Do you know what is Vacuum Degasser and its function? 
It is the 2nd phase solids control equipment, which is used after shale shaker, to separate various gas from the invasive drilling mud, so that it can protect decander, desilter cone and centrifugal pumps impeller.
Different with Derrick vacuum degasser, this GN vacuum degasser do not need suction pump, it has self-suction ability, so it can save energy and drilling cost.