I’ve been working with HCL synthesis for some time now, but I’m not sure how the flow rate of water absorbed during the production of 31% hydrochloric acid is calculated

Generally, based on the load of the furnace, it is possible to determine the amount of water that needs to be added per hour or per shift. Then, by considering the concentration of hydrochloric acid produced, the amount of pure water required can be calculated, and by adding these two values together, the output of hydrochloric acid can be determined. (Other impurities can be ignored) or it can be calculated directly by comparing the amount of pure water used with the hydrochloric acid concentration. First, determine the production volume of hydrochloric acid based on your requirements, and then use that to figure out the amount of water to be added. The amount of water added can remain constant over a certain period, unless it is necessary to adjust the load. Then, adjust the amounts of chlorine and hydrogen fed into the furnace according to the production requirements. This amount fed into the furnace can be calculated, but chlorine is greatly affected by pressure fluctuations and purity variations, so it cannot be determined entirely based on theoretical calculations. In the automated control process, the pressure of hydrogen entering the furnace is adjusted according to that of chlorine; the instability in the purity of chlorine also affects the flow control of hydrogen. Therefore, many chlor-alkali plants use manual control to adjust the feed rate into the furnace. All the criteria for judgment boil down to the acid concentration; the amounts of chlorine and hydrogen fed into the furnace can be adjusted based on the specific gravity of hydrochloric acid. The measurement of specific gravity can be carried out either through online monitoring or by manual intermittent sampling. The chlorine-to-hydrogen ratio still needs to be determined based on the flame color. The amounts of chlorine and hydrogen introduced, as well as the volume of water used for absorption, can all be calculated theoretically. However, it is difficult to achieve absolute precision in the flow rates of chlorine and hydrogen; therefore, it is more practical to first reduce the amount of water used for absorption according to the theoretical values, and then determine a more accurate control range through regular analyses