[0001] A method and apparatus for moistening bundles of flexible material in particular
bundles of tobacco leaves.
[0002] The invention relates to a method of moistening bundles of flexible material, in
particular bundles of tobacco leaves, by placing the bundles at the base thereof into
a clamping means and passing the same through a space in which there is atomized a
liquid, such as water. Such a method is known. According to said known method the
bundles are placed in upright'position into a clamp and are passed through a space
in which water is sprayed onto the bundles. This treatment is effected because a certain
moisture content is necessary in order to avoid pulverisation in particular during
the subsequent working up thereof. Tobacco leaves may have a very different structure
and
'accordingly it is of utmost importance that the proper amount of moisture is applied
in such a manner that distribution thereof will be uniform and in the proper amount
everywhere.
[0003] Tobacco leaves are supplied in bundles the stalk ends of which are tied together
by means of a tobacco leave or rush. Previously it was known to remove this tie and
to moisten the leaves separated from each other within a drum. This method is complicated
and time consuming.
[0004] However in the above described known method in which bundles are placed in upright
position there is the drawback that the leaves fall down and remain in lying position.
Upon falling down the leaves of the bundle will cover each other thus inhibiting a
uniform moistening.
[0005] The object of the invention is to provide a method and an apparatus not subject to
said drawbacks.
[0006] This object is achieved in accordance with the invention in that the bundles are
passed through said space while being suspended from the base thereof and being rotated
about the axis of said base. Where the bundles hang downwards the rotation will force
the leaves to move apart while the leave assume a more or less slanting fanning position
accordkg to the number of revolutions. Where leaves cannot fall flat said leaves will
remain loose from each other and will moreover be subject to a mutual movement resembling
a flitting motion due to the movement in the air during the rotation.
[0007] This effect may yet be enhanced if during the passage through the moistening space
the direction of rotation is altered one or more times. Upon alteration of the direction
of rotation the bundle of leaves will assume each time a limply drooping position
before being fanned out again when the rotation in the opposite direction is restarted.
[0008] Preferably the air within a'the moistening space is kept yet also in turbulent motion,
it being preferred to impart this turbulent motion to the air by means of air jets
for atomizing the liquid.
[0009] An optimum Effect is attained when in-stead of a moistening by means of thin water
jets there is utilized in accordance with the invention a fine atomization by atomizing
the water by means of air jets whereby the current of air laden with fine water droplets
may reach the rotating bundles of leaves from all sides while said current of air
per se provides for moving the leaves apart from each other.
[0010] The invention furthermore relates to an apparatus for carrying out the above described
methods, said apparatus comprising first of all an endless conveyor guide and a conveyor
chain guided therein, said conveyor chain being provided with a plurality of mutually
spaced clamping or holding means for clamping or holding, respectively, the bundles
to be treated, said clamping or holding means being fastened to said chain in downwards
hanging position and operable to be rotated about a vertical axis, said chain passing
consecutively through an insert. station, a moistening space and a discharge station.
The rotary movement of the clamping or holding means may be brought about in several
ways.
[0011] However according to the invention this may be realized in a simple manner by suspending
said clamping means in a freely rotatable manner and providing the same with a cylindrically
arved surface coaxially with respect to the axis of rotation and by providing an endless
belt operative to be driven and extending parallel to the direction of conveyance
in said moistening space, said belt being operable to engage said cylindrically curved
surface. Hence upon entering the moistening space the holding or clamping means will
immediately engage a driven belt, whereby said clamping or holding means are set in
rotation causing the leaves to fan out. By utilizing several belts operable to impart
an opposite direction of rotation to the holding or clamping means, the bundles may
be rotated consecutively in the one direction and after a short interruption accompanied
by a stand still of the leaves in the other direction.
[0012] For enhancing the feeding operation of the apparatus it is preferred to use clamping
means of a type that automatically closes upon insertion of a bundle. In principle
several constructions are conceivable for attaining such object. At the location of
the discharge station there may then be provided means causing the release of the
clamping means.
[0013] The atomizers may be provided in the bottom part and the top part of the moistening
space, it being preferred in accordance with the invention to make provisions that
the atomizers in the bottom part of the moistening space are adjustable in vertical
sense in order to adapt the position there of to the size of the leaves.
[0014] Preferably the clamping or holding means are rotatably supported in sealing plates
connected to each other to form a chain, said sealing plates being accommodated between
the driving cylinder and the clamping means per se and being operative to be guided
on the side walls of the guide slot present in the top part of said moistening space.
In this way there is achieved not only a sealing of the conveying means and the guiding
means with respect to the humid enviroiment in the moistening space but also a guide
providing for a stable conveyance through the moistening space in spite of the inavoidable
unbalance during the rotation.
[0015] The invention will now be elucidated in further detail with reference to the drawings,
in which
Fig. 1 diagrammatically shows a plan view of the apparatus according to the invention,
Fig. 2 is a cross section along the line II-II in Fig. 1, and
Fig. 3 is a cross section along the line III-III in Fig. 1.
[0016] In Fig. 1 the reference numeral 1 indicates the path of an endless conveyor guide
in which there is accommodated a conveyor chain 2. This chain runs over reversing
sprockets 3 and 4 which have been represented diagrammatically only and of which the
sprocket 3 is connected to a drive mechanism 5.
[0017] This conveyor guide follows an elongated path having two straight parts one of Wich
runs through a moistening space 7.
[0018] Clamping means 8 spaced apart with respect to each other are suspended from the chain.
These clamping means are suspended from the chains in a freely rotatable manner and
have been provided with a cylindrically curved driving surface 9. The clamping means
are provided with operating means 10 by means of which the spring pressurized not
shown clamping jaws may be opened.
[0019] With reference to Fig. 2 there is shown in the right hand part the insertion operation
performed within the region 6 (Fig. 1).
[0020] In the moistening space 7 there are accommodated two driving belts 11 and 11' which
run parallel to the direction of conveyance and which may come into frictional engagement
with the cylindrically curved driving surface 9 of the clamping or holding means 8.
The belt 11 will force the holding means to rotate to the right and the belt 11' to
the left. At the location of the reversing wheels thereof said belts are both driven
by a belt 12 running over rollers mounted on the shafts of the reversing wheels,a
drive roller 13 on the shaft of a motor 14 and atensioning roller 15.
[0021] With reference to Fig. 2 there is shown how a driving roller 16 drives the belt 11
by way of the shaft 17, said belt 11 engaging the cylindrical surface 9 of the clamping
means 8, which clamping means is suspended from the chain 2 and is operative to be
rotated by means of a not shown bearing present above the cylinder 9. By means of
a not shown bearing each clamping means is furthermore rotatably mounted in a sealing
plate 18; a chain being formed by said sealing plate 18 together with corresponding
sealing plates 18'.
[0022] With reference to Figs. 2 and 3 it is shown that this chain is guided in a sealing
manner through the guide slot 19 of the moistening space 7 made in the form of a box
in which the sealing plates 18 are in contact with anti-friction plates 20 inserted
in the side wall portion of the guide slot.
[0023] Thereby the moistening space 7 is closed moisture tight to the top thereof, while
moreover a stabilization is achieved so that the clamping means will not be able to
acquire an oscillating motion under the influence of the unbalance caused by the bundles
of leaves. Furthermore the proper engagement with the driving belt will be assured
thereby.
[0024] With reference to Fig. 2 it is shown that in the wall at the top of the space 7 there
are provided compressed air operated atomizers 21 for atomizing water. Furthermore
in the bottom part of the space there are provided atomizers 22 distributed, like
shown in Fig. 1 in the longitudinal direction which atomizers 22 are mounted on a
frame 23 which is adjustable in the direction of the height thereof. This adjustment
is performed by means of screw spindles 24 and'a drive mechanism 25. The adjustment
is made between the lowermost position drawn in full lines and the uppermost position
23' shown in interrupted lines.
[0025] The moistening space is joined to the discharge station 26 accommodated above a transverse
conveyor 27. The driving belt 11' extends into this discharge station at which there
are provided two guide bars 28 which will engage the operating means 10 projecting
at both sides thereof whereby also due to the rotation the clamping means is opened
so that the moistened bundle will drop down therefrom.
[0026] If the clamping means is of the type that is self locking in the open position the
clamping means will move in opened position to the insert station 6. If such is not
the case, the opening of the clamping means at this insert station will have to be
brought about in an other way.
[0027] Furthermore the discharge station 26 is provided with an exhaust 29 for exhausting
moisture emanating from the moistening space.
[0028] At the location of the entrance of the moistening space 7 a similar exhauster 30
may be provided.
[0029] The entrance and exit of the moistening space may be adapted to the shape of the
bundle like indicated by the line 31 in Fig. 2.
[0030] By utilizing the apparatus according to the invention it becomes feasible to adapt
the throughput and the speed of rotation by adjustment of the number of revolutions
of the drive motors independently to the degree of moistening which is desired to
be achieved and which is dependent on the kind of tobacco to be treated. The atomized
sprays emanating from the nozzles enhance the separation of the leaves so that the
moisture may penetrate well and uniformly every-where.
[0031] The moisture leaving the moistening space 7 may be collected in a filter box 32 arranged
therebelow and, if desired, may be returned to the liquid supply vessel 33.
[0032] At 34 there are provided atomizers by means of which the part of the bundle inserted
in the clamping means may be moistened.
1. A method of moistening bundles of flexible material in particular bundles of tobacco
leaves, by placing the bundles at the base thereof into a clamping means and passing
the same through a space in which there is atomized a liquid, such as water, characterized
in that said bundles are passed through said space while being suspended from the
base thereof and being rotated about the axis of said base.
2. The method according to claim 1, characterized in that during the passage through
said moistening space the direction of rotation is altered.
3. The method according to claim 1 or 2, characterized in that a turbulent motion
is imparted to the air within said moistening space.
4. The method according to claim 3 characterized in that the turbulent motion is imparted
to the air by means of air jets for atomizing the liquid.
5. An apparatus for carrying out the method according to any one of the preceding
claims characterized in that said apparatus comprises an endless conveyor guide and
a conveyor chain guided therein and provided with a plurality of mutually spaced clamping
or holding means for clamping or holding respectively, the bundles to be treated,
said clamping or holding means being fastened to said chain in downward hanging position
and operable to be rotated about a vertical axis, said chain passing consecutively
through an insert station, a moistening space and a discharge station.
6. The apparatus according to claim 5 characterized in that said clamping means are
suspended in a freely rotatable manner and are provided with a cylindrically curved
surface coaxially with respect to the axis of rotation and that in said moistening
space there is provided an endless belt operative to be driven and extending parallel
to the direction of conveyance, said belt being operable to engage said cylindrically
curved surface.
7. The apparatus according to claim 6 characterized in that in said moistening space
there are provided several endless belts arranged in succession in the direction of
conveyance said belts being operable to drive the clamping or holding means in opposite
direction of rotation on said cylindrically curved surface.
8. The apparatus according to any one of the preceding claims 5-7, inclusive, characterized
in that said clamping means are of the type that automatically closes upon insertion
of a bundle.
9. The apparatus according to any one of the preceding claims 5-8, inclusive, characterized
in that said clamping or holding means are rotatably supported in sealing plates accommodated
between said cylindrically curved surfaces and said holding means, said sealing plates
being canected to each other to form a chain and being operative to fit slidingly
in the moistening space between the side walls of the guide slot present in the top
part of said moistening space.
10. The apparatus according to any one of claims 5-9, inclusive, characterized in
that both in the bottom part and the top part of the moistening space there are provided
compressed air operated liquid atomizers.
11. The apparatus according to claim 10 characterized in that the atomizers provded
in the bottom part of the moistening space are adjustable in vertical sense.
12. The apparatus according to claim 10 or 11 characterized in that in the top part
of the moistening space there are provided atomizers (34) at the level of the clamping
means said atomizers being directed to said clamping means.