Patent GB-552966-A (GB)
Title: Improvements in or relating to absorption refrigerating apparatus
IPC: F25B15/10
Filed: 1942-05-14
Abstract: 552,966. Refrigerating. WATSON, F. (Aktiebolaget Elektrolux). May 14, 1942, No. 6549. [Classes 29 and 64 (ii)] Absorption systems.-A continuous-cycle inert gas system is provided with an auxiliary gas-lift pump adapted when in operation to raise absorption solution to a higher level and deliver it to an apparatus member other than the absorber, for control of the system or for defrosting the evaporator. In the system shown in Fig. 1 a generator 11 is welded to a heating tube 10 and the main gas bubble pump 30 for raising the liquor to the top of the generator is also welded to the tube 10. The auxiliary pump tube 40 is welded to a perforated sleeve 45 welded to the other side of the heating tube and delivers liquor to a conduit 60 connected with the air-cooling portion of the evaporator 17. Normally, heat transfer through the sleeve 45 is insufficient to operate the pump 40, but when a conducting rod 46 is lowered into the sleeve, by manual, thermostatic or other means, the conduction is sufficient to effect operation of the pump and liquor is discharged into the evaporator and effects defrosting. The liquor finds its way back to the absorber 19 through the gas heat exchanger 18. In one modification the main and auxiliary pump tubes are welded to opposite sides of and at different levels on a common heating tube fitted with an electric heating cartridge, which is lowered in the tube when the auxiliary pump is to be heated. In the system shown in Fig. 4 the generator is in the form of a tube 11 welded to a main heating tube 10 and communicating with the liquor heat exchanger 22 and with the condenser by conduits 51, 52, 12. A riser tube 53 connects the generator with the conduit 60 receiving liquor from the auxiliary pump tube 40. When the pump tube 40 is in operation the level in the generator and in the riser tube 53 sinks and hot vapour passes through the riser to assist in defrosting the evaporator. A liquid seal may be formed in a part of conduit 60 and this may be broken by controlled heating of the seal, to open the conduit to gas flow. The auxiliary pump tube may be continuously heated, as shown in Fig. 7, with the generator and main pump tube. Control is then effected by movement of a flexible conduit 71 to vary the liquid content of the auxiliary pump tube. A controllable closed condensing heat transfer system may be used for heating the auxiliary pump tube, as shown in Fig. 8, The heat transfer system 83 - - 87 is connected by welding, to the generator heating tube 10 and the auxiliary pump tube 40, and has a condenser element 80 which may be raised or lowered through a flexible tube 81 to bring the system into or out of action. The auxiliary pump may deliver the liquor to the known gas pressure vessel 21 and thence to the evaporator. The liquor this raised may convey corrosion-preventing media to parts of the apparatus. As media in the heat tansfer system an aqueous solution of an anticorrosive agent such as a chromate, and aniline, benzene, toluene, xylene and other hydrocarbons are mentioned. Specification 550,796 is referred to.