Патент USA US2410944код для вставки
Nov. 12, 1946. w. F. JOHNSON 2,410,944 SYSTEM FOR SINTERING Filed May 13, 1943 IVENTOR. BY Val/a]? fo?mmn/ atented ov. 12, 1946' STATES"2,410,944PATENT OFFICE SYSTEM FOR SINTERING Walter F. Johnson, Berkeley, Calif., assignor to American Smelting and. Re?ning Company, New York, N. Y., a corporation of New Jersey ‘ Application May_13, 1943, Serial No. 486,798 6 Claims. (Cl. 266-21) 1 This invention relates to metallurgical opera tions and more particularly to a system for auto ing the usual structural frame members, “I, ll, l2, cars l3 provided with wheels i4 riding on suitable tracks IS in the upper part of the ma chine and tracks iii in the lower part. The cars or pallets l3 are engaged\by the rotatable bull wheel I‘! at the feed end .of the machine which causes them to be pushed in the direction of arrow l8 on tracks i5 where they are turned over and dumped at the discharge end. The matically controlling the operation of sintering machines. ‘ ' ' In the process of roasting ores on a sintering machine, and especially sulphide ores, it fre quently is highly desirable to recover the S02 evolved in the reaction between the oxygen of the combustion supporting air and the sulphur pallets then travel upside down along the inclined trackways Hi again to be engaged by the bull wheel to continue their cyclic travel. Mounted above the path of travel of the pal of the ore. For reasons known in the art, it is advantageous to produce a gas from the roast ing or sintering operation which is uniform with respect to volume and S02 concentration in addi tion to producing a uniformly sintered product. lets at the feed end is a charge hopper or chute This is particularly so when the S02 containing 15 l9. Material to be sintered is fed into the hop gas is to be used for the production of sulphuric per l9 by a turntable 20 on to which the mate acid or other products of sulphur dioxide. rial is charged from a .bin 2i. A suitable plow Heretofore the control of the operation of the or scraper indicated at 22 de?ects a'predeter machine has been left largely to the manual skill mined amount of material from the surface of I of the operator who, ‘among other things, may be‘. 20 the turntable in a manner-known in the art. It charged with the duty of controlling the speed will be understood, of course, that the material of the machine as well as other factors by a sys A will be augmented with such combustible as may tem of rather hit or miss‘ tests and observations be necessary to insure suf?cient heat for sinter from which he manually changes the controls ing in the event the sulphides in the ore are ,from time to time in his efforts to produce the 25 de?cient. As the pallets pass‘ under the discharge end‘ desired uniformity both with respect to the sinter 23 of the chute i9 they are supplied with an ad In accordance with this invention there is pro iusted amount of material to be sintered, called vided a system for automatically controlling the the charge. An adjustable back plate 24 may operation of a sintering machine whereby most, 80 be used to level off the surface of the charge in if not all, of the personal equation involved in the pallets Ill. The charge is then given an initial prior conventional practice is eliminated with ignition by means of a ?ame mu?‘le or igniter 25 consequent improved results with respect to uni after which the pallets pass over a windbox and formity of sinter and relatively high concentra under a hood designated generally byv reference tion S02 gas produced which, in turn, re?ects a 35 numbers 26 and Y27,‘ respectively. higher over-all e?lciency of the entire sintering In this machine the windbox is interiorly operations. divided by a, partition member 28 provided with The invention is hereinafter more fully de- . a baille 29 to provide in effect a first windbox 30 scribed in connection with the operation of that and a second windbox 3! which preferably are and S03 gas. _ ' ' ' . type of sintering machine which has come to be 40 of unequal size, the ?rst being larger. The hood known in the art as a Dwight-Lloyd straight line machine but it will be apparent as the descrip tion proceeds that the invention will lend itself extends over the top of the machine and com pletely covers the second windbox 3| and all but to other sintering machines. a small portion of the ?rst .windbox. The sides 2‘! surrounding the discharge end of the machine Although the novel features which are believed 45 of the hood extend downwardly around the to be characteristic of this invention will be par tracks and engage the windboxes in a manner ticularly pointed out in the claims appended to provide a substantially air-tight hood having hereto, the invention itself, asto its objects and an opening 32 through which atmospheric air advantages, and the manner in which it may is drawn into the hood chamber 83. Extending be carried out, may be better understood by re 50 from the end of the hood 2'! nearest the igniter ferring to the following description taken in con— 25~for a substantial distance over the ?rst wind nection with the accompanying drawing forming box 30 is an inner hood 84. There is a seal be a part thereof in which Fig. 1 is a view in eleva tween the windbox and the pallets and the ma chine is provided with a dead plate beyond the tion, partly in cross-section and partly diagram matic, of a sintering machine of the Dwight 55 windbox as is known in machines of this type. Lloyd type embodying the system of the inven The second windbox is provided with a circu tion, and Fig. 2 is a cross section taken on the lating pipe 35 which leads from the second wind line 2-2 of Fig. 1. ' ' box 3l to a suction blower or fan 36 and thence Referring to the drawing, there is shown a into a pipe 38 which opens into the hood cham sintering machine of the straight-line type hav do ber 21 over the first wind box 30. A discharge 2,410,944 ing through the charge'bears a proportional re pipe 40 interconnects windbox 30 with ?ue 4i lationship to the draft or suction in the hood. To take advantage of this condition to auto matically control the operation of the machine there is provided a conduit 44 which connects the interior of the hood chamber 33a above the via suction blower or fan 42. In operating a machine of this type in con ventional manner, air for the‘ sintering opera tion is drawn through the opening 32 through the hood chamber and down through the sul phide charge on the pallets into second windbox 3| by fan 36, the gases from the second windbox first windbox with a controller (designated gen , erally by reference character 50) which will operate a speed reducer mechaism 5| in re passing therefrom through circulating pipe 35 thence through circulating pipe 38 and thence 10 sponse to changes in pressure (suction) within the hood; the speed reducer being driven by a into the main hood above the ?rst windbox. A bailie 3.5a in the hood 21 prevents the air ‘drawn into the machine at the discharge end from ?ow ing freely and directly over the charge above the first windbox 30. . suitable prime mover 52 by a belt 53. The controller is shown more or less diagram matically and its mechanism per se may be of _ various forms. Such an instrument, now offered for sale under the trade name “Bristol,” may be By providing for recirculation of the gases a used for the purpose. higher concentration of S02 in the gas ultimately As shown, the conduit 44 is connected to a discharged from the machine is obtained than recorder or indicator type of draft measuring otherwise. However, due to variable, factors entering into the sintering operation, it is dim 20 instrument 54. The controller instrument desig nated :ifi has an arrangement or controlling de cult, and sometimes impossible, to obtain a uni vice vhich is operative, at a predetermined draft formly sintered product and a uniform volume of setting, to open a small valve when the draft SO: gases of uniform, relatively high concentra exceeds the setting, to allow air under pressure tion. . to pass through conduit 55 which is connected One very important factor in obtaining uni to a suitable source of compressed air (not formity is controlling the speed of travel of shown). The valve arrangement is such that the pallets so that the charge will be burned the air pressure may thus be caused to ?ow into through to the grate bars of the pallets when conduit 58 when the draft exceeds a predeter the pallets have passed over the last windbox. It has not been uncommon practice for the 30 mined setting and to_?ow‘ out of conduit 56 when the draft falls below a predetermined workmen to dig into the charge with a bar be amount. Conduit 56 is connected to the inte fore it is discharged from the machine to see rior of a bellows 51 which is contractible and if the product is sintered satisfactorily and then expansible in response to the air pressure there by hand adjust the mechanism which controls the rate of travel of the pallets. Because the 35 in. The bellows 51 which is carried on a suit- ' ably mounted bracket 58 also mounts a rod 59 charge may vary, the rate of sintering also may slidable in an aperture in the bracket. The vary. An operator might dig into one or two ' outer end of the rod is linked to a lever 60 as by pallets and believe the charge burned out too a pin 6|. The lever is pivoted to the bracket much; so, he would speed up the machine to overcome this, only to ?nd the next pallets mov 40 at one end providing a fulcrum 62. The other end of the lever is attached to a rack 63 by ing along might not warrant the extra speed. means of a pin 64' slidable in a slot 65' in the In. accordance with the invention, these un lever. desirable drawbacks are eliminated by provid The rack 63 meshes with a pinion 84 ?xed to ing a controller responsive to the amount of air a shaft 85 which is a part of the variable speed passing through the charge and suitable mecha reducer 5|. A rotation of pinion 84 will cause nism operatively connected whereby the speed of the pallets will automatically be adjusted to produce uniform sintering. At the same time, the volume of combustion gases produced may be kept substantially constant, with a relatively‘ high concentration of 802. When the charge passes under the igniter, it is given an initial ignition and the combustible material burns, thus eliminating the volatile substances and driving off the water.- As this 55 progresses, as the pallets travel over the wind a contraction or spreading of conventional cone shaped driving pulleys fixed to shaft 65 in known manner and thus control the linear speed of driving belt 61 which in turn rotates the bull wheel. I‘! through pulleys 68 and 8B and a train of gears 68, 10, ll. Shaft 65 is driven, as indi cated, by the drive shaft 12 to which is fixed pulley 73 driven by belt 53. Also driven by the speed reducer is a belt ‘I4 which rotates turntable 20 on its axis through a set of bevel gears and shafts,"l5, 18. ll, 18, 19 and ‘80. Hence, it will box, the charge becomes progressively more po be observed that the speed of rotation of the rous and more air is pulled through, consequently turntable 20 is correlated with the speed of the the porosity largely determines the amount of air pulled through and therefore the rate of 60 bull wheel II. A speed indicator 8| connected by a belt 82 to the speed control shaft 85 currently burning of the combustible in the charge. indicates the speed of travel of the pallets, the Hence, under usual conditions of operation in hand 83 being movable over a graduated dial 44. order to obtain uniformity of sinter, the speed In the operation of the machine, the rate of of the machine should increase automatically when the volume of air passing through the 65 feeding the charge from the turntable, through the chute I9 is adjusted and also the speed of charge increases beyond a predetermined the pallets is regulated in accordance with the amount, and the speed should automatically draft in chamber 33a over the ?rst windbo'x decrease when the volume decreases. Thus, the ill to produce a desired amount of sintering when volume of air passing through the charge may be maintained substantially constant by regu 70 the sintered charge is dumped from the pallets at the end of discharge end of the machine. lating the speed to take care‘of such variations The controller device 50 is adjusted for these so that the charge will be burned to the grate conditions and the setting to maintain the draft bars by the time the pallets, reach the end of the constant within narrow limits. The mechanism last windbox. The amount of air entering the hood and pass 75 is such that if the draft increases in the chem 2,410,944 ber 3311 over the. ?rst windbox the controller ' sintering machine 'having a train of pallets ' automatically operates the lever‘ 60 when the, ’ movable over a.windbox, means to cause said draft exceeds the setting. This causes a corre pallets to 'move in tandem over said windbox, sponding movement of rack 63 to rotate pinion a substantially enclosed hood over said windbox' 65 and thus causes the speed reducer mechanism forming a chamber, an igniter to ignite the charge to speed up the rotations of the bull wheel and on the pallets, and a blower to ‘draw air into said consequently the speed of travel of the pallets. chamber through an ignited charge on the pallets into said windbox to sinter the charge; a draft This is desirable because an increased draft in dicates too much burning before the pallets measuring instrument connected to said cham reach the end of the windbox. Speeding up the rate of travel compensates this so that the charge will be burned the. right amount just as the pallets leave the windbox 3 I. On'the other hand. if the draft decreases, that indicates not enough ber; a controller mechanism connecting with said instrument and operative in response to a change in draft measured by said instrument; and a variable speed reducer mechanism con nected to ‘operate the pallet moving means, said speed reducer mechanism and controller mecha nism being operatively connected with each other to change the driving speed of said speed re :lucer mechanism in response to a change in draft in said chamber to automatically control the ‘burning, as the porosity is insuiiicient to pass the desired constant volume of air through. the charge. When this condition exists,v the con troller mechanism through the rack and pinion 83 and 65 operates to reverse the movement of the rack to slow down the speed of the pallets a 20 speed of travel of said pallets over the windbox in correlation with draft conditions in said cham corresponding amount. Thus, a balance is main ber. ' tained and variations in the sinter and the SO: 4. Apparatus for’ producing uniform sinter gas produced may be substantially eliminated by from ores amenable to sintering which cornautomatic control. While certain novel features of the invention‘ 25 prises a frame mounting upper and lower-track \ ways, a train of pellets movable on said track“ have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the system of the in vention illustrated and in its operation may be 3.0 made by those skilled in the art without depart ing from the spirit of the invention. “What is claimed is: ways, a'wheel to move said pallets, means to charge said pallets at one end of the upper track- > ways, an igniter to ignite the charge in the pallets, a hood beyond the igniter forming a hood cham ber over the pallets in their path of travel, a " ' windbox below said vhood and beneath pallets - ' travelling on said upper trackways, a blower - connected to said windbox to draw air into said 1. Apparatus for sintering ore which comprises, in combination, a driven variable speed reducer 35 chamber, thence through the ignited charge into said windbox, a speed ‘reducer r mechanism having a driving means and a means to change driven by a prime mover, said speed . reducer the driving speed of the said driving means; a sintering machine driven by said driving means, said sintering machine having a substantially ' mechanism ‘being connected to rotate said wheel to move said pallets, a controller connected to closed hood, a windbox and a blower mechanism 40 said hood chamber and operative in response to a change of a condition in said chamber to cause. to draw air into the hood chamber, through the said speed reducer to change its driving speed charge and through the windbox of said machine; and a controller‘ mechanism connected to said ' to change the speed of travel of said pallets under . ' said hood. chamber and to said speed reducer, said con 5. Apparatus'for sintering ores comprising the troller being operative in response to a change 45 combination with a sintering machine of the of pressure in said chamber to increase the speed down-draft type de?ning a path ‘of travel for, of said driving means upon a predetermined in the charge and having variable-speed driving crease in the draft in said chamber and to de means for conveying the charge along said path crease the speed of said driving means upon a of travel, of means for measuring the draft at a predetermined decrease in the draft in said 60 selected point in the system, and controller means . chamber. operative in response to signi?cant changes in 2. Apparatus for sintering ore which comprises, said draft to automatically actuate said driving in combination, a driven variable speed reducer means to increase the rate at which the charge having a driving means and a means to change conveyed along said path of travel when the the driving speed of the said driving means; a 55 is draft increases at said selected point and to de/-' rotary charger tumtable' to feed the charge to be crease the rate at which the charge is conveyed vsintered driven by said driving means; a sintering along said path of travel when the draft de machine driven by said driving means, said sinter creases at said selected point. - ing'machine having a substantially closed hood, ' 6. Apparatus for uniformlysintering ore com- I a windbox and a blower mechanism to draw air 60 prising the combination with a straight-line into the hood chamber. through the charge and sintering machine of the Dwight-Lloyd type hav through the. windbox; and a controller mecha ing pallets i for supporting the ore/and driving nism connected to, said chamber and to- said means for moving the. pallets through the ma speed reducer, said controller being operative in‘ chine, ,of -a ‘ draft-measuringlinstrument for response to a change of pressure in said chamber measuring the draft under which the sintering , I to increase the speed of said driving means upon ‘operation is conducted, and controller mechanism a predetermined increase in the draft, in said responsive to material deviations in said draft chamber and to de'crease the speed of said driving means upon a predetermined decrease in the draft in'said chamber. ' ' > a 3, Apparatus fbr sintering ores- comprising: a automatically effecting a compensating change ‘ in the speed of the pallet driving means. 70 ' wan'mar'. JOHNSON.