**Complete guide for maintenance and repair of Roots blower**
The stable operation and long lifespan of Roots blowers rely on scientific maintenance and upkeep. The following is a detailed maintenance plan, key operating steps, and common troubleshooting methods divided by cycles:
---
**1、 Daily maintenance (performed by operators)**
1. * * Operation monitoring**
-Record: current, outlet pressure, bearing temperature (≤ 75 ℃), vibration value (≤ 4.5mm/s).
-Auscultation: Use a listening stick to check for abnormal noises in the gearbox (high-frequency metal sounds indicate gear wear).
2. * * Appearance inspection**
-Oil level in the oil window (maintain at 1/2~2/3).
-Pipeline/flange leakage (soap water detection).
3. * * Urgent handling**
-If the oil color turns black or emulsified, immediately stop the machine and change the oil.
---
**2、 Weekly maintenance (performed by maintenance personnel)**
1. * * Air intake system**
-Clean/replace the air filter element (must be replaced when the pressure difference is greater than 50Pa).
-Check if the muffler is blocked (observe with a flashlight).
2. * * Tightening inspection**
-Anchor bolt (torque recheck: M16 bolt ≈ 120N · m).
-Coupling/belt tensioning (deflection 10-15mm).
---
**3、 Monthly maintenance**
1. Lubrication system**
-Sampling and testing of lubricating oil (if the moisture content is greater than 0.1 or the particulate matter is greater than NAS level 10, it needs to be replaced).
-Lubricating grease supplementation (bearing grease injection amount=1/3 of bearing chamber, use lithium based grease NLGI 2).
2. * * Sealing inspection**
-Mechanical seal: Check the flushing fluid pressure (>0.2 bar).
-Packing seal: The leakage rate of the gland is ≤ 30 drops/minute.
---
**4、 Quarterly maintenance**
1. * * Rotor system**
-Gap measurement (plug gauge detection, standard value of 0.10~0.25mm):
-Gap between rotors
-Gap between rotor and shell
-Manually turn the wheel 2 times to confirm there is no friction.
2. * * Electrical system**
-Motor insulation test (≥ 1M Ω, 500V megohmmeter).
-Check the cooling fan of the frequency converter (if any).
---
**5、 Annual major maintenance (downtime of more than 8 hours)**
1. * * Disassembly inspection**
-Gear wear: If the backlash is greater than 0.15mm, it needs to be replaced (new gear meshing spots ≥ 60).
-Bearing clearance: Replace with a new one (SKF/C4 grade bearing) if the radial clearance is greater than 0.1mm.
2. * * Replacement of key components**
-Coupling elastic block (replace when crack>2mm).
-Seals (mechanical seals typically have a lifespan of 2-3 years).
3. * * Performance testing**
-No load test for 1 hour, vibration value ≤ 2.8mm/s.
-Load test: The pressure rises to the rated value, and the current does not exceed 105 on the motor nameplate.
---
**6、 Lubricating oil management**
|* * Oil type * * | * * Replacement cycle * * | * * Applicable working conditions * *|
|--------------------|------------------|----------------------------------|
|Mineral oil (ISO VG68) | 2000 hours or 6 months | Clean air at room temperature (-10~40 ℃)|
|Synthetic oil (PAO) | 4000 hours or 12 months | High temperature (>60 ℃)/corrosive gas|
|Ester oil | 3000 hours | Sulfur containing media such as biogas|
**Oil change steps * *:
1. Heat engine oil discharge (flowability at 60 ℃).
2. Clean the fuel tank with flushing oil (ISO VG32).
3. Add new oil after filtering (β ≥ 200).
---
**7、 Quick Reference Table for Common Fault Handling**
|* * Fault Symptoms * * | * * Possible Causes * * | * * Repair Methods * *|
|------------------|-----------------------------|-----------------------------------|
|Excessive vibration * * | Dust accumulation on rotor/loosening of foundation | Dust removal+dynamic balance correction (residual unbalance ≤ 1g)|
|Insufficient air volume | Seal leakage/belt slippage | Replace seals+adjust belt tension|
|* * Abnormal noise (gearbox) * * | Gear tooth breakage/poor lubrication | Gear replacement+oil upgrade|
|* * High oil temperature * * | Blockage/overpressure operation of cooler | Clean cooler+check system resistance|
---
**8、 Recommended specialized tools**
1. * * Laser alignment instrument * * (coupling alignment accuracy ≤ 0.05mm).
2. * * Infrared thermal imager * * (quickly locate hotspots).
3. * * Vibration analyzer * * (detects early bearing faults).
---
**9、 Key measures for extending lifespan**
1. * * Preventive maintenance * *: Develop plans based on hours rather than calendar time (shorten 20 cycles under high load conditions).
2. Spare parts reserve: regular bearings, seals, and belts (accounting for 3-5% of the equipment value).
3. * * Operation Training * *: It is strictly prohibited to perform illegal operations such as closing valves and starting, or operating the chiller at full load.
---
**Maintenance Specification * *:
-After shutdown, manual turning is required to confirm that the rotor has stopped.
-Close the inlet and outlet valves before maintenance and hang a "Do Not Operate" sign.
-Copper tools (hardness C ＜ 25) are used in explosion-proof areas.
By strictly implementing this maintenance plan, the Roots blower can operate stably for 6-10 years (with a major overhaul cycle of>30000 hours). Suggest establishing digital maintenance records to track the health status of equipment.
