US2469562A

US2469562A - Material drying apparatus

Info

Publication number: US2469562A
Application number: US501939A
Authority: US
Inventors: Joseph E Kennedy
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-09-11
Filing date: 1943-09-11
Publication date: 1949-05-10
Anticipated expiration: 1966-05-10

Description

May 10, 1949.

J. E. KENNEDY MATERIAL DRYING APPARATUS 5 Sheets-Sheet 1 Filed Sept. 11, 4 1943 IN V EN TOR. Jos'ep/i 6'. Ken/lady BY d May 10, 1949.

J. E. KENNEDY MATERIAL DRYING APPARATUS Filed Sept. 11, 1943 3 Sheets-Sheet 2 IN V EN TOR. Jqsepfi 6'. Knapp/y WjW May 10, 1949. J. E. KENNEDY MATERIAL DRYING APPARATUS 3 Sheets-Sheet 3 Filed Sept. 11, 1943- IIV lll INENT OR Joseph 49'. filmed? Patented May 10, 1949 2 5159562 MATERIAL DRING APPARATUS- J seshfl tsane n w i rkz n l ei e.Seawater. 1943, S r a NQ- 1.3

.1 Claim This invention relates to apparatus for drying. material; andwhile adapted to dry. difierent kinds. of material it isparticularly adapted. for. drying.

one end constituting the inlet into. which. the.v

material is fed and =conveyed bythelrotation. of

the cylinder therethrough anddischarged. from, the opposite end constituting the. outlet of the.

cylinder. To dry thematerial a dryingmedium.

in the form of a'heated flj-uid, such. asshot. gases of combustion, are passed through. ahousing. s 1r.-.

rounding the cylinder heat. transfer relation. to the cylinder, and from the housing through.

the cylinder in heat transfer relationtdthe. material conveyed therethrough. To. enclose. the greater part of the cylinder-in a housing the cylinder has heretofore been rotatably supponted immediately adjacent the opposite ends of: the.

cylinder so that the greater portion. of. the. cylinder will be exposed to the interior of the housing. The

cylinder is relatively long and byso supporting.

the same the weight ofthe cylinder. exerts. a sidewise force on the rotatable supporting. means causing the same tobecome. quickly worn and.

requiring frequent renewal ot-"the. supporting.

means. Also by sosupportingIthe cylinder the.

weight exerts a'sagging force'between the sup.-v

port'ing means which tends tospring: the..plates.

from which the cylinder is constructed.

It is the primary object oi the invention to.pro.-.

vid-e an improved constructionancl arrangement. of apparatus of this character-lay.arranging. the.

supporting means tosupport the cylinder. at a considerable distance inwardlyfrom the. ends thereof by supporting the cylinder at points intermediate the tranefer center ot the cylinder. and

the ends thereof, andtoprovide a housing including chambers enclosing the portions of the cylinder between and at the outer. side. of. the supporting means and connected. tov eachv by portions above the cylinder.supportingmeans, and said housing arrangedso that the. inlet end of the cylinder opens tothe exterionotthe. 110.113";

ing and the outletend isinopen.communication. with the housing, and the housing. having aninlet for the drying medium tothe chamhen 07.11301 n enclosing the inlet "end-portion oi the cy. den, and the provision of means tofeedamaterialto be. dried into the inlet end of the cylinder and adapted to also connect meansto said cylinder 2- end operative to induce, the. flows of.- thed-rying. medium. into and throughthe... housing in heat. transfer. relation to the. cylinder anctirom thehousing into. the outletlendlofi. andzthmugh the. cylinder inv heat transfer. relation with the..ma.- terial therein.

Culm, or coal. refuse. collected. at. anthracite. coal mines, contains coal and also slate, rbclsandt otherforeign substances. usuallyof, larger. size than thecoal, anddn order-t0 reclaim the. coal content. of the. culm itis. necessary .to separate. the coal; from said foreignsubstances,

It. is. anothenobject of the inventiqnto. provide. an improved. material drying. apparatus of; this. character... including, an.elongated rotatablecylinr derl and .the. provision of. a Screen. at. theLoutlet (in discharge end on. the. cylinder. for the separating. of: coal within .a predetermineiilsize, from the. sub..- stances. of the. culm. and}. deliver. the. same... to .a. place. of storage, or. to means to feed .the ser rated coal to a pulverizer, anddeliver. the fQEeignsub; stances. to. a. place. remote fromv the... separatcdi coal.

otherv objects and. advantages. of the invention. will hereinafter appear.

In the. drawings. accompanying. and forming, a part. ofthis, applicatione- Figure, 1 is aside elevation tcoalidr ine s; paratus. showing. an embodiment. of: my inven tion.

Fi ur 2 is a longitudinal secti nal. view. ihe. leit hand end; portion. oh the apparatus shown in. Figure. 1.

Eigurefi is a longitudinalsectional view of the right. hand. end; portion. oi the apparatus hown. in Figure 1.

Figure 4 is a sectional. view. taken on the line. 4-4 of Figure. 2-.

Figure. 5. is a. cross sectional viewv taken on: the line 5-5 of. Il-i-gura Figure. 6' is. a. fragmentary view. in. perspective looking at thefinsideof the. screen. end of the cylinder. to show the. manner. of connecting, the screen to the cylinder.v and, the. construction and; arrangement of lifters and Figures 7, 8v and 9 are cross. sectional views taken on the. lines. 1-1, 8 & and 9 8', respec: tivlely, of. Figure 3.

Figure. 10 is a cross sectional View talgen on the line l.0lilof Eigure 2.

In the.emboclimentillustrated for carrying. out the invention there is. provided an elongated cylinder ll. oneendofiwhich constitutes the inlet, t andzth opp s eendz heQuilt? @911 the CW?- der. The cylinder is snpporte d; to rotate about.

3 an axis declining to the horizontal from the inlet end to the outlet end of the cylinder by a pair of riding rings l2, l3 encircling and fixed to .the cylinder at points within the opposite ends of the cylinder a distance substantially equal to one-quarter the length of the cylinder, as shown in Figures 1, 2, and 3. Each of the supporting rings engages a pair of supporting rollers i l rotatably mounted in bearing members 15 mounted upon foundations [6, the rollers being disposed below the riding rings at opposite sides of the axis of the cylinder. To hold the cylinder against longitudinal displacement and with the riding rings in engagement with the rollers l t a pair of thrust rollers are mounted in bearing members mounted on the foundations It to rotate on axes at opposite sides of the ring extending at a right angle to the axis of the cylinder and with the thrust rollers engaging at opposite sides of the riding rings. The cylinder is rotated by a motor M operatively connected to and driving a speed reducing mechanism ll mounted on a foundation l8 at a side of the axis of the cylinder, and a pinion on the output shaft of the speed reducing mechanism meshing with a ring gear l9 encircling and fixed to the cylinder adjacent the ring 13.

The portions of the cylinder between the mounting means and the end portions at the outer side of the mounting means are enclosed by a housing H (Figure 1), said portions of the housing being in the nature of chambers a, b, 0, respectively, connected in communication with each other through passages of the housing above the riding rings. The inlet end of the cylinder opens to the exterior of the housing through the end wall of the housing chamber 1), and the outlet end of the cylinder is in open communication with a portion of reduced height of the housing chamber 0. The housing is adapted for the passage therethrough of a heated fluid medium, such as hot gases of combustion, and for this purpose a side wall of the housing chamber b at the bottom thereof is provided with an opening adapted to be connected to a source of and enter the heating medium into the housing. As shown, the source of the heating medium comprises a coal burning furnace F to which the coal is fed by a stoker, shown in a conventional manner at S. The upper portion of the combustion chamber of the furnace opens to the upper portion of a chamber 20 disposed relative to the rear wall of the furnace and the bottom portion of said chamber. The gases of combustion flow in the direction indicated by the arrows in Figure 1 from the combustion space of the furnace into and through the chamber 20 and the member 2| into the housing chamber 1) and flows upwardly in said housing chamber transversely of and in heat transfer relation with the inlet end portion of the cylinder, the gases flowing from said chamber through the connecting passage with the housing chamber a, into the top of said latter housing chamber. The gases of combustion are caused to flow downwardly transversely and then upwardly transversely of and in heat transfer relation with the portion of the cylinder in the housing chamber a by a bai'fle in the form of a partition wall 22 (Figures 1 and 3) intermediate the ends of ing downwardly from the top of the housing to adjacent the cylinder. The gases of combustion flow from the housing chamber a into the housing chamber 0 through the portion connecting said chambers above the riding ring l3 and drivsaid housing chamber a and extendh ing gear IS, the gases flowing downwardly in housing chamber 0 transversely of and in heat transfer relation with the portion of the cylinder in said housing chamber 0, and from said chamber into and through the reduced portion c thereof into the outlet end of and through the cylinder in heat transfer relation with the material being conveyed therethrough.

Means are provided to prevent leakage of the hot gases through the clearance spaces between the cylinder and the openings in the wall 23 (Figure 2) of housing chamber b, the walls 24, 25 of the housing chamber a, the wall 26 of the housing chamber 0 and in the end wall 23' through which the inlet end of the cylinder extends. This means is shown in Figure 4 as arranged at the outer surface of each of said walls and said means are of like construction and description of one will suffice for all of said means. As shown in Figure 4, said means comprises an annular plate 21 of resilient material secured, as by welding, at the outer peripheral portion to an angle portion of an annular member 28 of Z-form in cross section secured at the other angle portion by suitable means to the housing Wall. The inner peripheral portion of the annular plate 21 is loosely disposed about the cylinder and slidably engages between a pair of

rings

29, 30 encircling and fixed to the cylinder.

The material to be dried is fed from a source or supply thereof, as from a bin, (not shown), into the inlet end of the cylinder through a chute 3i opening to a vertical portion of an elbow conduit 32 extended into the inlet end of the cylinder, the portion of said inlet opening exterior of said conduit 32 being shut off from the atmosphere by a plate 33 having an opening through which said conduit 32 extends and has a tight fit therein, the plate being secured at the peripheral portion, as by welding, to a laterally extending annular flange of a tubular member 34 supported and secured, as by welding, to the annular member of Z-form in cross section to which the plate 33 is secured. The elbow conduit is supported by a bracket 35.

Suction means is provided to induce the flow of the hot gases of combustion from the furnace into and through the housing in transfer relation with the cylinder and from the housing into the outlet end of and through the cylinder in heat transfer relation with the material fed into and conveyed through the cylinder by the rotation thereof, and shown as comprising a fan 36 connected to the vertical portion of the elbow conduit 32. As shown, the inlet of the fan is connected by a conduit 31 to the outlet of a separator 38 and the inlet to the separator connected by a conduit 39 to the conduit 32, the separator being operative to separate solids from the gases drawn from the cylinder into and through the separator and discharging said solids from the separator through an outlet conduit 40.

To separate from the material conveyed through the cylinder coal within a predetermined size from larger pieces of foreign material or substances, such as slate, rock, roots and other substances, an annular member of screen material 4| is fixed to and extends from the outlet end of the cylinder in the portion 0' of the housing. As shown in Figure 6, the screen is connected to the cylinder with the ends in abutting relation by a flat annular plate 42 engaged about the abutting ends of and secured to the cylinder and screen. The screen is supported by bars 43 circumferentially spaced about and 5? extending transversely of and secured to the screen,. as by welding; with one; end of the bars extending into. the end of the. cylinder and. secured thereto, as by welding. The outer end of said bars. is bent. at; substantially a right angle. as at 44,. and extends radially inward of the screen and carry an annular plate; 45. welded thereto to. extend inwardly of and constitute. an

annular flange at. the outlet end of the screen; As. the material is conveyed. from: the cylinder into the screen it. is agitated by said bars and lifting. members arranged relative; to alternate bars- 43 cause coal. within. a predetermined size to pass through. the screen. and discharge the same into. a hopper 46 of a chute 41 extended through thebottomof the housing, as shown, in Figures 1,. 3,. 5 and '7. The lifters consist of a bar 48' secured. at outer end to the inner surface of the plate 4.5 adjacentthe inneredge thereof and converge from said plate toward the inner end of the screen and secured at the. inner end toa bar 43', and bars 49 secured: at one. end to the end of the laterally extending portion 44'. of the bars 43' and at the opposite end? secured to an intermediate portion of the bar 48, asat 50. The bars 48 and 49' are secured by suitable means, but are preferably secured by welding. As the screen rotates with the cylinder material larger than a predetermined size is lifted by the lifters 48, 49) and deliveredthrough the-end. of the screeninto a hopper 51' mounted in an opening in the end wall of the portion 0' of the housing and having a portion extended through the screen into the end of the cylinder, as; shown in dotted lines in Figure 3. The outlet of the hopper is normally closed by a closure 52 pivotall y suspended fromabove the outlet and: normally moving towardthe outlet by gravity toclose thesame and thus shut off the housing from the atmospherethrough said hopper. Material delivered tosaidhopper from the screen: will move toward the outlet opening of the hopper by gravity and engage with and move the closure 52 to open po-- sition and permit passage of such' material from thehopper outlet.

The hot gases of combustion circulating through the housing may be of relatively high temperature, and should the gases pass from the housing into thecylinder at too high a temperature it might ignite and cause combustion of the material being dried. It may therefore be desirable to mix cool a-i-r with said gases at" or' as they enter the outlet of the cylinder: For this purpose the end wall of the portion 0 of the housing isprovided with an opening, preferably above the axis of the cylinder, and a tubula-rmember mounted in and projecting from said' opening, as shown at 53'. To regulate the area of said opening and the amount of cooling air entered into the housing regulating means is. provided, and shown as a damper 54 pivotally mounted in the tubular member 53. Additional. tempering air may be entered into the housing through ducts 59 opening. to the lower portion of the housing chamber 17,. as. at 60, said ducts being provided with air inlets in the form of tubular members 61 mounted in the topof the ducts and the entrance of air through said'inlet members into the housing controlled by regulating valves, shown in the form. of a damper 62.

As stated, it is. quite possible thatthe drying mediumor gases may be heated to: such. a hightemperature as to. ignite and cause. combustion of. the. material. in: the cylinder and. meansv are:

adaptedror' connection: to; arsource- 0t steam:

The: stieanznmayiv also be: entered. into the; housings by nozzles 56 connected to branch pipes. 5:1KeXe tended: through:' the: lower wall: of the; archportions otthez housing. above the supporting means;;, and! said." branch pipes connected. to pipesz: 5.8.1;

adapted 'tobes'commectedtto a-source of'steam...

The furnace. the. chamber: 20;: connecting:

thenfurnacewith; the? housingris of suitable refraxztoryr material,: and: the. inn-er.- surface s of the-'5;

housing walls are: provided. with. a. facing of. re:-

fractoryv material; such asv brick, and. thEJlOWBD:

walli of' the arch portions. connecting the cha/m'e bersi-ofii'the housingare also constructed .onsucln.

refractory material. The housing? is; provided: with; suitable clean-out openings: at-theside; and bottom: thereof provided with; suitable: closures; as-shown-sat Having: described my'invention; I'cl'aim:

1; In material drying apparatus, anzopenlendx cylinder, one. end? constituting the: inlet: to and; theopposite end-Ltthe outlet from the cylinderiontheimaterial to be dried, riding. ringsvmountedr on .thecyli-n'der within=.the. opposite.- ends thereon a distance substantially equal to: one quarterv the:

'length'of the: cylinder, engaged by: thesrid I ing ri-ngs to support the-cylinder to rotate about. its/axis and? to decline from: the inlet to the out::-.

let end of? the cylinder and: convey material;

through the cylinder by'rthe' rotation. thereof; asourceof a heatedtfluid medium,v a housing arranged with chambers enclosingv the portions of thecylinder between: and. at'the outer sides of the riding rings: and: cylinder supporting means and said:- chambers. connected? in communication. with eacltzother'through: arch portions spaced" above the: portions. of. the cylinder arranged: with the riding rings. and the material: outlet end ofrthe-cylind'er opening to the.=h0using and: the

material: inlet endof the cylinder openingto: the. exterior of the: housing; .and'sai'dihousing: having. arrinl'et openingtowthe' portion enclosing the materiall-inl'et" end. portion of the-cylinder connected: to the source of: auditor the entranceand: flow" oritlie:heatedvfiuid=me*dium i'nto and'through the housing: in: heat; transfer'relation, with-the cylin denand'fromrthehousing into the outlet endof and through thecylinder iniheat: transfer. relation: to-Ithe; material.passing-therethrough, and means:

connected to the inletend ofzthe cylinder opera-t tive' toinducettthe flow of the heatedfiuid medium from the source there-ct into. and" through: the.

. ltousin giandrfrom the housing into the outlet: end.

cal! and through: the :cylinder.

2-: lln. material dryingapparatusan elongated:

cylinder. orieencl" constituting the inlet and the;

opposite: end: the; outlet for the material" to be dried, means" to rotatably support the cylinderwtthintheopposite ends a. distance substantially canalto: one quanterthe; length of the cylinder, a: source: oi; heated gases, a housingv having chambers. enclosing theintermediate portion of the:

1 cylinder between. the supporting: means and: the

end portions of the cylinder at the outer: sides; of the supporting: means withthe material inlet endotthecylind e-r opening to the-exterior ofthe housing and the outlet end. opening to thenhouse ing, and saidhousing having, arch-portions con necting the housing chambers in communication with each other spaced above the cylinder relative to the cylinder supporting means, means to conmeet the housing chamber disposed relative to the material inlet end of the cylinder to the source of heated gases, and means for inducing the flowof the heated gases from the source thereof into and through the housing chambers and from the housing into the outlet end of and through the cylinder.

3. In material drying apparatus, an elongated cylinder having a material inlet at one end and a material outlet at the opposite end adapted for the passage therethrough of the material to be dried, means to rotatably support the cylinder within the opposite ends a distance substantially equal to one-quarter the length of the cylinder, a housing including chambers enclosing the portions of the cylinder between and at the outersides of the supporting means with the material. inlet end of the cylinder opening to the exteriorof the housing chamber at said end of the cylinder and the material outlet opening to the housing chamber at said outlet end of the cylinder and. having portions connecting the chambers with. each other above the portions of the cylinder at which the cylinder is supported, a source of heated gases connected in communication with the housing chamber at the inlet end of the cylinder, means connected to the inlet end of the cylinder through which to feed material into the cylinder, and means connected to said latter means operative for inducing the flow of the heated gases from the source into and in a circuitous passage through the housing chambers in heat transfer relation with the cylinder and from the housing through the cylinder from the outlet end to the inlet end in heat transfer relation with the material in the cylinder.

4. In material drying apparatus, an open end cylinder, one end constituting the material inlet to and the opposite end the material outlet from the cylinder, means to connect driving means to the cylinder to rotate the same and rotatably support the cylinder connected to the cylinder within the outlet end thereof, means to rotatably support the cylinder connected to the cylinder within the inlet end thereon, a housing including connecte cl chambers enclosing the portions of the cylinder between and at the outer sides of thesupporting means and having portions disposed above the portions of the cylinder at which it is supported connecting the chambers in communication with each other with the chamber at one end of the housing in communication with the outlet end of the cylinder, a combustion chamber connected in communication with the housing chamber at the inlet end of the cylinder, suction means, and means in communication with the suction means connected to the material inlet of the cylinder adapted for feeding material to be dried into the cylinder and for connecting the suction means to the cylinder to induce the flow of the gases of combustion from the combustion chamber through the housing chambers in a circuitous passage transversely of and in heat transfer relation with the cylinder and from the housing chambers into the material outlet end of and through the cylinder to the material inlet end in heat transfer relation with the material therein.

5. In material drying apparatus, an elongated cylinder, one end of which constitutes the material inlet to and the opposite end the material outlet from the cylinder, rotatable supporting means for the cylinder spaced inwardly from the opposite ends of the cylinder adapted to support the cylinder to rotate about its axis, a furnace, a housing comprising chambers enclosing the portions of the cylinder between and at the Outer sides of the supporting means and portions above the cylinder relative to the supporting means connecting the chambers at the outer sides of the supporting means in communication with the chamber between the supporting means, with the material inlet end of the cylinder opening to the exterior and the cylinder outlet opening to the interior of the housing, the housing chamber at the inlet end of the cylinder having an inlet for heated gases to the lower portion thereof, means connecting said inlet to the housing in communication With and for the flow of the hot gases of combustion from the furnace into the housing, a bafde extended downwardly from the top of the chamber between the cylinder supporting means to cause the gases in said chamber to flow downwardly and then upwardly transversely of the cylinder in said chamber, means connected in communication with the material inlet end of the cylinder adapted for connection of means for feeding material therethrough into the cylinder, and suction means connected to said latter means in communication with the material inlet of the cylinder operative for inducing the flow of the hot gases of combustion from the furnaces into the inlet of and through the housing and from the housing into the material outlet end of and through the cylinder.

6. In material drying apparatus as claimed in claim 1, nozzles mounted in and opening to the housing and outlet end of the cylinder, adapted to be connected to a source of and discharge a non-combustible medium into the housing to quench and extinguish material burning in the cylinder.

7. Material drying apparatus as claimed in claim 5, wherein the housing has an opening to the atmosphere through the end wall at which the material, outlet end of the cylinder opens to the housing for admitting air into the housing, and means for regulating the area of and intake of air through said opening into the housing.

8. In material drying apparatus as claimed in claim 2, a hopper in the housing at and adapted to receive material discharged from the outlet end of the cylinder and having an outlet opening through the bottom of the housing.

9. In material drying apparatus an elongated cylinder, one end constituting the inlet and the opposite end the outlet for the material to be dried, means to rotatably support the cylinder within the opposite ends a distance substantially equal to one-quarter the length of the cylinder, a source of heated gases, a housing having chamhers enclosing the portion of the cylinder between the supporting means and the end portions of the cylinder and at the outer sides of the supporting means with the inlet end of the cylinder opening to the exterior and the outlet end opening to the housing and said housing having arch portions connecting the housing chambers in communciation with each other spaced above the cylinder relative to the cylinder supporting means, means to connect the housing chamber at the inlet end of the cylinder to the source of heated gases, means for inducing the flow of the heated gases from the source thereof into and through the housing chambers and from the housing into the outlet end of and through the cylinder, an annular screen fixed to and extending from the outlet end of the cylinder within the housing having an inwardly extending annular flange at the outer end and adapted to receive material from the cylinder and discharge material within a predetermined size therethrough, a hopper in the housing having an outlet opening to the exterior of the housing adapted to receive material discharged through the screen, a chute opening to and within the flanged end of the screen having an outlet through the end wall of the housing, a pivotally supported closure adapted to have closing movement toward the outlet of said chute and normally moving to closing position by gravity, and lifters within and rotatable with the screen by the rotation of the screen with the cylinder operative to lift material on the screen from below the axis of the screen and deliver the same into said chute, and the weight of said material delivered into the chute adapted to actuate the closure for the chute to open position and discharge said material from the chute.

10. In material drying apparatus, an elongated cylinder, one end constituting the material inlet to and the opposite end the outlet from the cylinder, means to rotatably support the cylinder at points intermediate the transverse center and the opposite ends of the cylinder, an annular screen fixed to and extending from the outlet end of the cylinder, a source of a heated fluid medium, a housing including a series of chambers connected in communication with each other enclosing the intermediate portion of the cylinder between the supporting means and the end portions of the cylinder at the outer sides of the supporting means with the material inlet end of the cylinder opening to the exterior of the housing chamber at the inlet end of the cylinder and the screen end opening to the housing chamber at the outlet end of the cylinder, and said housing having an inlet to the chamber at the inlet end of the housing connected to and adapted for the flow of the heated fluid medium from the source thereof into and through the housing chambers in heat transfer relation to the cylinder and from the housing into the screen end of and through the cylinder, means connected to the material inlet end of the cylinder operative to induce the flow of the heated fluid medium from the source thereof into and through the housing and from the housing through the cylinder, a hopper extended into the screen with the inlet end disposed below the axis of the screen and having an outlet to the exterior of the housing, a closure for said hopper outlet normally assuming outlet closing position, and lifters within and extending transversely of the screen adapted to lift material from below the axis of the screen and deliver the same into said hopper and said material adapted to move by gravity through the hopper and the weight thereof actuate the closure for the hopper outlet to open position and discharge said material through the hopper outlet.

11. In material drying apparatus, an elongated cylinder, one end constituting the material inlet to and the opp site end the material outlet from the cylinder, means to rotatably support the cylinder at points within the opposite ends a distance equal substantially to one-quarter the length of the cylinder, means connected to the inlet end of the cylinder to feed material into the cylinder adapted to be conveyed through the cylinder by the rotation thereof, a source of a heated fluid medium, a housing including chambers enclosing the portions of the cylinder between and at the outer sides of the supporting means and having portions connecting the chambers in communication with each other above the cylinder supporting means with the inlet end of the cylinder opening to the exterior of the housing and the outlet end terminating within the housing, said housing having an inlet to the bottom portion of the housing chamber enclosing the inlet portion of the cylinder connected to and for the entrance of the heated fluid medium from the source thereof and circulation of the heated fluid medium through the housing chambers in heat transfer relation with the cylinder and from the housing into the outlet end of and through the cylinder in heat transfer relation with the material therein, suction means connected to the inlet end of the cylinder for inducing the flow of the heated fluid medium from the source thereof into and through the housing and cylinder, air inlet ducts at the side of and opening to the bottom of the chamber enclosing the inlet end portion of the cylinder and air inlets in the top of the ducts opening to the atmosphere, adjustable closures for regulating the area 01' said latter air inlets, an air inlet member in the end wall of the housing opening to the atmosphere and the housing chamber enclosing the outlet end of the cylinder, and an adjustable closure for said latter inlet member for regulating the area thereof.

JOSEPH E. KENNEDY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 138,823 Strawn May 13, 1873 501,539 Scharf July 18, 1893 636,928 Snyder et a1. Nov. 14, 1899 808,481 Schaffer Dec. 26, 1905 1,044,084 Rundle Nov. 12, 1912 1,123,222 Behnke et a1 Jan. 5, 1915 1,212,264 Rosendahl Jan. 16, 1917 1,431,037 Prindle Oct. 3, 1922 1,477,823 Grindle Dec. 18, 1923 1,517,596 Stebbins Dec. 2, 1924 1,623,540 Hunt Apr. 5, 1927 1,841,625 Musso Jan. 19, 1932 2,093,446 Huyett Sept. 21, 1937 2,193,163 Chenoweth Mar. 12, 1940 FOREIGN PATENTS Number Country Date 16,294 Great Britain Aug. 10, 1905