Oil Free - Shanghai Model

Emeraude ALE IV

Motor Power

132 – 400 kW

Discharge air flow

19.2 – 66.8 m3/min

oil free compressor

Ultimate Energy Efficient KOBELCO's Flagship

By developing state-of-the-art air-ends and optimized package design, we achieved best in class specific power consumption as well as utmost durability. Here, new standard of oil-free compressors starts.

Class-leading specific power consumption

Comparison of specific power consumption

New ALE’s performance is evaluated by specific power consumption as per JIS B 8341:2008 (1801217 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,

Newly designed high efficiency rotors

A 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
  • Improvernent of shaft sealing structure

Package design for no wasted energy

Internal piping design, high efficiency motors and fans contribute to snergy 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.

Partial-load performance of Inverter model

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.


Performance curve of KOBELCO Inverter model

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

Stable pressure control of Inverter model keeps the line pressure lower. And the pressure fluctuation is kept within 0.01MPa. 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.

Unique design to ensure "Oil-free"

KOBELCO’s proven dual vent holes design prevents oil entry in compressor chambers during unload running.

Class 0 certified

KOBELCO has received Class 0 certification ( IS08573-1 [-:-:0] ) for <Emeraude ALE> series from international test institute called TUV which certifies the highest level of purity for quality classifications of compressed air.

Long life cycle

Long Overhaul cycle has !um achieved thanks to long Me cycle bearings.


Standard Overhaul cycle

Superior Anti-corrosion performance

Proven 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 

Outstanding quietness

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


Comparison of noise level

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.



Newly designed suction and discharge silencers reduce noise level.

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

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

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

Key Components

Plate fin gas cooler (water cooled)

80% of pressure drop has been cut compared with shell & tube type. Additionally, because discharge air temperature has been reduced by optimization of cooler size, auxiliary equipments are downsized.

Discharge silencer

KOBELCO Patented Expansion & Porous Silencer reduces noise level in broad frequency band.

*Expansion Silencer for 200kW and above


Capacity control valve

Proven pneumatic capacity control valve having quick response and high durability. Maintenance parts have been reduced thanks to built-in blow-off silencer.

Oil pump

Oil pump attached to gear box is driven by a high
efficiency main motor.
The risk of oil leakage is reduced by no-piping design.


Main motor


  • IPM motor for Inverter model Heat loss is small and high efficiency is kept even during low load condition.
  • Comparison of motor efficiency

  • Comparison of structure (for reference)

  • IE3 motor for fixed speed model Fixed speed model (380-460V) has 1E3 high efficiency induction motor.