US2141506A

US2141506A - Apparatus for charging furnaces

Info

Publication number: US2141506A
Application number: US22896A
Authority: US
Inventors: Francois-Bongarcon Aime Joseph
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-06-06
Filing date: 1935-05-22
Publication date: 1938-12-27
Anticipated expiration: 1955-12-27

Description

Dec.; 27, 1938# A.A P. J. FRANAcols-BNGARCON 2,141,505

APPARATUS FOR CHARGING FURNACES Filed May 22, 41935 Patented Dec. 27, 1938 Y 2,141,506 APPARATUS Fon CHARGING FUnNAcEs Aim. Pierre Joseph Franois-Bongaron,

Paris, France Application May 22, 1935, Serial No. 22,896 In France June 6, 1934 7 Claims. (Cl. 214-36) The present invention has for its object an im- Y provement in the chargingy of blastfurnaces, shaftY furnaces and the like, in order' to ensure a better distribution of the charges.

Usually, the drop of the materialsV charged, for example in a blast furnace, takes place around the cone closingthe base ofthe throat, or of a truncated distributing cone located below.

'Ihese materials thus drop on to an annular zone and can only spread out on the charging plane of the blast furnace by tumbling. Now, the angle of repose varies in particular with. the nature of the materials and their degree of division. 'I'he result is that the alternate layers of coke and of ore do not have a uniform thickness.A Furthermore, a classification of the materials takes place according to their size. As the coke and the large pieces of ore rollon the slopes, they accumulate towards the centre and the periphery,

Whereas the fine ore remains in the zone of descent. The gases pass with greater difculty in this Verticalv zone than in the rest of the section of the blast furnace. This gives rise to irregularities in the heating of the materials, an incomplete reduction of the oxides by the gases and an exaggerated consumption of coke.

According to the invention, these drawbacks are avoided by distributing the materialsover the surface of charge, in concentric zones, forming by their juxtaposition, alternate layers of coke and of materials to be smelted whichY are practically horizontal, thereby avoiding tumbling. Furthermore, these concentric zones aresupplied with coke and materials to be smelted in constant proportions, whereby the respective superposed layers of coke and of materials to bersmelted offer a constant resistance to the passage of the gases in the whole of the section of the blast furnace.

The actual number of concentric zones in the plane of charge is not limited, but is chosen in each case to give the best results and taking into account the extentof the surface of charge.

. The yaccompanying drawing illustrates, by way .i5 of examplaone embodiment of a device for carrying out this method of charging, along three concentric zones, by means of aparticular ar-y rangement of the cone closing` the throat (or of the truncated distributing cone) 50 Fig. l is a perspectiveview of the modified cone.

Fig. 2 is the corresponding plan View. Figs. 3, 4 and 5 are sections along III-III, IV-IV, and V-V, of the preceding figure.

Fig. 6 shows, on a smaller scale, the general ar- 55 rangement of the modified throat.

Fig. '7 is a diagrammatic View of a modified arrangement of baille plates, and

Fig. 8 is a diagrammatic View of a further modification of baffle plates.

'I'he throat shown in Fig. 6 is applicable to 5 blast furnaces charged by a xed hopper. The conventional elements of the charging throat are found therein. However, the lower cone l of the hopper I is modified and has cut-out

portions

2, 3 provided with

partitions

4, 5 and 5. 10.

The portions of the cone corresponding tothe non-cut-out surfaces are intended to pour a portion of the materials charged, on to the outer zone of charge. They are bordered by guides 1, limiting the spacing of the materials in their fall. 15 The cut-out

portions

2 and 3 are intended for supplying the two other zones, towards which the

partitions

4 and 5, 5 guide the materials. 'Ihe partition 4, which is fixed vertically or slightly inclined, opposite the cut-out portion 2, prevents 20 the materials overflowing on to the outer zone and throws them back into the medial zone. 'I'he partition 5` forms, with the partitions 5', a chute which is inclined in an oblique direction with respect to the axis of the furnace and which directs towards the inner zone material entering the cut out portion 3. The partition 5 also extends towards the left so as to cause a spreading of the charge for the inner zone over a circumference of. greater angular extent than the cut out 3v of the distributor cone. These arrangements are shown diagrammatically by Figs. 3, 4 and 5, in which has been illustrated at 8 the wall of the blast furnace, at 9 its axis. The cone is shown in full lines in its closed position and in dotted lines in itsopen position. a, b, c are the various zones of charge.

The full portions and the cut-out portions of the cone are arranged in pairs, symmetrically with respect to the axis of the cone. The full and cut-out portions are measured respectively by their angles at the center of the furnace which vary in size proportionally to the zones to be supplied. In the example chosen, the projections on a horizontal plane of the full portions take up an angle of 180 and those of the cut-out

portions

2 and 3, respectively, 120 and 60. In order to obtain in the three zones a, b, c, layers of materials of equal heights, the width of the zones is calculated as follows:

The portion fed by the full portions totalling 180 of the surface of the cone will receive 18%60 or 1/2` of the total charge. The portion fed by the smallest cut-out totalling will receive 60/360 or 1A; of the total charge. The 120 portion will re- 575 4said chutes pour the materials overV 60 of the zone, due to the 180 cone section feeding it, the

area of thisrzone should be 1/2 thertotal area or 1r/2- The radius m of the circle dividing the outer zone from the central zones would thenrbe found from the equation Similarly, the radius y of the circle separating the central zones would be found from the equation 2 l Yee Since the area of the innermost theoretical circle is 1/6 of the total area, being fed by 60 of the distributor cone. Therefore, r2 Yequalling The radii of the circles separating the furnace cross section into three Zones furnish a measure of the widths of the Zones. YThe outer or largest zone has a width of 1-0.'707 or 0.293. The middle zoneis 0307-0408 or 0.299.V Y

Having these figures of width available the distributor is provided with. means associated with each charging region ofthe cone surface'for directing its charge into therproper band or Zone. The partition-guides I collect, overan angle of 60.` of the outer Zone, the materials which run out over the' full portions of the cone. Similarly the outlet opening of

theV chutes

5, 5 is such that inner Zone. Y

At each charge, the cone thus distributes between the various zones of the plane of charge portions of the material poured into the hopper, which portions are shown diagrammatically at a', b', c. For the following charge, the cone is rotated through such an angle that the fresh supplies ofmaterials are juxtaposed in each Zone with respect to the preceding ones. In the exr-V ample chosen, said angle is Y60". After the cone has been .rotated half a lturn, allrthe Zones are thus completely charged. `For such a division of the cone and of.Y the surfaceof charge, the quan-Y tities of materials falling into each zone are pro; portional to the surfaces of thesaid zones,Y and the heights of the layers of coke and of materials to be smelted are respectively equal in each zone. By modifying the surfaces of the full and cutoutportions'of thecone, while retaining the same zones of charge, or conversely,Y while retaining the surfaces of the full and cut-out portionsgbut modifying the width of the zones of` descent, that is to say, by changing the slope and the length of the surfaces and of the'guides of the cone, a

fuller charge can be obtained in one or several zones with respect to the others.

However, since this increase of supply takes place both for the coke and for the materials to be smelted, the proportion between the coke and the materials is not modified, and the resistance of the charges to the passage of the gases remains constant for the various zones. sibility enables a horizontal level to be retained in Ythecharge of the materials,even if the descent of such materials is more active for certain annular zones. VThis case occurs frequently in furnaces having a wide hearth, in which the combustion does not take place over the whole section of the plane of the tuyres, but only over an annular zone; the more rapid descent vertically through Y Y this zone is'compensated by a Vgreater supply in the corresponding zone at the topV of the blast furnace.

In order to enable the cone to be rotated, ac-A cording to Fig. 6, its suspension rod I!) has been said rod has been mounted `a worm wheel II which is fixed in position and in which the said rod can slide. Said wheel'is driven by a worm I2. VIt is quite obvious, moreover, that an apparatus which is quitesimilar to and independent of the closure cone can be used in the event of it not being desired to rotate the closure cone. It is suicient in this case to provide a cone having cut-out portions and guides, located below the closure cone and actuated in an identical manner by a shaft passing inside the hollow rod effecting the opening and the closing ofr the cone of the throat.

The distributor 'cone I is suspended on the rod I which is rotatable through its worm wheel II as described. The rod I0 is supported against'vertical movement by means of the thrust plate I which is carried on the frame I6 through bearings I8. The frame I6 is supported by means of rods orthe like I'I whereby it may be elevated or dropped. By reason of the sliding engagement of the section I9 of the shaft VII] in the worm gear II the cone I is made to followl the movements of the rod I1. A closure cone assembly I3 surmounts thedistributor cone I and is connected Vto the frame I6 and rods I1 for movement therewith.V The object of the cone I3 is to permit the free rotation of the distributor I without opening {thehopper I' and the cone I3 isV small enough so asnot to overlap the portionsrof the distributor Y cone which'separate the charge.

Vthe partition 4 which will serve to retain flowing chargingY materials within the boundaries of the proper zone.VV Y Y, ofcourse, theinvention is not limited to what is described and illustrated, but can-give rise to modifications ensuing fromrthe same principle of `distribution of the charges. This method of chargingrspecially described with respect to its use in blast furnaces, is applicable to any industrial apparatus having a vertical shaft andthe satisfactory operation of which relies on a supply f in Yhorizontal and regular layers of materials, Vas

for example lime kilns, plaster kilns, or ore roasting furnaces, vertical carbonization furnaces etc.

I claim:

1. In a charging device -for a shaft furnace,

This pos-V givena polygonal or equivalent Vsection and on the parti- Y a cone having peripheral portions cut out, said cone being of such a width as to place its periphery at a radial portion in the furnace just short of an outer circumferential charging zone, said cut out portions being cut towards the apex of the cone to place the inner edge of the portion at a radial position in the furnace just short of a middle circumferential charging Zone, a deector placed below certain of said cut out portions in a vertical position in the furnace between the outer and middle charging zones to direct a charge falling in such .portions to the middle zone, and a deector placed below the others of said cut out portions in an obiique position in the furnace extending from the line between the outer and middle zones to a position approximate- 1y on the line between the middle and the inner charging zones to direct a charge falling in such portions to the inner zone, the magnitudes of the cut out and uncut portions of the cone measured by angles at the apex thereof being in direct proportion to the areas of segments in the zones fed cut by a single angle measured from the center of the furnace.

2. A device for charging a shaft furnace comprising a distributing con-e with a diametrically opposed pair of uncut portions of 90 of the circumference of the cone each, a pair of diametrically opposed cut-out portions of 60 each, a pair of diametrically opposed cut-out portions of 30 eachl said portions adapted to distribute a charge in the furnace near the wall thereof, a substantially vertical baffle on the cone beyond the end of the 60 portions to confine a charge within a ring lying radially inside of the charge distributed by the 90 portions, and a downwardly and centrally sloping. baiiie on the cone beyond the end of the 30 cut-out portions to distribute a charge to the center of the furnace without overlapping the charge distributed by the 60 portions.

3'. A device for charging circular furnaces comprising below the feeding funnel a distributing cone the surface of which is divided up into two diametrically opposed solid portions measuring 90 each at the apex of the cone, two diametrically opposed cut out portions of 60 each measured at the apex of the cone, and two diametrically opposed portions of 30 each measured at the apex of the cone, and means associated with each of said portions for directing a charge lowingrdown rthe cone surface into three concentric zones of theV furnace. f

4. A device for charging circular furnaces comprising below the feeding funnel a distributing cone divided into two diametrically opposed solid portions of 90 each measured at the apex of the cone, two diametrically opposed cut out portions of 60 each measured at Vthe apex of the cone,

face to drop within an angle of 60 measuring from the apex of the cone, whereby two diametrically opposed portions of the said zone are provided with a charge filling an angle measuring 60 from the center of the furnace at each charging operation.

5. A device for charging circular furnaces comprising below the feeding funnel a distributor cone the surface of which lis divided into two diametrically opposed portions of 90 each measuring from the apex of the cone, two diametrically opposed portions of 60 each measuring from the apex of the cone, two diametrically opposed portions of 30 each measuring from the apex of the cone, means on said cone in the region of said 90 portions for restricting a charge to fall within a zone in the furnace measuring 60 from the center, and means on said cone in the region of said 30 portions for restricting a charge to fall within a zone in the furnace measuring 60 from the center.

6. A device for charging circular furnaces comprising below the feeding funnel a distributor cone the surface of which is divided into two diametrically opposed portions of 90 each measuring from the apex of the cone, two diametrically opposed portions of 60 each measuring from the'apex of the cone, two diametrically opposed portions of 30 each measuring from the apex of the cone, means on said cone in the region of said 90 portions for restricting a charge toifall within a zone in the furnace measuring 60 from the center, means on said cone in the region of said 30 portions for restricting a charge to fall within a Zone in the furnace measuring 60 from the center, said 60 portions and said 30 portions being cut away towards the apex of said cone, baiiles on the cone in the region of said 60 portions to restrict a charge falling through said cut out portions to an intermediate circular Zone in the furnace, and bailies on said cone adjacent said 30 portions for directing a charge falling through said portions to the center of the furnace, said 90 portions being solid and the charge from said portions feeding an outer circular zone in said furnace.

7. A charging device of the character described comprising a distributor cone the surface of which is divided into feeding portions separated from one another and adapted to divide up a charge owing down said cone, said feeding portions being adapted to feed a number of concentric circular furnace zones, said portions being laid out on the surface of said cone along angles measured at the apex of said cone which angles vary in magnitude in proportion to the areas of the zones cut by a single angle measured from the center of the furnace, and means associated with said feeding portions for directing the respeotive charges to cover areas of the respective zones equal to the corresponding areas cut by said single angle.

AIM PIERRE JOSEPH FRANoIs-BONGARQON.