In the design or manufacture stage of centrifugal induced draft fan, there is no sealing requirement, so there is often no sealing at the chassis and transmission shaft of centrifugal induced draft fan. This is because this part of the fan is under negative pressure when it is running, and it will not leak out without sealing in time. But after the fan is put into operation, the resistance and medium will change because of the pipeline network transformation, which requires additional sealing at the shaft hole of the casing to prevent gas leakage.
There are generally two ways to install the seal between drive shaft and casing of centrifugal induced draft fan. One is to dismantle the casing of centrifugal induced draft fan, remove impeller and moving transmission group, and install new packing seal or mechanical seal. The advantage of this method is that the new type of seal is optional and the installation is standardized, but the workload is large and time-consuming.
Another is to add a simple packing seal without any disassembly of the centrifugal induced draft fan. Each set of packing seal consists of a filler, two pressing parts and two four semi-circular workpieces. How to operate the packing seal?
Firstly, the two workpieces marked with organic shell are welded into a ring on the shaft and the groove is directed towards the bearing box. Then, two semi-circular workpieces with unlabeled case type are also set on the transmission shaft, and the groove is welded to a ring in the direction of the case. In this way, the drive shaft passes through two rings and the grooves are opposite.
Secondly, the ring marked with organic shell is welded on the shell. It should be noted that the inner circle of the ring is equal to the clearance of the transmission shaft. Then, the bolt hexagonal heads of the two pressing parts are welded on the casing separately so that one end of the pressing part can be pressed on the ring.
Finally, a piece of disc root is cut and wound in the groove of the ring, and the nut of the fastener is fastened so that one end of the ring is pressed. Thus, a recommended condiment seal is installed successfully. This method of installation and sealing of centrifugal induced draft fan only needs to machine the workpiece in the early stage, and the installation workload in the later stage is very small. It is very suitable for centrifugal induced draft fan which is not required for sealing. It does not need to consume much time and is simple and convenient.