US3665723A - Apparatus for defrosting evaporator of a refrigeration unit - Google Patents
Apparatus for defrosting evaporator of a refrigeration unit Download PDFInfo
- Publication number
- US3665723A US3665723A US31249A US3665723DA US3665723A US 3665723 A US3665723 A US 3665723A US 31249 A US31249 A US 31249A US 3665723D A US3665723D A US 3665723DA US 3665723 A US3665723 A US 3665723A
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- Prior art keywords
- refrigerant
- heat exchanger
- compressor
- condenser
- conduit
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Links
- 238000005057 refrigeration Methods 0.000 title claims abstract description 18
- 238000010257 thawing Methods 0.000 title abstract description 7
- 239000003507 refrigerant Substances 0.000 claims abstract description 53
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- 238000001704 evaporation Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 abstract description 28
- 238000000034 method Methods 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 19
- 239000000498 cooling water Substances 0.000 description 5
- 230000008016 vaporization Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 240000007049 Juglans regia Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000007792 gaseous phase Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
Images
Classifications
-
- 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
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
- F25B47/022—Defrosting cycles hot gas defrosting
Definitions
- the present invention relates to an apparatus for defrosting the evaporator coils of a conventional refrigeration unit. More particularly, the invention relates to an apparatus for applying heat to the evaporator coils of a conventional refrigeration unit to melt and vaporize frost which is formed on the evaporator coils.
- frost i.e., condensed and frozen moisture vapor
- the frost accumulated on the evaporator coils of conventional refrigeration units has been removed either by hand or by applying electrical heat to the evaporator coils for melting and vaporizing the frost.
- the refrigeration operation is stopped (e.g. the compressor at least) and electrical heat is applied to the evaporator coils by means of resistance or like heaters.
- resistant heaters can be used to heat an airstream which is in turn blown across the evaporator coils. The net effect of any of these systems, however, is the disruption of the operation of the compressor of the refrigeration unit.
- lt is an object of the present invention to eliminate the difficulties and disadvantages noted above in connection with the use of electrical heat for removing frost from evaporator coils and to provide a process and apparatus to accomplish the same.
- the invention has as its basis, the discovery of a means of vusing the compressor of a conventional refrigeration apstated, the present invention resides in the use of compressed refrigerant gas, which has been heated during compression, for supplying heat to the evaporator coils for defrosting the evaporator coils.
- the heated, compressed gas is passed through the evaporator coils in a direction opposite to that which the gas is passed through the evaporator coils during a cooling cycle.
- FIGURE shows in diagrammatic illustration a conventional refrigeration apparatus which has been modified according to the present invention.
- a cooling unit 1 containing a conventional evaporator coil 1a which would correspond to, for example, a conventional freezer having an evaporator coil in an operable relation thereto.
- a conventional electrically driven compressor 2 operates to compress a refrigerant gas (any conventional refrigerant gas, such as the Freons, may be used) and the compressor is in communication with the evaporator coil la via compressor discharge conduits 2a, 2b and 20.
- condenser 3 Between compressor conduits 2a and 2b is disposed condenser 3 for cooling and condensing the refrigerant gas compressed by compressor 2. In other words, this is a conventional condenser coil.
- the condenser 3 may, optionally, be cooled by blowing air over the heat exchanger surfaces by means of a fan or like device, but preferably the condenser is cooled by a flow of water, in a conventional manner, as noted in the drawing.
- the compressor, condenser and evaporator coil are operated in a conventional manner whereby refrigerant gas is compressed in compressor 2, condensed to a liquid in condenser 3, passed through an expansion valve 4, of conventional design, and allowed to evaporate in the evaporator coil 1a of cooling unit 1 to cool the cooling unit.
- the evaporated refrigerant is returned to the compressor via return conduits lb and 1c to compressor 2.
- the hot, compressed refrigerant gas passes through conduit lb, as shown by the dashed arrows, and into cooling unit 1 and evaporator coil 1a. Since the evaporator coil is cold, due to the condensed and frozen moisture thereon, the evaporator coil will cool the hot refrigerant gas and at least partially condense the same. However, this exchange of heat causes the frost on the evaporator coil to melt and vaporize.
- the at least partially condensed refrigerant passes through evaporator coil 1a and to valve V3, as shown by the dashed arrow at conduit 2c. After the refrigerant passes through valve V3, it is expanded through expansion valve 7 and is allowed to vaporize as it passes through conduit 8 located in heat exchanger 5.
- the vaporized refrigerant passes into cooling coils 6 via conduit 6a, as shown by the dashed arrow.
- the refrigerant is substantially completely vaporized while passing through cooling coil 6 and then passes, as shown by the dashed and solid arrows, via conduit 1c, back to the intake (low-pressure side) of compressor 2.
- the gas is then compressed (and heated during compression) in the manner described above and recirculated through evaporator coil 1a to further melt and/or evaporate frost condensed on that coil.
- Valves V1, V2 and V3 may be manually operated, if desired, or those valves may be automatically operated on a timed sequence or they may be actuated via a frost-sensing device on evaporator coil In, such devices being conventional and known in the art.
- the apparatus described can be changed from a cooling mode in the cooling unit to a defrosting mode in the cooling unit simply by changing the flow position of three valves and without any disruption of the compressor operation.
- cooling water may be used in the cooling condenser 3, and as noted in the figure, that cooling water may also circulate through heat exchanger 5 before being ultimately discharged.
- condenser 3 and heat exchanger 5 may have separate cooling water sources, or instead of water, cooling unit 1 and/or heat exchanger 5 may use a coolant other than water.
- cooling coils 6 are disposed in heat exchanger and, optionally, the cooling water from condenser 3 may be circulated over the exterior surfaces thereof.
- the refrigerant which passes through valve V2 in the normal cooling operation will be thoroughly vaporized and can be fed to compressor 2 without the normal holding tanks and like devices for separating liquid and gas, as is normally required in conventional refrigeration apparatus.
- the apparatus of the invention utilizes conventional components and the invention resides in the combination of these conventional components and the manner of use thereof.
- any conventional materials and designs of the individual components are acceptable to the present invention so long as the materials and designs function in the manner described.
- conventional steel, aluminum or copper conduits may be used in the evaporator and cooling coils, as well as for transporting the refrigerant.
- the coils may be finned coils, if desired.
- the above describes an apparatus for defrosting the evaporator coil of a refrigeration unit by disrupting the flow of compressed refrigerant gas from the high-pressure side of a compressor to the evaporator coil, passing hot, compressed refrigerant gas through the evaporator coil, preferably in an opposite direction to that direction used during the cooling cycle, causing heat exchange from the hot compressed refrigerant gas to the frost on the evaporator coil, thereby melting and vaporizing frost, removing the cooled and at least partially condensed refrigerant from the evaporator coil, passing the cooled refrigerant through an expansion valve, expanding the refrigerant in a heat exchanger and thereby vaporizing the refrigerant, compressing the vaporized refrigerant, and returning the hot, compressed refrigerant gas to the evaporator coil in the cyclic mannervof the foregoing steps to melt and evaporate the frost on the evaporator coil.
- a refrigeration unit comprising a compressor, condenser, expansion valve and evaporator coil, each of which is operably connected in the named conventional order by conduit means for flowing a refrigerant therethrough in a conventional path, the improvement comprising:
- conduit means connecting the discharge side of the compressor with the evaporator coil for passing compressed and heated refrigerant gas through the evaporator coil, whereby the refrigerant gas is cooled and at least partially condensed and frost on the evaporator coil is melted;
- conduit means connecting the evaporator coil with a second expansion valve for transporting the cooled and at least partially condensed refrigerant to the second expansion valve;
- heat exchanger means connected by a conduit to said expansion valve, for evaporating the expanded, cooled and partially condensed refrigerant, whereby the refrigerant becomes substantially completely gaseous;
- conduit means connecting the heat exchanger means with the compressor for returning the gaseous refrigerant to the intake side of the compressor
- valve means for disrupting the said conventional path of refrigerant and providing the path of refrigerant defined by elements 1) through 4);
- conduit means connecting the condenser and heat exchanger means for passing the water from the condenser to the heat exchanger; and means for circulating the water about the heat exchanger means.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Defrosting Systems (AREA)
Abstract
An apparatus is provided for defrosting the evaporator coils of a conventional refrigeration unit by passing hot compressed refrigerant gas to the evaporator coil prior to any cooling, condensing or expansion of the refrigerant gas. Thereafter the refrigerant gas is condensed, expanded and recompressed for recycle for the process and apparatus.
Description
United States Patent Okutus 51 May 30, 1972 [s41 APPARATUS FOR DEFROSTBQG 2,694,904 1111954 Lange .s2/27s EVAPORATOR OF A REFRIGERATION 2,916,893 12/1959 Kramer... .....62/278 I 3,195,321 7/1965 Decker ..62/278 [72] Inventor: Teruhiko Okutus, l, 18 Higashi Maitocho, Minami-ku, Yokohama, Japan [22] Filed: Apr. 23, 1970 [21] Appl.No.: 31,249
521 u.s.c1. ..62/196, 62/278 [51] lnt.Cl. ..F25b4l/00 [581 Field 01 Search ..62/ 196, 278
[56] References Cited UNITED STATES PATENTS 2,530,440 11/1950 Nussbaum ..62/278 UNIT W19 Til? aarz. Er 1' 7 Primary Examiner-Meyer Perlin Attorney-Cushman, Darby & Cushman [57] ABSTRACT 1 Claim, 1 DrawingFigure Za I W475! ON 7457' M69753 l/YLET a Patented May 30, 1972 I I 3,665,723
W075? OUTLET 11/ 97517 l/YLET Con/054 55 INVENTOR /QQM APPARATUS FOR DEFROSTING EVAPORATOR OF A REFRIGERATION UNIT The present invention relates to an apparatus for defrosting the evaporator coils of a conventional refrigeration unit. More particularly, the invention relates to an apparatus for applying heat to the evaporator coils of a conventional refrigeration unit to melt and vaporize frost which is formed on the evaporator coils.
As is well known in the art, the evaporator coils of a refrigeration unit will accumulate frost, i.e., condensed and frozen moisture vapor, after a period of operating time and when the evaporator coils are operated at a temperature below the freezing point of water. These conditions are encountered in both domestic and industrial refrigerators which are used for storing various materials, e.g., food, chemicals etc.
l-leretofore, the frost accumulated on the evaporator coils of conventional refrigeration units has been removed either by hand or by applying electrical heat to the evaporator coils for melting and vaporizing the frost. Conventionally, when it is necessary to remove frost from the evaporator coils, the refrigeration operation is stopped (e.g. the compressor at least) and electrical heat is applied to the evaporator coils by means of resistance or like heaters. Optionally, resistant heaters can be used to heat an airstream which is in turn blown across the evaporator coils. The net effect of any of these systems, however, is the disruption of the operation of the compressor of the refrigeration unit.
For many cases, it is desirable not to disrupt the compressor operation but to keep the compressor in substantially continuous operation. In these cases, it would be desirable if the evaporator coils of a conventional refrigeration apparatus could be cleared of frost without disrupting the compressor operation. While the compressor operation could be continued even during an electrical heating of the evaporator coils to remove the frost, the compressor would, in eifect, be bucking the heat applied to the evaporator coils and would result in a grossly inefficient operation.
lt is an object of the present invention to eliminate the difficulties and disadvantages noted above in connection with the use of electrical heat for removing frost from evaporator coils and to provide a process and apparatus to accomplish the same.
The invention has as its basis, the discovery of a means of vusing the compressor of a conventional refrigeration apstated, the present invention resides in the use of compressed refrigerant gas, which has been heated during compression, for supplying heat to the evaporator coils for defrosting the evaporator coils. Preferably, the heated, compressed gas is passed through the evaporator coils in a direction opposite to that which the gas is passed through the evaporator coils during a cooling cycle.
For a full description of the invention and a detailed embodiment thereof, attention is now directed to the drawing where the FIGURE shows in diagrammatic illustration a conventional refrigeration apparatus which has been modified according to the present invention.
In the FIGURE, there is shown a cooling unit 1 containing a conventional evaporator coil 1a which would correspond to, for example, a conventional freezer having an evaporator coil in an operable relation thereto. A conventional electrically driven compressor 2 operates to compress a refrigerant gas (any conventional refrigerant gas, such as the Freons, may be used) and the compressor is in communication with the evaporator coil la via compressor discharge conduits 2a, 2b and 20. Between compressor conduits 2a and 2b is disposed condenser 3 for cooling and condensing the refrigerant gas compressed by compressor 2. In other words, this is a conventional condenser coil. The condenser 3 may, optionally, be cooled by blowing air over the heat exchanger surfaces by means of a fan or like device, but preferably the condenser is cooled by a flow of water, in a conventional manner, as noted in the drawing. The compressor, condenser and evaporator coil are operated in a conventional manner whereby refrigerant gas is compressed in compressor 2, condensed to a liquid in condenser 3, passed through an expansion valve 4, of conventional design, and allowed to evaporate in the evaporator coil 1a of cooling unit 1 to cool the cooling unit. The evaporated refrigerant is returned to the compressor via return conduits lb and 1c to compressor 2. In order to ensure that all of the refrigerant entering compressor 2 is in the gaseous phase, it may pass through a heat exchanger 5. The evaporated refrigerant is therefore recompressed in compressor 2 and the operation is continued in a conventional manner to produce cooling in cooling unit 1. All of the above simply il lustrates a conventional refrigeration unit and no further detail or discussion thereof is required.
After cooling of the cooling unit 1 is carried out for a sufficient length of time that frost has been formed on the evaporator coil In of cooling unit 1, the frost is removed by performing the following operation. Valve V2, which is open during the cooling operation and is disposed in the return conduit, is closed, and valves V1 and V3, which are closed during the cooling operation, are opened. With these valve position arrangements, the compressed high-pressure gas leaving compressor 2 flows through valve Vl, as shown by the dashed arrow, instead of going through condenser 3, as shown by the solid-line arrow. The gas does not go through condenser 3 as a result of the back pressure exerted by expansion valve 4 on the refrigerant in the conduit leaving condenser 3. The hot, compressed refrigerant gas passes through conduit lb, as shown by the dashed arrows, and into cooling unit 1 and evaporator coil 1a. Since the evaporator coil is cold, due to the condensed and frozen moisture thereon, the evaporator coil will cool the hot refrigerant gas and at least partially condense the same. However, this exchange of heat causes the frost on the evaporator coil to melt and vaporize. The at least partially condensed refrigerant passes through evaporator coil 1a and to valve V3, as shown by the dashed arrow at conduit 2c. After the refrigerant passes through valve V3, it is expanded through expansion valve 7 and is allowed to vaporize as it passes through conduit 8 located in heat exchanger 5. After vaporization in conduit 8, the vaporized refrigerant passes into cooling coils 6 via conduit 6a, as shown by the dashed arrow. The refrigerant is substantially completely vaporized while passing through cooling coil 6 and then passes, as shown by the dashed and solid arrows, via conduit 1c, back to the intake (low-pressure side) of compressor 2. The gas is then compressed (and heated during compression) in the manner described above and recirculated through evaporator coil 1a to further melt and/or evaporate frost condensed on that coil.
After all of the frost has been melted and/or evaporated or otherwise removed from the cooling unit 1, as by draining away the melted moisture, the cooling operation in cooling unit 1 is again commenced simply by closing valves V1 and V3, while opening valve V2. Valves V1, V2 and V3 may be manually operated, if desired, or those valves may be automatically operated on a timed sequence or they may be actuated via a frost-sensing device on evaporator coil In, such devices being conventional and known in the art.
As can be seen from the above, the apparatus described can be changed from a cooling mode in the cooling unit to a defrosting mode in the cooling unit simply by changing the flow position of three valves and without any disruption of the compressor operation.
As noted above, cooling water may be used in the cooling condenser 3, and as noted in the figure, that cooling water may also circulate through heat exchanger 5 before being ultimately discharged. However, as is quite apparent, no cooling water may be used, condenser 3 and heat exchanger 5 may have separate cooling water sources, or instead of water, cooling unit 1 and/or heat exchanger 5 may use a coolant other than water.
As discussed above, cooling coils 6 are disposed in heat exchanger and, optionally, the cooling water from condenser 3 may be circulated over the exterior surfaces thereof. One result of this arrangement is that the refrigerant which passes through valve V2 in the normal cooling operation will be thoroughly vaporized and can be fed to compressor 2 without the normal holding tanks and like devices for separating liquid and gas, as is normally required in conventional refrigeration apparatus.
As is quite apparent from the above description, the apparatus of the invention utilizes conventional components and the invention resides in the combination of these conventional components and the manner of use thereof. Hence, any conventional materials and designs of the individual components are acceptable to the present invention so long as the materials and designs function in the manner described. For example, conventional steel, aluminum or copper conduits may be used in the evaporator and cooling coils, as well as for transporting the refrigerant. Optionally, the coils may be finned coils, if desired.
Hence, the above describes an apparatus for defrosting the evaporator coil of a refrigeration unit by disrupting the flow of compressed refrigerant gas from the high-pressure side of a compressor to the evaporator coil, passing hot, compressed refrigerant gas through the evaporator coil, preferably in an opposite direction to that direction used during the cooling cycle, causing heat exchange from the hot compressed refrigerant gas to the frost on the evaporator coil, thereby melting and vaporizing frost, removing the cooled and at least partially condensed refrigerant from the evaporator coil, passing the cooled refrigerant through an expansion valve, expanding the refrigerant in a heat exchanger and thereby vaporizing the refrigerant, compressing the vaporized refrigerant, and returning the hot, compressed refrigerant gas to the evaporator coil in the cyclic mannervof the foregoing steps to melt and evaporate the frost on the evaporator coil.
While the principles of the invention were hereinbefore described with reference to the drawing and preferred embodiment, the specific illustrations of the invention are intended to only exemplify, rather than limit, the invention, and the invention is applicable to the extent described above, and as defined in the claims.
What is claimed is:
1. In a refrigeration unit comprising a compressor, condenser, expansion valve and evaporator coil, each of which is operably connected in the named conventional order by conduit means for flowing a refrigerant therethrough in a conventional path, the improvement comprising:
1. conduit means connecting the discharge side of the compressor with the evaporator coil for passing compressed and heated refrigerant gas through the evaporator coil, whereby the refrigerant gas is cooled and at least partially condensed and frost on the evaporator coil is melted;
2. conduit means connecting the evaporator coil with a second expansion valve for transporting the cooled and at least partially condensed refrigerant to the second expansion valve;
3. heat exchanger means, connected by a conduit to said expansion valve, for evaporating the expanded, cooled and partially condensed refrigerant, whereby the refrigerant becomes substantially completely gaseous;
4. conduit means connecting the heat exchanger means with the compressor for returning the gaseous refrigerant to the intake side of the compressor;
5. valve means for disrupting the said conventional path of refrigerant and providing the path of refrigerant defined by elements 1) through 4);
6. means for circulating water about the condenser;
7. conduit means connecting the condenser and heat exchanger means for passing the water from the condenser to the heat exchanger; and means for circulating the water about the heat exchanger means.
Claims (7)
1. In a refrigeration unit comprising a compressor, condenser, expansion valve and evaporator coil, each of which is operably connected in the named conventional order by conduit means for flowing a refrigerant therethrough in a conventional path, the improvement comprising: 1. conduit means connecting the discharge side of the compressor with the evaporator coil for passing compRessed and heated refrigerant gas through the evaporator coil, whereby the refrigerant gas is cooled and at least partially condensed and frost on the evaporator coil is melted; 2. conduit means connecting the evaporator coil with a second expansion valve for transporting the cooled and at least partially condensed refrigerant to the second expansion valve; 3. heat exchanger means, connected by a conduit to said expansion valve, for evaporating the expanded, cooled and partially condensed refrigerant, whereby the refrigerant becomes substantially completely gaseous; 4. conduit means connecting the heat exchanger means with the compressor for returning the gaseous refrigerant to the intake side of the compressor; 5. valve means for disrupting the said conventional path of refrigerant and providing the path of refrigerant defined by elements (1) through (4); 6. means for circulating water about the condenser; 7. conduit means connecting the condenser and heat exchanger means for passing the water from the condenser to the heat exchanger; and means for circulating the water about the heat exchanger means.
2. conduit means connecting the evaporator coil with a second expansion valve for transporting the cooled and at least partially condensed refrigerant to the second expansion valve;
3. heat exchanger means, connected by a conduit to said expansion valve, for evaporating the expanded, cooled and partially condensed refrigerant, whereby the refrigerant becomes substantially completely gaseous;
4. conduit means connecting the heat exchanger means with the compressor for returning the gaseous refrigerant to the intake side of the compressor;
5. valve means for disrupting the said conventional path of refrigerant and providing the path of refrigerant defined by elements (1) through (4);
6. means for circulating water about the condenser;
7. conduit means connecting the condenser and heat exchanger means for passing the water from the condenser to the heat exchanger; and means for circulating the water about the heat exchanger means.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US3124970A | 1970-04-23 | 1970-04-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3665723A true US3665723A (en) | 1972-05-30 |
Family
ID=21858400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US31249A Expired - Lifetime US3665723A (en) | 1970-04-23 | 1970-04-23 | Apparatus for defrosting evaporator of a refrigeration unit |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3665723A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4946345U (en) * | 1972-07-24 | 1974-04-23 | ||
| EP0207230A2 (en) * | 1985-06-28 | 1987-01-07 | Marin Tek, Inc. | Fast cycle water vapor cryopump |
| US4646537A (en) * | 1985-10-31 | 1987-03-03 | American Standard Inc. | Hot water heating and defrost in a heat pump circuit |
| EP0301728A1 (en) * | 1987-07-29 | 1989-02-01 | S.E.E.R. Systems Inc. Super | Hot gas defrost system for refrigeration systems and apparatus therefor |
| US4877046A (en) * | 1986-12-09 | 1989-10-31 | A/S Finsam International Inc. | Closing and injection valve especially for hot gas defrosting in freezing and cooling installations |
| US6644067B2 (en) | 2000-11-10 | 2003-11-11 | Telmark Cryogenics Limited | Discontinuous cryogenic mixed gas refrigeration system and method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2530440A (en) * | 1947-07-26 | 1950-11-21 | Kramer Trenton Co | Defrosting system for refrigerating apparatus |
| US2694904A (en) * | 1951-10-12 | 1954-11-23 | Sporlan Valve Co Inc | Defrosting arrangement for refrigeration systems |
| US2916893A (en) * | 1954-02-01 | 1959-12-15 | Mercer Engineering Co | Refrigerating system with hot gas defrosting means and adapted for use with a low temperature compressor |
| US3195321A (en) * | 1964-05-28 | 1965-07-20 | Dunham Bush Inc | Refrigeration system including defrosting means |
-
1970
- 1970-04-23 US US31249A patent/US3665723A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2530440A (en) * | 1947-07-26 | 1950-11-21 | Kramer Trenton Co | Defrosting system for refrigerating apparatus |
| US2694904A (en) * | 1951-10-12 | 1954-11-23 | Sporlan Valve Co Inc | Defrosting arrangement for refrigeration systems |
| US2916893A (en) * | 1954-02-01 | 1959-12-15 | Mercer Engineering Co | Refrigerating system with hot gas defrosting means and adapted for use with a low temperature compressor |
| US3195321A (en) * | 1964-05-28 | 1965-07-20 | Dunham Bush Inc | Refrigeration system including defrosting means |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4946345U (en) * | 1972-07-24 | 1974-04-23 | ||
| EP0207230A2 (en) * | 1985-06-28 | 1987-01-07 | Marin Tek, Inc. | Fast cycle water vapor cryopump |
| EP0207230A3 (en) * | 1985-06-28 | 1989-07-26 | Marin Tek, Inc. | Fast cycle water vapor cryopump |
| US4646537A (en) * | 1985-10-31 | 1987-03-03 | American Standard Inc. | Hot water heating and defrost in a heat pump circuit |
| US4877046A (en) * | 1986-12-09 | 1989-10-31 | A/S Finsam International Inc. | Closing and injection valve especially for hot gas defrosting in freezing and cooling installations |
| EP0301728A1 (en) * | 1987-07-29 | 1989-02-01 | S.E.E.R. Systems Inc. Super | Hot gas defrost system for refrigeration systems and apparatus therefor |
| US6644067B2 (en) | 2000-11-10 | 2003-11-11 | Telmark Cryogenics Limited | Discontinuous cryogenic mixed gas refrigeration system and method |
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