JPH0919710A - Edge heater device for hot billet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make equipment small and simple and to suppress construction cost or the like by oppositely arranging burners for jetting flames on both sides of the transporting route of a hot billet on a roller table on the right and left sidewalls of a furnace casing in which a roller table for transporting the hot billet loaded on it is constructed. SOLUTION: The burners 14 is fired before starting rolling, the hot billet 11 which is transported from a continuous cast machine with the roller table 16a on the outside of the furnace is received in the furnace casing 13 through a charging port 13a. While the hot billet 11 charged into the furnace is successively moved toward the outlet 13b with the roller table 12 in the furnace, the billet is wrapped in flame K jetted from the burners 14, so its peripheral sides, end faces and edge parts are heated and their temps. are raised up to a prescribed temp. in a short time (The center part of the hot billet 11 is held at the final rolling temp.). And, the hot billet 11 finished heating is taken out of the outlet 13b, loaded on the roller table 16b outside the furnace and transported to a rolling line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot billet edge heater device capable of directly connecting steel rolling to hot rolling.

[0002]

2. Description of the Related Art Generally, hot rolling determines the final temperature of rolling.
It is necessary to secure at least the Ar ₃ transformation point. Therefore, HD
In either case of R (a method of directly rolling a hot billet discharged from a continuous casting machine without passing through a heating furnace) or HCR (a method of reheating a hot billet discharged from a continuous casting machine in a heating furnace to perform rolling) It is important to transport the hot billet from the steel mill to the heating / rolling line in the next process while keeping the temperature as high as possible.

[0003] In particular, when aiming for HDR, it is necessary to ensure thorough heat insulation and heat retention of the hot billet and transport it to the rolling line in the shortest possible time. It is necessary to compensate for the temperature drop, and as a facility therefor, an induction heating type heating device has been conventionally used.

[0004]

However, the above-mentioned induction heating type heating device not only consumes a large amount of power, but also increases the size and complexity of the equipment, resulting in high construction costs, running costs, and maintenance costs. There was a problem.

In view of the above points, the present invention reduces the size of equipment.
It is an object of the present invention to provide a direct-fired hot billet edge heater device that can be simplified and keep construction costs, running costs, and maintenance costs low.

Another object of the present invention is to provide a hot billet edge heater device capable of uniformly heating a hot billet over its entire length in a short time by rapidly heating the periphery and edge of the hot billet during transportation.

Another object of the present invention is to provide a hot billet edge heater device which eliminates the temperature deviation of the hot billet during conveyance and does not generate skid marks or seal marks.

Still another object of the present invention is to provide a hot billet edge heater device having a furnace body which is capable of raising the temperature for a short time by repeating daily temperature raising and lowering and has a furnace body resistant to thermal shock. .

[0009]

In order to achieve the above object, the first aspect of the present invention is to provide a hot table on the left and right side walls of a furnace body on which a roller table for carrying a hot billet is laid. A burner that can inject flames is placed oppositely across the billet transport path, and the hot billet is wrapped in flames.

According to a second aspect of the present invention, one or more of the burners are installed on the wall surface between the rollers of the roller table, respectively, and the periphery of the hot billet, the end face and the edge portion are heated to a desired temperature in a short time. It is configured to be warm.

Further, each roller of the roller table is formed in a shaft water cooling type so that the temperature difference between the hot billet and the conveying surface with which it directly contacts does not become large, and the temperature of the furnace body changes. Made of ceramic fiber refractory that does not expand or contract.

[0012]

In general, when a material to be heated is heated in an oxidizing atmosphere, an oxidation phenomenon occurs and scale is generated. The scale loss amount G due to normal heating is calculated by the following equation. _{G = K 3 (tes, μ} A) T H + K 4 (tes, μ A)
T _H ^0.5 G; oxidation of the metal _{^{(mg / cm 2) T H}} ; heating time (min) tes; metal surface temperature (° C) μ _A; air-fuel ratio K _3, K _4; furnace atmosphere (the metal surface temperature Based on)

Therefore, in order to suppress the generation of scale, it is necessary to lower the heating temperature and shorten the heating time as much as possible within the range where the quality is not adversely affected. Unlike a heating furnace that heats up to the core, it is heating to compensate for the temperature drop around the hot billet, end face, and edge from the continuous casting machine. Absent.

Moreover, the hot billet conveyed is preferably wrapped by the flame tips of the burner injected from the left and right side walls of the furnace body, so that the periphery, end faces and edge portions are uniformly heated and heated over the entire length thereof. The Rukoto.

Further, in the present invention, each roller constituting the roller table for carrying the hot billet in the furnace is water cooled by the shaft, and the temperature of the carrying surface of the hot billet is not lowered, so that skid marks and seal marks due to temperature deviation are caused. It is possible to obtain a rolled product of high quality without the occurrence of

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on the embodiments shown in the accompanying drawings. As shown in FIGS. 1 and 2, the apparatus 10 of the present application has a conveyance path for the hot billet 11 moving on the roller table 12 on the left and right side walls of the furnace body 13 on which the roller table 12 for laying and conveying the hot billet 11 is laid. A burner 14 capable of injecting a flame K is sandwiched between the burners 14 so as to face each other.

The charging port 13a of the furnace body 13 is connected to the continuous casting machine 15 via the outside-roller table 16a as shown in FIGS. 3 and 4, and the outlet 13b is connected to the outside-roller table 16 of the outside furnace.
It is connected to the rolling line 17 via b.

Each of the rollers 12a forming the roller table 12 is composed of a shaft portion 12b and a large diameter portion 12c forming the conveying path H of the hot billet 11 as shown in FIG. 2, and the shaft portion 12b is a furnace. It penetrates through both side walls of the body 13, is rotatably supported by bearing members 17a and 17b outside the furnace, and one end side thereof is connected to an outside-motor motor 18. In the present embodiment, the rollers 12a ... Are driven independently by the out-of-furnace motor 18, but they may be commonly driven from one drive source through an endless member.

Further, the shaft portion 12b is formed in a double pipe structure composed of an inner pipe A and an outer pipe B as shown in FIG. 2, and the water 21 pumped from the water tank 19 by the pump 20 is
It enters from the inner pipe A and returns to the water tank 19 through the outer pipe B. The water returned to the water tank 19 is circulated so as to be mixed with a large amount of water accumulated in the water tank, cooled, and supplied to the inner pipe A again. That is, the roller table 1
Each of the rollers 12a, ...

The large diameter portion 12c of the roller 12a is the shaft portion 1
The water-cooled shaft portion 12 is composed of collar bodies 22 and 22 fixed to 2b and a cylindrical body 23 supported between the collar bodies 22 and 22.
It is insulated from b through the air layer 24. That is, a large-diameter portion 12c forming the transport path H of the hot billet 11,
It is configured so that there is no temperature difference with the hot billet 11.

The burner 14 is a roller table 12.
1 on each side wall between the rollers 12a constituting the
As shown in Fig. 1, they are installed one by one, but if it is understood that the furnace length is lengthened, it is possible to install them one by one on the same wall, and there is sufficient space on the side wall between each roller. If it is possible, it is possible to install two or more units opposite to each other on the same wall. As a matter of course, it goes without saying that as the number of burners increases, the periphery, end face and edge portion of the hot billet 11 can be heated and heated in a shorter time.

The burner 14 is provided with a flame guide 25 by removing the furnace wall, and a gas injection nozzle 26 and an air injection pipe 2 which are provided in the flame guide 25 through the center of the rear end wall.
7 are provided.

The gas injection nozzle 26 has a gas pipe 28.
It is connected to the fuel gas supply means 29 via the, and the fuel gas (propane gas, natural gas, etc.) is distributed from the supply means 29. A gas adjusting valve 30 is provided at an appropriate position of the gas pipe 28 to control the gas injection amount, and the flame K
The firepower of can be adjusted arbitrarily.

The air injection pipe 27 is connected to a blower 32 through a conduit 31 so that the fuel gas and the air injected from the gas injection nozzle 26 can be mixed to an almost ideal ignition concentration. It has become.

The air injection pipe 27 is provided with an air adjusting valve 33 in the middle of the conduit 31 so that the air injection amount can be controlled according to the injection amount of the fuel gas. That is, the air regulating valve 33 is the same as the gas regulating valves 30 and 1
By linking to 1: 1, the ratio of fuel gas and air can be maintained at an ideal mixing ratio at all times.

On the side wall, ceiling and bottom of the furnace body 13,
Ceramic fiber refractory 34 is used. This is because the ceramic fiber 34 does not expand or contract due to temperature change. That is, the continuous casting machine 15 and the rolling line 17
The device of the present application which operates in synchronism with the above-mentioned operation is designed so as not to receive a thermal shock caused by repeated temperature increase and temperature decrease.

In the figure, reference numeral 35 denotes a scale collecting groove provided on the bottom surface of the roller table 12 immediately below each roller 12a.

In the above embodiment, the device 10 of the present application is operated in synchronization with the operation of the continuous casting machine 15 and the rolling line 17, but normally the burner 14 is operated 20 to 30 minutes before the start of rolling.
And the hot billet 11 conveyed from the continuous casting machine 15 by the roller table 16a outside the furnace is charged into the charging port 13
It is received in the furnace body 13 through a.

The hot billet 11 charged in the furnace is
The flame K injected from the burner 14 while being sequentially moved toward the outlet 13b by the roller table 12 in the furnace.
Since it is wrapped by, the surroundings, end faces, and edge parts are heated / heated to a predetermined temperature in a short time (hot billet 11
The final rolling temperature is kept in the center of the.

Then, the hot billet 1 which has been heated
No. 1 exits from the outlet 13b, is placed on the outside-furnace roller table 16b, and is quickly conveyed to the rolling line 17 and rolled.

[0031]

INDUSTRIAL APPLICABILITY As described above, the present invention is for compensating for the temperature drop around the hot billet, the end face and the edge part, which is discharged from the continuous casting machine, between the continuous casting machine and the rolling line. Unlike the heating furnace used in the method, it is compact and has a simple structure, and the construction cost of the equipment is fixed and the fuel consumption is improved.
It can be expected to eliminate scale loss and improve maintainability.

Further, according to the present invention, the left and right side walls of the furnace body provided with the roller table for carrying and carrying the hot billet,
Since a burner capable of injecting flames is installed oppositely across the hot billet transport path on the roller table, the moving hot billet is suitable for being wrapped in flames from both sides, and the periphery, end face and edge where the temperature easily drops. Since the part can be heated and the temperature can be raised, it is possible to maintain the part at the final rolling temperature.

Further, according to the present invention, although each roller of the roller table is formed by the axial water cooling method, the large-diameter portion serving as the hot billet conveyance path is not cooled, and the hot billet is subject to temperature deviation. A rolled product of high quality can be obtained without generating skid marks or seal marks.

Furthermore, since the furnace body is made of a ceramic fiber refractory, there is no expansion or contraction due to temperature changes, and the furnace wall is operated and stopped daily, and the furnace wall repeatedly raises and lowers its temperature. Even so, there is an advantage that it can withstand long-term use without being affected by thermal shock.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a furnace body of the apparatus of the present application, showing a burner section.

FIG. 2 is a front sectional view of a furnace body of the apparatus of the present application, showing a roller table section.

FIG. 3 is a plan view in which a middle part of the device of the present application is omitted.

FIG. 4 is a side view in which an intermediate part of the device of the present application is omitted.

[Explanation of symbols]

 10 Apparatus of the Present Application 11 Hot Billet 12 Roller Table in Furnace 12a Each Roller 13 Furnace Body 13a Inlet 13b Outlet 14 Burner 15 Continuous Casting Machine 16a Outer Roller Table 16b Outer Roller Table 17 Rolling Line 18 Outer Motor 19 Water Tank 20 Pump 21 Water 22 Collar 23 Cylinder 24 Air Layer 25 Gas Guide 26 Gas Injection Nozzle 27 Air Injection Pipe 28 Gas Piping 29 Fuel Gas Supply Means 30 Gas Regulator Valve 31 Conduit 32 Blower 33 Air Regulator Valve 34 Ceramic Fiber Refractory 35 Scale Recovery Masu K Flame Flame H Transport path

Claims (4)

[Claims] 1. A burner capable of injecting flames is provided opposite to the left and right side walls of a furnace body on which a roller table for carrying a hot billet is laid so as to sandwich a hot billet carrying path on the roller table. Hot billet edge heater device. 2. The hot billet edge heater device according to claim 1, wherein at least one burner is installed on a wall surface between the rollers of the roller table. 3. The roller of the roller table comprises a shaft portion and a large-diameter portion forming a hot billet conveying surface, and the shaft portion is water-cooled. The hot billet edge heater device according to 1 or 2. 4. The hot billet edge heater device according to claim 1, wherein the furnace wall of the furnace body is formed of a ceramic fiber refractory material.