Anti Surge Control

Contact the compressor manufacturer in the first instance.

Thanks, the compressor manufacturer is MHI, yet the anti surge control were planning is probably out of their scope as the units is already more than 5 years. We would just like the concept of anti-surge control for a fixed speed driver and centrifugal compressor. The compressed gas is residual gas from condenser unit of geothermal steam turbine. What we need is the required signal going to the anti-surge transmitter, and the transmitter output to the anti-surge valve.

What is MHI? How many stages? How is the arrangement of stages? How a centrifugal compressor is supplied without Anti-surge control system? Are you running the compressor without Anti-surge control system since last 5 years? For this best is to contact the manufacturer.

Anti-surge control system should work basically to sense the safe minimum flow rate required through the compressor and give signal to open bypass valve to prevent surging. For this first of all you need a bypass line (about half the size of discharge pipe) from discharge to suction along with a pneumatic operated valve to be called 'Anti-surge Valve' with an auto control system. After this you have to plot surge curve by actually surging the running machine at different discharge pressure. Draw a line parallel to surge line just before surge limit for setting the controller to open the valve. It should be fail open. Anti-surge control valve Open condition should be starting inter-lock for compressor.