JPH03183718A - Brick laying structure for molten iron receiving hole in torpedo car for pre-treating molten iron - Google Patents

Abstract

PURPOSE:To prevent erosion of refractory in a molten iron receiving hole at high temp. and to improve working rate of a torpedo car by forming the molten iron receiving hole in the oxygen top-blowing type torpedo car of the specific monolithic refractory and also setting receiving brick between bottom of the monolithic refractory inner lining refractory brick in he torpedo car body at the lower part thereof. CONSTITUTION:The molten metal tapped off from a blast furnace is received into the torpedo car, and in order to uniformize the quality and prevent temp. lowering of the molten iron at the time of executing pre-refining of desiliconization, etc., the oxygen top blowing is execute. By this method, in order to prevent the erosion of molten iron receiving hole 4 at high temp., the inner lining 3 of Al2O3-SiC-C series or high alumina series refractory brick is arranged at inside of the iron shell 2 in the torpedo car body 1 and the lining at the molten iron receiving hole 4 part is constituted of the receiving brick part 5 having inner diameter d1 larger than inner diameter d2 of the lining 3 and further, on the brick part 5 the same refractory brick 7 of Al2O3-SiC-C series, etc., and monolithic refractory 8 of high refractoriness and high erosion resistance of Al2O3-MgO series or Al2O3-SiC-C series are provided. The torpedo car can be used under excellent working rate without generating erosion of the refractory material in the molten iron receiving hole 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the structure of a pigtail receiving port of a pig iron mixing car, which is particularly suitable for hot metal pretreatment.

[Conventional technology]

Traditionally, the receiving port of a pig iron mixer car has been constructed using fired bricks. However, since the opening is formed in the cylindrical part of the pig iron mixer, it is necessary to use a combination of bricks with complex shapes, and pre-setting machining is required, making it difficult for actual furnace construction work. It had a long time. In addition, since the shape is complex, irregularly shaped bricks must be used, and since machine molding is not possible, hand-hammered bricks are used, which poses problems in terms of brick quality.

Therefore, in recent years, for example, Japanese Patent Application Laid-Open No. 61-281804
As shown in the above publication, it has become common practice to provide a monolithic refractory lining to the pigtail receiving port.

On the other hand, the use of pig iron mixing cars for hot metal pretreatment has been established and implemented as a normal process.

In order to prevent a drop in the temperature of the hot metal during such preliminary treatment of hot metal, an operation is carried out in which oxygen top blowing is also used during the treatment. At this time, secondary combustion caused by the injected oxygen causes the temperature inside the furnace to become extremely high during operation, causing localized abnormal melting of the monolithic refractory at the receiving mouth.

The reason for this is that the durability of the monolithic refractories applied to the pigtail hole is lower than that of the AixO = Sac C bricks that are lined with bricks, and that the boundary between the monolithic refractories and the bricks has an acute angle structure. This is thought to be because the monolithic refractories peel off and wear out first.

As a result, the life of the monolithic refractory at the pigtail receiving port is shortened, the frequency of repair of the pigtail receiving port is increased, and operational problems such as a reduction in the operating rate of the pig iron mixing vehicle have also occurred.

As a countermeasure to this problem, attempts are being made to improve the durability of the monolithic refractories themselves installed in the pig iron receiving port, but this alone will not extend the life of the receiving port to the level of conventional hot metal transport vehicles. is difficult.

Another countermeasure is to build the entire pigtail hole with bricks, which has traditionally been done in order to improve the sharp-angled structure at the boundary between the monolithic refractory and the bricks, but this method takes a long time to construct. There's a problem.

In addition, by partially bricking, it is possible to improve the acute-angled structure at the boundary between the monolithic refractory and the bricks, but this creates a structure in which the operating surface is expanded and the back surface is narrowed, resulting in the problem of bricks falling off. There is.

[Problem to be solved by the invention]

The present invention solves the problem of shortening the life of the pig iron receiving port when using such a mixed pig iron car for pre-treatment of hot metal, equalizes the balance of melting loss of the entire pig iron receiving port, and aims to improve the life of the pig iron receiving port.
It also aims to reduce the frequency of repairs, reduce repair costs, and improve the operating rate of mixed iron and iron trucks.

[Means to solve the problem]

The lining structure of the pigtail receiving port of the pig-mixing car of the present invention is such that the lower part of the lining, which is defined by the monolithic refractory, is continuous at least in the height direction with the receiving brick provided on the brick lining inside the pig-mixing car body. The present invention is characterized in that both ends in the furnace length direction of the cylindrical body of the lining formed by the bricks are supported by the lining bricks in the pig iron mixer body.

[Effect]

During the hot metal pretreatment operation that uses oxygen top blowing, the erosion of the pig iron receiving muzzle is localized, and only the parts of the monolithic refractories at the receiving port that are locally affected by large erosion are replaced with bricks. Therefore, it is possible to equalize the erosion balance of the entire pigtail hole.

Large bricks are used to cover the locally eroded parts of the monolithic refractories in the pig iron receiving hole of the pig iron mixer car for hot metal pretreatment, and jack arches are installed in the longitudinal direction of the pig iron mixer car to prevent the bricks from falling into the furnace. structure is adopted. After constructing the bricks for the jack arch structure, the frame is set in the conventional manner, and then the monolithic refractory material is poured into the receiving port, so there is no problem that the construction process takes a long time.

Unlike the case of bricking the entire pigtail hole, it is complicated.

There is no need to use irregularly shaped bricks, and mechanical forming allows the bricks to be used without impairing their original characteristics. especially,
High durability A whose characteristics are greatly influenced by the molding method
Allows the use of l1o3-SiC-C bricks.

Next, by partially turning it into bricks, it is possible to improve the acute angle structure at the boundary between the bricks as a monolithic refractory. In this case, a jack arch structure is used to prevent bricks from falling off.

〔Example〕

1 to 3 show embodiments of the present invention.

Fig. 1 shows a longitudinal cross-sectional view at the center position of the pigtail mixing car receiving hole, Fig. 2 shows a plan view taken from the line ■-■ in Fig. 1,
Further, FIG. 3 is a diagram showing a longitudinal cross-sectional structure shown by the line ``--'' in FIG.

In these figures, reference numeral 1 indicates a cylindrical furnace body that is tiltably mounted on two bogie carts (not shown). The furnace body 1 has An! inside the outer shell 2. 2os-3i C-C
Lining 3 disciplined by quality and high alumina bricks
has. Reference numeral 4 indicates a pigtail receiving port provided above the lining 3 at approximately the center of the pig mixer car.

The lining of the 4th part of the pigtail hole is the lining 3 of the cylindrical part.
A receiving part 5 is formed at the upper part of the receiving part 5, the inner diameter d1 of which is larger than the inner diameter d of the lining 3 of the cylindrical part.

Reference numeral 6 indicates a refractory lining of the receiving hole formed above the receiving brick portion 5. The fireproof lining 6 is a brick B7 integrally molded at least at the connection part with the receiving brick part 5.
and the upper part thereof is formed from a monolithic refractory part 8. Further, as shown in FIG. 2, the brick portion 7 has a jack arch structure in the furnace length direction of the pig iron mixer car, and is restrained by lining bricks 3 inside the furnace body, as shown in FIG.

The connection brick part 7 is made of a refractory material such as unfired Altos SICC brick or high alumina from the viewpoint of corrosion resistance and spalling resistance.
Aj! from the point of view of corrosion resistance! 20*-5iC-CSAj!
It is made of to+-MgO refractory material.

The bricks forming the brick part 7 of the part continuous with the receiving brick part 5 above the cylindrical part of the receiving port are designed to prevent local melting based on the wear profile of monolithic refractories in the actual furnace. In order to sufficiently cover the area and to enable mechanical molding, we created 1 to 5 existing bricks, with a size of 100 bricks.
It is desirable that the distance be between 500mm and 500mm. If it is less than 1 piece or less than 100M in size, it will be difficult to cover the erosion area sufficiently.
Since it is a jointed structure of two to three sheets, joints may occur, and there is a risk that erosion from the joints will progress. Moreover, if there are 5 or more bricks, and if the size is 500 mm or more, mechanical molding of the bricks becomes impossible, the quality of the bricks deteriorates, and the durability also decreases.

In the longitudinal direction of the furnace body, by adopting a jack arch structure supported by lining bricks forming the inner surface of the cylindrical furnace body, it is possible to achieve high durability and unburnt aA1 without using specially shaped bricks. By using mechanically molded .03-5iC-C bricks, strong structural restraint is possible, and bricks can be prevented from falling off.

〔Effect of the invention〕

The brick-laid structure of the pig iron car receiving port for hot metal pretreatment of the present invention can provide the following effects.

(1) Lining construction is much simpler than brick masonry for the entire pigtail hole.

0) By bricking the localized melted areas of the monolithic refractories of the pigtail receiving port, the melting loss balance of the entire receiving port can be made uniform.

(3) It is possible to reduce the frequency of repair of the pigtail hole and the repair cost, and to ensure the operation rate of the mixed pig iron truck.

(4) Even under hot metal pretreatment operating conditions, the life of the pig iron receiving port can be improved to a level exceeding that of the conventional method.

[Brief explanation of drawings]

FIGS. 1 to 3 of the accompanying drawings show embodiments of the present invention, and FIG.
The figure is a vertical cross-sectional view at the center position of the mixed-traffic car reading port, 91!
FIG. J2 is a plan view taken along the line ■--■ in FIG. 1, and FIG. 3 is a diagram showing the vertical cross-sectional structure taken along the line ■--■ in FIG. 1: Furnace body 2: Outer shell 3: Furnace body lining brick 4: Pighole 5: Receiver brick part 6: Pighole refractory lining 7: Receiver mouth brick part 8: Monolithic refractory part whistle diagram whistle Figure diagram

Claims (1)

[Claims] 1. In the lining of the pigtail receiving port of a pig iron mixer car made of monolithic refractory material, the lower part of the lining has an integral shape that is continuous in the height direction at least with the receiving brick provided on the brick lining in the pigtail mixer car body. Brickwork for a hot metal mixer car receiving port for hot metal pretreatment, in which the cylindrical body of the lining made of the same bricks is supported by the lining bricks in the mixer car body at both ends in the furnace length direction. structure.