US2385775A - Continuous retort - Google Patents

Description

Oct MOGARVEY CLINE 2,355,775

CONTINUOUS RETORT or inal Filed May a, 1939 a sheets-511851 1 401 8i 9p I V O9 c I {40 .75

L I r I i y l w H? N 78 85 I v 1 a 85 97 420 I MOGARVEY cum:

CONTINUOUS RE'I'ORT Original Filed- May a, 1959 a Sheets-Sheet 2 llllllllllll I l l l I l I l Oct. 2, 1945. M GARVEY CLINE 2,385,775

connnuous RETORT Original Filed May 3, 1939 8 Sheets-Sheet 5 Oct. 2; 1945. IMOG'ARVEYCLINE 2,385,775 I CONTINUOUS RETORT I 7 ori inal Filpd May :5, 1939 a Shets-Sheer. 4

d v a ti MGGARVEY CL'JNE 2,385,775

CONTINUOUS RETORT Original Filed May 3, 1939 8 Sheets-Sheet 5 M =GARV EY CLI NE I 2,385,775

I courinuous RETORT Original Filed May 3, 1939 '8 Sheets-Sheet 7 Oct. 2, 1945. MOGARVIEY CLINE 2,385,775

commuous RETORT I Original Filed May a, 1939 a 'Sheets-Shee t a Jill Patented Oct. 2, 1945 CONTINUOUS RETORT McGarvey Cline, Jacksonville, Fla.

Original application May 3, 1939, Serial No. 271,595. Divided and this application January 21, 1942, Serial No. 427,661

22 Claims; (Cl. 202-104) This invention relates to continuous retorts for subjecting materials to the action of heat, and more particularly to retorts in which the heating medium does not come in contact with the materials being processed and where the products resulting from the action of heat on the materials may be readily recovered. The present application is a division of my prior co-pending application Serial No. 271,595, filed May 3, 1939.

While the invention is primarily adapted for processing solid material in finely divided form, it may also be applied to the treatment of certain concentrated solutions or suspensions, and other liquids. Among the substances which may be treated are wood in the form of small chips, sawdust or powder; concentrated liquors prodduced in the paper pulp industry; agricultural waste products such as straw, corn stalks, tobacco stems, wheat and cat hulls, etc., when such materials are finely divided or shredded; and nut hulls, seed pits, shredded bone, etc.

In its broadest aspects, the invention isapplicable to the simple drying of materials such as those above mentioned, but it is intended more particularly for the destructive distillation of such materials, whereby they are completely carbonized, and, at the same time, the vapors and gaseous products resulting from the distillation may be recovered. The invention has special utility when used for the destructive distillation of resinous wood, such as that of the southern pine.

Many efforts have been made to successfully distill the large amount of waste pine wood available in this country both in the form of stumps, limbs, etc., left in the operation of saw mills, or in the form of finely divided chips produced in the wood naval stores industry and left as a residue after the oleo-resinous materials have been extracted by means of solvents. The destructive distillation of such material, however, has heretofore presented difficult practical problems, owing to the peculiar nature of the material, and it is the general object of the present invention to devise efiective means for carbonizing resinous woods, particularly the spent chips above referred to, with the coincident recovery of valuable products such as phenols and other distillates.

The apparatus of the present invention may be considered as a further development of and improvement on that disclosed in my prior Patent No. 1,763,758, issued June 1'7, 1930, and while the present invention relates to apparatus of the same general type as that of said patent, it possesses marked advantages thereover.

Among the specific objects of the present invention are to provide improved means for supporting and rotating the retort shell; and improved means for supportingthe top or superstructure of the retort; to devise an improved hollow heating element having means for causing the hot gases to flow therethrough more effectively; to arrange a plurality of such elements in superposedrelation to constitute a stack, and to cause the hot gases to fiow upwardly through all of such elements in series; to provide improved conveyor elements for handling the material more effectively; to provide improved feeding mechanism which will serve to deliver measured quantities of material into the retort in such a manner as to prevent packing and jamming and will, at the same time, prevent the escape of gaseous products; to provide means for separating the dust and'fine particles of solid matter from the vapor and gaseous products rising from the the material being treated; and

to provide means for positively ejecting from the conveyors any material which, due to coking or for other reasons adheres thereto and fails to be discharged by gravity.

With the above and other objects in view, the invention consists in the construction and arrangement of parts hereinafter described and claimed,and illustrated in the accompanying drawings forming part of this specification, and in which:

Fig. 1 is a sideelevation of my improved retort complete, parts being broken away and parts being shown in section;

Fig. 2 is a plan view on an enlarged scale of the top of the apparatus, parts being omitted for the sake of clearness, and parts being broken away;

Fig. 3 is a fragmentary, vertical, central section on an enlarged scale through the lower part of the apparatus shown in Fig. 1;

Fig. 4 is a similar section on the same scale through the upperpart of the apparatus;

Fig. 5 is a plan view of one of the improved heating elements;

Fig. 6 is a transverse section thereof substantially on the line 66 of Fig. 5, looking in the direction of the arrows;

Fig. '7 is a plan View of the supporting ring on which the lowermost heating element rests;

Fig. 8 is a transverse section on the line 8-8 of Fig. 7, looking in the direction of the arrows;

Fig. 9 is a fragmentary side elevation on an cylindrical web ll. "cylindrical webs or rings l6 and H form, with Fig. 13 is a central transverse section therethrough; a H

Fig. 14 is a horizontal section substantially on the line I l-14 of Fig. 3, looking in the direction of the arrows.

Referring to the drawings in detail, and more particularly first to 'Fig. 1,'my improved apparatus comprises a supporting baseA and associated parts, a rotatable vertical cylindrical shell indrical shell I9, to the lower ed e of which is secured an angle ring l8, mating with and at-- tached to the angle ring 9.

Resting on the base plate 3 is a supporting ring 25, shown as of frusto-conical form, having a horizontal base flange 2i terminating in a short vertical flange 22, which fits snugly within the opening -in the base plate 3. This supporting ring is best shown in Figs, '7 and 8, and is adapted to be secured to the base plate 3 by 'means of bolts passing through holes 21 which,

B, constituting the body of the retort, and a which. the rotary cylindricalv shell revolves, as I hereinafter described,

Thi'sshell comprises a lower section 6, to which is' secured a horizontal annular flange 5, from which depend an intermediate vertical cylindrical web 'i' and an outer concentric web 8 spaced apart as shown. Also secured to the cylindrical section 6 .is an angle flange 9, adaptedto support a similar flange, secured to the lower end of the main cylindrical shell of the retort. To the outer want is secured an angle flang H), to the underside of which is secured, by bolts H, an annular ring gear l2 having teeth on its outer periphery. 1

Mounted beneath the ring gear l2 and secured theretoas by means of some of the bolts H are a plurality of rollers l3 adapted to bear against the outer vertical surface of the ring rail 4.

Secured to the upper surface of the ring gear -l2 are a plurality'of bearing housings or journal boxes 54, containing bearings in which are journalled the spindles of supporting wheels I5, which J3, bearing against the outer face of the ring rail.

Secured to the base plate 3 at a point just inside of and spaced from the depending web I is an upstanding cylindrical web it, and also secured to the base plate 3 just outside of and spaced from the web I is a similar upstanding It will thus be seen that the the base plate 3, an annular trough into which the depending web or ring 1 extends. This trough is partially filled with some suitable liquid (not, shown) into which the web 1 dips so as to form a gas-tight seal around the bottom of the retort.

The main body B of the retort comprises a cylshown, are preferably spaced 22 apart.

This is done so that the supporting ring may be angularly adjusted with respect to the base plate and set in any desired one of sixteen different positions.

At the upper edge of the ring 29 is a groove 23 preferably having tapered sides, as shown, for the purpose of making a tight joint with the lowermost heating element, as hereinafter described. r v a The ring Zllis provided with an inwardly projecting lug 2 3, with a'series of strengthening webs 25, and with'a series of eight pairs of radially extending lugs 2d, the purpose of which will be hereinafter explained. V 1

Asin my former patent, above referred to, the retort comprises a vertical series or stack of hollow annular heating elements or units. In the present case, however, these heating ele'me'nts'or units,

designated in their entirety by the reference numeral 27, are of improved construction, the details of which are best shown in Figs. 5 and 6. 'Each annular heating element or unit has, at its loweredge, a conical flange adapted to fit into the groove '23 of the supporting ring. 2i), or into a similar groove 32 formed 'at the upper edge of each heating element or unit, as the casemay be,

are sealed and their interiors are in continuous communication.

7 Referring again to Figs. '5 and 6, each improved 4.)

heating elementcomprises spaced bottom and top walls-2t and 30, united at their outer peripheries and reinforced by radial connecting webs 3|, and

"are preferably formed-by casting. It will be understood that thesejwebs 3 l-are preferably spaced similar to the webs 25; shown in Fig. 8, each in the embodiment shown, being -22 apart, so that when the superposed elements are assembled in the .form of a stack, these strengthening. Webs will be -in vertical alignment throughout the stack Supported by the'webs 3i and extending between the upper and lower-wallsZi and 3U-is an annular bafile 33, of somewhat dished form, "as shown. Around the inner periphery of this bafile is'a thickened vertically disposed rib orfiange 34, extending bothabove and below the same, and projecting horizontally inward from this thickened rib is 'anarrow; annular; horizontal flange .35.v The inner portion of the bafile 33 is preferably provided with a plurality of radially extending slots 35 for permitting expansion and contraction'of the ba'file under changing temperature conditions.

'As in my' prior patent, each heating element is provided with a notch or sector-shaped opening 38 of approximately 22 in extent, the hollow interior of the heating element being closed by radial walls '39 at either side of this notch.

. Each heating element isprovided, at itslower edge, adjacent the said notch, witha downwardly projecting. lug 23, adapted to engage the lug 24 on the base ring 25 (Fig.7) or to engage a similar lug 24', (Fig. formed at the upper edge of each heating element, so as to angularly position one with respect to the other.

Each heating element 21 is further provided adjacent its upper edge with a series of eight pairs of inwardly projecting radial lugs 31, and adjacent its lower edge with a similar series of eight pairs of inwardly projecting radial lugs 31, the lugs of one series being staggered with respect to those of the other, so that in plan view, as shown in Fig. 5, there is a pair of lugs every 22 /2 around the inner periphery of the heating element.

From the foregoing, it will be obvious that in assembling the heating elements on the supporting ring 20 and on each other to form a stack, as shown in Figs. 3 and 4, each heating element may be so positioned that the notch 38 therein is angularly displaced 22 from the notch in the heating element next below, whereby the notches are arranged in a broken spiral around the stack, and are not in vertical alignment, but oifset from each other, asshown in Fig. 9. It will further be understood that, the supporting ring 20 having once been bolted in position with the lug 24 at the desired point, this lug will determine, by means of the key lug 28 on the heating elements, the angular position of the lowest heating element and the location of the notch 38 therein. The remaining heating elements can then be progressively angularly displaced so that the notches therein define a spiral as above mentioned, the notch in the lowermost heating element being disposed at the left hand side of the apparatus adjacent the discharge mechanism, as shown in Fig. 3, and the notch in the uppermost heating element being disposed almost in the same vertical line but displaced therefrom a distance of 22 in a counter-clockwise direction, as illustrated in dotted lines in Fig. 2. When the series of heating elements have been assembled on the supporting ring 20, and on each other in superposed relation, and in the desired relative angular positions, they are secured together by means of bolts 4| passing through vertically aligned pairs of lugs 37' and 26 or 31, as the case may be (see Fig. 3). No attempt has been made to illustrate all of these lugs in Figs. 3 and 4, however, only one or two pairs being illustrated for the sake of clearness.

On the underside of each heating element adjacent the opening or notch therein is formed a series of concentric depending ribs 40 having bevelled or inclined lower surfaces 40 as shown in Fig. 9. The purpose of these ribs will be hereinafter explained.

As best shown in Figs. 3 and 4, the space between the inner peripheries of adjacent bafiles 33 is closed by means of short cylindrical sections or walls 42. The edges of these sections fit within the annular shoulders 34 formed on the baffles and engage and are separated by the radial flanges 35.

It will thus be seen that the cylindrical sections 42 provide a continuous,-central, vertical flue or conduit extending from the top to the bottom of the stack of heating elements.

It will further be observed that the cylindrical walls 42 are spaced inwardly from the meeting edges of the heating elements 21, thus providing an annular opening between the interiors of adjacent elements.

Depending from the lower side of the base plate 3 and concentric with the above mentioned conduit formed by the cylindrical sections 42, i a

cylindrical'casing 43, having a bottom plate 44 provided with a concentric opening. Extending upward from this opening is a pipe 45 (Fig. 3). Beneath this opening and the lower end of pipe 45 is a chamber 46, from which extends a radial duct 46 (Fig. 3), to which is preferably connected an induction fan (not shown), as in my said parent application, such fan delivering into a suitable discharge stack.

The inside of the cylinder 43 and the outside of the pipe 45 are preferably covered with a layer of heat resistant material 41, and this is shown as continued up through the supporting rin by means of an additional section 48, on the top of which rests an annular ring 49, snugly fitting within the lowermost cylindrical section 42. It

will thus be seen that the pipe 45 andwall 48 forms a continuation of the vertical axial conduit comprising the sections 42, and that this conduit communicates at its lower end with the radial duct 46'.

Supported on and forming a tight connection with the uppermost heating element 21 is a top plate 50 having a central opening 5| therein (see Fig. 4) above which opening is secured a cylinder 52 having at its upper end a detachable cover plate 53.

Tapping the side of the cylinder 43 (see Fig. 3) is a radial conduit 54, connected outside the base I with an enlarged section 55, both preferably lined with heat resisting material, as

shown. The enlarged section 55 is connected at its outer end with a furnace (not shown) or other source of hot gases.

Supported by and movable over the flat, horizontal upper surface 30 of each heating element is an annular conveyor element of improved construction. As clearly shown in Figs. 12 and 13, this conveyor element comprises an inner ring 69, an outer angle ring '10, and a series of spaced radial bars H rigidly connecting said rings and forming therewith an annular series of cells closed on all four sides. These conveyor elements are adapated to be rotated by the cylindrical shell [9 through the medium of short drag chains 12 attached at one end to the ring 10 and at the other end to the shell. The preferable point of attachment of these chains is to the inner wall of flanged hand holes or openings 13, as shown in Figs. 3'

and 4, provided with cover plates 14.

At the bottom of the retort adjacent and surrounding the supporting ring 20 is a special conveyor element comprising inner and outer rings 69' and 10' connected by radial bars H, these bars being considerably deeper than the bars H of the standard conveyor elements and arranged with their lower edges just above the base plate 3. This special conveyor element fits snugly within the cylindrical section 6, at the bottom of the retort, and is supported on lugs 6 secured to the inner surface thereof. (See Fig. 3.)

On the topmost heating element is mounted another special conveyor element comprising an outer angle ring 10 inverted as compared with the rings 10, and an inner angle ring 69 (see Figs. 4 and 11) This inner angle ring 69 is disposed with its upper horizontal leg overhanging the outer edge of the plate 50, as shown. Extending up from this horizontal leg is a lug (Fig. 11), the purpose of which will hereinafter appear.

Coming now to the superstructure of the apparatus and referring more particularly to Figs. 2 and 4, I provide a top plate 15, shown as substantially square, and support this plate at its opposite sides upon longitudinal beams 16, which fitting within the same.

beams may conveniently constitute part of the framework of the building or shed in which the apparatus is housed. The longitudinal beams .16 rest upon and are connectedbysuitably spaced cross beams 17, as shown. 1

Depending from the lower side of the plate 35 is a cylindrical web or skirt "18 of slightly smaller diameter than the main cylindrical'shell J9, and To the upper end of the shell i9 is secured an annular trough '85, 88, and into this trough depends a second annular web or skirt 84, supported by the top plate 15, :concen trio with and spaced from the skirt l8. The trough 85 is adapted to contain a suitable liquid :into which the skirt 84 dips, thus forming a fluid tight seal at the upper end-of the rotating shell l9, between such shell 'and'the stationary superstructure associated with the top plate 75, It will be here observed that thereis no connec ticn whatever between this superstructure and other parts of the retort, the superstructure being supported entirely by the beams or framing 76, '53, and the cylindrical shell l9 freely rotating beneath same and out of contact therewith. n

The top plate whats a central Opening, from the inner edge of which depends a circular shell '59, concentric with the skirt it but spacedinwardly therefrom. The top plate 15 has an opening 15 extending between the elements 7-8 and l9, as shown in Fig. 4, and at both the front and rear of this opening, as viewed in Fig. l, are'vertical plates 89, bridging the space between the elements '18 and i9, and forming therewith a closed chute, immediately below the opening 55 Above this opening is .a housing '85, into which the material to be treated is fed, as hereinafter described. The top of the housing 8! may formed with a hand hole provided with a removable cover 3W.

Extending upwardly from the top plate 15 and registering with the central opening therein and forming a continuation of the circular wall 19,

the

y is a cylinder 82 provided with a cover plate-33,

To the bottom of the circular wall i9 is secured a horizontally disposed annular plate 8]. (Figs. 2 and 4.) At one point in its circumference, as shown at the right hand side of Fig. 5, the wall is is provided with an opening .83, which merges at its lower end with a similar opening or notch 88*, formed in the plate 8 (Fig. 2).

Depending from the plate 87 isa curved diagonally extending scraper blade 8.9, the purpose of which will'be hereinafter described.

Referring to Figs. 4, l9, and 11*, I provide a rotary member comprising an annularplate I85, hav ing a depending peripheral flange 9|, to the upper side of which plate is secured a vertical cylinder '92 having an internal flange 93 at the upper end thereof, such cylinder being of substantially less diameter than the plate 96; The inner edge of the annular plate 98 makes -free sliding cantact with the stationary cylinder-52.

When assembled, the lower edge. of the'flalnge 95 of the plate Qilrests upon and is supported by-the upper horizontal leg of the angle ring 69 and inside of the flange 9! is formed a lugS-fl (Figifll which is adapted to engage the lug 5% (Fig. lb

so that the'plate 8'0 and associated parts are caused to rotate with the conveyor element comprising the angle-ring 52s. The plate 195! is centered and held against substantial lateral d splacement by means ofthecylinder E2. 1 V 1 The rotary cylinder $2 is of such sizeas to rnalre a free sliding fit within the annular plate -81.

aw-111 now be apparent that the elements 7 9,

.81 and 92 together form-an annular trough, the bottom and outer wall of which are stationary and the inner wall of which rotates. V

Rigidly secured to the flange 93 at the top of the cylinder-92 is a pair of scrapers, each comprising a bracket 94 with blades 94 and 94 extending upwardly and downwardly therefrom (Figs. 10 and 11 Strengthening ribs 95 preferably connect the blades with the bracket 94. 7

By reference to Fig. 4, it will now be seen that the edges 94 of the blades 94* travel in close proximity to the inner surface of the cylindrical chamber 82 and that the lower edges 94" of the blades 94 work in close proximity to the annular plate 8! constituting the bottom of the trough, above referred to. When, therefore, the scrapers revolve-the blades scrape from the-inner walls of the cylindrical chamber any solid matter which has been deposited thereon. This solid matter falls by gravity into the trough above described, and is moved along the bottom -87 thereof by means of the scraper blades and discharged downwardly through the opening '88 therein (Fig. 2). The discharged material falls upon the annular plateilii (Fig. 4) from which it is swept outwardly by the scraper 89 and is deposited into theupper conveyor element comprising the rings 69 and Ell Extending radiall out from the cylindrical.

chamber 82 is a discharge pipe 96 for the gases and vapors resulting from the heat treatment of the material. This is connected at its outer end with the top of a suitable condenser 91, which is provided at its lower end with an outlet Sl for discharging the non-condensible gases, which gases may be conducted to and burnt in the furnace. The condensed liquids pass through the pipe 98 into the well 93 from which they overflow through the spout 99 into a suitable pipe or receptacle 92 The improvedmeanswhich I have devised for feeding the finely divided material into the retort will now be briefly described, special reference being had to Figs; 2 and 4.

It has been found that when attempting to feed finely divided material from a'hopper, as for example by means of a discharge screw or a plunger, trouble is often experiencedbyreason of packing and arching of the material :in the hopper. It has also been found that infeeding.

such materials by means of a piston and cylinder communicating directly witharhopper, the material is likely to become jammed or packed'in the cylinder, with resultant strain or damage to the apparatus. t

In designing my improved mechanism, I have succeeded in obviating both of the foregoing diificulties, first, by avoiding tlteuse of ahopper containing a fixed mass of material, and second,

by delivering predetermined quantities of material into the discharge cylinder.

M improved apparatus is supported, on a pair of spaced beams it supported on the cross beams El, and comprises, a feed chute 10!! and "a horiat a-point near the rear thereof, r

Near

The trough IOI, at its forward or discharge end IOI', passes between a pair of guide plates I01, extending upwardly from a chamber I08, from which chamber extends a delivery pipe or conduit I09 to the housing 8 I.

Adapted to reciprocate within the chamber I08 is a horizontal plunger or piston II 0, connected with the trough IOI. The plunger or piston III) is held in proper position by means of a pair of auxiliary plungers II disposed one at each side of the piston and rigidly secured to a bracket IIO formed integral therewith. The plungers I I0 work in fixed guides II0 and thus maintain the piston at all times in axial alignment.

Also formed integral with the bracket H0 is a boss II0 in which is set a pin IIB to the lower end of which is attached one end of a connecting rod II'I, the other end of which is attached to a similar pin I I8 set in a crank arm I I 9 secured to the upper end of a vertical shaft I journalled in a bearing bracket I2I. Beneath this bracket, the shaft I20 is connected by a suitable universal joint With the upper end of a hollow shaft lzilawhich extends down to the rotating and discharging mechanism hereinafter described.

Referring to Fig. 4, I mount in an inclined position within'the housing 8| just in front of the end of the delivery conduit I09, a pressure plate I09, pivoted at its upper end at I09 and having secured to its lower edge adjustable weights I09 the number of which may be varied as desired.

The operation of the feeding mechanism above described will now be briefly set forth. The finely divided material is fed continuously from the chute I00 into the trough IIlI, filling and overflowing the same. Meanwhile, the piston H0 is being reciprocated by means of the connecting rod II I, and causes a similar reciprocation of the trough IOI.

The connection between the piston and trough is such that, at the extreme forward position of the piston H0, in which position its forward end enters the end of the conduit I09, the discharge end I0! of the trough IOI registers substantially with the forward edge of the cylinder I08, and the trough is retracted, when the piston moves back, into the position shown. Thus, the piston and trough reciprocate together. Starting with the trough in the position shown in the drawings, the material will fill and overflow the trough at a point immediately in front of the fixed angle bracket I00, this material entering the trough between the fixed bracket and the movable vertical plate I04. Upon forward movement of the trough from this position, more material falls in behind that which is already there and in front of the angle bracket I06. Upon backward movement of the trough, this material is pushed forward by the angle bracket I05, and at the same time the vertical wall or stripper plate I04 serves to level off the material in the trough so that the material is never heaped up in the trough at any point forward of the stripper plate, but the trough is maintained level full, the cover plate I03 preventing any material entering the trough in advance of the stripper plate I04.

Upon successive reciprocations of the trough, additional quantities of material enter the rear portion thereof until the trough becomes full throughout its entire length in front of the bracket I06. After the trough has become full, it will be apparent that, upon the next return or rearward movement, a measured quantity of material is discharged from the forward end IOI' of the trough into the cylinder I08. This measured quantity represents a mass of a section equal to the cross section of the trough and of a length equal to the stroke thereof.

The volume of the batch of material delivered at each stroke is, of course, proportional to the length of the stroke of the trough or, in other words, to the longitudinal dimension of the mass of material which is ejected from the end of the trough upon its. return stroke.

From the foregoing, it will be understood that the material is fed into the trough at a rate in excess of the maximum rate at which it is to be delivered into the retort, and that the reciprocating trough serves to intercept a portion of the stream of material passing through the chute and deliver such intercepted portion in the form of successive batches of predetermined volume in front of the piston IIO. In this way, the dimculties heretofore experienced in the feeding of finely divided materials from filled hoppers is avoided on the one hand, and on the other hand, the danger of overfeeding material in front of the piston and thus producing abnormal stresses in the mechanism is eliminated. With my improved arrangement, the volume of material deposited in front of the piston is automatically limited.

Referring again to Fig. 4, the material forced by the piston IIO out of the cylinder I08 passes into and through the conduit I09, and finally accumulates against the weighted pressure plate I09. When the space within the conduit and beneath the pressure plate becomes completely filled with material, the pressure of the piston causes the plate I09 to swing upwardly on its pivot at each stroke and permit a definite amount of materialto pass and to be discharged through the opening 15 and down the chute 80, it being understood that at each stroke of the piston the same amount of material is forced past the pressure plate I09 as is delivered by the trough IOI into the cylinder I08.

The purpose of the pressure plate, therefore, is to maintain the delivery conduit I09 completely filled with a compact mass of material, so as to form a substantially tight seal-to prevent the escape of gaseous products out through the feed mechanism.

At its lower end, the hollow shaft I20 is connected by a suitable universal joint to the upper end of a vertical shaft I22 journalled in bearings I23 carried by the top of a gear casing I25, and bearings I24 mounted within said casing, which casing is supported on the base plate 3. Between the bearings I23 and I24, there is rigidly secured to the shaft I22 a bevel gear I26 meshing with a similar gear (not shown) secured to a drive shaft I27 (Fig. 1) connected with a suitable'motor.

On the lower end of the shaft I22, below the bearing I24, is secured a pinion I29, which meshes with a ear I30, secured to a short vertical shaft I3I, journalled in suitable bearings and carrying at its lower end gear I32. The gear I30 meshes with and drives the ring gear I2 secured to the rotating cylindrical shell of the retort, as above described, and the gear I32 meshes with a gear I33, secured to the upper end of a vertical shaft I34. This shaft is journalled in bearings formed in a-short cylindrical casing having upper and lower parallel walls I36 and I 40. Fitting snugly between these walls andfiwithin the cylindrical sides I33 of the casing is a discharge whe'el co'm" prising a hub I33, and, a plurality 'of spokes I38 combination with the cylinder 538, forming closed cells.

I36 has an opening MI adapted to register sucradiating therefrom (Fig; '14), these spokes, in

At the side adjacent the retort, the top plate c'essivelywith the cells between the spokes I39 as the discharge wheel rotates, and on the opposite side of the casing, the bottom plate I45 is provided with a vertical discharge opening Mi With which the cells in the discharge Wheel'are likewise adapted to,successiveiy register (Fig. 3).

is idisplaced"22 ina counter-clockwise direction from; the position shown at 33 in Fig; 2, until the notch 38 in the lowermost heating element,'as shown in Fig. 3, is directly under the housing 81 (Fig. 2)]Wheie the material enters theretort.

The spent material'discharged from the lowermost heating element passes through the opening 3 in the base plate and thence through the chute I42 into-the discharge .wheel I39, whence it is delivered from the discharge opening Mi The discharge mechanism, above described, in which the material enters the cells at one side of the cylindrical casing and is discharged from'the opposite side thereof, provides a gas-tight seal to prevent the passage of gaseous products therethrough. It will be noted that the discharge mechanism is also geared to the shaft I22 so that it is always driven at'a speed which bears 1 a, fixed ratio to the rotation of the main cylindriat a point 61-.

rectly above'the opening I 31 is'a discharge open-. ing 3%, and a chute I42 is arranged to conduct thematerial from the opening 3* and deliver it.

into the opening I iI- I 7 General operation Pb-i e f b in up ied by. t motor :28. the

vertical shaft I22 and with it the hollow shaft:

I 29 and. vertical shaft [20 is driven and through he a s. I an 5.36 and ring sear l he yl drical shell of the retort is rotated. Thisshell sw th tin its rota n n t on y t e Vario cgnvg o lem nt whi r con ec ed o itbv,

The mate bein s int t o s n 3!. s

abve d s fi ed dischar e d wnw rd through the opening 15 and chute 80, into the cells 6f the topmost conveyor elementj A v It'willbe acted that suite the" feedmechanism and the cylindricalshellrotatingmechanism are" geared together, they operate Witha constant speed ratio, "and tyfpropehy'sneetihg this ratio, it "is'possible 'to so 'affan'g'e' the apparatus'that a" oftheconveyor element passes under the chute. In other Words, successive measured batches 'of material are delivered into successive"ce11sas the topmost conveyor element rotates. in my prior patent, above identified,''the 50 speed of the drive shaft I27.

One of the chief practical difiiculties in the processing of finely divided resinous wood and cal shell and the operation of the feed mechanism. The capacity of the cells I39 in the discharge wheel is preferably somewhat greater than the volume of the maximum measured batches of material fed into the retort at the top.

Since measured batches of material of uniform volume are successively fed into the cells of the uppermost conveyor element, it will be seen that when these cells are filled (either partly or wholly full, depending upon the stroke of the feeding mechanism, as above explained) the material therein is in the form of a layer of uniform thickness, and the rotation of the conveyor elements causes this layer to slide along in contact with the upper surface of the heating elements. have found that this method of subjecting finely divided material to indirect heat, namely, by confining it within cells having closed sides, or, in the form of a layer of uniform thickness, and

causing this layer to slide progressively over the surface of a hot plate, is a very efficient one and possesses marked advantages.

Inasmuch as the rotating means, feeding means and discharging means are all geared to-' 45, gether, it is possible to Vary the time during whichthe material is subjected to the action of heatwithout varying the thickness of the layer of material or makingany other relative adjustmerits. This may be done simply by varying the other-materials, of this nature is the tendency of such materials to cake 'or coke under the'in- "fiuence of heat, and adhere to the surfaces with material falls; cascade fashion,"from theupper horizontal surface of oneheating' element 'to'that 1 of another, passing 'thI'OIlgh theopenings "or' notches "38; which notches are offset from "each otherand arranged in the form of a spiral. 'It will be understood that the direction of rotation which they are 'in'con'tact. Thus, in continuous retorts of the "type described herein, in which the material is intended to fall by gravity through the openings or notches in successive heating elements, it frequently happens that as indicated by the arrow in Fig. 9, the successive notchesyin the heating elements being offset in.

the directionindicated in Fig. 9 In this way, the

owing to caking orcoking, the material clings to the side walls of theconveyor element and is not discharged therefrom by gravity when it passes over the openings in the heating elements.

This results-in interrupting the how of material material deposited on oneheating element makes fifteen-sixteenths of a complete revolution before being discharged through the notch onto the heating element next below. Thus','in Fig'. 2, the" notches in'the topmost heating element is displaced in a counterclockwise direction onethrough the retort and jamming or choking of the apparatus.

One of the importantfeatures of the present invention is the provision of means for forcibly 7o ejecting caked masseso'f material from the consixteenth of a'revolution or 2 2 from the chute 1 8&3 under the housing 8l, atwhich point the material is deposited, and each successive n0tch,.

progressively'downthe series of heating elements,

ried' byf the lower face of each heating element veyor cells. This is the purpose of the arcuate ribs it having. the lower inclined surfaces te as shown in Figs. 5, 6 and'Q. By reference'to' Fig.9, it will be observed that these ribs are carand overlying the notch or opening '38 of the heating element next below, the lowest point of the inclined surface of the ribs being immediately above such opening. It will further be observed by reference to Fig. 9 that the depth of the ribs increases progressively in the direction of rotation of the conveyor elements, as shown by the arrow, and the lowest point lies slightly above the plane of the upper surface of the conveyor element.

As long as the material remains as a layer of uniform thickness in the cells of the conveyor element, or as long as it does not project above the upper surface of such cells, the ribs to have no effect. If, however, the material should fail to fall out of any cell as it passes over the opening in the heatin element, and this cell should travel around again and receive another charge of material on top of that already in the cell, so that the material is heaped up in the cell, as

10WI1 in Fig. 9, then when this mass of heaped up material is carried underneath the inclined surface of the ribs 49, such inclined surface will serve to force the material downward and eject it from the cell through the opening below, breaking up any caked masses and disengaging them from the side walls of the cell. Experiments have shown that no matter how badly the material may be caked in a cell, the device just described will serve to effectively break it loose and clear the cell for receiving the next charge.

It will thus be understood that hot gases from the furnace are delivered into the radial duct 54, (Fig. 3), from which they pass into the annular space within the base and thence upwardly through the supporting ring 25 into the interior of the lowermost heating element 2'5, and thence successively upward through the interiors of each heating element in turn. It will be observed that the position of the baffles 33 is such that the hot gases are caused to follow a radially zig-zag path, flowing outwardly over the bottom wall of the heating element and thence radially inward along the upper wall.

As shown in Fig. 4, the hot gases emerging from the uppermost heating element, and passing around the topmost baffle 33, flow downwardly through the central axial conduit formed by the cylindrical sections 42, and thence out through the radial duct 46', to the discharge stack.

It remains to describe the path of the vapors and gaseous products given off from the material bein processed. It is preferable that the heating elements be thoroughly heated prior to the introduction of the material being processed, and that the mass and temperature of the heating gases being circulated through the heating elements be such that th desired temperature of the heating elements is maintained after the processing of the material is started. It has been found that a highly satisfactory temperature range for the circulating heating gases is that they should enter the bottom heating element at approximately 1,300 degrees R, and leave the radial duct 45' 'at approximately 900 degrees Fahrenheit. This temperature range keeps the topmost heatin element at substantially the temperature at which the carbonization of'wood progresses as an exothermic reaction.

As above pointed out, thefinely divided Wood or other material is fed in at the top of the retort in successive measured amounts to form a layer Within the rotating topmost conveyor element, which moves the layer, without substantial agitation, or the particles composing it, in sliding contact with the top surface of the heating element. Each conveyor element delivers the material carried by it, in cascade fashion, to the next lower conveyor element and thus the stream of material being processed is successively moved over the surfaces of the entire number of heating elements; each succeeding lower element being progressively of higher temperature. In cascading from one heating element to the next lower element the particles composing each layer of the material being processed are substantially rearranged. The porous layers of finely divided particles are very poor conductors of heat and only those particles in direct contact with the top surface of the heating element are subjected to a rapid rise in temperature. These contacting particles, however, very quickly approach the temperature of the heating element. It has already been observed that it is preferable to have all the heating elements maintained at temperatures in excess of the temperature required to produce the exothermic breakdown of the material, via, approxi-v mately 850 degrees F. in the case of Wood. The particles of each layer contacting the heating element, therefore, are very quickly carbonized and the resultant vapor and gaseous products move Vertically away from the surface of the heating element and flow through the superimposed porous layer of cooler particles, and rapidly transfer their heat, in the case of vapors, by condensation. With each transfer of the porous layers ofmaterial from one heating element to the next lower heating element, fresh particlesof wood or other material are brought in contact with the surface of the heating element and in turn are rapidly carbonized with a continued movement of the gaseous and vapor products upward through the cooler material with consequent condensation and transfer of heat to the cooler materials. As the temperature of the entire porous layer of material is rapidly increased by this dual method of heating, reevaporation of the liquids, resulting from the previous condensation of vapors, takes place. The dual method of heating, above referred to, includes heating by conduction from the hot surface of the heating elements, and heating by the exothermic reaction brought about by the breakdown of the material particles in contact with the heating element, the exothermic heat being stored in the vapor and gaseous products. In the above-mentioned reevaporation, the lower boiling liquids are first vaporized and the higher boiling liquids remain mixed with the particles composing the layer. There is thus an accumulation of high boiling liquids in thelayer as it rapidly approaches the critical temperature at which the remainder of wood particles contained in it break down with a further liberation of exothermic heat. The presence of the accumulation of high boiling liquids in the layer serves to absorb this exothermic heat as heat of vaporization, thus serving to quickly cool the vapor products of carbonization to a degree that materially inhibits cracking.

The vapors and gases which escape from any layer of material flow to the opening 33 in the heating element immediately above the layer of material and mingle with the stream of gases and vapors from other layers of material flowing upward through the broken spiral passageway formed by the said openings in the heating elements, and moving through Zones of progressively decreasing temperature, thus further inhibiting the cracking of the vapor products.

The greater part of the gaseous products emerge through the opening 38 in the topmost heating element, this opening being in the position shown The products then.

ametrically opposite side of the retort.

From the opening 88, the gaseous products pass upward-1y into the cylindrical chamber'82, and are thendischarged radially therefrom through the conduit 96.

Thus the gaseous products'fiowing through the sharply change their direction at a number of points. This sudden change in direction tends to cause any solid particles entrained or carried along with the gases to be deposited either in the trough 8! .or on the walls of the cylindrical posited material is continuously removed by the rotating scraper blades and returned to the topmost conveyor element.

My process, which has been described in con- 1 nection with the movement of finely divided woods and other similar materials, over a succession of hot heat-conducting surfaces in the order of ascending temperature, opens a broadly interesting'field of modifying vapor products of destructive distillation by contacting them with acid or other vapors derived from materials added to the finely divided wood prior to its introduction'into my apparatus, and by contacting them with active gases such as chlorine or sulphur dioxide which i may be admitted in controlled amounts at the base of the apparatus. Various catalytic agents may also be added to the finely divided materials being processed and the aggregate layer of material subjected to the action of heat delivered by direct contact of the material with the heat conducting surface.

While in the claims I have used the word retort in defining the invention, it will, of course,

be understood that this term is intended to be 1 broad enough -to include apparatus for drying or otherwise processing material, as well as for j subjecting the same to destructive distillation.

What I claim is: 1. .A retort comprising a vertical cylindrical hell, a stackof hollow superposed annular heating elements having spaced top and bottom walls united .at their outer peripheries, inside of .said

' shell, eachelement being-preformed as a complete unit, substantially horizontal baffle .means withinand carried by each element at a'po'int between said walls, said bafilemeans being spaced means connecting the interiors of said elements I so as to form with said walls and bafile means a continuous vertically zigzag fluid passageway through all of said elements in series from the bottom to the top of the stack.

2. In a retort, a heating element comprising a horizontally disposed hollow annular structure having spaced upper and lower walls united at their outer peripheries, and an annular baille mounted concentrically within said'ho'llow structure between and rigidly connected with said walls, and means for feeding material to be treated onto and discharging it from the surface of the upper wall of said element.

3. In a retort, a heating element comprising a horizontally disposed unitary hollow annular structure having spacedupper and flower walls united at their outer peripheries, and an annular I bafiie mounted concentrically Within'said hollow superstructure, as above described, are caused to 1 chamber t2, and, as above described, such' de- I att ns structure between and integral with said walls, the outer diameter of said bafile being smaller than that of said walls and the inner diameter of said annular baffle being less than that of said heating element, and means for feeding material to be treated onto and discharging it from the surface of the upper wall of said element.

4. A retort comprising a vertical cylindrical shell, a stack of independent, hollow superposed annular heating elements inside of said shell, each pro-formed as a complete unit and. having a horizontal surface, mean engaging and connecting adjacent elements so as to form a continuous vertical fluidpassageway through the interiors of all of them in serie from the bottom to the top of the stack, said means also forming a separate fluid conduit extending continuously axially through the stack of annular elements, mean for causing hot gases to circulate successively through said passageway and conduit, and. means for causing material to be treated to travel over the horizontal surface of said elements.

from .the' outer peripheries :of said walls, and

5. Aretort comprising a vertical cylindrical shell, a stack of independently formed, separable hollow superposed annular heating elements inside of said shell each having a'horizontal surface, means for feeding solid material to be treated onto and discharging it from the horizontal surface of said elements, means connecting the interiors of said elements so as to form a continuous fluid passageway through all of them in series from the bottom to the top of the stack, means forming a separate fluid conduit extending continuously axially through the stack of annular elements, and means for causing hot gases to circulate upwardly through said passageway and thence downwardly through said co duit.

6. A retort comprising a vertical cylindrical shell, a stack of separately formed hollow superposed annular heating elements insideof said shell each having a horizontal surface, means for feeding solid material to be treated onto and dis-' charging it from the horizontal surface of said elements, means connecting the interiors of said elements so as to form a continuous fluid passageway through all of them in series from the bottom to the top of the stack, and means for causing hot gases to flow upwardly through the interiors of all of said elements in series and thence downwardly axially through the centers thereof.

'7. A retort comp-rising a vertical cylindrical shell, a stack of hollow-annular heating elements, disposed one above the other in a vertical series inside of said shell and'each having a horizontal pper surface, means for feedin solid material to be treated onto and discharging it from the horizontal surface of said elements, means forming a fluid passageway connecting the hollow interibrs of said elements and extending from the bottom to the top of the stack, means forming a separate fluid conduit extending continuously axially through .the stack of annular elements, and means for causing hot ases tocirculate upwardly through said passageway and thence downwardly through said conduit.

8. A retort comprising a vertical cylindrical shell, a stack of separately formed, superposed heating units within said shell, each unit comprising a hollow,-annular structure having a horizontal upper surface, means for feeding solid material to be treated onto and discharging it from-the horizontal surface of said annular structures, means-connecting the interiors of said units 7 gases to flow upwardly through the interiOrs of all of said units in series and thence downwardly axially through the centers thereof.

9. In a retort of the type comprising a series of independent superposed heating elements and means for causing material to be treated to travel downwardly over the surface of each of said elements in succession, said heating elements each comprising a unitary hollow annular structure having spaced upper and lower walls united at their outer peripheries, an annular baflle mounted concentrically within said hollow structure between said walls and rigidly connected therewith, and balile having an outer diameter less than that of said walls, and an annular wall formed separately from said bafile, bridging and closing the space between the inner peripheries of adjacent pairs of bafiles, said wall being spaced from the inner peripheries of said hollow structures to provide an annular passageway therebetween.

10. In a retort, the combination of a, series of superposed hollow annular heating elements, each constructed as a complete, pre-formed unit, and each having spaced upper and lower walls united at their outer peripheries, means for causing hot gases to pass continuously through the interiors of said series of elements, means within and constituting an integral part of each element to cause the gases to flow radially outward over the bottom wall and radially inward back along the inner surface of the upper wall, and means for causing material to be treated to travel over the outer surface of the upper walls of said elements.

11. In a, retort, the combination with an annular, horizontal heated element having an opening therethrough, of a conveyor element supported thereon and comprising an annular series of cells open at the top and bottom, means for rotatin said conveyor element, means for continuously feeding successive quantities of material into said cells as they pass a fixed point, and means operating as each cell passes over said opening, to force the material downwardly out of any cell in which it may have become heaped up above the normal level.

12. In a retort, the combination with an annular, horizontal heated element having an opening therethrough, of a conveyor element supported thereon and comprising an annular series of cells open at the top and bottom, means for rotating said conveyor element, means for feeding material successively into said cells as they pass a fixed point, and means forcibly ejecting from each cell and down through said opening any material which fails to fall through said opening by gravity.

13. In a retort, the combination with an annular, horizontal heated element having an opening therethrough, of a conveyor element supported thereon and comprising an annular series of cells open at the top and bottom, means for rotating said conveyor element, means for continuously feeding successive batches of material into said cells as they pass a fixed point, and mean for breaking up and ejecting downwardly through said opening caked material adhering to the walls of any cell as it passes over said opening.

14. In a retort, the combination with an annular heated element having an opening therethrough, of a conveyor element supported thereon and comprising an annular series of cell open at the top and bottom, means for rotating said conveyor element, means for continuously feeding successive quantities of material into said cells as they pass a fixed point, and a fixed inclined surface overhanging said conveyor element and having its lowest point immediately over said opening and justabove the normal level of material in said conveyor cells.

15. In a retort, the combination with an annular heated element having an opening therethrough, of a conveyor element upported thereon and comprising an annular series of cells open at the top and bottom, means for rotating said conveyor element, means for continuously feeding successive quantities of material into said cells as they. pass a fixed point, and a fixed inclined surface overhanging said conveyor element and extending progressively closer and closer thereto in the direction of its rotation, the closest point of approach being directly over said opening.

16. In a retort, a stack of superposed annular heating elements, each having an opening, said openings being progressivel angularly displaced, means for feeding onto the topmost element material to be treated, a conveyor element supported on each heating element, means for rotating said conveyor elements, and a cam member carried by each heating element above the next lowest conveyor element, said cam member being of progressively increasing depth in the direction of rotation of said conveyor elements and having its maximum depth at a point immediatel over the opening in the next lowest heating element.

17. The combination with a horizontal supporting plate having an opening therethrough, of a substantially rigid conveyor element resting thereon and comprising an annular series of cells open at thetop and bottom, means for rotating said conveyor element so that said cells pass successively over said opening, means for feeding material into said cells as they pass a fixed point, and means operating, as each cell passes over said opening, to force the material downwardly out of any cell in which it may have become heaped up above the normal level.

18. In a retort, a stack of superposed circular heating elements, means for feeding material to be treated downwardly over one after another of said elements in succession, an annular chamher over the topmost element, means for delivering gaseous products rising from the material on the lower of said elements into one side of said annular chamber, and means for discharging them from the opposite side of said chamber, whereby said'products are caused to flow circumferentially of said annular chamber,

19. In a retort, a stack of superposed circular heating elements, means for feeding material to be treated downwardly over one after another of said elements in succession, an annular chamher over the topmost element, means for delivering gaseous products rising from said material axially into said chamber, and means for causing them to flow circumferentially of said chamher and then be discharged radiall inwardly from the inner side thereof.

20. In a retort, a stack of superposed circular heating elements, means for feeding material to be treated downwardly over one after another of said elements in succession, an annular chamher over the topmost element, a smaller concentric cylindrical chamber above said annular chamber, means ior delivering gaseous products rising from said material into said annular chamber at one point, the inner Wall of said annular chamber having, at another point angu- V larly displaced from the first, an opening communicating with said cylindrical chamber, and.

means for discharging the products radially outward from said cylindrical chambeigtwhereby the gaseous current is caused to sharply change its direction at a plurality of points.

21. Ina retort, a stack of superposed circular heating elements, means for feeding material to be treated downwardly over one after another of said, elements in succession, an annular trough 1 above and spaced a substantial distance from n the topmost element, a cylindrical chamber surmountinglsaid trough and of substantially the same diameter as the top thereof, means for causing gaseous products rising from the material to pass into and through said chamber,

' and'means including a scraperfor catching and returning to said conveyor element any solid matter carried off by the gaseous products rising from said material under the influence of heat.

MoGARVEY CLINE.

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