CONCENTRATION MEASURING METHOD OF HYDROCHLORIC ACID IN SOLUTION OF HYDROCHLORIC ACID CONTAINING CHLORINE

摘要

PURPOSE:To make it possible to measure the concentration of hydrochloric acid in a solution of hydrochloric acid at any temperatures with high accuracy, by measuring the temperature difference between a test solution to be measured and a reference solution and, the electromotive force between chlorine electrodes inserted in respective solutions. CONSTITUTION:A storage tank 2 which stores anolyte is positioned above an electrolytic cell 1. A gas/liquid separator 3 for the cathode is placed at the side of the cathode of the electrolytic cell 1. Moreover, a liquid sink 4 is provided in an anolyte circulating line between the storage tank 2 and the cell 1, in which tank 4 an iridium wire electrode is inserted to be a chlorine electrode 5 of a test solution. In the meantime, a solution of hydrochloric acid 7 having chlorine saturated which is a reference solution is brought into tough with the anolyte in the storage tank 2 through a solution connecting section 6. An iridium wire electrode is inserted into the solution 7 to form a chlorine electrode 8 of the reference solution. Then, an electromotive force between the electrodes 5 and 8 is inputted into a concentration controller, with an electromotive force because of the temperature difference between the test solution and reference solution being led in by the use of a thermocouple 9. Thereafter, hydrochloric acid is introduced from an inlet 10, and the hydrochloric acid is discharged out of an outlet 11 of the used hydrochloric acid. Accordingly, the concentration of the hydrochloric acid in any solution can be measured accurately.