Patent GB-703797-A (GB)
Title: Improvements in or relating to a gas-operated absorption refrigerator
IPC: F25B49/04
Filed: 1951-10-25
Abstract: 703,797. Refrigerating; temperatureresponsive actuating-elements. MASCHINENFABRIK SURTH ZWEIGNIEDERLASSUNG DER GES. FUR LINDE'S EISMASCHINEN AKT.-GES. Oct. 25, 1951 [Oct. 26, 1950], No. 24997/51. Classes 29 and 64(2) [Also in Groups XI and XXIX] The quantity of gas supplied to the burner of a continuous cycle absorption refrigerating system is regulated by a valve operated by a thermal element responsive to the heat of the gas flame so as to maintain constant the heating of the thermal element. As shown in Fig. 3, gas is supplied through a pipe 17 to a valve casing 14 on which'is mounted a burner 16, the supply of gas to which is regulated by a throttle valve 15 mounted on a rod 15a connected to one end of a bimetallic strip 18. The strip 18 is heated by the flame and is mounted on a spring 19. To change the level of heating, the strip 18 can be moved to and from the flame by a linkage 20b, 20a operated by turning an "on-off" valve 20 in pipe 17. Valve 20 has an "off" position and an "on" position, the latter covering 90 degrees of arc during the traverse of which the valve 20 is fully open but the distance between the flame and the strip 18 is varied. According to Fig. 2 (not shown), the distance-varying mechanism is omitted and the strip 18 is mounted on the casing 14. As shown in Fig. 4, the bimetallic strip 22 is formed as an ellipse mounted in a closed casing 14a, the flame 16a being adjacent the wall thereof. The level of heating is controlled by movement of a screen 24 between the wall 23 and the flame 16a. As shown in Fig 7, the valve 15 is actuated by a differential expansion device 29, 30 mounted on the casing 31 and, subject to the flame of burner 16 which is mounted on an elastic or part elastic feed pipe 17<SP>1</SP> which can be moved to and from the device 29, 30 by a rod 25. Rod 25 is actuated by a cam 28 turned by operation of a valve 27 similar to valve 20, a spring 32 being interposed between the cam and rod 25. Rod 25 is also moved by a bellows 31 actuated by a thermal element 12' in the refrigerated chamber to keep the temperature thereof constant. The device 29, 30 comprises an outer tube of brass and an inner rod of porcelain. According to Fig. 5 (not shown), the cam 28 can act directly on the rod 25, the spring 32, bellows 31 and thermal element 12<SP>1</SP> being omitted. According to Fig. 8 (not shown), the cam 28 is replaced by a screw and nut mechanism, the screw being coupled by a dog-clutch to the rotary plug of valve 27 so as to vary the level of heat by rotation of valve 27 in the "on" position. As shown in Fig. 9, the regulating valve comprises a valve member 41 actuated by the differential expansion device 29, 30 so that when the burner is out, it seats against seat 40 to cut off the gas supply and when the burner is alight it co-operates with seat 39 to control the supply of heat. The seat 39 may allow a small gas flow even when the member 41 is seated thereon. Rod 30 bears on the head of a bolt 43 fixed to the member 41 by a nut 42, a resilient washer 44 being interposed to prevent damage to the seat 40 at low ambient temperatures. Seat 40 be vertically adjusted within casing 31 by a screw connection. As shown in Fig 10. a pilot burner 53 can be lit through a flash back tube 50 and when lit it heats the differential expansion device 54 and so opens the safety valve to supply gas to the main burner. The pilot burner may be lit automatically by an electric element when the "on-off" valve 20 or 27 is turned from "off" position. Alternatively valve 20 or 27 can have an " ignition " position which supplies gas to the pilot for a predetermined time only. An incandescent element may be mounted in the main flame and, to indicate that the gas is lit, it may be viewed either through a lens at the end of tube 50 or in a 45 degrees mirror at the top of the flue of the refrigerator boiler.