Automatic control system for operation and protection of electrodialysis system

Abstract

An automatic control system for operation and protection of an electrodialysis system comprises an electrodialysis unit, a dosing unit and an automatic control unit. The electrodialysis unit comprisesan electrodialysis membrane stack, a fresh water storage tank, a concentrated water storage tank and an electrode water storage tank, wherein a fresh water chamber circulating pipeline, a concentrated chamber circulating pipeline and an electrode chamber circulating pipeline are formed. The dosing unit comprises an acid dosing unit and a reducing agent dosing unit. The automatic control unit comprises a PLC module and a human-machine interface HMI. The system composition is optimized, each sensor monitors material water inlet indexes such as turbidity, ORP value, pH value, pressure, temperature and the like in real time, and a corresponding regulation and control mechanism is made, so that an electrodialysis membrane stack is prevented from being damaged or polluted; in addition, all thesensors cooperate with one another through a PLC, normal and automatic operation of the electrodialysis system is guaranteed, and operation accidents are reduced.

Description

technical field [0001] The invention relates to the technical field of water treatment, in particular to an automatic control system for the operation and protection of an electrodialysis system. Background technique [0002] The electrodialysis process is a combination of an electrochemical process and a dialysis diffusion process. Driven by an external DC electric field, the selective permeability of the ion exchange membrane is used (that is, cations can pass through the cation exchange membrane, and anions can pass through the anion exchange membrane). Anions and cations move to the anode and cathode, respectively. In the process of ion migration, if the fixed charge of the membrane is opposite to that of the ions, the ions can pass through; if they have the same charge, the ions are repelled, so as to achieve the purpose of desalination, concentration, refinement or purification of the solution. Electrodialysis was developed in the 1950s and was originally used for des...

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Problems solved by technology

[0004] Although the automatic control of frequent electrode reversal electrodialysis system (EDR) can alleviate the fouling problem inside the membrane stack, the factors affecting the performance of the electrodialyzer during the operation are not only unilateral, but in most cases are caused by a combination of various factors. For example, oxidation-reduction substances cause corrosion damage to the membrane matrix, pigment adsorption causes membrane selectivity to decline or even disappear, high temperature causes membrane "scald", high pressure causes membrane tearing, high turbidity causes membrane stack water channel blockage, high pH value Cause plate coating to fall off, membrane surface fouling, high concentration difference causes ion migration speed to decrease, high voltage and current cause "membrane burning", etc., all of which will lead to a decline in the operating performance of the electrodialyzer

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