Hitachi Industrial Equipment Systems Co., Ltd.

Akihiro Nagasaka

Hideharu Tanaka

Masahiko Takano

In an oil-cooled air compressor for controlling a temperature of a lubricant by changing a flow rate of a cooling medium supplied to a heat exchanger for the lubricant, for obtaining an energy saving effect by variable control of the flow rate of the cooling medium and preventing securely a condensed water from occurring in a compressor unit even when an exhaust duct is arranged inappropriately, a lubricant flow rate adjustor is arranged to measure a temperature of the lubricant and decreasing a flow rate of the lubricant supplied to the heat exchanger so that the lubricant temperature becomes Tto satisfy T&#x3e;T&#x2267;TD when Tis a control temperature of the lubricant and TD is a condensed water occurrence critical temperature at which a condensed water occurs in the compressor.

Oil-cooled air compressor

An air compressor, for enabling to restart a fan motor when an inverter trip generates within an inverter control of the fan motor, as well as, to continue supplying of compressed air therefrom, comprises: a compressor main body; a compressor motorfor driving this compressor main body; a fan motorfor driving a fan; an inverter for controlling the fan motor; and a controllerfor controlling driving of the compressor motorand driving of the fan motor. The controllerconducts such control that the fan motoris brought into a restart waiting condition while continuing operation of the compressor motorwhen an inverter trip generates, and thereafter to restart the fan motor

Air compressor

Provided is a water-cooled air compressor which is capable of restraining lowering of the performance of a plate type compressor for heat-exchanging compressed air from a compressor body, with cooling water due to clogging of gaps between plates in the heat-exchanger by dust or the like, incorporating a first solenoid valve and a second solenoid valve connected respectively in a cooling water supply pipe line and a cooling water discharge pipe line of the heat-exchanger, an air feed pipe line connecting between a compressed air supply pipe line on the outlet side of the heat-exchanger and the cooling water discharge pipe line, a third solenoid valve and a check valve connected in the air feed pipe line, a discharge pipe line connected in a discharge pipe lineso as to branch therefrom, a fourth solenoid valve connected in the discharge pipe line, and a control device for controlling opening and closing of the first to fourth solenoid valves.

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Shizuoka, Japan

Akihiro Nagasaka