JPH05339636A - Furnace equipment for heating and soaking of high-temperature billet - Google Patents

Abstract

PURPOSE:To heat continuously cast billets prior to rolling to the continuously cast billets having a uniform temp. distribution with excellent heating efficiency by disposing a heating furnace having a specific construction between a continuous casting device for steel and a rolling device for the continuously cast billets and passing the continuously cast billets through this furnace. CONSTITUTION:The continuously cast billets 2 transported from the continuous casting device are cooled before arriving at the hot rolling device and, therefore, the billets are heated to the rolling temp. in the heating furnace provided in the middle thereof. Since the continuously cast billets in a heating furnace inlet 3 are higher than the internal temp., the flow of the high-temp. combustion gas from burners 5 for heating are paralleled with the heat transfer direction of the continuously cast billets 2 while the continuously cast billets 2 are moved toward an outlet 6 in the heating furnace equipped with the burners 5 near the inlet 3. The temp. of the combustion gas rapidly heats the surfaces of the continuously cast billets 2 and increases the temp. thereof. The internal temp. of the continuously cast billets 2 are once lowered by the heat transfer to the surfaces but is made into the same temp. as the surface temp. by the reverse heat transfer from the surfaces heated at the high temp. The continuously cast billets are thus taken out of the outlet 6 as the continuously cast billets having the soaking distribution of small temp. deviations and are then subjected to hot rolling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating / soaking furnace facility for high-temperature cast slabs between a continuous casting process and a rolling process.

[0002]

2. Description of the Related Art In recent steel processes, attempts have been made to make continuous casting equipment and rolling equipment continuous and to continuously perform continuous casting-rolling. However, in order to establish this process, there is a problem that the temperature of the slab on the continuous casting equipment side must be increased, the equipment cost must be increased such as heat retention enhancement in the transportation equipment, and the quality must be solved. Is in the stage of. Generally, high-temperature slabs from continuous casting equipment are once put in furnace equipment (heating furnace, soaking furnace, etc.) and heated and soaked within the temperature and temperature deviation required by rolling equipment, so-called hot charge operation. Has been taken.

Although the fuel consumption rate can be greatly reduced by the hot charge operation, an operation method different from that of the conventional furnace equipment for heating the cold piece for further energy saving,
For example, Japanese Patent Publication 58-17243 and Japanese Patent Publication 58-1840.
1 is proposed. These proposals aim to reduce the fuel consumption rate by improving the estimation accuracy of the charging temperature of the slab and reflecting it in the temperature control in the furnace. It was the same as the furnace equipment.
That is, the combustion exhaust gas flow from the burner and the traveling direction of the slab in the furnace are orthogonal to each other, so that the furnace atmosphere temperature on the charging side is lower than that on the extraction side.

[0004]

SUMMARY OF THE INVENTION The inventor has found that for a high temperature slab having a low surface temperature and a high internal temperature distribution, the atmosphere temperature inside the furnace on the charging side is high and the furnace temperature increases toward the extraction side. We have found that the condition is that the temperature of the inside atmosphere is lowered and becomes almost the same as the surface temperature of the slab. In the prior art, such an atmosphere temperature pattern in the furnace could not be obtained, which resulted in an excessively large furnace facility scale and was not optimal in terms of energy saving. In view of the above points, the present invention intends to provide furnace equipment that rapidly raises the surface temperature of a high-temperature slab and realizes a furnace atmosphere temperature pattern for efficient heating and soaking. is there.

[0005]

According to the present invention, a burner is installed on the high temperature slab charging side in furnace equipment, and the combustion exhaust gas flow from the burner and the in-furnace advancing direction of the slab are made parallel to extract the high temperature slab. It is characterized in that a flue suction port for guiding the combustion exhaust gas to the chimney is provided on the side.

[0006]

The operation will be described based on the temperature change of the high temperature slab in FIG. The high-temperature cast slab having the temperature distribution shown in FIG. 3 charged in the furnace equipment has its surfaces B and C rapidly heated by a burner installed on the charging side. The temperature A inside the high-temperature slab temporarily drops due to heat transfer to the surface, but the surface heats up rapidly, so heat transfer disappears, and conversely increases due to heat transfer from the surface.

As the high temperature slab is conveyed to the extraction side in the furnace, the combustion heat from the charging side burner deprives the slab and the refractory material in the furnace of heat, and the temperature of the atmosphere in the furnace is lowered, and the surface temperature of the slab is decreased. Is almost the same as For this reason, the surface temperatures B and C that have rapidly increased in temperature gradually decrease, and the temperature deviation from the internal temperature A that has increased due to heat from the surface becomes smaller, and a soaking distribution can be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiment shown in FIG. The high temperature slab 2 sent to the furnace equipment by the out-of-furnace table 1 is charged into the furnace by the in-furnace table 4 from the charging port 3. A burner 5 is installed on the charging front wall, and combustion exhaust gas from the burner flows toward the extraction port 6. The high-temperature slab is conveyed in the furnace by a walking beam, a walking hearth, etc., and is sent to the extraction furnace table 7. The slab is extracted to the rolling line outside the furnace by this table inside the extracting furnace. A flue suction port 8 is provided on the extraction side, and combustion exhaust gas from the burner is exhausted to the chimney through this flue suction port. FIG. 4 is a comparative example showing a conventional furnace profile and a furnace atmosphere temperature pattern.

[0009]

The inventor made trial calculations on the time required to heat and soak the slab having the temperature distribution shown in FIG. 3 by the conventional technique and the technique of the present invention, and compared them. As a result, the conventional technique requires 35 minutes, while the technique of the present invention can shorten the time to 20 minutes, which is about 40%.

It was confirmed that by shortening this time, the scale of the furnace equipment can be reduced, the fixing of the furnace body and the amount of heat loss can be reduced, and a great effect can be obtained in terms of equipment cost and energy saving.

[Brief description of drawings]

FIG. 1 is a plan view showing a preferred embodiment of the present invention, a vertical cross-sectional view, and a diagram showing the temperature of the atmosphere in the furnace. FIG. 2 is a diagram showing the temperature transition of high-temperature slabs. FIG. 4 is a vertical cross-sectional view showing a vertical cross-section showing an example of the prior art and a diagram of atmosphere temperature in a furnace.

[Explanation of symbols]

1: Out-of-furnace table, 2: High temperature slab, 3: Charging port,
4: Charging-side furnace table, 5: Burner, 6: Extraction port, 7: Extraction-side furnace table, 8: Flue suction port.

Claims (1)

[Claims] 1. In a furnace facility for heating and soaking high temperature slabs from a continuous casting facility, which is located between the continuous casting process and the rolling process, the slabs are heated and soaked to the charging side of the furnace body. Furnace equipment for heating and soaking high-temperature slabs, which is equipped with a burner and a flue suction port on the extraction side.