US1208817A

US1208817A - Electric furnace.

Info

Publication number: US1208817A
Application number: US8647116A
Authority: US
Inventors: James W Moffat
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-03-24
Filing date: 1916-03-24
Publication date: 1916-12-19
Anticipated expiration: 1933-12-19

Description

J. W. MOFFAT, mcmc'runm'ce; APPLICATION HLED 141.24.

Patehted Dec-19,1916.

W! TNE555.

zzvvs vraa reduction chamber which UNITED STATES PATENT OFFICE.

JAMES W. MOFFAT, OF TORONTO, ONTARIO, CANADA.

ELECTRIC FURNACE.

To aZl whom it may concern. Be it known that I, JAMES W. MOF'FAT, ot the city of Toronto, in the county of York.

all arranged in fixed relationship to oneanother. Various troubles were experienced in tapping this furnace so as to satisfactorilv separate the slag and metal, and as an improvement the furnace described and claimed in United States Patent No. 1,108,924 of September 1, 1914 was devised o overcome the troubles experienced and successful. advantages,

the reduction chamber takes place owing to of making a tight joint between the two When the crucible is tilted.

also arrange tiltable together as a unit. I ore roasting in connection with the stack an device which will not only thoroughly dry the charge but also preheat it and partially reduce it. Trouble is also experienced when the ore and flux are showered same opening through which the furnace gases escape owin to the fine particles be ing carried up with the gases A further object of devise means for so leadin off the g and feeding in the ore an losses from this cause are minimized. This object I attain by leading off the flue gases from points adjacent the inner wall of the fines connect with a chamber forming part of the stack and by feeding in the ore through an opening sub- Specification of Letters Patent. Patten ted Dec, 19, 1916. Application filed larch 24 I ,1816. Scria1No.86,471.

stantially at the center of the top of the ,re-

uction chamber. I

y invention is hereinafter more specifically described and illustrated in the accompanying drawings in Which *igure 1 is a vertical Section of the furnace; Fig. 2 a side elevation partly in section; and Fig. 3 a plan view partly in section.

ferent figures.

1 is the reduction chamber of the furnace secured in fixed relationship to the crucible l communicating therewith. The crucible is electrically heated, 3 being the electrodes which are preferably six in number and are shown diagrammaticall 4 are tap holes or spouts, one at each side. These tap holes are of different sizes.

The crucible is supported in any suitable manner so that it may with the reduction chamber be tilted to facilitate the withdrawal of slag through the larger of the tap holes and the subsequent pouring of the molten contents of the crucible through the smaller one.

ing shown preferably spindles 9 which are geared totrunnion Wheel 7.

shown for simultaneous operation.

e reduction chamber- 1 has its provided with openings for the exit the introduction of the six openings 11 are proin the top for the passage of gases.

ardizing of brick shapes. The hole 25 in the center is intended for the introduction of the ore and flux. The ore thus falls through a central dead space in which the gases are comparatively quiescent or may even be caused to eddy by suitably directing the air through the openings 22 which are d to provide air for the combustion of any surplus reducing gas. The fine partipossible, four of the dues are led through the bottom of the furnace, the remaining two through one end of the chamber as shown. Between this chamber and the upright part 17 of the stack is located a rotatable cylinder "18 suitable for the pre-heating of ores, this cylinder thus forn'iing' part of the stack. While a tube roaster is mentioned any other type of roaster suitable to the work may be used.

The hot furnace gases, when the furnace is in operation, pass into the chamber 16, thence over and through the charge passing through the cylinder 18 and up the stack, pro-heating and roasting the charge in their passage. 19 of the ordinary type is providedfor the introduction of the charge of ore and flux into the rotatable cylinder. The ore, mixed with any necessary ux, is fed in through the top of the reduction chamber through a spout 20, the mouth of which is located below the end of the cylinder 18. This spout extends through the floor of the combustion chamber, through the plate 13 and through the central hole in the top 10 of the reduction chamber. When the reduction chamber and crucible are to be tilted this spout must be raised out of the way. Any means may be provi for this pur ose. I show, however, a lever .21 suitably ulcrumed to the floor 14 and to the spout. By operating this lever the spout can be raised clear of the to of the reduction chamber which is thus eft free to tilt.

23 are openings through which carbonaceous matter may be injected to produce the reducing atmosphere necessary.

Reduction is carried out by showering the ore and flux in pulverulent condition through the top of the reduction chamber down to the crucible below. This charge having been pre-heatml and partially roasted is thoroughly dry and in such condition as to be readily reduced in the reducing atmosphere present in the reduction chamber. After a suliicient quantity of the reduced material has accumulated in the crucible the spent 20 is raised and the reduction chamber and crucible tilted to pour off the slag and subsequently the metal as hereinbefore referred to. Owing to the fact that the reduc- Gl tion chamber and crucible tilt together there the reduction is very little escape of heat from the crucible, so that the furnace is in a condition for the immediate resumption of opcration as soon as it has been restored to its normal position. The plate 13 may be made of suificient dimensions to close the openings 11 when the furnace is tilted.

With this furnace a maximum of convenience in operation is secured. The proper separation of the slag and the pouring of the metal til the right time is insured, and owing to the [ire-heating of the charge the operation of the furnace is very efficient and economical.

What I claim as my invention is l. A furnace comprising a stationary stack; and an unobstructed reduction cham ber and a crucible in fixed relationship to one another and tiltable as a unit, the reduction chamber normally communicating with said stack.

2. A furnace comprising a stationary stack; and an unobstructed reduction chamber and a crucible in fixed relationship to one another and tiltable as a unit, the reduction chamber normally communicating with said stack and adapted when tilted to sub- 7 stantially close off the stack.

3. A furnace comprising a stationary stack; an unobstructed reduction chamber and a crucible in fixed relationship to one another and tiltable as a unit, the reduction chamber havin a plurality of holes formed in its top; a p ate having openings therein adapted to register with the openings in the top of the reduction chamber; and fines communicating with the openings in the said plate and with the stack.

4. A furnace comprising a stationary stack; an unobstructed reduction chamber and a crucible in fixed relationship to one another and tiltable as a unit, the reduction chamber having a plurality of holes formed in its top; a p ate having openings therein adapted to register with the openings in the top of the reduction chamber and a charge hopper adapted to feed through a central opening in the top of the reduction chamber when the latter is in normal position; and flues communicating with the other open ings in the said plate and with the stack.

5. A furnace comprising a stationary stack including charge pie-heating means and a chamber for the reception of furnace gases through which the preheating means discharges; and an unobstructed reduction chamber and a crucible in fixed relationship to one another and tiltable as a unit, the reduction chamber normally communicating with the chamber of said stack.

6. A furnace comprising a stationary stack including charge pre-heatin means and a chamber for the reception 0 furnace gases through which the pro-heating discharges provided with an exit opening for the charge and an opening for the entrance of furnace gases; and an unobstructed reduction chamber and a crucible in fixed relationship to one another and tiltable as a unit, the reduction chamber being provided with openings normally communicating with the aforesaid openings of the chamber of said stack.

7. A furnace comprising an unobstructed reduction chamber having a top provided with a central hole for the introduction of the ore and a plurality of holes for the escape of furnace gases adjacent the wall of the chamber, means being provided for the introduction of air adjacent the said Wall near the top and for the introduction of carbon near the bottom; a crucible below said reduction chamber in communication therewith; means for feeding ore and flux to said central hole; and means for conducting the furnace gases over the ore and flux before it is fed into the reduction chamber.

Signed at Toronto, Canada, this 9th day of arch, 1916, in the presence of the two undersigned witnesses.

JAMES W. MOFFAT.

Witnesses E. P. HALL, N. R. TYNDALL.