ZS Screw blower Sittisak.T
ZS Low Pressure Screw blower Agenda Applications Products range Scope of supply Why is the screw so much more efficient? ISO1217 2
3 Low pressure applications
4 Low pressure applications
(bar(g)) Low Pressure Product Portfolio 4 ZE/A 2-6 1.5 ZB + 1.0 ZS + ZS HSI MC series 0.5 HSI HT series 0 0 2.000 4.000 6.000 8.000 16.000 (m3/hr) 70.000 5 5
Low Pressure screw blower Scope of supply Basic Base frame with forklift slots 100% oil free element (Class 0) Integrated gear-box (no belts) TEFC IP55 motor Air-outlet (silencer, BOV) Oil-circuit (pump and cooler) Air-inlet (filter) Discharge pressure gauge Oil pressure switch Decoupling between air filter and element Decoupling between element and pulsation damper Comes with fixed speed (Y/Δ) motor as standard. VSD type motor as an option ZS55 basic 6
ZS Low Pressure screw blower Scope of supply Standard Base frame with forklift slots 100% oil free element (Class 0) Integrated gear-box (no belts) TEFC IP55 Air-outlet (silencer, BOV) Oil-circuit (pump and cooler) Air-inlet (filter) Discharge pressure gauge Oil pressure switch Decoupling between air filter and element Decoupling between element and pulsation damper Canopy 78 db(a) at 1 bar and full speed. 74 db(a) at 0.6 bar and full speed Comes with fixed speed (Y/Δ) motor as standard. VSD type motor as an option No starter and no Elektronikon ZS55 standard 7
ZS Low Pressure Screw blower Scope of supply ZS + VSD Base frame with forklift slots 100% oil free element (Class 0) Integrated gear-box (no belts) TEFC IP55 Eff 1 motor Air-outlet (silencer, BOV with pressure control) Oil-circuit (pump and cooler) Air-inlet (filter) Decoupling between air filter and element Decoupling between element and pulsation damper Elektronikon controller for improved performance larger turndown Improved sound enclosure (72 db(a)) Integrated VSD converter ZS37 + VSD 8
ZS Low Pressure Screw blower Scope of supply Air filter Dry paper filter Same as used on ZR/T range Efficiency SAE fine particle size 0,001 mm 98 % 0,002 mm 99.5 % 0,003 mm 99.9 % Air filter differential gauge Provides visual view of air filter pressure differential. Change air filter when differential reaches 50 mbar Air discharge pressure gauge 50 mm diameter Bar and psi display Dry type 9
ZS Low Pressure Screw blower Scope of supply Flexible hose To provide a vibration decoupling between the element and the filter housing. On tri-lobe blowers serious cracking on the filter housing can occur due to having no de-coupling On ZS it is not a concern but we can use this feature as a positive design feature over tri-lobes 10
ZS Low Pressure Screw blower Scope of supply compression element ZS element 100% oil free element (Class 0) Coated with the same coating as the Z stages Coating consists of a teflon & a teflon grahite layer Timing gears like the Z s but on drive end Non-drive end is greased for life bearings 11
ZS Low Pressure Screw blower Scope of supply compression element Timing gears on the non-drive end Lubricated bearings on both drive end and non-drive end 12
ZS Low Pressure Screw blower Scope of supply Flexible hose To provide a vibration decoupling between the element and silencer On tri-lobe units serious failures of the silencers can occur. It is not an issue on the ZS due to the screw element delivering higher frequency, low pulsation air but let s use it to attack lobes. 13
ZS Low Pressure Screw blower Scope of supply Gearbox Transfers motor power to element more efficiently than belt / pulley Belt / pulley = approx. 93% efficient Gearbox = approx. 98% efficient No risk of misalignment Belts needs to be replaced every year 14
ZS Low Pressure Screw blower Scope of supply Start up valve Closes when the pressure builds between 0.1 bar and 0.2 bar (1.5 psi and 3psi) The valve is in the open position when the blower is off. When the blower is started against a counter pressure, the air is blown off through the main opening of the valve (1). By increasing the air flow, a slight overpressure is generated in the pipe (2) and the bellows (3) are filled with air. When the pressure on the surface of the base plate (5) in the bellows has become bigger than the pressure on the main opening of the valve (1), the base plate closes the valve. The unit is in load status. 1 3 2 5 15
ZS Low Pressure Screw blower Scope of supply Start up valve When the unit will be stopped, the air in the bellows will escape through the pipe. The pressure on the base plate diminishes and the springs (4) will open the valve. 4 16
ZS Low Pressure Screw blower Scope of supply Bursting disc The bursting disc is the safety device to ensure that any over pressure is released quickly. It is designed to protect the blower from over pressure. The bursting disc is used for PED accuracy and cost. Once the disc breaks it has to be replaced with a new one. 17
ZS Low Pressure Screw blower Scope of supply Check valve Swing type Prevents air from network entering the element. Low pressure drop design Silencer Reduce noise and pulsations generated by element Damping material is stainless steel wool 18
ZS Low Pressure Screw blower Scope of supply oil circuit Oil pump Pumps oil from the tank (15 litre) to the bearings and gears 50 Hz: 370 watt; 400V; 3phase 60 Hz: 430 watt; 440-460V; 3 phase Oil filter Filters any particles from the oil Genuine Atlas Copco oil filter Oil cooler and cooling fan To cool the oil prior to lubrication of gears This is a big selling feature. Cooled oil has a much longer lifetime 50Hz: 95 watt; 230V; 1 phase 1690 m3/hr cooling air flow 60Hz: 94 watt; 115V; 1 phase 1420 m3/hr cooling air flow Oil type Roto Z 19
ZS Low Pressure Screw blower Why is the screw so much more efficient? p 1bar atm Screw Roots Working principle and pv-diagram 200m³/h 5000m³/h flow Adiabatic efficiency Air temperature at outlet Pressure pulsations Conclusions 20
Roots blower working principle Air intake at inlet side Air transport Air transport External compression by back flow Force out air to discharge line 21
Roots blower : pressure-volume diagram p pe 3 Wt 2 p 1 = air intake pressure pe = working pressure (external system pressure) Vs = displaced volume p1 4 Vs 1 V 4-1 : Air intake; volume increase to Vs 1-2 : Compression by back-flow from receiver to blower 2-3 : Air delivery from blower to receiver Rectangle area 1-2-3-4 represents the compression work Wt Power consumption is proportional with blue area 1-2-3-4 22
Working principle Example: B111 Inlet port Male rotor Female rotor 23
Working principle Volume of inlet chamber increases when rotating the rotors: air is sucked in 24
Working principle Volume of inlet chamber increases when rotating the rotors: air is sucked in 25
Working principle Volume of inlet chamber increases when rotating the rotors: air is sucked in 26
Working principle Inlet port closes: Air is trapped between between rotors and housing 27
Working principle Inlet port closes: Air is trapped between between rotors and housing 28
Working principle Outlet port: much larger than OIS or OFS When rotors rotate the volume between the rotors decreases : compression of the air 29
Working principle When rotors rotate the volume between the rotors decreases down to the built-in volume ratio : compression of the air 30
Working principle The outlet ports opens when the volume is reduced: compressed air is released from between the rotors to the outlet port 31
32 Working principle
33 Working principle
34 Working principle
Screw blower Working principle : displacement compressor with internal compression Pressure-Volume diagram p 3 2 pi=pe Wt 1-2 : internal compression in screwblower 2-3 : Air delivery from screwblower to receiver p1 4 Vs/vi 1 Vs V 35
Screw blower Working principle : displacement compressor with internal compression Pressure-Volume diagram p 3 2 Wt 1 Energy saving due to internal compression Power consumption is proportional with blue area V 36
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ZS Low Pressure Screw blower Summary 43 Roots type blowers Max 0.8 to 1.0 bar(e) Poor efficiency, No package performance warrantee High outlet temp High noise level: 75-90 db(a) Pressure pulsations External VSD,Narrow turndown: 800m 3 /hr to 1100m 3 /hr, Speed window and high temp Limited reliability and lifetime Installation cost, check valve, safety valve, Flexible hose Screw blowers + 1.25 bar(e) or more + High efficiency (~30% less SER), Package warrantee + Lower outlet temp + Noise level: 70-73 db(a) + Higher frequency pulsations + Internal VSD,Large turndown: 200m 3 /hr to 1100m 3 /hr on ZS37+ VSD, VSD s motor,no speed window. + Integrated concept: small footprint + Oil cooler: High reliability and lifetime + Complete package,no hidden cost
44 ISO 1217
Committed to sustainable productivity. 45