In 1862, the British Guibel invented a centrifugal fan. Its impeller and casing are concentric circles. The casing is made of bricks. The wooden impeller adopts straight backward blades. The efficiency is only about 40%. It is mainly used for mine ventilation.
In 1880, people designed a volute casing for mine exhaust and air supply, and a centrifugal fan with backward curved blades. The structure has been relatively complete.
In 1892, France developed a cross-flow fan; in 1898, the Irish designed a forward-blade Sirocco centrifugal fan, which was widely used in various countries; in the 19th century, axial flow fans were used in mine ventilation and metallurgical industry. However, the pressure is only 100-300 Pa, and the efficiency is only 15-25%. It was not until the 1940s that the rapid development was achieved.
In 1935, Germany first adopted axial flow equal pressure fans to ventilate and induce the boiler; in 1948, Denmark made an axial flow fan with adjustable moving blades in operation; rotary axial flow fans, meridian acceleration axial flow fans, diagonal flow fans and Cross flow fan: In 2002, China's explosion-proof centrifugal fan was widely used in chemical, petroleum, machinery and other fields, and Changlindong explosion-proof centrifugal fan was also developed. Centrifugal fans are commonly used auxiliary production equipment for stone processing enterprises. They are mainly used in ventilation and dust removal devices. For example, cyclone dust collectors and bag dust collectors in the stone cutting and polishing processes require the use of centrifugal fans to remove dust on the production site to ensure production The environment is clean to protect the physical and mental health of the producers. Fan is a kind of high-energy-consuming equipment. The power resource of the fan is a large proportion in stone processing. With the current increasing shortage of energy in my country and the popularization and application of high-yield and high-efficiency working surfaces, energy saving and consumption reduction have become stone production. Enterprises are generally concerned about issues, many stone production enterprises regard reducing the power consumption of fans as an important task at present. In addition to improving the efficiency of the fan itself, to reduce the power consumption of the fan, it is most important to choose the adjustment method of the fan reasonably.
Fans need to adjust the flow frequently according to the load of the host. At present, the energy-saving adjustment methods of fans in stone processing enterprises are relatively outdated, and throttling is generally adopted. When throttling is used, the flow of the fan is mainly adjusted by adjusting valves or throttling baffles. The throttling flow of the fan is large, even when the load is low, the throttling is more than 50%. Due to the throttling loss and deviation from the high-efficiency zone operation, Energy waste is very serious. And if the fan speed is adjusted, the throttling loss can be eliminated, and the fan can always run in the high-efficiency area, so it can greatly save power. It can be said that adjusting the speed of the fan to run the fan is an effective energy-saving method, which reflects the new trend of the current building materials industry production.
