US2388092A - Smelter - Google Patents

Description

Oct. 30, V1945.

F. G. VsHAUxa ET Al. 2,388,092

SMELTER Filed Oct. 24, 1942 4 Sheets-Sheet 2 f6. @Mme c:- n c/vnrnj JNVENToR BY Caw, Q. 4 @6M Odi. 30, 1945,- l F. G. SHAUB ET Al. 2,388,092

sMELTER Filed 001.24, 1942 4 sheets-sheet 3 INI/ ENTORJ Oct. 30, 1945. F. G. SHAUB ET AL 2,388,092

SMELTER Filed oct. 24, 1942 4 sheets-sheet 4 INVENTOR BY M/z (1 y Patented Oct. 30, 1945 SMELTEB, n Frank G.'Shaub and Arthur E. `J'ennens, Detroit,

Mich.,

assignors' -to Ford Motor Company',`

Dearborn-Mich., a corporaton'of Delaware Application October 24, 1942, Serial No. 463,144

(Cl. B14-L30) Claims.

`This invention relates to furnace construction and-.loperatiom and, more particularly, to retort furnaces used in the production of metals.

`While the disclosure of this applicationmay be used under different conditions, as a particular example a'furnace to be used in the ferrosilicon reduction of magnesium is shown. This is essentially a retort procedure in which the reacting substances are placed in a closed retort, subjected to vacuum. or to an inert atmosphere. and heated to the `reaction temperature, the products of. the reaction` being segregated `by condensation or other means and. thereafter removed for further processing. In the example, the reaction constituents are briquettes of a mixture of ferroslicon :and a.- ca-lcined dolomite. The magnesiumformed in theV reaction .is in. vapor form andeondenses in a cooler part of the retort from which'` it is removed in theform of reguline metal. The residue ofthe reaction consists of the briquettes in' whichsubstantial portions of magnesium havelbeen replaced by silicon and. which are normally oilsubstantially the shape Yand size as when they" wereplaced` inthe retort though they maybe slightly softer or may beglazed with a slagfdepending upon conditions obtaining.- This process .im generali is. old. andy nocl'aim is made toit.l

.One of the particular diniculties of this opera tion is the temperaturestat Which` reaction. takes placer., They are` highwell above 2000 F'.-and the normal life of a metal retort under these' conditions is very: short. liurther,- at the temperatures obtaining, oxidation or both the exterior of the tube within the furnace andthe interior' of the tube while the same is open and being loaded or unloaded is a serious problem. Another consideration is that preheating of the briquette'ct chargeis sometimesv desirable before it is placed in the retort, bothto harden the briquettesviand to bring them more nearly to' the temperature existing in the retortto avoid un'- even temperature distribution. An advantage of this invention is that the furnace design provides a'- maximum retort capas# ilty and `makes full provision-for the preheating' of the-briquette charge. The arrangement shown gives maximumproductive capacity as measured against-furnace sizeffor a particularl Afurnace building; and, moreover, permits the `use of' the charging and unloading' device; described herein in some detail, to serve a great number of individu'al' furnaces. Another advantage isl that charging and unirn-ding` time isl reduced toa `mins murn andthe over-all productive capacity per retort increased accordingly. AAnother advantage is that the termal efciency of the system is increased byutilizing whatotherwise would be stack heat `in thebriquette preheating operation. Another advantage is that by the provision of condensing areas at each end of the retort,` the length, through which the reaction products must' travel before condensation, is shortened accordingly and the tendency toward reversal of fthe reaction is diminished. Another advantage is the saving in operating labor and avoidance' of wear and tear on the retort tube.

With these and other objects in View, the in- Figure .4l is a front view of the iurnaceshown,V

in Figure 1v.

Figure 5 is a; View taken as indicated by the line- 5-li` of Figure 2, thel gear case covers being removed and a portion of the carriage broken away.

VReferring to Figure 1, the smelter building is indicated generally as Ill4 and in it are arranged two opposed banks of furnaces Il, there being a clear central bay I2 between the banks. Mounted in this bay is the overhead crane I3 which carries the charging hopper I4 and the charger I5; both the crane` and charger being movable along the bay between the furnace banks. A belt or similar conveyor means I6 is provided to supply the rawmaterials to theV charging hopper.

The furnaces I`I` which are preferably gasfi'red, although they may be ofi` the molten salttype Shown in: copending application Serial 454,580, vinclude a; chamber If'I in which' are' mounted, in staggered relationsl'lip-,-k a number of tubular retorts t8- which have ends I9 extending on the outside of the furnace. Closuresl are `provided for each of the retorts so" that they may 'be tightly sealed and a .vacuum connection: .2I- leads from the interiorfof the retort to suitable vacuum pumps which are not shown. These retortsl are mounted on rollers 2f2f at various points along their lengths andso' supported, are free for 1onother conventional heating means may be employed. Dump cars 29 are provided along the front of the furnaces to receive the residue when unloaded for disposal to pits 30. Y

Attention is now directed to charger I5 which ports 26 and brought to the desired temperature. The charger I5 is then brought opposite the doors 21 of the particular chamber by means of a movable bridge 4| and the carriage 36 is raised by means of the hydraulic plunger 44 to the elevation of the preheating chamber oor. During this operation, of course, the trolley 40 is located on the bridge at the far sideoi the bridge remote from the particular furnace to be charged. The trolley 4U is then moved forwardly and the peel bucket 46 is scooped into the preheated briquette i and filled. rThe trolley is then reversed and the is an essential part of the operation vof' the installation. It will be noted that the retort tubes I8 are in staggered arrangement, some of them being higher than others, and that their diameters are such that ordinary charging means may not be used. Further, after the reaction, it will be found that the residue which remains is at a white heat and it is difcult to remove this caked mass. Provision must also be made for the transfer of the preheated material from the preheating chamber 23 to the interior of the various retorts. To effect this, ther charger includes the central column 35 supporting carriage 36, on which is mounted a peel 31. The central col'- umn is secured to table 38 which in turn is rotatably mounted by rollers 39 on a trolley 40. The trolley, as best seen in Figure 2, is rollably mounted in a bridge 4| which in turn runs along the bay I2 on the rails 42.

The carriage 35 is mounted on wheels 43 which run on the central column 35 and a hydraulic plunger 44secured to the table 38 makes it possible to raise and lower the carriage at will.; The carriage also includes, partially as a counterweight for the peel, an operatinglplatformv 45 at which the Various controls for operating the charger are centralized. Thev peel itself comprisesa bucket 46 open at the top andj secured to the tube 41 which is rotatably. mounted in a bearing 48 in the forward part of the carriage 36. A drive motor 49 is operably connected through the coupling E0 to the gear case `5I|..and the tube 41 to rotate the tube 41 axially,.as.best shown in Figure 5. This connection includesthe pinion 6| keyed tothe driveshaft 52 and a meshing gear 63 secured to the extreme rear end of the tube 41 as it projects through the housing 55.

Enclosed within the tube 41 is the pusher r5I which'includes an-Archimedean screw 52,.having at its forward end a breaking knifev 53, as shown in Figure 3. Suitable provision is made onA the opposite side of the carriage to revolve the pusher axially independently of themovement of the' tube 41. This, as shown in Figure 5, includesa motor 45 mounted on the carriage 36-driving a shaft 65 through a coupling 60. A pinion 65.1 is keyed to the shaft 65 and meshes with the gear 61 slidably mounted on the shaft 54 and. re-

strained from rotation thereon by the spline 65.

The pusher 5| has'a long rearwardly extending shaft 54 enclosed in the housing 55 and atfthe rearward end is operably connected to a hydraulic cylinder 5B by means of which thef pusher may be advanced or retracted at the will vof the"operator.

It will of course be understood that theaxial rctation of the pusheris independent .of .this lo-ngitudinal movement, as is the axial rotation of the tube. f

-In' operation, the briquetted vcharge is.. rst placed in a preheating chamber 23 through the bucket withdrawn, the carriage lowered to the elevation of the retort to be charged and the carriage again advanced moving the bucket into the retort as shown in Figure 1. Forward movement Y is continued until the bucket is adjacent the rear end of the retort at which point the drive motor 49 isoperated and the bucket is revolved axially dumping the load within the retort or the pusher may be advanced to unload the bucket. The bucket is then withdrawn andthe same operation is repeated fromV the preheating chamber until the retort is filled. In the event that the'preheating is not utilized, the bucket maybe filled directly from the hopper I4. Thev closures'ZIl are then applied to the retortand the retorts are evacuated through the `connection 2| while the furnace is heated to the desired reaction temperature. When the reaction is completed, the retort is again opened and the magnesium, in reguline form, will be found condensed adjacent the end of the retort. This isremoved and the unloading process commenced.

As stated above, theY residue which is still largely in brquette form, is a hot glowing mass and may be slightly slagged or coked into a fairly cohesive mass. To remove this, the carriage is brought tothe elevation of the retort andthe peel is positioned adjacent its mouth as shown in Figure 3. A hydraulic cylinder 56 is then actuated, which advances the pusher 5| into the retort.. At the same time, .the pusher rotating motor is operated and the pusher screw 52 is given a rotary movement whichl breaks up the coked mass of residue Vand propels it rearwardly, as shown in Figure 3, into thedisposal car; This operation may be effected at considerable speed, which is important inasmuch as'it lessensA the period that the `interior of the furnace is exposed to oxidation. It will be understood that the retort at this timezis'still very hot and it is important toA minimize the exposure. yAnother advantage of this particularV structure is that the steel'bucket may beutilizedto some extenttorealign the retort which is subject to localizedzdis-f tortion due to the strains imposed bythe load and the heat; and there is considerable power available to force thebucket through the retortand restore it to proper alignment.; v l The operation of one furnacer has beendescribed and it isapparent that by rotating the table 38, the same operation may be carried out on the opposite bank of furnaces where, by mov-, ing the charger bridge, an entire bank on either side can be serviced at the preheatinglevel and each of the retort levels. However, lthe operation may be conducted expeditiously so that la minimum of physical equipment iswrequired to maintain a number of retorts in operation. `Some changes may be made in the arrangement, construction and lcombination ofthe ,various parts of the improved device without departing from the spirit of the invention and it is the intention to cover the claims such ,changes as may be reasonably included within the scope thereof.

The invention claimed is:

1. In a smelter charging device, a peel comprising a tube, a bucket at one end of said tube,

said tube being mounted for axial rotation, a screw conveyor enclosed within said tube, means to extend said screw conveyor from said tube and means to impart axial rotation to said screw conveyor.

2. In a smelter charging device, a peel, comprising a tube, a bucket mounted on said tube, said tube arranged for axial rotation, a pusher mounted within said tube, means to extend said pusher from' said tube, means to impart axial rotation to said pusher, and a screw means formed on said pusher.

3. In a smelter charging means, comprising, a vertical support, a carriage mounted thereon for vertical movement, a peel supported on said carrlage, a bucket at the end of said peel, pusher means normally enclosed within said peel, means to extend said pusher means from said peel, means to impart axial rotation to said pusher means, and material screw conveying means associated with said pusher means.

4. In a smelter charging device, comprising, a bridge means arranged for transverse movement with respect to said smelter, a trolley means mounted on said bridge means and arranged for longitudinal movement with respect thereto, a supporting means rotatably mounted on said trolley means, a vertical support on said supporting means, a carriage mounted on said vertical support for vertical motions thereon, a peel carried by said carriage and extending therefrom, a bucket at the end of said peel, a pusher means comprising an Archimedean screw normally within said peel, means to extend said pusher means from said peel, means to impart -rotation to said pusher means.

5. In a retort-charging device, a peel means FRANK G. SHAUB. ARTHUR E. JENNENS.

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