Distn. plant and process for mixed liq.(s) esp. alcohol mfr. - has pressure reduction device in return line from distn. column tail to evaporator

摘要

- The liq. is boiled in an evaporator at reduced temp. and pressure. The resulting vapour is compressed in a compressor which delivers to the foot of a distn. column operating at a pressure higher than that in the evaporator. The temp. of condensation in the distn. column is significantly higher than the temp. of liq. in the evaporator. The heat available from condensing the distillate is employed in boiling the liq. in the evaporator. The liq. phase collected at the foot of the distn. column is piped into the evaporator via a pressure-reducing device. - The process is used to treat a mixt. of two or more liqs. in a distn. plant in which the evaporator operates at a pressure between 20 mbar and 1200 mbar while the distn. column operates at between 150 mbar and 5000 mbar. The pressure in the evaporator should not be more than 70 per cent of the pressure in the distn. column.