JPH0445029Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a hot isostatic pressing device (hereinafter referred to as HIP) for producing high-density products by applying isostatic pressure to the object to be processed at high temperatures. ) relates to the structure of a heat insulating layer disposed and used within a pressure vessel.

(Prior art) HIP equipment generally has a pressure vessel 1 as shown in Fig. 4.
and an upper lid 2 for sealing the upper and lower openings of the pressure vessel 1.
and a lower lid 3, and a heat insulating layer 6 disposed within the high pressure chamber defined by the pressure vessel 1 and the upper and lower lids 2 and 3.
The main elements are a heater 5 inside the heater 5 and a product table 7 placed and held on the lower lid 3.The heat insulating layer 6 absorbs pressure from the heater 5 in order to keep the furnace chamber space inside the heater 5 at a high temperature. It has the function of suppressing heat transfer to the container 1.

By the way, since it is necessary to suppress radiation and natural convection for the heat insulating layer of such HIP equipment, flexible graphite sheets have an emissivity of around 0.6 even at temperatures above 1500°C, and ordinary graphite has an emissivity of around 0.6.
Considering that it is 0.9 or more, it is often used because it has favorable characteristics for suppressing radiation.
It is possible to obtain sheets with a thickness as thin as 0.1 mm, and it is easy to reduce the overall thickness when stacking multiple layers, so a structure consisting of multiple layers of flexible graphite sheets is most commonly applied. has been done.

FIG. 5 shows an example of the heat insulating layer of a conventional HIP device using such a flexible graphite sheet. A cylindrical body in which flexible graphite sheets 13d to 13g are arranged concentrically, and a plurality of canopies 13a, 1 each made of multiple layers of flexible graphite sheets 13a and 13g.
3b, non-flexible short cup-shaped graphite caps 9 and 10 that are placed over the upper part of the body between and outside the canopies 13a and 13b, and the outside of the outer graphite sheet 13g. It is composed of metal cups 11 and 12 and a ceramic fiber 14 filled between them.

In this case, the graphite sheet 1
A more specific aspect of the winding structure of 3d to 13g is shown in FIG.
No. 1, No. 177927, etc., have been described and proposed in detail.

Here, the graphite caps 9 and 10 are for suppressing the gas flow flowing upward between the layers of the graphite sheets 13d and 13f. Each of the 13 f forms one tip shape.

Further, the graphite sheets 13e and 13g play a role of filling the gap created by the bodies of the graphite caps 9 and 10. The greater the number of graphite caps, the better the heat insulation effect.

(Problem to be solved by the invention) However, in the heat insulating layer having the above structure, there is a restriction that the thickness of the body of the graphite cap cannot be made extremely thin due to strength reasons. If the number of required layers of graphite sheets is small, it becomes difficult to cover with a plurality of graphite caps. Therefore, the number of graphite caps is limited, and the insulation performance of the upper part of the insulation layer deteriorates, which becomes a problem when considering the life of the insulation layer.

The purpose of this invention is to address the above-mentioned problems with the heat insulating layer and to prevent the insulation performance of the upper part of the heat insulating layer from deteriorating even when the number of graphite layers is small by improving the shape of the graphite cap body. It is something to do.

(Means for solving the problem) That is, the configuration of the present invention that meets the above purpose is
An explanation will be given based on the basic embodiment shown in the figure.The heat insulating layer consists of a cylindrical part made of multiple layers of flexible graphite sheets wound, and a short cap-shaped graphite cap 16a closely arranged at the upper end of the cylindrical part. The body part 17b has an inverted cup-shaped graphite tip 8 as a core, and has multiple layers of flexible graphite sheets wrapped around the outer side.
It is the same as the conventional structure in that a body canopy 17a is disposed, and the body 16c of the graphite cap 16a and the graphite sheet-wound body 17d form a cup shape.
6a is provided with a step 16b, and this and the graphite sheet winding body 17c form another tip shape.

Here, the step is not limited to one place, but may be provided at two or more places to form two or more inverted cup shapes, and the wall thickness of the graphite sheet wound body 16c is similar to that of the conventional graphite body. However, the depth of the step 16b is determined in consideration of the number of layers of graphite sheets.

Furthermore, providing a convex portion or a concave portion in the portion of the body of the graphite cap around which the graphite sheet is wound is a particularly preferred embodiment for further improving the gas sealing property between the graphite cap and the graphite sheet.

(Function) According to the configuration of the present invention as described above, even one graphite cap can have functions equivalent to at least two conventional graphite caps, and even when the required number of graphite sheet layers is small, Also, without increasing the number of graphite caps, the heat insulating performance of the upper part of the heat insulating layer is improved by providing substantially the same effect as increasing the number of graphite caps.

Also, in Figure 1, the graphite cap is set to 2.
If you wanted to make it into individual pieces, you would have to wrap an extra graphite sheet by the thickness of the body, but that is no longer necessary.

(Embodiments) Hereinafter, other embodiments of the present invention will be described with further reference to FIGS. 2 and 3.

FIG. 2 shows a case where the embodiment shown in FIG. 1 has one step, but two steps 18b and 1 are provided.
8c and one graphite cap 18a forms three caps.

In this case as well, basically the same as in Fig. 1, the core is an inverted cup-shaped graphite tip 8, and the cylindrical body 19e and canopy are made of multiple layers of flexible graphite sheets wrapped around the outside. 19a, and the configuration that constitutes the main part of the present invention is applied to the outside thereof.

That is, two steps are made on the graphite cap 18a.
18b and 18c are provided, and the inner graphite cap body 18d and the graphite sheet-wound body 19d form a cup shape as in the conventional case. A graphite sheet is wrapped around the part 18c, and the graphite cap and the graphite wound body parts 19b and 19c each form a cup shape, resulting in one graphite cap 18.
Create three cup shapes with a.

In this case as well, the body 18d of the graphite cap
The wall thickness of the graphite cap is approximately the same as that of the body of a conventional graphite cap, but the depth of each step 18b, 18c is determined in consideration of the number of layers of graphite sheets.

Figures 3A and 3B show a more preferred embodiment in which the gas sealing property between the graphite cap and the graphite sheet-wound body is improved in the heat insulating layer of the present invention as described above. A convex portion 20 or a concave portion 21 is formed in the part where the graphite sheet is wrapped in the body of 16a.
has been established.

Of course, this embodiment may also be provided on both graphite cap bodies when there is a step difference in two locations as shown in FIG. 2, or may be provided on a portion of the graphite cap, for example, only on one body.

In this way, the gas sealing property between the graphite cap and the graphite sheet will be improved, and a greater heat insulation effect can be expected.

(Effects of the invention) As described above, the present invention has a heat insulating layer consisting of a body made of multiple layers of flexible graphite sheets and a short cap-shaped graphite cap on top of the body. By providing at least one step in the section and wrapping a graphite sheet around each step, it is possible to form at least two or more inverted cup shapes with one graphite cap. One unit can have the functions of at least two conventional graphite caps,
Even if the number of graphite sheet layers is small, it is possible to improve the insulation performance of the upper part of the heat insulation layer without increasing the number of graphite caps, and it can be used as a heat insulation layer for HIP equipment. Practicality can be improved.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of a main part showing a basic embodiment of the heat insulating layer according to the present invention, Fig. 2 is a partial sectional view of a main part showing another embodiment of the heat insulating layer of the present invention, Fig. 3 A, B is a partial sectional view of each main part showing a more preferred embodiment of the present invention, FIG. 4 is a schematic sectional view showing an example of a HIP device using the heat insulating layer of the present invention, and FIG. 5 is a part showing a known heat insulating layer structure. The cross-sectional view and FIG. 6 are explanatory diagrams showing an example of how to wind a graphite sheet in a heat insulating layer. 8...Graphite tip, 16a, 18a...
...graphite cap, 17a, 19a...canopy, 16b, 18b, 18c...step, 16c,
18d...Graphite cap body similar to conventional one, 17b, 17c, 17d...Graphite sheet wound body part, 19b to 19d...Graphite sheet wound body part, 20...Convex part, 21...Concave part .

Claims (1)

[Claims for Utility Model Registration] 1. Hot isostatic pressing consisting of a cylindrical body formed by winding multiple layers of flexible graphite sheets, and a short cap-shaped graphite cap closely placed on top of the cylindrical body. In the heat insulating layer for a pressure equipment, at least one step is provided in the body of the graphite cap, and a graphite sheet-wrapped body is formed by wrapping the graphite sheet around each step with the top thereof touching. A heat insulating layer for a hot isostatic pressing device, characterized in that one graphite cap forms at least two or more inverted cup shapes. 2. The heat insulating layer for a hot isostatic pressing device according to claim 1, wherein the graphite cap has a convex portion or a concave portion in the portion where the graphite sheet is wrapped around the body.