JPS62218511A - Walking hearth type heating furnace - Google Patents

Abstract

PURPOSE:To provide a titled heating furnace which can prevent the self-rolling of billets by upward camber and bending by providing turn-over positioning parts of the billets when the difference between the upper and lower temps. of the billets under conveyance in a walking hearth attains a specific value at plural points in the conveying direction. CONSTITUTION:The top firing type heating furnace 1 in which the billets 14 are passed is internally disposed and provided with the walking hearth 12 for conveying the billets 14 charged into the furnace from an inlet 7 toward a discharge port 10. The billets 14 passing in the above-mentioned walking hearth 12 arrive at the billet turn-over positioning part 15 and the difference between the upper and lower temps. of the billets 14 attains approximately 60 deg.C, then the billets 14 are turned over 180 deg. in this state. The positioning parts 15 are preferably provided at 2-6 points. Namely, the temp. difference of the billets 14 is corrected at every arrival at the above-mentioned positioning parts 15, by which the self-rolling of the billets 14 by upward camber and bending generated heretofore is prevented.

Description

[Detailed description of the invention] The present invention aims to solve the following problems.

(Industrial Application Field) The present invention relates to a walking hearth type heating furnace used for heating steel slabs using a single-firing type heating furnace equipped with a walking hearth consisting of a fixed hearth and a movable hearth.

(Prior Art) When a steel billet is transported using a walking hearth in this type of top-firing heating furnace, the temperature of the upper side of the steel billet rises faster than that of the lower side. And the 11th.
As shown in Fig. 12, the steel piece may bend upward in an arched shape and roll from itself in the conveying direction. As a result of this transfer, the steel billet becomes in a disordered state different from the aligned state at the time of charging, which poses a problem that makes automatic extraction work at the exit difficult.

(Problems to be Solved by the Invention) This invention eliminates the above-mentioned conventional problems and is configured to facilitate the automatic extraction operation at the exit of the billet toward the exit in an orderly state similar to the arrangement state at the time of charging. The present invention aims to provide a walking hearth-type heating furnace.

The configuration of the present invention is as follows.

(Means for Solving the Problems) The present invention takes the measures as described in the claims above, and its effects are as follows.

(Function) In the walking hearth, a plurality of steel billet inversion positioning units are installed in the conveyance direction, each of which rotates the steel billet by 180 degrees when the temperature difference between the upper and lower sides of the steel billet during conveyance reaches approximately 60°C. Since the steel piece is provided at a certain position, the steel piece is turned over before rolling from itself, and the temperature difference between the upper and lower sides is corrected, and the above-mentioned bow-like upward bending does not occur.

(Embodiments) The drawings showing the embodiments of the present application will be explained below. The members indicated by reference numerals 1 to 14 in FIG. 1 are well known in this type of walking hearth type heating furnace, but will be briefly explained.

1 indicates a heating furnace, 2, 3.4, in order, a preheating zone, a heating zone,
In the soaking zone, 5 indicates the burner position in the top firing type, 6 indicates the discharge port, 7 indicates the inlet of the billet 14, 8 indicates the shift button, 9 indicates the charging roller, and 10 indicates the billet outlet. ,
11 indicates an extraction roller. Reference numeral 12 denotes a walking hearth, which is composed of a fixed hearth 16 and a movable hearth 17, which will be shown next time, and a movable hearth 17 arranged side by side. Reference numeral 13 indicates the locations of members that support the fixed hearth and members that support and drive the movable hearth. The above-mentioned walking hearth type heating furnace is a simplified example, but in this case, the present invention can be implemented in a walking hearth type heating furnace of other configurations as long as a walking hearth is present.

Next, reference numeral 15 exemplifies the setting location of a steel piece reversal positioning part that should be present in a part of the walking hearth. This location should be determined by considering the following circumstances, but the number should preferably be 2 to 6. First, the relationship between the furnace temperature in the heating furnace shown in FIG. 1 and the temperature difference between the top and bottom of the steel billet 14 is the relationship shown in FIG. 2 shown at the bottom of FIG. Please note the positional relationship between this figure and FIG. 2.

That is, the furnace temperature inside the heating furnace changes as shown in FIG. 2 from the entrance lower toward the exit 10. Further, the temperature difference between the upper and lower sides of the steel piece is shown in FIG. 2 in relation to the heating time.

In the above case, assuming that the steel billet is not reversed in the billet reversal positioning section 15, the temperature relationship will be as shown by the broken line in FIG. There is a risk of rotation. However, when the steel billet is reversed at the reversing and positioning section, the temperature relationship becomes as shown by the solid line in FIG. 2, and there is little difference in temperature between the top and bottom, there is little warping, and there is no risk of rotation. Note that the above-mentioned phenomenon of upward warpage varies depending on the cross-sectional area, length, and material of the steel piece. Some pieces of steel do not roll even if the temperature difference between the top and bottom is 100°C, but if the temperature difference is kept to 60°C, rolling will not occur. Furthermore, if the temperature of the steel hot water exceeds 750°C, it will warp and become fermented.

Next, an example of the mechanism of the steel piece reversal positioning unit for reversing the steel piece will be explained using FIGS. 3 to 6.

Reference numerals 161 to 169 indicate the upper surface of the fixed hearth 16;
71 to 176 indicate the upper surface of the movable hearth 17. The movable hearth 17 repeats the movements shown by reference numerals 18 to 21 in FIG. For example, the movement width of the lift 18 is 200 m.
(and Travel 19 is set to 280fi).

Therefore, when the movable hearth is operated in the order from FIG. 3 to FIG. 6, material C, for example, rides on the slope 172 between FIG. 3 and FIG.
be done. Next, in FIG. 5, it is above the corner 164, and by descending in the direction of arrow 20, it moves to the slope 165, and as shown, it falls 90 degrees and rides on the receiving surface 167. After that, move to material D and material E in order.

Further beyond that, if there is a structure similar to that shown in Figures 3 to 6, C
All the pieces of steel, including the material, are rolled another 90 degrees, and end up being flipped 180 degrees.

Next, the example shown in FIGS. 7 to 10 shows another configuration in which the rope piece 14e is reversed by 180 degrees. That is, material A rotates 90 degrees in one cycle. Then, in the next cycle (at the position of material C), it rolls another 90 degrees.

It should be noted that the parts that are considered to have the same or equivalent structure as those shown in FIGS. 3 to 6 in terms of function are given the same reference numerals and the letter "e" as in the previous section, and redundant explanations are omitted.

(Effects of the Invention) As described above, in the present invention, in a top-firing heating furnace, a walking hearth consisting of a fixed hearth and a movable hearth is used to transport a steel billet as in the conventional case. Not only can the steel billet be heated at multiple locations during transportation, but even if the upper side of the steel billet rises in temperature significantly compared to the lower side during transportation, the steel billet can be heated at multiple locations during transportation. The steel billet is reversed at the steel billet reversal positioning unit installed in the steel billet, and the temperature difference between the upper and lower sides is corrected each time.As a result, the steel billet is prevented from being transferred from itself due to upward curvature, which conventionally occurs. . This creates the advantage of increasing the possibility of automatic brewing operations at the brewing end of the furnace.

[Brief explanation of drawings]

The drawings show an embodiment of the present application. Fig. 1 is a longitudinal sectional view showing the position of the reversing positioning part of the steel billet using a conventional walking hearth type heating furnace, and Fig. 2 shows the temperature and heating time. Graphs showing the relationship, Figures 3 to 6 are explanatory diagrams showing the operation in the steel billet reversal positioning section, Figures 7 to 10 are explanatory diagrams showing other operation examples, and Figures 11 and 12 are The front view and the perspective view which show the upward curve of the rope piece. 1... Heating furnace, 12... Walking hearth, 14
... Steel piece, 15... Steel piece reversal positioning part.

Claims (1)

[Claims] A top-fired heating furnace equipped with a steel billet inlet on one side and a steel billet outlet on the other side has a walking mechanism configured to transport the steel billets charged from the inlet toward the outlet. In a walking hearth type heating furnace equipped with a hearth, the above-mentioned walking hearth is designed to invert the steel billets by 180 degrees when the temperature difference between the top and bottom of each steel billet during transportation reaches approximately 60 degrees Celsius. A walking hearth type heating furnace characterized in that a plurality of steel billet reversal positioning sections are provided in the conveying direction.