| 摘要 |
<p>PROBLEM TO BE SOLVED: To recover useful hydrochloric acid from a waste hydrichloric acid and to highlu reduce thevolume of a concentration residue by providing a steam compression type concenration technique small in equipment and low in equipment cost and operation cost. SOLUTION: 1. In a treating method of a waste hydrochloric acid using an evaporator 12, (1) a process for introducing a waste hydrochloric acid original liquid whike disttobuting in an upper part of the evaporator 12, (2) a process for heating and evaporating the liquid in the outside of a heat exchanger pipe 27 by supplying a vapor compressed by a compressor 9 and elevated in the temp. into the inside of the heat exchanger pipe 27 in the evaporator 12, (3) a process for cooling the vapor generated in the evaporator in a cooler 14 and recovering it as a hydrochloric acid aq. solution, (4) a process for recovering the condensate of the vapor from the inside of the heat exchanger pipe 27 in the evaporator 12, (5) process for controlling the temp. in the evaporator and/or the output of the compressor 9 corresponding to a signal exhibiting the recovered hydrochloric acid aq. solution quantity, and (6) a process for taking out a concentrated liquid from the bottom of the evaporator 12 and charging it to a concentrated liquid storage tank 25 corresponding to a signal exhibiting the height of the liquid level in the evaporator 12 are provided.</p> |
