Roots pump and Roots blower are two types of mechanical equipment designed based on the Roots principle, used for vacuum extraction and gas transportation respectively. There are significant differences in their working principles, structural characteristics, and application fields.
1、 Roots pump
1. Working principle
Roots pump belongs to the positive displacement vacuum pump, which forms a volume change in the pump chamber through two synchronously rotating blade rotors, achieving gas suction, compression, and discharge.
Maintain small gaps between rotors and between rotors and pump chamber walls, without direct contact, and achieve oil-free operation through gap sealing.
2. Structural characteristics
No internal compression: Gas is not compressed in the pump chamber, and the compression process depends on the preceding pump or external system.
High speed operation: The rotor speed is usually 1500-3000 rpm, with excellent dynamic balance performance and low vibration.
High pumping speed: Maintain high pumping speed within a wide pressure range (such as 100-1 Pa), suitable for high vacuum requirements.
3. Application Fields
Vacuum industry: vacuum smelting, vacuum coating, vacuum drying, vacuum packaging, etc.
Research fields: material preparation, surface science experiments, etc.
2、 Roots blower
1. Working principle
Roots blower belongs to the positive displacement blower, which forms a volume change in the cylinder through two synchronous and reverse rotating blade rotors, achieving gas suction, compression, and transportation.
Maintain small gaps between rotors and between rotors and cylinder walls, without direct contact, and achieve oil-free operation through gap sealing.
2. Structural characteristics
Forced gas delivery: The gas is compressed in the pump chamber and forcibly discharged, resulting in a high output pressure (such as 9.8-196 kPa).
Low speed: The rotor speed is usually 150-3000 rpm, with a wide flow range (such as 0.6-824.6 m3/min).
Low noise: The three blade rotor design has lower noise and smoother operation than the two blade rotor.
3. Application Fields
Environmental protection field: sewage treatment aeration, pneumatic conveying, etc.
Chemical industry: gas transportation, pressurization, etc.
Cement industry: powder conveying, etc.
3、 The core difference between Roots pump and Roots blower
Characteristics Roots pump Roots fan
Functional vacuum extraction, gas transportation, and pressurization
Pressure range: Low pressure to high vacuum (100-1 Pa), low pressure to medium pressure (9.8-196 kPa)
High speed (1500-3000 rpm) and low speed (150-3000 rpm)
Application scenarios include vacuum industry, scientific research and environmental protection, chemical industry, cement, etc
4、 Selection and usage precautions
1. Roots pump
It needs to be used in series with the front stage pump (such as rotary vane pump, slide valve pump) to avoid overloading caused by separate operation.
Suitable for high vacuum and low pumping speed scenarios, it is necessary to regularly check the rotor clearance and sealing performance.
2. Roots blower
It can run independently and is suitable for low-pressure and high flow scenarios. Attention should be paid to the intake temperature and dust content of the medium.
Regularly check the lubricating oil and bearing temperature to avoid overloading operation.
5、 Summary
1. Although Roots pumps and Roots blowers are based on the same principle, their functional positioning is different:
2. Roots pumps focus on vacuum extraction and are suitable for high vacuum requirements;
3. Roots blower focuses on gas transportation and pressurization, suitable for low-pressure, high flow scenarios.
4. When selecting, it is necessary to match the specific working conditions (pressure, flow rate, medium, etc.) and usage requirements (vacuum degree, operational stability, etc.).
