Centrifugal Air Compressor Surge

Compressor capacity should be stated at plant conditions which are actual cubic feet per minute acfm.

Centrifugal air compressor surge.

They achieve a pressure rise by adding kinetic energy velocity to a continuous flow of fluid through the rotor or impeller this kinetic energy is then converted to an increase in potential energy static pressure by slowing the flow through a diffuser. The fluid is then slowed down in a volume called the plenum where the kinetic energy is converted into potential energy in form of a. The chief protecting agent of a centrifugal compressor is the anti surge line valve that recycles cold gas from the discharge side cooler back to the suction scrubber to keep the operating point away from the surge line. Centrifugal compressors sometimes called radial compressors are a sub class of dynamic axisymmetric work absorbing turbomachinery.

Centrifugal compressor surge is seen as a very dangerous and detrimental phenomenon in compressed air systems dangerous because it causes the compressor to vibrate and detrimental because it causes damage to the compressor parts. Centrifugal air compressor delivered flow or capacity is dependent on inlet density. Surge is defined as the operating point at which centrifugal compressor peak head capability and minimum flow limits are reached. The surge usually starts in one stage of a multistage compressor and can occur very rapidly.

The lower mass flow reduces the ability of the first stage. As more compressed air is produced than needed the centrifugal compressor must unload or deliver less air to avoid over pressure. The addition of the turbo air and msg centrifugal compressors expands our market coverage to higher pressure higher flow and process gas compression applications. Choke and surge occur at the extreme ends of the performance curve and should be avoided.

Actually the working principle of a centrifugal compressor is increasing the kinetic energy of the fluid with a rotating impeller. Compressor surge control using anti surge valve asv cold gas recycle. Msg process gas and api compressors. Each centrifugal compressor has a maximum pressure it can reach for specific inlet conditions that will cause the airflow to reverse and surge shutting off the compressor to avoid damage from the resultant vibrations.

A centrifugal air compressor will surge earlier based on amps on a hot day than on a cold day. Hot gas recycle valve. If the density drops due to higher inlet temperature the volume flow actually reduces. Centac c800 centrifugal air compressor.

When a centrifugal compressor surges there is an actual reversal of gas flow through the compressor impeller. The surge is starting with the instant flow reverses shown in the. Now we will see how the surge starts in a compressor.