JPS6286115A - Skid - Google Patents

Abstract

PURPOSE:To decrease skid marks as far as possible by using non-water-cooled skids for at least parts to be disposed in a holding zone among the skids installed on the hearth of a heating furnace and using water-cooled skids for the parts to be disposed on the other zones. CONSTITUTION:This invention relates to the skids to be installed on the hearth of the heating furnace for heating materials to be heated to a prescribed temp. At least the parts of such skids to be disposed in the holding zone are constituted of the non-water-cooled skids 1 formed by coating the outside peripheral surfaces of skid pipes 3 with a caster layer 4 consisting of a heat insulating material, successively joining plural pieces of molded materials 5 consisting of heat resistant ceramics into the hollow hole of each pipe 3 along the axial direction thereof in such a manner that the respective end faces thereof contact each other and fixing the same by monolithic refractories 6 into the hollow hole. The parts to be disposed on the other zones are constituted of the water- cooled skids 2 formed by coating the outside peripheral surface of the skid pipes 3 with the caster layer 4 for heat insulation and passing cooling water into the hollow holes thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a skid that is installed, for example, in the hearth of a heating furnace that heats a material to be heated to a predetermined temperature.

(Prior art and its problems) The skid installed on the hearth of a continuous heating furnace, for example, in the case of a set of pushers, is either water-cooled over its entire length or non-water-cooled using heat-resistant ceramics. It is common to use something.

However, when the former water-cooled skid is used, the equipment cost is low, but as shown in FIG. 6, the skid marks become large and there is a quality problem. Therefore, in order to reduce the size of skid marks, there are some systems in which the skid on the extraction side is slightly shifted in the width direction of the furnace, but even in this case, although the skid marks are slightly smaller, new There is a problem in that skid marks occur (see Fig. 7).

Furthermore, when the latter non-water-cooled skid is used, the skid marks are small, but the equipment cost is extremely high compared to the case where a water-cooled skid is used.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a skid with relatively low equipment cost and with small skid marks.

(Means for Solving the Problems) The present invention provides a skid installed in the hearth of a heating furnace that heats a material to be heated to a predetermined temperature, in which at least a portion of the skid disposed in a soaking zone is replaced with a non-water cooling skid. Another key feature is that the part placed on the other band is a water-cooled skid.

Here, the water-free cooling skid and the water-cooling skid may be arranged in either a linearly connected manner or a position shifted in the furnace width direction.

The reason why at least a waterless cooling skid is disposed in the soaking zone in the present invention is based on the following reason.

In other words, according to the inventor's experiments, as shown in Fig. 5, in the case of only a water-cooled skid (when the non-water-cooled skid length is 0), the amount of skid marks at the extraction port is 120°C.
However, if the length of the non-water cooling skid from the extraction port is increased (as the length of the non-water cooling skid is increased, the amount of skid marks will become smaller, and if all the skids are non-water cooling skids (when the non-water cooling skid length is L)
The minimum amount of skid marks was 25°C. However, this rate of decrease in the amount of skid marks is extremely small when the water-free cooling skid length exceeds the soaking zone (furnace length 173 or more), and in exchange, the equipment cost becomes extremely high.

Further, in the present invention, the reason why a water-cooled skid is not disposed on the extraction side of the non-water-cooled skid is that new skid marks are generated by the water-cooled skid.

(Function) Since the skid of the present invention is constructed by effectively combining a non-water-cooled skid and a water-cooled skid, it is possible to reduce skid marks as much as possible with low equipment costs.

(Example) The present invention will be described below based on an example shown in FIGS. 1 and 2.

Figure 1 shows the non-water-cooled skid 1 and water-cooled skin 2 arranged in a straight line, and Fig. 2 shows the non-water-cooled skid 1 and the water-cooled skid 2 installed with their positions slightly shifted in the furnace width direction. FIG. 2 is a schematic diagram showing the waterless cooling skid 1 installed only in the soaking zone.

Incidentally, the structures of the non-water-cooled skid 1 and the water-cooled skid 2 used in the present invention are not equally limited, but for example, those shown in FIGS. 3 and 4 may be used.

That is, FIG. 3 shows an embodiment of a waterless cooling skid 1, in which the outer peripheral surface of the skid pipe 3 is covered with a single layer of heat-insulating casters 4, and the inside of the hollow hole of the skid pipe 3 is
A plurality of heat-resistant ceramic shaped members 5 are arranged along the axial direction.
are connected so that their end surfaces abut each other, and are fixed in a hollow hole with a monolithic refractory 6.

The shape of the ceramic shaped material 5 may be a rectangular parallelepiped with a rectangular cross section as shown in FIG. It may be left as is, or it may be filled with a monolithic refractory.

Moreover, when the cross-sectional area of each ceramic shaped material 5 is relatively small, a plurality of them may be arranged in parallel in the hollow hole.

FIG. 4 shows an embodiment of the water cooling skid 2, which has a structure in which the outer circumferential surface of the skid pipe 3 is covered with a single layer of heat-insulating casters 4, and cooling water is allowed to flow through the hollow holes thereof.

In addition, 7 in FIG. 3 and FIG. 4 is a skid rider or rail provided protrudingly on the upper surface of the skid pipe 3.

(Experimental Results 1) The skid of the present invention (a non-water-cooled skid and a water-cooled skid arranged in a straight line) was applied to a continuous heating furnace for thick steel plate slabs with a furnace temperature of 1200° C., a furnace width of 8000 mW, and a furnace length of 30 m.

The average dimensions of the material to be heated are 210fi thickness x 1B00w+i width x 2500mm length, and the average time in the furnace is 3 hours.

Skid mark is 120 when using conventional water cooling skid only.
℃, and there was a large thickness deviation in this part, which caused quality problems. Furthermore, in the case of only a non-water cooled skid, the skid marks were reduced to 25°C, but the equipment cost was very high.

However, in this heating furnace, the allowable amount of skid marks was 40°C, so the skid of the present invention was applied. That is, in the case of the present invention, of the total length of 30 m, 10 m on the extraction side of the furnace was a non-water-cooled skid, and 20 m on the charging side of the furnace was a water-cooled skid.

As a result, it was possible to suppress skid marks to 38° C. and to reduce equipment costs significantly.

(Experimental Results 2) The skids of the present invention (water-free skids and water-cooled skids were placed in the same heating furnace as in (Experimental Results 1) above, with a distance of 250 mm in the width direction of the furnace.
(installed at different locations) was applied. The material to be heated and the average time in the furnace were also the same as (experimental result 1).

In the case of a conventional water-cooled skid having a full length, the skid mark was 120° C., and two skid marks were generated in the width direction of the material to be heated because there were two skids.

Therefore, in order to reduce the skid marks, the extraction side of the water-cooled skid was placed 10 meters away from the furnace width by 250 degrees, and the conventional skid marks were 50'C.
However, skid marks at 20°C occurred when the position of the extraction side was shifted. In other words, a problem has arisen in that the measures originally taken to reduce skid marks generate new skid marks.

However, in the case of the skid of the present invention, that is, when the 10 m extraction side was a non-water-cooled skid, no skid marks were generated on the non-water-cooled skid portion. As a result, there were only two 50°C skid marks that had occurred from the charging side of the heating furnace.

(Effects of the Invention) As explained above, the skid of the present invention can reduce skid marks as much as possible without increasing equipment costs, and the amount of cooling water can be reduced by 25% compared to the case of using only a water-cooled skid. This is a great invention that has industrial applications, such as being able to reduce overheating of the material to be heated.

[Brief explanation of drawings]

1 and 2 are schematic plan views showing an embodiment of the skid of the present invention, and FIGS. 3 and 4 are sectional views showing an embodiment of the skid employed in the skid of the present invention. 4 shows a water-cooled skid, FIG. 5 shows the rate of change in skid mark amount at the extraction port when the length of the water-free skid is changed from the extraction port, and FIG. FIG. 7 is a diagram illustrating skid marks when a conventional skid is applied. 1 is a non-water cooled skid, 2 is a water cooled skid. Patent applicant: Sumitomo Metal Industries, Ltd.
Kubota Iron Works Co., Ltd. Figure 1 71 Water incense ~ l to 2 water incense l ~ tsu) - to m- ゛14-water to 5th, y
- / Obsessive Now 7 V - - 1 E Dan Planning \ 2 v - 1 H + - 1 Fig. 5ゝ7'17. %-JL” No. 7140d,
Noj facing El

Claims (1)

[Claims] (1) In a skid installed in the hearth of a heating furnace that heats the material to be heated to a predetermined temperature, at least the portion of the skid placed in the soaking zone is a non-water cooling skid, and the portion placed in other zones is a skid. A skid characterized by being water-cooled.