JPS5856472Y2 - curved pipe - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a curved pipe used in a conduit for conveying powder or granular material by means of a gas flow.

In a pipe in which powder and granules are transported by a gas flow generated by sucking or discharging air, as shown in Figure 3, the powder and granules transported by the gas flow are transported through a straight pipe as shown by arrow a. 31 into the bent pipe 32, due to inertia the bent pipe 3
2 (the point where the axial extension of the straight pipe 31 intersects with the inner surface of the curved pipe 32).

Therefore, the inner surface of the curved pipe 32 near the point p was locally worn due to the intensive collision of powder and granules, and the life of the curved pipe 32 was extremely short.

Therefore, conventionally, a protrusion 33 with a chevron-shaped cross section is provided along the tube axis direction, as shown in FIG. A proposal was made to divert the flow to

According to this method, the collision part of the granular material was dispersed in two locations, which made it possible to slow down the progress of wear.
Even in this case, the wear of the inner surface portions 34 of the curved tube 32 on both sides of the protrusion 33 was significant, and it was not possible to sufficiently extend the life of the curved tube 32.

The present invention provides a curved pipe that can sufficiently extend its life by reducing wear on the inner surface of the curved pipe, and its configuration is as follows:
On the inner surface of the arc-shaped tube body, a protrusion with a chevron-shaped cross section along the tube axis direction is provided so as to be located on the side with a smaller curvature of the tube body, and the inner surface of the tube body adjacent to both sides of the protrusion is made into a flat surface. It was formed.

An example of this will be described below based on FIGS. 1 and 2.

1 is an outer tube, and 2 is an inner tube slidably fitted into the outer tube 1. The outer tube 1 and the inner tube 2 are curved in an arc shape.

The tube body 2a of the inner tube 2 has a circular cross-sectional shape, and a protrusion 3 is provided on the inner surface of the tube body 2a along substantially the entire length in the tube axis direction.

The protrusion 3 has a triangular chevron cross section and is provided so as to be located on the small curvature side of the tube body 2a.

In other words, the circumferential position of the protrusion 3 with respect to the tube body 2a is such that the ridge line 4 of the protrusion 3 is on the small curvature side of the arc-shaped tube body 2a within the plane α passing through the curved tube axis l of the tube body 2a. This is the place where it is located.

The end portion 3a of the protrusion 3 on the non-fitting end 5 side of the tube body 2a has a protrusion height that is gradually reduced in a tapered shape.

The inner surface portions 6.6 of the tube body 2a adjacent to both sides of the protrusion 3 are flat surfaces perpendicular to the plane α.

In other words, the inner surfaces 6, 6 are arcuate plate-like surfaces parallel to the tube axis 1.

With such a configuration, when the straight pipe 7 is connected to the non-fitting end 5 of the tube body 2a and a gas flow containing powder or granules flows into the tube body 2a from the straight pipe 7, the powder or granules are Point Q on the inner surface of the pipe body 2a (the point where the axial extension of the straight pipe 7 intersects with the inner surface of the curved pipe 32)
trying to converge towards.

However, the powder particles are divided into two on both sides of the protrusion 3 by the protrusion 3 and collide with the inner surfaces 6, 6 on both sides of the protrusion 3.

At this time, since the inner surfaces 6, 6 are flat surfaces, the powder particles are dispersed over a wide area of the inner surfaces 6, 6 and collide with each other.

Therefore, the progression of wear on the inner surfaces 6, 6 is alleviated.

In addition, if the inner surfaces 6, 6 are flat surfaces and the tube wall thickness between the inner surfaces 6, 6 and the outer surface of the tube body 2a is thick, it can be used as is even if wear progresses, resulting in good durability. .

It is sufficient to provide the protrusion 3 only in the vicinity of the point Q, but if it is provided over substantially the entire length of the tube body 2a as in the embodiment, a smooth flow can be obtained.

As explained above, according to the present invention, since the inner surface of the tube on both sides of the protrusion provided on the inner surface of the tube body is made into a flat surface, the flow of powder particles converging toward the protrusion is reduced. After being divided into two parts by the protrusion, the pipe spreads over a wide area of the inner surface area and collides with the pipe body, thereby alleviating the progress of local wear on the inner surface of the tube body, thereby extending the life of the pipe body.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view taken along line I-I in Fig. 1, Fig. 3 is a longitudinal sectional view of a conventional curved pipe, and Fig. 4 is a conventional FIG. 3 is a cross-sectional view of another example of a curved pipe. 1...Outer tube, 2...Inner tube, 2a...Pipe body, 3.
...Protrusion, 4...Ridge line, 6...Inner surface portion, 1...
Tube axis, α...plane.

Claims (1)

[Scope of utility model registration request] On the inner surface of the arc-shaped tube body, a protrusion with a chevron-shaped cross section along the tube axis direction is provided so as to be located on the side with a smaller curvature of the tube body, and the inner surface of the tube body adjacent to both sides of the protrusion is made into a flat surface. A curved pipe characterized by the fact that it has been formed.