US1133829A - Metallurgical furnace. - Google Patents

Description

U. WEDGE.

METALLURGICAL FURNACE.

APPLICATION FILED JAN. 4, 1 913.

Patented Mar. 30, 1915.-

2 SHEETS-SHEET 1.

1 7M 23 z 7 i- '24 :1

l6 /6 %za /7 M A? a /7 QM. v WTNESSES 6 INVENTOR JA UTLEY WEDGE U. WEDGE.

METALLURGICAL FURNACE.

Patented Mar. 30, 1915.

2 SHEETS-SHEET 2.

.REY TDNT rNLERH v w YA E S mH Y B WPTNE'SSES Mr FFIGE.

UTLEY WEDGE, OI? ARIDMORE, PENNSYLVANIA.

METALLURGICAL FURNACE.

Specification of Letters Patent.

Patented Mar. 30, 1915.

'Applicationfiled January 4, 1913. Serial No. 740,104.

To all whom it may concern:

Be'it known tha I, UTL'EY'WEDGE, a citi zen of the United States, residing in Ardmore, Pennsylvania, have invented certain Improvements inMetallurgical Furnaces, of which the following is a specification.

' My invention relates to that type of furnace having its hearth or series of superposed hearths surrounding a central rotat-' ing shaft which usually carries projecting arms provided with depending rabbles for stirring and feeding the ore or other ma terial deposited upon the hearth or hearths of the furnace, my invention providing for the thorough heating of said material without unduly heating the rabble arms when the same are employed, permitting the use of either gas, oil, or an electric current as the heating medium, and providing simple and effective means for the use of the electric current as such heating medium.

In the accompanying drawings-Figure 1 is a transverse vertical section of part of a superposed hearth furnace of the type to which my invention relates, illustrating one method of using oil as the medium for heating the treating chamber ofthe furnace;

Fig. 2 is a similar View illustrating means for employing gas as the heating medium; I

Fig. 3 is a view similar'to Figs. 1 and 2 but illustrating a means of employing an electric currentas a heating medium; Fig. 4 is. a her 5011... section of the furnace on the line a/a, Fig. 3, and Fig. 5 is a transverse section, on an enlarged scale, on the line b-b, Fig. 3.

In Figs. 1, 2 and 3 of the drawing, 1 rep resents the outer wall, 2 the roof, 3 thetop hearth and 3 the top treating-chamber of a furnace of the superposed hearth type to which my invention is particularly adapted, although it may, if desired, be applied to a furnace having but a single hearth and a single treating chamber.

The hearth 3 and treating chamber 3* are annular and surround a central shaft,

which, by preference,consists of a metallic cylinder .4 provided with a suitable covering of refractory material 4' to protect it from the heat. This shaft is combined with any available means for causing rotation of the same, as for instance the means shown in my Letters Patent No. 777,577, dated December 13, 1904.

Secured to the shaft and projecting radially therefrom into the treating chamber 3 are a pair of diametrically opposite rabble'arms 5 which are intended to be provided, in the ordinary manner, with depending rabbles for stirring and feeding the material on the hearth 3, as the shaft 4 is rotated. Also mounted upon the shaft 4 and rotating therewith are a pair of oil burners 6, which are, by preference, diametrically opposed and disposed at right angles to or midway between the rabble arms 5, these oil burners receiving their supply of oil from a tank 7 at the top of the shaft and also receiving a supply of steam or air under pressure through branches 8 from a central pipe 9, which rotates with the shaft and has, at the top, a suitable stuffing box connection with the fixed supply pipe 10 above the shaft.

The flame from the 'burners 6 is projected outwardly across the annular treating chamber 3 and comes directly into contact with the material lying upon the hearth 3, and, as the shaft 4 and the burners 6 rotate, the jets of flame are carried around over the entire hearth and all portions of the material lying upon the hearth are therefore subjected to the action of the flame.

In the construction shown in Fig. 2 the heating of the treating chamber 3 is effected by a jet of gas from a burner 11 or by downwardly directed jets from a pipe 12 projecting into the treating chamber, the central gas pipe 13 communicating with the fixed gas pipe 14 above the shaft and being in communication with the burner 11 by means of a branch pipe 15 and in direct communication with the pipe 12.

In the construction shown in Fig. 3 an electric current is used as the heating medium, arms 16 projecting into the treating chamber from the shaft 4 which arms are segmental in cross section, as shown in Fig. 5, and cary an electrode 17 which is mounted in a ring-like portion of the outer end of the arm and in an insulating bushing 18 at the innerend of the arm. Rings 19 and 20 are mounted upon the upper end of the shaft 4 so as to be insulated therefrom and from each other, the ring 19 being in contact with a brush '21, which is connected to one pole of an electric generator, and the ring 20 being in contact with a brush 22, which is connected to the other pole of said generator... The ring 19 is connected by wires 23 to each of the arms 16 and the ring 20 is connected by wires 24 toeach of the electrodes 17, consequently electric current is caused to flow from the ring 19 through the wire 23 to the arm 16 and thence back through the electrode 17 and wire 24 to the ring 20. The electrodes 17 being of resisting material becomes highly heated and radiates its heat onto the material lying upon the hearth of the furnace. By reason of the mounting on the electrode 17 on the under side of the arm 16, said electrode can approach closely to the surface of the material lying upon the hearth and the concave form of the arm above the electrode serves to dedeflect heat onto the material and prevents it from being radiated into the upper portion of the treating chamber, consequently the structure described provides for economical operation and'constitutes one of the features of my invention.

The sheets of flame from the burners 6 of Fig. 1 and from the burners 11 and 12 of Fig. 2, and the heated electrode 17 of Fig. 3 are all relatively remote from the rabble arms, consequently the latter are not excessively heated and the rapid burning out ofthe arms or other injuries thereto due to excessive heat are thereby prevented.

To prevent excessive heating of the arms 16 the latter may have linings 28 of material which is a non-conductor or a-poor conductor of heat, or the arms may also be cooled by a flow of water or other cooling fluid through the same, as is common in rabble arms, or both of these methods may be adopted.

I claim:

1. The combination, in a furnace, of a central rotating hollow shaft and a hearth surrounding the same and-having above it 1 a closed treating chamber, said hearth and chamber being in close relation to the shaft, rabble arms and heating devices carried by and rotating with said shaft, said heating devices being disposed at points remote from the rabble arms, and means disposed within said hollow shaft for conveying the heating, agent to said heating devices.

2. The combination, in a furnace, of a central rotating shaft and a hearth surrounding the same, with an electrical heating device carried by and rotating with the shaft and having an electrode projecting over the material upon the hearth of the furnace.

3. The combination, in a furnace, of a central rotating shaft and a hearth sun-- rounding the same, with an electrical heating device carried by and rotating with the shaft, and comprising an arm projecting over the material on the hearth of the furnace and having on its under side an elec trode to be heated by the passage of the electric current.

4. The combination, in a furnace, of a central rotating shaft and a hearth surrounding the same, with an electrical heating device carried by and rotating with the shaft and comprising an arm of segmental cross section projecting from the shaft over the material on the hearth and carrying upon its under or concave side an electrode to be heated by the current.

5. The combination, in a furnace, of a central rotating shaft, a hearth surrounding the same, and an electrical heating de vice comprising an arm projecting from the shaft over the material on the hearth, an electrode carried by said arm and in conducting contact With the same at one end, means for insulating the electrode from the arm except at such point of contact, means for connecting the arm with one pole of the electric generator, and means for connecting the electrode with the other pole of the same.

6. In a mechanical furnace provided with a revolving shaft carrying a rabble arm, a burner having a flame opening at its end carried substantially radially by said shaft.

7. In a mechanical furnace provided with a hollow revolving shaft, carrying a rabble arm, a burner carried by said shaft, located at a predetermined distance in advance of said rabble arm.

8. In a mechanical furnace provided with a hollow revolving shaft carrying a rabble arm, a burner carried substantially radially by said shaft, located at a predetermined distance in advance of said rabble arm.

9. In a mechanical furnace provided with a hollow revolving shaft carrying a rabble arm, a plurality of burners, having flame openings at their ends carried substantially radially by said shaft, said-burners and the flames thereof being out of contact with said'rabble arm.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

UTLEY WEDGE. Witnesses:

KATE A. BEADLE, HAMILTON D. TURNER.

Copies. of this patent may be obtained for five cents each, by addressing the Commissioner 0! Patents,

Washington, D. G.

Images