JPS6128002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for transporting materials in a split-carriage walking beam heating furnace.

In recent years, the ingot making and blooming processes at steel plants have been replaced by continuous casting machines. In this case, the process is
The process goes from a converter or arc furnace to a continuous casting machine to a heating furnace to a rolling mill, and in order to save energy and achieve continuity, the steel billets from the continuous casting machine are heated in a hot state. As a heating furnace used in such a process, a walking beam heating furnace of a split-truck type, in which the carriage can be divided and driven independently, is most suitable. The reason for this is that, for the purpose of energy saving and process continuity, it is common knowledge these days to charge the hot steel billet from the continuous casting machine into the heating furnace without cooling it. Continuous casting machine: It is preferable to process one batch of billets per lot in a converter or arc furnace, and to roll one batch of billets continuously in order to achieve optimal heat treatment and rolling treatment of the billets. The loading (charging) speed of steel billets supplied to the heating furnace is much slower than the extraction speed required by the rolling mill, and therefore serves as a buffer to absorb the difference in capacity between the continuous casting machine and the rolling mill. For example, a heating furnace with semi-batch and semi-continuous characteristics is required.

For this purpose, the walking beam cart is divided into several parts in the furnace length direction, and the size of one cart is reduced to one group of billets (one lot of converter or arc furnace, sometimes 1/2 lot, or two lots by connecting the carts). )
The size is such that it can be loaded so that it can be processed in bulk.
In addition, a split-truck type walking beam heating furnace is employed in the process, in which each divided carriage is driven independently at different speeds.
It should be noted that one truck may be used for the 1/2 steel billet group or 2 steel billet groups, or a plurality of bogies may be combined in succession.

When processing a group of steel slabs at once using the above-mentioned split-carriage type walking beam heating furnace, it is naturally desirable to control the temperature on a unit of steel slab group or on a car-by-cart basis. For this purpose, as shown in FIG. 1, it is necessary to partition the heating chamber 2 of the heating furnace 1 into several independent sections in the direction of conveyance of the steel billets. In this case, the ceiling 3 is deformed to provide a partition wall 4 that can protrude downward, and the partition wall 4 is installed in the lower part.
A partition wall 6 corresponding to the heating chamber 2 is erected on the hearth 5 to divide the heating chamber 2 and have independent temperature control performance.

However, when batch processing is carried out by loading, for example, one group of steel slabs on each of the carts A and B, conventionally the steel slabs are stacked so that a predetermined gap G is provided between each steel slab 7, as shown in Fig. 2. The billets are transported in a charging pitch with billet width W + gap G, and the billet groups S ₁ and S ₂ are charged with the same gap G as above, and transferred between carts. The steel billet is heated while it is repeatedly staying on the truck, but when the steel billet is staying on the truck, the steel billet located directly below the upper partition wall 4 and directly above the lower partition wall 6 is heated. It is well known that the heat transfer is poor and the temperature is difficult to rise.

On the other hand, when charging steel billets, the actual pitch of movement relative to the planned charging pitch always includes mechanical and control errors. For example, in a truck loaded with 20 steel slabs, the gap between the steel slabs is 100 mm, and the 1 pitch error is +
To explain the case where an error of 3 mm occurs, an error of 3 mm is not a problem when the gap between steel pieces is 100 mm. However, the cumulative error from the beginning to the end of one bogie is 20×3
mm=60mm. In practice, since positioning is performed using a phototube or the like at the beginning of each group of steel slabs, this cumulative error is absorbed by the 100 mm gap between the groups of steel slabs. Therefore, the gap between the steel slab groups is 100 mm - 60 mm = 40 mm. Considering the bending of the steel pieces, this number may indicate contact between the steel pieces.

To prevent this, conventional techniques have been to (1) employ an expensive control method to reduce each pitch error;

(2) Increase the gap between the steel pieces in advance. Other methods have been tried.

However, in the case of the former, equipment costs are extremely high;
In the latter case, the pitch will be increased, and the length of the furnace will become longer. For example, if the gap is lengthened by 60 mm, the disadvantage is that when loading 20 pieces of steel, the length of the car will be 60 mm x 20 pieces/one car = 1200 mm/one car.

The present invention was made for the purpose of uniformly heating each steel billet and obtaining good temperature control when the steel billets are retained on a trolley. In this process, the steel slabs of the steel slab group are loaded on each truck at an equal pitch, and the steel slab groups are loaded so that there is a space between the steel slab groups that is wider than the gap between each steel slab, and the steel slab groups are separated at the partition wall. A split-truck type walking beam characterized in that the carriage can be stopped by detecting the position of the leading steel piece, and the group of steel pieces is transported so that the space portion is located between the upper and lower partition walls while the group of steel pieces is retained. This invention relates to a method and device for transporting materials in a type heating furnace.

Embodiments of the present invention will be described below with reference to the drawings.

Basically, as shown in FIG. 3, when the steel slabs 7 are sequentially loaded on each bogie A, B at an equal pitch and one group of steel slabs is loaded, the steel slab groups S ₁ , S ₂ Groups of steel slabs S 1 and S ₂ are loaded on a trolley so that there is a _{space of 1 pitch or 2 pitches equal to the above pitch between them, and the steel slab groups S 1 and} S ₂ are transferred and retained in the furnace repeatedly. The empty space 8 created between the steel billet groups S ₁ and S ₂ is located between the upper partition wall 4 and the lower partition wall 6.

To explain one embodiment, the length of each steel billet support 9 of bogies A and B in the steel billet feeding direction is
The steel billet groups S ₁ and S ₂ are configured to be longer by 1 or 2 pitches than the number of billets, and when the billet groups are loaded on the support 9, the portion lengthened by 1 or 2 pitches becomes the empty space 8. and the empty space 8
is formed on the front end side or the rear end side of adjacent carts A and B, so that the empty space 8 is located between the upper partition wall 4 and the lower partition wall 6 that partition the heating chamber. A truck forward and backward movement device (not shown) is configured to be able to control the movement stroke of the truck.

To transport the steel billets, first, the billets are loaded onto cart A at a charging speed at equal pitches, and then loaded into the converter or arc furnace for 1 lot (or 1/2 lot or 2 lots). A group of steel slabs _S1 is loaded onto a truck A. Next, carts A and B are interlocked at a transfer speed so as to transfer the steel billet group S ₁ onto the next cart B, and the steel billet group S ₁ on cart A is transferred onto cart B. When the transfer is completed, the trolley A is operated independently at the charging speed to charge the next group of billets _S2 .
Cart B sends the steel billet group _S1 to the extraction side. In this way, the steel billet groups charged into the heating furnace 1 are sequentially heat-treated in each heating chamber while repeating transfer and retention for each group of steel billets, and are extracted from the extraction side. At this time, the length of the support 9 part of the truck is made longer by the required pitch with respect to the number of steel billets in the group of steel billets, so when the group of billets is retained on the truck, there is a gap between each group of billets. A space 8 corresponding to the above pitch will be opened. That is, if the steel slabs 7 are loaded on the truck in sequence so that no empty space is left in one group of steel slabs, the empty space 8 will always be at the front or rear end of the truck. Partition walls 4 and 6 are installed in the empty space 8 at the front or rear end of this cart, and a leading steel billet position detector (not shown) such as a phototube or transfer counter is installed just in front of the partition wall. For example, by detecting the position of the leading steel piece and stopping the cart at that position, the empty space 8 is always located directly below the partition wall 4 and directly above the partition wall 6 when the cart is always retained. Therefore, when different groups of steel slabs are processed under different temperature conditions in each heating chamber 2 partitioned by the partition walls 4 and 6, the steel slabs near the boundary between the groups of steel slabs are directly under the upper partition wall 4 and Since the steel pieces do not stay directly above the lower partition wall 6, the steel pieces do not have temperature deviations compared to other steel pieces, and can be heated uniformly.

Furthermore, the presence of the empty space 8 between the groups of steel billets allows the empty space 8 to absorb stroke errors in conveyance. In other words, even if stroke errors in the conveying pitch of each billet accumulate, due to the existence of the empty space 8, deviations in heating are less likely to occur and troubles in conveyance can be reduced, and the charging pitch of each billet can be reduced. Easy to control.

In the above explanation, two carts A and B are shown as a split-cart walking beam heating furnace, but even if the cart is split into three or more parts, there will be a corresponding number of heating chambers. It is sufficient if the partition walls 4 and 6 are used to form a partition. It goes without saying that the present invention also includes a method of transporting materials in which one pitch is transported by two cart movement strokes.

As described above, according to the present invention, (i) In order to prevent steel pieces from accumulating between the upper and lower partition walls in the heating furnace, there are no poorly baked pieces of steel; There is no variation in temperature between each steel billet in a group of steel billets, allowing for uniform heating.

(ii) Since empty spaces are provided between the steel pieces, errors in the steel piece conveyance stroke can be absorbed by this empty space.

(iii) Since the steel billet is heated for each lot (or for each cart) without temperature deviation, heating adjustment for each lot is easy.

It can produce excellent effects such as

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of a walking beam heating furnace with a split trolley type, Fig. 2 is a cross-sectional view showing the state between groups of steel pieces by a conventional conveyance method, and Fig. 3 is a diagram showing an embodiment of the present invention. . A, B... Trolley, 1... Heating furnace, 4... Upper partition wall, 6... Lower partition wall, 7... Steel piece, 8... Empty space.

Claims (1)

[Scope of Claims] 1. In a walking beam heating furnace with split trolleys, steel slabs of groups of steel slabs are loaded on each trolley at equal pitches, so that there is a space between the groups of steel slabs that is wider than the gap between each slab. A group of steel slabs is loaded on the partition wall, and the position of the leading steel slab of the group of steel slabs is detected at the partition wall so that the bogie can be stopped.While the group of steel slabs is accumulated, the space above is located between the upper and lower partition walls. A method for transporting materials in a walking beam heating furnace with a divided trolley, characterized by transporting materials in the same position. 2. In a split-carriage walking beam heating furnace, the length of each cart shall be long enough to load more steel billets than the number of steel billets in the group of loaded steel billets, and between the upper partition wall and lower partition wall of the heating furnace. A leading steel billet position detector is provided to detect the position of the leading steel billet of the steel billet group so that the empty space between the steel billet groups comes and stays, and the movement stroke of the back and forth movement device of the bogie can be controlled. A material conveying device for a walking beam heating furnace with a split trolley.