WIS Series - NewGate Technologies

1 Screw CompressorsCompressed air treatmentWIS SeriesExclusive Supplier of GrassAir CompressorsFew 5-75 HP oil-free air compressors can match the GRASSAIRWIS Series Water-Injected Screw Compressor in three criticalareas: Efficiency, Simplicity and WIS uses treated water as a coolant instead of oil. This resultsin a near Isothermal Compression, the most efficient way tocompress any gas. Energy savings in the range of 10-40% areachievable, compared to other compressors. The WIS is the simplest of all oil free compressors available in themarket today. The combination of a simple rotary screw design withwater injection results in far fewer parts than other compressors inits class. Water injection makes possible the use of a single-stagedesign with one set of rotors, and a water cooler replaces theconventional oil cooler+ air after-coolerand moisture separatorcombination.

2 There are no elaborate timing gears, no expensive oiland air/oil separator elementto replace, no gasketsand zeropossibility of are also no inter-coolers, no valvesand piston ringsto replace, and noenvironmentally damaging oily condensateto worry about. Finally, the WIS is the most reliable of all oil-free compressors in its class. Water injection means lowoperating temperatures, resulting in extended component life. Low operating speeds also means lesswear and tear, resulting in minimal the best in each of these areas puts the GrassAir s WIS Series Water Injected RotaryScrew Compressor truly in a class by Rotary Screw designCompact, quieter (as low as 65 dBA), simple and vibration-freeNo foundation, no valves, no piston ringsSimple to install and maintain Water Injection Isothermal Compression/ Greater Efficiency10 to 40% greater energy savings than other compressors Water InjectionOnly one coolerrequiredNo oil coolers, Inter-coolers, after-coolers or moisture separatorsLess maintenance Single-stage operation50% fewer moving partsLower maintenance costs and Increased reliability Belt DriveNo cumbersome timing gears, very simple and inexpensive to repair and maintain Ceramic RotorsNo rusting or corrosionLower maintenance costs and Increased reliability Corrosion resistant Aluminum-Eliminates corrosion and alloy air end housingImproved reliability Oil free designNo oil filters or separators to change.

3 No expensive oil to buyAbsolutely no danger of oil contaminationLower maintenance costs and increased reliability WIS Seriesoil-free rotary screw compressorsIn a Class by ItselfEfficiency, Simplicity and ReliabilityAtmospheric air is drawn into the air-end (12)through the air intake filter (1) and the inlet valve (2).Simultaneously, cool water returning from the heatexchanger (8) is also injected into the air end. In theair-end, the air/water mixture is compressed up tothe discharge pressure and is let into the waterseparator vessel (13).The air and water are separated in the waterseparator. The saturated compressed air is thendischarged through a minimum pressure valve (4)directly into the plant air system. If the air pressurein the water separator is at any time less than 50 Psig, the minimum pressure valve will not the water separator vessel, most of the water isseparated from the air and drops to the bottom of theseparator.

4 Differential pressure allows the water toflow from the separator to the heat exchanger, whereit is cooled to within 15 F of the ambient airtemperature (air-cooled unit) or cooling water (water-cooled unit).The water removes almost all of the heat ofcompression. It also has high capacity to hold heat. Asa result, the air/water mixture in the separator isonly about 25 F above the air intake (ambient)temperature. As such, no after-cooler is required forthe air. The discharge air is always saturated withwater vapor. Depending on the RH and temperatureof the intake air, water vapor will either condense intothe cooling water or will evaporate into the air streamduring the process of compression, thus adding to orsubtracting from the cooling water in the the level of water, controlled by two capacitancesensors, in the separator is too high, the high levelcap.

5 Sensor (S3) will open the bleed valve (Y4) anddischarge the water to the drain. On the other hand,if the level of water in the separator is too low, theLow level cap. Sensor (S4) will open the water supplyvalve (Y5) and supply make-up water into the suctionside of the air-end. Both water bleed valves have atime delay of 5 heat exchanger (8) will be a fin & tube type for aircooled units and shell & tube type for water-cooledunits. In a water-cooled unit, instead of city water, aclosed-loop glycol-cooling system can be Heat-Exch 1 Reverse Osmosis FiltrationCompressorY51212Y418413S3S411Y 11678101. Air Intake2, Inlet valve4. Minimum pressure valve7. Water filter8. Water cooler10. Ball Valve11. Non return valve12. Air-end13. Water separator vessel16. Waterfilter Strainer17. Valve18. Pressure GaugeS3. Capacitance Sensor-High levelS4. Capacitance Sensor-Low levelY1. Water injection valveY4.

6 Drain valveY5. Supplemental water make-up valveHowThe WIS WorksIsothermal Compression meansLowest Compression EnergyAt top is the theoretical PV diagram forIsothermal and adiabatic compression area ADEF represents the work requiredwhen operating on the Isothermal basis (PV =Constant); and ABEF, the work required on theAdiabatic basis (PVk= Constant). Clearly, ittakes more work to compress and deliver a gaswhen the compression is adiabatic than when itis Isothermal, the difference being representedby the shaded area. For 100 Psig aircompression, this difference is about 27%.Water Injection results in Isothermal CompressionIn Isothermal compression, all the heat equivalent of compressor work is carried away as thegas is being compressed. By using water as a coolant, the GRASSAIR WIS unit accomplishesnear-isothermal compression. As seen below, this results in an energy savings from 10% upto 40% when compared to other compressors in its class.

7 Additionally, it also transforms tohigher component life and fewer number of components in the conventional oil-free rotary screw or lobetype compressors, removing the heat ofcompression is a big challenge. These designstherefore resort to two stages with inter-cooling. This means two air-ends to service,more seals, bearings, rotors, gears and , they use an inter-cooler withmoisture separator and trap, after-cooler withmoisture separator and trap and an oil-coolerwith an oil conventional oil-injected screw compressors,a minimum oil injection temperature needs tobe maintained in order to prevent moisturecondensation and the resulting GRASSAIR WIS compressor, by usingtreated and purified water as a coolant,eliminates this problem. Air dischargetemperature is so low that after-cooling isunnecessary. Consequently, no MoistureSeparator and traps are required.

8 Isothermal Compression meansHigher Component LifeBelow is a thermograph illustrating thetemperature profile inside the compressionchamber (air-end) of the GRASSAIR WIS oil-freecompressor v/s that of a conventional oil-floodedscrew compressor. Water injection results in anoperating temperature of only 125 F in the WIS unit compared to about 225 F in a conventionaloil-flooded screw compressor, and 320 F in atwo stage lobe compressor. This low operatingtemperature results in less thermal stresses andmuch higher component Compression means Simple Unit with Fewer ComponentsCeramic RotorsDecades of research at GRASSAIR has led to thedevelopment of a high-quality ceramic material foruse in the manufacture of the rotors in the WIS compressors. This material is extremely hard andinsensitive to corrosion and wear. This, incombination with a housing made of a speciallydeveloped Aluminum-Bronze alloy, and utilizingpurified and treated water (see below) as thelubricant, makes for a nearly perfect, efficient anda very reliable ReliableBelt DriveThe GRASSAIR WIS Compressor, unlike most otheroil-free compressor designs in its class, uses thetime-tested V Belt Drive.

9 No complicated Bull Gears,Timing Gears, Couplings and associated bearings -all needing lubrication, prone to failure andrequiring continuous ControlThe GRASSAIR WIS Compressor is equipped with astate-of-the-art microprocessor control panel forinstant monitoring and control of the compressorcomplete with shutdown annunciation. Whileproviding critical information for schedulingnormal maintenance, it also minimizestroubleshooting time in the event of a shutdown, bypinpointing the cause of the panel has separate On-Off switches and thefollowing display menus: A Status Menu to indicate operational parameterslike critical pressures and temperatures An Operational Settings Menu for setting theLoad and Unload pressures, and Time delaybefore shutdown A Timer Menu to indicate Total hours, Load hours,Air filter hours and Service hours A Fault Log Menu that indicates complete faultdiagnosticsCompressed AirBetter by DesignReverse OsmosisA reverse osmosis unit is standard with everyGrassAir WIS compressor and ensures that themakeup water is purified before being added to theclosed loop water injection circuit.

10 In addition, ahigh quality water filter incorporated within thesystem further reduces any threat of watercontamination and guarantees long air-end life. Performance and ConnectionsNEWGATETECHNOLOGIES, SW 7TH ROAD OCALA, FLORIDA 34474 TEL: [352] 351-9992 FAX: [352] 351-9979 WIS ModelHP Capacity, CFMAir LevelDimensionsWeight100 Psig125 PsigInchesdB(A)LWHlbs5521153 1 227243 1 1 1 1 TemperatureRefrigerated DryersDesiccantDryersAir-CooledAftercool ersIntegratedRefrigerated DryersComplimentary air purification products from NewGate Technologies , 5 to 30 Models 40 to 75 WIS Seriesoil-free rotary screw compressorsCompressedAir Filters