Roots-type blowers take air from one side and transport it to the other using two lobes rotating in opposite directions inside the casing. The lobes do not touch each other or the casing; thus, there is no oil in the compression chamber, and the discharged air remains clean. They are the primary machines for applications requiring high air delivery at low and medium pressure.
Working principle
With each rotation of the rotor, the volume of air trapped between the lobes and the casing is transferred from the suction side to the discharge side. Blowers do not compress the air internally; pressure is generated when the air reaches the discharge line. Therefore, the flow rate is largely independent of pressure and varies in direct proportion to the rotational speed.
Difference between straight lobe and helical lobe
In conventional blowers, the lobes have a straight cross-section. When each lobe reaches the discharge port, the air is released suddenly; this leads to pressure fluctuations, vibration, and high noise.
In helical (twisted) lobed rotors, however, the lobe is twisted at a gentle angle along the rotor length. Air is delivered to the discharge port gradually rather than all at once. The results of this are:
- Smoother, less fluctuating air flow
- Lower vibration and noise levels
- Less load on bearings and gears, resulting in longer service life
Fields of application
- Aeration in wastewater treatment plants
- Pneumatic conveying of powder and granules
- Fish farms and pool aeration
- Process air in cement, food, and chemical plants
The ZNS helical lobe blower series is manufactured in a capacity range from 330 m³/h to 11,000 m³/h. You can share the required flow rate and pressure information with us to select the model suitable for your application.
