JPS6059514B2 - Furnace viewing window device - Google Patents

Description

[Detailed Description of the Invention] The present invention is applicable to a furnace that melts, heats, or performs various other treatments on various materials inside a wall-enclosed interior, especially a heat treatment furnace. The present invention relates to a viewing window device used for observing or monitoring the inside of a furnace in a furnace with poor atmospheric conditions or in a furnace with a strong light source inside, such as an arc furnace or a plasma furnace.

A conventional viewing window device, as shown in FIG. 7, for example, includes a glass 41 for seeing through the inside, a member 42 for holding the glass, and a tube for supporting the glass 41 and attaching it to the furnace wall 2. A sealing material 20 is further provided to prevent the atmosphere inside the furnace from leaking to the outside.

In the case of a viewing window device with such a configuration, the window hole 1 must be opened from inside the furnace.
There is a problem in that the glass 41 is easily soiled by powder particles and spatter that fly towards the glass 41 through the glass 41, and the visibility quickly deteriorates. To solve this problem, tube 16
It is also possible to make the length of the glass 41 longer so that the glass 41 is separated from the inside of the furnace.
There is a problem that the field of view θ through 1 becomes narrow, making it impossible to accurately see the inside of the furnace. In addition, in order to prevent the glass from getting dirty, for example, as shown in FIG. It has also been considered to provide a shutter 46 that can be freely moved to prevent the glass 41i from becoming dirty due to the rotating glass 44 or the shutter 46. However, various parts such as the rotating glass 44 and the shutter 46 are
As is clear from the figure, there is a problem in that the field of view θ becomes extremely narrow.

Therefore, the present invention is designed to eliminate the above-mentioned problems, and it is possible to prevent the screen from becoming dirty and maintain good visibility over a long period of time, and it is also possible to widen the field of view for observing the inside of the furnace. The present invention aims to provide a viewing window device for a furnace. The drawings showing the embodiments of the present application will be described below.

In a plasma melting furnace 1 shown as an example of a furnace in FIG. 1, a wall 2 is supported by a support 3. The plasma melting furnace 1 shown in FIG. In the members disposed in the internal space 4 of the wall body 2, 5 indicates a crucible, and 6 indicates a material to be melted in the crucible 5.
Reference numeral 7 denotes a plasma torch, which can irradiate a plasma arc toward the object 6 to be melted.

Further, this plasma torch 7 is supported by a well-known lifting device 8 provided outside the wall 2 so as to be able to move up and down. 9
is a well-known take-out device, which is a device for taking out the material to be melted 6 that has been melted in the crucible 5.

Reference numeral 11 indicates a viewing device mounted on the wall 2.

Reference numeral 12 denotes a camera that can take pictures of the inside of the furnace through the viewing device 11.

Reference numeral 13 indicates a monitor television for displaying images taken by the camera 12.

Next, the above-mentioned viewing device 11 will be explained in detail with reference to FIG. 2.

15 is a window hole opened in the wall body 2; 16 is a cylinder attached to the wall body 2 in communication with the window hole 15; 18 is a screen plate; the surface of this screen plate 18 facing the inside of the furnace; Alternatively, a screen 19 is provided on the opposite side.

As the screen 19, for example, a ground glass surface or a semi-transparent layer which has an effect equivalent to that of ground glass, that is, can project an image, is used. Note that any known material can be used for the screen plate 18 and the screen 19 attached thereto. 20 is attached to the screen plate 18 and the cylinder body 16. This is a sealing material interposed between the furnace and the flange 17, which is used to prevent the atmosphere inside the furnace from escaping to the outside.

A pinhole plate 21 is attached to the cylindrical body 16 and has a pinhole 22 in its center.

Furthermore, the pinhole 22. The size is related to the amount of light reaching the screen 19 and the blur of the image projected on the screen 19, and is generally 0.3 to 0.57077 in diameter.
! is preferred. 23 is the screen 19 in the cylindrical body 16
This air supply port is provided between the pinhole plate 21 and the gas supply port 21, and is provided as a gas supply section.
3 is connected to a gas supply device via an air supply pipe.

In the case of the above configuration, the image of the object
9, and the image of the object X appears on this screen 19 as an inverted image. Therefore, the observer can see this screen 19
By looking at the image reflected in the image, which is exactly the same as the inside of the furnace, you can get a first-hand idea of the inside of the furnace. In the above case, instead of looking directly at the screen 19, the observer may use a camera as shown in FIG. 1 to observe the image displayed on the monitor television 13. In this case, if the distance from the object Even if the camera 12 is in focus, the camera 12 remains focused on the screen 19, allowing observation to be made in good focus at all times. Furthermore, the above also means that even if the observer using the camera 12 is changed, the camera 12 only needs to be focused on the screen 19; The situation inside the furnace can always be photographed under the same conditions. Note that the distance from the window hole 15 to the pinhole plate 21 and the distance from the pinhole plate 21 to the screen 1
The distances up to 9 should be set to desired values depending on the width of the area inside the furnace that is desired to be projected on the screen 19 or the size of the image that is desired to be projected on the screen 19. Next, if spatter or dust flies toward the pinhole 22 from materials undergoing various treatments in the furnace, gas is introduced into the space between the screen 19 and the pinhole plate 21 through the air supply port 23. send in.

The fed gas passes through the pinhole 22 and heads into the furnace. Therefore, even if the dust or spatter flies toward the pinhole 22, the gas flow pushes the spatter or dust back in the opposite direction, or diverts the flying direction from the direction toward the pinhole 22. This can prevent the pinhole 22 from being clogged with spatter or dust. It is preferable to use the same gas as the atmosphere inside the furnace as the gas fed through the air supply port 23. Next, FIGS. 3 to 5 show different examples of pinhole and pinhole plate formation structures, respectively. First, FIG. 3 shows an example in which a thin metal plate is used as the pinhole plate 21 and a pinhole 22 is bored in the center thereof.

The pinhole 22 may be formed as shown in FIG. Next, FIG. 4 shows an example in which the pinhole plate 21 is formed from a thick metal plate, a thin part 21a is formed at the center of the plate, and a pinhole 22 is bored at the center position of the thin part. be.

Next, FIG. 5 shows that the main body part 2'' of the pinhole plate 21 is made of a thick and strong metal plate, and the thin auxiliary pinhole plate 2'' is attached to this main body part 21'' with a presser plate 26. This shows an example in which pinholes 22 are bored in the auxiliary pinhole plate 21''.

Note that the pinhole 22 can be formed using any other method. Next, FIG. 6 shows a different embodiment of the present application, in which a part of the furnace wall 2e is connected to a pinhole plate 21.
pinhole 2 on the pinhole plate 21e.
2e is shown.

It should be noted that parts that are functionally the same or equivalent to those in the previous figure are given the same reference numerals as in the previous figure with the letter e, and redundant explanations are omitted.

As described above, in this invention, since the image of the inside of the furnace is projected on the screen 19, it is possible to know the situation inside the furnace by looking at the image reflected on the screen 19. . Moreover, in the present invention, since the pinhole plate 21 that acts as a screen against the screen 19 is provided at a position closer to the inside of the furnace than the screen 19,
When various materials are melted at high heat inside the furnace, dust and spatter may scatter from the materials to be melted toward the screen 19.
Or high heat from the above-mentioned material to be melted or other
Even if the screen is exposed to dust, spatter, or high heat, the pinhole plate 21 can block the dust, spatter, or high heat, prevent the screen from getting dirty, and maintain good visibility for a long period of time. It is also useful in preventing thermal damage to the screen.

Furthermore, since the configuration is as described above, in the case of internal observation, even if the pressure inside the furnace rises rapidly, the screen 1
This has the effect of preventing damage to the 9.9 and protecting the safety of the observer.

Moreover, even if the present invention is provided with a screen as described above, the screen, that is, the pinhole plate 21 has pinholes 22.
Since the pinhole 22 is provided, the inside of the furnace can be projected onto the screen 19, and the above-mentioned observation can be carried out without any hindrance.

Moreover, in that case, since the pinhole 22 is provided closer to the inside of the furnace than the screen 19 as described above, the direction forms a large angle with respect to the central axis 25 of the viewing device 11 as shown in FIG. The light coming from A and B can also reach the screen 19, and the situation in a wide range of places inside the furnace can be reflected on the screen 19, so that the situation inside the furnace can be accurately known. There is also.

Furthermore, in the present invention, the above-mentioned In this case, even if dust or spatter flies toward the pinhole, the gas flow can prevent it from reaching the pinhole, preventing the pinhole from clogging and extending its life. It has the effect of making it possible.・Brief explanation of the drawings The drawings show the embodiment of the present application. Fig. 1 is a schematic sectional view of the plasma melting furnace, Fig. 2 is a longitudinal sectional view of the viewing device, and Figs. 3 to 5 are pins. FIG. 6 is a view similar to FIG. 2 showing different embodiments of the present application, and FIGS. 7 and 8 are sectional views showing conventional examples.

2... Wall, 19... Screen, 2
1...Zenhole board, 22...Zenhole.

Claims (1)

[Scope of Claims] 1. A viewing window device for a furnace in which a viewing device is attached to a part of the wall of the furnace so that the inside of the furnace can be viewed from outside, and the viewing device is configured to display an image of the inside of the furnace. It consists of a screen for displaying images, and a pinhole plate that has a pinhole in its center and is placed closer to the inside of the furnace than the screen, and the pinhole allows an inverted image of the inside of the furnace to be displayed. is reflected on the screen. 2. In a furnace viewing window device in which a viewing device is attached to a part of the wall of the furnace so that the inside of the furnace can be viewed from the outside, the viewing device is a screen for projecting an image of the inside of the furnace. , a pinhole plate having a pinhole in its center and disposed closer to the inside of the furnace than the screen, and an inverted image of the inside of the furnace is projected onto the screen by the pinhole. Furthermore, a gas supply unit is arranged at a position inside the furnace of the pinhole plate to supply gas for generating a gas flow toward the inside of the furnace through the pinhole. A furnace viewing window device characterized by: