GB2593167A

GB2593167A - Extraction apparatus

Info

Publication number: GB2593167A
Application number: GB2003748.7A
Authority: GB
Inventors: Hartley Marcus
Original assignee: British American Tobacco Investments Ltd
Current assignee: British American Tobacco Investments Ltd
Priority date: 2020-03-16
Filing date: 2020-03-16
Publication date: 2021-09-22
Also published as: GB202003748D0

Abstract

An apparatus, such as a packaging machine for tobacco products, for extracting recyclable material 2 away from an extraction surface 3, the apparatus comprising: an extraction passage 6 defined between opposing first 4 and second 5 surfaces, the extraction passage having an entrance opening 7 at one end and a discharge opening 8 at an opposite end, and an air flow system including an air flow outlet 14, the air flow outlet being configured to direct a flow of pressurised air through the extraction passage 6 in a direction towards the discharge opening 8 to generate a reduced pressure proximate the entrance opening 7, such that material to be extracted proximate the entrance opening can be drawn into the entrance opening and through the extraction passage towards the discharge opening.

Description

Extraction Apparatus

Field

The present invention relates to an apparatus, system and method, for extracting 5 material away from a surface.

Background

Methods of extracting material from a surface in a manufacturing process may consist of a mechanical removal mechanism, such as teeth or fingers to engage a material to be io extracted. These removal methods may include a mechanism which is moveable towards a surface when there is material to be extracted, and moveable away from the surface when no extraction is necessary, which may take time to execute and/or may not always reliably engage and remove the material to be extracted. In the manufacturing industry, process efficiency and reliability is important and affects /5 production speed and cost, and so such material extraction methods may therefore adversely impact a manufacturing process.

Summary

In accordance with some embodiments described herein, there is provided an apparatus for extracting material away from an extraction surface, the apparatus comprising: an extraction passage defined between opposing first and second surfaces, the extraction passage having an entrance opening at one end and a discharge opening at an opposite end, and an air flow system including an air flow outlet, the air flow outlet being configured to direct a flow of pressurised air through the extraction passage in a direction towards the discharge opening to generate a reduced pressure proximate the entrance opening, such that material to be extracted proximate the entrance opening can be drawn into the entrance opening and through the extraction passage towards the discharge opening.

Advantageously an apparatus according to embodiments described herein may have a low number of, or even no moving parts which can reduce maintenance time and costs. Furthermore, that may reduce start-up time for the apparatus over known material extraction apparatuses. This can help make a manufacturing production line more efficient.

One or more of the first surface and the second surface may comprise a leading edge at the entrance opening of the extraction passage The leading edge can cause ambient air proximal to the entrance opening to bifurcate at the leading edge. The leading edge can define a stagnation point where the local velocity of the air flow is zero and a portion of the ambient air is thus entrained into the extraction passage. Entraining ambient air into the extraction passage can mean less air needs to be supplied from the air flow system to create a material-entraining air flow though the extraction passage. This can improve the overall efficiency of the apparatus.

The first surface or the second surface may comprise a trailing edge at the discharge opening of the extraction passage.

Advantageously this may help enable material collected away from the surface to be expelled such that it can be recycled, re-used or disposed of in the appropriate manner.

The air flow outlet may comprise a pathway which narrows towards the extraction passage, such that a velocity of the air flow is increased as it travels through the pathway.

Taking advantage of the fluid behaviour of the Venturi effect, air flow through the extraction passage may be accelerated through the narrowed section, enhancing the air pressure reduction and increasing the effectiveness of at least one of material extraction and ambient air entrainment. This may also reduce the volume of pressurised air or needed to be supplied to the apparatus.

The apparatus may further comprise a lifter on one or more of the first surface and the second surface, to assist in lifting the material from the extraction surface. The lifter can comprise a set of teeth on the second surface.

Advantageously a lifter can provide a secondary lifting system if there is a delay or fail in initiating the extraction apparatus. Generally the lifter provides an initial assistance in lifting the material from the extraction surface.

The lifter may be adjustable relative to at least one of the first surface and the second surface. At least one of the first surface and the second surface may be adjustable -3 -relative to the other of the first surface and the second surface. The first surface may be adjustable relative to the second surface.

Advantageously this can enable different configurations of the apparatus to optimise the extraction of the material. It can enable the same apparatus to be used for different types of material, for example, particulate material such as tobacco dust, foil or paper which can all have a different shape and mass. It also can enable variations of pressure and flow to be catered for in the air supply. This adjustment can also vary the configuration of the extraction passage.

The first surface may be a mirror image of the second surface. Where the first and second surfaces are identically shaped and formed, each with an air flow outlet and disposed oppositely to one another, the air flow through the extraction passage may be easier to balance evenly, which may help encourage material to be extracted from the extraction surface to pass more centrally through the extraction passage. This may help avoiding material sticking on either of the first or second surfaces and/or reduce the risk ofjamming or tumbling of the material in the extraction passage or into the rest of the machinery.

The air flow outlet may be disposed proximal to the entrance opening of the extraction passage. The air flow outlet maybe disposed downstream of the entrance opening, within the extraction passage.

The air flow outlet being proximal to the entrance opening or downstream of the or entrance opening enables the air flow to be directed towards the discharge opening, generating an area of reduced pressure proximate the entrance opening. This reduced pressure causes suction to lift and draw away the material from the extraction surface.

The air flow outlet may be an elongate slot to generate a blade of air. A blade of air can mean that the pressurised air leaving the air flow outlet exits in a laminar flow pattern such that the air flow is similar across the width of the first and second surfaces at the air flow outlet. This can also assist in directing the extracted material into the extraction passage.

The air flow outlet may be configured to generate a laminar air flow along one or more of the first surface and the second surface. If extracted material is caught in the laminar -4 -flow then it can travel more smoothly and efficiently along the first or second surface and away from the extraction surface. The laminar flow also provides a barrier between the material and the first and/or second surface such that the risk of the material sticking to the first and/or second surface is reduced.

One or more of the first surface and the second surface may comprise the air flow outlet. This enables a number of different configurations of the extraction apparatus to optimise the extraction of material from an extraction surface.

/t) The air flow outlet may be integrally formed with one or more of the first surface and the second surface. This reduces the number of parts simplifying the design for manufacture and assembly. It also reduces the number of parts which need to be replaced or serviced over time.

Each of the first surface and the second surface may comprise an air flow outlet. This may help balance air flow through the extraction passage, and may enable a convergence point of air flow from the air flow outlets of the first and second surface to be formed. If the convergence point is proximal to the centre of the extraction passage then this urges the material to remain in the centre of the extraction passage once extracted from the surface.

One or more of the first surface and the second surface may comprise a plurality of air flow outlets. A plurality of air flow outlets can act as a blade of air, or as individual jets of air depending on the configuration. Each air flow outlet may be independently or opened or closed such that the same extraction apparatus can be used for the removal of various material, for example, tobacco dust, particulate material or sheet material such as paper or foil. A profile of the air flow from the air flow outlets can also be adjusted to optimise the extraction in different atmospheric conditions.

One or more of the first surface and the second surface may further comprise a body including a plenum chamber which is in fluid communication with the air flow outlet.

A plenum chamber may help provide an even air distribution through the air flow outlet. It can also provide a chamber for the air to be heated or compressed further 35 before being directed into the extraction passage. -5 -

The extraction passage may comprise a narrowed section and the extraction passage may widen from the narrowed section towards the discharge opening. The narrowed section may be disposed intermediate the entrance opening and the discharge opening. The air flow outlet may be disposed upstream of the narrowed section.

The extraction passage may narrow from the entrance opening to the narrowed section. This may enhance entrainment of ambient air from around the entrance opening The discharge opening may be wider than the entrance opening.

The apparatus may further comprise a third surface disposed between the first and second surfaces to define a first extraction passage and a second extraction passage. The third surface may comprise a plurality of apertures through said third surface.

/5 Advantageously a number of configurations can be envisaged to tailor the apparatus to the type of material to be extracted and the extraction surface or machinery that the apparatus is to be used with. The third surface can be slotted or otherwise include a plurality of apertures therethrough, which may enable air to pass through the third surface. The apparatus may comprise a fourth surface such that material to be extracted is encouraged to be extracted between the third and fourth surfaces. Preferably the convergence point is at the third surface, or between the third and fourth surfaces where a third and/or fourth surface exists.

The apparatus may comprise an air knife which includes one of the first and second surfaces. The apparatus may comprise a first air knife and a second air knife, wherein the first air knife includes the first surface and the second air knife includes the second surface. The apparatus may comprise a pair of similar air knifes.

Air knifes provide a number of advantages, for example but not limited to, fewer moving parts, a saving in the usage of compressed air compared to air being supplied directly to nozzles, and air is supplied at a constant pressure. A pair of similar air knifes have the advantages associated with a single air knife, but they can also have a convergence point from the outlets of the pair of air knifes, located in the centre of the extraction passage.

The apparatus may further comprise a heating mechanism configured to heat the air flow which is directed through the extraction passage. The heating mechanism may be -6 -configured to heat the air before it is discharged from the discharge opening. The air may be heated within the plenum chamber.

The apparatus may further comprise an ioniser to ionise the air flow which is directed 5 through the extraction passage. The ioniser may be configured to ionise the air before it is discharged from the discharge opening. The air may be ionised within the plenum chamber.

In accordance with embodiments described herein, there is provided a system for rri extracting a material away from a surface comprising: an apparatus of any of the configurations described above, and a surface for supporting a material to be extracted, wherein the apparatus is arranged such that the entrance opening of the extraction passage is disposed proximate the surface and the discharge opening is disposed distal to the surface.

The extraction apparatus causes an area of reduced pressure proximal the entrance opening, therefore the suction of the material from the surface is improved if the entrance opening is proximate the extraction surface. The discharge opening being away from the extraction surface can ensure that any material extracted through the extraction passage is directed away from the surface, to help prevent the material jamming or tumbling into any part of an associated machinery or production line.

The extraction surface may further comprise a lifter configured to assist in lifting the material from the extraction surface. The extraction surface may comprise a plurality of or apertures therethrough and a suction system in communication with the apertures and configured to hold a material onto the extraction surface, and an interrupter valve configured to stop suction being applied to at least some apertures in the extraction surface to enable the material to be lifted from the extraction surface.

The interrupter valve can be activated when faulty material has been detected upstream such that the suction on the extraction surface to hold the material down is interrupted. Therefore an edge of the material can be entrained in the suction provided by the extraction apparatus more easily than if the material was being held against the extraction surface. -7 -

One or more of the first surface and the second surface may be adjustable relative to the extraction surface. This enables optimal configuration of the extraction apparatus relative to the extraction surface.

The system may comprise a heating mechanism to heat the air flow before it is discharged from the discharge opening. Heat can cause the air to expand, increasing the air pressure within a given volume and so helping to accelerate the air as it passes through the air flow outlet and/or through the narrowed section, further enhancing the Venturi effect. As an example, air can be heated at the air flow outlet or in the jo extraction passage. This may also reduce the volume of air needed to the supplied to the air flow system, and/or the energy expended in pressuring the compressed air supply.

The system may further comprise an ioniser to ionise the air flow before it is discharged from the discharge opening. This can enable the reduction of static charge on the material to be extracted and/or on the extraction system and apparatus. This static charge can be caused by moving parts of machinery.

The extraction surface may be a conveying surface configured for conveying a material 20 to be extracted. As part of a system, material can be extracted from moving surfaces such as a rotating drum or a conveyor belt. The system can also be introduced to an existing manufacturing system.

In accordance with embodiments described herein, there is provided a method of *-') or extracting a material from an extraction surface, using the apparatus of any configuration described above, the method comprising: generating an air flow from the air flow outlet and through the extraction passage in a direction towards the discharge opening to generate a reduced pressure proximate the entrance opening; extracting the material from the extraction surface, through the entrance opening and towards the discharge opening of the extraction passage, discharging the material from the extraction passage through the discharge opening.

Advantageously in many manufacturing processes, it can be determined upstream in a manufacturing line that a material is faulty, surplus, or needs to be removed for some 35 other reason. Such a determination may allow the extraction apparatus to be operated only when it is required and at a time calculated when the material to be extracted -8 -passes the extraction apparatus. This improves the efficiency of the apparatus and in the embodiments where compressed air is supplied to the apparatus, efficient use of the compressed air supply.

The method described above may be used where the extraction surface is a conveying surface for conveying a material to be extracted, for example a rotatable drum surface.

The material may be, for example, a particulate material such as tobacco dust or paper cuttings or a sheet material such as foil or paper.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic view of a manufacturing machine for the manufacture of packages of tobacco industry products; Figure 2 shows a cut-away perspective view of a first embodiment of an extraction apparatus, suitable for use in the manufacturing machine illustrated in Figure 1; Figure 3 shows a cross-sectional side view of the first embodiment of Figure 2; Figure 4 shows a cross-sectional side view of another embodiment of an extraction apparatus which comprises an intermediate surface within an extraction passage; Figure 5 shows a cross-sectional side view of another embodiment of an extraction apparatus comprising an extraction passage which is substantially constant in cross sectional area from an entrance opening to a discharge opening; Figure 6 shows a cross-sectional side view of another embodiment of an extraction apparatus comprising an arrangement of a plurality of extraction apparatuses similar to that of Figures 2 and 3 disposed in series; Figure 7 shows a schematic cross-sectional side view of another embodiment of an 35 extraction apparatus comprising air flow outlets disposed at the entrance opening; -9 -Figure 8 shows a schematic cross-sectional side view of another embodiment of an extraction apparatus comprising a receiving means for receiving and retaining extracted material; Figure 9 shows a schematic cross-sectional side view of another embodiment of an extraction apparatus comprising a plurality of air flow outlets on both the first and second surfaces; Figure 10 shows a schematic cross-sectional side view of another embodiment of an jo extraction apparatus wherein the first and second surfaces converge to, and diverge from, a narrowed section of an extraction passage, and the first and second surfaces are not components of a plenum of an air supply system; Figure n shows a cross-sectional side view of another embodiment of an extraction apparatus configured to extract a material from a flat conveying surface; Figures 12A to 12C show an enlarged partial cross-sectional side view of another embodiment of an extraction apparatus comprising an adjustable passageway in different positions; Figure 13 shows a perspective view of part of a manufacturing system including a rotating conveyor drum comprising a curved outer surface and an interrupter valve; and Figure 14 shows a perspective view of the drum of Figure 13.

Detailed Description

Figure 1 schematically illustrates a portion of a manufacturing machine 101 for manufacturing packages of tobacco industry products 102. Bundles 103 of tobacco industry products 102 are formed and conveyed to a first station where a card inner frame 104 is formed around each bundle 103. Foil material 105 is conveyed as a continuous strip 106 to a rotating drum 107 where the foil is cut into sections 108. The sections 108 are then fed onto the curved outer surface 3 of the drum 107. The surface 3 of the drum 107 comprises a plurality of apertures 109 in fluid communication with a closed interior space within the drum 107. The apertures 109 are configured to provide -10 -suction when a source of negative pressure or a vacuum is applied to the interior space within the drum 107, to hold the sections 108 on the surface 3 of the drum 107. The manufacturing machine 101 may comprise a quality control detector, such as a sensor, camera or other means (not shown) which is configured to determine whether any of the sections 108 are defective, misaligned, or otherwise unsuitable for use in the process. If a section 108 is detected which does not meet the predetermined quality control standard, then it may need to be removed from the drum 107. It would be undesirable to have to stop the machine 101 each time a foil section 108 is to be removed from the production line as this would negatively impact process production jo and cost efficiency, and also possibly require operator intervention. Accordingly, advantageously the foil section 108 can be removed while the machinery 101 is running.

Figures 2 and 3 illustrate an extraction apparatus 1 of a first embodiment for removal of a material 2 from an extraction surface 3.

The extraction surface 3 is depicted as a surface of a rotating drum in Figure 2. However, it can be appreciated that there are a number of moving or stationary surfaces from which the extraction apparatus 1 described herein can remove material. The extraction surface 3 may be for example, but not limited to, a flat horizontal conveyor belt, an inclined flat conveyor belt, a rotating drum, a stationary drum, a profiled surface or conveyor and a smooth surface or conveyor. The extraction surface 3 can be part of the rotating drum 107 of Figure 1.

The material 2 is depicted as a flat sheet of material, particularly but not exclusively a or foil, plastic or paper wrapper for wrapping a bundle of tobacco industry products or smoking articles, to be extracted. It can be appreciated that the material 2 to be extracted could alternatively be a particulate material such as tobacco dust or paper cuttings or any other sheet material.

It is also appreciated that the extraction apparatus 1 described herein, may be used in combination with other manufacturing processes or machinery and industries other than those associated with the tobacco industry.

The apparatus 1 comprises a first surface 4 and an opposing second surface 5. The first 35 surface 4 opposes the second surface 5 to define an extraction passage 6 between the first 4 and second 5 surfaces. In use, the apparatus 1 is located proximate the extraction surface 3 such that material 2 can be extracted from the extraction surface 3 and through the extraction passage 6, in a direction away from the extraction surface 3.

The extraction passage 6 comprises an entrance opening 7 and a discharge opening 8.

In use, the apparatus 1 is orientated relative to the extraction surface 3 such that the entrance opening 7 of the extraction passage 6 is disposed proximate the extraction surface 3. In some embodiments the extraction passage 6 increases in cross sectional area from the entrance opening 7 to the discharge opening 8. However, it can be appreciated that in some embodiments the cross sectional area of the extraction /o passage 6 may be substantially consistent from the entrance opening 7 to the discharge opening 8 as illustrated in Figures 5, 7, 8 and 9.

The extraction passage 6 comprises a narrowed section 35 at which the cross sectional area of the extraction passage 6 is less than that at the entrance opening 7. The narrowed section 35 is disposed along the length of the extraction passage 6 between the entrance opening 7 and discharge opening 8 such that the distance between the first and second surfaces 4,5, and therefore the cross-sectional area of the extraction passage 6, reduces from the entrance opening 7 to the point of the narrowed section 35. The distance between the first and second surfaces 4, 5, and therefore the cross-sectional area of the extraction passage 6, then increases from the narrowed section 35 towards the discharge opening 8.

The apparatus 1 comprises an air flow system (described in more detail below) which is configured to direct a flow of air through the extraction passage 6 in a direction from or the entrance opening 7 towards the discharge opening 8. The air flow system includes an air flow outlet 14 which directs air along the extraction passage 6. In the embodiment in Figures 2 and 3, the air flow outlet 14 is disposed proximate the entrance opening 7 and upstream of the narrowed section 35 (as used herein, the terms "upstream" and "downstream" are in relation to the air flow direction through the extraction passage from the entrance opening 7 to the discharge opening 8).

The discharge passage 6 narrowing from the entrance opening 7 to the narrowed section 35 increases the velocity of the air flowing through the extraction passage 6 by virtue of the Venturi effect. This results in a region of reduced pressure at the narrowed section 35 which generates suction at the entrance opening 7 to draw material 2 from the extraction surface 3 and through the extraction passage 6. The entrance opening 7 -12 -being wider than the narrowed section also enhances entrainment of ambient air from around the entrance opening 7, which in turn facilitates collection of the material 2 intended to be extracted. The configuration of the extraction apparatus 1 is advantageously optimised, for example, by taking advantage of the Venturi effect on fluid flow and the entrainment of ambient air, such that the apparatus 1 is efficient with minimal losses and to minimise the volume of air that needs to be supplied to the air flow system (described below) to achieve the desired suction and air flow effect.

The extraction passage 6 has a primal)/ axis 9 extending from the entrance opening 7 to /o the discharge opening 8, the primary axis 9 being equidistant between the first and second surfaces 4, 5 at the entrance opening 7. it can be appreciated that, as illustrated in Figure 2, if the first and second surfaces 4,5 are symmetrical with each other, the primary axis is a central axis, equidistant from the first and second surfaces 4, 5 at each point along the primary axis 9. Preferably the primary axis 9 is disposed substantially perpendicular to the extraction surface 3 in use. The apparatus 1 is disposed relative to the extraction surface 3 such that the material 2 is extracted and directed away from the extraction surface 3. Although it is preferable that the primary axis 9 of the extraction passage 6 is disposed perpendicular to the extraction surface 3 it can be envisaged that the apparatus may equally function if the primary axis 9 is orientated at an angle other than the perpendicular.

The term 'proximal' as used herein will refer to an end of the apparatus 1 closest to the extraction surface 3 in use, and at the entrance opening 7 end of the apparatus 1. The term 'distal' as used herein will refer to an end of the apparatus 1 furthest from the or extraction surface 3 in use, and at the discharge opening 8 end of the apparatus 1.

The first surface 4 comprises a leading edge 10 and a trailing edge ii. The leading edge lo is at a proximal end 12 of the first surface 4. The trailing edge 11 is located at a distal end 13 of thc first surface 4.

The leading edge lo is shaped to entrain ambient air into the extraction passage 6. As illustrated in Figures 2 and 3 the leading edge lo is curved in shape which enhances the entrainment of ambient air.

The trailing edge ii comprises an angled portion 29. There are two stagnation points, one at the leading edge 10 where the air flow bifurcates and one proximate the trailing -13 -edge 11. Air flow approaching the trailing edge 11 flows towards the second stagnation point. In the absence of an angled trailing edge 11, air flow approaching the trailing edge ir flows round the trailing end ri and vortexes are generated. An angled portion 29 enables air flow which is approaching the trailing edge ri to flow away from the trailing edge it smoothly and thereby minimise vortexes from being generated.

The first surface 4 is part of a first body 20 of the apparatus 1 which comprises an air knife 15. The first body zo further comprises an outer peripheral surface 16 which extends between the leading edge 10 and the trailing edge ri of the first surface 4 and is ro spaced from the first surface 4. The first body zo further comprises side portions (not shown) which extend between the first surface 4 and the peripheral surface 16 to define a plenum chamber 21 within the first body zo.

The first body zo comprises an air inlet 17 which is in fluid communication with the plenum chamber 21. The air inlet 17 is configured to be coupled to an air supply for the supply of pressurised air into the plenum chamber 21.

The first surface 4 comprises a fore portion 4a and an aft portion 4b extending between the leading edge 10 and the trailing edge 11. The aforementioned air flow outlet 14 is disposed between the fore portion 4a and the aft portion 4b. The first surface 4 is a continuous surface from the leading edge 10 to the trailing edge 11, interrupted only by the air flow outlet 14.

The air flow outlet 14 is in fluid communication with the plenum chamber 21 via an air flow pathway 22. The air flow outlet 14 is configured to direct a flow of air from the plenum chamber 21 through the extraction passage 6 in a direction towards the discharge opening 8 to generate a reduced pressure proximate the entrance opening 7.

The pathway 22 is configured to accelerate air from the plenum chamber 21, through the pathway 22, out of the air flow outlet 14 and into the extraction passage 6. The pathway 22 is curved and narrows towards the air flow outlet 14, i.e. the cross sectional area of the pathway 22 decreases from the plenum chamber 21 towards the extraction passage 6. The cross-sectional area of the pathway 22 is referred to as a "gap" herein. Where the gap is relatively wider the air flow is slower, and where the gap is relatively narrower, the air flow velocity is higher due to the Venturi effect. As air flows from within the plenum chamber 21 towards the air flow outlet 14, the air is accelerated by -14 -the configuration of the pathway 22 which means that a faster flow or air may be generated from a given pressure of air supplied to the plenum chamber 21, than would be possible if the pathway was of a constant cross-section along its length. This advantageously enables more efficient use of compressed air supplied to the plenum chamber 21 to create an accelerated fast flow of air into the extraction passage 6. Furthermore, the curved configuration of the pathway 22 advantageously facilitates the flow of air from the plenum chamber 21 to the air flow outlet 14 by reducing resistance to air flow and making the air flow more efficient, minimising pressure losses through the pathway 22. Again, this advantageously reduces the required air pressure in the ro plenum chamber 21 for a predetermined air flow rate or air flow velocity out of the air flow outlet 14 into the extraction passage 6.

The second surface 5 is part of a second body 20 of the apparatus 1 which comprises a second air knife 23 and which is a mirror image of the first body zo, and similarly comprises a leading edge 24 and a trailing edge 25. The leading edge 24 is at a proximal end 12 of the second surface 5 and the trailing edge 25 is located at a distal end 13 of the second surface 5. The second surface comprises a fore portion 5a and an aft portion 5b and an air flow outlet 14 is disposed between the fore and after portions 5a, 5b. The second surface 5 is a continuous surface, from the leading edge 24 to the trailing edge 25, interrupted only by the air flow outlet 14. Like features of the first and second air knives 15, 23 retain the same reference numerals and so description of such features will not be repeated here.

The air flow outlet 14 of the second air knife 23 is also configured to direct a flow of air or towards the discharge opening 8, as with the air flow outlet of the first air knife 15. The angle of the air flow leaving the air flow outlets 14 is arranged such that a laminar flow is generated along at least one of the first or second surfaces 4, 5, and advantageously along each of the respective first and second surfaces 4, 5. A section 34 of the first and second surface 4, 5, where the air flow exits the air flow outlet 14, is substantially straight to encourage this laminar flow. The laminar flow assists in reducing tumbling of extracted material 2 as it is conveyed through the extraction passage 6. The air flow leaving the air flow outlet 14 flows along the straight portion 34 until it reaches an angled point 32 which, in the first embodiment illustrated in Figures 2 and 3, is located at the narrowed portion 35 of the extraction passage 6.

-15 -A converging point 33 is illustrated in Figure 3, and represents a point within the extraction passage 6 where air flow from the opposing air flow outlets 14 on the first surface 4 and the second surfaces respectively meet. This is dictated by the angle of exit of the air flow from each air flow outlet 14, and the shape of the first and second surfaces 4,5. The converging point 33 is preferably downstream of the narrowed portion 35, and advantageously is located substantially equidistantly spaced from the first and second surfaces 4, 5. At the convergence point, the air flow from the air flow outlets 14 meet and combine to form a consolidated extraction air flow through the extraction passage 6 within which material 2 being extracted may be entrained and jo conveyed through the extraction passage 6.

The proximal end of the second surfaces comprises a lifter 26 for lifting the material 2 from the extraction surface 3. As illustrated in Figures 2 and 3 the lifter 26 is a set of teeth, configured to engage an edge of the material 2, to provide an initial lift of the edge of the material, away from the extraction surface and towards the area of reduced pressure.

In use of the apparatus 1, when a section 108 of material 2 is detected to be extracted from the extraction surface 3, for example, if defective, misaligned or otherwise undesirable, the reduced pressure within the interior space of the drum 107 is isolated from the apertures 109 on the drum surface 3 in the region of the drum surface 3 of the defective section 108, as that section 108 rotates to proximate the entrance opening 7 of the extraction apparatus 1. This isolation of the apertures 109 from the reduced pressure source stops the suction force that holds the material section 108 onto the or drum surface 3 (The mechanism by which the reduced pressure is isolated from the drum apertures 109 is described in more detail hereafter).

Pressurised air is supplied to the plenum chambers 21 of the first and second bodies zo through the air inlets 17, and the supplied air flows through the passageways 22 and out of the air flow outlets 14, generating an air flow through the extraction passage 6 as described above. As the material section 108 is no longer held against the drum surface 3, it can be drawn away from the drum surface 3 by the reduced air pressure around the entrance opening 7 and the surrounding air being drawn into the entrance opening 7. The material section 108 is thereby entrained into the air flow into the entrance opening 7 and through the extraction passage 6 and is ejected through the discharge opening 8. Advantageously, a substantially laminar air flow through the extraction -16 -passage 6 means that tumbling of the extracted material section 108 is reduced as it passes through the extraction passage 6. This can help make the material section 108 pass through the extraction passage 6 more quickly and also help prevent blockage of the extraction passage 6 by the extracted material section 108.

The reduced pressure proximate the entrance opening 7 should be sufficient to draw the material section 108 away from the drum surface 3, although to further ensure removal of the material section 108, the lifter 26 lifts the material section 108 from the drum surface 3 if the material section 108 reached the lifter 26 without having been jo drawn away from the drum surface 3 by air flow into the entrance opening alone. The portion of the lifter 26 closest to the drum surface 3 is spaced from the drum surface 3 by a distance slightly greater than the thickness of the material portion 1o8, so that when the material portion 108 is held on the drum surface by suction of the apertures 109, the material section 108 is not engaged by the lifter 26. However, when the suction force is stopped, the material section 108 will lift away from the drum surface 3 slightly and the lifter 26 is then able to engage and guide the material section 108 to be extracted, away from the drum surface 3 to be drawn into the entrance opening 7.

Another embodiment is illustrated in Figure 4. The apparatus 1 is substantially as described with reference to the first embodiment and like features retain the same reference numerals. One difference of this embodiment is that the apparatus comprises a third, intermediate surface 27 disposed between the first surface 4 and the second surface 5.

The embodiment illustrated in Figure 4 comprises two extraction passages separated by the third surface 27, a first extraction passage 6a and a second extraction passage 6b. The third surface 27 may not extend entirely to the discharge opening 8 such that the first extraction passage 6a and the second extraction passage 6b converge to form one extraction passage towards the discharge opening 8.

The third surface 27 includes a plurality of apertures therethrough which allow air pressure to equalise between the first and second extraction passages 6a, 6b and also for the air flow to cross the third surface 27. This can help guide material 2 being extracted to be conveyed through the extraction passages 6a, 6b. The third surface 27 is disposed proximate the converging point 33 which helps guide extracted material 2 along the third surface 27 and towards the discharge opening 8. This configuration -17 -advantageously promotes efficient removal of the extracted material 2 along the extraction passage 6 and also helps prevent material 2 tumbling as it is conveyed through the extraction passage 6.

In one embodiment (not shown) there is a fourth surface disposed between the first and second surfaces, and configured such that the material 2 being extracted is guided between the third 27 and fourth surfaces by air flow from the air flow outlets 14.

Another embodiment is illustrated in Figure 5 and is similar to the previously- /0 described embodiments, and like features retain the same reference numerals. One difference of this embodiment is that the extraction passage 6 is substantially constant in cross section from the entrance opening 7 to the discharge opening 8. Additionally, the air flow outlets 14 and passageways 22 are of a different configuration to that illustrate in previous embodiments. However, the air flow is still generated as a laminar air flow air knife from within a plenum chamber 21 of the respective bodies zo.

Although the air flow would not be accelerated within the extraction passage 6 by a Venturi effect due to the absence of a narrowed section 35, the fast flow of air from the air flow outlets 14 would still act to draw in ambient air from around the entrance opening 7 and entrain with it material 2 to be extracted, as described previously.

Another embodiment is illustrated in Figure 6 which is similar to the previously-described embodiments and in which like features retain the same reference numerals. One difference of this embodiment is that two sets of opposing first and second bodies 20 are provided in series so as to provide an extended extraction passage 6. Such a configuration advantageously allows for material 2 to be transported further away from the extraction surface 3. Such an arrangement can also enable the apparatus to be used in a modular format, in which a plurality of pairs of opposing bodies zo can be provided in series and in a number in dependence upon the requirements of the manufacturing machinery.

Another embodiment is illustrated schematically in Figure 7 and features common to the previously-described embodiments retain the same reference numerals. One difference of this embodiment is that the air flow outlets 14 do not feed pressurised air flow from a plenum chamber 21, but instead, the air flow outlets 14 are separate ducts from the first and second surfaces 4, 5. The air flow outlets 14 are disposed at the entrance opening 7 of the extraction passage 6 and are arranged to generate air flow -18 -through the extraction passage 6 from the entrance opening 7 and out through the discharge opening 8. A further difference of the embodiment illustrated in Figure 7 is that the extraction passage 6 is substantially constant in cross sectional area from the entrance opening 7 towards the discharge opening 8. Although the Venturi effect of accelerating air flow through a narrowing of the passage will not be achieved in this arrangement, the air flow through the passage 6 by pressurised air being expelled from the air flow outlets 14 will still cause a reduced pressure at the entrance opening and entrain ambient air into the extraction passage 6, and serve to extract material 2 from the extraction surface 3. Such an arrangement may also be simpler and more cos- /o effective to manufacture and maintain.

Another embodiment is illustrated in Figure 8. The apparatus 1 is substantially as described herein before and like features retain the same reference numerals. One difference of this embodiment is that the apparatus includes a receiving means 36 such as a tray or vessel to collect the extracted material 2. This receiving means 36 can include retaining means to keep the extracted material in the vessel. For example, magnets if the material is metallic, air flow inlets providing suction or a wall or a configuration such that once the material 2 enters the vessel it is retained within it. Therefore, the extracted material 2 can be reused, recycled or disposed of appropriately. This also ensures the extracted material 2 is contained such that it cannot fall into any nearby machinery, reducing the risk of disrupting the manufacturing process.

Another embodiment is illustrated in Figure 9. The apparatus 1 is substantially as or described herein before and like features retain the same reference numerals. One difference of this embodiment is that the first and second surfaces 4,5 comprise a plurality of air flow outlets 14 substantially intermediate the entrance opening 7 and discharge opening 8 of the extraction passage 6. The plurality of air flow outlets 14 may enhance consistent and/or greater flow rate of air flow through the passage 6, and may enable a lower pressure air supply to be used as the air flow is supplemented through the length of the passage 6.

Another embodiment is illustrated in Figure 10. The apparatus 1 is substantially as described herein before and like features retain the same reference numerals. One 35 difference of this embodiment is that the passage comprises a narrowed section in combination with the air flow outlets 14 being provided through the first and second -19 -surfaces, 4, 5, but the air flow outlets 14 are not fed from a plenum chamber 21, and instead are ducts fed otherwise from a source of pressurised air (not shown).

Another embodiment is illustrated in Figure ii. The apparatus 1 is substantially as described herein before and like features retain the same reference numerals. One difference of this embodiment is that the extraction surface 3 is a flat conveyor surface. The apparatus 1 is arranged perpendicular to the direction that the material 2 is conveyed. Although the orientation of the apparatus 1 of Figure 11 is different in use to that of the previous embodiments, the operation would be substantially as described /o previously, and in the arrangement of Figure 11, material 2 to be extracted would be travelling from left to right on the extraction surface to be entrained in the extraction passage 6 as it passes the entrance opening 7.

Another embodiment is illustrated in part in Figures 12A to 12C, which shows a portion of the body 20 comprising the first surface 4 and peripheral surface 16. The apparatus 1 is substantially as described herein before and like features retain the same reference numerals. One difference of this embodiment is that the body 20 is comprised of two portions which are adjustable relative to each other. In the embodiment shown, the space between the aft portion 4b of the first surface and the peripheral surface 16 can be adjusted to alter the size and shape of the passageway 22 of the air flow outlet 14.

This enables the air flow volume and velocity to be adjusted to optimise and control the air flow into and through the extraction passage 6.

Figure 12A shows the apparatus configured with the peripheral surface 16 relatively or closely spaced with the aft portion 4b of the first surface 4, such that the passageway 22 and air flow outlet 14 is relatively narrow. This will create a higher speed but lower volumetric flow of air into the passage 6. Figure 12B shows the peripheral surface 16 relatively further spaced apart from the aft portion 4h of the first surface 4, such that the passageway 22 and air flow outlet 14 is relatively wide. This will create a relatively lower speed but higher volumetric flow of air into the passage 6 than the configuration shown in Figure 12A. Figure 12C shows a relative position of the peripheral surface 16 and aft portion 4b of the first surface 4 intermediate the positions shown in Figures 12A and 12B. It will be appreciated that although Figures 12A -12C shown the body 20 which comprises the first surface 4 as having an adjustable passageway 22 and air flow outlet 14, the body 20 that comprises the second surface 5 may also, or alternatively, be configured to be adjustable as described above. This control of the air flow volume and -20 -velocity can be used to optimise the apparatus 1 to extract material 2 of certain dimensions, mass, and/or to operate with a manufacturing process of different material conveyance speeds.

Figures 13 and 14 show a part of a system comprising a rotating drum 107 of a manufacturing machine 101 with which the extraction apparatus 1 may be configured to operate. The apparatus 1 is substantially as described herein before and like features retain the same reference numerals. The system comprises an interrupter valve 31 and a suction chamber 37. The suction chamber 37 comprises an interior space of the jo rotating drum 107. The suction chamber 37 comprises a plurality of suction ports and is in fluid communication with the apertures 109 on the extraction surface 3. in use, a vacuum or reduced pressure supply is fluidly communicated with the suction chamber 37 to apply suction to the apertures 109 to retain the foil sections 108 on the drum surface 3. The interrupter valve 31 is configured to interrupt the suction supplied to apertures 109 on the drum extraction surface 3. When a defective material 2 is detected upstream of the extraction apparatus 1 with respect to the manufacturing line, the interrupter valve 31 is activated at a time when the material 2 on the extraction surface 3 is disposed proximal to the entrance opening 7. As the material 2 is thereby no longer held against the drum surface 3 by the suction force, the material 2 can be drawn away from the surface 2 of the drum 107 and into the extraction passage 6. If the material 2 is not removed entirely from the drum surface by the air flow of the apparatus 1, the lifter 26 (shown in Figures 2 to 5 and 11) will catch a separated edge of the material 2 to mechanically lift the material 2 from the drum surface and to encourage the material 2 to be entrained in the air flow though the extraction passage 6.

In some embodiments, the peripheral surface 16 or the aft portion 4b of the first surface 4 may be pivotable relative to the other, or alternatively may be moveable by translation towards or away from each other.

In embodiments within the scope of the invention, it is envisaged that the first surface 4 may be moveable relative to the second surface 5, which may be achieved by the first body 20 being moveable relative to the second body 20. In some embodiments the first surface 4 is moveable relative to the extraction surface 3. In some embodiments the second surface 5 is moveable relative to the extraction surface 3. Yet further, it is intended that the first and second surfaces may be independently moveable relative to the extraction surface.

-21 -In some embodiments the air supplied to the air outlet 14 can be heated. The air flow can be heated before being supplied through the air inlet 17, whilst in the plenum chamber 21, as it travels through the pathway 22 or as it leaves the air outlet 14. Such heating of the air can help in controlling the air flow and/or in the efficiency of the air flow supply system, as described above. For example, heating the air will cause the air to expand which, if within the plenum chamber, will cause the air to accelerate out of the air flow outlet(s) 14 to provide a greater air flow rate for a given air supply pressure.

jo In some embodiments, vapour, for example, water vapour, may be added to the air flow to increase the mass of the air flow. This can help to improve the ability to entrain particulate material if the material 2 is, for example, tobacco dust, paper cuttings, and/or wood shavings. Such water vapour may be introduced via a mist or vapour supply source into the extraction passage, or within one or more of the air flow outlets, or within one or more of the plenum chambers 21.

In another embodiment the air supplied or entrained into the extraction passage 6 is ionised to control the static charge in the apparatus 1. Static charge can come from many areas, particularly from moving parts of machinery. In some embodiments the air is ionised to neutralise or reduce static in the system. This can be to avoid the material 2 sticking to the first or second surfaces 4, 5. The air can also be ionised to assist in lifting the material 2 from the extraction surface 3. The air can be ionised in the plenum chamber 21 before it flows through the pathway 22 of the air flow outlet 14 and into the extraction passage 6. Alternatively or in addition, an air ioniser may be located or proximate the entrance opening 7 either outside or inside the extraction passage 6 to ionise the entrained ambient air.

The apparatus 1 may also include a control means which could control one or more of the amount of air supplied to the plenum chamber 21, adjusting the size of the passageway 22 of the air outlet, operating the air outlets 14, independently if required, and/or actuating movement and positioning of the location and position of the first surface 4, second surface 5 or the lifter 26 relative to each other and/or other components of the apparatus or system.

-22 -In some embodiments the air knife 15, 23 is manufactured as one piece, for example by 3D printing. Alternatively the air knife 15, 23 is an assembly of separate components coupled together.

In some embodiments the first surface 4 and the peripheral surface 16 form a continuous edge, broken only by the air flow outlet 14 and the air flow inlet 17.

Although the embodiments described above illustrate both the first and second surfaces 4, 5 as identical or similar, the apparatus 1 can equally comprise a first and second /0 surface 4, 5 which are dissimilar. For example in some embodiments the first surface 4 can be part of a first air knife 15 as described above and the second surface can be a flat surface which does not comprise an air outlet. It can be appreciated that the second surface 5 is any surface which opposes the first surface 4 to form an extraction passage 6 as described above. The second surface 5 could be for example, but not limited to, a flat member, a member shaped in the same form as the first surface 4, a wall, a part of machinery, a hollow or solid vessel.

Although the primary axis 9 is described above as being centrally disposed in the extraction passage 6, it is appreciated that if the first 4 or second surface 5 is not similar 20 to the other of the first 4 or second 5 surface then the primary axis 9 may not be centrally disposed in the extraction passage 6.

Although leading edges to of the embodiments described above comprise a number of straight portions or a combination of curved and straight portions, it will be or appreciated that the leading edges ro equally may not be curved or inclined.

One or more of the first surface 4 and the second surface 5 may be a smooth uniform surface. Alternatively in some embodiments, one or more of the first surface 4 and second surface 5 includes formations or grooves to reduce the surface area in contact with the material 2 as it is extracted. Depending on the desired characteristics of the air flow and the properties of the material 2, the material 2 can stick to the first and/or second surfaces 4, 5. In some embodiments the third 27 or fourth surface also include formations or grooves. Such grooves may advantageously extend in a direction of the air flow through the extraction passage 6 from the entrance opening 7 to the discharge opening 8.

-23 -The extraction passage 3 can be a number of different shapes in cross-section, for example but not limited to, square, rectangular, circular and oval. Where the extraction passage 3 is circular or oval in cross section, the first and second opposing surfaces 4, 5 may comprise first and second opposing surface portions. The first and second surfaces 4, 5 can be opposing surface portions of the same continuous surface.

Preferably the air flow outlet 14 is closer to the entrance opening 7 than the discharge opening 8. Although the above described embodiments illustrate the air flow outlet proximal the entrance opening, it is appreciated that the air flow outlet 14 may be rri disposed closer to the discharge opening 8 than is shown in the Figures.

The air flow outlet 14 can be an air nozzle, an aperture in the first 4 and or second 5 surfaces, a plurality of air flow outlets or a blade of air formed from an elongate slot in the first 4 and or second 5 surfaces.

In the above described embodiments the air flow inlet 17 is located in the peripheral surface 16; alternatively the air flow inlet 17 may be located in one of the side portions. In one example the or each body 20 comprising the air knife/knives 15 may comprise more than one air flow inlet 17.

In one embodiment at least one of the air flow outlet 14 and the air flow inlet 17 comprises a valve (not shown). This may help facilitate the apparatus to be switched on and off, which may be controlled in order to make the extraction apparatus 1 more efficient, for example, by being activated when required.

Although the pathway 22 is described as being curved, equally may be linear. Although the pathway 22 is described as narrowing towards the extraction passage 6, equally the pathway 22 can be constant in size from the plenum chamber 21 to the air outlet 14.

Although in the above described embodiments the second surface 5 comprises a lifter 26, equally the lifter can be disposed on the first surface 4, the side portions or any combination of the surfaces or side portions. The lifter 26 can be for example, but not limited to, a continuous protrusion, one or more teeth, a blade or a brush. The lifter 26 can be flexible or rigid and can be made from any suitable material, for example, metal, rubber, plastic, ceramic or natural fibres.

-24 -The lifter 26 can also be one or more further fluid outlets configured to generate a lifting air flow to assist in lifting and detachment of the material 2 from the surface from which it is to be extracted.

In one embodiment the lifter 26 is moveable relative to at least one of the first surface 4, second surface 5 and the extraction surface 3. In some embodiments the lifter 26 can be further adjusted, for example where the lifter 26 is a set of teeth, a tooth can be adjusted relative to an adjacent tooth. As a further example, if the lifter is a combination of a set of teeth and a brush, the brush may be adjusted relative to the set /o of teeth.

The apparatus may include more than one of the above described lifters 26 or any combination of the above described lifters 26 in combination with the interrupter valve 31.

In some embodiments the interrupter valve 31 is configured to not only interrupt the suction provided to the apertures log as described with reference to Figures 13 and 14, but also to provide air pressure to force at least a portion of the material 2 from the extraction surface 3, to assist in entraining an edge of the material 2 into the extraction passage 6. Such arrangement may also be considered a lifter within the scope of the present disclosure.

Where components are described herein as moveable or adjustable, it can be appreciated that they are movable or adjustable manually or automatically.

Although in the above described embodiments the third surface 27 has a smaller dimension in a direction from the extraction opening 8 to the discharge opening relative to the first or second surface 4, 5, equally the third surface 27 can extend beyond the discharge opening 8.

In some embodiments the third surface 27 may not be flat as illustrated, but curved, and/or can comprise more than one surface in series. The third surface 27 may comprise a combination of linear and curved surfaces. In some embodiments the third surface 27 is a continuous surface comprising no apertures.

In some embodiments the material 2 to be extracted is the sections io8 of Figure 1.

-25 -It will be appreciated that a number of different features have been described in relation to specific embodiments. However, it can be appreciated that the features in the above described embodiments can be combined in any manner to form an 5 extraction apparatus 1 according to the invention.

As used herein, the term "smoking article" includes smokeable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn Jo (HnB) products, and other nicotine delivery products such as aerosol generation devices including e-cigarettes. The smoking article may be provided with a filter for the gaseous flow drawn by the smoker.

A "tobacco industry product" refers to any item made in, or sold by the tobacco industry, typically including a) cigarettes, cigarillos, cigars, tobacco for pipes or for roll-your-own cigarettes, (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes); b) non-smoking products incorporating tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes such as snuff, snus, hard tobacco, and heat-not-burn (HnB) products; and c) other nicotine-delivery systems such as inhalers, aerosol generation devices including e-cigarettes, lozenges and gum. This list is not intended to be exclusive, but merely illustrates a range of products which are made and sold in the tobacco industry. In one embodiment, a tobacco industry product is not a conventional cigarette. -0or

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced and provide for a superior apparatus for extracting material away from a surface. The advantages and features of the disclosure arc of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed features. it is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably -26 -comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

Claims

-27 -Claims 1. An apparatus for extracting material away from an extraction surface, the apparatus comprising: an extraction passage defined between opposing first and second surfaces, the extraction passage having an entrance opening at one end and a discharge opening at an opposite end, and an air flow system including an air flow outlet, the air flow outlet being configured to direct a flow of pressurised air through the extraction passage in a direction towards the discharge opening to generate a reduced pressure proximate the entrance opening, such that material to be extracted proximate the entrance opening can be drawn into the entrance opening and through the extraction passage towards the discharge opening. 2. 3. 4. -0or 5. 6. 7.
An apparatus according to claim 1, wherein one or more of the first surface and the second surface comprises a leading edge at the entrance opening of the extraction passage.
An apparatus according to claim 1 or claim 2, wherein the first surface or the second surface comprises a trailing edge at the discharge opening of the extraction passage.
An apparatus according to any of claims ito 3, wherein the air flow outlet comprises a pathway which narrows towards the extraction passage such that a velocity of the air is increased as it travels through the pathway.
An apparatus according to any of claims ito 4, wherein the apparatus further comprises a lifter on one or more of the first surface and the second surface to assist in lifting the material from the extraction surface.
An apparatus according to claim 5, wherein the lifter is adjustable relative to at least one of the first surface and the second surface.
An apparatus according to claim 5 or claim 6, wherein the lifter comprises a set of teeth on the second surface.
-28 - 8. An apparatus according to any of claims ito 7, wherein at least one of the first surface and the second surface is adjustable relative to the other of the first surface and the second surface.
9. An apparatus according to any of claims ito 8, wherein the first surface is a mirror image of the second surface.
10. An apparatus according to any of claims ito 9, wherein the air flow outlet is disposed proximate to the entrance opening of the extraction passage.
An apparatus according to any of claims ito fo, wherein the air flow outlet is disposed downstream of the entrance opening, within the extraction passage. 12. 13.or 15. 16. 17. 18.
An apparatus according to any of claims ito 11, wherein the air flow outlet is an elongate slot to generate a blade of air.
An apparatus according to any of claims ito 12, wherein the air flow outlet is configured to generate a laminar air flow along one or more of the first surface and the second surface.
An apparatus according to any of claims ito 13, wherein one or more of the first surface and the second surface comprises the air flow outlet.
An apparatus according to claim kb wherein the air flow outlet is integrally formed with one or more of the first surface and the second surface.
An apparatus according to claim 14 or claim 15, wherein each of the first surface and the second surface comprises an air flow outlet.
An apparatus according to any of claims 14 to 16, wherein one or more of the first surface and the second surface comprises a plurality of air flow outlets.
An apparatus according to any of claims ito 17, wherein one or more of the first surface and the second surface further comprises a body including a plenum chamber which is in fluid communication with the air flow outlet.
19. An apparatus according to any of claims ito 18, wherein the extraction passage comprises a narrowed section and the extraction passage widens from the narrowed section towards the discharge opening.
20. An apparatus according to any of claims ito 19, wherein the narrowed section is disposed intermediate the entrance opening and the discharge opening.
21. An apparatus according to claim 19 or claim zo, wherein the extraction passage narrows from the entrance opening to the narrowed section.
22. An apparatus according to any of claims 19 to 21, wherein the air flow outlet is disposed upstream of the narrowed section.
23. An apparatus according to any of claims ito 22, wherein the discharge opening is wider than the entrance opening.
24. An apparatus according to any of claims ito 23, further comprising a third surface disposed between the first and second surfaces to define a first extraction passage and a second extraction passage.
25. An apparatus according to any of claims ito 24, wherein the third surface comprises a plurality of apertures through said third surface.
26. An apparatus according to any of claims 1 to 25, comprising an air knife which or includes one of the first and second surfaces.
27. An apparatus according to any of claims ito 26, comprising a first air knife and a second air knife, wherein the first air knife includes the first surface and the second air knife includes the second surface.
28. An apparatus according to any of claims ito 27, further comprising a heating mechanism configured to heat the air flow which is directed through the extraction passage.
29. An apparatus according to claim 28, wherein the heating mechanism is configured to heat the air before it is discharged from the discharge opening.
30. An apparatus according to claim 29, when dependent upon claim 19, wherein the air is heated within the plenum chamber.
31. An apparatus according to any of claims ito 30, further comprising an ioniser to ionise the air flow which is directed through the extraction passage.
32. An apparatus according to claim 31, wherein the ioniser is configured to ionise the air before it is discharged from the discharge opening.
33. An apparatus according to claim 32, when dependent upon claim 19, wherein the air is ionised within the plenum chamber.
34. A system for extracting a material from an extraction surface comprising: an apparatus according to any of claims ito 33, and an extraction surface for supporting a material to be extracted, wherein the apparatus is arranged such that the entrance opening of the extraction passage is disposed proximate the extraction surface and the discharge opening is disposed distal to the extraction surface.
35. A system according to claim 34, wherein the extraction surface further comprises a mechanism configured to force material away from the extraction surface.
36. A system according to claim 34 or 35, wherein the extraction surface comprises a plurality of apertures therethrough and a suction system in communication with the apertures and configured to hold a material onto the extraction surface, or and an interrupter valve configured to stop suction being applied to at least some apertures in the extraction surface to enable the material to be lifted from the extraction surface.
37. A system according to any of claims 34 to 36, wherein one or more of the first surface and the second surface is adjustable relative to the extraction surface.
38. A system according to any of claims 34 to 37, wherein the extraction surface is a conveying surface configured for conveying a material to be extracted.
39. A method of extracting a material from an extraction surface, using the apparatus of any of claims 1 to 33, the method comprising: -31 -generating an air flow from the air flow outlet and through the extraction passage in a direction towards the discharge opening to generate a reduced pressure proximate the entrance opening; extracting the material from the extraction surface, through the entrance opening and towards the discharge opening of the extraction passage, discharging the material from the extraction passage through the discharge opening.
40. A method according to claim 39, wherein the extraction surface is a conveying /0 surface for conveying a material to be extracted.