High temperature during the operation of Roots blowers (usually referring to bearing, housing, or exhaust temperature exceeding the normal range) is a common fault that may be caused by various factors. The following are the main reasons, judgment methods, and solutions for the temperature increase of Roots blower, for your system investigation:
---
**1、 Common causes classification and treatment measures**
**1. Mechanical friction related issues**
|* * Reason * * | * * Performance Characteristics * * | * * Solution * *|
|-------------------------|--------------------------|--------------------------------|
|* * The rotor clearance is too small * * | The entire shell is heating up, accompanied by friction noise | Stop the machine and adjust the rotor clearance (usually 0.2~0.4mm)|
|* * Bearing damage/oil shortage * * | Local high temperature and increased vibration in the bearing seat | Replace the bearing and replenish lubricating grease (such as lithium based grease)|
|* * Synchronous gear wear * * | High gearbox temperature and regular noise | Replace the gear and check the meshing alignment|
|The belt is too tight or the coupling is not aligned properly. The temperature on the motor side increases synchronously. Adjust the belt tension and recalibrate the alignment|
**2. System resistance and operational parameter issues**
|* * Reason * * | * * Performance Characteristics * * | * * Solution * *|
|-------------------------|--------------------------|--------------------------------|
|* * Export pressure exceeds the set value * * | Current overload, exhaust temperature soaring | Check if the pipeline is blocked and add a pressure relief valve|
|* * Imported filter clogged * * | Vacuum gauge shows increased negative pressure | Clean or replace the filter (if the pressure difference is greater than 5kPa, it needs to be dealt with)|
|* * High speed * * | Continuous high motor current | Adjust the frequency converter or replace the pulley to reduce speed|
|* * Medium density too high * * | Obvious when transporting high temperature/high-density gases | Calculate gas density and replace temperature resistant fans|
**3. Cooling and lubrication issues**
|* * Reason * * | * * Performance Characteristics * * | * * Solution * *|
|-------------------------|--------------------------|--------------------------------|
|Cooling system failure | There is no temperature difference in the cooling water pipe, and the fan stops running | Clean the scale on the cooler and repair the fan circuit|
|Lubricating oil deterioration or insufficiency | Bearing temperature>80 ℃, oil color turns black | Replace lubricating oil (recommended ISO VG68)|
|* * Incorrect lubrication method * * | Oil spills or dries up | Use drip lubrication or forced circulation lubrication system instead|
**4. Environmental and installation issues**
|* * Reason * * | * * Performance Characteristics * * | * * Solution * *|
|-------------------------|--------------------------|--------------------------------|
|* * High ambient temperature * * | Continuous operation in summer is prone to overheating | Add ventilation facilities or sunshades|
|* * Installation of enclosed space * * | Hot air circulation in the computer room | Installation of exhaust fans or deflectors|
|* * Basic vibration conduction * * | Abnormal temperature at the anchor bolt | Strengthen the foundation and install shock-absorbing pads|
---
**2、 The hazards of temperature rise**
1. * * Mechanical damage * *: Bearing burnout, rotor thermal deformation and jamming.
2. * * Sealing Failure * *: High temperature causes shaft seal hardening and leakage.
3. * * Decreased efficiency * *: The gap expands and the internal leakage intensifies.
4. * * Hidden danger * *: May cause lubricating oil explosion (high risk when>200 ℃).
---
**3、 Diagnostic process (step-by-step investigation)**
1. * * Temperature measurement point * *:
-Bearing temperature>90 ℃ → Focus on checking lubrication/bearings.
-Exhaust temperature>120 ℃ → Check system resistance/medium.
2. * * Abnormal noise * *:
-Metal friction sound → rotor/gear problem.
-Regular impact → bearing damage.
3. * * Check the parameters * *:
-Current exceeds the standard → load is too large.
-Pressure fluctuation → pipeline blockage.
---
**4、 Emergency handling measures**
1. * * Immediate shutdown * *: If the bearing temperature is greater than 95 ℃ or the motor current exceeds the set value by 15.
2. * * Forced cooling * *: Use a fan to blow air onto the casing (do not directly splash water to cool down!).
3. * * Pressure relief operation * *: Open the bypass valve to reduce system pressure.
---
**5、 Preventive maintenance recommendations**
1. * * Daily monitoring * *:
-Record bearing temperature (infrared thermometer), current, and vibration values.
2. * * Regular maintenance * *:
-Clean the cooler every 3 months and replace the lubricating oil annually.
3. * * Renovation and Upgrade * *:
-High temperature conditions can choose water-cooled shell type Roots blower.
-Install a pre cyclone separator in dusty environments.
---
**6、 Special case reference**
-Case 1: The temperature of the Roots blower bearing in a chemical plant suddenly rose to 110 ℃
-Reason: Lubricating grease is contaminated with sulfides, leading to acidification failure.
-* * Treatment * *: Replace corrosion-resistant lubricating grease (such as perfluoropolyether grease).
-Case 2: The exhaust temperature of the fan in the sewage treatment plant continues to exceed 130 ℃
-Reason: Blockage of the aeration head leads to excessive back pressure.
-* * Treatment * *: Clean the aeration disc and install a pressure alarm device.
---
By systematically investigating the above factors, the high temperature problem of the 90 Roots blower can be effectively solved. If the fault cannot be eliminated, it is necessary to check whether the fan design matches the working conditions (such as incorrect selection of flow and pressure).
