Roots blower and screw blower are common types of blower, they have some differences in structural design, operating principle, application range and so on. Here's how they compare:

- Structural design:

- Roots blower: consists of two rotating Roots impellers, which rotate in a synchronous manner and are driven by gears.

- Screw blower: consists of two screws (twin screws) or a screw and a CAM (single screw), which rotate by engaging.

- Operation principle:

- Roots blower: The airflow is generated by the rotation of the Roots impeller. When the Roots impeller rotates, the gas is drawn into the air intake of the blower, and then compressed and discharged.

- Screw blower: Through the rotation of the screw or screw and CAM to achieve the compression and discharge of gas.

- Compression efficiency:

- Roots blower: Due to the design of the impeller, there is a certain gap and rotation area during the compression process, and there may be some leakage and energy loss.

- Screw blower: The design allows the gas to be carried out more continuously and evenly during the compression process, thus increasing the efficiency.

- Noise and vibration:

- Roots blowers: The noise and vibration generated during operation are relatively large, and some measures need to be taken to reduce the noise and vibration levels.

- Screw blowers: Generally more quiet and smooth in this regard.

- Scope of Application:

- Roots Blower: Suitable for applications requiring larger gas flow and lower pressure, such as ventilation, burners, particle transport, etc.

- Screw blowers: Often used in applications requiring higher gas pressure and lower noise requirements, such as sewage treatment, water treatment, power plants, etc.

In summary, Roots blowers and screw blowers have their own advantages in different application scenarios. When choosing a blower, it is necessary to consider it comprehensively according to the specific needs and application scenarios.