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
  • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces
  • F27B3/08—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces heated electrically, with or without any other source of heat
  • F27B3/085—Arc furnaces
• • 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; Electric arc furnaces ; Tank furnaces
  • F27B3/10—Details, accessories or equipment, e.g. dust-collectors, specially adapted for 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
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/18—Door frames; Doors, lids or removable covers
  • F27D1/1858—Doors
• • 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
  • F27D1/18—Door frames; Doors, lids or removable covers
  • F27D1/1858—Doors
  • F27D2001/1875—Hanging doors and walls

Definitions

• Such an electric arc furnace is generally known.
• molten metal is charged into an electric arc furnace through the slag door.
• the slag door is located at an angle opposite the limited angular range.
• charging molten metal through the slag door is not possible. This is particularly true if the ladle containing the molten metal is delivered within the limited angular range, where the tap hole of the lower vessel is also located.
• the object of the present invention is to create possibilities by means of which a reliable and efficient operation of an electric arc furnace of the type mentioned above is possible even when the ladle containing the liquid metal is delivered in the limited angular range.
• the protective cover also adequately protects the horizontal cover. Therefore, the protective cover is not a channel through which the metal is intended to flow, but purely a protective covering.
• this channel is not a fixed element of the electric arc furnace within the scope of the present invention. Rather, the channel can, for example, be part of a transport device by means of which the ladle containing the liquid metal is transported. A cover for the channel and a funnel arranged upstream of the channel can also be components of the transport device.
• the limited opening angle is typically less than 90°. For example, it may be around 60° (+/- 10°).
• the horizontal cover is usually water-cooled on its upper surface.
• a hydraulic cylinder unit may be associated with the closure for opening and closing the opening.
• the upper vessel typically has a water cooling system on its inner side. Therefore, the protective cover preferably has a projection that extends beyond the water cooling system and into the furnace chamber. This ensures that the protective cover not only protects the horizontal cover but also the area of the upper vessel below the opening or the protective cover itself.
• the closure when closed, is flush with the inside of the upper vessel and also features a refractory reinforcement on its inner surface that becomes thicker towards the bottom. This protects the protective cover from the scrap during the initial loading of the container. This is especially true if the refractory reinforcement of the closure extends inwards beyond the protective cover.
• the closure has a cleaning edge on its underside for removing slag and/or metal residue from the top of the protective cover when the closure is closed. This prevents contamination of the protective cover as much as possible.
• the opening is positioned off-center with respect to the limited angular range. This particularly simplifies access to the tapping area of the lower vessel, which is usually also located in the bay window area.
• the protective cover is arranged in a retaining frame that is detachably attached to the upper vessel, in particular by being hooked onto the upper vessel.
• This allows the protective cover to be easily attached to and detached from the upper vessel, so that the protective cover can be serviced and possibly repaired independently of the operation of the electric arc furnace. In particular, this allows for the continuation of operation. of the electric arc furnace if, during this time, the removed protective cover is replaced by another protective cover.
• the protective cover is designed as a sheet metal tray with a fire-resistant lining on its upper surface. This design is simple, robust, reliable, and cost-effective.
• the protective cover is inclined towards the lower vessel so that any metal or slag striking the protective cover is directed into the lower vessel. This minimizes contamination of the protective cover.
• the angle of inclination relative to the horizontal is preferably at least 0.5° and at most 10°. Typically, the angle of inclination is between 2° and 5°.
• the closure is designed as a pivoting flap whose pivot axis runs horizontally and is located at the upper edge of the flap. This design has proven to be particularly advantageous in tests.
• the closure is made of copper. This facilitates cooling of the closure. Furthermore, the closure is preferably water-cooled. This allows for particularly good heat dissipation.
• the supply of liquid metal to the electric arc furnace is usually accomplished by means of a ladle carriage with a tilting ladle that can be moved to the arc furnace.
• a ladle carriage is also present in this invention.
• a pouring trough can be arranged on the ladle carriage, the end of which can be moved through the opening into the interior of the electric arc furnace as the ladle carriage is moved. This allows liquid metal in the ladle to flow from the ladle into the lower vessel via the pouring trough.
• the trough can, in particular, be heated.
• FIGS. 1 to 4 They show the same electric arc furnace and are therefore explained together below.
• the electric arc furnace has a lower vessel 1.
• the lower vessel 1 is mounted in a base 2 (usually referred to as a cradle).
• the lower vessel 1 has, see in particular FIG 4 - on its upper surface, a cross-section has a main region 3. Often, the main region 3 forms a vertical central axis 4.
• the electrodes 5 of the electric arc furnace are arranged exactly or at least approximately uniformly around the central axis 4.
• the upper surface of the lower vessel 1 also has a bay window 6 adjacent to the main region 3. The bay window 6 extends from the central axis 4 over a limited angular range ⁇ .
• the electric arc furnace further comprises a vertically projecting upper vessel 7, which extends upwards from the top of the lower vessel 1 and surrounds the main area 3.
• the upper vessel 7 typically has a water cooling system on its inner side, into which FIGS. 1 to 3 Recognizable by the indicated cooling water pipes.
• a furnace lid 8 of the electric arc furnace covers the furnace vessel 7 at its top.
• the electric arc furnace has a horizontal cover 9 (bay window panel) that covers the bay window area 6.
• an opening is arranged in the upper vessel 7 within the limited angular range ⁇ .
• the opening is closed by a closure 10.
• the closure 10 is preferably made of copper.
• the closure 10 is preferably water-cooled.
• the closure 10 closes in the closed state (see FIG 1 ) is usually flush with the inside of the upper vessel 7.
• the closure 10 is preferably designed as a pivotable flap, the pivot axis 10' of which runs horizontally and is arranged at the upper edge of the flap or closure 10.
• a protective cover 11 is arranged in the area of the closure 10.
• the protective cover 11 protects the horizontal cover 9 from splashes of metal and slag that occur when liquid metal is fed into the lower vessel 1 via the opening.
• the opening is preferably arranged off-center with respect to the limited angular range ⁇ . This is particularly advantageous because FIG 4 evident, because in FIG 4 The off-center protective cover 11 is recognizable, which in turn is located below the opening.
• the supply of liquid metal to the lower vessel 1 via the opening is carried out according to the following procedure: A ladle car 12 with a ladle 13 containing liquid metal 14 is moved to the electric arc furnace. A feed trough 15, usually called a launder, is also arranged on the ladle car 12. Before the end of the feed trough 15 reaches the lower vessel 1, the opening is opened (i.e., the closure 10 is moved accordingly) so that the end of the feed trough 15 can be moved through the opening into the interior of the electric arc furnace. The ladle 13 is then tilted so that the liquid metal 14 flows from the ladle 13, via the feed trough 15, into the lower vessel 1. The ladle car 12 is then moved away from the electric arc furnace so that the opening can be closed again. Before the liquid metal 14 is tilted into the feed trough 15, the feed trough 15 is preferably heated, for example, by means of gas burners.
• the protective cover 11 has a projection 11' that extends inwards beyond the water cooling (cooling water pipes) into the furnace chamber.
• the closure 10 In the closed position, the closure 10 is flush with the inner surface of the upper vessel 7.
• the closure 10 preferably has a refractory reinforcement 10" on its inner surface, which becomes thicker towards the bottom.
• the refractory reinforcement 10" can, in particular, extend inwards beyond the protective cover 11 – including its projection 11'.
• the protective cover 11 is preferably arranged in a retaining frame 16, which in turn is detachably attached to the upper vessel 7.
• the retaining frame 16 can, in particular, be hooked onto the upper vessel 7.
• the protective cover 11 is inclined towards the lower vessel 1.
• the angle of inclination ⁇ relative to the horizontal is usually at least 0.5°, in particular at least 1° or at least 2°. This ensures that any metal 14 or slag (not shown) striking the protective cover 11 is directed into the lower vessel 1.
• the protective cover 7 is designed according to FIG 6 usually designed as a sheet metal tub 17, which is provided on its upper side with a fireproof lining 18.
• the closure 10 in turn, shows according to FIG 6
• a cleaning edge 19 is provided on its underside. This makes it possible to remove slag and/or metal residues from the top of the protective cover 11 when closing the closure 10.
• the present invention has many advantages.
• One advantage lies in the arrangement of the opening. Because of the off-center arrangement of the opening, it is possible to ensure that the opening does not obscure an area of the bay window 6 located above a tap hole of the lower vessel 1, nor does it impede access to this area of the bay window 6.
• a further advantage is that the feed trough 15 is not a fixed component of the electric arc furnace and can therefore be maintained and preheated independently of the electric arc furnace.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Vertical, Hearth, Or Arc Furnaces (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=90924957

Family Applications (1)

Country Status (2)

Citations (3)

• 2024
  • 2024-04-30 EP EP24173369.0A patent/EP4644812A1/fr active Pending
• 2025
  • 2025-04-22 WO PCT/EP2025/060871 patent/WO2025228722A1/fr active Pending

Patent Citations (3)

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