Patent Application
20050178397
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 10 2004 007 841.6, filed on Feb. 17, 2004, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The invention relates to a method for operating a rod maker (rod-making machine) for tobacco processing, in which a tobacco flow is sifted in a chamber of the rod maker by a first air flow so that tobacco ribs are separated from the tobacco flow, in which the sifted tobacco flow is conveyed in the chamber by the first and/or a second air flow, in which a third and a fourth air flow are provided which convey air out of the chamber. The invention further relates to a rod maker of the tobacco processing industry comprising a tobacco sifter, a suction rod conveyor and a device for conveying tobacco to the suction rod conveyor, in which the device for conveying tobacco defines a chamber, in which an air flow for sifting and for conveying can be introduced into the chamber.
The invention finally relates to an air conveyor system for a rod maker of the tobacco processing industry, including a circulation fan and a suction fan, in which air can be conveyed by the circulation fan into a chamber in which a tobacco flow can be sifted and conveyed in particular by the conveyed air, and where the suction fan is connected to the chamber, and air can be suctioned out of the chamber.
2. Discussion of Background Information
A corresponding method, a corresponding rod maker and a corresponding air conveyor system is known from EP 0 727 156 A1. A corresponding rod maker is sold by the applicant under the name Protos 100.
However, with such a method, such a rod maker and such an air conveyor system, the effect occurs that the rib discharge from the tobacco flow to be sifted changes with the productive capacity of the rod maker. Thus, e.g., when the productive capacity is cut back, more tobacco is sifted out, which leads to a deterioration of the efficiency of the method and of the rod maker. Ultimately, this means the cigarettes correspondingly produced have different properties.
In contrast, an aspect of the invention is to disclose a method for operating a rod maker, a rod maker, and an air conveyor system for a rod maker of the tobacco processing industry by which it is possible to produce qualitatively uniform cigarette rods.
This aspect is attained with a method for operating a rod maker of the tobacco processing industry, in which a tobacco flow is sifted in a chamber of the rod maker by a first air flow so that tobacco ribs are separated from the tobacco flow, in which the sifted tobacco flow is conveyed in the chamber by the first and/or a second air flow, in which a third and a fourth air flow are provided which convey air out of the chamber, that is further developed in that the sum of the air throughput of the third and fourth air flow is essentially constant irrespective of the productive capacity of the rod maker.
Within the scope of the invention, the term productive capacity means in particular the speed of a rod formed from the sifted tobacco flow or a length of a cigarette rod per time unit. Within the scope of the invention, the chamber is in particular a chamber in the rod maker which comprises a rolling chamber, a fluidized bed chamber, and a chamber in which a tobacco flow is sifted. The tobacco sifter can be a pre-sifter. The tobacco sifter can also comprise a post-sifter.
Furthermore, within the scope of the invention the term air throughput means the conveyed quantity of air per time unit or the conveyed air volume per time unit.
By keeping the sum of the air throughput of the third and fourth air flow to an essentially constant value, irrespective of the productive capacity of the rod maker, it is possible to influence the air pressure in the chamber such that a uniform sifting of the tobacco flow is rendered possible. The lower the productive capacity of the rod maker, the faster the suction belt of the suction rod conveyor, which can also be a suction belt conveyor within the scope of the invention, seals up by the application of tobacco so that less air in the form of the third air flow is carried away out of the chamber via the suction rod conveyor. The air throughput conveyed out of the chamber in the form of the fourth air flow should then be increased accordingly so that the air speed at the sifter, comprising a pre-sifter and optionally a post-sifter, does not change too much and preferably remains constant so that the rib discharge from the tobacco flow also remains constant. This effect occurs essentially because the pressure in the chamber remains essentially constant so that the air speed at the sifter does not have to be changed. The sum of the air throughputs of the third and fourth air flow is kept constant automatically or when the rod maker is running.
If an air distributor is arranged upstream of the chamber, where air is discharged from the air distributor into the surroundings, a particularly effective and simple opportunity is provided to change the air throughput conveyed out of the chamber by the fourth air flow. The first, second and fourth air flows are usually part of the circulating air system that is driven by a circulation fan. In the event that air is released from the air distributor into the surroundings, and the air distributor is also part of the circulating air system and is arranged between the circulation fan and the chamber, the circulation fan conveys a greater air quantity due to the smaller pressure difference between inlet and outlet, i.e., the air throughput increases. The air throughput suctioned out of the chamber is thus automatically increased.
The air distributor can also be an air pipe with a branch pipe. Furthermore, air can be released from the air distributor into the surroundings via another air pipe. Preferably, the air throughput released into the surroundings is changed. If a throttle flap is adjusted in a discharge pipe of the air distributor to change the released air throughput, a particularly cost-effective implementation of the method is possible. Within the scope of the invention, the discharge pipe can also be a release pipe and is in particular a diffuser or ends in a diffuser.
Preferably an essentially constant pressure is established in the chamber. In this connection, the chamber comprises in particular the rolling chamber or fluidized bed chamber of the rod maker.
Preferably the air throughput of the fourth air flow conveyed out of the chamber is controlled or regulated. The control or regulation can occur continuously so that the productive capacity of the rod maker can also be changed continuously without the quality of the cigarette rod produced being impaired. To this end, e.g., the air pressure in the chamber is measured and preferably in the area of the sifter or in the rolling chamber. If the control occurs progressively, e.g., by predetermined positions of the throttle flap, a particularly cost-effective process control is possible.
The aspect is further attained through a rod maker of the tobacco processing industry comprising a tobacco sifter, a suction rod conveyor and a device for conveying tobacco to the suction rod conveyor, in which the device for conveying tobacco defines a chamber, in which an air flow can be introduced into the chamber for sifting and conveying, in which the air throughput removed from the chamber is essentially constant irrespective of the productive capacity of the rod maker. According to the invention this occurs automatically or when the machine is running.
Within the scope of the invention the term a device for conveying tobacco includes an apparatus for conveying and/or guiding an air flow or several air flows by which tobacco can be moved. Furthermore, the device for conveying tobacco also comprises, e.g., drop ducts, a fluidized bed, and other devices in a rod maker of the tobacco processing industry.
Preferably an air distributor is arranged upstream of the chamber in the conveyor direction of the air flow, and the air distributor features an outlet into the surroundings. A particularly precise conveying of air flow in the rod maker is thus possible. If the air throughput that can be released into the surroundings is variable, a particularly effective and simple opportunity is realized of achieving a uniform tobacco rod even with differing productive capacities of the rod maker. A particularly cost-effective implementation is provided by providing a throttle flap in the outlet.
Preferably a pressure sensor is provided in the chamber. By the pressure sensor, it is easily possible to implement a control or regulation of the air throughput that can be released into the surroundings. To this end, the pressure sensor is preferably arranged in the area of the sifter or in the rolling chamber of the fluidized bed. A control or regulating device is provided to control or regulate the air throughput that can be released into the surroundings. In a particularly preferred embodiment of the invention the control or regulation is rendered possible continuously. It is thus possible to change the productive capacity of the rod maker continuously as well without the quality of the endless rod suffering. If the control or regulation is rendered possible progressively, predetermined productive capacities can be established where the endless rods produced with these productive capacities in any case feature a high quality. An interpolation can take place between the corresponding productive capacities whereby a correspondingly high quality of the endless rod is rendered possible even with no predetermined productive capacities. Preferably, at least two throttle flap positions can be predetermined. Through this, a particularly simple and cost-effective realization of the rod maker is provided, especially as in operation two different productive capacities are normally used by cigarette manufacturers in cigarette production or cigarette rod production.
The aspect is further attained through a rod maker of the tobacco processing industry, including a tobacco sifter, a suction rod conveyor and a device for conveying tobacco to the suction rod conveyor, in which the device for conveying tobacco defines a chamber, in which an air flow for sifting and for conveying can be introduced into the chamber, in which at least part of the air flow can be released into the surroundings upstream of the chamber with respect to the conveyor direction of the air flow, in which the air throughput that can be released into the surroundings is dependent on the productive capacity of the rod maker. It is thus rendered possible in a simple manner for the air throughput that can be conveyed out of the chamber by a circulating air system to be varied depending on the productive capacity of the rod maker, so that essentially a constant pressure can be achieved in the chamber and so that the tobacco sifter has an air flow available at an essentially constant speed.
Preferably the air throughput that can be released into the surroundings can be increased at lower productive capacity. A particularly effective embodiment of the rod maker according to the invention is provided if an air distributor is arranged upstream of the chamber in the conveyor direction of the air flow, and the air distributor features an outlet into the surroundings. A cost-effective solution is given if a throttle flap is provided to change the air throughput that can be released into the surroundings.
The aspect of the invention is finally attained through an air conveyor system for a rod maker of the tobacco processing industry comprising a circulation fan and a suction fan, in which air can be conveyed by the circulation fan into a chamber in which a tobacco flow can be sifted and conveyed, in particular by the conveyed air, and in which the suction fan is connected to the chamber, and air can be suctioned out of the chamber, in which the air throughput that can be conveyed out of the chamber is essentially constant irrespective of the productive capacity of the rod maker.
An air distributor is preferably arranged downstream of the circulation fan and upstream of the chamber. A particularly effective air guidance is rendered possible in the air conveyor system if by releasing air upstream of the chamber it is made possible to keep constant the air throughput that can be conveyed out of the chamber. It is expedient to provide a throttle flap in a pipe discharging air into the surroundings. Preferably, an essentially constant pressure can be established in the chamber. To this end, e.g., a pressure sensor can be used in the chamber. The aspect can be attained very effectively if a control or regulating device is provided to control or regulate the air throughput released into the surroundings. The control or regulation preferably occurs continuously or progressively, and with the latter alternative two positions or three positions of the throttle flap are preferably provided or two or three predetermined air throughputs can be predetermined.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.
One aspect of the invention includes a method of operating a rod maker for tobacco processing that includes sifting a tobacco flow in a chamber of the rod maker with a first air flow to separate tobacco ribs from the tobacco flow and conveying the sifted tobacco flow in the chamber by at least one of the first air flow and a second air flow. Moreover, the method includes conveying air out of the chamber via a third air flow and a fourth air flow, where a sum of an air throughput of the third air flow and the fourth air flow is substantially constant, irrespective of a productive capacity of the rod maker.
In a further aspect of the invention, an air distributor can be arranged upstream of the chamber, and the method can further include discharging air into the surroundings from the air distributor. Furthermore, the method can include varying the air throughput discharged into the surroundings. Additionally, the method can include adjusting a throttle flap in a discharge pipe of the air distributor to change the air throughput discharged. The method can further include establishing an essentially constant pressure in the chamber. Moreover, the method can include one of controlling and regulating the air throughput of the third air flow conveyed out of the chamber. Additionally, the one of the controlling and regulating can further include one of continuously controlling and continuously regulating. Moreover, the method can include progressively controlling the air throughput. Furthermore, a rod maker for tobacco processing can be structured and arranged to perform the above-noted method.
Yet another aspect of the invention includes a rod maker for tobacco processing that includes a tobacco sifter, a suction rod conveyor, and a device structured and arranged for conveying tobacco to the suction rod conveyor. Moreover, the device includes a chamber, structured and arranged to receive an air flow for sifting and for conveying. Additionally, an air throughput removed from the chamber is substantially constant, irrespective of the productive capacity of the rod maker.
In a further aspect of the invention, the rod maker can include an air distributor, arranged upstream of the chamber in a conveying direction of the air flow, comprising a discharge arranged to discharge air into the surroundings. Moreover, the air throughput dischargeable into the surroundings can be variable. The rod maker can further include a throttle flap positioned in the discharge. Furthermore, the rod maker can include a pressure sensor positioned in the chamber. Additionally, the rod maker can include one of a controller and regulator structured and arranged for one of controlling and regulating the air throughput dischargeable into the surroundings. Moreover, one of the controller and regulator are configured to operate continuously. Furthermore one of the controller and regulator are configured to operate progressively.
Another aspect of the invention includes a rod maker for tobacco processing that includes a tobacco sifter, a suction rod conveyor, and a device structured and arranged for conveying tobacco to the suction rod conveyor. The device including a chamber structured and arranged to receive an air flow for sifting and for conveying the tobacco. Moreover, the rod maker includes at least part of the air flow is releasable into the surroundings upstream of the chamber with respect to the conveyor direction of the air flow, and an air throughput releasable into the surroundings is variable depending on the productive capacity of the rod maker.
In a further aspect of the invention the air throughput releasable into the surroundings can increase with lower productive capacity. Moreover, an air distributor can be arranged upstream of the chamber in the conveyor direction of the air flow, and the air distributor includes a discharge arranged to discharge air into the surroundings. Additionally, the rod maker can include a throttle flap structured and arranged for changing the air throughput releasable into the surroundings.
Yet another aspect of the invention includes an air conveyor system for a rod maker for tobacco processing. The system includes a circulation fan structured and arranged for introducing conveying air into a chamber to sift and convey a tobacco flow, and a suction fan, connected to the chamber, operable to suction air out of the chamber. Moreover, an air throughput conveyed out of the chamber is substantially constant, irrespective of the productive capacity of the rod maker.
In a further aspect of the invention the air conveyor system can further include an air distributor arranged downstream of the circulation fan and upstream of the chamber. Moreover, the air throughput conveyed out of the chamber can be kept constant by releasing air upstream of the chamber. Furthermore, the system can include a throttle flap positioned in a pipe to discharge air into the surroundings. Additionally, a substantially constant pressure can be generatable in the chamber. Moreover, the system can include one of a controller and a regulator structured and arranged to control or regulate the air throughput discharged into the surroundings.
The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
Tobacco is conveyed from a tobacco supply by a steep wall conveyor 11 to a retaining duct 12. Tobacco is removed from the retaining duct 12 by a removal roll 13 and a beater roll 14 and delivered essentially separated to a duct 15. A tobacco flow 38, directed downwards, forms in the duct 15.
The tobacco flow 38 reaches the area of a sifter, and in particular, an area of a pre-sifter 16 in which the tobacco flow 38 is pre-sifted by an air flow from an air flow pipe 321, such that the light tobacco flow components are conveyed in the direction of a fluidized bed 18 and the heavy tobacco flow components, essentially tobacco ribs, fall through downwards. The tobacco flow components falling through downwards are post-sifted in a post-sifter 17. Sifting tobacco is known per se so no further details about sifting need to be addressed.
By the air flow, which is directed from an air flow pipe 322 of the post-sifter onto the tobacco flow 38′, and by the air flow from the pre-sifter 16, the sifted tobacco flow 38′ reaches the fluidized bed 18 in which through further air flow pipes 323 air flows through corresponding nozzles, e.g., Coanda nozzles, the sifted tobacco flow 38′ is conveyed further in the direction of the suction rod conveyor 19.
The ribs that have been sifted out arrive via the rib duct 25 in the direction of a shaking trough 26 out of which smaller tobacco components are shaken so that essentially only ribs are carried away.
Some air flow pipes 321, 322, 323, 324, 325, 326, 327, 328, 329, 3210, 3211, and 3212 are provided in the rod maker according to the invention in order to convey the corresponding air flows.
A circulating air system 44 is provided that includes a circulation fan 24. The circulation fan 24 conveys compressed air controlled or regulated via a throttle flap 23 into an air distributor 21 from which compressed air is guided via a throttle flap 22 to the pre-sifter 16. Furthermore, the air distributor 21 guides compressed air to the post-sifter 17 and via further pipes 323 to the nozzles in the fluidized bed 18. The air is then guided out of the rolling chamber 20 via an air pipe 324 to a dust-extraction cyclone that separates the air from tobacco dust conveyed with the air. Another part is conveyed via pipes 325 to the air circulation of the suction rod conveyor fan 27.
A part of the corresponding air flow or air throughput controlled or regulated via the throttle flap 23 is fed to the circulation fan again. Furthermore, an air flow is guided out of the rolling chamber 20 by the suction rod conveyor 19 and fed via two throttle flaps 28 and 29 to a suction rod conveyor fan 27. The throttle flap 28 is used to shut off vacuum intake air when the suction rod conveyor is lifted. The throttle flap 29 is used to reduce the air capacity of the suction rod conveyor fan 27 when the rod maker is stopped.
Furthermore, the suction rod conveyor fan 27 draws air out of the surroundings via another pipe 326 that opens between the throttle flap 29 and the suction rod conveyor fan 27. Compressed air is blown to the air control center from the suction rod conveyor fan 27, and the throttle flap 31 is provided to establish the vacuum in the suction rod conveyor and the throttle flap 30 establishes a pressureless transition such that the amount of air suctioned off from the control center is somewhat greater than the amount of air discharged from the machine. This thus compensates for the pressure fluctuations of the central dust extraction and the heat produced is discharged at least partially from the machine. Finally, a further pressure line 327 leads from the shaking trough 26 into the discharge pipe from the suction rod conveyor fan 27 so that an air flow is entrained there too.
With falling productive capacity, with rod makers of the prior art or with corresponding methods for operating a rod maker of the tobacco processing industry, it has now transpired that the rib discharge or tobacco discharge or the percentage rib discharge has increased with falling productive capacity. It has hereby been realized that with falling productive capacity the increasing rolling chamber pressure or the increasing pressure in the area of the chamber around the sifter, the pre-sifter 16 and the post-sifter 17, has a restricting impact on the respective sifters 16 and 17 so that the rib quantity or the sifted out rib quantity or tobacco quantity is increased.
It was now determined according to the invention that by keeping constant the sum of the air throughput conveyed out of the rolling chamber or out of the sifting chamber, the percentage rib discharge or the percentage tobacco discharge can be kept constant, even with reduced productive capacity. This occurs, e.g., according to the exemplary embodiment of
The automatic adjustment of the throttle flap 34 for the diffuser 35 can preferably occur through a compressed-air cylinder. Two positions are in particular suitable for this, in particular with stops that can be precisely adjusted, if two productive capacities of the machine are used. Thus, for example, the productive capacities of 10,000 cigarettes per minute and 6,000 or 4,000 cigarettes per minute can be used. With reduced productive capacity an increased air throughput is suctioned out of the rolling chamber via the circulation fan 24, which is achieved by a greater air throughput being released into the surroundings from the air distributor 21 via the pipe 32′. By releasing compressed air via the diffuser or the pipe 32′ into the surroundings, there is a smaller difference in pressure between the inlet and the outlet of the circulation fan so that the air throughput through the circulation fan is increased, which ultimately leads to an increase in the air throughput of the air flow discharged from the rolling chamber, which essentially compensates for the reduced air throughput with reduced productive capacity through the suction rod conveyor.
The productive capacity of the rod makers is, e.g., restricted if the reservoir that lies between the rod maker and a corresponding packing machine is full. In this respect it actually also happens in the production of cigarettes and the subsequent packing that the machine capacity or productive capacity has to be throttled. This can happen, e.g., when the packing machine comes to a stop, and the rod maker is still functioning properly.
Air flows 326, 327 from the atmosphere also arrive in the rolling chamber in the area of the pre-sifter. The air distributor 21 also guides an air flow 337 to the suctioning off of the ribs. The correspondingly discharged ribs arrive at a shaking trough 26 with the gravitational force and an air flow 336 and are then brought to a rib storage 37 via an air flow 332. Through the air flow 322 guided from the air distributor 21 to the post-sifter, an air flow 335 also arises from the atmosphere, which air flow changes into an air flow 324. Moreover, from the rolling chamber 36 an air flow 330 reaches the dust extraction cyclone 33 from which an air flow 334 that can be controlled or regulated with a throttle flap is guided back to the circulation fan 24 again.
The air distributor 21 also discharges an air flow 325 that can be controlled or regulated via the throttle flap 34. This air flow 325 ends in a diffuser 35 and subsequently in the surrounding air. The air throughput conveyed out of the rolling chamber 36 via the air flow 330 is controlled or regulated via the air flow 325. A regulation is taking place in the exemplary embodiment of
The control or regulating device 40 controls or regulates the throttle flap 34 via a control line 43. A continuous regulation can take place, as indicated in
Due to the suctioning of tobacco or the vacuum in the suction rod conveyor 19 an air flow 328 is also marked that originates from the atmosphere. The pressure in the suction rod conveyor is in the range of −80 mbar. An air flow 329 is guided from the suction rod conveyor to the suction fan. The suction fan or suction rod conveyor fan 27 works at a capacity of 7.5 kW and guides in the air flow 333 an air throughput to the control center that features an essentially constant air throughput during production and during stoppage. Accordingly, another air flow leads to the control center from the rib storage 37.
Furthermore, an air flow 338 is provided in order to introduce dust into the system on a return conveyor belt. Another air flow 339 reaches the suction rod conveyor fan 27 from the flute gear. The circulating air system and suction air system are connected to one another via the air flows 331.
The circulation fan works at a capacity of approximately 5.5 kW. The fluidized bed chamber has a pressure of approximately 0 mbar. A control of the throttle flap 34 for the so-called diffuser air 325 with two or more discrete positions represents a very simple and cost-effective solution. A regulation of the position of the throttle flap 34 to a constant rolling chamber pressure leads to a stability of the function of the sifter at all productive capacities.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
List of Reference Numbers
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 007 841.6 | Feb 2004 | DE | national |
