JPH0238376A - Method for joining between ceramic member with glass - Google Patents

Abstract

PURPOSE:To enable sealing between ceramic members using a small-sized heating equipment and reduced energy for heating by carrying out local heating between members of a lid and vessel of ceramic. CONSTITUTION:For example, a material to be sealed such as radioactive waste is housed in a ceramic vessel 1 and then a lid unit 2 is mounted in a state leaving space of a joining part 3. Then the vessel 1 and lid unit 2 adjacent to the joining part 3 are heated by flames from two burners 4-1 and 4-2 provided on the joining part 3. Then a glass powder having low melting point is fed from a powder feed port 5 to the joining part 3 or melted glass 7 having low melting point is poured from a melt liquid charging inlet into the joining part 3. Thereafter, the glass powder or glass is cooled to provide the vessel whose joining part 3 is sealed with the glass 7 having low melting point.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for sealingly bonding ceramic members, and particularly to a method for sealingly bonding ceramic members by local heating.

(Prior Art) Conventionally, hermetic bonding, which requires airtightness between ceramic members, is preferably carried out by an overall heating method in which low melting point glass is applied to the bonding surfaces and the whole is heated in a heating furnace. It was common.

(Problems to be Solved by the Invention) However, when heating and sealing the entire ceramic container as described above, a large heating device is required, and heating the entire container causes a large energy loss.
Furthermore, depending on the substance housed inside, the quality of the housed substance changes due to the heating of the entire body, making it impossible to heat the whole body during sealing. In particular, when trying to seal and store low-level radioactive waste generated from nuclear power plants in ceramic containers, conventional whole heating systems have been problematic.

An object of the present invention is to solve the above-mentioned problems and provide a glass sealing method that uses local heating between a ceramic lid body and a container, which can seal between ceramic members without heating the entire body. be.

(Means for Solving the Problems) The method of glass bonding between ceramic members of the present invention is such that when sealing a ceramic container with a ceramic fluid, the joint portion between the lid and the container is locally heated with a burner, and the glass is bonded to the ceramic container. The device is characterized by being sealed with a ceramic lid.

(Function) In the above-mentioned configuration, after the burner heats only the joint part locally, for example, by supplying glass powder and melting it, or by supplying molten glass, it is possible to avoid heating the entire joint. In both cases, a bond with sufficient sealing performance can be achieved with only local heating.

(Example) FIGS. 1(a) to 1(d) are diagrams showing the glass sealing method of the present invention in the order of steps. In this embodiment, first, an object to be sealed, such as radioactive waste, is placed in the ceramic container 1, and then the ceramic lid 2 is attached leaving a gap between the joints 3. Next, as shown in FIG. 1(a), the flame from two burners 4-1 and 4-2 installed on the joint 3 destroys the ceramic container 1 and the ceramic lid 2 near the joint 3. Heat.

A normal propane gas burner can be used as the burners 44, 4-2.
1.4-2 is rotated at a low speed, and the ceramic container 1 is further rotated at a low speed in the opposite direction.

Further, during burner heating, it is preferable to cover parts other than the joint part 3 with a heat insulating material.

The heating rate during burner heating is preferably controlled to 90"C/hr or less, as cracks may occur if it is too fast.Also, the holding temperature of the joint 3 after heating varies depending on the melting point of the glass used. -For example, when using low melting point glass with a melting point of about 400°C, 50
It is preferable to hold the temperature at 0 to 520°C for 1.5 to 2 hours.

At this time, if the holding time is too short, a temperature difference may occur between the ceramic container 1 and the ceramic lid body 2 in the vicinity of the joint portion 3, which may cause cranking.

Next, as shown in FIG. 1(b), preferably low-melting glass powder is supplied to the joint 3 from the powder supply port 5, or
As shown in Figure (C), melted low melting point glass is poured into the joint 3 from the melt inlet 6. When powder is supplied to the joint 3 as shown in Fig. 1(b), it must be melted by the heat of the joint 3, so if the powder is fine, it will cause problems in terms of meltability, fluidity, etc. Therefore, it is preferable to use granules with a particle size of about 5 μm. Although commercially available low melting point glasses can be used, it is preferable to use one whose coefficient of thermal expansion is as close as possible to the coefficients of thermal expansion of the ceramic container 1 and the ceramic lid 2.

Furthermore, in both cases of FIGS. 1(b) and 1(C), it is preferable to rotate the ceramic container 1 at a low speed.

As shown in Figure 2, the shape of the joint is such that both the tip of the ceramic container and the periphery of the lid have an angle α of 50 to 85 degrees.
and the wall thickness of the joint at the tip of the ceramic container (
It is preferable that the thickness (T) of the container is 172 or more, and that the surface to be bonded is uniformly heated and the shape facilitates glass bonding. This has the effect of reducing thermal damage to the bonded material due to thermal stress.

Finally, the low melting point glass is supplied to the joint part 3 and then cooled so that the joint part 3 becomes the low melting point glass 7.
A sealed container can be obtained. Incidentally, no cranking occurred in the obtained container.

The present invention is not limited only to the embodiments described above, and numerous modifications and changes are possible. For example, although the above-mentioned embodiment shows an example in which two burners are used, the number of burners is not limited to two (it is also possible to further increase the number of burners). Needless to say, there is no particular limitation on the material, and any ceramic can be used.

(Effects of the Invention) As is clear from the detailed explanation above, according to the glass sealing method of the present invention, after the joint is locally heated with a burner, for example, low melting point glass powder is supplied or melted glass powder is supplied. By supplying melting point glass, the ceramic container and the ceramic lid can be hermetically bonded together without heating the entire container. Therefore, there is no need for large heating equipment, and there is less energy loss for heating.
Furthermore, even if the object to be stored is radioactive waste, which would be inconvenient if heated, it can be suitably sealed in a ceramic container.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(d) are diagrams showing the glass sealing method of the present invention in the order of steps, respectively, and FIG. 2 is a diagram showing an enlarged view of the shape of the joint. ■... Ceramic container 2... Ceramic lid body 3
...Joint part 4-L 4-2...Burner 5...Powder supply port 6...Melt injection lower...
・Low melting point glass

Claims (1)

[Claims] 1. Glass bonding between ceramic members, characterized in that when sealing a ceramic container with a ceramic lid, the joint between the lid and the container is locally heated with a burner to seal the ceramic container with glass. Method.