JP2022185379A - Furnace interior observation window - Google Patents

Abstract

To provide a furnace interior observation window having a structure capable of restraining gas from the interior of a furnace from reaching a transparent plate without requiring a large amount of blowing gas.SOLUTION: A furnace interior observation window 101 comprises: a cylindrical member 1; and a transparent plate 2 attached to an end part of the cylindrical member 1, and for observing the interior of a furnace 51. The furnace interior observation window 101 comprises: slit-like gas supply holes 3a-6a formed in the cylindrical member 1, and extending in a direction intersecting with an axial direction Z of the cylindrical member 1; and a guide mechanism 7 for guiding gas supplied to the interior of the cylindrical member 1 from the slit-like gas supply holes 3a-6a, to the side of the interior of the furnace 51.SELECTED DRAWING: Figure 1

Description

The present invention relates to an in-furnace peephole installed in an incinerator.

As this kind of technique, there are conventional techniques described in Patent Documents 1 and 2, for example. The conventional technology is as follows.

In the in-furnace peephole device described in Patent Document 1, a first gas supply port for blowing a gas flow toward the inside of the furnace is provided at the rear side portion of the peephole main body, and the tip open portion of the peephole main body is provided with the above-described gas supply port. A second gas supply port is provided for blowing a gas flow in a direction intersecting the gas flow.
With the above configuration, the in-furnace gas flowing from the inside of the furnace toward the peephole is sealed in the vicinity of the opening of the peephole main body by the curtain air blown out from the second gas supply port. It is said that the intrusion of internal gas is prevented.

In the viewing window described in Patent Document 2, a purge fluid supply means for supplying a purge fluid is provided in the vicinity of the transparent plate in the cylindrical member, and a cylindrical porous body for straightening the flow of the purge fluid supplied from the purge fluid supply means. I have a board.
It is said that the above configuration can effectively replace the gas in the tubular member and prevent the transparent plate from being stained.

JP-A-55-79989 JP-A-2005-90870

However, the techniques described in Patent Documents 1 and 2 have the following problems. First, regarding the technique described in Patent Document 1, the direction of the curtain air is perpendicular to the direction of the in-furnace gas that is about to move from the inside of the furnace toward the viewing window. Therefore, in order to seal the furnace gas with this curtain air, a large amount of gas is required as curtain air.

Next, in the technique described in Patent Document 2, the purge fluid is discharged from the holes of the cylindrical perforated plate into the cylindrical member parallel to the transparent plate. With this configuration, of the purge fluid discharged from the holes of the cylindrical perforated plate, part of the flow of the purge fluid discharged from the holes closer to the transparent plate temporarily flows toward the transparent plate. Therefore, if the cylindrical member is short, the gas from inside the device may be caught in the purge fluid heading toward the transparent plate and reach the transparent plate. As a result, the transparent plate is stained with dust contained in the gas. In order to prevent the gas from inside the device from reaching the transparent plate, it is necessary to either supply a large amount of purge fluid into the tubular member or lengthen the tubular member.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a furnace having a structure capable of suppressing the gas from the furnace from reaching a transparent plate without requiring a large amount of blown gas. It is to provide an inner peep window.

The present invention is a furnace viewing window installed in a furnace, comprising a tubular member having one end attached to the furnace, and a tube attached to the other end of the tubular member for viewing the inside of the furnace. and a transparent plate. The in-furnace viewing window is formed in the tubular member and includes a slit-shaped gas supply hole extending in a direction intersecting the axial direction of the tubular member, and a guide mechanism for guiding the supplied gas to the inside of the furnace.

According to the present invention, the gas supply hole has a slit shape extending in a direction intersecting the axial direction, and the guide mechanism causes the gas supplied into the cylindrical member to counterflow toward the transparent plate. As a result, the gas from the furnace can be prevented from reaching the transparent plate without requiring a large amount of blown gas.

1 is a plan cross-sectional view of an in-furnace peephole according to a first embodiment of the present invention; FIG. 2 is an AA arrow view of the in-furnace peephole shown in FIG. 1. FIG. FIG. 2 is a plan view of a single tubular member that constitutes the in-furnace peephole shown in FIG. 1 ; FIG. 7 is a plan cross-sectional view of an in-furnace peephole according to a second embodiment of the present invention; FIG. 11 is a plan cross-sectional view of an in-furnace peephole according to a third embodiment of the present invention; FIG. 5 is a plan view of a single tubular member for showing a modification of gas supply holes formed in the tubular member; FIG. 10 is a cross-sectional plan view of an in-furnace peephole according to a comparative example; It is a figure which shows the verification method when verifying the effect which can suppress that the gas from the inside of a furnace reaches a transparent plate.

EMBODIMENT OF THE INVENTION Hereinafter, it demonstrates, referring drawings for the form for implementing this invention. The in-furnace peep window of the present invention is installed, for example, in a furnace for incinerating radioactive waste, but the in-furnace peep window of the present invention may be installed in an incinerator for a purpose other than the above furnace. good.

(First embodiment)
A furnace viewing window 101 according to a first embodiment of the present invention will be described with reference to FIGS. The furnace viewing window 101 includes a tubular member 1 attached to the furnace 51 at one end, and a transparent plate 2 attached to the other end of the tubular member 1 for viewing the inside of the furnace 51 . 1 and the like, the end surface of the tubular member 1 and the inner surface of the furnace 51 are flush with each other, but a part of the tubular member 1 may be inserted into the furnace 51.

The cylindrical member 1 of the present embodiment has a rectangular cross-sectional shape perpendicular to the axial direction Z, that is, a rectangular duct. Note that squares are included in rectangles. The cylindrical member 1 has four rectangular plate members 3, 4, 5, 6 that are perpendicular to each other.

Slits 3a, 4a, 5a, and 6a as slit-shaped gas supply holes are formed in the plate members 3, 4, 5, and 6, respectively, extending in a direction crossing the axial direction Z of the cylindrical member 1. there is That is, the slit-shaped gas supply holes are formed in all four circumferential surfaces of the tubular member 1 . The slits 3a to 6a extend in a direction orthogonal to the axial direction Z of the tubular member 1, but may extend in a direction slightly inclined with respect to the direction orthogonal to the axial direction Z. FIG.

The slits 3a to 6a are formed on the side of the transparent plate 2 between the furnace 51 and the transparent plate 2 and near the transparent plate 2. As shown in FIG. The slits 3a to 6a are preferably formed from one end to the other end in the width direction W of each of the plate members 3 to 6 (the width direction W shown in FIG. 1 is the width direction of the plate members 3 and 5). In the case where each surface of the cylindrical member 1 is formed by one plate member 3 to 6 in consideration of ease of manufacture, as in this embodiment, both ends in the width direction W of each plate member 3 to 6 Slits 3a to 6a are formed except for a small portion of . Even if each surface of the cylindrical member 1 is formed of two plate members, the two plate members can be supported by a flange plate 12 and a box member 14, respectively, which will be described later. A continuous slit may be formed in the tubular member 1 over the entire circumference of the tubular member 1 .

A guide plate 7 is arranged inside the tubular member 1 as a guide mechanism for guiding the gas supplied to the inside of the tubular member 1 from the slits 3 a to 6 a to the inside of the furnace 51 .

The guide plate 7 of this embodiment is a truncated quadrangular pyramid guide plate, and is composed of four plate members 8 , 9 , 10 and 11 . The plate members 8 to 11 are arranged at positions facing the slits 3a to 6a, respectively. The angle is not particularly limited as long as the angle allows the gas supplied to the inside of the cylindrical member 1 to be guided to the inside of the furnace 51, but each plate member 8 to 11 (guide plate 7) is a transparent plate In the direction from 2 to the furnace 51, it is preferably inclined inwardly with respect to the inner surface of the opposing tubular member 1 at an angle α greater than 0° and less than or equal to 60°. According to this configuration, it is possible to further suppress the generation of a countercurrent toward the transparent plate 2 . In this embodiment, the angle α is set to 45°.

Negative pressure prevention holes 3b, 4b, 5b, and 6b are provided on the transparent plate 2 side of the tip P of the guide plate 7 inside the furnace 51 and on the transparent plate 2 side of the slits 3a to 6a. ing. The negative pressure prevention holes 3b to 6b are formed in the plate members 3 to 6 forming the cylindrical member 1, respectively. Further, in the present embodiment, each of the negative pressure prevention holes 3b-6b is formed in plurality in each of the plate members 3-6.

A box member 14 for supplying (blowing) gas into the cylindrical member 1 through the slits 3a to 6a and the negative pressure prevention holes 3b to 6b is provided on the outer periphery of the cylindrical member 1 on the side of the transparent plate 2. is installed. The box member 14 is composed of a tubular casing 15 and a plate member 16 fixed to the end surface of the tubular casing 15 . A gas supply port 15a is formed in the tubular casing 15, and gas from a gas supply means (blower, gas compressor, etc., not shown) is introduced into the box member 14 through the gas supply port 15a. After that, the air is supplied into the cylindrical member 1 through the slits 3a to 6a and the negative pressure prevention holes 3b to 6b. The amount of gas supplied into the cylindrical member 1 from each of the slits 3a to 6a is made larger than the amount of gas supplied into the cylindrical member 1 from the corresponding negative pressure prevention holes 3b to 6b. It is preferred that For example, the total opening area of each of the slits 3a-6a is made larger than the total opening area of each of the negative pressure prevention holes 3b-6b.

In this embodiment, one gas supply port 15a is formed in the cylindrical casing 15, and the gas introduced into the box member 14 from the one gas supply port 15a flows through the slits 3a to 6a and the negative pressure prevention holes. The gas is supplied into the cylindrical member 1 from 3b to 6b, but a plurality of gas supply ports 15a may be formed. The gas supplied (blown) into the tubular member 1 to prevent the transparent plate 2 from being soiled is air and an inert gas such as argon gas.

A flange plate 12 is attached to the end surface of the tubular member 1 , and the transparent plate 2 is fixed to the flange plate 12 via a support frame 13 . Note that the method of fixing the transparent plate 2 to the cylindrical member 1 is not limited to this. The material of the transparent plate 2 is heat-resistant glass, for example.

The effect of preventing stains on the transparent plate 2 will be described. In FIG. 1, solid-line arrows in the cylindrical member 1 indicate flows of gas blown into the cylindrical member 1 from the slits 3a to 6a. Strictly speaking, solid-line arrows in the tubular member 1 indicate flows of gas blown into the tubular member 1 through the slits 4a and 6a. In FIG. 1, dotted arrows in the cylindrical member 1 between the guide plate 7 and the transparent plate 2 indicate gas blown into the cylindrical member 1 from the negative pressure prevention holes 3b to 6b. shows the flow of Strictly speaking, the dotted arrows in the cylindrical member 1 indicate the flow of gas blown into the cylindrical member 1 from the negative pressure prevention holes 4b and 6b.

When the gas is blown into the cylindrical member 1 through the slits 3a to 6a, the blown gas is guided to the inside of the furnace 51 by the guide plate 7. As shown in FIG.

Here, if the slits 3a to 6a are not slit-shaped gas supply holes but a plurality of holes formed at predetermined intervals, the pressure between the adjacent holes is higher than that near the holes. A part of the gas blown into the cylindrical member 1 flows countercurrently toward the transparent plate 2 on the opposite side of the furnace 51. It is feared that

However, in the in-furnace viewing window 101 of the present embodiment, the slits 3a to 6a are used as the gas supply holes, so that the gas is blown into the cylindrical member 1 in the form of a so-called "surface". Non-uniformity of gas pressure is suppressed in the part. Furthermore, the gas blown into the cylindrical member 1 through the slits 3a to 6a is guided to the inside of the furnace 51 by the guide plate 7. As shown in FIG. As a result, it is possible to suppress the occurrence of the countercurrent flowing toward the transparent plate 2 . As a result, it is possible to prevent dust-containing gas from inside the furnace 51 from being caught in the countercurrent and reaching the transparent plate 2, thereby preventing the transparent plate 2 from being soiled.

In addition, in the present embodiment, gas is supplied from the negative pressure prevention holes 3b to 6b to the space between the guide plate 7 and the transparent plate 2, so that the space between the tip P of the guide plate 7 and the transparent plate 2 is reduced. It is suppressed that the pressure in the space becomes lower than the space on the furnace 51 side of the tip P of the guide plate 7, that is, the space between the tip P of the guide plate 7 and the transparent plate 2 becomes negative pressure. , the generation of the countercurrent toward the transparent plate 2 can be further suppressed.

The result of verifying the effect of suppressing the gas from the furnace 51 from reaching the transparent plate 2 will be described. FIG. 8 is a diagram showing the verification method.

The above verification was performed using the in-furnace peep window 101 according to the first embodiment shown in FIGS. 1 to 3 and the in-furnace peep window 150 according to the comparative example shown in FIG. The differences between the in-furnace peep window 101 according to the first embodiment and the in-furnace peep window 150 according to the comparative example shown in FIG. 7 are as follows. The in-furnace viewing window 150 according to the comparative example does not have the guide plate 7 (guide mechanism) and the negative pressure prevention holes 3b to 6b. Other configurations of the in-furnace viewing window 150 are the same as those of the in-furnace viewing window 101 .

As shown in FIG. 8, the electric fan 52 is arranged at a position 1.5 m away from the tip of the in-furnace peep window 101 (in-furnace peep window 150), and 0.5 m from the fan 52 toward the in-furnace peep window 101. The water spray means 53 is arranged at the position of . Although not shown in the drawings, one of the four surfaces of the cylindrical member 1 constituting the in-furnace peephole is formed of a transparent acrylic plate to avoid slits, etc., so that it can be easily viewed from the side. I was able to see the inside. The wind from the electric fan 52 simulates the gas from the furnace 51, and the water spray from the water spray means 53 simulates dust contained in the gas.

The conditions of the verification experiment are as follows. The shape of the tubular member 1 constituting each of the in-furnace observation windows 101 and 150 is 100 mm long×150 mm wide×300 mm long (depth). The plate members 3 and 5 of the four surfaces of the tubular member 1, that is, the slits 3a and 5a formed on the long sides have a shape of 4 mm wide×140 mm long. The shape of the plate members 4 and 6, that is, the slits 4a and 6a formed on the short sides is 4 mm wide and 90 mm long.

Further, the number of negative pressure prevention holes 3b, 5b formed in the plate members 3, 5 of the four surfaces of the cylindrical member 1 of the in-furnace viewing window 101 is φ5×6, respectively. Negative pressure prevention holes 4b and 6b formed in the plate members 4 and 6 of the cylindrical member 1 of the in-furnace peep window 101 are φ5×4, respectively. The total opening area of the slits 3a-6a is four times the total opening area of the negative pressure prevention holes 3b-6b.

Further, the flow rate of air blown into the cylindrical member 1 from the gas supply port 15a of each of the in-furnace observation windows 101 and 150 was 30.2 m ³ /h, 55.3 m ³ /h, 69.9 m ³ /h, 77.9 m 3 /h. It was changed in 4 stages of 4 m ³ /h. The wind velocity from the fan 52 to the in-furnace observation windows 101 and 150 was set to 3.7 m/s at the exit of the fan 52 (measured value). The particle size of the spray water sprayed from the tip of the water spray means 53 is 130 μm. The velocity of the spray water at the tip of each in-furnace viewing window 101, 150 is 3.1 m/s (calculated value).

The results of the verification experiment are as follows. First, in the in-furnace viewing window 150 according to the comparative example, in all cases where the flow rate of the air blown into the cylindrical member 1 from the gas supply port 15a was changed in four stages, the water sprayed on the wind of the electric fan 52 entered the cylindrical member 1 and adhered to the transparent plate 2 as water droplets. At the exit of the in-furnace viewing window 150 (the exit of the air blown in from the gas supply port 15a), the air flow seemed to be stable, but as described above, the air flow was blown by the wind of the electric fan 52. The sprayed water adhered to the transparent plate 2 as water droplets. That is, there is a high possibility that the air flow is disturbed inside the cylindrical member 1 .

Even with the in-furnace viewing window 150, adhesion of sprayed water to the transparent plate 2 can be prevented by blowing a large amount of gas into the cylindrical member 1 from the gas supply port 15a through the slit. is assumed.

On the other hand, in the in-furnace viewing window 101 according to the first embodiment of the present invention, the spray water is It did not adhere to the transparent plate 2. It was confirmed that the sprayed water carried by the wind of the electric fan 52 entered the cylindrical member 1, but the sprayed water was blocked by the air flow blown from the supply port 15a in front of the guide plate 7, and the sprayed water was stopped. I didn't go inside. From this verification experiment, it can be seen that the in-furnace viewing window 101 can prevent the transparent plate 2 from being contaminated with dust-containing gas from the inside of the furnace 51 without requiring a large amount of blown gas.

(Second embodiment)
FIG. 4 shows an in-furnace viewing window 102 according to a second embodiment of the present invention. The difference from the in-furnace viewing window 101 of the first embodiment is as follows. Regarding the in-furnace peep window 102 according to the second embodiment, the same members as those of the in-furnace peep window 101 of the first embodiment are denoted by the same reference numerals (the same applies to other embodiments).

In the furnace viewing window 101 of the first embodiment, the negative pressure prevention holes 3b to 6b are formed in the tubular member 1. As shown in FIG. On the other hand, in the in-furnace viewing window 102 of the present embodiment, the guide plate 7 is formed with the negative pressure prevention hole 10a. 4 shows only the negative pressure prevention hole 10a formed in the plate member 10 that constitutes the guide plate 7, the remaining plate members 8, 9, and 11 (see FIG. 4) that constitute the guide plate 7 are shown. 2) is also preferably formed with a negative pressure prevention hole.

According to this configuration, the space between the tip P of the guide plate 7 and the transparent plate 2 is under negative pressure, as in the furnace viewing window 101 of the first embodiment in which the negative pressure prevention hole is provided in the cylindrical member 1. can be prevented from becoming

As described above, the position of the negative pressure prevention hole may be on the side of the transparent plate 2 from the tip P of the guide plate 7 (guide mechanism). Prevention holes 10a may be formed. Like the in-furnace viewing window 101 of the first embodiment, the negative pressure prevention holes 3b to 6b are formed in the tubular member 1, and the gas is supplied to the inside of the tubular member 1 from the negative pressure prevention holes 3b to 6b. This is preferable because it is possible to forcibly suppress the negative pressure in the space between the guide plate 7 and the transparent plate 2 . In addition, since the gas from the gas supply means (blower, gas compressor, etc.) not shown is generally clean, the gas is supplied to the guide plate 7 and the transparent plate 2 through the negative pressure prevention holes 3b to 6b. By blowing the air into the space between , a preliminary effect of cleaning the transparent plate 2 can be obtained, and it is possible to further suppress contamination of the transparent plate 2 with gas containing dust from the inside of the furnace 51 .

(Third embodiment)
FIG. 5 shows an in-furnace viewing window 103 according to a third embodiment of the present invention. The difference from the in-furnace viewing window 101 of the first embodiment is as follows.

The in-furnace viewing window 103 of the present embodiment does not have the guide plate 7 provided in the in-furnace viewing window 101 of the first embodiment. In this embodiment, as the slits 4a and 6a are shown in FIG. 5, the depth of the slits 3a to 6a as gas supply holes is made longer than the slits 3a to 6a in the first embodiment, so that the inside of the furnace 51 is Each of the slits 3a to 6a itself serves as a guide mechanism for guiding gas to the side. That is, in this embodiment, the slit-shaped gas supply hole and the guide mechanism for guiding the gas to the inside of the furnace 51 are integrated.

Specifically, as shown in FIG. 5, for example, a plate member 17 having a predetermined thickness is fixed to all four outer peripheral surfaces of the tubular member 1 in order to increase the thickness of the portion where the transparent plate 2 is adjacent. be. Then, the cylindrical member 1 and the plate member 17 are subjected to co-hole processing to form long slits 3a to 6a. The angle is not particularly limited as long as the angle allows the gas supplied to the inside of the cylindrical member 1 to be guided to the inside of the furnace 51. In the direction, it is preferably inclined inwardly with respect to the inner surface of the tubular member 1 at an angle β of more than 0° and less than or equal to 60°. In this embodiment, the angle β is set to 45°.

As a simpler structure, if the tubular member 1 has a certain thickness, the tubular member 1 can be fixed by fixing the plate member 17 to the outer peripheral surface of the tubular member 1 as in the present embodiment. A slit oblique to the axial direction Z is formed in the tubular member 1 without locally increasing the thickness, and the gas supplied from the slit to the inside of the tubular member 1 is guided to the inside of the furnace 51. You may do so.

However, disposing the guide plate 7 inside the tubular member 1 as in the first embodiment and the second embodiment ensures that the gas supplied to the inside of the tubular member 1 can flow inside the furnace 51 . I can lead you to the side.

In the case of this embodiment, as shown in FIG. 5, the tip of the guide mechanism is the tip P of each of the slits 3a to 6a on the furnace 51 side, and the negative pressure prevention holes 3b to 6b are connected to this guide mechanism. is positioned closer to the transparent plate 2 than the tip of the .

(Modification of slit)
FIG. 6 shows a modification of the slit-shaped gas supply holes. As shown in FIG. 6, instead of elongated rectangular holes such as the slits 3a shown in FIG. The hole 18 may be a slit-shaped gas supply hole.

The embodiments of the present invention have been described above. In addition, it is possible to make various modifications within the scope that a person skilled in the art can imagine.

For example, the tubular member 1 may be a cylindrical member. Similarly, the transparent plate 2 may be circular or the like.

The negative pressure prevention hole provided closer to the transparent plate 2 than the tip of the guide mechanism, which is the inner side of the furnace 51, is not essential.

1: Cylindrical member 2: Transparent plates 3a, 4a, 5a, 6a: Slits (slit-shaped gas supply holes)
3b, 4b, 5b, 6b, 10a: Negative pressure prevention hole 7: Guide plate (guide mechanism)
51: Furnace 101, 102, 103: Furnace peephole

Claims (6)

A furnace peephole installed in a furnace,
a tubular member having one end attached to the furnace;
a transparent plate attached to the other end of the cylindrical member for viewing the inside of the furnace;
with
a slit-shaped gas supply hole formed in the tubular member and extending in a direction crossing the axial direction of the tubular member;
a guide mechanism for guiding the gas supplied to the inside of the cylindrical member from the gas supply hole to the inside of the furnace;
Furnace viewing window. The in-furnace peephole according to claim 1,
An in-furnace peep window further comprising a negative pressure prevention hole provided on the transparent plate side of the tip of the guide mechanism, which is on the inside of the furnace. In the in-furnace peephole according to claim 2,
The negative pressure prevention hole is formed in the cylindrical member,
A furnace viewing window through which gas is supplied to the inside of the cylindrical member from the negative pressure prevention hole. In the furnace viewing window according to any one of claims 1 to 3,
An in-furnace viewing window, wherein the guide mechanism is a guide plate disposed inside the cylindrical member. In the in-furnace peephole according to claim 4,
The furnace observation window, wherein the guide plate is inclined inwardly with respect to the inner surface of the opposing cylindrical member at an angle of more than 0° and 60° or less in the direction from the transparent plate to the furnace. . In the furnace viewing window according to any one of claims 1 to 5,
The cylindrical member has a rectangular cross-sectional shape perpendicular to the axial direction,
An in-furnace observation window, wherein the gas supply holes are formed on all four circumferential surfaces of the cylindrical member.

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