Air-cooled negative pressure Roots blowers (also known as air-cooled Roots vacuum pumps) are a specific type of Roots blower. They use air cooling to dissipate the heat generated during operation and create a negative pressure (vacuum) environment in the system through their working principle. Combining the inherent durability of Roots blowers with the simplicity of air-cooling technology, they are an ideal choice for suction and vacuum requirements in many industrial applications.

1. Core Features

Air Cooling: Relying on an internal fan and heat dissipation fins on the casing, heat is dissipated through airflow. No additional cooling water system is required, avoiding complex water pipe installation, scale buildup, and water waste, making it particularly suitable for areas with water scarcity or hard water.

Negative Pressure Generation: The core function is to draw air or gas from a closed system to create a vacuum, with an operating pressure range of 0 kPa to -50 kPa.

Oil-Free and Clean: The rotors rotate synchronously in opposite directions within the pump chamber, with tiny gaps between them and between them and the pump chamber, eliminating contact and the need for internal lubrication. The transported medium is pure and oil-free, making it ideal for oil-sensitive applications.

Simple and durable structure: Primarily composed of a casing, a pair of three-lobe (or two-lobe) rotors, synchronous gears, and bearings. The structure is robust, highly resistant to sudden load changes, and operates stably and reliably.

Energy-saving and economical: The air-cooled design reduces the energy consumption and cost of auxiliary facilities, resulting in high overall operating efficiency and good economic performance.

2. Working Principle

Suction Process: A pair of precision-machined rotors rotate in opposite directions at high speed within the pump chamber, driven by synchronous gears. A minute gap is maintained between the rotors and between the rotors and the pump casing at all times.

Volume Change: As the rotors pass the inlet, a certain volume of gas is sealed between the two rotors and the casing.

Delivery Process: As the rotors continue to rotate, the sealed gas is pushed uncompressibly along the inner cavity of the casing to the exhaust port.

Exhaust Process: As the rotor passes the exhaust port, the pumped gas is expelled from the pump, simultaneously creating a new negative pressure at the inlet side, thus continuously drawing in gas.

Air Cooling Principle: A cooling fan mounted on the shaft end draws in ambient air. The airflow blows across the pump casing with cooling fins and the surface of the lubricating oil tank (if present), forcing convection cooling and effectively dissipating the heat generated by compression and friction into the atmosphere.