The development of fan in China has a long history. In many years B.C., China has produced a simple wooden hungu windmill. Its working principle is basically the same as that of modern centrifugal fan. The principle of high-pressure fan is that under the design conditions, the fan with 30 kPa~200 KPa air pressure or compression ratio e=1.3~3 belongs to the category of high-pressure fan. At present, air-ring vacuum pump is generally classified as high-pressure fan in the industry.
At present, high-pressure fans are mostly used in industrial production, and are widely used in environmental water treatment, such as aeration of sewage, to meet the oxygen demand of aerobic microorganisms in activated sludge and the conditions of full contact and mixing of sewage and activated sludge, so as to degrade various organic substances in water to achieve the purpose of sewage purification, and also to meet the needs of aerobic microorganisms in activated sludge. Playing the role of stirring, as well as electroplating bath stirring, aquaculture, are playing the same role.
With the progress and development of the times, people are not satisfied with the pressure and air volume requirements of centrifugal air pumps, and the noise of centrifugal air pumps has become more and more a headache in the factory. Therefore, Japan first introduced a fully enclosed flow measurement fan, that is, today's high-pressure fan (scroll vacuum pump). With its fine appearance and noise, this fan first met the social demand for high-pressure fans at that time. Later, the fan was upgraded one after another, and developed to single-stage, double-stage and three-stage impeller high-pressure fan. The maximum pressure of the high-pressure fan was refreshed to 230 kPa at one time, but this is only the limit pressure of the blower.
With the extensive use of fans, various kinds of equipment have a standard process of its operation. Through a large number of experimental data, we know that the exhaust pressure (vacuum) of high-pressure fans increases, the flow rate of high-pressure fans decreases, the shaft power increases, the total efficiency curve is parabolic, and there is a maximum point. The working curve of the high-pressure fan clearly shows that the efficiency of the high-pressure fan is lower under the condition of positive pressure air supply, the maximum efficiency is only 44%, but the efficiency of the high-pressure fan is lower under the condition of suction, the maximum efficiency is only 32%, so sometimes the high-pressure fan can be used as a rough vacuum generator.
The application of high pressure fan has been widely used in industry and agriculture, covering infrastructure, environmental protection, automobile industry, electroplating industry, aquaculture industry, industrial dust collection, packaging machinery industry, printing machinery industry, plastics industry, chemical industry, food, pharmacy, medical treatment, electronics, light industry and textile industry. Weaving, shipping, railway and aerospace projects make our world more environmentally friendly.