In 1862, the British inventor Guillermo del Guébert invented the centrifugal fan. Its impeller and casing were concentric circles, the casing was made of brick, and the wooden impeller used backward-curved straight blades. Its efficiency was only about 40%, primarily used for mine ventilation.
In 1880, centrifugal fans with volute casings and backward-curved blades for mine ventilation were designed, and their structure became relatively complete.
In 1892, France developed a cross-flow fan; in 1898, an Irishman designed the Sirocco centrifugal fan with forward-curved blades, which was widely adopted by various countries. In the 19th century, axial flow fans were used for mine ventilation and blasting in the metallurgical industry, but their pressure was only 100-300 Pa, and their efficiency was only 15-25%. Rapid development only began after the 1940s.
In 1935, Germany first adopted axial flow isobaric fans for boiler ventilation and induced draft; in 1948, Denmark manufactured an axial flow fan with adjustable blades during operation; cyclone axial flow fans, meridional acceleration axial flow fans, diagonal flow fans, and crossflow fans were also developed; in 2002, China's explosion-proof centrifugal fans were widely used in chemical, petroleum, and machinery industries, and Changlindong explosion-proof centrifugal fans also saw development. Centrifugal fans are commonly used auxiliary production equipment in stone processing enterprises, mainly used in ventilation and dust removal devices. For example, cyclone dust collectors and bag dust collectors in stone cutting and grinding processes all require centrifugal fans to remove dust from the production site, ensuring a clean production environment and protecting the health of workers. Fans are high-energy-consuming devices, and the proportion of electricity consumed by fans in stone processing is relatively large. With the increasing energy shortage in my country and the promotion and application of high-yield and high-efficiency working surfaces, energy conservation and consumption reduction have become a common concern for stone production enterprises, and many stone production enterprises have made reducing the power consumption of fans an important task.
Reducing the power consumption of fans requires more than just improving their efficiency; the most crucial factor is the appropriate selection of fan regulation methods. This is because the load in stone production constantly changes according to process requirements, and most fans need frequent flow rate adjustments based on the main unit load. Currently, energy-saving regulation methods for fans in stone processing enterprises are relatively outdated, generally employing throttling regulation. When using throttling regulation, the fan flow rate is mainly adjusted using regulating valves or throttling baffles. The throttling effect is large, sometimes exceeding 50% at low loads. However, due to throttling losses and operation outside the high-efficiency zone, energy waste is significant. Adjusting the fan speed, on the other hand, eliminates throttling losses and ensures the fan always operates within the high-efficiency zone, thus significantly saving energy. Therefore, adjusting the fan speed is an effective energy-saving method, reflecting a new trend in current building materials industry production.
