SOLVENT RECOVERY FROM STOCK SOLUTION INCLUDING NONVOLATILE MATTER BY HEAT PUMP METHOD

摘要

PURPOSE: To prevent packing and trays in a tower from being fouled or clogged and to increase purifying separation efficiency of solution including nonvolatile liquid or solid by making the part of a heat pump distillation tower from the top to the reboiler the concentrating one of the distillation tower and adopting a system where the bottom liquid of the heat pump distillation tower is fed to an evaporator. ;CONSTITUTION: Supplying stock solution 1 to the bottom of a heat pump distillation tower A makes the tower A the concentrating part 2 only to prevent nonvolatile matter from being brought into contact with the concentrating part 2. After the bottom liquid from the tower A is delivered to an evaporator 15 to separate the nonvolatile matter 17 in the evaporator 15, vapor from the evaporator 15 is fed to an ordinary distillation tower B. When distillates 31, 26 from the towers A, B and bottoms 30 from the tower B are withdrawn as products, equipment is operated under the following operating conditions. Compression ratio of a compressor 5 for vapor from the top of the tower A: Pd/Ps≤10 (Pd: compressor delivery pressure, Ps: compressor suction pressure), and temp. difference between saturated condensation temp. of vapor on the delivery side of the compressor, Tdb and boiling point of liquid in the lower part of the condensing part which is the bottom liquid of the tower A, Tbb: Tdb-Tbb≥30°C.;COPYRIGHT: (C)1993,JPO&Japio