Apparatus for the recovery of volatile constituents in liquids containing fractions having different boiling points

摘要

PICT:0673544/III/1 Liquid is evaporated by passing it through a heat-exchanger wherein it is heated by hot water and then introducing it into a film evaporator. The hot water for the heat-exchanger is obtained from a tank heated by steam, and the supply of steam is thermostatically controlled with respect to the temperature of the liquid about to enter the evaporator, or of the water leaving the heat-exchanger. The liquid-to-be-evaporated is pumped through heat-exchanger 14 and then through heat-exchanger 16 which lies behind heat-exchanger 14. Hot water is pumped from tank 17 to heat-exchanger 16 via pipes 19, 20, 21, and back again to the tank via pipes 22, 23, 24. The heated liquid passes through pipe 25 into evaporator 11. The water in tank 17 is heated by injection of steam through pipe 31; and the steam-supply is controlled by valve 32 operated by a diaphragm which is subject to air pressure in the valve part 33 which is connected by pipe 35 to regulator 34. The temperature-sensitive element of regulator 34 extends into the heated liquid as it enters the evaporator. The evaporator may be of the form disclosed in Specifications 595,597 and 673,543. The vapours from the evaporator are condensed in condenser 27, and the condensate is collected in tank 28. Unevaporated liquid leaves the evaporator through pipe 29, and is circulated through heat-exchanger 14, before finally passing out of the system through outlet 30. Specification 673,545 also is referred to.