JPS61231117A - Re-heating furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to reheating and temperature control of hot copper ingots, especially slabs, rolled materials, continuous casting slabs, etc. above the hot forming temperature. a reheating furnace for
Relating to a furnace space equipped with a burner and an exhaust hole.

BACKGROUND OF THE INVENTION In steel factories, efforts are being made to hot form copper ingots placed in molds as directly as possible after their production, thus without prior cooling. In particular, in continuous casting equipment, the generated slabs, billets, blooms, etc., use the heat retained in the copper metal during the casting process in the next process to save energy.

(Problems to be Solved by the Invention) The problem in this case is that the surface of the copper base metal becomes colder than the center. In particular, the corners of the steel material quickly cool down significantly while the center remains at a high temperature that allows hot forming. Furthermore, in so-called direct rolling of continuously cast materials, reheating of the material and temperature adjustment in the cross section are unavoidable.

A well-known method for this purpose is to charge the hot copper metal into a conventional heating furnace (walking beam or bush furnace). However, this furnace is designed exclusively to heat cold copper to above the hot-forming temperature, and is therefore not suitable for raising the temperature of hot copper by a small amount (3). In such furnaces, excessive heating of the hot copper metal occurs. Another disadvantage is that furnaces become less efficient when fully loaded, increasing the price of the final product.

As is well known in the metallurgical industry (e.g.
Pocket book for people involved in iron metallurgy (Huette,
Ta5chenbuch fur Eisenhuet
tenleute), 5th edition, pages 425.806)
, a low-temperature furnace is used for temperature control of steel blocks. In such cryogenic furnaces, chambers are provided each containing one block. Such low temperature furnaces require a large number of burners, provide uneven heating, and are poorly controllable. There is also a risk of localized overheating.

The object of the invention is to provide a furnace which avoids these disadvantages and disadvantages, and the object of the invention is to provide a furnace which, from an economical point of view, is capable of reheating and temperature of the hot copper metal. To provide a furnace in which a burner provided in the furnace can be used optimally without fear of overheating copper metal.

(Means for Solving the Problems) The reheating furnace according to the present invention consists of a reheating section and a soaking section whose furnace space is divided by a partition wall, and a burner is installed at the inlet side end of the reheating section. , an exhaust hole is arranged at the outlet side end,
The temperature distribution in the reheating section is characterized by being formed such that the temperature is the highest at the inlet side end and the lowest temperature at the outlet side end.

Embodiment In an embodiment of the invention, the exhaust hole is placed below the transport surface of the furnace for good mixing of the furnace atmosphere.

A furnace for heating long billets is disclosed in German Patent No. DE-PS-152,851.

This furnace is equipped with high-speed burners and achieves a good heating course even under the most unlikely temperature differences.

In an embodiment of the invention, in the reheating section, high speed burners are located above and/or below the transport surface.

Particularly effective for setting the desired temperature distribution is the provision of burners arranged on the transport surface of the reheating section on the front wall of the reheating section and oriented in the transport direction.

It is further preferred for temperature control that the burners arranged below the transport plane of the reheating section are provided on the side walls of the reheating section and are oriented transversely to the transport direction.

In an embodiment according to the invention, a sensor for measuring the temperature of the exhaust gas is provided in said exhaust hole, said sensor being coupled to the control circuit of one or both of the fuel controller and the burner controller. .

In order to be able to reheat copper bullion that is supplied periodically and unevenly, a charging zone is connected in front of the reheating zone, and this charging zone includes a reheating zone and a soaking zone. A transport system independent of the transport system is provided for selective post-processing of the individual billets.

Furthermore, it is preferred that the charging strip is equipped with a walking beam conveyor, the walking beam of which is divided transversely to the conveying direction into individual hearths that can be raised and lowered. The length of the hearth in the direction of conveyance corresponds approximately to the width of the billet, and the hearths adjacent in the direction transverse to the direction of conveyance can be raised or lowered together.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 2, the furnace space l of the reheating furnace 2 includes reheated copper ingots 3.3. It consists of three parts, each processing... These three parts are a charging zone 5 which is first arranged in the feeding direction 4 of copper ingots 3°3, . . . , a reheating zone 6 following this, and a soaking zone 7 following this. .

The height 8 of the space in the charging band 5 is set low.

Copper metal 3,3. ... (in this example, a slab or bloom produced by continuous casting) is placed under tension in the charging strip 5 with its longitudinal axis 9 oriented perpendicular to the feeding direction 4 of the copper ingot 3. A refractory roof 10 is placed in the furnace with a relatively small spacing. The charging strip 5 is not equipped with any burners. The inlet opening 11 receives the copper bullion 3.3. charged into the charging band 5 which is closed by the charging door 12. ... are transported to the reheating section 6 in the transport direction 4 of the charging belt section 5 on the transport surface 15 by the walking beam conveyor 13 forming the bottom of the charging belt section 5, and then to the reheating section 6. 6, it is transported by another walking beam transport machine 15 to the soaking zone 7 and further out of the furnace. The walking beam carriers 15 present in the soaking zone 7 and in the reheating zone 6 are of conventional construction and in particular are formed as walking beam carriers 15 which are provided together on both strips 6, 7. Ru. On the other hand, the walking beam conveyor I3 of the charging band section 5 carries the copper ingots 3, 3, . ... are configured to be transported individually. For this reason, copper metal 3.3. ... are charged into the charging zone 5 at different time intervals, e.g. even when continuous cast slabs are transported to the reheating furnace as a bulk load, but not at exact sampling intervals. , retropical part 6
Copper metal 3.3. ... exist adjacent to each other.

Hearth provided in walking beam conveyor 13 of charging band 5 +7.17. . . . is a fixed beam 1 which is divided horizontally with respect to the conveying direction 4 and is fixed.
It is between 6.16 and can rise and fall. The length 18 of this hearth 17 in the conveyance direction 4 approximately corresponds to the width of the copper base metal 3. Furthermore, the two-king beam conveyor 13 is
Wheels 19, 19. ... is provided with a conveying structure 21 movable in the conveying direction 4 against the pressure medium cylinder 20. In this conveying structure 21, each hearth I7 is provided so as to be able to rise and fall. Moreover, the hearths 1 are arranged across the width of the charging band 5 in a direction transverse to the conveying direction 4.
7,17. ... is raised and lowered together with -. For this reason, these hearths 17.17. Copper metal on top of...3.3. ...are all the hearths carrying copper metal 17.1? It will rise with ,...

The lifting structure 22 is located transversely to the conveying structure 21 so that it can be conveyed in a direction transverse to the conveying direction 4 and serves for raising and lowering. The push-up structure 22 is pushed up by the pressure medium cylinder 23 in the direction of the double arrow 2
It is movable in 4 directions.

This push-up structure 22 has traveling rollers 25, 25 . ... is supported by the transport structure 21 on the one hand and the transport structure 26 on the other hand. This conveying structure 26 has a hearth 17.17. which can be raised and lowered together. ... can be installed. Furthermore, push-up wedges 27, 27 .・・・
・is fixed.

Between the fixed refractory inner wall 28 of the furnace and the hearth 17 or between the hearth 17 and the fixed beam 16, a water filling part 29,
29. ... systems, each surrounding the support structure 30 of the hearth I7, and the conveying structure 26.
is fixed. The diving back 31 fixed to the fixed furnace inner wall 28 or fixed beam 16 and the diving back 32 fixed to the hearth 17 are immersed in this water filling part 29 to seal the atmosphere of the furnace. has been done.

Therefore, the walking beam conveyor 1 of the charging band 5
3, it is possible to do the following through such a group of copper metals. That is, one copper bullion 3 is added to the copper bullion 3.3 already lying at the outlet 33 of the charging strip 5 at each summer step and independently of the pace of the system of the walking beam conveyor 15. ．． It can be transported to...

Therefore, copper bullion 3,3. ... have a constant interval in the retropic zone 6, and no empty places occur.

The reheating section 6 has an essentially larger inner furnace chamber in cross section than the charging zone 5, and the roof section 34 and the bottom section 35 are arranged at a greater distance from the conveying surface 14. has been done. Roof portion lO and bottom portion 13 of charging band portion 5
The vertical front walls 36 and 37 transform into a roof 34 and a bottom 35 of the reheating section 6.

The upper front wall 36 is equipped with a high speed burner, for example a so-called impact burner, as clearly shown in FIG. The front wall 36 is pierced by a burner stone 39 providing passage openings 40 leading into the inner chambers of the furnace.

A separate burner 41 is provided outside the burner stone 39 and is connected to a fuel gas line 42 and a combustion air line 43 . The flame 44 burning within the passage opening 40 causes the exit velocity of the fuel gas to be high, thereby creating a strong circulation of the combustion gas within the reheating section 6.

If necessary, near the end 45 on the inlet side of the reheating section 6, in addition to the high speed burner 38 on the front wall 36, burners 46, 46. ...is provided on the side wall. This burner 46 is likewise designed as a high-speed burner. This burner 46.46. ... are arranged below the conveyance surface 14. Gas exhaust holes 48 are provided at the outlet end 47 of the reheating section 6, if necessary on the underside of the supply surface 14.

The soaking zone 7, which is formed by a normal construction method, is
It is connected to the reheating section 6 by a separation wall 49 extending toward the copper base metal 3. The separation wall 49 serves to keep the combustion gas atmosphere in the soaking zone 7 from being influenced by the combustion gas atmosphere in the reheating zone 6. Therefore, the temperature distribution within the retropical zone 6 is
It does not essentially affect the soaking zone 7. In the soaking zone 7 according to the usual construction method, side wall burners 50, 50 . ...
is provided. The combustion gas from the soaking zone 7 is guided into the furnace space of the reheating section 6 from the end 52 on the inlet side of the reheating section 7 . The outlet end 53 is provided with a bottom opening 54 which simultaneously accommodates the igniter.

As shown in FIG. 5, in the reheating furnace the temperature distribution 55 is adjusted in its longitudinal direction. The temperature values shown in this figure indicate the temperature of the furnace inner wall. The maximum temperature 56 occurs at the inlet end of the reheating section 6 and is approximately 1290'C (at the drawing temperature of the continuously cast slab of 1250C). Artificial opening 1 of charging band 5
The temperature 57 of No. 1 is controlled at approximately 1200° C., corresponding to the average surface temperature of the hot slab. The temperature 58 of the end 47 on the exit side of the reheating section 6 is controlled to about 1260°C. In the soaking zone 7, a constant temperature of about 1250° C. is maintained in the longitudinal direction.

In the reheating furnace 2 according to the present invention, essentially, in the reheating section 6, the combustion gas is guided from the inlet side end 45 to the outlet side end 47, and at the inlet side end 45. Controlled to maximum temperature. With this method, the cold surface parts of the continuously cast slab 3 are reheated in a short time and without local heating.

In order to control or stabilize a desired temperature distribution in the reheating furnace 2, a temperature sensor 59 for measuring the temperature of the exhaust gas is provided in the gas exhaust hole 48 of the reheating furnace 2. In the embodiment shown in FIG. 6, a combustion operation controller 62 that operates a fuel gas control valve 63 is connected from a temperature sensor 59 via a control circuit 60. The fuel gas pipe 42 includes
A fuel gas amount measuring device 64 is provided, and the combustion air piping 43 is provided with a combustion air amount measuring device 65. The combustion air amount measuring device 65 and the fuel gas amount measuring device 64 send input signals to a fuel/combustion air related controller 66, and this controller 66
Further control pulses are sent to the combustion air control valve 67.

In the embodiment shown in FIG. 6, the amount of fuel gas and the amount of combustion air are respectively decreased or increased by valves depending on the combustion gas temperature.

In the modified embodiment shown in FIG.
9 transmits a signal to the fuel line controller 62 which acts on the burner controller 68. This burner control device 68 controls individual or multiple high speed burners 38.46, 46.・・・
・Close or open. That is, the charging time or charging cycle of individual or multiple high speed burners 38, 46, 46, .
and combustion air using the fast shutoff valve 70. This embodiment is suitable for high speed burners 38, 46, 46 . It is preferable because the stirring action of ... is reduced by the square of the burner efficiency.

In both embodiments of burner control in the reheating zone, the burners 50, 50 . ... are controlled by well-known methods that will not be explained in detail here. Burners 50, 50 in the soaking zone 7. The gas supply for... is controlled by the control valve 71.
．． 72. These valves 71.72 are
Burner 50, 50. It is equipped with piping 73, 74 for fuel gas and combustion air leading to... A fuel gas amount measuring device 75 and a combustion air amount measuring device 76 are present in these pipes.

The required combustion air is controlled by control valves 71, 72 by comparing the flow rate of the combustion air quantity and the fuel gas quantity.

The invention is not limited to the embodiments described, but is also capable of various modifications. For example, in the charging band 5, the copper bullion does not have to be transported at a pace. Also, the placement of the high speed burners 38, 46 on the front wall 36 and side walls can be selected as desired. For example, a group of burners may be excluded depending on the situation.

(Effects of the Invention) In the reheating furnace 2 according to the present invention, essentially, the exhaust gas generated by combustion is guided from the end 45 on the population side to the end 47 on the outlet side in the reheating section 6. , inlet end 4
5, the temperature is controlled to the maximum.

By this method, copper metal (for example, continuously cast slab) 3
cold surface areas are reheated in a short time and without local heating.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a reheating furnace. FIG. 2 is a longitudinal cross-sectional view of the furnace. FIG. 3 is a sectional view taken along the line ■-■ in FIG. 2. FIG. 4 is an enlarged sectional view of the portion marked ■ in FIG. 2. FIG. 5 is a graph of temperature changes in the longitudinal direction of the reheating furnace. 6 and 7 are diagrams similar to FIG. 2, respectively, of control equipment for adjusting a predetermined temperature distribution in the furnace space. 3.3. ...... Copper metal, 6... Re-tropical zone, 7... Soaking zone, 38... Burner,
45... Inlet side end, 46, 46. ... Burner, 47... Outlet side end, 49... Separation wall, 55... Temperature distribution. Patent Applicant Hoest Albin Akchengesellschaft Agent Patent Attorney Aoyama Aoyama and 2 others 1st drawing ff 5 3rd drawing

Claims (8)

[Claims] (1) The furnace space consists of a reheating zone and a soaking zone that are separated by a partition wall, and a burner is placed at the inlet end of the reheating zone and an exhaust hole is placed at the outlet end of the reheating zone. A reheating furnace characterized in that the temperature distribution is formed such that the temperature is the highest at the inlet side end and the lowest temperature at the outlet side end. (2) The reheating furnace according to claim 1, wherein the exhaust hole is arranged below the transport surface of the furnace. (3) The reheating furnace described in claim 1 or 2 is characterized in that, in the reheating section, a high-speed burner is disposed above or below the transport surface, or both. reheating furnace. (4) In the reheating furnace according to any one of claims 1 to 3, the burner disposed above the transport surface of the reheating section is mounted on the front wall of the reheating section. A reheating furnace characterized in that it is equipped with a reheating furnace and is oriented in the direction of transportation. (5) In the reheating furnace according to any one of claims 1 to 4, the burner disposed below the transport plane of the reheating section is arranged on the side wall of the reheating section. A reheating furnace, which is provided in (6) In the reheating furnace according to any one of claims 1 to 5, a sensor for measuring the temperature of exhaust gas is provided in the exhaust hole, and the sensor is coupled to a control circuit of one or both of a fuel controller and a burner controller. (7) In the reheating furnace according to any one of claims 1 to 6, a charging zone is connected in front of the reheating section, and the charging zone is connected to the charging zone. , a reheating furnace characterized in that a transport system independent of the transport systems of the reheating zone and the soaking zone is provided for selective post-treatment of individual billets. (8) In the reheating furnace according to any one of claims 1 to 7, the charging band is equipped with a walking beam conveyor, and the walking beam conveyor is provided with a walking beam conveyor. The walking beam of the machine is divided into individual hearths that can be raised and lowered in a direction transverse to the conveying direction. Reheating furnace characterized in that adjacent hearths in the lateral direction can be raised or lowered together.