Structure, Features and Pressure Capacity of Kiln Fans

Structure, Features and Pressure Capacity of Kiln Fans

Kiln fans possess excellent characteristics such as high airflow, high air pressure, resistance to dust accumulation, wear resistance and a long service life, and are highly regarded by customers in the dust removal sector. Kiln fans are suitable for use in furniture factories, timber mills and cement plants to handle mixed air containing wood shavings, fibres and dust. Kiln fans are classified into two types: right-hand and left-hand. When viewed from the front of the fan, if the impeller rotates clockwise, it is referred to as ‘right-hand’ rotation; if it rotates anti-clockwise, it is referred to as ‘left-hand’ rotation. The outlet angle of the kiln fan. The outlet position of the kiln fan is indicated by the outlet angle of the casing; ‘left’ and ‘right’ can be any of six angles: 0°, 45°, 90°, 135°, 180° or 225°. The structure of the kiln fan primarily consists of the impeller, casing, inlet and transmission assembly. 1. Impeller: Consists of 10 backward-curved blades made of A3 material, welded between a ring-shaped shroud and a flat disc. After dynamic and static balancing, it operates smoothly. 2. Housing: Formed into a complete volute by welding ordinary steel plates. 3. Inlet: Bolted to the inlet side of the outer casing to form a converging, streamlined integral structure. 4. Gearbox assembly: Comprising the main shaft, bearing housing and pulley. The main shaft is made of high-quality steel, and the bearing housing is of monobloc construction. The rolling bearings are lubricated with grease. A key feature of centrifugal fans used for dust removal in kiln fans is that dust does not easily accumulate, and they offer excellent wear resistance. Kiln fans utilise high-speed rotating impellers to accelerate gas based on the principle of converting kinetic energy into potential energy; deceleration alters the flow direction, converting kinetic energy into potential energy (pressure). In a single-stage centrifugal fan, gas enters the impeller axially, changes direction to radial flow as it passes through the impeller, and then enters the diffuser. Within the diffuser of the kiln fan, the gas changes direction, the cross-sectional area of the duct increases, and the airflow decelerates. Through this deceleration, kinetic energy is converted into pressure energy. The rise in pressure occurs primarily at the impeller, after which the diffusion process continues. In multi-stage centrifugal fans, a counter-flow arrangement is used to direct the air into the next impeller, generating higher pressure.