GB350057A - Improvements in processes of defrosting heat exchangers in apparatus for the liquefaction or separation by liquefaction of gaseous mixtures - Google Patents

Abstract

350,057. Refrigerating. SOC. L'AIR LIQUIDE SOC. ANON. POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES G. CLAUDE, 48, Rue St. Lazare, Paris. March 14, 1930, No. 8318. Convention date, March 15, 1929. [Class 29.] In apparatus for the partial liquefaction or separation by liquefaction of gaseous mixtures having two coolers, one of which is defrosted while the other is in normal operation, the defrosting is effected either by the whole or a part of the gas resulting from the liquefaction which is first passed through the cooler in normal operation and then through the cooler to be defrosted in the same path but in the opposite direction to its passage therethrough when the cooler is in normal operation. In the treatment of compressed coke-oven gas, the gas enters the pipe A and, assuming the cooler B is to be defrosted, passes through the cooler C, in which its condensable constituents, e.g. benzol, are deposited, to the outlet D which is connected to a lower temperature cooler. From the latter cooler issues gases rich in hydrogen, carbon monoxide or nitrogen, and marsh gas which enter pipes H, I, G respectively and pass through the tubes in the cooler C in countercurrent to the coke-oven gas to outlets H<1>, I<1>, N<1>, a part of the gases rich in marsh gas being diverted through the pipes of a steam-heater R to the cooler B to be defrosted and discharging therefrom through the outlet G<1>. Defrosting is effected when the fall in pressure of the coke-oven gas on the outer side of a cooler reaches one atmosphere.