Apparatus for the automatic concentration control of aqueous caustic soda solution

摘要

An apparatus for the automatic concentration control of an aqueous caustic soda solution in a cloth treating tank through which a cloth to be treated is continuously transported, comprising the provision of a means for adding a neutralization agent to a sample of the caustic soda solution which was squeezed out of a cloth that had been soaked with an aqueous caustic soda solution while in a cloth treating tank; a sensor for detecting the neutralization point of said caustic soda sample solution, to which the neutralization agent is added on the basis of electrical conductivity; a means for detecting the caustic soda concentration of said caustic soda sample solution prior to the addition of the neutralization agent on the basis of the amount of the neutralization agent added until said caustic soda sample solution becomes neutralized as detected by means of said sensor; and a means for supplying a supplementary caustic soda solution to the caustic soda solution in said cloth treating tank so that its concentration is controlled to a prescribed value on the basis of the caustic soda concentration of the caustic soda sample solution detected by said detection means.