JP3732084B2 - Plating pot for hot dip galvanizing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lining material lined in a plating pot of a hot dipping equipment.
[0002]
[Prior art]
In general, in a hot dip galvanizing facility, a steel strip annealed in a continuous annealing furnace is immersed in a hot dip zinc bath of a plating pot provided in a plating facility disposed on the outlet side of the continuous annealing furnace, Plating is performed by attaching molten zinc to the surface. FIG. 6 is a longitudinal sectional view of a conventional plating pot. The plating pot 21 and a continuous annealing furnace (not shown) are connected via a snout 5, and the steel strip 6 annealed in the continuous annealing furnace enters the plating pot 21 via the snout 5 and is a sink roll. After being turned at 4, it is pulled up onto the plating pot 21, during which galvanization is performed. The hot dip zinc 7 in the hot dip galvanizing pot 21 is maintained at a constant temperature. The plating pot 21 has a structure in which a heat-insulating brick 9 is applied to the iron shell 3 so as to withstand the molten zinc temperature, and a refractory brick 8 is lined as a refractory material thereon.
[0003]
[Problems to be solved by the invention]
Thus, in the plating pot 21, the refractory brick 8 is lined so as to withstand the temperature of the molten zinc 7, but the refractory brick 8 has the following problems.
First, when the plating pot 21 is used over a long period of time, zinc erodes from the mortar between the refractory bricks 8 and 8. Due to this erosion, there was a problem that the heat insulating brick 9 having low heat resistance cracked. In addition, the erosion of the molten zinc 7 causes a problem that the refractory brick 8 having a specific gravity lower than that of the zinc floats particularly at the bottom of the plating pot.
[0004]
Furthermore, the work of lining the refractory brick 8 while applying mortar is not easy for anyone. Since the size of the brick is fixed, the dimensions will gradually become unmatched unless the brick is lined while mortar is applied to an appropriate thickness. Therefore, this work requires special techniques by craftsmen, but the number of craftsmen is decreasing year by year. Of course, the construction took a long time. In addition, it takes time to dry the mortar after lining. In addition, since the refractory brick 8 is heavy, the iron skin 3 needs to have sufficient strength to withstand the weight of the refractory brick in addition to the molten zinc, and the thickness of the iron skin 3 is large. Accordingly, the weight of the entire plating pot is bulky, and capital investment such as a cart for installation is large.
[0005]
In order to prevent such zinc erosion from the medals, there is also a plating pot in which a castable is lined as a refractory material instead of a refractory brick. In the case of castable, the problem of molten zinc erosion is eliminated because there is no thread, but the lining work is to be done after mold mounting and castable kneading, so the work of lining the side of the plating pot is very It was difficult to do and took time. It also requires drying time after lining. Further, in the case of the castable, the weight is large as in the case of the refractory brick 8, so that the thickness of the iron skin 3 is large and the weight of the entire plating pot is increased.
[0006]
In recent years, plating pots that employ ceramics instead of refractory bricks have become the mainstream. This is because workability is better than refractory bricks, durability is high, and handling is easy as a refractory material. However, since ceramics are expensive, there is a demand for a cheap plating pot among those skilled in the art.
In view of the above problems, an object of the present invention is to provide a hot dip galvanizing pot that does not require special technology, can be lined in a short time, is light in weight, and is less expensive than ceramics. To do.
[0007]
[Means for Solving the Problems]
Ceramic fiber which is compression-molded to 250 to 350 kg / cm ³ as a refractory material of a hot dip galvanizing facility in which a steel strip is immersed in a hot dip galvanizing pot to plate the surface of the steel strip It is characterized by lining the block.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a hot dip galvanizing pot of the present invention. In addition, the same number is attached | subjected about the same thing as a prior art.
The hot dip galvanizing pot 21 of the present invention has a two-layer structure in which a fiber blanket 2 is placed inside an iron skin 3 and a ceramic fiber block 1 is lined as a refractory material. This ceramic fiber block 1 has no problem in terms of heat resistance as long as it can withstand the temperature of molten zinc.
[0009]
Conventionally, ceramic fiber is generally used as a refractory material for heat treatment furnaces because it has a lower specific gravity and higher heat insulation effect than brick. However, it could not be considered for use in hot dip galvanizing pots. This is because ceramic fibers generally have a low density, and there is a concern that molten zinc penetrates between the fibers and erodes the iron skin. The present invention has been variously studied to solve this problem, and has arrived at the present invention. That is, the ceramic fiber was made into a block, and the one formed by compression molding at the time of making the block was adopted.
[0010]
FIG. 2 is a graph showing the relationship between the compression density of the ceramic fiber blanket and the iron skin temperature of the plating pot. In the figure, the vertical axis represents the temperature of the iron skin 3 of the plating pot, and the horizontal axis represents the compression density of the ceramic fiber blanket. As can be seen from this, when the compression density of the ceramic fiber is smaller than 250 kg / cm ³ , the molten zinc penetrates between the ceramic fibers, so that the iron skin temperature rises. On the contrary, when the compression density is higher than 350 kg / cm ^{3, the} thermal conductivity is increased, so that the iron skin temperature similarly increases. Therefore, the ceramic fiber block 1 is preferably compressed in the range of 250 to 350 kg / cm ³ .
[0011]
Next, a method for lining the ceramic fiber block will be described. FIG. 3 shows a lining construction method for the ceramic fiber block 1. In this embodiment, the ceramic fiber is used as a block. As shown in FIG. 3, the ceramic fiber block 1 before being lined is formed by wrapping a ceramic fiber blanket folded in an accordion shape with a card board 11, and further winding it vertically and horizontally with a PP band 10. When processing into such a block shape, this ceramic fiber block is compression molded in the range of 250 to 350 kg / cm ³ .
[0012]
Further, bolts 14 for locking the ceramic fiber block are welded to the iron shell 3 at a predetermined pitch. A fiber blanket 2 is lined on the iron skin 3, and the bolt 14 penetrates the fiber blanket 2. When lining the ceramic fiber block 1, first, a guide pipe 15 is inserted into the bolt 14, the guide pipe 15 is aligned with the center hole 17 of the ceramic fiber block 1, and the ceramic fiber is aligned along the guide pipe 15. Block 1 is inserted. When the center hole 17 of the ceramic fiber block 1 reaches the position of the bolt 14, the guide pipe 15 is removed, and the nut 12 is attached to the bolt 14 with the box wrench 13, and the ceramic fiber block is fixed in the plating pot.
[0013]
4 is a partial perspective view of the inner surface of the plating pot, and FIG. 5 is a partially enlarged view of the bottom ceramic fiber block. When the ceramic fiber block 1 is laid, as shown in the drawing, the fold mountain portion 16 of the ceramic fiber 1 is laid on the inner surface of the plating pot 21 at the plating pot bottom 18 and the side portions 19 and 20. By doing so, the ceramic fiber block 1 can be prevented from rising more reliably. Basically, the ceramic fiber blocks 1 are arranged in a staggered pattern on the inner surface of the plating pot 21 so that the direction of the folds of adjacent ceramic fiber blocks 1 is different (vertical and horizontal directions). Can be. However, the ceramic fiber block 1 lining above the plating pot side portions 19 and 20 is arranged so that the fold ridge portion 16 visible on the inner surface of the plating pot 21 is in the vertical direction in order to prevent the fiber from floating up. To do.
[0014]
After laying the ceramic fiber block 1 in this way, when the PP band 10 is cut and the card board 11 is removed, the compression-molded ceramic fiber blocks 1 try to open each other, so that there is a gap between the ceramic fiber blocks 1. It is compressed evenly and there is no gap between the ceramic fiber blocks 1. The plating pot 21 in which the ceramic fiber block 1 is lined as a refractory material by the above-described procedure can sufficiently withstand molten zinc, both in terms of heat resistance and strength. In such a plating pot 21, the steel strip 6 enters the hot dip galvanizing pot via the snout 5, is pulled up to the outside of the plating pot 21 via the sink roll 4, and the steel strip 6 is plated with zinc. The
[0015]
Although the example applied to the hot dip galvanizing pot has been described here, it is of course possible to apply the present invention to a melting pot for dissolving a zinc ingot in advance. In addition, it can also be used for a basket used when moving the molten zinc from the melting pot to the hot dip galvanizing pot. Generally, this ridge is lined with refractory bricks, but since zinc is cooled and solidified on the surface of the refractory bricks and gradually accumulates, it is difficult for zinc to flow during the movement of molten zinc. Also, it is necessary to keep the refractory bricks warm so that zinc is not hardened as much as possible.
[0016]
Similarly to the present invention, a groove is formed in a compressed ceramic fiber block, and a refractory material obtained by connecting the blocks is fixed to the main body to form the flange. Since zinc does not adhere to the surface at least, molten zinc flows smoothly. Of course, no electric fuel is required to keep warm. Thus, the present invention can be applied anywhere as long as it is a container for molten zinc.
[0017]
【The invention's effect】
As described above, in the present invention, since the compression molded ceramic fiber block is used as the refractory material in the plating pot of the hot dipping equipment for plating the steel strip, the mortar is applied like a refractory brick. There is no time. Therefore, since there is no erosion of molten zinc from the medals, the temperature of the iron skin does not rise. Moreover, unlike the refractory brick, the ceramic fiber block at the bottom does not rise. Also, since it is a simple mounting method using bolts and nuts, no special technology is required during lining. Furthermore, no drying process is required. Therefore, compared to the case of lining refractory bricks and castables, the construction time can be reduced by about 30%.
[0018]
In addition, since the thermal conductivity is low compared to refractory bricks and castables, the temperature drop of molten zinc is small. Therefore, it is possible to reduce the electric power required for the induction heating device used when the molten zinc is kept warm. Also, the thickness of the refractory material can be reduced. Furthermore, since the weight is 1/20 or less compared to refractory bricks and castables, the iron skin strength can be reduced, and the weight of the plating pot can be reduced. Therefore, capital investment such as a cart during installation can be kept low. The service life is equivalent to or better than that of refractory bricks, and the material cost is lower than that of ceramics.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a hot dip galvanizing pot of the present invention.
FIG. 2 is a graph showing the relationship between the compression density of a ceramic fiber blanket and the iron skin of a hot dip galvanized pot.
FIG. 3 is an explanatory diagram of lining construction of the ceramic fiber block of the present invention.
FIG. 4 is a partial perspective view of the inner surface of the plating pot.
FIG. 5 is a partially enlarged view of the ceramic fiber block at the bottom of the plating pot.
FIG. 6 is a longitudinal sectional view of a conventional hot dip galvanizing pot.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ceramic fiber block 2 Fiber blanket 3 Iron skin 4 Sink roll 5 Snout 6 Steel strip 7 Molten zinc 8 Refractory brick 9 Heat insulation brick 10 PP band 11 Card board 12 Nut 13 Box wrench 14 Bolt 15 Guide pipe 16 Folding part 17 Center hole 18 Plating pot bottom 19 Plating pot side 20 Plating pot side 21 Plating pot

Claims (1)

Ceramic fiber which is compression-molded to 250 to 350 kg / cm ³ as a refractory material of a hot dip galvanizing facility in which a steel strip is immersed in a hot dip galvanizing pot to plate the surface of the steel strip Plating pot for hot dip galvanizing equipment, characterized by lining the block.

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