US3900117A - Feeding ring for feeding ore into furnaces - Google Patents

Feeding ring for feeding ore into furnaces Download PDF

Info

Publication number
US3900117A
US3900117A US443977A US44397774A US3900117A US 3900117 A US3900117 A US 3900117A US 443977 A US443977 A US 443977A US 44397774 A US44397774 A US 44397774A US 3900117 A US3900117 A US 3900117A
Authority
US
United States
Prior art keywords
shelf
feeding
stationary
scraper
tight
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
US443977A
Other languages
English (en)
Inventor
Frans Heikki Tuovinen
Seppo Ilmari Blomquist
Risto Markus Heikkila
Jorma Bruno Honkasalo
Kalevi Johan Kunttu
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.)
Outokumpu Oyj
Original Assignee
Outokumpu Oyj
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 Outokumpu Oyj filed Critical Outokumpu Oyj
Application granted granted Critical
Publication of US3900117A publication Critical patent/US3900117A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/0025—Charging or loading melting furnaces with material in the solid state
    • 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
    • F27B19/00—Combinations of furnaces of kinds not covered by a single preceding main group
    • F27B19/04—Combinations of furnaces of kinds not covered by a single preceding main group arranged for associated working
    • 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
    • F27B3/183—Charging of arc furnaces vertically through the roof, e.g. in three points
    • 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
    • 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
    • F27D3/18—Charging particulate material using a fluid carrier
    • 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
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • 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
    • F27B9/18—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 under the action of scrapers or pushers
    • 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
    • F27B9/20—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 substantially straight path tunnel furnace
    • F27B9/24—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 substantially straight path tunnel furnace being carried by a conveyor
    • F27B9/2469—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 substantially straight path tunnel furnace being carried by a conveyor the conveyor being constituted by rollable bodies
    • 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

  • ABSTRACT A feeding device for feeding materials into the batching silos of a light are furnace or similar, said device having a ring shaped shelf for receiving the material, a stationary ring shaped roof above the shelf provided with an opening for feeding the material onto the shelf, at least one stationary side wall constituting together with the roof and the shelf a circular space surrounding the material supported on the shelf, essentially gasand dust-tight seals between the shelf and the stationary parts related thereto and scrapers operable to be brought near the shelf surface to force the material carried thereon to fall down over the shelf edge into the receiving silos.
  • the present invention relates to a device for controlled feeding of materials into the batching silos of a light arc furnace or the like.
  • the material may e.g., be in the form of pellets of different size and composition fed into a melting furnace.
  • the specific weights of the various components of the feed mixture may vary within a rather extensive range (e.g., about 1-4 g/cm) as may the particle size (e.g., diameter about 3-25 mm), which tends to complicate feed control.
  • a feeding device which comprises a ring shaped horizontal material shelf supported rotatably about its vertical axis and positioned above batching silos, a ring shaped roof mounted stationary above a material shelf and provided with at least one opening for pouring the material onto the shelf, at least one stationary ring shaped wall joining the roof and closely related to the material shelf, substantially gas-tight and dust-tight tightening means between the material shelf and stationary parts related thereto, and at least two working scrapers supported movably adjacent the shelf to be brought periodically near the shelf surface thereby deflecting material on the shelf over the shelf edge down into the batching silos.
  • the feeding ring can be made gasand dust-tight and can be linked to the other process apparatuses in a gasand dust-tight manner.
  • the feeding rate of the feeding ring can be controlled within a wide range.
  • the feeding ring is suitable for feeding both hot and cold material.
  • the cooling of a heated feed in the feeding ring is less than 5 For example, compared with a telfer conveyor previously used, the operation and maintenance costs of the feeding ring are considerably less.
  • FIG. 3 shows a cross section, at point AA in FIG.
  • FIG. 4 shows a cross section, at point BB in FIG. 2, of a covered feeding ring
  • FIG. 5 shows a cross section, as in FIG. 3, of another embodiment of the invention.
  • FIG. 6 shows a cross section, as in FIG. 4, of the embodiment according to FIG. 5,
  • FIGS. 7 and 8 show one embodiment of the feeding ring scrapers as seen from the side and from above
  • FIGS. 9 and 10 show another embodiment of the feeding ring scrapers as seen from the side and from above, and
  • FIGS. 11 and 12 show different embodiments of the feeding ring supporting rollers.
  • the cylindrical furnace 2 discharges the heated feed into the feeding ring, from where it is fed further into the batching silos 4 of the light are furnace 3.
  • the material shelf 6 is a steel-structured, circular ring (FIGS. 2 and 3 One side of the shelf 6 'has been provided with a rim 7 which prevents the feed from flowing to the wrong side.
  • the material shelf 6 has been lined with fire-resistant lining 8 because of the hot feed 9.
  • the lining material is concave at the bottom of the feeding ring 5.
  • the so-called cold feed 10 remaining in the concavity protects the bottom lining of the material shelf from wear and tear and from an excessive heat load.
  • the feeding ring rotates continuously in one direction, but when so desired it may also be constructed to rotate in both directions or reciprocally.
  • the material shelf 6 can also be without the side rim 7, in which case the discharging of the feed can be carried out, when sodesired, from either side or from both sides, as shown in FIGS. 5 and 6. When a cold feed is used, no fire-resistant lining is necessary.
  • the bottom of the material shelf can also be straight.
  • the feeding ring has been enclosed in a' closed circular space consisting of a roof 11, a side part 12, a feeding ring material shelf 6, and a rim 7.
  • the spaces be tween the feeding ring and the roof 11 and the side part 12 are sealed by circulating cool water.
  • the water circulates in troughs l3 and 14 attached to the edge of the feeding ring and to the side part 12.
  • the sealing plates 15 and-l6 which have been directed downwards and attached gas-tightly to the inner edge of the roof and the lower edge of the material shelf are constantly partly immersed in the water in the troughs.
  • the water flows first into the upper trough 13, from where it flows as an overflow into the lower trough l4 and from there away as an overflow carrying with it part of the impurities from the troughs.
  • the sealing water can be replaced with other suitable harmless liquids or applicable pulverous materials.
  • the sealling can also be carried out with slide seals in which the seals consist of slide surfaces which are situated opposite each other or tangent to each other and are made from a suitable material.
  • Therole of the scrapers 17 shown in FIGS. 2, 4, and 6 is to remove the feed mixture from the feeding ring at the desired point and at the desired moment.
  • the scrapers 17 work in a vertical direction.
  • Their driving devices are hydraulic cylinders which raise and lower the scrapers 17 at the desired moment.
  • the driving devices of v the scrapers 17 are automatically or manually controlled.
  • the scraping of the feed mixture from 'the feeding ring takes place when the scraper is in the lower, or scraping, position.
  • a scraper consists of a fireand wear-resistant blade 18 which can be changed, a scraper body 19 with arms 20 and securing members 21, and a water-cooled scraper box 22 with its guide surfaces.
  • the box 22 of a scraper 17 also serves as a supporting and guiding structure of the scraper and scraper 17 is in the upper position, the water-cooled scraper box 22 rapidly conducts heat away from the scraper, thereby promoting the cooling of the scraper,
  • the scraper 17 consists of two parts. The parts are at an angle in relation to each other so that they form a plough and push the feed over both edges of the material shelf.
  • the scraper 17 can also be structurally and operationally a plate-like blade which pushes from the side, a jointed knife working from the side in a vertical direction, a propeller rotating about its horizontal axis and provided with one or more blades, or a platelike blade which turns around its vertical or horizontal axis.
  • the scraper 17 consists of a screw feeder 23 which can be moved in a vertical direction.
  • the scraper shown in FIGS. 9 and 10 is a propeller 24 which rotates about its vertical axis and is provided with one or more blades.
  • the material shelf 6 rests through rails 25 attached to its bottom on roller pairs 26 blades at regular intervals.
  • the roller pairs'26 can be changed even during the operation owing to their easy and simple securing manner.
  • the supporting roller system 26 can also be attached to the material shelf as shown in FIG. 11.
  • the supporting roller systems can also be replaced with rings of rollers or balls 27 (with one or several rows of them). One such embodiment is shown in FIG. 12.
  • the driving machinery of the feeding ring consists of a direct-current motor 28, a gear 29, and a spike wheel 30, which transmits the power from the driving machinery through a toothed wheel 31 to the feeding ring material shelf 6, thereby rotating the latter.
  • the rotating velocity of the driving machinery and thereby that of the material shelf can thus be controlled.
  • the driving device can also be, as in the embodiment according to FIG, 5, a hydraulic motor 32, coupled to the shaft 33 of the material shelf supporting wheel either directly or through gears.
  • the power to the material shelf 6 can be also transmitted by chain transmission or friction transmission.
  • the material shelf is kept on its 2 correct path by a number of supporting wheels 34 or centering members, spaced evenly at the inner circumference of the material shelf, provided with adjustable spring-loaded lever arms supported from the floor.
  • Spring loading can be replaced with torsion bar springs of rubber or with hydraulic or pneumatic cylinders.
  • the power transmission devices of the operating machines can serve as centering members, or the supporting wheels 26, supporting rollers 27, or the respective device of the material shelf 6 can be constructed so that they also serve as the centering device of the material shelf. If the situation allows, the material shelf can be attached with bearings at its center point of rotation, in which case separate centering members are not necessary.
  • a device for feeding and distributing a heated material, especially a charge of preheated ore concentrates into the batching silos of a light are furnace, which comprises a ring shaped horizontal material shelf supported rotatably about its vertical axis and positioned above said batching silos,
  • a ring shaped roof mounted stationary above the material shelf and provided with at least one opening for pouring the heated material onto the shelf
  • At least two working scrapers supported movably adjacent the shelf to be brought periodically near the shelf surface thereby deflecting material on the shelf over the shelf edge down into the batching silos, and a water cooled scraper box for each scraper into which the scraper is withdrawn periodically between periods of material deflecting operation.
  • a device wherein the material shelf, the roof and at least one stationary wall constitute an essentially ring-shaped gas-tight and dusttight space surrounding the material supported on the shelf.
  • the tightening means comprises at least two continuous circular trough fixed to the stationary parts and filled with a sealing material, and corresponding circular sealing plate members fixed to the rotating material shelf and partially immersed into the sealing material.
  • a device wherein the continuous troughs are filled with a liquid and have an overflow to keep the liquid level constant in the trough.
  • a device wherein the two troughs are positioned at different heights and the liquid flowing from the upper trough is directed as an overflow into the lower trough.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Furnace Charging Or Discharging (AREA)
  • Furnace Details (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
  • Filling Or Emptying Of Bunkers, Hoppers, And Tanks (AREA)
US443977A 1973-02-26 1974-02-20 Feeding ring for feeding ore into furnaces Expired - Lifetime US3900117A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FI730572A FI50028C (fi) 1973-02-26 1973-02-26 Syöttörengas

Publications (1)

Publication Number Publication Date
US3900117A true US3900117A (en) 1975-08-19

Family

ID=8504310

Family Applications (1)

Application Number Title Priority Date Filing Date
US443977A Expired - Lifetime US3900117A (en) 1973-02-26 1974-02-20 Feeding ring for feeding ore into furnaces

Country Status (7)

Country Link
US (1) US3900117A (es)
JP (1) JPS5520150B2 (es)
FI (1) FI50028C (es)
SE (1) SE406979B (es)
TR (1) TR17905A (es)
YU (1) YU37016B (es)
ZA (1) ZA741211B (es)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4705474A (en) * 1984-06-27 1987-11-10 Outokumpu Oy Method and apparatus for batch preparation and feeding into the smelting process
US4836732A (en) * 1986-05-29 1989-06-06 Intersteel Technology, Inc. Method and apparatus for continuously charging a steelmaking furnace
US5887016A (en) * 1994-03-04 1999-03-23 Mannesmann Aktiengesellschaft Charging device for arc furnaces
US6017179A (en) * 1995-04-07 2000-01-25 Seeger Gmbh Ring conveyor
US6544470B1 (en) * 1997-12-05 2003-04-08 Sms Demag Ag Feeding device for electrical shaft furnaces with an electrode-receiving central tube
WO2006027413A1 (en) * 2004-09-09 2006-03-16 Outokumpu Technology Oyj Distributor of hot feed material
US20100104234A1 (en) * 2007-03-20 2010-04-29 Schaeffler Kg Rolling bearing having a braking device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59154895U (ja) * 1983-03-31 1984-10-17 株式会社島津製作所 タ−ボ分子ポンプの潤滑装置
JPS633518U (es) * 1986-06-23 1988-01-11

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1208248A (en) * 1916-04-27 1916-12-12 Utley Wedge Feeding device for furnaces.
US2297289A (en) * 1939-07-31 1942-09-29 Collis Company Furnace discharging device
US2480726A (en) * 1944-01-22 1949-08-30 Kaiser Company Inc Rotary cooling bin
US2619256A (en) * 1949-12-09 1952-11-25 Dow Chemical Co Weigh feeder
US2699249A (en) * 1951-11-17 1955-01-11 Houdry Process Corp Apparatus for handling resilient granular material
US2804309A (en) * 1954-07-26 1957-08-27 Brantford Coach And Body Ltd Sand spreader
US2889786A (en) * 1956-07-20 1959-06-09 John A Maffei Automatic cooking devices

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1208248A (en) * 1916-04-27 1916-12-12 Utley Wedge Feeding device for furnaces.
US2297289A (en) * 1939-07-31 1942-09-29 Collis Company Furnace discharging device
US2480726A (en) * 1944-01-22 1949-08-30 Kaiser Company Inc Rotary cooling bin
US2619256A (en) * 1949-12-09 1952-11-25 Dow Chemical Co Weigh feeder
US2699249A (en) * 1951-11-17 1955-01-11 Houdry Process Corp Apparatus for handling resilient granular material
US2804309A (en) * 1954-07-26 1957-08-27 Brantford Coach And Body Ltd Sand spreader
US2889786A (en) * 1956-07-20 1959-06-09 John A Maffei Automatic cooking devices

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4705474A (en) * 1984-06-27 1987-11-10 Outokumpu Oy Method and apparatus for batch preparation and feeding into the smelting process
US4836732A (en) * 1986-05-29 1989-06-06 Intersteel Technology, Inc. Method and apparatus for continuously charging a steelmaking furnace
US5887016A (en) * 1994-03-04 1999-03-23 Mannesmann Aktiengesellschaft Charging device for arc furnaces
US6017179A (en) * 1995-04-07 2000-01-25 Seeger Gmbh Ring conveyor
US6544470B1 (en) * 1997-12-05 2003-04-08 Sms Demag Ag Feeding device for electrical shaft furnaces with an electrode-receiving central tube
WO2006027413A1 (en) * 2004-09-09 2006-03-16 Outokumpu Technology Oyj Distributor of hot feed material
US20070257406A1 (en) * 2004-09-09 2007-11-08 Outokumpu Technology Oyj Distributor Of Hot Feed Material
EA009539B1 (ru) * 2004-09-09 2008-02-28 Ототек Оюй Устройство для распределения горячего загружаемого материала
CN101014819B (zh) * 2004-09-09 2010-09-01 奥图泰有限公司 热进料物质的分配装置
US20100104234A1 (en) * 2007-03-20 2010-04-29 Schaeffler Kg Rolling bearing having a braking device
US8376095B2 (en) * 2007-03-20 2013-02-19 Schaeffler Technologies AG & Co. KG Rolling bearing having a braking device

Also Published As

Publication number Publication date
FI50028C (fi) 1975-11-10
TR17905A (tr) 1976-11-01
DE2408713A1 (de) 1974-10-03
JPS5520150B2 (es) 1980-05-31
JPS5025408A (es) 1975-03-18
SE406979B (sv) 1979-03-05
FI50028B (es) 1975-07-31
YU47774A (en) 1982-06-18
ZA741211B (en) 1975-01-29
DE2408713B2 (de) 1975-10-09
YU37016B (en) 1984-08-31

Similar Documents

Publication Publication Date Title
US3900117A (en) Feeding ring for feeding ore into furnaces
US4480797A (en) Installation for treatment of waste metal and liquid dross
CN110608614A (zh) 一种矿热炉加料系统驱动装置及具有其的加料系统
US4113413A (en) Rotary scraper in a rotary drum assembly
US3689679A (en) Device for continuous liquefaction of siliceous material
US3896257A (en) Electric arc furnace for melting metals and metal melting method using such furnace
US3985545A (en) Metal melting method using electric arc furnace
US3964892A (en) Apparatus for advancing particulate material
US4133718A (en) Method for agglomerating finely divided agglomerative materials in a rotary drum assembly
US1496232A (en) Stock feeding and distributing apparatus for electrical furnaces
EP1794525B1 (en) Distributor of hot feed material
US3704011A (en) Discharge mechanism for shaft kiln
EP0247923A1 (en) Method and apparatus for continuously charging a steelmaking furnace
US5887016A (en) Charging device for arc furnaces
US3534891A (en) Distributor for granular materials
US4949940A (en) Charging arrangement for shaft furnaces, in particular blast furnaces
Tzonev et al. Recovering aluminum from aluminum dross in a DC electric-arc rotary furnace
AU769631B2 (en) Method and device for melting down finely particulate material containing metal, such as sponge iron
US3895175A (en) Apparatus for movement of charge within an electric smelting furnace
CN217709216U (zh) 一种载板玻璃加料装置
PT85865B (pt) Processo e aparelho para a liquefaccao de um material pulverulento
US2420653A (en) Kiln charging means and method
US3215421A (en) Rotary barrel salt bath metal melting and testing furnaces
US4431406A (en) Rotary hearth furnace plant
US2606111A (en) Agglomeration of metal bearing materials