Operation of Roots blower
1. All parts of the fan shall be comprehensively inspected to see whether they are complete, the tightness of bolts and nuts, the installation quality of fasteners and locating pins, and the installation quality of air inlet and exhaust pipes and valves.
2. For the safe operation of the blower, it is not allowed to bear external loads such as pipes, valves and frames.
3. Check the centering and alignment quality of blower and motor.
4. Check whether the base of the unit is fully padded and whether the foundation bolts are fastened.
5. Fill the oil tank with mechanical oil of specified brand into the oil level line, and the lubricating oil brand is N220 medium load working gear oil.
6. Check whether the rotation direction of the motor meets the pointing requirements.
7. The belt cover (protective cover) shall be installed at the belt pulley (coupling) for safe operation.
8. Fully open the inlet and outlet valves of the blower, and turn the rotor of the blower. It should rotate flexibly without impact and friction. Only when it is confirmed that everything is normal can the blower be started for trial operation.
9. No load test run of blower
(1) Newly installed or overhauled fans shall undergo no-load test run.
⑵ The concept of no-load operation of Roots blower is to put it into operation when the inlet and outlet valves are fully opened.
⑶ There is no abnormal smell or smoke, collision or friction sound, and the radial vibration speed of the bearing is not greater than 6.3mm/s.
⑷ Run with no load for about 30 minutes. If the condition is normal, put it into load operation. If the operation is abnormal, check and eliminate it, and still need to run with no load.
10. The blower operates continuously under normal load
(1) It is required to gradually and slowly adjust the load to the rated load. It is not allowed to adjust the load to the rated load at one time.
(2) The so-called rated load refers to the static pressure difference between the inlet and exhaust ports, according to the calibrated pressure value on the nameplate. When the pressure at the exhaust port is normal, pay attention to the pressure change at the air inlet to avoid overload.
⑶ During the normal operation of the fan, it is strictly prohibited to completely close the inlet and outlet valves. Pay attention to the pressure condition regularly, and check whether the safety valve acts to exhaust in case of overload. Otherwise, the safety valve should be adjusted in time, and overload operation is not allowed.
⑷ Due to the characteristics of Roots blower, it is not allowed to directly return the gas from the exhaust port to the air inlet of the blower for a long time (changing the temperature of the air inlet), otherwise the safety of the machine will be affected. If it is necessary to take reflux regulation, cooling measures shall be taken.
(5) Always pay attention to the oil quantity position of lubricating oil, check regularly, and make records to ensure the oil quantity. Equipment maintenance of Roots blower can be carried out by automatically injecting lubricating oil, as shown in the figure:
11. The blower should not be stopped suddenly under full load. It should be stopped after gradually unloading the load to avoid damage to the machine. Users can draw up rules for emergency shutdown.
12. The safe operation and service life of the blower depend on correct and frequent maintenance, and attention should be paid to any accident. In addition to general maintenance procedures, attention should be paid to the following points.
Characteristics of Roots blower
Due to the adoption of the three blade rotor structure and the reasonable structure at the inlet and outlet of the housing, the fan has low vibration and noise.
The impeller and shaft are of integral structure, and the impeller is free of wear. The performance of the fan is permanent and can operate continuously for a long time.
The fan has large volume utilization rate, volume, compact structure and flexible installation mode.
The model can meet the needs of different users for different purposes.
Operating conditions of Roots blower
1. Generally, the inlet steam temperature of the conveying medium shall not be higher than 40 ℃.
2. The content of particles in the medium shall not exceed 100mg/m3, and the large size of particles shall not exceed half of the small working gap.
3. During operation, the bearing temperature shall not be 95 ℃, and the lubricating oil temperature shall not be 65 ℃.
4. The operating pressure shall not be within the pressure rise range specified on the nameplate.
5. The clearance between the impeller and the casing, between the impeller and the side plate, and between the impeller and the impeller of Roots blower have been adjusted in the factory, and this clearance is required for reassembly.
6. When roots blower is running, the oil level of main oil tank and auxiliary oil tank is between the two red lines of oil level gauge.
7. Check whether the inlet and outlet connection parts have forgotten to fasten, and whether the supporting parts of piping are complete. For blowers and vacuum pumps requiring cooling water, check whether the installation of cooling water meets the requirements.
Roots blower principle
Roots blower is a type of volumetric fan. There are two three blade impellers that rotate relatively in the space sealed by the casing and wall plate. Since each impeller is involute or the envelope of the epicycloid, the three blades of each impeller are identical, and the two impellers are identical, which greatly reduces the processing difficulty. The impeller is processed with numerical control equipment. When the center distance between the two impellers is constant, no matter where the two impellers rotate, a certain minimum clearance can be maintained, so that the gas leakage is within the allowable range.
The two impellers rotate in opposite directions. Because the clearance between impellers and impellers, between impellers and casings, and between impellers and wallboards is very small, a vacuum state is formed at the air inlet. The air enters the air inlet chamber under the action of atmospheric pressure. Then, two of the blades of each impeller form a sealed chamber with wallboards and casings, The sealing chamber formed by two blades is constantly taken to the exhaust chamber, and because the impellers in the exhaust chamber are meshed with each other, the air between the two blades is squeezed out. In this way, the air is continuously transmitted from the air inlet to the air outlet, which is the whole working process of Roots blower.
