**Technical analysis and application guide for backwash Roots blower**
The backwash Roots blower is a special fan designed specifically for scenarios such as backwashing filtration systems, membrane cleaning, and filter material regeneration. It achieves cleaning function through high-pressure airflow backwashing. The following are the core technical points and selection criteria:
---
**1、 Working principle of backwash system**
1. * * Core Process**
```mermaid
graph TB
A [Normal filtering] -->| Differential pressure alarm | B [Switch to backwash mode]
B -->C [Roots blower high-pressure airflow reverse injection]
C -->D [Pollutant Stripping Emissions]
D -->E [Restore Filter]
```
2. Comparison of Air Pressure Characteristics**
|* * Mode * * | Pressure Range | Airflow Direction | Duration|
|----------------|----------------|---------------|---------------|
|Normal filtration | 10-30kPa | Positive | Continuous|
|Backwash | 50-80kPa | Reverse flow | 30-120 seconds/time|
---
**2、 Key design features**
1. * * Bi directional anti pollution structure**
-* * Impeller * *: Made of stainless steel 316L material (resistant to particle impact)
-Sealing: Double end mechanical seal (to prevent backflow particles from entering)
-* * Intake filter element * *: detachable double-layer filter (precision 5 μ m)
2. * * Quick switching valve group**
-Type: Pneumatic butterfly valve (response time<1 second)
-Sealing grade: ANSI VI grade (leakage rate<0.1)
3. * * Pressure buffering system**
-Buffer tank capacity: ≥ 3 times the volume of single backwash air
-Pressure fluctuation control: ± 5 set value
---
**3、 Selection of technical parameters**
|* * Parameter * * | Calculation Method/Standard Value | Example (Backwash of Sewage Plant Filter)|
|------------------|--------------------------|------------------------|
|* * Backwash gas volume * * | \ (Q=0.6A \ sqrt {\ Delta P} \) | Filter area 50 ㎡ → 35m3/min|
|* * Backwash pressure * * | 3-5 times normal working pressure | Normal 20kPa → Backwash 80kPa|
|* * Frequency of flushing * * | Set according to the blockage rate | Once every 8 hours|
|Instantaneous power * * | Conventional power x 1.3 (impulse load) | 45kW fan → 58.5kW peak|
---
**4、 Typical system configuration**
1. * * Water treatment filter backwash**
-Fan model: -150RB (specially optimized for backwashing)
-Supporting equipment:
-Gas water combined backwashing device
-PLC timing controller (controlling backwash duration)
2. Industrial dust removal system**
-Special requirements:
-Anti static design (surface resistance<10 Ω)
-Explosion proof motor (Ex d Ⅱ BT4)
3. * * Membrane module cleaning**
-Technical points:
-Pulse back blowing (0.5-1Hz frequency)
-Aseptic air treatment (filtered to 0.01 μ m)
---
**5、 Maintenance and troubleshooting**
|* * Fault phenomenon * * | Root cause | Solution|
|--------------------|-------------------------|-------------------------|
|Insufficient backwash pressure | Seal leakage/clogged filter element | Replace seal+clean filter element|
|Switching valve stuck | Particle intrusion | Installing a pre magnetic filter|
|Motor overload | Excessive instantaneous starting current | Installing a soft starter|
---
**6、 Energy efficiency optimization plan**
1. * * Variable frequency control**
-During the backwash phase, increase the frequency to 55Hz (increase the impulse)
-Reduce the frequency to 40Hz during normal operation (saving 30% energy)
2. * * Waste heat recovery**
-Compressed heat is used to heat process water (recovery efficiency>60)
3. * * Intelligent prediction backwash**
-Optimization of Backwash Cycle Based on Differential Pressure Sensor and AI Algorithm
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**Note * *: For corrosive media (such as seawater desalination reverse osmosis membrane cleaning), titanium alloy impellers and PTFE coated pipelines should be selected. It is recommended to control the backwash airflow speed between * * 15-25m/s * *. If it is too low, cleaning will not be possible, and if it is too high, it may damage the filter material.
