GB648673A - Improvements in absorption refrigerating apparatus - Google Patents

Abstract

648,673. Refrigerating; cooling gases. ELECTROLUX, Ltd. Oct. 30, 1946, No. 32213. Convention date, Nov. 8, 1945. [Classes 29 and 64(iii)] In an absorption refrigerating system of the continuous cycle inert gas type, the inert gas streams passing through an upper precoolinig evaporator 13, an intermediate low-temperature evaporator 17 and a lower high-temperature evaporator 32 are so controlled that the rate of flow through the low temperature evaporator is greater than the rates of flow through the other two evaporators respectively. Liquid refrigerant from a condenser 12 enters the pre-cooler 13 and passes to chamber 15 whence it overflows through the low temperature evaporator 17 and the high temperature evaporator 32 and a U-tube 44 into a chamber 33. Weak insert gas from the absorber 18 traverses the gas heat exchanger 19 and flows through the evaporator 17 to the chamber 15 in counterflow to the liquid refrigerant. It then flows down a pipe 30 to a point 31 where it divides, part passing through the evaporator 32 and part passing into the chamber 33. The latter part flows into a pipe 38 and again divides, part flowing through a pipe 40 to the precooler 13 and part entering the gas heat exchanger at 42. The return inert gas, flowing through pipes 41, 42 and 36, enters the gas heat exchanger at points where the main gas stream temperature is equal to the temperature of the incoming gas. If the liquid refrigerant is not entirely vaporized in evaporator 32, the chamber 33 fills with liquid until the pipes 30, 38 are blocked which forces the entire gas stream through the evaporator 32 to evaporate the refrigerant therein. The pipes 30, 38 have holes 45, 46 within the chamber 33 so that a little gas may flow through to evaporate the liquid in the chamber and thus reset the control arrangements. In a modification, Fig. 2 (not shown), the inert gas flows in counterflow to the refrigerant in the evaporator 32 as well as in the evaporator 17 and the gas outlet from evaporator 32 is not introduced into the gas heat exchanger but is led in heat exchange therewith and is united with the gas from the precooler. This mixture is led into the absorber vessel and there undergoes a drop in partial pressure of ammonia before reaching the absorber coil where it unites with the gas stream from the evaporator 17. Fig. 4 (not shown) illustrates a practical form of apparatus and also embodies a pressure vessel and a U-tube to drain liquor from the rectifier into the absorber. Numerical examples of partial pressures of ammonia and the volumes of gas flowing in the several parts of the system are given. Specifications 494,693 and 648,737 are referred to.