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(11) | EP 0 101 271 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Tobacco opening and conditioning apparatus |
| (57) tobacco opening and conditioning apparatus has an approximately horizontal cylinder
(10) at the input end of which is a plenum chamber (15) containing air at high humidity
and means (e.g., 17) are provided in the plenum chamber for splitting the tobacco
bale into slices and means are provided for driving the tobacco through the plenum
chamber into the cylinder. |
[0002] It is a requirement in the tobacco industry that compressed cases, bales or hogsheads of tobacco laminae have to undergo a preconditioning process before they can be handled. This process gives the laminae a temperature increase and a consequent condensation moisture gain. All known techniques for preconditioning embody temperature and moisture gain. The preconditioning process softens the tobacco, thus reducing degradation during subsequent handling in the process of tobacco. The next stage of processing generally is a consolidation of the moisture gain to a point where the laminae may be cut.
[0003] This initial conditioning is generally a batch process followed by line conditioning process, often a rotating cylinder.
[0004] There are also several methods of continuous bale opening and preconditioning of compressed laminae notably :-
1. The cases being driven onto rotating doffers as described for example in UK Patent Nos. 1,364,839, 1,136,439, 2,0072,962A and 2,047,070A and thereafter conditioning the tobacco.
2. Slices of laminae being removed with a jet knife as described in International Application No. W0.82/02324 in which the addition of moisture occurs simultaneously with the opening process.
3. Slices of tobacco being produced by dry slicing and fed directly into a conditioning cylinder.
[0005] An object of the invention is to provide a conditioning cylinder type, wherein the need for dry slicing the tobacco in a separate process is obviated.
[0006] According to the invention there is provided an apparatus for opening and conditioning a bale or hogshead of laminations of tobacco, comprising a cylinder rotatable about a substantially horizontal axis or an axis slightly inclined to the horizontal, a plenum chamber situated at the inlet end of said cylinder, means within said plenum chamber for splitting the tobacco placed within the plenum chamber, means for providing high humidity on said plenum chamber, and means for driving the tobacco through the plenum chamber and into the cylinder.
[0007] The means for splitting the tobacco may be in the form of a plurality of projections extending upwardly from the base of said plenum chamber disposed along axes which diverge in the direction of travel of the tobacco from the plenum chamber to the cylinder, said projections causing said tobacco to divide between laminations as the tobacco passes through the plenum chamber towards the cylinder. The means for driving the tobacco through the plenum chamber may be in the form of a ram, conveyor belts or the projections which may comprise driven wheels of wedge-shaped radial section (throwing discus shaped wheels).
[0008] The compressed lamina case will be orientated such that the laminations are vertical and the case being fed into the process along its length. The whole case will then be fed into the plenum chamber which is large enough to take the whole case.
[0009] The invention will now be described by way of example with reference to the accompanying drawing, in which :-
FIGURE 1 is a perspective view, partly broken, of the apparatus comprising the rotary cylinder and plenum chamber, according to the invention;
FIGURE 2 is a side elevation of the apparatus;
FIGURE 3 is an end elevation;
FIGURE 4 is a part section taken along the line A-A of Figure 2;
FIGURE .5 is a section of the cylinder taken along the line B-B of Figure 2, showing flow control weir plates;
FIGURE 6 is a section of the cylinder taken along the line C-C of Figure 2, showing a tobacco opening ring with internal pins, and
FIGURES 7 - 11 show various modifications of the splitting and feeding mechanism within the plenum chamber.
[0010] A rotary conditioning'cylinder 10 is located in a housing 10A which is mounted on a support 10B. The cylinder 10 is mounted on rollers 11 carried on a support frame 12. The axis of the cylinder is inclined to the horizontal whereby the tobacco travels along the cylinder as it tumbles. The cylinder is provided with known drive means (not shown), a fan 13 (Figure 3) for recirculating the temperature controlled conditioning air and water sprays 14 controlled to feed water to the cylinder in an amount dependant upon the moisture content of the processed tobacco. These components are well known in the art and need no further description.
[0011] Adjacent the inlet end of the cylinder 10 is arranged a fixed plenum chamber 15. A platform 16 for supporting the case of tobacco inside the plenum chamber has a series of wedge form wheels 17 in the base of the support platform disposed along diverting axes 18 (Figure 4). The number and size of the wheels are arranged so that when the whole case is fed into the plenum chamber, the wedge shaped wheels, which protrude through the support platform, cause the case to split and separate vertically along appropriate lines of lamination. Thus the case is split, but fully contained in the plenum chamber in the moist warm conditioned air environment.
[0012] Inside the cylinder at the feed end is a series of concentric rings 19 which are fronted with integral internal pins 20 (Figure 6). The rings increase in diameter further into the cylinder. The rings occur over the intial 1.5 m. of the cylinder. Downstream of the rings are internal annular weir plates 21 (one shown only), after which are product lifting pins and paddles (not shown).
[0013] The compressed case C of laminae vertically disposed, is fed into the plenum chamber at which time the case is split. Feed from the plenum chamber is effected by a conveyor belt 22 and a ram 23 into the cylinder whereupon the case cascades through the diverging concentric rings 19 with internal pins 20. It is during this period that the case substantially reduces to the constituent parts of laminae. The discharge rate of the case through the cylinder is controlled by the annular weir. The water sprays dose the product at this time to ensure the desired exit product moisture content.
[0014] The apparatus may have provision for feeding parts of the case that have been split in the plenum chamber. This feature is used on low flow rate applications.
[0015] Figure 1 shows a conveyor 22A for feeding a case forwards followed by a ram 23A for feeding it laterally, a conveyor 23B for feeding it again forwards, the conveyor 23B being vertically movable to bring the case level with the conveyor 22.
[0016] In modification shown in Figure 7 the splicing wheels have been replaced by a pronged separator 30 (shown in plan view in Figure 7a) arranged to reciprocate in horizontal planes and descend as the slices of tobacco are removed. A front stop 31 for the tobacco bale also descends in timed relationship with the separator 30. Processing air enters through opening 32. The arrangement in Figure 8 shows a platform 35 raised by a lifting mechanism indexed upwardly (not shown), and a tined stripping band 36 within the plenum chamber for continuously removing the layers of tobacco and driving them into the cylinder 10. Alternatively, the tobacco may be loaded in a stationary platform and the stripping band indexed downwardly.
[0017] Figure 9 shows another form of reciprocating splitting ram 40 in the form of a bladed ram used in conjunction with a lifting platform 41 which is indexed upwardly. Alternatively, the tobacco is loaded on a stationary platform and the splitting ram indexed downwardly.
[0018] The Figure 10 construction incorporates the use of splitting wheels 45 mounted on a frame (not shown) in such a manner that the wheels can be retraced downwardly. In this example the tobacco is fed into the plenum chamber 15 with the laminations transverse to the direction of movement of the tobacco into the cylinder. A ram 46 drives the split tobacco incrementally.
[0019] In Figure 11 showing a plan view of a further embodiment, the tobacco bales are driven towards the plenum chamber 15 in a continuous series by conveyors 51, 52 and mechanical slicing and feeding by blades 50 take place at the leading end of the bale. As shown in Figure 11a the blades are driven by linkage (not shown) each travelling along a triangular path, although a rectangular path is possible.
[0020] The principal advantages of the invention are :
1. Case splitting occurs in a process air environment of high humidity;
2. Lamina spillage, including any smalls on case separation that occurs during splitting, is contained and may be fed directly into the cylinder by a screw conveyor;
3. Whole cases are conditioned;
4. The cascade rings in the cylinder avoid an excessive drop of the split case.
1. Apparatus for opening and conditioning a bale or hogshead of laminations of tobacco,
comprising a cylinder rotatable about a substantially horizontal axis or an axis slightly
inclined to the horizontal, characterized in that there are provided -
a plenum chamber (15) situated at the inlet end of said cylinder (10);
means (17) within said plenum chamber for splitting the tobacco placed within the plenum chamber;
means (14) for providing high humidity in said plenum chamber; and
means (22) for driving the tobacco through the plenum chamber and into the cylinder.
2. Apparatus as claimed in Claim 1, characterized in that the means for splitting
the tobacco may be in the form of a plurality of projections (17) extending upwardly
from the base of said plenum chamber disposed along axes which diverge in the direction
of travel of the tobacco from the plenum chamber to the cylinder, said projections
causing the tobacco to divide between laminations as the tobacco passes through the
plenum chamber towards the cylinder.
3. Apparatus as claimed in Claim 2, characterized in that said projections are wheels
(17) of wedge-shaped radial section.
4. Apparatus as claimed in Claim 1, 2 or 3, characterized by having disintegrating
means (19, 20) in the cylinder for reducing the tobacco laminae to its constituent
parts.
5. Apparatus as claimed in Claim 4, characterised in that the disintegrating means
comprise a plurality of annular arrays of inwardly projecting projections (20) in
the input end of the cylinder through which the sliced tobacco is fed.
6. Apparatus as claimed in Claim 5, characterized in that the projections (20) are
carried by a plurality of rings (19) that are concentric with the cylinder and of
increasing diameter from the input end of the cylinder inwardly.
7. Apparatus as claimed in Claim 6, characterized by having a weir ring (21) spaced
inwardly from the innermost ring.
8. Apparatus as claimed in Claim 1, characterized by having a tined splitting device
(30) movable horizontally for splitting and vertically for slice location, and a vertically
adjustable front stop (31).
9. Apparatus as claimed in Claim 1, characterized by having a tined endless belt (36)
for slicing the tobacco and a vertically movable tobacco support (15).
10. Apparatus as claimed in Claim 1, characterized by having a combined splitting
blade and ram (40) for slicing the tobacco and feeding the slices to the plenum chamber
(15).
11. Apparatus as claimed in Claim 1, characterized by having means for feeding the
tobacco transversely to the axis of the cylinder over splitting means, and means (46)
for pushing the tobacco with the cylinder axially.
12. Apparatus as claimed in Claim 1, having splitting means (50) on opposite sides
of the tobacco and are moved inwardly and forwardly for separating the slices.