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WO2009059345A1 - Four à cuve à chauffage électrique - Google Patents

Four à cuve à chauffage électrique Download PDF

Info

Publication number
WO2009059345A1
WO2009059345A1 PCT/AT2008/000405 AT2008000405W WO2009059345A1 WO 2009059345 A1 WO2009059345 A1 WO 2009059345A1 AT 2008000405 W AT2008000405 W AT 2008000405W WO 2009059345 A1 WO2009059345 A1 WO 2009059345A1
Authority
WO
WIPO (PCT)
Prior art keywords
shaft furnace
furnace according
graphite
heating
rods
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.)
Ceased
Application number
PCT/AT2008/000405
Other languages
German (de)
English (en)
Inventor
Alfred Edlinger
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.)
Patco Engineering GmbH
Original Assignee
Patco Engineering GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from AT18032007A external-priority patent/AT506021B1/de
Application filed by Patco Engineering GmbH filed Critical Patco Engineering GmbH
Priority to ES08847704T priority Critical patent/ES2409739T3/es
Priority to PL08847704T priority patent/PL2255139T3/pl
Priority to EP08847704A priority patent/EP2255139B1/fr
Publication of WO2009059345A1 publication Critical patent/WO2009059345A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • F27B1/00—Shaft or like vertical or substantially vertical furnaces
    • F27B1/08—Shaft or like vertical or substantially vertical furnaces heated otherwise than by solid fuel mixed with 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
    • F27B9/06—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity heated without contact between combustion gases and charge; electrically heated
    • F27B9/062—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity heated without contact between combustion gases and charge; electrically heated electrically heated
    • F27B9/063—Resistor heating, e.g. with resistors also emitting IR rays
    • 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
    • F27D11/00—Arrangement of elements for electric heating in or on furnaces
    • F27D11/02—Ohmic resistance heating
    • 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
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0001—Heating elements or systems
    • F27D99/0006—Electric heating elements or system
    • 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
    • H05B3/00—Ohmic-resistance heating
    • H05B3/62—Heating elements specially adapted for furnaces
    • 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
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/22—Furnaces without an endless core

Definitions

  • the invention relates to an electrically heated shaft furnace with at least one heating element formed by electrical conductors.
  • WO 2006/079132 A1 proposed a method and a device for reducing metal oxide-containing slags or glasses and / or degassing mineral melts, in which the molten slags were fed onto an inductively heated coke bed.
  • the batch was fed to a shaft furnace and the coke bed was inductively heated to temperatures which ensured that a melt would be formed until the tapping point or that the melting temperature would be maintained.
  • inductively heated coke a bed with high reduction potential was provided, so that the reduction of oxidic or organics contaminated slags and metallurgical dusts could be carried out even with high levels of chromium oxide and vanadium oxide slag in a simple manner.
  • Induction heated ovens are also known as crucible furnaces.
  • electrically heated furnaces the electrical resistance of the melt was mostly utilized and the electrical energy was applied via electrodes immersed in the melt.
  • the transfer of heat by induction only with high efficiency succeeds when only small distances must be bridged between the induction coil and the inductively heated medium.
  • melts this means that corresponding heat is also radiated into the induction coils, so that in the case of copper windings water-cooled copper pipes have been proposed as a conductor.
  • water-cooled conductors have a significant power loss.
  • the invention now aims to provide an embodiment for the electric heating of a shaft furnace, in which high power energy can be introduced with low power loss or alternatively other forms of electrical heating can be realized and with the provided in the prior art complex water cooling can be avoided.
  • the invention electrically heated shaft furnace of the type mentioned initially consists essentially in that the heating elements of carbon, in particular graphite exist.
  • the choice of carbon or graphite for the conductor and thus the heating element has the consequence that here a highly refractory material is used, which requires no expensive cooling more.
  • the conductivity of carbon or of graphite increases with increasing temperature, so that a corresponding stepwise heating seems advantageous, for which at the beginning, for example, the conductor can be switched in the manner of a resistance heater.
  • the heating elements as embedded in or on a refractory support or arranged conductor tracks made of graphite and preferably be formed by Graphitringen or ring segments or alternatively by coal, coke or graphite rods.
  • Graphite usually has less than half the conductivity of copper, whereby correspondingly large graphite inducers or graphite conductor cross sections must be provided. In a particularly simple manner, this can be ensured that the formation is made such that the jacket of the shaft furnace made of refractory material and grooves on its inner surface, in particular helical grooves for receiving conductor tracks formed of graphite having.
  • the conductor layer or the graphite rings can in this case be incorporated directly into the refractory jacket of the shaft furnace, with graphite itself being an excellent refractory material and remaining dimensionally stable even at very high temperatures.
  • the induction losses in the case of inductive heating increase quadratically with the distance between the inductor and the material to be coupled, for example a coke bed, the induction losses can be substantially minimized by the conductor being embedded directly in the refractory material, with only a corresponding electric current Isolation between a coke bed and the inductor is required, but for which particularly simple measures are sufficient.
  • the training is in this case made such that the inner shell is lined with a refractory insulating layer or foil or insulation mat, wherein preferably the refractory material and / or the insulating layer of MgO or Al 2 O 3 is formed.
  • the coke bed can be treated simultaneously with a correspondingly large grain size such that the depth of the grooves in the jacket is greater than the width of the strip conductors or of the graphite rings is and the radial distance of the conductor tracks from the axis or the inner diameter of the graphite rings is greater than the inner diameter of the shell of the shaft furnace is selected.
  • the electrical connection to the conductor tracks succeeds such that the graphite rings are slotted on their circumference and the free ends of the rings can be applied in parallel or in series to a current source.
  • the training can be made with advantage so that the tracks of mashed graphite powder or a with electrically conductive substances, in particular thermally dissociating salts are doped.
  • the heating elements are formed along a helical line or annularly arranged conductor tracks made of carbon, but can be made in a particularly simple manner, the formation that the heating elements of coal, coke or graphite rods are formed.
  • the arrangement is preferably such that the heating rods are arranged substantially parallel to the axis of the tubular shaft furnace, wherein advantageously the shaft furnace is cylindrical and a plurality of heating rods are arranged on a circle extending concentrically to the axis.
  • the shaft furnace is cylindrical and a plurality of heating rods are arranged on a circle extending concentrically to the axis.
  • the corresponding electrode material can be graphitized and is characterized by extremely high, even mechanical, stability.
  • heating elements parallel to the axis of a shaft furnace allows for all abundance to realize any circuits of these heating elements, the training can be made with advantage so that the heating elements each at one end to an adjacent end of an adjacent heater in the circumferential direction of the shaft furnace are connected.
  • connection of adjacent heating rods can advantageously be switchable, wherein the heating elements can be connected to one another or can be connected separately to the power source.
  • steel or slurry (CaF 2 / Al 2 0 3 / Ca0) can be melted, wherein due to the high temperatures, the melting or the reducing melting of silicon, silicon carbide, iron silicon or phosphorus succeeds in an advantageous manner.
  • Induction melting furnaces in which refractory steel alloys are melted under vacuum or under inert gas, are a possible application example here.
  • the possible risk of explosion is eliminated because, in the case of leaks, leakage of water may result in the formation of oxyhydrogen gas, in which case hydrogen could diffuse into the molten steel.
  • the use of the refractory conductor material makes it possible to choose the temperature of the conductor substantially equal to the temperature of the material to be treated, whereby the conductivity increases significantly.
  • a further increase in the conductivity at higher temperatures succeeds, as already mentioned above, by admixing thermally dissociating metal salts, which are very good conductors at high temperatures.
  • the electrically heated shaft furnace according to the invention is suitable both as an induction furnace and as a conductively heated furnace, wherein in the case of electrically conductive batches and in particular in the case of a coke bed or a crucible with molten steel temperatures of about 2300 ° C can be readily realized.
  • Graphite remains dimensionally stable in a reducing atmosphere up to temperatures of about 3400 ° C, with pure resistance heating, the heat transfer via radiation and conduction with very high efficiency succeeds.
  • FIG. 1 is a plan view of a slotted graphite ring
  • FIG. 2 is a sectional view in the direction of arrow II - II of FIG. 1
  • FIG. 3 is a sectional view in the direction of arrow III - III of FIG. 1.
  • the sectional view FIGS. 2 and 3 each show only half the shaft furnace in section.
  • Fig. 4 shows an axial section through a modified embodiment of the shaft furnace with rod-shaped heating elements
  • Fig. 5 is a section along the line V, V of Fig. 4
  • Fig. 6 shows a modified embodiment in a representation corresponding to FIG. 5
  • 7 shows a cross section through a modified embodiment with axially parallel conductor tracks.
  • Fig. 1 denotes a slotted graphite ring, whose free ends open into end faces 2 and 3. About these end faces 2 and 3, the slotted graphite rings can be contacted electrically and are acted upon accordingly with direct current, low frequency or high frequency alternating current.
  • the free end faces 2 of the slotted rings can be seen in each case.
  • current is applied to the lowermost end face 2 over the region a and contacting the following graphite ring 1 takes place via adjacent end faces 3 in the vertical direction in turn - twisted by an angle of about 180 ° - the contacting of adjacent end faces 2 to achieve a series connection of the rings takes place.
  • About the terminals 6 and 7 can be supplied here DC or low-frequency alternating current.
  • a parallel circuit is recommended, as can be seen in the axial region b, the corresponding terminals are designated here 8 and 9 and two each in Achsrich- tion successive rings 1 are connected in parallel.
  • Such a parallel connection leads to a reduction of the required voltage in the case of inductive heating, so that the danger and rollover potential is reduced.
  • the training on the axial height of the shaft furnace 5 can be chosen flexibly and it can optionally be made in individual axial Busch a parallel circuit or a serial circuit in order to be able to take into account the respective lent temperature profiles.
  • Fig. 4 shows a cross section through a shaft furnace 10, in the refractory shell 11 rod-shaped heating elements 12 are embedded.
  • the rod-shaped heating elements 12 are formed here by graphite rods.
  • the adjacent ends of such graphite rods 12 may be selectively connected to each other via conductive connections 13 at one end and conductive connections 14 at the other end of the rods, whereby a series connection of three adjacent graphite rods 12 can be realized.
  • the ends of the total resistance and the total inductance achieved by this series connection can be used correspondingly both when used as inductive heating with the connection of alternating current, and from conductive heating with connection of direct current.
  • the circuit of the individual bars results here from the sectional view of FIG. 7, wherein a total of a cage made of graphite rods can be formed as an inductor, wherein the individual graphite rods of the cage can be connected in parallel or in series.
  • the slightly modified embodiment according to FIG. 6, the illustration of which corresponds essentially to the illustration according to FIG. 5, reveals a multilayer construction of the jacket and is preferably used at maximum temperatures in order to obtain graffiti. to cause reactions.
  • the heating elements 12 are in this case surrounded by a first jacket made of graphite, wherein this first jacket 15 can be composed of individual segments.
  • the freestanding graphite rods or graphite electrodes can, if necessary, be purged with inert gas if necessary, for which inlet openings 16 are provided.
  • the graphite shell 15 is surrounded on the outside by another shell made of refractory material, which is denoted by 17.
  • Such a design can be used, for example, for the graphitization of carbon rods, as indicated schematically by a coextruded rubber 18, which can be conveyed in the direction of the arrow 19 through the shaft furnace.
  • graphitization of coke extrudate 18 can also be achieved, as a result of which the crystallization of the carbon in the coextrudate 18 can be effected.
  • Fig. 7 schematically different application examples of the shaft furnace are shown, again a modified design of the shaft furnace is provided.
  • the shell 11 of refractory material grooves 20 are provided here, which are dovetail-shaped and the conductor tracks or graphite rods 21 included.
  • the inner surface of this graphite rod or strip is in this case at a greater radial distance from the shaft 22 of the shaft furnace than the inner wall 23 of the refractory shell, so that in the case of the use of a Koksbettes for smelting reduction directly conductive contact between the coke bed and the graphite bar is prevented.
  • Such a feed or such a use of a coke bed is indicated by the Koks publishede.
  • a melt can be produced and the shaft furnace as a crucible for melting Steel are used.
  • the melt is indicated schematically at 24 here.
  • the method can be used so that a graphite heat exchanger, indicated by the reference numeral 25, is used for the production of tertiary slag.
  • the graphite rods can be operated both as a conductor and as an inductor, the field lines extending through the axial cavity of the shaft furnace.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Furnace Details (AREA)

Abstract

L'invention concerne un four à cuve (5) à chauffage électrique, comportant au moins un élément de chauffage (12) composé de conducteurs électriques, le ou les éléments de chauffage (12) étant réalisés en carbone.
PCT/AT2008/000405 2007-11-08 2008-11-10 Four à cuve à chauffage électrique Ceased WO2009059345A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
ES08847704T ES2409739T3 (es) 2007-11-08 2008-11-10 Horno de cuba calentado eléctricamente
PL08847704T PL2255139T3 (pl) 2007-11-08 2008-11-10 Elektrycznie ogrzewany piec szybowy
EP08847704A EP2255139B1 (fr) 2007-11-08 2008-11-10 Four à cuve à chauffage électrique

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
AT18032007A AT506021B1 (de) 2007-11-08 2007-11-08 Elektrisch beheizter schachtofen
ATA1803/2007 2007-11-08
AT20042007 2007-12-11
ATA2004/2007 2007-12-11

Publications (1)

Publication Number Publication Date
WO2009059345A1 true WO2009059345A1 (fr) 2009-05-14

Family

ID=40625270

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AT2008/000405 Ceased WO2009059345A1 (fr) 2007-11-08 2008-11-10 Four à cuve à chauffage électrique

Country Status (4)

Country Link
EP (1) EP2255139B1 (fr)
ES (1) ES2409739T3 (fr)
PL (1) PL2255139T3 (fr)
WO (1) WO2009059345A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114704958A (zh) * 2022-04-12 2022-07-05 西安慧金科技有限公司 煤气电加热装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104048513B (zh) * 2014-06-06 2015-10-21 西安航空制动科技有限公司 一种组合式石墨发热体
DE102024203318A1 (de) * 2024-04-11 2025-10-16 Sms Group Gmbh Verfahren und metallurgisches Gefäß zur Direkt-Reduktion von Erzen

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE201202C (fr) *
DE2235706A1 (de) * 1971-07-20 1973-02-01 Tno Verfahren zur herstellung einer metallschmelze und kupolofen zur durchfuehrung des verfahrens
DE2311467A1 (de) * 1973-03-08 1974-09-26 Vaw Ver Aluminium Werke Ag Verfahren und vorrichtung zur kontinuierlichen grafitierung von kunstkohlekoerpern
ES8507421A1 (es) * 1984-02-29 1985-09-01 Menendez Del Valle Fermin Procedimiento y dispositivo para la produccion carbotermica en continuo de carburo de silicio
DE3601014A1 (de) * 1986-01-16 1987-07-23 Vaw Ver Aluminium Werke Ag Verfahren und vorrichtung zur kontinuierlichen stranggrafitierung von kohlenstoff-formkoerpern
WO1996001033A1 (fr) * 1994-06-29 1996-01-11 Beckley John P Four electrique portable a levage vertical

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE201202C (fr) *
DE2235706A1 (de) * 1971-07-20 1973-02-01 Tno Verfahren zur herstellung einer metallschmelze und kupolofen zur durchfuehrung des verfahrens
DE2311467A1 (de) * 1973-03-08 1974-09-26 Vaw Ver Aluminium Werke Ag Verfahren und vorrichtung zur kontinuierlichen grafitierung von kunstkohlekoerpern
ES8507421A1 (es) * 1984-02-29 1985-09-01 Menendez Del Valle Fermin Procedimiento y dispositivo para la produccion carbotermica en continuo de carburo de silicio
DE3601014A1 (de) * 1986-01-16 1987-07-23 Vaw Ver Aluminium Werke Ag Verfahren und vorrichtung zur kontinuierlichen stranggrafitierung von kohlenstoff-formkoerpern
WO1996001033A1 (fr) * 1994-06-29 1996-01-11 Beckley John P Four electrique portable a levage vertical

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 198611, Derwent World Patents Index; AN 1986-070799, XP002514045 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114704958A (zh) * 2022-04-12 2022-07-05 西安慧金科技有限公司 煤气电加热装置
CN114704958B (zh) * 2022-04-12 2023-09-26 西安慧金科技有限公司 煤气电加热装置

Also Published As

Publication number Publication date
EP2255139B1 (fr) 2013-01-02
EP2255139A1 (fr) 2010-12-01
PL2255139T3 (pl) 2014-03-31
ES2409739T3 (es) 2013-06-27

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