US1166904A - Machine for agglomerating ores. - Google Patents

Description

P. 0(HARDING. MACHINE FOR AGGLOMERATING omzs.

APPLICATION FILED JULY 3. 191 5.

Patented Jan. 4, 1916.

2 SHEETS-SHEET I.

N UE nd-m fn; QAAQL P..0. HARDING.

MACHINE FOR' AGGLOMERATING ORES.

APPLICATION FILED JULY 3. I9I5- I I I Patented Jan. 4, 1916.

2 SHEETSSHEIET 2.

II I'l'll INVENTOR iron, is, because of its finely divided condition, diflicult to handle, and the'recovery of To all whom may concern:

UNITED TA Q A ENTT OFFEEQY 1 PHILIP o. HABDING, or r rrrs nunemrnnns nvanm.

MACH-inn FOR aeenomnm'rine omas.

specification of Letters Patent}, Pateflte d lg ls; original'application filed June 12, 1915, serial No. 33,767.. Divided and this application filed m a, 1915.

" Serial No. 31,922.-

Beit known that I, PHILIP O.'HAnn1'Nc, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Machines for Agglomerating- Ores,

of which improvements the following is a.

specification. N v I Myinven'tion relates to the agglomeratlng' of ore, particularly of ironore, a procedure.

commonly-called sintering.

In the ordinary operation of' blast furnaces, particularly when finely pulverized ore is used, there is a large production of flue dust. This flue dust, though'rich in its iron content has been found to be 'so costly that great quantities of flue dust from.

- blast furnaces have been regarded as waste.

Of late years efi'ortshave been made to" bring the flue dust to a condition better adapted for re-introduction into the blast furnace as part of the furnace charge, by

submitting it first to the sintering operation. The flue dust is mixed with finely-divided ore and the mixture is ignited. The flue for a suitable supply of air to'sustain combustion, the mixture is changed by burning from a loose friable material to. an agglomerated, clinker-like mass.

The precise chemical changes which cur are obscure and but imperfectly under.- stood. Necessarily, they vary as the chemical composition of the mass under treat-- ment varies. But the physical change, in-

' dicated above, is the one which is "important to the furnace operator.

It has been found a matter ofgreat difli-I culty to obtain a uniform agglomeration and produce an article which does not 'contain withinits'body pockets of unaltered and friable material. Furthermore, apparatus heretofore devised such as is productive of material nearest to'thefurnace mans requirements is exceedingly costly both to install and to maintainin repair.

My invention consists primarily'infisubjecting a body of material to befagglomer-v ated "(which ordinarily will beja mixture of flue dust and finely divided iron ore)?" to a progressive combustion whicha*-advan'ces through the body, in causingthe .c'a'urrent'jozt' combustion-sustaining gas (which ordinarlly will be atmospheric'air) to flow,to the region of combustion through that portion of the body which has already been SubJected to the agglomeratingfire, and at. the same time effecting a breaking-up or fragmentation ofthat portion of the body mingled with. air and brought to propertemperature, it will undergo ignition and agglomeration.

; 'My invention further consists in apparatus for performing the operation herein above. defined. This apparatus is illus-' trated in the accompanying drawings, and I to the method. -My present invention so far as concerns method is claimedina .copending application filed June 12th, '19 1 5,

Serial No. 33,767. I v

Figure 1 shows the apparatusin'preferred form and in vertical medial section; Fig.2 I s a view on larger scale-and n vertical me-' I v dial section. of the spreader and pusher detached, which in Fig. l is shown in operative posit-i-on;.F;ig.' 3 is an end view of the said spreader and-pusher; Fig. 4' is a view corresponding to Fig.1 showing the 'appara tus in modified form; Fig. 5 shows in Zlon tudinal section the of the apparatus of ig. 4; Fig..6'is a view in end elevation and Fig. 7 a view in trans- I verse section of the tube of'Fig. 5, the plane of section of Fig. 7 being indicated 'by the and in end elevation an extractor applicable elevation an extractor of another form. f

Referring first to Fig. 1, 1 indicates a chamber wlthin which is contained a body of material under treatment. Within this,

chamber the ignition occurs which efie'cts, agglomeration, and this ignition takes place progressively through the body of material. Such a procedure is conveniently accom: plished by making the chamber of the tubu-- lars form shown', maintaining a zone of combustion" at an intermediatev-pomt 1n the 1-10 shall explain my invention by reference thereto. In'this application I lay no claim 90.. f riassageway or' hot tu e" ,line VII-VII, Fig. 5; Fig. 8 shows in side 7 tube.

length of the tube (near the intake end) and in causing the material under treatment to advance by continuous feed through the The zone of combustion is conveniently defined and combustion maintained by a heat-giving apparatus surrounding the tube. As shown in the drawings, this apparatus takes the form of an annular reverberatory chamber 2. The particular nature and character of this heat-imparting apparatus are not of the essence of the 'in vention in its broader aspect, and indeed a proper selection and mixture of material to be treated and a proper control of the sup ply of combustion-sustaining gas may render-the employment of any such heat-imparting apparatus unnecessary.

In Fig. 1 A indicates that portion of the body of material under treatment which has just been introduced into tube 1, B indicates the portion which is undergoing combustion, and C the portion which has already been agglomerated. The air for nourishing combustion in the advancing body of material A, B, C is drawn through the material itself and through that portion which has already undergone agglomeration; that is to say, air flows through the portion of the charge marked C, to the portion undergoing combustion, marked B. The material as it advances from the zone or region of combustion is broken up, for the purpose already defined. The means resorted to in the apparatus shown in Fig. 1

are these: The tube 1 is arranged vertically; it fiares downwardly; and the charge within the tube rests upon a support 3. This support is conveniently of circular plan, arranged concentrically beneath the vertically arranged downwardly fiaring tube, and it is spaced at an interval from the lower edge of the tube. Through this space the finished material finds escape. The support 3 4 is conveniently conical, as shown, and it is rotary on a central axis. The efiect of rotation of the support 3 is that the downward sinking body of material is discharged through the annular orifice between the support 3 and the lower edge of pipe 2, and the further effect is to subject the whole agglomerated portion of the charge, marked 0, to strains which cause it to break up, to separate into fragments. And the conseuence is that the indrawn streams of air ow freely through the crevasses so opened, and where the indrawn air encounters friable and un-agglomerated material it will blow such material back into the zone of combustion where it will undergo the combustion which it had fortuitously escaped. Suction is maintained, to draw the air through tube 1 by means of suction pipe 4. It is desirable, for purposes presently to be stated, to form above tube 1 and communicating with it an air-exhausting chamber 5,

from which chamber air is drawn through pipe 4. The lower portion of this chamber, adjacent the point of communication with the tube 1 is, as shown, upwardly flaring and hopper-shaped. This conformation is advantageous because the velocity of the current of air flowing from tube 1 is thus rapidly checked and accordingly the arrested current of air deposits practically all of whatever burden of powdery material it desired. The chamber 5 thus is seen to be a closed chamber. The drawings show a feed pipe 7 leading to it and a worm feed within the pipe. It will be understood that such a feeding mechanism may be employed to feed in the material, continuously or intermittently as desired, and without serious interference with the maintenance of a draft through tube 1 by the means which have been described.

A spreader and pusher is indicated at 8 and more fully illustrated in Figs. 2 and 3. It consists essentially of a sweep like arm or arms 9 carried on a shaft 10 which is mounted centrally above tube 1. Shaft 10 is rotatable and as it turns the arm 9 (which is arranged within tube 1 and at its upper end at the level ofthe normal surface of the body of infed material) sweeps and levels the material which is gradually being fed in through conduit 7. It will be observed, in this connection, that the hopperlike bottom of chamber 5 serves not merely to check the rise of dust (as explained) but to collect and deliver to tube 1 whatever. dust settles from the inflowing stream of air and whatever portion of the material fed in from conduit 7 falls to one side. Thus the spreader 8 maintains an even distribution of the charge in tube 1. .A sweep 20 mav be carried on shaft 10, rotating with it but preferably free to slide upon. it as the shaft moves longitudinally. This sweep traverses the slopinghopper surfaces and assists in carrying into tube 1 whatever material lodges on these sloping surfaces. At times in the course of the operation the tube 1 may become clogged by material skulling and caking within it. The member 8 is further arranged to serve as a pusher, to loosen and drive downward the agglomerated material whenever it tends to skull or cake in or near the zone of combustion.

. a that, nd the shaft man-ad. not

' only, for rotation but .also for longitudinal reciprocation.

iently carried on a properly weighted lever or walking beam 11 and a suitable handle.

' 12 may be provided for driving the member 8. up ,and'down to effect the ends described.

It remainsonlyto call attention to cer- I tain further features of the apparatus which feed and'discharge shall be atfa constantly maintained relative rate. The lower portion of tube 1 and the support 3 may as indicated be perforate, to afford freer access of entering air to the body of materlal within tube 1. The tube 1 and the proximate portions of chamber 5, where high temperatures are maintained, may be formed of fire brick built in an iron frame work. The

stem'and head of the spreader and pusher may as shown be provided with internal passages for the circulation of water.

The apparatus of Figs. t-9 will readily be understood with a few additional words of explanation. The tube 1, instead of being vertically arranged, lies in horizontal position; the conduit 7 fon feeding in the material extends into the mouth of tube 1,

and the spreader. and pusher are dispensed with. The intake end of tube 1 is provided, as particularly shown in Figs. 5 and 6, with lugs 13, against which the conduit 7 makes bearing and between which the current of air is drawn, through an annular suction chamber 5 which surrounds the conduit 7. This chamber may, at least in that part adjacent tube 1, be filled with a body 14 of loosely packed pebbles which serves to entagle and retain whatever burden of dust the stream of air which flows through may carry with it. As particularly shown in Figs. 5 and 7, the intake end of the tube 1 is modified by having radially extending slots 15 formed in its Walk These radial slots will less readily become packed with the entering body of material, and by their presence the freedom of flow of the stream of air may be insured. The heater 2 surrounds the tube 1' and defines a zone of combustion, as in the case shown in Fig. 1.

In dotted lines, 15, Fig. 4, is shown a gas-supply pipe, directed into the discharge end of tube 1. By such provision and by so feeding in combustible gas with the stream of air or other combustion-nourishtube may be facilitated or intensified, and

' the external heater 2 may or may not be The structure is convenprogress. ing gas, combustion within the body in the a... .1 at. th apgiaratus trxi ia ig The worm feed within conduit '7' is-water cooled as shown. A shaft 17, rotatable and-capable of being advanced and-retracted longitudinally, is mounted opposite the diseharge end of tube 1. Upon it may be. mounted, either the extractor of Fig. 8, withits blades forming. an interrupted helix,.or the crown-like drill of-Fig. 9. vThese are the means in this case employed to break up and form fissures in the body of materialas it advances from;

the zone of combustion and agglomeration, and also to assist in the extraction of the agglomerated material from tube l. Such terms as a body of material to be 'agglomerated', and have said that this will ordinarily.

be a mixture of flue dust and finely divided ore. It remains only to observed that I place no limitation upon my invention in this matter of the particular nature-of the material to be treated. For example, it is not essential to mix flue dust with iron ore in order to obtain material which may be agglomerated; coke braize may be mixed with iron ore and the mixture will be amenable to my procedure, an iron ore which has a larger sulfur content needs no admixture with any carbon-containing substance, but may itself be agglomerated. These instances will sufiice to indicate that my invention in its broader aspect is not limited to any particular material or to the mixture of any particular materials, but is applicable generally to the treatment of ores which because of their finely divided condition are diflicult to handle in reducing furnaces, and it requires only this that the material shall be susceptible to agglomeration.

I claim as my invention:

'1. In a machine for agglomerating ore the combination of means for causing the gradual advance of a process of combustion through the body of material under treatment, means for breaking into fragments such portions of said body as have been subjected to the said process of combustion, and means for maintaining a gaseous stream flowing through that portion of the said body which has been subjected to combustion and fragmentation and from such portion to the point where combustion is in 2. In a machine for ag'glomerating ore the combination ofa vertically arranged downwardly flaring passageway, means for heat ing from outside said passageway, means for feeding material to be treated to the upper end of said passageway, and means for drawing combustion sustaining gas upward through said passageway.

3. In a machine for agglomerating ore the combination of a vertically arranged downwardly flaring passageway, an upwardly flaring exhaust chamber continuous therewith, means for feeding material for treatment to said passageway, and means for exhausting air from said exhaust chamber.

4. In a machine for agglomerating ore the combination of a hopper, a downwardly flaring passageway continuous with said hopper, a load sustaining member arranged beneath the lower end of said passageway, a closure for said hopper above, and means for exhausting air from such closed-in hopper.

5. In a machine for agglomerating ore the combination of a vertically arranged down- 20 6. In a machine for agglomerating ore the 25 combination of a hopper closed in above, and of a vertically arranged passageway arranged incontinuity with the gullet of said hopper, a rotary extractor arranged at the lower end of said passageway, and a'feed 30 mechanism discharging to said inclosed hopper.

In testimony whereof I have hereunto set my hand.

' PHILIP O. HARDING.

Witness FRANCIS J. ToMAssoN.

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