Due to the development of coal mine, chemical industry, pharmaceutical industry and paper industry, the requirements of water ring vacuum pump are more and more large-scale. Before 2000, there were only 3-4 enterprises in China that could produce water ring vacuum pump with pumping capacity of more than 100 m3 / min, and the annual output of the whole country was only dozens of units. However, only three years later, by 2003, more than 10 manufacturers (including 7-8 in Zibo) were able to produce more than 100 m3 / min large pumps in China. According to incomplete statistics, the output of large pumps in China has reached more than hundreds. These products are mainly used in:

(1) Coal mining industry

As the state has strengthened the safety requirements for coal mines, water ring vacuum pumps, especially large-scale water ring vacuum pumps, have become the necessary safety requirements of the coal mining industry. For example, a Mining Bureau in Shaanxi Province ordered several super large water ring vacuum pumps with a pumping capacity of 400 m3 / min, which were used to remove gas, and some large coal mines used 100 m3 / min to remove gas There are 7-8 large pumps on. With the further strengthening of national safety work, large and extra large water ring vacuum pump will be more and more widely used in coal mine system.

In addition, due to the rapid increase of coal production, the vacuum filters used for coal washing and coal preparation in coal mines are also developing to large scale. In the 1980s, most of the SZ-4 water ring vacuum pumps with a pumping capacity of 27m3 / min, which was also large at that time. In recent years, coal mine filters have been equipped with large-scale water ring vacuum pumps with pumping capacity of 80-150 m3 / min, some of which reach more than 200 m3 / min, and there is a trend of increasing gas volume.

(2) Chemical industry

a) Chlor alkali industry

In recent years, many large-scale capital construction and technological transformation projects have been launched in China. The real children of these projects need a lot of PVC materials. Especially the prosperity of real estate has promoted the development of PVC industry. According to the statistics of chlor alkali industry, China produced 4.1 million tons of PVC last year and imported 200 tons. According to the forecast of the industry, the national demand will reach 8 million tons in 2005, and 15 million tons in 2010. It is precisely because of the rapid increase in demand that the enterprises in the chlor alkali industry in China will be transformed and expanded, and many new enterprises have been established in the past one or two years. The development of chlor alkali enterprises must be equipped with water ring vacuum pump and water ring compressor J. the largest water ring vacuum pump and water ring compressor used to extract and compress acetylene and hydrogen used to be only 30 m 3 / min in the past, but now the enterprises with an annual output of 100000 tons of caustic soda and 100000 tons of PVC need more than 70 m 3 / min of water ring vacuum pump and water ring compressor.

It is the development of this industry that promotes and accelerates the development and production of high I force water ring compressor.

For a long time, when the suction pressure is 1 atm or slightly lower than the upper pressure, the discharge pressure is 0.1MPa, that is, the compression ratio is 2. Some enterprises have produced water ring compressors with discharge pressure up to 25mpag, and only 1-2 specifications. In order to adapt to the production of polyvinyl chloride, 91 former State Council major equipment office put forward the research and development of vinyl chloride recovery water ring compressor in the "Eighth Five Year Plan" major technical equipment research and development of 4 tons of low polymerization degree PVC equipment. This kind of water ring compressor for recovery of vinyl chloride monomer requires that the discharge pressure be under normal pressure or micro negative pressure The force should reach 0.55-0.6mpag, and the displacement should reach 700m3 / min.

In recent years, this kind of water ring compressor has been popularized and applied under the situation of PVC project in China, and has completely replaced the import.

b) Chemical fertilizer industry

The chemical fertilizer industry, especially the production of phosphate fertilizer, is also a key industry supported by China's macro-control. As the new projects and the technical transformation of old enterprises are mainly above the level and scale, large and super large water ring vacuum pumps have also been applied here. For example, a phosphate fertilizer enterprise in Yunnan Province added three extra large water ring pumps with a pumping capacity of 300m 3 / min.

In addition, there are many phosphate fertilizer enterprises, the process requirements are still greater than 80 -- 100hPa absolute pressure, so two-stage water ring vacuum pump and two-stage water ring vacuum pump with atmospheric ejector have unique advantages when used in this condition. Many fertilizer enterprises have eliminated reciprocating vacuum pump with high vibration noise and high vacuum degree, and use two-stage water ring vacuum pump It can be said that the two-stage water ring vacuum pump will be more and more widely used in this industry.