JPH0747768B2 - Charging method for heating furnace - Google Patents

Description

TECHNICAL FIELD The present invention relates to a charging method for a heating furnace in which the temperature of a steel slab to be charged into the heating furnace is measured in advance during transfer to perform charging classification. .

[Prior Art] The heating furnace used in the conventional steel rolling process is
It was designed to charge a steel slab at room temperature around 25 ° C and heat the slab to a temperature suitable for rolling. However, in order to reduce the fuel consumption rate, hot-charge rolling is performed by charging the billet immediately after slabbing or immediately after continuous casting into a heating furnace without cooling and heating it to an appropriate temperature. . The charging temperature of the steel slab into the heating furnace in this case varies depending on the elapsed time after slabbing or continuous casting and the size of the steel slab, but there is a difference of about 200 to 700 ° C.

As a furnace temperature control method for more efficiently heating these billets having different charging temperatures, there is a heating furnace control method disclosed in Japanese Patent Publication No. 58-18401.

This control method calculates the extraction temperature from the charging temperature of the hot steel billet into the heating furnace, and among the possible combinations of the temperature of each furnace zone such that the calculated temperature becomes the target value, the charging side By adjusting the temperature of each furnace zone to the one with the lowest furnace temperature,
It is intended to set an appropriate furnace temperature and reduce the fuel consumption rate.

[Problems to be Solved by the Invention] In such a charging and controlling method, since the charging temperature of the steel slab is usually intended to measure the charging temperature into the heating furnace, for example, As shown in FIG. 5, the steel piece 53 transferred from the slab yard 51 onto the transfer table 52 is measured by a thermometer 56 installed near the charging table 55 near the heating furnace 54 charging port. It was common.

On the other hand, in the case of a direct transfer machine from a continuous casting machine, the temperature is
Some of them exceed 1000 ° C, and depending on the material, it is not preferable to charge them into the heating furnace as they are because they will be kept in the temperature range near the transformation point for a long time. Furthermore, by charging steel pieces in a wide temperature range from room temperature to 1000 ° C into the same heating furnace,
Since the fuel consumption rate deteriorates, it has become necessary to temporarily put the steel materials sent from the continuous casting machine in the slab yard, and to sort the heating furnace according to the charging temperature of the steel materials. Under such circumstances, if the charging temperature of the steel slab 53 was measured near the charging inlet of the heating furnace 54, the subsequent transportation of the steel slab and the sorting operation of the heating furnace would be complicated, and the work efficiency would be high. There is a problem in that the temperature of the billet decreases and the unit consumption of fuel also deteriorates.

The present invention solves the above problems, and provides a heating furnace charging method that facilitates sorting work by measuring the temperature of a steel slab in advance during transfer and improves the fuel consumption rate.

[Means for Solving the Problems] In the present invention, in the crane transfer process in the process of transporting a billet to a heating furnace, the billet temperature is measured by a temperature detector attached to a jig for holding the crane. The steel pieces are classified into predetermined temperature ranges based on the measured values, and only the steel pieces in the temperature range are conveyed and charged into the designated heating furnaces.

[Operation] The present invention detects a temperature attached to a crane in a continuous casting machine, or in a crane transfer process before transferring to a charging table of the heating furnace in a transfer process from the slab rolling process to the heating furnace. By measuring the temperature of the billet with a vessel, the billet can be classified into a predetermined temperature range by a processing device, etc. during transfer by a crane, and the billet can be loaded into the heating furnace in this process. Designate the heating furnace to be charged by judging whether it is the optimum temperature, or which of the heating furnaces is the best to be charged from the viewpoint of heating effect and fuel consumption rate, and after loading on the charging table It is directly transferred to the designated heating furnace and charged. Therefore, it is not necessary to sort the heating furnace on the charging table, the flow of the steel material becomes smooth, and the temperature loss is reduced.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a process of transporting a steel slab to a heating furnace.
Figure is a block connection diagram of the temperature detection and classification circuit, and Figure 3 is the second.
Drawing showing the logic judgment in the calculator of figure, and also 4
The figure is a side view showing an example in which a temperature detector is attached to a gripping jig of a crane.

In the figure, reference numeral 1 is a crane for loading a high temperature steel slab 2 sent from a continuous casting machine or the like from a transfer table 3 to a loading table. As shown in FIG. A temperature detector 7 such as a radiation thermometer for measuring the temperature of the steel slab 2 is attached. Reference numeral 10 denotes a heating furnace, and the three heating furnaces 10a, 10b, and 10c each have a temperature range of a steel slab to be charged to 200 ° C. through the charging table 4, for example.
Above 500 ° C, 501 ° C to 700 ° C, above 701 ° C and below 1000 ° C.

Here, the temperature of the steel slab 2 measured by the temperature detector 7 according to a command from the crane controller 11 shown in FIG. 2 is converted into a predetermined electric signal by the converter 12 and input to the calculator 13. The calculator 13 classifies the measured temperatures of the steel slab 2 based on the comparison information from the management calculator 13a. This classification will be described with reference to FIG. 3. First, it is determined whether the measured temperature is the charging temperature limiting material for the heating furnace based on the comparison information, and then the temperature is higher than the upper limit or lower than the lower limit. Determine if there is. If it exceeds the upper limit of the control range, an instruction for temporarily placing the steel piece 2 for cooling, for example, is issued, and at the same time, the temporary placement time is set according to the temperature. The bill 2 having the temperature within the upper and lower limits of the limit range is instructed to be charged into the furnace No. as originally planned, and if it is less than the lower limit of the limit range, an instruction to change the furnace No. is issued. This instruction is output as a work instruction sheet 14 or displayed on the display panel 15,
The crane operator carries the steel slab 2 to a predetermined temporary placement position or the charging table 4 according to this instruction.

At this point, the steel pieces 2 loaded on the charging table 4 have already been classified by temperature, and the heating furnaces 10a, 10
Since it is decided whether or not to charge into b and 10c, the charging work can be done smoothly without the time loss required for sorting, etc., and each steel slab is suitable for the subsequent heating according to its temperature. Are selected, so that heating is effectively performed.

The temperature data of each steel slab measured by the temperature detector 7 and input to the calculator 13 can be used as heating furnace temperature control data after charging the steel slab 2 into the heating furnace 10.

In the present embodiment, one temperature detector 7 for temperature measurement is attached to the central portion, but if a plurality of temperature detectors 7 are attached in the width direction or length direction of the billet, the temperature distribution of the billet can be grasped. It is also possible to do so. In addition, by doing this, it is possible to know in advance the length considering the thermal expansion of the steel slab,
On the charging table 4, the steel slab 4 can be accurately stopped at the charging position of the heating furnace 10, and the charging operation becomes smoother.

[Effects of the Invention] As described above, according to the charging method, the steel slab to be charged into the heating furnace is measured in advance during the crane transfer process, and the steel slab is charged and heated based on the measurement data. Decide on the furnace,
It is used for post-conveyance, charging, and heating control.Therefore, it is not necessary to perform complicated work such as temporary placement and sorting of the steel pieces in front of the heating furnace, and the steel pieces can be smoothly set to the specified size. Can be charged into the furnace. Further, since the billets to be charged are classified in advance in each predetermined temperature range, the billets in the furnace are heated uniformly and effectively so that the fuel consumption is reduced and the fuel consumption rate is reduced. Can be reduced.

[Brief description of drawings]

1 to 4 show an example of an apparatus for carrying out the present invention,
FIG. 1 is a plan view showing a process of transporting a steel slab to a heating furnace, FIG. 2 is a block connection diagram of a temperature detection classification circuit, FIG. 3 is a drawing for explaining logic judgment in a calculator of FIG. FIG. 4 is a side view showing an example in which a temperature detector is attached to a holding jig of a crane, and FIG. 5 is a plan view showing a carrying process to a conventional heating furnace. 1 ... Crane, 2 ... Steel, 3 ... Transport table, 4
…… Charging table, 5 …… Gripping jig, 6 …… Tongs,
7 ... Temperature detector, 10,10a, 10b, 10c ... Heating furnace, 11 ...
Crane controller, 12 …… Converter, 13,13a …… Calculator, 14
…… Work instruction sheet, 15 …… Display panel

Claims (1)

[Claims] 1. A steel slab temperature in a process of transferring a steel slab to a heating furnace, the temperature of the steel slab is measured by a temperature detector attached to a jig for gripping the crane, and the steel is measured based on the measured value. A method for charging a heating furnace, characterized in that the pieces are classified into predetermined temperature ranges, and only the steel pieces in the temperature range are conveyed and charged into the designated heating furnaces.