EP1285592A2 - Apparatus for forming a tobacco rod in a rod making machine - Google Patents

Abstract

A supplier supplies a constituent such as shreds of tobacco leaf laminate to a foraminous conveyor (41). A guide has a surface defining path for advancement of the constituent to the conveyor. A sifter (12) is arranged to supply the constituent and air towards a metering device, from the conveyor.

Description

The invention relates to an arrangement for the construction of at least one tobacco rod in a cigarette rod maker, with dosed and sighted tobacco on one a Saugstrangförderer leading, a tobacco / air layer forming flow area conductive delivery means.

The initially described arrangement is known in the tobacco processing industry as a so-called distributor and in the context of the invention as a tobacco air mixture leading to a Saugstrangförderer concave nozzle trough fluid bed distributor of a cigarette rod machine of the type shown for example in US-PS 5,645,086.
Particularly in the case of the last-named fluidized bed distributor, which is predestined for exact compliance with prescribed test parameters, defined flow conditions and a balanced air balance of the fluidic components which are significantly involved in the strand construction are of particular importance.

The invention is based on the object by an optimized structural and fluidic Design of the tobacco delivery means the positive effect of Fliesssbettverteilers still reinforce and stabilize.

This object is achieved according to the invention in that the supply means have a view means arranged upstream of a dosing agent opening into the flow area in relation to the conveying direction of the tobacco. In this way, regardless of the particular composition with respect to the particle size (ribs, dust, leaf fibers) of the tobacco supplied due to prior separation of undesirable components always ensures an exact dosage of tobacco for the purpose of building a constant fluid bed current.
This effect, which is particularly favorable for the structure of the fluidized bed current, is further enhanced according to a further proposal by the fact that the viewing means arranged upstream of the dosing means are designed as a substantially vertically aligned pneumatic zig-zag sifter, whereby an even better separation of tobacco fibers and ribs is reached.
A specific combination of zig-zag sifter and stowage structurally and fluidically optimizing development is that between the zig-zag sifter and above a removal roller having a vibrating shaft outlet stowage a tobacco / air separator is arranged.
By a further embodiment, according to which the tobacco / air separator designed as a Coanda separator and the zig-zag separator are integrated into a circulating air system operated by a frequency-controlled cross-flow fan, air and tobacco are separated from one another with a high degree of separation and the process air recovered in one homogeneous velocity distribution maintained in the recirculation system, so that a balanced air balance can be kept in the classifier system with minimal energy consumption.

The efficiency of the zig-zag sifter can be increased by the number of zig-zag stages, but this is paid for by increasing the height. A disadvantage of this embodiment according to the invention, on the other hand, is that the zig-zag classifier below the last lower discharge stage is assigned a pneumatic end-of-line separator designed as an air box defined by a sieve. In this way, the visual effect is again improved at the same height that any entrained with the tobacco ribs lighter tobacco fibers are transported back into the main air stream of the classifier again.
In order to realize the operation of the Nachsichters easily without additional effort, it is further proposed that the Nachsichter is connected to a the tobacco / air layer forming concave flow surface acting on the air circulation system.
In order to produce a balanced air balance in the classifier system in spite of the additionally supplied classifying air of the indenter, it is provided according to a development that the recirculation system of the zig-zag classifier is provided with a bypass branching off downstream of the cross-flow fan in relation to the flow direction of the circulating air the same amount of air is sucked, which is supplied by the indenter the Sichtersysem.
In order to avoid that there is a buildup of dust in the recirculation system of the classifier circuit, the bypass is branched off in the course of the outer radius of a Umluftkrümmers the circulating air system, ie at a point where dust particles are safe in the extraction area.
With the aid of an additional embodiment, according to which the zigzag sifter in the region of the last lower sifter stage is provided with a rotary beater roller opposite the defroster, tobacco clumps can also be detected and dissolved.
When building a tobacco rod on Saugstrangförderer it is common to supply tobacco in excess and then separate the excess from the strand and returned to the supplied tobacco stream. An embodiment of the invention solves this excess return in a particularly uniform and tobacco-friendly manner, characterized in that the view means is provided with a in the area of the last upper level of the zigzag sifter in the air circulation opening pneumatic excess return. Here, according to a preferred embodiment, the air circulation system of the zig-zag classifier is modified and utilized such that the transport air of the excess return is branched off in the course of the inner radius of Umluftkrümmers from the air circulation system of the zig-zag sifter.
In order to optimize the efficiency of the viewing device, it is further proposed that the zig-zag separator is provided with a leading in the middle height section, downwardly leading, and feedable by means of an addition roller tobacco feed chute.

In order to ensure the effectiveness of the zig-zag sifter and the quality and uniformity of the sighting permanently and to be able to intervene if necessary corrective, it is further provided that the speed of the cross-flow fan depending on a prevailing in the zigzag sifter differential pressure controllable is. For this purpose, according to a further proposal, a differential pressure-monitoring differential pressure gauge is linked to a measuring point provided above the last upper viewing stage and a measuring point provided at the level of the lower discharge stage of the zig-zag separator.
The inventive linkage of the storage shaft with the zig-zag sifter is optimized according to a development to ensure correct operation of the storage shaft characterized in that the speed of the addition roller is controlled in dependence on the tobacco level in the stowage.

To achieve a space-saving design of the overall arrangement in the form of a distributor of a cigarette rod machine is provided according to a modified embodiment that the zigzag sifter can be loaded by a tobacco from a reservoir entnehmendes steep conveyor belt.
In the narrowed construction of the distributor effected in this way, according to a further development, an excellent visual result is guaranteed by the fact that the steep conveyor belt is connected to a tobacco feed chute opening into the zigzag sifter above the middle height section.

Also in this design, the possibility of pneumatic return of excess tobacco is given in the upper flow region of the zig-zag separator. Since the tobacco reservoir of the steep conveyor belt has a sufficient volume, it is provided according to an alternative embodiment that removed excess tobacco is traceable by a screw conveyor into the tobacco reservoir of the steep conveyor belt.
In order to optimize a correct operation of the Stächachtes also proposed in this variant, to control the conveying speed of the steep conveyor belt depending on the tobacco level in the stowage.

The advantage achieved by the invention is that at a reduced aerodynamic energy expenditure and a balanced air balance optimal degree of separation of quality-reducing tobacco components is achieved, so that even with different tobacco conditions a good visual outcome and thus ensuring a high recycling rate of desirable tobacco components is. Ultimately, this means that the quality of the end product remains consistently high in the long term guaranteed.

The invention is described below with reference to further illustrated in the drawing Details explained in more detail.

Figur 1

Einen Querschnitt durch einen Verteiler einer Zigarettenstrangmaschine,

Figur 2

einen Schaltplan des Prozessluft-Systems der Maschine,

Figur 3

steuerungstechnische Einzelheiten zur Überwachung und Korrektur des Betriebs der Dosier- und Sichtmittel und

Figur 4

einen Querschnitt durch eine variierte Ausführungsform des Verteilers.

Hereby show:

FIG. 1

A cross section through a distributor of a cigarette rod machine,

FIG. 2

a circuit diagram of the process air system of the machine,

FIG. 3

Control details for monitoring and correcting the operation of dosing and sighting devices and

FIG. 4

a cross-section through a varied embodiment of the distributor.

The cigarette machine distributor shown in Figure 1 is provided in a known manner with a pneumatic tobacco feed lock 1 and a pre-distributor 4 consisting of two intermeshing rake rolls 2 and 3.
The pre-distributor 4 opens into a tobacco reservoir 6, the discharge side is associated with an addition roller 7, which cooperates with a tobacco combing paddle roller 8 and tobacco with a downwardly leading feed chute 9 knocking out separating roller 11. The feed chute 9 opens laterally into the middle section of a viewing means in the form of a vertically arranged zig-zag separator 12.
The zig-zag sifter 12 is part of a circulating air fan 14 operated by a cross-flow fan 13 according to FIG 2. Relative to the flow direction of the air circulation system 14, a Umluftkrümmer 17 is provided downstream of the cross-flow fan 13, which branches off in the region of its outer radius in one of the air circulation system 14 Bypass passes 18 and in the region of its inner radius in a surplus flow channel 19, in which a Tabaküberschusstransportmittel in the form of a screw conveyor 21 and a cellular wheel 22 opens. On the other hand, the excess flow channel 19 is connected on the output side to the recirculation system 14 via a return line 23 which leads back tobacco in the last upper level of the zig-zag classifier 12 into the classifier circuit.
In the recirculation system 14 of the classifier circuit also designed as a Coanda separator tobacco / air separator 16 is integrated, which is connected on both sides of a Abscheidekante 26 on the one hand to the suction side of the crossflow fan 13 and on the other hand into a above a stowage 27 arranged rotary valve 28 opens.
The substantially perpendicularly arranged stowage compartment 27 ends with its lower end formed as a vibrating shaft outlet 29 via a removal roller 32 cooperating with a rollover roller 31.

Below the removal roller 32 extends a guide channel, which is delimited by a curved guide surface 33, which merges into a two-lane contrasting flow surface 34 of a rolling chamber 36.
The rolling space 36 is integrated according to FIG. 2 into a further circulating air system 37, which generates a tight-fitting, tobacco-conveying air flow by means of a circulating-air blower 38 on the flow surface 34. The rolling space 36 has a connection to the atmosphere via an upper screen cover 39.
The two-part, upwardly leading flow surface 34 opens below a strand assembly 41 of a double-strand machine.
The strand-forming unit 41 designed as a suction-strand conveyor is operated by a suction-belt blower 42, as shown in FIG.
The zig-zag sifter 12 is also equipped with a pneumatic Nachsichter 43, which opens below the last lower discharge stage 44 in the zig-zag classifier 12 and is formed as defined by a sieve 46 air box 47. The Nachsichter 43 is connected according to Figure 2 with the pressure side of the flow area 34 of the rolling chamber 36 acting on the air circulation system 37. To compensate for the additional air introduced into the air intake system 14, the bypass 18 is connected to the suction side of the Saugstranggebläses 42 for the purpose of producing a balanced air balance.
Below the Nachsichters 43 a discharge system 48 is provided, consisting of a screw conveyor 49 and a rotary valve 51. In addition, the zig-zag separator 12 is provided in the region of the last lower discharge stage 44 with the Nachsichter 43 opposite rotary beater roller 52. For the purpose of detecting faults (blockage, incorrect setting, etc.) in the sifter area of the zig-zag sifter 12, differential pressure monitoring is provided according to FIG. 3 by installing pressure sensors 53 and 54 at the top and bottom of the sifter, which are equipped with a differential pressure gauge 56 are linked. To correct the visual parameters, a motor 58 is activated by means of a control unit 57 to increase or decrease the rotational speed of the cross-flow fan 13.
In addition, a per se known sensor unit 59 is linked to the level monitoring in the stowage 27 with a control unit 61 which activates a motor 62 for correcting the speed of the zig-zag separator 12 charging addition roller 7 in case of impermissible height variations in the stowage 27.

The mode of operation of the separator system, which is used to prepare a fleece-like tobacco stream which has been converted into a strand-forming path and integrated into the distributor of a cigarette rod machine, is as follows:
Tobacco passes through the feed lock 1 and the pre-distributor 4 into the tobacco reservoir 6 for the addition roller 7, from which the separator system is charged with a continuous stream of tobacco by combing tobacco from the tobacco reservoir 6 with the addition roller 7 equipped with steep conveying combs to form a tobacco roll. In order to achieve a uniform occupancy of the addition roller 7, excess tobacco is scraped off by the paddle roller 8. By monitoring the roller speed, a machine stop can be triggered at reduced rated speed, for example, to prevent damage by foreign bodies.
The tobacco lying on the addition roller 7 passes into the area of action of the separating roller 11, which accelerates the tobacco into the zig-zag separator 12 by rough pre-singling and whose speed is set in terms of a compromise between tobacco destruction and necessary singling, preferably in one Range between 800 and 900 revolutions per minute.

Due to the characteristic shape of the zigzag classifier 12, on the one hand light tobacco fibers of the tobacco stream are transported upwards and on the other hand the tobacco stream is displaced in a direction transverse to the main flow. Since the flow profile is inhomogeneous, resulting in areas of high and low air velocity, which put the tobacco fibers in a circular motion, so-called vortex rolls. In this way, the ribs contained in the tobacco stream are extracted and moved by gravity down. Lightweight tobacco fibers are repeatedly transported step by step in the zigzag sifter 12 upwards. This process takes place in each trained as a gob sight stage.
The ribbed material dropping out of the zigzag sifter 12 is blown through the viscous separator 43 with the aid of sifting air diverted from the circulating air system 37, with the result that lighter tobacco particles which may still be adhering to the ribs are transported back into the main air stream.
With the help of the arranged at the lower output of the zig-zag sifter 12 racquet roller 52 possibly existing tobacco clumping are detected and resolved. This crushing operation is effected by the clamping effect of the spikes of the racket roller 52 to a counter-sheet enclosing this by the lumps are drawn by the counterclockwise rotating racket roller 52 inwardly through the slots of the racket roller and discharged again below.
The finally falling out of the zig-zag separator ribbed material enters the screw conveyor 49 of the discharge system 48, which transports the ribs in the longitudinal direction (perpendicular to the plane) over the full distribution width to below arranged rotary valve 51.
The fiber stream freed from all unwanted constituents is added to excess tobacco in the underpressure region of the upper classifier outlet via the return line 23, which tobacco cake is taken off in the known manner in the trim area of the suction belt conveyor 41 and transported away by means of screw conveyors 21. This excess tobacco is combined in accordance with the invention on the rotary valve 22 with the overflow channel 19 on the pressure side from the air circulation system 14 of the separator circuit branched transport air and directed into the return line 23.

The sifted tobacco stream, combined with the excess tobacco, passes into the tobacco / air separator 16, in which the separation of tobacco and air takes place by the centrifugal force and the Coanda effect, whereby the tobacco fibers are in the form of a curved outside due to the centrifugal force on the outer geometry 64 of the separator 16 are moved along and the air due to the Coanda effect on the inner radius of the geometry in the form of a cylindrical surface of a tubular body 66 applies. At the Abscheidekante 26, the final separation of air and tobacco takes place, the air separated from the tobacco is fed back to the crossflow fan 13, which has a uniform flow profile or over the width (perpendicular to the plane) of the distributor a homogeneous velocity distribution.
A portion of the recirculating or stream of air flow along the outside wall of the recirculating air manifold 17 on the pressure side of the crossflow fan 13 is tapped via the bypass 18 to compensate for any leakage and for the purpose of producing a balanced air balance in the classifier system. This is achieved by the same amount of air is sucked off, as is supplied by the Nachsichter 43 to the classifier system. This is associated with a further advantage by concentrating tobacco dust particles in the bleed air guided in the manner proposed and with it being removed, so that dust accumulation in the separator cycle is prevented.
The enriched with tobacco dust bleed air is separated according to Figure 2 by connecting the bypass line 18 to an axial cyclone 67 of the operated by the Saugstrangbläse 42 Saugstrangkreislaufs and returned recyclable tobacco dust in a manner not shown in the cigarette manufacturing process.

The separated by the tobacco / air separator 16 tobacco is discharged through the rotary valve 28 from the viewing system and enters in a known manner in the stowage 27, from which he out by means of the removal roller 32 and the racket roller 31 in a finely divided form on the curved guide surface 33rd is transferred to the nozzle surface designed as a nozzle, the rolling space 36 limiting flow area 34. With the help of in the flow area 34, indicated in Figure 2 symbolically Blasluftzuführungen 68, 69, 71 of the circulating system 37 is on the flow surface 34 while maintaining an ideal pressure in the form of a slight negative pressure in the vicinity of 0 mb in a known manner a tight-fitting tobacco fluid bed Flow to the strand assembly unit 41 produced out whose height is monitored in a manner not shown and optionally corrected by adjusting a connected to a Nebenluftansaugung 73 control unit 72 of the Umluftsytems 37 according to Figure 2.
Since a certain amount of air is required in the strand assembly unit 41 during suction strand conveyance, which is drawn off from the rolling space 36, via the blast air supply lines 68, 69, 71 a smaller quantity of air is supplied or air loaded via the screen cover 39 with dust via a deduster 74 the Wälzraum is deducted, in addition to the supplied via the Nebenluftabsaugung 73, controlled by the control unit 72 air quantity dedusted by the dust collector 74 the air supplied to the axial cyclone and created by an atmospheric connection 76 of the Wälzraumes 36 another compensation air flow.
With 77 to 81 additional control units for setting and maintaining optimum flow conditions and monitored by display devices 82 to 87 monitored pressure conditions.

In the variant of the distributor shown in Figure 4 are the same or the same effect Elements with a hundred increased reference numbers provided.

In this embodiment, the addition roller 7 is replaced according to Figure 1 by a steep conveyor belt 107 which takes tobacco from a tobacco reservoir 106, transported upwards and transferred by means of the separating roller 111 in the tobacco feed chute 109 above the central height portion of the zig-zag classifier 112 ,
In the strand forming process removed excess tobacco is guided by means of a screw conveyor 121 in the tobacco reservoir 106 of the steep conveyor belt 107 back.
The transport speed of the steep conveyor belt 107 can be controlled in the manner shown in Figure 3 depending on the tobacco level in the stowage 27.

Claims (19)

Arrangement for constructing at least one tobacco rod in a cigarette rod machine, with metered and sighted tobacco on a leading to a Saugstrangförderer, a tobacco / air layer forming flow surface conductive supply means, characterized in that the supply means - based on the conveying direction of the tobacco - a in the Having flow surface (34) opening dosing means (27) upstream upstream of the viewing means (12). Arrangement according to claim 1, characterized in that the metering means (27) arranged upstream of the dosing means (12) is designed as a substantially vertically oriented zig-zag separator. Arrangement according to claim 1 or 2, characterized in that a tobacco / air separator (16) is arranged between the zig-zag sifter (12) and the delivery shaft (27) having a vibrating shaft outlet (29) above a removal roller (32) , Arrangement according to one of Claims 1 to 3, characterized in that the tobacco / air separator (16) designed as a Coanda separator and the zig-zag separator (12) are operated in a circulating air system (14) operated by a frequency-controlled cross-flow fan (13). are integrated. Arrangement according to one of claims 1 to 4, characterized in that associated with the zigzag sifter (12) below the last lower discharge stage (44) as a by a sieve (46) delimited air box (47) formed pneumatic Nachsichter (43) is. Arrangement according to claim 5, characterized in that the indifferent (43) with a the tobacco / air layer forming concave flow surface (34) acting on the air circulation system (37) is connected. Arrangement according to one of claims 1 to 6, characterized in that the recirculation system (14) of the zigzag sifter (12) with a - based on the flow direction of the circulating air - downstream of the cross-flow fan (13) branching bypass (18) is provided , Arrangement according to claim 7, characterized in that the bypass (18) in the course of the outer radius of a Umluftkrümmers (17) of the circulating air system (14) is branched off. Arrangement according to one of claims 1 to 8, characterized in that the zigzag sifter (12) in the region of the last lower sifter stage (44) is provided with a rotary beater roller (52) opposite the baffle (43). Arrangement according to one of claims 1 to 9, characterized in that the viewing means is provided with a in the last upper classifier stage of the zigzag sifter (12) in the air circulation system (14) opening pneumatic excess return (23). Arrangement according to claim 10, characterized in that the transport air of the excess return (23) in the course of the inner radius of the Umluftkrümmers (17) from the air circulation system (14) of the zigzag sifter (12) is branched off. Arrangement according to one of claims 1 to 11, characterized in that the zigzag sifter (12) is provided with a leading in the region of the middle height section, downwardly leading and by means of an addition roller (7) feedable tobacco feed chute (9). Arrangement according to one of claims 1 to 12, characterized in that the rotational speed of the cross-flow fan (13) in dependence on a pressure prevailing in the zig-zag separator (12) differential pressure is controllable. Arrangement according to Claim 13, characterized in that a differential pressure gauge (56) monitoring the differential pressure is provided with a measuring point (53) provided above the last upper viewing stage and a measuring point provided at the level of the lower rejection level (44) of the zigzag sifter (12) (54). Arrangement according to one of claims 1 to 14, characterized in that the speed of the addition roller (7) is controllable in dependence on the tobacco level in the storage shaft (27). Arrangement according to one of claims 1 to 11, characterized in that the zig-zag sifter (112) by a tobacco from a reservoir (106) entnehmendes steep conveyor belt (107) can be fed. Arrangement according to Claim 16, characterized in that the steep conveyor belt (107) is connected to a tobacco feed chute (109) which opens into the zigzag sifter (112) above the middle height section. Arrangement according to claim 16 or 17, characterized in that removed excess tobacco by a screw conveyor (121) in the tobacco reservoir (106) of the steep conveyor belt (107) is traceable. Arrangement according to one of claims 16 to 18, characterized in that the conveying speed of the steep conveyor belt (107) in dependence on the tobacco level in the stowage bay (27) is controllable.

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