Routine Maintenance and Care of Roots Blowers

Daily Maintenance and Care of Roots Blowers:
1. The blower should not be installed in areas frequently accessed by people to prevent injuries and burns.
2. The blower should not be installed in places where flammable, explosive, and corrosive gases may be generated to prevent fires and poisoning accidents.
3. According to the direction of the intake and exhaust ports and maintenance needs, there should be adequate space around the foundation.
4. When installing the blower, check whether the foundation is solid, whether the surface is flat, and whether the foundation is elevated above the ground.
5. When the blower is installed outdoors, a rain shelter should be set up.
6. The blower can be used for a long time in an environment with a temperature not exceeding 40℃. If it exceeds 40℃, cooling measures such as exhaust fans should be installed to extend the blower's service life.
7. When conveying air, the dust content should generally not exceed 100mg/m3.
8. Precautions for operation and use
(1) A comprehensive inspection of all components of the blower should be conducted, checking for completeness of parts, the tightness of all bolts and nuts, the installation quality of all fasteners and locating pins, and the installation quality of the intake and exhaust pipelines and valves.
(2) To ensure the safe operation of the blower, external loads such as pipelines, valves, and frames are not allowed.
(3) Check the alignment and centering quality between the blower and the motor.
(4) Check whether the base of the unit is fully supported and whether the anchor bolts are tightened.
(5) Inject the specified grade of mechanical oil into the oil tank up to the oil level line, with the lubricant grade being N220 medium load working gear oil.
(6) Check whether the motor's rotation direction meets the directional requirements.
(7) A belt cover (guard) should be installed at the pulley (coupling) to ensure safe operation.
(8) Fully open the intake and exhaust valves of the blower, rotate the blower rotor, which should turn smoothly without impact or friction. Only after confirming everything is normal can the blower be started for trial operation.
9. Empty Load Trial Operation of the Blower
(1) Newly installed or overhauled blowers should undergo an empty load trial operation.
(2) The concept of empty load operation for Roots blowers is: operating under the condition that the intake and exhaust valves are fully open.
(3) There should be no abnormal odors, smoke, or collision or friction sounds, and the radial vibration speed at the bearing should not exceed 6.3mm/s.
(4) Run under empty load for about 30 minutes. If the situation is normal, it can be put into load operation. If any abnormal operation is found, it should be checked and eliminated, and then an empty load trial operation should be conducted again.
10. Normal Load Continuous Operation of the Blower.
(1) It is required to gradually and slowly adjust the load until the rated load is reached; it is not allowed to adjust directly to the rated load at once.
(2) The so-called rated load refers to the static pressure difference between the intake and exhaust ports, according to the pressure value marked on the nameplate. Under normal exhaust pressure conditions, attention should be paid to the pressure changes at the intake to avoid overload.
(3) During normal operation of the blower, it is strictly prohibited to completely close the intake and exhaust valves. Regular observation of pressure conditions is required, and whether the safety valve operates to exhaust during overload; otherwise, the safety valve should be adjusted in time, and overload operation is not allowed.
(4) Due to the characteristics of Roots blowers, it is not allowed to let the exhaust gas flow back directly into the intake port for a long time (changing the temperature of the intake port), otherwise it will affect the safety of the machine. If backflow adjustment is necessary, cooling measures must be taken.
(5) Regularly check the oil level position of the lubricant, conduct periodic inspections, and keep records to ensure oil quantity.
11. Stopping
The blower should not be suddenly stopped under full load; it must gradually unload before stopping to avoid damaging the machine. Regarding emergency stop principles, users can formulate their own detailed rules.
12. The safe operation and service life of the blower depend on correct and regular maintenance and care, and attention should be paid to any signs of accidents. In addition to general maintenance procedures, the following points should be emphasized.
1. Check the fastening conditions of each part and whether there is any looseness in the locating pins.
2. There should be no oil leakage inside the blower body.
3. There should be no scaling, rust, or peeling inside the blower body.
4. Pay attention to whether lubrication and heat dissipation are normal, check the quality of the lubricant, listen for any unusual noises during blower operation, ensure the unit is not operating under non-compliant conditions, and regularly add grease.
5. Overloading of the blower may not be immediately apparent, so attention should be paid to the trends in intake and exhaust pressure, bearing temperature, and motor current to determine whether the machine is operating normally.
6. Before disassembling the machine, measure the dimensions of each fit of the machine, keep records, and mark the components to ensure that the original fit requirements are maintained after assembly.
7. For new machines or blowers after major repairs, the oil tank should be cleaned, and the operation should be carried out according to the usage steps. It is recommended to replace all lubricating oil after running for 8 hours.
8. Maintenance and repair should be based on specific usage conditions to formulate a reasonable maintenance system, conduct periodic maintenance, and keep records. It is recommended to overhaul once a year and replace bearings and related wear parts.
9. Major repairs of the blower are recommended to be carried out by this company or professional maintenance personnel.

Common Faults and Troubleshooting Methods:
1. Friction between the impeller and the impeller
(1) There are contaminants on the impeller, causing the gap to be too small; remove the contaminants and check for any damage to the internal components.
　　(2) Gear wear causes large side clearance; adjust the gear clearance, if the gear side clearance is greater than the average value of 30% to 50%, the gear should be replaced;
　　(3) The gear is not securely fixed, cannot maintain the synchronous operation of the impeller; reassemble the gear, ensuring the contact area of the taper fit reaches 75%;
　　(4) Bearing wear causes increased play. Replace the bearing.
2. The impeller and the wall panel, the top of the impeller and the casing.
　　(1) Incorrect installation clearance; readjust the clearance;
　　(2) Operating pressure is too high, exceeding the specified value; identify the cause of overload and reduce the pressure to the specified value;
　　(3) Operating temperature is too high; check the installation accuracy and reduce pipeline tension;
　　(4) Deformation of the casing or base, failure of fan positioning; check and repair the bearing, and ensure the play.
　　(5) Poor axial positioning of the bearing.
3. High temperature.
　　(1) Too much, too thick, and dirty oil in the oil tank; lower the oil level or remove oil;
　　(2) Filter or silencer blockage; clear the blockage;
　　(3) Pressure exceeds the specified value; reduce the pressure difference through the blower;
　　(4) Excessive wear of the impeller, large clearance; repair the clearance;
　　(5) Poor ventilation, high indoor temperature, causing high inlet temperature; open ventilation openings to lower the room temperature;
　　(6) Operating speed is too low, causing belt slippage. Increase the speed to prevent belt slippage.
4. Insufficient flow.
　　(1) Inlet filter blockage; clear the dust and blockages from the filter;
　　(2) Impeller wear, excessive increase in clearance; repair the clearance;
　　(3) Belt slippage; tighten the belt and increase the number of belts;
　　(4) Large inlet pressure loss; adjust the inlet pressure to reach the specified value;
　　(5) Ventilation leakage caused by the pipeline. Check and repair the pipeline.
5. Oil leakage or oil leaking into the casing.
　　(1) The oil tank is too high, leaking from the oil outlet; lower the oil level;
　　(2) Seal wear causes oil leakage at the shaft end; replace the seal;
　　(3) Pressure exceeds the specified value; clear the ventilation openings, install a valve with a 2mm aperture in the middle chamber, and open the valve under the wall panel;
6. Excessive current.
(1) Voltage is too low; stop the fan operation, and replace with a high-power motor if necessary;
(2) Filter or pipeline blockage; clear the blockage;
(3) Changes in the internal clearance of the fan, causing friction and collision; analyze the cause of the clearance change and eliminate it, repair the friction parts;
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(4) Excessive load; check the cause of the overload and eliminate it, adjust to the rated load;
(5) Motor failure; repair the motor, and replace it if necessary;
7. Abnormal vibration or noise.
(1) Bearing damage, excessive play; replace the bearing;
(2) Foreign objects entering the impeller hole disrupt balance, or foreign objects stuck inside the fan; remove foreign objects and check for any damage to the fan;
(3) Overload, overheating, etc. causing friction and collision inside the fan; eliminate factors causing abnormal working conditions and check for any damaged components;
(4) Coupling misalignment; adjust the coupling;
(5) Belt tension too high or too low; adjust the belt tension;
(6) Loose bolts at the relevant connection points; tighten the connecting bolts.