PURPOSE: To prevent the lowering of performance and an increase in load of a vacuum generator at the time of concentrating an aq. soln. liberating an alkaline noncondensable gas or acidic noncondensable gas by providing a neutralizing means for bringing a neutralizing soln. into contact with a current in a steam duct to the steam duct.
CONSTITUTION: A spray nozzle 19 is provided in a steam duct 13, a neutralizer feed pipeline 20 is connected to a concd. water discharge pipeline 9 to a condensed water discharge pump 8, a neutralizing soln. pipeline 22 branched from a condensed water discharge pipeline 21 from the pump 8 is connected to the nozzle 19, and a neutralizing soln. is sprayed into the steam duct 13 from the nozzle 19. An acidic neutralizer is supplied from the pipeline 20 when an aq. soln. supplied into an evaporation chamber 1 liberates an alkaline noncondensable gas, and an alkaline neutralizer is supplied from the pipeline 20 when the aq. soln. liberates an acidic noncondensable gas.
HIRANO SATORU
NISHIMURA YASUSHI
