COMPRESSOR
Mechanical device which imparts kinetic energy to the fluid in impeller and conversion of this energy into pressure by decreasing velocity in diffuser.
SURGING
According to the standard operating curve of compressor, maximum discharge pressure is obtained at minimum flow rate. So, if maximum head capacity is reached, then pressure in diffuser will be greater than pressure at impeller outlet, this will prevent fluid from moving towards discharge and cause the fluid in diffuser to flow back towards impeller. Reversal of flow takes place.
IT CAN
Mechanical device which imparts kinetic energy to the fluid in impeller and conversion of this energy into pressure by decreasing velocity in diffuser.
SURGING
According to the standard operating curve of compressor, maximum discharge pressure is obtained at minimum flow rate. So, if maximum head capacity is reached, then pressure in diffuser will be greater than pressure at impeller outlet, this will prevent fluid from moving towards discharge and cause the fluid in diffuser to flow back towards impeller. Reversal of flow takes place.
IT CAN
- Damage bearings.
- Damage other rotating parts.
- Cause high vibrations.
REMEDY
- Anti-surge valve.
CHOKING
According to the given below graph, compressor run in between of surge point and stonewall point which also known as Choking point. As it is described in the above para that if flow is decreased and pressure is increased Surging will occur. Now, flow increases and discharge pressure decreases which means less back pressure on fluid and less resistance to flow as a result flow increases to a velocity approachable to MACH=1 also known as Sonic velocity and choking occurs.
IT CAN
- May cause very severe damage to the compressor.
REMEDY
- Anti-choke valves.
