Addtime： 2020-07-18 Browse times： 2254
Liquid ring pump
Although the liquid ring pump belongs to the crude vacuum pump, it still has a large market in the fields of petroleum, chemical industry, electric power, light textile, papermaking, medicine and other fields in China.
In foreign countries, the sales volume of liquid ring pump accounts for 14% of the total vacuum pump market, second only to dry pump. Because most of the liquid ring pumps are castings, and their processing requirements are not high, they are labor-intensive products. Therefore, domestic liquid ring pumps have competitive advantages in price. The key is to improve design, reduce volume, reduce weight, improve efficiency and reduce energy consumption.
Slide valve pump
As the slide valve pump is more durable and reliable, the slide valve pump is used as the front stage pump for various vacuum furnaces, coating machines, drying and impregnation equipment at home and abroad. However, the casting of the slide valve pump is heavy and the processing workload is large. Therefore, foreign vacuum factories are looking for partners in China. In order to make the domestic slide valve pump enter the international market, we must further reduce the vibration and noise of the pump, put an end to oil injection and oil leakage, and improve the long-term operation reliability of the slide valve pump.
Direct rotary vane pump
With the continuous expansion of vacuum technology in various application fields, the demand for direct coupled vane pump is increasing. Because of the large quantity of this kind of pump, the workload of processing and assembling is very large, and the price is very low, some foreign vacuum manufacturers have set up professional factories in China. Domestic small and medium-sized direct vane pump has passed the technical requirements and its price is much cheaper than foreign pumps. Therefore, domestic pumps still have competitive advantages. The key is to solve the problems of shaft seal oil leakage, performance and quality of rotary vane materials and vacuum pump oil, so as to ensure stable performance and reliable operation of direct coupled pump at high speed and high temperature, and further improve the steam extraction of domestic direct coupled vane pump Ability.
Roots pump
From the overseas production of Roots pumps, several large foreign companies, such as LEYBOLD, Balzers, alcatell, Edwards and ULVAC, account for no more than 5% of the global sales of Roots pumps. The total sales of these five Roots pumps are only 20%. The output of Roots pumps is small, but the price of Roots pumps at home and abroad is much higher than that of domestic pumps. Almost all large or small high vacuum and medium vacuum systems at home and abroad are equipped with roots pumps in order to shorten the pumping time and improve the production efficiency. Therefore, domestic roots pumps must try to enter the international market on the basis of occupying the domestic market. In this way, we must further reduce the vibration and noise of Roots pumps, thoroughly solve the problem of shaft seal oil leakage, improve the appearance quality of pumps, and improve the appearance quality of pumps High finish and cleanliness in the pump. In addition, the power frequency of some countries and regions is 60Hz, and the long-term operation reliability of roots pump under the condition of increasing rotating speed should be ensured.
The development of air-cooled direct exhaust roots pump in China is very fast and the technology is mature. Because this kind of pump is equipped with a gas cooler under the exhaust port, part of the cooled gas returns to the pump cavity through the pipe to cool the rotor, so that the compression heat is balanced, so the pump can directly discharge the atmosphere. In order to meet the requirements of different limit vacuum degrees, this kind of pump can be used in series. Generally, an air-cooled direct exhaust air roots pump is added in front of the pump, and the ultimate vacuum reached is an order of magnitude higher than that of the previous stage pump. Because there is no working medium in the pump cavity, this kind of pump is also a dry pump. This kind of air-cooled direct exhaust roots pump and its unit have been tested in petroleum, chemical, plastic, pesticide, steam turbine rotor dynamic balance, aerospace space simulation and other devices for a long time, so it should be vigorously promoted and applied in China.
Molecular pump
Molecular pumps are used to replace low-temperature pumps in many foreign semiconductor fields, especially in sputtering, etching and LCVD devices.
The exhaust time of molecular pump is longer than that of cryogenic pump because the pumping speed of molecular pump is only one fourth of that of cryogenic pump with the same diameter. In order to improve the pumping speed, a low temperature cold plate from - 130 ℃ to - 150 ℃ is installed at the inlet side of the molecular pump, which is called low temperature molecular pump. The application of the low temperature molecular pump in the vacuum coating device not only improves the production efficiency but also improves the film quality. With the rapid development of China's semiconductor industry, thin film industry and scientific research, molecular pump should be the focus of the development of China's vacuum pump manufacturing industry. First of all, a complete series of molecular pumps should be established from small to large to meet the needs of different occasions.
Dry pump
The continuous growth of foreign dry pump market is mainly driven by the rapid development of semiconductor industry, chemical industry and thin film industry. In Japan, the semiconductor industry has all replaced oil sealed mechanical pumps with dry vacuum pumps. More than 45% of European and American semiconductor industries have replaced oil sealed mechanical pumps with dry vacuum pumps, greatly improving the performance and quality of products. In order to meet the requirements of different application fields and working conditions, there are multi-stage Roots vacuum pump, multi-stage claw vacuum pump, screw vacuum pump, scroll vacuum pump, reciprocating piston vacuum pump and turbine oil-free vacuum pump. The limit pressure is from 10 Pa to 10 ^ - 2 PA, and the pumping speed is from 20 m 3 / h to 500 m 3 / h.
Water ring pump
Water ring vacuum pump (hereinafter referred to as water ring pump) is a kind of coarse vacuum pump. It can obtain the limit vacuum of 2000 ~ 4000Pa and the series atmospheric ejector can reach 270 ~ 670pa. Water ring pump can also be used as a compressor, called water ring compressor, is a low-pressure compressor, its pressure range is 1 ~ 2 × 10 ^ 5pa gauge pressure.
Water ring pump was initially used as self suction pump, and then gradually used in petroleum, chemical, machinery, mining, light industry, medicine and food and many other industrial sectors. In many industrial processes, such as vacuum filtration, vacuum water diversion, vacuum feeding, vacuum evaporation, vacuum concentration, vacuum moisture regain and vacuum degassing, water ring pump has been widely used. Due to the rapid development of vacuum application technology, water ring pump has been paid attention to in the aspect of obtaining rough vacuum. Because the gas compression in the water ring pump is isothermal, it can extract flammable and explosive gas, in addition to the gas containing dust and water. Therefore, the application of water ring pump is increasing day by day.
A proper amount of water is installed in the pump body as the working fluid. When the impeller rotates clockwise in the figure, the upper inner surface of the water ring just contacts the tip of the blade (in fact, the blade has a certain insertion depth in the water ring). At this time, a crescent shaped space is formed between the impeller hub and the water ring, and this space is divided into several cavities equal to the number of blades by the impeller. If the lower 0 ° of the impeller is taken as the starting point, then the volume of the small cavity changes from small to large when the impeller is 180 ° before rotation, and it is connected with the suction port on the end face. At this time, the gas is inhaled, and when the suction end, the small cavity is isolated from the suction port; when the impeller continues to rotate, the small cavity becomes smaller and the gas is compressed; when the small cavity is connected with the exhaust port, the gas is discharged from the pump.
To sum up, water ring pump is to achieve suction, compression and exhaust by the change of pump chamber volume, so it belongs to variable volume vacuum pump.
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