JPH0381012A - Heat compensation device in direct rolling process - Google Patents

Abstract

PURPOSE:To contrive energy saving and to improve productivity by providing a edge heating means and whole heating device on the 1st route and 2nd route respectively which are provided in a part of transfer route. CONSTITUTION:A cast billet 8 which is released from a continuous casting machine 10 is transferred by the transfer route 1 and the temperature is measured before the branch point of the 1st route 4 and the 2nd route 5 and the billet which only edge heating is needed is fed to the 1st route 4 and the billet which whole heating is needed is fed to the 2nd route 5. By this way, the cast billet 8 for which whole heating is needed can be heated by taking longer time than the interval of the releasing time of the cast billet 8. Therefore, heat efficiency, construction cost and repair cost for the whole heating means 3 are considerably reduced and productivity can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a method of directly hot rolling slabs cast from a continuous casting machine (continuous casting machine) in a high temperature state without passing through a reheating furnace. The present invention relates to a heat-compensated supply device used in a direct rolling process in which rolling is performed by feeding into a machine.

[Conventional technology]

Recently, in the production of steel products, for the purpose of high productivity and energy saving, continuous casting machines and hot rolling mills are directly connected through conveyance paths such as table rollers, and the continuously cast high temperature slabs are immediately hot rolled. Direct rolling methods and equipment are beginning to be used in some areas.

However, with these direct rolling methods and equipment, it is rare that all the slabs discharged from the continuous caster maintain a temperature sufficient for hot rolling, and therefore , as shown in FIG.

A heat compensator, which is a heating means, is installed between the continuous caster and the rolling mill to heat the slab to a temperature sufficient for rolling.

FIG. 7 is a graph showing the temperature drop state of the slab after it is taken out from the continuous caster. As is clear from this figure, the temperature drop is particularly large at the edge of the slab, and if heat compensation is not performed in this area, defects will occur at the edge during rolling, resulting in a reduction in yield during rolling, resulting in large losses. .

Also, depending on the operating conditions of the continuous casting machine, the temperature of the slab on the outlet side of the continuous casting machine may decrease even in a part other than the edge part, such as the center part.
It may not be possible to maintain the temperature necessary for rolling when the product reaches the rolling mill. Furthermore, there are cases where it is necessary to inspect the quality of the slabs removed from the continuous casting machine, and in that case, the temperature will drop even further due to the time required for the inspection.

By heating slabs that do not have the temperature necessary for such rolling,
As mentioned above, in some cases, temperature compensation is performed by heating the edge portion or the temperature of the entire slab to the temperature required for rolling. These techniques are disclosed in Japanese Patent Application Laid-open Nos. 130458-1982 and 1983-130458,
147701, JP-A-57-121803, JP-A-57-187102, JP-A-62-244517, and the like.

[Problem to be solved by the invention]

In a direct rolling process having such a heat-compensated supply device, it is desirable that the time interval at which the continuous casting machine unloads the slab into pieces is equal to the time interval at which the rolling mill takes out the slab into large pieces. If the spacing between the supports does not match, the slab will accumulate between the continuous caster and the rolling mill, causing problems such as a drop in temperature of the slab and a decrease in productivity.

Now, it is assumed that the intervals between the supports are equal, and slabs are taken out from the continuous casting machine at intervals of one hour, as shown in FIG. At this time, if the temperature of the slab is Δθ short of the rolling temperature due to operating conditions of the continuous casting machine, for example, a heat compensation ability is required to heat up this Δθ in time t. In cases where it is only necessary to slightly heat the edges of the slab, there are few problems.1For example, when it is necessary to heat the entire slab, the entire slab can be heated in a limited time t. must be heated, and in that case, it becomes necessary to set the capacity of the heat compensation means to an excessive value, which results in a loss of thermal energy, etc.

An invention described in Japanese Patent Application Laid-Open No. 62-244517 mentioned above is an attempt to solve the problem from the viewpoint of energy. This invention relates to edge heating means for slabs, and the method is such that the continuously cast slabs are advanced while being conveyed to the rolling process.

By heating while repeatedly retracting, the length of the heating furnace can be shortened and thermal energy can be saved. If it is necessary to heat the entire slab, the slab is further conveyed to the entire surface heating means and heated.

However, in this invention, although the length of the heating furnace can be shortened, it is necessary to increase the heating time due to the necessity of reciprocating the slab.

Therefore, it becomes necessary to set a large interval between the cast slabs from the continuous caster, which reduces the manufacturing speed, resulting in a decrease in productivity. moreover.

If the temperature of the slab after edge heating has not reached the rolling temperature, it is necessary to transport it to a heating means for the entire surface and heat it, and this decrease in productivity becomes more significant.

In addition, there is also an invention described in JP-A-50-159404 in which the electromagnetic steel and the ordinary cast slab are heated through a heating furnace in order to heat them efficiently.

In the direct rolling process, some slabs can be supplied to the rolling process without heating, which results in excessive equipment, which goes against energy conservation.

The present invention was devised in view of these problems, and an object of the present invention is to provide a heat-compensated supply device for a direct rolling process that saves energy and has excellent productivity.

[Means to solve the problem]

As a means for that purpose, in a direct rolling process in which the continuous caster 10 and the hot rolling mill 11 are directly connected, the continuous casting machine IO and the hot rolling mill 11 are installed in parallel at least in a part of the conveyor 1 that directly connects the continuous casting machine IO and the hot rolling mill 11. A first route 4 and a second route 5 were established. An edge heating means 2 for heating the edge portion of the slab 8 was provided on the first route 4, and a whole surface heating means 3 for heating the entire slab 8 was provided on the second route 5.

In addition, a third route 6 is formed by installing in parallel with the second route 5,
The second route 5 can be provided with the hot piece heating means 3a, and the third route 6 can be provided with the cold piece heating means 3b.

[Effect]

The operation of the present invention will be explained with reference to FIGS. 1 and 2.

The slabs 8 discharged from the continuous casting machine 10 are conveyed by the conveyance path 1, and the temperature is measured before the branch point of the first route 4 and the second route 5. Those that require only edge heating are transferred to the first route. 4, and those that require total heating are sent to the second route 5.
sent to.

Here, as shown in FIG. 2, it is assumed that the first slab 8a, the second slab 8b, and the third slab 8C are ejected from the continuous casting machine 10 at equal time intervals t. The first slab 8a that is tapped first requires heating as a whole, and the second slab 8a that is tapped second
It is assumed that only edge heating is required for the third slab 8C, which was released third. In that case, the first slab 8a is distributed to the second route 5 and is entirely heated by the entire surface heating means 3.

Since the second slab 8b requires only edge heating, it is distributed to the first route 4, heated slightly to the required temperature by the edge heating means 2, and rolled into large pieces before the first slab 8a. Edge heating.

This is because it is only necessary to heat the 8 ends of the slab.

Easy to heat in a short time.

The first slab 8a, which needs to be entirely heated by the entire surface heating means 3, passes through the second route 5, where it is sufficiently heated in its entirety by the entire surface heating means 3, taking a longer time than via the first route 4. be done. This first slab 8a is rolled N after the second slab 8b that is tapped second and before the third slab 8c that is tapped third and requires only edge heating.
In the case where the first cast piece 8a is to be made into large pieces in 11, it is sufficient to heat the first cast piece 8a for a period of time equal to or longer than the time required for releasing the pieces. Furthermore, if the first slab 8a is to be cut into large pieces after the third slab 8c, it is sufficient to heat the first slab 8a to the required temperature for a time of 2 hours or more. Therefore.

In this case, the heating power per unit time of the 9-surface heating means 3 can be halved.

The operation of the present invention will be explained with reference to the graph shown in FIG. This shows the relationship between time and thermal efficiency when heating slab 8 at 1100°C to 50°C. The heating means is by combustion. From this table.

Doubling the heating time increases thermal efficiency by approximately 20%.

It can be seen that if the heating time is tripled, the thermal efficiency will be improved by about 30%.

This is a trial calculation of thermal efficiency only, but the price of the constituent materials of the entire surface heating means 3 of the heat compensator increases significantly in proportion to the heat resistance, so the temperature within the entire surface heating means 3 is kept low. If it is possible to do so, it can be manufactured at a lower cost and therefore more economical. or.

Construction costs and repair costs can also be reduced by suppressing the temperature within the entire surface heating means 3.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In this embodiment, the first route 4 is the main transport route 1, and the second route 5 is formed in the form of a bus. The edge heating means 2 is arranged on the first route 4, and the entire surface heating means 3 is arranged on the second route 5. This is based on the fact that among the slabs 8 discharged from the continuous caster 10, there are more slabs that require only heating of the edges than those that require heating of the entire slab.

FIG. 3 shows another embodiment. This is a configuration in which a third route 6 is provided in parallel to the second route 5 (and the first route 4). Both the second route 5 and the third route G are means 3 for heating the entire surface of the slab 8, but the second route 5 is provided with the entire surface heating means 3a for hot slabs, and the third route 6 is provided with the entire surface heating means 3b for cold slabs. has been established. The term "warm piece" as used herein refers to one that reaches a rolling temperature by slight heating, and the term "cold piece" refers to one that reaches a temperature from about 00°C to room temperature. Full surface heating means 3
By dividing the temperature into those for hot pieces and those for cold pieces, a longer time can be spent on heating in the cold piece whole surface heating means 3b, which further contributes to improved productivity.

In the above embodiment, the second route 5 is arranged in a bypass manner, but conversely, the first route 4 may also be arranged in a bypass manner, or the eight routes can be detoured almost equally. Also good.

A more detailed embodiment is shown in FIGS. 4 and 5. This is a three-dimensional second route 5 directly above the first route 4 which is a part of the conveyance path 1 in which the slab 8 is conveyed by the rollers 12.
At the same time, the slab 8 is raised and lowered by an elevating section 7 to be conveyed. In this case, the edge heating means 2 is provided on the first route 4, which is the lower stage, and the entire surface heating means 3 is provided on the second route 5, which is the upper stage. In this way, by arranging the first route 4 and the second route 5 three-dimensionally above and below, the installation area can be reduced, which is economical.

This embodiment is particularly effective when the continuous casting machine 10 and the rolling mill 11 are close to each other and when most of the slabs 8 do not require heating or only require edge heating.

In addition, the third route 6 is added to this.

You can also make it three levels, top and bottom, if necessary.

More is possible.

In the above embodiment, the first route 4 and the second route 5 are arranged three-dimensionally one above the other, but of course.

It may be arranged flat.

〔Effect of the invention〕

In this way, in the present invention, at least the first route and the second route are provided in parallel in a part of the conveyance path 1, and the edge heating means is provided on the first route, and the entire surface heating means 3 is provided on the second route. Because I set it up.

By distributing slabs that only require heating of the edges and slabs that require heating of the entire slab to their respective routes, the time interval between slabs that require heating of the entire slab can be reduced. It can be heated over a longer period of time. As a result, the thermal efficiency of the entire surface heating means 3, construction and repair costs, etc. can be significantly reduced, contributing to improved productivity.

Also, for slabs that only require heating of the edges.

After the heating of the edge portion is completed via the first route, the slab is cut into large pieces by a rolling mill at intervals of time when the slab is taken out, so that the slab is processed quickly without being retained in the conveyance path.

In addition, by arranging multiple routes such as the first route and the second route three-dimensionally above and below, and by transporting and recovering the slabs to the upper route using the elevating section.

The present invention has many excellent effects, such as being extremely economical and requiring only a small installation area.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the time intervals of slab ejection, FIG. 3 is a schematic configuration diagram showing another embodiment of the present invention, and FIG. 4 is a schematic side configuration diagram showing a more specific embodiment. FIG. 5 is a schematic cross-sectional tank bottom view taken along the line A-A in FIG. 4. FIG. 6 is a schematic configuration diagram showing the direct rolling process, FIG. 7 is an explanatory diagram showing the temperature drop state of the slab, and FIG. 8 is a graph showing the relationship between heating time and thermal efficiency. Code explanation 1:! 11 feeding path, 2: edge heating means. Full surface heating means, 3a: Full surface heating means for hot piece. Full surface heating means for cold pieces, 4: First route. 2nd route, 6: 3rd route. Lifting part, 8: slab, 8a: first slab. Second slab, 8c: Third slab, 9: Multiple passages. Continuous casting machine, II: Hot rolling machine, 12: Rollerf eupheda 8CI--E speaking method 5b-4 □ Sanchin 10- Ho disease wax 11--- 8- Ventilation 8c- Grass l pus? i 9-Fin entanglement 4 pottery 1 fiit power

Claims (3)

[Claims] (1) In the direct rolling process in which the continuous casting machine (10) and the hot rolling mill (11) are directly connected, the continuous casting machine (10) and the hot rolling mill (11) are directly connected, and a part of the continuous casting machine (10) and the hot rolling mill (11) are directly connected. A conveyance path (1) with at least a first route (4) and a second route (5) arranged in parallel to form a plurality of paths (9); A heat compensation device in a direct rolling process, comprising an edge heating means (2) that heats the edge portion, and an entire surface heating means (3) that is provided on the second route (5) and that heats the entire slab (8). . (2) A third route (6) installed in parallel with the second route (5) is added to the plurality of routes (9), and the second route (5) is provided with the entire surface heating means (3a) for the hot piece, and the 2. The heat compensation device for a direct rolling process according to claim 1, wherein the third route (6) is provided with a whole surface heating means (3b) for the cold piece. (3) A plurality of passages (9) are arranged vertically in three dimensions, and an elevating part (7) is provided, and the elevating part (7) allows the slab (8) to be
3. The heat compensator for a direct rolling process according to claim 1, wherein the heat compensator is moved up and down to be conveyed to an upper route and collected.