Water-Cooled Rotary Screw Air Compressor

i Product Description

The LGS series is the water-cooled branch of Kaishan’s LG single-stage range: a family of electric motor driven, fixed-speed, oil-injected rotary screw compressors from 75 kW to 400 kW, all sharing the same design logic and differing mainly in frame size and air end. Choosing within one series rather than across unrelated models means a plant can standardise its air station on a single platform, from a 14 m³/min unit feeding a small workshop up to a 72 m³/min machine carrying a central air header, and keep spares, maintenance routines and operating habits consistent across the site.

Across the whole range the mechanical approach is the same. The compression element is Kaishan’s own screw host with Y-profile rotors, driven directly by the motor without belts, so there is no belt slip and no belt change interval on the maintenance schedule, and rotor speed stays tied to motor speed. Bearings are sized for continuous industrial duty and rigid rotor-to-motor alignment keeps vibration low. The canopy is built for stationary installation, running at a moderate noise level without the fan roar of an air-cooled machine.

The air and control systems follow one pattern from the smallest to the largest frame. Capacity is regulated steplessly from 0 to 100 percent through the inlet valve, so the machine tracks air demand rather than switching between full load and idle in large steps. A temperature control valve keeps oil temperature above the dew point to limit condensate build-up, and a minimum pressure valve maintains the internal pressure needed for oil circulation and separation before air leaves the package. Instrumentation and protection are handled by the unit controller, with the usual discharge temperature, pressure and motor protection interlocks.

The lower ratings from 75 kW to 280 kW are standard catalogue builds. The 315, 355 and 400 kW models are non-standard builds, marked with an asterisk in the table, and one further 355 kW variant, the LGS355GB, is a high-flow configuration that delivers 65.00 m³/min at 0.8 MPa against 60.60 m³/min from the standard LGS355 on the same installed power and a slightly longer base. For the large frames, delivery schedule and detailed configuration such as cooling-water connections and flow, control and monitoring scope, and foundation and lifting provisions are agreed with the factory at enquiry stage.

Typical installations across the series include general manufacturing, textile and dyeing, chemical and pharmaceutical processing, steel and metalworking, cement and mineral processing, and any site that already runs a cooling-water circuit. Kaishan is the brand of Zhejiang Kaishan Compressor Co., Ltd., a compressor manufacturer with 70 years of history, more than 300 patents, a national enterprise technology center, and equipment installed in over 90 countries.

T Technical Specifications