by the system.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/767,179 US20130153170A1 (en) | 2009-05-06 | 2013-02-14 | Precooler/Chiller/Reheater Heat Exchanger System |
PCT/US2013/033515 WO2014126598A1 (en) | 2013-02-14 | 2013-03-22 | Precooler/chiller/reheater heat exchanger system |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US17607109P | 2009-05-06 | 2009-05-06 | |
PCT/US2009/066975 WO2010128993A1 (en) | 2009-05-06 | 2009-12-07 | Water separator and system |
US201013001904A | 2010-12-29 | 2010-12-29 | |
US13/767,179 US20130153170A1 (en) | 2009-05-06 | 2013-02-14 | Precooler/Chiller/Reheater Heat Exchanger System |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2009/066975 Continuation-In-Part WO2010128993A1 (en) | 2009-05-06 | 2009-12-07 | Water separator and system |
US201013001904A Continuation-In-Part | 2009-05-06 | 2010-12-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130153170A1 true US20130153170A1 (en) | 2013-06-20 |
Family
ID=48608924
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/767,179 Abandoned US20130153170A1 (en) | 2009-05-06 | 2013-02-14 | Precooler/Chiller/Reheater Heat Exchanger System |
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US (1) | US20130153170A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160377350A1 (en) * | 2015-06-29 | 2016-12-29 | Honeywell International Inc. | Optimized plate fin heat exchanger for improved compliance to improve thermal life |
US20220233999A1 (en) * | 2021-01-27 | 2022-07-28 | Akg Verwaltungsgesellschaft Mbh | Device for cooling and drying air |
US11426694B2 (en) * | 2017-10-23 | 2022-08-30 | Ceccato Aria Compressa S.R.L. | Perfected heat exchanger and air drying system using the aforesaid heat exchanger |
US11579094B2 (en) | 2015-11-12 | 2023-02-14 | Carrier Corporation | Moisture sensing system for heating, ventilation and air conditioning systems |
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US4098328A (en) * | 1977-06-16 | 1978-07-04 | Borg-Warner Corporation | Cross-flow radiator deaeration system |
US5845505A (en) * | 1997-05-30 | 1998-12-08 | American Precision Industries Inc. | Precooler/chiller/reheater heat exchanger for air dryers |
US20050284157A1 (en) * | 2004-06-29 | 2005-12-29 | Fijas David F | Precooler/chiller/reheater heat exchanger system for providing warm dried air |
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2013
- 2013-02-14 US US13/767,179 patent/US20130153170A1/en not_active Abandoned
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US4098328A (en) * | 1977-06-16 | 1978-07-04 | Borg-Warner Corporation | Cross-flow radiator deaeration system |
US5845505A (en) * | 1997-05-30 | 1998-12-08 | American Precision Industries Inc. | Precooler/chiller/reheater heat exchanger for air dryers |
US20050284157A1 (en) * | 2004-06-29 | 2005-12-29 | Fijas David F | Precooler/chiller/reheater heat exchanger system for providing warm dried air |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160377350A1 (en) * | 2015-06-29 | 2016-12-29 | Honeywell International Inc. | Optimized plate fin heat exchanger for improved compliance to improve thermal life |
US11579094B2 (en) | 2015-11-12 | 2023-02-14 | Carrier Corporation | Moisture sensing system for heating, ventilation and air conditioning systems |
US11426694B2 (en) * | 2017-10-23 | 2022-08-30 | Ceccato Aria Compressa S.R.L. | Perfected heat exchanger and air drying system using the aforesaid heat exchanger |
US20220233999A1 (en) * | 2021-01-27 | 2022-07-28 | Akg Verwaltungsgesellschaft Mbh | Device for cooling and drying air |
EP4036510A1 (en) * | 2021-01-27 | 2022-08-03 | AKG Verwaltungsgesellschaft mbH | Device for cooling and drying air |
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Owner name: GENERAL ELECTRIC CAPITAL CORPORATION, ILLINOIS Free format text: SECURITY INTEREST;ASSIGNOR:API HEAT TRANSFER INC.;REEL/FRAME:032911/0249 Effective date: 20140507 |
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STCB | Information on status: application discontinuation |
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