Thread Content
Roots blower I. Product overview The three-blade series of Roots blowers are new products developed by our factory by drawing on advanced international technologies. They feature a novel design, low energy consumption, low noise levels, excellent performance, and low maintenance costs. Product development makes use of advanced CAD design techniques, as well as sophisticated manufacturing processes and high-quality CNC equipment. This product is widely used in various industrial sectors such as metallurgy, chemicals, light industry, building materials, mines, textiles, pneumatic conveying, sewage treatment, and the ceramics industry. II. Product Features 1. Wide range of flow rates and pressures, broad application scope, excellent quality, and low price ； 2. The impeller profile of this product features a special composite envelope shape, resulting in good meshing, low leakage, high efficiency, small pressure pulses, and low noise ； 3. Due to the special shape of the rotor, the rigidity of the shaft is increased, which enhances the pressure-raising capacity of the fan ； 4. The synchronous gears are made from high-quality alloy steel and precision-machined, which effectively reduces mechanical transmission noise ； 5. The rotating components are carefully balanced, resulting in almost no vibration in the entire machine ； 6. The entire machine features a rational cooling structure, which effectively extends the service life of gears and bearings ； 7. The overall design of the machine is compact and simple, making it easy to maintain and repair. III. Working Principle: Within the machine, synchronized gears cause the two rotors to rotate in opposite directions relative to each other. Due to the appropriate working gaps between the impellers as well as between the impellers and the casing, air intake chambers are formed. By means of rotor rotation, the gas inside the machine is moved from the intake chamber to the exhaust chamber without any internal compression, and then expelled from the machine, thereby achieving a blowing effect. (1) Round A: State when intake is about to close and exhaust is about to open ； Round B: Open status. (2) Round A: Closed and vented state ； Round B: Open status. (3) Round A: Open state ； Phase B: The intake is about to close while the exhaust is about to open. IV. Performance parameters table (see the relevant catalog for each model) V. Dimensions and installation dimensions (see the relevant catalog for each model) VI. Usage instructions 1. Requirements for use: (1) Intake air temperature should not exceed 40°C. (2) The content of solid particles in the gas should not exceed 100 mg/m2; the largest particles should be no larger than half of the assembly clearance ； (3) The bearing temperature shall not exceed 95℃ ； (4) The lubricating oil temperature shall not exceed 65℃ ； (5) It must not exceed the pressure range specified on the label. 2. Preparations before startup: (1) Check the installation quality of all fasteners and positioning pins ； (2) Check the installation quality of the intake and exhaust pipes, valves, etc ； (3) Check whether the area around the base of the unit is fully padded, and ensure that any foot bolts are tightened ； (4) Fill the gearbox with lubricating oil of the specified grade up to the oil level mark; apply the specified grease on the drive side in sufficient quantity ； (5) Fully open the intake and exhaust valves of the blower, rotate the rotor, and pay attention to listening for any abnormal noises from various parts ； (6) For fans that require water cooling, the water temperature shall not exceed 25°C. 3. No-load test run of the fan: (1) All fans that have been newly installed or overhauled should undergo a no-load test run ； (2) No-load operation refers to starting the machine with the intake and exhaust valves fully open ； (3) There are no abnormal odors or smoking, nor any sounds of collision or friction; the radial vibration at the bearing area is not greater than 6.3 mm/s ； (4) Run under no-load conditions for about 30 minutes; if everything is normal, it can then be put into operation under load. If any abnormalities are detected, stop the machine immediately for inspection. Even after the issues are resolved, operation under no-load conditions is still required. 4. Continuous operation under normal load: (1) It is required to increase the voltage gradually and slowly, loading the system until it reaches the rated load; it is not allowed to adjust it to the rated load all at once ； (2) During normal operation of the fan, it is strictly prohibited to completely close the intake and exhaust valves ； Overloading is also not allowed ； (3) Due to the characteristics of rotary vane blowers, it is not permissible to allow the exhaust gas to flow back directly for an extended period; therefore, cooling measures must be employed ； (4) The blower should not be stopped suddenly under full load to avoid damaging its components. 5. Maintenance and repair: (1) Check the tightness of all components and whether the positioning pins are loose ； (2) Regularly check the machine for oil leaks ； (3) Pay attention to whether the lubrication is functioning properly, monitor the amount of lubricating grease used, regularly check for any abnormal noises during the fan’s operation, and ensure that the unit is operating under specified conditions ； (4) Lubricating oil (grease): The lubricating oil is a medium-load industrial gear oil (grade 220, dynamic viscosity of 198–242 mm2/s at 40°C, flash point ≥200°C) ； The lubricant is butter (synthetic lithium-based grease with a penetration of 220–250 and a drip point of ≥190°C); after 200 hours of operation, the oil and grease should be replaced for the first time, and again after one month of operation. In the future, it should be replaced according to the usage environment and the quality of the oil (fat); it is recommended to replace it every three months ； (5) Regularly inspect the gas filter at the air inlet, and clean or replace the filter element in a timely manner ； (6) The overload of the blower may not be apparent immediately; therefore, it is necessary to pay attention to the trends in inlet and outlet pressures, bearing temperature, and motor current in order to determine whether the blower is operating properly ； (7) Before disassembling or assembling the machine, its dimensional tolerances should be measured and recorded, and markings should be made on the components to ensure that the original fit requirements are maintained after assembly ； (8) After a new machine is installed or after a major overhaul, the fuel tank should be cleaned, and the machine should be put into operation following the prescribed procedures. It is recommended to replace all lubricants after 8 hours of operation. VII. Common Fault Causes and Troubleshooting Methods Sequence Number Fault Possible Causes Troubleshooting Methods 1 Friction between the impeller and blades (1) Contaminants on the impeller cause an excessive small gap ； (2) Gear wear, resulting in a large side clearance ； (3) The gears are not securely fixed, failing to keep the impeller synchronized ； (4) Bearing wear causes an increase in clearance. (1) Remove debris and check for any damage to the internal components ； (2) Adjust the gear clearance; if the gear side play is 30%–50% higher than the average value, the gear should be replaced ； (3) Reassemble the gears, maintaining the taper so that the contact area reaches 75% ； (4) Replace the bearing ； 2 The installation clearance between the impeller and the wall plate, as well as between the top of the impeller and the casing (1), is incorrect ； (2) Operating pressure is too high, exceeding the specified value ； (3) Operating temperature too high ； (4) Deformation of the casing or base, resulting in failure of fan positioning ； (5) The bearing has poor axial positioning. (1) Readjust the gap ； (2) Identify the cause of overloading and reduce the pressure to the specified value ； (3) Check the installation accuracy to reduce pipeline tension ； (4) Inspect and repair the bearings, and ensure the proper clearance. 3 Excessively high temperature (1) Too much oil in the tank, oil that is too thick, or oil that is very dirty ； (2) Clogged filter or silencer ； (3) Pressure is higher than the specified value ； (4) Excessive wear of the impeller, large clearance ； (5) Poor ventilation and high indoor temperatures result in high inlet temperatures ； (6) The operating speed is too low, causing the belt to slip. (1) Lower oil level or carry oil ； (2) Remove blockages ； (3) Reduce the pressure difference across the blower ； (4) Repair gap ； (5) Install ventilation openings to lower room temperature ； (6) Increase the rotational speed to prevent belt slippage. 4 Insufficient flow (1) Clogged inlet filter ； (2) Wheel wear, with excessive increase in clearance ； (3) Belt slippage ； (4) High inlet pressure loss ； (5) Pipelines cause ventilation leaks. (1) Remove dust and blockages from the filter ； (2) Repair gap ； (3) Tighten the belt and increase the number of strands ； (4) Adjust the inlet pressure to the specified value ； (5) Inspect and repair the pipes. 5 Oil leakage or seepage into the casing (1) High oil level in the tank, causing leakage from the oil drain port ； (2) Sealing wear, resulting in oil leakage at the shaft end ； (3) Pressure is higher than the specified value ； (4) The vents of the wall panels and fuel tank are blocked, causing oil to leak into the casing. (1) Lower oil level ； (2) Replace the seal ； (3) Clear the ventilation openings; install a plug with a 2mm aperture in the middle chamber, and open the plug under the wall panel ； 6 Abnormal vibration and noise: Stop the machine immediately. (1) The clearance of the rolling bearings exceeds the specified value or the bearing housings are worn ； (2) Excessive gear clearance, misalignment, and loose fixation ； (3) Collisions between impellers and between the impellers and the casing caused by foreign objects and dust ； (4) Impeller collision caused by overload and shaft deformation ； (5) Friction between the impeller and the inlet of the casing caused by overheating ； (6) The impeller loses balance due to scale or foreign objects ； (7) The anchor bolts and other fasteners are loose. (1) Replace the bearing or bearing housing ； (2) Reinstall the gear and ensure proper side clearance ； (3) Clean the blower and check whether the casing is damaged ； (4) Check the back pressure, verify whether the impeller is aligned, and adjust the clearance accordingly ； (5) Check the filter and back pressure, and increase the clearance between the impeller and the inlet of the casing ； (6) Clean the impeller and casing to ensure the proper working clearance of the impeller ； (7) Tighten the foot bolts and level the base. 7 Motor overload (1): The pressure difference is large compared to the specified value; in other words, the back pressure or inlet pressure is too high ； (2) Compared to the flow rate required by the equipment, the fan’s flow rate is too high, resulting in increased pressure ； (3) Clogging of the inlet filter, obstruction or blockage in the outlet pipeline ； (4) Collision and friction (sticking) of rotating parts ； (5) Oil level too high ； (6) The narrow V-belt is overheating, there is excessive vibration, and the pulley is too small. (1) Reduce the pressure to the specified value ； (2) Release excess gas into the atmosphere or reduce the blower speed ； (3) Remove obstacles ； (4) Shut down immediately and check the cause ； (5) Adjust the oil level to the correct position ； (6) Check the belt tension and replace it with a pulley of larger diameter. ________________________________________