The EDC Series is Zhongtian's oil-free claw vacuum pump range, designed for industrial applications requiring clean, dry vacuum generation without lubricating oil in the pumping chamber. Two synchronized non-contact claw rotors create positive-displacement pumping action, while timing gears maintain precise rotor clearance and synchronization. The series is available in single-stage and two-stage configurations, with both air-cooled and water-cooled versions for different process and thermal requirements. With pumping speeds from 40 to 650 m³/h and ultimate pressure down to 2000 Pa on selected two-stage water-cooled models, the EDC Series provides a versatile oil-free vacuum solution for packaging, automation, drying, centralized vacuum and general industrial applications.
Working Principle
The EDC Series operates on the dry claw positive-displacement principle. Two claw-shaped rotors rotate synchronously in opposite directions inside the pumping chamber. The rotors do not contact each other or the chamber wall during normal operation. As the rotors turn, gas is drawn into the expanding working chamber and trapped between the claw rotors and pump housing. Continued rotor rotation transports the trapped gas toward the discharge side, where the chamber volume decreases and the gas is compressed before being discharged. Timing gears located outside the pumping chamber maintain precise rotor synchronization. Because no lubricating oil is required inside the pumping chamber, the process gas is not exposed to pump oil during normal operation.
Key Features
Oil-Free Pumping Chamber
The EDC pumping chamber operates without lubricating oil. Lubrication is confined to the gearbox and bearing sections, which are separated from the process chamber. This design helps prevent process-gas contamination by pump oil and eliminates the need for vacuum oil inside the pumping chamber.
Non-Contact Claw Rotors
The two claw rotors operate without mechanical contact inside the pumping chamber. Precision timing gears maintain rotor synchronization and operating clearances, helping reduce wear in the gas-contacting pumping section.
Water-Cooled Configurations
Water-cooled EDC configurations are available for applications requiring improved thermal control during continuous or higher-load operation. Water cooling helps stabilize pump temperature and supports reliable operation under demanding thermal conditions. The standard EDC Series is intended primarily for clean, dry and compatible process gases. For applications involving condensable vapours, corrosive gases or particulate contamination, process conditions should be reviewed and suitable purge, material or protection configurations selected where available.
*Performance values measured under standard test conditions. Ultimate pressure varies by model and configuration — see table.
*Single-stage air-cooled: 10,000–25,000 Pa. Single-stage water-cooled: 6,000 Pa. Two-stage air-cooled: 3,000 Pa. Two-stage water-cooled: 2,000 Pa.
*Pumping-speed tolerance: ±10%.
Typical Applications
Oil-free vacuum generation for packaging and sealing equipment
Pick-and-place, lifting, clamping and automated handling systems
Compatible dry-process vacuum drying applications
Oil-free centralized vacuum generation for industrial plants
Vacuum suction, paper transport and printing equipment
Machine-integrated dry vacuum for compatible industrial processes