Vacuum Degasifiers

A vacuum degasifier is typically used as part of a demineralizer system to remove entrained gasses like CO2 and oxygen from boiler-feed water for high-pressure boilers. It is located between the cation and anion exchangers in the demineralizer train. Since the vessel has to bear full vacuum, a steel ASME code vessel with a rubber lining is used. Polypropylene tower packing is utilized in the same fashion as forced draft degasifiers. However, in lieu of a counter current of air to strip CO2 and volatiles, vacuum is drawn on the vessel to remove all entrained gases. A vacuum pump with or without an ejector typically is used on the vessel. Steam jet educator systems can also be used. Depending on conditions and quality required, the degasifier can have one, two or three stages. Other applications include the removal of oxygen to control corrosion of steel pipes.