Installation and commissioning of Roots blowers

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Rotoary fan installation: The rotoary fan is pre-assembled before leaving the factory; all that is needed is to connect the inlet silencer to the inlet, the outlet silencer to the outlet, and then connect the outlet silencer to the pipeline. Now, let’s talk about the installation precautions: 1. The Roots blower should be installed in a solid and stable area on the ground, with sufficient space around it to facilitate inspection, maintenance, and upkeep. 　　 2. The foundation under the Roots blower should be level; it is recommended to use shock-absorbing rubber pads at the four corners of the base or to install it using bolts, in order to ensure smooth operation of the Roots blower with minimal vibration. 　　3. The connection pipes between the Roots blower and the system must be securely sealed. For small vacuum pumps, metal pipes with oil-resistant rubber gaskets can be used; for small Roots blowers, vacuum hoses can be employed. The diameter of the pipes must be no smaller than the suction port size of the Roots blower, and the pipes should be short with as few bends as possible. (When welding pipelines, slag in the pipes must be removed; it is strictly prohibited for slag to enter the vacuum pump chamber.) 4. In the connection pipeline, the user can install a valve and a vacuum gauge above the air inlet of the Roots blower, allowing for the constant monitoring of the blower’s maximum pressure. 　　5. Connect the power supply in accordance with the specifications indicated on the motor’s nameplate, and provide a ground wire as well as install fuses and thermal relays of appropriate ratings. 　　6. When testing the Roots blower under power, the motor belt must be removed, and it can be put into use only after confirming that the rotation direction of the vacuum pump is correct; otherwise, oil will be sprayed due to the reverse rotation of the Roots blower. (Steer in the direction indicated by the guard) 7. For Roots blowers equipped with cooling water, connect the cooling water as specified. 　　8. When installing a solenoid valve at the inlet of a Roots blower, the valve and the Roots blower should operate simultaneously. 　　9. When the gas discharged by the Roots blower affects the working environment, a pipe can be installed at the exhaust outlet to direct the gas away, or an oil mist filter can be installed. Commissioning of Roots blowers: The commissioning of Roots blowers includes: jog testing, no-load operation testing, full-pressure testing, and full-system testing. 1. Jog debugging refers to the process of completely disconnecting the fan from the system on-site, by breaking the connections of the air inlet and outlet pipes of the fan. Manually turn the shaft to ensure there is no jamming inside the machine, then start the fan and shut it down immediately afterward. Next, check whether the rotation direction of the fan matches the direction indicated on the machine; if not, for a three-phase motor, swap the cables of any two phases and reconnect them. Due to the structure of the Roots blower, it cannot be reversed. 2. No-load operation testing refers to starting the fan, building on the results of the previous step and confirming that the fan rotates in the correct direction, and then running it continuously for half an hour to check whether its operation is stable and to detect any abnormal noises or vibrations. 3. The full-pressure test involves installing a valve at the fan’s outlet (a silencer is connected behind the valve to reduce noise). After starting the fan, the valve is gradually closed to apply a simulated load to the fan until its pressure reaches the value indicated on the nameplate. The fan is then run continuously for about 2 hours to ensure that there are no abnormal noises, that the temperature remains stable (the temperature rises as the fan’s pressure increases; this usually takes either half an hour or up to 2 hours before the temperature stabilizes and stops rising; if it continues to rise, there is likely a problem), and that the fan’s current stays within the range specified on the nameplate. 4. System-wide testing refers to connecting the fan to the operating system and starting up a trial run, which should last for more than half an hour. Since designs generally include a margin for safety, after the fan is integrated into the system, the actual operating pressure and current should be lower than those indicated on the nameplate. If an overload condition occurs, it usually indicates an inappropriate selection of the fan, and a thorough investigation is needed to identify the problem.