What Is a Centrifugal Fan?

Centrifugal fan is a machine that relies on the input of mechanical energy to increase the pressure of gas and discharge gas. It is a driven fluid machine. Centrifugal fans are widely used in ventilation, dust extraction and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; ventilation and induced draft of boilers and industrial furnaces; cooling and cooling of air conditioning equipment and household appliances Ventilation; drying and sending of grain; wind tunnel wind source and inflation and propulsion of hovercraft.

• Centrifugal fans use high-speed rotation based on the principle of converting kinetic energy to potential energy.

  In 1862, British Guerbel invented the centrifugal fan. Its impeller and casing are concentric, and the casing is made of brick. The wooden impeller uses backward straight blades, which has an efficiency of only about 40%. It is mainly used for mine ventilation.

  In 1880, people designed volute casings for exhaust air supply in mines and centrifugal fans with backward curved blades. The structure was relatively complete.

  In 1892, a cross-flow fan was developed in France. In 1898, the Irish designed a sirocco centrifugal fan with forward blades and it was widely used in various countries. In the 19th century, axial flow fans were used in mine ventilation and metallurgy industry. However, the pressure is only 100-300 Pa, and the efficiency is only 15-25%. It has not developed rapidly until the 1940s.

  In 1935, Germany first adopted axial flow isobaric pressure

  With the advancement of China's industrialization process, the industrial industry is vigorously carrying out energy conservation and consumption reduction, industrial upgrading and integration and reorganization, and industrial basic equipment needs a lot of updates. Centrifugal fans, as important supporting equipment for the industry, will be used more in the fields of electricity, cement, petrochemicals, coal, mining and environmental protection. Under the new economic development situation, the centrifugal fan industry will continue to maintain rapid growth in the future. It is estimated that by 2022, the market size of the centrifugal fan industry will reach 96 billion yuan.

  The centrifugal fan is essentially a variable flow constant pressure device. When the speed is constant, the theoretical pressure-flow curve of the centrifugal fan should be a straight line. Due to internal losses, the actual characteristic curve is curved. The pressure generated in a centrifugal fan is greatly affected by changes in intake air temperature or density. For a given amount of intake air, the lowest pressure occurs at the highest intake temperature (lowest air density). For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When

  Centrifugal fan drive parts wear is a common equipment problem, including exhaust fan bearing position, bearing room wear,

  Centrifugal fan industry space

  The main products of domestic centrifugal fan manufacturers include large-scale industrial blowers, fans, gas blowers, coke oven blowers, multi-stage high-pressure centrifugal blowers, single-stage high-speed centrifugal blowers and more than fifty series, and more than 400 specifications of energy-saving centrifugal fans Widely used in iron and steel smelting, thermal power generation, new dry process cement, petrochemical, sewage treatment, waste heat recovery, gas recovery and nuclear power.

  Traditional businesses benefit from energy-saving transformation. Over the next three years, production capacity will replace the market capacity of 2.16 billion yuan. More than 95% of the domestic large-scale industrial centrifugal fan business revenue will come from the four major industries of steel, cement, thermal power, and petrochemicals. The construction of new capacity will slow down, but with the large-scale industrial structure upgrade in China, energy-saving transformation projects such as large generations and small ones, energy conservation and consumption reduction, and industrial environmental protection will continue, which will generate a large demand for centrifugal fans. According to the State Council's "Notice on Further Strengthening the Elimination of Backward Production Capacity", it is required to close down 100 million tons of backward production capacity such as steel, cement and thermal power within 2-3 years. According to preliminary estimates, large-scale capacity replacement in downstream industries will increase the market capacity of large-scale centrifugal fans by 2.16 billion yuan. The core competitive advantage lies in the "three excellent model" of leading R & D strength + excellent energy saving + advanced services. ^[3]

  Common types of centrifugal fans

  The common types of centrifugal fans are as follows:

  1.Industrial centrifugal fans

  2.Dust removal / environmental protection fan

  3.Anti-corrosion / explosion-proof fan

  4.High temperature boiler induced draft fan