**Roots Blower Detailed Explanation**
**1、 Basic Definition**
Roots blower is a type of volumetric gas conveying equipment, which uses two interlocked rotors to rotate inside the casing and forcefully push the gas for conveying. Its core feature is * * no internal compression * *, and the pressure is determined by the resistance at the back end of the system, so it is also known as a "constant volume fan".
**2、 Core Features**
1. * * No internal compression**
-Gas is only pushed inside the fan and not compressed (pressure is generated by pipeline/equipment resistance).
2. * * Constant traffic**
-When the speed remains constant, the flow rate is almost unaffected by pressure changes (in contrast to centrifugal fans).
3. * * Simple structure**
-Mainly composed of rotor, synchronous gear, and housing, without valves or complex seals.
**3、 Working principle**
1. * * Inhalation stage * *: When the rotor rotates, the volume on the inlet side increases, and gas is sucked in.
2. * * Closed transport * *: The gas is enclosed in the chamber formed by the rotor and the housing, and moves towards the exhaust port.
3. * * Forced discharge * *: When the rotor rotates to the exhaust port, gas is forced out (pressure is established by system resistance).
**4、 Main structure**
|* * Component * * | * * Function * *|
|----------------|--------------------------------------------------------------------------|
|* * Rotor * * | 2 or 3 blade type, rigidly engaged, with a clearance of 0.1~0.4mm (determining sealing performance)|
|* * Synchronous gear * * | Ensure non-contact synchronous rotation of the two rotors (with a fixed phase difference)|
|* * Shell * | Made of cast iron or stainless steel, forming a closed working chamber|
|* * Drive mode * * | Direct connection () or belt drive (adjustable speed)|
**5、 Performance parameter range**
|* * Parameter * * | * * Typical Range * *|
|----------------|----------------------------------------|
|Flow rate | 0.5~300 m3/min|
|Pressure | Single stage ≤ 0.5 bar, dual stage ≤ 1.0 bar|
|Power | 0.75~250 kW|
|Speed | 500~3000 rpm|
**6、 Application scenarios**
1. * * Sewage treatment * *: Aeration tank oxygen supply (constant flow key).
2. * * Pneumatic conveying * *: Pipeline transportation of powder particles such as cement and grains.
3. * * Vacuum system * *: Reverse connection can be used as a vacuum pump (such as a packaging machine).
4. Chemical metallurgy: Transporting corrosive/flammable gases (requiring explosion-proof design).
**7、 Comparison of advantages and disadvantages**
|Advantages | Disadvantages|
|----------------------------|----------------------------|
|Simple structure, easy maintenance | High noise (requires muffler)|
|Resistant to dirt and suitable for dusty gases | Low energy efficiency (more pronounced under high pressure)|
|Stable flow, no risk of surge | Reverse rotation may damage the rotor|
**8、 Selection key**
1. * * Traffic * *: Select based on actual demand+10 margins.
2. * * Pressure * *: Need to match system resistance (overpressure requires valve installation).
3. Gas properties: Corrosive gases require stainless steel material.
**9、 Difference from centrifugal fan**
-Roots blower: positive displacement, constant flow rate, suitable for low pressure.
-Centrifugal fan: dynamic, flow rate varies with pressure, suitable for medium and high pressure.
**10、 Precautions**
-* * Reverse rotation is strictly prohibited * *: it may cause damage to the rotor due to collision.
-* * Regular inspection * *: Gear oil, bearing temperature, rotor clearance.
Roots blower is one of the main gas conveying equipment in the industrial field, and its selection requires comprehensive consideration of pressure, flow rate, and medium characteristics. If specific model recommendations are needed, detailed operating parameters can be provided!
