US3519719A - Method of operating metallurgical furnaces - Google Patents

Description

y 7, 1970 w. FADLER METHOD OF OPERATING METALLURGICAL FURNACES Original Filed Feb. 20, 1967 2 Sheets-Sheet 1 INVENTOR M4176? M0452 018a ATTORNEYS July 7, 1970 w. FADLER 3,519,719

METHOD OF OPERATING METALLURGICAL FURNACES Original Filed Feb. 20, 1967 2 Sheets-Sheet 2- l NV ENTOR Mil-T62 FAmee ATTORNEYS United States Patent 3,519,719 METHOD OF OPERATING METALLURGICAL FURNACES Walter Fadler, Vienna, Austria, assiguor to Wiener Schwachstromwerke Gesellschaft m.b.H., Vienna, Austria Original application Feb. 20, 1967, Ser. No. 617,396. Divided and this application Nov. 21, 1968, Ser. No. 792,184 Claims priority, application Austria, Feb. 22, 1966, A 1,608/66 Int. Cl. H05b 5/00 US. Cl. 13-34 1 Claim ABSTRACT OF THE DISCLOSURE A method of operating a barrel-type, metallurgical induction furnace by rotating it so that a selected one of two induction heaters extends upwardly above the melt while the other extends downwardly from below the bottom of the furnace. The downwardly extending induction heater operates to heat the material inthe furnace whereas the upper one is switched off. In the event the lowermost heater is to be replaced or allowed to be switched off for a period of time, the barrel-type furnace is rotated to a second position in which the heater positions are reversed.

This application is a division of application Ser. No. 617,396, filed Feb. 20, 1967.

This invention relates, in general, to the method of operating metallurgical furnaces and, in particular, to a new and useful barrel-type furnace constructed and arranged so that it may be oriented with selected one of two inductive heaters in an effective position and with the other of the heaters positioned to permit replacement thereof.

The durability of the lining of a furnace depends principally on the wall thickness of the lining. In the case of induction furnaces which include crucible inductors which are secured to the furnace vessel, the lining of the crucible inductors must necessarily be thinner than the lining of the furnace vessel in order to minimize the stray field. As a result, the crucible inductors do not last for the life of the furnace and they must be frequently replaced. It is important that the replacement of the inductors be carried out as quickly as possible in order that the operation of the furnace be not unduly interrupted and in order to insure that the temperature does not drop inside the furnace by a considerable amount.

In accordance with the invention, there is provided a barrel-type induction furnace which is mounted so that it may be rotated and disposed in either a first position with a first inductive heater arranged at the lowermost end thereof in an operative position and second inductive heater arranged in an uppermost position at an inoperative location or it may be rotated to a second position in which the inductive heater positions are reversed. In the preferred arrangement, the inductive heaters are formed as lateral extensions of the barrel-type furnace and they are arranged in diametrically opposite extensions formed on the furnace. The extensions provide a mounting for a replaceable crucible inductor which will be oriented in the same manner as the extensions with their axes inclined in respect to the central axis of the barrel furnace. The induction heaters are also advantageously arranged symmetrically to the central axis of the barrel furnace.

During operation of the furnace, the furnace is oriented so that one of the induction heaters extends upwardly above the surface of the melt whereas the other one extends downwardly from below the bottom of the furnace.

p ICC The downwardly extending induction heater would be in an operative position to heat the material in the furnace and the upper one of the induction heaters would be switched off. In the event that the lowermost heater must be replaced or be allowed to be turned off for a period of time, it is merely necessary to rotate the barrel-type furnace in order to position the opposite heater in an operative position at which it extends downwardly from the bottom of the furnace. When this is done, the other one is automatically positioned in an uppermost position at which it may be turned off and left inoperative. In this inoperative position, it may be removed and the extension portion of the furnace may be plugged if desired, or the defective induction heater may be replaced by a new induction heater.

In accordance with a further feature of the invention, the barrel-type furnace includes two diametrically opposite pouring spouts. One of the spouts arranged on one side of the furnace defines a passage which will extend upwardly when the other spout defined on the opposite side of the furnace has the passage defined thereby turned downwardly. During operation, the downwardly turned spout may be plugged and the upwardly turned spout may be used for pouring 01f the melt by tilting the furnace in a direction to move the discharge end thereof downwardly below the level of the melt. In addition, it is a simple matter to plug either or both of the spout passages to permit complete rotation of the barrel-type furnace where desired.

Accordingly, it is an object of the invention to provide an improved barrel-type furnace which includes a tubular furnace member which is mounted to be rotated between a first position and a second position and which includes inductors which are arranged at diametrically oppositely extending sides, one of which will be positioned uppermost in the first position of the barrel furnace and the other of which will be positioned lowermost, the barrel being rotatable to change the position of the inductors in the second position to permit replacement or removal thereof or operation thereof as desired.

A further object of the invention is to provide a rotatable barrel-type furnace which includes a plurality of inductor heaters which may be selectively moved between an operative and an inoperative position in order to permit the inductors to be either used to heat the melt or shut-off and either replaced or removed as desired.

A further object of the invention is to provide a metallurgical furnace which is of barrel configuration and is mounted for rotation and which includes spout members formed at diametrical sides, with one of the spout members defining a downwardly extending passage and the other of the spout members defining an upwardly extending passage, the spout with the downwardly extending passage being adapted to be plugged to permit the other passage to be used for pouring the melt or both of the passages being adapted to be plugged to permit rotation of the barrel furnace.

A further object of the invention is to provide a metallurgical furnace which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a longitudinal sectional view of a barrel furnace constructed in accordance with the invention;

FIG. 2 is a section taken on the line 2-2 of FIG. 1; and

FIG. 3 is a view similar to FIG. 2 indicating the barrel furnace in a rotated position.

Referring to the drawings in particular, the invention embodied therein comprises a metallurgical furnace including a barrel-type furnace vessel generally designated 1 which is rotatably supported on a pedestal 10.

In accordance with the invention, the barrel-type furnace includes diametrically oppositely formed extension portions 12 and 14 which are provided for mounting crucible inductors 4 and 3, respectively. During operation of the furnace, one of the inductors, that is, the inductor 3 in the drawing, is disposed in an operative position below the bath surface 5 to provide a means for heating the melt. A feature of the construction is that the opposite inductor, the inductor 4, is disposed in a position above the melt surface 5 so that it can be removed from the furnace and replaced if desired.

In the event that it is desired to discontinue the operation of the inductor 3, then the furnace is rotated from the position indicated in FIG. 1 to cause the inductors 3 and 4 to be positioned in the dotted line position indicated at 3 and 4'. The rotation takes place about the center line 2. After the rotation is completed, the inductor 3 will be in the position 3' so that it can be either removed and replaced or the extension 14 can be plugged to permit operation only with the inductor 4. In the event that it is decided to remove an inductor and to plug the extension, it is usually advisable to provide a cover construction which is water-cooled in order to avoid any loss of heat by radiation.

A further feature of the invention is indicated in respect to the showings of FIGS. 2 and 3. The barrel-type furnace of the invention includes a spout formation 16 on its one side with an upwardly directed passage 6 and a spout formation 17 on its opposite side with a downwardly directed passage 7. As indicated in the drawing, the passage 7 is plugged at the opposite end by tightly securing at the discharge end a plug or stopper member 8. In the operating condition indicated in FIG. 2, the tapping duct 6 may be employed for tapping the melt 3. To accom- 4 plish this, the furnace 1 is rotated in the direction of the arrow 9 to bring the passage discharge end down below the surface of the melt 5 and to cause the outpouring of the melt material.

In order to permit the furnace to be rotated such as for the replacement of an inductor, the ends of each of the passages 6 and 7 are plugged with suitable plugs as indicated in FIG. 3.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A method of operating a barrel-type furnace which comprises a furnace vessel which is rotatable about its axis and includes a crucible inductor extending downwardly from one end and upwardly from an opposite end comprising operating the furnace with the downwardly extending inductor turned on and continuing the operation thereof until the inductor requires deenergizing, and rotating the furnace to position the downwardly extending inductor in an upwardly extending position and the upwardly extending inductor in a downwardly extending position and thereafter operating the furnace with the downwardly extending inductor energized.

References Cited UNITED STATES PATENTS 1,094,354 4/1914 Wilmowsky l3-10 2,406,147 8/1946 Hopkins 1310 2,754,346 7/1956 Williams 13-6 X 3,088,182 6/1963 Tama et al. 26633 3,244,495 4/1966 Apple et al. 13-6 X BERNARD A. GILHEANY, Primary Examiner H. B. GILSON, Assistant Examiner US. Cl. X.R.

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