US2165143A - Coal treating process and apparatus - Google Patents

Description

July 4, 1939. L. c. KARRICK COAL TREATING PROCESS AND APPARATUS.

Original Filed June 14. 1928 2 Sheets-Sheet 1 INTRODKIW H07 COMBUSTION GASES T0 HEAT COAL IN ,BINJ' TEAM .Sl/PER HE ATER DRY-Ql/E/VCI-IING STEAM Til-.12.

(20550 (OILS CfiRRV/NG SUPER/154750 STEAM IN VEN TOR.

y 4, 1939- L. c. KARRICK 2,165,143

COAL TREATING PROCESS AND APPARATUS Original Filed June 14, 1928 2 Sheets-Sheet 2 5750M Sl/PER' HEATER Sl/PFL Y- I/V6 CLOSED (O/L5 AND ERNAL 0/5 7711.115 6750M COURSES 0F COAL OVER SUPPORT/N6 $HELVES Tiq5 I N VEN TOR.

Patented July 4,1939 i UNITED STATES PATENT OFFICE COAL TREATING PROCESS AND APPARATUS Lewis 0. Karrick, Salt Lake City, Utah Original application June 14, 1928, Serial No.

285,426. Divided and this application December 11, 1933, Serial No. 701,838

7 Claims. (Cl. 202-15) Q This is a divisional application of my former to about 1200 F. by the endothermic reaction application for Retort, filed June 14, 1928 under with the coke and, as it rises to the mid-point Serial Number 285,426, Patent No. 1,938,596. of the chamber, the steam now cooled to say- This invention relates to the process and ap- 1200 together with the as fi paratus'for treating coal and other carbonaceous serve to furnish the internal heat required for materials to obtain solid, liquid and gaseous low temperature distillation in the upper zone products th f o of the carbonizing chamber. In treating some An object of the invention is to distil such coals it is desirable to subject the lumps while materials under controlled conditions or low at low temperatures to sudden blast of highly temperature carbonization to produce coke of heated stem so as to quickly char or carbonize improved physical and chemical properties," with .the surfaces, thereby case hardening the lumps accompanying high yields of tar-oils and gases. and in such cases I introduce the steam at points Further objects of the invention are to subnear the top of the chamber and remove partor ject sized coals to variations in pressure during all of the steam and volatiles at the mid-point different stages of distillation so as to compress of the chamber. 15

the lumps of coke and prevent their excessive In the preferred form of the invention, I also swelling or disintegration; to produce lumps of heat the carbonizing chamber externally by passdense coke in substantially the sizes of the lumps ing hot gases or superheated steam through conof coal treated; to increase the life and efllciency tinuous vertical fiues, or jackets, surrounding or of the metal retorts particularly by providing comprising the walls of the chamber. These 20 means for preventing warping or buckling in the jackets are preferably installed in independent regions of highest temperature; to increase the units surrounding the low temperature and. high capacity of carbonizing chambers while controltemperature zones of the carbonizing chamber ling the efiective weight of the contained mateso that the chamber walls can be separately rial at all points therein; to provide an improved heated to the desired temperatures best suited 25 economical process and apparatus employing suto the reactions in the several parts of the perheated steam as the principal heating niechamber. I also provide radiators heated with dium for distilling carbonaceous materials; and superheated steam which are placed in the disto provide an improved quick-acting gas-tight tilling zone to supply indirect internal heat when valve for controlling the flow of the solid maneeded to control the temperature and quality 30 terial, of the vapors. Beneath the lower end of the In carrying out the invention carbonaceous carbonizing chamber I provide means for intromaterial, preferably sized dust-free coal, is lowducing saturated steam to dry-quench the coke ered by gravity through a heated retort or carproduct. This steam is employed in a quantity bonizing chamber counter-flow to a rising cursufiicient to cool the coke to near the tempera- 35 rent of superheated steam which carries the ture of the steam, after which it passes up volatile distillates upwardly. In some cases, through the carbonizing chamber abstracting however, I pass the steam and gases in parallel further heat from the descending coke, thereby flow with the coal as hereinafter described. In becoming superheated and assisting the distillathe preferred embodiment of the invention the tion of the coal in the upper part of the cham- 40 superheated steam, preferably heated above her. Only such amount of dry-quenching steam 1200 F.. is introduced near the mid-point of the is used as will economically cool the coke withchamber and passes out at the top with the out reducing the inside operating temperature volatiles from the coal, and thence passes to of the carbonizing chamber.

the condensers in which the tar-oils are sepa- From an economic standpoint it is desirable 45 rated from the gases into fractions, and the wato pass the maximum possible tonnage through ter is removed. If it is desired to increase the the carbonizing chamber. If a descending colyield of gas from the coal by removing addiumn of lump coal is heated very slowly, which tional quantities of the residual volatiles, and is the case if the coal descends slowly in the to convert part of the coke to water-gas, I incarbonizing chamber, the weight supported by 50 troduce steam which is more highly heated into a lump of coal (the effective weight of the colcontact with the active coke toward the bottom umn exerted on any lump) is less than when of thechamber. The steam and the active coke the coal descends rapidly. This is because with from the process react rapidly above 1200 F. to the slower rate of distillation the coal becomes form water-gas. This steam is quickly cooled more plastic and compressible and tends to arch 55 to. increase the height of the carbonizing chamher and the corresponding rate of downward movement of the coal. In actual practice, however, it has heretofore been impossible -,to increase the capacity in this manner because of the added weight to which the coal is subjected by virtue of the increased height of the column,

and the resulting tendency of the coal to agglom erate and clog the chamber.

This diiilculty is overcome by the present invention which provides means for materially increasing the height and capacity of the carbonizing chamber without increasing, but in fact actually decreasing, as required, the effective weight or pressure to which the lumps are subiected throughout the entire treatment. This is accomplished by providing a plurality of supporting members, spaced at predetermined distances or relation inside the carbonizing cham-' her, to control the load supported by each lump of coal at any stage of its passage through the chamber. In one embodiment, hereinafter described, the distilling lumps are caused to roll one upon another as they descend. This latter treatment is beneficial in the case of some coals, causing the resulting lumps of coke to become rounded while experiencing very little abrasion. In all embodiments a certain amount of loading of the coal (pressure) is permitted at all times in order to control the density of the final coke product, but the loading is so gauged and of such amount that the result will be beneficial at each step. Regulated pressure is applied when the coal begins to expand or soften. The pressure is then reduced as the plasticity increases, but it then reaches a maximum as the stage arrives where rigid coke is forming. Finally the pressure is reduced when excessive pressure might cause crushing of the rigid coke.

In the preferred form of the inventiona plurality of variably spaced sloping shelves are mounted'within the carbonizing chamber to regulate the pressure on the lumps of coal at different stages of the heat treatment as the coal descends in contact with the superheated steam. In the simplest form, say for a coal that has practically no plastic or very weak stage in its distillation, I provide stationary sloping supports mounted in staggered relation on opposite walls of a carbonizing chamber which may be tapered or parallel. For this type of coal, the supports may be equally spacedand of such angle that the coal readily slides from one to another as it descends through the carbonizing chamber. The size, slope and spacing of the supports, as well as the clearance between the lower edge of the supports and the opposite wall, depend upon the size and shape of the coal to be treated, the mobility of the coal column, the nature of the treatment, and the size and shape of the carbonizing chamber, as hereinafter more fully described. In another form of the invention the supporting means for controlling the pressure on the lumps of. coal may be in the form of a vertically moving element, such as a downwardly moving link chain having lateral extensions, or a continuously descending helical support which may be varied as required. The feature of loading" may also be accomplished arcaua simultaneously by the irregular spacing of sloping. side-wall supports used in combination with central moving supports.

Another feature of the invention resides in a novel construction which increases the life and eiliciency oi all-metal retorts, particularly by preventing warping or buckling. of the walls even in the region of greatesttemperature. Heretofore it has been thought necessary to construct gas retorts and coke ovens of non-metallic materials in order to obtain satisfactory service under high operating temperatures encountered. The commercial Scottish oil shale retort, which applies temperatures within the range used by my processes is constructed with brick walls in the lower (high temperature) zone, and cast iron walls in the upper (low temperature) zone. I provide an all-metal retort, preferably employing a chromeiron'alloy in cast or rolled plate form for the walls and lines in the high temperature zone, and calorized steel plate or cast steel inthe lowtemperature zone. The seams throughout are welded or upset to insure a gas-tight structure when operated under pressure. Calorized steel will give good service in the lower zone, if the process is operated principally for low temperature distillation treatment of coals and not at extremely highgtemperatures for the production of large quantities of water gas.

In order to prevent the metal walls from warping due to stresses produced by sudden or uncontrolled fluctuations of the temperatures in the heat sources, the metal walls and reinforcing ribs are left free to expand and contract independently of-the enclosing brickwork. Also, in heating-with gas, I prefer to use air and gas mixing blowers and burners that will insure a uniform and controlled quantity and quality of fuel, and which operation will be independent of atmospheric influences; such devices are perfected and are coming rapidly into wide commercial use. It is very important to minimize the pressure or weight stresses on the metal walls, particularly in the hottest region, and this I accomplish preferably by suspending the retort from a point near its upper end where the temperatures of the retort walls are suiliciently low to obviate any danger of warping caused by the weight of the superimposed structure. I provlde a simple and emcient arrangement ,of weights and counterbalances adjusted to take all the load off the portion of the steel walls which are subjected to the greatest temperature, and preferably maintain such portions of the walls under slight tension especially if the walls below are subject to .dangerously high temperatures. The extreme tension to which the uppermost part of the metal walls is subjected will have no damaging effect because of their lower temperatures and greater metal strength. The arrangement of counterbalancing the weight of the retort provides constant metal tension at all times as the retort expands and contracts upwardly and downwardly with changes in temperature. In order to allow the vertical movement of the retort to be independent of the coal charging means, I provide a gas-tight slip-joint between the bottom of coal charging means and top closure of carbonizing chamber. I

These and other featuresof the invention will be described in connection with the accompanying drawings in which similar reference characters indicate corresponding parts of the several views, and in which:

arcane izing apparatus embodying the invention;

Fig.2 is a section taken on line inf-2a of Fig. 1;

Fig. 3 is a view similar to Fig. 1, showing a modified construction of thesupporting means for controlling the pressure on the coal and a novel arrangement for heating the walls of the carbonizing chamber; Fig. 4 is a section taken on Fig. 3;

-. Fig. 5 is a view similar toFig. 1, showing still another arrangement for controlling the pressure on thedescending lumps of coal;

' Figs. 6, '7, 8and 9 are diagrammatic views showing various arrangements of sloping supports within the carbonizing chambers to regulate the pressure 'onthe coal at different stages of treatment; Fig. 8 also shows a system of connections used for supplying direct and indirect internal heat to the chamber;

Fig. 10 is a sectional view of a quick-acting gastight valve for controlling the supply of'solid material; and

Fig. 11 is a plan view partly in section thereof.

In Fig. 1 the metal reaction chamber I is surrounded by a system of fines 2 enclosed in heat insulating walls 3. Dust-free coal of substantially uniform size is charged into bunker 4 and is fed through valve 5 into magazine 6 from which it flows continuously by gravity through valve 1 into the reaction chamber I which remains full of coal at all times. At the bottom of the reaction chamber is a discharge device comprising a wheel having pockets 8 which is rotated continuously in the direction shown with arrow by means of any suitable power device, not shown, which withdraws coke from the reaction chamber and drops it into receiving bin 9 through valve I0 which normally remains open. At the bottom of the bin 9 is valve II which remains closed while bin 9 is being filled. After bin 9 has been filled the valve I0 is closed and valve I I opened momentarily to permit the contents to be'removed, after which valve I I is closed again and valve II) opened and the operations repeated.

superheated steam, or superheated steam and water-gas, for use in distilling the coal is preferably introduced into the reaction chamber .by means of insulated pipe I2. 'I'his steam rises counter-flow to the descending column of coal while giving up its superheat to the coal, and is drawn off together with the volatiles from the coal by vapor pipe I3 and thence passes into the main I4 leading to the suitable fractionating condensers. Leading into the top of the reaction chamber are insulated pipes I5 by which superheated steam may be directed into contact with the incoming coal. I have found that some coals soften excessively when subjected to the dissolving and disintegrating effect of heavy condensates from the tar-oils which may precipitate or condense on the coal lumps which are at lower temperature toward the top of the chamber. Steam may be introduced through move such heavy tar-oils and prevent them from condensing on the coal in the upper zone of the chamber. superheated steam which may contain water gas at very high temperature may also be introduced through pipes I5 in order to quickly carbonize the outer surface of the coal lumps and thereby produce a shellor protective layer of coke on the lumps of coal. This latter procedure is used when the coal is of a fusing or a weak type. In some cases the steam introduced through pipes I5 may be drawn oil either partly or entirely at the line 411-411 of I reaction chamber.

the pipes I5 to repipe I2 and is then carried to condensers by means of conduits, not shown.

Near the bottom of the chamber'l is another insulated pipe I8 by which superheated steam may be introduced into the reaction chamber when it is desired to form water gas by the reaction of the superheated steam and the coke formed in the upper zone. When superheated steam is introduced into the reaction chamber by pipe IS, the

amount of superheated 'steam introduced through pipe I2 or pipes I5 may be reduced; or may be entirely shut off.

In order to dry-quench the col-re formed by the .process, and impart highly reactive properties thereto, saturated steam is introduced into the reaction chamberthrough pipe I1 located at the bottom of the receiving bin 9. This steam rises counterflow to the coke and abstracts its heat, thereby becoming superheated and assisting the distillation of the coal in the upper part of the When valve I0 is closed momentarily for the purpose of permitting the bin 9 to be emptied, the saturated steam is introduced through supplypipe I8 while pipe I1. is shut off. The reaction chamber I is heated externally by burning gas in the fiues 2 which surround the chamber. A plurality of gas burners I9 and provides at different levels along the walls of the chambers means for regulating the amount of heat supplied to the various fiues, and serves to control the temperature at different heights in the fines.

The reaction chamber l is provided with sloping supports 2| projecting from the side walls and mounted in staggered relation at varying distances from the top to the bottom. Thesesupports are substantially fiat, are placed at an angle steep enough to permit the lump coal to slide oil the upper surface, and are spaced at suitable distances apart to prevent the lumps of coal at any point in the reaction chamber from being subjected to excessive weight such as would cause their agglomeration or disintegration. The sloping supports project part way across the reaction chamber leaving ample clearance between their-outermost edges and the opposite wall, and between the adjacent supports, so that the coal will not arch and interrupt the continuous downward movement of the column. The tendency of most coals is either to fuse or disintegrate to some extent while being devolatilized. The provision of the sloping supports 2|, however, largely prevents the coals from falling to pieces or compressing into agglomerated masses, so that the coke product remains in lumps substantially the size of the original lumps of coal and becomes sufficiently dense to withstand the Wear and tear of handling. I have found that a coal of the fusing type may, when in lump form, be heated slowly so that all portions of the lump are at the same temperature at the same time, and thereby the lump becomes uniformly plastic or fused rigid coke while the interior is still plastic. If

the lump is subjected suddenly to very high temperatures the outsides distils very rapidly or scorches and turns to coke so quickly that it tends to fall to pieces due to the quick changes volume of the surface layers as they change from coal to coke while the interior of the lump is still unaltered. These properties and the phenomena are best exemplified by the behavior of large lumps of coal where the mass factor is important in relation to the temperature differences at different depths, to the progress of the changes of state as distillation moves inwardly, and to change of volume of the concentric layers of the distilling lump, etc. When a very small 'lump or dust-size particle is subjected to the same heating conditions the above phenomena are substantially surface reactionsand mass and thickness become inconsequential as factors limiting the rates or temperatures at which heat may be applied.

I Dust-size particles may be distilled or gasified by steam in a fraction of a second, but I have found that with such sizes the reactions are best accomplished by passing the material in suspension through externally heated tubes. as described, for example, in my U. S. Patents No. 1,950,558 and No. 1,901,170.

The intermediate sizes of coal such as are com monly known as pea, nut,"egg, etc., present problems of handling while distilling which are quite different from those met in handling the above extreme sizes and it is to such classes of coal that the present invention is particularly directed. The application of the invention is best illustrated by reference to the treatment of Utah coal fromthe Mesa Verde formation which is a high oxygen coal of bituminous rank containing about forty percent volatiles. When lumps of Utah coal sized to 4 inches were confined under pressure of contacting lumps and surrounded by steam at 1200" F. the surface of the lumps of coke flaked badly. However, when another similar charge of coal was distilled by heating with very gradual rise in temperature the lumps were substantially intact but were deformed somewhat by the pressure of adjacent lumps due to expansion of the mass. I havefound that lumps of 4-inch coal will not be excessively deformed by the weight of a moving column less than twenty feet high. Coal sized to 2 inches and heated similarly did not flake off badly, but the lumps were more extensively deformed when subjected to gradual rise in temperature. This coal will not be deformed when distilled under the weight of a moving column 15 feet high. Goal of l -inch was less affected by contacting with steam at 1200 F. but when subjected to gradual rise in temperature the lumps could be completely distorted by continuous pressure. This coal was not materially deformed when distilled under a moving column ten feet high. Goal of l+%-inch was very little affected by flaking when subjected to contact with steam at 1200 F., but when gradually heated under continuous pressure the lumps were pressed into a dense homogeneous aggregate. This coal would deform and cohere considerably when distilled under a moving column 6 feet high. When coal was of still smaller size the sudden hot blast of steam at 1200 F. did not cause disintegration of the particles if in a confined space such as a moving or stationary column. However, the small size of the coal particles permits about equal degree of fusion to take place throughout the particle so that -inch coal coheres in a moving column 4 feet high and in a stationary column barely 2 feet high, whereas V -inch coal coheres in a moving column 1 foot high and in a stationary column barely 4 inches in height. The'sloping supports 2| are substantially flat, as shown, and slope downwardly toward the opposite wall of the reaction chamber I, serving not only to support portions of the moving column but also to deflect the distilling lumps of coal repeatedly during their descent through the chamber. The clearance space between thelower edge of any support and the opposite wall should not be less than five times the maximum diameter of the largest lumps of coal comprising the charge since otherwise the largest might form a rigid arch and 'stop the coal movement. The vertical spacing of the supports 2| will vary in different heating zones, depending upon the size and the character of the coal treated, and should be the maximum that the distilling coal can support without disintegrating or agglomerating thereby obtaining a maximum compression which results in producing extremely dense lumps of coke. When the walls of the chamber I are substantially vertical, as shown in Fig. 6, or slope outwardly very slightly as shown in Fig. 1, the vertical spacing of the supports 2| should increase somewhat from top to bottom so as to cause continuous increase in cross-section of the coal channel from top to bottom of the chamber, as shown.

Near the top of the reaction chamber I, I provide coils 22 placed under the sloping supports and carrying superheated steam. These coils serve as a means of supplying internal radiated or conducted heat to the contents of the reaction chamber and thereby prevents condensation of heavy tar-oils from the rising current of fluids. The superheated steam is heated tothe proper temperature to accomplish the desired transfer of heat and, for the sake of economy, is then preferably returned to the second superheater in which it is reheated and introduced through pipes I2, I5 or I6 to react with the coal by direct contact, the apparatus for circulating and reheating thesteam in this manner being similar to that shown in Figs. 3 and 8. The coils 22 may be connected in series or parallel in order to govern the temperature gradient and amount of heat delivered to the upper portion of the distilling zone. The hot combustion gases passing upwardly through the fiues 2 pass through insulated pipes 23 and are circulated by means of blower 24 into the bottom of the bunker 4 and serve as a flexible means for preheating and drying the coal. By preheating the coal in bunker 4 to about 400 F. by means of stack gases very little condensation of the heavy tar-oils will take place on the coal as it passes down through the distilling region of chamber I. If the coal is of the fusing type, the hot gases, supplemented by air supplied through the branch pipe 25 serves to oxidize the outer surface of the lumps and reduce the tendency to cake or fuse.

The pipes I5 for the introduction of highly heated steam to the upper part of the reaction chamber may also be employed continuously in the modified distilling operation, mentioned above, by permitting part of the steam introduced therethrough topass out through the top of the reaction chamber I, and withdrawing the balance along with the mixed volatiles from the coal through pipe I2 at the mid-point of the chamber. When the coal comes suddenly into be increased by constructing the lower portion of" the metal reaction chamber I of alloys of chromium and iron, or of calorized steel, this portion being in the zone of highest temperature. The upper part of the chamber I may be of cast steel or calorized steel plate. The chamber is made gas-tight for operating under pressure, by welding or other suitable means. The space 2 is constructed with clearance to permit the walls of the chamber I to move freely in a lateral direction as they expand and contract. Means are provided for permitting the metal walls to move freely in a vertical direction, and to insure that such vertical movement will be substantially linear, thus preventing warping or buckling due to expansion in the region of greatest temperature under the weight of the superimposed structure. This is accomplished by providing a continuous upward tension on the walls of the chamber. In the forms illustrated in Figs. 1, 3 and 4, beams 21 rest on fulcrums 28- supported by the brick walls 3. 7 One end of the beams 21 engage a lug 29, these lugs being fastened adjacent the top on opposite sides of the walls I. The opposite end of each beam 21 is counter-balanced by weight 30. The weight 30 is adjusted to cause a slight tension in the metal in the hottest zone so as to prevent any tendency of the metal to warp or sag from downward pressure at any part of the metal walls. The lower end of the magazine 6 is connected to the top of the carbonizing chamber by means of a gas-tight slip-joint 3I which permitsthe walls of the chamber I to expand and contract vertically without permitting gas to leak out. A

similar gas-tight slip-joint 32 is provided in the insulated pipe 23. The several supply pipes, such at I2, I and I6 which penetrate the brick wall 3 are provided with ample clearance around them to allow for expansion. The openings through the brick work are preferably provided with a yielding plug or bushing 33 of asbestos yarn or other similar material held in place by close-fitting metal discs or shields 34 surrounding the pipes.

Fig. 3 shows a modified arrangement for externally heating the walls of the reaction chamher, and a continuous device extending from top to bottom of the retort for supporting the weight of the column of coal during its downward movement. One or more continuous flexible members 36, which may be in the form of chains, are each provided with laterally extending projecting portions 31 spaced apart an amount depending upon the size and character of the lumps of coal being treated. Each continuous flexible member 36 passes through a vertical gas-tight housing 35 and is moved downwardly through the'chamber I by means of any suitable driving mechanism 38, passing around sprockets 39, 40 and 4 I thence through liquid seal 42 and around sprocket 43, and over sprockets 44 and.45 to the top of the reaction chamber. The liquid in the seal 42 is preferably high-boiling tar-oils produced by the process, and serves to prevent the superheated steam from passing into housing 35. The lateral supports 31 of the flexible member 36 provide a continuous foothold for the coal, permitting the coal to arch against the lateral supports 31. In other words, the device provides a continuous falling or receding support againstwhich the coal arches-or is supported at many points. In this device, the effective load on any lump of coal at any position in the reaction chamberis approximately equal to the weight of a column of 'coal the height of which is slightly greater than, the diameter of the retort, i. e., equal to the arching height of the coal undergoing treatment.

' In Fig. 3 the walls of the reaction chamber are heated externally by means of jackets 48 and 49 supplied with. superheated steam. The superheated steam enters the jacket 49 through insulated pipe 50 and passes out through pipe 5I. The source of this steam may be re-heated steam exhausted from coils 22 when such coils are employed in the manner'shown and described in connection with Figs. 1 and 8. The temperature of the steam supplied to the jacket 49 is equal to or greater than the superheated steam introduced into the reaction chamber I by means of pipe I2 in Fig. 1. The steam passing out through pipe 5| may be passed through pipe 52 into the heating jacket 48 either directly or after first passing through a separate superheater, not shown, to raise the temperature if required. The superheated steam passes from the jacket 48 by way of pipe 53, and may then be heated by a separately fired superheater and then admitted to the interior of the reaction chamber I to contact with the coaltherein. As illustrated, the pipe 53, which is broken away to simplify the showing, conducts the steam to a separate superheater 54 from which the superheated steam is passed through pipes I2 and I6 into the interior of the reaction chamber I to contact directly with the coal therein.

In Fig. 5 the arrangement of the hot gas flues 2 for externally heating the walls of the carbonizing chamber is similar to that shown in Fig. 1. In Fig. 5, however, a modified device for supporting the descending column of coal is shown, comprising a rotating screw 55 disposed between the walls of the chamber I and driven by means of gears 55. The flights of the screw provide a foothold on which the lump coal arches against the side walls. This screw thereby provides a modified means of relieving the amount of downward pressure on the lumps during their entire passage through the carbonizing chamber.

I have found that with this type of device some In the construction using sloping supports, as in Fig. 1, to allow the coal to receive the amount of pressure needed to increase its density while carbonizing, and yet preventv agglomeration of the lumps, I provide for irregular spacing of the sloping supports as, illustrated diagrammatically in Figs. 6 and '7. The exact spacing and size or the sloping supports throughout the carbonizing chamber, as well asthe question of using vertical center and of such diameter that it is flush with the interior wall of the valve on one side and over- I channel or recess 14 on its inner surface on three corresponding points on adjacent supports on the same side of the carbonizing chamber. Fig. 8 also shows in larger scale the closedheating coils 22-. placed under the sloping supports and the superheated steam inlets i5-with one form of interconnection between them. The exhaust steam from coils 22 may be heated in superheater 54, or may be passed around the superheater. 54 by means of valves, and then introduced into pipes l5, as shown, as well as into. pipes l2 and iii in the lower walls of the chamber as shown in Figs. 1 and 3. Fig. 9illustrates a means of arranging sloping supports extending from the sidewalls of a reaction chamber of larger-lateraldimensions and extending also-from both sides of the centrally disposed wall 58, and is useful as a means of adapting large carbonizing chambers to the treatment of small sized coal.

Figs. 10 and 11 illustrate a gas-tight coal valve suitable for charging and discharging the magazines and receiving bins of the carbonizer. The

valve comprises an outer'casting 59 with top and bottom flanges 60 and 61 and an'extended compartment 62. Flange coupling 63 cooperates with flange 60 and has an opening placed oflfhangs the interior wall of the valve by a small distance on the other side as shown at 65. Bottom flange 66 cooperates with flange 6| and is similar to top flange 63. A sliding gate 61, provided with valve stem 68 is actuated by lever 69 and link 10 to move in and out of compartment 62. Stufling' box 1| provides means for operating the valve without leakage of gas. Within the valve casting 59 are provided flanged steel linings 12 and 13 which are cut at an angle to cooperate with the respective sidesof the valve gate 61.

The cooperating surface of the valve gate and the linings are ground to-form gas-tight contacts.

The valve casting 59 is provided with a steam sides directly opposite the contiguous edges of the valve gate. A source'of high pressure steam is connected to steam channel 14 by means of pipe and fittings 15. A valve 16 which controls the flow of high pressure steam is actuated by the lever 69 and linkage 11 to' deliver steam to the interior of compartment 62 and into steam channel 14 asthe valve gate is forced downwardly into place. It will be noted that the scavenging effect of the steam in removing the dust from the valve seat is greatest as the gate approaches its seat due to the tapered construction of the ate 61. I

In order to arrest the flow of coal prior to closing the valve gate, a means is provided comprising a shaft 18 and a plurality of independent steel fingers 19 actuated by handle 80. Prior to closing the gate 61 the handle 80 on shaft 18 is set in a horizontal position, whereupon the spring fingers 19 clearly adjust themselves within the descending column of lumps and cause it to arch well above the line of gate 61. In a few moments the lever 69 is forced inwardly a short distance,

Fig. 8 shows a thus opening the steam valve 16 and releasing the steam into the space 62 and 14. The further movement of lever 69 causes the gate to move into its seat. .In order to provide a simple adjustment for seating the valve, I provideleaf shims 8| of any suitable material, such as metal, which may be removed as the cooperating .surfaces of the valve gate 61 and linings 12 and 13 wear, to make a gas-tight fit. The gate 61 comprises a tapered plate with fiat surfaces, as described above, and it is therefore easily resurfaced. Likewise, the cooperating surfaces of the linings 12 and 13 are flat plain surfaces and may be removed and ground smooth on a polishing with little effort if adjustment becomes necessary. I have found that the gate operates with lessbinding if placed at anangle, either downward or upward, when cutting through a stream of lump material and I show it in this form since it may be desirable at times to quickly close the gate before the flow-arresting means 19, 80 have had time to function. The valve is also suitable for use in conduits carrying highly heated steam in whichcase the linings 12 and 13, and the gate 61 will be of alloys such. as chromium, iron, and nickel. The valve will be surrounded with insulating material to prevent loss of heat.

The coke produced as described above has desirable kindling and burning properties; it ignites as readily as raw coal, .and burns smokelessly'in all types of household and industrial appliances.

The coke lumps are extremely dense and can be handled and shipped without breaking. The coke is also active chemically and has adsorptive properties which I use to impart special kindling, light-giving and odor-producing properties thereto. I have immersed the hot dry-quenched coke in solutions of sodium nitrate or chlorate and found that the resulting dried coke was easily ignited with a match flame without additional kindling agents. This coke will adsorb metallic copper from solutions of copper chloride, thereby copper-plating the cell walls; this fuel on burning gives a permanent blue flame, and the color-producing ingredient is not volatilized until the fuel is consumed. I have also found that oil of pine, cedar, etc., when adsorbed in the coke, give pleasant odors as the treated fuel is burned in open fireplaces. These finished low-temperature coke products are obtained in the processes described above by introducing the desired ingredients into the receiving bin at the base of the carbonizing chamber where the adsorptions take place immediately as the coke is dry-quenched.

I claim:

1. A process for converting sized lumps of fusible coal into lumps of low-temperature coke which comprises lowering a column of such coal by gravity through an enclosed reaction chamber, passing highly heated steam into the upper portion of the' column to quickly scorch the surfaces of said coal lumps and render them rigid, passing superheated steam into the interior of the column near the lower end thereof to gasify part of the coke formed in the upper part of the chamber, passing saturated steam into a still lower point in the chamber to dry-quench said coke, removing the volatiles from the coal and the steam introduced at the said three points at the mid-point of the chamber, and controlling the pressure between the lumps during their passage through the said reaction chamber.

2. The combination with a carbonizing chamber having substantially upright walls, of means for loweringa column of carbonaceous material by gravity through said chamber, means for heating the material during its passage through said chamber to distil same to coke, a plurality of connected supporting member centrally disposed within the column in said chamber to support a portion of the weight of said column, means for moving said supporting members in a direction to control the rate of downward movement of said column and means for introducing counterfiow cooling gases into the base of the column.

3. The combination with a carbonizing chamber having supply means for feeding a column or lump coal into the chamber, substantially upright walls, fluid heating means for heating the coal during its passage through said chamber to distil same to coke, internally disposed heaters within said chamber comprising conduits containing high-pressure superheated steam, a flexible element having a plurality of spaced'supports disposed intermediate the walls of said chamber to support a portion of the weight of said column, and means for moving said flexible element downwardly to support the moving coal and permit the downward movement thereof.

' 4. Thecombination with a carbonizing chamher having substantially upright walls, of superposed means for lowering a column of sized lump coal downwardly into said chamber, means for supplying hot gases for heating the material during its passage through said chamber to distil same to coke, a longitudinal vertical shaft disposed intermediate the walls of said chamber and having outwardly extending convolutions to maintain equal pressure on the lumps at all points in said column of coal, means for rotating said shaft to lower the coal downwardly through the chamber, and means for introducing dry quenching steam counterflow to the coked product into the base of the column.

5. A continuous process of coking softening coals oi the Utah type to form a substantially inirangible smokeless fuel product in lump condition which includes introducing a'stream of such coals into the top of a coking chamber, in-

jecting superheated steam to form a coke shell for the lumps, and injecting superheated steam into the chamber atone or more levels while the charge is descending by gravity past a series of flow retarding points spaced at various levels thereby preventing an increase in pressure as the charge descends, heating the charge during its descent to destructively distil the same, removing the volatile products from the oven and dry quenching the coked product.

6. In combination, a vertical carbonizing chamber, supply means thereabove for feeding softening type coal in a column of sized lumps into the carbonizing chamber, a steam-heating jacket for heating the column upon entrance through the carbonizing chamber without contacting therewith, lateral flues for heating gases around the carbonlzing chamber, means directing the heating gases from the fiues to heat the coal in the supply, means directing superheated steam in the carbonizing chamber to distil and soften the coal therein, a plurality of stationary supports within the carbonizing chamber successively engaged by the softening lumps and spaced to control pressures on the l'umpsto avoid crushing, means for exhausting volatile products of distillation from the carbonizing chamber, means for dry quenching the solid products of distillation and means for removing said solid products at the bottom of the carbonizing chamber.

7. In combination, a carbonizing chamber, means for passing a stream of sized Utah softening type coal lumps therethrough, means dividing the chamber into a plurality of communicating compartments one above another, said compartments being of such height as to limit the effective weight of the column on the coal in each compartment to a predetermined value and prevent crushing of the lumps, and means for passing highly superheated steam into contact with the coal during the passage through said chamber.

LEWIS C. KARRICK.

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