US3063582A - Feeder for pelletizing furnace - Google Patents

Description

Nov. 13, 1962 P. STEFFENSENY FEEDER FOR PELLETIZING FURNACE INVENTOR 1 811 L. S {ff/6126612, fmjia fifi.

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Original Filed March 18, 1953 Nov. 13, 1962 P. L. STEFFENSEN FEEDER FOR PELLETIZING FURNACE 5 SheetsSheet 2 Original Filed March 18, 1955 I INIVEN'R )R Ferny b. 511 92116612.

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ATTORN Y Nov. 13, 1962 P. 1.. STEFFENSEN FEEDER FOR PELLETIZING FURNACE Original Filed March 18, 1953 5 Sheets-Sheet 3 En \b kw M \N INVENTUR Party L. Staflansen L .2 I 4%." Wm H Mm Nmmmwwwwwhmw ME D BY KM E P. L. STEFFENSEN FEEDER FOR PELLETIZING FURNACE Nov. 13, 1962 Original Filed March 18, 1955 5 Sheets-Sheet 4 INVENTUR TTORZY StWens'eze Jim/Z4 R ait Pang L Nov. 13, 1962 P. L. STEFFENSEN FEEDER FOR PELLETIZING FURNACE Original Filed March 18, 1953 5 SheetsSheet 5 INVENTOR ATTUR! United States Patent ,i 3, FEEDER FQR PELLETIZING FURNACE Percy Lea Stefiensen, Cornwaii, Pa, assignor to Bethlehem Steel Company, a corporation of Pennsyivania Original application Mar. 18, 1953, Ser. No..343,13.8, now Patent No. 2,918,267, dated Dec. 22, 1959. Divided and this application May 29, 1956, Ser. No. 588,034 9'iaims. 31214-18) My invention relates to apparatus for charging and uniformly distributing sized balls or pellets of iron ore into the top of a vertical shaft furnace or the like in which the descending balls are fired at a temperature.

sufficiently high to give the. necessary strength and hardness to withstand subsequent handling.

It is therefore an object of this invention to provide means for charging a furnace of the vertical shaft type wherein the heated ore charge forms a continuous column of downwardly-moving material in. the stack.

Another object is to provide means for distributing the incoming balled feed evenly over the charge in the furnace.

Another object is to provide means for maintaining uniform and continuous flow of the charge in the furnace.

Another object is to provide means to hold the top of the charge at asubstantially uniform level.

In the attached five ('5) sheets of drawings:

FIG. 1 is a top plan view showing the arrangement of the conveyor belt shuttle car, feed distributor, and furnace top division plates;

FIG. 2 is a detail section, taken on the line i -4w of FIG. 4, of the transverse belt drive;

FIG. 3 is an end elevation of the shuttle car, showing. the manner in which the feed distributor is tilted to direct the, fall of the pellets. from the transverse belt;

FIG. 4 is a detail section on the line 4'4 of FIG. 2;

FIG. 5 is a side elevation of the shuttle car and longitudinal belt;

FIG. 6 is an enlarged broken top plan view, showing the feed distributor portion of the apparatus shown in FIG. 1;

FIG. 7 is a detail view, partly in section, showing the speed change unit with external gear means by which the feed of the conveyor belts is modified in accordance with the speed and direction of travel of the shuttle car;

FIG. 8 is a side elevation of the apparatus shown in FIG. 6;

FIG. 9 is an end elevation of the apparatus shown in FIGS. 6 and 8; and FIG. 10. is a diagrammatic side elevation of a modification of the feed distributor employing a parallelogram type of drive.

It will be understood that for uniformly satisfactory and predictable results in the induration of ore pellets in a shaft furnace it is essential to maintain a substantially constant height and density of the pellet column and a relatively level stockline in the furnace. Thetype of furnace shown in the drawings is rectanguar in horizontal section, being divided by a vertical central Wall 27 into a pair of shafts which are operated practically as one, and the normal height of the charge is usually carried at about the top of the vertical central wall 27. Where the area to which the charge must be delivered is essentially rectangular, as in the furnace disclosed herein, it is necessary to fill in at the corners with pellets, which is practically impossible with conventional revolving feed devices.

Referring to FIGS. 1 to 10, inclusive; therefore, I have shown a mechanism which is especially adapted for charging and evenly distributing ore pellets or the like 3,063,582 Patented Nov. 13, 1962 into any vertical shaft type furnace of rectangular section, together with means for maintaining sufficient separation between sections of the charged pellets to preserve the porosity of they charge.

Adjacent to said furnace top 32 and parallel thereto is a suitably supported pair of rails 79, constituting a track over which a shuttle car or carriage mounted on wheels 81 and axles 82 is adapted to be reciprocated beneath a stationary feeder 83. Said axles 82 are journaled in bearings 84' on which is supported. a longitudinal frame 85; fabricated of rolled steel members, and having a lateral extension frame 86 secured thereto by welding or the like. Suitably journaled on the longitudinal frame 85 are rear and front pulleys 87 and 88 and interposed idlers 89 supporting longitudinal troughed' conveyor belt 99 having an adjusting screw 91 (see FIG. 5). Alsomounted on said longitudinal frame 85 are platforms 92 and 93 supporting belt drive motor 94 and car drive motor 95 respectively. On the lateral extension frame $6 are journaled pulleys 96' and 97 and idlers 9.8 supporting conveyor belt 99 moving transversely beneath the longitudinal belt 90. A platform 1% supporting feed distributor motor 101, and terminal side plates 102 connected by a transverse shaft 103 pivotally supporting a feed distributor or flipper 104, are also mounted on the lateral extension frame 86.

Since the conveyor belts 90'. and. 99 should maintain a constant speed ratio, they are preferably driven by one constant speed electric motor 94, through coupling 105, input shaft 106 and output shaft 107 ofa shaft mounted gear reducer 108, sprocket 109, chain 110, and; sprocket 111 on one end. spindle 112- of the front or drive pulleys 88 of the longitudinal belt, and. thence from the opposite spindle 113, of said drive pulley 88 through sprocket 11 4 thereon, chain 115, sprocket 116, shaft 117, bevel gears I18 and 119, shaft 120, sprocket 121 and chain 122 to sprocket 123 on spindle 124 of the rear pulley 96. driving transverse belt 99. As shown in FIGS. Q, and 4, the bevel gears 118 and 119, shaft and sprocketv 1 .1 re protectively enclosed in gear box case 125.

Shuttle car 80 is adapted to be moved forward or backward. on the rails 79 by the motor 95, through coupling 126, conventional foot mounted gear reducer 127, dQuble sprocket 128, chain 129, and sprocket on the axle 82 of a wheeli81.

It is importantto note that with the use of the moving shuttle car 80, the uniform belt loading necessary for uniform beddi u of. h harged m teri l vin h furnace cannot be, had with ordinary constant speed, .or fixed drive, conveyor belts, and some means of varying belt speed. to orrect different al loa ing becomes essential. For example, referring to FIGS. 1 and 5, and assuming the stationary feeder 83. to be delivering material at a constant rate to a fixed drive conveyor belt 90 which will convey the ma erial, from. lef t gh t be will be loaded, at a uniform light load per foot when. the car is also moving from le t o h When the a is m0- tioulesS,, the belt will be loaded at a uniform medium load per foot, When the car is moving from right to left, the belt will be given a uni-form but heavier load per foot. As a result of'thisdilferential belt loading, the furnace charge line will take approximately the form shown by the lower dot-and-dash line A of FIG. 5, which in the case of the double shaft furnace illustrated is particularly disadvantageous because the left shaft will thus constantly receive more feed than the right shaft. The desired charge line is indicated by the upper dot-and-dash line B.

The speed of the conveyor belt 90 relative to the sta 70 tionary feeder 83- is a function of the speed and direction of travel of the shuttle car 80. For example, in order to maintain a uniform belt speed of 216 feet per minute relative to the fixed location of the feeder 83, if the car 80 is moving from right to left at 15 feet per minute, the belt speed relative to the shuttle car must be increased 15 feet per minute; if the car is not moving, no change in belt speed is required; but if the car is moving from left to right at 15 feet per minute, the belt speed relative to the shuttle car must then be reduced 15 feet per minute.

A uniform rate of belt speed relative to the feeder 83, and consequently of feed from the belts 90 and 99 to the furnace, is maintained regardless of the speed and direction of movement of shuttle car 80, by means of the large external gear 131 which is made integral (as by welding or the like) with the outer casing 132 of the gear reducer 1&8 (FIG. 7). Said gear reducer 108 is of the shaft mounted type shown, for example, in Letters Patent No. 2,116,166, issued May 3, 1938 to Joseph D. Christian, and having a round outer casing 132 concentric with the input and output shafts 186 and 167 thereof. As will be understood from the above-mentioned Letters Patent No. 2,116,166 to Christian, in FIG. 7 hereof inside the casing 132 a large input sun gear 105a and a smaller output sun gear 107a are individually mounted on the input and output shafts 1G6 and 107 respectively. A countershaft 108a is also journaled in the casing 132 in parallel spaced relation to said input and output shafts'lGfi and 167. A small planet gear or pinion ltitib is secured on said countershaft 1&8 in meshing engagement with the input sun gear 166a, and a larger planet gear 1fl7b is secured on the countershaft in engagement with the small output sun gear 1074:. Any desired reduction in speed ratios, of course, may be obtained by varying the sizes, spacing and numbers of teeth of gears or pinions and their order of engagement. The casings of such gear reducers, being without fixed bases, are normally restrained against rotation by torque arms. The gear 131 engages with pinion 133 on shaft 134, mounted on bearings 135 and 136 and carrying a sprocket 137, connecting by chain 138 with the double sprocket 128. Gear 131 and pinion 133 thus serve in lieu of a torque arm when the shuttle car 80' is stationary, and add to or subtract from the speed of the output shaft 107 in accordance with the direction and speed of the car when the car is moving. Even if the car is being driven at varying speeds in order to obtain a particular irregular feed pattern in the furnace, the de .vice will still maintain a unifrombelt-loading.

It is necessary, of course, to have proper coordination between the ratios of the various chains and sprockets and gears and speed reducers. Thus, with a car drive motor 95 having a speed of 720 r.p.m., a 72:1 ratio gear reducer 127 will. give a'speed of rpm. to the double sprocket 128. With a ratio of 2:1between the sprockets 128 and 136 connected by the chain 129, the resultant axle speed of.5 r.p.rn. applied to a wheel 81 three feet in circumference will provide a car speed of feet per minute.

A belt drive pulley 88 three feet in circumference and driven through a 1011 ratio gear reducer 108 by a 720 rpm. motor 84 will furnish a belt speed of 216 feet per sprocket 128 (1.12 to 1) connected'by the chain 138, and

between the external gear 131 and pinion gear 133 (2:1).

The tilting feed distributor or flipper 104 comprises a pair of rectangular metal plates'139, preferably of stainless steel or the like,forrning sloping pellet-deflecting surfaces in the shape of an inverted V, welded over triangular side plates 140 and braced by vertical stifieners 141 and bottom stiifener' '142 also welded thereunder.

The triangular side plates 14% are riveted or welded to the lower ends of upright pivot arms 14 3 having flange type bearings 144 and spacers 147 thereabove through which the transverse shaft 103 extends with its threaded ends secured by nuts 148 and lock nuts 149 to terminal side plates 102. The upper ends of the pivot arms 143 are fastened together by a tie rod 150 having threaded ends 151 with nuts 152 and lock nuts 153 thereon. The motor 101 driving the feed distributor is of the reduced speed gear head type, of about '11 r.p.m., driving through eccentric arm 154, connecting rods 155' and 156 adjustably joined by turnbuckle 157, and connecting plate 158 having a bearing 155 in which the tie rod 154) is pivotally mounted.

. Referring to FIG. 10, an alternative form of feed distributor 161 may also be used, in which the inverted V shape is retained but the feed distributor instead of swinging in an arc is moved horizontally by a parallelogram drive, comprising the rotating cam 162, connecting rod 163 pivot arm 164 and horizontal arm 165 with suspension arm 166, which imparts a substantially straightline reciprocating motion to said feed distributor 161. The pivot arm 164 and suspension arm 166 are pivoted at fixed points 167 and 168 on the framework supporting the transverse belt 99. The function of either type of feed distributor is -to spread the pellets and facilitate getting an even division of material. The resulting feed pattern, instead of a single sharp high ridge in which all the fines and broken pellets are concentrated, is practically flat, as shown in FIG. 10, with only two rounded low ridges running substantially parallel to the agitator rocker shafts 55 in the lower part of the furnace.

A proper separation of the charged pellets may be maintained by vertical division plates 169, as shown in FIGS. 1 and 3, extending in uniformly spaced relation substantially across the furnace stack 32 with their upper edges at the stockline, and suspended there by means of bars 171? and 171, with the lower ends of said bars being welded to said division plates 169 and their upper ends welded to members 172 and 173 of the furnace superstructure.

The top division plates 169 will practically eliminate the irregularity of movement of the furnace charge caused by the formation of large masses of pellets. The increased void space resulting from the contact of the round pellets with the fiat plate surfaces allows the hot gases and the heat line to penetrate ,the surface of the charge, and the thickness of the plates permits a slight lateral or horizontal reorientation of the pellets after they have descended past the bottom edge of the plates, so that the formation of large masses of pellets is prevented, or at least the size of any such masses is limited to relatively thin Weak slabs which readily break apart as they move down through the furnace.

The operation of the furnace is continuous, the moist ore pellets being changed at the top of the shafts and moving slowly downward as the fused and agglomerated product is discharged from the bottom hoppers.

Although I have thus shown and described my invention hereinabove in considerable detail, I do not wish to be limited narrowly to the exact and specific details mentioned, but I may also use such substitutes, modifications or equivalents thereof as are embraced within the scope and spirit of the invention and of the appended claims. a

This application is a division of my co-pending application Serial No. 343,138, filed March 18, 1953, now

Patent No. 2,918,267, issued December 22, 1959.

. I claim: 1

'1. A machine for conveying material received from a stationary feeding device and charging it evenly into a shaft furnace or the like, comprising a track in parallel spaced relation to the furnace, a wheeled car mounted on said track, a conveyor belt'mounted on the longitudinal axis of the car, a second conveyor belt extending transversely from beneath the delivery end of the first belt and terminating above the furnace, means for reciprocating the car on the track, and gear mechanism operatively controlled by said car reciprocating means for changing the speed of the conveyor belts in accordance with the speed and direction of travel of the car.

2. A machine for conveying material received from a stationary feeding device and charging it evenly into a rectangular shaft furnace or the like, comprising a pair of horizontal rails in parallel spaced relation to the top of the furnace, a shuttle car mounted on said rails, motor means for driving said car, a conveyor belt mounted on the longitudinal axis of the car, a second conveyor belt extending transversely from the car to above the center line of the furnace, means including a motor and a shaft mounted speed reducer for driving the two conveyor belts in synchronism with each other, said speed reducer having a circular outer case and a gear mounted externally thereon concentric with the shafts of the speed reducer, and a pinion gear engaging said gear and operatively connected to the car-driving motor means.

3. A machine for distributing material over an area, comprising a stationary feeder for supplying the material, an endless belt below said feeder for receiving and conveying the material, first motor means for driving the belt, a carriage supporting the belt, second motor means for reciprocating the carriage, a planetary gear train interposed between said first motor means and said belt and mechanical means operatively actuating the planetary gear train and controlled by the second motor means.

4. A machine as defined in claim 3 in which said planetary gear train includes a planet gear, a housing for said planet gear, and means for rotating the housing in accordance with the direction of movement and speed of said carriage.

5. A machine as defined in claim 3 in which said planetary gear train includes coaxial input and output shafts each having a sun gear thereon, a pair of planet gears mounted on a common shaft and engaging said sun gears, a housing for said planet gears journaled on said input and output shafts, and means for rotating said housing in accordance with the direction of movement and speed of the carriage.

6. A machine as defined in claim 3 in which said planetary gear train includes an input shaft with a sun gear thereon, an output shaft also with a sun gear thereon, planet gears mounted on a common shaft and engaging said sun gears, a housing for said planet gears, an external ring gear on said housing, a pinion gear engaging said external ring gear, and means for driving said pinion gear in accordance with the direction of movement and speed of said carriage so as to maintain constant the speed of the belt relative to the stationary feeder.

7. A machine as defined in claim 3 in which said planetary gear train comprises a cylindrical housing, separate input and output shafts journaled concentrically in said housing, a parallel spaced countershaft journaled within the housing, an input sun pinion on the input shaft,

an output sun gear on the output shaft, a planet gear on the countershaft in engagement with the input sun pinion, a countershaft-mounted pinion in engagement with the output sun gear, and means for rotating the housing in accordance with the direction of movement and speed of the carriage.

8. A machine for distributing feed material over an area, comprising a feed hopper, an endless belt below said feed hopper for receiving and conveying feed material discharged therefrom, mechanism for traversing said carriage beneath the hopper in reciprocating motion parallel to the direction in which the belt is driven, and means for driving said belt; said latter means comprising a constant speed motor having a drive shaft, a driven shaft in operative relationship with the belt, a planeary gear train including a planet gear operatively connecting said drive shaft and said driven shaft, a carrier member for said planet gear, a shaft in operative engagement with the carriage reciprocating mechanism and rotating in accordance with the speed and direction of movement of the can riage, and means actauted by said last mentioned shaft for imparting like rotation to said carrier member whereby the speed of rotation of the driven shaft is varied in accordance with the speed and direction of movement of the carriage so as to maintain constant the speed of the belt relative to the hopper.

9. A machine for distributing feed material uniformly over an area, comprising a stationary feed hopper, an endless belt below said hopper for receiving and conveying material dischanged therefrom, a second endless belt below the discharge end of said first mentioned belt and at right angles to said belt for receiving material discharged therefrom and conveying it to said area, a carriage for said belts, means for reciprocating said carriage in a path parallel to the direction of said first mentioned belt, and a common drive for both said belts comprising a constant speed motor, a planetary gear train having an input shaft operatively connected to said belts, a planet gear in said gear train mounted on a carrier member rotatable coaxially with but independently of said input and output shafts, and means operatively connecting said carriage reciprocating means with said carrier member for rotating said carrier member in accordance with the speed and direction of the carriage.

References Cited in the file of this patent UNITED STATES PATENTS 727,942 Hebb May 12, 1903 895,064 Bennett Aug. 4, 1908 923,064 Morenus May 25, 1909 1,668,968 Lambot May 8, 1928 2,008,572 White July 16, 1935 2,636,606 Dunasky et a1 Apr. 28, 1953 2,709,530 Haley et al. May 31, 1955 2,739,800 Sisco Mar. 27, 1956 FOREIGN PATENTS 645,334 France June 26, 1928

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