US1696731A - Apparatus and process for utilizing coal - Google Patents

Description

Dec. 25, 1928.

H. S. REED ET AL APPARATUS AND PROCESS FOR UTILIZING COAL 0N @Winer-OU E .'Arv: E n

Dec. 25, 1928.

H. S. REED ET AL APPARATUS AND PROCESS FOR UTILIZ'ING COAL Filed Oct. 16, 1925 2 Sheets-Sheet 2 Patented Dec. 25, 1928.

UNITED STATES HARRY S'. REED, 0F EAST LANSING, AND

RALPH D. LAMIE, 0F LANSING, MICHIGAN.

APPARATUS AND PROCESS FOR UTILIZIING COAL.

Application tiled- October 16, 1925. Serial No. 62,856.

The object of this invention is the more elicient utilization of coal by providing an apparatus and process for (1) recovering the valuable volatile constituents of coal in the form of gas, light oil, and tar; (2) producing a coke or semi-coke in powdered form ready for use as powdered fuel; and (3) delivering this powdered coke or semi-coke at practicall incandescence continuously as produced to tlie fireboxl under a boiler or other furnace or to a press at the desired temperature for briquetting. 4

A further object is to provide an equipment of low initial cost and maintenance., of simple construction andv of large daily capacity.

Objects pertaining to details of construction and operation will appear from the detailed description to follow. The invention is defined and pointed out in the claims.

A structure which is a preferred embodiment of our invention is illustrated more or less diagrammatically in the accompanying drawing, forming a part of this application, in which Fig. 1 is a. generalassembly View of the apparatus, the olf-take being on reduced scale, part being a vertical longitudinal section through the apparatus taken on line 1 1 of Fig. 2, the retort being in full lines with part of its shell broken away, and the furnace and burner for the powdered fuel being indicated diagrammatically.

Fig. 2 is a vertical cross section taken on line 2 2 of Figs. 1 and 10, showing details of the furnace.

Fig. 3 is an enlarged longitudinal sectional view of the retort taken on irregular line 1 1 of Fig. 2, and on line 3 3 of Figs. 4, 5, 6 and 7, the feed screws appearing in full lines.

Fig. 4 is a cross section of the retort takenk on line 4 4 of Figs. 1 and 3. showing the discharge clippers and structure.

Fig. 5 is a cross section taken on line 5 5 of Figs. 1 and 3, showing the scalloped retaining plate at the discharge end of the retort and the adjustable support-ing rollers for the revolving retort.

Fig. 6 is a cross section taken on line 6 6 of Figs. 1 and 3, showing the partition retaining and grading plate Within the body of the retort.

Fig. 7 is a cross sectional View 7 7 of Figs. 1 and 3, screws.

Fig, 8 is a perspective view of the angular tumbllng, grinding, scraping elements, of tetrahedral and different angular forms.

A Fig. 9 is a perspective view of the ball tumbling milling elements.

Fig. 10 is a detail plan view looking down on the top of the stack, air forcing means being omitted.

Fig. 11 is a detail vertical sectional view taken on line 11 11 of Figs. 2 and 10, showing details of the flue structure and hot air supply to the furnace burners, air pressure omitted.

Fig. 12 is a detail sectional View on line 12/ 12 of Figs. l and 3, showing details of the ilushinghpipe for steam or gas and the connections to the device.

The parts of the drawings will be referred to by their numbers which identify like parts in al1 the views.

taken on line showing the feed 1 is the brick work of the furnace, which` is provided with the usual fire brick lining. 2 is the chimney structure. 3 is a burner for the furnace. 4 is the combustion chamber or fire box. 5 is the heating chamber for heating the retort. 6 is the direct flue from this chamber. 7 is the auxiliary indirect Hue for directing heat to the preheater. 8 is the cylindrical retort. 9 is the preheater in the form of a feed conduit trough, with conveyor screw 91. 10 is the bunker or hopper for supplying and feeding the coal. 11 is the telescopic feed connection to the feed means 12. 13 is the discharge for the residue from the retort 8. 14 is the adjustable roller support. 15 is the driving gear for the retort. 16 is a steam supply. 17 is the vapor and gas outlet for the distilled material from the retort.

The furnace 1 may be heated in any suitable way, but gas for the furnace is especially available, it being produced asa product of distillation. This is supplied to the burner through pipe 185 from the storage tank or gas holder 184. The gas burners deliver into the combustion chamber and entrain hot ai]` `from the down air flue from the chimney, which is under pressure as well. rlllnis heated air and products of combustion are circulated in chamber' 5 around the retort 8 and then powdered fuel discharge pass through flue 6 to the chimney. A portion of it is by-passed through the auxiliary iiue 7. The direct iue 6 is controlled by the damper 61 and the flue 7 is controlled by the damper 71, and thus by regulating the dampers 61 and 71 the extent of the heating of the preheater 9 is controlled.

10 is the hopper for the coal which is to be distilled. This hopper delivers into the U- shaped trough 9 of the preheater which, as stated, is provided with a feed screw 91 which is driven by the pulley or gear 92 and carries the coal through the preheater trough, dropping it through the telescopic pipe 11 into the multiple screw feeder 12, which is composed of a large outer tubular shell 121 in the bottom of which is a propeller feed screw 122. A pair of small semi-circular troughs of different lengths are disposed above the feed screw 122, the shorter one 123 containing the feed screw 124 and the longer one 125 containing the feed screw 126. These details are seen in Figs. 3 and 7. These feed screws are actuated by a suitable gear train 127 of any convenient design, and they may be actuated separately or geared together in any suitable and well-known way. This feed is made integral with the gas delivery 17 and in central spaced relation therefrom. The multiple screws and feed troughs of di'erent lengths deliver the coal evenly and distribute it in the retort so that the heat is readily maintained and the material is quickly and evenly heated.

The retort 8 isl made of steel boiler plate preferably, and cylindrical in form. 1t is supported on pairs of adjustable supporting rollers by which the relative elevation of the 'ends-and the inclination may be controlled by suitable adjusting screw' 142 of usual construction. rllhe opposite ends of the retort are provided with projecting tires 141 which rest on the rollers for controlling and permitting the rotation of the same. An annular gear 15 is provided at the discharge end of the retort, adapted to be driven by any suitable power means, not necessary to be shown. These parts are all standard commercial devices.

A residue discharge 13 for the retort is tubular in forni and contains a screw conveyor 131 driven by a suitable gear or pulley 132 and delivers into the vertical telescopic discharge pipe 134 which is controlled by a star valve 135 which maintains a gas tight connectionat that point. The discharge 13 is provided with a suitable stung box connection to the head 81 of the retort 8. A pipe 16 is provided to deliver steam or fixed gas into the retort at the driven and discharge end.

rlhe gas o-take 17, as before indicated, is tubular in form and connected by stung box 171 to the head 82 of the reto-rt 8. This gas discharge connects to the telescopic gas odtake 18 `which delivers to condensers 181 and scrubbers 182. The suction pump 183 draws neeen'ei off the product, as indicated, and discharges the non-condensible gas into the holder or gas tank 184, where it is available for use. A part is delivered through pipe 185 to the furnace for fuel, as before indicated.

The smoke and products of combustion pass up the smoke iue 21. The down air flues 22 are disposed each side thereof and are separated b y comparatively thin walls of fire brick 23. The heated air is delivered downwardly by the blow fan 221 through header 222 and air connections 223 to the combustion burners and entrained by the burners and passes on to the combustion chamber for heating the retort (see Figs. 2 and 11).

The retort 8 is divided by partitions 83, 83 and 84, into distilling chambers 85, 86 and 87 and discharge chamber 88. The partitions 83 are scalloped around the edges at 831 and contain a series of radial slots 832 of appropriate size to retain the milling and tumblingl elements in each chamber and provide a passage to the next succeeding chamber to permit the coal which is being distilled to pass freely on. Fine particles pass ordinarily throng i the scallops 831.

` The partition 84 is not perforated and 1s scalloped at 841 and permits the discharge of the thoroughly pulverized residue from the coal into the discharge chamber 88.

Within the discharge chamber 88 and connected to the Walls thereof are a series of buckets 881 which are disposed radially and are adapted to convey the residue from the coal upwardly and discharge it into the fixed hopper 136 which delivers into the discharge conduit 13, where the feed screw 131 discharges the same, as indicated ln the first or main distilling chamber 85 we supply milling elements of heat conducting material, preferably chilled cast iron, which are angular in form, as indicated in Fig. 8, some having square ends, some trianl gular, and some disks. It is only necessary that these elements have one flat side and a scraping edge. In the first chamber some of these irregular elements are three inches and some six inches in diameter or cross section in their shortest diameter. With these we provide 'a quantity of balls or round elements (see Fig. 9), the exact spherical form not being essential, from three to six inches in diameter, to assist in the flow or tumbling of the angular scraping milling elements so that they will scrape the sides of the retort and free it of any accumulation d-ue to the fluxing of the coal that is being distilled. Also, the angular scraping elements serve to clean the balls and the balls react so that the milling elements are all kept clean, while at the same time scraping and cleaning the retort. vThe coal is thus also broken up as soon as it is fiuxed in the process of distillin and the reduced pieces passed to the secon compartment 86. The sticky condition of the .distilling mass is overcome in the first pieces are further considerably reduced in size and similar milling and scraping elements are made use of, from one and one-half toet-wo inches in diameter, with preferably a somewhat increased proportion of balls. These further pulverize the material, break up the surfaces and expose the same to the heating elements and the heated walls of the retort. The material is still further reduced and passed in the smaller size to the third Alistilling chamber 87 vwhere the tumbling and scraping elements are one and one-half inches in diameter and the final milling of the material is accomplished, where it is reduced to a powder and the residue delivered out to the discharge chamber 88 and carried away, as indicated.

The pipe 16 delivers steam or fiXed gas axially through the stuffing box 161 through the hollow shaft of the screw feed 131 into the third distilling chamber 87, steam being preferred. The volume of steam delivered at this point quickly carries -along with it all of the distilled products and `carries them oft' through the gas discharge .17 to the gas oif-take pipe 18, as before indicated. Because 0f the passage of this steam the distillate is not unduly heated and is passed off before it is injured, and the cracking of any of the products of distillation is thus reduced.

The powdered coal is delivered to the furnace 19. 191 is the feeder for the hot powdered coal. 192 is `the conveyor screw controlled by the variable gear 193. 194 is the coal. delivery nozzle. 195 is the conduit-for the primary air of combustion. 196 is the blower fan for the primary air. 197 are the draft openings for secondary air.

Having described the complete apparatus, we will indicate itscourse of operation. The coal .in the hopper 10 drops into the Ypreheater 9 where it is carried forward by the feed screw 91, thence through-the feed pipe 11 to the multiple feed screw 12 where it is delivered into the first compartment 85 of the retort 8. The retort is heated on all Sides by the products of combustion circulating around the same, as indicated, and the heating of the preheater is controlled by adjustment of the dampers 61 and 71, as pointed out.

yCoal is distributed in the retort chamber 85 by the three feed screws 122, 123 and 1,25, as indicated. In this retort are the tumbling, milling and scraping bodies, about half of which are round and from three to six inches in diameter, and the remainder are ofangular scraper form. as illustrated in Fig. 8. As the retort is slowly revolved and is adjusted to the proper inclination for the particular grade or kind of coal, the coal advancesin the same and is heated by these milling bodies and the heated walls of the retort. The coalquickly fluxes and this tends to adhere to the walls of the retort or to the heating bodies, but this is prevented by the angular elements because the motion imparted. to these bodies by the rotation lof the retort is less than the speed of either the periphery of the retort or the round milling bodies. Hence they act as scraping devices and keep the walls of the retort and the surfaces of the round milling elements and themselves free from any hard carbonaceous dcposit which would insulate or out down the free heat transfer of these elements coacting with each other and the surface of the retort. Further, by reason of these angular elements an irregular snake-like movement is imparted to the whole mass within the retort, thereby assisting in scraping the inner walls of the retort and advancing the charge through the chamber. The entire mass is broken and then dried out and becomes more or less like coke in character, and passes readily through the first partition 83 tothe second distilling chamber 86. There the milling elements are of the same character but ofy smaller size. They act upon the coal to reduce it to smaller dimensions and it is still further distilled and thence passes to the third and distilling chamber 87, where the milling elements are comparatively small and of the same character, the proportion of the balls being increased.

The powdered coke or fuel is delivered direct from the improved apparatus to the furnace 19, heated substantially to incandescence. It passes down through the conduitv 134 and the star valve 135. By this method the fuel after being powdered is not allowed to take up moisture and is delivered to the lire box in a. dry stato, thus conserving its` sensible heat. Beyond this, the fuel being hot readily ignites and burns, developing and delivering all the heat with great. economy in the furnace. The fuel is delivered at the desired rate .through the down pipe 194 to the ignition chamber of the furnace. The fuel is supplied at this point with primary air by the blower 196 delivering-through pipe 195. Secondary air is admitted throughair ports 197 to the extent required to completely consume the fuel.- The heat of the furnace is regulated by the amount of fuel delivered.

The vapors that are developed by the heat would soon be cracked and injured if allowed to remain in thehot retort. They arc carried away by a current of steam coming through the pipe 16 in a small volume which is superheated and expanded.y The steam circulates freely through the retort and takes up any of the vapors and passes them along through the outlet 17 to the gas off-take 18. There they pass to the condensers 181 and serubbers 182.

These products are drawn along by the pump 183 and thus deliverel into the gas holder. The pump is sufficient in capacity to maintain a minus pressure. The non-condensible gas is forced into tank 184 and preserved and storedl This non-condensible gas is readily available for use in the furnace, which uses a part of the same to maint-ain the required temperature in the retort. There is still an amount of gas that is available for general use for various purposes, as in internal combustion engines or gas furnaces. All of the volatile products have been recovered. by this method, in their most valuable form.

The heat is very much conserved by our im proved apparatus. As soon as it has done its work of distillation, it is passed to the uptake flue where it heats the air in the down air fines which deliver this heated air to the burners and furnace to help maintain combustion. The heat contained in the air is thereby conserved. A considerable amount of the volatiles would be recovered readily in a single retort, like the compartment 85, but by providing the same in steps and ren ducing the size of the milling elements, it is found that substantially all o f the volatile content will be recoverable, and by making use of the usual condensers and scrubbers the same is made available, either as liquid or gaseous products of the various forms derivable.

By dividing the retort into separate compartments the mass of milling and scraping elements can be disposed throughout the length of the retort as necessary for greatest eiciency. For example, the plastic state of the coal during distillation occurs in the first chamber, therefore a greater heat transfer and milling and scraping action are necessary, and so in this chamber we introduce a greater weight of larger milling and scrap# in elements. By subjecting the mass un dergoing distillation to successive steps in reduction and grading, We insure a thorough reduction and removal of all the volatiles.

It will thus appear that we utilize slack which is usually an inexpensive fuel and secure the valuable content in a simple and effective manner. The plant may be operated by delivering the hot powdered fuel to a ,briquetting machine. The distilling .and milling part of the apparatus here shown is illustrated in application for patent filed conl currently herewith Serial No. 62,855, for an improvement in process of distilling shale,

shale being a materialrequiring special treatment and special flushing. We desire to claim the process broadly in the present application and also the apparatus, as defined in the appended claims.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

l. The continuous process of distilling solid carbonaceous material and burning the powdered residue as a fuel in an externally heated sealed tumbling barrel ball mill retort containing angular grinding elements and ball grinding elements of heat conducting material consisting in, subjecting t-he carbonaceous material in lumpy condition to the action of such retort and grinding elements to successively heat the said carbonaceous lumps until coking begins at the surface, grinding away thecoked part and repeating the operation until the volatiles are distilled away and the solid is reduced to a powder, delivering the heated powder toa combustion furnace, delivering primary air thereto sufficient for ignition and partial combustion, and delivering a secondary air supply to producev complete combustion.

2. The continuous process of distilling solid carbonaceous material, and burning the powdered residue as a fuel in an externally heated sealed tumbling barrel ball mill retort containing angular grinding elements and ball grinding elements of heat conducting material consisting in, subjecting the carbonaceous material in lumpy condition to the action of such retort and grinding elements to successively heat the said carbonaceous lumps until coking begins at the surface, grinding away the coked part and repeating the operation until the volatiles are. distilled away and the solid is reduced to a powder, and delivering the heated powder to a combustion furnace. v

3. The continuous process of 'dist-illing solid carbonaceous material in an externally heated sealed tumbling barrel ball mill retort containing angular grinding elementsl and ball grinding elements of heat conducting material admixed 'in proportion to insure the flowing tumbling action of such grinding elements consisting in, continuously introducing and subjecting said material in a lumpy condition to the simultaneous tumbling action resulting from the rotation of said retort and the grinding action of such elements to progressively heat the said material lumps unt-il coking begins at the surface, grinding away the coked part and repeating the operation on the residuary lumps until the volatilesare distilled away and the residue is reduced to a powder and discharged. y

4. In a distilling apparatus for solid carbonaceou's material the combination of an externally heated sealed tumbling barrel ball mill retort, subdivided by foraminous partitions into a series of ball mill chambers, each succeeding partit-ion having progressively smaller openings, and each succeeding chamber containing'angular grinding ele- `ments and ball grinding elements of heat conducting material`admixed in proportion to insure the tiowing and tumbling action of.

such grinding elements of progressively smaller .size and ot' a dimension to be rctained by each said foraminous partition, a feed i'or the intalie end ot the retort comprising u series of troughs with screw conveyors delivering at diti'crent positions within the iirst chamber of the retort, 'a'. gas take-ott' opening above the level oi the solid contents` a take-oli i'or the solid residue comprisingl a stationary cylindrical discharge connected to the retort by a trunnion with stufiing box, a Conveyor therein, a star valve in the discharge t'or maintaining the retort gas sealed while delivering the solid residue, 'a combus-L tion furnace tor receiving and burning the said heated pondered solid residue, aprimar),1 air supply delivered into the stream ot iiuely pondered fuel to ignite the same and a se .'oi1dai' v air supply l'or completing the combustion.

ln a distilling apparatus for solid carbonaceous material the combination ot an externally heated sealed tumbling barrel ball mill retort, subdivided by foramiuous partitions into a series ot ball mill chambers, each succeeding partition having progressively smaller openings, and each succeeding chamber containing angular grinding elements and ball grinding elements ot' heat conducting material admixed in proportion to insure the flowing and tumbling' action otl such grinding elements of progressively smaller size and ot la dimension to be retained by each said foraminous partition, a feed t'or the intake end ot the retort comprising a se'- ries otl troughs with screw conveyors delivering at ditterent positions within the first chamber of lthe retort, a gas take-ott opening above the level'of the solid contents, a takeofl' tor the solid residue comprising a stationary cylindrical dischargeI connected to the retort by a trunnion with stufling box, a conveyor therein, a star valve in the dis charge tor maintaining the retort gas sealed while delivering the solid residue, and a combustion furnace for receiving and burning the said heated powdered Solid residue.

6. In a distilling apparatus for solid carbonaceous material the combination yof an externally heated sealed tumbling barrel ball mill retortsubdivided by oraminous partitions into a series of ball mill chambers, each succeeding partition having progressively smaller openings, and each succeeding chamber containing angular grinding elements and ball grinding elements ot heatl conducting material admixed in proportion to insure the tlowing and tumbling action of such grinding elements of progressively smaller size and ot a dimension .to be retained by each said foraminous partition, a teed for the in-V take end of the retort comprising a series of troughs with screw conveyors dellvering at different positions Within the tirst chamber of the retort, a gas take-oft' opening above the level of the solid contents, a take-olf :tor the solid residue comprising a stationary cylindrical discharge connected to the retort by a trunnion with stuffing box, a conveyor therein, and a star valve in the discharge for maintaining the retort gas sealed while deliverinfr the solid residue.

In a distilling apparatus forlsolid car bonaceous material the combination ot' an externally heated sealed tumbling barrel ball mill retort., angular grinding elements and ball grinding elements Within the said retort admixed in proportion to insure the flowing and tumbling action of such grinding elements, means for delivering said solid carbonaceous material to the retort, a gas take-ofi' opening above the level ol the `solid contents, a takeott for the solid powdered residue comprising a stationary cylindrical discharge connected to the retort by a trunnion, al conveyor therein, a star valve in the discharge for maintaining the retort gas sealed while delivering the solid residue, and a combustion furnace for receiving and burning the heated powdered solid residue as specified.

8. In a distilling apparatus for solid carbonaceous material the combination of an externally heated sealed tumbling barrel ball mill retort, angular grinding elements and ball grinding elements within the said retort, admixed in proportion to insure the iiowing and tumbling action of such grinding elements, means for delivering solid carbonaceous material to the retort, a gas takeott' open/ing above the level of the solid contents, a take-oit tor the solid powdered residue comprising a stationary cylindrical discharge connected to the retort by a t-runnion, a conveyor therein, and means to maintain the outlet sealed against gas.

9. In an apparatus for heat treating solid material the combination of an externally heated tumbling barrel ball mill retort, subdivided by foraminous partitions into a series of ball mill chambers, each succeeding partition having progressively smaller openings and each succeeding chamber containing angular grinding elements and ball grinding elements of heat conducting material admiXed in proportion to insure the flowing and tumbling action of such grinding elements of progressively smaller Size and'ot a dimension to be retained by each said foraminous partition, a feed for the intake end of the retort and a take-oit discharge for the pulverized material from the retortns'ispecitied.

l0. In an apparatus for heat treating' solid material the combination of an externally heated tumbling barrel ball mill retort containing angular grinding elements and ball grinding elements ot heat conducting inatorial admixed in proportion to insure the Howing and tumbling action of such grinding elements, a 'feed for the intake end of the retort and a take-G` discharge for the pnlverized material from the retort as specified.

11. An apparatus for heat treating solid material the combination of an externally heated tumbling barrel hall mill retort and angular grinding elements and ball grinding i0 elements of heat conducting material adrnixed in proportion to insure the flowing and tumbling action of Such grinding elements disposed therein to insure the grindin and tumbling action of solid material ing ground in the mill.

In Witness whereof We have hereunto set our hands. l

HARRY S. REED. RALPH D.` LAMIE.

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