As a substitute for pipeline elbow in pneumatic conveying system of cement and power plant, star elbow is widely used in pneumatic conveying of large and medium-sized power plants and cement plants because of its advantages of simple manufacture, convenient installation and good durability. However, due to the small quantity often needed and the urgent maintenance demand, regular manufacturers must be selected to ensure the quality and delivery date of the star elbow.

What is the wear principle of spherical elbow?

In the pneumatic conveying system, the common elbow is the fastest wearing part. When the material-gas mixture flows through the elbow, it is washed against the outside of the elbow under the action of inertia force, which makes it quickly worn through and reduces the service life. The flow of material-gas mixture in spherical elbow is different from that in ordinary elbow. As can be seen from Figure 1③, when two pipes A and B make a 90-degree turn through a spherical elbow, the velocity of fluid flowing from pipe A into the ball first decreases by 3-5 times (because the cross-sectional area increases by 3-5 times). Secondly, when the airflow enters the spherical elbow, it is difficult to directly scour the inner surface of the ball, but it will rub with the eddy current in the ball to exchange material and energy. Therefore, the direct wear of the ball by the fluid is buffered and weakened. It is the vortex in the ball that directly wears the ball wall. However, the swirl speed of the vortex is low, and it is concentrated in the connection parts C, D, E and F between the inlet and outlet pipes and the sphere (Figure 1③). This became the first place where the spherical elbow was worn through. Even so, the service life of spherical elbow is 3 ~ 5 times longer than that of ordinary elbow without reinforcement, and the service life can reach more than ten years (conveying cement). If the spherical surface at the joint between the inlet and outlet pipes and the sphere is reinforced and welded, the service life will be longer.

manufacturing process

1. Press the wear-resistant ball, select the die for pressing the wear-resistant ball according to the design requirements, and heat the steel plate several times.

2. Spherical tee and elbow should be precision cast according to the thickness and material of wear-resistant layer.

3, spherical tee, elbow assembly, assembly according to the processing drawings, ensure the structure size and concentricity.

4, spherical tee, elbow welding, professional welder welding, wear-resistant layer does not crack, welding forming is good.

5, acceptance of spherical tee, elbow, inspector inspection one by one, qualified storage.