Sodium hydrosulfite electrolytic cell process control system

A centralized controller based process control system for the operation of an electrolytic membrane cell to continuously produce an aqueous product solution in the cell which has a cathode compartment, an anode compartment, a cation exchange membrane separating the anode compartment and the cathode compartment, comprising:

• (a) a core process control program to control operating conditions including the feed of raw materials to the catholyte in the cathode compartment and to the anolyte in the anode compartment and to maintain the feed within tolerances of desired set points for a desired rate of feed by initiating self-correcting instructions to actuators controlling the rate of feed of the raw materials, the core process control program also sensing alarm conditions when an operating condition is out-of-tolerance;
• (b) an alarm monitoring program to receive sensings of alarm conditions of out-of-tolerance conditions from the core process control program, to analyze the sensings and data on the operation of the cell, and to issue instruction and commands in response thereto;
• (c) at least one sequencer program that is put into operation by a command from the alarm monitoring program and which sends commands to the core process control program to initiate a cell corrective procedure when any predetermined one of the alarm conditions sensed by the core process control program exists;
• and
• (d) a timer program that is initiated by the sequencer program to initiate timing an out-of-tolerance condition and activating at least one sequencer program to initiate the cell corrective procedure.