Patent Grant
11708617
The present invention relates to a method for forming a brick lining to construct a hollow approximately cylindrical-shaped sidewall (inner sidewall) of a kiln/furnace, such as a blast furnace, an air heating furnace (hot blast stove), a converter, an electric furnace, a ladle, or a vacuum degassing furnace.
For example, a sidewall of a converter is typically constructed by sequentially arranging a plurality of bricks on an inner surface of a peripheral portion of the converter in a circumferential direction of the peripheral portion to form a tier of bricks, and stacking a plurality of the tiers of bricks along the peripheral portion in an upward-downward direction. Each of the bricks has a key (crown) shape or a similar shape thereto. Specifically, in a state in which the converter is lined with the bricks, each of the bricks has two circumferentially opposed side faces formed to define a tapered shape in a radially inward direction when view in the upward-downward direction. Heretofore, two types of bricks shaped differently in terms of taper angle have been used for lining each of a plurality of tier regions of the inner surface of the peripheral portion each corresponding to a respective one of the tiers of bricks. This is because such two types of differently-shaped bricks can be used in various combinations to cope with any lining even when lining two or more of the tier regions different in terms of pre-lining radius, in one kiln/furnace, so that it is possible to minimize the number of brick shapes, thereby suppressing a manufacturing cost of bricks. This method of combining the two types of bricks shaped differently in terms of the taper angle can also be applied to any of other kilns/furnaces slightly different in terms of inner diameter.
However, the above method requires preliminarily determining a combination (ratio) between the two types of differently-shaped bricks, and selecting one of the two types of differently-shaped bricks such that the selected brick is oriented in a direction more closely perpendicular to the peripheral portion than the other brick, in each circumferential region, thereby leading to a problem that brick lining forming work becomes complicated and requires time and effort.
With a view to solving this problem, there is a method which comprises preliminarily arranging (packing) the two types of differently-shaped bricks in a pallet in a given order. Although this method can facilitate kiln/furnace lining work, there is a problem that it takes time and effort for packing of the bricks. Moreover, during the brick lining forming work, it is necessary to check the bricks for shape one-by-one, although the bricks are arranged in the given order.
It is also conceivable to use a plurality of identically-shaped bricks in each of the tier regions. In this case, efficiency of the brick lining forming work is improved. However, it is necessary to prepare many kinds of differently-shaped bricks, for each of two or more of the tier regions different in terms of the pre-lining radius, or for each of plural types of kilns/furnaces different in terms of the pre-lining radius, thereby leading to a problem that it takes a lot of time for exchange work of molding dies (a metal frame and a vertical liner) during molding of the bricks.
[Parent Document]
A technical problem to be solved by the present invention is to provide a method for forming a brick lining to construct a sidewall of a kiln/furnace, while improving efficiency of brick lining forming work without causing any increase in manufacturing cost of bricks to be used.
The present invention provides a brick lining forming method having features described in the following sections 1 to 4.
(1) A brick lining forming method comprising stacking a plurality of tiers of bricks, respectively, on a plurality of tier regions of an inner surface of a hollow approximately cylindrical-shaped peripheral portion of a kiln or furnace to construct a side wall of the kiln or furnace, wherein two or more of the plurality of tier regions are different in terms of pre-lining radius of the kiln or furnace, wherein, assuming that, on a basis of a posture of each of the bricks in a state in which the kiln or furnace is lined with the bricks: two circumferentially opposed side faces of the brick are defined as circumferential side faces; an angle between the circumferential side faces is defined as a taper angle; and a circumferential dimension of a back face of the brick is defined as a back face width, only bricks identical in terms of the taper angle and height dimension are used, except for an adjustment brick, in each of the two or more tier regions different in terms of the pre-lining radius, wherein bricks identical in terms of the taper angle, the height dimension and length dimension, and different in terms of the back face width, are used in at least a part of each of the two or more tier regions.
(2) The method as described in the section 1, wherein only bricks identical in terms of the taper angle and the height dimension are used, except for an adjustment brick, in each of the remaining tier regions identical in terms of the pre-lining radius, wherein bricks identical in terms of the taper angle, the height dimension, the length dimension and the back face width, are used in at least a part of each of the remaining tier regions.
(3) The method as described in the section 1 or 2, 3, wherein each of the bricks is molded while pressure is uniaxially applied to a mixture in a manner allowing a pressure-receiving part of the mixture to be formed as at least one of the circumferential side faces.
(4) The method as described in any one of the sections 1 to 3, wherein the kiln or furnace is a converter.
In each of the two or more tier regions different in terms of the pre-lining radius, by using bricks identical in terms of the taper angle, the height dimension and the length dimension, it becomes possible to manufacture bricks shaped differently (in terms of back face width), while suppressing a manufacturing cost (molding cost) of the bricks. Specifically, during manufacturing of the bricks, each of the bricks is molded while pressure is applied to a mixture in a direction allowing a pressure-receiving part of the mixture to be formed as at least one of the circumferential side faces. Thus, bricks different in terms of the back face width can be molded by adjusting the amount of mixture to be used, without exchanging any liners used as upper and lower pressure-applying surfaces, so that it is possible to suppress the manufacturing cost.
Further, during lining to construct the sidewall of the kiln or furnace, the lining can be formed by continuously using basically identically-shaped bricks, so that it is possible to significantly improve efficiency of brick lining forming work. Additionally, there is no need to preliminarily arrange bricks in a given order, so that there is no concern about an increase in burden of packing work.
As shown in
In the peripheral portion of the sidewall of this converter, a straight barrel part whose inner surface consists of 3rd to 13th tier regions corresponding to 3rd to 13th tiers of bricks is constant in terms of pre-lining radius, whereas a remaining part whose inner surface consists of 1st, 2nd and 14th to 18th tier regions corresponding to 1st, 2nd and 14th to 18th tiers of bricks varies in terms of the pre-lining radius. Here, the term “pre-lining radius” means a distance between a central axis of the converter and the inner surface of the permanent refractory material.
As mentioned above, the three types of bricks 3A to 3C are identical in terms of the taper angle α, the height dimension H and the length dimension L. Thus, during manufacturing of the bricks, each of the bricks is molded while pressure is uniaxially applied to a mixture in a manner allowing a pressure-receiving part of the mixture to be formed as one of the circumferential side faces 34, as shown in
As just described, the bricks to be used in the respective tiers are molded to be identical in terms of the taper angle α, the height dimension H and the length dimension L even though the corresponding tier regions are different in terms of the pre-lining radius, so that it is possible to form these bricks into desired shapes, using a common set of a metal frame and a vertical liner, as mentioned above. Thus, there is no need for exchange work of molding dies (the metal frame and the vertical liner) during molding, and there is no concern about an increase in molding cost (manufacturing cost) even if the number of brick shapes increases. Particularly, in the converter, upper and lower parts of the peripheral portion is inwardly inclined (narrowed) as shown in
Further, in each of the tier regions identical in terms of the pre-lining radius, i.e., the 3rd to 13th tier regions, identically-shaped bricks can be used, so that it is possible to improve efficiency of the lining work without causing any increase in cost of packing work
In
Further, only bricks identical in terms of the taper angle and the height dimension are used, except for an adjustment brick, in each of the remaining tier regions identical in terms of the pre-lining radius, wherein bricks identical in terms of the taper angle, the height dimension, the length dimension and the back face width are used in at least a part of each of the remaining tier regions. With regard to the “at least a part” configuration in this case, the above rate is also applied.
In the case where two types of bricks different in terms of the length dimension are used in each tier region (in the above “at least part” configuration), the number of brick shapes per tier in the conventional brick lining forming method is four, whereas the number of brick shapes per tier in the present invention is only two. Thus, it is possible to obtain an advantageous effect of reduction in workload of molding work, workload of the packing work and workload of the lining work.
Further,
As mentioned above, as bricks for use in the present invention, plural types of bricks shaped differently in terms of the inner face width and the back face width can be molded by uniaxially applying pressure to a mixture in manner allowing a pressure-receiving part of the mixture to be formed as at least one of the circumferential side faces, using one set of the metal frame and the vertical liner, while adjusting the amount of the mixture to be put inside the metal frame. Here, manufacturing steps other than molding, i.e., kneading, drying, heat treatment and the like, can be conducted in the same manner as before. Further, in the above embodiment, a key shape and a similar shape thereto are shown as brick shape. Alternatively, an arch shape and a wedge shape may be used.
Next, an inventive example in which the brick lining forming method of the present invention is applied to an actual converter will be described.
In a peripheral portion of this converter, the 7th to 36th tier regions form an inner surface of a straight barrel part having a pre-lining radius of 4000 mm, and a part thereof below the 6th tier regions is reduced in the pre-lining radius. A brick having a length dimension of 720 mm was used in the 1st to 5th tier regions. Further, a brick having a length dimension of 810 mm was used in the 6th to 17th tier regions, and a brick having a length dimension of 900 mm was used in the 18th to 36th tier regions. Further, all bricks had a taper angle of 2.25°, and a height dimension of 150 mm. However, the back face width of the brick in the straight barrel part (the 7th to 36th tier regions) was set to 157 mm, and the back face width of the brick in the tier region having a relatively small pre-lining radius was set to be less than that of the brick in the straight barrel part.
Table 1 shows a brick shape, a packing method, a molding method and workloads of various works, in the inventive example, in such a manner as to compare them with those in a comparative example. The comparative example is a conventional brick lining forming method in which two types of bricks shaped differently in terms of the taper angle are used in each tier region. Further, each of the bricks used in the inventive and comparative examples was molded under the condition that a pressure-receiving part (a contact part with a vertical liner) of a mixture is formed as the circumferential side faces.
With reference to Table 1, the inventive and comparative examples will be described in detail below. It should be noted here that each of the workloads of various works is expressed as an index calculated on the assumption that a respective one of the workloads of various works in the comparative example is 100.
[1st to 5th Tiers]
In the inventive example, total five types of differently-shaped bricks were used, wherein the number of brick shapes was one in each tier, but each tier was different in terms of the back face width and the inner face width. As the packing method, only identically-shaped bricks were packed in one pallet. Further, during molding, the amount of mixture to be put in a metal frame was changed to change the width dimension. Therefore, only a set of one type of metal frame and one type of vertical liner was used for all bricks.
On the other hand, in the comparative example, two types of bricks shaped differently only in terms of the taper angle were used. As the packing method, the two types of differently-shaped bricks were arranged and packed in one pallet in a given order according to which the bricks are laid in a converter. Further, during molding, two types of vertical liners were used to change the taper angle.
With regard to the total number of brick shapes, in the inventive example, it was five because each of the 1st to 5th tiers was different in terms of the width dimension. On the other hand, in the comparative example, it was two, wherein the two brick shapes were different in terms of the taper angle.
In a brick molding process, in the inventive example, bricks can be molded using one type of vertical liner, because the bricks are identical in terms of the length dimension and the taper angle, whereas the comparative example requires using two types of vertical liners to change the taper angle, so that it is necessary to additionally perform vertical liner exchange work, resulting in an increase in workload of the molding work.
With regard to the workload of the packing work, in the inventive example, it is only necessary to pack identically-shaped bricks in one pallet, whereas in the comparative example, it is necessary to arrange two types of differently-shaped bricks in one pallet in a given order, resulting in a significant increase in workload of the packing work.
With regard to the workload of the lining work, in the comparative example, when the bricks arranged in the given order are taken out from the pallet, it is necessary to check the bricks for shape one-by-one, so that efficiency of the lining work was inferior to that of the inventive example.
[6th and 7th Tiers]
In the inventive example, total two types of differently-shaped bricks were used, wherein the number of brick shapes is one in each tier, but each of the two tiers was different in terms of the back face width and the inner face width. As the packing method, only identically-shaped bricks are packed in one pallet. These bricks are different from the bricks in the 1st to 5th tiers in terms of the length dimension. Thus, during molding, a set of a metal frame and a vertical liner having a length dimension greater than that of the set for the bricks in the 1st to 5th tiers was used. Here, the width dimension was changed by changing the amount of mixture to be put in a metal frame. Therefore, only a set of one type of metal frame and one type of vertical liner was used for all bricks.
On the other hand, in the comparative example, two types of bricks shaped differently only in terms of the taper angle were used. As the packing method, the two types of differently-shaped bricks were arranged and packed in one pallet in a given order according to which the bricks are laid in a converter. Further, during molding, a set of a metal frame and a vertical liner having a length dimension different from that of the set for the bricks in the 1st to 5th tiers was used, and, differently from the inventive example, two types of vertical liners were used to change the taper angle.
With regard to the total number of brick shapes, in the inventive example, it was two because each of the 6th and 7th tiers was different in terms of the width dimension. On the other hand, in the comparative example, it was two, wherein the two brick shapes were different in terms of the taper angle.
In a brick molding process, the inventive example requires work for exchanging the set of the metal frame and the vertical liner, because the bricks are different from those in the 1st to 5th tiers in terms of the length dimension, whereas the comparative example further requires using two types of vertical liners, so that it is necessary to additionally perform vertical liner exchange work, resulting in an increase in workload of the molding work.
With regard to the workload of the packing work, in the inventive example, it is only necessary to pack identically-shaped bricks in one pallet, whereas, in the comparative example, it is necessary to arrange two types of differently-shaped bricks in one pallet in a given order, resulting in an increase in workload of the packing work.
With regard to the workload of the lining work, in the comparative example, when the bricks arranged in the given order are taken out from the pallet, it is necessary to check the bricks for shape one-by-one, so that efficiency of the lining work was inferior to that of the inventive example.
[8th and 17th Tiers]
In the inventive example, the same brick as that in the 7th tier was used, wherein, as the packing method, identically-shaped bricks were packed in one pallet, and a set of one type of metal frame and one type of vertical liner was used for all bricks.
On the other hand, in the comparative example, two types of bricks shaped differently in terms of the taper angle were used as with the bricks in the 7th tier. As the packing method, the two types of differently-shaped bricks were arranged and packed in one pallet in a given order according to which the bricks are laid in a converter. Further, during molding, two types of vertical liners were used to change the taper angle.
In a brick molding process, both the inventive example and the comparative example do not require metal frame exchange work, because the same brick as that in the 7th tier can be used in each of the examples. However, the comparative example requires using two types of vertical liners to change the taper angle, so that it is necessary to additionally perform vertical liner exchange work, resulting in an increase in workload of the molding work.
With regard to the workload of the packing work, in the inventive example, it is only necessary to pack identically-shaped bricks in one pallet, whereas, in the comparative example, it is necessary to arrange two types of differently-shaped bricks in one pallet in a given order, resulting in a significant increase in workload of the packing work.
With regard to the workload of the lining work, in the comparative example, when the bricks arranged in the given order are taken out from the pallet, it is necessary to check the bricks for shape one-by-one, so that efficiency of the lining work was inferior to that of the inventive example.
[18th to 36th Tiers]
In the inventive example, identically-shaped bricks were used, wherein, as the packing method, the identically-shaped bricks were packed in one pallet. However, the bricks are different from those in the 7th to 17th tiers in terms of the length dimension. Thus, during molding, a set of a metal frame and a vertical liner having a length dimension greater than that of the set for the bricks in the 7st to 17th tiers was used,
On the other hand, in the comparative example, two types of bricks shaped differently in terms of the taper angle were used. As the packing method, the two types of differently-shaped bricks were arranged and packed in one pallet in a given order according to which the bricks are laid in a converter. Further, during molding, a set of a metal frame and a vertical liner having a length dimension greater than that of the set for the bricks in the 7th to 17th tiers was used, and two types of vertical liners were used to mold bricks different in terms of the taper angle.
In a brick molding process, the inventive example requires work for exchanging the set of the metal frame and the vertical liner used for the bricks in the 7th to 17th tiers for a set of a metal frame and a vertical liner having a longer length dimension. On the other hand, the comparative example further requires work for exchanging the two types of vertical liners to mold two types of bricks shaped differently in terms of the taper angle, so that the comparative example needs a larger workload of the molding work.
With regard to the workload of the packing work, in the inventive example, it is only necessary to pack identically-shaped bricks in one pallet, whereas, in the comparative example, it is necessary to arrange two types of differently-shaped bricks in one pallet in a given order, resulting in an increase in workload of the packing work.
With regard to the workload of the lining work, in the comparative example, when the bricks arranged in the given order are taken out from the pallet, it is necessary to check the bricks for shape one-by-one, so that efficiency of the lining work was inferior to that of the inventive example.
The inventive and comparative examples have been described without making mention of the use of an adjustment brick. When bricks are laid along the circumference of the shell (inner periphery of the permanent refractory material), the shape of a brick to be lastly laid is likely not to be constant due to fluctuation of the size of a finally formed gap. As used in this specification, the term “adjustment brick” means a brick which is produced by measuring the size of the gap and processing a brick material in conformity to the measured size, and is to be driven into the gap so as to fill the gap and prevent the laid bricks from being untightened in a circumferential direction. In the above inventive and comparative examples, the adjustment brick is appropriately used. However, a workload caused by using the adjustment brick is approximately the same between the inventive and comparative examples. Thus, the use of the adjustment brick does not exert any influence on the aforementioned comparison between the workloads of the inventive and comparative examples.
In the above inventive example, the 1st to 36th tier regions are lined by the brick lining forming method of the present invention, and the 37th to n-th tiers are lined by the conventional brick lining forming method. It is to be understood that the inventive example falls within the scope of the present invention as defined by the appended claims, as long as the 1st to 36th tier regions are lined by the brick lining forming method of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-234403 | Dec 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/042597 | 11/19/2018 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/111683 | 6/13/2019 | WO | A |
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| 10281212 | Yanagi | May 2019 | B2 |
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| 3342078 | Mar 1986 | DE |
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| Entry |
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| International Search Report dated Dec. 25, 2018, for PCT/JP2018/042597, filed Nov. 19, 2018. |
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| International Preliminary Report on Patentability dated Jun. 9, 2020, with Written Opinion, for PCT/JP2018/042597, filed Nov. 19, 2018 (English translation). |
| Number | Date | Country | |
|---|---|---|---|
| 20210140002 A1 | May 2021 | US |
