Centrifugal Air Compressor Surge

As more compressed air is produced than needed the centrifugal compressor must unload or deliver less air to avoid over pressure.

Centrifugal air compressor surge.

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. Choke and surge occur at the extreme ends of the performance curve and should be avoided. 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. 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.

Centac c800 centrifugal air compressor. When a centrifugal compressor surges there is an actual reversal of gas flow through the compressor impeller. Centrifugal air compressor basics key concepts centrifugal compressors are most effective when running at full capacity. The addition of the turbo air and msg centrifugal compressors expands our market coverage to higher pressure higher flow and process gas compression applications.

The surge usually starts in one stage of a multistage compressor and can occur very rapidly. Centrifugal compressors sometimes called radial compressors are a sub class of dynamic axisymmetric work absorbing turbomachinery. 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. Centrifugal air compressor delivered flow or capacity is dependent on inlet density.

Compressor capacity should be stated at plant conditions which are actual cubic feet per minute acfm. 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. Surge is defined as the operating point at which centrifugal compressor peak head capability and minimum flow limits are reached. Now we will see how the surge starts in a compressor.

Actually the working principle of a centrifugal compressor is increasing the kinetic energy of the fluid with a rotating impeller. Compressor surge only occurs in dynamic compressors axial and centrifugal due to their nature. The lower mass flow reduces the ability of the first stage. Msg process gas and api compressors.

Compressor surge control using anti surge valve asv cold gas recycle. The surge is starting with the instant flow reverses shown in the. Compressor surge is a form of aerodynamic instability in axial compressors or centrifugal compressors the term describes violent air flow oscillating in the axial direction of a compressor which indicates the axial component of fluid velocity varies periodically and may even become negative.