The types and development status of mechanical chemical process pumps
The chemical process pump is a general term for various pumps in the chemical production process. There are many varieties of chemical process pumps, which can be divided into vane pumps according to their principle of action, such as centrifugal pumps, axial flow pumps, mixed flow pumps, partial flow pumps, vortex pumps, etc.; volumetric pumps, such as reciprocating pumps (including plunger pumps, pistons) Pumps, diaphragm pumps, etc.; rotary pumps (including screw pumps, liquid ring pump gear pumps, vane pumps, Roots pumps, radial piston pumps, etc.); other types of pumps, such as jet pumps, electromagnetic pumps, water hammer pumps Wait. According to the production process or product characteristics, it can be divided into high pressure methylamine pump, cryogenic pump, phosphoric acid slurry pump and so on.
In chemical or petrochemical production, the pump works under high temperature, low temperature (or ultra low temperature), high pressure, flammable, explosive, toxic and corrosive medium, and some are still high inlet pressure, high lift, high viscosity, small flow, Working under high cavitation conditions places very stringent requirements on the performance of chemical pumps, especially for corrosion resistance, leakage (for toxic media) and wear resistance. In order to meet the special requirements of chemical production, special chemical pumps are also produced in the chemical industry, such as plastic pumps, glass pumps, ceramic pumps, graphite pumps, shield pumps, magnetic pumps, and impurity pumps. The mediums to be transported during the production of phosphate fertilizer mainly include phosphate rock slurry, phosphoric acid slurry, various filtrates, concentrated phosphoric acid phosphoric acid, concentrated sulfuric acid, dilute sulfuric acid and fluorosilicic acid. The pump is highly susceptible to corrosion or corrosion of the medium and wear and tear.
Phosphate slurry pump is a general term for various pumps in the production process of phosphate fertilizer. It is a representative type of strong corrosion and wear resistant pump. In the early stage of the development of phosphate fertilizer industry, the common chemical corrosion-resistant pumps have a life of only one week. Therefore, experts at home and abroad have carried out extensive research and development on the structural design, material testing and sealing research of phosphoric acid slurry pumps. In the design of the phosphor slurry pump, the first problem to be solved is corrosion resistance or corrosion and erosion wear. Therefore, special consideration should be given to the structural design and the matching between the pump casing and the impeller. The metal materials used in foreign phosphate slurry pumps are different series according to the medium conditions. Domestic manufacturers and research units have also studied the corrosion properties and wear resistance of various materials, and created their own ferritic stainless steel, duplex steel, austenitic stainless steel and other materials series. There are many professional manufacturers of phosphoric acid slurry pumps in China, as well as Chinese Academy of Sciences, universities, design institutes, research institutes, etc., and the localization of phosphate slurry pumps has been basically solved.
Among the large, medium and small-scale phosphate compound fertilizer production projects that have been built in China, there are about 30 to 40 slurry pumps for large and medium-sized installations, and 20 to 30 slurry pumps for medium and small-sized plants. The average life of each pump is 6 months, and the market space is relatively large. In addition, some large phosphate fertilizer production enterprises in China have just been completed or the infrastructure is still in progress, and a number of small and medium-sized ammonium phosphate expansion and expansion projects have provided a broad market space for domestic phosphate fertilizer pumps.