When the Roots blower experiences high pressure, it must be dealt with promptly, otherwise it may lead to serious consequences such as motor overload, bearing damage, rotor wear, and even pipe bursting. The following are the troubleshooting and solutions for the system:
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**1. Check system resistance (primary step)**
**Possible reasons * *:
-The outlet valve is not open (due to misoperation or valve malfunction).
-Pipeline blockage (accumulation of dust, foreign objects, or scaling).
-* * Muffler/filter clogged * * (left uncleaned for a long time).
**Solution * *:
**Manually adjust the outlet valve * *:
-Gradually open the outlet valve and observe if the pressure gauge drops (operate slowly to avoid airflow impact).
**Cleaning pipeline system * *:
-Open the pipeline to check for blockages, especially at bends and reducers.
**Replace or clean the filter/muffler * *:
-If the pressure difference is greater than 10kPa, the filter element needs to be cleaned or replaced immediately.
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**2. Fan selection error**
**Possible reasons * *:
-The rated pressure of the fan is lower than the actual demand (such as underestimating the system back pressure during selection).
**Solution * *:
**Re calculate system resistance * *:
-Calculate the total pressure loss of pipelines, valves, and equipment to ensure that the fan pressure margin is ≥ 10.
**Replace the appropriate fan * *:
-If it operates under long-term overpressure, it is necessary to replace it with a higher pressure model (such as a two-stage Roots blower) or switch to a screw blower.
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**3. Abnormal increase in rotational speed**
**Possible reasons * *:
-* * Motor frequency converter parameter error * * (frequency set too high).
-Belt pulley ratio error (the wheel diameter ratio was not adjusted after replacing the belt).
**Solution * *:
**Check the motor speed * *:
-Measure the actual speed with a tachometer and compare it with the rated speed on the nameplate (such as 2900rpm).
**Adjust the frequency converter/pulley * *:
-Variable frequency control: Reduce the frequency to the rated value (such as 50Hz).
-Belt drive: recalculate the wheel diameter ratio (formula: 'fan speed=motor speed x driving wheel diameter/driven wheel diameter').
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**4. Changes in gas temperature or density**
**Possible reasons * *:
-The medium temperature is too high (due to thermal expansion causing pressure rise).
-Increased gas density (such as conveying humid air or high dust concentration).
**Solution * *:
**Reduce gas temperature * *:
-Install a cooler (shell and tube/air-cooled) to control the intake temperature below 40 ℃.
**Adjust working conditions * *:
-Wet air requires an air-water separator, and dust and gas require enhanced filtration.
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**5. Mechanical malfunction (requiring shutdown for maintenance)**
**Possible reasons * *:
-The rotor clearance is too small (due to wear or installation errors causing friction).
-Gearbox malfunction (abnormal speed caused by gear wear).
**Solution * *:
**Measure rotor clearance * *:
-Use a feeler gauge to check the radial/meshing clearance (standard value 0.15~0.25mm), and adjust it if it is too large or too small.
**Overhaul gearbox * *:
-Check the meshing status of the gears, replace worn gears, and add new lubricating oil.
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**6. Protective measures**
If the pressure continues to be too high and cannot be immediately resolved, emergency measures should be taken:
**Install valve * *:
-Install a valve in the outlet pipeline and set the pressure relief value to 1.1 times the rated pressure (e.g. 65kPa for a 58.8kPa fan).
**Interlocking shutdown * *:
-Set the pressure sensor linkage shutdown function (automatically cut off the power supply when the pressure exceeds the limit).
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**Operation flowchart**
```mermaid
graph TD
A [High pressure] -->B {Check outlet valve}
B -->| Valve closed | C [Fully open valve]
B -->| Valve is open | D {Check for pipeline blockage}
D -->| Blockage | E [Cleaning pipeline]
D -->| No blockage | F {Check speed}
F -->| High speed | G [Adjust frequency converter/pulley]
F -->| Normal speed | H {Check gas status}
H -->| Abnormal temperature/density | I [cooling/filtering]
H -->| Normal | J [Maintenance of mechanical components]
```
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**Preventive advice**
1. * * Regular maintenance * *: Check valve flexibility monthly and clean filters quarterly.
2. Monitoring instruments: Install pressure gauges and thermometers and record data.
3. * * Train operators * * to avoid accidentally closing valves or overloading operations.
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**Summary**
Excessive pressure in Roots blowers is often caused by increased system resistance or improper operation, and priority should be given to checking valves and pipelines. If the problem persists, it is necessary to check the mechanical condition or reselect the model** Long term overpressure operation is strictly prohibited, otherwise it will significantly shorten the lifespan of the fan!
