Test Installation A by-pass line was taken from the borehole pumping main and returned back at the same injection point previously used by the mechanical Compressors. The Jet Compressor system comprised a 1.1 Kw booster pump, pressure indicator, atmospheric air pipework with non-return Valve and by-pass water pipework. Performance The Pumping station included three borehole pumps which delivered a maximum total flow of 60 litres/sec. to the filtration system. A Booster Pump, in the by-pass line, raised the water pressure to approx. 4.5 barg to power the Liquid Jet Compressor which entrained atmospheric air and discharged the aerated water back into the main at a pressure of approx. 4 m W.C.. The measured D.O. rose steadily to between 40 and 50 % of saturation (depending upon how many borehole Pumps were in operation). This compared favourably to the mechanical Compressors which could only maintain an unsteady D.O.of 20 to 30 % of saturation. This increase in D.O. improved the quality of the potable water supply because more iron and manganese could be removed by filtration. The existing mechanical Compressors were each fitted with 7.88 Kw motors whereas the Liquid Jet Compressor Booster Pump was fitted with a 1.1 Kw motor, which will result in an annual saving in running costs of approx. £6000. Expensive edible oil used to lubricate the mechanical Compressors which is normally dissipated into the potable water was not needed.
Mechanical Compressors are expensive and require regular planned maintenance with duty / standby installations common practice for process security. Transvac Liquid Jet Compressors are inexpensive and as they are made from stainless steel with no moving parts and no maintenance is needed. A simple low cost standard Booster Pump is the only unit which will require some planned maintenance. An optional simple atmospheric air control system, linked to D.O., can be added if control of the D.O. is preferred. | 
