US1841625A

US1841625A - Retort furnace

Info

Publication number: US1841625A
Application number: US259406A
Authority: US
Inventors: Musso Alfred
Original assignee: WILLIAM P DEPPE
Current assignee: WILLIAM P DEPPE
Priority date: 1928-03-06
Filing date: 1928-03-06
Publication date: 1932-01-19
Anticipated expiration: 1949-01-19

Description

Jan. 19, 1932. A. Musso 1,841,625

RETORT FURNACE Filed March e, 1928 s sheets-sheet 1 Jan. 19, 1932. A. Musso 1,841,625

RETORT FURNACE Filed March 6, 1928 3 Sheets-Sheet 2 FW. d

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RETORT FURNACE Filed March 6, 1928 3 Sheets-Sheet 3 f/f I Q INVENTUR ATTORNEY Patented Jan. 19, 1932 UNITED STATES PATENT I oFFlcE vALFRED MUSSO, F EAST ORANGE, NEW JERSEY, ASSIGNOR 0F ONE-HALF TO '.WILEIIANIIII 1. BEPPE, OF NEW YORK, N. Y. i'

RETORT FURNACE Applicationled March 6, 1928.` Serial No. 259,406.

This invention relates tometallurgical reduction furnaces.

One object of the invention is to provide a furnace of the character described which )*includes an improved retort for the continuous treatment ofthe mineral.

Another object of the invention is, to pro- Vide a retort, the gases wherein may be exhausted at any desired pressure.

Another object of the invention is 'the provision of a furnace of the nature set forth comprising improved means for externally firing the retort.

' A further object of the invention is to produce a furnace of the type specified wherein the setting of the retort co-operates therewithto furnish a substantially gas tight compartment about the retort at the openings of the latter for obviatlng leakage of al1' i' 20 thereinto.

Still another object of the invention is the production of a furnace of the nature referred to in which an improved seal is provided at. the opening of the retort.

A still further objectof the invention is to create a furnace of the type mentioned in which a uniform temperature gradient may be maintained along the retort.

Further objects will be seen to reside in the provision of a furnace having an externally fired retort in which the retort and furnace lining are made of suitable refractory material to withstand the temperature generated, and the furnace lining to sustain the pressure of the combustion gases; in which the retort is of a rotary type and includes means to scrape the interior wall of the retort and to aid in the mixing of the mineraltherein; and in which the fuel is consumed according to the principle of surface combustion in improved blocks of refractory material; the feeding of the fuel being preferably taken care of by automatic temperature control; and in which an improved system for the circulation of the combustion gases about the retort is provided; and in which the volatilegases generated in the retort are withdrawn at the low temperature end there- Tn order to indicate the practical coaction and the functional relationship of the parts ofthe apparatus, and also by way of general description, reference may advantageously be had to the method of `use and the results obtained by the invention. The sameis particularly adapted for the reduction of ores by coal or other carbonaceous materials out of contact with air and without the deleterious iniuence of the presence of combustion gases.` Therefore a retort is provided which is h eated without combustion therein, and preferably externally. The gases generated by the reduction are rapidly continuously withdrawn as fast as generated` by means of pumps or the like, and causing a decreased ambient pressure in the retort. Hence the latter must be sealed tight, and as the charge is continuously fed into and out of the retort simultaneously with the forcible exhaustion of the gases, the retort has means to permit such movement of the charge with-v out entrance of air. As the chargeis in finely divided form, and constant agitation thereof is necessary, the retort is preferably rotatable and may be inclined at an angle to the horizontal so that the charge is simultaneously uniformly agitated and fed through the retort. The exhaustion of the gases from the retort is preferably spaced from and inde, pendent of the movement of the finely divided charge for assuring uniformity in operation and reliability in control. The retort rotation requires a relatively light retort, although the apparatus is intended for large scale industrial application; therefore the retort includes a metal component or may be wholly made of metal for combined strength and lightness. Moreover, the transmission of heat into the retort, as from external .heating means is thereby increased. For maximum eiiciency of heat transfer, a highly radiant or incandescent heating means, operating as by surface combustion may be employed outside of the retort, and which may thus consume the gases generated in the retort itself. To prevent burning the retort, the heating means is spaced along the retort wall to maintain temperatures therein insuflicient to melt the metalor gangue. Unir form peripheral heating lmay be obtained by the provision of circular heating means, which may, moreover, be arranged to prevent iame contact with the retort. A n automatic temperature control may be utilized coordinated with the charge feeding and the exhausting meanswhereby the exhaustion of gases from the retort is regulated in proportion to the generation of gases, and to mantain a predetermined general pressure-temperature relationship in the retort. By arranging the heating means to afford a temperature gradient, the reduction of the ore gradually increases to a point of substantial completeness, and the gases generated may, in course of exhaustion serve to impart heat to the incoming charge. Thus a solid carbon reduction of an ore may be quickly and completely attained under a reducedpressure ambient with constant removal of all gases as fast formed and under low temperatures insufficient to melt the metal or gangue produced. Other features and functions of the apparatus are more particularly described ence characters throughout the several views,

and in which- Figure 1 is a sectional elevation of a furnace embodying the invention.

Fig. 2is an enlarged fragmentary section showing details of the retort seal.

Fig. 3 is a similar view showing the firing means.

Fig. 4t is a similar View showing the low temperature end of the furnace.

Fig. 5 is a similar view of the intake end of the furnace.

Fig. 6 is a front elevation of the furnace.

Figs. 7 to 10 are enlarged sectional views taken on corresponding lines of Fig. l.

Fig. 11 is an enlarged vertical sectional view taken online 11-11 of Fig. 1 and showing a drive for the retort. Fig. 12 is a vertical sectional view taken on line 12-12 of Fig. 3.

Fig. 13 is an enlarged fragmentary sectional view of a portion of the apparatus shown A in Fig. 1.

The advantages of the invention as here outlined are best realized when all of its features and instrumentalities are combinedin one and the samestructure, but useful devices may be produced embodying less than the whole. l

It will be obvious to those skilled in the art to which the invention appertains, that the same may be incorporated in several different' constructions. The accompanying drawings, therefore, i's submitted merely as showing the preferred exempliiication of the invention.

The herein described furnace is particularly adapted for use in the invention on a process of mineral reduction and metal extraction as described in my co-pending applicatio-n for patent, Serial No. 208,103, filed July 25th,

' cous products of the reduction and the volatile substances liberated. v

Referring in detail to the drawings, 15 denotes a. furnace embodying the invention. The same includes the walls and roof 16 of the furnace made of a high temperature materi al, as for example, silica, and resting upon a concrete floor 17. Within the furnace is mounted a cylindrical retort 18, atvone end of which is a hopper 19, and at its other end a discharge device 20. IThe said hopper may receive the pulverized mineral and coal according to the process hereinbefore mentioned.

rlhe retort or heating chamber 18 is coaxial with the furnace chamber 21 and is of smaller diameter than the same to provide an annular firing space. rlhe said retort may be made of any suitable material, as, for example, mild steel which has been chromoplated, or also of a chrome alloy steel. The

\ said retort is rotatable and is likewise downare providedthat constitute a'slip connection 23 aording/ substantially gas tight communicationbetween the retort and the hopper.

ylnthe bottom of the hopper' is a feed screw 24k mounted ona hollow shaft 25. vThe said hollow shaft 25 is secured tothe retort by an internal bracket 26 so that the screw 24 rotates in unison with the retort. At its other end this shaft is journaled in the bearing 27 of the hopper. An exhaust pipe 28 for gases generated in the retort may extend through thesaid hollow shaft, whereby the gases inthe retort may be rapidlyI withdrawn the firing chamber. The said plate is formed with an annular groove 30 to receive the edge of the enlarged cylindrical end extension 31 of the ret/ort. The said extension 31 constitutes a positive-acting rotary conveyor, being provided with spaced plates 32 that form a series of pockets' 33 disposed about theaxis lurality of circular wall of the rotor. A members 34 are rigidly secured to the plate 29 and form closures for the pockets 33. The said members 34 are connected together by a cover plate 35`for'the retort, which' plate is in spaced substantially parallel relation to the end plate 29. The plate 35 is formed with a bottom opening 36 that gages and regulates the flow of mineral from the retort into the pockets 33. For adjustment of the material from the retort, the gage plate 35 is vertically movable,^or may be replaced by another similar plate having an opening 36 of a different area. t will be seen from Fig. 9 that thev conveyor plates 32 form a closure with the circular plates 34 that substantially prevents air from flowing into the retort through the discharge device. The pockets 33l raise the material therein to the top of the device 20, after which this material is dumped into veyor, havingsimplitied and improved coac tion with the heating chamber. l

It will be -understood that the device 20 can be used also at the intake end of the ed through the plate 35. The screw and the device 20 may both be regarded as representing positive conveyors'that rotate with the retort. v A

To scrape from the wall of the retort any material that may adhere thereto, a stationary shaft 38 is extended centrally through the retort and is journaled onbrackets 39 secured thereto. The said shaft projects through the plate 35 and is secured at one of its ends in the end plate bearing 40. Where the shaft passes through plate 35, a slot may be provided if vertical adjustment of the said plate is desired as aforesaid.

Extending downward from the shaft 38 at an angle with the vertical are a series ofarms 41 spaced yalong the shaft. To the lower end of said arms is attached a mixing and scraping device which may take the form of acontinuous chain or flexible mat 42 that rests on thev bottom of the retort. With the latter rotating in the direction of arrow a, the said mat partly depends from the arms 41 toward the vertical central plane of the retort. .Thus the mat effectively scrapes loose from the retort wall any adhering material, and at the same time aids in the mixing of the heaped material M in the retort.

The furnace is fired by surface combustion. For this purpose masses of porous refractory material are disposed circumferentially about the retort to impart heat thereto from all sides with substantial uniformity.

Y The combustion gases on leaving the masses of refractory material are caused to circulate about the retort to further impart heat thereto. Spaced burner nozzles are arranged in any desired number to discharge gas and air under pressure into the masses of refractory, and with the object of obtaining a substantially even radiation of heat therefrom, on the retort. p Further, the combustion meansr is so constructed, that the burning gases substantially permeate all parts of the ,y refractory. On leaving the refractory masses, the gases are caused to travel therefrom along the retort for uniformly heating the same in conjunction with the action of the refractory masses on the retort.

The refractory masses y43 are made of any suitable porous material and may be of ring form, coaxial with the furnace and seating A against the inner wall of the chamber 21.

The said masses 43 are in spaced relation at theirv inner peripheries with the wall of the retort to avoid corrosive action on .th

latter.

`The material of which the said refractory consists may be graphite mixed with tar and calcined to drive oft' the volatile constituents of the tar, thus leaving a porous block. Then again, carborundum'or alundum refractory may be formed into a ring.

Each of the rings 43`forms a high temperature combustion chamber being inclosed on all sides except at one portion which forms an outlet 44 for the gases. Preferably the inclosu're aforementioned is formed by glazing the said ring.

Although the heating rings exemplify the preferred embodiment of the invention, it will be appreciated that surface combustion can also be practised in other ways Well known in the art, and the retort heated in a compact furnace out of Contact with the flame, by direct or semi-direct radiation, with or without contact with the products of combustion. Theprimary object is to obtain uniform heating peripherally and longitudinrlly of the retort.

The porosity of the ring and the voids therein are predetermined to permit a desired quantity of fuel to be 'consumed therein and to pass therethrough at a given pressure. Since the gas is burned with but 1% 55. 'resisting material and project from the nace wall into pro-ximity to the retort. Co-

of excess oxygen, combustion proceeds with explosive velocity, and the flame will be .slightly reducing to obviate oxidation ofthe retort.

Communicating with each ring 43 is a burner 45 having a plurality of nozzles 46 branching therefrom in opposite directions to inject the gas and air into the ring. The colmbustion thus takes place in two streams of flame moving upwardtoward the outlet 44. The mixture of gas and air is discharged from the burner nozzle at a pressure of approximately fifteen pounds per square inch, and th-e burner is carefully packed with fire clay 47 and the like, or other insulating material. In this way concentration of heat at the burner is avoided. y

In the furnace chamber 2l the pressure of flue gas is considerable and may be as high as severalpounds per squareinch. To take care of this pressure, the inner wall of the said chamber is glazed, rendering the furnace wall substantially impervious to the flue gas.

Gas and air are fed through

separate pipes

48 and 49 respectively into a central mixing chamber 50, from which they -pass through a. butterfly mixer 5l into al burner 45. The said butterfly mixer may be of any suitable type but preferably includes a fan (not shown) which is rotated by the thereon impinging air and gas and serves to thoroughly intermix them.

An automatic temperature control 52 may be provided operating with the usual thermocouple 53 to control the supply of mixture fed to the burner by "means of a valve 54.

Any other'suitable type of burner and control therefor can be used depending, in part, upon the method of firing the furnace.v

By means of the said temperature control and the spacing of the combustion blocks as shown, a desired temperature gradient can be easily maintained in the furnace, this ranging from 9500 C. as a maximum to ap proximately 28 C. at the retort inlet. Also economy in operation of the furnace is obtained, this result being aided by the fact that the gases generated in the retort are exhausted at the rear end thereof through the aforesaid suction pipe 28.

The gases leaving the refractory blocks through the outlets 44 therein are caused to circulate about the retort by means of baffles These are made of any suitable leat actling with these baffles is a flue by-pass 56 *intheroof of the furnace whereby, after circulation of the gases has occurred, the same are rapidly transferred to circulate about the i material receiving end of the retort soy that the available-heat of the fuelis rendered as high as possible. f

vSecured about*` the said retort are a plurality of flanged members 57 that have sliding sealing contact with the baffles 55.

Between the first two combustion blocks' 43a and 43?) at the high temperature end of the furnace is an annular passageway 58 into' ing with one of these baffles is'another upward extending baille 55a, so that an annular portion 60 of the furnace is shut off from the combustion gases. rlhe arrows clearly indicate the circulation of the flue gas.

Between the combustion blocks 430 and 43d, a plurality of downward extending baffles 55 are provided. A passage 6l connecting with the bypass 56 is formed between the block 43d and the adjacent baffle. Coacting with the last mentioned baffle, is an upward extending baille 55a, so that the flue gas from block 430 is caused to circulate twice down and up before entering the by pass 56.

Beyond the combustion block 43d, but in proximity thereto are a plurality of spaced downward extending baflles 55 with one of which coacts an upward extending baffle 55a. Between the said baffles 55there communicates a passage 62 throughA which lue gas from block 43d passes into the flue by-pass 56. An annular passageway 63 is formed between the said coacting baffles on one side and engaging

baffles

64, 65 on the other side. The function o f this passageway 63 will be hereinafter described. Beyond this passageway 63, the iiue by-pass 56 discharges through an opening 66 into the low temperature end of the furnace chamber.

The said low vtemperature end of the furnace chamber is broken by a series of uniformly spaced downward extending baffles 67 and a similar series of upward extending baffles 68. The

baffles

67 and 68 are staggered with respect to'each other so that a uniform and continuous circulation-of flue gas about the retort is insured. The flue gas is finally discharged through a flue 69.

It will be understood that while reference has been made herein to a specific baffle construction and arrangement, the same is capable of a high degree of variation as is well known in the art, within the scope of the invcntion.

It is seen that this furnace is through the circulation of gases hereinbefore described, particularly adapted for producing a uniaccordingly provided.

To afford support tothe retort intermediate of its end bearings the retort is surrounded with rings 70 of metal, o'r the like, which seat on spaced rollers 71. Thissupporting construction is housed in the annular passages 60 and 63. Plugs 72 of re clay or similar material are removable for inspection or repair of the rollers.

To rotate the retort, any suitable drive may be provided, as shown in Fig. 11. A motor 7 3 by means of reduction gearing 74 turns a main gear that extends around the retort in proximity to the hopper.

The invention thus produces an improved heating chamber or retort, from which the gases may be withdrawn rapidly and exhausted at any desired pressure, to aid the react-ion and the obtaining of a comparatively pure product, and in which the operation is continuous and uniform both from a mechanical and chemical viewpoint, the heating being uniform and even, and the temperature gradient accurate, the invention being adapted for long use with a minimum of inspectionrepair, or cleaning.

Various changes and modifications can be made in the invention, the construction shown being intended in an illustrative not in a limiting sense, and it will be appreciated that within certain principles of the invention, various objects may be substituted for the retort, and the claims are to be construed according to the spirit of the invention, the terminology being relied on to clearly define the invention. c

I claim.:

l. A device? of the character described, including a furnace, a retort therein having a receiving end and a discharge end, refractory material inV the furnace, and spaced means to raise the refractory to incandescence to form a series of zones radiating heat von the retort at the portion thereof toward the. discharge end, and baliies between the retort and the furnace wall and intermediate of said zones, there being a by pass inthe furnace to cause the baflled combustion gases to flow tol the other portion of theretort.

2. device of the characterl described, including a retort, a positive conveyorwithin the retort coaxial therewith to move a charge longitudinally of the retort, unitary means to rotate-the retort and the-conveyor, said conveyor including a plurality of pockets, and a relatively stationary closure means for the pockets, saidmeans being constructed to permit materials in the retort to enter a lower pocket and to discharge the materials from an upper pocket.

3. A device of the character described, including a retort, a positive conveyor substantially concentric with the retort to move a charge longitudinally with respect to the retort, and to rotate the conveyor and the retort at the same speed, and other means to close the pockets at apredetermined portion of the path of travel.

4. A device of the character described, including a rotary retortfa relatively stationary transverse means including a drum therefor, and rotary means along the edge of the drum forming therewith a closure for the retort, said rotary means having a plurality of recesses angularly spaced around said drum and closed thereby, each of said recesses coacting with the drum to receive a charge from the retort at one side of the said drum, and discharging-the said charge in its high position on the other side of said drum.

5. A device of the character described', including a furnace, a rotary retort therein, the furnace having a mass of porous refractory in proximity to the retort and extending therearound, but having a clearance space with the retort, and means to internally fire the said mass.

6. A device of the character described, including an elongated retort, a furnace enclosing the same, internally fired elements spaced along the retort on the outside thereof, at one end Aportion of the retort, and means. to receive the products of combustion at a plurality of points in proximity to said ele-v ments and discharge the same for circulation about the other end portion of the retort.

7. A device of the character described, including an elongated retort, a furnace enclosingthe same, internally fired elements spaced along the retort on the outside thereof, at one end portion of the retort, baflles for the products of combustion intermediate of said elements, and means to receive the products of combustion at a plurality of pointsin proximity to said elements andv discharge the same for circulation about the other endV portion-fof theretort.

8. A device of the character described, including a retort, means to externally heat the same, means to feed a charge into the retort at one end of the same, means to discharge the charge at the other end of the retort, and means at the intake end of the retort to with-I draw gases from the retort, the means for heating the retort including firing means at the discharge end thereof, and means to circulate the products of combustion of the firing means about the inlet end'of the retort.

9. A device of the character described, in-

cluding a furnace chamber, an elongated retort therein, means to feed a charge into the retort at one end thereof and-to withdraw the charge from the retort at the other end thereof, combustion means in the furnace chamber at the discharge end portion of the retort at points spaced lengthwise of said portion to heat the same, the products of combustion iowing to the inlet end portion of the retort, and a plurality of spaced baiiies at said inlet end portion to cause the products of' combustion to circulate around the retort.

10. A device of the character described, including a furnace, an elongated retort therein, the retort having a comparatively low temperature end and a relatively high temperature end, and combustion means at'the high temperature end, the furnace having a by pass in the wall thereof to cause the products of combustion to flow to the low tem perature end of the retort.

11. vA device of the character described, including a furnace, an elongated retort therein, the retort having its ends at different temperatures, combustion means at the high temperature end of the retort, and channels for the products of combustion between the retort and the wall of the furnace, the furnace having a by pass communicating with the channels to receive the products of combustion therefrom and cause the same to flow to the low temperature end of the retort.

12. A device of the character described, including a furnace, a retort therein, refractory tubes in the furnace extending inward of the furnace wall, and combustion means to internally fire the tubes, said tubes being spaced to provide radiation on the retort from the walls of the tubes facing the retort as well as from the side walls of said tubes, said tubes being filled with porous refractory material.

13. A furnace for reducing iron ores mixed with carbonaceous fuels in a substantially air tight retort, at temperatures which will not cause combustion in the retort or melt the iron, including means for feeding the materials tothe retort and discharging same, means for keeping the materials mixed, heating means for said retort of refractory materials to be heated to incandescence, means to regulate the flow of materials into and out of the retort, means to continuously exhaust the gases developed in the retort from the materials being treated therein, and means to regulate the flow of heat producing elements to the refractory heating means, coordinated with the heating means to produce and maintain predetermined temperature limits in the retort.

14. A furnace for reducing iron ores in a substantially air tight rotary retort, external heating means of incandescent refractory materials, means to control the combustion of combustibles and air therein, with means to continuously exhaust the gases developed in the retort from materials therein, means for feeding the materials into and out of the retort, means to apply the heat to the retort in a rising temperature gradient from the inlet end of the retort to the outlet end, the refractory heating means being spaced away from and along the retort walls.

15. A furnace for reducing metal bearing ores, consisting of a substantially air tight retort, enclosed therein, heating means being provided of refractory materials in which combustion takes place under surface combustion temperatures, means to pass the hot exhaust gases around the retort after passing through the refractory heating means, means to control the flow of combustibles and air to produce and vmaintain the predetermined temperature limits, means to control, agtate, and feed the materials into, through and out of the retort, means to continuously exhaust the gases developed in the retort from the materials being treated therein as fast as developed.

16. A substantially air tight retort and enclosed elongated tubular combustion heating means for heating the retort by radiation, the retort` being out of contact with the burning gases in the heating means producing the heat, and with the means in which the combustion is taking place, said heating means being spaced away from and along the retort walls to produce and maintain uniform heating conditions, the heat transfer being by conduction and radiation to the retort andthe materials therein under treatment, and means to control iow of air and fuel gas to produce and maintain a temperature gradient in the retort and materials being treated.

17. A substantially air tight retort and enclosed combustion heating means therefor of sutlicient length to afford a substantial travel for the fuel consumed therein, the materials being heated in the retort, and the retort being out of contact with the burning gases in the heating means producing the heat, and with the means in which the combustion is taking place, said heating means being spaced away from and along the retort walls to produce and maintain uniform heating conditions, the heat transfer being by conduction and radiation to the retort and the materials therein under treatment, and associa-ted means for continuously charging and discharging the materials being treated, and means to continuously exhaust the'/ gases developed in the retort from materials being heated.

18. A furnace for reduction of metal bearing ores having an externally heated retort, in which the retort is made of materials capable of withstanding high temperatures, from heat developed in refractory materials surrounding the retort, enclosing walls for the refractory'materials sustaining the pressure of the combustion gases burning in the refractory with surface combustion, and the temperatures causingincandescence in the refractory material surrounding the retort, the refractory heating materials and enclosing walls being spaced away from and along the walls of the retort in which the materials `to be reduced are being treated. l

19. A furnace for reducing metal ubearing ores including a retort externally heated, by

' '..nieans of refractory materials spaced away i rounding theretort and the exhaust gases therefrom to flow towards the intake end portion of the retort on the outside of the walls of the retort shell.

20. An apparatus for ,the low temperature reduction of iron ores with solid carbonaceous fuels intimately mixed therewith, including a rotary retort, automatic means for rotating the same, the retort having means,

associated therewith for moving the charge into and out of the retort, said means being co-ordinated with the retort to operate according to the speed of rotation of the ulatter, means extending in a curved line around the outside of the retort for externally heating the retort, means for automatically con-Y trolling the heating means, closure means for the ends of the retort through which the ma terials enter and discharge from the retort,

and means for exhausting the gases from the retort through said closure means.

1 21. An apparatus for the heat treatment vwithout agglomeration of a pulverized charge of ironY ore and coal, including a rotary metallic inclined retort of cylindrical form, a furnace enclosing said retort, stationary radiant firing means in, the furnace for uniformly'peripherally heating the retort from the outside thereof, burner means so co-ordinated with the radiant ring means and the retort as to imjpart a larger quantity of heat to the former than to the latter for maintaining uniform heating vat relatively low temperatureon the constantly rotating retort, stationary closure means for the ends of the retort including conveyor means for moving the cha-rgefor aA heating through a required time period, and means for exhausting the gases and maintaining a reduced pressure in the retort.

22. A device for the uniform reduction-at ka low temperature of an yiron ore with coal i in intimately mixedfpulverized condition, including means forreceiving and constantly' agitating the charge, said means including a rotary elongated retort, a furnace enclosing the same, means inthe furnace outside of the retort `for-heating thesame with a temperature gradient from end to end of the retort, said means including surface combustionv means spaced from the retort for obtaining a uniform heating of the same at a low temperature although the said means are at a high temperature for efficient radiation, means for automatically`controlling thetemperature of the heating means, means for exhausting from the retort the gases therein to produce a decreased pressure, and means for l controlling `the movement of the charge to and from the retort. Y

23. An apparatus for reducing an ore with coal according to a temperature gradient 35 whose maximum temperature is relatively low, includinga furnace, an elongated retort therein, firing zones in the furnacespaced v along the retort on the outside thereof, said firing zones having means restricting vthe spread of flame therefrom, said firing zones being spaced more closely near one than near the other end of the retort to produce the temperature gradient, together with means for feeding the charge into the retort at the p low temperature end thereof and simultaneously removing the charge from the high temperature end of the retort for a continuous reduction of the iron ore.

24, A low temperature continuous ore rei duction apparatus, including' a furnace, a

rotary retort therein for receiving and agitating the chai'ge, means co-ordinated withl said retort to operate in constant speed relation thereto for feeding a charge to and from the retort, means forheating the retort uniformly peripherally from the outside, said means including a plurality of spaced firing means lthe spent gases of which fow consecutively in the same direction in the furnace, no means in the furnace for drawing off said gases at successive points in the paths thereof, and other means for separatelyexhaust-y ing the gases from the retort.

25. An apparatus for the direct reduction of iron ore with coal in pulverized condition a-nd without fusion or agglomeration, but with the reduction occurring uniformly and in constant grada'tion, including a furnace, a rotary metallic retort therein for receiving and agitating thecharge, meansto uniformly continuously feed materials to and from the retort atlopposite ends thereof, said retort being inclined for co-ordinated action with charge," means for constantly exhausting yfrom the retortthe. gases therein without withdrawing pulverized particles therefrom, means vfor exhausting from the inlet end of the retort the gases in the. retort to reduce the pressure therein, means for uniformly heating the retort from the outside thereof accordy termined relation to the pressure.

26. A device including a furnace, a rotary retort therein for receiving and agitating a charge, means in the furnace for heating the retort, said retort comprising a cylinder por-- tion and a relatively stationary end portion, and conveyor means for moving the charge with respect to the retort, said conveyor means being of annular form and engaging the cylinder portion and the end portion to form a closure therebetween.

27. A solid carbon oie reduction device including a furnace, a rotary retort therein for receiving and agitating a charge, high teinperature means in the furnace for heating the retort from the outside to a relatively low temperature without flame contact with the retort, said retort being made of a high temperature metal for eflicient heat transfer, means at opposite ends of the retort for uni-l formly continuously feeding into and discharging materials from the retort, means for exhausting the gases in the retort and reducing the pressure therein, and means for automatically regulating the temperature, whereby a desired relation of temperature, pressure and speed of reduction of the ore may be maintained.

28. A device including a rotary metallic retort for large scale metallurgical operations, and heating means therefor, said heating means including firing members extending in spaced relation along the retort, and means enclosing said firing members to cause operation of the latter Without flame contact with the retort, the enclosing means being separate of the retort and having a relatively tliin radiation wall of large area opposed to and facing the retort Wall on the outside thereof to heat the retort by radiation.

29. An apparatus for inetallurvical operations, including an elongated retort, means for continuously charging and discharging the same, andheating means for the retort, said heating means including a plurality of firing members extending in spaced relation lengthwise of the retort, and separate combustion means for the several firing members, said combustion means including refractory enclosures of sufficient size and area for causing the firing members kto operate Without flame contact with the retort and With substantial radiation upon the latter through certain Walls of the enclosures.

30. A device including means for receiving and constantly stirring a charge, said means including a retort, and means for heating the same from the outside, the heating means including a furnace having an internally fired enclosure extending peripherally around the retort in spaced relation thereto, and a burner discharging into the enclosure, the latter having an opening remote from the burner for passing the products of combustion around the retort within the chamber of the furnace.

3l. A device including a metallic retort and means for externally heating the same without llame contact with the retort, the heating means including a plurality of spaced tubular channels extending circularly transversely along the wall of the retort in spaced relation thereto, and means to cause combustion in said tubular channels to heat the same to a relatively high temperature for efficient radiation upon the retort from Walls of said channels, said channels being of suiicient length to cause the combustion to be terminated therein.

32. A device including a flota-ry retort, conveyor means coaxial with the retort, said conveyor means extending along and being connected to the wall of the retort, said conveyor means including pockets .rotatable with the retort, and means closing the pockets but opening the same in predetermined positions of the rotation for receiving and discharging a material, the last mentioned means coacting with the pockets to form a closure for the retort.

33. A device including a rotary retort, a conveyor therein coaxial with the retort, said conveyor including pockets rotatable with the retort, and relatively stationary closure means for the retort coacting With the pockets to close the same andopen an upper and a lower pocket for entrance of material into a lower pocket and discharge of material from an upper pocket.

34:. A device including a retort, and closure means therefor, said closure means including a rotary conveyor of ring form including a plurality of pockets arranged so that a pocket receives material in a 10W position and discharges the material in an upper position, the closure means having other means Wholly closing the pocket in intermediate positions.

35. A large scale metallurgical apparatus including a furnace, a retort therein, a plurality of spaced tubular chambers in the furnace independent of the retort and extending along the outside thereof, a porous refractory mass filling said chambers, and firing means for the interior of said chambers whereby al low temperature may be maintained in the retort While operating said refractory mass at high temperature and radiation eliiciency.

36. A device including a rotary cylindrical metallic retort, a furnace enclosing the same, a circular refractory tubular enclosure extending around the outside of the retort., a mass of granular refractory material Iilllng said enclosure, and means for discharging a fuel and a supporter of combustion into said enclosure, whereby the fuel is consumed in the interstices of said mass, and the enclosure heats the retort by radiation from the wall of the former.

37. A large scale industrial ore reduction device including a rotary retort, a hollow elongated refractory tubular enclosure outside of a relatively small section of the retort in close proximity thereto and spaced from the retort for mechanical clearance, said enclosure being of curved forni substantially concentric with the retort, and means for internally firing said enclosure without iiame contact with the retort.

38. A device including an elongated rotary metallic retort, a furnace enclosing the same, a refractory tube outside of the retort and within the. furnace, said tube being disposed around the retort in a plane transverse thereto, said tube being in relatively close proximity to the retort and having only a clearance spacing therewith, a porous mass of refractory in the tube, and'means for internally firing the tube.

39. A device including a retort, a'furnace enclosing the same, a mass consisting of pieces of refractory material, said mass having a continuous wall inthe nature of a fused coating disposed toward the retort, and means to lire said mass within 'the interstices thereof. I

40. A device including a-retort',a furnace enclosing the same, a block in the furnace consisting of pieces of material united by fusion at the surface of the block lto provide an otherwise uniformly internally porous block, and means to internally fire said block for heating the retort from the outside thereof by radiation from the block.

4:1. A device, including a furnace, an elongated retort therein, a plurality of tubular refractory rings spaced along the retort and extending around the outside thereof transvers'ely to the retort, a porous refractory mass in said rings,\and means to inject a fuel and a supporter of combustion at spaced points in said rings, said rings heating the retort by radiation and having outlet openings for the products of combustion remote from said means.

42. A device including a furnace an elongated metallic retort therein, a plurality of refractory tubes extending around the retort transversely thereto around the outside of the retort out of contact therewith, said tubes being spaced from each `other lengthwise of the retort, means to inject into thetubes a fuel and a supporter of combustion at spaced points in the tubes, and surface combustion means filling the tubes, the latter having each an opening remote from the injecting means at an edge thereof and an opening in the wall,

an annular series of pockets spaced angularl around the curved Wall and revolving wit the retort, said pockets4 being co-ordinated with the curved wall of the closure to cause a movement of the charge in the retort from one to the other side of the said closure through the opening thereof, with the pockets successively registering with said opening. 45. A device including a retort elongated in a generally horizontal direction, a furnace enclosing the retort, and firing means for the retort in the furnace, said firing meansincluding a tubular means extending around the retort in a transverse direction thereto, means for internally firing the tubular means adjacent to a lower portion of the retort, the latter having an opening at an upper portion of the retort for discharging the burnt gases.

46. A device including a rotary cylindrical retort extending in a generally horizontal direction, a furnace enclosing the same, means lto constantly feed materials through the retort, and a separate relatively stationary internally fired tubular means extending around a portion of the retort and radiating yheat thereon.

47. A device of the character described, including a furnace, a-cylindri.cal retort therein, arcuate refractory tubes in the furnace extending inward of the furnace wall and transversely of the retort, and combustion means to internally fire the tubes, said tubes being spaced from each other to provide radiation on the retort from side walls of the tubes as well as from the walls of said tubes facing the retort.

48. A substantially air tight retort, and enclosed high temperature combustion heating means for heating the retort at a relatively low temperature, the retort being substantially out of contact with the products of combustion, and with the means in which the combustion is taking place, and said heating means being spaced away from and in-l cluding portions spaced longitudinally along the retort walls to roduce and maintain uniform heating con itions, the heat transfer being by conduction and radiation to the retort and the materials therein under treatment.

49. A rotatable substantially air tight re- 'zo' l tort for reducing metal bearing ores, positive conveyor means associated with the retort to move the materials therein, and combustion heating means for the retort outside of the same, the combustion means being so enclosed that the retort is heated without contact with gases from the combustion means, the retort being out of contact with the means in which the combustion is taking place, said heating means being spaced away from and along the retort walls to produce and maintain uniform heating conditions, the heat transfer being by conduction and radiation to the retort and the materials therein under treat-ment.

50. A substantiallyair tight metallic, ore reduction retort and enclosed surface combustion heating means for uniformly heating the retort at a relatively low temperature, the retort being out of contact with the burning gases producing the heat, and with the means in which the combustion is taking place, said heating means being spaced away from and along the metallic retort walls to produce and maintain uniform heating conditions, the heat transfer being by conduction and radiation to the retort and the niaterials therein under treatment, and means for continuously charging and discharging the materials being treated.

51. A substantially air tight rotary metallic retort and enclosed surface combustion heating means therefor, the retort having stationary end Walls and being out of contact with the burning gases producing the heat, and with the means in which the combustion is taking place, said heating means being spaced awa from and along the retort side Walls to ro uce and maintain uniform heatin conditions, the heat'transfer being by con uction and radiation to the retort and the materials therein under treatment, and means for continuously exhausting the gases developed in the retort from the materials being treated as fast as developed and to maintain any desired pressure in the retort, said means communicating with the retort through a stationary end wall.

52. A device of the character described, in cluding a furnace, an ore reduction retort therein,vthe Wall of which includes a metal component, the furnace wall having hollow portions', a mass of porous refractory material associated with said hollow portions through which refractory the combustion gases flow without flame contact with the retort, means to internally fire said hollow portions with the fuel burning in the refractory material with surface combustion and the said material radiating heat on the retort, and automatic temperature control means for regulating the supply lof fuel to the firing means.

53. A device including a chamber having a circular upright wall member therein, the

periphery whereof is spaced from the Wall of the chamber, and a rotary annular conveyor' having a plurality of pockets, said conveyor extending around the outside of the periphery of the member with the pockets in substantial contact with said periphery, certain of said pockets communicating with the space in the chamber on opposite sides of said member.

54. A` large scale industrial heating apparatus including a furnace, an elongated chamber therein, and internally fired granular` refractory means in the furnace extending around the chamber in a plurality of planes spaced longitudinally of the chamber and transverse to the longitudinal axis thereof, whereby the incandescent heat obtained in said refractory means produces a relatively low temperature in the chamber.

55. An ore reduction apparatus including a furnace, an elongated inclined retort therein, means for continuously feeding a charge into one end of the retort and out from the other end thereof, said means coacting with theretort to seal the same against entrance of air, means for heating the retort Without combustion therein, the heating means maintaining the retort at a relatively low ,uniform temperature, and means spaced from and independent of the feeding means for exhausting from the retort the gases therein.

56. An ore reduction apparatus including a retort, means for feeding a charge into and out ofthe same at opposite ends of the retort, means for heating the retort along an arcuate zone extending around the retort, and means for exhausting from the retort the gases therein, the exhausting means being v substantially uniformly spaced from the heatf ing means.

57. An ore reduction apparatus including a retort, means for continuously feeding a charge into and out of the retort, means for heating the retort to produce a volume of gases therein dependent upon the rate of feed and the temperature of the heating means, and means for exhausting the gases from the retort, the heating means being co-ordinated with the feeding and the exhausting means so that the exhausting means normally maintains a reduced pressurein the retort.

58. An ore reduction apparatus including means forreceiving and constantly agitating a charge, said means including a retort, means for continuously feeding the charge into and out of the retort, means for uniformly peripherallyheating the retort at a relatively low temperature, means for positively exhausting from the retort the gases therein, and means for automatically controlling the heating means to maintain a predetermined temperature-pressure relation in the retort.

59. An ore reduction apparatus including means forreceiving and constantly stirring a charge, said means including a retort, means for continuously feeding the charge into and CII out of the retort at opposite ends thereof, means for heating the retort according to a temperature gradient, means for forcibly exhausting from the retort the gases therein, the temperature l gradient of the heating means increasing from the inlet to the outlet end of the retort, and the exhausting means having such communication With the retort as to cause gases in the retort to flow toward the low temperature end thereof.

60. A device of the character described including a furnace, a rotatable metallic retort therein, said retort being adapted for use in the industrial reduction of ores mixed with coals or similar lcarbonaceous materials, the retort having a Wall all portions of which are spaced at a comparatively large distance from a central point Within the retort, radiant heating means disposed at a plurality of points about the outside of the retort to uniformly heat the same, automatic means to control the flow of combustibles to the heating means, co-ordinated with means controlling the flow of materials into, through and out of the retort, and coacting automatic means for forcibly and continuously exhausting all gases as fast as formed, whereby maximum temperatures in retort are maintained below the melting points of solid materials being treated in retort, under conditions therein.

In testimony whereof I aflix my signature.

- ALFRED MUSSO.