US2941927A

US2941927A - Charcoal retort

Info

Publication number: US2941927A
Application number: US612737A
Authority: US
Inventors: Wilkins John Riley
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-09-28
Filing date: 1956-09-28
Publication date: 1960-06-21
Anticipated expiration: 1977-06-21

Description

June 21, 1960 J. R. wlLKlNs 2,941,927

cHARcoALREToRT Filed Sept. 28, 1956 4 Sheets-Sheet 1 1.08 FIG. u lo) 2O 28 CHARGING PRE-HEATING CARBONIZING PRECOOLING QDISCHARGE JOHN R. WILKINS ATTORNB June 2l, 1960 J. R. wlLKlNs 2,941,927

CHARCOAL RETORT Filed Sept. 28, 1956 4 Sheets-Sheet 2 INVENTOR JOHN R. WILKINS VA y J. R. WILKINS CHARCOAL RETORT June 21, 1960 Filed Sept. 28, 1956 4 Sheets-Sheet 3 INVENTOR JO HN R. WILKINS i ATTORNEYS J. R. wlLKlNs cHARcoAL RETORT June 21, 1960 4 Sheets-Sheet 4 Filed Sept. 28, 1956 INVENTOR JOHN R. WILKINS ATTORNEYS nite States Patentt O CHRCOAL -RETRT Y John Riley Wilkins,P.0. Box 307, Steelville, Mo. Filed Sept. 28,'L 1956, Sel'. N0. 612,737A

2 Claims. (Cl. 20L-9.8)

This invention relates-toY lthe-carbonizati'on' of wood' and more particularly to improvedA apparatus and method of making charcoal. One of the problems heretofore presentin the carbonization of wood is thata considerable amount of the -heat requiredto carbonize'tlie-woo'd' is lost or otherwise dissipated outside the retortlsothatl the' heat is lot eciently utilize'd'todo 'the Work offmakingY charco Accordingly, it is` an object of the present invention to provide a charcoal retort having improvedY means for tiring the wood or other material which is `to b e carbonized, which means is highly eicient and results in a minimum of heat loss so that a maximum amount of the heat generated is utilized in the carbonizing of the Wood.

Another problem in producing charcoal resides in the cooling of `the carbonized wood after the samehas been heated suil'lciently to drive oli the distillation products. Unless the temperature of the charcoal is reduced below that capable of firing' the same upon contact with oxygen, ignition will occur and, consequently, reduction in the quality of the charcoal results.

It is, therefore, another objectof the invention to provide a retort of the type described having improved means for cooling the carbonized material under accurately controlled conditions so as to eliminate thev possibility of ignition by maintaining the carbonized material out of -contact wth oxygenaconta'ininggas until thecarbonized material has been cooled to alow enough tempera-ture to precludeignition kat atmosphericcon'ditions.'

A still further object of the present-invention is the provision of a charcoal retort of the' type described which is substantially continuous in operation, which insures an .accurate temperature control of the charcoal during carboniztion and which insures the coolingof the; charcoal with a minimum danger of ignition.

A still further object of the presentl invention is the provision of -a charcoal retort of the type described having improved means for handling the charges as they move through the retort chambers.

Still another object of the present invention is the` provision of a novel method of making charcoal which embodies the steps of continuously introducing charges of.

-discharging the charges into a receiving chamber wherel they are finally cooled while substantially preventing any contact therewith of an oXygen-containing' gas.

A further object of the present invention is the provii Ptented June 21, 1960 ice 2f Still? anothen object;v ofi the: invention.y is; the provision of afzretortoftthetypezdescribed.A havingl improved-.means for'recoveringrthez combustible gases driven, oil iirornJ the Woodilorotherr material duringcarboni'zation, thereof; and utilizing the combustible; gases to. provideheat .for further car-bonization.

Still anotheriobjectiofgthe inventionisthe provision-of az retort of: the. type .described having; improved means for dischargingY successivexcharges from. the heating ,chamber lafter carbonization and some cooling hasbeencompleted.

These-` and` other. objectsVA will become more. apparent during the; course of-ftheiollowing detailedV description and appendedfclaims.

The. invention may; bestbe understood. with:V reference to theY accompanyingdrawings: wherein an` illustrative embodiment is shown.

Inthedravvings:l

Figurel isfa .somewhatschematic side. elevational View ofl a retort embodying theaprinciplesof .the present. invention;

Figure4 2 is, an, enlarged. end. view of` the; retort. with parts broken away lfor'thepurpose offclearer illustration;

Figure 3 is ar vertical sectional View of the entrance chamber-of they retort: illustrating the, manner in lwhich successive -charges are', vmoved `from Y.the :entrance chamber into=theheatingchamber of the retort;l

Figure 4 isa side elevational view of the discharge tend of the. retortwith parts. broken away to;l illustrate the manner in which successive:chargesareVr removedfrom thefiringchamber and discharged ,into the; cooling.4 chamber; and' Figure 5 is across-sectional ,view takenalong lineSg-S of Figure 4.

Referring now more-particularly to. the` dra-,vs fings, lthere is shown in Figure l4 -a schematic view of a retort, generally' indicated. at 10,V embodying, the principles.- oithe present invention. The retort is preferably oontinuous--v in nature and disposed in a straightline softhat.' Successive charges of-.wood or. other materialto-becarbonizedfmay be introduced into the ifront. end: and.v discharged. after carbonization has been completed from the rearA end thereof. Of course, while itis preferred to construct the retort ina straight relationship it will be apparenti that acircuitous-path may be employed, if desired. Ingeneral, the retort isv divided into four separatecompartments or chambers. Preferably, the rst. three compartments areV in general longitudinal. alignment with each. other while theflatter two. may bev vertically stacked, asv will hereinafter be more.. fullyY described.

Theforwardend of the retort deiines anentnancecompartmentor chamber, 1-2 which is arranged to receivesuccessive bins or` hampers 14 charged with suitably formed wood or other. material to be: converted into charcoal. Figure 3 illustratesv generally. theconstruction ofr the bins or hampers which are preferably handled when outside the retort by wheeledcarts or dolliesY 16. Disposed wit-hin the entrance chamber` 12 is a meansgenerally indicated at 18, for receiving theV hampers and for moving the lsame into a central tiring or heatingcompartment or chamber 20 of the retort. The. entrance chamber V12 is, closed. at its forward end'v by doors` 22, and at vertically movable door 24 is disposed' at. its other endr between the., entrance chamber 12 land ringl chamber 20. The. means 18is arranged to move successive charged hampers. from the entrance chamber whereinthey are supported bythe dollies l1'6Y through the door. 24. land into thef heating or tiring chamber 20. Inside the firing, chamber there. is. plolvi'ded suitable heating means, generally indicated` at 2.6,fwliich is arranged so that successive charges during their. travel through the firing` chamber are yfirst preheated, then carbonized and iinally precooled to aY substantial extent. After the precooling of'- successive charges has been faccomplished, the latter are moved out of the firing chamber and into a discharge compartment or chamber, generally indicated at 28. A means is provided within the discharge chamber 28 for opening and closing off the iring chamber with respect to the discharge chamber, for receiving the precooled carbonized wood-containing hampers from the tiring chamber and moving the same into the discharging chamber, and for discharging the contents of the hampers into a receiving and cooling chamber or compartment, generally indicated at 32. The opening and closing means is also operable to discharge the empty hampers from the discharge chamber at the rear end of the retort.

In general, the operation of the retort is carried on substantially continuously so that when a charged hamper 14 is -moved from the entrance chamber 12 into the ring chamber 20 nby the operation of the means 18, a

hamper containing carbonized and precooled material will be simultaneously moved out of the rear end of the tiring chamber 20 and into the discharge chamber 28. The means 30 in the discharging chamber then dumps the charge from the hamper and discharges the empty hamper at the rear end of the retort.

The retort is preferably arranged so that the forward end is at an elevation slightly higher than the rearward end. That is, the retort is Iprovided with a `gradual slope of the order of -one degree which facilitates the movement of the hampers therethrough. Of course, the operation of the retort can be carried out on any time cycle,

but of primary significance is the fact that the entire operation is automatic so as to reduce to a minimum the requirements for attendants. The hampers which have been passed through the firing chamber are subsequently handled in a substantially oxygen-free chamber by means capable of dumping the carbonized and precooled contents thereof into a cooling chamber which likewise is maintained substantially free of oxygen. This discharging operation could not 'be accomplished manually since the temperatures present would prevent an attendant from gaining access thereto. Hence, the present arrangement insures that the carbonized material will be cooled to a suiciently low temperature, without ignition, so that when the same is finally brought into contact with oxygencontaining gas, ignition is no longer possible.

Referring now more particularly to Figure 3, vthe construction ofthe entrance chamber 12 of the retort is shown in detail as including vertical sidewalls 34 connected at their upper ends by an upper wall 36. The floor of theV chamber is preferably provided with tracks 38 for receiving and guiding the dollies 16. The dollies 16 may be of any suitable construction and, as shown in Figure 3, include a skeletonized frame 40 mounted on wheels 42. Suitably mounted on the upper surface of the frame 40 is a plurality of longitudinally spaced rollers 44 having outer anges 46 thereon disposed to receive and guide the lower surface of the hampers 14.

The hampers 14 may also be of any suitable construction and, as shown, include a skeletonized box-like frame 48 having upper transverse end members 59 extending across the forward and rearward extremities thereof.

Extending upwardly from the upper end of the skeletonized frame 48 at a position spaced inwardly from each end thereof -is a pair of upright rigid members 52'carrying rollers 54 on the upper ends thereof.

The means 18 comprises a huid pressure-operated ram unit 56 suitably mounted on the exterior of the chamber 12, as by bracket 57, in a position above the forward door 22 thereof. The ram unit 56 includes a plunger 58 which extends through the forward wall of the chamber 12 above the door 22 and into the chamber. Pivotally mounted on the rearward end of the plunger 58 is a hamper-engaging arm or member `60. A spring 62 is connected between the element 60 and the plunger so as to resiliently urge the latter against a stop element 64 rigidly secured to the plunger S8. In this manner, a fully charged hamper moved into the entrance chamber 12 through the doors 22 will engage the element 60 and move the same Irearwardly until the hamper reaches it fully extended position within the charging chamber. At this point, the trailing -transverse member S0 of the hamper will have passed beyond the element 60 and the spring 62 will act to move the latter into a position 'behind the transverse member 50. This position is illustrated in Figure 3 and it will be noted that upon actuation of the fluid pressure-operated ram unit 56, as by suitable controls, not shown, the hamper 14 may be moved from the entrance chamber 12 into the heating or firing chamber 20 when the door 24 is open.

The door 24 is mounted for vertical sliding movement in an apertured partition `66 separating the

chambers

12 and 20. Mounted on each side of the door 24 is a vertically extending rack 63. Each rack is engaged by a kpinion 70 mounted on a common shaft 72 rotatably supported by any suitable means above the upper wall of the entrance chamber 12. Ihe pinions 70 may be rotated by any suitable means, such as a reversible motor 74, connected to drive the shaft 72 as by a pair of sprockets 76 and a cha-in 78 trained thereabout. It will be understood that 'by actuating the motor 74 selectively in either direction, the door 24 may be selectively moved into an upper open position or a lower closed position.

The heating or firing chamber 20 preferably comprises side wails 80, each of which includes an exterior plate 82 of metal or the like and an interior wall 84 of brick or other refractory material and an intermediate layer 86 of a suitable insulating material. An upper Wall 88 extends between the upper ends of the side walls 89 and includes an exterior plate 90 and interior transversely extending I-beams 92 or the like mounted on the upper ends of the interior walls 84. A layer of insulation 94 is mounted between the beams 92 and the exterior plate 90. Extending downwardly from the I-beams 92 is a plurality of hangers 96 which support a longitudinal housing 98 extending throughout the entire firing compartment 20. The housing 98 is rectangular in cross section and has a pair of transversely spaced tracks 100 mounted on the interior surface of the upper wall thereof. The tracks 100 may be of any suitable construction and (as shown, are in the form of conventional i-beams which provide channels within which the rollers 54 of the hampers 14- may ride. The tracks lf3@ thus serve to support the hampers in the tiring chamber for movement through the housing 98 thereof.

As best shown in Figures l and 2, the heating means 26 preferably comprises a plurality of gas burners 102. These burners are disposed in the lower portion of the firing chamber below the housing 98 therein, which lower portion terminates intermediate the ends of the chamber 20, as shown in Figure 1. r[he terminal end of the lower portion of the chamber is open to the atmosphere, as at 104, for the introduction of air sufficient to support combustion of the burners. The forward end of the retort adjacent the entrance door 22 includes a lateral passageway 106 which leads to a stack 10S through which the com-bustion air in the tiring chamber may discharge.

Of course, the placement of the burners with respect to the firing compartment will vary in accordance with the capacity of the retort. As shown, the first burner is disposed approximately midway between the ends of the chamber. There are two additional burners provided which are spaced toward the discharge end of the cham- *ber and disposed within the area defined by the irst burner and the opening |104 in the lower portion of the compartment. Of course, the heat generated by the burners will be Imost intense in the area immediately above the burners and lSince the ow of heated air is toward the forward end of the ring chamber, the rear end of the chamber will have the lowest temperature, with the temperature of the forward end gradually diminishing towardthefstaclc. In this mannen; the fresh charges. entering the tiring chamber through the door 24rwil1 be preheated during their movement through the housing 98'for approximately one-half of their travel. This rst areaconstitutes a-preheating area'where the sap. ormoisture in the wood or material being treated is driven off. Next, the charges enter a canbonizing. area which is: immediately abovethe burners whereY the products. of distillation are driven off. Sincefthe pressurecreated--by the heat Within the housing- 98 is greater than atmospheric pressure, the products of distillation can. be conveniently directedto the burners 102, as by pipes or. conduits 110. In this manner, the combustible gases drivenoff inthe carbonizing processare utilized to tire-the burners, thus greatly increasing the. eiciency ofthe retort.l After. the canbonizing area immediately above the burners 102 has been passed, thecarbonized chargesmove toward .the rear endof the-.fringchamber which constitutesY aprecooling area thereof. During this portion of. travelthe temperature ofthe charges is substantially reduced..

The discharging cham-ber 28 comprises a substantially semi-cylindrical vertical wall 112 of any suitable construction extending from opposite sides ofthe. rear end ofthe tiring. chamber and having an upper. wall 114 covering. the same. Extending along the portion ofthe cylindrical wall112 adjacent the end of lthe firing.V chamber 20 are upper and lower closure guide elements 116 within. which `an arcuate closure member l118 is slidably mounted. The closure member 1:1Svincludes an opening 120. which isarranged'to 'be moved between a position adjacent the rear end ofthe tiring compartment to permit discharge of the hampers therefrom and' a position adjacent an. openingV 122 in the wall 112 which enables the empty hampers to be discharged from the chamber 28.

As best shown in -Figure 4, the closure member 118 includes rigid arms 124 extending radially therefrom to a verticalY shaft. 126 pivotally supported at itslow'er end on a Ibearing block 128 or the like suitably mounted on the iloor of the discharge chamber. At the upper end ofthe shaftV 124, the upper walll1f12,A is provided` in a position Ito engage theV inner periphery of" the ring` plate 132. In this manner, the upper end of -t-he shaft is mountedfor pivotal movement anda substantiallyairtight seal impervious to heat is formed at' the point where the shaft extends out of the discharger chamber.

The shaft 126 and hence the closuremember 118 is.

selectively moved in either direction =by' any suitable means, such as a reversible electric motor'1'40 secured to the exterior of the upper wall as bybracket 142. The drive shaft of the motor 140 is provided withk a pinion 144 arranged to -drive a large spur gear'146 or the like rigidly mounted on the upper extremity of the shaft 126.

The central portion of the shaft`126f is formed with a v horizontal aperture 148 and a horizontal sleeve 150 is rigidly'secured, asby bracing 152, to the shaft 12'6'in Yalignment with the aperture 148 and extends'towardithe closure member 118. A screw conveyor 154'hasv itsrearward. endA portion journaled within the sleeve 150` and shaft aperture 148 and its forward end extendingY to a point adjacent the closure member opening120.V The screw conveyor 154 is thus mounted' forpivotal movementwiththe shaft 126 and is rotated about its own axis: by, anyv suitable means, rsuch as a reversi-ble electric motor. 156-fixedly mounted. on the gear 146. I'he drive shaft of the motor 156is. provided with a pinion 158 V.Which meshes with `a cooperatinggear 160-xed to the upper end of. a verticalr conveyor drive shaft 162. The shaft! 162 extends. downwardly through suitablegasketed apertures formed-inthe gear 146 and plates 136 to a point adjacent therear. extremity of the yscrew conveyor 154. The lower end portion of the conveyor drive shaft- 162 is journaledwithin suitable bearings 164 secured to the shaft126-and itsflower extremity has a bevel gear 166 xedtheretox which:v meshes with a cooperating hevel gear l168 fixedA` to the rear extremity of the screw conveyor. l

Again, itv willbeunderstood that by selectively operating the motorA 156 the screw conveyorp154 may be selectively' rotated in either direction. This conveyor is adapted to receive the leading transverse member 5t) of eachV successive hamper and, through its own rotation, to move thesamef into` the discharging chamber in conjunction with its. movement. out of the ring chamber as av result-ofsacharged hamper being introduced into the forward endf'rofthechamber.. Itwill be noted that the position ofthesupporting rollers of'each hamper is such thatthe-trailing. end. of the same will leave the tracks within thehousing before the trailing transverse member 50 reaches a position. sufficient to engage the screw conveyor 154. Consequently, as the trailing, rollers. leave the tracks, the trailing end of the hamper will swing downwardly with the connection ofthe leading transverse member with the conveyor acting as a pivot. In this manner, the fired contents of each hamper are dumped-into a funnel-shaped bin 170 suitably mounted below the discharging'chamber at its forward end and leading to. the-v receiving land cooling chamber 32.

rA rotary valve assembly, generally indicated at 172, is disposed. below the pin 170 so as to control the entrance of the heated4 charcoal. into the receiving and cooling chamber'v 32. As best. shown in Figure 4, the assembly 172 comprises a substantially cylindrical housing 174 having. anupper opening 176 communicating with the lower endof the bin. 170 and a lower discharge opening`A 178i communicating with the chamber 32. Journaled withinithe housingis a rotatable member 180 including av pair of spaced radial walls interconnectedby a peripheral wall `so asf to deiine a wedge-shaped pocket 182. The member180 is rotated by any suitable means, such as a motor 184 connected with the shaft thereof, as by abelt 186'andpulleys 188 and 190. l

TheI member. 180 is preferably rotated continuously so that. it.will. make av complete revolution each time au hamper` is. dumped. It will be noted that the construction of the rotary member 180 is such that whenV the pocket182; is in. communicationwith the upper housing opening 176, the peripheral wall closes the discharge opening1178 and conversely, when the pocket is in communication with the lower opening, the upper opening is closed. The pocket 182 receives a full load of dumped materialthrough the upper opening and during the rotation of the member 180, the load is passed through the` lower openingand into chamber 32 when the pocket 182 moves into communication therewith.

Thereceivingand cooling chamber may be of any suitable construction and as schematically illustrated in Figure. l, the floor ofthe chamber is inclined downwardly from the valve assembly 172 so that successive loads from thelatter will move downwardly by gravity. The lower end ofthel chamberis provided withl suitablefmeans (not shown) for permitting the cooled charcoal to beremoved `therefrom .withoutsubstantial introduction of air. For example, a valveV assembly similar to the assembly 172 may be -utilizedfor this purpose. Where gravity feed is impractical, a` drag chain may be provided inthe chamber 32for..rnovingsuccessive loads from the valve assembly 1.72 tothe discharge endV of the chamber 32.

Theretort ofthe present invention is adapted to be continuously operated. andtheY time interval in which successive charged. hampers are introduced intov the retort variesin accordance with the capacity desired. It will rear end of the firing compartment.

be understood that the empty hampers are first loaded with suitable charges of material, such as wood or the like, which are to be made into charcoal. Durin'gthe loading of the hampers 14, the dollies 16 are utilized to handle the same outside the retort so that they may i be readily introduced therein through the entrance chamber 12. A freshly charged hamper 14 is moved into the entrance chamber 12 on a supporting dolly 16 by opening doors 22 and moving the dolly inwardly on tracks 38 until the leading end engages partition 66. During this movement, the hamper-engaging member 60 is pivoted out of the way and spring urged back into anoperative position capable of engaging the trailing transverse member t) of the hamper. Doors 22 ,are immediately closed after the entrance of the hamper. Eefore actuation of the ram unit 56, the door 2.4 must be opened and, hence, motor 74 is actuated for this purpose. lt will be noted that the manner in which the hampers are moved through the housing 98 is by interengagement with each other and, hence the movement of a newly charged hamper into the lforward end of the chamber will also result in the movement of a hamper containing carbonized and precooled charges out of the Consequently, the closure member 118 of the discharging compartment must be moved from its normally closed intermediate position into a position in which the opening 12) is aligned with the rear end of the tiring chamber. Consequently, the motor 140 of the means 30 is simultaneously actuated with the motor 74 so that both the forward and rearward ends of the tiring compartment are open.

After door 24 is opened, the hydraulic ram unit 56 is actuated so as to move the plunger 58 thereof and,`

hence, the member 6@ into engagement with the hamper. This movement of the fluid-operated ram urLt 56 moves the newly charged hamper 14 into the firing compartment and the hamper containing a carbonized and precooled charge out of the rear end thereof. It will be noted that the leading rollers 54 of the hamper in the entrance chamber are positioned with respect to the leading end of the hamper so that they will enter the adjacent ends of the tracks 100 before the center of gravity of the hamper moves beyond the leading edge of the dolly 16. That is, the weight of the hamper 14 is supported by the dollies until the leading rollers 54 engage within the tracks. Further movement of the fluid-operated ram unit 56 will also engage the trailing rollers 5d within the ends of the tracks 100. In this regard, it will be noted that the position of the trailing rollers with respect to the trailing end of the hamper is such that they will enter the ends of the tracks before the trailing end of the hamper leaves the leading end of the dolly. That is, the dolly serves to support the trailing end of the hamper until the trailing rollers 54 enter the tracks 11MB.

At the same time that the ram unit 56 is actuated to move the newly charged hamper 14 into the tiring chamber, the motor 156 controlling the screw conveyor 154 is also actuated so that when the leading rollers 54 leave the ends of the tracks i! the leading transverse member 50 will fall on the conveyor 154 and be moved rearwardly by the rotation thereof. In this regard, it will be noted that the leading transverse member 50 is disposed ahead of the leading rollers 54 thus enabling the same to move into an overlying position while the hamper is supported in a horizontal position by the engagement of the lrollers within the track. Conversely, the trailing rollers are disposed ahead of the trailing transverse member so that they will leave the ends of the tracks before the trailing transverse member will have moved into an overlying position with respect to the screw conveyor 154. In this manner, as was briey noted above, the trailing end of the hamper is allowed to swing downwardly, with the engagement of the leading trans- 8 verse member 50 with the screw conveyor acting as a pivot', and dump the contents into the bin 170. It will be understood that the leading transverse member 50 may be formed with suitable central U-shaped portions (not shown) or the like which would center the hamper thereon and effectively prevent lateral tilting thereof.

When the newly charged hamper has been moved completely into the tiring chamber, that is, at the end of vthe ram unit stroke, a suitable means, such as a switch or the like (not shown), is engaged which serves to Vreverse the operation of the ram unit and, hence, retract the same and at the same time reverse the operation of the motor 74 so as to effect closure of the door 24.

Simultaneous with this movement, the hamper in the discharge chamber moving on the screw conveyorv 154 engages a suitable means, such as a switch or the like (not shown), when it reaches an inner limiting position on the screw conveyor. This switch serves to shut off the motor 156 or at least reverse its operation and also to actuate vthe motor 140 so as to pivot the shaft 126 in a counterclockwise direction as viewed in Fig. S. The initial portion of the movement of the shaft 126 will effect the closure of the` rear end of the firing compartment by the l closure member 118 and upon further movement thereof the opening 120 registers with the opening 122 to permitrthe hamper to be discharged therethrough. When `the shaft has been rotated into its limiting position, as shown in dotted lines in Figure 5, another switch or the like, is actuated which de-energizes the motor and again energizes the motor 156 in reverse direction so as to operate the screw conveyor 154 and, hence, move the hamper out through the opening 122. At the end of this movement another switch is actuated to move the shaft and closure member to its normally closed position intermediate its limiting positions.

From the `above it can be seen that for each newly charged hamper which 4is moved into the forward end of the firing chamber, there is a hamper containing carbonized and precooled material leaving the rear end of Athe chamber. In this manner, the charges are moved substantially continuously through the charging chamber and are handled at each end thereof by means which can be made to operate fully automatic by the use of a suitable electrical circuit or the like, as is well known in the art. As was briey noted above, the operation and position of the burners in relation to the flow of air suicient to 'support combustion is such that the hampers disposed in the forward portion of the tiring chamber are preheated so that the sap and other moisture, in the case of wood, will be driven otf before the charges are moved into a position directly above the burners where the heat is most intense. The construction of the housing within the walls of the ring chamber is such as to most efficiently transfer the heat of the burners to the charges of the hampers. The walls of the chambers are highly insulated and a good circulation around the entire housing 98 is obtained. The walls of the housing are preferably good heat conductors, but are also imperforate so that the pressure within the housing will be maintained v somewhat higher than in the lower portion of the charnber where the ow of combustion air occurs. With this arrangement a very rapid heat transfer is obtained and the gases discharging through the stack 10S do not carry otf a substantial amount of heat which would be addi- ,Y tionally useful in carbonizing the charges.

The arrangement also makes possible the recovery of combustible gases driven olf from the charges during the carbonization thereof. As was noted above, the carbonizing of the charges occurs when the same are moved through the area of the housing disposed directly above the burners. Since the pressure within the housing is greater than the pressure existing in the lower portion of the chamber, the combustible products of distillation in the form of gases or the like may simply be directed to the burners through suitable conduits connected between the burners and the interior of the housing. f course, with this arrangement a substantial saving in the amount of fuel utilized to heat the charges and carbonize the same is effected. After the hampers move past the area within the chamber directly above the burners, the temperature is reduced somewhat and the carbonized material is allowed to cool while within the tiring chamber. This precooling of the carbonized charges before discharge from the tiring chamber is significant in that the gas medium contained within the housing 98 is substantially free from oxygen and, hence, combustion of the carbonized material is precluded. When the hampers reach the rearward end of the tiring chamber the'temperature ofthe charges therein has been substantially reduced. However, if placed in contact with the atmosphere, combustion would result due to its temperature and the oxygen in the air. The discharge chamber 28 is maintained closed during most of the operation of the retort and when the rear end of the firing chamber is open and communicates therewith, it will be understood that, due to the heat in the tiring chamber, its pressure will be above that within the discharge chamber. Consequently, any ow of gaseous medium between the chambers when they are in communication will be from the firing chamber into the discharge chamber. In this manner, during the normal operation of the retort the discharge chamber is also filled with a gaseous medium which is at most very low in oxygen content, if not entirely free thereof. At any rate, with the -rear end of the firing chamber in communication with the discharge chamber the tendency is for the gaseous medium in the former to flow into the latter. Thus, as the hamper moves out of the ring chamber and into the discharge charnber substantially no oxygen will come in contact therewith. As was stated above, the action of the rotary valve assembly 172 is such as to prohibit free communication between the discharge chamber and the receiving and cooling chamber. Consequently, the carbonized material is cooled to a temperature below which combustion would be caused in the atmosphere, while at all times preventing contact of any gas which would contain suicient oxygen to support combustion. This arrangement insures that a high-grade charcoal will be produced.

It thus will be seen that the objects of this invention have been fully and efectively accomplished. It will be realized, however, that the foregoing specic embodiment has been shown and described only for the purpose of illustrating the principles of this invention and is subject to extensive change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

I claim:

1. In a charcoal retort, the combination comprising: means dening a discharge chamber for the retort including an arcuate wall having a rst opening therein for receiving successive hampers containing fired charges of material to be made into charcoal and a second opening for discharging empty hampers from the chamber; an arcuate closure plate for selectively closing said openings; an upstanding member pivotally mounted about the axis of said arcuate wall and closure plate, means connecting said closure plate for pivotal movement with said member; and means carried by said member for pivotal movement therewith between a rst position in alignment with said rst opening and a second position in alignment with said second opening for handling successive hampers within said chamber, said last-mentioned means being operable in said rst position to engage successive hampers entering said first opening and dump the contents thereof and operable in said second position to discharge successive empty hampers through said second opening.

2. 'Ihe combination as dened in claim 1 wherein said last-mentioned mean comprises a screw conveyor.

References Cited in the le of this patent UNITED STATES PATENTS 297,517 Haldane Apr. 22, 1884 432,939 Hanlon July 22, 1890 687,304 Grondal Nov. 26, 1901 782,953 Dungan Feb. 21, 1905 980,640 Hughes Ian. 3, 1911 1,043,695 Hausell Nov. 5, 1912 1,602,819 Jakowsky Oct. 12, 1926 2,232,116 Koppers Feb. 18, 1941 2,526,459 Cartwright Oct. 17, 1950 2,650,190 Steinschlaeger Aug. 25, 1953 FOREIGN PATENTS 67,850 Austria 1915 157,219 Germany Dec. 29, 1921 250,661 Great Britain Apr. 14, 1925 650,005 France Sept. l1, 1928 23,660 Great Britain July 24, 1935 102,375 Sweden Aug. 26, 1941 68,406 Norway Oct. 16, 1944

Claims

1. IN A CHARCOAL RETORT, THE COMBINATION COMPRISING: MEANS DEFINING A DISCHARGE CHAMBER FOR THE RETORT INCLUDING AN ARCUATE WALL HAVING A FIRST OPENING THEREIN FOR RECEIVING SUCCESSIVE HAMPERS CONTAINING FIRED CHARGES OF MATERIAL TO BE MADE INTO CHARCOAL AND A SECOND OPENING FOR DISCHARGING EMPTY HAMPERS FROM THE CHAMBER, AN ARCUATE CLOSURE PLATE FOR SELECTIVELY CLOSING SAID OPENINGS, AN UPSTANDING MEMBER PIVOTALLY MOUNTED ABOUT THE AXIS OF SAID ARCUATE WALL AND CLOSURE PLATE, MEANS CONNECTING SAID CLOSURE PLATE FOR PIVOTAL MOVEMENT WITH SAID MEMBER, AND MEANS CARRIED BY SAID MEMBER FOR PIVOTAL MOVEMENT THEREWITH BETWEEN A FIRST POSITION IN ALIGNMENT WITH SAID FIRST OPENING AND A SECOND POSITION IN ALIGNMENT WITH SAID SECOND OPENING FOR HANDLING SUCCESSIVE HAMPERS WITHIN SAID CHAMBER, SAID LAST-MENTIONED MEANS BEING OPERABLE IN SAID FIRST POSITION TO ENGAGE SUCCESSIVE HAMPERS ENTERING SAID FIRST OPENING AND DUMP THE CONTENTS THEREOF AND OPERABLE IN SAID SECOND POSITION TO DISCHARGE SUCCESSIVE EMPTY HAMPERS THROUGH SAID SECOND OPENING.