Vacuum pump from high/super vacuum to thick/low vacuum, its products can be roughly divided into 14 categories:
High/ultra-vacuum — cryogenic pump, molecular pump, sputtering ion pump, titanium sublimation pump, diffusion pump.
Medium vacuum – dry pump, double – stage vane pump, roots pump, oil booster pump, steam jet pump.
Coarse/low vacuum — single-stage rotary vane pump, piston vacuum pump, liquid ring pump, reciprocating vacuum pump.
The vacuum pump market changes dynamically according to the needs of users. The growth of the market is mainly driven by the rapid development of the semiconductor industry and the expansion of dry pump and molecular pump applications.
Although the liquid ring pump belongs to the crude vacuum pump, but in China’s petroleum, chemical, electric power, light textile, paper, medicine and other fields still have a large market. In foreign countries, the sales of liquid ring pump accounted for 14% of the whole vacuum pump market, second only to dry pump, investment in China to build factories or establish sales network, expanding the market share in China. Because most of the liquid ring pumps are castings, processing requirements are not high, labor intensive products, so domestic liquid ring pumps have competitive advantages in price, the key is to improve the design, reduce the volume, reduce weight, improve efficiency, reduce energy consumption.
Because the piston vacuum pump is more durable and reliable, all kinds of vacuum furnace at home and abroad, coating machine and drying, macerating equipment are using the piston vacuum pump as the vacuum pump, but the piston vacuum pump casting weight, processing workload is larger, so foreign vacuum factories are looking for partners in China. In order to make the domestic piston vacuum pump can enter the international market, we must further reduce the vibration noise of the pump, put an end to oil injection and oil leakage, improve the reliability of the long run piston vacuum pump.
With the continuous expansion of vacuum technology in various application fields, the demand for the rotary vane pump is increasing. As a result of this kind of vacuum pump quantity is a lot of, processing assembly workload is very big, the price is very low, so some foreign vacuum manufacturer establishes the specialized factory in China. Domestic small and medium-sized rotary vane pump in technology has passed, the price is far cheaper than foreign vacuum pumps, so the domestic pump still has a competitive advantage, the key is to solve the shaft seal leakage and rotary vane material and vacuum pump oil performance and quality problems, to ensure that the pump in high speed, high temperature performance stability and reliable operation, but also to further improve the ability of domestic rotary vane pump to remove water vapor.
4. Roots pump
At present, the domestic air – cooled vertical exhaust roots pump has made rapid progress and is technically mature. Because the vacuum pump is fitted with a gas cooler below the vent, some of the cooled gas is piped back to the vacuum pump chamber to cool the rotor, thus balancing the heat of the compression, the vacuum pump can discharge directly into the atmosphere. In order to meet the requirements of different limit vacuum, this kind of pump can be used in series, generally in front of an air-cooled direct exhaust air roots pump, the ultimate vacuum to reach a higher order of magnitude than the previous pump. This pump because there is no working medium in the pump chamber, is actually a dry pump. At present, the air-cooled direct exhaust air roots pump and its units have been in the petroleum, chemical, plastics, pesticides, turbine rotor dynamic balance.
Molecular pumps are used to replace cryogenic pumps in many processes in the semiconductor field, especially in sputtering, etching and LCVD devices.
Since the molecular pump to water vapor pumping rate is only a quarter of the pumping speed of the cryogenic pump of the same caliber, the molecular pump exhaust time is longer than the cryogenic pump. In order to improve the pumping speed, a low-temperature cold plate of -130℃ ~ -150℃ is installed on the inlet side of the molecular pump in foreign countries, which is called the low-temperature molecular pump. The water vapor is captured by the low-temperature plate, while other gases are extracted by the molecular pump. The application of low temperature molecular pump in vacuum coating device not only improves the production efficiency but also improves the film quality. With the rapid development of China’s semiconductor industry, film industry and scientific research, molecular pump should be the focus of the development of China’s vacuum pump manufacturing industry. First of all, molecular pumps from small to large to establish a complete series, and research and development of a variety of composite molecular pumps, traction pumps and low temperature molecular pumps, to meet the needs of different occasions.
6. Dry pump
Foreign dry pump market growing, the main drive from the semiconductor industry, chemical industry, the rapid development of the film industry. In Japan, the semiconductor industry has fully use dry vacuum pump instead of mechanical pump oil seal type, more than 45% in Europe and the semiconductor industry with dry vacuum pump instead of mechanical pump oil seal type, greatly improving the product performance and quality. In order to meet the requirements of different applications and different working condition, abroad have multilevel roots vacuum pump, multistage claw type vacuum pump, screw vacuum pump, the vortex type vacuum pump, reciprocating piston vacuum pump and turbine type oil-free vacuum pump, etc. The ultimate pressure ranges from 10Pa to 10-2pa, and the pumping speed ranges from 20m3/h to 500m3/h. According to statistics, the application of domestic dry pump is less than 1%, the domestic semiconductor industry with the dry pump imported from abroad, its price is very expensive. Therefore, our country should vigorously research and develop the dry pump, make the dry pump become our country vacuum industry new economic growth point.