ZERO EMISSION COMPRESSOR SYSTEM

Ing. Guenter KirstenIstanbul / Turkeykirstenguenter@gmail.comPhone: 0090 507 6035013

Why the Initial worldwide Interest in Water Injection?

Water injected rotary screw air compressors have been developed toprovide an 100% oil free alternative to conventional dry compressionmachines. Benefits include the obsolescence, or reduction, oflubricating 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 injectedscrew air compressor and it need years of expirıence to handle thewater 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 pressisionengineering ensure that the water injected screw compressor is highly energyefficient.

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

Res

idu

al O

il C

onte

nt

PP

M

Why 100% Oil Free Air Activated Carbon Filters

Lifetime of active coal filters in function of temperature

NO USE AT AMBIENT TEMPERATURES ABOVE 40°Cif you don’t cool down the compressed air, or clean thecooler on time it will makeproblems quick.

An active coal filter non-saturated absorbs the oil vapor like a spongeabsorbs 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

dryeroil 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 Pressure Pressure

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 Bar0 3000 6000

Operating Hours

Oil Free water injectedCompressor

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 generallyused in which two screw rotors, one male rotor with four teeth and one female rotor with six slots, are rotating alongeach other like a gear mechanism. The first one rotates 50 percent faster than the latter. In order to achieveacceptable efficiencies in this compressor system, very high speeds and, thus, circumferential speeds must beperformed. Speeds of the male rotor ranging from 80 to 120 m/sec. are normal throughout. So, the internal backflowlosses 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 alongthe rotor shaft by the use of special non-contact labyrinth seals. Other seals prevent any ingress of oil from the rotorbearings into the compression chamber. A two-stage configuration with intermediate cooling is required for a finaltemperature of 6 to 10 bar. The temperatures come up to 180°C per stage at an intake temperature of 20°C. Thegreatest advantage of these compressors is the level of popularity as for the ZR compressors of Atlas Copco whichheld a unique position for years. When viewing the "flow chart", the significance of oil in these "oil-free" compressorscan be easily discerned.Oil is needed for lubrication of the synchronous gears in both stages, the bearing and gear transmission. To ensureavailability of such oil in a closed circuit, cooling by means of a cooler must take place. An air-oil collector isintegrated in the gear venting system as leakage air permanently enters into the lubrication circuit through thelabyrinth seals. Escape of oil and oil vapors cannot be prevented. Further, this features an additional maintenanceinterface with required disposal cost. Notwithstanding the shaft seal, oil may enter from the bearing side into thecompression chamber a phenomenon that is not immediately discerned, in particular, in idle run of thesecompressors as there is a distinct under pressure on suction side due to the closure of throttle valve. This results inoil-containing compressed air the segregation only being possible by means of expensive filter combinations due tothe high temperatures. In factories where highest quality demands are made on compressed air, it is indispensable touse superfine filters.This compressor system needs three high-value coolers: intermediate cooler, after cooler and oil cooler. Accordingto 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 toenormous wage and material cost. Condensation water deposition in the intermediate cooler is also of particularimportance, all liquid parts should be segregated as this condensation water is acid i.e. aggressive. Coating of rotorsto minimize corrosion and friction as well as possible contact due to the increased compression temperature is alsovery important.This coating, normally PTFE, gradually peels off. Consequently, backflows are produced within the stage causing areduction of the rate of delivery by up to 15 percent i.e. to ensure availability of the full rate of delivery, by 15 percenthigher energy cost must be spent. Even in case of high-quality coatings, losses in the rate of delivery of at least 5percent may still occur. This wear already occurs after 2,000 to 4,000 hours of operation. That is why a fine filtershould 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 areparticularly expırienced in control and regulation features which can be adjusted correctly only with plenty ofexperience. Contamination or overheating of packages will cause substantial damages in the air ends. Replacementas 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. arenormal throughout. So, the internal backflow losses can be minimized and the final temperaturecontrolled. This also calls for special demands made on the bearings of In most cases, the male rotor isdriven by a gear transmission whereby the male rotor drives the female rotor via synchronous gearmechanism. Mechanical contacts of tooth flanks are excluded.A small gap dimensioned to the operating temperature of compressor is provided in between the rotorsurfaces. 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 thecompression 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 ofthese compressors is the level of popularity as for the ZT compressors of Atlas Copco which held a uniqueposition for years.When viewing the "flow chart", the significance of oil in these "oil-free" compressors can be easilydiscerned. Oil is needed for lubrication of the synchronous gears in both stages, the bearing and geartransmission. This compressor system needs three high-value coolers: intermediate cooler, after coolerand oil cooler. According to experience, sediments and wearing in the coolers after approx. 10,000 hoursof operation are frequently incurred. Periodical cleaning of all the coolers with the need of dismountingwork is absolutely required.This gives rise to enormous wage and material cost. Condensation water deposition in the intermediatecooler is also of particular importance, all liquid parts should be segregated as this condensation water isacid i.e. aggressive. Coating of rotors to minimize corrosion and friction as well as possible contact due tothe increased compression temperature is also very important. This coating, normally PTFE, graduallypeels off. Consequently, backflows are produced within the stage causing a reduction of the rate ofdelivery by up to 15 percent i.e. to ensure availability of the full rate of delivery, by 15 percent higher energycost must be spent. Even in case of high-quality coatings, losses in the rate of delivery of at least 5 percentmay still occur. This wear already occurs after 2,000 to 4,000 hours of operation. That is why a fine filtershould be installed in the pressure line of dry-running tooth-type rotary compressors to extract theabrasion 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 correctlyonly with plenty of experience. Contamination or overheating of packages will cause substantial damagesin the air ends. Replacement as well as repair costs are very high.

How many water is in the compressed Air of a water injectedcompressor? Absolute the same then in all other

compressors.

This diagrams show how many wateris in the air under differentconditions, pressure and temperaturs.All compressors that compress Airhas the same content of water . Watercan only reduced by coolıng anddrying of the pressed air with arefrigeratıon, absorbtion oradsorption dryer, this is up to theprocess what the costumer need.

How to handle the water tradement internal the system andfrom external?

The Water tradement and cleaning system is theimportants device in a water injected compressor.Atlas Copco and all other use a Reverse OsmosisSystem to clean the drinking water and fill it in themachine when the water level is low. This is sure notenough to control the water quality in the compressorsystem. The water system is not a closed system. Theair that coming in from the atmosphere bring a lot ofbad ions in the system, the water wash all this out andnow the ions are in the water system. Further thewater ever take ions from the material inside thesystem, and try to find balance .

A real water tradement has to messuring and clean permanently thewater system. Only the from Kirsten patented system can do this andgive the absolute security under all conditions that the water qualityin the machine is around the world the same. 30 years of expiriencewith water lubricated and water injected screw compressors hasshown the way how to do this. When the water in the compressorsystem is regulated between a conductivity from 5 to 10 microsiemens by 20°C, the system runing under safe conditions, waterlubricated bearings life time will more then 50.000 hours.

What are the benefit to use the NEW water injected screw compressor technologie?

The Maintenance EngineerThe oil in compressed air aftercompression will attackdownstream equipment, causingincreased maintenancerequirements and increasedplant downtime

The Financial ManagerLow cost oil lubricatedcompressors may look attractive,But when considering the totaloperating costs compared to Oilfree compressors, the extrainvestment in a water injectedscrew compressor will easily payfor itself

The Application EngineerEvery application can benefit fromoil free air compressors with totalproduct safety, lower operating,and maintenance costs and ahealthier working environment

The General ManagerIf 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 ManagerBreathing oil fumes is definitely not a goodidea and oil Condensate can damage theenvironment So why do it the hard way,when you can do it the smart way with oilfree water injected compressors

The Quality ManagerDo not accept the possibility ofproduct contamination, and reducedproduct quality. Only 100% Oil freecompressors can offer a 100%Guarantee of Oil Free Air