JPS6034015Y2 - heating furnace - Google Patents

Description

[Detailed description of the invention] The present invention relates to a heating furnace that heats a steel ingot to be rolled. More specifically, the invention relates to a heating furnace that heats a steel ingot to be rolled. More specifically, skid marks occur on the steel ingot as the steel ingot moves on the skid rail in the heating furnace. This invention relates to a heating furnace that can eliminate energy and save energy.

The steel ingot to be subjected to the rolling process is heated to a predetermined temperature by passing through a heating furnace, and then sent to the rolling process.

FIG. 3 is a schematic cross-sectional view showing the structure of the heating furnace. A plurality of skid rails 3 arranged in a straight line inside the furnace are temporarily lifted by a walking beam (not shown) and sent intermittently in the direction of the arrow, and extracted from the soaking zone 1b to the outside of the furnace. .

Burners 4 are provided in the upper and lower parts of the heating zones 1a, 1a' and the soaking zone 1b, and the steel ingot 2 moving in the heating furnace 1 is heated to a high temperature and rolled in a subsequent stage (not shown). It is now sent to the processing process.

The steel ingot 2 moving in such a heating furnace 1 always moves in contact with the same part of the skid rail 3, and because the contact time is long, the contact part loses heat by the skid rail 3 and comes into contact with it. The temperature of the steel ingot in some parts is 50'C higher than in other parts.
The temperature decreases by as much as ~80°C, and low-temperature heated areas called skid marks occur, which complicates rolling control and causes problems such as poor finished dimensional accuracy.

To reduce the negative effects caused by the occurrence of skid marks, it is necessary to However, a decrease in operational efficiency is unavoidable, and in order to extend the residence time without decreasing operational efficiency, it is necessary to extend the soaking zone hearth, which requires a large amount of equipment space, etc. It is also not economically viable.

Another solution is to divide the skid rail into multiple parts in the longitudinal direction of the furnace and arrange them in a staggered manner so that the position where the steel ingot contacts the skid rail is determined each time the steel ingot passes through each divided area. Modifications have also been made to prevent the same parts of the steel ingot from coming into contact for extended periods of time.

In this case, the structure of the skid rail becomes complicated.

Further, there is no effect unless short skid rails are arranged in a staggered manner on the final heating position side of the steel ingot.

Furthermore, even if a steel ingot at around 100°C is placed on a skid rail for a few seconds, the temperature of the steel ingot at the contact area will drop to 20°C.
This method is also not conclusive as it results in a drop of ~30°C.

Still another method is to arrange a skid rail in which the length direction of the skid rail is oblique with respect to the moving direction of the steel ingot.

In this case, the contact area between the steel ingot and the skid rail is
As the steel ingot moves, the skid mark gradually moves and follows, so it has almost no effect.

Still another method is to average the time the steel ingot is on the walking beam and the skid rail, but this method is not effective as it complicates the structure inside the furnace.

In order to solve the above-mentioned problem, this invention arranges a small capacity burner to locally heat the skid mark part in the soaking zone hearth of the heating furnace, and uses this burner to place the skid mark at the final heating position of the steel ingot. By heating the part locally, skid marks disappear and the temperature of the steel ingot becomes uniform, making it possible to produce high-quality rolled material that is satisfactory in terms of metallurgy and method accuracy. In addition, we have proposed a heating furnace that can reduce the fuel consumption of the entire heating furnace.

EMBODIMENT OF THE INVENTION Hereinafter, the heating furnace based on this invention will be explained in detail by the drawing which shows an Example.

FIG. 1 is a partial plan view of a soaking zone hearth, which is a main part of the heating furnace according to the present invention, and FIG. 2 is a partial side view of the soaking zone hearth in FIG. 1.

In FIGS. 1 and 2, 10 is a soaking zone hearth provided on the steel ingot extraction side B of the soaking zone in the heating furnace, in which refractory bricks 11 are stacked in a staggered manner so that the top surface is flush with the horizontal surface. It is formed.

At the end of the soaking zone hearth 10 opposite to the steel ingot extraction side B, that is, the heating zone side A, a rail installation portion 10a cut out to an appropriate width and depth is provided in the width direction of the soaking zone hearth 10. A plurality of locations (two locations in the figure) are formed at appropriate intervals.

A plurality of (two in the figure) skid rails 12, 12 with one end positioned and the other end extending toward the heating zone side A are arranged in parallel in each of the rail installation portions 10a. are doing.

A walking beam 13 for intermittently moving the steel ingots W on these skid rails 12 is arranged in parallel to the skid rails 12.

By this walking beam 13, the skid rail 12
The upper steel ingot W is intermittently moved to the hearth side and placed in the soaking zone hearth 10.
The steel ingot W that has reached the top is successively pushed out in the direction of the steel ingot extraction side B by the subsequent steel ingots W.

Soaking hearth 10 on the extension line of skid rail 12
A burner arrangement hole 15 having a rectangular opening and an appropriate depth is formed in the upper surface of the skid rail 12 at a position near the end thereof.

The burner arrangement hole 15 is surrounded by stacked burner tiles 16 that can withstand the high temperature of the burner.

The lower side surface of the burner arrangement hole 15 is formed with a fuel pipe arrangement hole 17 that communicates with the burner arrangement hole 15 and extends horizontally in the soaking zone hearth 10 in the steel ingot extraction side B direction. A fuel pipe 18 is installed in the installation hole 17, and a burner 19 is attached to the tip thereof facing upward.

Further, the upper side of the burner arrangement hole 15 is connected to the skid rail 12.
Soaking zone hearth 10 along the steel ingot extraction side B direction on the extension line of
It communicates with a shallow waste gas guide groove 20 whose upper surface is open.

The end of the waste gas guide groove 20 is open at the inner end of the furnace.

Therefore, when the burner 19 is ignited, the high temperature combustion gas is blown out toward the opening of the burner arrangement hole 15.

When the steel ingot W that has moved on the skid rail 12 is pushed out onto the soaking zone hearth 10 and is positioned above the burner placement hole 15, the burner 19 locally removes the area where the skid mark has occurred. Heats up to eliminate skid marks in a short time.

Further, as other steel ingots W are subsequently pushed out onto the soaking zone hearth 10, the steel ingots W located above the burner arrangement hole 15 are sequentially pushed out and moved in the direction of the steel ingot extraction side B. .

On the other hand, the combustion gas that has reached the upper part of the burner arrangement hole 15 and heated the skid mark part flows through the waste gas guide groove 20 whose upper part is closed by the steel ingot W, and its residual heat continuously damages the skid mark occurrence part. The steel ingot W is heated continuously to make the temperature of the steel ingot W more uniform.

Further, the residual heat of the combustion gas of the burner 19 can be used effectively without waste.

Skid marks disappear from the heated steel ingot W, and the steel ingot W, which has a uniform temperature, is sent to the rolling process.

It is possible to improve the quality of steel products formed by plastic working in terms of metallurgy and dimensional accuracy.

In the case of the heating furnace according to the present invention configured as described above, the burner 19 in the burner arrangement hole 15 provided in the soaking zone hearth 10 is used to locally remove skid marks generated by moving on the skid rail 12. In order to heat the steel ingot W'
0') It can be extinguished in a short time using a small capacity burner 19 at the final heating position.

Therefore, while moving on the skid rail 12, the temperature of the steel ingot other than the part that contacts the skid rail may be heated to a predetermined temperature.
It is no longer necessary to take care to raise the temperature of the part that comes into contact with the furnace, and the fuel consumption of the entire heating furnace 1 can be reduced accordingly.

By completely eliminating skid marks, the temperature of the steel ingot W becomes uniform, making it possible to simplify control in the rolling process, and supply rolled products with uniform quality and high dimensional accuracy. The present invention has excellent effects such as being able to do the following.

It goes without saying that the present invention can also be applied to a bushing type heating furnace.

[Brief explanation of drawings]

Figure 1 is a partial plan view of the soaking zone hearth showing the main parts of the heating furnace according to the present invention, Figure 2 is a partial side sectional view of the soaking zone hearth in Figure 1, and Figure 3 is a general view of the heating furnace. FIG. 1a, 1a'... Heating zone, 1b... Soaking zone, 2°W... Steel ingot, 3, 12...
Skid rail, 10... Soaking hearth, 13.
... Walking beam, 15 ... Burner arrangement hole, 19 ... Burner, 20 ...
Waste gas guide groove.

Claims (1)

[Scope of utility model registration request] In a heating furnace in which heated steel is extracted from the furnace through a soaking zone hearth while moving on a skid rail, a burner arrangement hole is opened in the upper surface of the hearth on the extension line of the skid rail in the soaking zone hearth. and a waste gas guide groove communicating with the burner arrangement hole, and a burner is provided in the burner arrangement hole.