GB354868A - Absorption refrigeration - Google Patents

Abstract

354,868. Refrigerating. BERTSCH, J. C., 1838, Bayle Street, Montreal, Canada. May 22, 1930, No. 15748. [Class 29.] Absorption systems.-In a continuous-cycle inert gas system the refrigerant is generated at a pressure above that of the condenser and is expanded through one or more ejectors in series on its way to the condenser, the ejectors serving to circulate the strong solution from the low-pressure space of the absorber to the higher pressure generator. A system having three ejectors 11, 21, 31 is shown schematically in Fig. 1, the generator being shown in Fig. 2 and the absorber and evaporator in Fig. 12. Refrigerant gas evolved in the generator 1 passes by pipe 2 to the first ejector 11 and lifts solution from a chamber 13 to a separator chamber 12, whence the solution flows through pipe 15 to the generator and the gas to the second ejector, where it lifts liquor from a chamber 23, and so on. The weak liquor flows from the generator through a pipe 4 located in an open-ended pipe 5, and after passing through a vessel 17 and heat exchanger 53 flows through coils 51, 55 within the absorber 38 to a jet 59, which discharges into a conduit 57 to induce a flow of inert gas from the absorber to the evaporator 62. The liquor from the jet collects beyond and overflows a baffle 60 and descends over a spiral baffle 42 in the absorber. It is then directed through a spiral channel 49 traversed by the weak liquor coil 51 and flows down the interchanger 52 to the end chamber 33 of the ejector devices. The expanded gas from the final separator 32, Fig. 1, passes over baffles 9 in the rectifier and then to a condenser coil 36 and finally enters the evaporator as liquid through a jet pipe 67. A safety plug 78, Fig. 11, fusible at high temperatures is fitted at the condenser outlet, and discharges gas through a pipe 79 into the cooling water. The cooling water from the condenser tank is led through a jacket 75, Fig. 2, around the rectifier. When a water valve 76 is opened the lower part of the rectifier is strongly cooled, and refrigerant is condensed therein. The solution then boils over into the condenser and evaporator and defrosts the latter. Check valves 19, 26 are fitted in the strong liquor pipe to prevent back flow. The evaporator may be gilled and located in a gilled brine tank 70 from and to which brine may be circulated by a pump 72, Fig. 1. It is fitted with a spiral baffie 64, which like that of the absorber, may consist of perforated sheets enclosing absorbent fibrous material. The inert gas may enter through a central pipe 63, Fig. 12, or an external pipe 68, Fig. 1, and the rich gas mixture leaves by a conduit 58 extending through the conduit 57 and serves to cool the weak liquor coil 55 in the top of the absorber. The ejector lift pipes may be fitted with spiral baffles, and the cooling water conduit may be coiled around the absorber or on the surface of the spiral baffle. The several chambers 12, 23, 33 serve to preheat the strong liquor and are located at the bottom of the generator, as shown in Fig. 2. Where gas or oil fuel is used the generator is arranged in a heatinsulated flue 28, Fig. 2, but electric heating or a steam jacket may be employed. For small plants a single ejector may be used and the condenser may be on a level with the evaporator. Ammonia in water, or methylchloride, isobutane or ether in mineral oil or in tetrachloroethane may be used, with air mixed with hydrogen, helium or methane as inert gas.