Ultrapure water online ph measurement equipment

Abstract

Ultrapure water online pH measurement equipment according to the present invention comprises: an ultrapure water pipe device; a first flow controller for pure water; a second flow controller for foreign substances; a nitrogen supply and recovery device; a mixer; a foreign substance storage tank; a control device; and a foreign substance recovery unit. The mixer mixes ultrapure water supplied from the ultrapure water pipe device and foreign substances supplied from the foreign substance storage tank, and the nitrogen supply and recovery device maintains a constant internal pressure in the mixer and the foreign substance storage tank. The pH of the solution inside the foreign substance storage tank is measured using a foreign substance pH sensor, the temperature is measured using a storage tank thermometer, and the pressure is measured using a storage tank pressure gauge. The control device stores flow data of a foreign substance flow transmitter, the opening degree of a foreign substance supply flow control valve, flow data of an ultrapure water flow transmitter, and the opening degree of a pure water supply flow control valve. On the basis of the flow data from a flow transmitter and the degree of opening of a flow control valve stored in the control device, the opening degrees of the foreign substance supply flow control valve and the pure water supply flow control valve are adjusted by setting the ratio of the flow rate of a mixture flow transmitter to "foreign substance setting value 1" and "pure water setting value 2". The mixture of foreign substances and pure water is recovered and reused via a first resin unit or a second resin unit, and the foreign substances are recovered by a foreign substance recovery unit and reused.

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