The introduction of centrifugal blower
Centrifugal blowerare defined as: blowers with a pressure ratio greater than 1.02 but less than 1.1, a reference Mach number (sound velocity of 1) less than 0.15, and a corresponding pressure rise of 2kPa to 10kPa. Its impeller and casing are concentric circles, and the casing is made of brick. The wooden impeller adopts backward straight blades, and the efficiency is only about 40%. It is mainly used for mine ventilation.
Practical application
Centrifugal blowers are widely used in factories, mines, tunnels, cooling towers, vehicles, ships and buildings for ventilation and cooling; ventilation and induction of boilers and industrial furnaces; cooling and cooling of air-conditioning equipment and household appliances. Ventilation; drying and selection of grain; wind tunnel wind source and inflation and propulsion of hovercraft, etc.
Working principle
The common medium-pressure fan is a centrifugal fan, the impeller of which is covered with a mechanical casing, and the center of the impeller is the air inlet. When the medium-pressure fan is working, the power equipment runs to drive the impeller to rotate, and the air is sucked in from the air inlet. During the rotation of the blades of the centrifugal fan, power is applied to the gas to increase the pressure and speed of the gas, and the gas is discharged from the exhaust port along the blade path under the action of centrifugal force.
During the working process of the medium-pressure fan, although the rotation of the impeller increases the pressure and speed of the gas, the various changes of the gas are small. Therefore, in the design and use of the centrifugal fan, the gas is usually regarded as incompressible. fluid to handle. The gas treatment process of medium pressure fans is completed in the same radial plane, so medium pressure blowers are also called radial flow centrifugal blowers.
Performance parameters
Among the performance parameters of centrifugal blowers, the more important ones are gas flow, pressure, delivered power, efficiency and impeller speed, etc., which must be paid attention to during the selection process. The gas flow parameter of the medium-pressure fan represents the volume of gas that the fan can handle per unit time, while the pressure of the medium-pressure fan refers to the internal gas pressure value during the working process of the medium-pressure fan.
The efficiency of the medium pressure fan refers to the ratio between the shaft power of the medium pressure fan and the effective power of the actual processed gas. The total pressure efficiency of centrifugal fans is about 90%, and in the future development of centrifugal fans, the efficiency value will be one of the further goals pursued by researchers.
Maintenance
When using the centrifugal blower, pay attention to cleaning the dust on the surface of the fan, checking and cleaning the bearings, and tightening the bolts of each part. Check the air inlet and outlet, adjust the tightness of the V-belt, check the lubricating parts, and replace the lubricating oil and sealing ring.
