Pay attention to the gap adjustment during the installation of Roots blower?

Roots blower is used frequently in circulating fluidized bed power plant. It can be seen from chemical water treatment, limestone powder transportation and fine ash fluidization in ash silo. It plays an important role in the operation of the power station. The maintenance of Roots blower mainly involves the adjustment of radial clearance and axial clearance. The radial clearance is mainly determined by the processing technology when the equipment leaves the factory; Axial clearance is mainly determined by adjustment during installation. In recent years, the axial clearance of Roots blower has been determined by experience in the maintenance. The result of this method is that in many cases, the equipment is directly damaged, or even cannot be repaired. According to the characteristics of the expansion of the axis and the positioning of the thrust bearing at the tail end during the operation of Roots blower, Xiaobian adjusts the axial clearance of Roots blower in a simple and effective way. Good practical results have been achieved.

During the installation of Xinqian Shun Roots blower, attention should be paid to clearance adjustment and other issues:

Roots blower is mainly composed of the casing and two involute waist shaped fan impellers. The gear on the driving rotor drives the gear on the driven rotor to make the two rotors rotate synchronously and reversely. There is no valve device at the exhaust port. Therefore, there are very small gaps between rotors and between rotors and casings, so that the rotors can rotate freely without excessive gas leakage in the machine. The general product description requires a clearance of 0.45~0.50mm between the blades and 0.20~0.49mm between the blades and the casing. However, during actual installation, the clearance is generally adjusted as follows, that is, the average clearance between the blades is 0.35~0.50mm, the average clearance between the blades and the casing is 0.20~0.30mm, and the clearance between the blades and the wallboard is 0.20~0.30mm. However, the clearance at the right wallboard side must be greater than that at the left wallboard side by more than 0.05mm.

As the clearance is too large, the internal leakage is serious, the pumping volume is significantly reduced, and the fan efficiency is reduced. If the clearance is too small, it is easy to cause friction due to temperature rise, vibration and other factors. During installation, it is allowed to adjust the clearance to specific use conditions, but clearance control is an important indicator that must be strictly checked during installation. In addition, due to the small clearance, the purging must be carried out before the single unit commissioning.