EP2521462B1 - Method and device for separating foreign bodies from a flow of tobacco - Google Patents

Description

The invention relates to a method for foreign body separation from a first tobacco stream, wherein the first tobacco stream is promoted in the region of a first foreign body detection device with an air flow, and detected by means of the first foreign body detection device based on at least one property foreign body in the first tobacco stream and then with a blast of compressed air from the first Tobacco stream are removed, so that the liberated from foreign bodies first tobacco stream and a second stream of entrained by the blast of compressed air tobacco particles and foreign bodies form.

The invention further relates to a device for foreign body separation from a first tobacco stream having a device supplying the first tobacco stream to a first foreign body recognition device (delivery device) and a first foreign body ejection device downstream of the first foreign matter detection device, wherein the first tobacco stream delivery device comprises a source of pressurized air, and wherein the first foreign matter discharge device comprises a first nozzle device by means of which foreign bodies are removable from the first tobacco stream with compressed air, resulting in a second stream of foreign matter and by the compressed air entrained tobacco particles results.

A method for foreign body separation from a tobacco stream and a corresponding device are, for example DE 10 2004 015 463 B4 known. By this method and this device, it is known to examine a tobacco stream for foreign substances at a high tobacco throughput and weed out accordingly foreign bodies.

The property which serves to detect the foreign body in the tobacco stream may be an optical property of the tobacco or of the foreign body, such as the brightness, shape and / or color or another physical property, such as, in particular and within the scope of the invention the humidity, the specific gravity or the presence of corresponding elements (carbon or metals).

The foreign body recognition is preferably carried out by means of a detection of the brightness and / or color of the objects contained in the tobacco stream. By objects is meant in particular tobacco, tobacco leaves, cut tobacco and foreign matter. The conveying speed of the tobacco stream is according to the DE 10 2004 015 463 B4 and also according to the invention between 6m / s and 30m / s, in particular between 17m / s and 30m / s. The preferred speed is a very effective promotion of tobacco flow provided, whereby a very high throughput is possible. In particular, the embodiments according to the DE 10 2004 015 463 B4 with respect to the drawing of the tobacco stream transversely to the conveying direction in the one direction and the tapering of the tobacco stream transversely to the conveying direction and in the other direction, which is also transverse to the one direction, also provided.

Out EP 1 838 464 B1 For example, a method and apparatus for sorting a stream of generally flat and lightweight articles of different dimensions are known, wherein the articles to be sorted out are extracted by suction by suction from the main stream by suction.

Out EP 1 576 897 B1 For example, an apparatus and method for scanning and sorting tobacco leaves is known, wherein a rejection device is provided which responds to a rejection signal and is arranged to force unacceptable tobacco leaves and unwanted particles from the delivery channel.

EP 1 591 172 A1 discloses a method and apparatus for foreign body deposition from a material stream. In this case, a material flow is conveyed by means of an air flow and by means of a foreign body recognition device, foreign bodies are detected from this material flow and removed from the material flow.

EP 1 576 897 A1 discloses an apparatus and method for scanning and sorting tobacco leaves. The scanning and sorting happens here in two stages.

The devices and the method according to the prior art all have the disadvantage that after sorting the Foreign bodies which are sorted out with any sorted out and actually good or acceptable tobacco leaves in a relatively large amount, so that a relatively high tobacco loss arises. As a result, a re-sorting is necessary, which is carried out in the prior art on conveyor belts in an optical process. This leads to a very high expenditure on equipment and, in spite of everything, to results which can be improved.

Object of the present invention is to allow an improved rate of rejected foreign body to tobacco particles.

This object is achieved by a method for foreign body separation from a first tobacco stream, wherein the first tobacco stream is promoted in the region of a first foreign body detection device with an air flow, and detected by means of the first foreign body detection device based on at least one property foreign body in the first tobacco stream and then with a blast of compressed air are removed from the first tobacco stream so that the first tobacco stream freed from foreign bodies and a second stream of tobacco particles and foreign bodies entrained by the blast of compressed air, which is further developed that the second stream is accelerated away from the first tobacco stream and by a second foreign body detection device again foreign bodies are detected by at least one property in the second stream and then removed with a blast of compressed air, wherein the acceleration of the second stream upstream of the second Fremdk Body recognition device is done by a reduction in volume of a discharge channel for the second stream.

In the context of the invention, foreign bodies are also understood to mean tobacco products which are unacceptable for further processing. in this connection For example, they are too large tobacco ribs.

The invention adopts the idea that in the state of the art with regard to the discharged stream of foreign bodies and entrained tobacco particles, which would be suitable for further processing, thought was given, which on the one hand ensures efficient removal and on the other hand Ensures further efficient sorting of foreign bodies with a high sorting rate or high delivery rate.

The first idea according to the invention, namely to accelerate the second stream away from the first tobacco stream, serves, in particular, to prevent lighter foreign bodies, such as feathers, from being drawn back into the first tobacco stream by turbulence, for example. Due to the acceleration in the discharge channel, an efficient removal of all particles sorted out by the pressure surge, namely corresponding foreign bodies and also entrained tobacco particles, is made possible. The further idea according to the invention, namely to provide a second foreign body recognition device, which again recognizes foreign bodies by means of at least one property in the second stream and subsequently removes them with a blast of compressed air, ensures that at the end there is a particle stream which essentially consists only of tobacco, which is efficient can be reused and recirculated. Since this all happens in an airflow system, a very efficient, small scale equipment can be realized which efficiently enables very high throughput foreign matter separation from a tobacco stream.

In the case of a tobacco stream quantity of about 1 t / h to 10 t / h to be separated or deposited by foreign bodies, for example, 1% of still good tobacco has been obtained by the foreign body separation with excreted. According to the invention, there are now only about 0.05% of the good tobacco that is excreted as a whole.

Preferably, the second de-energized second stream is added to the first tobacco stream upstream of the first foreign-matter-detecting device. Thus, the second stream, which then consists only of further processed tobacco particles, traceable or is returned to the first stream of tobacco. This recirculation can be done, for example, on a feed trough, for example a vibrating trough, or in the region of a feed lock or in the area of the first flow conveyed by an air flow. This recycling is preferably done upstream of the first foreign matter detecting device, but may be done downstream of the first foreign matter detecting device and the first foreign matter ejecting device.

It is particularly preferred if the second stream freed from foreign bodies is conveyed to a feed device which mechanically conveys a first tobacco stream and subsequently discharges it into the air stream.

According to the invention, the second stream upstream of the second foreign matter detection device is made to accelerate by a volume reduction of a second stream discharge channel. The taper of Abförderkanals thus happens in the conveying direction of the second stream. Here, the Bernoullie effect is exploited. As a result, the foreign bodies and tobacco particles ejected or separated from the first tobacco stream are thus reduced by volume reduction or cross-sectional area reduction of the discharge channel in the conveying direction and thus acceleration entrained in the particle.

Preferably, the conveying speed of the first tobacco stream is controlled or regulated in the region of the first foreign body recognition device. As a result, very high foreign body deposition rates can be achieved and, correspondingly, a very accurate or precise sorting out of foreign bodies.

The object is further achieved by a device for foreign body separation from a first tobacco stream with a device supplying the first tobacco stream to a first foreign body recognition device (delivery device) and a foreign body ejection device downstream of the first foreign body recognition device, wherein the delivery device for delivering the first tobacco stream comprises a compressed air source, and wherein the first foreign body ejection device comprises a first nozzle device by means of which foreign bodies from the first tobacco stream with compressed air are removable, resulting in a second stream of foreign bodies and tobacco particles entrained by the compressed air, which is further developed by a discharge channel is provided, through which the second Strom is conductive, wherein the discharge channel is at least partially tapered in the conveying direction and a second foreign body detection device and a second Foreign body ejection device is provided downstream of the second foreign body detection device having a second nozzle device by means of which foreign bodies from the second stream are removable, wherein the discharge channel is formed immediately adjacent to the supply device tapered.

The subsequent discharge channel or branch channel of the is branched off from the conveyor channel or conveyor shaft is thus immediately afterwards tapered. This can then later in the flow direction again widened or be widening or be formed with a constant volume or constant cross-sectional area. First, however, is essential to the invention for the one essential part of the invention that the subsequent channel or discharge channel is tapered or will, so as to exploit the Bernoullie effect for the expelled foreign body and tobacco particles can.

Preferably, the discharge channel, which is immediately adjacent to the supply device, a space in which a flow body is arranged. By providing the flow body in the space, it is in fact possible, the immediately subsequent discharge channel, in which the foreign body and the entrained Tobacco particles are thrown to form tapering in the conveying direction. Namely, the flow body forms with the walls of the space an at least initially tapering channel in the conveying direction. Preferably, an extension of the flow body is provided downstream of the flow body to prevent backflow.

Preferably, the discharge channel in which the second stream, in particular freed from foreign bodies, can be conveyed, opens in or upstream of a device which promotes a first tobacco stream. In this way, a type of circulation of the tobacco particles, which are already freed from foreign bodies, happen, so that the entrained by the first foreign body separation tobacco particles that were otherwise lost or consuming as in the art on conveyor belts would have to be spotted again, immediately again can be given in the first tobacco stream. This can be done before conveying with conveying air, directly into the conveying air, before the first foreign body detection device or in the flow after the first foreign body detection device.

Particularly preferred is the measure in which a control or regulating device is provided which controls or regulates the conveying speed of the first tobacco stream in the region of the first foreign body recognition device. As a result, a very accurate and efficient foreign body separation is possible. Preferably, a control input parameter is the frequency or speed of a fan for generating the compressed air or the conveying air flow.

The conveying air flow may preferably be generated by compressed air or suction air and in particular preferably by a combination thereof.

Fig. 1

eine erfindungsgemäße Fremdkörperabscheidungsvorrichtung in schematischer Darstellung,

Fig. 2

einen Teil der Vorrichtung aus Fig. 1 in einer ersten Ausführungsform in schematischer Darstellung,

Fig. 3

einen Teil der Fig. 1 in einer zweiten Ausführungsform in schematischer Darstellung und

Fig. 4

einen Teil der Vorrichtung der Fig. 1 in einer dritten Ausführungsform in schematischer Darstellung.

The invention will be described below without limiting the general inventive idea by means of embodiments with reference to the drawings, reference being expressly made to the drawings with respect to all in the text unspecified details of the invention. Show it:

Fig. 1

a foreign body deposition device according to the invention in a schematic representation,

Fig. 2

a part of the device Fig. 1 in a first embodiment in a schematic representation,

Fig. 3

a part of Fig. 1 in a second embodiment in a schematic representation and

Fig. 4

a part of the device of Fig. 1 in a third embodiment in a schematic representation.

In the following figures, identical or similar elements or corresponding parts are provided with the same reference numerals, so that a corresponding renewed idea is dispensed with.

In Fig. 1 schematically a foreign body separation device according to the invention is shown. First, a first tobacco stream 13 is transported on a vibrating trough 10 in the conveying direction 14. The first tobacco stream 13 contains tobacco particles 15, foreign bodies 17 and heavy parts 16, which are also to be regarded as foreign bodies. Left at the end of the vibrating channel 10 is a chute into which the first tobacco stream 13 passes. The first tobacco stream 13 is thus conveyed into a feed lock 11, the dosage for the first Tobacco stream 13 can serve. This promotes the first tobacco stream 13 in a space in which there is a conveying air flow. The conveying air flow is produced inter alia by a compressed air flow 32 ', which is generated by a fan 51 and is introduced by a schematically illustrated feed pipe 33 in a corresponding housing 55 and passes through sieves 54 as conveying air stream 34 into the delivery chamber. Another portion of the conveying air flow 34 has its origin in a fresh air supply 12 and the suction effect of the discharged air 32nd

In the housing 55 is located in the lower part of a lock 37, which receives downwardly falling heavy parts 16 and emits in a Schwerteilbehälter 38. The lighter parts, namely the intended for further processing tobacco particles 15 and foreign bodies 17, which may be springs or not for further processing to be used tobacco particles or, for example, an aluminum foil piece are carried by the conveying air stream 34 vertically upwards into the feed chute 22. To the introduced by the fan air stream 32 ', which is transformed into the conveying air streams 34, a certain amount of fresh air is still introduced via the fresh air supply 12 into the housing 55 via the lower region of the feed lock 11.

The first tobacco stream 13, from which the heavy parts 16 have fallen due to their weight, is now conveyed in the conveying shaft 22 by means of the conveying air flow 34 in the conveying direction 18 in the region of a first foreign body detection device, which is shown here as a first camera 20. If the first camera 20 now recognizes a foreign body 17, the first nozzle device 21 is activated precisely at the time which, at a known conveying speed, results from the time offset from the area of the foreign body recognition to the area of foreign body separation in the area the first nozzle device 21 calculated. It is at the right time a compressed air blast 28 for discharging the foreign body 17 is generated to the right into the discharge chute 23.

It should be noted that the delivery shaft 22 has a depth perpendicular to the plane of the plane Fig. 1 is, that is dependent on the flow rate. The depth can be, for example, 60 cm, 120 cm or 180 cm, for 3 tons of tobacco per hour, 6 tons of tobacco per hour or 9 tons of tobacco per hour. Accordingly, the first camera is preferably a line scan camera with a corresponding depth. Accordingly, the first nozzle device 21 is also a nozzle device which has a plurality of nozzles in the depth, for example a nozzle every 2 mm, so that only a few nozzles need be actuated to detect a compressed-air impact per recognized foreign body 17.

For example, if a foreign object is detected by the first camera 20 at a depth of 20 cm, calculated from the front wall of the delivery chute 22, then eight nozzles, which are arranged approximately 19 cm to 21 cm in depth, can be actuated, to safely eject the foreign body. Naturally, tobacco particles 15, which can be used for further processing, are naturally also ejected from the first tobacco stream and conveyed away into the discharge chute 23.

The thus forming second stream 15 of reusable tobacco particles 15 and foreign bodies 17 is conveyed away in Abförderrichtung 19 and initially accelerated by tapering the Abförderschachtes 23. The taper of Abförderschachtes 23 is in Fig. 1 only minimal to not provided. The taper, which is preferably provided, is correspondingly in the other figures better represented.

The tobacco particles 15 and the foreign bodies 17 then pass, for example, onto a corrugated sheet 39 and slide there on the corrugated sheet 39 down into the region of a second foreign body recognition device in the form of a second camera 24, which may also be a corresponding line scan camera with a corresponding depth. If the second camera 24 detects a foreign body 17, a second nozzle device 25 is again correspondingly activated in order to discharge the foreign bodies 17 into a foreign body container 26. The remaining tobacco particles arrive in the feed direction 27 on the first tobacco stream 13, which is located on the Schüttelrinne 10. This tobacco is then returned to the further processing process.

The non-excreted or conveyed tobacco particles are further conveyed downstream of the first nozzle device 21 in the conveying direction 18 'in the conveyor shaft 22 to an air separator 29, in which the conveying air is separated by a sieve 30 of the tobacco particles 15. The conveying air is then returned via a discharge pipe 31 to the fan 51. In this case, some conveying air in the direction of the tobacco stream 35 can be lost. For this reason, some additional air, namely fresh air 12 is always added. The tobacco stream 35 then passes, for example, on a conveyor belt 36 and can be further processed, for example, be issued in cigarette production.

In order to control or regulate the conveying speed of the first tobacco stream 13 in the conveying direction 18 in the region of the first camera 20, a control or regulating device 52 is provided which, for example, determines the frequency or the rotational speed of the fan the conveying speed of the tobacco stream controls or regulates. Alternatively, the speed can also be controlled or regulated via a pressure measurement by a pressure sensor 53 in the tobacco-free air flow in the feed pipe 33 or in the discharge pipe 31. It is also possible that a portion of the conveying air for the regeneration, for example, for cooling, is discharged from the discharge pipe 31. In the container 55 and in the delivery shaft 22, for example, delivery air quantities of about 24,000 m ³ / h are provided.

Fig. 2 shows an alternative embodiment of a part of the device according to the invention, namely the part in which the foreign body deposition from the first tobacco stream 13 in the region of the first nozzle device 21 is done. It can be seen that the first nozzle device 21 has a nozzle bar 43 with a plurality of nozzles, each of which generates a corresponding pressure surge 40. By the promotion or the conveying speed 118, the example in Fig. 2 shown with an arrow, resulting in a resulting stream 41 or a stream with an added speed of conveying speed 118 and pressure surge velocity of abgegeförderten particles, namely foreign bodies 17 and entrained tobacco particles 15. These arrive in the discharge chute 23, immediately following the Delivery shaft 22 is tapered.

In this embodiment ( Fig. 2 ), the delivery chute 22 is provided upstream of the first nozzle device with a larger volume or larger cross-sectional area than downstream of the discharge chute 23, resulting in an increase in the speed downstream of the discharge chute. In addition, it can be seen that the second stream, which is passed through the discharge chute 23, is initially accelerated, in order subsequently to be conveyed again in a region of the discharge chute 23 to be, which expands again, so that in itself results in a reduction in speed. The discharge chute 23 can, however, be designed so that a constant speed prevails there after acceleration, since gravity also causes acceleration for delivery with compressed air. A correspondingly provided uniform speed is particularly advantageous in the area between the second camera and the second nozzle device, which in Fig. 2 but not shown.

In Fig. 3 is an alternative to Fig. 2 no free fall of the second stream provided, but a slippage of the second stream on a checker plate 42, which of course provides in the conveying direction through the corrugation corresponding tracks for the second stream. Instead of a Riffelblechs 42 can also be a corrugated sheet 39 as in Fig. 1 be provided or a smooth sheet. It can be seen in particular that in this embodiment, the discharge chute 23 is tapered at least up to the second camera 24.

In Fig. 4 an alternative embodiment is shown, in which instead of a simply trained Abförderschachts 23 a space 44 is provided, in which a flow body 45 is provided. in connection with the wall sections 47 to 47 ^VI forms a corresponding discharge channel. Again, the forming discharge channel is tapered in the conveying direction of the second stream, with continuously decreasing distance of the flow body 45 to the corresponding wall 47 to 47 "', so that the distance correspondingly continuously reduced from 48 to 48". Subsequently, the discharge chute 23 widens correspondingly again, as shown by the distances 48 "'and 48"" 47, 47 ', 47 ", 47"', 47 ^IV , 47 ^V and 47 ^VI can also be formed without edges to each other and thus correspondingly curved.

In order to prevent a backflow, an extension 46 of the flow body 45 is still provided.

The vibrating chute used 10 serves to provide a good and uniform pre-distribution of the first tobacco stream, to a desired width or depth, depending on which variant of the foreign body separation device according to the invention is provided, namely, for example, for 3 tons of tobacco material to be conveyed and sorted per hour to 60 cm, at 6t / h to 120 cm and 9t / h to 180 cm. Preferably, corresponding devices are provided with a depth of 50 cm to 3 m.

With the invention, it is no longer necessary, as is necessary in the prior art, to use band sorters. Magnets are no longer necessary because the heavy parts, which are usually magnetic, can be automatically removed by gravity from the tobacco stream.

For the material discharged through the first nozzle device, a streamlined channel is preferably provided, which ensures that all discharged material is also transported away and does not pass back into the first tobacco stream. Preferably, the air in the discharge channel 23 or 47 is additionally removed or sucked off. Preferably, a plurality of adjacent nozzles of the first or second nozzle device is driven to surely segregate foreign matter from the respective stream.

By means of the device according to the invention and the method according to the invention, a very good foreign body separation with low tobacco losses can be achieved at very high processing rates. Tobacco losses are more than an order of magnitude better than in the prior art.

All mentioned features, including the drawings alone to be taken as well as individual features that are disclosed in combination with other features are considered alone and in combination as essential to the invention. Embodiments of the invention may be accomplished by individual features or a combination of several features.

LIST OF REFERENCE NUMBERS

10

vibrating conveyor

11

sluice feeder

12

Fresh air

13

first tobacco stream

14

conveying direction

15

tobacco particles

16

heavies

17

foreign body

18, 18 '

conveying direction

19

removal direction

20

first camera

21

first nozzle device

22

production well

23

Abförderschacht

24

second camera

25

second nozzle device

26

Debris container

27

feed direction

28, 28 '

Blast of compressed air

29

Luftseparierer

30

scree

31

Abförderrohr

32, 32 '

Conveying air stream

33

Zuförderrohr

34

conveying air

35

tobacco stream

36

conveyor belt

37

lock

38

Difficult part container

39

corrugated iron

40

pressure surge

41

resulting current

42

Riffelblech

43

nozzle bar

44

Abförderraum

45

flow body

46

renewal

47, 47 ', 47 ", 47"', 47 ^IV , 47 ^V , 47 ^VI

wall section

48, 48 ', 48 ", 48''', 48 ^IV

distance

50

second stream

51

fan

52

control device

53

pressure sensor

54

control device

55

casing

118

conveyor speed

Claims (8)

1. Method for separating foreign bodies from a first tobacco stream (13), which first tobacco stream (13) is conveyed in the region of a first foreign body detection device (20) by means of an air stream (12, 32, 32', 34'), and foreign bodies (17) in the first tobacco stream (13) are detected by means of the first foreign body detection device (20) on the basis of at least one property and then removed from the first tobacco stream (13) by means of a jet of compressed air (28), thereby forming the first tobacco stream (13) from which foreign bodies (17) have been removed and a second stream (50) of tobacco particles (15) and foreign bodies (17) entrained by the jet of compressed air (18), characterised in that the second stream (50) removed from the first tobacco stream (13) is accelerated and foreign bodies (17) in the second stream (50) are detected again by means of a second foreign body detection device (24) on the basis of at least one property and then removed by means of a jet of compressed air (28'), and the second stream (50) is accelerated upstream of the second foreign body detection device (24) due to a reduction in the volume of a discharge passage (23, 44) for the second stream (50).
2. Method as claimed in claim 1, characterised in that the second stream (50) from which foreign bodies (17) have been removed is fed to the first tobacco stream (13) upstream of the first foreign body detection device (20).
3. Method as claimed in claim 1 or 2, characterised in that the conveying speed of the first tobacco stream (13) is controlled or regulated in the region of the first foreign body detection device (20).
4. Device for separating foreign bodies from a first tobacco stream (13) comprising a device (10, 11, 22) (intake device) feeding the first tobacco stream (13) to a first foreign body detection device (20) and a first foreign body ejection device (21) downstream of the first foreign body detection device (20), which intake device (10, 11, 22) comprises a compressed air source (51) for conveying the first tobacco stream (13), and the first foreign body ejection device (21) comprises a first nozzle device (21) by means of which foreign bodies (17) can be removed from the first tobacco stream (13) by means of compressed air (28), thereby resulting in a second stream (50) of foreign bodies (17) and tobacco particles (15) entrained by the compressed air, characterised in that a discharge passage (23, 44) is provided, through which the second stream (50) can be directed, and the discharge passage (23, 44) is of a tapering design in the conveying direction (19) in at least certain regions, and a second foreign body detection device (24) and a second foreign body ejection device (25) disposed downstream of the second foreign body detection device (24) and having a second nozzle device (25) are provided, by means of which foreign bodies (17) can be removed from the second stream (50), and the discharge passage (23, 44) is of a tapering design directly adj oining the intake device (22).
5. Device as claimed in claim 4, characterised in that the discharge passage (23, 44) is provided in the form of a chamber (44) directly adjoining the intake device (22) in which a stream body (45) is disposed.
6. Device as claimed in claim 4 or 5, characterised in that the discharge passage (23, 44) in which the second stream (50) can be conveyed opens into or upstream of a device (10, 11, 22) conveying the first tobacco stream (13).
7. Device as claimed in one of claims 4 to 6, characterised in that a control or regulating device (52) is provided, which controls or regulates the conveying speed of the first tobacco stream (13) in the region of the first foreign body detection device (20).
8. Device as claimed in claim 7, characterised in that a control input parameter is the frequency of a fan (51) for generating the conveying air stream (32, 32').

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