JPS6025488B2 - Continuous heating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous heating furnace that has a chopstick effect for continuously heating materials to be heated such as steel ingots or steel slabs.

Generally, the rolling capacity of rolling mills for shaped steel, twilled steel, wire rods, etc. has increased significantly, and whether or not this rolling capacity can be fully utilized depends on the heating capacity of the heating furnace.

Therefore, uniform heating of the material to be heated has become a major issue in order to improve the heating capacity of the heating furnace and to minimize the influence on the rolling of the material to be heated. Therefore, as a solution to the above problem, a continuous heating furnace with three upper and lower zones as shown in Figure 1 and a continuous heating furnace with five upper and lower zones as shown in Figure 2 have been used. In any of the heating furnaces, the material to be heated 1 is conveyed in the direction of the arrow by a pusher or the like on a tubular water-cooled skid race 2 supported by a support pipe 3, while passing through a heating zone upper burner 5, a heating zone lower burner 6, and the like. The temperature is raised by an upper preheating zone burner 8 and a lower preheating zone burner 9 provided in addition to the burners shown in FIG. In this case, as shown in Fig. 3, since water is flowing through the water-cooled skid rail 2, the temperature is naturally lower than the atmosphere temperature inside the furnace, so it is exposed to heat. Even if the heating material 1 is heated and its temperature rises to a certain degree, the contact surface of the heated material with the water bath skid rail remains at a lower temperature than the other heated parts.

Next, when the heated material 1 is rolled in such a temperature state, that is, the low temperature part and the high temperature part are clearly distinguished,
Skid marks that cause various operational and quality problems occur in the low-temperature parts. Therefore, in order to prevent such skid marks from occurring, it is necessary to reduce the temperature difference in the skid mark part as much as possible. As a countermeasure to this problem, the soaking zone hearth 4, as shown in Fig. 4, should be made of a refractory or steel with excellent high temperature resistance, oxidation resistance, and abrasion resistance. There is a method of burying the rail 11 and supporting the heated material 1 on the rail.
This is because the temperature of the soaking zone hearth is not sufficiently raised at the start of furnace operation, so the temperature difference between the upper and lower surfaces of the material to be heated increases, and even when furnace operation is started, the hearth temperature remains constant. It takes a long time to reach a certain level of steady-state temperature, which has the drawback of having an adverse effect on the operation of the furnace and rolling mill or on the quality control of the product.

In contrast, the present invention aims to provide a continuous heating furnace that can eliminate all of the above-mentioned drawbacks, and its gist is that the steel core or steel core charged from one side of the furnace body In a type of furnace in which the material to be heated, such as a steel billet, is conveyed on skid rails inside the furnace, the material is heated to a high temperature and extracted from the other side of the furnace body, and the material to be heated is exposed to the burner flame and the high-temperature combustion gas atmosphere. In this case, the reversing device reciprocates the movable pedestal on fixed pedestals to be installed on both sides of the hearth corresponding to the scorching hearth or heating zone hearth. A front and back movement cylinder for reciprocating the movable base and a rotation cylinder for rotating the heated material are provided at the center and above the movable base, respectively, and are arranged so as to move or follow the movable base. A rotating cylinder is drivingly connected to the opposite end of a rotary shaft in which a receiving fitting for the material to be heated is attached to the inner shaft end of the furnace, through a pair of meshing gears, and the receiving fitting for the heated material is driven by the receiving fitting for the heated material. According to the present invention, the material to be heated is exposed to the burner flame and the high-temperature combustion gas atmosphere for several minutes to several minutes. By installing a reversing device for the material to be heated at either the soaking zone or the heating zone, the material to be heated can be heated to 180 degrees.
Since the skid mark area, which was previously at a low temperature after being turned over, is heated by Korean radiation heat and the combustion gas atmosphere inside the furnace, the skid mark can be easily removed and the equipment can be used to its full potential from the start. This makes it possible to save energy and shorten the start-up time until operation.

Further, according to the present invention, the material to be heated is automatically received in the furnace, turned over, and sent out in a series of operations, so there is no need for other equipment or a reheating furnace, and there is no need for a soaking area. By reducing the length of the reactor, we can expect to save resources.

Next, the present invention will be explained in further detail with reference to two embodiments shown in FIGS. 5 to 11, in which the same parts as in FIGS. 1 to 4 are denoted by the same reference numerals. First of all, FIGS. 5 and 6, which show the first embodiment of the present invention, show a top and bottom three-zone type (top and bottom five-zone type) continuous heating furnace that adopts the top discharge method.
7 and 8 showing the second embodiment of the present invention respectively show an upper and lower four-zone continuous heating furnace employing a side discharge method, and in the former case, the reversing device 20 for the material to be heated 1 is In the soaking zone hearth 4, in the latter case, the heating zone hearth 2
As shown in FIG. 8, a dry skid rail 22 is embedded in the heating zone hearth, and a side extraction window 23 is opened on the side surface. As shown in FIG. 8, a reversing device 2 for the material to be heated 1 is installed on both the left and right sides of the furnace body 26 (soaking zone hearth 4 or heating zone hearth 21) as a set of a fixed pedestal 24 and a movable pedestal 25. Since the device is installed and is symmetrical in terms of structural arrangement, only the left half of the device will be explained below, and the right half will be omitted.

On the fixed frame 24 provided in the longitudinal direction of the furnace body 26,
As shown in Figures 9 and 10, parallel roller type rollers 27
and a movable frame 25 via a cam follower (roller) 28.
are layered so as to reciprocate in the longitudinal direction (or back and forth), and a back-and-forth movement cylinder 29 is located in the center of the movable frame between a bracket 30 on the fixed frame and a lower bracket 31 of the movable frame. The movable frame is moved back and forth by the operation of the cylinder.

Furthermore, one of the rotary motion cylinders 32 to be disposed directly above the longitudinal motion cylinder 29 is pivotally connected to the upper bracket 33 of the movable frame 25, and the other end is connected to the movable frame 25 via a pair of bearing boxes 34. It is pivotally connected to a drive lever 36 that is integral with a drive shaft 35 that is pivotally supported on both sides of the drive shaft, and a large gear 37 that is driven and rotated by the rotation cylinder is attached to the drive shaft. Also, as shown in FIG. 11, directly above the drive shaft 35, the outer side is pivotally supported by the movable frame 25 via a pair of bearing boxes 38, and the inner side is supported by the furnace body 25. A rotating shaft 40 that passes through the wall hole 39 and reaches the end of the conveyance line for the heated material 1 is disposed, and the small gear 41 attached to the shaft is engaged with the large gear 37 of the drive shaft to perform rotational operation. The small gear is driven and rotated by the operation of the cylinder 32, so that the receiving fitting 42 for the heated material attached to the tip of the rotating shaft is reversed by a predetermined angle, for example, 180 degrees. Further, a water-cooled seal metal fitting 43 is installed on the outside of the wall hole 39 formed in the furnace body 26, and is installed perpendicularly to the rotating shaft 40' and integrally connected between the furnace body 26 and the movable frame 25. The attached seal plate 44 is constantly pressed against the water-cooled seal hardware by the tension of a spring 46 wrapped around a pin 45 attached to the movable frame, and is pressed by a guide 47 provided on the metal hardware. They are guided and made to move back and forth. Next, to describe the operation of the reversing device 20 for the material to be heated 1 having the above-mentioned configuration, the material to be heated starts from the position shown in FIG. The material to be heated is reversed to heat the skid marks on the bottom surface of the material, remove the skid marks, and then send it out of the furnace. 29 is drawn to the bracket 30 as shown in FIG. 10, that is, as shown in FIG. 12 A to FIG. Next, the gear ratio is set in advance to 2:
When the large gear 37 on the driving side, which is set to 1, is rotated 900 turns by the operation of the rotary cylinder 32 and the drive lever 36, the small gear 41 on the driven side, which is meshed with the gear, becomes 18.
Accordingly, the receiving metal fitting 42 attached to the tip of the rotating shaft 40 to which the small gear is fixed also rotates 1800 times, resulting in the state shown in FIG. 12C. If the back-and-forth operation cylinder 29 is extended in this state, as shown in FIG. send to. Thereafter, the back-and-forth operation cylinder 29 is operated to return it to the intermediate point as shown in the tree in FIG.
2 is reversed by 1800 degrees to enter the standby state shown in FIG.
By repeating similar operations thereafter, stable operation of the heating furnace can be achieved. From the above, according to the present invention, in FIG. 5, the heated material 1 heated and heated by the heating zone upper burner 5 and the heating zone lower burner 6 is transferred on the water-cooled skid rail 2 in the direction of the arrow. As the heat is absorbed by the water-cooled skid rail 2 in the heated material 1 that has come to the scorching hearth 4, a skid mark portion is created where the temperature is lower than other parts, and this skid mark is efficiently erased. Therefore, the material to be heated is reversed by the reversing device 201. In this case, if the material is rotated by 90 degrees, the skid mark portion will come into contact with the hot surface of the subsequent material to be heated, and if the material is rotated by 180 degrees, the skid mark portion will be brought into contact with the hot surface of the material to be heated. is exposed to the burner flame and the high-temperature combustion gas atmosphere, so that the skid mark portion rapidly absorbs heat due to the subsequent contact with the hot surface of the heated material, and due to heat diffusion inside the heated material, the skid marks are exposed to the burner flame and the high temperature combustion gas atmosphere. The skid mark part, which is exposed to the high-temperature combustion gas atmosphere by facing upward as well as erasing the mark, is efficiently removed by the radiation heating from the burner flame and the high-temperature combustion gas atmosphere and by thermal diffusion inside the heated material. , and can be erased in a short time.

In addition, in FIG. 7, the heated material 1 heated and heated by the child zone upper burner 8, the child zone lower burner 9, the heating zone upper burner 5, and the heating zone lower burner 6 moves on the water-cooled skid rail 2 in the direction of the arrow. A heating zone hearth 21 is provided at a part of the final end of the heating zone, and a reversing device 20 is installed at the hearth.
By inverting the heated material, skid marks can be rapidly erased for the same reason as mentioned above.

Therefore, it is possible to eliminate the drawbacks of conventional continuous heating furnaces, and to achieve the same effect without providing a scorching zone. To solve problems such as the long time it took to start operation and the inability to fully utilize the ability to supply materials to the rolling mill, remove the material to be heated 1' from the furnace when work is completed before a holiday. By determining that the work is completed when the work is taken out, the burner is fired to raise the temperature inside the furnace at the start-up before the start-up after the holiday, and in this way, it is the preparation time to heat and raise the temperature of the material to be heated 1, the walls and ceiling of the furnace. The tip portion 4' of the soaking zone hearth 4 or the heating zone hearth 21, which is a space, is heated and heated in the same manner.

In addition, when the operation is started and the heated material 1 is transferred, the scorching hearth 4 to the heating zone hearth 21 have sufficient heat stored at the time of heating and temperature increase, so that the heated material 1' is more heated than the heated material 1'. Since the material is not taken away, there is no problem in passing the material to be heated. Therefore, it is possible to fully utilize the capacity of the equipment from the time of starting the operation, and it is possible to shorten the start-up time until the start of operation. In the case of the side discharge method as shown in FIG. 7, the position of the extractor can be fixed because the most extreme stopping position of the material to be heated 1' can be kept constant.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a conventional three-zone continuous heating furnace, Fig. 2 is a longitudinal cross-sectional view showing a conventional five-zone continuous heating furnace. m in Figures 1 and 2
5 is a longitudinal sectional view of the upper and lower three-zone continuous heating furnace according to the present invention, and FIG. 6 is a sectional view taken along the W-machi line in FIG. 5. 7 is a longitudinal cross-sectional view showing the upper and lower four-zone continuous heating furnace according to the present invention, FIG. 8 is a cross-sectional view taken along the OX-OX line in FIG. 7, and FIG. 9 is a cross-sectional view of the material to be heated. This shows the reversing device, and shows a cutaway front view taken along line K-K in Figure 11, Figure 10 is a side view as before, Figure 11 is a plan view as before, Figure 12 A - Wood is heated. It is an explanatory view showing the reversal operation of the material. Note that the correspondence between the main parts shown in the figures and the symbols is as follows. 1... Material to be heated, 1'... Inverted material to be heated, 2... Skid rail, 4... Soaking hearth, 20... Material to be heated reversing device , 21...
... Heating zone hearth, 40 ... Rotating shaft, 42
...Bracket. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 8 Figure Mountain Boat Figure Boat Figure Boat Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. In a type of furnace in which the material to be heated, such as a steel ingot or billet, is charged from one side of the furnace body, is heated while being conveyed through skid rails in the furnace, and is extracted from the other side of the furnace body. A reversing device for the heated material is provided at a position where the heating material is exposed to the burner frame and the high-temperature combustion gas atmosphere, and in this case, the reversing device is installed on both sides of the furnace body corresponding to the soaking zone hearth or heating zone hearth. A movable pedestal is placed on a fixed pedestal to be installed so as to move back and forth or back and forth, and a back-and-forth movement cylinder for reciprocating the movable pedestal below and above the center of both movable pedestals, respectively, and the heated object. providing rotary cylinders for rotating the material, and drivingly connecting these rotary cylinders to the opposite end of a rotating shaft to which a receiving fitting for the material to be heated is attached to the shaft end inside the furnace via a pair of meshing gears; A continuous heating furnace characterized in that the material to be heated is received in the furnace by the receiving metal fitting by the operation of both cylinders, and is turned 180 degrees and sent out.