What is the reason for the low suction of Roots blower? Flowchart for troubleshooting 7 major fault points**
**Keyword Core: Fault Diagnosis Methodology**
**1、 Fault Tree Analysis (FTA)**
```mermaid
graph TD
A [Insufficient suction] -->B {Mechanical system}
A -->C {Gas System}
B -->B1 [Belt slippage]
B -->B2 [Bearing wear]
C -->C1 [Filter blockage]
C -->C2 [Pipeline Leakage]
```
**2、 Seven step on-site investigation method**
1. * * Current measurement * *: Below rated value → Belt/voltage issue
2. * * Abnormal noise * *: Metal friction sound → Bearing failure
3. * * Touching vibration * *: Axial vibration>7.1mm/s → Unbalanced impeller
4. Check the pressure difference: If the pressure difference between the two ends of the filter is greater than 6kPa, it needs to be replaced
5. * * Check the seal * *: Soap water test at the flange for air leakage
6. * * Check the oil level * *: The gearbox oil is below 1/2 of the viewing window
7. * * Back pressure measurement * *: outlet pressure>nameplate 110 → excessive system resistance
**3、 Typical case**
-* * Fault in a power plant * *: suction drops by 30%. Upon dismantling and inspection, it was found that:
-The thickness of scaling on the impeller reaches 3mm (restored after cleaning)
-Coupling alignment deviation of 0.15mm (laser calibration)
---
**4. How much pressure is normal for a Roots blower? The operating range that engineers must know**
**Keyword core: pressure threshold management**
**1、 Pressure grading standards**
|Grade | Pressure Range (kPa) | Representative Model | Sealing Requirements|
|------------|---------------|-----------------|-------------------|
|Low pressure | ＜ 49 | CSR-80 | Ordinary rubber seal|
|Medium pressure | 49-98 | CSR-145 | Fluororubber seal|
|High pressure |>98 | CSR-200 | Mechanical seal+water cooling|
**2、 Experimental data on overpressure hazards**
|Overpressure ratio | Decreased bearing life | Increased power consumption | Typical case|
|----------|--------------|----------|------------------|
|10 | 35 | 8 | Valve of a certain pharmaceutical factory accidentally closed|
|20 | 72 | 18 | Pipeline blockage and explosion|
**3、 Pressure protection scheme**
1. * * Hardware Configuration * *:
-Valve setting value=rated pressure × 1.1
-Pressure transmitter+PLC linkage shutdown
2. * * Operating Standards * *:
-Before starting up, manually turn the car to confirm that there are no blockages
-Test the valve popping pressure every week
