GB683781A - Improvement in the functioning of continuous vacuum distillation or rectification apparatus - Google Patents

Abstract

<PICT:0683781/III/1> In the recovery of volatile compounds, e.g. alcohol, escaping with gases and air from the last stage of a vacuum distillation or rectification plant, e.g. for distilling alcohol, the mixed gases and vapours are drawn off by a liquid ring-type pump and discharged with the liquid operating the pump into a washing column where the vapours are condensed by contact with a liquid, e.g. water, flowing down the column, while the gases are evacuated to the atmosphere, and the liquid collecting at the base of the column is in part recirculated as the working liquid of the pump, the remainder being drawn off and made up for by the fresh washing liquid introduced into the column, thus maintaining constant the percentage of alcoholic &c. vapours dissolved in he pump-operating cycle. Vapours from a distillation plant (not shown) enter a tubular condenser A through pipe 1, condensate being withdrawn by a pipe 16. Residual vapours and gases are withdrawn through pipe 2 by a ring pump B and injected into a column CD through a tangentially arranged orifice 4 which in conjunction with a baffle 7 gives a gyratory movement to the liquid-gas mixture. Vapours and gases rise through the plates 8 against a downward flow of washing liquid fed through line 15. The vapours are condensed by the washing liquid while gases are evacuated to the atmosphere through line 17. The aqueous alcohol collects in a tank E provided with cooling tubes F and is recirculated in part by a pump G to the ring pump B. The alcoholic content of the solution is stabilized by removing part of the water through line 13 provided with a flow gauge H and controlling by a float cock J the supply of washing water in the pipe 15 to maintain a constant level in the tank E. The aqueous alcohol taken off at 14 is returned to the process. The arrangement described is stated to reduce the noise of the ring pump.