US1379083A - clevenger - Google Patents

Description

Patented May 24, 1921.

2 SHEETS-SHEET l.

/AKMJ l 7 .viril/5111.

G. H. CLEVENGER. APPARATUS Foa mimmo oREs 0R THE LIKE.

APPLICATION FILED APR. l0, |919.

G. H. CLEVENGER. APPARATUS FOR TREATING ORES 0R THE LIKE.

APPLICATION mio APn.1o,|919.

1,379,083. Patented May 24,1921.

2 SHEETS-SHEET 2.

- UNi'rED Asia'rias PATENT OFFICE.

G'ALEN H. CLEVENGIR, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO RESEARCH CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW `l YORK.l

APPARATUS FOR TREATING ORFS OR THE LIKE.

Specioation of Letters Patent.

Patented May 24, 1921.

Application led April 10, 1919. Serial No. 289,061.

To all whom it may concern:

Be it known that I, GALEN H. CLavnN- GER a citizen of the United States, residing at ashington, in the District of Columbia, have invented certain new and use ful Improvements in Apparatus for Treating Orcs or the like, of which the following is as eciication.

his invention relates to apparatus for the heat-treatment of ores or other materials. More particularly, the invention has to do with furnacesfor continuously treating ores under precisely regulated conditions of temperature, reduction, oxidation, etc.

While the furnace of the present invention is useful for a variety of operations, its special application is in the carrying out of the process of treating ores containing oxids of manganese described in a copendin application filed by myself and M. H. Earon on Sept. 23, 1918, Ser. #258,388, and in Patent No. .1,298,454, granted March th, 1919, to said M. H.

25 Caron. f

According tol the aforesaid process, the reduction of the manganese oxids in the ore is fre uired to take place under carefully` regulated conditions and with cooling of; the deoxidized or ypartially deoxidlzed ore in suchmanner that material reoxidation is avoided.

The furnace of the present invention 1s So constructed that the ore can be continuously treated according to the rocess referred to under precisely contro led conditions of temperature, reduction, etc., both in the furna'cing step per se and in the subse uent cooling operation.

40 (The invention will be further described in connection with the accompanying drawin s, wherein: u

igure 1 is a diagrammatical plan view of one type of furnace embodying my 1mprovements;` i

Fig. 2 is a diagrammatical side view of the same, partly in section;

I Fig. 3 is an end vlew and Fig. 4 a section of the stuffing-box connection between the rotary part of the 'furnace and the stationary discharge housing Fig. 5 is a section and Fig. 6 an end view of the couiling which oins two dissimilar portions o the kiln or mace;

1 7 is a section of the kiln along the line -7 of Fig. 2;

Fig. 8 is a sectional view showing a pyrometer tube and the manner in which it is mounted in the furnace;

Fig. 9 and Fig. 10 show in section stuflingbox connections between the air pipe and certain stationary parts of the apparatus;

Fig. 11 is a sectional view through one of the sampling-tubes of the kiln; and

Figs. 12 and 13 are sectional views, in cross-planes, of a burner located near the lower or foot end of the furnace.

Referring to Figs. 1 and 2, the furnace 1, shown as an inclined kiln, is supplied with the ore or other material to be treated at its head or upper end from a hopper or the like 2 by means of suitable conveying mechanism 3. The end of the kiln extends into a flue 4 connecting with a stack 5. The inclosed conveyer 3 carries the ore across the flue and deposits it under regulation within the kiln, referably in a bed of substantial depth. Il)ischarge of the ore from the elevated end of the furnace 'is revented by a circular ring or plate 6 on t e end of the furnace, having however a central opening large enough to accommodate the casing of the conveyer and to permit free efllux of the gases from the kiln.

The lower end or foot of the furnace extends into a discharge chamber 7, being rotatably mounted in the front wall thereof through the intermediar of the packed joint 8 shown in detail in igs. 3 and 4. As one of a number of suitable arrangements for effecting discharge of the ore from the kiln Without admitting air thereto, the lower end 9 of the discharge chamber 7 is vshown as submerged in a well 10 containing water or some so ution and the treated material from the kiln is removed from the well 10 as it arrives from the chamber 7 by means of suitable conveying-means 11.

To the top of the discharge chamber 7 is connected a pipe or conduit 12 by means of which a gas may be supplied to the furnace from any suitable source. An air pipe 13 passes through the rear wall of the chamber 7, and is rotatably mounted therein through the medium of a stuffing-box connection 14 such as that illustrated in Fig. 9. A pipe 15 leading from a blower or other supply of air is connected with pipe 13 through the lagen'cy vof ga suitable packed jo1nt 16, such as is illustrated in Fig. 10, insuch mainner that the portion 13 yof the air pipe can turn freely with respect to the stationary supply-portion 15 of the air pipe .without permitting escape of the air at the joint.

In Fig. 10, the stationary pipe 15 1s shown as provided with a flange 17 secured Vto or ,integral with avthimble 18 to which is bolted in the well-knownmanner a gland 19 which fesses. againstk theV packingV 20.

' The packe connection 14 between the 4chamber 7 and the air-pipe 13 kbeing quite'similar to` vthat ofthecoupling 16and obvious in construction from Fig. `9, no further description thereofis Athought necessary. A

' suitable pedestal 21 may be provided to as- .sist in the support of the air-pipe, and it may be integral with the female member 18 of the stuffing-box as indicated in Fig. 10.

p Withinthe` kiln the air-pipe may be supported in position by one or more spiders 22.

The rotary kiln shown by way of illustration only, is provided .at intervals with the customary removable tires 23 whereby thev furnace is rotatably supported upon pairs of roller-bearings 24. Rotation of the yfurnace maybe effected in any suitable manner, the means shown comprising a removable circular rack 25 and a pinion 26, the latter receiving `rotary movement through gearing or the like 27 from any suitable source of power.

v .The kiln proper comprises two sections, an upper lined section 28 including the greater part of the length of the furnace and a shorter unlined section 29 at the discharge end.

As indicatedin section in Fig. 7, the upper portion 28 of the furnace comprises an outer shell 30, a fire-brick lining 31 and an intermediate lining or layer 32 of kiesel- Vguhr or the like. The shell 30 may be provided with additional heat-insulating means if' desired. Radially protruding bricks or ore-lifters 33 extendlongitudinally of the yfurnace throughout the length of its lined section except at its extreme upper end where the ore-feed screw 3 is located.

The lined and unlined sections of the furnace are joined by any suitable connecjvtion 34. The coupling shown, for example, -in detail in Figs. 5 and 6 comprises a metal ,other securing means 40.V In order .to vtake care of expansion and consequent relative movements of the parts, springs41 are interposed between the nuts 40 and the face of the collar 38. f

From the standpoint of ore-treatment, the furnace may be considered as comprising threedivisions or zones: (1) the preheating zone; (2) the reducing zone, and (3) the coolin zone. These zones are roughly indicated in Fig. 2 of the drawings by thel letters A, B and C, respectively.

Mounted in the furnace at intervals inthe reducing zone B are pipes 42,.c'onnected at their outer ends with an extension 43 (Figs. 1 and 13) of theair pipe 13 and bent at their inner ends toward the feed-end of the furnace to form a series of spaced air-jets 44.

The exterior portion of the pipes 42 are pro- 'y vided with suitable valves 45 `for controlling the air-supply to the jets and the tubes are held in fireproof plugsl 46 presently to be described in detail in connection withla particular jet. The extension 43 of the airpipe is connected with the axially disposed portion 13 of the air-pipe by a joined short pipe 47 (Fig. 2) or other suitable connection passing through the wall of the .furnace v which insures constant ignition of the gas at that point is established near the end of the reducing zone by the burner, and the latter is regulated as to the amount of reducing gas passing to the same by an angularly adjustable, perforated, register platev 50 mounted on the jet against the real` wall of the hood. 'Y

In Figs. 12 and 13 is also shownuonearrangement whereby the 'et-pipes 42 are Y mounted in the furnace. e outer part of each pipe is formed or provided with a laterally extending plate 51 which is bolted or otherwise secured to the upper face of a boss-plate 52, the under surface whereof con- .j formsto the curved surface of the furnacei shell 3Q to which it in turn is fastened. An annular sleeve 53 extends inwardly from the plate 51. The sleeve 53 preferably increases in thickness toward its inner end and its outer face conforms in shape to and fits snu ly against the inside of the opening54 in t e furnace wall. This opening is shown 35 the plugs as oval in cross-section, but it may be circular or lygonal. The sleeve 53 due to its increasingl thickness thus forms about the pipe 42 a ta ring cket and this pocket 1s packed wit a suitable cementitious fireproof filling 55. To assist the sleeve 53 in maintaining the lli in place, a flange or key 56 ma be forme on or secured to the pipe-42. e connections between the alrpipe extension 43 or the valved sections 57 and the pipes 42 are preferably separate from the pipes 42, as shown in Flgs. 12 and 13, and are secured to the latter by, for instance, screw-bolts 58 which engage the 15 plates 51. At intervalsvalong the reducing zone of the furnace, I provide suitable samplingtubes 59, Figs. 2 and 11, to facilitate ascertaining of the condition of the material being treated as it rogresses through the kiln. The sampling-tu s are carried by collars or the like 60 to which they may be welded, and the tubes are held in place in suitable openings in the furnace wall by the collars which {are-secured to the shell 30 by convenient means-such as bolts 61, the under sides of the collars being concave to fit the cylindrical curvature of the shell 30.

A series of steel pyrometer tubes 62 (Figs. 2 and 8) carried by screw-plugs 63 are a so provided at intervals along the furnace. The tubes extend a suitable way into the furnace through openings 64, being held in position by engagement of the threads of 63 with corresponding threads in the shell. These tubes may be connected up in the well-known manner with a pyrom.- eter when it is desired to ascertain the temperatures at any of the various points.

e0 In operating the furnace, the s eed of rotation and the inclination of the iln are so adjusted as to insure the proper depth of ore in the bed and the progress of this bed in regulated manner through the kiln.

A The ore isV fed continuously into the upper end of the furnace, passes through the several zones A, B and C, successively, and is finally discharged at the lower end of the apparatus, cool and unsusceptible to atmospheric oxidation. A suitable reducing gas,

such as produceras, is introduced throu h the pipe 12 and ows upward through t e kiln inthe direction opposite to that of the movement of the ore. Air is supplied through pipes 15 and 13 to the jets 44 and the amount admitted to the kiln is regulated by the individual valves 45.

`In the preheating zone A, the cold incoming material meets the hot waste gases from the reaction zone and these gases,

which may be slightly reducing or neutral give up their heat to the materlal as it advances. When the furnace is properly operated, the material should be at the temperature necessary for reduction by the time it reaches the reducing zone. In this zone any moisture in the material is driven off as are also an constituents volatile at the temperature o the zone.

In zone B Where the greatest amount of reduction takes place it is necessary to supply the heat lost through radiation and through the endothermic reactions which occur.

This is attained in a precisely regulated manner through progressive burning of the combustible gas brought about by the admission of air at intervals through the jets 44. The reduction may take place by this means at constant or decreasing or increasing temperature, regulated through the admission of air. In this zone, of course, the material reaches its maximum temperature.

In the coolin zone C, the sensible heat of the downward y moving reduced ore or other material is transferred in part to the entering gas and air. Such additional cooling as 1s required to lower the temperature of the reduced material below that at which it will reoxidize in Ithe air is obtained by radiation throu h the bare steel wall 29 of this section of t e kiln. If necessary or desirable, the cooling may be augmented by one or more water-sprays playing on the shell.

It will be observed that the operation in my furnace roceeds under the counter-current princip e. The cold incoming material is heated up by the waste gases until by the time it arrlves at the zone B it is substantially at the reduction or reaction. temperature. By controlling the individual airjets, this temperature is maintained until the reaction has continued to the desired extent, by which time the material has reached the entrance to the unlined cooling section of the furnace. The temperature of the treated material decreases in this section, its heat being transferred in part to the incoming reducing gas, until in a relatively cool condition it leaves the system at the discharge end of the furnace. The cool gas coming from the producer or the like enters at the discharge end of the cooling section and becomes rapidly hearted up by the hot material which has been treated as it passes therethrough, until when it reaches the reaction zone it has attained a suiiiciently high temperature to burn. Meeting at the localizing point of the burner 48 120 a limited amount of air, incipient combustion of the gas sets in, sufficient in degree or intensit only to maintain the temperature require for the reaction-conditions desirable at this point, without interfering with the reducing action of the gas upon the material. As more air is supplied to the moving column of gas at the intervals where the successive air-jets are located in the zone B, the degree of combustion progresses until,

. etc., but in certain operationsy if desired, by the time'the entrance "tothe preheating zone is reached, z'. e. when it has passed the last burner or air-j et 44, complete combustion o-f all of the fuel-gas has been effected. A

By such counter-current operation substantially allheat-losses are avoided and'all the fuel values are used up. By maintaining the temperature in the reaction zone in the manner described the time required for the reduction is reduced to a minimum.

The'particular temperature maintained in the reaction zone varies with the character of the material undergoing treatment, the rapidity of its progress throu h the kiln, have con#` ducted with ores ofy the aforesaidcharacter, I found that an ore-temperature'of about 600o C. gave good results. The temperature of the gas is ofcourse somewhat higher than that of the ore.

While I have specifically described a rotary-inclined kiln embodyingmy invention, it Will be obvious that-its application is not restricted to this type of apparatus. -It is equally applicable,.for instance, to a multiple-hearthl furnace of the McDougalltype or any other type in fact wherein the ma-l terial is caused to progress in its treatment from one region to another. Numerous changes can ofcoursebe made in the details of arrangement without departing from the spirit and scope of my invention. v

It will be understood that bythe expression reaction zone as used herein, I intend v to define the zonein which substantial heattreatment occurs whether the process be one of reduction or of oxidation or one in which the atmosphere is neutral. l

It is also to be understood that the invention is not confined to the treatment of ores and the use of thatlterm in the claimsis not to be construed as a limitation to the scope of its application. Y f

Furthermore, it will be obvious that in-l stead of having an arrangement like that shown wherein the preheating, reaction and cooling zones are integral, it is quite possible to have either the preheating section or the cooling section or both separate from the reaction section. The cooling apparatus may be of the form of any of the standard types such as the Baker cooler.

I claim:

l. A furnace having a reaction zone through which material to be heated is moved progressively, means for passing a lcombustible gas through said zone and means for progressively burning said gas.

- 2. A furnace having a reaction zone through which material is moved progressively, means for passing a combustible material through said zone and airxjets at intervals along said vrione for g.oontoll'ablyintroducing air into said', zone. 1 1 1f 3. A furnace having a reaction ,l rione' through which -material to bebes/,ted is moved progressively, means ,-forpassing va combustibley gas through vsaid zone counter current to said material, means fori'gniting said gas adjacent the end 'of said .zone 1to- Ward Whichvsaid material moves,`and means at intervals along said zone for introducf havingan extended reaction zone, and means for variably admitting air at intervals along said reaction zone. f Y

6. A furnace for reducingores or the like, having an extended reaction zone, means for passing reducing gas through said zone, and means for variablyA admitting lair at intervals along saidzone;

7. A furnace for treating ores or thelike,

having an extended reaction zone,' a plurality of air-,jets arranged at intervals along Said zone, and means for independently controlling' the admissionof air to said jets.

8. A rotary furnace for treating ores or the like, havingian extended reaction zone, a plurality of jet-pipes arranged to admit air at intervals along said zone and rotating With the furnace, and means for independently controlling the admission of air to said jets. I v

9. A furnace for reducing ores or thelike, having lan extended reaction zone, means for introducing from Without the furnace a reducing gas through said zone, Aand means arranged kat intervals along said zone yfor regulably effecting combustion of said gas therein. v f .Y

10. A furnace for .reducing ores or the like, Vhaving an extended reaction zone through which the orev is progressively moved, means for introducing a reducing gas at one end of the zone, and a plurality of air-jets arranged at intervals along said zoneto effect progressive combustion of the gas in said zone.

l1. A lfurnace for reducing ores or 'the like, having an extended reaction -zone through Which the ore is progressively moved, means for introducing a reducing gas at one end of the zone, a plurality of airjets arranged at intervals along said zone to effect progressive combustion of the gas in said zone, and means for independently controlling the admission of air to said jets.

12. A rotary furnace for reducing ores or the like, having an extended reaction zone throu h which the ore is progressively move means for introducing a reducing gas at one end of the zone, and a plurality of jet-pipes rotating with the furnace and arranged to admit a1r at intervals along said zone to effect progressive combustion of the gas in said zone.

13. A rotary inclined furnace for reducing ores, or the hke, having an extended reaction zone through which the ore is progressively moved toward the lower end, means for introducing a reducing gas at the lower end of the furnace, and a plurality of jetpipes rotating with the furnace and arranged to admit air at intervals along said zone to effect progressive combustion of the s in the furnace.

14. A furnace for the progressive treatment of ores or the like, having an orereheating zone, a reaction zone and a coo ing zone, means for introducing a reducing gas through said cooling zone into the reactlon zone, and means for variably admitting air at intervals alon said reaction zone to effect progressive comustion of the gas.

15. A rotary furnace for reducin ores or the like, having a reaction zone an a cooling zone into which the ore progresses upon reduction, means for introducin a reducing s into said cooling zone, an means for disc arging the cooled reduced ore from the furnace without admitting air thereto.

16. A rotary inclined furnace for reducing ores or the like, having a reaction zone and a cooling zone into which the ore ros u n reduction, means for intro uclng a ucin gas into the cooling zone, means for variably admitting air at intervals along said reaction zone, and means for discharging the cooled reduced ore from the furnace without admitting air thereto.

17. A furnace for reducing ores or the like, havin a reaction zone and a cooling zone into w ich the ore progresses upon reduction, a burner intermediate said zones, means for su plying air to said burner from the outside o the furnace and means for supplying reducing gas to the burner from wit 1n the furnace.

18. A rotary furnace for reducin ores or the like, having a reaction zone an a cooling zone into which the ore rogresses u on reduction, means for intro ucing a re ucing gas into said cooling zone, and a plurality of jet-pipes rotating with the furnace and arranged to variably admit air at intervals along said reaction zone, one of said jets near the end of the reaction zone having a perforated hood therearound to provide a burner into which some of said reducing gas passes.

19. A metallurgical furnace through which the material progressively travels, comprising a refractory-lined portion in which the substantial reaction occurs and an llllnlined cooling portion contiguous therewit 20. A metallurgical furnace throu h which the material progressively trave comprising a refractory-lined portion in which the substantial reaction occurs, means at intervals along the reaction section for variably admitting air to precisely regulate the temperature in such portion, and an unlined cooling portion contiguous with said I ined portion.

In testimony whereof, I aix my signatune GALEN H. CLEVENGER.

Images