US2505313A - Tobacco curing apparatus - Google Patents

Description

A ril 25, 1950 w. T. WAGONER TOBACCO CURING APPARATUS 2 Sheets-Sheet 1 Filed Oct. 1, 1946 lH V-EZH TOR Wk: IAM 771mm Mao/v52 A TTOR:

April 25, 1950 w. T wAGONER 0 v TOBACCO CURING APPARATUS #Qled Oct. 1, 1946 2 Sheets-Sheet 2 IHVEHTOIQ: WILL/AM Tug/v52 l V/lao/vse Patented Apr. 25, 1950 UNITED STATES PATENT OFFICE TOBACCO CURING APPARATUS William Turner Wagoner, Elon College, N. 0. Application October 1, 1946, Serial No. 700,476

3 Claims. (01. 23753) This invention relates to the curing of tobacco and more particularly to the combination of a drying house and an associated heating system for subjecting uncured green tobacco to the proper temperatures during the curing process.

In the production of flue-cured tobacco, the green uncured tobacco is gathered from the field and suspended within a house where it is subjected to a curing process incurring temperatures ranging upwardly from 85 degrees to 200 degrees Fahrenheit over a period of approximately 100 hours. If high quality tobacco is to be produced, it is very important that the temperatures be carefully maintained within certain prescribed limits during each stage of the curing process in accordance with the response of the particular type of tobacco to heat. If, for example, a bright leaf tobacco is being cured, either an excess or deficiency of heat for a substantial period during the early stages of the process will result in a darkened or discolored cured product.

Heretofore, Various heating systems, such as furnaces, oil burning units, and combinations of furnaces and oil burning units, have been employed in association with drying houses for eifecting the above named process. These systerms have been objectionable, due to the lack of economy or difiiculty in operation, or both. In view of the high temperatures prevailing within the house during certain curing stages, it is very desirable to locate the source of heat on the exterior to avoid the necessity of exposing the attendant to high temperatures for comparatively long periods when regulating the heat. It is equally important that a maximum amount of the heat produced on the exterior be conveyed without loss to the tobacco on the interior of the house. Where furnaces alone or a combination of furnaces and oil burners are employed, the drying house floor absorbs a large portion of the heat produced, thereby impairing the efliciency.

It is an object of this invention to provide a tobacco curing apparatus which will obviate the above-mentioned problems encountered with prior devices of this character.

It is another object of this invention to provide a tobacco curing apparatus wherein the combustion chamber of a heating unit extends inwardly through a wall of the associated drying house inspaced relation to the floor of the latter to prevent an excessive amount of heat radiation from the chamber to said floor.

It is another object of this invention to provide a tobacco curing apparatus of the character described in which a heating element, such as an oil burner, is located in that portion of the combustion chamber disposed on the exterior of the house, and in which a flue system is connected to the inner end of the chamber whereby the heat is uniformly distributed over the bottom area of the house and below the tobacco suspended from above.

It is still another object of this invention to provide a heating unit for a drying house, comprising'a hollow elongated frusto-conical combustion chamber having the larger end thereof disposed on the exterior and the smaller end disposed on the interior of the house, said larger exterior end being provided with a heating means, and the wall thickness of said chamber progressively decreasing in thickness with the increase in distance of any portion of the wall from the heating means.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which:

Figure 1 is an isometric view of a drying house and associated heating system employed for curing tobacco;

Figure 2 is a sectional plan view taken through the lower portion of Figure 1;

Figure 3 is a cross-sectional detail view taken along the line 3-3 in Figure 1, illustrating the means for varying the air draft in the heating system;

- Figure 4 is a vertical sectional detail view taken alongthe line 4-4 in Figure 2, showing the relative positions of the heating system and the suspended tobacco within the drying house;

' Figure 5 is an enlarged vertical sectional view taken along the line 5-5 in Figure 2, illustrating structural details of the combustion chamber and the associated heating means; Y

Figure 6 is a sectional detail view taken alon the lines 66 in Figures 2 and 5;

Figure '71s a sectional plan view taken along the line 1-4 in Figure 6, illustrating the means for vertically adjusting the position of the heating means with relation to the combustion chamberjand' Figure 8 is an'e'xploded isometricview of the combustion chamber and portions 'of the heating means. V

Referring more particularly to the drawings,

' the numeral I 0 broadly designates a drying house, which house comprises sidewalls l l and I2, front wall lt,rear wall I5, floor It, and roof H, the side wall H being provided with a door l8. Suitable horizontally disposed tier poles l9 are supported 3 by side walls H and I2 approximately seven feet above the floor l6, and these poles in turn are adapted to support a number of sticks or holders 28 having uncured tobacco plant leaves 2! suspended thereon in the proper position to be subjected to the curing process.

As previously stated, the curing of bright leaves is usually completed within about 100 hours after he green leaves are gathered from the field, and hence the application of heat is necessary. .Also, the skill with which the attendant maintains the proper amount of heat during the various stages of the curing process determines to a large degree the final color and quality of :the cured tobacco. Furthermore, the ability of the attendant to properly regulate the heat "is dependent upon the sensitivity and efliciency of the curing apparatus, which in the present instance is the combination of a drying house and a heating system.

Accordingly, a pair of horizontally disposed :frusto- conical combustion chambers 26 and 26 .have been mounted in the front wall 14 of the drying house in in spaced relation to'floor it. It will be observed that both of these chambers and their associated heating and fuel supply means are substantially identical. Therefore, only the chamber 26 and "associated heating and fuel supply means will be described, and like reference characters with prime notations added will be applied to corresponding parts of chamher 245 and its associated structure.

The larger end of frusto-conical chamber 26 projects a short distance beyond the exterior surface of the wall It, whereas the smaller end projects into thedrying house a somewhat greater distance beyond the innersurface of this same wall. Chamber 26 comprises an outer metallic Irusto-conical casing 21 which is lined with a suitable heat resistant material :28 such as fire clay. The outerend of metallic casing 2.! is provided with a lug :29 fitting into a slot 3.0 of an inspection door -34, which door is likewise provided with a lining 3-2 of fire clay or other suitable material. In order to maintain the door .3! in closed position, suitable bolts 33.,project from "the enlarged end of theacombustion chamber and are adapted to penetrate holes in the door 3| when the latter is closed. Wing nuts 34 on the projecting portions of bolts 33 serve :to clamp the door in closed position. A handle 3la is provided so that door 31 can be swung about hinge point 2-9; from bold line to dotted line position, as shown in Figure after the wing nuts 34 are removed from bolts 8.3, thereby providing'access to the interior of the chamber from the exterior ofthe-drying house.

.By observing Figures 5 and 8i it will be seen that the lower wall :portion at :larger end-ofchamberzii has zan opening 35=therein disposed adiacent the inspection (door .31.. A heating means-is mounted :ior vertical adjustment iwithin opening :35, :said heating rmeansgpreierably comprising an =oil burner; however, .it :is fitment that go hfil sourcescf ihea't may be -employed. This heating means comprises a heat retaining plate ajzhavl-n an outsidersizesandshapesuhstantially centeri in to opening at, zbllt somewhat ismaller' so as to provide operating clearances 38. The central portion for" plate '31! has ea .:rectangu1ar opening so therein, said plate Ibeing adapted rtoiirestmnfln the upturned flanges iof channelmembcr 14.0 55. thatwopening 39 will becentrally positioned with .irespectztobm nercupP4,!rmountediupomthemhaninel-web :thereioelow. The iinperrrimanortion'qo'f cup M is positioned immediately below the level of the lower surface of the plate 31.

A U-shaped oil supply pipe 45 is provided with vertical leg portions 45a and 45b, the leg 45b leading downwardly from the central interior portion of cup 4!, and through the web of channel member 43. Leg 451) is adiustably clamped in fixed position to a stake 46 by means of hook bolts 41, said bolts penetrating the stake and having wing nuts 48 threadably secured on the projecting ends (Fig.7). By manipulating wing nuts 48, the pipe 45 and the associated burner structure designated by reference characters 31, and 44 may be adjusted vertically in the desired positions to thereby properly space the burner with respect to the ceiling of the combustion chamber and the opening 35.

The upper end of leg b is connected to a regulating valve 58, and leading from this valve is a comparatively flexible supply pipe 5!, the ether end of the latter pipe being connected at E52 to a third supply pipe 53 (Figs. 1 and 2). Pipe 153 communicates with the interior of oil supply tank 54 and has ashut-ofi valve .55 therein.

From the .;foregoing description it is apparent that the valve 5!! is employed to vary the flow of oil from supply tank 154 to the burner cup 4|, and hence the heat generated will vary accordingly. If the flow of oil should be suflicient to overflow the rim of cup 41, at least a portion of the excess will be retained on the web of channel member Ali] by means of beads 40a and 401) where, the surface area of the ;flame will be enlarged. Should the oil also overflow the beads Alto and 4th, the latter overflow will drop into pit .S'Land when ignited will serve to preheat the oil passing through U-shaped supply pipe =35, as well as to supplement the heat produced by the burner 'thereabove.

Leading from the smaller inner end of combustion chamber ,26 in parallel relationship to :side and back walls [2 and I5 is an L,-shaped flue-pipe 58. At, a point approximately at the mid portionof'the back-wall, the pipe 58 is con- 'nected to a pipe -59 which projects forwardly and slightly upwardly to a point outside the front wall M. The projectingendof pipe 58communisates With'the lower endof arsmoke stack 65, said stack extending upwardly to a point above the house :roof 1 l.

In order tovary the draft produced by the flue system and stack -6!! a suitable draft regulator is provided, comprising a cylindrical band 6! having :an opening 'S'latherein. Band ti is rotatably mounted around the stack and has a handle .5!?) by means of which the band is roatated (Figs. '1 and .3) When the opening Sla in the band :is brought into coincidence with the aopening 58a in the stack, the draft in the flue system is correspondingly diminished.

Particular attention is invited to the manner .of positioningcharnber 25 in wall Hi. It will be noted that the longitudinal axis of the chamber is inclined -slightly upwardly as the latter extends into the drying house,'-thereby causing the upper- ;mostiinter-ior portion of the chamber to be substantially horizontal whereas the bottom inside portioni-s inclined'to-a greater extent than the "longitudinalaxis. Such an arrangement permits the 'iheat'produced-at the burner to readily flow intothekfiue pipe system, and also facilitates the removal of ashes, soot and the like from the :chamberwhen the inspection door 3-! isopened.

The-'frusto-conical streamlined shape of the sombustionchamberxis designed with a view of offering a minimum resistance to the flow of the heat currents within the chamber from the exterior to the interior of the drying house. At

the point where the flame is generated the heat intensity is greater, and hence there is a greater necessity for more space, as well as for a thicker fire clay lining 26. At points more remote from the flame, the intensity of the heat decreases; consequently, the thickness of the fire clay and the cross-sectional area of the chamber are correspondingly reduced. Such a construction permits substantially uniform heat radiation over the entire length of the chamber to the interior of the house. When an excess of heat is permitted to radiate from an area of a tobacco curing flue system, the tobacco suspended directly thereabove is also subjected to an excess of heat, resulting in scorching and damage to the cured tobacco.

In the drawings and specification there have been set forth a preferred embodiment of the invention, and although specific terms have been employed they are used in a generic sense and not for purposes of limitation, the scope of the invention being set forth in the following claims.

I claim:

1. In a tobacco curing apparatus, the combination of a substantially horizontally disposed elongated hollow member having the entire inner and outer wall surfaces thereof respectively concentric about and uniformly convergent toward a common longitudinal axis from one end to the other of said member, the pitch of said inner convergent surface being less than that of said outer convergent surface with respect to said axis to thereby define a wall of progressively decreasing thickness from said first-named end to said other end of the member, means providing an opening in the lower portion of said wall and at the first-named larger end of said member, an

oil burner vertically positioned within said open ing along an axis disposed substantially at right angles to said concentric axis, and an access door for normally closing the first-named larger end of said hollow member.

2. Tobacco curing apparatus as defined in claim 1 wherein said inner and outer surfaces of the elongated hollow member are each frustoconically shaped, and wherein said access door, when closed, comprises one side of said opening.

3. Tobacco curing apparatus as defined in claim 1, further comprising a drying house, one wall of said house supporting the larger and smaller ends of said horizontally disposed elongated member in cantilevered positions respectively on the exterior and interior of said house, whereby clear space is provided beneath said exteriorly located larger end for manipulation of the burner and whereby clear space is also provided beneath the interiorly located smaller end to retard heat conduction to the drying house fioor.

WILLIAM TURNER WAGONER.

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

UNITED STATES PATENTS Number Name Date 171,481 Millner Dec. 18, 1875 337,677 Forbis Mar. 9, 1886 646,218 .I-Iollingsworth Mar. 27, 1900 1,077,324 Williams Nov. 4, 1913 2,223,301 Dowless Nov. 26, 1940 FOREIGN PATENTS Number Country Date 71,672 Switzerland Feb. 1, 1916

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