What is anti-surge system in centrifugal compressor?

“Surge” phenomenon is common in Centrifugal compressors. To prevent the compressor from surges, a reversal of flow, process instability, and compressor damage, the compressor discharge flow is diverted to compressor suction via an anti-surge / recycle control valve. …

What is surge and anti-surge in compressor?

Application Overview. Compressor anti-surge protection is vital for all centrifugal and axial compressors. Compressor surge occurs when the downstream process flow demand quickly decreases (such as in an emergency shut-down), causing a rapid increase in downstream pressure and changing the compressor’s operating point.

What is the function of anti-surge valve?

Overview. These valves detect when a process compression stage is approaching to surge and subsequently take action to reverse the movement of the operating point towards the surge line. This decreases the plenum pressure and increases the flow through the compressor, resulting in stable working conditions.

How do you control the surge on a centrifugal compressor?

Hence over-sizing pipes can be detrimental.

  1. Re-Positioning Anti-surge Tap off- Point. Points to Remember.
  2. Slowing Compressor Speed during Coast down. Points to Remember.
  3. Discharge Side Gas Flaring. Points to Remember.
  4. Hot Gas Recycle Valve Installation. Points to Remember.

What causes a centrifugal compressor to surge?

Surge occurs when there is no forward flow of gas through the compressor and a reversal of flow occurs. The gas that is being compressed gets pushed backward through the centrifugal compressor. When this surge (flow reversal) occurs, which can happen in milliseconds, the rotor is affected.

What causes surging in a centrifugal compressor?

Meaning of Centrifugal Compressor Surge Centrifugal compressor surge is a characteristic behavior of the compressor that occurs in situations when inlet flow is reduced and the compressor head developed is so low that it can not overcome the pressure at the compressor discharge.

What happens during compressor surge?

Surging can cause the compressor to overheat to the point at which the maximum allowable temperature of the unit is exceeded. Also, surging can cause damage to the thrust bearing due to the rotor shifting back and forth from the active to the inactive side. This is defined as the surge cycle of the compressor.

How bad is compressor surge?

The difference is that compressor surge occurs while you’re on the throttle and compressor blades in the turbo stalls. This causes loss of boost pressure, thus loss of horsepower, probably bad AFR. Over time, repeated compressor surges damages the bearings in the turbo and it goes kaputz.

What is a surge control valve?

Pilot operated surge relief valves are typically used to protect pipelines that move low viscosity products like gasoline or diesel. This style of valve is installed downstream of the pump/valve that creates the surge. The valve is controlled by an external, normally closed pilot valve.

What is anti surge system?

an anti surge system can be installed to prevent such cases, the anti surge system is simply a spill back valve (similar to a check valve), that provides a pressure relief path at the receiver’s end, it can be calibrated to open the path at the critical amount of surge pressure, to prevent flow reversal in the compressor.

What is anti surge control?

The anti surge control system is designed so that the compressor will not experience the surge by blow off some portion of the discharge flow. The anti surge controller together with the anti surge control valve will do this very important task in a very fast manner.