Method for reducing power consumption in a liquid-cooled rotary compressor by treating the liquid

Claim 1

In the method of operating a liquid-cooled type rotary compressor of the type which includes a cylinder having an inlet opening and an outlet opening, rotary means provided in said cylinder, at least one compression chamber defined between said rotary means and said cylinder, an unloader connected to said cylinder to communicate with said inlet opening, said cylinder also having a delivery chamber in a lower part of the cylinder, said delivery chamber having an upper opening, gas outlet and a liquid drainage opening, said upper opening communicating to said outlet opening, a reservoir having a gas space for compressed gas and a liquid space for liquid for cooling, lubricating and sealing, first conduit means connecting the lower part of said cylinder and said reservoir to communicate with said gas outlet and the gas space in said reservoir, second conduit means connecting said reservoir and the lower part of said cylinder to communicate with said liquid drainage opening and said liquid space in said reservoir, a liquid drainage pump provided in said second conduit means, third conduit means connecting said cylinder and said reservoir to communicate with said at least one compression chamber and said liquid space in said reservoir, and a regulator provided in said third conduit means for adjusting the amount of liquid to be injected into said at least one compression chamber, the improvement characterized by the steps of delivering from said compression chamber into said delivery chamber a mixture of said compressed gas and liquid, separating the gas and liquid components of said mixture immediately after the mixture is delivered into said delivery chamber, the liquid taking its own way in said second conduit means separately from the gas in said first conduit means, and pumping said liquid from said delivery chamber into said reservoir whereby the pressure in the delivery chamber can be decreased to reduce back pressure in the compressor and thereby reduce the power consumed by the compressor.