US1433355A - Apparatus for treating ores to sinter them - Google Patents

Description

A. S. DWIGHT.

APPARATUS FOR TREATING ORES TO SINTER THEM.

APPLICATION FILED MAR. 25, 1.912. RENEWED AUG. 1, I914.

1 y 3 5 o v Patented Oct. 24, 1922;

Wateuted Uet. 2t, WEE.

ARTHUR S. DWIGHT, OlF.NEW YORK, N. Y., ASSIGNOR TO DWIGHT a LLOYD METAL- LURGICAL COMPANY, OF YORK, N. 51., A CORPORATION OF NEW JERSEY.

APPARATUS FOR TREATING ORES T0 SINTER THEM.

Original application filed December 23. 1907, Serial No. 407,860. Divided and this application filed March 25, 1912, Serial No. 685,910. Renewed August 1, 1914, Serial No. 854,559.

To all whom it may concern:

Be it known that l, ARTHUR S. DWIGHT, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Apparatus for Treating Ores to Sinter Them, of which the following is a specification, reference being had therein to the accompanying draw- My invention relates to the art of treating ores for the purpose of sintering them, especially such ores as contain or have mixed with them a readily combustible element or substance and are of such nature that combustion may be carried on therein after an initial igniting of the mass has been effected; and which may, by reason of the said combustion, be sintered or have the particles thereof agglomerated into masses which are well suited for subsequent treatment in blast furnaces. I may mention as one example of an ore such as the process and apparatus herein to be described are adapted to treat,

a sulfid ore in which the combustible constituent, sulfur, is in sufficient quantity to permit the ore to be readilyignited and to urn if supplied with air or other supporter of combustion; and as another example of the material to be treated, I may mention a mixture of pulverized or finely crushed ore and pulverized coal or other form of carbon.

The invention relates particularly to the means employed for eflecting the initial ignition of the ore above referred to, which means are capable of combination with any of various sorts of mechanisms for supporting and carrying the ore; and in respect to such apparatus and carrying features the present invention is not limited.

For the purpose of illustrating how the invention may be practically carried into effect, have represented in the accompanying drawings, the mechanism for supplying, transporting and sintering ore, and finally delivering it in sintered masses, which is shown, described and claimed in my application for patent filed December 23, 1907,

original Serial Number 407,860, on whichissued Patent No. 1,027,110, dated May 21, 1912, of which case this applicatlon is a division.

Fig. 1 is a side elevation of an ore sintering machine such as just referred to and with .thereto.

For the purposes hereof it is sufiicient to note that, in the drawings, A rep-resents an air suction box, over or across the open end of which travel the ore-supporting cars or pallets B, these constituting individual elements of a carrier for the ore. Each of these elements carries one or more grate sections, C, suitably supported, and is mounted upon wheels D adapted to travel upon tracks or guides, shown at F, 15", F

K indicates a hopper or feeder which is supplied with ore, initially, and from which it is delivered in charges or in a stream to the cars or pallets B, so that each element supports a thin pervious bed or layer of the ore.

Q indicates the igniter which is in the form of a b-razier across the open bottom of which is stretched a suitably perforated screen Q. This brazier is placed over the ore carrier close to the ore hopper and over the suction box, so that the air currents which are induced to pass through'the body of ore and into the air box act in part through the brazier or holder Q. This brazier or holder is filled with charcoal, coke or other solid fuel, which is ignited from above, and the downdraft, caused by the general movement of the air surrounding the brazier, and induced by the air moving apparatus U connected with the air box, causes the hot gases of combustion to be brought into direct and intimate contact with the ore, starting the ignition thereof at that ortion of its surface over which the holder & is located. As the fuel burns the ashes drop through the perforated screen Q upon the ore, and fresh fuel, charcoal, for instance, fed from above, is ignited by upward radiation. The brazier is open to the atmos phere at its upper end so that the air which is drawn downwardly into it supports the combustion taking place therein, and then passes, either unchanged, or chemically combined with the fuel contained in the holder erate to confine and direct the heated prodnets of combustion, preventing their dissipation by moving air currents which may pass over the exposed surface of theore body. The lower open end of the holder is of such size that a relatively wide area of the surface of the ore is simultaneously subjected to treatment for ignition, with the advantage that no portions of the surface of the ore escape initial firing even though some parts or areas thereof may be less inflammable than others owing to a deficient supply of the combustible constituent of the mass at such particular places or parts. The application of the highly heated products of combustion to the ore surface I for ignition is but temporary, for after completing ignition, through the relative movement of ore mass and igniter, the igniting products of combustion cease to act upon the ore, and the sintering of the mass is completed without further assistance from the igniter.

After this temporary application of the burning products, which is maintained sufficiently long for perfect ignition, the ore is subjected to a more or less extended and continuous action of the air currents which are induced to pass through the body of ore by the air moving mechanism U connected with the air box or chamber A. In operating with the mechanism illustrated in the drawings the ore carrier, formed of the units designated B, is slowly moved across the open end of the air chamber A, the length of such open end, and the speed at which the carrier moves, determining the length of time during which the ore is subjected to the action of the air currents passing through the ore body, during which time such internal combustion takes place within the ore mass as to cause the desired sintering thereof, and the desulfurizing, when a sulfid ore is being treated. At the end of the track section F, which is the section adjacent to the open end of the wind box or air chamber A, and which, as shown, preferably extends some distance beyond the end of the wind box, the ore carriers pass to the downwardly curved track section or guide, F, with which the wheels of the pallets or individual ore carriers engage and by which their course is directed. From this part of the guide-way the pallets or cars move to theincIined and returning part of the track, F along which they travel in inverted position. At H there are lifting and power transmitting wheels, adapted to engage with the pallets or cars and carry them upward to the track section F, and then by a pushing action impart forward travel to them during their next cycle. The wheels H are rotated by the belt T connected with their shaft.

At U there is an air forcing apparatus, here shown as a suction fan connected by a trunk or duct J, with the air box A, and adapted to exhaust the air from the latter, causing currents of air to pass downward through the ore on the pallets or cars, as indicated by the arrows in Fig. 1.

During the sintering operation the loose pulverulent mass of ore material is changed into a porous cake or biscuit, parts of which are apt to extend through the holes or perforations in the supporting grate, thus uniting the sintered mass to the carrier or sup port therefor. I have found, however, that an easy breaking'of the sintered mass or masses into pieces or cakes of convenient sizes for use, and the separation of these from the supporting grate surfaces is effected by the tilting of the grates as the pallets pass around the discharge end of the machine, being directed by the guides F.

It will be apparent that by apparatus such ,as I herein describe a relatively wide area of the ore surface will be directly subjected to an intense heat which is drawn into intimate contact with the ore and somewhat into the body thereof by the airmoving apparatus connected with the air box A. In these respects the igniter herein described and illustrated differs from that which I have illustrated in earlier patents of mine, for instance in Patent 916,391, of March 23, 1909, wherein I show an igniter consisting of a perforated gas pipe extending across the apparatus supporting the ore and arranged to direct small open jets of burning gas against the surface of the ore along a narrow line.

As has been herein pointed out my invention relates to the art of sintering or agglomerating metalliferous substances that are initially in a pulverulent or fine condition; and one of the elements-of the apparatus ,has been termed the igniter. This element is, as its name suggests, a device or means for merely setting fire to the combustible constituent of the mass of material being treated,which material is, after ignition, caused to be sintered or agglomerated by internal combustion carried on Within the mass; and it is in use, acting upon a particfw lar body or mass of material, for a comparatively brief time only, considering the total period of time required to treat Such mass or body to effect the sintering or agglomerating lessens result desired. Such igniter is to be dis tinguished from the fire chamber of a reverberatory ore r'oasting apparatus or furnace and from the burners employed in such fur; naces, where the material to be treated is subjected to the, action of flame'throughout the entireperiod of treatment, and where the reasting, calciningyor other desired result, is

directly and primarily efi'ected by the action of the flame to which it issubjected.

Neither do I inthis case claim that method or process which consists in forming a pervi-- ous bed of fine metalliferous material in which is a combustible constituent and igniting the combustible constituent of such mass b applying to a relatively broad area thereo a laterally defined body of materials heated to a temperature suflficient to igniteair currents to pass through said body of ore,

an igniter comprising a holder for-burning solid fuel arranged above the exposed surface of the ore having its bottom open and close thereto, whereby the products of such combustion are delivered directly to the surface of the ore, and said holder having an opening to'permit. the passage of air to support the combustion offuel. therein.

2. The combination with-a support for a thin pervious bed of ore igniter comprising a holder for bur-n'ng fuel arranged above the surface of the ore the said holder being open at top and bottom and at its lower end provided with a perforated support for the fuel, and means for-"drawing currents of air downwardly through the 'ore and.- also through the said holder whereby-.theiproducts of the combustion taking place there" in are drawn directly into engagement with the surface of the. ore. 1

thin pervious bed of ore, an igniter comprising a holder for burning fuel arranged above he exposed surface of the ore, having its ottom open and arranged close tosuch sur face, and provided 'with, a perforatedf'sup port for the fuel means for drawing ,cur-

tents of air downwardly through the. said holder thereby carrying the products of the combustion taking place therein directly into engagement .with the surface of the ore to ignite it, and means for causing a separation between. the body of ore and the said heated products of combustion from the said fuel holder and permitting internal combustion within-the ore mass to continue apart'from and without assistance frorn'the burning fuel in said holder. 1 4:. The combination with a pervious su portfor a thin bed of ore, an igniter containing a chamber enclosed at its sides and provided near its lower open end with a perforated support whereby it is arranged to have its lower portion filled with burning material arranged relatively near the surface of the said bed to ignite it and its upper por tion open for the-entrance of atmospheric air, and means for causing currents of a ,gaseous supporter of combustion to pass through the bed of ore in a downward direction, whereby the products of combustion from the said chamber are carried ectly into engagement with the surface of the ore,

and the. combustion in the ore is continued after the ignition has commenced.

' In testimony whereof I afix my signature, in presence of two Witnesses.

ARTHUR S. DWIGHT. Witnesses:

.Rrorman L. lLrorn, Lon-rs .H.HY'DE.

3. The combination with a support for a

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