PROCESSO E SISTEMA DE CONTROLE EFICIENTE DO PH

摘要

Efficient control of the pH of a flowing alkaline wastewater stream is accomplished by monitoring the pH of the flowing stream, generating a signal in response to the pH monitored, and injecting CO2 as necessary to reduce the pH. High pressure liquid CO2 is supplied to a proportional control valve which is operated in response to the signal to change the high pressure CO2 fluid to an intermediate pressure CO2 fluid in a manner so as to significantly reduce its density by creating a significant gaseous fraction. This lower density CO2 fluid is supplied to a spring-loaded injector having an orifice in communication with the flowing stream. The intermediate pressure is above the pressure at which the injector opens whereby the lower density CO2 fluid is injected into the flowing stream, allowing particularly precise control to be achieved.