Screw Blowers

In wastewater aeration, pneumatic conveying, and process air supply for chemical and cement plants, blowers often run all year without rest and account for a substantial power bill year after year; the noise and pulsation of a traditional Roots blower also force many companies to place it in a corner far from the workshop.

Fusheng's screw blowers are currently led by the BWV Series PM VSD screw blower, replacing the traditional Roots structure with screw rotors and combining a permanent magnet motor with VSD control, improving both energy efficiency and noise.

1. Where a Roots Blower's Energy Goes

A Roots blower pushes gas with two rotors; back pressure at the outlet causes reverse flow and pulsation, and most models run at fixed speed, so when air volume changes they can only adjust by blowing off or throttling, wasting energy noticeably; the clearance between the rotors and the casing also causes leakage, and the higher the pressure, the more pronounced the loss.

2. What the Screw Structure Brings

A screw blower uses intermeshing screw rotors, and gas is compressed continuously and smoothly in the rotor chamber before being discharged. Compared with push-type transport, its airflow pulsation is smaller and discharge steadier, so vibration and noise are lower — the basis for its advantage in continuous operation.

3. Permanent Magnet Motor and VSD Control

With a high-efficiency permanent magnet motor and a high-precision VSD, blower speed can be adjusted to demand and air output matched as needed, avoiding the waste of fixed-speed operation and achieving energy savings of 25%–35% compared with a traditional Roots blower.

4. Technical Specifications

5. Applications and Selection Advice

• Wastewater treatment: aeration needs a continuous, stable air supply;
• Pneumatic conveying: air conveying of powders and granular materials;
• Chemical and cement: process air supply and combustion air supply.

In selection, first determine the required air volume and pressure, and avoid over-specification based on the maximum duty; where air volume fluctuates noticeably, give priority to evaluating the energy savings of VSD control; and finally include running energy consumption and maintenance cost in a whole-life comparison.