Water cooled screw compressor

Abstract

A water cooled rotary screw compressor system.

What is claimed is: 
     
         1 . A rotary screw compressor system, comprising:
 a housing including a surface defining at least a portion of an internal working fluid volume free of oil, at least a portion said surface including an abradable coating;   a first pair of oil lubricated bearings;   a second pair of oil lubricated bearings;   a male screw rotor rotatable on said first pair of oil lubricated bearings, said male screw rotor having a first outer surface disposed within said internal working volume;   a female screw rotor rotatable on said second pair of oil lubricated bearings, said female screw rotor having a second outer surface disposed within said internal working volume and intermeshing with said male rotor, at least one of said outer surfaces including a second abradable coating;   a power source coupled with and operable to rotate said rotors;   a temperature controller in fluid communication with said internal working fluid volume and operable to deliver a quantity of water to the working fluid within the internal working fluid volume to remove a portion of the heat of compression to obtain a predetermined discharge temperature for the working fluid without flooding the internal working fluid volume; and   wherein the internal working fluid volume is isolated from said oil lubricated bearings to isolate the working fluid from oil contamination.   
     
     
         2 . The rotary screw compressor system of  claim 1 , wherein said temperature controller delivers a continuous spray of water onto at least one of said rotors. 
     
     
         3 . The rotary screw compressor system of  claim 1 , wherein said temperature controller delivers a continuous spray of water onto both of said rotors. 
     
     
         4 . The rotary screw compressor system of  claim 1 , wherein the quantity of wafer delivered to the working fluid within said internal working fluid volume is no more than about five percent of the quantity of water necessary to define a flooded environment. 
     
     
         5 . The rotary screw compressor system of  claim 4 , wherein the quantity of water delivered to the working fluid within said internal working fluid volume is within a range of about two percent to four percent of the quantity of water that would be necessary to define a flooded environment. 
     
     
         6  The rotary screw compressor system of  claim 1 , wherein the compression ratio is about 10:1. 
     
     
         7 . The rotary screw compressor system of  claim 1 , wherein the compression ratio is about 8:1. 
     
     
         8 . The rotary screw compressor system of  claim 1 , wherein the quantity of water delivered to the working fluid within said internal working fluid volume is no more than five percent of the quantity of water that would be utilized to define a flooded environment,
 wherein said temperature controller includes a volume of clean water;   wherein the compression ratio is at least about 8:1; and   wherein said predetermined discharge temperature is about 250° F.   
     
     
         9 . The rotary screw compressor system of  claim 8 , wherein the volume of clean water is defined by potable water. 
     
     
         10 . The rotary screw compressor system of  claim 8 , wherein the compression ratio is about 10:1; and
 wherein said male and female rotors are driven at about 10,000 RPM.   
     
     
         11 . A rotary screw compression system, comprising:
 a power source;   a rotary screw compressor having a housing with a male and a female rotor rotatably disposed therein, said rotors driven by said power source to increase the pressure ratio of an oiless working fluid, at least one of said rotors include a sealing coating; and   a cooling system disposed in fluid communication with said rotors and operable to deliver a dose of water to at least one of said rotors, said dose being about five percent of the dose of water required to define a flooded environment.   
     
     
         12 . The rotary screw compression system of  claim 11 , wherein said dose is a continuous stream of water, and the working fluid is air. 
     
     
         13 . The rotary screw compression system of  claim 11 , wherein said dose is a pulsed stream of water, and the working fluid is air. 
     
     
         14 . The rotary screw compression system of  claim 11 , wherein said dose keeps the discharge temperature of the working fluid below 250 degrees Fahrenheit. 
     
     
         15 . The rotary screw compression system of  claim 11 , which further includes a sensor for sensing the temperature of the working fluid at the discharge of said rotary screw compressor; and
 said dose is dependent upon the temperature at the discharge of said rotary screw compressor.   
     
     
         16 . The rotary screw compression system of  claim 11 , wherein said rotary screw compressor is the sole mechanism for compression. 
     
     
         17 . The rotary screw compression system of  claim 11 , which is limited to a single stage of compression. 
     
     
         18 . The rotary screw compression system of  claim 11 , wherein said dose is a continuous stream of water;
 the working fluid is defined by air;   wherein said dose keeps the discharge temperature of the working fluid below a predetermined value of 250 degrees Fahrenheit; and   which further includes a sensor for sensing the temperature of the working fluid at the discharge of rotary screw compressor; and   said dose is dependent upon the temperature at said sensor.   
     
     
         19 . The rotary screw compression system of  claim 18 , wherein there is only a single stage of compression. 
     
     
         20 . The rotary screw compression system of  claim 11 , wherein said dose is a pulsed stream of wafer;
 the working fluid is defined by air;   wherein said dose keeps the discharge temperature of the working fluid below 250 degrees Fahrenheit;   which further includes a sensor for sensing the temperature of the working fluid at the discharge of said rotary screw compressor; and   said dose is dependent upon the temperature at said sensor.   
     
     
         21 . The rotary screw compression system of  claim 20 , wherein there is only a single stage of compression. 
     
     
         22 . The rotary screw compression system of  claim 11 , which further includes a second rotary screw compressor with a second male and a second female rotor disposed therein, said rotors operable to increase the pressure ratio of an oiless working fluid delivered from said rotary screw compressor.