Innovative dry screw pump for industrial vacuum applications


GXSEdwards Ltd is one of the pioneers of dry vacuum pump technology. It recently launched its new GXS range of dry running vacuum pumps. The GXS range is the latest iteration of dry vacuum technology introduced by Edwards in 1986.

In the intervening 25 years, the Edwards has delivered more than 150,000 dry vacuum pumps to customers around the world.

Dry pump performance is now well established in arduous vacuum applications involving dust and liquid contamination, with contaminated gas streams typically being difficult for other types of vacuum pump to accommodate.

Edwards says that the new GXS series improves efficiency, improves the vacuum capability and greatly extends service intervals, while retaining the proven toughness of their dry screw technology.

In addition to the enhanced screw design, the GXS range benefits from long-life ceramic bearings, long-life synthetic lubricants and pumping chamber temperature control. Edwards considers the latter to be important where the incoming gas stream contains contaminants which are prone to condense if the pumping chamber is too cold or, alternatively, burn onto pump surfaces if too hot.

Because of its importance, pumping chamber temperature control is an integral part of the GXS range, not an add-on.

The end result, according to Edwards, is a robust pump suitable for a wide range of normally difficult vacuum applications.

Water Cooled Temperature Management System

In most cases, the GXS range can easily replace other types of vacuum pumps. Because the patented tapered variable pitch screw rotors deliver high pumping speed and efficiency, the GXS pumps are typically more compact than rotary vane vacuum pumps of equivalent capacity.

The water cooled temperature management system significantly reduces plant room heat load and the non-pulsating,vibration-free nature of the pumping cycle reduces noise output.

As an example, the 740 cubic meter per hour capacity GXS pump emits a noise level of less than 70 dB(A).

This compares with about 78 dB(A) from a similar capacity rotary vane vacuum pump. The compact size and clean exterior of the GXS pump facilitates easy installation and the low noise level and low heat output often permit installation in open factory areas and eliminate the need for an expensive plant room.

Other technical advances for the GXS include options such as automated high flow purging and solvent flushing. These provide on-going internal cleaning without need for disassembly. Along with the fully enclosed, high efficiency motor, advanced bearing and lubrication technology, the end result is reduced power consumption and long service intervals – 5 years in most applications.

On a population basis, New Zealand’s food industry, in particular, is a heavy user of vacuum technology.

Several local vacuum duties are prone to contamination, including milk powder conveying and degassing, vacuum packaging of meats and cheeses (often prone to liquid carryover from wash-down, or high water vapour loads from hot-boned meat) and freeze drying.

Vacuum users in these applications experiencing high maintenance costs and down time from existing vacuum pumps should consider the Edwards GXS as a long-term cost saving replacement.

The GXS pump should also be considered as a fire risk reduction strategy for dairy factories and the like presently using oil sealed rotary vane pumps discharging exhaust air through long exhaust lines.

Unlike the oil-sealed rotary vane pump, the pumping cavity of the GXS pump is oil-free and temperature controlled. The GXS pump cannot initiate an exhaust line fire.

GXS pumps include serial, LAN and web-serving communication capabilities as standard. Parallel (digital I/O) and Profibus modules are available as options. PID vacuum control is a standard on-board feature.

The Edwards GXS pumps are distributed by VABS Limited (Vacuum And Blowing Solutions). Members of the VABS team have a long running involvement with Edwards, dating back to 1987.

For more information:


Tel: 0800 822 726

Email: [email protected]