CA1144361A - Electric heat conductor, preparation thereof, use thereof in a wear part which can be heated, and process for production of such wear parts using the heat conductor - Google Patents
Electric heat conductor, preparation thereof, use thereof in a wear part which can be heated, and process for production of such wear parts using the heat conductorInfo
- Publication number
- CA1144361A CA1144361A CA000344139A CA344139A CA1144361A CA 1144361 A CA1144361 A CA 1144361A CA 000344139 A CA000344139 A CA 000344139A CA 344139 A CA344139 A CA 344139A CA 1144361 A CA1144361 A CA 1144361A
- Authority
- CA
- Canada
- Prior art keywords
- heat conductor
- heating element
- wear
- electrical heating
- wear member
- 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
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 16
- 239000004020 conductor Substances 0.000 title abstract description 49
- 238000000034 method Methods 0.000 title abstract description 12
- 239000002184 metal Substances 0.000 claims abstract description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000000843 powder Substances 0.000 claims abstract description 12
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 10
- 239000010439 graphite Substances 0.000 claims abstract description 10
- 239000000203 mixture Substances 0.000 claims abstract description 6
- 239000011819 refractory material Substances 0.000 claims abstract 4
- 238000010438 heat treatment Methods 0.000 claims description 18
- 239000000919 ceramic Substances 0.000 claims description 12
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- 239000004033 plastic Substances 0.000 claims description 6
- 239000004927 clay Substances 0.000 claims description 5
- 239000011888 foil Substances 0.000 claims description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
- 229920000728 polyester Polymers 0.000 claims description 2
- 239000004952 Polyamide Substances 0.000 claims 1
- 229910052593 corundum Inorganic materials 0.000 claims 1
- 229920002647 polyamide Polymers 0.000 claims 1
- 229910001845 yogo sapphire Inorganic materials 0.000 claims 1
- 239000000306 component Substances 0.000 description 18
- 239000000463 material Substances 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000002320 enamel (paints) Substances 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000161 steel melt Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/02—Macromolecular compounds
- C04B26/26—Bituminous materials, e.g. tar, pitch
-
- 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
- B22D41/14—Closures
- B22D41/22—Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings
- B22D41/28—Plates therefor
- B22D41/36—Treating the plates, e.g. lubricating, heating
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/001—Mass resistors
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Dispersion Chemistry (AREA)
- Mechanical Engineering (AREA)
- Organic Chemistry (AREA)
- Structural Engineering (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Electromagnetism (AREA)
- Materials Engineering (AREA)
- Resistance Heating (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
- Ceramic Products (AREA)
- Sliding Valves (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An electrical heat conductor, its method of manu-facture and a component incorporating the heat conductor and a method of manufacturing the component are described herein.
The heat conductor consists of 50 to 70% graphite, 2 to 10%
Si metal powder and approximately 10% binding pitch. In the manufacture of the heat conductor the Si metal powder and the binding pitch are mixed together before the graphite is added to the mixture. The heated wear component is in the form of a refractory concrete in which the electrical heat con-ductors are embedded. In the process for the production of the wear components, a passage is formed in the body of the wear component and the heat conductor is introduced into the passage either as a shapeless mass or as a preformed heat conductor element. Alternatively, preformed heat conductor elements may be located within a mould and the refractory material from which the wear component is manufactured may be cast about the heat elements.
An electrical heat conductor, its method of manu-facture and a component incorporating the heat conductor and a method of manufacturing the component are described herein.
The heat conductor consists of 50 to 70% graphite, 2 to 10%
Si metal powder and approximately 10% binding pitch. In the manufacture of the heat conductor the Si metal powder and the binding pitch are mixed together before the graphite is added to the mixture. The heated wear component is in the form of a refractory concrete in which the electrical heat con-ductors are embedded. In the process for the production of the wear components, a passage is formed in the body of the wear component and the heat conductor is introduced into the passage either as a shapeless mass or as a preformed heat conductor element. Alternatively, preformed heat conductor elements may be located within a mould and the refractory material from which the wear component is manufactured may be cast about the heat elements.
Description
3~i~
This invention relates to electric heat conductors, their method of manufacture and components incorporating the heat conductors and the method of manufacture of the components.
In conventional wear parts, e.g. parts in the form of sliding plates for gate valves on containers for metal melts according to Swiss Patent No. 444,390, a metal resistance wire is embedded or moulded in the part to serve as a heat conductor.
German Patent No. 402,861 discloses, by way of example, a process for the production of heating elements from silicate materials containing carbon. In this process the red-hot basic part is exposed to a stream of oxygen which oxidises the carbon on the surface to carbon dioxide and after this oxygen treatment the surface is provided with an enamel coating which renders the element airtight. In this way the carbon exposed to the oxygen in the air is preserved. German Patent No. 82,455 discloses a process for the production of heating rods, in which ~e principal constituents are silicon and carbon, and which are obtained by heating carbon-containing members in a bed which produces silicon vapour, so that various parts of the member to be treated are embedded in various bed mixtures in order to produce varied silicon content at various points.
The object of the present invention is to provide an electric heat conductor which when used in wear parts, particu-larly those made from refractory concrete, make it possible to heat these wear parts for a relatively long time to relatively high temperatures of, for example, 1500C, so that these wear parts can be used in gate valves in which the steel melt can ,",.. .~
be effectively prevented from freezing so that the gate valve can be used for multiple pourings.
According to one aspect of the present invention, an electric heat conductor suitable for embedding or moulding in re-fractory parts such as wear parts made from refractory concrete whirh come into contact with melt metal, for example plates or housings of gate valves, comprises approximately 50 to 70%, pre-ferably approximately 60%, graphite (e.g. natural graphite com-prising crystal platelets of some tenths of a millimeter in size), approximately 2 to 10%, preferably approximately 8% Si metal powder and approximately 10% binding pitch.
A heat conductor of this type is not solid even at 1500C but remains soft. Thus it cannot crack, is not affected by expansio~ and contraction of the plate material and constantly absorbs thermal variations in length and volume. The conductor can be set so that an optimum specific resistance of 0.05 Ohm.cm can be achieved. The ma~mum current density should not exceed 30 A/cm . The heating capacity can be 1.5 to 2kW. The heat con-ductor is refractory and thus a refractory component of the wear part. Thus simple production of a refractory member with electrical resistance heating for relatively high temperatures is possible, whereas this was not possible in earlier metal resistance wires.
No thermal tension occurs in the wear parts which can be heated.
With the graphite content the conductivity of the heat conductor can be altered, the Si metal dust improves the oxidation stability since it holds off oxygen from the graphite, and the binding pitch, apart from its binding function, also serves to set the heat resistance at the most uniform current density.
According to a further aspect of the present invention, the electric heat conductor has a content of approximiately 5 to 20~, preferably 10~, anhydrous clay. The anhydrous wind-dried plastic binding clay improves the workability of the heat conductor.
Preferably the heat conductor also comprises approxi-mately 5 to 20%, and preferably 10~, SiC powder which provides an optimum strength characteristic.
According to a further aspect of the present invention, there is provided a method of manufacturing a heat conductor of the type described above wherein initially the quantities of Si metal powder and powdered or liquid binding pitch and optionally clay and/or SiC powder are mixed together and then the quantity of graphite is added to the mixture. This method has been found to provide the best possible conductivity of the heat conductor.
In use, the electric heat conductor of the present in-vention is embedded or moulded in a wear component, preferablymade from refractory concrete, wherein the component is adapted for use in the discharge region of a gate valve of containers for a metal melt such as steel, the component being in the form of plates or housing with the heat conductor made from an electric heat conductor of the type described above.
The heat conductor may be preformed and isostatically pressed before insertion into passages in the body of the wear component. Alternatively, the material from which the heat conductor is to be made may be introduced into passages formed within the body of the wear component and cured therein.
A heat conductor may be located within an A12O3 ceramic pipe.
This serves to ensure that the heat conductor will have a uni-form cross-section. In addition, the ceramic pipe serves to protect the heat conductor against oxidation and also to pro-vide protection against breaking of the heat conductor rods.
The ceramic pipe may also be protected against oxida-tion by surrounding it by a plastic foil made from polyamideor polyester.
It should be noted that an optimum heating effect can be achieved with the heat conductor when it is arranged in the form of straight unbent rods. For this reason, a wear com-ponent in the form of a slide plate preferably has at least two parallel embedded heat conductor rods with a diameter of preferably between approximately 5 and 10 mm, the working sur-face being located between the heat conductor rods and the rods being located at a distance preferably from approximately 10 to 30 mm from the discharge opening.
The wear component may be in the form of a housing characterized by having several heat conductor rods distributed about the periphery thereof and extending substantially axially of the housing. Again, the heat conductor rods are preferably straight. The heat conductor rods of the wear component preferably project approximately 20 to 50 mm from the wear component so that it is possible to locate the electrical 4361.
connections externally of the wear components so that they can be cold.
The electrical connections are preferab~y arranged over an area of 1 to 5 cm2 on the surface of the projecting part of the preformed heat conductor rods so as to prevent overheating.
The wear component is preferably impregnated with a tar which provides additional protection against oxidization.
The wear component is burned before its first use.
According to a further aspect of the present invention there is provided a process for the production of a wear component wherein a proportion of the material capable of vibration and made from chemically or hydraulically setting refractory concrete, produced for example on the basis of tabular alumina with cement, is introduced into a mould, vibrated and a groove or passage is formed therein, the heat conductor is then introduced into the groove or passage as a shapeless material or as a preformed heat conductor element, optionally after being introduced into an A1203 ceramic pipe and optionally surrounded by a plastic foil, and then the second proportion of the refractory concrete material is put into the mould and vibrated to compress it, hardened and then optionally impregnated with tar and/or burnt.
According to yet another aspect of the present inven-tion, a process for the production of a wear component in-cludes the steps of arranging preformed isostatically pressed elements, optionally after insertion in an A12O3 ceramic pipe and optionall~ after surrounding with a plastic foil, in a mould in the position they are to take up in the moulded product and then a material which is capable of being vibrated and which is made from chemically or hydraulically setting refractory concrete, produced for example on the basis of tabular alumina with cement, is introduced into the mould, vibrated, compressed and hardened and optionally impregnated with tar and/or burnt.
The invention will be more clearly understood after reference to the following detailed specification read in conjunction with the drawings wherein, Fig. 1 is a diagrammatic representation of a slide plate of a gate valve in horizontal seciton;
Fig. 2 is a diagrammatic pictorial representation of a housing with heat conductor elements located therein;
Figs. 3a and 3b are partially sectioned end views of a wear component illustrating alternative methods of forming the current connections.
The sliding plate 4 shown in Fig. 1 has two straight conductor rods which are parallel to the longitudinal edges and to each other and which are accommodated in A1203 ceramic pipes 1, the ends of which project from the sliding plate 4.
Between the heat conductor rods 2 are the discharge opening 6 and the working surface 9 of the sliding plate 4. In each opening of the ceramic pipes 1 the current supply 5 is led to cap-shaped dlectrical connections 3 which are let into the heat conductor 2.
3ti~
In a housing 7, which is a wear part, the heat con-ductor rods 2 extend substantially in the axial direction, i.e.
with only a slight inclination which is between the inclina-tion of the inner surface of the housing and that of the outer surface thereof. These heat conductor rods 2 are equally straight and are held in ceramic pipes 1, the ends of which project from the housing 7 where the current is supplied as shown in Fig. 1. In the illustrated example four heating rods 2 each offset by 90 are arranged in the wall of the housing 7.
Fig. 3a shows in detail the arrangement of the electri-cal connection 3 to the current supply 5 which has already been described in connection with Fig. 1.
Fig. 3b shows in detail a current connection 3 of a heat conductor 2 which is inserted in a passage 8 without a special ceramic pipe 1.
This invention relates to electric heat conductors, their method of manufacture and components incorporating the heat conductors and the method of manufacture of the components.
In conventional wear parts, e.g. parts in the form of sliding plates for gate valves on containers for metal melts according to Swiss Patent No. 444,390, a metal resistance wire is embedded or moulded in the part to serve as a heat conductor.
German Patent No. 402,861 discloses, by way of example, a process for the production of heating elements from silicate materials containing carbon. In this process the red-hot basic part is exposed to a stream of oxygen which oxidises the carbon on the surface to carbon dioxide and after this oxygen treatment the surface is provided with an enamel coating which renders the element airtight. In this way the carbon exposed to the oxygen in the air is preserved. German Patent No. 82,455 discloses a process for the production of heating rods, in which ~e principal constituents are silicon and carbon, and which are obtained by heating carbon-containing members in a bed which produces silicon vapour, so that various parts of the member to be treated are embedded in various bed mixtures in order to produce varied silicon content at various points.
The object of the present invention is to provide an electric heat conductor which when used in wear parts, particu-larly those made from refractory concrete, make it possible to heat these wear parts for a relatively long time to relatively high temperatures of, for example, 1500C, so that these wear parts can be used in gate valves in which the steel melt can ,",.. .~
be effectively prevented from freezing so that the gate valve can be used for multiple pourings.
According to one aspect of the present invention, an electric heat conductor suitable for embedding or moulding in re-fractory parts such as wear parts made from refractory concrete whirh come into contact with melt metal, for example plates or housings of gate valves, comprises approximately 50 to 70%, pre-ferably approximately 60%, graphite (e.g. natural graphite com-prising crystal platelets of some tenths of a millimeter in size), approximately 2 to 10%, preferably approximately 8% Si metal powder and approximately 10% binding pitch.
A heat conductor of this type is not solid even at 1500C but remains soft. Thus it cannot crack, is not affected by expansio~ and contraction of the plate material and constantly absorbs thermal variations in length and volume. The conductor can be set so that an optimum specific resistance of 0.05 Ohm.cm can be achieved. The ma~mum current density should not exceed 30 A/cm . The heating capacity can be 1.5 to 2kW. The heat con-ductor is refractory and thus a refractory component of the wear part. Thus simple production of a refractory member with electrical resistance heating for relatively high temperatures is possible, whereas this was not possible in earlier metal resistance wires.
No thermal tension occurs in the wear parts which can be heated.
With the graphite content the conductivity of the heat conductor can be altered, the Si metal dust improves the oxidation stability since it holds off oxygen from the graphite, and the binding pitch, apart from its binding function, also serves to set the heat resistance at the most uniform current density.
According to a further aspect of the present invention, the electric heat conductor has a content of approximiately 5 to 20~, preferably 10~, anhydrous clay. The anhydrous wind-dried plastic binding clay improves the workability of the heat conductor.
Preferably the heat conductor also comprises approxi-mately 5 to 20%, and preferably 10~, SiC powder which provides an optimum strength characteristic.
According to a further aspect of the present invention, there is provided a method of manufacturing a heat conductor of the type described above wherein initially the quantities of Si metal powder and powdered or liquid binding pitch and optionally clay and/or SiC powder are mixed together and then the quantity of graphite is added to the mixture. This method has been found to provide the best possible conductivity of the heat conductor.
In use, the electric heat conductor of the present in-vention is embedded or moulded in a wear component, preferablymade from refractory concrete, wherein the component is adapted for use in the discharge region of a gate valve of containers for a metal melt such as steel, the component being in the form of plates or housing with the heat conductor made from an electric heat conductor of the type described above.
The heat conductor may be preformed and isostatically pressed before insertion into passages in the body of the wear component. Alternatively, the material from which the heat conductor is to be made may be introduced into passages formed within the body of the wear component and cured therein.
A heat conductor may be located within an A12O3 ceramic pipe.
This serves to ensure that the heat conductor will have a uni-form cross-section. In addition, the ceramic pipe serves to protect the heat conductor against oxidation and also to pro-vide protection against breaking of the heat conductor rods.
The ceramic pipe may also be protected against oxida-tion by surrounding it by a plastic foil made from polyamideor polyester.
It should be noted that an optimum heating effect can be achieved with the heat conductor when it is arranged in the form of straight unbent rods. For this reason, a wear com-ponent in the form of a slide plate preferably has at least two parallel embedded heat conductor rods with a diameter of preferably between approximately 5 and 10 mm, the working sur-face being located between the heat conductor rods and the rods being located at a distance preferably from approximately 10 to 30 mm from the discharge opening.
The wear component may be in the form of a housing characterized by having several heat conductor rods distributed about the periphery thereof and extending substantially axially of the housing. Again, the heat conductor rods are preferably straight. The heat conductor rods of the wear component preferably project approximately 20 to 50 mm from the wear component so that it is possible to locate the electrical 4361.
connections externally of the wear components so that they can be cold.
The electrical connections are preferab~y arranged over an area of 1 to 5 cm2 on the surface of the projecting part of the preformed heat conductor rods so as to prevent overheating.
The wear component is preferably impregnated with a tar which provides additional protection against oxidization.
The wear component is burned before its first use.
According to a further aspect of the present invention there is provided a process for the production of a wear component wherein a proportion of the material capable of vibration and made from chemically or hydraulically setting refractory concrete, produced for example on the basis of tabular alumina with cement, is introduced into a mould, vibrated and a groove or passage is formed therein, the heat conductor is then introduced into the groove or passage as a shapeless material or as a preformed heat conductor element, optionally after being introduced into an A1203 ceramic pipe and optionally surrounded by a plastic foil, and then the second proportion of the refractory concrete material is put into the mould and vibrated to compress it, hardened and then optionally impregnated with tar and/or burnt.
According to yet another aspect of the present inven-tion, a process for the production of a wear component in-cludes the steps of arranging preformed isostatically pressed elements, optionally after insertion in an A12O3 ceramic pipe and optionall~ after surrounding with a plastic foil, in a mould in the position they are to take up in the moulded product and then a material which is capable of being vibrated and which is made from chemically or hydraulically setting refractory concrete, produced for example on the basis of tabular alumina with cement, is introduced into the mould, vibrated, compressed and hardened and optionally impregnated with tar and/or burnt.
The invention will be more clearly understood after reference to the following detailed specification read in conjunction with the drawings wherein, Fig. 1 is a diagrammatic representation of a slide plate of a gate valve in horizontal seciton;
Fig. 2 is a diagrammatic pictorial representation of a housing with heat conductor elements located therein;
Figs. 3a and 3b are partially sectioned end views of a wear component illustrating alternative methods of forming the current connections.
The sliding plate 4 shown in Fig. 1 has two straight conductor rods which are parallel to the longitudinal edges and to each other and which are accommodated in A1203 ceramic pipes 1, the ends of which project from the sliding plate 4.
Between the heat conductor rods 2 are the discharge opening 6 and the working surface 9 of the sliding plate 4. In each opening of the ceramic pipes 1 the current supply 5 is led to cap-shaped dlectrical connections 3 which are let into the heat conductor 2.
3ti~
In a housing 7, which is a wear part, the heat con-ductor rods 2 extend substantially in the axial direction, i.e.
with only a slight inclination which is between the inclina-tion of the inner surface of the housing and that of the outer surface thereof. These heat conductor rods 2 are equally straight and are held in ceramic pipes 1, the ends of which project from the housing 7 where the current is supplied as shown in Fig. 1. In the illustrated example four heating rods 2 each offset by 90 are arranged in the wall of the housing 7.
Fig. 3a shows in detail the arrangement of the electri-cal connection 3 to the current supply 5 which has already been described in connection with Fig. 1.
Fig. 3b shows in detail a current connection 3 of a heat conductor 2 which is inserted in a passage 8 without a special ceramic pipe 1.
Claims (13)
1. An electrical heating element of the type which may be embedded in refractory materials comprising about 50 to 70 %
graphite, about 2 to 10 % Si metal powder and about 10 % binding pitch.
graphite, about 2 to 10 % Si metal powder and about 10 % binding pitch.
2. An electrical heating element as claimed in Claim 1 further comprising about 5 to 20 % anhydrous clay.
3. An electrical heating element as claimed in Claim 1 or 2 further comprising about 5 to 20 % SiC powder.
4. A method of manufacturing an electrical heating element which consists of about 50 to 70 % graphite, about 2 to 10 % Si metal powder and about 10 % binding pitch comprising the steps of initially mixing the Si metal powder and the binding pitch and thereafter adding the graphite to the mixture.
5. A method of manufacturing an electrical heating element as claimed in Claim 4 wherein anhydrous clay is included in the initial mixture in an amount of about 5 to 20 %.
6. A method of manufacturing an electrical heating element as claimed in Claim 4 wherein SiC powder is included in the initial mixture in an amount of about 5 to 20 %.
7. A wear member for use in contact with molten metal or the like comprising:
i) a body of refractory material; and ii) at least one electrical heating element embedder in said body, said heating element comprising about 50 to 70 % graphite, about 2 to 10 % Si metal powder and about 10 %
binding pitch.
i) a body of refractory material; and ii) at least one electrical heating element embedder in said body, said heating element comprising about 50 to 70 % graphite, about 2 to 10 % Si metal powder and about 10 %
binding pitch.
8. A wear member as claimed in Claim 7 wherein said heating element is enclosed in an Al2O3 ceramic pipe.
9. A wear member as claimed in Claim 8 wherein said ceramic pipe is surrounded by a plastic foil made from polyamide.
10. A wear member as claimed in Claim 8 wherein said ceramic pipe is surrounded by a plastic foil made from polyester.
11. A wear member as claimed in Claim 7 wherein at least two electrical heating elements are embedded in said body, each element being cyclindrical in shape and having a diameter of about 5 to 10 mm, said elements being arranged in a spaced parallel relationship.
12. A wear member as claimed in Claim 11 wherein a plurality of heating elements are located at spaced intervals throughout said body.
13. A wear member as claimed in Claim 7, 11 or 12 wherein said body of refractory material is adapted to form the discharge receiving region of a gate valve of a container for molten metal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792910151 DE2910151A1 (en) | 1979-03-15 | 1979-03-15 | ELECTRIC HEATING CONDUCTOR, YOUR PREPARATION, YOUR USE IN A HEATABLE WEARING PART AND A METHOD FOR PRODUCING SUCH WEARING PARTS WITH THE HEATING CONDUCTOR |
| DEP2910151.7 | 1979-03-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1144361A true CA1144361A (en) | 1983-04-12 |
Family
ID=6065449
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000344139A Expired CA1144361A (en) | 1979-03-15 | 1980-01-22 | Electric heat conductor, preparation thereof, use thereof in a wear part which can be heated, and process for production of such wear parts using the heat conductor |
Country Status (7)
| Country | Link |
|---|---|
| BE (1) | BE881259A (en) |
| CA (1) | CA1144361A (en) |
| DE (1) | DE2910151A1 (en) |
| ES (1) | ES488798A1 (en) |
| FR (1) | FR2451694A1 (en) |
| GB (1) | GB2045737B (en) |
| IT (1) | IT1125907B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3109941A1 (en) * | 1981-03-14 | 1982-09-23 | Carl G.O. Dipl.-Ing. 7752 Insel Reichenau Korn | Process for recording and reproducing signals at very high frequency on magnetic tapes |
| DE3930866C1 (en) * | 1989-09-15 | 1991-02-28 | Didier-Werke Ag, 6200 Wiesbaden, De | |
| DE10058213A1 (en) * | 2000-11-23 | 2002-05-29 | Sms Demag Ag | Slider closure for metallurgical vessels, furnaces and the like. |
| DE10210677A1 (en) | 2002-03-12 | 2003-10-09 | Sgl Carbon Ag | Carbon-containing molded body for heating rooms |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE402861C (en) * | 1923-06-15 | 1924-09-19 | Drahtlose Heiz U Widerstands K | Process for the production of heating elements from carbon-containing silicate mass |
| DE457074C (en) * | 1925-02-28 | 1928-03-08 | Studien Ges Fuer Wirtschaft Un | Silicate-containing electrical heating conductor |
| DE482455C (en) * | 1928-01-28 | 1929-09-14 | Siemens Planiawerke A G Fuer K | Process for the production of heating rods which contain silicon and carbon as main components |
| DE1019019B (en) * | 1951-05-29 | 1957-11-07 | Hermann Knipping | Electric heating element |
| US3352549A (en) * | 1964-10-29 | 1967-11-14 | Blaw Knox Co | Composite carbonaceous members for furnace rolls and other high temperature members |
| CH444390A (en) * | 1966-08-30 | 1967-09-30 | Interstop Ag | Method for casting metals from a casting vessel with a slide closure |
| DE1910707C3 (en) * | 1969-03-03 | 1982-12-16 | 6200 Wiesbaden Didier-Werke Ag | Bottom slide closure for the pouring opening of vessels containing molten metal and a method for operating the same |
| CH545249A (en) * | 1971-04-15 | 1973-12-15 | Lonza Ag | Process for making an isotropic graphite material |
| DE2401784A1 (en) * | 1974-01-15 | 1975-07-24 | Sibirsk Nii Energetiki | Electrically conducting material - for resistors and building components made from mixt of cement, graphite and a filler |
| IT1072241B (en) * | 1976-12-17 | 1985-04-10 | Cselt Centro Studi Lab Telecom | ITFORNACE ELECTRIC MOLD RESISTANT LA WITH POWDER GRAPHITE RESISTIVE ELEMENT |
| DE2709462C2 (en) * | 1977-03-04 | 1979-01-11 | Martin & Pagenstecher Gmbh, 5000 Koeln | Slide closure for containers containing molten metal |
-
1979
- 1979-03-15 DE DE19792910151 patent/DE2910151A1/en not_active Withdrawn
- 1979-12-04 IT IT27865/79A patent/IT1125907B/en active
- 1979-12-27 FR FR7931792A patent/FR2451694A1/en active Pending
-
1980
- 1980-01-21 BE BE0/199049A patent/BE881259A/en not_active IP Right Cessation
- 1980-01-22 CA CA000344139A patent/CA1144361A/en not_active Expired
- 1980-02-21 ES ES488798A patent/ES488798A1/en not_active Expired
- 1980-03-14 GB GB8008823A patent/GB2045737B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2045737B (en) | 1983-03-09 |
| IT1125907B (en) | 1986-05-14 |
| BE881259A (en) | 1980-05-16 |
| FR2451694A1 (en) | 1980-10-10 |
| IT7927865A0 (en) | 1979-12-04 |
| ES488798A1 (en) | 1980-09-16 |
| GB2045737A (en) | 1980-11-05 |
| DE2910151A1 (en) | 1980-10-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1144361A (en) | Electric heat conductor, preparation thereof, use thereof in a wear part which can be heated, and process for production of such wear parts using the heat conductor | |
| US4605635A (en) | Carbon-containing refractory | |
| EP0198925A1 (en) | Composition which is capable of being converted into an aluminium oxynitride refractory | |
| US4395026A (en) | Refractory gas-permeable structural unit | |
| CA2012235A1 (en) | Transfer tube with insitu heater | |
| CA1154250A (en) | Prefabricated multiple density blast furnace runner | |
| JPH07187755A (en) | Refractory ceramic molding compound | |
| JPS6132378B2 (en) | ||
| JPS6126548A (en) | Electric resistance heater | |
| JPS61215238A (en) | Refractory heat insulator and manufacture | |
| JP4399579B2 (en) | Castable molded product and method for producing the same | |
| JPS6046168B2 (en) | Molded body for gas injection | |
| JPS5767011A (en) | Manufacture of graphitic molding | |
| JPS6013993B2 (en) | Manufacturing method for carbon-containing refractories | |
| JPS61238909A (en) | Lance for treating molten metal | |
| SU1728888A1 (en) | Composite current-conducting material | |
| JPS61236651A (en) | Manufacture of sic sintered body | |
| JP2592221B2 (en) | Carbon-containing refractory and method for producing the same | |
| KR970000516B1 (en) | Tubular ceramic articles, method and apparatus for their manufacture | |
| KR101011078B1 (en) | Method for Preparing Castable Block Improving Corrosion and Oxidation Resistance | |
| JPH0421625B2 (en) | ||
| JPS62148063A (en) | Sliding nozzle plate for continuous casting | |
| JPH1112048A (en) | Ceramic aggregate on which dentate corrugation is formed, and amorphous refractory using the same | |
| JP2961029B2 (en) | Method for producing carbon-containing refractories | |
| JPS5811555B2 (en) | Groove lining structure of a groove-type induction furnace for metal melting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |