Aerzen Rotary lobe blowers - Pulsation Cancellation Feature

Principle of operation of a rotary lobe blower

Synchronized by precision ground helical timing gears, two symmetrical rotors convolute without making contact. The medium to be conveyed is displaced in a positive manner from inlet to discharge via the chambers formed between the rotors and the housing. At the very moment the rotor tip clears the discharge, the volume of gas displaced is compressed by the back flow from the discharge end. The final pressure automatically adjusts itself to the system’s back pressure.

Pulsation inherent to rotary lobe blowers

How it works : The air or gas stream pulsates as a result of its operating principle. Patented in Aerzen blowers, internal pulsation interference channels in conjunction with 3-lobe rotors reduce the pulse in the discharge air stream by as much as 90% or 20 dB at the lobe-passing frequency. This significant attenuation contributes strongly to reducing vibrations in the entire package and lowering the noise emitted by the downstream piping. In addition, a discharge silencer is used as a secondary measure.

The noise levels stated by Aerzen cover the complete rotary blower package, therefore including the contribution by the inlet or exhaust noise and the noise emitted by the accessories / components.

The standard Aerzen rotary lobe blowers (“PD blowers”) are three-lobe blowers (sometimes called "tri-lobe blowers™" ) where the discharge pulsations inherent to Roots® type blowers are all but cancelled at the source by a patented interference system.