How to solve the problems in circulating cooling water pump system

The manufacturer of high-voltage electrostatic circulating water will explain to you that improper control of water treatment, high turbidity of make-up water, introduction of fine silt and colloidal substances into the cooling water system, or untimely killing of bacteria and algae, serious corrosion and many corrosion products will aggravate the formation of dirt. Due to its large volume and loose texture, it is also called soft dirt. When such water flows through the surface of the heat exchanger, it is easy to form dirt deposit, especially when the water goes through the shell, the dirt deposit is more in the slow flow part. A large amount of dirt deposition will cause corrosion under the scale, and at the same time, it is a hotbed for the survival and reproduction of some bacteria (anaerobic bacteria).

Control of dirt: the formation of dirt is mainly composed of dust, debris, dead bodies of bacteria and algae and their secretions, fine scale and corrosion products.

When water containing more bicarbonate is used as cooling water, when it passes through the heat transfer surface of heat exchanger, it will be decomposed by heating: the cooling water passing through the cooling tower is equivalent to an aeration process, and the dissolved CO2 will escape, so the pH value of water will increase. At this time, bicarbonate will react under alkaline conditions. Both calcium carbonate and calcium phosphate are slightly soluble salts, and their solubility is much smaller than that of calcium chloride and calcium bicarbonate. In addition, the solubility of calcium carbonate and calcium phosphate is different from that of ordinary salts. They do not increase with the increase of temperature, but decrease with the increase of temperature. Therefore, on the heat transfer surface of heat exchanger, these micro soluble salts are easy to reach supersaturation state and crystallize from water. When the water flow velocity is small or the heat transfer surface is rough, these crystal deposits are easy to be on the heat transfer surface. In addition, when the product of anionic and cationic solubility of calcium sulfate, calcium silicate and magnesium silicate dissolved in water exceeds its own solubility product, precipitation will also be formed and deposited on the heat transfer surface. Such deposits as described above are generally referred to as scale. Because these scales are composed of inorganic salts, they are also called inorganic scales; because they are dense and hard, they are also called hard scales. They are usually firmly attached to the heat exchange surface and are not easily washed away by water. In most cases, the scale formed on the heat transfer surface of heat exchanger is mainly carbonate scale.

Scale control: if there is no excessive PO43 - or SiO2 in cooling water, calcium phosphate scale and silicate scale are not easy to form. Calcium carbonate scale is easy to form in the system. In this paper, sediment control mainly refers to how to prevent the precipitation of carbonate scale.