US80279A - Improved fubttace fob tbeating oees - Google Patents

Description

`2 Sheets-Sheet 2. S. H.l FLSOM.

Furnace for Treating Ores. No. 80,279. Patented July 28, 1868."

N-PETERS. PHOYO-IJTHDGRAPHEH. WASHINGTON. D C.

SAMUEL H. roLSoM, or WINCHESTER, MASSACHUSETTS;

Letters Patent No. 80,279, dated July 28, 1868.

IMPROVED FURNAUE POB TREATING GRES.'l

iig ttnule returns tri in time rttert rtrnt mit mating tart tf tige armi.

To ALL WHori 1r MAY coNcnnNi Be it known that I, SAMUEL H. FOLSOM,` of Winchester, in the county of Middlesex, and State of Massa chusetts, have invented certain Improvements in Furnaces for Roasting, Desulphurizing, and Chloridizing Orcs, of which the following is a full, clear, and exact description, reference being hadto the accompanying drawings, making part of this specification, in which- I Figure 1 is an elevation of one side of my improved furnace. Figure 2 is an elevation of the opposite side. Figure 3 is a longitudinal vertical section. Figure 4 is a plan with the roof of the furnace removed, to show the interior construction. Figure 5 is a perspective'view of one ot' the stationary stirrers. i Figure 6 is a horizontal-section on the line c: x of fig. 1. l The first part of my invention consists in a furnace provided with a series of two or more revolving tables `constitutingits bottom, said tables being so 'arranged within the furnace, that the pulp or pulverized ore may .bo transferred vfromV one to `the other, whereby it is subjected to a gradually-increased heat, (as is necessaryto produce agood re3ult,) as it approaches nearer to the furnace, without the necessity of regulating the heat, as has heretoforebeen necessary, while the heat is utilized to a greater extent than heretofore, as that which l passes over the table nearest to the furnace is further employed to effect the roasting of the ore on the table L or tables beyond, instead of passing directly to the-ii'ue and being'wasted, as ih ordinary furnaces, thus economining fuel and facilitatingr the process of roasting. I i v i The second part of my invention consists in a vertical iiuc provided with aseries of revolving cylinders, in combination with inclined planes or guides, whereby the ore is uniformly delivered with more or lessv rapidity, as may be desired, and the time regulatednvhich it occupies in passing through the flue, by which means the ore is subjected to the action of the products of combustion contained in the flue ihr such length of time as may be necessary to effect the requisite degree of roasting in this part of the process; and my invention also consists in certain details to be fully described hereafter.

To enable others skilled inthe art to understand and use my invention, lwill proceed to describe the i manner in which I have carried it out.

In the said drawings, A is the furnace, composed 'of brick-work, at the front end of which is the fire-box B. C Dare two revolvingr tables or platforms, of aY circular form, which constitute the bottom of the furnace, and receive the pulp or pulverized ore to be roasted. Each of these tables is supported upon a series of frictibn-wheels, a, (see fig. 3, and in dotted lines in Eg; 4,) and is steadied and held in place by a vertical shaft, b, which revolves in a step, c. The tables are provided with teeth' upon their underside, and are revolved by bevel-gears cl e upon the short horizontal shaftfg, seen in dotted lines in g. 4, which extend out through the side of the furnace, where they are connected, by means of bevel-gears 7L j k, with a long shaft, E, hung in bearings Z, and revolved by any suitable power. 1

The products of combustion pass (as indicated by the blue arrows, iig. 3,) from the tire-box B, over and in contact with the ore upon the revolving tables D C, to the vertical flue G, through a hopper, H, at the top of which the pulpf or pulverized ore is introduced, so that it will pass down in contact with the heated products of combustion within the iiue, and thus be subjected to a preliminary roasting before being delivered on to the revolving table C. The ore is not, however, allowed to pass directly from the top to the bottom of the flue, but is carried down uniformly and retained in contact with the products of combustion for a considerable length of time, in the following manner: m n o are a series of metallic cylinders, which may bc covered with fire-brick if desired, and are placed .within the ilue G, extending entirely across it,their 'shafts passing through the sides of the ue and resting upon friction-wheels p, the journals of which have their bearings in the bars I. Each of the shafts of the'cylinders'm n o carries, at one extremity, a ratchet-wheel, J, and over these wheels, and a guide-wheel, K, passes an endless chain, q, which also passes over a similar wheel, r, seen in dotted lines in g. 1, on a shaft, s, carrying at its outer end a bevel-Wheel, L, which is driven by a small bevel-gear upon the shaft E, the motion of which is thus communicated to the cylinders m'n o, which revolve in the directions indicated by the red arrows, iig. 3. Above these cylinders are Ifixed inclined plates or guides, t u v, the Vlower edges of which are on one side of a vertical' line passing through the centre of the cylinders, and are raised above the latter only a suficient distance to allow of their revolution, the length of the guides corresponding to that of the cylinders, as seen in fig. 6. The ore, as it drops from the hopper H, falls upon the inclined guide t, by which it is conducted on to. the cylinder m, the lower edge of the guide being, las before stated, on one side, instead of directly over the centre of the cylinder, thus leaving a space upon its upper surface from 8 to 9, for the reception of the pul- -vcrized ore, and as the latter iscarried by the revolution of the cylinder beyond the point-9, it is discharged on to the incline u, whence it passes on to the cylinder n, from which itis discharged in'a similar manner onto the incline v and `cylinder o, passing from the latter over an inclined guide, w, to the surface of the revolving table C. K Y It will thus be seen that the pulverized ore is delivered with uniformity and regularity from one cylinder to another, the speed at which the cylinders revolve determining the length of time occupied by tlie'ore in passing through the'ilue G, and by this means itvmay be subjected to the action of the products of combustion for aA longer or shorter period of time, as may be found necessary to effect the desired degree of roasting in this part of the process. The quantity of ore fed through the' hopper H in a given'timc should be in proportion to the speed at which the cylinders are revolved, so that the ore Will be properly delivered by their revolution. v

.The flue G, represented in the drawings, contains three revolving` cylinders, but it is evident that the number may be varied, if found desirable, and that they may be actuated by any suitable mechanism other than that shown. By the employment of the line Gr, constrnctedas above described, in addition'to the advantage secured in roasting by the retention of the ore in Contact with the products of combustion, the chlorine gas which may escape from thc-decomposition of the salt mixed with' the oreion the tables C D, is taken up as it comes into contact with the ore in passing 11p-through the flue, thus utilizing the chlorine gasvwhich is ordina- `rily lost. As the ore is delivered from the llue G on to the revolving table C, it is spread over its surface by .means of stationary stirrers d b', which rest on the table, and are attached to a bar, M. These stirrers consist of plates set at an angle, as seen in figs. 4 and 5, the plates aon ono side being set so as to carry the ore from the circumference toward the centreof the table, and the plates b', on the opposite side ofthe bar, being` set so as to carry the ore Afrom the centre toward the eircumferencf-i.'y Any suitable number of these stirrers may be attached tothe -bar M. It will be seen that by means of these stirrers the ore is continually transferred from one portion of the table to another, and thus thoroughly stirred and exposed to the action ofthe heat and air, which prevent it from slugging and caking. The stirrers also serve to thoroughly distribute the salt which is introduced through the hopper N. A great 'amount of manual labor formerly required to stir the ore while being'roasted is thus dispensed with by the use of these stirrers, whereby-a material saving is effected.

It will be seen that the ore uponl the table'C being removed a considerable distance from the lire-box B, is exposed to only a moderate degree of heat, and, 'after being partially roasted, it is transferred to the table D,'. (a portion of which lies under the table C,`as seen in figs. 3 and 4,) by inserting a long bar or other suitable instrument, through the opening c', figs. 2, 3, and 4, at such an angle that asi-the table C'revolves, the ore will be forced over'its edge on to the table D, over the surface of which it is spread by means of stirrers similar to those above described, and the ore'is thus subjected to a greater degree of heat on account of its proximity to the lire-boxB. I A

The revolution ofthe tables C and D causes all portions ofthe ore upon their surfaces to be brought successively to the point where the heat is most intense, but in order to facilitate the process, a circular dellector, O, is placed in the centre of each of the tables@ D, which serve to more thoroughly distribute the products of combustinovcr the surface of the ore. The surfaces of the tables C and D are covered with fire-brick,A and beneath the table C is a projecting ledge or shelf, e, which serves to catch any ore which may fall over the edge cf the table, a series of scrapers`,`f, attached to the under side ofthe table,` carrying it round and forcing it on to the table D, and'by this means 'the orc is saved from being Wasted, and prevented from accumulating beneath the table and interfering with its revolution. l

In a similar manner the ore which falls over the edge of the table D is caught upon a projectingedge or shelf, a series ofscrapers on the under 'side of this table carrying it roundand discharging it at an opening, h', 2. After the .orc has been exposed upon the table D for a sulicient length of time to eifectual'ly complete the process of roasting and chloridizing,`it may be removed thr'ongh the opening z", igs.l2 and 4, by meansA of a hoe or other suitable instrument, and the orevwhich has been partially roasted upon the table C transferred to the table D, as before described, and the operation continued as before, the heatj employed to complete the roasting ofthe orc upon the table D, passing over 'the table C, and effecting the partial roastingof the ore upon its surface,'after which it passes to the flue G, and is still further utilized in partially roasting the orc passing down through it, as before described. i I

The products ofcombustion pass from the flue G through an opening, 12,lig. 6, into a settling-chamber, P, which serves to collect whatever ore-dust is carried over into it, and thence Vby a passage, t, seen in dotted lines in fig. 3, to the chimney-stack.' I

' l is a door at the bottom of the chamber P, which may be opened to allowof the removal of the ore-dust after it has settled. v Y.

m areopenings through which air (previously heated by contact with the` lower portions of the furnace) is admitted to the [ire-box B, above the'fuel, for the purpose of facilitating combustion, and the openings cand z" are provided with doors, so that they may be closed when necessary. i

In the drawings two revolving tables are shown, but in practice I prefer to use three, as a better result `is produced; the number may therefore be varied as may be found most desirable. In furnaces as heretofore constructed, the heat required to be regulated, as it was necessary to expose the ore to a moderate heat for a cousiderable length of time, and afterward to a much greater degree of heat, but in my improved furnace the necessity of regulating the heat is entirely avoided, as the ore is exposed to a gradually-increasing degree of heat from the time it leaves the hopper H, at the top of the iiue G, until it reaches the table D nearest to the fire, while all the heat is utilized, as -that which completes the roasting of the ore upon the table D, passes over the table or tables beyond, and` thence into the due, effecting the preliminary roasting of the ore in its passage, instead o f beingrwasted, as heretofore; and the ore having been thus partially roasted before it reaches the table D, requires to remain upon the latter for a much shorter period of time than where a single table is used.V

The process is thus made continuous, and a great saving in fuel and manual labor is effected, and myimproved furnace enables me to produces. much greater quantity of roasted ore than has heretofore been possible withv a furnace of equal capacity, as the several stages in the process are all conducted simultaneously.

I do not conne myself` to the use of a series of revolving tables in connectlon with the tlue G, provided with a series of revolving cylinders and inclined guides, as described, as either of these portions of my invention might be used to advantage separately; a better result is, however, obtained when they are used together, as

shown and described.

` Claims.

What I claim as my invention, and desire to secure by Letters Patent, is

A series of two or more revolving tables placed within a furnace, A, and operating substantially as described for the purpose herein set forth.

I also claim the revolving cylinders m n o, with their inclined guides, in combination with the Hue G, o per` ating substantially as described, for the purpose set forth.

I also claim a central deilector, 0, applied to a table, C or D, for the purpose ofmorethoroughly distributing the dame over its surface, substantially as set forth. l

I also claim the inclined stationary stirrers a b, in combination with a. revolving table, C or D, substantially as described.

I also claim the Scrapers f', on the under surface of a table, C or D, in combination' with a. projecting edge or shelf, e', beneath the table, substantially as andfor the purpose set forth.

SAML H. FOLSOM.

Witnesses:

P. E. 'fascism/menen,- W. J. CAMBRIDGE.

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