INVERTER DRIVING TYPE OILLESS SCREW COMPRESSOR AND ITS OPERATION CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To reduce motive power at the time of a low load and low rotation on an oilless screw compressor using an inverter. ;SOLUTION: An air discharge piping 22 one end of which is opened to the atmosheric air by branching it to the primary side of a check valve 13 of a main body discharge piping 21, a large bore diameter bidirectional solenoid valve 26 is interposed on this air discharge piping 22, a small bore diameter bidirectional solenoid valve 27 is provided in parallel with this large bore diameter bidirectional solenoid valve 26 on the air discharge piping 22 and a pressure detector 24 to detect compression air pressure in a discharge piping 15 on the downstream side of the check valve 13 and a control device 17 to control opening and closing of the large bore diameter bidirectional solenoid valve 26 and the small bore diameter bidirectional solenoid valve 27 in accordance with output of the pressure detector 24 and the number of rotation of an electric motor are provided on an oilless screw compressor to control the number of driving rotation of the electric motor by using an inverter.;COPYRIGHT: (C)2001,JPO