A device that transfers energy to a continuously flowing fluid by the dynamic action of the blades on the rotating impeller or drives the blades to rotate by the energy transmitted from the fluid is called an impeller machine. In turbomachinery, the rotating blades do positive or negative work on the fluid, increasing or decreasing the pressure of the fluid. Turbomachinery is divided into two categories: working machines, from which the fluid absorbs power to increase the head or head, such as vane pumps and fans; and prime movers, in which the fluid expands, reduces pressure, or produces a head power, such as steam and water turbines. People call the prime mover a turbine, while the working machine is a vane type fluid machine.

According to the different working principles of the fan, it is divided into two categories: vane type and volumetric type, of which the vane type can be divided into axial flow, centrifugal and mixed flow. According to the level of pressure generated by the fan, it can be divided into a blower, a compressor and a ventilator. my country's current machinery industry standard JB/T2977-92 stipulates: a fan is a fan whose outlet pressure (gauge pressure) is less than 0.015MPa under the condition that the inlet is standard air inlet; the outlet pressure (gauge pressure) is between 0.015MPa and 0.2MPa. If the outlet pressure (gauge pressure) is greater than 0.2MPa, it is called a compressor.

The main components of the blower are: volute, collector and impeller.

The collector can guide the gas to the impeller, and the airflow condition at the impeller inlet is guaranteed by the geometry of the collector. There are many shapes of current collectors, mainly: cylindrical, conical, cylindrical conical, arc, cylindrical arc, arc conical and so on.

The impeller is generally composed of four parts: wheel cover, wheel disc, blade, and shaft disc. The connection methods of its structure are mainly welding and riveting. According to the different installation angles of the impeller outlet, it can be divided into three types: radial, forward and backward. The impeller is the most important part of the centrifugal fan. It is driven by the prime mover and is the heart of the centrifugal impeller machinery. It is responsible for the energy transmission process described by Euler's equation. The flow inside the centrifugal impeller is affected by the rotation of the impeller and the surface curvature. flow, backflow and secondary flow phenomena, which make the flow in the impeller very complex. The flow condition inside the impeller directly affects the aerodynamic performance and efficiency of the whole stage and even the whole machine.

The volute is mainly used to collect the gas from the impeller, and at the same time, the kinetic energy of the gas can be converted into the static pressure energy of the gas by moderately reducing the gas velocity, and the gas can be guided to leave the volute outlet. As a fluid impeller machine, the blower is a very effective method to improve its overall performance and work efficiency from the research of its internal flow field. In order to understand the real flow conditions inside the centrifugal blower and improve the design of the impeller and the volute to improve the performance and efficiency, scholars have done a lot of basic theoretical analysis, experimental research and numerical simulation calculations for the centrifugal impeller and volute.

Other structures of the blower:

Rotor: consists of shaft, impeller, bearing, synchronous gear, coupling, bushing, etc.

Bearings: Type 3000 double row radial spherical roller bearings are selected as the positioning end near the coupling end. 32000 type single row radial short cylindrical roller bearing is selected as the free end near the gear end to adapt to the axial displacement of the rotor during thermal expansion.

Synchronous gear: It is composed of a ring gear and a hub, which is easy to adjust the impeller clearance.

Body: It consists of a casing and left and right wall panels. The left and right wall panels and the bearing seats and sealing parts installed in the left and right wall panels can be used in common with each other.

Base: The medium and small fans are equipped with a common base, and the large fan is only equipped with a fan base, which is easy to install and debug.

Lubrication: The gears are immersed and the bearings are splash lubricated. Good lubrication effect, safe and reliable.

Transmission mode: The coupling is mainly connected directly. If the performance specification requires, the V-belt pulley speed change method can also be used. The coupling adopts elastic coupling, which can alleviate the impact and compensate a small amount of axis deviation. In addition to the motor as the driver, the large flow fan can also use a steam turbine or other drivers.