JPH0142715Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a wear-resistant bent pipe for transporting powder and granular materials.

(Prior art) This type of bent pipe suffers severe local wear only on the outer periphery of the bent pipe due to contact with powder particles.
For this reason, the entire bent pipe would have to be replaced.

Since transportation must be stopped during the exchange, the operating efficiency of the entire related equipment is reduced, which is extremely uneconomical.

Wear of a bent pipe generally progresses from the outer inner surface of the bent pipe.

However, it is practically impossible to reinforce only this part, and if you dare to do so, you will have to split the curved pipe into two in the axial direction and use methods such as spraying wear-resistant metal or pasting ceramic tiles. It becomes very expensive.

In order to solve this problem, attempts have been made to insert and fix a donut-shaped object made of wear-resistant material such as ceramic into the curved pipe, but this results in a narrower cross-section of the pipe, and also requires fixing methods such as adhesives and fillers. This resulted in unevenness on the inner surface of the bend portion, resulting in an increase in transport pressure loss, and it was found that this was not an effective solution.

Furthermore, curved pipes in which a metal layer or reinforcing plate is welded to the outer circumferential side (for example, conventional examples of Japanese Utility Model Publication No. 1609/1983 or Japanese Utility Model Application Publication No. 55/58537) have been proposed and implemented for some time, but due to uneven weight. Another disadvantage is that the flange is easily damaged due to increased weight.

(Purpose) The purpose of this project is to provide a long-life bent pipe that is easy to manufacture and uses the minimum necessary amount of wear-resistant metal.

Furthermore, the present invention provides a mechanically strong bent pipe that has the same overall outer diameter, can be easily flange-connected to a transport pipe to be connected, and is mechanically strong.

(Structure) In the bent pipe of the present invention, a wear-resistant metal layer is formed by spraying a wear-resistant metal on the outer peripheral surface of the bent transport pipe, and a protective outer cylinder is further attached to the bent transport pipe via a filler layer on the outer peripheral surface. The connecting flange is fixed to both ends of the bent transport pipe and both ends of the protective outer cylinder.

(Effects) This product uses thermal spraying to form a wear-resistant metal layer on the outer circumferential surface of the curved pipe with the thickness required depending on the degree of wear on the bent portion, which reduces manufacturing costs and is relatively thin and durable. Since the wear-resistant metal layer with low impact strength is protected by the filler and the protective outer cylinder, it is strong against external forces.

In other words, in the bent pipe of the present invention, the thickness of the wear-resistant metal layer can be adjusted freely by the thermal spraying method, so only the parts that are heavily worn can be made thicker, thereby minimizing the material cost and reducing the manufacturing work. Since it is an external work, it has good workability and can be manufactured at a lower cost than conventional methods.

In addition, during use, even if the inner wall of the bent pipe is scraped and holes are formed due to friction caused by high-velocity particles inside the pipe, the wear-resistant metal layer is exposed after that, slowing down the progress of wear and extending the life of the entire pipe. It is possible to do so.

While wear-resistant metal itself is strong against wear,
Although it is weak against shock and does not have sufficient strength and resistance to pressure inside the pipe, it is reinforced by the outer circumferential filler, so even if the strength of the internal transport pipe decreases, it can maintain the mechanical strength necessary for continued transport. be.

Furthermore, in the bent pipe of the present invention, since both ends of the bent transport pipe and the protective outer cylinder are fixed to a common flange, the connection strength to the flange is large, and there is an effect that the pipe can be firmly and stably connected to the connecting transport pipe.

(Example) To explain the configuration of the present invention with reference to the drawings, 1 is a curved transport pipe made of ordinary materials such as carbon steel or stainless steel, and 2 is a wear-resistant metal layer provided on the outer peripheral surface of the pipe. .

The wear-resistant metal layer 2 is formed by spraying a wear-resistant metal, such as a metal or alloy such as stellite, chromium alloy, molybdenum, or tungsten, using a high-temperature burner or a plasma method.

3 is a protective outer cylinder, and the bent transport pipe 1 as described above is
are supported and accommodated concentrically.

Reference numeral 4 denotes a filler enclosed in order to protect the wear-resistant metal layer on the outer periphery of the bent tube and to integrate the bent tube and the protective outer cylinder.

Reference numerals 5 and 6 indicate flanges commonly fixed to the ends of the bent pipe and the protective outer cylinder, and serve as supporting means for the bent pipe and the protective outer cylinder. When enclosing the filler, a suitable spacer 7 may be adhered to the bent tube in advance as shown in FIG. 2, and the whole may be inserted into the protective outer cylinder before the filler is injected. Enclosing the filler 4 can be easily carried out from the tube end, or, if the tube end is not open, by making an injection hole and an air vent hole in the protective outer cylinder.

The filler in this proposal is one that reinforces the mechanical strength such as pressure resistance and impact resistance of the wear-resistant metal layer 2, and the filler can be used without any particular restrictions. company made denka
OSA combination) is preferred.

The transport pipe of the present invention can be used not only for gas transport but also for slurry transport for the same purpose.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the bent pipe according to the present invention, and FIG. 2 is a cross-sectional view of another embodiment. 1... Bent pipe, 2... Wear-resistant metal layer, 3... Protective outer cylinder, 4... Filler.

Claims (1)

[Scope of utility model registration request] In a bent pipe inserted in the middle of a transport pipe that transports powder and granular materials, a wear-resistant metal layer is formed by spraying a wear-resistant metal on the outer peripheral surface of the bent transport pipe, and a filler layer is further applied to the outer peripheral surface of the bent pipe. A wear-resistant bent pipe, in which a protective outer cylinder is concentrically covered with the bent transport pipe through a protective outer cylinder, and connecting flanges are fixed to both ends of the bent transport pipe and to both ends of the protective outer cylinder. .