Vacuum Silencers

Vacuum Blower Silencers

There are three types of vacuum blowers for which Stoddard Silencers manufactures silencers.

• Dry Rotary Positive Displacement Blowers
• Water sealed Rotary Positive Displacement Blowers
• Liquid Ring Vacuum pumps

Each pump has its own unique application and requires a different style of silencer. Using the wrong style of vacuum blower silencer can reduce the efficiency of the vacuum blower and result in unsatisfactory noise control.

Dry Vacuum Rotary PD Blowers: For many years dry vacuum blowers were limited to the depth of vacuum they could achieve. With Rotary Positive Displacement Blowers (Rotary PD Blowers) the heat generated within the blower is dissipated by transfer to the air being passed through it. As the level of vacuum becomes greater there is less and less air actually flowing to help achieve this heat transfer.

At a given level the heat within the blower will rise to a point where it is damaging to the blower. With the addition of jet ports to inject cooling air into the discharge side of the blower the heat can be transferred and deeper vacuum levels achieved. With jet port blowers a silencer is required on the jet port and on the blower discharge.

Proper sizing of the discharge silencer is required to insure that a standing noise wave is not generated. This standing wave can travel long distances and create objectionable noise levels in the surrounding environment.

Water Sealed Rotary PD Blowers:

Another method of cooling the blower during operation is to inject water into the blower inlet. The water seals the blower allowing deeper vacuum levels and absorbs much of the generated heat. Different silencers are available to remove either 95% or 99% of the free water contained in the discharge air stream.

Water Ring Vacuum Pumps:  Water Ring Vacuum Pumps use a column of water and multiple vanes to create the vacuum necessary for the application. They are particularly suited for wet applications where there is water already present in the system prior to the pump. Iin these cases a separator silencer is required prior to the pumps inlet to remove the entrained water. A similar separator is required on the discharge to remove and recirculate the water that is used to affect the vacuum within the pump.

Stoddard Silencers manufactures three different models of separator silencers for the Water Ring Vacuum Pumps. Although all models separate 99% of all free water in the discharge air stream, each model has a different attenuation capability.