EP0046994B1 - Roller hearth furnace - Google Patents

Roller hearth furnace Download PDF

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Publication number
EP0046994B1
EP0046994B1 EP81106714A EP81106714A EP0046994B1 EP 0046994 B1 EP0046994 B1 EP 0046994B1 EP 81106714 A EP81106714 A EP 81106714A EP 81106714 A EP81106714 A EP 81106714A EP 0046994 B1 EP0046994 B1 EP 0046994B1
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EP
European Patent Office
Prior art keywords
kiln
cooling
zone
cooling zone
firing
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.)
Expired
Application number
EP81106714A
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German (de)
French (fr)
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EP0046994A1 (en
Inventor
Gottfried Dr. Cremer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BUCHTAL GMBH KERAMISCHE BETRIEBE
Original Assignee
Buchtal Keramische Betriebe GmbH
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Publication of EP0046994A1 publication Critical patent/EP0046994A1/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
    • F27B9/12—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
    • 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 tunnel furnace
    • F27B9/24—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 tunnel furnace being carried by a conveyor
    • F27B9/2407—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 tunnel furnace being carried by a conveyor the conveyor being constituted by rollers (roller hearth furnace)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D7/00—Forming, maintaining, or circulating atmospheres in heating chambers
    • F27D7/06—Forming or maintaining special atmospheres or vacuum within heating chambers
    • 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
    • F27B2009/124—Cooling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D9/00—Cooling of furnaces or of charges therein
    • F27D2009/007—Cooling of charges therein
    • F27D2009/0072—Cooling of charges therein the cooling medium being a gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D9/00—Cooling of furnaces or of charges therein
    • F27D2009/007—Cooling of charges therein
    • F27D2009/0081—Cooling of charges therein the cooling medium being a fluid (other than a gas in direct or indirect contact with the charge)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D5/00—Supports, screens, or the like for the charge within the furnace
    • F27D5/0062—Shields for the charge

Definitions

  • the invention relates to the formation of the cooling zone for a roller furnace consisting of preheating, firing and cooling zones, through which the firing material, preferably ceramic tiles, is passed through in one layer without supporting firing aids made of refractory material.
  • roller kilns burning in a single layer and without firing aids made of refractory material the kiln passes through the preheating, burning and cooling zone on a roller carpet, the rollers of which are made of special steel or ceramic refractory material are driven from outside the furnace.
  • the particular advantage of these ovens is that there is no need for trolleys and refractory kiln furniture. These transport and support means represent a considerable mass that must be heated by the furnace and brought to cool again in the cooling zone. A considerable part of the energy supplied to the furnace for the firing of the material to be burned is thus wasted.
  • tumble cooling is generally used, i.e. H.
  • Appropriate amounts of air are introduced into the cooling zone and brought into effect on the firing material. This inevitably results, even if the firing zone is closed off from the cooling zone by an apron, to repercussions from the cooling zone into the firing zone and, if this is operated in a reducing manner, to reoxidation of the combustible material in the cooling zone and at least in the area adjacent to the cooling zone the burning zone.
  • the object of the invention is to use the simplest means to prevent the combustion goods in the cooling zone and in the area adjacent to the cooling zone from being affected by the atmosphere of the cooling zone and thus a corresponding reoxidation of the combustion goods and to provide a simple way of influencing the surface of the combustion goods .
  • the cooling zone is indirectly cooled by means of a flowing heat transfer medium and that it has introducing elements which can be adjusted in terms of its direction and throughput and which have an influence on the surface of the firing material and do not serve for cooling.
  • a liquid heat transfer medium is preferably used as the flowing heat transfer medium.
  • the coils or coils are preferably arranged transversely to the direction of travel of the firing material through the furnace, because then the feeding and removal of the heat transfer medium is particularly simple.
  • the arrangement and operation of the shield is much easier with such an arrangement of the coils or coils.
  • the adjustable shielding preferably consists of rotatable, paddle-like elements arranged in the manner of blinds. When the shield is closed, these elements practically completely cover the cooling coils or coils and, by twisting them slightly, leave slots free through which the existing coils or coils are strong cooled atmosphere can suddenly fall down on the firing material.
  • slotted plates can also be used, which can be pushed over each other in the desired manner so that more or less large openings are available for the passage of the cooled atmosphere down onto the firing material. Due to the adjustability of the shielding, it is also possible to influence the cooling process in the cooling zone in any way.
  • a major advantage of the invention is that the pipe coils or registers carrying the heat transfer medium can be connected to the heat-recovering or reusable systems or furnace parts.
  • DE-B 12 77 288 describes a heat treatment furnace with a heating zone through which hot gases flow and a subsequent cooling zone, but there is no quiescent atmosphere in the cooling zone; rather, the gases are always drawn through the cooling zone and possibly also heated there by additional burners.
  • the roller furnace according to the invention is first of all to create the conditions for a dormant atmosphere in the cooling zone and then to use the dormant atmosphere created in this way to influence the surface of the firing material by introducing suitable media.
  • the introduction takes place through separate insertion elements and not via the controllable shielding of the coils or registers and does not serve to cool the firing material.
  • a preheating zone VZ In a furnace charged with the material to be burned, in particular ceramic plates, in the direction of arrow A, a preheating zone VZ, a firing zone BZ which is heated in the direction of arrows B by a burner, and a cooling zone KZ are provided, from which the finished fired and cooled Firing material emerges.
  • the fired material B is transported through the furnace by means of rollers, one of which can be seen at 1 in FIG. 2 and several, also denoted by 1 in FIG. 3.
  • rollers form a roller carpet from the furnace inlet to the furnace outlet and are driven from the outside, so that they convey the firing material B stored on them through the furnace.
  • cooling has so far been carried out using cooling air which was introduced into the cooling zone by means of fans fitted above and below the roller carpet.
  • the combustion of the material B to be burned in the cooling zone KZ is not carried out by blowing in cooling air, but by indirect cooling by means of a flowing heat transfer medium, preferably a liquid heat transfer medium, such as water, through the cooling coils, which are preferably laid transversely to the direction of travel of the combustion material -register 3 is passed in the upper part of the cooling zone.
  • a flowing heat transfer medium preferably a liquid heat transfer medium, such as water
  • the atmosphere in the cooling zone remains calm and there can no longer be any repercussions in the firing zone.
  • this calm atmosphere z. B. introduced in their direction and in their throughput lances 8 a reducing gas, salt vapors or similar media influencing the surface of the material in the desired manner. Since the introduction into a quiescent atmosphere takes place, the dosing is simple and uncomplicated and can be carried out in such a way that there are no repercussions on the neighboring area of the firing zone.
  • fixed shielding as can be seen in FIG. 4, is provided and shielding in the form of a kind of Venetian blind, as indicated at 5.
  • This blind consists of paddle-like elements extending across the cooling zone, which can be adjusted so that they practically close the gaps between the fixed shields 4. This measure not only ensures additional protection of the firing material on the rollers 1, but it is also possible to meter the cooling process.
  • an arrangement can also be provided which is composed of slotted plates extending transversely across the cooling zone or in the longitudinal direction of the cooling zone, the slits of which can be more or less aligned with one another, so that more or less Large openings are created through which the cooling coils or registers have a cooling effect on the firing material conveyed on the rollers 1.
  • Fireproof insulation 6 is located beneath the roller carpet consisting of rollers 1.
  • the cooling coils or register 3 can in not shown, be connected to systems or furnace parts, for example be led to the preheating zone, so that part of the thermal energy of the heat transfer medium can be used to preheat the firing material. You can the heat absorbed by the heat transfer medium in other ways, for. B. continue to use for drying.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Tunnel Furnaces (AREA)

Description

Die Erfindung betrifft die Ausbildung der Kühlzone für einen aus Vorheiz-, Brenn- und Kühlzone bestehenden Rollenofen, durch den das Brenngut, vorzugsweise keramische Fliesen oder Platten, ohne es zu stützende Brennhilfsmittel aus feuerfestem Material einschichtig hindurchgeführt wird.The invention relates to the formation of the cooling zone for a roller furnace consisting of preheating, firing and cooling zones, through which the firing material, preferably ceramic tiles, is passed through in one layer without supporting firing aids made of refractory material.

Bei das Brenngut einschichtig und ohne Brennhilfsmittel aus feuerfestem Material brennenden Rollenöfen durchläuft das Brenngut die Vorheiz-, Brenn- und Kühlzone auf einem Rollenteppich, dessen aus einem Spezialstahl oder keramischen feuerfesten Material bestehende Rollen von außerhalb des Ofens angetrieben werden. Der besondere Vorteil dieser Öfen besteht darin, daß der Einsatz von Wagen und feuerfesten Brennhilfsmitteln entfällt. Diese Transport- und Stützmittel stellen eine erhebliche Masse dar, die vom Ofen aufgeheizt werden muß und in der Kühlzone wieder zur Abkühlung gebracht wird. Es wird also ein erheblicher Teil der dem Ofen zum Brand des Brenngutes zugeführten Energie ungenutzt verschwendet.In the case of roller kilns burning in a single layer and without firing aids made of refractory material, the kiln passes through the preheating, burning and cooling zone on a roller carpet, the rollers of which are made of special steel or ceramic refractory material are driven from outside the furnace. The particular advantage of these ovens is that there is no need for trolleys and refractory kiln furniture. These transport and support means represent a considerable mass that must be heated by the furnace and brought to cool again in the cooling zone. A considerable part of the energy supplied to the furnace for the firing of the material to be burned is thus wasted.

Mit solchen einschichtig und ohne Einsatz von Transport- und Brennhilfsmitteln betriebenen Öfen wird nicht nur eine wesentliche Energieeinsparung erreicht, sondern es läßt sich auch der Brennvorgang schneller und gleichmäßiger durchführen. Man gelangt zu erheblich verkürzten Produktionszyklen.With such furnaces operated in one layer and without the use of transport and firing aids, not only is significant energy savings achieved, but the firing process can also be carried out faster and more uniformly. This leads to significantly shortened production cycles.

In der Kühlzone solcher Öfen wird im allgemeinen mit sogenannter Sturzkühlung gearbeitet, d. h. es werden geeignete Mengen von Luft in die Kühlzone eingeführt und auf das Brenngut zur Einwirkung gebracht. Dabei kommt es unvermeidbar, auch wenn die Brennzone gegen die Kühlzone durch eine Schürze abgeschlossen ist, zu Rückwirkungen aus der Kühlzone in die Brennzone und, wenn diese reduzierend gefahren wird, zu einer Reoxidierung des Brenngutes in der Kühlzone und wenigstens in dem der Kühlzone benachbarten Bereich der Brennzone. Will man eine solche Reoxidierung des Brenngutes in der Kühlzone und ein Zurückwirken der Reoxidierung in die der Kühlzone benachbarten Bereiche der Brennzone verhindern, so könnte dies nach der DE-OS 28 24 367 beispielsweise dadurch erfolgen, daß man die der Reduktion in der Kühlzone dienenden Mittel in den Ofen intermittierend unter hohem Druck und in solchen Anteilen und Zeitabständen eingibt, daß der nach jeder durch Eingabe eines Anteils erzielten Teilreduktion verbleibende Überschuß des Reduktionsmittelanteils so gering ist, daß er in den zwischen aufeinanderfolgenden Eingaben liegenden Pausen ohne zusätzliche Luftzuführung durch die neutrale Ofenatmosphäre abgebrannt wird.In the cooling zone of such ovens, so-called tumble cooling is generally used, i.e. H. Appropriate amounts of air are introduced into the cooling zone and brought into effect on the firing material. This inevitably results, even if the firing zone is closed off from the cooling zone by an apron, to repercussions from the cooling zone into the firing zone and, if this is operated in a reducing manner, to reoxidation of the combustible material in the cooling zone and at least in the area adjacent to the cooling zone the burning zone. If one wants to prevent such reoxidation of the firing material in the cooling zone and a repercussion of the reoxidation in the areas of the firing zone adjacent to the cooling zone, this could be done according to DE-OS 28 24 367, for example, by reducing the agents in the cooling zone enters the furnace intermittently under high pressure and in such proportions and intervals that the excess of the reducing agent portion remaining after each partial reduction achieved by inputting a portion is so small that it burns down in the pauses between successive inputs without additional air supply through the neutral furnace atmosphere becomes.

Es ist erkennbar, daß zur Durchführung eines solchen Verfahrens ein Außerordentlich kompliziertes Steuersystem erforderlich ist.It can be seen that an extremely complex control system is required to carry out such a method.

Aufgabe der Erfindung ist es, durch Anwendung einfachster Mittel die Beeinflussung des Brenngutes in der Kühlzone und in dem der Kühlzone benachbarten Bereich durch die Atmosphäre der Kühlzone und damit eine entsprechende Reoxidierung des Brenngutes zu verhindern und eine einfache Möglichkeit zur Beeinflussung der Oberfläche des Brenngutes zu schaffen.The object of the invention is to use the simplest means to prevent the combustion goods in the cooling zone and in the area adjacent to the cooling zone from being affected by the atmosphere of the cooling zone and thus a corresponding reoxidation of the combustion goods and to provide a simple way of influencing the surface of the combustion goods .

Diese Aufgabe wird erfindungsgemäß durch die Kombination gelöst, daß die Kühlzone mittels eines strömenden Wärmeträgers, indirekt gekühlt ist und daß sie in ihrer Richtung und ihrem Durchsatz einstellbare die Oberfläche des Brenngutes beeinflussende, nicht der Kühlung dienende Medien, einführende Einführungsorgane aufweist.This object is achieved according to the invention by the combination that the cooling zone is indirectly cooled by means of a flowing heat transfer medium and that it has introducing elements which can be adjusted in terms of its direction and throughput and which have an influence on the surface of the firing material and do not serve for cooling.

Vorzugsweise wird als strömender Wärmeträger ein flüssiger Wärmeträger verwendet.A liquid heat transfer medium is preferably used as the flowing heat transfer medium.

Bei Einsatz eines flüssigen Wärmeträgers, beispielsweise Wasser, das durch Rohrschlangen oder -register in der Kühlzone über dem Brenngut geführt wird, ergibt sich ebenfalls eine schroffe Abkühlung des Brenngutes in der Kühlzone, ohne daß jedoch die Gefahr der Beeinflussung der Atmosphäre durch eingeführte Kühlluft besteht. Gleichzeitig wird damit aber in der Kühlzone eine praktisch ruhende Atmosphäre geschaffen, mit der es nunmehr möglich ist, Luft oder ein sonstiges, die Oberfläche des Brenngutes beeinflussenden Medium hinsichtlich Menge und Richtung gesteuert in die Kühlzone einzuführen. So kann man beispielsweise zur Beeinflussung der Glasur ein entsprechendes Gas oder einen entsprechenden dampf einführen.When using a liquid heat transfer medium, for example water, which is led through coils or registers in the cooling zone above the material to be fired, there is also a sudden cooling of the fuel in the cooling zone, but without the risk of the atmosphere being influenced by the cooling air introduced. At the same time, however, a practically calm atmosphere is created in the cooling zone, with which it is now possible to introduce air or another medium, which influences the surface of the combustion material, into the cooling zone in a controlled manner with regard to quantity and direction. For example, an appropriate gas or vapor can be introduced to influence the glaze.

Um zu vermeiden, daß von den den Wärmeträger führenden Rohrschlangen oder -registern abplatzender Zunder od. dgl. auf das Brenngut fällt, lassen sich diese Rohrschlangen oder -register gegen das Brenngut abschirmen, wobei in weiterer Ausbildung der Erfindung die Strahlungsflächen der den Wärmeträger führenden Rohrschlangen oder -register gegen das Brenngut regelbar abgeschirmt sind, so daß nicht nur das Brenngut geschützt wird, sondern der Kühlvorgang auch in beliebiger und optimaler Weise gesteuert werden kann.In order to avoid that scaling or the like from the pipe coils or registers carrying the heat carrier falls onto the firing material, these pipe coils or registers can be shielded against the firing material, in a further development of the invention the radiation surfaces of the pipe coils carrying the heat carrier or registers are shielded from the firing stock in a controllable manner, so that not only is the firing stock protected, but the cooling process can also be controlled in any desired and optimal manner.

Vorzugsweise sind die Rohrschlangen oder -register quer zur Fahrtrichtung des Brenngutes durch den Brennofen angeordnet, weil dann die Einspeisung und Ableitung des Wärmeträgers besonders einfach ist. Auch die Anordnung und Bedienung der Abschirmung ist bei einer solchen Anordnung der Rohrschlangen oder -register wesentlich einfacher.The coils or coils are preferably arranged transversely to the direction of travel of the firing material through the furnace, because then the feeding and removal of the heat transfer medium is particularly simple. The arrangement and operation of the shield is much easier with such an arrangement of the coils or coils.

Die regelbare Abschirmung besteht vorzugsweise aus jalousieartig angeordneten, verdrehbaren, paddelartigen Elementen. Diese Elemente decken im geschlossenen Zustand der Abschirmung die Kühlschlangen oder -register praktisch vollständig ab und lassen durch leichtes Verdrehen Schlitze frei, durch die die um die Kühlschlangen oder -register vorhandene stark gekühlte Atmosphäre nach unten sturzartig auf das Brenngut zur Einwirkung gelangen kann.The adjustable shielding preferably consists of rotatable, paddle-like elements arranged in the manner of blinds. When the shield is closed, these elements practically completely cover the cooling coils or coils and, by twisting them slightly, leave slots free through which the existing coils or coils are strong cooled atmosphere can suddenly fall down on the firing material.

Anstelle der jalousieartigen Vorhänge kann man auch Schlitzplatten verwenden, die sich in gewünschter Weise wechselseitig so übereinanderschieben lassen, daß mehr oder weniger große Öffnungen für den Durchtritt gekühlter Atmosphäre nach unten auf das Brenngut zur Verfügung stehen. Durch die Verstellbarkeit der Abschirmung ist es auch möglich, den Kühlprozeß in der Kühlzone in beliebiger Weise zu beeinflussen.Instead of the blind-like curtains, slotted plates can also be used, which can be pushed over each other in the desired manner so that more or less large openings are available for the passage of the cooled atmosphere down onto the firing material. Due to the adjustability of the shielding, it is also possible to influence the cooling process in the cooling zone in any way.

Ein wesentlicher Vorteil der Erfindung besteht darin, daß die den Wärmeträger führenden Rohrschlangen oder -register an die Wärme wiedergewinnende oder wiedernutzbarmachende Anlagen oder Ofenteile angeschlossen werden können.A major advantage of the invention is that the pipe coils or registers carrying the heat transfer medium can be connected to the heat-recovering or reusable systems or furnace parts.

Aus der US-A-2 968 894 ist ein Ofen zum Anlassen von Glasplatten oder zum Vergüten von Bandstählen bekannt, der allerdings keine Dreiteilung in Vorwärmzone, Brennzone und Kühlzone aufweist. Zwar ist bei diesem Ofen vorgesehen, in einem dem Austrittsende benachbarten Bereich zusätzliche Brenner anzuordnen, die auch regelbar sein können, jedoch dienen diese Brenner nicht der Einführung von Medien, die die Oberfläche des Brenngutes beeinflussen sollen.From US-A-2 968 894 a furnace for tempering glass plates or for tempering strip steels is known, which, however, has no tripartite division in the preheating zone, combustion zone and cooling zone. Although this furnace is provided to arrange additional burners in an area adjacent to the outlet end, which can also be controllable, these burners are not used to introduce media which are intended to influence the surface of the material to be burned.

In der DE-B 12 77 288 ist zwar ein Wärmebehandlungsofen mit von heißen Gasen durchströmter Heizzone und daran anschließender Kühlzone beschrieben, jedoch herrscht in der Kühlzone keine ruhende Atmosphäre, vielmehr werden die Gase immer durch die Kühlzone gesaugt und dort gegebenenfalls auch durch Zusatzbrenner erhitzt.DE-B 12 77 288 describes a heat treatment furnace with a heating zone through which hot gases flow and a subsequent cooling zone, but there is no quiescent atmosphere in the cooling zone; rather, the gases are always drawn through the cooling zone and possibly also heated there by additional burners.

Im Gegensatz zu diesen beiden bekannten Behandlungsöfen geht es beim Rollenofen nach der Erfindung darum, zuerst einmal die Voraussetzungen für eine ruhende Atmosphäre in der Kühlzone zu schaffen und dann unter Ausnutzung dieser so geschaffenen ruhenden Atmosphäre die Oberfläche des Brenngutes durch Einführen von geeigneten Medien zu beeinflussen.In contrast to these two known treatment furnaces, the roller furnace according to the invention is first of all to create the conditions for a dormant atmosphere in the cooling zone and then to use the dormant atmosphere created in this way to influence the surface of the firing material by introducing suitable media.

Die Einführung erfolgt dabei durch gesonderte Einführorgane und nicht über die regelbare Abschirmung der Rohrschlangen oder -register und dient nicht der Kühlung des Brenngutes.The introduction takes place through separate insertion elements and not via the controllable shielding of the coils or registers and does not serve to cool the firing material.

Die Zeichnung zeigt in

  • Figur 1 eine schematische Draufsicht auf einen Brennofen ;
  • Figur 2 einen Schnitt längs der Linie 11-11 der Fig. 1 ;
  • Figur 3 einen Teillängsschnitt durch die Kühlzone.
The drawing shows in
  • Figure 1 is a schematic plan view of a kiln;
  • Figure 2 shows a section along the line 11-11 of Fig. 1;
  • Figure 3 shows a partial longitudinal section through the cooling zone.

Bei einem in Richtung des Pfeiles A mit dem zu brennenden Gut, insbesondere keramische Platten beschickten Ofen sind eine Vorheizzone V. Z., eine Brennzone B. Z. die in Richtung der Pfeile B mittels Brenner beheizt wird, und eine Kühlzone K. Z. vorgesehen, aus der das fertige gebrannte und gekühlte Brenngut austritt. Das Brenngut B wird mittels Rollen durch den Ofen transportiert, von denen eine bei 1 in Fig. 2 und mehrere, ebenfalls mit 1 bezeichnet in Fig. 3 erkennbar sind. Solche Rollen bilden vom Ofeneingang bis zum Ofenausgang einen Rollenteppich und sind von außen her angetrieben, so daß sie das auf ihnen lagernde Brenngut B durch den Ofen hindurchfördern. In der Kühlzone K. Z. erfolgte die kühlung bis jetzt durch Kühlluft, die mittels über und unter dem Rollenteppich angebrachten Gebläse in die Kühlzone eingeführt wurde. Trotz eines bei 2 in Fig. 1 angedeuteten Schurzes zwischen Brennzone und Kühlzone ist es nicht möglich, eine Rückwirkung dieser Kühlluft auf die Brennzone und damit eine Beeinflussung der dort herrschenden Atmosphäre zu verhindern. Gemäß einem Merkmal der Erfindung erfolgt die Kühlung des Brenngutes B in der Kühlzone K. Z. nicht durch Einblasen von Kühlluft, sondern durch indirekte Kühlung mittels eines strömenden Wärmeträgers, vorzugsweise eines flüssigen Wärmeträgers, wie Wasser, der durch die vorzugsweise quer zur Fahrtrichtung des Brenngutes verlegten Kühlschlangen oder -register 3 im oberen Teil der Kühlzone hindurchgeführt wird. Die Atmosphäre in der Kühlzone bleibt dabei in Ruhe und es kann nicht mehr zu einer Rückwirkung in die Brennzone kommen. In diese ruhende Atmosphäre werden z. B. über in ihrer Richtung und in ihrem Durchsatz steuerbare Lanzen 8 ein reduzierendes Gas, Salzdämpfe oder ähnliche, die Oberfläche des Brenngutes in der gewünschten Weise beeinflussende Medien eingeführt. Da die Einführung in eine ruhende Atmosphäre erfolgt, ist die Dosierung einfach und unkompliziert und so durchführbar, daß Rückwirkungen auf den benachbarten Bereich der Brennzone nicht auftreten. Um ein Abfallen von sich allenfalls an den kühlschlangen oder -registern 3 bildenden Zunder o. dgl. auf das Kühlgut zu verhindern, ist einmal eine feste Abschirmung, wie sie bei 4 erkennbar ist, vorgesehen und zum anderen auch eine Abschirmung in Form einer Art von Jalousie, wie sie bei 5 angedeutet ist. Diese Jalousie besteht aus paddelartigen, sich quer über die Kühlzone erstreckenden Elementen, die so eingestellt werden können, daß sie die Lücken zwischen den festen Abschirmungen 4 praktisch schließen. Mit dieser Maßnahme ist nicht nur ein zusätzlicher Schutz des Brenngutes auf den Rollen 1 gewährleistet, sondern es ist auch möglich, den Kühlvorgang zu dosieren. Selbstverständlich kann anstelle der in Fig. 3 wiedergegebenen paddelartigen Elemente auch eine Anordnung vorgesehen werden, die sich aus quer über die Kühlzone oder in Längsrichtung der Kühlzone erstreckenden Schlitzplatten zusammensetzt, deren Schlitze gegenseitig mehr oder weniger zur Deckung gebracht werden können, so daß mehr oder weniger große Öffnungen entstehen, durch die von den Kühlschlangen oder -registern her die kühlende EinWirkung auf das auf den Rollen 1 geförderte Brenngut erfolgt.In a furnace charged with the material to be burned, in particular ceramic plates, in the direction of arrow A, a preheating zone VZ, a firing zone BZ which is heated in the direction of arrows B by a burner, and a cooling zone KZ are provided, from which the finished fired and cooled Firing material emerges. The fired material B is transported through the furnace by means of rollers, one of which can be seen at 1 in FIG. 2 and several, also denoted by 1 in FIG. 3. Such rollers form a roller carpet from the furnace inlet to the furnace outlet and are driven from the outside, so that they convey the firing material B stored on them through the furnace. In the cooling zone K.Z., cooling has so far been carried out using cooling air which was introduced into the cooling zone by means of fans fitted above and below the roller carpet. In spite of a skirt between the combustion zone and the cooling zone indicated at 2 in FIG. 1, it is not possible to prevent this cooling air from reacting to the combustion zone and thus from influencing the atmosphere there. According to a feature of the invention, the combustion of the material B to be burned in the cooling zone KZ is not carried out by blowing in cooling air, but by indirect cooling by means of a flowing heat transfer medium, preferably a liquid heat transfer medium, such as water, through the cooling coils, which are preferably laid transversely to the direction of travel of the combustion material -register 3 is passed in the upper part of the cooling zone. The atmosphere in the cooling zone remains calm and there can no longer be any repercussions in the firing zone. In this calm atmosphere z. B. introduced in their direction and in their throughput lances 8 a reducing gas, salt vapors or similar media influencing the surface of the material in the desired manner. Since the introduction into a quiescent atmosphere takes place, the dosing is simple and uncomplicated and can be carried out in such a way that there are no repercussions on the neighboring area of the firing zone. In order to prevent any scaling or the like forming on the cooling coils or registers 3 from falling onto the refrigerated goods, fixed shielding, as can be seen in FIG. 4, is provided and shielding in the form of a kind of Venetian blind, as indicated at 5. This blind consists of paddle-like elements extending across the cooling zone, which can be adjusted so that they practically close the gaps between the fixed shields 4. This measure not only ensures additional protection of the firing material on the rollers 1, but it is also possible to meter the cooling process. Of course, instead of the paddle-like elements shown in FIG. 3, an arrangement can also be provided which is composed of slotted plates extending transversely across the cooling zone or in the longitudinal direction of the cooling zone, the slits of which can be more or less aligned with one another, so that more or less Large openings are created through which the cooling coils or registers have a cooling effect on the firing material conveyed on the rollers 1.

Unter dem aus den Rollen 1 bestehenden Rollenteppich befindet sich eine feuerfeste Isolierung 6.Fireproof insulation 6 is located beneath the roller carpet consisting of rollers 1.

Die Kühlschlangen oder -register 3 können in nicht dargestellter Weise an Anlagen oder Ofenteil eangeschlossen sein, beispielsweise zur Vorheizzone geführt sein, so daß ein Teil der Wärmeenergie des Wärmeträgers dort zum Vorheizen des Brenngutes dienen kann. Man kann die von dem Wärmeträger aufgenommenen Wärmemengen auch in anderer Weise, z. B. zum Trocknen weiterverwenden.The cooling coils or register 3 can in not shown, be connected to systems or furnace parts, for example be led to the preheating zone, so that part of the thermal energy of the heat transfer medium can be used to preheat the firing material. You can the heat absorbed by the heat transfer medium in other ways, for. B. continue to use for drying.

Claims (6)

1. A roller kiln comprising a preheating zone, a baking zone and a cooling zone, the firing material being directed in one layer through the kiln in the form of ceramic tiles or plates without any supporting kiln furniture of refractory material, characterized by the combination of features, that the cooling zone (K. Z.) is cooled indirectly by means of a heat tranfer medium in flux, and that the K. Z. comprises introducing agents with an adjustable direction and rate of flow for introducing media which do not serve the purpose of cooling and for affecting the surface of the firing material (B).
2. A kiln as in claim 1, characterized in that pipe coils or registers (3) conducting the heat transfer medium are arranged in the cooling zone (K. Z.) above the filing material (B), the areas of radiation of these pipes being adjustably shielded (at 5) against the firing material (B).
3. A kiln as in claim 2, characterized in that the pipe coils or registers (3) are arranged at right angles to the direction of movement of the firing material (B).
4. A kiln as in claim 2 or 3, characterized in that the shielding (5) comprises rotatable, paddle-like elements in a louver-like arrangement.
5. A kiln as in claim 2 or 3, characterized in that the shielding (5) comprises mutually displaceable slotted plates.
6. A kiln as in one or more of the above claims, characterized in that the pipe coils or registers (3) conducting the heat transfer medium are connected to equipment or kiln parts which recover the heat or make it reusable.
EP81106714A 1980-08-28 1981-08-28 Roller hearth furnace Expired EP0046994B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3032452A DE3032452C2 (en) 1980-08-28 1980-08-28 Roller oven
DE3032452 1980-08-28

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EP0046994A1 EP0046994A1 (en) 1982-03-10
EP0046994B1 true EP0046994B1 (en) 1984-12-19

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EP (1) EP0046994B1 (en)
JP (1) JPS57501793A (en)
DE (1) DE3032452C2 (en)
WO (1) WO1982000876A1 (en)
ZA (1) ZA815987B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3514085A1 (en) * 1985-04-18 1986-10-23 Buchtal Gmbh, 8472 Schwarzenfeld ROLLER OVEN FOR BURNING A FLAT OR PLATE-SHAPED CERAMIC COMBUSTION
DE3514086A1 (en) * 1985-04-18 1986-10-23 Buchtal Gmbh, 8472 Schwarzenfeld ROLLER OVEN FOR BURNING A PLATE-SHAPED CERAMIC COMBUSTION
DE3514084A1 (en) * 1985-04-18 1986-10-23 Buchtal Gmbh, 8472 Schwarzenfeld ROLLER OVEN FOR BURNING A FLAT OR PLATE-SHAPED CERAMIC COMBUSTION
CN102735069B (en) * 2012-06-27 2014-03-19 佛山市新明珠卫浴有限公司 Hot-blast air combustion-supporting intelligent control system for roller bed kiln furnace
CN109668428B (en) * 2018-12-29 2024-06-14 湖南金炉科技股份有限公司 Heat treatment kiln
CN115218674B (en) * 2022-07-11 2024-04-16 中国人民解放军国防科技大学 High-temperature cracking device suitable for preparing fiber reinforced ceramic matrix composite

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE976094C (en) * 1948-12-28 1963-02-21 Gottfried Dr Cremer Tunnel kiln for firing ceramic and related products
DE975458C (en) * 1951-04-10 1961-11-30 Gottfried Dr Cremer Tunnel furnace with at least partially indirect cooling of the cooling zone
US2968894A (en) * 1955-03-04 1961-01-24 Selas Corp Of America Annealing lehr
DE1177062B (en) * 1957-02-26 1964-08-27 Gottfried Cremer Dr Tunnel kiln for firing ceramic and related products
GB954674A (en) * 1959-11-12 1964-04-08 Aton Planungs & Baugesellschaft Fuer Die Keramische Industrie Mbh Tunnel kilns
DE1277288B (en) * 1960-12-31 1968-09-12 Ofu Ofenbau Union Ges Mit Besc Heat treatment furnace with a cooling zone adjoining a heating zone through which hot gases flow
DE1245042B (en) * 1962-04-13 1967-07-20 Fetok Gmbh Waste heat recovery system for tunnel ovens
JPS5236115A (en) * 1975-09-18 1977-03-19 Takasago Kogyo Kk Tunnel furnace
JPS5240507A (en) * 1975-09-26 1977-03-29 Takasago Kogyo Kk Tunnel furnace
DE2708783C2 (en) * 1977-03-01 1985-02-28 IOB Industrieofenbau GmbH, 6940 Weinheim Arrangement for regulating the cooling intensity in the cooling zone of continuously operating annealing furnaces for the heat treatment of workpieces, in particular pipes made of cast iron
JPS53147704A (en) * 1977-05-31 1978-12-22 Ngk Insulators Ltd Method of burning glazed ceramics in tunnel kilns and kilns used therefore
DE2824367A1 (en) * 1978-06-01 1979-12-06 Keramische Ind Bedarfs Gmbh Pa Ceramics reducing atmosphere furnace control system - delivers reducing agents intermittently at high pressure into furnace

Also Published As

Publication number Publication date
JPS57501793A (en) 1982-10-07
EP0046994A1 (en) 1982-03-10
ZA815987B (en) 1983-01-26
DE3032452C2 (en) 1987-04-30
WO1982000876A1 (en) 1982-03-18
DE3032452A1 (en) 1982-04-01

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