Patent GB-639413-A (GB)
Title: Improvements in or relating to refrigeration systems
IPC: F25B15/06
Filed: 1947-07-10
Abstract: 639,413. Refrigerating; heat-exchangers. CARRIER ENGINEERING CO. Ltd., July 10, 1947, No. 18376. Convention date, July 13, 1946. [Classes 29 and 64(iii)] [Also in Group XXIX] Continuous cycle absorption refrigerating apparatus comprises two shells 4, 5 at different pressures, the former containing an evaporator 7 and an absorber space 6 cooled by water pipes 44 and the latter containing a lower generator space 12 heated by steam pipes 50 and a condenser 13 cooled by water pipes 54. The refrigerant may be water or ammonia and the absorbent lithium bromide, lithium chloride or sodium hydroxide solutions, or water respectively. Refrigerant flash-cooled in the evaporator 7 is withdrawn from the evaporator through a pipe 11 by a pump 8, circulated through an external cooling system and returned to the evaporator by a pipe 9. Vapour expelled in the generator 12 rises through liquid eliminators 55 and is condensed in condenser 13 whence it flows through a U-tube 30 cooled by water to the evaporator. Vapour evolved in the evaporator rises through eliminators 36 and descends to the absorber around the outside of the evaporator thus insulating it from the exterior of the machine. The refrigerant from pipe 9 is sprayed into the evaporator through sprays 10. Absorbent is sprayed into the absorber through sprays 48 and the rich solution is withdrawn through pipe 15 by a pump 14 which forces it in part through a pipe 17 to a liquid heatexchanger 18 and in part to an ejector 24 so as to entrain poor solution from the exchanger 18, the mixed solution flowing through a pipe 25 to the absorber sprays 48. Rich solution from the pipe 17 and exchanger 18 flows to the shell 5 by a pipe 19 feeding into a chamber 49 from which spaced openings 49<SP>1</SP> lead into the generator space. Poor solution flows from the generator through a pipe 20 to a trap 21 having a pressure equalizing connection 56 to the shell 5 and thence through a pipe 22, heatexchanger 18 and pipe 23 to the ejector 24. Foreign gases in the shell 5 flow into a longitudinal pipe 75 and thence through a pipe 74 to a chamber 67 cooled by a water coil 68. A steam ejector 71 draws foreign gases from the absorber space through a longitudinal pipe 72 and a pipe 73 and forces them into the chamber 67 whence all the foreign gases are withdrawn by an ejector 76. The condensor pipes 54 and absorber pipes 44 are connected to a cooling-water supply pump either in series or in parallel. The condenser pipe assembly is so mounted to allow for differential expansion relative to the shell 5. The cooling effected is controlled automatically by a system which forms the subject-matter of Specification 639,416 and comprises valves in the outflow of the pump 14, the steam supply to the generator and the cooling water supply to the condenser. A practical construction of the apparatus is described with references to drawings. Heat-exchange apparatus. The liquid heat - exchanger 18, Fig. 17, comprises several series connected members 78 for the relatively cool rich solution, and each member 78 contains a bank of tubes 79 for relatively poor solution, the tubes 79 being arranged as shown and spaced by wires 80, 81, 82 at intervals along the length of the tubes. The absorber cooling tubes 44, Fig. 4, are arranged in staggered tiers and the solution to be cooled is sprayed over them through nozzles 48 arraged on branches extending at right angles from pipes 47, the nozzles being so set, Fig. 14, that the spray contacts the tubes 44 at an angle. Some nozzles spray in a direction opposite to the direction of spray of others.