new ale logo



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Toward the new valuation standard

Compressors are evaluated by Specific energy consumption.


Emeraude ALE has achieved the class-leading Specific energy
consumption with technology innovation and drastically reduction of energy-losses.

Technology innovation

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Class-leading Specific energy consumption

● Comparison of Specific energy consumption

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 New ALE’s performance is evaluated by Specific energy consumption as per JIS B 8341:2008 (ISO1217 Edition3 equivalent). KOBELCO places an importance on not only shaft power but also compressor’s total input power  including energy loss in the compressor because  electricity consumption for customers is not shaft power and rated motor power but compressor’s total input power.

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*Comparison  of 132kw models

Newly designed high efficiency rotors

p3 4A new rotor profile has been designed using advanced analysis technology that KOBELCO has fostered in their long history since developing the first oil free screw compressor in Japan in 1956.  KOBELCO has achieved class-leading specific energy consumption thanks to
the new rotors which have been designed superior performance.

[Improved Points]

  • Optimization of the inter stage pressure
  • Optimization of rotor clearance
  • Improvement of shaft sealing structure


Package design for no wasted energy

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Internal piping design, high efficiency motors and fans contribute to energy savings. Moreover, gas coolers’ optimization decreases the discharge temperature and downsizes auxiliary equipment such as dryers.
This leads energy saving of not only compressors but also clean air systems.


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p4 2Proven Dual atmospheric vent holes

KOBELCO’s proven dual atmospheric vent holes prevent oil entry in compressor chambers during long unloading.

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p4 5A phase difference of 135° between vent hole A and B contributes to optimization of shaft seal’s length and performance up.

● 3 steps of reliable shaft seal structure (during unloading)

  1. Highly reliable oil seal prevents oil entry.
  2. Oil return groove pushes back oil even if oil break through oil seal.
  3. Oil is exhausted from atmospheric vent hole B even if oil breaks through oil return groove. Pressure between vent hole A and B is equal, so oil doesn't enter into compressor chambers.

Superior Anti-corrosion performance

p4 7Proven Teflon coating and 2nd stage’s Stainless steel rotors secure high durability against drain attack and prevent performance deterioration due to corrosion.

● Anti-corrosion test results

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Class 0 Certified


The Zero Class certification (ISO8573-1 [-:-:0]), which represents the highest level of purity for quality classifications of compressed air, was received for the〈Emeraude ALE〉series of products, in acknowledgement for the oil-free technology of Kobelco.

Longer life cycle

Long Overhaul cycle has been achieved thanks to long life cycle bearings.

● Standard Overhaul cycle

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Outstanding Quietness

Various noise control techniques has drastically reduced sound level. Making the working environment more comfortable.

● Comparison of noise level


*Noise measurement is as per ISO3744, ISO2151

● Package structure for noise reduction
Cooling air inlet points have been put into one place to reduce noise.

● Panel design
Noise absorbing material and high sealing ability against abrasive noise reduce noise leakage.

● Silencer
Newly designed suction and discharge silencers reduce noise level.

New measurement standard as per ISO3744, ISO2151 is more stringent than previous one because of 9point average and 1m around the unit


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(as per ISO3744, ISO2151)
9 point average measured at a distance of 1m around the unit or 1m above the unit

Previous measurement standard (as per manufacturer’s standard)
4 point average measured at 1m height and 1.5m around the unit


Easy maintenance

Easy access to key service parts for maintenance thanks to large panels and reduction of internal piping.

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Exhaust cleaner without power source
or instrument air

Filter type and compact exhaust cleaner has over 99% of oil mist  separation performance and keeps inside of unit clean.
Moreover, pressure resistance doesn’t increase for long time because oil mist is separated itself.

Automatic restart after power failure

● Momentary power interruption protection
: within 0.1-0.5sec

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● Automatic restart after power failure
: 0.1-20sec

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User-friendly controller with 7 inch large size touch screen panel

It’s easy to check and set running conditions.




Protection features

  • 7500V surge protector
  • Water flow switch (for water cooled model)
  • Emergency stop button
  • Motor winding temperature detection
  • Password protection

Data logging with USB

Running data (CSV file) can be output from monitor to USB memory stick.


Group control

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Max. 6 units can be automatically operated without a group control panel.

Energy saving & Engineering solution

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Partial-load performance of Inverter model

● Performance curve of KOBELCO Inverter model

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Inverter model’s partial load performance has been improved thanks to IPM motor and  superior rotor design.
Inverter model supplies required air volume in appropriate power consumption.


Stable pressure control of Inverter model
Energy saving logic of Fixed speed model

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Stable pressure control of Inverter model keeps the line pressure lower. And the pressure fluctuation is kept within 0.1bar. Energy saving logic of Fixed speed model forcibly switch loading to unloading at every capacity control cycle (min 23sec). Excessive pressure rise is eliminated and energy loss is minimized.

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From Air end performance toward Unit performance and Air system performance
KOBELCO provides advanced total solution

 p7_5.jpgKOBELCO, a pioneer of Compressor technologies in Japan, always explores the front-line with its proven history and advanced technology.
KOBELCO proposes suitable air system to meet customer’s various requests such as clean air system, high efficiency and automation.

① Group control

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Max 6 units can be operated without a group control panel in case of new ALE


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② Stable pressure control of Inverter model + Group control

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Because Stable pressure control of Inverter model leads  to lower down the parallel fixed speed models‘ discharge pressure, a lot of energy use  is saved.


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③ Line pressure control (Option)+ Stable pressure control of Inverter model + Group control

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Line pressure control optimizes the discharge pressure which has excessive margin. It’s possible to reduce energy loss with excessive pressure rise by monitoring of line pressure and pressure drop.

*Assumptions:160kw*4units, average load ratio: 62.5%, running time: 8000hr, Comparison to Load/unload control without group control