GB759493A - Process and equipment for the treatment of gases from low - temperature carbonization, more particularly of coal, utilising electrostatic precipitation - Google Patents

Abstract

759,493. Purifying gases. BRENNSTOFFTECHNIK GES. April 13, 1953 [April 18, 1952], No. 9936/53. Class 55(2). In a process for recovering pitch and tar oils from low temperature distillation gases, the gases are treated in an electrostatic precipitator at a temperature between 240‹-260‹C. and the condensate from the precipitator is used to scrub the gases in a scrubber before they enter the precipitator whereby the last traces of low boiling point tar oil and light oils are removed from the condensate. As shown in Fig. 1 crude gases pass via collecting main 2, line 3 and a heater or cooler 4 to a scrubber 5 and thence at a temperature of between 240‹-260‹C. by line 7 to an electrostatic precipitator 8 with plates 10 subjected to a high D.C. voltage and finally to a condenser 11 where light oils are separated from the gases which then leave by an outlet 12. Pitch and high boiling point oils are separated in precipitator 8 and pass through line 23 into a tank 19 where they are mixed with condensate from collecting main 2 and line 3. The mixture in tank 19 is pumped partly by pump 21 and line 22 to main 2 and partly by pump 24, heater or cooler 20 and line 25 to sprays 26 arranged in the scrubber 5. From the scrubber 5 the mixture, stripped of any low boiling point constituents, passes through a mixer 28 with an overflow leading back to the tank 19 and line 31 to a distillation unit 33, where it is distilled into pitch and high boiling point tar oil fractions which collect in tanks 34 and 35. The condensate from condenser 11 is treated in a separator 14 and water leaves by line 15 and tne light oils flow into a tank 17. In a modification the precipitator 8 and scrubber 5 are arranged in one housing, tde precipitator being superimposed on tne scrubber.