AIRCOMO- Air Compressor & Motor Products & Services
About the Kobelco KNW Series
The Kobelco KNW Series assembly is designed and constructed to exacting quality standards. These standards result in assemblies with long operating life, minimum maintenance, and low operating costs.
High Quality, Quiet and Attractive
The Kobelco KNW Series oil-free rotary screw air compressor is designed, manufactured, assembled, and tested in the United States and is delivered ready for operation. The two-stage rotary screw compressor provides completely oil-free air because no oil is allowed in the compression chambers.
Both compression stages employ a new-patented Super Rotor design, which is acknowledged to be the most efficient, two-stage, oil-free rotary screw air compressor on the market. This new asymmetric rotor profile provides the lowest power consumption per cubic foot of compressed air.
The efficiency is further enhanced by a unique load/unload control system that is simple and trouble free.
The compressor air-end is a heavy-duty, two-stage design with each stage driven by a common gear. These components are arranged in a single modular design to form a compact unit which is mounted on vibration isolators to a structural steel base. No special foundation considerations are required.
Precision machined timing gears are mounted on each rotor shaft to maintain accurate clearances between the rotors. The bearings are anti-friction type for long life and smooth operation. The electric motor is directly coupled to the input drive shaft through a flexible coupling.
Axial thrust is reduced by incorporating an air pressure operated thrust balance piston on each stage. This arrangement minimizes thrust loading thus increasing bearing life.
The state-of-the-art programmable microprocessor controller maximizes operating efficiency and versatility. Kobelco’s sound attenuated enclosure assures quiet operation. Doors are hinged and pinned allowing easy removal for inspection and maintenance.
Design Features>
Operator Interface/ PLC>
Additional Specs about Installation & Controls>
Design Features
High Efficiency Rotors
The new patented Super Rotor profile is the most efficient in the industry. The machined forged steel rotor sets have the most precise tolerances in the industry. FDA approved rotor coating further increases volumetric efficiency. In addition, the new profile provides 20% more displacement per revolution thus lowering rotor speeds and increasing bearing life.
Dual Vent Seals with Stainless Steel Rings
Each shaft seal consists of floating stainless steel rings and an oil labyrinth inserted between the rotor chamber and the bearings. Each seal is buffered by gas from the compression chamber which is purged to atmosphere ensuring that no lubricating oil or its vapor can enter the compression chamber.
Lubrication of Gears and Bearings
Lubrication prior to start-up, during operation and after shutdown is supplied by an independent motor driving gear pump. Compressor operation is not allowed until oil pressure is established. During the coast down period the oil pump continues to provide full lubrication until the compressor stops. This design increases gear and bearing life and is not standard on competitive units.
Capacity Control Valve
The efficient and simple capacity control system is a load/unload type with a direct operating disc valve and no discharge air recalculation. During unloading the bleed-off air is released to atmosphere through a muffler. This eliminates the need for a bleed-off cooler and the associated problem of condensed moisture entering the inlet of the compressor. The control is an electro-pneumatic device. No oil, hydraulic cylinders, or rolling diaphragms are used in the operation of this valve.
Load and Unload Control
This control provides energy efficient operation while eliminating adjustments and minimizing maintenance. When the compressor unloads the brake horsepower drops to approximately 18% of full load, significantly reducing overall energy cost. The compressor will shut down after operating unloaded for a period of time and will automatically restart on pressure demand.
Kobelco Operator Interface / PLC
Versatile Display
- Graphics Touch Screen Display - Readable in sunlight; 16 shades of gray allow crisp graphics and easy to read compressor data.
- Trending - Three (3) configurable graphs for historical trending. Two (2) pressures or temperatures are displayed on each graph.
- Package outlet air temperature display and alarm.
- Service notification for air and oil filter.
- Color display available as option.
Versatile Communications
- Allen Bradley Micro Logix 1500 PLC Standard.
- The Allen Bradley PLC allows for connection to DCS, FMS or SCADA connection by network or modem.
- Ethernet Option: Allows connection to intranet for data monitoring and alarm or event notification via e-mail. Ethernet option has built in web hosting for internet connection and alarm or event e-mail notification.
Operator Interface and PLC
The Kobelco KNW Series Oil-Free Rotary Screw Air Compressor uses an Allen-Bradley Programmable Logic Controller (PLC) to control and monitor compressor operations.
- Graphics touch screen display
- Sunlight readable grayscale or color
- Event alarm log
- Pre-alarm warnings
- Panel adjustable set points - temperature and pressure
- Password security
- Real time clock
- Alternate temperature units - degree F. or degree C.
- Continuous temperature displays
- Maintenance reminders
- Configurable graphs for trending
- Ethernet option
- Connection to DCS, FMS or Scada by network or modem
Installation and Start-Up Supervision:
A factory trained field representative will supervise installation and start-up. This same representative will also train your maintenance personnel in the operation and maintenance of the assembly. Our commitment is to provide a trouble free, reliable installation of which we can both be proud.
Factory Monitored Maintenance Program:
Compressor performance parameters are recorded by the customer on factory-supplied forms and then examined monthly by factory experts at no charge.
Controls and Instrumentation:
Service Indicators
- Air inlet filter condition indicator
- Oil filter condition indicator
- Oil level gauge
- Routine maintenance
Pressure Indicators
- First stage air discharge pressure gauge
- Second stage air discharge pressure gauge
- Oil pressure gauge
Temperature Indicators
- First stage air discharge
- Second stage air inlet
- Second stage air discharge
- Lube oil
Additional Indicators
- Stand-by mode light
- Oil pump run light
- Fan run light
- Compressor run light
- Compressor load light
- Alarm light
- Hour meter - running time
- Hour meter - load time
- Manual unload light and switch
Safety Devices:
All safety shutdowns are indicated by message on display and alarm light.- Compressor motor overload shutdown and light
- Oil pump motor overload shutdown and light
- Fan motor overload shutdown and light
- High first stage air discharge temperature shutdown and light
- High second stage suction temperature shutdown and light
- High second stage air discharge temperature shutdown and light
- High oil temperature shutdown and light
- Low oil pressure shutdown and light
- High cabinet temperature shutdown and light
- Starter failure light
- Temperature pre-shutdown alarm
Additional Devices:
- Start/stop push buttons
- Lamp test
- Audible alarm
- Acknowledge switch
- Reset Switch
- Common alarm contracts for remote indication
- RS485 network connection for DCS/FMS systems
Additional Features:
- Packaged Assembly
- Air-cooled or water-cooled
- Integral air-cooled or water-cooled aftercooler with moisture separator and automatic drain
- Cabinet ventilating fan
- Easy access for maintenance
- Removable hinged doors
- Low installation cost
- Few connections required for installation - compressed air, condensate drains, electrical and water (when required)
- Control settings easily accessible
- Full voltage motor starter (460 volt standard)
- CSA certified panel
Advanced Design: Super Rotor delivers more cfm per horsepower
Efficient Control : Load/Unload electro-pneumatic
Vibration Free
- No vibration generated in smooth rotary design
- No special foundation required
Low Water Usage (water-cooled units)
- Cooler selection is optimized to reduce cooling water requirements
- Automatic intercooler water regulating valve standard equipment
Options
- Single-stage design
- Duty sequencers for multiple compressor installations
- All types of reduced voltage starters
- Extended warranty programs
- Outdoor weather protection
- Freeze protection
- Non-standard motors
- Variable Speed Drive
Sample Compressors:
| FS Curtis | Boge Rotary Screw | Champion |
| Sullivan Palatek Rotary Screw | Saylor-Beall | Kobelco oil-free Rotary Screw |
| Dekker Vacuum Pumps | Busch Vacuum Pumps |