Vibration induced draft fan reason for boiler

1、Bearing damage, leading to cause vibration
2、Of the coupling, the two axis center misalignment
3、Impeller and casing milling touch phenomenon
4、Loose bolts or grouting is not good, basic is loose
5、In the operation of the dust or larger or more sebum, stick on the blade
6、Impeller after wear, produce the unbalanced weight