US516781A - Ore-roasting furnace - Google Patents

Description

(No Model.)

y 4 sheets-auen.

T. WA'LKE F. CARTER.

ORB R0' K URNAGB. No. 516,781. 1 Pate-ntedjMarf '20,.,11'894..

(No Model.) 4y Sheets-Sheet 2.

T.. WALKER R J. P. GARTRR.

' ,ORE ROASTING FURNAGB.

No. 516,781. I Patented MRI. Z0, 1894.

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3.7 awww NITED STATES vATENT linrit-1E.

THOMAS WALKER AND JOHN F. CARTER, OF PHILADELPHIA, PENNSYLVA- NIA, ASSIGNORS TO JOHN A. BARHAM AND JOSEPH A. VINCENT, OF SAME PLACE.

ORE-ROASTING FU RNACE.

SPECIFICATION forming part of Letters Patent No. 516,781, dated March 20, 1894.

Application led Deeemtee1 14,1892. serie1ne.455,1e5. (Ne model.)

To all whom it may concern:

Be it known that we, THOMAS WALKER and JOHN FoRsYTH CARTER, citizens of the United States, and residents of Philadelphia, Penn- Sylvania,haveinventedcertainImprovements in Ore-Roasting Furnaces, of which the following is a specification.

Our invention relates to certain improvements in ore roasting furnaces set forth in Io Letters Patent No. 280,102, of June 26, 1883,

and No. 311,052, of January 20, 1885; the object of our present invention being to prevent dusting, .and to improve the operation of the furnace;

In the accompanying drawingszFigure l, is a face view of a furnace constructed in accordance with our invention. Fig. 2, is a longitudinal sectional view. Fig. 3, is a sectional plan view. Fig. 4, is a transverse section on zo the line 1-2, Fig. 2. Fig. 5, is a transverse sectional view on the line 3 4, Fig. 2. Fig. 6,`is a transverse sectional view on the line 5 6, Fig. 2. Figs. 7, 8, and 9, are views of details of our invention.

To rapidly and thoroughly oxidize ores it is desirable first, to pass the finely divided ore through the retorts in the furnace in thin layers, keeping it in constant motion both laterally and longitudinally, so that the best pos- 3o sible results will' be obtained; and we have found that it is not only desirable,but essential, that the ore should pass from one retort to another in such a manner as to avoid dusting. We have found by'a series of experi- '35 ments, that the most practical method for passing the ore from one retort to another is through a system of inclined planes or chutes; thus the ore slides practically from one retort to the other, and consequently it is thus pre- 4o vented from dusting, and further, it is essential in roasting furnaces, to pass the fumes through the several retorts in such a manner that they will pass over the ore, and not through the body of ore. This we accomplish by so delivering the stream of ore to Vone side,

of the channel, and allowing thefumes to pass in a direct course from one retort to the other.

We have also found that better results ,canl

be obtainedin vibrating the rakes or stirring blades than by the method described in the Carter patent above mentioned, that is rotating the blades, as the agitation caused by the vibration of the blades is sufficient, and does not allow the ore to drop through the fumes in their passage through the retort. We have so constructed the coupling for the Water supply of the several tubular shafts, that they can be readily coupled, and are iexible, so that they will not interfere in any manner with the operation of the furnace.

We will now describe the construction of the furnace.

A is the main body of the furnace, which is preferably made of brick and supports the several sets of retorts B,-B, B2, B5; the lower retorts B, B', B2 are preferably made of fire clay, while the upper retorts B3 may be made of metal. The retorts are independently supported in the furnace. One retort does not support the one above it as in ordinary furnaces. We provide saddles or arches for each retort. These saddles S may be a single piece of tire clay, but in double furnaces as shown in the drawings, the saddles are composed of two end blocks s which project from the side walls of the furnace,and support a key block s'. These saddles are arranged at intervals throughout the length of each retort, and are recessed to receive the retorts; and in double torts when made of iron maybe` supported by rods b hung from the roof of the furnace as shown in Fig. 2. The retorts proper stop at the inner walls of the structure, but passages are formed in the front and back walls, and'partitions ct are so built as to form a circuitous passage for the ore and fumes shown in Fig. 2. The ore enters the furnace from a hopper C2 through apassage C. Suitable ore feeding mechanism is arranged in the hopper; the mechanism shown is what is termed screw feeding mechanism, by which the ore in given quantities is fed to the furnace. This mechanism is common in ore roasting furnaces of this class, and is particularly shown and described in the patent of January20, 1885, mentioned above. Other mechanism may be used without departing from our invention. The ore enters the upper retort,andis fed through this retort, and then y flows into the retort below it until it discharges through the outlet passage C. The fumes are carried inthe opposite direction,and over the ore to the fume outlet E. In this furnace rWe onlfy provide one outlet E for the escape of the fuine's or gases, this outlet being in the upper portion of the furnaeaand communicates with the upper retort, so that the furn'es will pass through the 'series of ietorts before they escp'ethrough the stacker into a fu'me chamber. While the several retorts communicate one with 'the other at one end for the passage of vapor or gases, the ore is passed down the inclin'ed'planes D to openings which communicate `with passages CZ in 'the walls of the furnace, the outlets d of these passages being as near "as practicable to the bottom of the retort, the ore following a curved y incline passing into the side walls of Athe chamber and "out into the retort below, as clearly shown in 'the drawings; thus the ore is carried from an "upper retort rto alow'er retortwithout dusting and Without coming in `contact with the gases or vapors, as there is suflicient flue space beyond the inclined chutes D to allow the vapor to pass up from one retort to the other without coming in contact in anywise 4with the ore. The furnace grate A is situated centrally below the two sets of retorts, 'and 'the products of combustion pass around and over the retorts in a Zig-zag course to the outlet a in the upper portion of the furnace.

Passing through each retort is a shaft F provided with a protective covering Y of suitable material which is supported by suitable bearings F mounted on brackets F?, adjustably secured to the front and rear of the furnace, as shownl in the drawings. On this shaft 'are mounted the agitating and convey- Q ing blades Gr which are made up of a series L of sections, each section having two sets off blades g which have their faces inclined in sncha 'manner as to feed the ore from one end of the retort to the other; the blades being so arranged that the ore will be carried from the upper portion of the furnace, through the series "of retorts, tothe outlet at` the bottom of the furnace.

Onthe frontend of each shaft F is secured an Aarn'l fwhich is coupled "to a connecting rod II connecting the several shafts in the retorts in a vertical line together. In the vided with belt wheels through which it is driven from any suitable motor. Thus the blades are vibrated slowly within the retorts, and the ore is constantly agitated, and at the same time moved forward. y

Each shaft F is hollow and is coupled to a water pipe I. There are two main pipes in the present instance, one situated on each side of the furnace atthe front, and onepipe communicates 'with the shafts on its side of the furnace, and the 'other pipe communicates with the shafts on its sine `or theL furnace. The connections are preferably of rubber hose looped sufficiently to allow forthe "nieveA ment of the shaft, and each "flexible connection t' is coupled to its 'shaft by a gooseeneclk fi', so as to 'make the moyernent as 'short "as possible. This goosfeneck 'as shown in Figs. 7 and '8, extends back of "the 'oeimn-` lino ajof the pipe, and at this point it is coupled to 'the flexible tubo t', thus preventing nio abrupt bending of the connectih g hose o'r tube. Each nexible connection 'L' may be provided with a s valve to cut off that particular section "when it is required to shut down for repairs, anda check valve 'i3 is "also provided to prevent the water from being forced back b'y the heat of the reto'rts. Each shaft in lthis instance has an independent water supply, and the 'water does not pass from one shaft to the other, as in the apparatus described in the patent of 1885 mentioned above.

By making the lower retorts comparatively flat on top, we "are enabled to decrease the height of the furnace, and by inaking the upper retort or re'tor'ts of metal, which are 'not as highly heated as the other retor'ts, we "are enabled to economize in the construction of the furnace. p

It will be understood that other constructions or modifications of the inclined `planes may be used without departing from our invention, the main idea of which is to carry the ore 'from one `retort to the other without dropping 'the ore through the fumes. s

In applications filed byus on May'23fl8'93, Serial Nos. 475,281 and 475,282, we have described modifications of our device embodying the main feature of our invention.

Atmospheric air is admitted into the furnace preferably through a hollow cast iron pipe WV set in the wall in close proximity to the fire box, as shown in Figs. 2 and 5, and this pipe has an admission valve or dainper w at one end, and is connected tothe lower retorts at the opposite end. At this end isa cold air valve w', on operating which cold air IOO IIO

can be admitted to the retorts, and the hot air from the pipe cutoff. I

The action of the furnace on the ore under treatment is as follows: Owing to the finely divided state of theore entering the furnace, many surfaces are presented; under the action of the heat `the sulphur in the ore is oxidized forming gases containing sulphur and oxygen, the oxygen in the air admitted into the furnace, combining with the iron forming oxide of iron Fe2 O3, and keeping up the combustion. The surface area of ore presented to the action of the heat and air in the eight retorts of the furnace illustrated, is about two hundred and'forty square feet; this surface changes at every oscillation of the shafts to which are attached the rakes, vanes, or stirrers. Owing to the action as above stated very rapid desulphurization and oxidation follow. The function of the rakes or vanes is to move the ore from one end of the retort to the other. In doing` this it spreads the ore on the bottom of the retort in a thin layer, and at the same time presents new surfaces to the action of the heat and air. The ore in going through this furnace as ordinarily constructed, moves a distance of about fortyeight feet, through four different degrees of temperature-the highest being in the last or lowest retort, and the lowest temperature in the uppermost retort.

We claim as our invention- 1. In an ore-roasting furnace, the combination of a series of retorts one mounted above the other, fume passages forming communication between the several retorts, and inclined planes in these passages extending from one retort to a retort below so that the ore as it passes from one retort to another will pass down the inclined plane `without dusting, the fumes passing through the retorts in the opposite direction, substantially as described.

2. The combination in an ore roasting furnace, of a series of retorts mounted one above another, agitating mechanism in each retort, and means for feeding the ore through the retorts, passages forming communications between the retorts, inclined planes in said passages upon which the ore is carried from one retort to the other, and a flue or flues communicating with the upper retorts by which the fumes are carried through the retorts to the outlet, the ore being directed clear of the fumes as it passes from one retort to the other, substantially as described.

3. The combination in an ore roasting furnace, of the body portion, a series of retorts mounted therein, the front and rear walls of said body portion having fume passages communicating with the retorts, inclined planes in said passages for the delivery of ore from one retort to another, shafts in each retort, agitatin g blades mounted on said shafts, with mechanism for vibrating the same, substantially as described.

4. The combination in an ore roasting furnace, of the body portion, a'series of retorts,

the front and rear Walls of the body portion having passages therein for the escape of fumes from one retort to another and to the outlet, with inclined planes extending from the lower surface of one retort to and through the side walls of the said passages and to the retort below, whereby the ore is carried from one retort to another without dusting and without` coming in direct contact with the fumes, substantially as described.

5. The combination in an ore roasting furnace, of a series of retorts, a hollow shaft in each retort, blades on said shafts, mechanism for operating the shafts, with a main water pipe and coupling pipe for each hollow shaft communicating with the said water pipe, said coupling being looped sufticiently'to allow for the vibrating movement of the shafts, substantially as described. i

6. The combination in an ore roasting furnace, of the combustion chamber, a series of retorts mounted therein, mechanism for trav ersing the ore through the said retorts a hot air pipe in the combustion chamber connected at one end to the lower retort, a valve fw at the inlet end of said pipe, and a valve w at the opposite end to cut off the hot air supply to the retorts, and to admit cold air, substantially as described. p

7. The combination in an ore roasting furnace of the retorts,a shaft in each retort, mechanism for vibrating said shafts, with two sets of Ablades carried by said shaft, each blade being V-shaped in cross section, whereby as the shaft is vibrated the material is not only gently moved laterally butalso longitudinally in one direction, substantially as described.

8. The combination in an ore roasting fur-v nace, of the series of retorts one mounted above another, said retorts being closed at each end to the atmosphere,vertical passages arranged alternately at each end of the furnace and communicating with-the severalretorts so that the fumes will pass through one retort then up and through another and soon to the outlet, with inclined planes in said passages, feeding mechanism in each retort for the ore under treatment so that the ore may pass through the retorts in a direction opposite to that of the fumes and pass from one retort to the other without dusting, substantially as described.

9. The combination in an ore'roasting furnace, of the body portion forming a combustion chamber, a tire pot at the base of the furnace, a series of retorts mounted one above the other in said combustion chamber, the lower retorts being made of tire clay, andthe upper retort or retorts being made of cast iron, substantially as described.

lO. The combination in an ore roasting furnace, of two or more retorts, one receiving material from another, in its passage through the furnace, agitating and feeding mechanism in each retort, fume passages, withapas- IOO IIO

sage forming a communication between the two retortsyinclined planes in said passage whereby the material is carried from one retort to the other without dusting, substantially as described.

11. The combination in a furnace of the hollow shaft, a retort, a water supply pipe, a goose-neck coupling attached to the side hollow shaft and extending away from the water 1o supply pipe and to the goose-neck back of the center line of the hollow shaft, substantially as described. 1

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

THOMAS WALKER. JOHN F. CARTER. Witnesses:

HENRY HoWsoN, JOSEPH H. KLEIN.

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