EP0044512B1 - Method and apparatus for the cooling of vessel parts of a metallurgical furnace, especially an electric-arc furnace - Google Patents

Method and apparatus for the cooling of vessel parts of a metallurgical furnace, especially an electric-arc furnace Download PDF

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Publication number
EP0044512B1
EP0044512B1 EP81105529A EP81105529A EP0044512B1 EP 0044512 B1 EP0044512 B1 EP 0044512B1 EP 81105529 A EP81105529 A EP 81105529A EP 81105529 A EP81105529 A EP 81105529A EP 0044512 B1 EP0044512 B1 EP 0044512B1
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EP
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Prior art keywords
cooling
heat exchange
cooling fluid
exchange surface
furnace
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EP81105529A
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German (de)
French (fr)
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EP0044512A1 (en
Inventor
Werner Dr. Marnette
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Primetals Technologies Germany GmbH
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Fuchs Systemtechnik GmbH
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    • 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
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
    • F27B3/24—Cooling arrangements
    • 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
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/12—Casings; Linings; Walls; Roofs incorporating cooling arrangements
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/06—Electrodes
    • 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
    • F27D2009/0002—Cooling of furnaces
    • F27D2009/001—Cooling of furnaces the cooling medium being a fluid other than a gas
    • F27D2009/0013—Cooling of furnaces the cooling medium being a fluid other than a gas the fluid being water
    • F27D2009/0016—Water-spray
    • 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
    • F27D2009/0002—Cooling of furnaces
    • F27D2009/004—Cooling of furnaces the cooling medium passing a waterbox

Definitions

  • the invention relates to a method according to the preamble of patent claim 1. Furthermore, it relates to a device according to the preamble of patent claim 8.
  • Evaporative cooling systems of this type which always operate at high system pressures, cannot be used in batch-operated electric furnaces, since heat flows which fluctuate spatially and temporally significantly during the melting process have to be dissipated over the outer surfaces of an electric furnace.
  • the object of the invention is to achieve good cooling over the entire heat exchange surface in a method or a device of the type mentioned in the introduction, despite strong local and temporal fluctuations in the thermal stress, utilizing the evaporation enthalpy. Despite the local and temporal fluctuations in the thermal stress, film boiling, which leads to an inadmissibly high local thermal stress on the heat exchange wall, should be reliably prevented.
  • the aim of the invention is also an apparatus for performing the method.
  • the cooling system according to the invention operates at normal pressure or a pressure slightly above 1 bar and ensures adaptation to the transient operating states of an electric furnace without dangerous cooling water accumulations occurring on the furnace vessel wall.
  • this technology can achieve cooling water consumption of 0.6 1 water / M2 - min.
  • Precision nozzles for example hollow cone, full cone or pneumatic atomizer nozzles, are suitable for generating finely distributed water flows.
  • Vibrating-mechanical atomizing devices that are excited, for example, with ultrasound can also be used.
  • the coolant is preferably applied to the surface to be cooled with a constant jet width, a constant drop spectrum (0-100 ⁇ m) and a constant drop speed (20-40 m / sec).
  • FIG. 1 shows an evaporative cooling system 1 with a closed coolant circuit.
  • the system pressure is approximately 1 bar.
  • the cooling water is applied through atomizing nozzles 3 in finely divided droplet form 4 to the surface 2 to be cooled.
  • the surface 2 to be cooled and a fastening surface 26 for the nozzles 3 form a space which is closed off from the outside.
  • the saturated steam generated during evaporation is fed to the condenser 6 by means of a saturated steam pump 5 through a saturated steam line 22.
  • the resulting condensed coolant is collected in a container 7 and pumped into a pressure container 18 with a liquid pump 8.
  • the pressure vessel 18 ensures a largely constant liquid pressure in the feed line 19.
  • Parts of the coolant that condense in an uncontrolled manner are fed to the container 7 through a condensate return line 9.
  • the temperature of the surface 2 to be cooled is continuously measured with a large number of independent thermal sensors 10. If the lower limit temperature, which corresponds to the boiling temperature of the water, is exceeded locally or over a large area, the corresponding spatially assigned atomizing nozzles are actuated by opening the valves 20.
  • the cooling water is then applied to the surface 2 with a constant volume flow until the lower limit temperature is reached.
  • the mode of operation of the atomizing nozzles 3 is thus intermittent.
  • the nozzle switch-on times can be controlled by a microprocessor 21, which processes the numerous temperature measurement values and converts them into corresponding commands for the valve actuators.
  • FIG. 2 shows the application of the cooling method shown in FIG. 1 using the example of the side wall 14 of an electric arc furnace.
  • the cooling system is also used in furnace vessel areas which are below the bath surface 11.
  • the melt 12 is located in a lower part of the furnace vessel, which is bricked up and stamped out with refractory material 13 and which is made of steel and is made of the side wall 14 and the furnace bottom 16.
  • the furnace vessel according to FIG. 2 is bricked up over the bath surface 11.
  • the section of the refractory lining marked with 15 is only partially cooled in conventional water-cooled walls for safety reasons, namely from above to the bath surface 11.
  • the bottom electrode 17 is in electrical contact with the electrically conductive melt 12 via a solidified partial quantity 23 of the melt and serves to dissipate the electrical current from the melt 12 which generally serves as an anode in direct current and plasma furnaces.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Furnace Details (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Discharge Heating (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)

Abstract

1. A process for cooling parts of the container structure of a metallurgical furnace, which parts are subject to thermal loadings which fluctuate in respect of time and position, comprising a cooling box which is fitted into the wall region to be cooled or which forms the wall region and which includes a heat exchange surface on to which a cooling fluid is sprayed, characterised in that the temperature distribution in respect of space and time, on the heat exchange surface, is detected by a plurality of independent temperature measuring means and cooling fluid is sprayed on to the heat exchange surface region associated with the measurement value, over a large area thereof or in a localised manner, only so lang as the respective measurement value is above the boiling point of the cooling fluid, and that the amount of cooling fluid so sprayed is limited to a value in respect of which the cooling fluid is caused to evaporate spontaneously avoiding the formation of a coherent film of fluid.

Description

Die Erfindung betrifft ein Verfahren gemäß dem Oberbegriff des Patentanspruchs 1. Ferner bezieht sie sich auf eine Vorrichtung gemäß dem Oberbegriff des Patentanspruchs 8.The invention relates to a method according to the preamble of patent claim 1. Furthermore, it relates to a device according to the preamble of patent claim 8.

Bei der Kühlung eines thermisch hoch beanspruchten Wandbereichs eines metallurgischen Ofens, insbesondere eines Lichtbogenofens, mit örtlich und zeitlich stark schwankender thermischer Beanspruchung der Wand besteht das Problem, ein Filmsieden zu verhindern, d. h. ein Auftreten von dünnen Dampfschichten an der Wärmeaustauschfläche, da diese stark Wärmeisolierend wirken, an dieser Stelle den Wärmeaustausch stark herabsetzen und es insbesondere bei Wasserkühlkästen, die selbst die Ofenwandung bilden, zu einer Beschädigung durch örtliche Überhitzung kommen kann. Um ein Filmsieden zu verhindern, ist es üblich, die Strömungsgeschwindigkeit des Kühlmittels im Bereich der Wärmeaustauschfläche zu erhöhen. Dies wird bei der Kühleinrichtung nach der DE-AS 1 108372 dadurch erreicht, daß die Kühlflüssigkeit der Wärmeaustauschfläche über mehrere Düsen zugeführt wird, die knapp oberhalb dieser Fläche liegen. Bei dem metallurgischen Ofen gemäß der DE-OS 2 722 681 wird die hohe Strömungsgeschwindigkeit und damit ein Verdampfen der Kühlflüssigkeit durch Verengen des Strömungsquerschnittes des Strömungskanals erreicht.When cooling a thermally highly stressed wall area of a metallurgical furnace, in particular an arc furnace, with thermal stress on the wall that fluctuates widely in terms of location and time, there is the problem of preventing film boiling, i. H. an occurrence of thin layers of steam on the heat exchange surface, since these have a strong heat-insulating effect, greatly reduce the heat exchange at this point and, particularly in the case of water coolers, which themselves form the furnace wall, damage can result from local overheating. In order to prevent film boiling, it is common to increase the flow rate of the coolant in the area of the heat exchange surface. This is achieved in the cooling device according to DE-AS 1 108372 in that the cooling liquid is supplied to the heat exchange surface via several nozzles which are located just above this surface. In the metallurgical furnace according to DE-OS 2 722 681, the high flow rate and thus evaporation of the cooling liquid is achieved by narrowing the flow cross section of the flow channel.

Bei Kühlwassersystemen mit zwangsgeführten Kühlwasserströmen werden an der Wärmeaustauschfläche Wärmeübergangskoeffizienten von 1000 bis 3000 W/K . m2 erreicht, die allerdings Strömungsgeschwindigkeiten von 1 -3 m/sec erforderlich machen. Bei wassergekühlten Ofenwänden oberhalb der Schmelzzone und einem Temperaturanstieg im Kühlwasser νon ≈ 10 K lassen sich unter günstigen Bedingungen spezifische Kühlwasserverbrauchszahlen von 30 bis 50 I Wasser/m2 . min erzielen. Im allgemeinen liegen diese Verbrauchszahlen jedoch bei 100 I Wasser/m2 . min.In cooling water systems with forced cooling water flows, heat transfer coefficients of 1000 to 3000 W / K are generated on the heat exchange surface. m 2 reached, which however require flow velocities of 1-3 m / sec. With water-cooled furnace walls above the melting zone and a temperature increase in the cooling water νon ≈ 10 K, specific cooling water consumption figures of 30 to 50 I water / m2 can be achieved under favorable conditions. achieve min. In general, however, these consumption figures are 100 l water / m 2. min.

Diese Verbrauchszahlen führen bei offenen Kühlwassersystemen, vorzugsweise in Ländern mit Wassermangel, zu einer erheblichen Kostenbelastung des Elektroofenverfahrens. Bei Verwendung geschlossener Kühlwasserkreisläufe wird die Einrichtung großer Pump-, Kühl- und Aufbereitungskapazitäten erforderlich.With open cooling water systems, preferably in countries with a water shortage, these consumption figures lead to a considerable cost burden for the electric furnace process. When using closed cooling water circuits, it is necessary to set up large pumping, cooling and treatment capacities.

Bei Ausnutzung der Verdampfungswärme des Wassers von 2257 KJ/Kg sowie der bei der Verdampfungskühlung erreichbaren Wärmeübergangskoeffizienten von 10000 bis 20000 W/K - m2 wäre ein wesentlich wirtschaftlicherer Betrieb möglich.If the heat of evaporation of the water of 2257 KJ / Kg and the heat transfer coefficients of 10,000 to 20,000 W / K - m 2 that can be achieved with evaporative cooling are used, a much more economical operation would be possible.

Verdampfungskühlsysteme werden bereits in vielfältiger Weise bei technischen Einrichtungen genutzt. Bei metallurgischen Öfen wird diese Kühltechnik beispielsweise an Hochöfen angewendet. Diese Öfen sind infolge der kontinuierlichen Prozeßführung durch weitgehend stationäre Betriebszustände gekennzeichnet und liefern damit nahezu konsante Wärmestromdichten an den Wärmeaustauschflächen. Diese Hochofenkühlsysteme können somit wie allgemein bekannte Abhitzeverwertesysteme betrieben werden.Evaporative cooling systems are already used in a variety of ways in technical facilities. In the case of metallurgical furnaces, this cooling technology is used for example on blast furnaces. As a result of the continuous process control, these furnaces are characterized by largely stationary operating states and thus supply almost constant heat flow densities on the heat exchange surfaces. These blast furnace cooling systems can thus be operated like generally known waste heat recovery systems.

Derartige Verdampfungskühlsysteme, die stets bei hohen Systemdrücken arbeiten, sind bei chargenweise betriebenen Elektroöfen nicht einsetzbar, da während des Schmelzverlaufes über die Außenflächen eines Elektroofens räumlich und zeitlich erheblich schwankende Wärmeströme abgeführt werden müssen.Evaporative cooling systems of this type, which always operate at high system pressures, cannot be used in batch-operated electric furnaces, since heat flows which fluctuate spatially and temporally significantly during the melting process have to be dissipated over the outer surfaces of an electric furnace.

Aufgabe der Erfindung ist es, bei einem Verfahren bzw. einer Vorrichtung der einleitend genannten Art trotz starker örtlicher und zeitlicher Schwankungen der thermischen Beanspruchung unter Ausnutzung der Verdampfungsenthalpie eine gute Kühlung über die gesamte Wärmeaustauschfläche zu erzielen. Es soll trotz der örtlichen und zeitlichen Schwankungen der thermischen Beanspruchung ein Filmsieden, das zu einer unzulässig hohen örtlichen thermischen Beanspruchung der Wärmeaustauschwand führt, sicher verhindert werden. Ziel der Erfindung ist ferner eine Vorrichtung zur Durchführung des Verfahrens.The object of the invention is to achieve good cooling over the entire heat exchange surface in a method or a device of the type mentioned in the introduction, despite strong local and temporal fluctuations in the thermal stress, utilizing the evaporation enthalpy. Despite the local and temporal fluctuations in the thermal stress, film boiling, which leads to an inadmissibly high local thermal stress on the heat exchange wall, should be reliably prevented. The aim of the invention is also an apparatus for performing the method.

Das erfindungsgemäße Verfahren ist durch die Merkmale des Anspruchs 1, die erfindungsgemäße Vorrichtung zur Durchführung des Verfahrens durch die Merkmale des Anspruchs 8 gekennzeichnet. Vorteilhafte Ausgestaltungen der Erfindung sind den übrigen Ansprüchen zu entnehmen.The method according to the invention is characterized by the features of claim 1, the device according to the invention for carrying out the method by the features of claim 8. Advantageous embodiments of the invention can be found in the remaining claims.

Durch die Erfindung lassen sich die Vorteile der Verdampfungskühlung auch für die Kühlung der Außenflächen eines Elektroofens nutzen. Ein wesentliches Merkmal dieser Erfindung ist, daß Elektroöfen bei sehr geringem Kühlwasserverbrauch auch unterhalb der Schmelz- und Schlackenzone gekühlt werden können, ohne daß eine Beeinträchtigung der Betriebssicherheit gegeben ist.The advantages of evaporative cooling can also be used by the invention for cooling the outer surfaces of an electric furnace. An important feature of this invention is that electric furnaces can also be cooled below the melting and slag zone with very low cooling water consumption, without impairing operational safety.

Das erfindungsgemäße Kühlsystem arbeitet bei Normaldruck oder einem geringfügig über 1 bar liegenden Druck und gewährleistet die Anpassung an die instationären Betriebszustände eines Elektroofens, ohne daß gefährliche Kühlwasseransammlungen an der Ofengefäßwand auftreten.The cooling system according to the invention operates at normal pressure or a pressure slightly above 1 bar and ensures adaptation to the transient operating states of an electric furnace without dangerous cooling water accumulations occurring on the furnace vessel wall.

Dies wird durch das Auftragen feinverteilter Kühlwassermengen mit definiertem Tropfenspektrum auf die zu kühlenden Außenflächen erreicht, wobei durch eine Temperaturmeßeinrichtung gewährleistet ist, daß bei Kühlmittelzufuhr die Außenflächentemperatur stets mindestens der Siedetemperatur des Wassers entspricht, damit eine spontane Verdampfung des Kühlwassers eintritt und die Ausbildung zusammenhängender Flüssigkeitsfilme auf der Wärmeaustauschfläche unterbleibt.This is achieved by applying finely divided amounts of cooling water with a defined drop spectrum to the outer surfaces to be cooled, whereby a temperature measuring device ensures that when the coolant is supplied, the outer surface temperature always corresponds to at least the boiling point of the water, so that spontaneous evaporation of the cooling water occurs and the formation of coherent liquid films the heat exchange surface is omitted.

Im Gegensatz zu bekannten Kühlsystemen, wie zum Beispiel in der Offenlegungsschrift 1 934486 beschrieben, wird bei der hier dargelegten Kühlung das Auftreten koexistierender flüssiger und gasförmiger Phasen bewußt vermieden.In contrast to known cooling systems, As described, for example, in laid-open specification 1 934486, the occurrence of coexisting liquid and gaseous phases is consciously avoided in the cooling described here.

Bei üblichen Verlustleistungen von 29 KW/m2 bei Elektroöfen im Bereich oberhalb der Schmelze kann mit dieser Technik ein Kühlwasserverbrauch von 0,6 1 Wasser/M2 - min erreicht werden.With conventional power losses of 29 KW / m 2 for electric furnaces in the area above the melt, this technology can achieve cooling water consumption of 0.6 1 water / M2 - min.

Der entsprechende theoretische Kühlwasserverbrauch bei einem mit Zwangskonvektion arbeitenden heutigen Kühlsystem liegt bei 41 ) Wasser/m2 . min.The corresponding theoretical cooling water consumption in today's cooling system working with forced convection is 41) water / m 2. min.

Zur Erzeugung feinverteilter Wasserströme sind handelsübliche Präzisionsdüsen, zum Beispiel Hohlkegel-, Vollkegel- oder Pneumatikzerstäuberdüsen, geeignet.Commercially available precision nozzles, for example hollow cone, full cone or pneumatic atomizer nozzles, are suitable for generating finely distributed water flows.

Schwingend-mechanisch arbeitende Zerstäubereinrichtungen, die beispielsweise mit Ultraschall angeregt werden, können ebenfalls Anwendung finden.Vibrating-mechanical atomizing devices that are excited, for example, with ultrasound can also be used.

Vorzugsweise wird das Kühlmittel mit gleichbleibender Strahlbreite, gleichbleibendem Tropfenspektrum (0-100 µm) und gleichbleibender Tropfengeschwindigkeit (20-40 m/sec) auf die zu kühlende Fläche aufgebracht.The coolant is preferably applied to the surface to be cooled with a constant jet width, a constant drop spectrum (0-100 μm) and a constant drop speed (20-40 m / sec).

Beispiele für die Verwirklichung des Erfindungsgedankens werden in den nachfolgend beschriebenen Figuren dargestellt.Examples of the realization of the inventive concept are shown in the figures described below.

Die Fig. 1 zeigt ein Verdampfungskühlsystem 1 mit geschlossenem Kühlmittelkreislauf. Der Systemdruck beträgt ungefähr 1 bar. Das Kühlwasser wird durch Zerstäuberdüsen 3 in feinverteilter Tropfenform 4 auf die zu kühlende Fläche 2 aufgebracht. Die zu kühlende Fläche 2 und eine Befestigungsfläche 26 für die Düsen 3 bilden einen nach außen abgeschlossenen Raum. Der bei der Verdampfung entstehende Sattdampf wird mittels einer Sattdampfpumpe 5 durch eine Sattdampfleitung 22 dem Kondensator 6 zugeführt. Das dabei entstehende kondensierte Kühlmittel wird in einem Behälter 7 gesammelt und mit einer Flüssigkeitspumpe 8 in einen Druckbehälter 18 gepumpt. Der Druckbehälter 18 gewährleistet bei geöffnetem Ventil 20 einen weitgehend konstanten Flüssigkeitsdruck in der Zuleitung 19.1 shows an evaporative cooling system 1 with a closed coolant circuit. The system pressure is approximately 1 bar. The cooling water is applied through atomizing nozzles 3 in finely divided droplet form 4 to the surface 2 to be cooled. The surface 2 to be cooled and a fastening surface 26 for the nozzles 3 form a space which is closed off from the outside. The saturated steam generated during evaporation is fed to the condenser 6 by means of a saturated steam pump 5 through a saturated steam line 22. The resulting condensed coolant is collected in a container 7 and pumped into a pressure container 18 with a liquid pump 8. When the valve 20 is open, the pressure vessel 18 ensures a largely constant liquid pressure in the feed line 19.

Teile des Kühlmittels, die unkontrolliert kondensieren, werden durch eine Kondensatrückführungsleitung 9 dem Behälter 7 zugeleitet. Die Temperatur der zu kühlenden Fläche 2 wird mit einer Vielzahl voneinander unabhängiger Thermofühler 10 ständig gemessen. Bei einem örtlich begrenzten oder großflächigen Überschreiten der unteren Grenztemperatur, die der Siedetemperatur des Wassers entspricht, werden die entsprechend räumlich zugeordneten Zerstäuberdüsen durch Öffnen der Ventile 20 betätigt. Das Kühlwasser wird dann mit gleichbleibendem Volumenstrom solange auf die Oberfläche 2 aufgebracht, bis die untere Grenztemperatur erreicht ist. Die Betriebsweise der Zerstäuberdüsen 3 ist somit intermittierend. Die Steuerung der Düseneinschaltzeiten kann durch einen Mikroprozessor 21 erfolgen, der die vielzähligen Temperaturmeßwerte verarbeitet und in entsprechende Befehle für die Ventilstellglieder umsetzt.Parts of the coolant that condense in an uncontrolled manner are fed to the container 7 through a condensate return line 9. The temperature of the surface 2 to be cooled is continuously measured with a large number of independent thermal sensors 10. If the lower limit temperature, which corresponds to the boiling temperature of the water, is exceeded locally or over a large area, the corresponding spatially assigned atomizing nozzles are actuated by opening the valves 20. The cooling water is then applied to the surface 2 with a constant volume flow until the lower limit temperature is reached. The mode of operation of the atomizing nozzles 3 is thus intermittent. The nozzle switch-on times can be controlled by a microprocessor 21, which processes the numerous temperature measurement values and converts them into corresponding commands for the valve actuators.

An Ofenbereichen, die räumlich und zeitlich stark schwankenden Wärmeflüssen ausgesetzt sind, können, wie in Fig. 1 dargestellt, die Düsen einzeln gesteuert werden. In Gebieten mit gleichmäßiger Wärmebelastung werden mehrere Düsen gruppenweise gesteuert.The nozzles can be controlled individually in furnace regions which are exposed to heat flows which fluctuate widely in space and time, as shown in FIG. 1. In areas with uniform heat loads, several nozzles are controlled in groups.

Nachfolgend werden die Kennzahlen eines Ausführungsbeispiels aufgeführt:

Figure imgb0001
The key figures of an exemplary embodiment are listed below:
Figure imgb0001

Die Fig. 2 zeigt die Anwendung des in Fig. 1 dargestellten Kühlverfahrens am Beispiel der Seitenwand 14 eines Elektrolichtbogenofens. In diesem Beispiel wird das Kühlsystem auch in Ofengefäßbereichen angewandt, die unterhalb der Badoberfläche 11 liegen. Die Schmelze 12 befindet sich in einem mit feuerfestem Material 13 ausgemauerten und ausgestampften aus der Seitenwand 14 und dem Ofenboden 16 gebildeten Ofengefäßunterteil, das aus Stahl gefertigt ist. Bei einer feuerfesten Neuzustellung des Elektrolichtbogenofens wird das Ofengefäß entsprechend Fig. 2 bis über die Badoberfläche 11 ausgemauert. Der mit 15 gekennzeichnete Abschnitt der feuerfesten Ausmauerung wird entgegen der in Fig. 2 dargestellten Kühltechnik bei herkömmlichen wassergekühlten Wänden aus Sicherheitsgründen nur teilweise, und zwar von oben her bis zur Badoberfläche 11 gekühlt. Da der Verschleiß der feuerfesten Baustoffe 13 im wesentlichen auf chemische Umsetzungen mit der flüssigen Schmelze 12 zurückzuführen und damit stark temperaturabhängig ist, ist bei einer Verwirklichung des Erfindungsgedankens entsprechend Fig. 2 mit einer erheblichen Verminderung des Verbrauches an feuerfesten Werkstoffen im Badbereich zu rechnen.FIG. 2 shows the application of the cooling method shown in FIG. 1 using the example of the side wall 14 of an electric arc furnace. In this example, the cooling system is also used in furnace vessel areas which are below the bath surface 11. The melt 12 is located in a lower part of the furnace vessel, which is bricked up and stamped out with refractory material 13 and which is made of steel and is made of the side wall 14 and the furnace bottom 16. In the case of a refractory relining of the electric arc furnace, the furnace vessel according to FIG. 2 is bricked up over the bath surface 11. Contrary to the cooling technology shown in FIG. 2, the section of the refractory lining marked with 15 is only partially cooled in conventional water-cooled walls for safety reasons, namely from above to the bath surface 11. Since the wear of the refractory materials 13 is essentially due to chemical reactions with the liquid melt 12 and is therefore strongly temperature-dependent, a considerable reduction in the consumption of refractory materials in the bathroom area can be expected if the inventive idea according to FIG. 2 is implemented.

Durch die gezielte Wärmeabfuhr in dem mit 15 gekennzeichneten Bereich wird die Isotherme der unteren Reaktionsgrenztemperatur für die chemischen Verschleißreaktionen genügend weit auf die dem Bad 12 zugewandte Seite der feuerfesten Zustellung verlegt, so daß eine ausreichende Reststeindicke und damit eine erhöhte Lebensdauer der Auskleidung erreicht wird.Due to the targeted heat dissipation in the area marked with 15, the isotherm of the lower reaction limit temperature for the chemical wear reactions is moved sufficiently far to the side of the refractory lining facing the bath 12, so that a sufficient residual stone thickness and thus an increased service life of the lining is achieved.

Die Fig. 3 zeigt die Anwendung des in Fig. 1 dargestellten Kühlverfahrens am Beispiel einer im Boden 16 eines Elektroofens eingesetzten Elektrode 17. Die Bodenelektrode 17 besteht aus einem Werkstoff mit geringem spezifischen elektrischen Widerstand und guter Wärmeleitfähigkeit. Bei den im Schrifttum bekannt gewordenen Bodenelektroden wurde als Elektrodenwerkstoff vorwiegend Kupfer verwendet.FIG. 3 shows the application of the cooling method shown in FIG. 1 using the example of an electrode 17 inserted in the bottom 16 of an electric furnace. The bottom electrode 17 consists of a material with low specific electrical resistance and good thermal conductivity ability. In the case of the floor electrodes that became known in the literature, copper was mainly used as the electrode material.

Die Bodenelektrode 17 steht in elektrischem Kontakt mit der elektrisch leitenden Schmelze 12 über eine erstarrte Teilmenge 23 der Schmelze und dient zur Abführung des elektrischen Stromes von der bei Gleichstrom- und Plasma- öfen im allgemeinen als Anode dienenden Schmelze 12.The bottom electrode 17 is in electrical contact with the electrically conductive melt 12 via a solidified partial quantity 23 of the melt and serves to dissipate the electrical current from the melt 12 which generally serves as an anode in direct current and plasma furnaces.

Gegenüber den bisher bekannten Kühleinrichtungen für derartige Bodenelektroden, die ausschließlich mit zwangsgeführtem Kühlwasser arbeiten, führt eine Kühlung nach dem hier dargelegten Erfindungsgedanken neben einer Herabsetzung der Kühlwasserverbrauchszahlen insbesondere zu einer bedeutenden Erhöhung der Betriebs- und Arbeitssicherheit.Compared to the previously known cooling devices for floor electrodes of this type, which work exclusively with positively guided cooling water, cooling in accordance with the inventive concept presented here, in addition to a reduction in the cooling water consumption figures, in particular leads to a significant increase in operational and occupational safety.

Bei dem hier dargestellten Beispiel dient das Stromrohr 24, das über die elektrisch leitende Befestigungsplatte 26 der Düsen 3 mit der Bodenelektrode 17 verbunden ist, zugleich als Sattdampfableitung 22. Die Bodenelektrode ist auswechselbar in der zylinderförmigen Halterung 25 befestigt.In the example shown here, the current tube 24, which is connected to the bottom electrode 17 via the electrically conductive mounting plate 26 of the nozzles 3, also serves as a saturated steam discharge line 22. The bottom electrode is fastened interchangeably in the cylindrical holder 25.

Claims (8)

1. A process for cooling parts of the container structure of a metallurgical furnace, which parts are subject to thermal loadings which fluctuate in respect of time and position, comprising a cooling box which is fitted into the wall region to be cooled or which forms the wall region and which includes a heat exchange surface on to which a cooling fluid is sprayed, characterised in that the temperature distribution in respect of space and time, on the heat exchange surface, is detected by a plurality of independent temperature measuring means and cooling fluid is sprayed on to the heat exchange surface region associated with the measurement value, over a large area thereof or in a localised manner, only so lang as the respective measurement value is above the boiling point of the cooling fluid, and that the amount of cooling fluid so sprayed is limited to a value in respect of which the cooling fluid is caused to evaporate spontaneously avoiding the formation of a coherent film of fluid.
2. A process according to claim 1 characterised in that the cooling fluid is sprayed on to the heat exchange surface with a drop size of a maximum of 100 pm.
3. A process according to claim 1 or claim 2 characterised in that the cooling fluid is sprayed on to the heat exchange surface by means of atomiser nozzles.
4. A process according to one of claims 1 to 3 characterised by use thereof for cooling the cover of an electric furnace, in particular an electric arc furnace.
5. A process according to one of claims 1 to 4 characterised by use thereof for cooling the outside surfaces of the furnace container structure of a metallurgical furnace below the melt and slag zone.
6. A process according to claim 5 characterised by use thereof for cooling an electrical contact means of an electric furnace, which contact means communicates with the melt bath and issues at the furnace container structure.
7. A process according to claims 1 to 6 characterised in that the cooling fluid used is water.
8. Apparatus for carrying out the process according to one of claims 1 to 7, comprising a cooling box which is fitted into the wall region to be cooled of a metallurgical furnace, in particular an electric arc furnace, or which forms the wall region and which includes a heat exchange surface and, disposed opposite thereto, a means for spraying a cooling fluid on to the heat exchange surface, characterised in that the cooling fluid can be sprayed by the spray means on to various regions of the heat exchange surface in a differently metered mode, and the spray means is controlled by a microprocessor on the basis of temperature measurement values supplied by a plurality of temperature measuring sensors which are distributed over the heat exchange surface.
EP81105529A 1980-07-19 1981-07-14 Method and apparatus for the cooling of vessel parts of a metallurgical furnace, especially an electric-arc furnace Expired EP0044512B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81105529T ATE6095T1 (en) 1980-07-19 1981-07-14 METHOD AND DEVICE FOR COOLING VESSEL PARTS OF A METALLURGICAL FURNACE, IN PARTICULAR AN ARC FURNACE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3027465A DE3027465C1 (en) 1980-07-19 1980-07-19 Method and device for cooling vessel parts of a metallurgical furnace, in particular an arc furnace
DE3027465 1980-07-19

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EP0044512A1 EP0044512A1 (en) 1982-01-27
EP0044512B1 true EP0044512B1 (en) 1984-02-01

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JP (1) JPS5752788A (en)
AT (1) ATE6095T1 (en)
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11619450B2 (en) * 2019-09-04 2023-04-04 Systems Spray-Cooled, Inc. Stand alone copper burner panel for a metallurgical furnace

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1257473A (en) * 1984-10-12 1989-07-18 Willard Mcclintock Furnace cooling system and method
NO155903C (en) * 1985-02-07 1987-06-17 Elkem As SIDE WALL IN A METALLURGICAL MELTING Oven.
GB8722354D0 (en) * 1987-09-23 1987-10-28 Davy Mckee Stockton Metallurgical furnace
US4815096A (en) * 1988-03-08 1989-03-21 Union Carbide Corporation Cooling system and method for molten material handling vessels
GB8908997D0 (en) * 1989-04-20 1989-06-07 Davy Mckee Stockton Vessels for containing molten metal
FR2652890B1 (en) * 1989-10-11 1995-01-20 Siderurgie Fse Inst Rech ELECTRICAL CONNECTION DEVICE FOR PLACING ON THE WALL OF A METALLURGICAL CONTAINER IN CONTACT WITH A MOLTEN METAL.
DE4026897C2 (en) * 1990-08-23 1994-05-05 Mannesmann Ag Metallic base electrode for metallurgical vessels
DE4103508A1 (en) * 1991-02-06 1992-08-13 Kortec Ag METHOD AND DEVICE FOR COOLING VESSEL PARTS FOR CARRYING OUT PYRO METHODS, IN PARTICULAR METALLURGICAL TYPE
GB9322696D0 (en) * 1993-11-03 1993-12-22 Davy Mckee Stockton Cooling of hot bodies
ATA147194A (en) * 1994-07-25 1997-11-15 Voest Alpine Ind Anlagen METHOD FOR COOLING A HOT SURFACE AND DEVICE FOR CARRYING OUT THE METHOD
US5561685A (en) * 1995-04-27 1996-10-01 Ucar Carbon Technology Corporation Modular spray cooled side-wall for electric arc furnaces
DE19529924C1 (en) * 1995-08-01 1996-10-31 Mannesmann Ag Arc furnace with simple arc spot displacement mechanism
FR2842215B1 (en) 2002-07-09 2004-08-13 Pechiney Aluminium METHOD AND SYSTEM FOR COOLING AN ELECTROLYSIS TANK FOR THE PRODUCTION OF ALUMINUM
FR2844582B1 (en) 2002-09-16 2005-06-17 H Raymond Guyomarc REGULATOR COOLING SYSTEM FOR CONTROLLING WALL TEMPERATURES SUBJECT TO THERMAL PRODUCTION
LU91142B1 (en) * 2005-02-28 2006-08-29 Wurth Paul Sa Electric arc furnace
LU91408B1 (en) * 2008-01-11 2009-07-13 Wurth Paul Sa Cooling of a metallurgical smelting reduction vessel
DE102009031355A1 (en) * 2009-07-01 2011-01-05 Siemens Aktiengesellschaft A method of cooling a cooling element of an electric arc furnace, electric arc furnace for melting metallic material, and control and / or regulating device for an electric arc furnace

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2275515A (en) * 1939-08-03 1942-03-10 George S Dunham Method of and apparatus for cooling blast furnaces
US2671658A (en) * 1951-02-14 1954-03-09 Meehanite Metal Corp Metal lined cupola
DE1133083B (en) * 1956-07-10 1962-07-12 Strico Ges Fuer Metallurg Melting zone cooling jacket for shaft ovens
DE1108372B (en) * 1956-11-01 1961-06-08 Josef Cermak Dr Ing Cooling device for thermally highly stressed walls
DE1043591B (en) * 1956-11-09 1958-11-13 Strico Ges Fuer Metallurg Device for regulating the amount of cooling water
FR1335903A (en) * 1962-10-11 1963-08-23 Bbc Brown Boveri & Cie System for regulating the temperature of the cooling medium passing through the cooling elements of the cooling zone of a heat treatment furnace
JPS505125B1 (en) * 1968-10-22 1975-02-28
DE1934486C3 (en) * 1969-07-08 1984-03-01 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 4200 Oberhausen Device for cooling masonry parts exposed to high temperatures, in particular metal melting furnaces
US4024764A (en) * 1976-04-22 1977-05-24 Bethlehem Steel Corporation Method and apparatus for measuring product surface temperature in a spray cooling chamber
US4091228A (en) * 1976-05-19 1978-05-23 United States Steel Corporation Water cooled shell for electric arc furnaces
SE410654B (en) * 1978-02-28 1979-10-22 Asea Ab DIAMOND CANDLES OVEN WITH AT LEAST ONE CATODICALLY CONNECTED ELECTRODE AND AT LEAST ONE BOTTOM CONNECTOR

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11619450B2 (en) * 2019-09-04 2023-04-04 Systems Spray-Cooled, Inc. Stand alone copper burner panel for a metallurgical furnace

Also Published As

Publication number Publication date
ES8205459A1 (en) 1982-06-16
ATE6095T1 (en) 1984-02-15
BR8104601A (en) 1982-04-06
JPS5752788A (en) 1982-03-29
DE3027465C1 (en) 1982-03-18
EP0044512A1 (en) 1982-01-27
ES504094A0 (en) 1982-06-16

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