EP0329485A2 - Überzug für Tiegelofen und Pfannen und Verfahren zum Anbringen dieses Überzuges - Google Patents

Überzug für Tiegelofen und Pfannen und Verfahren zum Anbringen dieses Überzuges Download PDF

Info

Publication number
EP0329485A2
EP0329485A2 EP89301615A EP89301615A EP0329485A2 EP 0329485 A2 EP0329485 A2 EP 0329485A2 EP 89301615 A EP89301615 A EP 89301615A EP 89301615 A EP89301615 A EP 89301615A EP 0329485 A2 EP0329485 A2 EP 0329485A2
Authority
EP
European Patent Office
Prior art keywords
liner
lining
vessel
furnace
lining according
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.)
Withdrawn
Application number
EP89301615A
Other languages
English (en)
French (fr)
Other versions
EP0329485A3 (de
Inventor
Robert J. Durbin
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.)
Ra Barnes Inc
Original Assignee
Ra Barnes Inc
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 Ra Barnes Inc filed Critical Ra Barnes Inc
Publication of EP0329485A2 publication Critical patent/EP0329485A2/de
Publication of EP0329485A3 publication Critical patent/EP0329485A3/de
Withdrawn legal-status Critical Current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
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/16—Making or repairing linings ; Increasing the durability of linings; Breaking away linings
    • F27D1/1626—Making linings by compacting a refractory mass in the space defined by a backing mould or pattern and the furnace wall
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
    • B22D41/02—Linings
    • 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
    • F27B14/00—Crucible or pot furnaces
    • F27B14/08—Details specially adapted for crucible or pot furnaces
    • F27B14/10—Crucibles
    • 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
    • F27D2003/0034—Means for moving, conveying, transporting the charge in the furnace or in the charging facilities
    • F27D2003/0038—Means for moving, conveying, transporting the charge in the furnace or in the charging facilities comprising shakers

Definitions

  • the present invention relates to linings for crucible furnaces, holding vessels and transfer vessels used to repetitively handle molten metal and provides an improved composite lining therefor. It also relates to a method for applying a lining to such furnaces and vessels. Linings of the invention also have more general application in for example, the petrochemical and gas transfer industries. In a particular application they can be used as internal linings for ducts adapted to carry media at high temperatures.
  • the metal to be heated is placed in a silicon carbide crucible supported on a pedestal within a furnace which is commonly heated by gas-fired or oil-fired burners acting on the crucible.
  • the furnace has a steel shell with an internal lining.
  • the working inner face (hotface) of the shell lining is subjected to the maximum temperature in the furnace and is spaced from the crucible a predetermined distance.
  • the present invention is directed at the provision of a lining for furnaces and vessels for holding or handling molten materials which is relatively thin overall to maximize capacity, and which has improved thermal efficiency to the extent of substantially decreasing fuel consumption and shortening the melting period in a crucible furnace.
  • the invention also seeks to provide a lining which is easy and quick to apply, has a long life, and is suitable for lining transfer vessels, such as ladles, crucible furnaces, and ducts adapted to carry media at high temperatures.
  • the lining of the present invention comprises a first, outer insulating liner selected for its good insulating ability, and a second, dense inner working liner with a durable hotface.
  • the working liner has a high heat-retention characteristic and low insulation value as compared to the insulation liner, and is preferably cast in position.
  • the insulating liner is usually supplied and fitted in board-like form and can have adequate structural strength to support the working liner at high temperatures.
  • the first liner can serve as an outer form complementing a portable removable inner form when the working liner is cast.
  • the present invention permits the working liner to be selected in terms of density, volume (thickness), K-­factor (thermal conductivity), and specific heat to define a heat-retention capability maximizing thermal efficiency. It has been found that, ideally, the heat-­ retention capability should approximate the heat required bo melt the metal being heated in the crucible and raise its temperature to casting temperature after taking into account exterior heat losses via the furnace shell.
  • the composite lining of this invention by providing a relatively thin, outer insulating liner or layer with a high insulating characteristic between the furnace shell and an inner working liner or layer of high heat-­retention ability, makes it possible to obtain the desired heat-retention capability for the working liner without increasing the overall lining thickness.
  • the working liner will normally be substantially thicker, usually several times thicker than the insulating liner, but nevertheless we have found it has been possible in some crucible furnace operations to decrease the overall lining thickness, and therefore increase the furnace capacity, while at the same time decreasing fuel consumption and decreasing the heating period for each cycle of bringing a charge (aluminium, for example) from room temperature to a casting state.
  • a readily castable, water-free refractory material for the working liner such as the "DRI-VIBE” refractories made by Allied Mineral Products, Inc., Columbus, Ohio.
  • a readily castable, water-free refractory material such as the "DRI-VIBE” refractories made by Allied Mineral Products, Inc., Columbus, Ohio.
  • This liner material is 60% Al2O3, 38% SiO2 and 2% TiO2, in addition to containing heat-setting sintering mechanisms, and has a density of about 145 pounds per cubic foot (2320 kg/ms). It develops adequate strength after one hour at 800°F (427°C) to initiate use.
  • a product such as "BARNESBOARD,” sold by R A Barnes Inc, Seattle, Washington, which is a fiberboard-type product containing silica (73%-91%), mineral wool or other suitable inorganic fibres (1%-6%), organic fibres (1%-3%), calcium silicate (3%-5%), diatomaceous earth (2%-5%), and binder (2%-8%), such as a suitable phenolic resin (all percentages by weight).
  • This product has a density in the range of about 40 pounds per cubic foot (640 Kg/ms) and a K-factor of about 0.25 at room temperature, compared to a K-factor of about 10.0 for the "DV60A" refractory material.
  • the insulation liner is one inch thick and is in sheet or board form, and may have parallel V-grooves extending at regular intervals along its length so that a sheet or board may be readily bent into circular cross-section with the sections between grooves forming chords of the circle.
  • the insulating liner should preferably have sufficient crushing resistance to support the working liner in all working conditions.
  • the above-identified fiberboard product preferred for the insulating liner, has an unusually low K-factor through a wide temperature range and also maintains adequate crushing strength through a wide temperature range to support the working liner.
  • a thermal conductivity test ASTM C-201, indicates that when the hotface of the insulating liner board is 1993°F (1090°C), the coldface is only 202°F (94°C); and a hot crushing test on two-inch cubes of the liner board indicates an average crushing pressure of 27 psi (130 N/m2) at 1000°F (538°C) and 11 psi (53N/m2) at 2000°F (1093°C) to reach 20% deformation.
  • the cold crushing strength is 225 psi (1077N/m2).
  • a typical crucible furnace has a cylindrical shell 10 with a flat closed bottom 10a.
  • the burner(s) extends through a side port 10b in the shell and lining.
  • sections of insulating board are fitted around the inside of the cylindrical side wall and over the round bottom wall of the furnace shell to provide an insulting liner 12.
  • Dry refractory material 14 for the working liner is then poured into the shell to a desired height from the bottom circular insulation liner portion and hand-tamped and de-aired to get a smooth, compact, level surface.
  • a vent hold is provided in the bottom by using a ceramic tube, wooden dowel or other suitable core.
  • a plug 16 is also provided for each burner port. Then a cylindrical steel form 18 is lowered into the shell, onto the bottom layer of refractory material, and its outer face engages the end of the burner port plug(s) 16, which is correspondingly shaped. Refractory material 14 is then poured between the steel form and the surrounding insulating liner 12, which then also functions as a form,
  • the next step is to vibrate the steel form 18 as by mounting a portable vibrating machine 20 on a rod 22 extending diametrically across the top of the form.
  • the refractory 14 is heated for at least one hour at 800°F (427°C) as by an heating torch set in the steel form, whereupon the form is cooled and lifted out of the furnace. Removal of the burner plug 16 completes the lining operation.
  • the theoretical heat requirements for a well-­designed 450-lb (200 Kgs) , gas-fired, aluminium-melt crucible furnace having a crucible and pedestal weight of 250 lbs (114 Kgs) and a steel shell weight of 500 lbs (225 Kgs) is as follows using the composite liner materials previously discussed and assuming a one-inch (2.54 cms) thick insulating layer and a five-inch (12.7 cms) thick working layer in a furnace having an inside diameter of 42 inches (107 cms) and an inside height of 39 inches (100 cms):
  • a typical, current, 6-inch (15.25 cms) thick lining system for such a furnace would have the top 20 inches (51 cms) of the 39-inch (100 cms) height as a ceramic fibre working layer to a thickness of 3 inches (7.6 cms), and would have the remaining 3 inches (7.6 cms) outside of the ceramic fibre and the 6 inches (15.25 cms) of lining below the ceramic fibre as a castable, dense refractory having, for example, a specific weight of 130 lb/ft3 (2080 kg/m3) and a K-factor of 4.0 at 1000°F (528°C) mean temperature.
  • a typical start-up of a crucible furnace with a composite liner of the present invention to achieve a first heat will typically take about twice as long as for subsequent heats.
  • the heat-retention ability of the lining can be selected to shorten the melt period. Since there is a maximum rate at which the metal charge being melted in the crucible will absorb heat, there is little advantage in having a surplus of heat-retention ability in the working liner. In fact, too much surplus can result in breakage of the crucible. Accordingly, it has been discovered that it is preferable to make the heat-­retention ability of the working lining approximately equal to the heat required to melt the charge and raise to casting temperature.
  • the composite lining of the invention is of value for holding vessels and molten metal transfer vessels such as ladles. Because of the increased heat retention by the lining, the tap temperature of the molten metal at the melt furnace can be lower at the start of the transfer operation than otherwise, thus saving energy and wear on the furnace, reducing oxidation of the molten metal, and allowing for more consistent temperatures in the casting operations. Furthermore, the lining in the ladle will last significantly longer than before. In this regard, a thin, third liner layer can be applied to the working liner as a wear surface to be replenished to increase the life of the rest of the liner.
  • Linings of the invention also have general application where media at high temperatures is to be handled.
  • a duct adapted to carry such media can usefully be provided with the lining described.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
EP89301615A 1988-02-19 1989-02-20 Überzug für Tiegelofen und Pfannen und Verfahren zum Anbringen dieses Überzuges Withdrawn EP0329485A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US15788188A 1988-02-19 1988-02-19
US157881 1988-02-19

Publications (2)

Publication Number Publication Date
EP0329485A2 true EP0329485A2 (de) 1989-08-23
EP0329485A3 EP0329485A3 (de) 1990-07-18

Family

ID=22565681

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89301615A Withdrawn EP0329485A3 (de) 1988-02-19 1989-02-20 Überzug für Tiegelofen und Pfannen und Verfahren zum Anbringen dieses Überzuges

Country Status (2)

Country Link
EP (1) EP0329485A3 (de)
PT (1) PT89767A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0428363A1 (de) * 1989-11-14 1991-05-22 Praxair Technology, Inc. Vorrichtung zum Warmhalten und Reinigen von geschmolzenem Aluminium
CN108247816A (zh) * 2018-03-26 2018-07-06 兖矿东华重工有限公司 一种用于炉具耐火材料浇筑的模具

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
LU71573A1 (de) * 1974-12-30 1976-11-11
FR2345253A1 (fr) * 1976-03-23 1977-10-21 Radiotechnique Compelec Creuset pour la fabrication d'un lingot de materiau cristallin
FR2451789A1 (fr) * 1979-03-22 1980-10-17 Daussan & Co Revetement thermiquement isolant pour recipients metallurgiques et procede s'y rapportant
DE3128099A1 (de) * 1980-09-10 1982-05-13 VEB Bandstahlkombinat Hermann Matern, DDR 1220 Eisenhüttenstadt Verfahren zur herstellung von verdampfertiegeln
GB2161591A (en) * 1984-07-14 1986-01-15 Ipw Limited Coreless induction furnace

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0428363A1 (de) * 1989-11-14 1991-05-22 Praxair Technology, Inc. Vorrichtung zum Warmhalten und Reinigen von geschmolzenem Aluminium
CN108247816A (zh) * 2018-03-26 2018-07-06 兖矿东华重工有限公司 一种用于炉具耐火材料浇筑的模具

Also Published As

Publication number Publication date
PT89767A (pt) 1989-10-04
EP0329485A3 (de) 1990-07-18

Similar Documents

Publication Publication Date Title
EP0696716A1 (de) Tiegelanordnung für einen Vakuumschmelzofen
US4469309A (en) Core for blow-forming the lining of vessel for molten metal, a lining method using said core, and a lining composition used in said lining method
US4059712A (en) Metal-ceramic composite and method for making same
EP0675862B1 (de) Feuerfeste zusammensetzungen
US4675879A (en) Induction furnaces
US4376374A (en) Metal-ceramic composite and method for making same
US5120029A (en) Linings for crucible furnaces and transfer vessels and method of applying same
CA2059796C (en) Burner block assembly and material
US3751571A (en) Refractory cement lining for coreless induction furnaces
US4734031A (en) Vessel for holding high temperature bulk materials
EP0329485A2 (de) Überzug für Tiegelofen und Pfannen und Verfahren zum Anbringen dieses Überzuges
US4759297A (en) Furnace burner block
EP0061263A1 (de) Verankerung von feuerfestem Material mit einer feuerfesten Auskleidung
US4580969A (en) Furnace component constituting a passage for gases escaping from a burner and a process for obtaining this
US4750717A (en) Tundishes
US4330107A (en) Teapot ladle and method of use
JP3016124B2 (ja) 溶湯容器およびアルミニウム溶湯保持炉
US5118085A (en) Steel ladle lip closure apparatus
CN115557796A (zh) 一种高强度硅系纤维板及其制备方法
US5318277A (en) Lined ladles, linings therefor, and method of forming the same
JP2000290079A (ja) 不定形耐火物が放射状にスリットを有する溶湯容器およびその製造方法
EP0446252B1 (de) Gefässe zur stahlherstellung
JPH058020A (ja) 鋳込み用取鍋およびタンデイツシユ
JPH07280456A (ja) 炉壁構造
GB2156057A (en) Tundish linings

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

17P Request for examination filed

Effective date: 19910111

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19920901