The petrochemical industrial pump is the largest rotating equipment in the petrochemical production plant. It transports various liquid media such as crude oil, refined oil, chemical raw materials, intermediate products and finished products to other places like the human heart delivers blood.
According to statistics, a medium-sized refinery has more than 1,000 pumps, of which centrifugal pumps account for 83%, reciprocating pumps account for 6%, gear pumps account for 3%, and the rest are screw pumps and vacuum pumps. A petrochemical plant has more than 2,000 pumps, of which 45% are centrifugal pumps, 23% are gear pumps, 12% are reciprocating pumps and screw pumps, and 6% are shielded pumps. These pumps are typically driven by a motor. The pressure of the medium pressure transmitted by the petrochemical pump is 300 MPa, and the temperature is from 140 ° C to nearly 500 ° C. Some media are viscous, some have solid particles, and most of the transport media are corrosive. Petrochemical pumps are the most energy-intensive equipment, accounting for about 50% of the electricity used in the whole plant.
China's petrochemical pumps have been developed over the years, and the varieties are relatively complete. Especially since the reform and opening up, many foreign advanced technologies have been introduced, and the technical performance and product quality have been greatly improved. However, in general, domestic pump products have many gaps compared with foreign countries: First, the standardization, serialization and generalization of pumps are poor. Due to the self-contained series of various manufacturers, the standardization and interchangeability of parts are low, and there is no uniform standard. The product specifications and models can not meet the needs of the development of the petrochemical industry. Second, the quality and reliability are poor. This is mainly because the domestic corrosion-resistant materials have few varieties or improper materials, and the processing precision is not high; in addition, the pump has a low sealing life and few varieties. The mechanical seal life of foreign countries can generally reach two years or so, and domestic petrochemical pumps have not yet reached this level. Third, the pump efficiency is low. Because the domestic pump design model is poor, the processing accuracy is not high, and the pump efficiency is generally 2% to 3% lower than that of foreign countries. Therefore, many chemical process pumps have to be imported from abroad.
In recent years, many domestic pump factories have introduced advanced technology from abroad, which has greatly improved the technical level of petrochemical pumps. For example, Dalian Sulzer Pumps and Compressor Co., Ltd. introduced the technology of Swiss Sulzer, which can produce 43 series of petrochemical pumps with more than 1000 specifications.
In the future, with the continuous development of petrochemical industry technology and scale, the requirements for petrochemical pumps are getting higher and higher. In addition to continuing to improve the quality of conventional pumps and expand the specifications, especially for pumping corrosive materials, the demand for pumps is increasing. Large, such as ethylene cracking equipment, polyethylene equipment and polypropylene equipment in ethylene production, PTA equipment (fine terephthalic acid), polyester equipment and polyester spinning equipment in chemical fiber production, so efforts should be made to develop corrosion resistance. technology. At present, the material of the corrosion-resistant pump is still a large number of ferrous materials and high-nickel alloy materials. In the future, more excellent corrosion-resistant materials such as titanium, zirconium and hafnium are required, as well as non-metallic materials such as ceramics, glass reinforced plastics and graphite.