Difference between Roots blower and centrifugal blower and explanation of working principle:

Roots Blower

Roots blower is a positive displacement fan, and the air volume delivered is proportional to the number of revolutions. There is always a small gap between the end face of the impeller and the front and rear end covers of the fan, as well as between the fan impellers. Driven by the synchronous gear, the air is delivered from the fan inlet to the exhaust side along the shell wall.

Centrifugal fan

Centrifugal fan is a kind of driven fluid machinery, which relies on the input mechanical energy to increase the gas pressure and discharge gas. Centrifugal fans are widely used for ventilation, dust removal and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; Ventilation and induced draft of boiler and industrial furnace.

Difference between Roots blower and centrifugal blower

1. The working principle is different. The centrifugal fan uses curved blades to throw the gas to the casing by centrifugal force, while the Roots fan uses two 8-shaped blades with a small gap between them. The gas is squeezed to the air outlet by the extrusion of the two blades.

2. Due to different working principles, their working pressures are generally different. The outlet pressure of Roots blower is relatively high, while that of centrifugal blower is relatively small.

3. The air volume is different. Generally, Roots blower is used in places with low air volume requirements but high pressure requirements, while centrifugal blower is used in places with low pressure requirements and high air volume requirements.

4. The manufacturing precision is different. Roots blower requires high precision and strict assembly requirements, while centrifugal blower is relatively loose. Of course, there are still some small communities.

5. If the load requires constant flow effect, roots blower shall be used. Because Roots blower is a constant flow fan, the main working parameter is the air volume, and the output pressure changes with the change of pipe and load, and the air volume changes little. Roots blower is a high pressure fan. Roots blower is a positive displacement fan. The air volume conveyed is proportional to the number of revolutions, and the gas is conveyed from the suction side to the discharge side. If the load needs constant pressure effect, centrifugal fan is used. Because the centrifugal fan is a constant pressure fan, the main working parameter is the air pressure, and the output air volume changes with the change of the pipeline and load, and the air pressure changes little. Centrifugal fan with low air pressure. The air compression process is usually carried out by several working impellers (or stages) under the action of centrifugal force. Centrifugal fan belongs to square torque characteristic, while Roots fan basically belongs to constant torque characteristic.

6. Roots blower generally has a large air volume and pressure, and also has a large noise. If the air volume is required to be small and the noise is required to be high, the rotary blower is selected. The rotary blower is also a constant flow fan. The main working parameter is the air volume. The output pressure changes with the change of pipes and loads, and the air volume changes very little, Rotary fan is variable volume compression, and its main characteristics are: low speed, low noise, low vibration, high efficiency, and high energy saving.

Fans commonly used in sewage treatment

1. Sewage treatment fan - Roots blower, if the load requires constant flow effect, roots blower will be used. Because Roots blower is a constant flow fan, the main working parameter is the air volume, and the output pressure changes with the change of pipe and load, and the air volume changes little. Roots blower is a high pressure fan. Roots blower is a positive displacement fan. The air volume conveyed is proportional to the number of revolutions, and the gas is conveyed from the suction side to the discharge side.

2. Sewage treatment fan - centrifugal fan is used if the load requires constant pressure effect. Because the centrifugal fan is a constant pressure fan, the main working parameter is the air pressure, and the output air volume changes with the change of the pipeline and load, and the air pressure changes little. Centrifugal fan with low air pressure. The air compression process is usually carried out by several working impellers (or stages) under the action of centrifugal force. Centrifugal fan belongs to square torque characteristic, while Roots fan basically belongs to constant torque characteristic.

3. Sewage treatment fan - rotary fan. Roots blower generally has large air volume and pressure, and also has large noise. If the air volume required is relatively small and the requirements for noise are high, the rotary blower is selected. The rotary blower is also a constant flow fan, and the main working parameter is air volume, The output pressure changes with the change of pipeline and load, and the air volume changes very little. The rotary fan is variable volume compression, and its main characteristics are: low speed, low noise, low vibration, high efficiency, and high energy saving.