Classifications

• • 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
  • F27D13/00—Apparatus for preheating charges; Arrangements for preheating charges
  • F27D13/002—Preheating scrap
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/52—Manufacture of steel in electric furnaces
  • C21C5/527—Charging of the electric furnace
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/56—Manufacture of steel by other methods
  • C21C5/562—Manufacture of steel by other methods starting from scrap
  • C21C5/565—Preheating of scrap
• • 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
  • F27B3/18—Arrangements of devices for charging
• • 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
  • F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
  • F27D17/001—Extraction of waste gases, collection of fumes and hoods used therefor
  • F27D17/003—Extraction of waste gases, collection of fumes and hoods used therefor of waste gases emanating from an electric arc furnace
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C2100/00—Exhaust gas
  • C21C2100/06—Energy from waste gas used in other processes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling

Definitions

• the invention relates to a scrap preheating device for a melting furnace according to the preamble of claim 1. Furthermore, the invention relates to a method for scrap preheating for a melting furnace, in particular using a Schrottenvor Suiteinraum invention.
• the prior art discloses various systems for utilizing the hot exhaust gases of a smelting furnace, in particular an arc furnace, for preheating scrap to produce a melt in the smelting furnace.
• systems which have a substantially vertically arranged shaft for feeding the scrap, which is arranged above the melting furnace, so that the exhaust gases or waste heat flow through the shaft during the ascent, thereby ensuring good utilization of the waste heat.
• the disadvantage here is the relatively large height of such a system consisting of the melting furnace and the Schrottvor Suiteinraum.
• scrap-preheating devices are known from the state of the art which, according to the so-called "Con Such a scrap preheating device known from DE 10 2008 037 1 1 1 A1 is characterized by a horizontally arranged conveyor belt or a horizontally arranged conveyor device for continuously feeding the scrap within a tube-like conveyor Between the input area for the scrap on the conveyor and the transfer area of the scrap from the conveyor into the melting furnace, a recess is formed in an upper wall of the scrap preheating housing, forming a suction area provided with a suction device for extracting
• the disadvantage here is that the cross section of the scrap preheating housing above the conveyor is not completely filled by the scrap, since this leads to a snagging or to a blocking of the scrap s in the scrap preheating, for example, in the targeted intake and thus could lead to a blocking of the conveyor, as is also known in the first-mentioned construction.
• the scrap fills only a partial cross-section of the scrap preheating housing, and the exhaust gases drawn by the exhaust are directed substantially between the top of the scrap and the scrap preheating housing for a portion of the distance between the input area and the transfer area.
• the efficiency of the system is relatively low, since the hot exhaust gases only come into operative connection with the upper portion of the scrap, while the conveying means facing portions of the scrap are at least substantially not preheated by the waste heat or hot exhaust gases.
• the Schrottvorutiliseinutter invention for a smelting furnace with the features of claim 1 has the advantage that it has the advantages of the two aforementioned designs (vertical feed chute or substantially horizontal, continuous delivery according to the "Con-Steel” method), without
• the scrap preheating device according to the invention has a particularly good utilization of the (hot) exhaust gases for scrap preheating which are produced in the melting furnace and thus a particularly high degree of efficiency To bring active compound with the scrap, that this is completely or homogeneously heated.
• the uniform heating takes place in that the cross section of the Schrottvor-40rmgeophuses can be completely filled with the scrap, since the scrap is not compressed during continuous conveying, in particular by an inclined arranged conveyor and thus not prone to snagging in the Schrotzvor-40rmgephaseuse and to block the conveyor.
• the scrap preheating device has a
• Extraction device with at least one suction on which is arranged on the side facing away from the transfer area of the input portion at a front end portion of Schrottvor-40rmgephaseuses and at least partially, preferably at least substantially acts on the cross section of Schrottvor-40rmgephaseuses and / or that the at least one suction in the area between the Input area and the transfer area, preferably in the input area, in the region of two opposite side walls of Schrottvor-40rmgephinuses is arranged, wherein the suction in the region of the side walls at least partially, preferably substantially, extend over the entire height of the Schrottvor-40rmgephaseuses.
• the Schrottvor duplex invention is characterized - in contrast to the generic state of the art - in that the hot exhaust gases are passed not only over the upper part of the conveyed in the Schrottvor-40rmgephaseuse scrap, but preferably over the entire cross-sectional area of the scrap, or in addition or alternatively over the entire height of the scrap through the laterally arranged in the region of the Schrottvor-40rmgephaseuses suction.
• the arrangement according to the invention or of the suction regions moreover makes it possible for the cross-section of the scrap preheating housing to be complete or as far as plant technology can be filled with scrap, without this adversely affecting the functionality of the Schrotter stiirmung or scrap promotion.
• the scrap is heated on its entire conveyor line on the conveyor, so that maximum exposure times of the exhaust gases result on the scrap.
• a preferred structural embodiment of the conveyor provides that the conveyor has a bottom with in the conveying direction of the scrap relative to each other movably arranged fin elements.
• Such a conveyor is particularly characterized in that the scrap is pulled (only) in the region of the bottom of the conveyor in the direction of the furnace by frictional effects, so in particular blocking or entanglement of the scrap in the ceiling area and the side walls of Schrottvor-40rmgephinuses is prevented and it at no time does the promotion lead to a reduction in the volume of cubes and thus to a compression of the scrap metal.
• the filling of the complete cross section of the scrap preheating housing with the scrap is made possible or favored.
• the tendency for the scrap to get caught on the walls of the scrap preheating housing is reduced as the cross-sectional area of the scrap preheating housing increases between the scrap receiving area and the scrap transfer area into the furnace.
• the feeding of the scrap in the direction of the melting furnace as well as the complete filling of the cross section of the Schrottvor-40rmgephases above the conveyor for optimum utilization of the hot exhaust gases can be improved if the bottom of the conveyor with respect to the horizontal at an oblique angle, preferably at an angle of at least 5 °, preferably at an angle between 5 ° and 15 °, is arranged so that the promotion of the scrap is supported by gravity effects.
• the conveyor is arranged along with the conveyor surrounding parts in addition longitudinally displaceable, in particular by an arrangement of the conveyor and the scrap preheating housing on roller elements. This makes it possible to arrange the conveyor at an increased distance to the furnace, so that when tilting the furnace this is not prevented by the conveyor or the Schrottvorskyrmgephinuse to the required tilting.
• Another aspect of the scrap preheating device according to the invention relates to the input area in which the scrap is fed to the conveyor or into the area of the scrap preheating housing.
• the input area is configured as a lock, such that access of ambient air in the direction of the scrap preheating housing can be blocked by at least one blocking element.
• a constructive design increases the efficiency of the scrap preheating device in that no undesirable outside air, which is cool with respect to the sucked-in hot exhaust gases, reaches the region of the conveying device or the scrap preheating housing and mixes there with the hot exhaust gases, thereby reducing their temperature.
• the lock-like design of the input area can be done by a plurality of relatively movable plates or doors, or for example, by a screw conveyor for the scrap, which is formed sealed at its outer periphery relative to the environment.
• an area of the conveying device below the lamellar elements is sealed off from the entry of ambient air by a housing which is sealed relative to the surroundings.
• the scrap preheating housing has a gas-permeable rear wall (for example in the form of a perforated plate or the like) on the side of the scrap preheating housing facing away from the transfer region of the scrap, which is arranged in register with the suction region of the suction device.
• An additional improvement of the promotion of the scrap in the direction of the melting furnace can be realized if in the region of the input area of the scrap conveyor independently of the conveyor independently operable conveying means for the scrap, in particular in the form of a slide is provided.
• This slider can also be formed in particular by the mentioned rear wall or the perforated plate.
• the transfer area of the conveyor or of the scrap preheating housing is designed to be closable in the direction of the melting furnace by means of a blocking element, the conveyor or the Schrottvor-40rmgephaseuse seal in the direction of the furnace.
• the suction device In order to thermally post-treat the exhaust gases sucked from the smelting furnace via the suction device, possibly contaminated by the scrap, or to treat them so that they can subsequently be released to the surrounding atmosphere, it is provided that the exhaust gases sucked in by the scrap by means of the suction device the suction device can be fed after passing through the scrap a Nachverbrennungs worn.
• the post-combustion device is connected via a manifold to an upper region of the melting furnace, and that the mixing ratio of the exhaust gases entering from the manifold of the melting furnace and additionally via the suction device into the afterburner and their temperature in the post-combustion device by means of flow-guiding, in particular in the form of adjustable flaps, is adjustable.
• the invention also relates to a method for scrap preheating for a smelting furnace, in particular using a scrap preheating device according to the invention as described above, in which the scrap is fed into an input area of an at least substantially horizontally conveying conveyor, wherein the conveying device scavengs the scrap using melt furnace heated hot exhaust gases along the conveying path between the input area and a transfer area in the furnace.
• the inventive method is characterized in that the exhaust gases sucked on at least over a portion of the perpendicular to the conveying direction of the scrap in the conveyor extending cross section of a Schrottvor-40rmgephaseuses on the side facing away from the transfer area of the input area be and / or that the exhaust gases are sucked in the region of two opposite side walls of a conveyor Vorierrmgephinuses surrounding Schrottvorskyrmgephaseuses.
• Very particular preference is given to a process described so far, in which the complete cross-section of the scrap preheating housing is at least substantially completely filled with scrap and a continuous delivery of the scrap takes place.
• a further preferred method feature is that at the filling end of the melting furnace, the scrap is conveyed back by a reversal of the conveying direction, in order to remove any scrap in the transition region to the furnace from this area and to facilitate closure of the Schrottvor-40rmgephinuses and the melting furnace by appropriate closure elements.
• the inventive method for scrap preheating using the Schrottvor Anlageninraum is characterized in that the scrap during its continuous promotion is not prone to compression and thus not to catch.
• 1 is a simplified longitudinal section through a system for
• FIG. 1 shows a cross section in the region of a conveying device of the scrap preheating device according to FIG. 1 and FIG
• Fig. 3 is a plan view in the direction of arrow III of FIG. 2 on the
• FIG. 1 shows a system 100 for producing a molten metal 1 in a melting furnace 50 in a greatly simplified manner.
• the melting furnace 50 is formed in a manner known per se with an inner space 51 and about an axis of rotation 52 which extends in the illustration of FIG. 1 perpendicular to the plane of the drawing of FIG. 1, arranged pivoting or tilting to those in the interior 51st melt 1 produced by the melting furnace 50 by tilting out of the melting furnace 50 in the region of an outlet, not shown, of the melting furnace 50 then continue to process.
• two of the three electrodes 55 connected to a voltage source (not shown) can be seen to generate the energy needed to liquefy the metal.
• the smelting furnace 50 further has a dome-shaped upper portion 58, which is connected via a manifold 59 to an afterburner chamber 60.
• the melt 1 is produced by adding scrap 5, which is melted by means of the electrodes 55, wherein the scrap 5 can be fed to the melting furnace 50 by means of a scrap preheating device 10 according to the invention.
• the Schrottvor Creekinutter 10 has, according to a synopsis of FIGS. 1 to 3, a tubular Schrottvorierrmgephase 4, the exemplary a rectangular Cross-section has and covered at least substantially horizontally arranged conveyor 15 at the top. As can be seen particularly clearly with reference to FIG.
• the Schrottvorierrmgepatuse 12 is substantially rectilinear, also purely by way of example or in the illustrated embodiment, the height h of Schrottvor-40rmgeophuses 12 and thus (constant width of Schrottvor-40rmgeophuses 12 assumed) and the cross-sectional area of the Schrottvor-40rmgeophuses 12 between an input portion 17 for the scrap 5 in the scrap preheating 12 in the direction of a transfer area 19 for the scrap 5 in the furnace 50 increases.
• the cross section of the scrap preheating housing 12 or the conveying device 15 can be closed or released by means of a closing slide 22 designed to be movable in the direction of the double arrow 21.
• the melting furnace 50 in the region of the transfer region 19 has an opening 23 which can be closed by means of an element (not shown) in order to transfer the scrap 5 into the melting furnace 50 and allow the melting furnace 50 to be sealed in this region when the opening 23 is closed
• 1 and 2 is also apparent that the conveyor 15 is slidably disposed together with the Schrottvor ⁇ rmgephaseuse 12 on roller elements 25 in the direction of the double arrow 26 to after completion of the filling of the furnace 50 with the scrap 5, the conveyor 15 and to arrange the Schrottvorskyrmgephase search 12 at a greater distance from the furnace 50 so that it can be tilted to remove the melt 1 about the axis of rotation 52.
• the input region 17 of the scrap 5 into the scrap preheating device 10 is arranged on the front side end region 30 of the scrap preheating casing 12 on its upper side 31 on the transfer region 19 and has a vertically upwardly projecting feed chute 32, which by means of two, one above the other and parallel to one another arranged, each in the direction of the double arrow 34 independently movable, serving as a lock or blocking elements transverse slides 36, 38 can be closed.
• a suction region 42 is arranged, the example by an air-permeable element, such as a Perforated plate 44, is arranged in operative connection with the cross section of the Schrottvorskyrmgephinuses 12.
• the arrangement of the suction region 42 is such that it is arranged at least partially, preferably predominantly, completely in coincidence with the scrap 5 conveyed within the scrap preheating housing 12 on the conveyor 15 or onto the cross section of the scrap 5 in one acts perpendicular to the at least substantially horizontal conveying direction 70 of the scrap 5 within the Schrottvorskyrmgekoruses 12.
• the perforated plate 44 or the suction region 42 extends from the height of the bottom region or the conveying plane of the conveyor 15, and extends to the region from which the feed chute 32 extends from the scrap preheating 12 upwards.
• the intake region 42 therefore has a height in the end region 30 which corresponds to the height h of the scrap preheating housing 12 in the end region 30.
• the intake region 42 is connected to a suction device 48 via an intake manifold 46.
• an adjustable flap 49 is disposed in the intake manifold 46 for adjusting the amount of hot exhaust gases sucked from the inner space 51 of the melting furnace 50 over the cross section of the scrap preheating housing 12 by the exhaust device 48.
• From the suction device 48 also pass the extracted exhaust gases via a Zuzhoukrümmer 62 and a supply line into the afterburner chamber 60, wherein in the manifold 59 by way of example an adjustable flap 64 is arranged so that the mixing ratio between the directly from the furnace 50 via the manifold 59 in the exhaust gas entering the region of the after-combustion chamber 60 and the exhaust gas entering the region of the after-combustion chamber 60 via the suction device 48 and the supply manifold 62 can be adjusted.
• thermocontrol means via a fresh air intake 66 with adjustable flap 68 in the region of the feed manifold 62 outside air for temperature control in the post-combustion chamber 60 by means not shown heating means to a temperature between 700 ° C to 800 ° C heated exhaust gases can be fed.
• the arranged next to the post-combustion chamber 60 conveyor 15 has, as can be seen in particular from the synopsis of Figs. 2 and 3, a plurality of parallel to each other and arranged in the longitudinal direction or in the conveying direction 70 of the scrap 5 lamellar elements 72 made of wear-resistant steel to form a bottom 73 on.
• twelve lamellar elements 72 are shown.
• the lamellar elements 72 form a sliding floor and extend over the entire length of the conveyor 15, wherein the lamellar elements 72 each have, for example, an equal width b of, for example, between 10 cm and 30 cm. In each case several of the lamellar elements 72 are simultaneously synchronously movable by means not shown drives.
• the conveying principle of the scrap 5 by means of the lamellar elements 72 is explained as follows: For example, it is assumed that twelve lamellar elements 72 are arranged next to one another. First, the first, fourth, seventh and tenth fin element 72 are retracted by a distance of, for example, 30 cm counter to the conveying direction 70. Then, the second, fifth, eighth and eleventh fin members 72 are also retracted by the same distance (30 cm). Subsequently, the third, sixth, ninth and twelfth fin members 72 are also retracted by the distance (30cm). Now, the conveying process of the scrap 5 by all twelve lamellar elements 72 are advanced simultaneously by the same distance (30cm) in the direction of conveyance 70.
• an angle ⁇ should still be encompassed by an at least substantially horizontal arrangement of the conveyor 15. This in particular in contrast or compared to conveyors in which this is at least substantially perpendicular or the scrap 5 is promoted by gravity of the scrap 5.
• the lamellar elements 12 below the scrap preheating housing 12 are surrounded by a housing 74, which may be part of the scrap preheating housing, on the one hand, the escape of hot exhaust gases from the scrap preheating housing 12 via the lamella elements 72 to the outer Environment to avoid, and on the other hand, the access of air from the outside environment via the lamellar elements 72 in the region of the Schrottvorskyrmgephinuses 12 also to avoid.
• the lamination elements 72 made of heat-resistant steel are each connected on the underside facing away from the scrap preheating housing 12 to cooling devices 76 which, for example in FIG. 2, have cooling channels through which cooling water can not flow.
• a movably arranged slide 78 can furthermore be provided, which conveys the scrap 5 in the direction of the melting furnace 50.
• the perforated plate 44 may be formed as a slide.
• the scrap preheating housing 12 is in the region of its two opposite side walls 80, 82 may also be arranged in operative connection with the suction device 48 via correspondingly configured suction regions 84.
• the side walls 80, 82 are permeable to air, for example with perforated plates. It is essential that the intake regions 84 are at least substantially also arranged over the entire height h of the scrap preheating housing 12 or the height of the scrap 5 conveyed in the scrap preheating housing 12, wherein the suction regions 84 are preferably likewise in the region of the input region 17 for the scrap 5 are disposed in the scrap preheating housing 12.
• the plant 100 or the scrap preheating device 10 described so far can be modified or modified in many ways without deviating from the idea of the invention.
• a further conveyor 90 is arranged, as shown in FIG. 2 is optionally shown.
• the further conveyor 90 is preferably arranged in the upper region of the Schrottvorskymaschinermgephinuses 12 and may be formed either in accordance with the conveyor 15 with fin elements 72 or in the manner of a conveyor belt, slide or o. ⁇ .
• Essential in the operation of the further conveyor 90 is that it promotes the coming of the feed chute 32 scrap 5 against the conveying direction 70 of the conveyor 15, preferably continuously.
• the further conveyor 90 causes by returning the scrap 5 in the upper region of the Schrottvorskyrmgeophuses 12 while conveying the scrap 5 by the conveyor 15 in the lower portion of the Schrottvorskyrmgeophuses 12 that jamming and compacting of the scrap 5 in the transition region from the feed chute 32 in the Schrottvorskyrmgepatuse12 reliable is avoided.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Environmental & Geological Engineering (AREA)
• Furnace Details (AREA)

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• 2017
  • 2017-10-17 DE DE102017124108.6A patent/DE102017124108A1/de active Pending
• 2018
  • 2018-09-19 CN CN201880066331.1A patent/CN111201332B/zh active Active
  • 2018-09-19 WO PCT/EP2018/075285 patent/WO2019076567A1/de active Search and Examination
  • 2018-09-19 EP EP18785512.7A patent/EP3697935A1/de active Pending

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