Patent GB-970620-A (GB)
Title: Improvements in or relating to refrigeration system impurity purge means
IPC: F25B43/04
Filed: 1962-10-18
Abstract: 970,620. Refrigerating. AMERICAN RADIATOR & STANDARD SANITARY CORPORATION. Oct. 18, 1962 [Nov. 7, 1961], No. 39517/62. Heading F4H. A refrigerant purging arrangement comprises a heat exchanger in which refrigerant vapour withdrawn from a refrigerating system is condensed, non-condensable gases being expelled from the heat exchanger under the control of means responsive to the pressure of said gases As shown in Fig. 1, refrigerant vapour is supplied to the bottom of a heat exchange unit 24 through a line 26 which contains a fixed or variable restrictor 28 and leads from the condenser 14 of the refrigeration system. The unit 24 contains a finned coil 30 which is wound about a core 34 and is supplied with liquid refrigerant from the upstream side of a float valve 16 disposed at the outlet of condenser 14. Refrigerant is condensed on the coil 30, condensate being discharged through an outlet line 52, and non-condensable gases accumulate at the top of the unit 24 from which they are discharged through an outlet 36 under the control of a solenoid valve 44 which is opened by a pressure responsive switch 50 when the gas pressure reaches a predetermined value. The liquid refrigerant from line 52 passes to a chamber 54 which contains a baffle 56 and a weir 58 so that a layer 66 of liquid impurities is formed on top of the refrigerant to the right of baffle 56 and may be tapped off through a standpipe 64. Liquid refrigerant passes beneath baffle 56 and over weir 58 to a chamber 62 which contains a float valve 70 and from which the refrigerant is passed through a line 74 to the evaporator 20. Refrigerant from the coil 30 is also passed to the evaporator through a line 40. In the embodiment of Fig. 3, non-condensable gases from the unit 24 and liquid impurities from the vessel 54 are led to a common chamber 80 through lines 82 and 64a respectively, the line 64a including a one-way valve 84. A solenoid valve 44a in the outlet 86 of the chamber is opened by switch 50 upon rise in gas pressure, which pressure serves to eject the liquid impurities from chamber 80. An electrically driven pump controlled by switch 50 may be included in the gas outlet line in either of the above embodiments when the purging apparatus is used in conjunction with a refrigeration system operating at below atmospheric pressure (Figs. 2 and 4, not shown). In the embodiment of Fig. 5, a second heat exchange unit 124, having a coil 130 through which cold water is circulated, is provided for purging the refrigerant when the refrigerating system is inoperative. Gaseous refrigerant is withdrawn from the system through line 26, inactive unit 24 and line 36 under the control of a pump 78 which supplies the unit 124 through a line 125. The valve 44 in line 36 is held open by a manual switch 127 during this operation and valves 131 and 133 in the outlet 52 and line 36 respectively are closed. Non-condensables are discharged through a valve 144 under the control of a switch 150 as before, while liquid refrigerant is passed to the vessel 54 through a line 129 and a valve 135. In Fig. 6 (not shown) the secondary unit is combined with a primary unit of the type shown in Fig. 3.