The following is a detailed introduction to the multi-stage centrifugal blower, covering its working principle, structural characteristics, model parameters, application scenarios, and selection guide:
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**1、 Overview of multi-stage centrifugal blower**
A multi-stage centrifugal blower compresses gas step by step through multiple sets of impellers connected in series, achieving medium to high pressure gas delivery (usually at pressures of 0.5 to 3 bar, with special designs reaching up to 10 bar or more).
**Core advantages * *:
-Higher pressure than single-stage centrifugal fans and better energy efficiency than Roots fans (efficiency can reach 75-85).
-Suitable for high flow, medium high pressure scenarios, such as sewage treatment, chemical industry, metallurgy, etc.
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**2、 Working principle**
1. Gas flow path:
-Gas enters the * * stage impeller * * from the inlet, and after centrifugal acceleration, it enters the * * diffuser * *, where kinetic energy is converted into static pressure.
-The gas passes through the subsequent impellers in sequence, with each stage pressurized by about * * 0.3~0.8 bar * *, and finally discharged from the exhaust port.
2. * * Cooling method * *:
-Inter stage cooling (internal or external cooler) prevents gas from overheating.
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**3、 Typical structural composition**
|* * Component * * | * * Function * *|
|-------------------|--------------------------------------------------------------------------|
|Multi stage impellers are connected in series from 3 to 10 stages, mostly made of stainless steel or titanium alloy (corrosion-resistant)|
|The diffuser converts the kinetic energy of gas into static pressure and reduces the flow rate|
|Inter stage cooler reduces gas temperature and improves compression efficiency (air-cooled or water-cooled)|
|* * Bearing System * * | Supports high-speed rotors, commonly using sliding bearings (oil lubricated) or magnetic levitation bearings (frictionless)|
|Sealing device * * | Maze seal, mechanical seal or dry gas seal to prevent gas leakage|
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**4、 Mainstream models and parameters**
**1. Common models (taking Shen Gu as an example)**
|Model * * | Flow rate (m3/min) * * | Pressure (bar) * * | Power (kW) * * | Stages * * | Application scenarios * *|
|----------------|------------------|---------------|--------------|----------|----------------------|
|C80-1.5 | 30~80 | 1.5 | 55~160 | Level 3 | Sewage Treatment Aeration|
|D150-2.8 | 100~200 | 2.8 | 250~500 | Level 5 | Chemical Process Gas Compression|
**2. Imported brands (such as Siemens and Atlas)**
|* * Model * * | * * Flow rate (m3/min) * * | * * Pressure (bar) * * | * * Features * *|
|----------------|------------------|---------------|-----------------------------------|
|Siemens STG * * | 50~300 | 1.0~4.0 | Magnetic levitation bearings, with energy efficiency 15% higher than traditional ones|
|* * Atlas ZR * * | 20~150 | 0.8~3.5 | Modular design, convenient maintenance|
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**5、 Performance curve characteristics**
-Flow pressure curve: steep drop characteristic, significant decrease in flow rate in high-pressure zone, and need to avoid surge (controlled by bypass valve).
-Zone * *: usually located within the range of 70-110 of rated flow.
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**6、 Key parameters for selection**
1. * * Flow rate * *: Determine based on process requirements, with a reserved margin of 10-15.
2. * * Pressure * *: It is necessary to calculate the pipeline resistance+process required pressure, and the higher the number of stages, the higher the pressure.
3. Gas properties: Corrosive gases require stainless steel or coated impellers.
4. * * Cooling method * *: High temperature gases (>80 ℃) require forced cooling.
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**7、 Application scenarios**
|* * Industry * * | * * Purpose * *|
|----------------|--------------------------------------------------------------------------|
|* * Sewage treatment * * | Aeration tank oxygen supply (pressure 1-1.5 bar)|
|* * Chemical * * | Compression of process gases such as chlorine and hydrogen (requiring explosion-proof design)|
|* * Electricity * * | Boosting of flue gas desulfurization (FGD) system|
|Metallurgy: Blast furnace blowing and gas recovery|
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**8、 Maintenance points**
1. * * Daily check * *:
-Bearing temperature (≤ 70 ℃), vibration value (≤ 4.5mm/s).
-Is the cooler blocked (pressure differential alarm).
2. * * Regular maintenance * *:
-Replace the lubricating oil every 5000 hours and check the wear of the impeller.
-Calibrate the dynamic balance annually to prevent excessive vibration.
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**9、 Comparison with Roots blower**
|* * Comparison item * * | * * Multi stage centrifugal blower * * | * Roots blower * *|
|------------------|--------------------------------|-------------------------------|
|* * Pressure range * * | 0.5~10 bar | 0.1~1.0 bar (dual stage can reach 1.2 bar)|
|* * Energy Efficiency * * | High (75-85) | Medium (50-70)|
|* * Noise * * | Low (70-85 dB) | High (80-95 dB)|
|* * Maintenance cost * * | High (precision bearings, cooling system) | Low (simple structure)|
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**10、 Selection suggestions**
-* * Prioritize multi-stage centrifugation * *:
-Demand pressure>1.5 bar and stable flow rate.
-Pay attention to energy efficiency and long-term operational economy.
-* * Choose Roots blower * *:
-Low pressure, dusty gas or constant flow rate required.
Provide specific operating conditions (flow rate, pressure, gas composition) and recommend suitable models for you!
