The (green) thermostatic valve on oil-flooded compressors

Oil-injected or oil-flooded (screw) compressors, mostly have a thermostatic valve to keep the oil temperature high enough to avoid condense / moister / emulsion in the oil circuit. In the past, these were passive thermostats with settings between 55°C to 95°C (131°F to 200°F ) depending pressure, and a worst case condition in summer time.

For 50 years this worked sufficient, but this method has issues. The 3 most important:

-      Efficiency losses, ideal compression should be isothermal.

-      90% of the time to warm

-      High oil vapour and high oil carry-over

By installing a controlled thermo-valve, the oil temperature will be set just above the condensation temperature depending of the moister load of the actual ambient air and the working pressure, with next advantages:

-      2% average efficiency increase (1% of every ?10°C or ?18°F)

-      Increase lifetime of parts & oil

-      Average oil emissions will be reduced by more than 50% (the green valve)

Bürkert has developed a simple but inventive thermo-valve. Please contact me for more info.

I believe, this is the best improvement since Variable-Speed-Drive on screw & vane compressors, do you agree?