1. Permanent magnet transmission, that is, permanent magnet coupling, is the safest solution for the machinery that needs to be sealed, and for harmful, toxic, polluted, dangerous, pure and valuable products and production processes, and its application range is very wide. Most of the liquids in petrochemical, pharmaceutical, film, electroplating, nuclear power and other industries are corrosive, flammable, explosive, toxic, and valuable. Leakage will bring waste of working liquid and environmental pollution; vacuum and semiconductor industries must prevent external Invasion of gas: food and medicine should ensure the purity and hygiene of the medium. Permanent magnet drive technology has found a place in these areas. British Howard Machinery Development Co., Ltd. (HMD) has been committed to the manufacture of sealless magnetic pumps since 1946, and has sold nearly 70,000 units in 37 countries around the world, with an annual sales of 28 million pounds. A pharmaceutical factory in the United States has hundreds of centrifugal magnetic pumps equipped with mechanical seals to handle various acids. Due to design problems, these magnetic pumps often run dry, and they can be destroyed after only 2 to 3 months of use. The K1516 series magnetic drive pump produced has been in operation since 1993 (4.8 hours per day, 365 days per year) to 1998. Container plate plant in the US Midwest, where synthetic caustic is a huge problem for rotary vane pump seals, engineers here call these pumps "a day in the maintenance night." Ansimag's ETFE-lined sealless magnetic pump was installed, running 11 month without downtime. A large U.S. chemical plant is facing serious difficulties in delivering methanol. Because methanol is flammable, it is close to boiling at 60°C, the flow rate is only 7m3/h, and the pressure difference is as high as 250m. The problem is solved by the Dickow magnetic drive multi-stage end suction magnetic pump. Its flow rate is 15m3/h and the pressure difference is 400m, which ensures zero leakage of methanol, ensures the safety of operators and the factory, and solves the problem of methanol containing air bubbles. delivery problem.
2. The technical performance of the magnetic pump is miniaturized and large-scale development In order to meet the needs of domestic and foreign markets, the complete set of equipment of petrochemical companies is developing into large-scale development. my country must have a number of oil refineries with an annual output of 10 million tons, million tons of oil refineries. Vinyl plant. Mechanical equipment must meet heavy load, long cycle, low energy consumption, and meet environmental protection requirements. my country found in the imitation of foreign products that the material and process requirements for manufacturing magnetic pumps are very high. Even if the small and medium power magnetic pump of 11~13kW, its reliability and manufacturing cost cannot be accepted by users. It is still blank for high-power magnetic pumps that are resistant to strong corrosion, high pressure and high temperature. At present, the development limit of the magnetic pump should be described by the products of HMD Company: the flow rate is from 1m3/h to 681m3/h, the pressure difference is from 10m to 500m, the temperature range is from -100℃ to 450℃, and the system pressure is from vacuum to 400bar. The engine power reaches 350kW. Miniature magnetic pumps are specially developed for certain departments, such as cooling of lasers, feeding of analytical instruments, replenishment of chemical agents, bioengineering, cooling cycles, and even nozzles of printers. The gear oil pump and the motor are integrated and closed, suitable for 24V, 36V DC power supply, and the speed is manually and automatically controlled. The minimum flow is 10ml/min and the differential pressure is 7bar. The flow range of MD series miniature magnetic transmission gear oil pump for electroplating and cooling cycle is 7.5~288L/min, and the transmission power is 1/25~1/3 horsepower.
3. Various types of centrifugal pumps can be transformed into magnetic pumps
Centrifugal pump is the leading product of magnetic pump. Although magnetic drive rotary displacement magnetic pump has a history of 25 years, only in the past seven or eight years, it has a broad foundation in terms of design and manufacturing level and high torque capacity. The focus is on the magnetic transmission gear oil pump and the screw pump, with a maximum transmission capacity of 400Nm and a power of 150kW at a speed of 3500r/min. Located at the U.S. border Utah Gas Power Plant, the lubricating pump of the turbo compressor is a constant rail external gear oil pump. The gear oil pump was scrapped due to excessive wear on average every two months due to the high differential pressure, causing the compressor to shut down. In 1992, the three-screw pump with magnetic drive was used, and it has been running continuously without any maintenance.
4. Magnetic drive compressor
The inner bearing of the magnetic drive is located in the sealed space, which is lubricated and cooled with a sealed medium. In view of my country's material manufacturing level, magnetic drive has not yet been applied in gas conveying machinery. The overpressure fan produced by Nova Magnetics Co., Ltd. in Canada has a leakage rate of 1cm3/h and a bearing life of more than 10,000h under 170bar helium pressure. Another series of pressurized fans has a free discharge flow rate of 750m3/h and a system pressure difference of 35MPa at a flow rate of 400m3/h, achieving zero leakage. In addition, the special properties of the magnetic drive are also used in leak-free agitators, valves and other equipment. The application in refrigerators has not yet obtained relevant information. The author is doing exploration work to realize the application of magnetic drive to refrigeration compressors. The leakage of refrigerants, especially Freon, will cause serious environmental problems.
