Structure of explosion-proof centrifugal fan

2021-04-16

Explosion-proof centrifugal fan-structural characteristics

The explosion-proof centrifugal fan is mainly composed of an impeller, a casing, an air inlet, a conditioning door and a transmission part.

(1) The impeller consists of 12 backward inclined wing-shaped blades welded between the arc-shaped wheel cover and the flat-shaped wheel disc. The wing-shaped blades are used to ensure the low noise and high strength of the fan. The impeller runs smoothly after static and dynamic balance correction. The impellers of the fan and induced draft fan of the same machine have the same structure.

(2) Case The case is a snail-shaped body welded with ordinary steel plates. The casing of the explosion-proof centrifugal fan is made into an integral structure. Regarding the induced draft fan, there is a dust-removing door on the snail-shaped plate, and at the same time, it is appropriately thickened to prevent the soot from wearing out and prolong its service life.

(3) The air inlet has a convergent streamlined overall structure and is fixed on the inlet side of the casing with bolts.

(4) The conditioning door is used to adjust the installation of the flow rate of the fan, No.8-12.5 is composed of 11 petal-shaped blades, No.l4-16

Composed of 13 braided blades, all axially installed in front of the air inlet. Due to the external transmission structure, the rotation is sensitive and convenient. The conditioning range is from 90° (fully closed) to 0° (fully open). The position of the handle of the conditioning door, viewed from the direction of the air inlet, is on the right side. With regard to right-handed fans, pushing the handle from bottom to top is from fully closed to fully open; for left-hand fans, the pull-down of the handle from top to bottom is from fully closed to fully open.

(5) The transmission mode of the transmission group is D type. It is composed of main shaft, bearing box, coupling, etc. The main shaft is made of high-quality steel. Adopt rolling bearing water-cooled integral bearing box. Therefore, it is necessary to install a water delivery pipe, and the water consumption varies with the ambient temperature. Generally, it is considered at 0.5~1m3/h. The bearing box is equipped with a thermometer and an oil level indicator.

The fixed parts of the explosion-proof centrifugal fan cause resonance

reason:

1. The cement base is too light or the grouting is poor or the plane size is too small, causing the fan base to be disconnected from the foundation, the anchor bolts are loose, the machine base is not firmly connected, and the base rigidity is not enough;

2. The base of the fan or the volute has just passed low;

3. The inlet and outlet pipes connected with the fan are not supported and softly combined;

4. Neighboring equipment is too close to the base of the fan, or it has just passed a small period;

Solution:

1. Reinforce the foundation or re-grouting, and tighten the nuts;

2. Enhance its rigidity;

3. Add support and soft connection;

4. Increase stiffness.