JPH0321453B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a powder transfer tube used to transfer powder such as radioactive substances by a conveying air flow and by gravity fall. It is something.

[Conventional technology]

BACKGROUND ART Conventionally, when transferring radioactive powder such as nuclear fuel material, air is caused to flow inside a pipe, and the radioactive powder is transferred by this air flow or by gravity fall. In this case, since the powder to be transferred is a radioactive substance, it is necessary to use a tube with excellent strength and corrosion resistance, and stainless steel tubes are usually used.

[Problem that the invention seeks to solve]

However, microscopically, the inner surface of the stainless steel tube has quite large unevenness formed therein, and radioactive substance powder may adhere to and grow on the unevenness, thereby clogging the inside of the tube. If this is left as is, not only will it be impossible to transport the radioactive powder, but the working environment may be harmed by the radiation emitted from the radioactive powder remaining inside the pipe. Therefore, the radioactive substance powder adhering to the inside of the tube is removed periodically, but there is a problem in that the removal process requires a great deal of effort.

[Means for solving problems]

In this invention, the above problem is solved by forming an aluminum oxide layer on the inner surface of the aluminum tube and coating the surface of the aluminum oxide layer with a hard resin having a smooth surface.

[Effect]

The surface of the hard resin is extremely smooth, making it easy for the radioactive substance powder to slide inside the tube.

〔Example〕

FIG. 1 and FIG. 2 are diagrams showing one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an aluminum tube, and an aluminum oxide layer 2 is formed on the inner surface thereof. The aluminum oxide layer 2 is formed by anodizing the inner surface of the aluminum tube 1, and has a thickness of 10 to 30μ.
It is desirable to set it to about m. On the surface of this aluminum oxide layer 2, a Teflon resin (hard resin, trade name) layer 3 is formed. This Teflon resin layer 3 is made by adhering Teflon resin to the surface of the aluminum oxide layer 2, and a portion of the resin forms a large number of pores 2a formed in the aluminum oxide layer 2 by the alumite treatment. , 2a... are filled to the inside thereof, thereby firmly adhering to each other. The surface of this Teflon resin layer 3 is extremely smooth, allowing the radioactive substance powder to easily slide inside the aluminum tube 1.

In the powder transfer tube with the above configuration,
Since the Teflon resin layer 3 is formed on the inner surface, it is possible to transfer the radioactive substance powder without adhering it.

Furthermore, in the powder transfer tube, since the Teflon resin layer 3 is formed on the surface of the aluminum oxide layer 2, the Teflon resin layer can be firmly adhered without peeling off. That is, even if the Teflon resin is brought into direct contact with the inner surface of the aluminum tube 1, the Teflon resin is easily peeled off. In this respect, the Teflon resin layer 3 described above has a part of the resin that forms the many pores 2 of the aluminum oxide layer 2.
Since the inside of a, 2a, etc. is filled, it is difficult to peel off. Furthermore, even if the Teflon resin layer 3 is worn out and disappears, the Teflon resin remains in the pores 2a, 2.
Since the aluminum oxide layer 2 is filled in the aluminum oxide layer 2, the surface of the aluminum oxide layer 2 is always kept smooth.

In the above embodiments, Teflon resin is used as the hard resin, but the same effect as described above can be obtained using other hard resins, such as (nylon).

〔effect〕

In this invention, an aluminum oxide layer is formed on the inner surface of the aluminum tube, and the surface of this aluminum oxide layer is coated with a hard resin with a smooth surface, so that radioactive substance powder does not adhere to the inner surface of the powder transfer tube. This prevents the inside of the pipe from becoming clogged. Therefore, not only is there no risk of harm to the working environment, but it is also possible to obtain the effect that the effort required for maintenance and inspection of the powder transfer tube can be considerably reduced. In addition, the hard resin coated on the surface of the aluminum oxide layer engages with the many pores on the surface of the aluminum oxide layer and is firmly adhered to it, making it difficult for this hard resin to peel off. The inner surface of the transfer pipe is kept smooth for a long period of time, and the cost of repairing the equipment can be significantly reduced.

Furthermore, since the outer side is an aluminum tube, by oxidizing the inner surface, an aluminum oxide layer can be easily formed on the inner surface.

[Brief explanation of the drawing]

1 and 2 are views showing one embodiment of the present invention, in which FIG. 1 is a perspective sectional view showing a powder transfer tube, and FIG. 2 is a sectional view taken along the line A-A in FIG. 1. It is. 1... Aluminum tube, 2... Aluminum oxide layer, 3... Teflon resin (hard resin) layer.

Claims (1)

[Claims] 1 Form an aluminum oxide layer on the inner surface of an aluminum tube, and make the surface of this aluminum oxide layer
A powder transfer tube characterized by having a surface coated with a smooth hard resin.