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EP0302301A1 - Cooled tube track for reheating industrial furnaces - Google Patents

Cooled tube track for reheating industrial furnaces Download PDF

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Publication number
EP0302301A1
EP0302301A1 EP88111648A EP88111648A EP0302301A1 EP 0302301 A1 EP0302301 A1 EP 0302301A1 EP 88111648 A EP88111648 A EP 88111648A EP 88111648 A EP88111648 A EP 88111648A EP 0302301 A1 EP0302301 A1 EP 0302301A1
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EP
European Patent Office
Prior art keywords
offset
support tubes
furnace
heating
cooled
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.)
Granted
Application number
EP88111648A
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German (de)
French (fr)
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EP0302301B1 (en
Inventor
Helmut Dipl.-Ing. Heuss
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EOn Ruhrgas AG
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Ruhrgas AG
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Publication date
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Publication of EP0302301A1 publication Critical patent/EP0302301A1/en
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Classifications

    • 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
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path
    • F27B9/201—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path walking beam furnace
    • 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
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path
    • F27B9/22—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path on rails, e.g. under the action of scrapers or pushers

Definitions

  • the invention relates to a cooled pipe string for industrial heating furnaces, the individual support tubes of which extend in the longitudinal direction of the furnace from the inlet towards the outlet, are at least partially provided with attachments for the heating material passing through, and have a common lateral side that extends beyond the width of the support tube Have offset.
  • the steel In heating furnaces, the steel should be heated to rolling temperature as evenly as possible. There is the problem that the material to be heated at the points where it rests on the water-cooled support tubes - usually with the interposition of attachments - has a lower temperature than the other areas, because on the one hand the heating by the burner located under the support tubes is disabled at these points and on the other hand, the heat can flow to the cooled support tubes. Before the rolling process, these points must also have reached the temperature required for this. This takes place in the compensation zone of the ovens.
  • the material to be heated is initially heated mainly on the surface, while the core of the slabs, blocks and the like takes a long time to reach the same temperature. This happens in the equalization zone. In this zone, the temperature should also be equalized with respect to the cooling shadows generated by the cooled support tubes in the heating zone. Several constructions are known for this.
  • DE-AS 2 039 507 discloses a cooled pipe string with a support pipe which runs in a straight line in the direction of flow of the heating material. Top sections are arranged one behind the other on the straight support tube. The top sections have heating material support surfaces that run either at an angle to the support tube or alternately on the left and right side of the support tube axis. Through this known support surface arrangement of the top pieces, the heat flow from the heating material to the cooled support tubes is made more uniform. For the formation of the cooling shadow, however, the relative position and size of the entire support tube with attachments to the material to be heated is decisive, and this relative position remains the same over the entire length of the furnace and causes a considerable shadow width when treating the material to be heated in the compensation zone.
  • Support pipes of the type mentioned are known from DE-PS 31 15 930 with the mandatory additional measures that they have the lateral offset at 10-30% of the furnace length at the outlet end and are equipped with attachments there.
  • This design change which essentially concerns the equilibrium zone, solves the problem of letting the hot slabs run from the bare support tubes onto the top sections, which had hitherto occurred in the entrance area of the furnace.
  • the invention has for its object to design a cooled pipe string of the type mentioned already outside the compensation zone of industrial heating furnaces so that the cooling shadow effects caused by the cooled support tubes can be reduced and practically completely degraded in a compensation zone.
  • the solution of the invention is that the support tubes have at least one other common offset in addition to the common, lateral offset, the length of each offset in the direction of flow of the heating material offset support tube section is shorter than that of the previous section.
  • the offset support tube sections in the invention are at least partially inevitably in the heating zone, as soon as the material to be heated reaches the first offset support tube section, the area of the heat product with the lower temperature previously shaded by the non-offset support tube Already during the heating up, free for heating to a higher temperature level in the places that were not yet in the supporting tube shade. Now that the support tube, possibly together with the top pieces, comes into contact with its hotter points when the hot goods are transported straight, an almost temperature equalization will soon occur.
  • the second offset is now provided in this area. This further reduces the temperature differences.
  • the last-mentioned arrangement will be the rule.
  • the offset support tube section located furthest downstream in the flow direction of the heating material ends at the outlet of the heating furnace.
  • the aforementioned support tube section advantageously ends at the fixed hearth. This can therefore be built with a full, undivided support surface, which minimizes wear from the slabs.
  • the invention can also be implemented in walking beam furnaces.
  • the walking beams expediently have the same dislocations as the support tubes and are also preferably water-cooled.
  • the offset walking beams have the same good effects as the offset support tubes, even if they come into contact with the gradually rollable slabs for a much shorter time.
  • the support tubes, together with the walking beams may have three staggered length sections, of which two sections downstream in the direction of flow are each approximately 1/3 shorter than the previous sections with a vertical heat material thickness of approx. 250 mm.
  • FIGS. 1 and 2 two longitudinal sectional views through a pusher furnace 1 that are perpendicular to one another are shown.
  • a pipe string 2 with individual, parallel water-cooled support pipes 3 is provided, which are arranged on vertical support pipes 4.
  • the heating material 6 (slabs or the like) is moved in a direction of passage 7 from an inlet 8 along a horizontal sliding surface through the pusher furnace 1 to its outlet 9.
  • the heating material 6 first passes through a preheating zone A arranged behind the inlet, then a heating zone B in which the heating material is heated up the treatment temperature is brought, and finally a compensation zone C, which ends at the outlet 9 of the furnace 1.
  • the support tubes 3 extend continuously from the inlet 8 via the preheating zone A and the heating zone B and end at the equalization zone C. Top pieces 10 rest on the support tubes 3.
  • the equalization zone C in the exemplary embodiment according to FIGS. 1 and 2 is formed in a fixed hearth 14 , whose bottom surface is completely covered with ceramic plates. The sliding surface of the heating material 6 formed by the surfaces of the top pieces 10 merges practically seamlessly into the level of the full plating of the fixed cooker 14.
  • the support tubes 3 in the preheating zone A run in a straight line and parallel to the direction of impact 7.
  • pronounced cooling shadows in the heating material 6 would lie directly above the support tubes 3 and the top pieces 10 placed thereon form if the straight line of the support tubes 3 would also continue over the heating zone B of the pusher furnace 1.
  • a first horizontal, lateral offset 11 is provided approximately at the boundary between preheating zone A and heating zone B.
  • the extent of the lateral offset 11 is preferably at least as large as the width of the support tube 3.
  • the support tubes 3 run around the lateral offset 11 parallel to their course in the preheating zone A.
  • an opposing lateral offset is provided. Behind the offset 12, the support tubes 3 with their attachments 10 are aligned again with the support tube profile in the preheating zone A.
  • a third offset point 13 is provided, at which the support tubes 3 are displaced again and brought into alignment with the support tube sections L1 .
  • the successively offset support tube sections L1, L2 and L3 are of different lengths.
  • the subsequent longitudinal sections L2 and L3 in the direction of flow 7 are in the preferred embodiment game each shortened by about 1/3 of the length of the immediately preceding offset length section L1 or L2.
  • the reference length of the first offset length section L 1 in the direction of passage 7 is determined by calculation.
  • a walking beam furnace 21 is shown schematically.
  • the design of the support tubes 3, the support tubes 4, the top pieces 10 and furnace inlet 8 and outlet 9 can correspond to that of the previously described pusher furnace 1, so that corresponding components of the walking beam furnace are designated by the same reference numerals as in the pusher furnace 1.
  • Also in the walking beam furnace 21 there is a preheating zone A shown in FIG. 3, a heating zone B and an equalization zone C in a sequence and relative length substantially the same as FIG. 1.
  • the cooled pipe string 22 has, in addition to the support pipes running parallel to the direction of passage 7, 3 walking beams 23, which are preferably also water-cooled.
  • the drive mechanism moving the walking beams 23 is known and is not shown in FIGS. 3 and 4. As can be seen in Fig.
  • both the support tubes 3 and the cooled walking beam 23 have pairs of common offset points 11, 12 and 13, which results in laterally offset longitudinal sections L1, L2 and L3.
  • the function of the lateral displacements 11, 12, 13 corresponds to that in the previously described pusher furnace, namely the avoidance of a pronounced formation of cooling shadows at the locations of the heating material 6 which rest on the cooled support tubes or walking beams over longer treatment times in the furnace 21.
  • the offset lengths L2 and L3 are therefore predominantly arranged in the compensation zone C adjacent to the furnace outlet 9.
  • the heating zone B is the first offset length section L 1 in the direction of flow 7 and the beginning of the subsequent second length section L 2.
  • the aspect ratios, that is, the connecting tongues of the lengths L2 and L3 compared to the respectively preceding lengths L1 and L2 are provided similar to the embodiment described above.
  • Three offset length sections with decreasing section length in the direction of passage 7 form a preferred exemplary embodiment of the invention. If necessary, two offset lengths L 1 and L 2 without the third length L 3 are sufficient to prevent the formation of a cooling shadow. On the other hand, it is also possible within the scope of the inventive concept to use more than three offset length sections with decreasing length towards the outlet 9.
  • the number of support tubes and / or walking beams which are preferably arranged parallel to one another and likewise preferably offset at the same points (11, 12 or 13), is not essential for the invention; what is essential is the arrangement and sequence as well as the relative length of the offset length sections on a support tube and, if appropriate, the associated walking beam arrangement.
  • the offset tube sections L1, L2 and L3 are at least partially arranged in the heating zone B in the invention.
  • the temperature compensation while preventing the formation of a cooling shadow on the material to be heated therefore already takes place in heating zone B during the heating period and is not limited to compensation zone C.
  • the staggering of the different lengths L2 and L3 ensures a particularly favorable cooling shadow removal and an optimal temperature compensation within the heat material 6 during the compensation treatment in zone C.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
  • Tunnel Furnaces (AREA)

Abstract

In Erwärmungsöfen wird der Stahl als Wärmgut (6) auf Walztemperatur erhitzt. Dabei wird er in der Regel auf geradeaus durchlaufenden, wassergekühlten Tragrohren verfahren, die im Bereich der Berührungsstellen das Erreichen der gewünschten Temperatur hemmen. Ein einmaliges seitliches Versetzen der Tragrohre oder ähnliche Maßnahmen konnten dieses Problem noch nicht lösen. Die Tragrohre (3) des vorliegenden Erwärmungsofens (1) weisen daher mehrfache seitliche Versetzungen (11, 12, 13) auf, die zwischen dem Eintritt (8) des Ofens (1) und dem Austritt (9) liegen oder beim Vorhandensein eines Festherdes (14) als Ausgleichszone bereits vor dieser im Ofenendbereich enden. Dabei ist jeder weiter stromab liegende Tragrohrabschnitt (L2, L3), der sich durch die Versetzung (11, 12, 13) ergibt, kürzer als der vorangegangene Abschnitt (L1). Diese Anordnung ist besonders bei Stoßöfen oder Hubbalkenöfen vorteilhaft.In heating furnaces, the steel is heated to the rolling temperature as the material to be heated (6). As a rule, it is moved on straight, water-cooled support tubes, which inhibit reaching the desired temperature in the area of the contact points. A single lateral displacement of the support tubes or similar measures could not solve this problem. The support tubes (3) of the present heating furnace (1) therefore have multiple lateral displacements (11, 12, 13), which lie between the inlet (8) of the furnace (1) and the outlet (9) or in the presence of a fixed stove ( 14) end as a compensation zone before this in the furnace end area. Each further downstream tube section (L2, L3), which results from the offset (11, 12, 13), is shorter than the previous section (L1). This arrangement is particularly advantageous for push furnaces or walking beam furnaces.

Description

Die Erfindung bezieht sich auf einen gekühlten Rohrstrang für In­dustrie-Erwärmungsöfen, dessen einzelne Tragrohre sich in Ofen­längsrichtung vom Eintritt in Richtung auf den Austritt erstrecken, zumindest zum Teil mit Aufsatzstücken für das durchlaufende Wärmgut versehen sind und einen gemeinsamen, über die Breite des Tragrohres hinausgehenden seitlichen Versatz aufweisen.The invention relates to a cooled pipe string for industrial heating furnaces, the individual support tubes of which extend in the longitudinal direction of the furnace from the inlet towards the outlet, are at least partially provided with attachments for the heating material passing through, and have a common lateral side that extends beyond the width of the support tube Have offset.

In Erwärmungsöfen soll der Stahl möglichst gleichmäßig auf Walztem­peratur erwärmt werden. Dabei besteht das Problem, daß das Wärmgut an den Stellen, an denen es auf den wassergekühlten Tragrohren - in der Regel unter Zwischenschaltung von Aufsatzstücken - ruht, eine gegenüber den übrigen Bereichen niedrigere Temperatur hat, weil einerseits die Beheizung durch die unter den Tragrohren befindli­chen Brenner an diesen Stellen behindert ist und andererseits die Wärme zu den gekühlten Tragrohren abfließen kann. Vor dem Walzvor­gang müssen auch diese Stellen die hierfür notwendige Temperatur angenommen haben. Dies erfolgt in der Ausgleichszone der Öfen.In heating furnaces, the steel should be heated to rolling temperature as evenly as possible. There is the problem that the material to be heated at the points where it rests on the water-cooled support tubes - usually with the interposition of attachments - has a lower temperature than the other areas, because on the one hand the heating by the burner located under the support tubes is disabled at these points and on the other hand, the heat can flow to the cooled support tubes. Before the rolling process, these points must also have reached the temperature required for this. This takes place in the compensation zone of the ovens.

Das Wärmgut wird zunächst hauptsächlich an der Oberfläche erhitzt, während der Kern der Brammen, Blöcke und dergleichen längere Zeit benötigt, um auf die gleiche Temperatur zu kommen. Dies geschieht in der Ausgleichszone. In dieser Zone sollte nun gleichzeitig auch der Temperaturausgleich bezüglich der durch die gekühlten Tragrohre in der Aufheizzone erzeugten Kühlschatten erfolgen. Hierfür sind mehrere Konstruktionen bekannt.The material to be heated is initially heated mainly on the surface, while the core of the slabs, blocks and the like takes a long time to reach the same temperature. This happens in the equalization zone. In this zone, the temperature should also be equalized with respect to the cooling shadows generated by the cooled support tubes in the heating zone. Several constructions are known for this.

Aus der DE-AS 2 039 507 ist ein gekühlter Rohrstrang mit einem in Durchlaufrichtung des Wärmguts geradlinig verlaufenden Tragrohr be­kannt. Auf dem geraden Tragrohr sind Aufsatzstücke hintereinander angeordnet. Die Aufsatzstücke haben Wärmgut-Stützflächen, die ent­weder zum Tragrohr schräg oder abwechselnd auf der linken und rech­ten Seite der Tragrohrachse verlaufen. Durch diese bekannte Stütz­flächenanordnung der Aufsatzstücke wird der Wärmeabfluß vom Wärmgut zu den gekülten Tragrohren einheitlicher gemacht. Für die Kühl­schattenbildung ist jedoch die Relativlage und Größe des gesamten Tragrohrs mit Aufsatzstücken zum Wärmgut maßgeblich, und diese Re­lativlage bleibt über die gesame Ofenlänge gleich und verursacht eine erhebliche Schattenbreite bei der Behandlung des Wärmguts in der Ausgeichszone.DE-AS 2 039 507 discloses a cooled pipe string with a support pipe which runs in a straight line in the direction of flow of the heating material. Top sections are arranged one behind the other on the straight support tube. The top sections have heating material support surfaces that run either at an angle to the support tube or alternately on the left and right side of the support tube axis. Through this known support surface arrangement of the top pieces, the heat flow from the heating material to the cooled support tubes is made more uniform. For the formation of the cooling shadow, however, the relative position and size of the entire support tube with attachments to the material to be heated is decisive, and this relative position remains the same over the entire length of the furnace and causes a considerable shadow width when treating the material to be heated in the compensation zone.

Tragrohre der eingangs genannten Art sind nach der DE-PS 31 15 930 mit den zwingenden, zusätzlichen Maßnahmen bekannt, daß sie den seitlichen Versatz bei 10-30 % der Ofenlänge am Austrittsende auf­weisen und dort mit Aufsatzstücken ausgerüstet sind. Diese kon­struktive Änderung, die wohlgemerkt im wesentlichen die Ausgliechs­zone betrifft, löst das Problem, die heißen Brammen von den bloßen Tragrohren auf die Aufsatzstücke auflaufen zu lassen, was bis dahin im Eingangsbereich des Ofens erfolgte.Support pipes of the type mentioned are known from DE-PS 31 15 930 with the mandatory additional measures that they have the lateral offset at 10-30% of the furnace length at the outlet end and are equipped with attachments there. This design change, which essentially concerns the equilibrium zone, solves the problem of letting the hot slabs run from the bare support tubes onto the top sections, which had hitherto occurred in the entrance area of the furnace.

Der Erfindung liegt die Aufgabe zugrunde, einen gekühlten Rohr­strang der eingangs genannten Art bereits außerhalb der Aus­gleichszone von Industrie-Erwärmungsöfen so zu gestalten, daß die durch die gekühlten Tragrohre verursachten Kühlschatten-Effekte vermindert und in einer Ausgleichszone praktisch vollständig ab­gebaut werden können.The invention has for its object to design a cooled pipe string of the type mentioned already outside the compensation zone of industrial heating furnaces so that the cooling shadow effects caused by the cooled support tubes can be reduced and practically completely degraded in a compensation zone.

Die Lösung der Erfindung besteht darin, daß die Tragrohre neben dem gemeinsamen, seitlichen Versatz zumindest noch einen weiteren ge­meinsamen Versatz besitzen, wobei die Länge eines jeden in Durch­laufrichtung des Wärmgutes weiter vorn liegenden versetzten Trag­rohrabschnittes kürzer ist als die des vorangegangenen Abschnittes.The solution of the invention is that the support tubes have at least one other common offset in addition to the common, lateral offset, the length of each offset in the direction of flow of the heating material offset support tube section is shorter than that of the previous section.

Da wegen der konstruktiven Kürze der Ausgleichszone die versetzten Tragrohrabschnitte bei der Erfindung zumindest zum Teil zwangsläufig in der Aufheizzone liegen, wird in vorteilhafter Weise, sobald das Wärmgut den ersten versetzten Tragrohrabschnitt erreicht, der durch das unversetzte Tragrohr bisher abgeschattete Bereich des Wärmguts mit der niedrigeren Temperatur schon während der Aufheizung frei für die Erwärmung auf ein höheres Temperaturniveau der Stellen, die noch nicht in Tragrohrschatten lagen. Da jetzt das Tragrohr, gege­benenfalls mit den Aufsatzstücken zusammen, beim Geradeaus-Transport des Warmgutes mit dessen heißeren Stellen in Berührung kommt, wird sich ein beinaher Temperaturausgleich alsbald einstellen.Since, due to the constructional brevity of the compensation zone, the offset support tube sections in the invention are at least partially inevitably in the heating zone, as soon as the material to be heated reaches the first offset support tube section, the area of the heat product with the lower temperature previously shaded by the non-offset support tube Already during the heating up, free for heating to a higher temperature level in the places that were not yet in the supporting tube shade. Now that the support tube, possibly together with the top pieces, comes into contact with its hotter points when the hot goods are transported straight, an almost temperature equalization will soon occur.

In diesem Bereich ist nun der zweite Versatz vorgesehen. Hierdurch werden die Temperaturdifferenzen weiter verringert. Das gleiche gilt für jeden weiteren Versatz der Tragrohre, der derart vorge­nommen werden kann, daß jeweils der nachfolgende Versatz das Trag­rohr in die alte Lage zurückbringt. Mit Rücksicht auf die Forde­rung, möglichst viele unterschiedliche Wärmgutlängen einsetzen zu können, wird die zuletzt erwähnte Anordnung die Regel sein.The second offset is now provided in this area. This further reduces the temperature differences. The same applies to every further offset of the support tubes, which can be carried out in such a way that the subsequent offset returns the support tube to the old position. In view of the requirement to be able to use as many different lengths of heating material as possible, the last-mentioned arrangement will be the rule.

Berechnungen lassen eine vorteilhafte Verminderung der Temperatur­differenzen um bis zu 75 % gegenüber unversetzten Tragrohren und um 25 % gegenüber denselben mit Aufsatzstücken erwarten.Calculations indicate that the temperature differences can be reduced by up to 75% compared to un-offset support tubes and by 25% compared to the same with top sections.

Um in zweckmäßiger Weise eine Ausgleichzone zu schaffen, endet der in Durchlaufrichtung des Wärmgutes am weitesten stromab befindliche versetzte Tragrohrabschnitt am Austritt des Erwärmungsofens.In order to create a compensation zone in an expedient manner, the offset support tube section located furthest downstream in the flow direction of the heating material ends at the outlet of the heating furnace.

Wenn in der Ausgleichzone ein Festherd vorgesehen werden soll, en­det der vorerwähnte Tragrohrabschnitt in vorteilhafter Weise am Fest­herd. Dieser kann somit mit voller, ungeteilter Auflagefläche ge­baut werden, wodurch ein Verschleiß durch die Brammen minimiert wird.If a fixed hearth is to be provided in the compensation zone, the aforementioned support tube section advantageously ends at the fixed hearth. This can therefore be built with a full, undivided support surface, which minimizes wear from the slabs.

Die Erfindung läßt sich auch bei Hubbalkenöfen verwirklichen. In diesem Falle weisen die Hubbalken zweckmäßigerweise die gleichen Versetzungen wie die Tragrohre auf und sind ebenfalls vorzugsweise wassergekühlt. Die versetzten Hubbalken bewirken die gleichen guten Effekte wie die versetzten Tragrohre, auch wenn sie für wesentlich kürzere Zeit mit den allmählich walzfähigen Brammen in Berührung kommen.The invention can also be implemented in walking beam furnaces. In this case, the walking beams expediently have the same dislocations as the support tubes and are also preferably water-cooled. The offset walking beams have the same good effects as the offset support tubes, even if they come into contact with the gradually rollable slabs for a much shorter time.

Nach Berechnungen ließen sich Richtdaten feststellen, die einen vorteilhaften Ofenbau für Brammen und dergleichen ermöglichen, deren Stärken um das meistvorkommende Maß herum liegen. In diesem Falle besitzen die Tragrohre gegebenenfalls zusammen mit den Hub­balken drei versetzte Längenabschnitte, von denen zwei in der Durch­laufrichtung stromab liegende Abschnitte bei einer vertikalen Wärm­gutstärke von ca. 250 mm nacheinander jeweils um ca. 1/3 kürzer sind als die vorangegangenen Abschnitte.According to calculations, guideline data could be determined, which enables advantageous furnace construction for slabs and the like, the strengths of which lie around the most common measure. In this case, the support tubes, together with the walking beams, may have three staggered length sections, of which two sections downstream in the direction of flow are each approximately 1/3 shorter than the previous sections with a vertical heat material thickness of approx. 250 mm.

Im folgenden wird die Erfindung anhand von in den Zeichnungen sche­matisch dargestellten Ausführungsbeispielen näher beschrieben.The invention is described in more detail below with reference to exemplary embodiments schematically illustrated in the drawings.

Es zeigen in Schnitten

  • Figur 1 einen Stoßofen von der Längsseite,
  • Figur 2 den selben Ofen von oben auf die Tragrohre gesehen,
  • Figur 3 einen Hubbalkenofen von der Längsseite und
  • Figur 4 den selben Ofen von oben auf die Tragrohre gesehen.
It show in cuts
  • FIG. 1 shows a pusher furnace from the long side,
  • FIG. 2 seen the same furnace from above on the support tubes,
  • Figure 3 shows a walking beam furnace from the long side and
  • Figure 4 seen the same furnace from above on the support tubes.

In den Figuren 1 und 2 sind zwei zueinander rechtwinklige Längs­schnittansichten durch einen Stoßofen 1 gezeigt. In dem Stoßofen 1 ist ein Rohrstrang 2 mit einzelnen, parallelen wassergekühlten Tragrohren 3 vorgesehen, die auf vertikalen Stützrohren 4 angeord­net sind. Das Wärmgut 6 (Brammen o.dgl.) wird in einer Durchlauf­richtung 7 von einem Eintritt 8 entlang einer horizontalen Gleit­fläche durch den Stoßofen 1 bis zu dessen Austritt 9 bewegt. Dabei durchläuft das Wärmgut 6 zunächst eine hinter dem Eintritt angeord­nete Vorwärmzone A, danach eine Heizzone B, in der das Wärmgut auf die Behandlungstemperatur gebracht wird, und schließlich eine Aus­gleichszone C, die am Austritt 9 des Ofen 1 endet. Die Tragrohre 3 erstrecken sich durchgehend vom Eintritt 8 über die Vorwärmzone A und die Heizzone B und enden an der Ausgleichszone C. Auf den Trag­rohren 3 ruhen Aufsatzstücke 10. Die Ausgleichszone C ist bei dem Ausführungsbeispiel gemäß den Figuren 1 und 2 in einem Festherd 14 gebildet, dessen Bodenfläche vollständig mit keramischen Platten ausgelegt ist. Die durch die Oberflächen der Aufsatzstücke 10 ge­bildete Gleitfläche des Wärmguts 6 geht praktisch übergangslos in die Ebene der Vollbeplattung des Festherdes 14 über.In FIGS. 1 and 2, two longitudinal sectional views through a pusher furnace 1 that are perpendicular to one another are shown. In the pusher furnace 1, a pipe string 2 with individual, parallel water-cooled support pipes 3 is provided, which are arranged on vertical support pipes 4. The heating material 6 (slabs or the like) is moved in a direction of passage 7 from an inlet 8 along a horizontal sliding surface through the pusher furnace 1 to its outlet 9. The heating material 6 first passes through a preheating zone A arranged behind the inlet, then a heating zone B in which the heating material is heated up the treatment temperature is brought, and finally a compensation zone C, which ends at the outlet 9 of the furnace 1. The support tubes 3 extend continuously from the inlet 8 via the preheating zone A and the heating zone B and end at the equalization zone C. Top pieces 10 rest on the support tubes 3. The equalization zone C in the exemplary embodiment according to FIGS. 1 and 2 is formed in a fixed hearth 14 , whose bottom surface is completely covered with ceramic plates. The sliding surface of the heating material 6 formed by the surfaces of the top pieces 10 merges practically seamlessly into the level of the full plating of the fixed cooker 14.

Wie in der Draufsicht gemäß Fig. 2 zu erkennen ist, verlaufen die Tragrohre 3 in der Vorwärmzone A geradlinig und parallel zur Stoß­richtung 7. Wie oben erwähnt, würden sich ausgeprägte Kühlschatten im dem Wärmgut 6 unmittelbar über den Tragrohren 3 und den diesen aufgesetzten Aufsatzstücken 10 bilden, wenn der geradlinie Verlauf der Tragrohre 3 auch über die Heizzone B des Stoßofens 1 fortge­setzt würde.As can be seen in the top view according to FIG. 2, the support tubes 3 in the preheating zone A run in a straight line and parallel to the direction of impact 7. As mentioned above, pronounced cooling shadows in the heating material 6 would lie directly above the support tubes 3 and the top pieces 10 placed thereon form if the straight line of the support tubes 3 would also continue over the heating zone B of the pusher furnace 1.

Erfindungsgemäß werden diese Kühlschatten durch seitliches Ver­setzen von Längenabschnitten L₁, L₂ und L₃ der parallelen Tragrohre 3 weitgehend vermieden. Ein erster horizontaler, seitlicher Versatz 11 ist etwa an der Grenze zwischen Vorwärmzone A und Heizzone B vor­gesehen. Das Ausmaß des seitlichen Versatzes 11 ist vorzugsweise mindestens ebenso groß wie die Breite des Tragrohrs 3. Über die Län­ge L₁, die rechnerisch ermittelt wird, verlaufen die Tragrohre 3 um den seitlichen Versatz 11 parallel verschoben zu ihrem Verlauf in der Vorwärmzone A. Danach, d.h. an einer zweiten Versatzstelle 12, ist ein gegenläufiger seitlicher Versatz vorgesehen. Hinter dem Versatz 12 verlaufen die Tragrohre 3 mit ihren Aufsatzstücken 10 wieder ausgerichtet mit dem Tragrohrverlauf in der Vorwärmzone A. Hinter dem Längenabschnitt L₂ ist eine dritte Versatzstelle 13 vor­gesehen, an der die Tragrohre 3 erneut versetzt und etwa in die Fluchtlinie der Tragrohrabschnitte L₁ gebracht werden. Wie in Fig. 2 deutlich zu erkennen ist, sind die aufeinanderfolgend ver­setzten Tragrohrabschnitte L₁, L₂ und L₃ von unterschiedlicher Län­ge. Die in Durchlaufrichtung 7 jeweils nachfolgenden versetzten Län­genabschnitte L₂ bzw. L₃ sind bei dem bevorzugten Ausführungsbei­ spiel jeweils um etwa 1/3 der Länge des unmittelbar vorausgehenden versetzten Längenabschnitts L₁ bzw. L₂ verkürzt. Die Bezugslänge des in Durchlaufrichtung 7 ersten versetzten Längenabschnitts L₁ wird rechnerisch ermittelt. Für Brammen einer in der Praxis häufig vorkommenden Stärke von ungefähr 250 mm, die in dem Ofen 1 auf Walz­temperatur erhitzt werden sollen, haben sich für die Rohrstrangab­schnitte L₁, L₂ und L₃ Längen von 4500 mm, 3000 mm bzw. 2000 mm als besonders zweckmäßig erwiesen.According to the invention, these cooling shadows are largely avoided by laterally displacing lengths L₁, L₂ and L₃ of the parallel support tubes 3. A first horizontal, lateral offset 11 is provided approximately at the boundary between preheating zone A and heating zone B. The extent of the lateral offset 11 is preferably at least as large as the width of the support tube 3. Over the length L 1, which is determined by calculation, the support tubes 3 run around the lateral offset 11 parallel to their course in the preheating zone A. Then, ie at a second offset point 12, an opposing lateral offset is provided. Behind the offset 12, the support tubes 3 with their attachments 10 are aligned again with the support tube profile in the preheating zone A. Behind the length section L₂, a third offset point 13 is provided, at which the support tubes 3 are displaced again and brought into alignment with the support tube sections L₁ . As can be clearly seen in Fig. 2, the successively offset support tube sections L₁, L₂ and L₃ are of different lengths. The subsequent longitudinal sections L₂ and L₃ in the direction of flow 7 are in the preferred embodiment game each shortened by about 1/3 of the length of the immediately preceding offset length section L₁ or L₂. The reference length of the first offset length section L 1 in the direction of passage 7 is determined by calculation. For slabs of a frequently occurring thickness of approximately 250 mm, which are to be heated to the rolling temperature in the furnace 1, lengths of 4500 mm, 3000 mm and 2000 mm for the pipe string sections L 1, L 2 and L 3 have proven to be particularly expedient .

In den Figuren 3 und 4 ist schematisch ein Hubbalkenofen 21 darge­stellt. Die Ausbildung der Tragrohre 3, der Stützrohre 4, der Auf­satzstücke 10 sowie Ofeneintritt 8 und -austritt 9 kann derjenigen des zuvor beschriebenen Stoßofens 1 entsprechen, so daß entsprechen­de Komponenten des Hubbalkenofens mit den gleichen Bezugszeichen wie beim Stoßofen 1 bezeichnet sind. Auch bei dem Hubbalkenofen 21 gibt es eine in Fig. 3 dargestellte Vorwärmzone A, eine Heizzone B und eine Ausgleichszone C in einer mit Fig. 1 im wesentlichen über­einstimmenden Folge und relativen Länge. Der gekühlte Rohrstrang 22 hat zusätzlich zu den parallel zur Durchlaufrichtung 7 verlaufenden Tragrohren 3 Hubbalken 23, die vorzugsweise ebenfalls wassergekühlt sind. Der die Hubbalken 23 bewegende Antriebsmechanismus ist be­kannt und in den Figuren 3 und 4 nicht dargestellt. Wie in Fig. 4 zu erkennen ist, haben sowohl die Tragrohre 3 als auch die gekühl­ten Hubbalken 23 paarweise gemeinsame Versatzstellen 11, 12 und 13, wodurch sich gegeneinander seitlich versetzte Längenabschnitte L₁, L₂ und L₃ ergeben. Die Funktion der seitlichen Versetzungen 11, 12, 13 entspricht derjenigen bei dem zuvor beschriebenen Stoßofen, näm­lich die Vermeidung einer ausgeprägten Kühlschattenbildung an den Stellen des Wärmguts 6, die über längere Behandlungszeiten im Ofen 21 auf den gekühlten Tragrohren bzw. Hubbalken ruhen.3 and 4, a walking beam furnace 21 is shown schematically. The design of the support tubes 3, the support tubes 4, the top pieces 10 and furnace inlet 8 and outlet 9 can correspond to that of the previously described pusher furnace 1, so that corresponding components of the walking beam furnace are designated by the same reference numerals as in the pusher furnace 1. Also in the walking beam furnace 21 there is a preheating zone A shown in FIG. 3, a heating zone B and an equalization zone C in a sequence and relative length substantially the same as FIG. 1. The cooled pipe string 22 has, in addition to the support pipes running parallel to the direction of passage 7, 3 walking beams 23, which are preferably also water-cooled. The drive mechanism moving the walking beams 23 is known and is not shown in FIGS. 3 and 4. As can be seen in Fig. 4, both the support tubes 3 and the cooled walking beam 23 have pairs of common offset points 11, 12 and 13, which results in laterally offset longitudinal sections L₁, L₂ and L₃. The function of the lateral displacements 11, 12, 13 corresponds to that in the previously described pusher furnace, namely the avoidance of a pronounced formation of cooling shadows at the locations of the heating material 6 which rest on the cooled support tubes or walking beams over longer treatment times in the furnace 21.

Bei dem Hubbalkenofen gemäß Fig. 3 und 4 ist auf einen Festherd ver­zichtet. Die versetzten Längenabschnitte L₂ und L₃ sind daher über­wiegend in der dem Ofenaustritt 9 benachbarten Ausgleichszone C an­geordnet. In der Heizzone B befindet sich der in Durchlaufrichtung 7 erste versetzte Längenabschnitt L₁ sowie der Anfang des nachfol­genden zweiten Längenabschnitts L₂. Die Längenverhältnisse, d.h. die Verkührzungen der Längen L₂ und L₃ gegenüber den jeweils voraus­gehenden Längenabschnitten L₁ bzw. L₂ sind ähnlich dem zuvor be­schriebenen Ausführungsbeispiel vorgesehen.3 and 4, there is no fixed hearth. The offset lengths L₂ and L₃ are therefore predominantly arranged in the compensation zone C adjacent to the furnace outlet 9. In the heating zone B is the first offset length section L 1 in the direction of flow 7 and the beginning of the subsequent second length section L 2. The aspect ratios, that is, the connecting tongues of the lengths L₂ and L₃ compared to the respectively preceding lengths L₁ and L₂ are provided similar to the embodiment described above.

Drei versetzte Längenabschnitte mit in Durchlaufrichtung 7 abnehmen­der Abschnittslänge bilden ein bevorzugtes Ausführungsbeispiel der Erfindung. Gegebenenfalls reichen aber auch zwei versetzte Längen­abschnitte L₁ und L₂ ohne den dritten Längenabschnitt L₃ zur Vor­beugung einer Kühlschattenbildung aus. Andererseits ist es im Rah­men des Erfindungsgedankens ebenfall möglich, mehr als drei ver­setzte Längenabschnitte mit abnehmender Länge zum Austritt 9 hin zu verwenden. Die Zahl der zueinander vorzugsweise parallel angeord­neten und ebenfalls vorzugsweise an den gleichen Stellen (11, 12 bzw. 13) versetzten Tragrohre und/oder Hubbalken ist für die Er­findung nicht wesentlich; wesentlich ist die Anordnung und Auf­einanderfolge sowie die relative Länge der versetzten Längenab­schnitte an einem Tragrohr und gegebenenfalls der zugehörigen Hub­balkenanordnung.Three offset length sections with decreasing section length in the direction of passage 7 form a preferred exemplary embodiment of the invention. If necessary, two offset lengths L 1 and L 2 without the third length L 3 are sufficient to prevent the formation of a cooling shadow. On the other hand, it is also possible within the scope of the inventive concept to use more than three offset length sections with decreasing length towards the outlet 9. The number of support tubes and / or walking beams, which are preferably arranged parallel to one another and likewise preferably offset at the same points (11, 12 or 13), is not essential for the invention; what is essential is the arrangement and sequence as well as the relative length of the offset length sections on a support tube and, if appropriate, the associated walking beam arrangement.

Die versetzten Trahrohrabschnitte L₁, L₂ und L₃ sind bei der Erfin­dung zumindest teilweise in der Heizzone B angeordnet. Der Tempera­turausgleich unter Vorbeugung eine Kühlschattenbildung findet am Wärmgut daher bereits während der Heizperiode in der Heizzone B statt und ist nicht allein auf die Ausgleichszone C beschränkt. Die Staffelung der unterschiedlichen Längen L₂ und L₃ sorgt für einen besonders günstigen Kühlschattenabbau und einen optimalen Tempera­turausgleich innerhalb des Wärmguts 6 bei der Ausgleichsbehandlung in der Zone C.The offset tube sections L₁, L₂ and L₃ are at least partially arranged in the heating zone B in the invention. The temperature compensation while preventing the formation of a cooling shadow on the material to be heated therefore already takes place in heating zone B during the heating period and is not limited to compensation zone C. The staggering of the different lengths L₂ and L₃ ensures a particularly favorable cooling shadow removal and an optimal temperature compensation within the heat material 6 during the compensation treatment in zone C.

Claims (5)

1. Gekühlter Rohrstrand (2, 22) für Industrie-Erwärmungsöfen (1, 21), dessen einzelne Tragrohre (3) sich in Ofenlängsrich­tung vom Eintritt (8) in Richtung auf den Austritt (9) er­strecken, zumindest zum Teil mit Aufsatztücken (10) für das durchlaufende Wärmgut (6) versehen sind und einen gemeinsamen, über die Breite des Tragrohres hinausgehenden seitlichen Ver­satz (11) aufweisen, dadurch gekennzeichnet, daß die Tragrohre (3) zumindest noch einen weiteren gemeinsamen Versatz (12, 13) besitzen, wobei die Länge eines jeden in Durchlaufrichtung (7) des Wärmgutes (6) stromab liegenden versetzten Tragrohrab­schnittes (L₂, L₃) kürzer ist als die des vorangegangenen Ab­schnittes (L₁).1. Cooled tube beach (2, 22) for industrial heating furnaces (1, 21), the individual support tubes (3) of which extend in the longitudinal direction of the furnace from the inlet (8) towards the outlet (9), at least partially with attachment pieces (10 ) are provided for the continuous heating material (6) and have a common lateral offset (11) going beyond the width of the supporting tube, characterized in that the supporting tubes (3) have at least one further common offset (12, 13), whereby the length of each in the flow direction (7) of the heat material (6) downstream offset support tube section (L₂, L₃) is shorter than that of the previous section (L₁). 2. Gekühlter Rohrstrang nach Anspruch 1, dadurch gekennzeichnet, daß der in Durchlaufrichtung (7) des Wärmgutes (6) am weite­sten stromab befindliche versetzte Tragrohrabschnitt (L₃) am Austritt (9) des Erwärmungsofens (1, 21) endet.2. Cooled pipe string according to claim 1, characterized in that the in the direction of passage (7) of the heating material (6) most downstream offset support tube section (L₃) at the outlet (9) of the heating furnace (1, 21) ends. 3. Gekühlter Rohrstrang nach Anspruch 1 für Industrie-Erwärmungs­öfen (1) mit eine volle Auflagefläche aufweisendem Ausgleich-­Festherd (14), dadurch gekennzeichnet, daß der in Durchlauf­richtung (7) des Wärmgutes (6) am weitesten stromab befind­liche versetzte Tragrohrabschnitt (L₃) am Festherd (14) endet.3. Cooled pipe string according to claim 1 for industrial heating furnaces (1) with a full contact surface having compensation fixed hearth (14), characterized in that in the direction of flow (7) of the heat material (6) most downstream offset support tube section (L₃) ends at the fixed hearth (14). 4. Gekühlter Rohrstrang nach Anspruch 1 oder 2 für Industrie-Hub­balkenöfen (21) mit dicht neben den Tragrohren (3) liegenden Hubbalken (23) dadurch gekennzeichnet, daß die Hubbalken (23) die gleichen Versetzungen (11, 12, 13) wie die Tragrohre (3) aufweisen und ebenfalls gekühlt sind.4. Cooled pipe string according to claim 1 or 2 for industrial walking beam furnaces (21) with close to the support tubes (3) lying walking beam (23), characterized in that the walking beam (23) has the same displacements (11, 12, 13) as that Have support tubes (3) and are also cooled. 5. Gekühlter Rohrstrang nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Tragrohre (3) gegebenenfalls zusammen mit den Hubbalken (23) drei versetzte Längenabschnit­te (L₁, L₂, L₃) besitzen und die zwei in der Durchlaufrichtung (7) stromab liegenden Abschnitte (L₂, L₃) bei einer vertikalen Wärmgutstärke von ca. 250 mm nacheinander jeweils um ca. 1/3 kürzer sind als die vorangegangenen Abschnitte.5. Cooled pipe string according to one of the preceding claims, characterized in that the support tubes (3) optionally together with the walking beams (23) have three offset length sections (L₁, L₂, L₃) and the two sections in the flow direction (7) downstream (L₂, L₃) with a vertical thickness of approx. 250 mm in succession are each approx. 1/3 shorter than the previous sections.
EP88111648A 1987-08-01 1988-07-20 Cooled tube track for reheating industrial furnaces Expired - Lifetime EP0302301B1 (en)

Applications Claiming Priority (2)

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DE3725607A DE3725607A1 (en) 1987-08-01 1987-08-01 COOLED PIPELINE FOR INDUSTRIAL HEATING OVENS
DE3725607 1987-08-01

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US5405264A (en) * 1992-04-23 1995-04-11 Loi Essen Industrieofenanlagen Gmbh Device for carrying a charge in a furnace
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US7241135B2 (en) 2004-11-18 2007-07-10 Honeywell International Inc. Feedback control for modulating gas burner
CN103334002A (en) * 2013-07-17 2013-10-02 上海诚达工业炉有限公司 Cross beam mechanism for steel feeding inlet of continuous heating furnace

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DE3880916D1 (en) 1993-06-17
DE3725607A1 (en) 1989-02-09
US4886450A (en) 1989-12-12

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