SU882944A1 - Electrolyzer for water treatment - Google Patents

Description

The invention relates to chemical technology and can be used for electrochemical control of the magnitude of the active reaction (pH) of the medium during the purification of natural and waste waters. The apparatus for electrocoagulation of dispersed systems is known, the electrode system of which consists of a solid anode and a mesh cathode pressed against the mesh gasket 1 separating them 1. Since the mesh gasket does not provide for separation of electrode products chemical changes in the pH of the anolyte and catholyte. A device for electrolytes for water is known, which includes a container and perforated electrodes placed in it, electrodes, pressing on both sides of the diaphragm 2 1. The disadvantages of the known device are the increased energy consumption for water treatment. This is due to the fact that part of the electricity is not productively expended on the electrolysis of a layer of water that is in the zone between the inner surface of the electrodes and the diaphragm. The purpose of the invention is to reduce the energy consumption for water treatment. The goal is achieved by the fact that the surface of the electrodes, facing the diaphragm, is covered with electrical insulating material, with cirn material, and the perforations of the electrodes are made coaxially. The drawing shows the device, the cross-section. The cell contains a housing 1, divided by the diaphragm 2 into anodic 3 and cathode 4 chambers. The perforated anode 5 and the cathode 6 are pressed to the diaphragm 2 on both sides. The perforations of the cathode and the anode are aligned. The surface of each electrode facing the diaphragm is coated with electrically insulating material 7. Vinyl plastic, polyethylene, plexiglas, as well as lacquer, paint, etc. can be used as an electrically insulating material.

The device works as follows.

When water is treated, electric current passes between the outer planes of the cathode 6 and the anode 5, resulting in an increase in the pH of the catholyte in the cathode chamber 4 and a decrease in the pH of the anolyte in the anode chamber 3. Since the inner surfaces of the electrodes 5 and 6 are covered with electrically insulating material 7, unproductive electrolysis in the zone between the diaphragm 2 and the electrodes 5 and 6, as well as in the pores of the diaphragm, is prevented. This makes it possible to reduce the cost of electricity to change the pH of the catholyte and anolyte.

An example. Electrochemical neutralization of the purified wash water of the electroplating workshop was carried out in the proposed (with electrical

material) and known (without electrically insulating material) electrolyzers for the purpose of re-using treated water in production.

Water treatment parameters: current density on the electrodes is 30 A / m, electrolysis voltage is 12 V. Epoxy resin was used as the electrical insulation material, diaphragm material - belting fabric, anodes and cathodes - Х18Н10Т steel. The initial pH of the water was 10.1.

Energy consumption data on the neutralization of purified wash water in the anode chamber of electrolyzers, depending on the pH of the treated water

are shown in the table. I

Thus, the use of the proposed device allows a 30–45% reduction in the consumption of electricity consumed for the electrochemical neutralization of the purified wash water. In addition, the neutralization of the aqueous phase produced in this case without reducing the total salt content allows the recycled water to be used in production.

Claims (2)

1. USSR author's certificate number 500811, cl. B 03 C 5/00, 1976. 2. Patent of Germany No. 2334647, cl. C 25 B 1/10, 1975 (prototype).