US1336820A

US1336820A - Electric furnace

Info

Publication number: US1336820A
Application number: US232349A
Authority: US
Inventors: Edwin L Crosby
Original assignee: Individual
Current assignee: Individual
Priority date: 1918-05-03
Filing date: 1918-05-03
Publication date: 1920-04-13
Anticipated expiration: 1937-04-13

Description

E. L.'CROS BY.

ELECTRIC FURNACE. I

' APPLICATION FILED MAY 3, I918.

Patented Apr.13,1920.

5 SHEETS-SHEET 1.

INVENTOR I &iwm'

nnbmvfr E. L. CROSBY.

eusc'pmc FURNACE. APPLICATION FILED MAY 3, 1918.

5 SHEETS-SHEET 2.

F 1 ER.

INVENTOR WWW ATTORNEY E. L. CROSBY. ELECTRIC FURNACE.

APPLICATION FILED MAY 3. I918.

Patented Apr. 13, 1920.

5 SHEETS-SHEET 3.

INVENTOR W K W Ami/Mr E.L.CROSBY{ ELECTRIC FURNACE.

APPLICATION FILED MAY 3. I918.

Patented Apr. 13, 1920. a 5 SHEETS-SHEET 4.

I I i INVENTOH W06 2M E. L. CROSBY.

ELECTRIC FURNACE.

ATIONFILED MAY APPLI 191s. 1,336,820. Patented pr- 13, 1920.

5 sum sssssss s.

r [Ii '2 wig/gran AT'TDRNEY UNITED STATES PATENT OFFICE.

EDWIN L. CROSBY, 01F HIGHLAND IARK, MICHIGAN.

ELECTRIC To all 'wlwmz't may concern:

Be it known that I, EDWIN L. CROSBY, a citizen of the United States, residing at Highland Park, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in Electric Furnaces, and declare the followin to be a full, clear, and exact description 0? the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to electric furnaces of the inclosed refractory cylinder type, and has for its object improvements in the construction and arrangement of parts designed to secure eflicient mingling of the metal components and more efficient heating, and the reduction, as far as possible, of the disintegrating influences of direct heat of the electric are employed for heating the metal, upon the refractory walls of thev furnacenot submerged or washed by the molten mass.

Among the combination of conditions required to be met in this type of furnace is the necessary absence of any mechanical agitator within the furnace chamber, since the high degree of heat emplo ed would cause the rapid disintegration 0 any such member; moreover, the presence and'operation of any such member would almost of necessity involve more or less of a leakage to the atmosphere of the gas generated during the melting of the metal, which, in turn would result in a high degree of loss of such relatively volatile components as zinc..

In the drawings:

Figure 1 is a perspective of my improved type of furnace, showing the electrode adjustment members, as well as the locking system of wedges interposed between the shell and the toothed gear ring, by whose action a portion of the agitation of the furnace contents is brought about.

Fig. 2 is an elevation of my improved device, showing the relative positioning of the electrodes with respect to the shell.

Fig. 3, is a side elevation, with portions; of the center of the furnace chamber broken away to show the meeting ends of the elec--.

1. located the toothed trodes within.

Fig. 4 is a plan view of the furnace and, its connected parts, half being shown in sectioii. 1 r

Specification of Letters Patent.

FURNACE.

Patented Apr. 13, 19 20.

. Application filed May 3, 1918. Serial No. 232,349.

Fig. 5 is a partly sectional elevation of one form of cooling coil, through which the electrodes pass into the refractory end walls of the furnace.

Fig. 6 is a perspective view of the device ofFlg. 5.

Fig. 7 is an end view of this form of cooling coil and its connected parts.

F ig. 8 is a partly sectional elevation of a modified or alternative form of cooling shell through which the electrode passes into the furnace shell. 4

Fig. 9 is a perspective view of the device of Fig. 8.

Fig. 10 is an end cooling shell.

Fig. 11 is a detail perspective view of one of the supporting roller members for the furnace shell and of its actuating gear mechanism.

The device as a whole rests upon four standards 12, through the top of which engages the pivot pin 13 which connects the strut members 14 therewith. Through each end of each of the strut members passes another pivot pin 15, on which are rotatably journaled the grooved or

troughed rollers

16 and 17, which are arranged in pairs in parallel planes, so that the travel ring or track 18 runs smoothly in their grooved portions. These travelrings 18 engage about the drum 19 near the ends thereof, but are spaced therefrom by a series of wedges 20, so that on one side of the drum the wedges under one of the travel rings space it from the shell of the cylinder to the maximum degree required, whereas the wedges under the other ring at that point of the shells periphery separate it from the surface of the drum by very slight space; the wedge effect on each ring being thus tapered about the periphery of the drum, it results that there are only two points in its complete phase of rotation at which the axis of the drum is in a truly horizontal position. At all other times it is more or less inclined in one direction or the other, right or left as the case may be, as regards the positioning shown in Figs. 1 and 3, thus effecting a wave motion in the mass of molten metal, to which further reference will be made later.

Side by side with the travel ring 18 are rings 21, which mesh ",with the teeth of driving gears 22, which 'may be actuated by any convenient source view of this form of of power, such as the reversing mechanism lll conventionally indicated at 24, to rotate them and the

rings

18 and 21 and the furnace cylinder 19. The rotation imparted may either be continuous or oscillatory, as the conditions of the particular heat of metal may require; in some cases less than a complete rotation back and forth will be found desirable. I desire, however, that any type of rotative actuation of the drum, any degree required be understood as within the $00 of this disclosure.

The urnace drum itself referably has an outer shell of metal, within which are ar: ranged one or more layers of refractory substance, so that the actual interior dimensions of the melting chamber are much less than those of the exterior dimensions of the drum. Access thereto may be had for char ing the furnace, and for pouring of the mo ten mass, through the hole 23, which is closed by the door 26 when the melting process is going on. 7

At each end of the furnace drum 19 is located a frame or spider 27, its apertured outer end being arranged coaxially with the drum, so that the outer end of the electrode stem 28, when retracted, can pro'ect beyond the spider. Rotatively su port of this spider is a han wheel 29, whose screw stem 30 is connected with the termior coils which are located in the refractory end walls of the furnace, and may be either of the coil type shown at 34 in Fig. 3 and in enlarged detail in Figs. 5,6. and 7 or of the trunnion t pe shown at 35 in Fig. 3, and in enlarged etail in Figs. 8, 9 andlO. The inner end of either of these types of cooling members may be spaced from the wall of the furnace 19 by centrally apertured pads 0r closure pieces 39.

The operation of this device is as follows:

The various components of the alloy desired having been placed within the furnace through the hole 23, the door 26 is fixed in position and the electrodes are individually adjusted by their wheels 29, so that their ends are the desired distance apart.

" The furnace drum being thus tightly closed and the electric current bein turned on, a high degree of heat is .quicklg generated within t e central chamber, as soon as by the end the metal component having the lowest melting point begins to liquefy, the rotation of the drum is started by means of the rotating driving gears 22 which mesh with the toothed rings 21. imparted may be an oscillatory one, the direction being reversed when a complete revolution of the drum has been accomplished, or it may be such a fraction of a complete rotation as will leave only the pro- {:01'131011 of the drumsdperiphery represented y the width of the oor unwashed by the molten mass in the furnace; in either event, that portion of the refractory inner surface of the drum, which at the outset of the heat constituted the cei or dome of the interior chamber untouch by the molten metal, is washed by it as the cylinder rotates, and a certain roportion of excess heat which it has absor d will in turn be absorbed by the molten metal; and that portion of the inner surface of the cylinder which in the outset com uted the bowl or metal-holding portion 0 the furnace, hecomes in turn the ceiling portion, and consequentl in turn subjected to the direct heati in uence of the exposed electrodes.

his rotation, either continuous or back and forth as may be desired, of course effects to a certain extent the commin ling of the components of the alloy so that t e tendency of the various components to stratify is ofl'set, but in many instances it would not efl'ect a sufficient mingling of the parts from end to end of the furnace drum. were it not for the axial rocking of the c linder from end to end, due to its un ua positioning with respect to the rings 1. brought about I? the wedging already referred to.

'hether the cylinders turning is complete or oscillatory, however, this constant variation in the sition of the central axis of the cylinder e eats a wave motion of the molten metal from end to end thereof, which accomplishes the further mingling of the alloys components to the degree desired. Care, of course, must be taken as to the total quantity of material put into the furnace before the heating is started, so that in allowing .for this wave motionfrom end to end, the

top surface of the molten mass will never rise quite to the level of the electrodes. I have illustrated this in Fig. 3 particular] by the dotted lines :v-z and y-y, which represent the position of the to surface of the molten mass within the heating chamber at the op ite extremes of axial inclination 'of the cy inder.

What I claim is:

1. In an electric furnace, in combination with a refractory shell member rovided with a vapor-tight door, a pair of ectrodes adjustablyengaging through the ends of said she coaxially therewith, means for projecting and saidelectrodee If desired, the rotation while permitting the maintenance of their coaxial position with respect to the shell member in all positions thereof, a pair of travel rings spacedly and variantly engaging about said shell member with respect to the axis thereof, and means for imparting rotative movement thereto, thereby effectin the rotation of the shell about an axis w ose position relatively to the horizon is constantly varying during the period of rotation.

2. In an electric furnace, the combination of a rotatable refractoryshell, a pair of travel rings engaging thereabout, means for eccentrically spacin said travel rings with respect to the perip ery of the shell and to each other, a series of supporting rollers whereon said travel rings move, thereby turning said shell about a constantly variant axis, means for positively causing the rotative movement of said travel rings, and electrode members adjustably engaging through the ends of said shell.

3. An electric furnace, having in combination with a refractory furnace chamber, electrodes adjustably engaging through the ends thereof in alinement with its central axis, means for regulating the positioning of the meeting ends of said electrodes with respect to one another, a pair of travel rings spacedly engaging about said furnace chamber near the ends thereof, wedgemembers interposed between the we" of the furnace chamber and the inner faces of said rings, whereby said rings are eccentrically disposed with respect to one another and to said furnace chamber, roller members w'hereon said travel ring members rest, and means for rotatably actuating said travel rings and thereby said furnace chamber. 4. An electric furnace, having in combination with a pair of travel ringsdisposed in parallel vertical planes, a refractory shell member about whose end portions said travel rings spacedly engage in varying degrass of eccentricity, a plurality of supporting rollers whereon said travel rings rotatably rest, means for imparting rotative movement to said travel rings and thereby to said refractory shell member, and electrode members adjustably engaging through the end walls of said shell member in coaxial relation to one another to said shell, member. Y

5. In an electric furnace, in combination with a shell member, a pair of adjustable electrode members arranged coaxially thereof, means for regulating the degree of projection ofsaid electrode members into the shell member, cooling members through which the ends of said electrode members pass to the interior of said shell member and by which said electrode members are spaced from direct contact with the surroundin portions of said shell member means -or rotativel member and means fbr varying the rotative axis of said shell member with respect to the horizon While its rotation is in progress.

6. In an electric furnace, the combination of an interiorly refractory shell member having centrally apertured end portions, longitudinally adjustable electrode members engaging through the apertured ends of the shell and arranged to rotate therewith, a pair of ring members spacedly disposed about said shell member at variant distances from the periphery thereof, rotatable supporting rollers whereon said ring members rest, means for rotatively actuating said ring members and with them said shell, thereby eifecting a constant variance of the position of its axis relatively to the horizon while the rotative movement is in pro ess.

7. An electric furnace, having, in combination with a terminally apertured shell member, a pair of ring members eccentrically disposed about the ends thereof, means for rotating the ring members about their common central axis, thereby causing a constant variance from the horizontal of the rotative axis of said shell member, electrode members coaxially engaging in the apertured ends of said shell member, means for regulating the degree of projection and of retraction of said electrode members, and cooling members interposed between said electrode members and the adjacent portions of said shell members.

8. In an electric furnace, in combination with a refractory shell member having centrally apertured ends, adjustable electrode members coaxially engaging through said apertured ends, cooling members engaging about said electrode members in a way to close the s ace between their outer surfaces and the a jacent edges of the apertures in the shell, a pair of travel rings spacedly engaging about said shell member at variant distances from the periphery thereof, 'and supporting rollers over which said travel rings move, thereby imparting to said shell member a variance in the position of its axis relatively to the horizon.

In testimony whereof I sign this specification in the presence of two witnesses.

EDWIN L. CROSBY. Witnesses:

HARRY F. MCMASTER, WILLIAM M. Swan.