GB2220332A

GB2220332A - Graphite electrode holder for electric furnace

Info

Publication number: GB2220332A
Application number: GB8909348A
Authority: GB
Inventors: Volokhonsky Lev Avramovich; Tsikerman Alexandr Leonidovich; Dolgy Valery Yakovlevich; Chernyak Alexandr Ivanovich; Kurlykin Vladimir Nikolaevich; Vlasov Mikhail Ivanovich; Novikov Jury Petrovich; Kisselman Mikhail Anatolievich; Shatsillo Valery Antonovich; Andreev Alexandr Leonidovich; Sedov Nikolai Mikhailovich; Protokovets Evgeny Georgievich; Neimatov Ibat Nasrulaevich; Piljukov Jury Fedorovich; Rakhmanin Alexandr Vasilievich
Original assignee: VNI PK I T I ELEKT OBORUD
Current assignee: VNI PK I T I ELEKT OBORUD
Priority date: 1987-08-28
Filing date: 1987-08-28
Publication date: 1990-01-04
Also published as: WO1989002211A1; SE8901488L; DE3791004T1; SE462513B; JPH02501159A; SE8901488D0; GB8909348D0

Abstract

The holder comprises a casing (2) and intermediate unit (3) consisting of a steel element (6), a copper element (9) and a steel element (12) joined together so as to form non-detachable bimetallic connections (10, 11), and of a partition (21) intended for deviating a cooling liquid flow in a chamber (20) formed by the copper element (9) and the casing (2).

Description

HOLDER OF GRAPHITE ELECTRODE FOR ELECTRIC FURNACE Technical Field The invention relates to the electrometal-lurgy and more speciafically to holders of graphite electrodes for an electric furnace.

Background of the Invention Known to the prior art is a graphite electrode holder comprising a housing internally accommodating pipes for discharge of a cooling medium and delivery of a gas, and also an adapter element with a seat for securing a nipple. A partition provided with passages for the cooling medium is disposed between the housing and the adapter element (cf., for example, French patent No.2363959, IPC H05B 7/12, 1978, patentee ??The Steel Company of Canada"), This holder features a low service durability because of design disadvantages of the adaptor element, and especially because of a poor cooling which results in a nonuniform rejection of heat which in its turn may cause a cracking and even a break of the graphite electrode.

Also known in the prior art is a holder of the graphite electrode for an electric furnace, comprising a housing with a pipe for delivery of a gas and an adapter unit with a cooling system. The adapter unit comprises a first steel element secured to the housing and a second copper element with a center hole for delivering the gas to the electric furnace through the graphite electrode connected to the copper element (cf., for example, US,A, No.4287381, IPC H053 7/08, NPC 13-18, 1981, patentee Robert W,Xontgomery, England, British Steel Company, England).

This holder also features the low service durability due to the causes mentioned herein above.

Summary of the Invention The invention is essentially aimed at providing a holder of the graphite electrode for an electric furnace, in which an adapter unit is made so that a high resistance of the holder to heat and electric loads is ensured.

This aim is attained by that in a holder of the graphite electrode for an electric furnace, comprising a housing and an adapter unit with a cooling system, and incorporating a first steel element secured to the housing, and a second copper element with a center hole for delivery of a gas to the electric furnace through the graphite electrode connected to this copper element, according to the invention, the adapter unit comprises a third steel element disposed in the center hole of the copper element which together with the housing forms a space for cooling the entire adapter unit, and this space internally accommodates a partition for guiding the flow of a cooling liquid, while the copper element together with the first and the third steel elements forms nonseparable bimetallic joints.

It is desirable that the copper element should have two cylindrical portions of different diameters and the cooling space should be formed by the cylindrical portion of a smaller diameter, the first steel element and the housing, and a partition made in the form of a cup should be disposed in said cooling space, Brief Description of the Drawing The invention will now be described in greater detail with reference to the specific embodiment thereof, taken in conjunction with the accompanying drawing, illustrating a section of the graphite electrode holder, according to the invention.

Best Mode for Carrying Out the Invention A holder of a graphite electrode 1 comprises a housing 2 and an adapter unit 3 to which the graphite electrode 1 is secured. The housing 2 internally accommodates a pipeline 4 for delivery of a gas and a pipeline 5 for delivery of a cooling medium, for example, water.

The adapter unit 3 comprises a first steel element 6 by means of which the adapter unit 3 is connected to the housing 2 through a partition 7 having a hole 8 for accommodating the pipelines 4 and 5. The steel element 6 internally accommodates a copper element 9 which, in conjunction with the internal surface thereof forms a nonseparable bimetallic joint 10, The internal surface of the copper element 9 forms another nonseparable joint 11 with one more steel element 12 disposed in the center hole of the copper element 9. The steel element 12 also has a center hole through which passes an end of the pipeline 4 acommunicating with a space 13.

The copper element 9 is also provided with a recess in which by means of a thread is installed a nipple 14 having a passage 15 communicating the space 13 with a passage 16 of the graphite electrode 1 for delivery of a gas therethrough to the space of an electric furnace (not shown in the drawing). The graphite electrode 1 is connected with the nipple 14 through the medium of a thread 17.

The copper element 9 is provided with a cylindrical portion 18 the outside diameter of which is equal to the inside diameter of the steel element 6 and with a cylindrical portion 19 the diameter of which is smaller than that of the first cylindrical portion 18, and forms in conjuction with the steel element 6 and the partition 7 a space 20 which internally accommodates a partition made in the form of a cup 21.

Made in the bottom of the cup 21 are two holes for passing the pipelines 4 and 5 of which the pipeline 5 is communicated with the space 20 to supply it with the water intended for cooling the adapter unit 3.

A pipeline 22 is communicated with a space 23 of the housing 2 for discharge of water in the process of the holder cooling.

The graphite electrode 1 with the nipple 14 is screwed in the copper element 9 of the adapter unit 3, the pipeline 4 being in communication with the passages 15 and 16, Then the graphite electrode 1 is installed in the electric furnace.

For cooling the holder and the adapter unit 3 thereof, water is supplied through the pipeline 5 and while flowing along the partition 21 the water gets in the space 20 and through the hole 8, in the space 23, and is discharged from the holder through the pipeline 22.

Despite high electric and heat loads acting on the electrode 1 and consequently on the holder thereof, the resistance of the electrode 1 of the proposed design is substantially increased, and even formation of microcracks, on said electrode or its break does not bring about an emergency situation, as in case of the break of the electode 1 the cooling medium is prevented from getting in the electric furnace due to its circulation in the spaces separated from the electric furnace by the copper element 9.

The proposed graphite electrode holder has a good current pick-off, as the greater surface of its elements, especially in the zone of maximum heat loads, is subjected to cooling.

If the adapter unit gets out of order, it may readily be replace with a new one.

Industrial Applicability The invention may be used for the electroslag remelting and casting of metals and alloys, as well as in electric arc steel-making furnaces.

Best Modes for Carrying Out the Claimed Invention It is preferred that in an adapter unit the copper element in conjunction with two steel elements should form nonseparable bimetallic joints and that a space isolated from the graphite electrode secured to the adapter unit should be formed between the copper element and the housing for cooling the adapter unit.

Claims

ClAIMS

1. A holder of the graphite electrode for an electric furnace, comprising a housing (2) and an adapter unit (3) with a cooling system, and having a first steel element (6) secured to the housing (2) and a second copper element (9) with a center hole for delivery of a gas to the electric furnace through a graphite electrode (1) connected to this copper element (9), c h a r a c t e r i z e d in that the adapter unit (3) incorporates a third steel element (12) disposed in the center hole of the copper element (9) which together with the housing (2) forms a space (20) for cooling of the entire adapter unit (3), and the space (20) internally accommodates a partition (21) for guiding the flow of a cooling liquid, white the copper element (9) in conjunction with the first steel element (6) and the third steel element (12) forms nonseparable bimetallic joints (10,11).

2, A holder according to Claim 1, c h a r a c t e r i z e d in that the copper element (9) has two cylindrical portions (18, 19) if different diameters, and the cooling space (20) is formed by a cylindrical portion (19) of a smaller diameter, the first steel element (6) and the housing (2), and said cooling space (20) internally accommodates a partition made in the form of a cup (21).