JPH02211976A - Method for closing bottom end of pd alloy pipe of gaseous hydrogen refining device - Google Patents

Abstract

PURPOSE:To surely close the bottom end of a Pd alloy pipe with a brazing material by putting a brazing material chip to the inner side of the bottom end of the Pd alloy pipe, drawing the bottom end of the pipe, heating the pipe, thereby melting the brazing filter metal chip and closing the bottom end. CONSTITUTION:The Pd alloy pipe 1 is penetrated and brazed to the bottom of an SUS cup of the gaseous hydrogen refining device. The bottom end of the pipe 1 is closed. The brazing material chip 5 formed by cutting a brazing wire rod is, thereupon put to the inner side at the bottom end 1a of the Pd alloy pipe 1. The bottom end 1a of the Pd alloy pipe 1 is then drawn. The pipe is then heated to melt the brazing material chip 5 and to close the bottom end 1a. The pipe having the closed bottom end is easily and inexpensively produced in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for sealing the lower end of a Pd alloy pipe in a hydrogen gas purification device.

(Prior Art) One of the hydrogen gas purification methods is a Pd-Ag alloy thin film permeation method. As shown in FIG. 2, the hydrogen gas purification equipment used for this purpose seals the lower end 1a of a vibrator 1 made of a large number of Pd-Ag alloy thin films, and seals the upper end 1b of the bottom 2a of a cup 2 made of SUS. It penetrates through the vibrator through-hole 3 and is brazed. By supplying pressurized raw material hydrogen gas to the outside of the vibrator 1 and raising the temperature to a certain temperature (usually 200 to 300°C), the vibrator l Hydrogen molecules in contact with the surface of the Pd dissociate into atoms, form a solid solution with Pd, and are incorporated into the Pd alloy. Then, the hydrogen atoms occluded in the metal diffuse from the outside of the vibrator 1 where the pressure is high to the inside where the pressure is low due to the hydrogen partial pressure inside and outside the vibrator 1, and become hydrogen molecules again on the inside surface, and are contained in the raw hydrogen gas. Since most of the impurities present do not react with the Pd alloy, they remain on the outside of the vibe 1, and the raw material hydrogen gas is completely purified.

In order to seal the lower end 1a of the Pd alloy vibe 1 that penetrates the bottom 2a of the SUS cup 2 of such a hydrogen gas purification device,
Conventionally, as shown in FIG. 3, a ball 4 made of the same Pd alloy and having a diameter larger than the inner diameter of the vibrator is pressed against the lower end 1a of the Pd alloy vibrator 1 and welded, or as shown in FIG. The method used was to melt the lower end 1a of the container as it was and seal it.

(Problem to be Solved by the Invention) By the way, as shown in FIG.
The method of pressing and welding requires too much time when creating the ball 4 because it requires a ball diameter accuracy close to the inner diameter of the vibrator 1. Also, in the method of melting and sealing the lower end 1a of the vibrator 1 as shown in Figure 4, the amount of melting is not constant, resulting in uneven lengths, and if it melts too much, the lower end 1a
However, the outer diameter of the vibrator 1 may become larger than the outer diameter of the vibrator 1 as shown by the dashed line, and thereafter it may become impossible to penetrate the vibrator through hole 3 in the bottom 2a of the SUS cup 2 shown in FIG.

Therefore, the present invention allows the sealing material to be easily produced, and allows Pd alloy to be used without changing the length of the Pd alloy vibrator or increasing the outer diameter of the lower end.
It is an object of the present invention to provide a method for sealing the lower end of an alloy pipe.

(Means for Solving the Problems) A method for sealing the lower end of a Pd alloy pipe of a hydrogen gas purification device of the present invention to solve the above problems is to use a method of sealing the lower end of a Pd alloy pipe by cutting a brazing wire inside the lower end of the Pd alloy pipe. The Pd alloy pipe is characterized by inserting a brazing material chip, then squeezing the lower end of the Pd alloy pipe, and then heating to melt the brazing material chip and sealing the lower end.

(Function) As described above, in the method for sealing the lower end of a Pd alloy pipe according to the present invention, a brazing material chip obtained by cutting a brazing wire is placed inside the lower end of the Pd alloy pipe, so the brazing material chip is prepared by refining. It is easy to manufacture and inexpensive because it does not require roughness and can be rough. In addition, the lower end of the Pd alloy pipe is squeezed and heated to melt the brazing filler metal chip and seal the lower end.In other words, the Pd alloy pipe does not melt, so the length does not change and the outer diameter of the lower end increases. It will never happen.

(Example) An example of the method for sealing the lower end of a Pd alloy pipe in a hydrogen gas purification apparatus of the present invention will be described with reference to the drawings.

As shown in Figure 1a, outer diameter 1.6+++m, inner diameter 1.47
2m [[l.

P d -A g 23 with wall thickness of 64 μm and length of 640 marks
Inside the lower end of wt% alloy pipe 1, an outer diameter of 1.3 mm
A brazing material chip 5 obtained by cutting an Au-Ni 18wt% brazing wire into two lengths is inserted as shown in FIG. 1, and then the lower end 1a of the vibrator 1 is inserted as shown in FIG. length 1
mm, the inner diameter was set to 1 mm, and then heated at 1050° C. for 2 minutes in a high-purity hydrogen atmosphere to melt the brazing material chip 5 and seal the lower end 1a as shown in FIG. 1d. .

Pd-Ag23wt with the lower end 1a sealed in this way
Since the lower end 1a of the vibrator 1 does not melt, the length of the alloy pipe 1 does not change, and the outer diameter of the lower end does not increase.

Therefore, after that, this vibrator 1 is made of SUS as shown in Fig. 2.
There is no problem in penetrating the pipe through hole 3 in the bottom 2a of the cup 2.

(Effect of the invention) As can be seen from the above explanation, the P of the hydrogen gas purification apparatus of the present invention is
According to the method for sealing the lower end of a Pd alloy pipe, the lower end of the Pd alloy pipe can be sealed with brazing material without melting, so the length does not change and the outer diameter of the lower end does not increase. Therefore, this Pd alloy pipe can easily pass through the pipe through hole at the bottom of the SUS cup.

Furthermore, in the method for sealing the lower end of a Pd alloy pipe of the present invention, Pd
Since the brazing material chips obtained by cutting the brazing wire are inserted inside the lower end of the alloy pipe, the preparation work does not require much time, precision is not required to create the brazing material chips, and a rough shape is fine. It is easy and inexpensive to manufacture. Furthermore, since the amount of the brazing filler metal chips can be easily adjusted by adjusting the cutting length according to the diameter of the Pd alloy pipe, the lower end of the Pd alloy pipe can be reliably sealed with the brazing filler metal regardless of the diameter.

[Brief explanation of the drawing]

1a to d are enlarged sectional views showing steps of an embodiment of the method for sealing the lower end of a Pd alloy pipe in a hydrogen gas purification apparatus of the present invention, FIG. 2 is a schematic diagram of the hydrogen gas purification apparatus, and FIG. 3 and FIG. 4 are diagrams showing a method of sealing the lower end of a Pd alloy pipe in a conventional hydrogen gas purification apparatus.

Claims (1)

[Claims] 1. When sealing the lower end of the Pd alloy pipe before penetrating the bottom of the SUS cup of the hydrogen gas purification equipment and brazing the upper end, cut a brazing wire inside the lower end of the Pd alloy pipe. The lower end sealing of a Pd alloy pipe for a hydrogen gas purification equipment is characterized in that the lower end of the Pd alloy pipe is sealed by inserting the brazing filler metal chips obtained through the process, then squeezing the lower end of the Pd alloy pipe, and then heating to melt the brazing filler metal chips and sealing the lower end. How to block.