EP1197155A2 - Method and apparatus for forming a tobacco rod - Google Patents

Abstract

Method for producing at least one strand (43, 44) of tobacco comprises feeding tobacco fibers to at least one air-permeable strand conveyor (7, 8), holding them in place using suction air, almost completely removing the dust contained in the suction air, dividing the dust into a coarse and a fine fraction, recycling the coarse fraction to the tobacco strand, and feeding the fine fraction to a central dust extractor. An Independent claim is also included for a device used for carrying out the method. Preferred Features: The dust removed is recycled to the strand conveyor and divided into the fractions using a sieving action. The dust removed is pneumatically transported to the strand conveyor.

Description

The invention relates to a method for forming at least one strand of tobacco, in which tobacco fibers in a wide shower at least one air permeable Strand conveyors are fed and on this conveyor by means of suction air are held, further contained in this air sucked by the strand conveyor Dust is largely completely separated from the air and this separated dust is partially added to the tobacco rod.

The invention further relates to a device for forming at least one tobacco rod with a distribution device for forming a wide shower Tobacco fibers, at least one air-permeable, endless circulating strand conveyor for removing the at least one tobacco rod formed from the shower, Feeding means for feeding the shower to the at least one Strand conveyor, a first vacuum chamber for applying a vacuum to a first section of the side of the at least facing away from the tobacco rod a strand conveyor, first suction means for suctioning through the air entering at least one strand conveyor into the first vacuum chamber, a separator for separating the air contained in this extracted Dust and means of transport with at least one discharge opening for transport of the separated dust to the at least one strand conveyor.

The term tobacco processing machines includes machines for manufacturing understanding of cigarettes, but also machines for producing tobacco cartridges, Cigarillos or cigars, insofar as they follow the procedure mentioned Use strand formation.

In the machines mentioned, tobacco is made from a distribution device Taken stock and a shower of largely isolated tobacco fibers spread. This tobacco shower is usually accelerated by transport air and distracted and finally on or under a revolving air permeable Strand conveyor heaped into an endless tobacco rod. This Strand is held on the strand conveyor by negative pressure, which by means of a first vacuum chamber on the side of the strand conveyor facing away from the strand is created. The air passing through the tobacco rod and the line conveyor is extracted by suction from the first vacuum chamber. About density To keep the tobacco rod as constant as possible, the tobacco is left with a surplus which is later trimmed by a leveler. In modern High-performance machines often turn the tobacco shower into several partial showers split to match multiple strands of tobacco at the same time To be able to fill up strand conveyors. A corresponding distribution device is z. B. described in DE 39 19 720 A1 of the applicant.

Experience has shown that it is in the machines in question from the first vacuum chamber extracted air is heavily contaminated with dust. The dust mentioned is there made of fine dust, which adheres to the tobacco fibers and during processing in the distribution device is replaced by these, from foreign shares such. B. sand and short tobacco fibers. On the one hand, these short fibers arise during the preparation of the tobacco and can in small numbers through openings get into the vacuum chamber in the strand conveyor. On the other hand, you can but also the ends of longer fibers partially through these openings slip, which causes the fibers to separate from the strand when the strand is detached Strand conveyors are torn and the ends also as short fiber fragments get into the vacuum chamber.

As a rule, all of the dust is removed with the extracted air and deposited in a central dedusting system. In such a dedusting plant usually dust-laden air is brought together from an entire factory and cleaned. After that, the dust is transformed into tobacco-like products in elaborate processes such as B. formed tobacco foil and fed again to the production process.

A method is known from US Pat. No. 3,282,270, this dust directly on the machine separate from the exhaust air and then pneumatically into the tobacco shower due. The dust is said to be due to the already partially shivered The tobacco rod is filtered out of the transport air and in the tobacco rod remain. The disadvantage here is that only coarse dust particles from the air be filtered out, while the fine dust fraction is released into the exhaust air again and so accumulates in the system because with the tobacco fed constantly more fine dust is added.

Therefore, the task arises to develop a method in which the rough Dust particles are added to the tobacco rod and at the same time there is a risk of There is no accumulation of fine dust. In addition, the task is to develop a device which enables this method to be carried out.

In a method of the type described in the introduction, the object is achieved according to the invention solved that the largely all dust in a coarse and a fine fraction is divided, the coarse fraction being added to the tobacco rod while the fine fraction is fed to a central dedusting unit.

This also expressly includes procedures in which a certain Part of the separated dust temporarily or continuously before fractionation for measuring or other purposes. Such procedures are also intended included in which, in addition to the exhaust air mentioned, exhaust air cleaned from other sub-processes of tobacco processing in dust separation as far as this additional exhaust air is also recyclable coarse tobacco parts contains.

Such a method can be designed particularly simply in that the Dust is fed back to the strand conveyor together with the tobacco shower and the division of the dust into the coarse and fine fractions by sieving of the strand conveyor and possibly already on this tobacco heaped up. The separated dust is transported back to the strand conveyor preferably pneumatic.

For a process for the simultaneous production of several tobacco strands, it is from Advantage if the entire separated dust is divided into several partial flows becomes. Each tobacco rod to be produced is preferably a partial stream of Dust supplied. The division is preferably made before or during the Transportes to the strand conveyors.

The sieving action can be used particularly advantageously when the addition the dust takes place on a width which is smaller than the width of the tobacco shower, the one passing through the strand conveyor in the area of dust addition Air and the fine dust contained in it are extracted separately and one Central dedusting is supplied. Below is the width of the tobacco shower To understand expansion in the conveying direction of the strand conveyor.

In order to add only very large dust particles to the tobacco rod, it is advantageous to add the dust before the tobacco shower is fed. In order, on the other hand, to remove only very fine dust particles into the central dedusting system it is beneficial to share the dust with part of the tobacco shower to add the strand conveyor, since then the sieve action of the strand conveyor reinforced by the sieving action of the tobacco rod, which has already been partially heaped up becomes. In this case, it is also advantageous to bring the dust to the tobacco shower admit that the coarse dust fraction in the tobacco rod outside the Strand area is deposited, which to ensure a uniform Strand density is trimmed in the further course of the process. Because more common with machines Design about a third of the heaped tobacco rod as excess the dust must be returned within the first two Third of the shower width, seen in the direction of conveyance of the strand conveyor, take place.

The dust with the tobacco shower before it is heaped up on the strand conveyor merged, it is particularly easy to merge this directly to be carried out before the embankment. From a constructive point of view, it can But it can also be an advantage to merge as soon as the Perform Schauers, also in every phase between the steps mentioned, in which the tobacco shower is easily accessible in the respective machine.

If the dust is conveyed to the strand conveyor before the tobacco shower or added to the tobacco shower immediately before it was filled onto the strand conveyor, So it is advantageous to give the dust a component of movement in the conveying direction to give the strand conveyor.

A particularly reliable function of the method is achieved in that the The amount of separately extracted air is controlled. The control is preferably carried out through a control loop, which advantageously ensures that the Vacuum runs steadily along the strand conveyor.

In a device of the type described in the introduction, the object is achieved according to the invention solved that in the area of the addition of the separated dust to the at least one strand conveyor, this at least one second vacuum chamber for applying a vacuum to a second section of the Associated side of the at least one strand conveyor facing away from the tobacco rod is to which second suction means are connected in order to achieve the minimum through the a strand conveyor entering the at least one second vacuum chamber To suck out air.

In a preferred embodiment of the device, the feed means for the tobacco shower special means for dividing the shower into several partial showers, from which a tobacco rod is piled up on several strand conveyors and include the means of transport for the separated dust also means for dividing the dust into several partial streams, which through several discharge openings can be fed to the individual strand conveyors. Further is every single strand conveyor in the area of the corresponding discharge opening a second vacuum chamber is assigned to the means of transport. In this Case, it is further advantageous if the device for dividing the dust Contains adjusting means by which the quantitative relationships of the individual partial flows of the dust can be controlled.

The means of transport for the separated dust are preferably pneumatic Delivery lines executed.

In an advantageous embodiment of the device, the extension is the second Vacuum chamber in the conveying direction of the strand conveyor much smaller than that the first vacuum chamber.

In a further advantageous embodiment of the device, the second vacuum chamber upstream of the first vacuum chamber in the conveying direction of the strand conveyor or integrated into this.

In order to ensure optimal removal of the fine dust, is in one Another embodiment of the device, the second vacuum chamber in the conveying direction of the strand conveyor larger than the delivery opening of the means of transport. A Further optimization is achieved in that the second vacuum chamber against the discharge opening of the transport means in the conveying direction of the strand conveyor is offset.

The device becomes structurally particularly simple if in a further embodiment the transport means with their discharge opening in the feed means for the Open tobacco shower.

The device runs particularly safely when it is in close proximity to the strand conveyor arranged discharge opening of the transport means with a component in the conveying direction of the at least one strand conveyor is aligned.

They are preferably located in the second vacuum chamber and / or in the first Vacuum chamber pressure sensors. Next are preferably adjusting means for the Control of the amount of air drawn off by the second suction means is provided. Furthermore, a control unit for controlling this amount of air is preferably provided.

Figur 1

zeigt eine schematische Darstellung einer bevorzugten Ausgestaltung einer erfindungsgemäßen Vorrichtung, in welcher gleichzeitig zwei Tabakstränge gebildet werden. Eine erfindungsgemäße Vorrichtung zum Bilden nur eines Tabakstranges ist aus der Darstellung ohne weitere Überlegung abzuleiten.

Figuren 2 und 3

zeigen Trennmittel zur Aufteilung eines Staubstromes in zwei Teil ströme vor bzw. nach der Aufgabe in eine pneumatische Förderleitung für den Einsatz in einer Vorrichtung gemäß Figur 1.

The invention is explained in more detail below with reference to the preferred embodiments shown in the drawings:

Figure 1

shows a schematic representation of a preferred embodiment of a device according to the invention, in which two tobacco rods are formed simultaneously. A device according to the invention for forming only one tobacco rod can be derived from the illustration without further consideration.

Figures 2 and 3

show separating means for dividing a dust flow into two partial flows before or after the task in a pneumatic conveying line for use in a device according to FIG. 1.

The device shown in Figure 1 consists of a distributor device 1, which Feed means 2 for guiding a tobacco shower 3 are arranged downstream. A such distribution device is such. B. described in DE 39 19 720 A1 of the applicant and component z. B. the cigarette production machine sold by the applicant PROTOS 2. In the feed means 2 are separating means 4 for dividing the tobacco shower 3 arranged in two partial showers 5, 6. The feed means 2 lead to two endless strand conveyors 7, 8, which around deflection rollers 9, 10, 11, 12 are guided and revolve in the direction of arrows 13, 14. The strand conveyors 7, 8 delimit a first vacuum chamber positioned opposite the feed means 2 15. At the downstream end in the conveying direction of the strand conveyors 7, 8 the first vacuum chamber 15, each of the strand conveyors 7, 8 is a leveler 16, 17 assigned. To the first vacuum chamber 15 are via a first exhaust line 18 and a dust collector 19 are connected to the first suction means 20. As Dust separator 19 can e.g. B. a Mahle industrial filter type SFK 1560 Knecht Filterwerke GmbH, Öhringen, can be used. From the dust collector 19 leads a conveyor line 21 to separating means 22 for dividing a dust flow to two further pneumatic conveying lines 23, 24. The separating means 22 can as a divided collecting shaft with subsequent pneumatic conveying be configured, such a configuration is shown in Figure 2. The release agent However, 22 can also be used as a fork in a pneumatic delivery line be configured, in this case the delivery line 21 is also a pneumatic Delivery line, which is preceded by an ejector 25. At the end of the pneumatic Delivery lines 23, 24 are arranged discharge openings 26, 27. Depending on Embodiment of the device open the discharge openings, represented by 26a, 27a, into the feed means 2 or the discharge openings, represented by 26b, 27b, are arranged upstream of the feed means 2 in the conveying direction of the strand conveyors 7, 8. In the former case, the opening of the discharge openings 26a, 27a can preferably be arranged in close proximity to the strand conveyors 7, 8, or on one another location between the distribution device 1 and the strand conveyors 7, 8, if this is particularly easy to access in the construction of the machine in question is. Each of the discharge openings 26, 27 is on the opposite one Side of the strand conveyor 7, 8 assigned a second vacuum chamber 28, 29 which depending on the position of the discharge openings 26, 27 either, represented by 28a, 29a, are arranged within the first vacuum chamber 15, or are shown through 28b, 29b, the first vacuum chamber 15 in the conveying direction of the strand conveyors 7, 8 are arranged. To the second vacuum chambers 28, 29 are over second exhaust air lines 30, 31, 32 and adjusting means 33, 34 second suction means 35 connected. As adjusting means 33, 34, for. B. Throttle valves can be used. Within the second vacuum chamber 28, 29 and within the first vacuum chamber 15, pressure sensors 36, 37, 38 are arranged, which with a Control unit 39 are connected, which in turn by control lines 40, 41, 42 is connected to the adjusting means 33, 34 and the second suction means 35.

The operation of the device shown in Figure 1 is explained below. Tobacco to be processed becomes a wide one in the distribution device 1 Spread tobacco shower 3, which is delivered into the feed means 2. By the separating means 4, the shower 3 is divided into two showers 5, 6. These will fed to the strand conveyors 7, 8 and to them by means of the first Vacuum chamber 15 applied vacuum to tobacco strands 43, 44, which are removed in the conveying direction of the strand conveyors 7, 8. Here, the equalizers 16, 17 excess portions 45, 46 of the Tobacco strands 43, 44 separated. By in the first vacuum chamber 15th prevailing negative pressure, air laden with dust 47 passes through the tobacco rods 43, 44 and the strand conveyors 7, 8 in the first vacuum chamber 15. This air is by means of the first suction means 20 through the first exhaust line 18 into the dust collector 19 promoted where the dust contained in it separated and into the Conveying line 21 is transferred. Through the separating means 22, the dust is then in accordance the description of Figures 2 or 3 divided into two sub-streams, which be introduced into the pneumatic conveying lines 23, 24. From the Conveying lines 23, 24 dust 48, 49 passes through the corresponding discharge openings 26, 27 in the direction of the corresponding strand conveyors 7, 8. flow the discharge openings, represented by 26a, 27a in the feed means 2, the Dust together with the partial showers 5, 6 from tobacco on the strand conveyors 7, 8 heaped up. Here, a coarse fraction 50, 51 is already created by the respective one partially retained tobacco rod 43, 44 and with this conveyed together. A fine fraction 52, 53, however, occurs due to the in the second negative pressure chambers 28a, 29a prevailing negative pressure by the corresponding tobacco rod 43, 44 and the corresponding strand conveyor 7, 8 through into the respective second vacuum chamber 28a, 29a. From there the fine Dust fraction 52, 53 by means of the second suction means 35 through the second exhaust air lines 30, 31, 32 suctioned off. If the discharge openings are as shown by 26b, 27b, in the conveying direction of the strand conveyors 7, 8 in front of the feed means 2, the coarse dust fraction 50, 51 is retained by the unused strand conveyors 7, 8 while the fine fraction 52, 53 passes through it into the second Vacuum chambers 28b, 29b occurs. The negative pressure in the second negative pressure chambers 28, 29 and in the first vacuum chamber 15 is by pressure sensors 36, 37, 38 measured. Depending on the measured values, the control unit 39 the throttle valves 33, 34 and / or the drive of the second suction means 35 controlled so that at the transitions between the first vacuum chamber 15 and the second vacuum chambers 28, 29 no pressure jumps occur.

The mode of operation of the release agents shown in FIG. 2 is as follows: In one Dust contained in air flow supplied through line 102 is removed by a Dust separator 101 separated from the air and through a lock 104, which z. B. can be designed as a rotary valve, in a collecting container 105 transferred. The cleaned air is discharged through a line 103. The Dust falling from the lock 104 into the collecting container 105 is removed by a pivotable partition 106 divided into two sub-streams, each of which by means of one of two ejectors 108, 109 into one of two pneumatic ones assigned to them Delivery lines 110, 111 is abandoned. By swiveling the partition 106 by means of a lever 107, the quantitative ratio of the partial flows of the Dust can be adjusted. Instead of the manually operated lever 107 can also an automatic, e.g. B. electromotive setting.

The mode of operation of the means shown in FIG. 3 is as follows: one in a feeding Pneumatic feed line 201 supplied dust stream is in one Branch area 203 through the pivotable end 205 of a partition 204 divided into two partial streams, which are discharged through the pneumatic conveying lines 202, 203 are transported away. By swiveling the swiveling The end 205 of the partition 204 can be the quantitative ratio of the partial flows can be set. As with the means shown in FIG. 2, this setting can be used manually using a lever, not shown, or automatically, e.g. B. electromotive, respectively.

Claims (26)

Method for forming at least one tobacco rod, in which tobacco fibers are fed in a wide shower to at least one air-permeable strand conveyor and are held on this conveyor by means of suction air, furthermore, dust contained in the air sucked by the strand conveyor is largely completely separated from the air and this separated dust partially added back to the tobacco rod, characterized in that the dust is divided into a coarse and a fine fraction, and that the coarse fraction is added to the tobacco rod, while the fine fraction is fed to a central dedusting unit. A method according to claim 1, characterized in that the entire separated dust is added to the at least one strand conveyor again and the division of the dust into said fractions is carried out by the sieve action of the strand conveyor and, if appropriate, tobacco already deposited on it. A method according to claim 1 or 2, characterized in that the separated dust is transported pneumatically to the strand conveyor. Method according to one of claims 1 to 3, characterized in that at least two strands of tobacco are formed simultaneously and the dust separated from the exhaust air is divided into at least two partial streams before being divided into the fractions. Method according to one of claims 1 to 4, characterized in that a partial flow of the separated dust is fed to each strand conveyor. Method according to one of claims 1 to 5, characterized in that the dust is added to the strand conveyor to a width which is substantially smaller than the width of the shower made of tobacco fibers, the air passing through the strand conveyor in the area of dust addition together with the the fine dust it contains is extracted separately. Method according to one of claims 1 to 6, characterized in that the dust is added to the strand conveyor before the shower of tobacco fibers. Method according to one of claims 1 to 6, characterized in that the dust is added to the shower of tobacco fibers before it is heaped up together with the dust on the strand conveyor. A method according to claim 8, characterized in that the dust is fed to the shower of tobacco fibers in such a way that the coarse fraction of the dust is separated in an area of the tobacco rod which is not trimmed off as an excess from the tobacco rod in a subsequent process step. Method according to one of claims 1 to 9, characterized in that a movement component in the conveying direction of the strand conveyor is given to the dust before it is added to the strand conveyor or to the shower of tobacco fibers. Method according to one of claims 6 to 10, characterized in that the amount of separately extracted air is controlled so that the negative pressure applied to the strand conveyor runs continuously in the conveying direction of the strand conveyor. Device for forming at least one tobacco rod (43, 44) with a distribution device (1) for forming a wide shower (3) made of tobacco fibers, at least one air-permeable, endless circulating strand conveyor (7, 8) for removing the at least one tobacco rod formed from the shower (43, 44), feed means (2) for feeding the shower to the at least one strand conveyor (7, 8), a first vacuum chamber (15) for applying a vacuum to a first section of the side of the tobacco rod (43, 44) facing away from the Extractor (7, 8), first suction means (20) for extracting the air passing through the extruder (7, 8) into the first vacuum chamber (15), a dust separator (19) for separating the dust (47) contained in this extracted air and conveying lines (21, 23, 24) with at least one discharge opening (26, 27) for transporting the separated dust (47) to the strand conveyor (7, 8), characterized in that in the area the addition of the separated dust (47) to the strand conveyor (7, 8), the latter at least one second vacuum chamber (28, 29) for applying a vacuum to a second section of the side of the strand conveyor (7, 8) facing away from the tobacco strand (43, 44) ) is assigned to which second suction means (35) are connected in order to extract the air passing through the strand conveyor (7, 8) into the second vacuum chamber (28, 29). Apparatus according to claim 12, characterized in that the feed means (2) contain separating means (4) for dividing the tobacco shower (3) into at least two partial showers (5, 6), which are fed to at least two strand conveyors (7, 8), the delivery lines (21, 23, 24) contain separating means (22) for dividing the stream of separated dust (47) into at least two partial streams (48, 49), each through a discharge opening (26, 27) of the delivery lines (23, 24) Tobacco rod (43, 44) are added, and that a second vacuum chamber (28, 29) is assigned to each strand conveyor (7, 8) in the area of the corresponding discharge opening (26, 27) of the conveyor lines (23, 24). Apparatus according to claim 13, characterized in that the means for dividing the dust flow contain adjusting means (107) for controlling the quantity ratios of the partial flows. Device according to one of claims 12 to 14, characterized in that at least some of the delivery lines (21, 23, 24) are pneumatic delivery lines. Device according to one of claims 12 to 15, characterized in that the second vacuum chamber (28, 29) in the conveying direction of the strand conveyor (7,8) has a substantially smaller extent than the first vacuum chamber (15). Device according to one of claims 12 to 16, characterized in that the second vacuum chamber (28b, 29b) is arranged upstream of the first vacuum chamber (15) in the conveying direction of the strand conveyor (7, 8). Device according to one of claims 12 to 16, characterized in that the second vacuum chamber (28a, 29a) is arranged within the first vacuum chamber (15). Device according to one of claims 12 to 18, characterized in that the extent of the second vacuum chamber (28, 29) in the conveying direction of the strand conveyor (7, 8) is greater than the extent of the discharge opening (26, 27) of the conveying lines (23, 24 ). Device according to one of claims 12 to 19, characterized in that the second vacuum chamber (28, 29) is offset in the conveying direction of the strand conveyor (7, 8) against the at least one discharge opening (26, 27) of the conveying lines (23, 24). Device according to one of claims 12 to 20, characterized in that the discharge opening (26a, 27a) of the conveyor lines (23, 24) opens into the feed means (2) for feeding the tobacco shower. Device according to one of claims 12 to 21, characterized in that the orientation of the discharge opening (26, 27) of the conveying lines (23, 24) has a component in the conveying direction of the strand conveyor (7, 8). Device according to one of claims 12 to 22, characterized in that at least one sensor (36, 37) for measuring the vacuum is arranged in the second vacuum chamber (28, 29). Device according to one of claims 12 to 23, characterized in that a sensor (38) for measuring the vacuum is arranged in the first vacuum chamber (15). Device according to one of Claims 12 to 24, characterized in that adjusting means (33, 34) are assigned to the second suction means (35) in order to control the amount of air extracted from the second vacuum chamber (28, 29). Apparatus according to claim 25, characterized in that a control unit (39) is provided for controlling the amount of air extracted, which is connected to the pressure sensors (36, 37, 38) and the adjusting means (33, 34).

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