METHOD OF CONTROLLING CONCENTRATION OF CONCENTRATED LIQUID AND APPARATUS FOR CONTROLLING CONCENTRATION OF CONCENTRATED LIQUID

摘要

PURPOSE: To control the concentration of a concentrated liquid without using a solvent densitometer and to prevent a large amount of a solute from being dissolved in solvent vapor due to excessive concentration by monitoring the temperature of heated vapor after heat exchange and controlling the operation based on the previously set temperature as a standard. ;CONSTITUTION: A steam concentrating apparatus has a heater 10, generates heated steam by heating clean water in a steam generating apparatus 9, and circulates the heated steam in a heat exchanger tube 11 in a concentration can 4 to concentrate the solution in the concentration can 4. Regarding this concentration controlling method for a concentrated solution, the temperature T2 of the heated steam is monitored by a thermometer 12. If, for example, a motor valve 8 is opened at the time, as concentrated solution discharge timing, when the heated steam temperature becomes 76°C, the concentrated solution with 20% of water content can be discharged. Since the liquid surface level lowers when the concentrated solution is discharged, a liquid surface level sensor detectes that and opens the motor valve 14 and thus raw liquid with a high water content is supplemented. As a result, excessive concentration of the concentrated solution is prevented and liquid to be discharged at a constant temperature is taken out.;COPYRIGHT: (C)1994,JPO