JP7629293B2 - Furnace inner wall support structure - Google Patents

Description

This relates to a support structure for supporting an inner wall of an incinerator or melting furnace that has an inner wall made of multiple firebricks laid inside a metal outer wall, so that the inner wall does not come off from the outer wall.

In incinerators and melting furnaces, a heat-resistant inner wall is often provided by laying (assembling while fixing) a large number of firebricks on the inside of a metal outer wall. However, in such incinerator and melting furnace walls, a defect occurs in which the firebricks protrude inward due to thermal expansion and the like as a result of continued use. Therefore, in order to eliminate such a defect, as shown in Patent Document 1, a support structure for the furnace inner wall is known in which support fittings extending continuously horizontally on the inner surface of the outer wall are welded vertically at specified intervals, and one tip of an anchor (tension fitting) formed in an inverted U shape is engaged with the mounting fitting, and the other tip of the anchor is engaged with an insertion hole drilled in the firebrick (anchor brick).

However, because the outer wall of a boiler-type furnace is made up of water-cooled pipes and metal plates, when constructing the furnace using the furnace inner wall support device of Patent Document 1, firebricks (anchor bricks) with insertion holes cannot be installed at a fixed distance from the outer wall, so multiple types of tension fittings must be prepared to match the distance between the support fittings welded to the outer wall and the anchor bricks, making the work cumbersome. Also, because the outer wall of a normal furnace deforms due to heat when used, even when repairing using the furnace inner wall support device of Patent Document 1, multiple types of tension fittings must be prepared, making the work cumbersome.

As mentioned above, when engaging a metal exterior wall and an anchor brick with a tension fitting, in order to deal with the situation in which there is variation in the distance between the support fitting welded to the exterior wall and the anchor brick, a tension fitting has been developed in which two L-shaped fittings, one of which has a screw thread at the tip, are connected by a cylindrical socket with a screw groove, making it possible to adjust the length, as in Patent Document 2.

Japanese Unexamined Patent Publication No. 2-192590 Japanese Patent Application Publication No. 6-11269

The tension fittings in Patent Document 2 can adjust the length to accommodate variations in the distance between the support fittings welded to the exterior wall and the anchor bricks, but are time-consuming to manufacture, which increases the cost of construction and repair. Furthermore, the length of the tension fittings in Patent Document 2 is adjusted using a screw mechanism, and a certain length is required, so they cannot be used in the construction or repair of furnaces in which there is no insulating layer between the exterior wall and the firebricks and the distance between them is close, such as in boiler-type furnaces in which the exterior wall is cooled by an integrated water-cooling pipe.

The object of the present invention is to provide a furnace inner wall support structure that solves the problems with the above-mentioned conventional furnace inner wall support structures and support fittings, can be used without problems even when constructing (constructing or repairing) a furnace where the distance between the outer wall and the anchor bricks is not constant, or when constructing a furnace such as a boiler-type furnace where the distance between the outer wall and the anchor bricks is short, can perform furnace construction work cheaply and easily, and can provide high support strength.

Among the present invention, the invention described in claim 1 is a support structure for supporting the inner wall of a furnace having an inner wall formed by laying a plurality of firebricks inside a metal outer wall, so that the inner wall does not detach from the outer wall, the support structure comprising a cylindrical body attached to the inner surface of the outer wall, a firebrick laid inside the outer wall near the cylindrical body having an insertion hole, the bent portion of a first L-shaped metal fitting (tension metal fitting) inserted into the cylindrical body and the bent portion of a second L-shaped metal fitting (tension metal fitting) inserted into the insertion hole in the firebrick, the first L-shaped metal fitting and second L-shaped metal fitting being fixedly attached, and the firebrick having the insertion hole formed therein has a recessed portion into which the portion of the second L-shaped metal fitting other than the bent portion is fitted, the recessed portion being formed in a substantially triangular shape with the insertion hole as its apex.

The invention as set forth in claim 2 is the invention as set forth in claim 1 , characterized in that the periphery of the recessed portion is tapered.

The support structure for the furnace inner wall described in claim 1 connects the outer wall and the inner wall by fixing a first L-shaped metal fitting (tension metal fitting) engaged with the cylindrical body of the outer wall and a second L-shaped metal fitting (tension metal fitting) engaged with the insertion hole of the anchor brick. Therefore, it can be used without problems even when constructing a furnace where the distance between the outer wall and the anchor brick is not constant, or when constructing a furnace such as a boiler where the distance between the outer wall and the anchor brick is close, and it can be constructed cheaply and easily, and can exhibit high support strength.

In the support structure for furnace inner walls described in claim 1 , the recessed portion for fitting the portion other than the bent portion of the second L-shaped metal fitting is formed in a triangular shape with the insertion hole as the apex, and this allows for a large degree of layout freedom when fitting the first L-shaped metal fitting with its bent portion inserted into the cylindrical body of the outer wall and the second L-shaped metal fitting with its bent portion inserted into the insertion hole of the anchor brick into the recessed portion. In other words, even if the relative position of the anchor brick to the cylindrical body of the outer wall is slightly misaligned, the first L-shaped metal fitting and the second L-shaped metal fitting can be stored in the recessed portion. Therefore, the support structure for furnace inner walls described in claim 2 makes construction and maintenance of the furnace very easy.

The support structure for the furnace inner wall described in claim 2 has a tapered periphery of the concave portion, so that during construction and maintenance of the furnace, the periphery (ridge) of the concave portion is less likely to be damaged or cracked due to collision with the L-shaped metal fittings.

FIG. 1 is an explanatory diagram showing the inside of a furnace that employs a support structure for the furnace inner wall (a schematic diagram showing a part of the furnace viewed from the inside). 1 is a horizontal cross section (cross section taken along line AA in FIG. 1) of a furnace that employs a support structure for the furnace inner wall. This is a vertical cross section (cross section taken along line B-B in Figure 2) of a furnace that employs a support structure for the furnace inner wall. 1A, 1B, and 1C are explanatory diagrams showing firebricks (anchor bricks) used in the support structure of the furnace inner wall (a is a front view, b is a plan view, and c is a left side view). 1A and 1B are explanatory diagrams showing metal fittings (tension fittings) used in the support structure of the furnace inner wall (a is a front view, and b is a plan view). 1A and 1B are explanatory diagrams (plan views) showing how metal fittings are stored in the concave portions of the anchor bricks (a shows the case where the distance between the cylindrical body and the insertion hole is short, and b shows the case where the distance between the cylindrical body and the insertion hole is long).

Below, one embodiment of the furnace inner wall support structure according to the present invention will be described in detail with reference to the drawings.

<Support structure of furnace inner wall>
1 to 3 show an example in which the support structure for the furnace inner wall according to the present invention is applied to a furnace (incinerator). The boiler-type incinerator 1 is formed in a hollow rectangular prism shape, and the outer periphery is covered by a metal (steel) outer wall 2. The outer wall 2 has a shape in which a number of cylindrical water pipes (cooling water pipes) C, C... are arranged vertically and connected with plates. In addition, inside the outer wall 2, a number of refractory bricks 3, 3... formed in a rectangular parallelepiped shape are laid (assembled and fixed with mortar) to form a cylindrical shape of a predetermined thickness, forming an inner wall 4 of a certain width. Furthermore, between the outer wall 2 and the inner wall 4, the inner wall 4 is fixed to the outer wall 2 with mortar.

The incinerator 1 has an inner wall support structure S on its wall surface, which is made up of the outer wall 2 and inner wall 4. The support structure S is made up of cylindrical bodies 5, 5... fixed in a scattered pattern to the inner surface of the outer wall 2, anchor bricks 3a, 3a... (fireproof bricks shown with diagonal lines in Figure 1) located near the cylindrical bodies 5, 5..., and L-shaped metal fittings 6, 6... that function as tension fittings.

The cylindrical body 5 is formed into a cylindrical shape with a specified inner diameter (φ16 mm) and a specified length (40 mm) from a metal plate (steel plate) of a specified thickness (2.0 mm). The cylindrical body 5 is fixed (welded) in a scattered manner with its longitudinal direction vertical to the inner surface (outwardly bulging portion) of the outer wall 2, which is made of steel and connects the cylindrical water pipes C, C... with plate material.

Then, on the inside of the exterior wall 2 adjacent to these cylindrical bodies 5, 5..., anchor bricks 3a, 3a... with processed surfaces are arranged. Figure 4 shows the anchor brick 3a, which, like the other firebricks 3, 3..., is made of firebrick material (alumina-chromia material) and is formed into a rectangular parallelepiped shape with a given size (length x width x height = 230 mm x 180 mm x 98 mm).

The top surface of the anchor brick 3a is provided with a cylindrical insertion hole 11 with a specified inner diameter (φ16.0 mm) for inserting the bent portion of the L-shaped metal fitting 6. Furthermore, the top surface of the anchor brick 3a is formed with a recess 12 of a roughly isosceles triangle shape with the insertion hole 11 as its apex, and the two sides forming the recess form an angle of approximately 90° (θ in FIG. 4(b)). The bottom surface of the recess 12 is flat, and is arranged parallel to the surface other than the recess 12 at a specified distance (16.0 mm).

In addition, a tapered surface 13 is formed in a band shape of a certain width (the same width as the inner diameter of the insertion hole 11) around the recessed portion 12 of the anchor brick 3a, and the tapered surface 13 is inclined at 45° with respect to the surface. Furthermore, the tapered surface 13 covers the periphery of the base end of the insertion hole 11 in an arc shape.

The anchor bricks 3a, 3a... as described above are arranged adjacent to the cylindrical bodies 5, 5... that are arranged (welded) in a scattered manner on the inner surface of the exterior wall 2. The insertion holes 11 of the anchor bricks 3a, 3a... and the cylindrical bodies 5 welded to the exterior wall 2 are connected using two L-shaped metal fittings (tension fittings) 6, 6. Figure 5 shows the L-shaped metal fitting 6, which is formed by bending a round metal (steel) bar with a specified diameter (φ12 mm) at a right angle (the length of the bent portion 6a of the L-shaped metal fitting 6 is 40 mm, and the length of the horizontal base portion 6b is 80 mm).

At the installation portion of the anchor bricks 3a, 3a... on the inside of the exterior wall 2, as shown in Fig. 2, one L-shaped metal fitting 6 has its bent portion 6a inserted into the cylindrical body 5 welded to the inner surface of the exterior wall 2, and its base portion 6b is placed on the bottom surface of the concave portion 12 of the anchor brick 3a. Also, another L-shaped metal fitting 6 has its bent portion 6a inserted into the insertion hole 11 of the anchor brick 3a, and its base portion 6b is placed on the bottom surface of the concave portion 12 of the anchor brick 3a. The base portions 6b, 6b of these two L-shaped metal fittings 6, 6 are welded together, and the two connecting metal fittings 6, 6 are integrated to connect the cylindrical body 5 welded to the inner surface of the exterior wall 2 and the anchor brick 3a.

<Effect of the support structure of the furnace inner wall>
As described above, the support structure S for the furnace inner wall is such that the cylindrical bodies 5, 5... are attached to the inner surface of the outer wall 2, insertion holes 11 are drilled in the anchor bricks 3a, 3a... laid inside the outer wall 2 near the cylindrical bodies 5, the bent portion of the first L-shaped metal fitting 6 is inserted into the cylindrical body 5, the bent portion of the second L-shaped metal fitting 6 is inserted into the insertion hole 11 of the anchor brick 3a, and the first L-shaped metal fitting 6 and the second L-shaped metal fitting 6 are welded together. Therefore, such a support structure S for the furnace inner wall can be used without problems even when constructing a furnace in which the distance between the outer wall and the anchor bricks is not constant or when constructing a furnace such as a boiler in which the distance between the outer wall and the anchor bricks is close, and it allows furnace construction work to be performed cheaply and easily, while also exhibiting high support strength. In addition, because the incinerator 1 is a boiler-type furnace, if welding is performed directly to the outer wall 2 during construction or repair, a water pressure test is required in a state where the outer wall 2 can be seen before the firebricks 3, 3... are assembled. However, as described above, when construction or repair is performed using the support structure S of the furnace inner wall, the L-shaped metal fittings 6, 6... are not welded to the outer wall 2, so there is no need to perform a water pressure test after welding, and the work can be carried out efficiently in a short amount of time.

In addition, the support structure S for the furnace inner wall has a recess 12 for fitting the part other than the bent part of the L-shaped metal fitting 6 in the anchor brick 3a with the insertion hole 11 drilled therein, which is formed in a substantially triangular shape with the insertion hole 11 as the apex. This allows for a large degree of freedom in the layout when fitting (storing) the first L-shaped metal fitting 6 with the bent part 6a inserted into the cylindrical body 5 of the outer wall 2 and the second L-shaped metal fitting 6 with the bent part 6a inserted into the insertion hole 11 of the anchor brick 3a in the recess 12. That is, as shown in FIG. 6(b), even if the relative position (left-right position) of the anchor brick 3a to the cylindrical body 5 of the outer wall 2 is shifted by about 1/3 of the length of the anchor brick 3a in the vertical direction (up-down direction in FIG. 4(b)), the first L-shaped metal fitting 6 and the second L-shaped metal fitting 6 can be stored in the recess 12. Therefore, the support structure S for the furnace inner wall makes it very easy to install and maintain the furnace.

Furthermore, because the support structure S for the furnace inner wall has a tapered periphery of the recessed portion 12, it is unlikely that the periphery (ridge) of the recessed portion 12 will be damaged or cracked due to a collision with the L-shaped metal fitting 6 during construction or maintenance of the furnace.

<Example of modification of furnace inner wall support structure>
The support structure of the furnace inner wall according to the present invention is not limited to the above-mentioned embodiment, and the materials, shapes, sizes, and other configurations of the outer wall, firebricks (anchor bricks), cylindrical bodies, and L-shaped metal fittings (tension metal fittings) can be appropriately changed as needed without departing from the spirit of the present invention. Furthermore, the type and structure of the furnace that employs the support structure of the furnace inner wall according to the present invention are not limited to the above-mentioned embodiment, and can be appropriately changed as needed.

For example, the support structure for the furnace inner wall according to the present invention is not limited to the above embodiment in which a first L-shaped metal fitting with a bent portion inserted into a cylindrical body and a second L-shaped metal fitting with a bent portion inserted into an insertion hole in a firebrick are welded together, but can also be modified to a structure in which a first L-shaped metal fitting with a bent portion inserted into a cylindrical body and a second L-shaped metal fitting with a bent portion inserted into an insertion hole in a firebrick are screwed together using bolts or the like.

In addition, the support structure for the furnace inner wall according to the present invention is not limited to a triangular recess with a 90° apex angle (with the insertion hole as the apex) for fitting the parts other than the bent parts of the L-shaped metal fittings, as in the above embodiment, and the shape of the recess can be changed as necessary. By making the shape of the recess a triangle with an apex angle (with the insertion hole as the apex) of 45° to 135°, it is possible to maintain a large degree of freedom in the layout when fitting the first L-shaped metal fitting and the second L-shaped metal fitting into the recess.

Furthermore, the support structure of the furnace inner wall according to the present invention is not limited to the above embodiment in which one anchor brick is connected to only one cylindrical body fixed to the outer wall (by two L-shaped metal fittings), but can be changed to one in which one anchor brick is connected to two or more cylindrical bodies fixed to the outer wall (by three or more L-shaped metal fittings) (i.e., one in which there are two first L-shaped metal fittings), etc. In addition, the support structure of the furnace inner wall according to the present invention is not limited to the above embodiment in which a single second L-shaped metal fitting is engaged with a single insertion hole drilled in the anchor brick, but can be changed to one in which two or more insertion holes are drilled in the anchor brick and two or more second L-shaped metal fittings are engaged with the respective insertion holes, etc.

Furthermore, the support structure for the furnace inner wall according to the present invention is not limited to the cylindrical body welded to the outer wall being cylindrical as in the above embodiment, but can be changed to one in which the cylindrical body is a rectangular prism such as a square prism or an octagonal prism, or an elliptical prism, etc.

On the other hand, the furnace in which the furnace inner wall support structure of the present invention is adopted is not limited to one in which the inner wall is formed by assembling rectangular refractory bricks as in the above embodiment, but may be one in which the inner wall is formed by assembling refractory bricks whose inner and outer surfaces are curved to match the curved shape of the outer wall.

Furthermore, the furnace in which the furnace inner wall support structure according to the present invention is adopted is not limited to the above embodiment in which the inner wall is made of refractory bricks made of alumina-chromia material and the outer and inner walls are fixed with mortar, and the material of the refractory bricks and the material filled between the outer and inner walls can be changed as necessary.

The furnace inner wall support structure of the present invention has the excellent effects described above, and can therefore be suitably used as a support structure for supporting the inner wall made of firebricks so that it does not detach from the metal outer wall in various furnaces such as incinerators and melting furnaces.

S: Support structure for furnace inner wall 1: Incinerator 2: Outer wall 3: Firebrick 3a: Anchor brick 4: Inner wall 5: Cylindrical body 6: L-shaped metal fitting (tension metal fitting)
11: Insertion hole 12: Concave portion 13: Tapered surface

Claims (2)

A support structure for supporting an inner wall of a furnace having an inner wall formed by laying a plurality of refractory bricks inside a metal outer wall so that the inner wall does not come off from the outer wall,
A cylindrical body is attached to the inner surface of the outer wall,
An insertion hole is drilled in a firebrick laid on the inside of the outer wall near the cylindrical body,
a bent portion of the first L-shaped metal fitting is inserted into the cylindrical body, a bent portion of the second L-shaped metal fitting is inserted into an insertion hole of the firebrick, and the first L-shaped metal fitting and the second L-shaped metal fitting are fixed to each other,
The refractory brick having the insertion hole is
a recessed portion into which the portion other than the bent portion of the second L-shaped metal fitting is fitted is formed in a substantially triangular shape with the insertion hole as a vertex. 2. The support structure for a furnace inner wall according to claim 1 , wherein the peripheral edge of said recessed portion is tapered.

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