EP0259510B1 - Hélice transporteuse pour fours métallurgiques en particulier fours à sole tournante - Google Patents

Hélice transporteuse pour fours métallurgiques en particulier fours à sole tournante Download PDF

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Publication number
EP0259510B1
EP0259510B1 EP86112533A EP86112533A EP0259510B1 EP 0259510 B1 EP0259510 B1 EP 0259510B1 EP 86112533 A EP86112533 A EP 86112533A EP 86112533 A EP86112533 A EP 86112533A EP 0259510 B1 EP0259510 B1 EP 0259510B1
Authority
EP
European Patent Office
Prior art keywords
coolant
hollow shaft
screw conveyor
chambers
furnaces
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP86112533A
Other languages
German (de)
English (en)
Other versions
EP0259510A1 (fr
Inventor
John K. Pargeter
John A. Macdougall
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.)
Vodafone GmbH
Original Assignee
Mannesmann AG
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
Application filed by Mannesmann AG filed Critical Mannesmann AG
Priority to DE8686112533T priority Critical patent/DE3677223D1/de
Priority to AT86112533T priority patent/ATE60432T1/de
Publication of EP0259510A1 publication Critical patent/EP0259510A1/fr
Application granted granted Critical
Publication of EP0259510B1 publication Critical patent/EP0259510B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/16—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a circular or arcuate path
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/10—Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
    • C21B13/105—Rotary hearth-type 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
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
    • F27B9/38—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
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/08—Screw feeders; Screw dischargers

Definitions

  • the invention relates to a screw conveyor for metallurgical furnaces, in particular for hearth furnaces, consisting of a central shaft which can be driven in rotation and a helix or conveying elements connected thereto, coolant being able to be conducted through a bore in the central shaft and the central shaft being connected to a rotatable coolant supply and a rotatable coolant discharge is.
  • the direct reduction of iron oxide and other metal oxides can be done in a hearth furnace, particularly in a rotary hearth furnace, using pelletized or briquetted feed that is placed on the stove.
  • Such a rotary hearth furnace is a continuous reheating furnace which is generally provided with a cylindrical inner wall which is arranged at a certain distance from a cylindrical outer wall. The space in between contains the actual rotary hearth. In order to retain the heat generated inside the oven, the walls are relatively low so that the lid can be close to the stove. Burners can be arranged in the inner and outer walls as well as in the lid.
  • the material to be reduced is usually fed or dropped onto the rotary hearth with a conveyor belt or a barn. After the material has been transported on the stove, it is removed with a screw conveyor. Because of the associated high temperatures (704 to 1260 degrees C), the feed screw is cooled with water. Such a screw conveyor is known from US Pat. No. 3,433,931. The gases are drawn off through a smoke duct arranged in the cover.
  • a conventional screw conveyor consists of a central shaft with a solid spiral welded onto it. A coolant is passed through a bore in the central shaft. In other known worm designs, a plurality of spirals spaced apart around the shaft are used.
  • the screw conveyor Because of the corroding effect of the gases and materials in the rotary hearth furnace and the high temperatures in the furnace, the screw conveyor often fails. The coils wear out overall. Corrosion and erosion, caused by high temperatures and interfering elements (sodium, sulfides, lead crystal, zinc, tin, iron, nickel and chromium) inside the furnace, eat up the screw conveyor and make it unusable after only three months. Expensive materials such as high-alloy steels (20% nickel, 20% chromium, rest iron) did not lead to a better result.
  • plumy fine material collects in the spaces between the spirals, which tends to cake. This fine material acts like a sponge, which absorbs and concentrates the corrosive gases present in the furnace.
  • a material processing device in which a bead element is attached to an axle tube, in which parts are spaced apart in the longitudinal direction, the resulting gaps being bridged by helical conveyor elements.
  • These conveying elements are in fluid communication with the interior of the axle tube. A parallel coolant flow thus flows through the axle tube and the conveyor elements of the screw conveyor.
  • the present invention is based on the object of proposing an improved screw conveyor which can better withstand the harsh operating conditions of an oven.
  • the central shaft is formed at its ends from a tube section, that between the ends there is a hollow shaft which surrounds the tube sections by means of caps, that chambers are subsequently formed on the caps, the coolant channels being one the pipe sections are connected via openings to one of the chambers, that are connected to the hollow shaft by means of which coolant flows through helices or conveying elements, the coolant channels of which are arranged with the chamber via slots in that an inner tube is arranged concentrically with the hollow shaft in the interior of the chamber between the chambers one of the chambers faces open and that in the area of the opposite end there are openings for the flow of coolant through a chamber, the hollow shaft are connected.
  • This not only cools the central shaft and the hollow shaft, but also the helix or conveying elements, which results in a significant improvement in durability.
  • the coolant flows through the screw in two stages, once through the coils and then in countercurrent through the hollow well before it is diverted to the outlet.
  • the screw conveyor according to the invention can also be produced very economically by at least the hollow shaft being made from mild steel.
  • the helixes or the conveying elements are provided with a support made of corrosion and erosion-resistant material. Such material wears extremely little with appropriate internal cooling.
  • the corrosion and erosion resistant material consists of hard metal.
  • FIG. 1 shows a greatly simplified illustration of a rotary hearth furnace 10.
  • the rotary hearth furnace 10 consists of an insulated outer wall 12 and an insulated inner wall 14.
  • a rotary hearth 16 rotates within the derhherd furnace 10 in the direction indicated by arrow 18.
  • a plurality of burners 20 are arranged distributed in the rotary hearth furnace 10.
  • Curtains 22 divide the rotary hearth furnace 10 into clearly separated sections. Material is placed on the stove with a loading device mounted in the lid (which is not shown) of the rotary hearth furnace 10.
  • the material is removed by the screw conveyor 26 and conveyed into a bunker (not shown) for later processing.
  • the conveyor screw 26 is driven by a motor and a mechanical linkage 28. Water is supplied to the screw conveyor 26 as a coolant through the coupling 30.
  • the screw conveyor 26 includes a hollow shaft 32 which is attached to two pipe sections 62, each of which has a bore 34 for the coolant flow (water).
  • a plurality of hollow auger coils 36 surround the hollow shaft 32. The use of six or seven coils 36 is preferred because more coils would tend to cause particles to stick between the coils 36.
  • the coils 36 are shown as right-handed helical lines.
  • the screw conveyor 26 rotates in the direction 38.
  • the coolant water is conducted into the screw conveyor at the water coupling end and exits at the drive end 42.
  • the coils 36 are hollow so that the coolant (water) can flow through them. Slots 46 in two sections of the hollow shaft 32 (see FIG. 4) allow the coolant to flow out of the bore 34 into the coil 36 and vice versa.
  • a corrosion-resistant pad 44 can be attached to the front edge of the helix 36.
  • hard metal was used as support 44, which, however, showed cracks after a certain time in some cases. The cracks then spread into the coil 36 and caused small coolant leaks. Although experience with certain carbide grades has sometimes caused problems, these are preferred for use as pad 44.
  • Fig. 4 shows a detail of the screw conveyor 26.
  • the ends 40 and 42 are attached to suitable fasteners (not shown) to ensure watertightness of the entire system and to allow the screw conveyor 26 to rotate.
  • the coolant flow is indicated by arrows 48.
  • the caps 74 and 76 prevent coolant from escaping from the screw conveyor 26.
  • the hollow shaft 32 causes the coolant to flow in a serpentine or countercurrent flow before exiting the screw.
  • the water flow (arrow 48) first flows from the (water coupling) end 40 through the pipe section 62 and then enters a chamber 50.
  • the chamber 50 has openings 52 which cause the coolant to flow into a second chamber 54 and then through the slide 46 into the coils 36.
  • only one slot 46 is shown at the (water coupling) end (or near end) 40, it goes without saying that the number of slots 46 is exactly the same as the number of coils 36.
  • the coolant flows through the coils 36 along their entire length to the distal end 42, where it re-enters the hollow shaft 32 through the slot 46 and a chamber 72.
  • the coolant then continues to flow through the opening 68 formed in a partition 66 into an annular space 56 between the hollow shaft 32 and an inner tube 58. Spacers 64 maintain the distance between the hollow shaft 32 and the inner tube 58.
  • the coolant flows in the opposite direction to the partition wall 60, where it is redirected again and forced to flow in the inner tube 58.
  • the coolant now flowing through the inner tube 58 flows through the opening in the partition 66 towards the learned end 42 and then out of the screw conveyor 26.
  • the coolant flowing through the coils 36 cools these parts and reduces their possible damage.
  • the coolant flowing back through the space 56 cools the area of the hollow shaft 32 between the coils 36. This area often encrusts with hot material, which, if not cooled, accelerates the destruction of the screw conveyor 26.
  • the coolant flowing through the inner tube 58 and the opening 52 keeps these parts relatively cool.
  • the screw conveyor lasted about two to three times longer than a conventional water-cooled screw conveyor. Such screw conveyors lasted only two to three months, while the screw conveyor according to the invention had a service life of four to nine months.
  • the pitch, pitch angle, length and number of coils 36 are of course dependent on the size of the hearth furnace, the surroundings and the material to be processed in the hearth furnace. Under special conditions, the temperature in the rotary hearth furnace was approximately 982 degrees C and the coils were approximately 4.9 m long. Hollow shaft 32 was about 0.45 m in diameter and the entire hollow shaft was 5.2 m long. The pitch angle 68 was about 35 degrees 15 ⁇ , and the pitch 70 about 33.8 cm (see FIG. 2). Because of the cooling for the screw conveyor 26, the coolant entered the screw conveyor 26 at a temperature of approximately 32.2 degrees C. and exited at approximately 49 degrees C. at a flow rate of approximately 1136 l / min. and about 69 to 103 kpa.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Charging Or Discharging (AREA)
  • Screw Conveyors (AREA)
  • Tunnel Furnaces (AREA)

Claims (4)

1. Vis sans fin pour fours métallurgiques, en particulier pour fours à sole, constituée d'un arbre central pouvant être entraîné en rotation et d'une hélice ou d'éléments de transport liés à celui-ci, un milieu de refroidissement pouvant être amené par un perçage dans l'arbre central et l'arbre central étant raccordé à une alimentation de milieu de refroidissement étanche en rotation et à une évacuation du milieu de refroidissement étanche en rotation, caractérisée en ce que l'arbre central, à ses extrémités (40, 42), est formé, à chaque fois, à partir d'un tronçon de tube (62), en ce que, entre les extrémités (40, 42), est agencé un arbre creux (32) entourant les tronçons de tube (62), à chaque fois, par des capuchons (74, 76), en ce que des chambres (50, 72) sont formées en étant raccordées aux capuchons (74, 76), les canaux de milieu de refroidissement d'un des tronçons de tube (62) étant reliés à une des chambres (50) par des orifices (52), et en ce que l'hélice (36) ou les éléments de transport traversés par le milieu de refroidissement sont raccordés à l'arbre creux (32), les canaux de milieu de refroidissement étant reliés à la chambre (50) par des fentes (46), en ce que, concentrique­ment à l'arbre creux (32), dans son espace interne entre les chambres (50, 72), est agencé un tube interne (58), qui est ouvert du côté d'une des chambres (50, 72), et en ce que, dans la zone de l'extrémité opposée, des orifices (68) sont prévus pour le passage du milieu de refroidissement d'une chambre (72) dans l'arbre creux (32).
2. Vis sans fin selon la revendication 1, caractérisée en ce qu'au moins l'arbre creux (32) est réalisé en acier doux.
3. Vis sans fin selon les revendications 1 ou 2, caractérisée en ce que les hélices (36) ou les éléments de transport sont munis d'un revêtement (44) en matière résistant à l'érosion et à la corrosion.
4. Vis sans fin selon la revendication 3, caractérisée en ce que la matière résistant à l'érosion et à la corrosion est du métal dur.
EP86112533A 1985-04-03 1986-09-10 Hélice transporteuse pour fours métallurgiques en particulier fours à sole tournante Expired - Lifetime EP0259510B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE8686112533T DE3677223D1 (de) 1986-09-10 1986-09-10 Foerderschnecke fuer metallurgische oefen, insbesondere fuer herdoefen.
AT86112533T ATE60432T1 (de) 1986-09-10 1986-09-10 Foerderschnecke fuer metallurgische oefen, insbesondere fuer herdoefen.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US06/719,310 US4636127A (en) 1985-04-03 1985-04-03 Conveying screw for furnace

Publications (2)

Publication Number Publication Date
EP0259510A1 EP0259510A1 (fr) 1988-03-16
EP0259510B1 true EP0259510B1 (fr) 1991-01-23

Family

ID=24889569

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86112533A Expired - Lifetime EP0259510B1 (fr) 1985-04-03 1986-09-10 Hélice transporteuse pour fours métallurgiques en particulier fours à sole tournante

Country Status (5)

Country Link
US (1) US4636127A (fr)
EP (1) EP0259510B1 (fr)
BR (1) BR8601447A (fr)
DE (1) DE3610490A1 (fr)
IN (1) IN165587B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19529925A1 (de) * 1995-08-01 1997-02-06 Mannesmann Ag Verfahren und Vorrichtung zur Eingabe von Schüttgut in einen Drehherdofen
US8518146B2 (en) 2009-06-29 2013-08-27 Gb Group Holdings Limited Metal reduction processes, metallurgical processes and products and apparatus

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US5885521A (en) * 1994-12-16 1999-03-23 Midrex International B.V. Rotterdam, Zurich Branch Apparatus for rapid reduction of iron oxide in a rotary hearth furnace
US5730775A (en) * 1994-12-16 1998-03-24 Midrex International B.V. Rotterdam, Zurich Branch Method for rapid reduction of iron oxide in a rotary hearth furnace
DE19543074C2 (de) * 1995-11-13 1999-07-15 Mannesmann Ag Direktreduktionsverfahren und Einrichtung zur Durchführung des Verfahrens
US5972066A (en) * 1997-04-22 1999-10-26 Iron Dynamics, Inc. Mixed bed iron reduction process
US5863197A (en) * 1997-04-25 1999-01-26 The International Metals Reclamation Company, Inc. Solid flight conveying screw for furnace
US5924861A (en) * 1997-08-28 1999-07-20 Maumee Research & Engineering, Incorporated Furnace discharge assembly
US6152729A (en) * 1997-08-28 2000-11-28 Maumee Research & Engineering, Inc. Spray cooled furnace discharge assembly
US6120577A (en) * 1998-03-25 2000-09-19 Ltv Steel Company, Inc. Treatment of steel mill waste metal oxides
JP3404309B2 (ja) 1999-01-18 2003-05-06 株式会社神戸製鋼所 還元鉄塊成物の製造方法および製造装置
US6390810B1 (en) 1999-03-15 2002-05-21 Maumee Research & Engineering, Inc. Method and apparatus for reducing a feed material in a rotary hearth furnace
CN1306045C (zh) 1999-08-30 2007-03-21 株式会社神户制钢所 粒状还原铁原料的供给方法及其装置
JP4287572B2 (ja) 2000-04-26 2009-07-01 株式会社神戸製鋼所 回転式炉床炉
JP3866492B2 (ja) 2000-06-29 2007-01-10 株式会社神戸製鋼所 回転炉床式還元炉の操業方法
US6814924B2 (en) * 2001-10-22 2004-11-09 Kobe Steel, Ltd. Rotary hearth furnace and screw thereof for discharging reduced iron
US7655181B2 (en) * 2006-04-06 2010-02-02 Nippon Steel Engineering Co., Ltd. Screw conveyor of rotary hearth furnace for discharging reduced iron
US9032871B1 (en) 2009-07-29 2015-05-19 Larry E. Koenig System and method for adjusting and cooling a densifier
US8851409B2 (en) 2010-12-09 2014-10-07 Mark E. Koenig System for crushing
CA2728377C (fr) 2010-12-09 2014-12-02 Komar Industries, Inc. Procede et systeme de broyage
US9403336B2 (en) 2010-12-09 2016-08-02 Mark E. Koenig System and method for crushing and compaction
US9586770B2 (en) 2011-08-05 2017-03-07 Mark E. Koenig Material waste sorting system and method
US9132968B2 (en) * 2011-11-04 2015-09-15 Mark E. Koenig Cantilevered screw assembly
US9346624B2 (en) 2011-11-04 2016-05-24 Mark E. Koenig Cantilevered screw assembly
CN104713371B (zh) * 2015-03-13 2016-05-11 南京航空航天大学 烧结环冷机矿料摊平装置及方法
JP6601046B2 (ja) * 2015-08-05 2019-11-06 日本製鉄株式会社 高炉内の原料排出用スクリューコンベア
CN105333737B (zh) * 2015-10-22 2017-07-21 桐乡市耀润电子有限公司 铁氧体球形颗粒原料进入预烧窑的落料设备
CN105300107B (zh) * 2015-10-22 2017-07-21 桐乡市耀润电子有限公司 用于铁氧体球形颗粒原料进入预烧窑的落料装置
CN105300108B (zh) * 2015-10-22 2017-07-21 桐乡市耀润电子有限公司 用于铁氧体球形颗粒原料进入预烧窑的落料设备
US9821962B2 (en) 2015-12-14 2017-11-21 Mark E. Koenig Cantilevered screw assembly
US10434483B2 (en) * 2017-02-15 2019-10-08 Wenger Manufacturing Inc. High thermal transfer hollow core extrusion screw assembly
CN107572199A (zh) * 2017-10-26 2018-01-12 江苏清溢环保设备有限公司 一种新型螺旋式进料装置
US11358895B2 (en) * 2018-11-15 2022-06-14 Owens-Brockway Glass Container Inc. Batch charger for a melting chamber

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19529925A1 (de) * 1995-08-01 1997-02-06 Mannesmann Ag Verfahren und Vorrichtung zur Eingabe von Schüttgut in einen Drehherdofen
US8518146B2 (en) 2009-06-29 2013-08-27 Gb Group Holdings Limited Metal reduction processes, metallurgical processes and products and apparatus

Also Published As

Publication number Publication date
US4636127A (en) 1987-01-13
DE3610490A1 (de) 1986-10-16
BR8601447A (pt) 1986-12-09
IN165587B (fr) 1989-11-25
DE3610490C2 (fr) 1988-03-31
EP0259510A1 (fr) 1988-03-16

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