GB2154379A - Leadthrough arrangement - Google Patents
Leadthrough arrangement Download PDFInfo
- Publication number
- GB2154379A GB2154379A GB08403943A GB8403943A GB2154379A GB 2154379 A GB2154379 A GB 2154379A GB 08403943 A GB08403943 A GB 08403943A GB 8403943 A GB8403943 A GB 8403943A GB 2154379 A GB2154379 A GB 2154379A
- Authority
- GB
- United Kingdom
- Prior art keywords
- arrangement
- conductor
- sheath
- wall
- furnace
- 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- Withdrawn
Links
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
- F27D99/00—Subject matter not provided for in other groups of this subclass
- F27D99/0001—Heating elements or systems
- F27D99/0006—Electric heating elements or system
-
- 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
- F27D99/00—Subject matter not provided for in other groups of this subclass
- F27D99/0073—Seals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B17/00—Insulators or insulating bodies characterised by their form
- H01B17/26—Lead-in insulators; Lead-through insulators
- H01B17/30—Sealing
-
- 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
- H05B7/00—Heating by electric discharge
- H05B7/02—Details
- H05B7/06—Electrodes
-
- 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
- H05B7/00—Heating by electric discharge
- H05B7/16—Heating by glow discharge
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Resistance Heating (AREA)
- Furnace Housings, Linings, Walls, And Ceilings (AREA)
- Connections Arranged To Contact A Plurality Of Conductors (AREA)
Abstract
A leadthrough arrangement for providing an electrical connection through the wall of a furnace, comprises a tubular body (1) having an electrical conductor (4) passing therethrough and electrically isolated therefrom, there being an insulating sheath (10) surrounding the conductor (4) throughout its length within the body (2), and a heat sink (9) mounted on the conductor (4) externally of the body (2). The body is mounted over an opening in a furnance wall in vacuum tight manner via mounting flange (2). <IMAGE>
Description
1
GB2 154 379A
1
SPECIFICATION Leadthrough arrangement
5 This invention relates to a leadthrough arrangement for providing an electrical connection through the wall of a furnace.
In plasma thermochemical treatment apparatus, for example in apparatus for plasma 10 carburising workpieces in a vacuum furnace, there is a need for a leadthrough arrangement which serves to take the HT electrical supply for the flow discharge through the wall of the furnace.
15 Normally the furnace wall itself constitutes the anode of the electrical supply, and thus the leadthrough arrangement must be capable of passing an electrical conductor through an opening in the wall of the furnace in vacuum 20 tight manner, with the conductor electrically isolated from the wall of the furnace, and must not be adversely affected by the high temperatures, of the order of 1000"C, which can occur in the furnace.
25 A particular difficulty which arises with known leadthrough arrangements when used in plasma carburising furnaces is that sooty deposits can build up on parts of the arrangement and provide arc tracking paths to earth 30 for the HT supply.
According to this invention there is provided a leadthrough arrangement, for providing an electrical connection through the wall of a furnace, comprising a tubular body 35 adapted to be mounted over an opening in said wall in vacuum tight manner; an electrical conductor passing through said body and electrically isolated therefrom; an insulating member serving to mount said conductor in 40 said body; and an insulating sheath surrounding said conductor throughout its length within said body.
A leadthrough arrangement embodying this invention will now be described by way of 45 example with reference to the drawing which is a longitudinal sectioned view of the arrangement.
The arrangement comprises a tubular body 1 of high-nickel steel, having welded to one 50 end thereof a mounting flange 2 by which the body 1 is in use secured over an opening in a furnace wall (not shown) in vacuum tight manner, for example by means of a clamp.
At its other end the body 1 carries an 55 annular ceramic insulating member 3 which is secured by vacuum brazing in an end portion of the body 1 and which projects therefrom.
Passing through the body 1 and insulating member 3 is a relatively small diameter metal 60 conductor rod 4 which within the furnace is connected to a worktable (not shown) and which serves to take an HT electrical supply into the furnace for establishing a glow discharge therein between the worktable and the 65 furnace wall which constitutes the other electrode of the supply.
The rod 4 projects beyond the free end of the insulating member 3 and has secured thereon a metal coupling member 5 which is carried by the insulating member 3 by way of a steel cap member 6 which is secured about a free end portion of the insulating member 3 and which has a hole therein through which a portion of the coupling member 5 projects. The coupling member 5 has a flange 7 which abuts the cap member 6, and the free end portion 8 of the coupling member 5 is externally threaded.
Screwed onto the portion 8 of the coupling member 5 is a finned heat sink 9 which also serves as the electrical connection to the rod 4 an HT supply lead (not shown) being connected to the heat sink 9, for example by means of a screw connection (not shown).
The rod 4 is thus held in position relative to the body 1 by means of the coupling member 5, cap member 6 and insulating member 3, and extends through the body 1 in electrically isolated manner.
Surrounding the rod 4 throughout its length within the body 1 is a ceramic insulating sheath 10 which extends through the insulating member 3 and terminates within the cap member 6.
The space defined by the cap member 6, the free end of the insulating member 3 and the end of the ceramic sheath 10 is filled with a potting material comprising refractory cement material 11 which has been fired to remove all traces of moisture.
In use of a leadthrough arrangement as described above, the body 1 is secured over an opening in a furnace wall, by means of the flange 2, with the conductor rod 4 and its surrounding sheath 10 extending into the furnace, the rod 4 being electrically connected as required at a worktable within the furnace. The HT electrical supply is then connected up with the furnace wall serving as the positive earth connection and the rod 4 serving as the negative connection, the voltage across the connection being of the order of 1000V. During operation of the furnace any heat conducted down the conductor rod 4 is dissipated by the heat sink 9 which would normally be fan cooled, thus ensuring that the arrangement is not subjected to excessive temperatures.
If the leadthrough arrangement is used in a plasma carburising furnace, the sheath 10 serves to prevent tracking between the rod 4 and the body 1 which is at the potential of the furnace wall, which tracking could be caused by soot deposits forming in the body 1.
The use of the refractory cement material 11 serves to prevent the possibility of a discharge within what would otherwise be an empty space, and in particular serves to avoid the occurrence of hollow cathode effects.
70
75
80
85
90
95
100
105
110
115
120
125
130
2
GB2154 379A
2
Further, the cooling effected by the heat sink 9 maintains the arrangement at a temperature which reduces soot formation to a minimum within the arrangement.
5
Claims (7)
1. A leadthrough arrangement, for providing an electrical connection through the wall of a furnace, comprising a tubular body
10 adapted to be mounted over an opening in said wall in vacuum tight manner; an electrical conductor passing through said body and electrically isolated therefrom; an insulating member serving to mount said conductor in
15 said body; and an insulating sheath surrounding said conductor throughout its length within said body.
2. An arrangement as claimed in claim 1, in which said insulating member projects from
20 one end of said body and carries at its free end a cap member having a hole therein through which said conductor passes, and within which said sheath terminates, the space defined by said cap member, the free
25 end of the insulating member, and the end of the sheath being filled with a potting material.
3. An arrangement as claimed in claim 2, in which the potting material is a refractory cement material which has been fired to re-
30 move all traces of moisture.
4. An arrangement as claimed in claim 2 or claim 3, in which said conductor carries a coupling member having a portion received in the hole in said cap member, and an exter-
35 nally threaded portion projecting outside said cap member.
5. An arrangement as claimed in claim 4, in which said externally threaded portion of said coupling member carries a heat sink.
40
6. An arrangement as claimed in any preceding claim, in which said sheath is of ceramic material.
7. A leadthrough arrangement substantially as hereinbefore described with reference
45 to the drawing.
Printed in the United Kingdom for
Her Majesty's Stationery Office. Dd 8818935. 1985. 4235. Published at The Patent Office. 25 Southampton Buildings. London, WC2A 1 AY, from which copies may be obtained.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08403943A GB2154379A (en) | 1984-02-15 | 1984-02-15 | Leadthrough arrangement |
EP85300995A EP0152307A3 (en) | 1984-02-15 | 1985-02-14 | Leadthrough arrangement |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08403943A GB2154379A (en) | 1984-02-15 | 1984-02-15 | Leadthrough arrangement |
Publications (2)
Publication Number | Publication Date |
---|---|
GB8403943D0 GB8403943D0 (en) | 1984-03-21 |
GB2154379A true GB2154379A (en) | 1985-09-04 |
Family
ID=10556624
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08403943A Withdrawn GB2154379A (en) | 1984-02-15 | 1984-02-15 | Leadthrough arrangement |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0152307A3 (en) |
GB (1) | GB2154379A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2163897B (en) * | 1984-08-29 | 1988-03-02 | Electricity Council | Charge-load support for a glow discharge furnace |
CN102769989A (en) * | 2012-07-17 | 2012-11-07 | 西安电子科技大学 | Insulating and sealing device for built-in cooled electrode of plasma discharge cavity |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB314808A (en) * | 1928-07-02 | 1930-11-03 | Siemens Ag | Means for protecting the insulating sleeves of electrical machine windings from glow discharge phenomena |
GB547967A (en) * | 1941-07-03 | 1942-09-18 | Percy Cox | Improvements in and relating to explosively actuated apparatus for perforating submerged or other articles |
GB793974A (en) * | 1955-10-28 | 1958-04-23 | British Thomson Houston Co Ltd | Improvements relating to electric insulating bushing assemblies |
GB1152482A (en) * | 1966-03-25 | 1969-05-21 | Telephone Cables Ltd | Improvements in and relating to Bonding Plastics Material |
GB1177559A (en) * | 1966-12-23 | 1970-01-14 | Philips Electronic Associated | Corrosion-Resistant Electrical Terminal. |
GB1254025A (en) * | 1969-08-13 | 1971-11-17 | Gen Electric Co Ltd | Improvements in or relating to sealing arrangements between tubular members |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR852026A (en) * | 1938-03-24 | 1940-01-22 | Electrical feedthrough for vacuum reaction apparatus | |
FR966111A (en) * | 1947-05-10 | 1950-10-02 | Bbc Brown Boveri & Cie | Passage or entry of electrodes or conductors in pressure or vacuum vessels |
FR1188732A (en) * | 1956-12-18 | 1959-09-24 | Plessey Co Ltd | Electrical connection device and its manufacturing process |
FR2049618A5 (en) * | 1969-06-13 | 1971-03-26 | Commissariat Energie Atomique | |
DE2201348A1 (en) * | 1972-01-07 | 1973-07-12 | Siemens Ag | ELECTRICAL THROUGHOUT |
DE2524217C3 (en) * | 1975-05-31 | 1980-03-20 | Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe | High voltage bushing |
FR2444834A1 (en) * | 1978-12-18 | 1980-07-18 | Procal | Second fitting for water tank corrosion protection electrode - comprises threaded cylinder secured to tank wall by nut and shoulder bearing against tank inside wall |
-
1984
- 1984-02-15 GB GB08403943A patent/GB2154379A/en not_active Withdrawn
-
1985
- 1985-02-14 EP EP85300995A patent/EP0152307A3/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB314808A (en) * | 1928-07-02 | 1930-11-03 | Siemens Ag | Means for protecting the insulating sleeves of electrical machine windings from glow discharge phenomena |
GB547967A (en) * | 1941-07-03 | 1942-09-18 | Percy Cox | Improvements in and relating to explosively actuated apparatus for perforating submerged or other articles |
GB793974A (en) * | 1955-10-28 | 1958-04-23 | British Thomson Houston Co Ltd | Improvements relating to electric insulating bushing assemblies |
GB1152482A (en) * | 1966-03-25 | 1969-05-21 | Telephone Cables Ltd | Improvements in and relating to Bonding Plastics Material |
GB1177559A (en) * | 1966-12-23 | 1970-01-14 | Philips Electronic Associated | Corrosion-Resistant Electrical Terminal. |
GB1254025A (en) * | 1969-08-13 | 1971-11-17 | Gen Electric Co Ltd | Improvements in or relating to sealing arrangements between tubular members |
Also Published As
Publication number | Publication date |
---|---|
GB8403943D0 (en) | 1984-03-21 |
EP0152307A3 (en) | 1988-08-24 |
EP0152307A2 (en) | 1985-08-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3130292A (en) | Arc torch apparatus for use in metal melting furnaces | |
NO170001B (en) | Nozzle for cover gas welding | |
GB2154379A (en) | Leadthrough arrangement | |
US5870424A (en) | Graphite electrode having joints | |
GB2121659A (en) | Electric arc furnace electrodes | |
US2992320A (en) | Gas shielded arc welding torch nozzle | |
US4433265A (en) | Cooled discharge lamp having a fluid cooled diaphragm structure | |
BR9106756A (en) | OVEN FOR FUSING PARTICULATED METAL OXIDES, AND PROCESS FOR CASTING PARTICULATED OXIDES | |
US3043972A (en) | High temperature implement | |
US3811029A (en) | Plasmatrons of steel-melting plasmaarc furnaces | |
GB2021366A (en) | Improvements in or relating to composite electrodes for electric arc furnaces | |
DE69200302D1 (en) | Wall electrode for metallurgical DC electric furnace. | |
ES8601625A1 (en) | Electrode assembly for arc furnaces. | |
EP0075534B1 (en) | Axially movable electrode holder for use in electric steel production | |
GB1172941A (en) | Continuous Electrodes | |
JPS56165378A (en) | Gas laser tube | |
US3749802A (en) | Vessel preheating method and apparatus | |
GB1223162A (en) | Improvements in electrodes for electric arc furnaces | |
ES8300034A1 (en) | Shielding gas welding torch. | |
KR920003207B1 (en) | Composite electrode for arc furnace | |
US4663763A (en) | Charge-load support for a glow discharge furnace | |
CA2035931A1 (en) | Metallurgical vessel having at least a trough-wall electrode | |
JPS5996691A (en) | Resistance heating furnace | |
KR910000484B1 (en) | Tuyere for blast furnace | |
RU2176856C2 (en) | Non-consumable electrode for ore-smelting and impoverishment multi-slag electric furnaces |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |