EP0199703A2 - Plant for heating steel material up to the hot-forming temperature - Google Patents

Plant for heating steel material up to the hot-forming temperature Download PDF

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Publication number
EP0199703A2
EP0199703A2 EP86890061A EP86890061A EP0199703A2 EP 0199703 A2 EP0199703 A2 EP 0199703A2 EP 86890061 A EP86890061 A EP 86890061A EP 86890061 A EP86890061 A EP 86890061A EP 0199703 A2 EP0199703 A2 EP 0199703A2
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EP
European Patent Office
Prior art keywords
furnace
flue gas
preheating furnace
combustion air
burners
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP86890061A
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German (de)
French (fr)
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EP0199703A3 (en
Inventor
Aktiengesellschaf Voest-Alpine
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Voestalpine AG
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Voestalpine AG
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Publication date
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Publication of EP0199703A2 publication Critical patent/EP0199703A2/en
Publication of EP0199703A3 publication Critical patent/EP0199703A3/en
Withdrawn legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/52—Methods of heating with flames
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/02—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces
    • F27B9/028—Multi-chamber type furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30—Details, accessories or equipment specially adapted for furnaces of these types
    • F27B9/3005—Details, accessories or equipment specially adapted for furnaces of these types arrangements for circulating gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30—Details, accessories or equipment specially adapted for furnaces of these types
    • F27B9/36—Arrangements of heating devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30—Details, accessories or equipment specially adapted for furnaces of these types
    • F27B9/40—Arrangements of controlling or monitoring devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B19/00—Combinations of different kinds of furnaces that are not all covered by any single one of main groups F27B1/00 - F27B17/00
    • F27B19/04—Combinations of different kinds of furnaces that are not all covered by any single one of main groups F27B1/00 - F27B17/00 arranged for associated working
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/12—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity with special arrangements for preheating or cooling the charge
    • F27B2009/122—Preheating

Definitions

  • the invention relates to a system for heating steel material to the hot forming temperature, with a preheating furnace and a preheating furnace combined therewith, wherein a transport device is provided between the inlet side of the preheating furnace and the outlet side of the preheating furnace and a flue gas duct leading from the preheating furnace to the preheating furnace is provided.
  • a system of this type is known from DE-A -2 706 345.
  • a preheating and reheating furnace By arranging a preheating and reheating furnace in series, the throughput of warmed steel is increased and the economy of heating the steel is improved, etc. especially by introducing the flue gas from the heating furnace into the preheating furnace.
  • a fan is provided in the flue gas line leading from the heating furnace to the preheating furnace for transporting the flue gas, so that the temperature of the flue gas must not exceed a certain level, since otherwise the fan will be damaged.
  • the system known from DE-A -2 706 345 only serves to warm up cold steel.
  • the aim is to subject the steel to be hot-formed as soon as possible after it has been produced, that is, without prior cooling, directly to the hot-forming process.
  • slabs, billets or blooms are to be subjected to further hot shaping in order to save energy by using the heat contained in the steel material by the casting process.
  • the invention aims to avoid these disadvantages and difficulties and has as its object to create a system of the type described in which cold steel or steel with a higher temperature, but a lower temperature than the hot forming temperature, can be used and in which an optimal one It is possible to use the flue gases generated in the heating furnace.
  • the transport device can be loaded from the preheating furnace on the one hand and from the outside on the other, that the preheating furnace is equipped with several high-speed burners and that the flue gas line opens into a region surrounding the jet of high-speed burners at the outlet openings of the high-speed burners, whereby hot flue gas can be drawn in from the heating furnace due to the suction effect of the high-speed burners.
  • a preferred embodiment, in which the heat content of the flue gases is used particularly well, is characterized in that the furnace interior of the preheating furnace is formed in two parts, both parts of the furnace interior being equipped with high-speed burners and the second part of the - viewed in the direction of passage of the steel material
  • Furnace interior has a flue gas discharge line, which leads to the high-speed burners of the first part of the furnace interior in the direction of passage of the steel material and opens into an area surrounding the fuel jet of the high-speed burners, and furthermore expediently the flue gas discharge line of the second part of the furnace interior is provided near its inlet end.
  • the latter measure ensures a particularly uniform heating of the steel material.
  • a heat exchanger is provided in the flue gas discharge line supplying the preheating furnace to the preheating furnace, through which combustion air from the combustion air supply flows, which after heating in the heat exchanger is fed to the burners in the reheating furnace.
  • a heat exchanger is advantageously provided in the flue gas discharge line of the preheating furnace, through which cold air flows, which on the one hand leads to the high-speed burners provided in the preheating furnace by means of a combustion air supply line and, on the other hand, to the heaters provided in the flue gas discharge of the preheating furnace burners provided in the heating furnace can be fed.
  • a further combustion air supply line leads into the combustion air supply line at a point between the branch to the high-speed burners of the preheating furnace and the heat exchanger provided in the flue gas discharge line of the reheat furnace, whereby the system can be easily adapted to the respective use of cold steel material or steel material of higher temperature is.
  • the combustion air supply line leading to the burners of the reheating furnace has a combustion air blow-off line which opens into the flue gas discharge line, which leads from the heating furnace to the preheating furnace, after the heat exchanger.
  • the combustion air blow-off device advantageously opens into the flue gas discharge line by means of a propellant nozzle, as a result of which the combustion air serves as a propellant gas for the flue gas stream which is fed to the preheating furnace.
  • FIG. 1 shows a schematically illustrated installation for heating steel material
  • FIG. 2 shows a high-speed burner in axial section
  • FIG. 3 shows a vertical section through a preheating furnace according to line 111-111 of FIG 1 and 4 show an expanded system for preheating, reheating and post-heating.
  • a transport device 3 for conveying and inserting the steel material 4 to be heated into the preheating furnace 1 leads to the inlet side of the preheating furnace 1.
  • a further transport device 5 is provided, by means of which the already preheated steel material 4 can be brought into the heating furnace 2 is.
  • a further transport device 6 by means of the steel material 4 of higher temperature to the transport device 5 leading from the preheating furnace to the heating furnace or directly to the input opening of the heating furnace 2, so that the steel material 4 of higher temperature bypassing the preheating furnace 1 directly into the Heating oven 2 can be used.
  • the steel material passes through the preheating furnace 1 and then the heating furnace 2, or only the heating furnace 2 alone.
  • the preheating furnace is for heating with high-speed burners 7, etc. so-called pulse burners.
  • One of these high-speed burners 7 is shown in section in FIG. 2.
  • the furnace top 8 or side wall (depending on the arrangement of the high-speed burners 7) is penetrated by a burner block 9 which has a passage opening 10 which narrows towards the interior of the furnace.
  • the actual burner 11 is provided on the outside of the burner block 9 and is connected to a fuel gas supply line 12 and to a combustion air supply line 13.
  • On the inside of the burner block there is a nozzle block 14 which has a central through-opening 16 which is aligned with the axis 15 of the passage opening 10 and into which a side inlet opening 17 opens at the end of the burner block.
  • the passage opening 16 is provided at the location of the mouth of the side inlet opening 17 with a radial extension 18 surrounding the mouth of the passage opening 10. In the outflow direction of the fuel gases, this radial enlargement 18 is followed by a rounded constriction 19, which is followed by a conical part 21 of the passage opening 16, which widens towards the furnace interior 20.
  • the burning jet 22 burning in the passage opening 10 and reaching into the passage opening 16 causes a high exit velocity of the fuel gases, causing gas to be sucked in through the side nlass opening 17 and entrainment and ejection of this gas at high speed in the furnace interior 20 according to the injector principle.
  • the side inlet opening 17 is connected to a flue gas duct 23 leading from the heating furnace 2 to the preheating furnace 1.
  • the supply of the high-speed burners 7 with combustion air takes place via the combustion air supply line 13 by means of a fan 24, the combustion air supply line 13 passing through a heat exchanger 25 which is provided in a flue gas discharge line 26 leading away from the preheating furnace 1 and connected to a chimney (not shown).
  • the combustion air supply line 13 also serves to (partially) supply the burners 27 provided in the heating furnace 2. These burners 27 are of conventional construction.
  • a further heat exchanger 29 is provided between the branch 28 to the high-speed burners 7 of the preheating furnace 1 and the burners 27 of the preheating furnace 2, which is interspersed with the flue gas discharge line 23 leading from the preheating furnace 2 to the preheating furnace 1 (see FIG. 4). .
  • combustion air supply line 13 also opens between the. Branch 28 to the high-speed burners 7 of the preheating furnace 1 and the heat exchanger 29 of the flue gas from the preheating furnace 2 to the preheating furnace 1 leading to the flue gas discharge line 23 a further combustion air supply line 31 acted upon by a fan 30. Combustion air is additionally supplied through this combustion air supply line 31 when cold steel 4 is introduced , since the high-speed burners 7 in this case consume all or a large part of the air which is supplied by the fan 24 via the combustion air supply line 13.
  • combustion air blow-off line 32 From the combustion air supply line 13 branches off, after the heat exchanger 29 provided in the flue gas discharge line 23 of the heating furnace 2, a combustion air blow-off line 32, which can be regulated by means of a control flap as a function of the temperature of the combustion air, which is measured by means of a temperature sensor.
  • the combustion air blow-off line 32 opens into a driving nozzle 33 which is installed in the flue gas from the heating furnace 2 into the preheating furnace 1 leading flue gas discharge line 23.
  • the combustion air thus acts as a propellant for the flue gas stream which is fed to the preheating furnace 1.
  • the flue gas emerging from the heating furnace 2 at approximately 1100 ° C. is fed to the high-speed burners 7 at 700 to 800 ° C.
  • its furnace interior 20 is formed in two parts by a separating weir 34 which extends close to the steel material 4 used.
  • the steel material 4 is continuously moved through the two parts 20 ', 20 "of the furnace interior 20 of the preheating furnace 1 by means of a conveyor, not shown, for example a walking beam conveyor.
  • a flue gas discharge line 36 is provided on the bottom side, but this does not open into a chimney, but the flue gas becomes the high-speed burners arranged in the conveying direction in the first part 20 'of the furnace interior 20 7, e.g. in the same way as is illustrated in Fig. 2.
  • the flue gas opens into an area surrounding the gas jet of the high-speed burners, whereby it is sucked by the high-speed burners 7 from the second part, as seen in the conveying direction 20 "of the furnace interior is suctioned off.
  • This embodiment shown in Fig. 3 allows a very - fast and effective preheating of the steel material 4, so that the preheating furnace 1 has only a very short length despite high performance.
  • FIG. 4 shows an expanded system for heating steel material 4 to the hot forming temperature, which can be used universally and meets all requirements.
  • two reheating furnaces 37 are provided, the input openings 38 of which lie on the transport device 6 leading to the steel material of higher temperature to the heating furnace.
  • the outlet openings 47 of the reheating furnaces are located on a transport device 39 which guides the finished steel material from the heating furnace to the hot forming device, for example to the rolling mill.
  • the flue gas flowing out of the reheating furnaces 37 is led in each case via flue gas lines 40 and heat exchangers 41 to the flue gas discharge line 23 leading the flue gas of the heating furnace 2 to the preheating furnace 1.
  • the heat exchangers 41 of the reheating furnaces 37 serve to preheat the combustion air supplied to the burners 43 by means of fans 42.
  • some of the flue gas from the reheating furnaces 37 or all of the flue gas the reheating furnaces 37 are fed to a separate chimney 46 equipped with a fan 45 via a waste heat boiler 44, in which steam is generated.
  • the system shown in FIG. 4 enables the use of cold, warm and hot steel material, the hot steel material, which has a temperature almost at the level of the hot forming temperature, only being led through the reheating furnaces.
  • the heating furnace 2 and the preheating furnace 1 serve to heat steel material to the rolling temperature, which for technological or other reasons cannot be used directly in the reheating furnaces 37.
  • the rolling mill is supplied with steel material during the operating phases, during which the reheating furnaces 37 cannot deliver steel material ready for rolling due to the lack of very hot steel material.
  • the insert is carried out bypassing the preheating furnace 1 directly into the heating furnace 2 by removing the steel material 4 is applied to the transport device 5 leading from the preheating furnace to the heating furnace.
  • the combustion air supply line 31 opening into the combustion air supply line 13 is shut down; the combustion air is then supplied via the two heat exchangers 25 and 29 provided in the combustion air supply line 13 and heated to approximately 550 ° C.
  • the high-speed burners 7 of the preheating furnace 1 are not in operation in this case, i.e. neither exposed to combustion gas nor combustion air.
  • the flue gases from the heating furnace 2 are either guided past the preheating furnace, for example via the flue gas line 40, the waste heat boiler 44, the suction fan 45 to the chimney 46, or via the mixing zone of the burners 7 through the preheating furnace 1, the flue gas duct 26 Recuperator 25 sucked in by the induced draft fan and conveyed to the chimney. This prevents the preheating furnace 1 from cooling, so that it can be put back into operation at any time or without any appreciable heating-up time after the insertion of cold steel.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
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  • Metallurgy (AREA)
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  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
  • Tunnel Furnaces (AREA)

Abstract

In such a plant with a preheating furnace (1) and, combined therewith, a heating furnace (2), there is provided between the entrance side of the heating furnace (2) and the exit side of the preheating furnace (1) a transport device (5) and also a flue gas line (23) which conducts flue gas from the heating furnace (2) to the preheating furnace (1). In order to be able to use cold steel material or steel material at higher temperature alternatively, the transport device (5, 6) can be charged on the one hand from the preheating furnace (1) and on the other hand from outside, the preheating furnace (1) is equipped with a number of high-speed burners (7) and the flue gas line (23) opens into a region of the outlet openings of the high-speed burners (7) which surrounds the flame jet (22) of the high-speed burners (7), it being possible to suck hot flue gas out of the heating furnace (2) by the suction effect of the high-speed burners (7). <IMAGE>

Description

Die Erfindung betrifft eine Anlage zum Aufwärmen von Stahlgut auf Warmformgebungstemperatur, mit einem Vorwärmofen und einem damit kombinierten Aufwärmofen, wobei zwischen der Einlaufseite des Aufwärmofens und der Auslaufseite des Vorwärmofens eine Transporteinrichtung vorgesehen ist und wobei eine Rauchgas vom Aufwärmofen zum Vorwärmofen führende Rauchgasableitung vorgesehen ist.The invention relates to a system for heating steel material to the hot forming temperature, with a preheating furnace and a preheating furnace combined therewith, wherein a transport device is provided between the inlet side of the preheating furnace and the outlet side of the preheating furnace and a flue gas duct leading from the preheating furnace to the preheating furnace is provided.

Eine Anlage dieser Art ist aus der DE-A -2 706 345 bekannt. Durch die Hintereinanderanordnung eines Vorwärmund Aufwärmofens wird der Durchsatz an aufgewärmtem Stahlgut erhöht und die Wirtschaftlichkeit der Erwärmung des Stahlgutes verbessert, u.zw. vor allem durch die Einbringung des vom Aufwärmofen stammenden Rauchgases in den Vorwärmofen.A system of this type is known from DE-A -2 706 345. By arranging a preheating and reheating furnace in series, the throughput of warmed steel is increased and the economy of heating the steel is improved, etc. especially by introducing the flue gas from the heating furnace into the preheating furnace.

Gemäß der DE-A -2 706 345 ist in der das Rauchgas vom Aufwärmofen zum Vorwärmofen führenden Rauchgasleitung zum Transport des Rauchgases ein Ventilator vorgesehen, wodurch die Temperatur des Rauchgases eine gewisse Höhe nicht überschreiten darf, da sonst der Ventilator Schaden erleidet. Die aus der DE-A -2 706 345 bekannte Anlage dient nur zum Aufwärmen von kaltem Stahlgut.According to DE-A -2 706 345, a fan is provided in the flue gas line leading from the heating furnace to the preheating furnace for transporting the flue gas, so that the temperature of the flue gas must not exceed a certain level, since otherwise the fan will be damaged. The system known from DE-A -2 706 345 only serves to warm up cold steel.

In modernen Stahlwerken besteht das Bestreben, warmzuverformendes Stahlgut möglichst unmittelbar nach dessen Herstellung, also ohne vorherige Abkühlung, direkt der Warmformgebung zu unterwerfen. Insbesondere bei Stranggießanlagen anfallende Brammen, Knüppel oder Vorblöcke sollen zwecks Energieeinsparung unter Heranziehung der durch den Gießvorgang im Stahlgut enthaltenen Wärme der weiteren Warmformgebung unterzogen werden.In modern steelworks, the aim is to subject the steel to be hot-formed as soon as possible after it has been produced, that is, without prior cooling, directly to the hot-forming process. In particular in the case of continuous casting plants, slabs, billets or blooms are to be subjected to further hot shaping in order to save energy by using the heat contained in the steel material by the casting process.

Infolge betriebsbedingter Umstände ist oft ein Direktwalzen nicht möglich und das Stahlgut weist daher oftmals eine unterhalb der Warmformgebungstemperatur liegende Temperatur auf, ist jedoch deutlich wärmer als kaltes Stahlgut. Bisher bereitete die Aufwärmung von sozusagen halbwarmem Stahlgut Schwierigkeiten, da herkömmliche Wärmeöfen (Hubbalken-oder Stoßöfen) infolge ihrer Auslegung ausschließlich zum Aufheizen von kaltem Stahlgut auf Warmformgebungstemperatur für die bei warmem Stahlgut geringere Temperaturerhöhung nicht ideal geeignet sind. Es kann zu Überhitzungen des Stahlgutes kommen. Ein weiterer Nachteil ist darin zu sehen, daß ein Wärmeofen beim Einsatz von warmem Stahlgut nur unzureichend ausgelastet ist.As a result of operational circumstances, direct rolling is often not possible and the steel stock is therefore often below the hot forming temperature, but is significantly warmer than cold steel. Up to now, the warming up of semi-warm steel goods, so to speak, has been difficult, since conventional heating furnaces (walking beam or push furnaces) are not ideally suited due to their design exclusively for heating cold steel goods to the hot forming temperature for the lower temperature increase in hot steel goods. The steel material may overheat. Another disadvantage is the fact that a heating furnace is only underused when hot steel is used.

Es ist in der Hüttenindustrie bekannt (vgl. Hütte, Taschenbuch für Eisenhüttenleute, 5. Auflage, Seiten 425, 806), Tieföfen zur Temperaturvergleichmäßigung von Stahlwerksblöcken zu verwenden, wobei solche Tieföfen mit Zellen zur Aufnahme je eines Blockes ausgestattet sind. Solche Tieföfen erfordern viele Brenner und ergeben eine ungleichmäßige Beheizung und weisen eine - schlechte Regelmöglichkeit auf. Es besteht die Gefahr örtlicher Überhitzungen.It is known in the iron and steel industry (cf. Hut, Taschenbuch für Eisenhüttenmänner, 5th edition, pages 425, 806) to use deep furnaces for the temperature equalization of steel mill blocks, such deep furnaces being equipped with cells for accommodating one block each. Such deep furnaces require many burners and result in uneven heating and have a poor control option. There is a risk of local overheating.

In Stahlwerken ist weiters oftmals auch auf Lager gelegtes abgekühltes Stahlgut aufzuwärmen, wofür in der Regel ein Wärmeofen herkömmlicher Bauart oder eine Anlage gemäß der DE-A 2 706 345 dient, welche Anlagen jedoch, wie oben erwähnt, für warmes Stahlgut nur unwirtschaftlich zu verwenden sind.In steelworks, it is often also necessary to heat up cooled steel stock, for which a conventional-type heating furnace or a system according to DE-A 2 706 345 is generally used, but which systems, as mentioned above, are only uneconomical to use for hot steel .

Die Erfindung bezweckt die Vermeidung dieser Nachteile und Schwierigkeiten und stellt sich die Aufgabe, eine Anlage der eingangs beschriebenen Art zu schaffen, in die wahlweise kaltes Stahlgut oder Stahlgut mit höherer Temperatur, jedoch einer geringeren Temperatur als der Warmformgebungstemperatur, einsetzbar ist und bei der eine optimale Ausnützung der im Aufwärmofen anfallenden Rauchgase möglich ist.The invention aims to avoid these disadvantages and difficulties and has as its object to create a system of the type described in which cold steel or steel with a higher temperature, but a lower temperature than the hot forming temperature, can be used and in which an optimal one It is possible to use the flue gases generated in the heating furnace.

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Transporteinrichtung einerseits vom Vorwärmofen her und andererseits von außen her beschickbar ist, daß der Vorwärmofen mit mehreren Hochgeschwindigkeitsbrennern ausgestattet ist und daß die Rauchgasleitung in einen den Brennstrahl der Hochgeschwindigkeitsbrenner umgebenden Bereich an den Austrittsöffnungen der Hochgeschwindigkeitsbrenner mündet, wobei durch die Saugwirkung der Hochgeschwindigkeitsbrenner heißes Rauchgas aus dem Aufwärmofen ansaugbar ist.This object is achieved in that the transport device can be loaded from the preheating furnace on the one hand and from the outside on the other, that the preheating furnace is equipped with several high-speed burners and that the flue gas line opens into a region surrounding the jet of high-speed burners at the outlet openings of the high-speed burners, whereby hot flue gas can be drawn in from the heating furnace due to the suction effect of the high-speed burners.

Eine bevorzugte Ausführungsform, bei der der Wärmeinhalt der Rauchgase besonders gut ausgenützt wird, ist dadurch gekennzeichnet, daß der Ofeninnenraum des Vorwärmofens zweigeteilt ausgebildet ist, wobei beide Teile des Ofeninnenraumes mit Hochgeschwindigkeitsbrennern ausgestattet sind und der -in der Durchlaufrichtung des Stahlgutes gesehen -zweite Teil des Ofeninnenraumes eine Rauchgasableitung aufweist, die zu den Hochgeschwindigkeitsbrennern des in der Durchlaufrichtung des Stahlgutes ersten Teiles des Ofeninnenraumes führt und in einen den Brennstrahl der Hochgeschwindigkeitsbrenner umgebenden Bereich mündet, und wobei weiters zweckmäßig die Rauchgasableitung des zweiten Teiles des Ofeninnenraumes nahe bei dessen einlaufseitigem Ende vorgesehen ist. Durch die letztere Maßnahme läßt sich eine besonders gleichmäßige Durchwärmung des Stahlgutes sicherstellen.A preferred embodiment, in which the heat content of the flue gases is used particularly well, is characterized in that the furnace interior of the preheating furnace is formed in two parts, both parts of the furnace interior being equipped with high-speed burners and the second part of the - viewed in the direction of passage of the steel material Furnace interior has a flue gas discharge line, which leads to the high-speed burners of the first part of the furnace interior in the direction of passage of the steel material and opens into an area surrounding the fuel jet of the high-speed burners, and furthermore expediently the flue gas discharge line of the second part of the furnace interior is provided near its inlet end. The latter measure ensures a particularly uniform heating of the steel material.

Vorteilhaft zur Nutzung der Wärme des Rauchgases des Aufwärmofens ist in der das Rauchgas vom Aufwärmofen dem Vorwärmofen zuführenden Rauchgasableitung ein Wärmetauscher vorgesehen, der von Brennluft aus der Brennluftzuführung durchströmt ist, die nach Aufwärmung im Wärmetauscher den Brennern im Aufwärmofen zugeleitet wird.Advantageously for using the heat of the flue gas of the reheating furnace, a heat exchanger is provided in the flue gas discharge line supplying the preheating furnace to the preheating furnace, through which combustion air from the combustion air supply flows, which after heating in the heat exchanger is fed to the burners in the reheating furnace.

Zwecks Ausnützung des Wärmeinhaltes der den Vorwärmofen verlassenden Rauchgase ist vorteilhaft in der Rauchgasableitung des Vorwärmofens ein Wärmetauscher vorgesehen, der von Kaltluft durchströmt ist, die mittels einer Brennluftzuführungsleitung einerseits zu den im Vorwärmofen vorgesehenen Hochgeschwindigkeitsbrennern und andererseits über den in der Rauchgasableitung des Aufwärmofens vorgesehenen Wärmetauscher zu den im Aufwärmofen vorgesehenen Brennern zuführbar ist.In order to utilize the heat content of the flue gases leaving the preheating furnace, a heat exchanger is advantageously provided in the flue gas discharge line of the preheating furnace, through which cold air flows, which on the one hand leads to the high-speed burners provided in the preheating furnace by means of a combustion air supply line and, on the other hand, to the heaters provided in the flue gas discharge of the preheating furnace burners provided in the heating furnace can be fed.

Zweckmäßig mündet in die Brennluftzuführungsleitung an einer Stelle zwischen der Abzweigung zu den Hochgeschwindigkeitsbrennern des Vorwärmofens und dem in der Rauchgasableitung des Aufwärmofens vorgesehenen Wärmetauscher eine weitere Brennluft zuführende Brennlufzuführungsleitung ein, wodurch die Anlage dem jeweiligen Einsatz von kaltem Stahlgut bzw. Stahlgut höherer Temperatur in einfacher Weise anpaßbar ist.Advantageously, a further combustion air supply line leads into the combustion air supply line at a point between the branch to the high-speed burners of the preheating furnace and the heat exchanger provided in the flue gas discharge line of the reheat furnace, whereby the system can be easily adapted to the respective use of cold steel material or steel material of higher temperature is.

Zwecks optimaler Regelung geht von der zu den Brennern des Aufwärmofens führenden Brennluftzuführungsleitung eine Brennluftabblasleitung aus, die in die Rauchgasableitung, die vom Aufwärmofen zum Vorwärmofen führt, nach dem Wärmetauscher mündet. Vorteilhaft mündet die Brennluftabblaseinrichtung in die Rauchgasableitung mittels einer Treibdüse ein, wodurch die Brennluft als Treibgas für den Rauchgasstrom, der dem Vorwärmofen zugeführt wird, dient.For the purpose of optimal regulation, the combustion air supply line leading to the burners of the reheating furnace has a combustion air blow-off line which opens into the flue gas discharge line, which leads from the heating furnace to the preheating furnace, after the heat exchanger. The combustion air blow-off device advantageously opens into the flue gas discharge line by means of a propellant nozzle, as a result of which the combustion air serves as a propellant gas for the flue gas stream which is fed to the preheating furnace.

Die Erfindung ist nachstehend anhand der Zeichnung an einem Ausführungsbeispiel näher erläutert, wobei Fig. 1 eine schematisch dargestellte Anlage zum Aufwärmen von Stahlgut, Fig. 2 einen Hochgeschwindigkeitsbrenner im Axialschnitt, Fig. 3 einen Vertikalschnitt durch einen Vorwärmofen gemäß der Linie 111-111 der Fig. 1 und Fig. 4 eine erweiterte Anlage zum Vorwärmen, Aufwärmen und Nachwärmen zeigen.The invention is explained in more detail below with reference to the drawing using an exemplary embodiment, wherein FIG. 1 shows a schematically illustrated installation for heating steel material, FIG. 2 shows a high-speed burner in axial section, FIG. 3 shows a vertical section through a preheating furnace according to line 111-111 of FIG 1 and 4 show an expanded system for preheating, reheating and post-heating.

Die Anlage gemäß Fig. 1 setzt sich im wesentlichen aus einem Vorwärmofen 1 und einem diesem nachfolgenden Aufwärmofen 2 zusammen. Eine Transporteinrichtung 3 zum Anfördern und Einsetzen des aufzuwärmenden Stahlgutes 4 in den Vorwärmofen 1 führt bis zur Einlaufseite des Vorwärmofens 1. Zwischen dem Vorwärmofen 1 und dem Aufwärmofen 2 ist eine weitere Transporteinrichtung 5 vorgesehen, mittels der das bereits vorgewärmte Stahlgut 4 in den Aufwärmofen 2 bringbar ist. Zu dieser Transporteinrichtung 5 führt eine weitere Transporteinrichtung 6, mittels der Stahlgut 4 höherer Temperatur auf die vom Vorwärmofen zum Aufwärmofen führende Transporteinrichtung 5 oder unmittelbar zur Eingabeöffnung des Aufwärmofens 2 bringbar ist, so daß das Stahlgut 4 höherer Temperatur unter Umgehung des Vorwärmofens 1 direkt in den Aufwärmofen 2 einsetzbar ist.1 essentially consists of a preheating furnace 1 and a heating furnace 2 following this. A transport device 3 for conveying and inserting the steel material 4 to be heated into the preheating furnace 1 leads to the inlet side of the preheating furnace 1. Between the preheating furnace 1 and the heating furnace 2, a further transport device 5 is provided, by means of which the already preheated steel material 4 can be brought into the heating furnace 2 is. To this transport device 5 leads a further transport device 6, by means of the steel material 4 of higher temperature to the transport device 5 leading from the preheating furnace to the heating furnace or directly to the input opening of the heating furnace 2, so that the steel material 4 of higher temperature bypassing the preheating furnace 1 directly into the Heating oven 2 can be used.

Je nachdem, ob kaltes Stahlgut oder Stahlgut mit höherer, jedoch noch unter der Warmformgebungstemperatur liegender Temperatur aufgewärmt werden muß, durchsetzt das Stahlgut den Vorwärmofen 1 und anschließend den Aufwärmofen 2, oder nur den Aufwärmofen 2 allein.Depending on whether cold steel material or steel material with a higher, but still below the hot-forming temperature, temperature has to be heated, the steel material passes through the preheating furnace 1 and then the heating furnace 2, or only the heating furnace 2 alone.

Der Vorwärmofen ist zwecks Beheizung mit Hochgeschwindigkeitsbrennern 7, u.zw. sogenannten Impulsbrennern, ausgestattet. Einer dieser Hochgeschwindigkeitsbrenner 7 ist in Fig. 2 im Schnitt dargestellt..Die Ofendecke 8 bzw. Ofenseitenwand (je nach Anordnung der Hochgeschwindigkeitsbrenner 7) wird von einem Brennerstein 9 durchsetzt, der eine sich zum Ofeninnenraum hin verengende Durchlaßöffnung 10 aufweist. An der Außenseite des Brennersteins 9 ist der eigentliche Brenner 11 vorgesehen, der an eine Brenngaszuführungsleitung 12 und an eine Brennluftzuführungsleitung 13 angeschlossen ist. An den Brennerstein schließt ofeninnenseitig ein Düsenstein 14 an, der eine zentrale, mit der Achse 15 der Durchlaßöffnung 10 -fluchtende Durchgangsöffnung 16 aufweist, in die an deren brennersteinseitigem Ende eine Seiteneinlaßöffnung 17 mündet.The preheating furnace is for heating with high-speed burners 7, etc. so-called pulse burners. One of these high-speed burners 7 is shown in section in FIG. 2. The furnace top 8 or side wall (depending on the arrangement of the high-speed burners 7) is penetrated by a burner block 9 which has a passage opening 10 which narrows towards the interior of the furnace. The actual burner 11 is provided on the outside of the burner block 9 and is connected to a fuel gas supply line 12 and to a combustion air supply line 13. On the inside of the burner block there is a nozzle block 14 which has a central through-opening 16 which is aligned with the axis 15 of the passage opening 10 and into which a side inlet opening 17 opens at the end of the burner block.

Die Durchgangsöffnung 16 ist an der Stelle der Mündung der Seiteneinlaßöffnung 17 mit einer radialen, die Mündung der Durchlaßöffnung 10 umgebenden Erweiterung 18 versehen. In der Ausströmrichtung der Brenngase folgt auf diese radiale Erweiterung 18 eine abgerundete Verengung 19, an die ein kegelförmiger, sich zum Ofeninnenraum 20 hin erweiternder Teil 21 der Durchgangsöffnung 16 anschließt. Der in der Durchlaßöffnung 10 brennende und bis in die Durchgangsöffnung 16 reichende Brennstrahl 22 bewirkt eine hohe Austrittsgeschwindigkeit der Brenngase, wodurch es zu einem Ansaugen von Gas durch die Seiteneinlaßöffnung 17 und einem Mitreißen und Ausstoßen dieses Gases mit hoher Geschwindigkeit in den Ofeninnenraum 20 nach dem Injektorprinzip kommt.The passage opening 16 is provided at the location of the mouth of the side inlet opening 17 with a radial extension 18 surrounding the mouth of the passage opening 10. In the outflow direction of the fuel gases, this radial enlargement 18 is followed by a rounded constriction 19, which is followed by a conical part 21 of the passage opening 16, which widens towards the furnace interior 20. The burning jet 22 burning in the passage opening 10 and reaching into the passage opening 16 causes a high exit velocity of the fuel gases, causing gas to be sucked in through the side nlass opening 17 and entrainment and ejection of this gas at high speed in the furnace interior 20 according to the injector principle.

Die Seiteneinlaßöffnung 17 ist an eine Rauchgas vom Aufwärmofen 2 zum Vorwärmofen 1 führende Rauchgasableitung 23 angeschlossen. Die Versorgung der Hochgeschwindigkeitsbrenner 7 mit Brennluft geschieht über die Brennluftzuführungsleitung 13 mittels eines Ventilators 24, wobei die Brennluftzuführungsleitung 13 einen Wärmetauscher 25 durchsetzt, der in einer Rauchgas vom Vorwärmofen 1 abführenden Rauchgasableitung 26, die an einen nicht näher dargestellten Kamin angeschlossen ist, vorgesehen ist.The side inlet opening 17 is connected to a flue gas duct 23 leading from the heating furnace 2 to the preheating furnace 1. The supply of the high-speed burners 7 with combustion air takes place via the combustion air supply line 13 by means of a fan 24, the combustion air supply line 13 passing through a heat exchanger 25 which is provided in a flue gas discharge line 26 leading away from the preheating furnace 1 and connected to a chimney (not shown).

Die Brennluftzuführungsleitung 13 dient auch zum (teilweisen) Versorgen der im Aufwärmofen 2 vorgesehenen Brenner 27. Diese Brenner 27 sind herkömmlicher Bauart. In der Brennluftzuführungsleitung 13 ist zwischen der Abzweigung 28 zu den Hochgeschwindigkeitsbrennern 7 des Vorwärmofens 1 und den Brennern 27 des Aufwärmofens 2 ein weiterer Wärmetauscher 29 vorgesehen, der von der Rauchgas vom Aufwärmofen 2 zum Vorwärmofen 1 führenden Rauchgasableitung 23 durchsetzt ist (siehe Fig. 4).The combustion air supply line 13 also serves to (partially) supply the burners 27 provided in the heating furnace 2. These burners 27 are of conventional construction. In the combustion air supply line 13, a further heat exchanger 29 is provided between the branch 28 to the high-speed burners 7 of the preheating furnace 1 and the burners 27 of the preheating furnace 2, which is interspersed with the flue gas discharge line 23 leading from the preheating furnace 2 to the preheating furnace 1 (see FIG. 4). .

In die Brennluftzuführungsleitung 13 mündet weiters zwischen der. Abzweigung 28 zu den Hochgeschwindigkeitsbrennern 7 des Vorwärmofens 1. und dem Wärmetauscher 29 der Rauchgas vom Aufwärmofen 2 zum Vorwärmofen 1 führenden Rauchgasableitung 23 eine weitere von einem Ventilator 30 beaufschlagte Brennluftzuführungleitung 31. Durch diese Brennluftzuführungsleitung 31 wird zusätzlich Brennluft zugeführt, wenn kaltes Stahlgut 4 eingebracht wird, da die Hochgeschwindigkeitsbrenner 7 in diesem Fall die gesamte bzw. einen Großteil der Luft, die durch den Ventilator 24 über die Brennluftzuführungsleitung 13 zugeführt wird, verbrauchen.In the combustion air supply line 13 also opens between the. Branch 28 to the high-speed burners 7 of the preheating furnace 1 and the heat exchanger 29 of the flue gas from the preheating furnace 2 to the preheating furnace 1 leading to the flue gas discharge line 23 a further combustion air supply line 31 acted upon by a fan 30. Combustion air is additionally supplied through this combustion air supply line 31 when cold steel 4 is introduced , since the high-speed burners 7 in this case consume all or a large part of the air which is supplied by the fan 24 via the combustion air supply line 13.

Von der Brennluftzuführungsleitung 13 zweigt nach dem in der Rauchgasableitung 23 des Aufwärmofens 2 vorgesehenen Wärmetauscher 29 eine Brennluftabblasleitung 32 ab, die mittels einer Regelklappe in Abhängigkeit von der Temperatur der Brennluft, die mittels eines Temperaturfühlers gemessen wird, regelbar ist. Die Brennluftabblasleitung 32 mündet in eine Treibdüse 33, die in der Rauchgas vom Aufwärmofen 2 in den Vorwärmofen 1 führenden Rauchgasableitung 23 eingebaut ist. Die Brennluft wirkt somit als Treibgas für den Rauchgasstrom, der dem Vorwärmofen 1 zugeführt wird.From the combustion air supply line 13 branches off, after the heat exchanger 29 provided in the flue gas discharge line 23 of the heating furnace 2, a combustion air blow-off line 32, which can be regulated by means of a control flap as a function of the temperature of the combustion air, which is measured by means of a temperature sensor. The combustion air blow-off line 32 opens into a driving nozzle 33 which is installed in the flue gas from the heating furnace 2 into the preheating furnace 1 leading flue gas discharge line 23. The combustion air thus acts as a propellant for the flue gas stream which is fed to the preheating furnace 1.

Im Fall des Einsatzes von kaltem Stahlgut 4 wird das aus dem Aufwärmofen 2 mit etwa 1100°C austretende Rauchgas mit 700 bis 800°C den Hochgeschwindigkeitsbrennern 7 zugeführt.If cold steel material 4 is used, the flue gas emerging from the heating furnace 2 at approximately 1100 ° C. is fed to the high-speed burners 7 at 700 to 800 ° C.

Gemäß der in Fig. 3 dargestellten Ausführungsform des Vorwärmofens 1 ist sein Ofeninnenraum 20 durch ein bis nahe zum eingesetzten Stahlgut 4 reichendes Trennwehr 34 zweigeteilt ausgebildet. Das Stahlgut 4 wird kontinuierlich durch die beiden Teile 20', 20" des Ofeninnenraumes 20 des Vorwärmofens 1 mittels eines nicht näher dargestellten Förderers, beispielsweise eines Hubbalkenförderers, hindurchbewegt.According to the embodiment of the preheating furnace 1 shown in FIG. 3, its furnace interior 20 is formed in two parts by a separating weir 34 which extends close to the steel material 4 used. The steel material 4 is continuously moved through the two parts 20 ', 20 "of the furnace interior 20 of the preheating furnace 1 by means of a conveyor, not shown, for example a walking beam conveyor.

Nahe dem eingangsseitigen Ende 35 des -in Förderrichtung gesehen -zweiten Teiles 20" des Ofeninnenraumes ist bodenseitig eine Rauchgasableitung 36 vorgesehen, die jedoch nicht in einen Kamin mündet, sondern das Rauchgas wird den in der Förderrichtung im ersten Teil 20' des Ofeninnenraumes 20 angeordneten Hochgeschwindigkeitsbrennern 7 zugeführt, u.zw. in gleicher Weise, wie dies in Fig. 2 veranschaulicht ist. Das Rauchgas mündet in einen den Gasstrahl der Hochgeschwindigkeitsbrenner umgebenden Bereich, wobei es durch die Saugwirkung der Hochgeschwindigkeitsbrenner 7 aus dem -in der Förderrichtung gesehen -zweiten Teil 20" des Ofeninnenraumes abgesaugt wird. Diese in Fig. 3 dargestellte Ausführungsform gestattet eine sehr - schnelle und effektive Vorwärmung des Stahlgutes 4, so daß der Vorwärmofen 1 trotz hoher Leistung nur eine sehr kurze Baulänge aufweist.Near the input end 35 of the second part 20 "of the furnace interior, as seen in the conveying direction, a flue gas discharge line 36 is provided on the bottom side, but this does not open into a chimney, but the flue gas becomes the high-speed burners arranged in the conveying direction in the first part 20 'of the furnace interior 20 7, e.g. in the same way as is illustrated in Fig. 2. The flue gas opens into an area surrounding the gas jet of the high-speed burners, whereby it is sucked by the high-speed burners 7 from the second part, as seen in the conveying direction 20 "of the furnace interior is suctioned off. This embodiment shown in Fig. 3 allows a very - fast and effective preheating of the steel material 4, so that the preheating furnace 1 has only a very short length despite high performance.

In Fig. 4 ist eine erweiterte Anlage zum Erhitzen von Stahlgut 4 auf Warmformgebungstemperatur gezeigt, die universell verwendbar ist und allen Anforderungen genügt. Zusätzlich zu dem oben beschriebenen Aufwärm-2 und Vorwärmofen 1 sind zwei Nachwärmöfen 37 vorgesehen, deren Eingabeöffnungen 38 an der Stahlgut höherer Temperatur zum Aufwärmofen führenden Transporteinrichtung 6 liegen. Die Auslauföffnungen 47 der Nachwärmöfen liegen an einer das fertig erhitzte Stahlgut vom Aufwärmofen zur Warmformgebungseinrichtung, beispielsweise zum Walzwerk, führenden Transporteinrichtung 39.4 shows an expanded system for heating steel material 4 to the hot forming temperature, which can be used universally and meets all requirements. In addition to the heating-up 2 and preheating furnace 1 described above, two reheating furnaces 37 are provided, the input openings 38 of which lie on the transport device 6 leading to the steel material of higher temperature to the heating furnace. The outlet openings 47 of the reheating furnaces are located on a transport device 39 which guides the finished steel material from the heating furnace to the hot forming device, for example to the rolling mill.

Das von den Nachwärmöfen 37 ausströmende Rauchgas wird jeweils über Rauchgasleitungen 40 und Wärmetauscher 41 zu der das Rauchgas des Aufwärmofens 2 zum Vorwärmofen 1 führenden Rauchgasableitung 23 geführt. Die Wärmetauscher 41 der Nachwärmöfen 37 dienen zum Vorwärmen der mittels Ventilatoren 42 den Brennern 43 zugeführten Brennluft. Je nach benötigter Rauchgasmenge kann ein Teil des Rauchgases der Nachwärmöfen 37 oder das gesamte Rauchgas der Nachwärmöfen 37 über einen Abhitzekessel 44, in dem Dampf erzeugt wird, einem eigenen, mit einem Ventilator 45 ausgestatteten Kamin 46 zugeführt werden.The flue gas flowing out of the reheating furnaces 37 is led in each case via flue gas lines 40 and heat exchangers 41 to the flue gas discharge line 23 leading the flue gas of the heating furnace 2 to the preheating furnace 1. The heat exchangers 41 of the reheating furnaces 37 serve to preheat the combustion air supplied to the burners 43 by means of fans 42. Depending on the amount of flue gas required, some of the flue gas from the reheating furnaces 37 or all of the flue gas the reheating furnaces 37 are fed to a separate chimney 46 equipped with a fan 45 via a waste heat boiler 44, in which steam is generated.

Die in Fig. 4 dargestellte Anlage ermöglicht den Einsatz von kaltem, warmem und heißem Stahlgut, wobei das heiße Stahlgut, das eine Temperatur nahezu in der Höhe der Warmformgebungstemperatur aufweist, lediglich durch die Nachwärmöfen geführt wird. Der Aufwärmofen 2 und der Vorwärmofen 1 dienen dazu, Stahlgut auf Walztemperatur aufzuwärmen, das aus technologischen oder anderen Gründen nicht direkt in die Nachwärmöfen 37 eingesetzt werden kann. Aus dem in Wärmeofen 2 und im Vorwärmofen 1 erwärmten Stahlgut wird die Walzstraße während der Betriebsphasen mit Stahlgut versorgt, während der die Nachwärmöfen 37 mangels Zufuhr von sehr heißem Stahlgut kein walzfertiges Stahlgut abgeben können.The system shown in FIG. 4 enables the use of cold, warm and hot steel material, the hot steel material, which has a temperature almost at the level of the hot forming temperature, only being led through the reheating furnaces. The heating furnace 2 and the preheating furnace 1 serve to heat steel material to the rolling temperature, which for technological or other reasons cannot be used directly in the reheating furnaces 37. From the steel material heated in heating furnace 2 and in preheating furnace 1, the rolling mill is supplied with steel material during the operating phases, during which the reheating furnaces 37 cannot deliver steel material ready for rolling due to the lack of very hot steel material.

Wenn Stahlgut 4 höherer Temperatur (etwa zwischen 400 und 700°C), welches nicht vorgewärmt zu werden braucht, auf Warmformgebungstemperatur aufgewärmt wird, erfolgt der Einsatz, wie oben bereits erwähnt, unter Umgehung des Vorwärmofens 1 direkt in den Aufwärmofen 2, indem das Stahlgut 4 auf die vom Vorwärmofen zum Aufwärmofen führende Transporteinrichtung 5 aufgebracht wird. In diesem Fall ist die in die Brennluftzuführungsleitung 13 mündende Brennlüftzuführungsleitung 31 stillgesetzt; die Brennluft wird dann über die beiden in der Brennluftzuführungsleitung 13 vorgesehenen Wärmetauscher 25 und 29 zugeführt und auf etwa 550°C aufgewärmt. Die Hochgeschwindigkeitsbrenner 7 des Vorwärmofens 1 sind in diesem Fall nicht in Betrieb, d.h. weder brenngas-noch brennluftbeaufschlagt. Die Rauchgase aus dem Aufwärmofen 2 werden in diesem Fall entweder am Vorwärmofen vorbeigeführt, etwa über die Rauchgasleitung 40, den Abhitzekessel 44, den Saugzugventilator 45 zum Kamin 46, oder aber über die Mischzone der Brenner 7 durch den Vorwärmofen 1, den Rauchgaskanal 26, den Rekuperator 25 vom Saugzugventilator angesaugt und zum Kamin gefördert. Damit wird eine Abkühlung des Vorwärmofens 1 vermieden, so daß dieser jederzeit bzw. ohne nennenswerte Aufheizzeit nach dem Einlegen von kaltem Stahlgut wieder in Betrieb genommen werden kann.If steel material 4 of higher temperature (approximately between 400 and 700 ° C), which does not need to be preheated, is heated to the hot-forming temperature, the insert, as already mentioned above, is carried out bypassing the preheating furnace 1 directly into the heating furnace 2 by removing the steel material 4 is applied to the transport device 5 leading from the preheating furnace to the heating furnace. In this case, the combustion air supply line 31 opening into the combustion air supply line 13 is shut down; the combustion air is then supplied via the two heat exchangers 25 and 29 provided in the combustion air supply line 13 and heated to approximately 550 ° C. The high-speed burners 7 of the preheating furnace 1 are not in operation in this case, i.e. neither exposed to combustion gas nor combustion air. In this case, the flue gases from the heating furnace 2 are either guided past the preheating furnace, for example via the flue gas line 40, the waste heat boiler 44, the suction fan 45 to the chimney 46, or via the mixing zone of the burners 7 through the preheating furnace 1, the flue gas duct 26 Recuperator 25 sucked in by the induced draft fan and conveyed to the chimney. This prevents the preheating furnace 1 from cooling, so that it can be put back into operation at any time or without any appreciable heating-up time after the insertion of cold steel.

Claims (8)

1. Anlage zum Aufwärmen von Stahlgut (4) auf Warmformgebungstemperatur, mit einem Vorwärmofen (1) und einem damit kombinierten Aufwärmofen (2), wobei zwischen der Einlaufseite des Aufwärmofens (2) und der Auslaufseite des Vorwärmofens (1) eine Transporteinrichtung (5) vorgesehen ist und wobei eine Rauchgas vom Aufwärmofen (2) zum Vorwärmofen (1) führende Rauchgasableitung (23) vorgesehen ist, dadurch gekennzeichnet, daß zum wahlweisen Einsatz von kaltem Stahlgut (4) oder von Stahlgut (4) höherer Temperatur die Transporteinrichtung (5, 6) einerseits vom Vorwärmofen (1) her und andererseits von außen her beschickbar ist, daß der Vorwärmofen (1) mit mehreren Hochgeschwindigkeitsbrennern (7) ausgestattet ist und daß Rauchgasleitung (23) in einen den Brennstrahl (22) der Hochgeschwindigkeitsbrenner (7) umgebenden Bereich (18) an den Austrittsöffnungen der Hochgeschwindigkeitsbrenner (7) mündet, wobei durch die Saugwirkung der Hochgeschwindigkeitsbrenner (7) heißes Rauchgas aus dem Aufwärmofen (2) ansaugbar ist.1. Plant for heating steel material (4) to the hot forming temperature, with a preheating furnace (1) and a combined preheating furnace (2), with a transport device (5) between the inlet side of the preheating furnace (2) and the outlet side of the preheating furnace (1) A flue gas discharge line (23) leading from the heating furnace (2) to the preheating furnace (1) is provided, characterized in that for the optional use of cold steel material (4) or of steel material (4) of higher temperature the transport device (5, 6) on the one hand from the preheating furnace (1) and on the other hand, it can be loaded from the outside that the preheating furnace (1) is equipped with several high-speed burners (7) and that the flue gas line (23) surrounds the combustion jet (22) of the high-speed burner (7) Area (18) at the outlet openings of the high-speed burner (7) opens, with the high-speed burner (7) suctioning hot flue gas from the heating furnace s (2) can be sucked in. 2. Anlage nach Anspruch 1, dadurch gekennzeichnet, daß der Ofeninnenraum (20) des Vorwärmofens (1) zweigeteilt ausgebildet ist, wobei beide Teile (20", 20') des Ofeninnenraumes (20) mit Hochgeschwindigkeitsbrennern (7) ausgestattet sind und der -in der Durchlaufrichtung des Stahlgutes gesehen -zweite Teil (20") des Ofeninnenraumes (20) eine Rauchgasableitung (36) aufweist, die zu den Hochgeschwindigkeitsbrennern (7) des in der Durchlaufrichtung des Stahlgutes (4) ersten Teiles (20') des Ofeninnenraumes (20) führt und in einen den Brennstrahl (22) der Hochgeschwindigkeitsbrenner (7) umgebenden Bereich - (18) mündet.2. Plant according to claim 1, characterized in that the furnace interior (20) of the preheating furnace (1) is formed in two parts, both parts (20 ", 20 ') of the furnace interior (20) being equipped with high-speed burners (7) and the - seen in the direction of passage of the steel material - second part (20 ") of the furnace interior (20) has a flue gas discharge line (36) leading to the high-speed burners (7) of the first part (20 ') of the furnace interior (20') in the direction of passage of the steel object (4) 20) leads and opens into an area - (18) surrounding the focal jet (22) of the high-speed burner (7). 3. Anlage nach Anspruch 2, dadurch gekennzeichnet, daß die Rauchgasableitung (36) des zweiten Teiles (20") des Ofeninnenraumes (20) nahe bei dessen einlaufseitigem Ende (35) vorgesehen ist.3. Plant according to claim 2, characterized in that the flue gas discharge line (36) of the second part (20 ") of the furnace interior (20) is provided close to the inlet end (35). 4. Anlage nach einem oder mehreren der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß in der das Rauchgas vom Aufwärmofen (2) dem Vorwärmofen (1) zuführenden Rauchgasableitung - (23) ein Wärmetauscher (29) vorgesehen ist, der von Brennluft aus der Brennluftzuführung (13) durchströmt ist, die nach Aufwärmung im Wärmetauscher (29) den Brennern (27) im Aufwärmofen (2) zugeleitet wird.4. Plant according to one or more of claims 1 to 3, characterized in that in the flue gas from the heating furnace (2) to the preheating furnace (1) supplying flue gas discharge line (23), a heat exchanger (29) is provided which is from combustion air from the Combustion air supply (13) flows through, which is fed to the burners (27) in the heating furnace (2) after heating in the heat exchanger (29). 5. Anlage nach einem oder mehreren der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß in der Rauchgasableitung (26) des Vorwärmofens (1) ein Wärmetauscher (25) vorgesehen ist, der von Kaltluft durchströmt ist, die mittels einer Brennluftzuführungsleitung (13) einerseits zu den im Vorwärmofen (1) vorgesehenen Hochgeschwindig keitsbrennern (7) und andererseits über den in der Rauchgasableitung (23) des Aufwärmofens (2) vorgesehenen Wärmetauscher (29) zu den im Aufwärmofen (2) vorgesehenen Brennern (27) zuführbar ist.5. Plant according to one or more of claims 1 to 4, characterized in that a heat exchanger (25) is provided in the flue gas discharge line (26) of the preheating furnace (1) Cold air flows through the combustion air supply line (13) on the one hand to the high-speed burners (7) provided in the preheating furnace (1) and on the other hand via the heat exchanger (29) provided in the flue gas discharge line (23) of the heating furnace (2) to the in the heating furnace ( 2) provided burners (27) can be fed. 6. Anlage nach Anspruch 5, dadurch gekennzeichnet, daß in die Brennluftzuführungsleitung (13) an einer Stelle zwischen der Abzweigung (28) zu den Hochgeschwindigkeitsbrennern (7) des Vorwärmofens (1) und dem in der Rauchgasableitung (23) des Aufwärmofens (2) vorgesehenen Wärmetauscher (29) eine weitere Brennluft zuführende Brennluftzuführungsleitung (31) einmündet.6. Plant according to claim 5, characterized in that in the combustion air supply line (13) at a point between the branch (28) to the high-speed burners (7) of the preheating furnace (1) and in the flue gas discharge line (23) of the heating furnace (2) provided heat exchanger (29) opens a further combustion air supply line (31) supplying combustion air. 7. Anlage nach Anspruch 5 oder 6, dadurch gekennzeichnet, daß von der zu den Brennern des Aufwärmofens führenden Brennluftzuführungsleitung (13) eine Brennluftabblasleitung - (32) ausgeht, die in die Rauchgasableitung (23), die vom Aufwärmofen (2) zum Vorwärmofen (1) führt, nach dem Wärmetauscher (29) mündet.7. Installation according to claim 5 or 6, characterized in that from the leading to the burners of the heating furnace combustion air supply line (13) is a combustion air blow-off line - (32) which in the flue gas discharge line (23) from the heating furnace (2) to the preheating furnace ( 1) leads after the heat exchanger (29) opens. 8. Anlage nach Anspruch 7, dadurch gekennzeichnet, daß die Brennluftabblaseinrichtung (32) in die Rauchgasableitung (23) mittels einer Treibdüse - (33) einmündet.8. Plant according to claim 7, characterized in that the combustion air blowing device (32) opens into the flue gas discharge line (23) by means of a propellant nozzle - (33).
EP86890061A 1985-04-04 1986-03-13 Plant for heating steel material up to the hot-forming temperature Withdrawn EP0199703A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT0102385A AT381790B (en) 1985-04-04 1985-04-04 PLANT FOR WARMING UP STEEL MATERIAL TO TEMPERATURE
AT1023/85 1985-04-04

Publications (2)

Publication Number Publication Date
EP0199703A2 true EP0199703A2 (en) 1986-10-29
EP0199703A3 EP0199703A3 (en) 1987-05-27

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Application Number Title Priority Date Filing Date
EP86890061A Withdrawn EP0199703A3 (en) 1985-04-04 1986-03-13 Plant for heating steel material up to the hot-forming temperature

Country Status (4)

Country Link
EP (1) EP0199703A3 (en)
JP (1) JPS61231116A (en)
CN (1) CN86102037A (en)
AT (1) AT381790B (en)

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ES2154947A1 (en) * 1996-11-21 2001-04-16 Morales Mateos Matias Continuous e.g. baking oven performance enhancement consists of forced extraction of air from the oven chamber to control the gas and air circulation
WO2010099929A1 (en) * 2009-03-02 2010-09-10 Sms Siemag Ag Method and installation for producing and/or processing a slab or a strip of metallic material
CN102242249A (en) * 2011-06-30 2011-11-16 首钢总公司 Heating device for improving heating quality of steel billets and using method thereof
EP2437018A1 (en) * 2010-10-04 2012-04-04 Frank Orlowski Tunnel kiln and burner for firing bricks
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IT973930B (en) * 1971-12-06 1974-06-10 Kawasaki Heavy Ind Ltd METAL LURGIC PRE-HEATER APPLIANCE AND OVEN THAT INCLUDES IT
DE2706345A1 (en) * 1977-02-11 1978-08-17 Mannesmann Ag OVEN ARRANGEMENT FOR HEATING SLABS
JPS552753A (en) * 1978-06-21 1980-01-10 Ito Seisakusho:Kk Method and apparatus for soaking treatment for cold billet and hot billet

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2154947A1 (en) * 1996-11-21 2001-04-16 Morales Mateos Matias Continuous e.g. baking oven performance enhancement consists of forced extraction of air from the oven chamber to control the gas and air circulation
WO2010099929A1 (en) * 2009-03-02 2010-09-10 Sms Siemag Ag Method and installation for producing and/or processing a slab or a strip of metallic material
TWI404582B (en) * 2009-03-02 2013-08-11 Ｓｍｓ史邁格股份有限公司 Method and apparatus for manufacturing and/or processing metal sheets or metal strips of metallic materials
EP2437018A1 (en) * 2010-10-04 2012-04-04 Frank Orlowski Tunnel kiln and burner for firing bricks
CN102242249A (en) * 2011-06-30 2011-11-16 首钢总公司 Heating device for improving heating quality of steel billets and using method thereof
CN102242249B (en) * 2011-06-30 2013-02-06 首钢总公司 A kind of heating equipment and using method for improving the heating quality of billets
CN105283728A (en) * 2012-11-19 2016-01-27 施瓦兹有限公司 Roller hearth furnace and method for heat treatment of metal sheets
CN105283728B (en) * 2012-11-19 2017-04-26 施瓦兹有限公司 Roller hearth furnace and method for heat treatment of metal sheets

Also Published As

Publication number Publication date
CN86102037A (en) 1986-11-26
JPS61231116A (en) 1986-10-15
ATA102385A (en) 1986-04-15
AT381790B (en) 1986-11-25
EP0199703A3 (en) 1987-05-27

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