NL2016053B1 - A device for collecting particles from a gaseous fluid stream, and cut tobacco processing equipment comprising such a device. - Google Patents

A device for collecting particles from a gaseous fluid stream, and cut tobacco processing equipment comprising such a device. Download PDF

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Publication number
NL2016053B1
NL2016053B1 NL2016053A NL2016053A NL2016053B1 NL 2016053 B1 NL2016053 B1 NL 2016053B1 NL 2016053 A NL2016053 A NL 2016053A NL 2016053 A NL2016053 A NL 2016053A NL 2016053 B1 NL2016053 B1 NL 2016053B1
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NL
Netherlands
Prior art keywords
fluidized bed
particles
separator
unit
particle separator
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Application number
NL2016053A
Other languages
Dutch (nl)
Inventor
De Jager Gerard
Adrianus Tukker Marinus
Original Assignee
J O A Tech Beheer B V
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Application filed by J O A Tech Beheer B V filed Critical J O A Tech Beheer B V
Priority to NL2016053A priority Critical patent/NL2016053B1/en
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Publication of NL2016053B1 publication Critical patent/NL2016053B1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D45/00—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces
    • B01D45/04—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by utilising inertia
    • B01D45/06—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by utilising inertia by reversal of direction of flow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
    • B01D46/106—Ring-shaped filtering elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/40—Particle separators, e.g. dust precipitators, using edge filters, i.e. using contiguous impervious surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/66—Regeneration of the filtering material or filter elements inside the filter
    • B01D46/74—Regeneration of the filtering material or filter elements inside the filter by forces created by movement of the filter element
    • B01D46/76—Regeneration of the filtering material or filter elements inside the filter by forces created by movement of the filter element involving vibrations
    • B01D46/762—Regeneration of the filtering material or filter elements inside the filter by forces created by movement of the filter element involving vibrations involving sonic or ultrasonic waves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D50/00—Combinations of methods or devices for separating particles from gases or vapours
    • B01D50/20—Combinations of devices covered by groups B01D45/00 and B01D46/00
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2275/00—Filter media structures for filters specially adapted for separating dispersed particles from gases or vapours
    • B01D2275/20—Shape of filtering material
    • B01D2275/201—Conical shape

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combined Means For Separation Of Solids (AREA)

Abstract

A device for collecting particles from a gaseous fluid stream comprising particulate matter including valuable and non-valuable particles. The device comprises an integrated particle separator/concentrator unit and a hindered settling fluidized bed particle separator unit. The particle separator/concentrator unit is arranged to produce, from the input fluid stream comprising the particulate matter, a fluid stream having a reduced quantity of non-valuable particles and an increased concentration of the valuable particles to be collected. In the fluidized bed particle separator unit the valuable particles are separated and collected from this concentrated fluid stream. The device is particularly suitable for use with cut tobacco processing equipment for recovering valuable cut tobacco fibers from an exhaust fluid stream, including regular tobacco and DIET fibers.

Description

Title A device for collecting particles from a gaseous fluid stream, and cut tobacco processing equipment comprising such a device.
Technical Field
The present invention relates generally to the separation and collection of particulate matter from a gaseous fluid stream and, more specifically, to the separation of valuable tobacco fibers in a dust extraction line (de-dusting) of a cut tobacco processing system and equipment, such as a cigarette maker.
Background of the Invention
In a cigarette maker cut tobacco delivered by a pneumatic conveying system is processed into cigarettes. During the manufacturing of cigarettes in the cigarette maker tobacco dust is generated, also called fines, such as particulates and tobacco fibers having typical lengths of, for example, 0.1 mm or less, and which are not used for producing cigarette rods.
Due to several process variations and imperfections in the equipment used, tobacco dust leaving the cigarette maker as waste material may comprise valuable tobacco fibers, also called shorts, having a typical length of about 0.5 mm or even lager and which, when recovered, can still be used for producing cigarettes or the like.
Summary
It is an object of the present invention to provide an efficient device for separating and collecting valuable particles from a gaseous fluid stream comprising particulate matter, such as collecting shorts from a gaseous fluid stream comprising fines and shorts in a dust extraction line of a cut tobacco processing equipment.
It is in particular an object of the present invention to provide such a device having relatively compact dimensions for use with (existing) tobacco processing equipment, such as a cigarette maker, for recovering valuable shorts and having a relatively small dimensional footprint such that the device can be used with tobacco processing equipment of several manufacturers.
In a first aspect, there is provided a device for collecting particles from a gaseous fluid stream comprising particulate matter including the particles to be collected, the device comprising a particle separator/concentrator unit and a hindered settling fluidized bed particle separator unit; the particle separator/concentrator unit comprising: - an elongated chamber, comprising a frustum shaped grating having a slotted lateral surface extending in longitudinal direction of the chamber from a base end to an apex end of the grating, - an inlet, arranged opposite the base end of the grating at a first end of the chamber, for receiving the gaseous fluid stream comprising the particulate matter, - a particles outlet, connected to the apex end of the grating, arranged for discharging particles to be collected from the chamber in a fluid stream having an increased concentration of the particles to be collected compared to the fluid stream received at the inlet, and - an outlet, arranged opposite the apex end of the grating at a second end of the chamber opposite the first end, for discharging gas and particulate matter not discharged at the particles outlet; the hindered settling fluidized bed particle separator unit comprising: - an elongated separating chamber having a first end and a second end opposite the first end of the separating chamber, - an ultrasonic separator screen or sieve, arranged at the first end of the separating chamber, for blocking particles to be collected from leaving the separating chamber and for passing particulate matter not comprising the particles to be collected, - a fluidized bed separator inlet, extending into the separating chamber from the first end of the separating chamber beyond the separator screen or sieve, and connected to the particles outlet of the particle separator/concentrator unit, - a plurality of vanes, extending into the separating chamber at an acute angle with and at a distance adjacent to and across the separating screen or sieve, - a fluidized bed separator particles outlet, arranged at the second end of the separating chamber, for discharging particles to be collected from the separating chamber, - a further fluidized bed separator inlet, arranged at the second end of the separating chamber between the fluidized bed separator inlet and the fluidized bed separator particles outlet, for receiving and discharging a further gaseous fluid stream in the separating chamber at a further gaseous fluid outlet, - a fluidized bed separator outlet, arranged at the first end of the separating chamber opposite the separating screen or sieve, for discharging from the separating chamber the further fluid stream and particulate matter not comprising the particles to be collected, and - a central flow guider element extending in longitudinal direction of the separating chamber between the fluidized bed separator inlet and the further gaseous fluid outlet.
It has been found that in a hindered settling fluidized bed particle separator unit, the separation of valuable particles from particulate matter in a gaseous fluid stream, such as the separation of shorts from particulate matter comprising non-valuable fines and valuable shorts of cut tobacco in air stream, improves as the concentration of the particles to be collected in the gaseous fluid stream increases. That is, with a higher concentration of shorts in a cut tobacco fluid stream comprising fines and valuable shorts, the separation of shorts in the separating chamber of a hindered settling fluidized bed particle separator unit improves.
The concentration of the particles to be collected is increased, in the device according to the invention, by subjecting the gaseous input fluid stream comprising the particulate matter to be separated to a separating/concentrating action in a separator/concentrator unit having a frustum shaped grating. The frustum shaped grating is operative to separate valuable particles and non-valuable particles from the gaseous particulate matter input stream, and to provide the valuable particles in a higher concentration in a gaseous output stream at the particles outlet of the separator/concentrator unit. Particulate matter and gas not collected at the particles outlet will be discharged at the outlet of the separator/concentrator unit. The thus concentrated particle fluid stream is then subjected to a separation action in the hindered settling fluidized bed particle separator unit.
By the separator/concentrator unit having such a frustum shaped grating, for example shaped like a truncated cone, a concentration factor ranging from 10-25 can be achieved, for example increasing the loading of an air flow from 1-10 g valuable particles/kg air to, for example, 10-250 g valuable particles/kg air. With the particle separator/concentrator unit, in practice, about 80-85 % of the nonvaluable particles will already be separated from the valuable particles to be collected.
As the concentrated particles fluid stream entering the fluidized bed separator unit comprises less amount of gas compared to the input fluid stream entering the separator/concentrator unit, the hindered settling fluidized bed particle separator unit, in the device according to the invention, can be operated with a further gaseous fluid stream comprising a less amount of gas for discharging the particulate matter not comprising the particles to be separated and collected from the separating chamber, compared to providing the particulate matter gaseous input fluid stream directly to the fluidized bed separator unit. The reduced gas capacity required for the operation of the fluidized bed separator unit translates into reduced dimensions of the device according to the invention, i.e. a reduced dimensional footprint, such that the device can be positioned in the vicinity, i.e. in the available area above or next to, of essentially any tobacco processing device used in practice, which is important for effective usage of factory space.
The static pressure fluctuation in the separating chamber of the fluidized bed particle separator unit is effectively stabilized by the ultrasonic separation screen or sieve, which provides a clear shorts versus fines cut-off point, i.e. the threshold to split the particulate matter entering the separating chamber in valuable particles to be collected and other non-valuable particulate matter, assuring that only the correct range of particles or fibers, i.e. the shorts of a tobacco stream, is collected. By using an ultrasonic screen or sieve fouling/plugging of the screen or sieve over time is effectively prevented. Especially tobacco needles are hard to remove from a screen or sieve, due to their tapered shape. The ultrasonic screen or sieve, due to the high vibration frequency, opens and closes its mesh continuously, which releases the trapped dust. Accordingly, the ultrasonic sieve provides a stable and sustainable operation of the hindered settling fluidized bed particle separator unit, guaranteeing the washing out of remaining fine dust, and returning same to the fluidized bed separator outlet after passing the separating screen or sieve.
In practice, many cigarettes produced by a cigarette maker in a cut tobacco processing system consist of a percentage of so-called Dry Ice Expanded Tobacco, abbreviated as DIET. DIET particles have a much lower specific weight, i.e. in the range of 75-200 kg/m3, compared to conventional cut tobacco. During operation, this results in a concentrated particle gaseous fluid stream comprising particles to be recovered having different specific weight, i.e. shorts of different specific weight in the case of cut tobacco fibers to be recovered. It has been observed that in such a mixed particles stream, the valuable particles of relative low specific weight do not just settle by gravity down through the fluidized bed, different from the particles to be collected of relative higher specific weight. Rather, the particles of relative lower specific weight tend to accumulate at the separator screen or sieve.
In the device according to the invention, by using an ultrasonic separation screen or sieve, the screen or sieve when in operation moves in longitudinal direction of the separating chamber of the fluidized bed particle separator unit with an amplitude of about 10 or more micron. At this amplitude-distance from the sieve deck in the separating chamber, the particles of relative lower specific weight are ‘floating’ in balance with the upward air velocity of the fluidized bed. As these particles are not in contact with the ultrasonic screen or sieve, they hardly have any resistance for moving along the mesh or deck of the screen or sieve.
The vanes which are placed under the screen or sieve deck create, in combination with the flow profile generated in the fluidized bed, a force on the ‘floating’ particles, acting perpendicular to the upward flow, and pushing the shorts to the vanes. In addition, the vanes create a lee zone between the sieve and the vanes that is allowing the particles trapped or caught at the vanes to be released therefrom, as the upward flow in this lee-zone is reduced to zero. By gravity the particles will leave the lee-area or lee-zone, while the vanes act as ‘slides’, and enter the fluidized bed to be recovered and collected.
The flow guider element, that is centrally arranged in the separating chamber of the fluidized bed particle separator unit operates, on the hand, to distribute the further gaseous stream discharged in the separating chamber from the further gaseous fluid outlet as evenly as possible in the area between the flow guider element and the inner wall of the housing, to provide a homogeneous fluidized bed flow in the separating chamber. On the other hand, the flow guider element operates to distribute the concentrated particles fluid stream received from the separator/concentrator unit as evenly as possible over the fluidized bed, i.e. across the area between the flow guider element and the inner wall of the housing of the particle separator unit.
The device for collecting particles according to the invention is very effective in separating and collecting particles from an input gaseous fluid stream comprising particulate matter including particles of different specific weight to be collected. Accordingly, the device according to the invention provides a more efficient particle separation and collection in terms of less invaluable or unwanted particulate matter, such as tobacco fines, among the separated and collected valuable particles, such as tobacco shorts.
In an embodiment of the device according to the invention, the ultrasonic separator screen or sieve is operatively connected to a transducer unit arranged for operating the separator screen or sieve with a vibration frequency in the range of 20-30 kHz.
In another embodiment of the invention vanes having a wing-type or wedge-type plate shape have been proven very effective in creating a lee-zone or lee-area from which particles trapped at a vane will be released and returned to the fluidized bed in the separating chamber. A number of 3-6 vanes that are circumferentially evenly distributed at the surface of the screen or sieve deck and extend substantially over a same distance into the separating chamber, measured from the screen or sieve, and at an acute angle between 45-75 degrees have proven to be very effective.
In an embodiment of the device according to the invention, the central flow guider element in the separating chamber of the fluidized bed particle separation unit comprises a rotationally symmetric elongated intermediate cylindrical mid part, extending centrally in the separating chamber, and comprises a first tip shaped end part and a second tip shaped end part, while the flow guider element has a closed outer surface. The first and second end parts are shaped such that the further gaseous fluid stream and the concentrated particles fluid stream are as much as possible evenly distributed across the area between the mid part of the flow guider element and the housing of the fluidized bed particle separator unit.
In an embodiment of the device according to the invention, the first and second tip shaped end parts of the flow guider element have hyperboloid type shaped outer surface.
The separation, from the concentrated particles fluid stream, of the valuable particles to be collected, in particulate particles having a lower specific weight compared to other particles to be collected from a same concentrated particles fluid stream, such as a concentrated particles fluid stream comprising conventional cut tobacco and DIET fibers, is further improved in an embodiment of the invention by comprising a controllable valve connected to the further fluidized bed separator inlet of the further gaseous fluid stream of the fluidized bed particle separator unit for gas velocity and capacity control of the further gaseous fluid stream entering the separating chamber of the fluidized bed particle separator unit.
In particular in an embodiment of the invention wherein the controllable valve is a pulsating valve.
That is, during pulsating operation of the controllable valve, when the discharge of the further gaseous fluid from the further gaseous fluid discharge outlet in the separating chamber is temporarily decreased or even interrupted, return of the particles of lower specific weight from the vanes into the fluidized bed is promoted.
The efficiency of the separator/concentrator unit is enhanced, in a further embodiment of the invention, by a fluid flow divider which extends over a distance inside and from the center of the grating. The fluid flow divider is dimensioned such that the distribution of the input particulate matter gaseous fluid stream over the slotted lateral surface of the grating is as evenly as possible over the length of the grating.
The fluid flow divider, in an further embodiment of the invention, has a rotationally symmetric elongated shape, with a first cone shaped end and a second cone shaped end, the base parts of which connect to each other or through an intermediate cylindrical part, for example, wherein the first cone shaped end is arranged at the base end of the grating and faces the separator/concentrator inlet, and the second cone shaped end is arranged at the apex end of the grating and faces the separator/concentrator outlet.
In yet another embodiment of the device according to the invention, the second end of the separating chamber of the fluidized bed particle separator unit is funnel shaped, having a base part and an apex part, and forms a particles collector for collecting the particles separated from the gaseous fluid stream comprising the particulate matter. The apex part of the separating chamber connects to the fluidized bed particles outlet which terminates in an air lock valve, in particular a rotary air lock valve. With the air lock valve the collected particles can be adequately recovered while avoiding loss of the further gaseous stream providing the fluidized bed in the particle separator unit, thereby keeping the fluidized bed stable.
In a compact embodiment of the device according to the invention, the separator/concentrator outlet and the fluidized bed separator outlet for discharging the further fluid stream and particulate matter not comprising the particles to be collected from the separating chamber, are in fluid communication, forming a single integral gas outlet of the device.
This compact embodiment is advantageous for collecting tobacco fibers from a gaseous fluid stream in tobacco processing equipment or a tobacco transport line of a cut tobacco processing system, for example, in particular wherein the separator/concentrator inlet for receiving the gaseous fluid stream comprising particulate matter being pipe shaped and the single gas outlet being pipe shaped for mounting the device in a pipe shaped transport line.
In an embodiment of the device according to the invention, the chamber of the separator/concentrator unit extends transverse of the separating chamber of the fluidized bed particle separator unit.
This embodiment is particularly suitable for mounting in a horizontal pipe of a tobacco processing equipment or tobacco processing line of a tobacco processing system or factory, for example, in particular a dust extraction line (dedusting), having the chamber of the separator/concentrator unit in a horizontal operating position and having the separating chamber of the fluidized bed particle separator unit in a vertical operating position.
In another embodiment of the device according to the invention, the chamber of the separator/concentrator unit and the separating chamber of the fluidized bed particle separator unit extend in-line.
This embodiment is particularly suitable for mounting in a vertical pipe of a tobacco processing equipment or tobacco processing system, for example, having both the chamber of the separator/concentrator unit and the separating chamber of the fluidized bed particle separator unit in a vertical operating position.
This in-line embodiment, in accordance with a further embodiment of the invention, can be provided with a relatively small dimensional footprint by having the separator/concentrator unit comprised in the fluidized bed particle separator unit.
In as second aspect, the invention provides a cut tobacco processing equipment, in particular a cigarette maker, comprising a transport line inlet for connection to a cut-tobacco delivery unit, a transport line outlet for connection to a transport line fluid flow control unit, and a dust removal system comprising a dust removal line incorporating a device according to the first aspect of the invention as disclosed above.
In an third aspect, the above disclosed device for collecting tobacco fibers from a gaseous fluid stream in accordance with the first aspect of the invention is positioned in a transport line of a cut tobacco processing system, in particular a dust extraction line, downstream of a cut tobacco processing equipment, wherein the inlet for receiving the gaseous fluid stream comprising particulate matter to be collected being pipe shaped and the single gas outlet being pipe shaped for mounting the device in the transport line.
In a particular embodiment of the device according to the invention for use in a cut tobacco processing equipment, the input gaseous fluid stream is an air stream, the particles comprise tobacco fibers and the further fluid stream is an air stream.
The above-mentioned and other features and advantages of the invention are illustrated in the following description with reference to the enclosed drawings which are provided by way of illustration only and which are not limitative to the present invention.
Brief description of the Drawings
Fig. 1 shows, in a schematic and illustrative manner, cut tobacco processing equipment comprising a cigarette maker and a maker de-dusting system, comprising a device for collecting valuable tobacco fibers from the processing equipment, in accordance with the invention.
Fig. 2 shows, in a schematic, partly transparent perspective and illustrative manner, an example of a device for collecting particles from a gaseous fluid stream in accordance with an embodiment of the invention.
Fig. 3 illustrates, in a schematic and simplified manner, operation of the particle separator/concentrator unit of the device shown in Fig. 2.
Fig. 4 illustrates, in a schematic and simplified manner, a further embodiment of the particle separator/concentrator unit shown in Fig. 3.
Fig. 5 illustrates, in a schematic and simplified manner, operation of the fluidized bed particle separator unit of the device shown in Fig. 2.
Fig. 6 shows, on an enlarged scale, a Computational Fluid Dynamics, CFD, image of an area comprising the screen or sieve and a vane of the particle separator unit shown in Fig. 5.
Detailed description
The invention will be disclosed, by way of example only, with a particular use thereof for collecting valuable cut tobacco fibers, also called shorts, from a flow or fluid stream comprising such shorts and other cut tobacco fibers, also called fines, being smaller in length than the shorts, after having processed the cut tobacco in a cut tobacco processing device, such as a cigarette maker producing cigarette rods.
Throughout the description and in the figures, parts having a same or like construction or functional operation, are indicated by like reference numerals.
Figure 1 shows, in a schematic and illustrative embodiment, an example of a system 10 for feeding cut tobacco from a delivery unit 12-1 to tobacco processing equipment 13, such as a cigarette maker, by a pneumatic conveying system 11. The cut tobacco, or in general fibrous material, is transported from the cut tobacco delivery unit 12-1 to the tobacco processing equipment 13 via an intermediate transport line 14, also called a feed line of the pneumatic conveying system 11.
The system 10 typically comprises a plurality of cut tobacco delivery units 12-1, 12-2..... 12-n (n > 1) each containing, for example, a different blend of cut-tobacco. For selecting a particular delivery unit 12-1, 12-2, ..., 12-n a so-called blend selector 15 is provided. The blend selector 15 comprises a plurality of inputs 16- 1, 16-2.....16-m (m > 1) that each connect to a respective output 17-1, 17-2, ..., 17- m of the blend selector 15. In the embodiment shown, delivery unit 12-1 connects via a feed line 18-1 to input 16-1 of the blend selector 15. At the corresponding output 17-1 of the blend selector 15 the feed line 14 to the cut-tobacco processing equipment 13 connects, such that cut-tobacco from the delivery unit 12-1 is introduced in the feed line 14 and is transported to the cut-tobacco processing equipment 13.
Besides conventional cut tobacco, some or all of the cut tobacco delivery units 12-1, 12-2, ..., 12-n may comprise so-called Dry Ice Expanded Tobacco, DIET. In the DIET process cut tobacco from a conventional primary process is fed to a carbon dioxide impregnation system in precisely weighed subbatches, and impregnated with liquid carbon dioxide. The frozen tobacco is discharged from the impregnators, and fed at a controlled mass flow to a specially designed air dryer in which the frozen tobacco is subject to a process gas stream consisting mainly of superheated steam. This causes the ‘dry ice’ or solid carbon dioxide contained within the tobacco cellular matrix to change state from the solid to the gaseous phase (sublimation). Due to the fact that the volume of gaseous carbon dioxide is vastly greater than the volume of dry ice, the tobacco is expanded, in some cases to double its original volume depending on the nature of the tobacco. As a result, DIET particles have a much lower specific weight compared to conventional, i.e. not expanded or inflated, cut tobacco.
For producing tobacco products by the tobacco processing equipment 13 having a different blend or constitution such as DIET, a respective one of the other delivery units 12-2, ..., 12-n has to be connected, with its feed line 18-x (x=2, ..., n), to input 16-1 of the blend selector 15, of course by first disconnecting the feed line 18-1. A particular delivery unit 12-1, 12-2, ..., 12-n may comprise several feed lines 19-x, 20-x, etc. (x=1, 2, ..., n) for connecting the respective delivery unit to a respective (other) input 16-1, 16-2, ..., 16-m of the blend selector 15, at each output 17-2, ..., 17-m of which, by a respective pneumatic conveying system, a further cut-tobacco processing device may connect.
In the embodiment shown, the pneumatic conveying system 11, downstream of the cut-tobacco processing device 13, comprises a unit 21, such as a fan or equivalent device for creating a low pressure or vacuum in the transport line 14. To prevent entrance of dust or other substances of cut-tobacco from the transport line 14 into the unit 21, a dust filter and collector 22 is provided in front of the unit 21, when viewed in the material transport direction, schematically indicated by arrows 24.
In the embodiment shown, the unit 21 is operative for a plurality of cut-tobacco processing devices 13, via a plurality of pneumatic conveying systems 11, the transport lines 14 of which are collected by a line collector unit 23 which collects, for example, six transport lines 14.
Tobacco transport in the transport line 14 is generally operated according to a demand driven start-stop process. For providing an amount of tobacco for processing by the cut-tobacco processing equipment 13, a so-called air lock 25 is incorporated in the transport line 14 at the cut-tobacco processing equipment 13. Behind the air-lock 25, when viewed in the transport direction 24, a valve 26 is included in the transport line 14. This valve 26, also called maker valve, is operated by the cut-tobacco processing equipment 13, such as a cigarette maker. The maker valve 26 operates for closing and opening of the transport line 14, i.e. for stopping and starting the material transport there through.
For controlling the pneumatic fluid flow in the transport line 14, a fluid flow control unit 27, for example in the form of at least one flow control valve such as a servo motor driven pressure regulator-reducer, is incorporated in the transport line 14 between the maker valve 26 and the line collector unit 23. The fluid flow control unit 27 is operated by a control system 28.
Reference numerals 29, 30 and 31 indicate devices of the control system 28 for determining physical parameters of the material and pneumatic fluid transport in the transport line 14. The values measured by any of the devices 29, 30 and 31 are provided to a digital processing device or electronic processor or computer 32. The processing device 32 is suitably programmed for processing the input received from the devices 29, 30, 31 for controlling the material transport in the feeding line 14 by suitably operating the fluid flow control unit 27. Such to provide, for example, a material transport in dune flow mode or dune and layer flow mode in the transport line 14 from its introduction at the delivery unit 12-1 to the cut-tobacco processing device 13, for example.
In operation, the unit 21 is operative to create a low-pressure or vacuum in the transport line 14, such that cut-tobacco and air is introduced into the transport line 14, from the material delivery unit 12-1, and transported to the cut-tobacco processing equipment 13. By the air-lock 25 cut-tobacco from the transport line 14 is received and collected. Once the cut-tobacco processing equipment 13 requires an amount of cut-tobacco, it closes the maker valve 26 and the cut-tobacco 33 is released from the air-lock 25 and delivered to the cut-tobacco processing equipment 13, after which the maker valve 26 is opened again. The amount of cut-tobacco 33 delivered and the flow mode of the fibrous material in the transport line 14 are typically achieved by controlling the pneumatic fluid in the transport line 14 from the control system 28 operating the flow control unit 27.
As mentioned above, the fluid flow or fluid stream entering the tobacco processing equipment 13, such as a cigarette maker, generally comprises valuable tobacco fibers, i.e. shorts, and tobacco dust, i.e. fines. In practice, valuable cut tobacco fibers for processing into cigarette rods, for example, have a typical length of about 0.5 mm or larger. Tobacco fines have a typical length of 0.1 mm (100 micron) or less. Due to several process variations and imperfections in the equipment used, not all of the cut tobacco fibres delivered at the cigarette maker are processed into cigarette rods, for example. Therefore tobacco dust, which has to be removed or exhausted from the processing equipment 13, may comprise fines and valuable tobacco fibers, i.e. shorts, which, when recovered, can still be used for producing cigarettes or the like.
In accordance with the invention, a particle collecting device 40 is provided, for removing dust from the processing equipment 13 and collecting valuable shorts from this dust, for feeding same back into the processing equipment 13 for further use. The device 40 comprises an integral arrangement of a particle separator/concentrator unit 41, comprising a frustum shaped grating acting as a particles separator and concentrator, and a fluidized bed particle separator unit 42.
In the embodiment shown, the particle collecting device 40 connects to a dust removal or exhaust line or pipe 36 terminating at one end in a maker fan 35 internal of the processing equipment 13. At another end, the dust removal line 36 comprises a unit 37, such as a fan or equivalent device for creating a low pressure or vacuum in the dust removal line 36, such that tobacco dust is sucked off from the processing equipment 13, via the maker fan 35 and dust removal line 36 to a dust filter and collector 38. To prevent entrance of dust or other substances of cut-tobacco from the dust removal line 36 into the unit 37, the dust filter and collector 38 is provided in front of the unit 37, when viewed in the dust transport direction, schematically indicated by arrows 39.
In the embodiment shown, the unit 34 is operative for removing dust from a plurality of cut-tobacco processing devices 13, i.e. the devices 40, via a plurality of dust removal lines 36 which are collected by a dust line collector unit 45 which collects, for example, six dust removal lines 36.
In the embodiment shown, the particle separator/concentrator unit 41, comprises an inlet 43 for receiving the fluid stream or fluid flow in the dust removal line 36 of the processing equipment 13, which fluid stream comprises particulate matter, i.e. dust, in the form of waste shorts and fines of cut tobacco, and a single integral outlet 44 for discharging gas from the fluid stream received at the inlet 43 and for discharging gas of a further gaseous fluid stream received from a gas source 46, such as a compressed air source, at an inlet 47 of the fluidized bed particle separator unit 42 of the particle collecting device 40.
Valuable shorts collected by the particle collecting device 40 are discharged at a particles outlet 48 of the fluidized bed particle separator unit 42 and may be directly fed to the tobacco processing section of the processing equipment 13, for example into the tobacco processing device trim belt. The amount of gas entering the particle collecting device 40 at the further gaseous fluid stream inlet 47 can be controlled via a remotely controllable valve 49 connected between the gas source 46 and the inlet 47. The valve 49 may be an electrically controllable valve which is controlled, for example, from the control system 28. It will be appreciated that the valve 49 may be incorporated in the housing of the particle collecting device 40.
Although the particle collecting device 40 is shown external from the processing equipment 13, in practice, due to the relatively small dimensional footprint of the device 40, same may be incorporated in the processing equipment 13, for example directly downstream of a cigarette rod build section in the case of a cigarette maker.
Figure 2 shows, in partly transparent and perspective manner, an embodiment of a particle collecting device 50 according to the invention for collecting particles from a gaseous fluid stream, indicated by arrow 63, comprising particulate matter such as waste shorts and fines of conventional cut tobacco or DIET and/or a mixture of conventional tobacco and DIET, for example. The device 50 comprises a particle separator/concentrator unit 52 and a fluidized bed particle separator unit 53 in fluid communication with each other.
The particle separator/concentrator unit 52 comprises a chamber 55 defined by an elongated circle cylindrical or pipe-shaped housing 54. The gaseous fluid stream 63 comprising the particulate matter enters the elongated chamber 55 of the particle separator/concentrator unit 52 at a first end or inlet 56 thereof. In the chamber 55 a frustum shaped grating 58 is arranged, having a slotted lateral surface 59 mounted at an elongated support piece 51, and having a base end 60 and an apex end 61. The grating 58, which in the embodiment shown has the shape of a truncated cone, extends in longitudinal direction of the chamber 55 with the base end 60 adjacent to a first end or inlet 56 and with the apex end 61 adjacent to a second end or outlet 57 of the elongated chamber 55.
The outlet 57, i.e. the second end of the chamber 55, is located downstream with respect to the direction of the gaseous fluid stream 63 and opposite the first end of the chamber 55, i.e. the inlet 56 thereof. The outlet 57 is in fluid connection with the slotted lateral surface 59 of the grating 58, for discharging gas, indicated by arrow 64, leaving the chamber 55 through the slotted lateral surface 59. The apex end 61 of the grating 58 terminates in a particles outlet 62 of the particle separator/concentrator unit 52, arranged in downstream direction of the fluid stream 63 between the inlet 56 and the outlet 57, for discharging particles to be collected from the concentrator chamber 55 in a concentrated particles fluid stream, indicated by arrow 78, having an increased concentration of particles to be collected compared to the fluid stream 63 received at the inlet 56.
The fluidized bed particle separator unit 53 comprises a separating chamber 65 defined by circle cylindrical or pipe-shaped elongated housing 66, having a first end or top part 68 and a second end or bottom part 69. The housing 66 of the fluidized bed particle separator unit 53 extends in transverse direction to the housing 54 of the separator/concentrator unit 52. The particles outlet 62 of the particle separator/concentrator unit 52 connects by a tubing 80 from the top part 68 into the separating chamber 65 of the fluidized bed particle separator unit 53. The open end of the tubing 80, extending into the separating chamber 65, forms a particles inlet 67 of the fluidized bed particle separator unit 53. This inlet 67 extends over a short distance in the separating chamber 65.
The bottom part 69 of the fluidized bed particle separator unit 53 is funnel shaped, having a base part 74 and an apex part 75, forming a particles collector of the device 50, for collecting the valuable particles separated from the gaseous fluid stream 63 inputted at the inlet 56 of the separator/concentrator unit 52. The base part 74 connects to the separating chamber 65 opposite of the fluidized bed separator inlet 67 and the apex part 75 terminates in a particles outlet 73. The bottom part 69 comprises further inlet 72 of the fluidized bed separator unit 53 for providing a further gaseous fluid stream, indicated by arrow 70, into the separating chamber 65. The further fluidized bed separator inlet 72 connects by tubing 94, 95 into the separating chamber 65.
Tube 94 is in fluid communication with the further fluidized bed separator inlet 72 and extends in a direction transverse to the elongated housing 66. Tube 95 extends in longitudinal direction of the elongated housing 66 and connects at one end to, i.e. is in fluid communication with, the transverse tube 94. The other open end of tube 95 forms a further gaseous fluid outlet 96 into the separating chamber 65. That is, a further gaseous fluid stream 70 provided at the further fluidized bed separator inlet 72 is discharged in upward direction in the separating chamber 65, i.e. in a direction towards the separator particulate matter inlet 67, from the further gaseous fluid outlet 96. The further gaseous fluid stream 70 may be controlled by operating a controllable valve 49 connected between the further fluidized bed inlet 72 and the further gaseous fluid outlet 96 (see also Figure 1).
Particles collected by the fluidized bed particle separator unit 53, indicated by dashed arrow 71, are discharged from the separating chamber 65 through a so-called air lock valve 79 connecting to the fluidized bed particles outlet 73, in particular a rotary air lock valve, used to prevent loss of gas from the further gaseous fluid stream 70 when discharging the particles 71.
In downstream direction of the further gaseous fluid stream 70 in the separating chamber 65 beyond the fluidized bed separator inlet 67, i.e. at the top part of 68 of the separating chamber 65, a fluidized bed separator outlet 77 is provided for discharging, from the separating chamber 65, the further fluid stream 70 and particulate matter of the gaseous fluid stream 63 not comprising the particles 71 to be collected at the fluidized bed particles outlet 73 of the separating chamber 65. The fluidized bed separator outlet 77 connects to, i.e. is in fluid communication with, the outlet 57 of the chamber 55 of the separator/concentrator unit 52, thereby providing a single gas discharging outlet 57 of the device 50.
The fluidized bed separator inlet 67 ends in the separating chamber 65 at a distance from a separator screen or sieve 89 located in the separating chamber 65 at the top part 68 thereof. That is, seen in upstream direction of the further gaseous fluid stream 70 in the separating chamber 65, the fluidized bed separator inlet 67 extends over a distance beyond the separator screen or sieve 89. This separator screen or sieve 89 covers the entire cross-section of the separating chamber 65 between the tubing 80 terminating in the fluidized bed separator inlet 67 and the inner wall of the elongated housing 66. The mesh of the screen or sieve 89 is selected such to block particles to be collected from leaving the separating chamber 65 and such that the further gaseous fluid 70 and particulate matter not comprising the particles to be collected may pass the separating screen or sieve 89, leaving the separating chamber 65 towards the fluidized bed separator outlet 77.
The separator screen or sieve 89 is a so-called high frequency ultrasonic screen or sieve. In use, due to the high vibration frequency of for example 20-30 kHz imposed by a transducer or vibrator unit 100 operatively connected to the ultrasonic screen or sieve 89, the mesh openings of the screen or sieve 89 are opened and closed continuously. Due to the high vibration frequency, the mesh of the ultrasonic screen or sieve 89 also vibrations over a short distance in longitudinal direction of the housing 66.
Also seen in upstream direction of the further gaseous fluid stream 70 in the separating chamber 65, adjacent to the screen or sieve 89, a plurality of vanes 101 extend into the separating chamber 65. The vanes 101 extend at a distance from and across the width of the screen or sieve 89 between the tubing 80 terminating in the fluidized bed separator inlet 67 and the inner wall of the elongated housing 66 of the fluidized bed particle separator unit 53. In an embodiment, the vanes 101 have a wing-type or wedge-type plate shape including an acute angle with respect to the mesh surface or deck of the screen or sieve 89. In an embodiment, a number of 3-6 vanes 101 are circumferentially evenly distributed at the screen or sieve deck including equal rotational angles and extend substantially over the same distance into the separating chamber 65 - measured from the screen or sieve 89 - as the fluidized bed separator inlet 67, for example a distance of 1-3 cm, and at an acute angle with the screen or sieve deck between 45-75 degrees.
In the centre of the separating chamber 65, between the fluidized bed separator inlet 67 and the further gaseous fluid outlet 96, a flow guider element 93 is arranged. In the embodiment shown, the flow guider element 93 has a closed outer surface comprised of a rotationally symmetric elongated intermediate cylindrical mid part 97 with a first tip shaped hyperboloid type end part 98 opposite the particulate matter inlet 67 and a second tip shaped hyperboloid type end part 99 opposite the further gaseous fluid outlet 96. The flow guider element 93 is suspended centrally in the separating chamber on thin rods 103 engaging the fluidized bed separator inlet 67, i.e. the tubing 80 forming the particles inlet, and the tip of the first end part 98 of the flow guider element 93. Those skilled in the art will appreciate that other suspending or fastening means may be used for this purpose, provided that the entrance of the concentrated particles fluid stream 78 into the separating chamber 65 is not disproportionally obstructed by such fastening means.
The purpose of the flow guider element 93 is, on the one hand, to distribute the concentrated particles fluid stream 78 received from the particle separator/concentrator unit 52 as evenly as possible in cross-section direction of the separating chamber 65, i.e. in the area between the flow guider element 93 and the inner wall of the housing 66. On the other hand, the flow guider element 93 operates to distribute the further gaseous stream 70, discharged in the separating chamber 65 from the further gaseous fluid outlet 96, as evenly as possible in the area between the flow guider element 93 and the inner wall of the housing 66, to provide a fluidized bed flow.
The first end part 98 of the flow guider element 93 improves the distribution of the concentrated particles fluid stream 78 received in the separating chamber 65, i.e. an improved distribution of the shorts and fines in a cut tobacco fluid stream 78. The design of the second end part 99 of the flow guider element 93 stimulates a more effective vertical flow of the further gaseous stream 70 in the separating chamber 65, i.e. the fluidized bed, for washing out the fines or dust from the shorts of a cut tobacco concentrated fluid stream 78.
It will be appreciated that, for example, the first end part 98 and the second end part 99 of the flow guider element 93 may have different or other shapes from what is shown in Fig. 2 and described above. The first 98 and/or second end part 99 may have an outwardly flaring shape even extending beyond the circumference of the mid part 97, such as a spinning top or revolutional diamond shape, for example.
Arrows 76 schematically indicate gas from the further gaseous fluid stream 70 and particulate matter, not comprising particles 71 to be collected at the fluidized bed separator particles outlet 73, being discharged from the separating chamber 65 through the screen or sieve 89 into the fluidized bed separator outlet 77, which outlet 77 terminates in, i.e. is in fluid communication with, the outlet 57 of the particle separator/concentrator unit 52.
Those skilled in the art will appreciate that the concentrated particles outlet 62 of the particle separator/concentrator unit 52 may be integral with the fluidized bed separator particles inlet 67, and that the fluidized bed separator outlet 77 may be integral with the outlet 57 of the particle separator/concentrator unit 52. In operation, the separator unit 53 is arranged such that the fluidized bed particles outlet 73, viewed in vertical direction, is positioned in a lower position and substantially opposite the fluidized bed separator inlet 67.
The operation of the particle separator/concentrator unit 52 is now elucidated with reference to Figures 3 and 4, respectively. Reference is also made to Figure 2 and the relating description of Figure 2. As illustrated in Figure 4, the elongated frustum shaped grating 58 has a slotted lateral surface 59, consisting of a plurality of circumferentially closed slats 84 spaced apart over a distance in longitudinal direction of the grating 58, thereby providing slots 83 between the slats 84. The slats 84 are arranged at a mutual distance in longitudinal direction of the grating 58 tuned to the dimensions of the particles to be collected, such that particles to be collected of the gaseous fluid stream 63, entering the chamber 55 at the inlet 56 of the particle separator/concentrator unit 52, are pushed towards the center of the grating 58, schematically indicated by curved arrows 82. Gas and particulate matter of the fluid stream 63 other than the particles to be collected escape via the slots 83 out of the grating 58, schematically indicated by curved arrows 81, resulting in a main gas stream comprising particulate matter 85 to be discharged 64 from the outlet 57 of the chamber 55. As result, at the apex end 61 of the grating 58 a concentrated particle fluid stream 78 is provided, having a higher load of particles to be collected per amount of gas compared to the fluid stream 63 entering the particle separator/concentrator unit 52. The particles thus separated and concentrated are discharged from the chamber 55 in the fluid stream 78 via the concentrated particles outlet 62.
After subjecting the particulate matter gaseous fluid stream 63 to the operation of the particle separator/concentrator unit 52, about 80 - 85 % of the nonvaluable particles will already be separated from this fluid stream and this quantity will leave the chamber 55 with the gaseous fluid stream 64 through the outlet 57 of the particle separator/concentrator unit 52. In an embodiment, the particle separator/concentrator unit 52 may, for example, increase the loading of valuable particles from 1-10 g of valuable particles/kg air to 10-250 g of valuable particles/kg air, i.e. a concentration factor ranging from 10-25, for example.
The efficiency of the particle separator/concentrator unit 52 is enhanced, in a further embodiment thereof, indicated by reference numeral 102, by a fluid flow divider 90 which extends over a distance inside and from the center of the grating 58. In the embodiment shown in Figure 4, the fluid flow divider 90 has a rotationally symmetric elongated shape, with a first cone shaped end 91 and a second cone shaped end 92, the base parts of which connect to each other or through an intermediate cylindrical part, for example.
The first cone shaped end 91 is arranged at the base end 60 of the grating 58 and faces the inlet 56 of the separator/concentrator unit 102, and the second cone shaped end 57 is arranged at the apex end 61 of the grating 58 and faces the concentrated particles outlet 62. In the embodiment shown, the first cone shaped end 91 extends over a shorter distance than the second cone shaped end 92.
In use, the flow divider 90, i.e. the first cone shaped end 91 thereof, forces the fluid flow stream 63 entering the chamber 55 in a radially outward direction inside the grating 58, i.e. towards the slotted surface 59 thereof. The release of gas and particulate matter not comprising the particles to be collected 81 from the grating 58 through the slots 83 is thereby improved. By the cone shaped second end 92 of the flow divider 90, particles 82 inside the grating 58 are guided towards the apex end 61 of the grating 58. As a result, the particle separator/concentrator unit 102 provides an improved concentration of particles at the concentrated particles outlet 62 compared to the embodiment of the particle separator/concentrator unit 52 shown in Figure 4.
Those skilled in the art will appreciate that the length of the flow divider 90 and the diameter of the base parts and length of the first cone shaped end 91 and the second cone shaped end 92 depend on the maximum diameter and length of the grating 58. In particular, the fluid flow divider is dimensioned such that the distribution of fluid flow at the slots 83 over the length of the grating 58 is as evenly as possible. Further, for forcing the fluid flow stream 63 entering the grating 58 in a radial outward direction and guiding the concentrated particles fluid stream 82 inside the grating 58 towards the concentrated particles outlet 62, other or different shapes of the flow divider 90 are feasible than the one shown and described, such as a flow divider having a curved outer surface, for example a parabolic shaped outer surface or the like, or a rounded, semi-spherical first end 91, for example.
The operation of the fluidized bed particle separator unit 53 is elucidated with reference to Figures 5 and 6, respectively. Reference is also made to Figure 2 and the relating description of Figure 2. As shown in Figure 5, the fluidized bed particle separator unit 53 operates in accordance with the ‘hindered settling’ principle. To this end, in the separating chamber 65, in upward direction thereof from the bottom part 69 to the top part 68, from the further fluid stream 70 entering the fluidized bed particle separator unit 53 at the further fluidized bed separator inlet 72, a so-called fluidized bed 86 fluid flow is created. The further fluid stream 70, discharged into separating chamber 65 from the further gaseous fluid outlet 96, first encounters the second end part 99 of the flow guider element 93 having a shape by which the further gaseous stream 70 is as much as possibly evenly distributed across the area of the separating chamber 65 between the mid part 97 of the flow guider element 93 and the inner wall of the housing 66, thereby providing the fluidized bed 86.
Particles to be separated are received in the separating chamber 65 from the fluidized bed separator inlet 67 in downstream direction of the flow of the further fluid stream 70, i.e. the fluidized bed 86. The concentrated particles fluid stream 78 entering the separating chamber 65 first encounters the first end part 98 of the flow guider element 93 which is shaped so as to distribute the concentrated particles fluid stream 78 as evenly as possible across the area of the separating chamber 65 between the mid part 97 of the flow guider element 93 and the inner wall of the housing 66. That is, the concentrated particles fluid stream 78 is as much as possible evenly distributed across the fluidized bed 86.
The ‘settling’ of the particles 71 to be collected from the concentrated particles fluid stream 78, i.e. the tobacco shorts, operates based on a higher downward hindered settling velocity, indicated by arrow 87, of the particles 71 to be collected compared to the upward velocity, indicated by arrow 88, created by the fluidization gas of the fluidized bed 86 in the separating chamber 65. This, because larger particles, which are to be collected, generally have a higher weight than the smaller particles, i.e. the tobacco fines or dust that may still remain in the concentrated particles fluid stream 78. The result is settling of the particles 71 at the apex part 75 of the separator unit 53 while other particulate matter, not comprising the particles 71 to be collected and experiencing a higher upward velocity compared to the downward hindered settling velocity of the particles 71, is discharged with the upward stream 76 created by the fluidized bed 86 in the separating chamber 65 at the fluidized bed separator outlet 77 at the top end 68 thereof. By adjusting the fluidized bed gas capacity 86 in the separating chamber 65, the operation of the fluidized bed particle separator unit 53 can be controlled.
The high frequency ultrasonic separation screen or sieve 89 is arranged for discharging from the separating chamber 65 the further fluid stream 70 and particulate matter not comprising the particles to be collected, i.e. particulate matter having dimensions smaller than the particles 71 to be collected. The screen or sieve 89 also balances the static pressure in the separating chamber 65 and stabilises the fluidized bed 86. In the case of a cut tobacco particulate matter fluid stream 78, comprising shorts and fines, the mesh size of the screen or sieve 89 is in the range of 400-800 micron (i.e. 0.4-0.8 mm). The cut-off point of the particles 71 to be collected in the fluidized bed particle separator unit 53 can be adjusted by appropriate selection of the mesh size of the screen or sieve 89.
In use, the mesh openings of the separation screen or sieve 89 are opened and closed continuously by operation of the vibrator unit 100, schematically indicated by a double arrow 106. Due to the high vibration frequency of, for example 20-30 kHz imposed by the vibrator unit 100, the mesh of the ultrasonic screen or sieve 89 also vibrations over a short distance in longitudinal direction of the housing 66, such as a distance of for example 10-20 micron, schematically indicated by a double arrow 104.
The separation screen or sieve 89 provides a clear particle recovery cut off point, assuring that only the correct range of particles is recovered, such as shorts of a cut tobacco stream to be send back to the cigarette maker. Use of an ultrasonic screen or sieve 89 is necessary for preventing fouling/plugging of the screen or sieve over time. Especially tobacco needles are hard to remove, due to their tapered shape. By continuously 106 opening and closing of the mesh openings of the screen or sieve 89, trapped dust is effectively released and the combination of a fluidized bed and ultrasonic screen or sieve provides a sustainable operation of the fluidized bed, guaranteeing the washing out of remaining fine dust and returning same with the upward stream 76 to the fluidized bed separator outlet 77 (see Fig. 2).
As indicated above, in use, the screen or sieve 89 vibrates 104 in longitudinal direction. By this vibration, particles 105 to be recovered, in particular particles 105 to be recovered having a lower weight compared to the other particles 71 to be recovered, will float below the sieve mesh 89, i.e. seen in upstream direction of the further fluid stream 70. Such particles 105 are ‘floating’ in balance with the velocity of the upward stream 76 leaving the separating chamber 65. As these particles 105 of lower weight are not in contact with the screen or sieve 89, they hardly have any resistance for moving over the sieve deck.
The vanes 101, that are positioned in the separating chamber 65 at a distance adjacent the screen or sieve 89, create in combination with the flow profile generated below the sieve deck, a force on the ‘floating’ particles 105 acting perpendicular to the upward stream 76, and pushing the particles 105 from the inner wall of the separating chamber 65 to the vanes 101, as schematically indicated by arrows Fs. The vanes 101 also create a lee-zone in the space between the screen or sieve 89 and the vanes 105, that allows the particles 105 that are caught by the vanes 101 to be released from the vanes 101, as schematically indicated by arrows Fg. In the lee-zone the upward flow on the particles 105 is reduced to zero and the vanes 101 act as ‘slides’ for the particles 105 that enter the lee-zone, such that the particles 105 return back into the separating chamber 65, to be recovered as valuable particles.
The operation of the vanes 101 in combination with the ultra-sonic screen or sieve 89 is detailed in Fig. 6, showing a Computational Fluid Dynamics, CFD, image of the area comprising the screen or sieve 89 and a vane 101. The lee-zone created in the space between the vane 101 and the vibrating 104 screen or sieve 89 is indicated by reference numeral 107, i.e. the lighter grey area in the CFD image. Particles 105 floating below the screen or sieve deck, i.e. indicated by arrow Fs, will collide on the vane 101 in the lee-zone 107. As the upward flow in the lee-zone 107 is reduced to zero, the particles glide or slide along the vane 101 back into the separating chamber 65, indicated by arrow Fg.
The efficiency of the fluidized bed particle separator unit 53 is enhanced, in a further embodiment thereof, by controlling the further fluid stream 70 at the further fluidized bed separator inlet 72 by a valve 49. To assure adequate settling of the particles 71, for recovery and feedback for further processing, the valve 49 operates in a pulsating manner thereby controlling the upward flow of the further fluid stream 70, i.e. the fluidized bed 86. Such a pulsating fluidized bed 86 improves the settling of the lower weight particles 105 to be recovered. The distribution of the particulate matter over the fluidized bed 86 may be further controlled by velocity control of the concentrated fluid stream 78.
In a further embodiment of the invention, the particle separator/concentrator unit with its elongated chamber and the fluidized bed particle separator unit with its elongated separating chamber extend substantially parallel, i.e. in-line. The inlet 56 and the outlet 57 of the particles separating and collecting device according to the invention may be arranged for mounting the device in a vertically positioned dust removal or exhaust line or pipe, such as the exhaust line or pipe 36 illustrated in Figure 1.
In another example of a device for collecting particles from a gaseous fluid stream in accordance with an embodiment of the invention, the dimensional footprint of the device is further reduced in that the particle separator/concentrator unit is comprised, i.e. integrated, in (part of) an exhaust line or pipe of the de-dusting 36. In this embodiment, the separating chamber of the fluidized bed particle separator unit directly connects to the exhaust line or pipe 36 by the separation screen or sieve.
The rotary air lock valve 79 may comprise several compartments for collecting valuable particles 71. By rotating the valve 79, a compartment can be discharged while an empty compartment can be filled with particles 71. In this way loss of the further gaseous stream 70 provided to the fluidized bed in the separating chamber 65 while discharging the valuable particles 71 from the device 50 is as much as possible prevented.
Tests have been performed for separating shorts from an air stream comprising cut tobacco dust, i.e. shorts and fines. The tests have been performed with a further air stream 70 entering the fluidized bed particle separator unit 53, having a pulsating inlet air velocity and capacity, and a constant dust sample, i.e. the having the same particulate distribution, however with different concentrations, i.e. load per amount of gas, of the concentrated particle fluid stream entering the fluidized bed separator unit 53 from the particle separator/concentrator unit 52.
An increase or concentration of the load by a factor 20, for example, from 4.9 gram shorts per m3 air to 98 gram shorts per m3, in the concentrated particles fluid stream 78 entering the fluidized bed particle separator unit 53, shows a reduction of about 20% of the amount of fines having a length shorter than 400 micron among the shorts collected by the fluidized bed separator unit 53.
The device according to the invention is suitable for handling an exhaust air capacity loaded with tobacco dust of tobacco processing equipment, such as a cigarette maker, ranging from 700-3500 m3 per hour. Depending on the maker type, such dust may contain 10-25 % valuable tobacco fibers, i.e. shorts, that are collected with the device according to the invention with a high efficiency.
The device according to the invention is suitable for collecting ‘conventional’ tobacco shorts, i.e. specific weight in the range of 250-400 kg/m3, as well as shorts of DIET, i.e. specific weight in the range of 75-200 kg/m3.
In addition to the placement of the device for collecting particles from a gaseous fluid stream 63 comprising particulate matter in a separate dust removal system 34, the device 40, may also be positioned in the pneumatic transport line 14 between the line collector unit 23 and the dust filter and collector 22, for example, for collecting shorts from the pneumatic fluid flow downstream of the tobacco processing equipment 13. The valuable particles recovered may be directly fed 47 into the processing equipment 13 for further processing thereof (not shown).
The invention may be practiced otherwise than as specifically described herein, and the above mentioned embodiments and examples are merely intended as an illustration to the skilled reader.

Claims (17)

1. Inrichting voor het verzamelen van deeltjes uit een gasvormige fluïdumstroom omvattende vaste deeltjes waaronder de betreffende te verzamelen deeltjes, welke inrichting een deeltjesscheider/concentratoreenheid en een weerstands-bezinkings-wervelbeddeeltjesscheidereenheid (“hindered settling fluidized bed particle separator unit”); welke deeltjesscheider/concentratoreenheid omvat: - een langwerpige kamer, omvattende een afgeknot kegelvormig rooster met een sleufvormig lateraal oppervlak dat zich in langsrichting van de kamer vanaf een basiseinde naar een topeinde van het rooster uitstrekt, - een inlaat, gelegen tegenover het basiseinde van het rooster aan een eerste einde van de kamer, voor het ontvangen van de gasvormige fluïdumstroom omvattende de vaste deeltjes, - een deeltjesuitlaat, verbonden met het topeinde van het rooster, ingericht voor het uit de kamer afvoeren van deeltjes in een fluïdumstroom met een verhoogde concentratie aan te verzamelen deeltjes in vergelijking tot de bij de concentratorinlaat ontvangen fluïdumstroom, en - een uitlaat, gelegen tegenover het topeinde van het rooster aan een tweede einde van de kamer tegenover het eerste einde hiervan, voor het afvoeren van gas en niet aan de deeltjesuitlaat afgevoerde vaste deeltjes, welke weerstandsbezinkings-wervelbeddeeltjesscheidereenheid omvat: - een langwerpige scheidingskamer met een eerste einde en een tweede einde tegenover het eerste einde van de scheidingskamer, - een ultrasoon scheidingsscherm of -zeef, gelegen aan een eerste einde van de scheidingskamer, om de te verzamelen deeltjes te blokkeren van het verlaten van de scheidingskamer en voor het doorlaten van vaste deeltjes welke niet de te verzamelen deeltjes omvatten, - een wervelbedscheiderinlaat, welke zich in de scheidingskamer uitstrekt vanaf het eerste einde van de scheidingskamer voorbij het scheidingsscherm of de -zeef en met de deeltjesuitlaat van de deeltjesscheider/concentratoreenheid is verbonden, - een veelheid schoepen, welke zich in de scheidingskamer uitstrekken onder een scherpe hoek met en over een afstand aangrenzend aan en dwars op het scheidingsscherm of de -zeef, - een wervelbedscheiderdeeltjesuitlaat, gelegen aan het tweede einde van de scheidingskamer, voor het uit de scheidingskamer afvoeren van te verzamelen deeltjes, - een verdere wervelbedscheiderinlaat, gelegen aan het tweede einde van de scheidingskamer tussen de wervelbedscheiderinlaat en de wervelbedscheider-deeltjesuitlaat, voor het in de scheidingskamer ontvangen en aan een verdere gasvormige-fluïdumuitlaat afvoeren van een gasvormige verdere fluïdumstroom, - een wervelbedscheideruitlaat, gelegen aan het eerste einde van de scheidingskamer tegenover het scheidingsscherm of de -zeef, voor het uit de scheidingskamer afvoeren van de verdere fluïdumstroom en vaste deeltjes welke niet de te verzamelen deeltjes omvatten, en - een centraal stromingsgeleidingselement dat zich in langsrichting van de scheidingskamer tussen de wervelbedscheiderinlaat en de verdere gasvormige-fluïdumuitlaat uitstrekt.A device for collecting particles from a gaseous fluid stream comprising solid particles including the particles to be collected, which device is a particle separator / concentrator unit and a resistance settling fluidized bed particle separator unit ("hindered settling fluidized bed particle separator unit"); which particle separator / concentrator unit comprises: - an elongated chamber, comprising a frusto-conical grid with a slit-shaped lateral surface extending longitudinally of the chamber from a base end to a top end of the grid, - an inlet opposite the base end of the grid at a first end of the chamber, for receiving the gaseous fluid stream comprising the solid particles, - a particle outlet, connected to the top end of the grid, arranged for discharging particles from the chamber into a fluid stream with an increased concentration. collect particles in comparison to the fluid flow received at the concentrator inlet, and an outlet located opposite the top end of the grid at a second end of the chamber opposite the first end thereof, for discharging gas and solid particles not discharged at the particle outlet , which resistance settling fluidized bed particle separator unit vessel: - an elongated separation chamber with a first end and a second end opposite the first end of the separation chamber, - an ultrasonic separation screen or screen, located at a first end of the separation chamber, to block the particles to be collected from leaving the separation chamber and for passage of solid particles which do not comprise the particles to be collected, - a fluidized bed separator inlet, which extends into the separation chamber from the first end of the separation chamber beyond the separation screen or screen and with the particle outlet of the particle separator / concentrator unit is connected, - a plurality of blades which extend into the separation chamber at an acute angle with and over a distance adjacent to and transversely to the separation screen or screen, - a fluidized bed separator particle outlet, located at the second end of the separation chamber, for the discharging particles to be collected from the separation chamber, - a further work velbedbed separator inlet, located at the second end of the separation chamber between the fluidized bed separator inlet and the fluidized bed separator particle outlet, for receiving a gaseous further fluid flow into the separation chamber and discharging a gaseous fluid flow outlet, - a fluidized bed separator outlet located at the first end of the separation chamber opposite to the separation screen or screen, for discharging the further fluid flow and solid particles from the separation chamber which do not comprise the particles to be collected, and - a central flow guide element which extends longitudinally of the separation chamber between the fluidised bed separator inlet and the further gaseous fluid outlet. 2. Inrichting volgens conclusie 1, waarin het ultrasone scheidingsscherm of de -zeef werkzaam is verbonden met een transducereenheid ingericht voor het aansturen van het scheidingsscherm of de -zeef met een vibratiefrequentie in een bereik van 20 - 30 kHz.Apparatus as claimed in claim 1, wherein the ultrasonic separation screen or screen is operatively connected to a transducer unit adapted to control the separation screen or screen with a vibration frequency in a range of 20-30 kHz. 3. Inrichting volgens een van de voorgaande conclusies, waarin de schoepen een vleugelvormige of wigvormige plaatvorm hebben.Device as claimed in any of the foregoing claims, wherein the blades have a wing-shaped or wedge-shaped plate shape. 4. Inrichting volgens een van de voorgaande conclusies, waarin een aantal van 3-6 schoepen gelijkmatig in omtreksrichting over het scherm of de zeef zijn verdeeld en zich in hoofdzaak over eenzelfde afstand in de scheidingskamer uitstrekken gemeten vanaf het scherm of de zeef onder een scherpe hoek tussen 45 - 75 graden.Device as claimed in any of the foregoing claims, wherein a number of 3-6 vanes are uniformly distributed in circumferential direction over the screen or the screen and extend substantially the same distance in the separation chamber measured from the screen or the screen under a sharp angle between 45 - 75 degrees. 5. Inrichting volgens een van de voorgaande conclusies, waarin het stromingsgeleidingselement een rotatiesymmetrisch langwerpig cilindrisch middendeel omvat, dat zich centraal in de scheidingskamer uitstrekt en een eerste puntvormig einddeel en een tweede puntvormig einddeel heeft, welk stromingsgeleidingselement een gesloten buitenoppervlak heeft.5. Device as claimed in any of the foregoing claims, wherein the flow guide element comprises a rotationally symmetrical elongate cylindrical middle part which extends centrally in the separation chamber and has a first pointed end part and a second pointed end part, which flow guided element has a closed outer surface. 6. Inrichting volgens conclusie 5, waarin de eerste en tweede puntvormige einddelen van het stromingsgeleidingselement hyperboloïdevormig zijn gevormd.The device of claim 5, wherein the first and second pointed end portions of the flow guide element are hyperboloid shaped. 7. Inrichting volgens een van de voorgaande conclusies, verder omvattende een stuurbare klep verbonden met de verdere wervelbedscheiderinlaat van de wervelbeddeeltjesscheidereenheid voor het sturen van de gassnelheid en hoeveelheid van de gasvormige verdere fluïdumstroom voor toevoer in de scheidingskamer van de wervelbeddeeltjesscheidereenheid.The apparatus of any preceding claim, further comprising a controllable valve connected to the further fluidized bed separator inlet of the fluidized bed particle separator unit for controlling the gas velocity and amount of the gaseous further fluid flow for supply into the fluidized bed particle separator separation chamber. 8. Inrichting volgens conclusie 7, waarin de met de verdere wervelbedscheiderinlaat verbonden stuurbare klep een pulserende klep is.Device as claimed in claim 7, wherein the controllable valve connected to the further fluidized bed separator inlet is a pulsating valve. 9. Inrichting volgens een van de voorgaande conclusies, verder omvattende een langwerpige fluïdumstroomdeler welke zich over een afstand binnen het rooster van de kamer van de deeltjesscheider/concentratoreenheid uitstrekt, welke fluïdumstroomdeler zodanig is gelegen dat de fluïdumstroom binnen het rooster gelijkmatig over het sleufvormige laterale oppervlak van het rooster wordt verdeeld.Device according to any of the preceding claims, further comprising an elongated fluid flow divider extending over a distance within the grid of the particle separator / concentrator chamber, said fluid flow divider being located such that the fluid flow within the grid is evenly over the slot-shaped lateral surface of the schedule. 10. Inrichting volgens conclusie 9, waarin de fluïdumstroomdeler een rotatiesymmetrische langwerpige vorm omvat, met een eerste kegelvormig einde en een tweede kegelvormig einde waarvan de basisvlakdelen via een tussengelegen cilindrisch deel op elkaar aansluiten, waarin het eerste kegelvormig einde bij het basisvlakeinde van het rooster is gelegen en naar de inlaat van de deeltjesscheider/concentratoreenheid is gekeerd en het tweede kegelvormige einde bij het topeinde van het rooster is gelegen en naar de uitlaat van de deeltjesscheider/concentratoreenheid is gekeerd.Device as claimed in claim 9, wherein the fluid flow divider comprises a rotationally symmetrical elongate shape, with a first conical end and a second conical end whose basic surface parts connect to each other via an intermediate cylindrical part, wherein the first conical end is at the basic surface end of the grid and faces the inlet of the particle separator / concentrator unit and the second conical end is located at the top end of the grid and faces the outlet of the particle separator / concentrator unit. 11. Inrichting volgens een van de voorgaande conclusies, waarin het tweede einde van de scheidingskamer van de wervelbeddeeltjesscheidereenheid trechtervormig is met een basisdeel en een topdeel en een deeltjescollector vormt voor het verzamelen van de, uit de gasvormige fluïdumstroom welke de vaste deeltjes omvat gescheiden deeltjes, waarbij het topdeel van de scheidingskamer aansluit op de wervelbed-deeltjesuitlaat welke eindigt in een luchtsluisklep, in het bijzonder een luchtsluisdraaiklep.11. Device as claimed in any of the foregoing claims, wherein the second end of the fluidized bed particle separator separation chamber is funnel-shaped with a base part and a top part and forms a particle collector for collecting the particles separated from the gaseous fluid stream comprising the solid particles, wherein the top part of the separation chamber connects to the fluidized bed particle outlet which terminates in an air sluice valve, in particular an air sluice rotary valve. 12. Inrichting volgens een van de voorgaande conclusies, waarin de kamer van de deeltjesscheider/concentratoreenheid zich dwars uitstrekt op de scheidingskamer van de wervelbeddeeltjesscheidereenheid.Device according to one of the preceding claims, wherein the chamber of the particle separator / concentrator unit extends transversely to the separation chamber of the fluidized bed particle separator unit. 13. Inrichting volgens een van de conclusies 1-11, waarin de kamer van de deeltjesscheider/concentratoreenheid en de scheidingskamer van de wervelbeddeeltjes-scheidereenheid zich in-line uitstrekken.The device of any one of claims 1 to 11, wherein the chamber of the particle separator / concentrator unit and the separation chamber of the fluidized bed particle separator unit extend in-line. 14. Inrichting volgens conclusie 13, waarin de deeltjesscheider/concentrator-eenheid in de wervelbeddeeltjesscheidereenheid is opgenomen.The device of claim 13, wherein the particle separator / concentrator unit is included in the fluidized bed particle separator unit. 15. Inrichting volgens een van de voorgaande conclusies, waarin de uitlaat van de deeltjesscheider/concentratoreenheid voor het afvoeren van gas uit de in de kamer van de deeltjesscheider/concentratoreenheid ontvangen fluïdumstroom en de wervelbed-scheideruitlaat voor het uit de wervelbeddeeltjesscheidereenheid afvoeren van de verdere fluïdumstroom en vaste deeltjes niet omvattende de betreffende deeltjes in stromingsverbinding staan en een enkele integrale gasuitlaat van de inrichting vormen.Device as claimed in any of the foregoing claims, wherein the outlet of the particle separator / concentrator unit for discharging gas from the fluid flow received in the chamber of the particle separator / concentrator unit and the fluidized bed separator outlet for discharging the further fluid flow from the fluidized bed particle separator unit and solid particles not including the particles in question are in flow communication and form a single integral gas outlet of the device. 16. Inrichting volgens conclusie 15, ingericht voor het verzamelen van tabakvezels uit een gasvormige fluïdumstroom in een pijpleiding van een gesneden-tabak-verwerkingssysteem, waarin de inlaat van de deeltjesscheider/concentratoreenheid voor het ontvangen van de gasvormige fluïdumstroom welke vaste deeltjes omvat pijpvormig is en de uitlaat van de deeltjesscheider/concentratoreenheid pijpvormig is voor het in de pijpleiding monteren van de inrichting.An apparatus according to claim 15, adapted to collect tobacco fibers from a gaseous fluid stream in a pipeline of a cut tobacco processing system, wherein the inlet of the particle separator / concentrator unit for receiving the gaseous fluid stream comprising solid particles is tubular and the outlet of the particle separator / concentrator unit is tubular for mounting the device in the pipeline. 17. Gesneden-tabakverwerkingsapparatuur, zoals een sigarettenvervaar-digingsinrichting, omvattende een transportleidinginlaat voor aansluiting op een gesneden-tabakafgifte-eenheid, een transportleidinguitlaat voor aansluiting op een transportleidingfluïdumstroom-stuureenheid en een stofverwijderingssysteem omvattende een stofverwijderingsleiding waarin een inrichting volgens een van de voorgaande conclusies is opgenomen.A cut tobacco processing equipment, such as a cigarette making device, comprising a conveyor line inlet for connection to a cut tobacco delivery unit, a transportation line outlet for connection to a transportation line fluid flow control unit and a dust removal system comprising a dust removal line wherein an apparatus according to any preceding claim is included.
NL2016053A 2015-12-30 2015-12-30 A device for collecting particles from a gaseous fluid stream, and cut tobacco processing equipment comprising such a device. NL2016053B1 (en)

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DE9016937U1 (en) * 1989-12-15 1991-03-07 Bergwerksverband Gmbh, 4300 Essen, De
USRE35300E (en) * 1991-12-11 1996-07-23 Epr Inc. Device for separating multiple-component fluids
WO2001003809A1 (en) * 1999-07-14 2001-01-18 Astrazeneca Ab Filter device
DE102004001619A1 (en) * 2004-01-09 2005-08-04 Andrey Kuzmin Gap filter for liquids or gases has a filtration element formed from multiple spaced apart segments with the total minimum gap flow area being proportioned to the internal flow area of the filtration element
WO2010023692A1 (en) * 2008-08-30 2010-03-04 Tata Steel Limited A novel method for production of iron ore concentrates suitable for iron and steel making processes.

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE9016937U1 (en) * 1989-12-15 1991-03-07 Bergwerksverband Gmbh, 4300 Essen, De
USRE35300E (en) * 1991-12-11 1996-07-23 Epr Inc. Device for separating multiple-component fluids
WO2001003809A1 (en) * 1999-07-14 2001-01-18 Astrazeneca Ab Filter device
DE102004001619A1 (en) * 2004-01-09 2005-08-04 Andrey Kuzmin Gap filter for liquids or gases has a filtration element formed from multiple spaced apart segments with the total minimum gap flow area being proportioned to the internal flow area of the filtration element
WO2010023692A1 (en) * 2008-08-30 2010-03-04 Tata Steel Limited A novel method for production of iron ore concentrates suitable for iron and steel making processes.

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