JPH054295B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pneumatic transportation device for powder and granular materials.

[Conventional technology]

In general, pneumatic transportation of powder and granules involves passing an air flow through a transport pipe having a circular cross section, and transporting the powder and granules by the air flow.

[Problem to be solved by the invention]

However, in high-concentration transportation or plug transportation, in which powder and granules are press-fitted into a transport pipe in the form of lumps and transported by the pressure difference in the transport pipe before and after the powder and granules, the powder and granules are If the frictional resistance with the inner wall of the channel becomes large, the transport pipe may be clogged by the powder and granules, making transport impossible.

In particular, the above-mentioned clogging phenomenon of transport pipes tends to occur in granular materials having a large specific gravity, granular materials that are easily entangled, and granular materials that are easily aggregated.

In order to eliminate this clogging phenomenon, air pipes are appropriately connected in the middle of the transport pipe to blow new air into the transport pipe, loosening the lump-like powder and granules and allowing the powder to flow through the transport pipe. Although attempts are made to avoid compaction of the material against the inner walls of the road, such means not only increase the amount of air required to transport the powder, but also become uneconomical.
Since it is necessary to install an air pipe for blowing air, there is a drawback that the production and maintenance costs of the device are high.

The present invention solves the above-mentioned problems, and aims to prevent clogging of the transport pipeline of a pneumatic transport device.

[Means to solve the problem]

In order to solve the above problems, in the powder pneumatic transport device of the present invention, one end of the pipe material is connected to the other end in the middle of the transport pipe line for feeding the powder material from the pressure tank to the collection tank. By twisting the tube in the circumferential direction, a concave portion that is smoothly depressed from the center of the tube cross section toward the outside of the tube and a convex portion that smoothly projects from the outside toward the center of the tube cross section are created in the wall of the tube cross section. An anti-occlusion tube is provided in which the concave portion and the convex portion are formed to extend spirally in the tube axis direction.

[Effect]

In the pneumatic transportation device for powder and granular material of the present invention, one end of the tube member is twisted in the circumferential direction relative to the other end, and a concave portion is formed in the powder and granular material that is fed from the pressure tank to the collection tank via the transport pipe. A turning force is applied by the anti-occlusion tube formed so that the convex portion extends spirally in the tube axis direction.

By applying swirling force to the pneumatically transported powder and granular material, it is prevented from being consolidated, the force with which the powder and granular material is pressed against the inner wall of the pipe is weakened, and clogging of the transport pipe is prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 show an embodiment of the anti-occlusion tube used in the pneumatic transportation device for powder and granular materials of the present invention. By this, a concave portion 1 that is smoothly depressed from the center of the tube cross section toward the outside of the tube, and a convex portion 2 that smoothly protrudes from the outside of the tube toward the center of the tube cross section are formed in the wall portion of the tube cross section, and By forming the concave portion 1 and the convex portion 2 to extend spirally in the tube axis direction, a spiral groove is provided in the tube inner circumferential wall.

In FIG. 1, numeral 3 indicates a circular cross section in which neither the concave portion 1 nor the convex portion 2 is formed, and 4 indicates a connecting flange.

Fig. 3 shows a high-concentration pneumatic transport device used for transporting metal powder in which a blockage prevention pipe 10 is arranged in the transport pipeline, 5 is a pressure tank, 6 is an outlet valve at the outlet of the pressure tank 5, and 7 is a pressure tank. A transportation pipe connecting the tank 5 and the collection tank 8, 9 a bag filter provided in the collection tank 8, 11 an air valve of the air pipe connecting the air compressor 12 and the pressure tank 5, and 13 a flow rate of the air pipe. 14 is a pressure gauge of the pressure tank.

The anti-occlusion pipe 10 has a pressure tank 5 and a collection tank 8.
It is installed in the transport pipe 7 that connects the transport pipe, and although the location is not particularly important, it is effective to install it immediately before the bend where the concentration of powder or granular material in the transport pipe increases, so in this example, It is placed just before the bend.

Hereinafter, the function of the blockage prevention pipe 10 will be explained using the above-mentioned high concentration air transport device as an example.
After the metal powder is introduced into the tank, the air compressor 12 blows compressed air into the pressure tank 5 through the air valve 11 to pressurize the pressure tank 5 and fluidize the metal powder to reduce the internal pressure of the pressure tank 5. When the pressure is increased to the set pressure, the outlet valve 6 is opened and the metal powder is sent to the collection tank 8 via the transport pipe 7.

The flow of metal powder flowing through the transport pipe 7 is controlled by a blockage prevention pipe 1 disposed just before the bend of the transport pipe 7.
When passing through 0, a swirling force is applied by the concave portion 1 and the convex portion 2, and the metal powder that attempts to form a nodule is loosened by the shearing action during the swirling and becomes solidly consolidated. The metal powder is blocked and the force pressing the metal powder against the inner wall of the pipe is weakened, so the transport pipe 7
is not blocked by metal powder.

As an example of this high-concentration air transportation device, the total distance from the outlet valve 6 to the collection tank 8 is 25 m, the nominal diameter of the pipe is 40A, and the length is 1 m just before the five bends in the middle of the transport pipe 7. anti-occlusion tube 1
When metal powder with a specific gravity of 4.95 was transported using a device with a structure in which a
Even at a speed of about 10 m/s, the transport pipe 7 was not blocked. On the other hand, when we replaced the anti-occlusion pipe 10 with a conventional pipe with a circular cross section, we found that the flow velocity was 20 m/min.
Transport pipe 7 was also blocked in s.

It should be noted that the pneumatic transportation device for powder and granular materials of the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention. Since the swirling flow provided by the twisting of the prevention tube continues for a certain distance after passing through the twisting portion, there is no need to make the twisting portion particularly long or to install a large number of obstruction prevention tubes.

〔Effect of the invention〕

As explained above, according to the pneumatic transportation device for powder and granular material of the present invention, by appropriately arranging the blockage prevention tube made of a twisted pipe of an appropriate length in the transportation pipe line with a circular cross section, the granule powder being transported is It can shear and loosen body lumps and prevent blockage of transport pipes.
Compared to conventional transportation means, it is possible to transport powder and granules even at a much lower speed, and the amount of air required for transport can be reduced, saving energy, and because it creates a swirling flow. Since the flow in the bend of the transport pipe is dispersed and the granules do not concentrate and collide at a single point in the bend, wear at the bend is reduced.

[Brief explanation of the drawing]

Fig. 1 is an external view of one embodiment of the anti-occlusion tube used in the pneumatic transport device of the present invention, and Fig. 2 is the - of Fig. 1.
The enlarged arrow view and FIG. 3 are layout diagrams of a high-concentration air transport device in which the anti-occlusion tube shown in FIGS. 1 and 2 is installed. In the figure, 1 is a concave part, 2 is a convex part, 5 is a pressure tank,
7 is a transport pipe, 8 is a collection tank, and 10 is a blockage prevention pipe.

Claims (1)

[Claims] 1. In the middle of the transport pipeline that feeds powder and granular material from the pressure tank to the collection tank, by twisting one end of the pipe material in the circumferential direction relative to the other end, the pipe is inserted into the wall of the pipe section from the center of the pipe cross section. A concave portion that is smoothly concave toward the outside and a convex portion that smoothly protrudes from the outside of the tube toward the center of the cross section of the tube are formed, and the concave portion and the convex portion are formed to extend in a spiral shape in the direction of the tube axis. A pneumatic transportation device for powder and granular material, characterized in that it is equipped with a blockage prevention tube.