US3827249A - Pressurized refrigerant recirculation system with control means - Google Patents
Pressurized refrigerant recirculation system with control means Download PDFInfo
- Publication number
- US3827249A US3827249A US00340638A US34063873A US3827249A US 3827249 A US3827249 A US 3827249A US 00340638 A US00340638 A US 00340638A US 34063873 A US34063873 A US 34063873A US 3827249 A US3827249 A US 3827249A
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- refrigerant
- accumulator
- separator
- pumping
- tanks
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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
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
-
- 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
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
Definitions
- ABStCT [22] Filed: Mar, 12, 11973 A refrigeration apparatus having an accumulatorseparator with a pair of pumping tanks which are se- [211 App! 340638 quentially operated by high pressure gas from the receiver for pumping liquid refrigerant to an evaporator.
- US. Cl 62/174, 62/218, 62/470 The apparatus provides a foolproof fail-safe automati- 62/512 cally operated system in which the accumulator- [51] Int. Cl.
- 43/00 separator a th pump ng tanks are f a size to ac- [58] Field at Search 62/174, 512 Commedate all f the r g rant ithin the system so i that a rise in pressure induced by temperature in- [56] References Cited crease caused by a power failure is not sufficient to UNITED STATES PATENTS rupture the System 2,871,673 2/1959 Richards 62/174 7 Claims, 4 Drawing Figures CONDENSER 2
- This invention relates generally to refrigeration apparatus and relates particularly to a pressurized refrigerant recirculation apparatus which recirculates liquid refrigerant through an evaporator by means of high pressure gas from the receiver.
- the present invention is a fail-safe reliable automatically operated refrigerant recirculation system having an accumulator-separator communicating with a pair of alternately operable pumping tanks which are operated sequentially in timed relationship, or are operated in accordance with the amount of liquid refrigerant within the accumulator as indicated by a float control. While one of the pumping tanks is receiving liquid refrigerant under low pressure conditions existing within the accumulator-separator, the other pumping tank is pressurized by high pressure gas from the receiver to force liquid refrigerant from such pumping tank to the evaporator.
- both of the pumping tanks automatically communicate with the accumulator-separator and are of a size to accommodate all of the refrigerant within the system so that a rise in pressure induced by a temperature increase of the refrigerant is not sufficient to rupture the system.
- FIG. 1 is a schematic layout of a recirculation system operated in accordance with the quantity of refrigerant charge in the system.
- FIG. 2 is a schematic layout similar to FIG. 1 in which the system is operated in. accordance with the amount of liquid refrigerant within the accumulator-separator.
- FIG. 3 is an electrical diagram of a time operated control system.
- FIG. 4 is an electrical diagram of a float operated control system.
- a relatively large refrigeration system having an evaporator which discharges a mixture of liquid and gaseous refrigerant to an accumulator-separator 11 through a discharge line 12.
- Gaseous refrigerant is withdrawn from the accumulator-separator through conduits l3 and 14 by the suction side of compressors 15 and 16, respectively.
- These compressors compress and discharge refrigerant through oil separators 117 and 18 and through conduits l9 and 20, respectively, into a condenser 21.
- Liquid refrigerant from the condenser is discharged through a conduit 22 into a receiver 23.
- liquid level is maintained at a predetermined level by a float operated valve 24.
- a normally closed pressure operated flow control valve 25 is connected by a conduit 26 to the float valve 24,
- conduit 27 connects the float valve structure to the accumulator-separator 11.
- Liquid refrigerant from the accumulator-separator drains by gravity through a conduit 32 into a header 33 and through a pair of conduits 34 and 35 having check valves 36 and 37 into a pair of pumping tanks 38 and 39, respectively.
- the pumping tank 38 is connected by a conduit 40 to a normally open pressure operated vent valve 41 which communicates with the accumulatorseparator 11 through a conduit 42.
- the pumping tank 39 is connected by a conduit 43 to a normally open pressure operated vent valve 44 which communicates with the accumulator-separator by a conduit 45 and the conduit 27. Under normal shutdown or no-power conditions, the vent valves 41 and 44 both are open and permit liquid levels to equalize within the pumping tanks 38 and 39.
- the vent valve 41 may be selectively closed by connecting the upper portion thereof to a pressure line 46 communicating with the upper portion of the receiver 23 to permit pressurized gas to flow through such line under the control of an in-line gate valve 47 selectively operated by a solenoid 48.
- the vent valve 44 may be selectively closed by connecting the upper portion to a pressure line 49 connected to a pressure line 46. Flow of gas under pressure through the pressure line 49 is controlled by an in-line gate valve 50 selectively operated by a solenoid 51.
- a tank pressurizing line having an in-line pressure regulating valve 56 is connected to the pressure line 46 which leads into the upper portion of the receiver 23 and the opposite end of the line 55 is connected to one side of a normally closed pressure operated flow control valve 57.
- the opposite side of such flow control valve is connected by a pressurizing line 58 to the conduit leading into the pumping tank 38 when the vent valve 41 is closed.
- a branch line 59 connects the tank pressurizing line to one side of a normally closed pressure operated flow control valve 60 and the opposite side of such valve is connected by a pressurizing line 61 to the conduit 45 which leads into the pumping tank 39 when the vent valve 44 is closed.
- the pressure operated valve 57 is connected by a vent line 62 to the accumulator-separator 11 and such vent line has an in-line gate valve 63 operated by a solenoid 64 to permit selective operation of the valve 57.
- the pressure operated valve 60 communicates with the accumulator-separator 11 through a vent line 65 having an in-line gate valve 66 selectively operated by a solenoid 67.
- the pressurizing of the pump tank 38 causes liquid refrigerant therein to be discharged through the conduit 34 and through an outlet conduit 68 having a check valve 69 into a discharge conduit 70 from which the pressurized liquid refrigerant flows through a strainer-drier 71 and through a conduit 72 to one side of a normally closed pressure operated flow control valve73.
- a vent line is provided in communication with the accumulator-separator 11 and such vent line has an inline gate valve 81 selectively operated by a solenoid 82.
- the opposite side of the flow control valve 73 is connected by a conduit 74 to the evaporator 10 with the direction of flow being controlled by a check valve 75.
- Refrigerant 22 (chlorodifluoromethane) normally is used in the present system and such refrigerant is miscible with oil from the compressors 15 and 16 and therefore an oil still 83 is provided having a heater 84 for separating liquid refrigerant from oil.
- a flow of refrigerant and oil passes through conduits 85 and 86 having throttling valves 87 and 88 respectively, and through check valves 89 and 90 to an inlet conduit 91 communicating with the oil still 8.
- Liquid refrigerant which has been separated within the oil still is discharged through a conduit 92 and returned to the accumulator-separator 11.
- the conduit 92 has a pressure regulating valve 93 to maintain the pressure within the oil still at a level less than the pressure within the pumping tanks 38 and 39 but greater than the pressure within the accumulator-separator l1, and above the crank case pressure of the compressors 15 and 16.
- Oil which is separated from the refrigerant within the still 83 is discharged through conduits 94 having an inline gate valve 95 controlled by a solenoid 96.
- the solenoid 96 is controlled by a thermostatic switch 97 within the oil still 83. From the conduit 94, oil from the still 83 flows through a conduit 98 connected to oil level devices 99 and 100 associated with the compressors l5 and 16, respectively.
- vent valves 41 and 44 and the flow control valves 25, 57, 60 and 73 have been illustrated and described as pressure operated valves, it is apparent that other conventional valves could be used.
- the structure thus far described with reference to FIG. 1 discloses a system in which the level of the liquid refrigerant within the accumulator-separator 11 is variable with the amount of refrigerant charge in the system.
- the amount of the refrigerant charge varies in accordance with the specific refrigerant recirculation system. As an example, an ice rink of approximately 85 feet wide by 200 feet long normally requires approximately 1,000 gallons or 7,000 pounds of refrigerant 22.
- the pressure operated valves 25, 41, 44, 57, 60 and 73 return to their normal operating position illustrated in FIG. 1.
- both of the pumping tanks 38 and 39 communicate with the accumulatorseparator 11 and such pumping tanks and accumulatorseparator are of a size to accommodate all of the refrigerant within the system so that a rise in pressure induced by a temperature increase of the refrigerant is not sufficient to rupture the system.
- a modified refrigerant recirculation system in which the level of liquid refrigerant within the accumulator-separator 11 is maintained by a float operated valve 101.
- the float valve 101 is responsive to the liquid level within the accumulator-separator so that when the liquid refrigerant therein drains into one of the pumping tanks 38 and 39, the float valve shutoff stem rises from its seat and permits liquid refrigerant from a relatively large receiver 23 to flow through a conduit 102 into the accumulator-separator and replenish the supply therein.
- An in-line gate valve 103 operated by a solenoid 104 permits liquid refrigerant to flow through the conduit 102 when the system is in operation but closes such conduit when the system shuts down.
- either of the modifications illustrated in FIGS. 1 and 2 can be controlled by a program timer, as illustrated in FIG. 3, or either of the modifications can be operated by float level switches, as illustrated in FIG. 4.
- a manual switch 105 (line 3) is moved on the On position to energize a program motor 106 (line 1) after the compressors have been started providing the compressor inlet pressure is below a level which will not overload the compressor driving motor.
- a pressure limiting switch 107 (line 3) provides the protection for the compressor driving motor.
- the program motor 106 is started, and an indicating signal such as a green light 108 (line 2) and a control relay 109 (line 3) both are energized.
- a cam 110 having lobes 111 and 112 is attached to the output shaft of the program motor 106.
- the lobe 111 operates switches 113 (line 4) and 114 (line 7) and lobe 112 operates switches 115 (line 6) and 116 (line 9).
- control relay switches CRS lines 4, 6, 10 and 12
- closed switch 114 (line 7) energizes solenoid 51 to open the gate valve 50 and permit refrigerant gas under pressure from the receiver 23 to close the vent valve 44 so that the pumping tank 39 is no longer vented to the accumulator-separator 11.
- switch 114 energizes a red indicator light or other signal 117 (line 8) to indicate that pumping tank 39 is being pressurized.
- Simultaneously closed switch 116 (line 9) energizes solenoid 67 to open the gate valve 66 and relieve the pressure within the flow valve 60 so that such valve opens.
- Gas pressure from the receiver 23 is constantly regulated by the pressure relief valve 56 as such gas passes through the pressurizing line 55, branch line 59, flow valve 60 and pressurizing line 61 into the pumping tank 39 to pressurize such tank and force the liquid refrigerant therein through the outlet conduit 76 into the discharge conduit 70, strainer-drier 71 and conduit 72 into the flow valve 73.
- solenoid 82 (line 10) was energized to open gate valve 81 so that introduction of liquid refrigerant under pressure into the flow valve 73 opens such valve and permits pressurized liquid refrigerant to flow through the conduit 74 into the evaporator 10.
- switches 114 and 116 deenergizes solenoids 51 and 67 so that the introduction of gas under pressure into the pumping tank 39 is interrupted by the closing of flow valve 60, and the opening of vent valve 44 vents the pumping tank 39 to the accumulator-separator 11. This permits liquid refrigerant within the accumulator-separator to drain through the conduit 32, header 33 and conduit 35 into the pumping tank 39.
- switches 113 and 115 energizes solenoids 48 and 64, respectively, so that the vent valve 41 closes and flow valve 57 opens to permit refrigerant gas under pressure to flow through the pressurizing line 55, valve 57 and pressurzing line 58 into the pumping tank 38.
- the closing of switch 113 (line 4) energizes a red indicator light or other signal 118 (line 5) to indicate that pumping tank 38 is being pressurized.
- the gas under pressure forces liquid refrigerant from the pumping tank 38 through the outlet conduit 68 into the discharge conduit 70, strainer-drier 71, conduit 72, flow valve 73 and conduit 74 into the evaporator.
- Alternate pressurizing of the pumping tanks 38 and 39 permits liquid refrigerant to flow under low accumulator-separator pressure into one of such pumping tanks while the other pumping tank is discharging liquid refrigerant to the evaporator.
- This cycle is continuously repeated until the refrigeration system is shut off by any means of control, such as thermostat, pressurestat, oil failure switch, manual shutdown, power failure, or other means at which time the program motor 106 stops.
- the absence of a completed circuit causes all valves to return to their normal position as indicated in FIGS. 1 and 2. In this position, both of the pumping tanks 38 and 39 are in non-pressurized condition so that liquid refrigerant from the accumulator-separator 11 drains into both pumping tanks.
- the electrical wiring diagram shown in full lines in FIG. 3 is for use with a refrigeration system as shown in FIG. 1 under program time control. If the system shown in FIG. 2 is used with a program time control, an additional connection for the solenoid 104 of gate valve 103 is added and such connection is shown by broken lines (line 11).
- each of the refrigeration systems shown in FIGS. 1 and 2 can be operated in accordance with the level of the liquid refrigerant within the pumping tanks 38 and 39.
- a float control device 120 is added to the pumping tank 138 and a float control device 121 is added to the pumping tank 139.
- the float control devices 120 and 121 are shown in broken lines in FIGS. 1 and 2.
- FIG. 4 a wiring diagram is shown for controlling the recirculation systems of FIGS. 1 and 2 when using float control devices 120 and 121. As indicated in FIG. 3, all connections located above the dotted line A-A of FIG. 4 are conventional for automatic compressor operation in refrigeration systems.
- manual switch 105 (line 2) is moved to the On position to energize control relay 109 (line 2) and the green light 108 (line 1), if the compressors 15 are running and the pressure is down to the level where pressure limiting switch 107 is closed.
- Energizing the control relay 109 closes all switches CRS (lines 4, 6, 10 and 1.4).
- a timer 122 (line 3) is energized and after a delay of approximately 30 seconds the timer 122 closes timer switch 123 (line 10) and remains closed until the timer 122 is deenergized.
- the 30 second delay prevents the energizing of a control relay 124 (line 11) and permits a control relay 125 (line 7) to energize and demobilize control relay 124 (line 11) by opening control relay switch 126 (line 10).
- control relay 125 closes normally open control relay switches 127 and 128 to operate solenoid 48 to open gate valve 47 and close the vent valve 41 and simultaneously operates solenoid 64 to open gate valve 63 so that high pressure from the pressurizing line 55 passes through the pressure operated flow valve 57 and introduces fluid under pressure into the pumping tank 38 to cause the liquid refrigerant therein to be discharged to the evaporator.
- a red indicating light 129 (line 8) is energized during the time of pressurization of the pumping tank 38.
- float switch 130 opens and deenergizes control relay 125 (line 7).
- switches 127 (line 7) and 128 (line 9) open and switch 126 (line 10) closes to energize control relay 124 (line 11). Closing of the control relay 124 opens normally closed control relay switch 131 (line 6) and closes normally open relay switches 132 and 133 (lines 11 and 13, respectively).
- Pressurizing of the pumping tank 39 discharges liquid refrigerant from the tank until the liquid level falls below the float control device 121 so that float switch 134 (line 10) opens and deenergizes control relay 124 (line 11).
- the deenergizing of control relay 124 closes control relay switch 131 (line 6) to energize control relay 125 (line 7), if sufficient liquid refrigerant from the accumulator-separator 11 has drained into the pumping tank 38 to a level high enough to close float switch 130 (line 6).
- a safe automatically operated refrigerant recirculation apparatus for circulating liquid refrigerant through an evaporator and usable with conventional compressor means and condenser means, said apparatus comprising an accumulator-separator for receiving liquid and gaseous refrigerant from the evaporator and separating liquid refrigerant from gaseous refrigerant, conduit means connecting said accumulator-separator with said compressor means for removing gaseous refrigerant from said accumulator-separator, said compressor means compressing said gaseous refrigerant and discharging the same to said condenser means, a receiver communicating with said condenser for receiving liquid and gaseous refrigerant therefrom under condenser pressure, means for discharging liquid refrigerant from said receiver into said accumulatorseparator, a pair of pumping tanks connected to said accumulator-separator and adapted to receive liquid refrigerant therefrom under pressure conditions existing in the accumulator-separator, means for sequentially
- each of said vent valve means is normally open and each of said flow valve means is normally closed so that refrigerant flows from said accumulator-separator into both of said pumping tanks when the compressor means is not operating.
- a refrigerant recirculation system having an evaporator, an accumulator-separator, at least one compressor receiving gaseous refrigerant from said accumulator-separator and discharging the same to a condenser, a receiver receiving refrigerant from said condenser, said receiver containing both liquid and gaseous refrigerant under condenser pressure, means for discharging liquid refrigerant from said receiver into said accumulator-separator, and a pair of pumping tanks for receiving liquid refrigerant from said accumulator-separator, the improvement comprising vent valve means associated with each of said pumping tanks for selectively relieving pressure therein, flow valve means associated with each of said pumping tanks for selectively introducing gaseous refrigerant under pressure into said tanks, each of said flow valve means communicating with the upper portion of said receiver for introducing gaseous refrigerant only under condenser pressure into said pumping tanks, and control means for selectively operating said vent valve means and said
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Abstract
Description
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US00340638A US3827249A (en) | 1973-03-12 | 1973-03-12 | Pressurized refrigerant recirculation system with control means |
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US00340638A US3827249A (en) | 1973-03-12 | 1973-03-12 | Pressurized refrigerant recirculation system with control means |
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US3827249A true US3827249A (en) | 1974-08-06 |
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US00340638A Expired - Lifetime US3827249A (en) | 1973-03-12 | 1973-03-12 | Pressurized refrigerant recirculation system with control means |
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Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4027496A (en) * | 1976-06-22 | 1977-06-07 | Frick Company | Dual liquid delivery and separation apparatus and process |
US4476695A (en) * | 1983-12-15 | 1984-10-16 | Tim Epps | Refrigerator condensation apparatus |
US5007247A (en) * | 1988-09-30 | 1991-04-16 | Danfoss A/S | Refrigeration or heat pump installation |
US5189885A (en) * | 1991-11-08 | 1993-03-02 | H. A. Phillips & Co. | Recirculating refrigeration system |
US5542261A (en) * | 1995-04-17 | 1996-08-06 | Albertson; Luther D. | Refrigerant evaporator over-pressure relief system including a fluid containment vessel |
US20130047636A1 (en) * | 2011-08-24 | 2013-02-28 | Louis Cording | Method and system for filling a refrigerant into a refrigeration system |
US20140053578A1 (en) * | 2012-08-24 | 2014-02-27 | Whirlpool Corporation | Integrated ice maker pump |
US20150020536A1 (en) * | 2013-07-18 | 2015-01-22 | Korea Institute Of Energy Research | Heat pump system capable of adjusting amount of refrigerant stored in liquid receiver |
US9671146B2 (en) | 2013-01-25 | 2017-06-06 | Trane International Inc. | Refrigerant cooling and lubrication system with refrigerant vapor vent line |
US20230071679A1 (en) * | 2021-08-24 | 2023-03-09 | Messer Industries Usa, Inc. | Depressurization system, apparatus and method for high pressure gas delivery |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2871673A (en) * | 1956-10-08 | 1959-02-03 | H A Phillips Company | Liquid return system |
US2952137A (en) * | 1959-01-02 | 1960-09-13 | John E Watkins | Low pressure refrigerating systems |
US3643460A (en) * | 1970-09-11 | 1972-02-22 | Frick Co | Gravity refrigerant recirculation |
-
1973
- 1973-03-12 US US00340638A patent/US3827249A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2871673A (en) * | 1956-10-08 | 1959-02-03 | H A Phillips Company | Liquid return system |
US2952137A (en) * | 1959-01-02 | 1960-09-13 | John E Watkins | Low pressure refrigerating systems |
US3643460A (en) * | 1970-09-11 | 1972-02-22 | Frick Co | Gravity refrigerant recirculation |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4027496A (en) * | 1976-06-22 | 1977-06-07 | Frick Company | Dual liquid delivery and separation apparatus and process |
US4476695A (en) * | 1983-12-15 | 1984-10-16 | Tim Epps | Refrigerator condensation apparatus |
US5007247A (en) * | 1988-09-30 | 1991-04-16 | Danfoss A/S | Refrigeration or heat pump installation |
US5189885A (en) * | 1991-11-08 | 1993-03-02 | H. A. Phillips & Co. | Recirculating refrigeration system |
US5542261A (en) * | 1995-04-17 | 1996-08-06 | Albertson; Luther D. | Refrigerant evaporator over-pressure relief system including a fluid containment vessel |
WO1996033376A1 (en) * | 1995-04-17 | 1996-10-24 | Albertson Luther D | Refrigerant evaporator over-pressure relief system including a fluid containment vessel |
US8950198B2 (en) * | 2011-08-24 | 2015-02-10 | Mahle International Gmbh | Method and system for filling a refrigerant into a refrigeration system |
US20130047636A1 (en) * | 2011-08-24 | 2013-02-28 | Louis Cording | Method and system for filling a refrigerant into a refrigeration system |
US9568231B2 (en) | 2012-08-24 | 2017-02-14 | Whirlpool Corporation | Integrated ice maker pump |
US8938980B2 (en) * | 2012-08-24 | 2015-01-27 | Whirlpool Corporation | Integrated ice maker pump |
US20140053578A1 (en) * | 2012-08-24 | 2014-02-27 | Whirlpool Corporation | Integrated ice maker pump |
US9671146B2 (en) | 2013-01-25 | 2017-06-06 | Trane International Inc. | Refrigerant cooling and lubrication system with refrigerant vapor vent line |
US10458686B2 (en) | 2013-01-25 | 2019-10-29 | Trane International Inc. | Refrigerant cooling and lubrication system with refrigerant vapor vent line |
US20150020536A1 (en) * | 2013-07-18 | 2015-01-22 | Korea Institute Of Energy Research | Heat pump system capable of adjusting amount of refrigerant stored in liquid receiver |
US9372015B2 (en) * | 2013-07-18 | 2016-06-21 | Korea Institute Of Energy Research | Heat pump system capable of adjusting amount of refrigerant stored in liquid receiver |
US20230071679A1 (en) * | 2021-08-24 | 2023-03-09 | Messer Industries Usa, Inc. | Depressurization system, apparatus and method for high pressure gas delivery |
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Owner name: CANADIAN IMPERIAL BANK OF COMMERCE Free format text: SECURITY INTEREST;ASSIGNOR:YORK INTERNATIONAL CORPORATION;REEL/FRAME:005156/0705 Effective date: 19881215 |
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Owner name: CANADIAN IMPERIAL BANK OF COMMERCE Free format text: SECURITY INTEREST;ASSIGNOR:YORK OPERATING COMPANY, F/K/A YORK INTERNATIONAL CORPORATION A DE CORP.;REEL/FRAME:005994/0916 Effective date: 19911009 |
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Owner name: CANADIAN IMPERIAL BANK OF COMMERCE Free format text: SECURITY INTEREST;ASSIGNOR:YORK INTERNATIONAL CORPORATION (F/K/A YORK OPERATING COMPANY);REEL/FRAME:006007/0123 Effective date: 19911231 |
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Owner name: CANADIAN IMPERIAL BANK OF COMMERCE Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:YORK INTERNATIONAL CORPORATION, A DE CORP.;REEL/FRAME:006194/0182 Effective date: 19920630 |