Centrifugal fan and kiln fan seem to be no different, in fact, they are different in many aspects. First of all, the installation of kiln fan is more complex than centrifugal fan, which requires more time and energy.
Secondly, centrifugal fans are often installed at the inlet and outlet of air-conditioning units, boiler blowers, induced draft fans, etc., while kiln fans are mostly installed in the air duct or the front end of the air duct outlet, for different purposes.
In addition, the connection mode of centrifugal fan and kiln fan motor is different, the former motor and fan are usually connected by belt-driven rotating wheel, while the latter motor is generally in the fan; in addition, the kiln fan does not change the flow direction of medium in the duct, the centrifugal fan changes the flow direction of medium in the duct; the discharge shell expands slowly to slow down the speed of air or gas flow. The kinetic energy is converted into useful static pressure.
In addition, there are oblique flow fans, whose air pressure coefficient is higher than that of kiln fans and flow coefficient is larger than that of centrifugal fans, so it can be used to fill the gap between kiln fans and centrifugal fans. Flow fan is very popular because it can change the flow rate by changing the blade angle in the upper inlet shell of impeller, and it is easy to install.
Francis fan combines the characteristics of kiln and centrifugal fan. Although it looks more like traditional kiln fan, its casing can have an open entrance, so that the motor can be placed outside the pipeline; and welding the curved plate blades on the conical steel hub is very simple.