Hitachi Oil-Free Rotary Screw Air Compressors

1. Air End Design
2. Hitachi oilfree DSP Design Advantages
3. Maintenance Friendly
4. DSP Model Versions Available by HP

Air End Design

• Rotors manufactured from SUS403 stainless steel
• First and Second stage rotors are stainless steel
• Dual lead tooth profile on the male and female rotors
• Tapered rotor design compensates for thermal expansion at operating conditions
• No PTFE
• A patented HX-18 coating is applied to the rotors at a uniform thickness
• HX-18 coating handles high operating temperatures
• Superior solid film lubricating performance

Hitachi oilfree Screw Design Advantages

Hitachi's DSP Series has several design advantages compared to its competitor's oilfree rotary screws. Hitachi's advantages:

Hi-Precooler

The Hi-Precooler is a stainless steel heat exchanger that removes heat of compression reducing the load on the aftercooler. Located between the airend and the checkvalve before the aftercooler the Hi-Precooler...

• Cools the compressed air that is purged to atmoshere during unload operation
• Protects the check valve from high temperature compressed air discharged from the airend
• Cools hot compressed air prior to the aftercooler

Oil Mist Remover

The Oil Mist Remover's (OMR) 99.99% efficient oil remover stops oil vapor from venting to atmoshere. Putting the vent oil back in the gear case keeps the compressor room clean. Plus, the frequency oil has to be added is reduced. This reduction saves labor hours and maintenance dollars spent on replacement oil.

How does Hitachi's OMR work? The OMR has an ejector that uses compressed air to generate vacuum pressure against the OMR system and gear case. This prevents the gear case's internal pressure from rising from resistance from the oil remover element.

Quiet Operation and Small Footprint

Hitachi strives to make DSP compressors the quietest oilfree screws available. To make them quiet Hitachi provides:

• Full enclosure as standard
• Mechanical and electrical vibration isolation
• Design to minimize leak paths
• Unit is compact in overall dimensions
• Panel access helps space conservation

Microprocessor Controller

• Narrow pressure band operation
• Variable speed design units quickly adapt to variation in demand
• Lead/Lag (2 units) is standard
• Instantaneous Power Interruption (IPI) restart is standar

• Current
• Active capacity control type
• Discharge air pressure
• Oil/Coolant pressure
• Accumulated operating hours
• Temperatures of Oil/Coolant etc
• Date and remaining operating hours until next maintenance
• Actual demand percentage compared to full load capacity

• Instantaneous Power Interruption restart
• Automatic motor on-off
• Remote operation dry contacts
• Lead-Lag operation
• Dryer pre-start dry contact

Matched Motor & Drive

• Inverter drive
• EPAct motors
• UL listing
• TEFC construction

DSP-Vplus and Vtype No Inlet Valve Design

1. No vacuum is generated at airend inlet and succeeded to obtain stable sealing performance even at slow running speed
2. No parts replacement is necessary in inlet valve
3. No temperature rise at capacity control as no vacuum exist at the inlet

Maintenance Friendly

The DSP compressor allows easy access to regular maintenance items like filters and for easy visual inspection of the compressor.

DSP Series Oilfree Rotary Screw Air Compressor Versions Available by Horse Power

Discharge Pressure 100 psig for Single stage models.
Discharge pressure 100 or 125 psig available for Two stage models.