Patent ID: 8016570

Claim:
A compressor system for gas supplied by a gas supply inlet which normally operates on a gas compression cycle but which also operates in a drier regeneration cycle, said system comprising: 1) a compressor driven by a motor, the compressor having at least a first stage inlet through which passes a flow of gas being compressed from a gas supply inlet; 2) a gas delivery outlet at the outlet of the compressor, for supplying gas to a delivery line; 3) a gas drier stage comprising a desiccant bed located in-line with the flow of gas passing through the compressor during the gas compression cycle; 4) a condenser also located in-line with the flow of gas passing through the compressor during the gas compression cycle, which condenser, during the compression cycle, is normally inactive; 5) temperature control means to control the temperatures of the desiccant bed and condenser which means are, during the compression cycle, inactive but, upon entering into a regeneration cycle, such means being actuatable to cause the desiccant bed to be heated and the condenser to be cooled; 6) valve means for switching the flow of gas from the delivery line to recirculate through the compressor, whereby, during the regeneration cycle arising from activation of the valve means, gas trapped within the compressor, desiccant bed and condenser is redirected from the outlet of the compressor for circulation in a closed loop as a recirculating gas flow through the compressor, with at least a portion of such recirculating gas flow passing through the desiccant bed and condenser to permit water evolved from the desiccant bed to be carried by the recirculating gas to the condenser where it condenses due to the low temperature condition maintained within the condenser by the temperature control means; and 7) wherein the compressor comprises a sealed casing with an interior volume connected to said gas supply inlet and to the first stage compressor inlet, said valve means further comprising a supply valve at said gas supply inlet that closes when the valve means switches the flow of gas to recirculate through the compressor casing and opens when compressed gas is passing to the delivery line, whereby, in accordance with the state of activation of the valve means, gas within the interior volume of the casing may be drawn-in by the first stage compressor from either said gas supply inlet or from said compressor outlet.