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Kirsten water-screw

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G
Guenter Kirsten

This document discusses zero emission compressor systems that use water injection instead of oil lubrication. It provides information on: - The main companies developing water injected screw compressor technology, including Atlas Copco, GrassAir, and Aerzener Maschinenfabrik. - The four main types of water injected screw elements, including the pure water injected Kirsten and Atlas Copco models, as well as hybrid models. - How water injection cools, seals, and lubricates the compression element, improving energy efficiency through near isothermal compression. - The benefits of water injected compressor systems compared to oil lubricated systems, such as eliminating oil contamination, reducing maintenance needs, and providing higher pressures and

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ZERO EMISSION COMPRESSOR SYSTEM Ing. Guenter Kirsten Istanbul / Turkey kirstenguenter@gmail.com Phone: 0090 507 6035013
Why the Initial worldwide Interest in Water Injection? Water injected rotary screw air compressors have been developed to provide an 100% oil free alternative to conventional dry compression machines. Benefits include the obsolescence, or reduction, of lubricating oils, a reduction in the number of system components, increased energy efficiency and high pressure capabilities. Who’s who in the WIS market? Water injected rotary screw elements have been developed or manufactured by seven companies: • Atlas Copco (Poly-ceramic Rotors) • GrassAir – Dutch (Poly-ceramic Rotors- hybrid) • GVM – Germany ( Poly-ceramic Rotors) • Mitsui Seiki – Japan (Monorotor Screw – hybrid) • IHI – Japan ( Poly-ceramic Rotors - hybrid) • SRM – Sweden (Poly-ceramic Rotors ) •Aerzener Maschinenfabrik Germany (stainless steel) The History
Basic Principles Why do we Inject Water into the Compression Element? Water is injected to cool, seal and lubricate the compression element. This results in much lower compression temperatures, nearing isothermal compression, and the associated increases energy efficiency. 4 generic types of WIS elements are available worldwide. Type 1 - The Pure WIS KIRSTEN • No oil or grease is used as a lubricant in the machine • Polymer ceramic rotors are fitted incl. bearings, produced without shaft • Hydro-dynamic/hydro-static bearings are fitted direct in the Rotors accommodate axial and radial loads. Type 2 - The Pure WIS ATLAS COPCO • No oil or grease is used as a lubricant in the machine • Polymer ceramic rotors are fitted • Hydro-dynamic/hydro-static bearings are fitted to the element to accommodate axial and radial loads.
Type 3 - The Hybrid WIS •The compression element is fitted with oil or grease lubricated bearings, or in combination with hydro- dynamic /hydro-static bearings and shaft sealing's. •Timing gears are used to synchronize the rotor motion in applications where stainless steel rotors are used. Type 4 - The Hybrid Mono Rotor Screw WIS • The compression element is fitted with grease lubricated bearings • A total of 6 bearings and shaft sealing’s are used • Main rotor is cast iron, nickel plated and the satellite rotors are a bronce with polymer material Basic Principles
System Configuration and water tradement What’s different? Many factors can influence the final configuration of a water injected screw air compressor and it need years of expirıence to handle the water system under all climatic conditıons. The main drivers include: • Bearing configuration of element • Element sealing • Rotor material and profile • Element casing material • No use of timing gears • No need of an after-cooler • Water treatment system • Inclusion of a start up water pump • Material of pipe work and components • Cooler material
Water Injected Screw Energy Efficiency Water Injected Screw Technology the right choice • Highly energy efficient The higly effective cooling capabilities of water injection combined with pressision engineering ensure that the water injected screw compressor is highly energy efficient. The nearer the compression process to Isothermal compression the more energy efficient it becomes.
Why 100% Oil Free Air Oil removal THE AIR QUALITY OF AN OIL LUBRICTED AIR COMPRESSOR IS RELIANT ON THE SCAVINGE SYSTEM OF THE OIL SEPERATOR An Orifice of 1 mm diameter and the seperator element is the critical component within this system IF IT BLOCKS THEN THE OIL SEPERATOR WILL FAIL AND ALL THE OIL WILL BE DELIVERED TO THE COMPRESSED AIR INSTALLATION
Why 100% Oil Free Air Oil removal Do Not Accept any Compromise When it comes to Production Efficiency, Quality and Safety OIL CARRY OVER COSTS YOU MONEY YES Do you accept ??? • Product contamination • Contaminated fumes and condensate • Increased energy cost • Increased maintenance costs • Increased maintenance down time • Increased installation costs • Increased floor space • Environmental costs • Dissatisfied customers NO Compressor 7 bar(e) 1 ppm = 1.2 mg/M³ Temperature of air °C ResidualOilContentPPM
Why 100% Oil Free Air Activated Carbon Filters Lifetime of active coal filters in function of temperature NO USE AT AMBIENT TEMPERATURES ABOVE 40°C if you don’t cool down the compressed air, or clean the cooler on time it will make problems quick. An active coal filter non-saturated absorbs the oil vapor like a sponge absorbs water A saturated active coal filter no longer absorb oil vapor just as a saturated sponge How do you know when active coal is saturated?
Energy Efficiency Pressure Reduction OIL INJECTED SOLUTION FOR INSTRUMENT AIR APPLICATION, USED ALSO İN VERY SENSIBLE APPLİCATIONS LIKE HOSPİTALS, PHARMACY, ETC. IS ONLY A RISK. Inlet valve Check valve Oil chamber and seperator After cooler Water seperator dryer oil removal Filter fine filter active carbon filter Control point Intake filter Compressor element New Lubricated Compressor Seperator outlet Oil Filter Dryer Fine Filter Carbon Filter In System Total 7.7 Bar 0.2 Bar 7.5 Bar 0.2 Bar 0.1 Bar 0.2 Bar 0.3 Bar 6.7 Bar 1 Bar Pressure Drop Pressure Drop Pressure Drop Pressure Drop PressurePressure Pressure Drop Pressure Pressure Drop Serviced Lubricated Non Serviced Lubricated 8.5 Bar 1 Bar 7.5 Bar 1 Bar 0.1 Bar 1 Bar 0.3 Bar 5.1 Bar 3.4 Bar 8.3 Bar 0.8 Bar 7.5 Bar 0.5 Bar 0.1 Bar 0.5Bar 0.3 Bar 6.1 Bar 2.2 Bar
Energy Efficiency Pressure reduction New oil Free Compressor outlet Dryer In System Total 7,7 Bar 7,6 Bar 0.1 Bar 7,6 Bar 0.1 Bar Pressure Pressure Pressure Drop Pressure Drop Pressure Serviced Oil Free 7,7 Bar 7,6 Bar 0.1 Bar 7,6 0.1 Bar Non Serviced Oil Free 7,7 Bar 7,6 Bar 0.1 Bar 7,6 Bar 0.1 Bar 0 3000 6000 Operating Hours Oil Free water injected Compressor Oil lubricated Compressor with Filters 80 90 100 110 120 130
Environmental Oil contamination Water injected Screw Compressor protects the environment by eliminating oil in compressed air, Conventional lubricated compressors generate a significant amount of oil contamination within compressed air - Disposal costs. Increasing installation costs Contaminating production processes Incurring cost for condensate treatment, Oil contamination damages the environment and increases the cost of compressed air. Installation and operating costs can be significantly reduced, with the purchase of a water injected compressor, by eliminating the costly removal of oil and the necessity for condensate treatment
Control and Monitoring Variable speed control 20 to 100% 0 10 20 30 40 50 60 70 80 90 100 0 12.5 25 40 50 60 75 80 100 FAD [%] PC[%] energy savings Traditional KIRSTEN The new Kirsten water injected screw compressor has a permanent magnetic AC high speed motor and can regulate the speed and power between 20 and 100%, which is the most efficient control method worldwide for compressed air systems with wide variations in air demand or systems that require a very narrow pressure operating band.
Oil free adiabatic compression Screw and Tooth compressor Two Stage Screw Compressor. As to oil-free air compression with dry-running, adiabatic and oil-free screw compressors, an air end is generally used in which two screw rotors, one male rotor with four teeth and one female rotor with six slots, are rotating along each other like a gear mechanism. The first one rotates 50 percent faster than the latter. In order to achieve acceptable efficiencies in this compressor system, very high speeds and, thus, circumferential speeds must be performed. Speeds of the male rotor ranging from 80 to 120 m/sec. are normal throughout. So, the internal backflow losses can be minimized and the final temperature controlled. This also calls for special demands made on the bearings of screws and gears. The air is prevented to escape along the rotor shaft by the use of special non-contact labyrinth seals. Other seals prevent any ingress of oil from the rotor bearings into the compression chamber. A two-stage configuration with intermediate cooling is required for a final temperature of 6 to 10 bar. The temperatures come up to 180°C per stage at an intake temperature of 20°C. The greatest advantage of these compressors is the level of popularity as for the ZR compressors of Atlas Copco which held a unique position for years. When viewing the "flow chart", the significance of oil in these "oil-free" compressors can be easily discerned. Oil is needed for lubrication of the synchronous gears in both stages, the bearing and gear transmission. To ensure availability of such oil in a closed circuit, cooling by means of a cooler must take place. An air-oil collector is integrated in the gear venting system as leakage air permanently enters into the lubrication circuit through the labyrinth seals. Escape of oil and oil vapors cannot be prevented. Further, this features an additional maintenance interface with required disposal cost. Notwithstanding the shaft seal, oil may enter from the bearing side into the compression chamber a phenomenon that is not immediately discerned, in particular, in idle run of these compressors as there is a distinct under pressure on suction side due to the closure of throttle valve. This results in oil-containing compressed air the segregation only being possible by means of expensive filter combinations due to the high temperatures. In factories where highest quality demands are made on compressed air, it is indispensable to use superfine filters. This compressor system needs three high-value coolers: intermediate cooler, after cooler and oil cooler. According to experience, sediments and wearing in the coolers after approx. 10,000 hours of operation are frequently incurred. Periodical cleaning of all the coolers with the need of dismounting work is absolutely required. This gives rise to enormous wage and material cost. Condensation water deposition in the intermediate cooler is also of particular importance, all liquid parts should be segregated as this condensation water is acid i.e. aggressive. Coating of rotors to minimize corrosion and friction as well as possible contact due to the increased compression temperature is also very important. This coating, normally PTFE, gradually peels off. Consequently, backflows are produced within the stage causing a reduction of the rate of delivery by up to 15 percent i.e. to ensure availability of the full rate of delivery, by 15 percent higher energy cost must be spent. Even in case of high-quality coatings, losses in the rate of delivery of at least 5 percent may still occur. This wear already occurs after 2,000 to 4,000 hours of operation. That is why a fine filter should be installed in the pressure line of dry-running screw compressors to extract the abrasion particles. Generally, maintenance, inspection of repair of these packages must be performed by shop experts only. Difficulties are particularly expırienced in control and regulation features which can be adjusted correctly only with plenty of experience. Contamination or overheating of packages will cause substantial damages in the air ends. Replacement as well as repair costs are very high.
Oil free adiabatic compression Screw and Tooth compressor Two Stage Tooth Compressor In order to achieve acceptable efficiencies in this compressor system, very high speeds and, thus, circumferential speeds must be performed. Speeds of the male rotor ranging from 60 to 100 m/sec. are normal throughout. So, the internal backflow losses can be minimized and the final temperature controlled. This also calls for special demands made on the bearings of In most cases, the male rotor is driven by a gear transmission whereby the male rotor drives the female rotor via synchronous gear mechanism. Mechanical contacts of tooth flanks are excluded. A small gap dimensioned to the operating temperature of compressor is provided in between the rotor surfaces. rotors and gears. The air is prevented to escape along the rotor shaft by the use of special non- contact labyrinth seals. Other seals prevent any ingress of oil from the rotor bearings into the compression chamber. A two-stage configuration with intermediate cooling is required for a final temperature of 6 to 8,5 bar. The temperatures come up to 180°C per stage at an intake temperature of 20°C. The greatest advantage of these compressors is the level of popularity as for the ZT compressors of Atlas Copco which held a unique position for years. When viewing the "flow chart", the significance of oil in these "oil-free" compressors can be easily discerned. Oil is needed for lubrication of the synchronous gears in both stages, the bearing and gear transmission. This compressor system needs three high-value coolers: intermediate cooler, after cooler and oil cooler. According to experience, sediments and wearing in the coolers after approx. 10,000 hours of operation are frequently incurred. Periodical cleaning of all the coolers with the need of dismounting work is absolutely required. This gives rise to enormous wage and material cost. Condensation water deposition in the intermediate cooler is also of particular importance, all liquid parts should be segregated as this condensation water is acid i.e. aggressive. Coating of rotors to minimize corrosion and friction as well as possible contact due to the increased compression temperature is also very important. This coating, normally PTFE, gradually peels off. Consequently, backflows are produced within the stage causing a reduction of the rate of delivery by up to 15 percent i.e. to ensure availability of the full rate of delivery, by 15 percent higher energy cost must be spent. Even in case of high-quality coatings, losses in the rate of delivery of at least 5 percent may still occur. This wear already occurs after 2,000 to 4,000 hours of operation. That is why a fine filter should be installed in the pressure line of dry-running tooth-type rotary compressors to extract the abrasion particles. Generally, maintenance, inspection of repair of these packages must be performed by shop experts only. Difficulties are particularly experienced in control and regulation features which can be adjusted correctly only with plenty of experience. Contamination or overheating of packages will cause substantial damages in the air ends. Replacement as well as repair costs are very high.
How many water is in the compressed Air of a water injected compressor? Absolute the same then in all other compressors. This diagrams show how many water is in the air under different conditions, pressure and temperaturs. All compressors that compress Air has the same content of water . Water can only reduced by coolıng and drying of the pressed air with a refrigeratıon, absorbtion or adsorption dryer, this is up to the process what the costumer need.
How to handle the water tradement internal the system and from external? The Water tradement and cleaning system is the importants device in a water injected compressor. Atlas Copco and all other use a Reverse Osmosis System to clean the drinking water and fill it in the machine when the water level is low. This is sure not enough to control the water quality in the compressor system. The water system is not a closed system. The air that coming in from the atmosphere bring a lot of bad ions in the system, the water wash all this out and now the ions are in the water system. Further the water ever take ions from the material inside the system, and try to find balance . A real water tradement has to messuring and clean permanently the water system. Only the from Kirsten patented system can do this and give the absolute security under all conditions that the water quality in the machine is around the world the same. 30 years of expirience with water lubricated and water injected screw compressors has shown the way how to do this. When the water in the compressor system is regulated between a conductivity from 5 to 10 micro siemens by 20°C, the system runing under safe conditions, water lubricated bearings life time will more then 50.000 hours.
What are the benefit to use the NEW water injected screw compressor technologie? The Maintenance Engineer The oil in compressed air after compression will attack downstream equipment, causing increased maintenance requirements and increased plant downtime The Financial Manager Low cost oil lubricated compressors may look attractive, But when considering the total operating costs compared to Oil free compressors, the extra investment in a water injected screw compressor will easily pay for itself The Application Engineer Every application can benefit from oil free air compressors with total product safety, lower operating, and maintenance costs and a healthier working environment The General Manager If you require maximum reliability and energy efficiency to improve your total operating costs, The ZERO EMISSİON SCREW COMPRESSOR provides you with the optimum compressed air generation solution without any risk The Safety and Environment Manager Breathing oil fumes is definitely not a good idea and oil Condensate can damage the environment So why do it the hard way, when you can do it the smart way with oil free water injected compressors The Quality Manager Do not accept the possibility of product contamination, and reduced product quality. Only 100% Oil free compressors can offer a 100% Guarantee of Oil Free Air

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Kirsten water-screw

  • 1. ZERO EMISSION COMPRESSOR SYSTEM Ing. Guenter Kirsten Istanbul / Turkey kirstenguenter@gmail.com Phone: 0090 507 6035013
  • 2. Why the Initial worldwide Interest in Water Injection? Water injected rotary screw air compressors have been developed to provide an 100% oil free alternative to conventional dry compression machines. Benefits include the obsolescence, or reduction, of lubricating oils, a reduction in the number of system components, increased energy efficiency and high pressure capabilities. Who’s who in the WIS market? Water injected rotary screw elements have been developed or manufactured by seven companies: • Atlas Copco (Poly-ceramic Rotors) • GrassAir – Dutch (Poly-ceramic Rotors- hybrid) • GVM – Germany ( Poly-ceramic Rotors) • Mitsui Seiki – Japan (Monorotor Screw – hybrid) • IHI – Japan ( Poly-ceramic Rotors - hybrid) • SRM – Sweden (Poly-ceramic Rotors ) •Aerzener Maschinenfabrik Germany (stainless steel) The History
  • 3. Basic Principles Why do we Inject Water into the Compression Element? Water is injected to cool, seal and lubricate the compression element. This results in much lower compression temperatures, nearing isothermal compression, and the associated increases energy efficiency. 4 generic types of WIS elements are available worldwide. Type 1 - The Pure WIS KIRSTEN • No oil or grease is used as a lubricant in the machine • Polymer ceramic rotors are fitted incl. bearings, produced without shaft • Hydro-dynamic/hydro-static bearings are fitted direct in the Rotors accommodate axial and radial loads. Type 2 - The Pure WIS ATLAS COPCO • No oil or grease is used as a lubricant in the machine • Polymer ceramic rotors are fitted • Hydro-dynamic/hydro-static bearings are fitted to the element to accommodate axial and radial loads.
  • 4. Type 3 - The Hybrid WIS •The compression element is fitted with oil or grease lubricated bearings, or in combination with hydro- dynamic /hydro-static bearings and shaft sealing's. •Timing gears are used to synchronize the rotor motion in applications where stainless steel rotors are used. Type 4 - The Hybrid Mono Rotor Screw WIS • The compression element is fitted with grease lubricated bearings • A total of 6 bearings and shaft sealing’s are used • Main rotor is cast iron, nickel plated and the satellite rotors are a bronce with polymer material Basic Principles
  • 5. System Configuration and water tradement What’s different? Many factors can influence the final configuration of a water injected screw air compressor and it need years of expirıence to handle the water system under all climatic conditıons. The main drivers include: • Bearing configuration of element • Element sealing • Rotor material and profile • Element casing material • No use of timing gears • No need of an after-cooler • Water treatment system • Inclusion of a start up water pump • Material of pipe work and components • Cooler material
  • 6. Water Injected Screw Energy Efficiency Water Injected Screw Technology the right choice • Highly energy efficient The higly effective cooling capabilities of water injection combined with pressision engineering ensure that the water injected screw compressor is highly energy efficient. The nearer the compression process to Isothermal compression the more energy efficient it becomes.
  • 7. Why 100% Oil Free Air Oil removal THE AIR QUALITY OF AN OIL LUBRICTED AIR COMPRESSOR IS RELIANT ON THE SCAVINGE SYSTEM OF THE OIL SEPERATOR An Orifice of 1 mm diameter and the seperator element is the critical component within this system IF IT BLOCKS THEN THE OIL SEPERATOR WILL FAIL AND ALL THE OIL WILL BE DELIVERED TO THE COMPRESSED AIR INSTALLATION
  • 8. Why 100% Oil Free Air Oil removal Do Not Accept any Compromise When it comes to Production Efficiency, Quality and Safety OIL CARRY OVER COSTS YOU MONEY YES Do you accept ??? • Product contamination • Contaminated fumes and condensate • Increased energy cost • Increased maintenance costs • Increased maintenance down time • Increased installation costs • Increased floor space • Environmental costs • Dissatisfied customers NO Compressor 7 bar(e) 1 ppm = 1.2 mg/M³ Temperature of air °C ResidualOilContentPPM
  • 9. Why 100% Oil Free Air Activated Carbon Filters Lifetime of active coal filters in function of temperature NO USE AT AMBIENT TEMPERATURES ABOVE 40°C if you don’t cool down the compressed air, or clean the cooler on time it will make problems quick. An active coal filter non-saturated absorbs the oil vapor like a sponge absorbs water A saturated active coal filter no longer absorb oil vapor just as a saturated sponge How do you know when active coal is saturated?
  • 10. Energy Efficiency Pressure Reduction OIL INJECTED SOLUTION FOR INSTRUMENT AIR APPLICATION, USED ALSO İN VERY SENSIBLE APPLİCATIONS LIKE HOSPİTALS, PHARMACY, ETC. IS ONLY A RISK. Inlet valve Check valve Oil chamber and seperator After cooler Water seperator dryer oil removal Filter fine filter active carbon filter Control point Intake filter Compressor element New Lubricated Compressor Seperator outlet Oil Filter Dryer Fine Filter Carbon Filter In System Total 7.7 Bar 0.2 Bar 7.5 Bar 0.2 Bar 0.1 Bar 0.2 Bar 0.3 Bar 6.7 Bar 1 Bar Pressure Drop Pressure Drop Pressure Drop Pressure Drop PressurePressure Pressure Drop Pressure Pressure Drop Serviced Lubricated Non Serviced Lubricated 8.5 Bar 1 Bar 7.5 Bar 1 Bar 0.1 Bar 1 Bar 0.3 Bar 5.1 Bar 3.4 Bar 8.3 Bar 0.8 Bar 7.5 Bar 0.5 Bar 0.1 Bar 0.5Bar 0.3 Bar 6.1 Bar 2.2 Bar
  • 11. Energy Efficiency Pressure reduction New oil Free Compressor outlet Dryer In System Total 7,7 Bar 7,6 Bar 0.1 Bar 7,6 Bar 0.1 Bar Pressure Pressure Pressure Drop Pressure Drop Pressure Serviced Oil Free 7,7 Bar 7,6 Bar 0.1 Bar 7,6 0.1 Bar Non Serviced Oil Free 7,7 Bar 7,6 Bar 0.1 Bar 7,6 Bar 0.1 Bar 0 3000 6000 Operating Hours Oil Free water injected Compressor Oil lubricated Compressor with Filters 80 90 100 110 120 130
  • 12. Environmental Oil contamination Water injected Screw Compressor protects the environment by eliminating oil in compressed air, Conventional lubricated compressors generate a significant amount of oil contamination within compressed air - Disposal costs. Increasing installation costs Contaminating production processes Incurring cost for condensate treatment, Oil contamination damages the environment and increases the cost of compressed air. Installation and operating costs can be significantly reduced, with the purchase of a water injected compressor, by eliminating the costly removal of oil and the necessity for condensate treatment
  • 13. Control and Monitoring Variable speed control 20 to 100% 0 10 20 30 40 50 60 70 80 90 100 0 12.5 25 40 50 60 75 80 100 FAD [%] PC[%] energy savings Traditional KIRSTEN The new Kirsten water injected screw compressor has a permanent magnetic AC high speed motor and can regulate the speed and power between 20 and 100%, which is the most efficient control method worldwide for compressed air systems with wide variations in air demand or systems that require a very narrow pressure operating band.
  • 14. Oil free adiabatic compression Screw and Tooth compressor Two Stage Screw Compressor. As to oil-free air compression with dry-running, adiabatic and oil-free screw compressors, an air end is generally used in which two screw rotors, one male rotor with four teeth and one female rotor with six slots, are rotating along each other like a gear mechanism. The first one rotates 50 percent faster than the latter. In order to achieve acceptable efficiencies in this compressor system, very high speeds and, thus, circumferential speeds must be performed. Speeds of the male rotor ranging from 80 to 120 m/sec. are normal throughout. So, the internal backflow losses can be minimized and the final temperature controlled. This also calls for special demands made on the bearings of screws and gears. The air is prevented to escape along the rotor shaft by the use of special non-contact labyrinth seals. Other seals prevent any ingress of oil from the rotor bearings into the compression chamber. A two-stage configuration with intermediate cooling is required for a final temperature of 6 to 10 bar. The temperatures come up to 180°C per stage at an intake temperature of 20°C. The greatest advantage of these compressors is the level of popularity as for the ZR compressors of Atlas Copco which held a unique position for years. When viewing the "flow chart", the significance of oil in these "oil-free" compressors can be easily discerned. Oil is needed for lubrication of the synchronous gears in both stages, the bearing and gear transmission. To ensure availability of such oil in a closed circuit, cooling by means of a cooler must take place. An air-oil collector is integrated in the gear venting system as leakage air permanently enters into the lubrication circuit through the labyrinth seals. Escape of oil and oil vapors cannot be prevented. Further, this features an additional maintenance interface with required disposal cost. Notwithstanding the shaft seal, oil may enter from the bearing side into the compression chamber a phenomenon that is not immediately discerned, in particular, in idle run of these compressors as there is a distinct under pressure on suction side due to the closure of throttle valve. This results in oil-containing compressed air the segregation only being possible by means of expensive filter combinations due to the high temperatures. In factories where highest quality demands are made on compressed air, it is indispensable to use superfine filters. This compressor system needs three high-value coolers: intermediate cooler, after cooler and oil cooler. According to experience, sediments and wearing in the coolers after approx. 10,000 hours of operation are frequently incurred. Periodical cleaning of all the coolers with the need of dismounting work is absolutely required. This gives rise to enormous wage and material cost. Condensation water deposition in the intermediate cooler is also of particular importance, all liquid parts should be segregated as this condensation water is acid i.e. aggressive. Coating of rotors to minimize corrosion and friction as well as possible contact due to the increased compression temperature is also very important. This coating, normally PTFE, gradually peels off. Consequently, backflows are produced within the stage causing a reduction of the rate of delivery by up to 15 percent i.e. to ensure availability of the full rate of delivery, by 15 percent higher energy cost must be spent. Even in case of high-quality coatings, losses in the rate of delivery of at least 5 percent may still occur. This wear already occurs after 2,000 to 4,000 hours of operation. That is why a fine filter should be installed in the pressure line of dry-running screw compressors to extract the abrasion particles. Generally, maintenance, inspection of repair of these packages must be performed by shop experts only. Difficulties are particularly expırienced in control and regulation features which can be adjusted correctly only with plenty of experience. Contamination or overheating of packages will cause substantial damages in the air ends. Replacement as well as repair costs are very high.
  • 15. Oil free adiabatic compression Screw and Tooth compressor Two Stage Tooth Compressor In order to achieve acceptable efficiencies in this compressor system, very high speeds and, thus, circumferential speeds must be performed. Speeds of the male rotor ranging from 60 to 100 m/sec. are normal throughout. So, the internal backflow losses can be minimized and the final temperature controlled. This also calls for special demands made on the bearings of In most cases, the male rotor is driven by a gear transmission whereby the male rotor drives the female rotor via synchronous gear mechanism. Mechanical contacts of tooth flanks are excluded. A small gap dimensioned to the operating temperature of compressor is provided in between the rotor surfaces. rotors and gears. The air is prevented to escape along the rotor shaft by the use of special non- contact labyrinth seals. Other seals prevent any ingress of oil from the rotor bearings into the compression chamber. A two-stage configuration with intermediate cooling is required for a final temperature of 6 to 8,5 bar. The temperatures come up to 180°C per stage at an intake temperature of 20°C. The greatest advantage of these compressors is the level of popularity as for the ZT compressors of Atlas Copco which held a unique position for years. When viewing the "flow chart", the significance of oil in these "oil-free" compressors can be easily discerned. Oil is needed for lubrication of the synchronous gears in both stages, the bearing and gear transmission. This compressor system needs three high-value coolers: intermediate cooler, after cooler and oil cooler. According to experience, sediments and wearing in the coolers after approx. 10,000 hours of operation are frequently incurred. Periodical cleaning of all the coolers with the need of dismounting work is absolutely required. This gives rise to enormous wage and material cost. Condensation water deposition in the intermediate cooler is also of particular importance, all liquid parts should be segregated as this condensation water is acid i.e. aggressive. Coating of rotors to minimize corrosion and friction as well as possible contact due to the increased compression temperature is also very important. This coating, normally PTFE, gradually peels off. Consequently, backflows are produced within the stage causing a reduction of the rate of delivery by up to 15 percent i.e. to ensure availability of the full rate of delivery, by 15 percent higher energy cost must be spent. Even in case of high-quality coatings, losses in the rate of delivery of at least 5 percent may still occur. This wear already occurs after 2,000 to 4,000 hours of operation. That is why a fine filter should be installed in the pressure line of dry-running tooth-type rotary compressors to extract the abrasion particles. Generally, maintenance, inspection of repair of these packages must be performed by shop experts only. Difficulties are particularly experienced in control and regulation features which can be adjusted correctly only with plenty of experience. Contamination or overheating of packages will cause substantial damages in the air ends. Replacement as well as repair costs are very high.
  • 16. How many water is in the compressed Air of a water injected compressor? Absolute the same then in all other compressors. This diagrams show how many water is in the air under different conditions, pressure and temperaturs. All compressors that compress Air has the same content of water . Water can only reduced by coolıng and drying of the pressed air with a refrigeratıon, absorbtion or adsorption dryer, this is up to the process what the costumer need.
  • 17. How to handle the water tradement internal the system and from external? The Water tradement and cleaning system is the importants device in a water injected compressor. Atlas Copco and all other use a Reverse Osmosis System to clean the drinking water and fill it in the machine when the water level is low. This is sure not enough to control the water quality in the compressor system. The water system is not a closed system. The air that coming in from the atmosphere bring a lot of bad ions in the system, the water wash all this out and now the ions are in the water system. Further the water ever take ions from the material inside the system, and try to find balance . A real water tradement has to messuring and clean permanently the water system. Only the from Kirsten patented system can do this and give the absolute security under all conditions that the water quality in the machine is around the world the same. 30 years of expirience with water lubricated and water injected screw compressors has shown the way how to do this. When the water in the compressor system is regulated between a conductivity from 5 to 10 micro siemens by 20°C, the system runing under safe conditions, water lubricated bearings life time will more then 50.000 hours.
  • 18. What are the benefit to use the NEW water injected screw compressor technologie? The Maintenance Engineer The oil in compressed air after compression will attack downstream equipment, causing increased maintenance requirements and increased plant downtime The Financial Manager Low cost oil lubricated compressors may look attractive, But when considering the total operating costs compared to Oil free compressors, the extra investment in a water injected screw compressor will easily pay for itself The Application Engineer Every application can benefit from oil free air compressors with total product safety, lower operating, and maintenance costs and a healthier working environment The General Manager If you require maximum reliability and energy efficiency to improve your total operating costs, The ZERO EMISSİON SCREW COMPRESSOR provides you with the optimum compressed air generation solution without any risk The Safety and Environment Manager Breathing oil fumes is definitely not a good idea and oil Condensate can damage the environment So why do it the hard way, when you can do it the smart way with oil free water injected compressors The Quality Manager Do not accept the possibility of product contamination, and reduced product quality. Only 100% Oil free compressors can offer a 100% Guarantee of Oil Free Air