WO2005096849A1

WO2005096849A1 - Device for fine cutting tobacco cake for cut tobacco expanding system

Info

Publication number: WO2005096849A1
Application number: PCT/JP2005/006779
Authority: WO
Inventors: Akira Kanazawa; Nobuyasu Endo; Susumu Uchida
Original assignee: Japan Tobacco Inc.
Priority date: 2004-04-08
Filing date: 2005-04-06
Publication date: 2005-10-20
Also published as: JPWO2005096849A1; EP1733634A1; US20070023057A1; CN1960647A; CA2560307A1; RU2328951C1

Abstract

A fine cutting device for an expanding system comprises a primary declamper for receiving an impregnated cut tobacco cake taken out from an impregnator and fine cutting the received tobacco cake into tobacco loaves and a secondary declamper for receiving the tobacco loaves from the primary declamper, fine cutting the tobacco loaves into tobacco chunks and then cutting more fine the tobacco chunks into tobacco lumps. The secondary declamper comprises a pair of rotary rakes, and a rotary drum rake (26) disposed under the rotary rake.

Description

Apparatus for subdividing tobacco cake for chopped tobacco swelling processing system

The present invention relates to a shredding device used in a shredded tobacco swelling treatment system, and the shredding device is configured to remove impregnated chopped tobacco before flash-drying shredded tobacco impregnated with liquefied carbon dioxide. Then, the tobacco cake formed by consolidation is subdivided.

Background art

[0002] Inflated shredded tobacco is used as one of the filling materials for cigarettes, and the expanded incense tapaco improves the filling efficiency of the filling material in the cigarette. Inflatable shredded tobacco is manufactured by an inflating treatment system, and the inflating treatment system includes an impregnation container. The chopped tobacco is supplied into the impregnation vessel, and the chopped tobacco is impregnated with the liquid carbon in the impregnator. Thereafter, the impregnated tobacco is also extracted from the impregnator and supplied to the flash dryer. The flash dryer dries the impregnated chopped tobacco rapidly, and by this drying, the solid dioxygen carbon in the impregnated minced tapaco is vaporized, and the dioxinated carbon gas is released from the impregnated minced tobacco. You. Such release of carbon dioxide increases the volume of chopped tobacco, and as a result, the impregnated minced tobacco is expanded.

[0003] When the impregnated minced tobacco is taken out, the impregnated minced tobacco often forms a large lump, a so-called tobacco cake, which is solidified with each other. And cannot be dried.

[0004] For this reason, the swelling processing system is provided with a crushing device for crushing the tobacco cake, and this crushing device is disclosed in, for example, US Patent No. 4,307,735. The milling device of the U.S. Patent includes a plurality of rotating shafts arranged parallel to each other in a horizontal plane, and a number of blades respectively mounted on these rotating shafts. The tobacco cake is fed to a number of blades by the upward force of the crusher, and crushed by the rotation of the blade

[0005] While crushing, the crusher of the US patent crushes the tobacco cake into fine pieces, so that the impregnated minced tobacco is significantly crushed. After this, such finely impregnated chopped tobacco Even if the tobacco is subjected to a drying treatment and formed into swelled tobacco, the swelled tobacco is not suitable as a filling material for cigarettes having a small particle size.

[0006] On the other hand, it is conceivable to use a general rotary rake-type subdivision device to break up the tobacco cake. While rotating, the rotary rake type comminuting device cannot completely subdivide the tobacco cake into tobacco lumps of a desired size or less, and a large lump having a size equal to or larger than the tobacco lamp is used. large masses), that is, tobacco loaf (tobacco

loaves) and medium masses, that is, a lot of tobacco chunks. If the tobacco loaf / tobacco chunk is supplied to the flash dryer as it is, the impregnated tobacco in the tobacco loaf and the tobacco chunk cannot be dried uniformly, and the quality of the expanded tobacco is reduced.

Disclosure of the invention

[0007] It is an object of the present invention to provide an apparatus for finely dividing a tapa cake, which is capable of suitably subdividing a coconut cake of impregnated minced tobacco obtained from an impregnation vessel of a leavening treatment system and capable of reducing crushing of impregnated minced tobacco. Is to provide.

[0008] To achieve the above object, a tobacco cake slicing device of the present invention receives a tobacco cake from an impregnating container, divides the received tobacco cake into tobacco loafs, and sends a primary declamper ( a primary de_clumper) and a secondary declamper that receives the tobacco loaf from this primary declamper and subdivides the received tobacco loaf.

The secondary declampers are horizontally spaced apart from each other, subdivide the tobacco loaf into tapa chunks, and are disposed below a pair of rotary rakes for delivering these tobacco chunks downward and a pair of rotary rakes. A movable rake wall that moves from one side of the rotary rake to the other side while vertically overlapping with the rotary rake and cooperates with the rotary rake to subdivide the tobacco chunks into tobacco lamps.

[0009] According to the above-described subdivision device, the tobacco cake is first roughly divided into tobacco loafs by the primary declamper, and then the tobacco loaf is further subdivided into two stages by the secondary declamper. That is, the primary and secondary declampers subdivide the tobacco loaf into tapa chunks by a pair of rotating rakes, and then further subdivide the tobacco chunks into cigarette lamps by the cooperative action of the pair of rotating rakes and the movable rake wall. As a result, the tobacco cake is The crushing capacity of the impregnated minced tobacco is greatly reduced because the crushing capacity required at each step is small because the crushing is performed stepwise.

[0010] The movable rake wall overlaps with the pair of rotating rakes so that the movable rake wall cooperates with the pair of rotating rakes to subdivide the tobacco chunk. In this case, the secondary declamper preferably further includes a lap adjusting device for adjusting the overlap between the rotating rake and the movable rake wall. Further, the secondary declamper may further include a speed adjusting device for adjusting the rotation speed of the rotating rake and the moving speed of the movable rake wall.

[0011] The lap adjusting device adjusts the size of the tobacco lamp obtained by reducing the crushing of the impregnated chopped tobacco and also subdividing the tobacco chunk force by adjusting the overlap described above.

[0012] The speed adjusting device adjusts the sub-processing capacity of the secondary declamper while reducing the crushing of the impregnated chopped tobacco.

[0013] Specifically, each rotating rake can include a rotatable roller and a plurality of rake rows provided on the outer peripheral surface of the roller. In this case, the plurality of rake rows are arranged at intervals in the circumferential direction of the roller, and have a large number of rake pins arranged at intervals along the axis of the roller.

[0014] Preferably, the rake pins are arranged between the pair of rotary rakes and arranged in the same phase with respect to the axial direction of the roller, and the force rail rows are different between the pair of rotary rakes with respect to the circumferential direction of the roller. They are arranged in phase. As a result, the rake pin covers the gap between the rollers regardless of the rotation angle of the rotating rake, and prevents the tobacco loaf from passing between the rollers as it is.

[0015] On the other hand, the movable rake wall is disposed below the pair of rotating rakes and at the center between the rotating rakes, and includes a rotating shaft extending in parallel with the rotating rake, and a number of rake disks provided on the rotating shaft. The rake disks are spaced apart in the axial direction of the rotating shaft and are located between the rake pins of the rotating rake. In this case, the rake disks and the rake pins of the rotating rake overlap each other.

[0016] The movable rake wall is disposed below the pair of rotary rakes and crosses the rotary rake. And a plurality of rake rows provided on the conveyor, wherein the plurality of rake rows are arranged at intervals in the width direction of the conveyor, and are spaced in the running direction of the conveyor. Have many rake pins lined up. When the conveyor runs, the rake train passes between the rake pins of the rotating rake. In this case, the rake pins of the conveyor and the rake pins of the rotating rake overlap each other.

Brief Description of Drawings

FIG. 1 is a diagram schematically showing a shredded tobacco swelling processing system.

FIG. 2 is a plan view showing a secondary declamper of the embodiment.

FIG. 3 is a perspective view showing a part of a secondary declamper of FIG. 2.

FIG. 4 is a diagram showing a power transmission system for a secondary declamper of FIG. 2.

FIG. 5 is a diagram schematically showing an adjusting device for adjusting the height level of the drum rake of FIG. 2.

FIG. 6 is a graph showing the relationship between the number of rotations of a secondary declamper and the remaining ratio of cigarette lamps.

FIG. 7 is a graph showing the relationship between the rotational speed of the secondary declamper and the average particle size of the impregnated minced tobacco.

FIG. 8 is a graph showing the relationship between the interval between the rotating rake and the drum rake and the average particle size of the impregnated cut tobacco.

FIG. 9 is a schematic view showing a secondary declamper according to a modification.

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] The tobacco swelling treatment system of FIG. The impregnator 2 receives the cut tobacco, and impregnates the received cut tobacco with liquid carbon. Thereafter, the impregnated cut tobacco is taken out of the impregnator 2 and supplied to the flash dryer through the subdivision device 4.

In this embodiment, the subdivider 4 includes a primary declamper 6, a storage bin 8, and a secondary declamper 10. More specifically, as is evident from FIG. 1, the primary declamper 6 has a grid 12, which extends horizontally and is formed from a plurality of parallel bars 12a. A plurality of rotating rakes 14 are disposed directly above the dalid 12, and these rotating rakes 14 are grouped. The rods 12 are positioned at predetermined intervals in the longitudinal direction. Each rotary rake 14 has a rotatable roller 14a and two rows of rake pins 14b protruding from the outer peripheral surface of the roller 14a. The two rows of rake pins 14b are spaced apart from each other in the diameter direction of the roller 14b, and each rake pin 14b has a tip bent in the direction of rotation of the roller 14a.

[0020] The impregnated chopped tobacco taken out of the impregnator 2, ie, the tobacco cake, is also supplied to the primary clamper 6 with the upward force of the primary declamper 6. The primary clamper 6 subdivides the tobacco cake into a large number of tobacco colophes by the cooperation of the rotation of the rotary rake 14 and the dalid 12 and supplies these tobacco loafs to the storage bin 8. The size of the tobacco loaf is determined primarily by the pitch between the rake pins 14b and the spacing between the parallel bars 12a in the grid 12.

[0021] The storage bin 8 temporarily stores the tobacco loaf. After that, the tobacco loaf is supplied from the storage pin 8 to the secondary declamper 10.

[0022] When the tobacco cake passes through the primary declamper 6, the primary declamper 6 is capable of generating individual impregnated tobacco separated from the tobacco cake and the tobacco loaf, and the impregnated tobacco is also stored together with the tobacco loaf. It goes without saying that it is supplied to bin ⁸ .

Next, the secondary declamper 10 will be described below with reference to FIGS.

As shown in FIG. 2, the secondary declamper 10 has a housing 16, and the upper and lower surfaces of the housing 16 are open. A pair of rotating rakes 18 are arranged in the housing 16, and these rotating rakes 18 are horizontally separated from each other.

Each of the rotary rakes 18 includes a roller 20, similarly to the rotary rakes 14 described above. The roller 20 has a roller shaft, and both ends of the roller shaft are rotatably supported by the housing 16. The roller 20 has four rake rows 22 on its outer peripheral surface, and these rake rows 22 are arranged at equal intervals in the circumferential direction of the roller 20. Each rake row 22 has a number of rake pins 24, which project from the outer peripheral surface of the roller 20. The rake pins 24 of each rake row 22 are distributed at the same pitch P and the same phase in the axial direction of the roller 20.

As is clear from FIG. 2, the rake pins 24 of the pair of rotary rakes 18 are In the same direction. Thus, a pair of rotating rakes 18 have four rake pins 24 located in the same vertical plane.

As is apparent from FIG. 3, the rotational phases of the pair of rotary rakes 18 differ from each other by 45 ° around their axes. Therefore, when a pair of rotating rakes 18 are rotated in opposite directions at the same speed, the rake trains 22 of both rotating rakes 18 alternately pass between the rollers 20 of the rotating rakes 18. As a result, when the pair of rotating rakes 18 are viewed from above, the gap between the rollers 20 and 20 is always covered by the rake train 22 of one of the rotating rakes 18.

[0028] Specifically, each rake pin 24 has a length slightly shorter than half the interval between the rollers 20, and a diameter of approximately 9 mm. It is desirable that the pitch P between the rake pins 24 is smaller than the pitch between the rake pins 14b described above, which is a force set according to the inlet size of the flash dryer. In this embodiment, the pitch P between the rake pins 24 is 100 mm or less.

Further, a movable rake wall, that is, a drum rake 26 is disposed below the pair of rotary rakes 18. The drum rake 26 has a rotating shaft 28, which is positioned centrally between the rollers 20. Further, the rotating shaft 28 extends in parallel with the roller 20 and has both ends rotatably supported by the housing 16.

[0030] The rotating shaft 28 further includes a number of rake disks 30, and these rake disks 30 are arranged at equal intervals in the axial direction of the rotating shaft 28, and are respectively positioned at the centers between the rake pins 24 described above. Have been. Accordingly, the pitch between the rake disks 30 is the same as the pitch P between the rake pins 24, and the pitch between the rake disks 30 and the rake pins 24 adjacent in the axial direction of the rotating shaft 28 is PZ2.

In this embodiment, the rotating shaft 28 has a diameter substantially equal to the diameter of the roller 20, and the rake disk 30 has an outer diameter substantially equal to the outer diameter of the rotating rake 18.

[0032] The pair of rotary rakes 18 and drum rakes 26 are rotated by a common electric motor 32. FIG. 4 shows a power transmission path from the electric motor 32 to the rakes 18, 26.

[0033] The roller shaft of each roller 20 has one end protruding from the housing 16, and sprockets 34 and 36 are attached to these ends as shown in Fig. 4, respectively. The rotating shaft 28 also has one end protruding from the housing 16 and a sprocket 38 is attached to this end. [0034] Referring to Fig. 4, the sprocket 36 disposed on the electric motor 32 side has a double structure, and has sprocket portions 36a and 36b. The sprocket portion 36a and the outflow stub 40 of the electric motor 32 are connected via an endless drive chain 42.

Further, a tension sprocket 44 is rotatably supported by the housing 16, and the tension sprocket 44 is disposed on the electric motor 32 side. The tension sprocket 44, the sprocket portion 36b, the sprocket 34 and the sprocket 38 are wound around an endless linking chain 46. Therefore, when the electric motor 32 is driven, this driving force is first transmitted to one roller 20, that is, the rotating rake 18 on the electric motor 32 side via the driving chain 42, and the rotating rake 18 is shown in FIG. As you can see, it is rotated counterclockwise as indicated by the arrow.

[0036] Further, since the driving chain 42 runs the interlocking chain 46 via the sprocket portion 36b, the other rotary rake 18 and the drum rake 30 are also rotated in conjunction with the one rotation rate 18. Here, the other rotary rake 18 and drum rake 30 are rotated clockwise as indicated by arrows in FIG. In FIG. 4, the rotating rake 18 is indicated by a rotation trajectory drawn by the tip of the rake train 24! / ヽ.

As shown in FIG. 2, the electric motor 32 is electrically connected to an inverter type speed adjuster 48. The speed adjusting device 48 can adjust the rotating speed of the electric motor 32, that is, the pair of rotating rakes 18 and the drum rake 26.

Further, the drum rake 26 is supported by the housing 16 via a level adjusting device, and the level adjusting device is a height level of the drum rake 26 with respect to the pair of rotary rakes 18, that is, the drum rake 26 and the pair of rotary rakes 18. The distance D between can be adjusted vertically

More specifically, as shown in FIG. 5, the level adjusting device 49 includes a pair of slots 50 formed in the housing 16, and these slots 50 extend in the up-down direction. The rotating shaft 28 of the drum rake 26 has both ends passing through a pair of slots 50, respectively. At both ends of the rotating shaft 28, support plates 52 are respectively mounted via bearings. The support plates 52 have four corners each having four housing bolts 54 and nuts (not shown). It is fixed to. [0040] A large number of through holes 56 are formed in the housing 16 for the mounting bolts 54. These through holes 56 are arranged on both sides of the slot 50, respectively, and have a predetermined space in the vertical direction. Are distributed. Therefore, the height level of the drum rake 26, that is, the above-mentioned distance D can be adjusted by selecting the through hole 56 through which the mounting bolt 54 is to be inserted.

When the distance D is adjusted, the amount of overlap of the rake disk 30 with respect to the rake pin 24 is varied within the range of the length of the rake pin 24. In the case of this embodiment, the interval D is adjusted within the range of 85 mm (the maximum value of the overlap amount) to 155 mm (the minimum value of the overlap amount).

The tension sprocket 44 described above is also supported on the housing 16 so as to be movable in the vertical direction, and the height level of the tension sprocket 44 can be adjusted in the same manner as the drum rake 26. Therefore, even if the distance D is adjusted, the tension sprocket 44 can apply a desired tension to the driving chain 46.

When the tobacco loaf is supplied to the secondary declamper 10 from the storage bin 8, the tobacco loaf is rotated by a pair of rotating rakes 18, that is, by the rake pins 24 of the rotating rakes 18. It is further subdivided into smaller tobacco chunks, and these tobacco chunks are fed onto a drum lake 26.

The rake pin 24 has a diameter enough to withstand the load required for subdividing tobacco loaf. However, the diameter of the rake pin 24 is as thin as about 9 mm. Therefore, when the tapacoloaf is broken by the rake pins 24, the shattering of the impregnated minced tobacco is reduced.

[0045] Thereafter, as the tobacco chunk passes through the drum rake 26, the rake disc 30 cooperates with the rotating rake 18 to further break the tobacco chunk passing between the rotating rakes 18 into a desired size smaller than the tobacco chunk. Into tobacco lamps (tobacco lumps).

[0046] Accordingly, tobacco lamps are sent out from the secondary declamper 10 together with the individual impregnated chopped tobacco. Impregnated minced tobacco includes not only impregnated minced tobacco generated during tobacco cake subdivision, but also impregnated minced tobacco generated during tobacco loaf and tobacco chunk subdivision.

[0047] Thereafter, the tobacco lamp and the impregnated tobacco sent out from the secondary declamper 10 are It is supplied to the flash dryer described above, and is rapidly dried in this flash dryer, that is, expanded.

[0048] The secondary declampers 10 of the embodiments E1 to E4 having different intervals PZ2 and intervals D between the rake pin 24 and the rake disk 30 are used by changing the rotation speed of the rotary rake 18 and the drum rake 26. FIG. 6 shows the results of measuring the residual ratio of the tobacco lamp sent from the secondary declamper 10 and the average particle size of the impregnated chopped tobacco.

[0049] Table 1 below shows PZ2 and spacing D of Examples E1 to E4.

table 1

[0050] The remaining ratio of the tobacco lamp indicates the remaining amount of the tobacco lamp when the amount of the tobacco loaf to which the primary declamper 6 power is also supplied is expressed as 100%. As is clear from FIG. 6, the remaining ratio of the tobacco lamps of Examples E1 to E4 is reduced to about 40% or less.

[0051] Considering that the initial average particle size of the cut tobacco before the impregnation treatment is 2.41 mm, as is clear from Fig. 7, the impregnated cut tabaco obtained from the secondary declamper 10 of Examples E1 to E4. The average particle size is only reduced to 80-93% of the initial average particle size.

The broken line in FIG. 7 indicates the average particle size (1.66 mm) of the impregnated chopped tobacco obtained from the secondary declamper of the comparative example. The secondary declamper of this comparative example includes a rotor and a spiral rake pin array provided on the outer peripheral surface of the roller. In addition, the remaining ratio of the tobacco lamp obtained from the secondary declamper of the comparative example was about 80% or more, and the average particle size of the impregnated tobacco was reduced to about 70% of the initial average particle size.

[0053] As a result, according to the subdivision device 4 including the secondary declampers 10 of Examples E1 to E4, the tapaco cake is satisfactorily subdivided, and thereafter, the impregnated chopped tobacco is uniformly dried. Further, since the crushing of the impregnated shredded tobacco is reduced, it is possible to produce high-quality shredded shredded tobacco.

On the other hand, as is clear from FIGS. 6 and 7, in any of the secondary declampers 10 of Examples E1 to E4, as the rotation speed of the secondary declamper 10 increases, the remaining of the tobacco lamp remains. amount And the average particle size of the impregnated chopped tobacco decreases.

Therefore, the relationship between the rotational speed of the secondary declamper and the average particle size of the impregnated cut tobacco as shown in FIG. 8 is derived from the measurement results of FIG. Figure 8 shows that if the rotation speed of the secondary declamper is the same, the larger the distance D between the rotating rake 18 and the drum rake 26, the smaller the decrease rate of the average particle size of the impregnated tobacco becomes. I have. Therefore, the average particle size of the impregnated minced tobacco can be controlled to a desired range by adjusting the distance D, that is, the amount of overlap between the rake pin 24 and the rake disk 30.

[0056] Explaining this point in detail, as the distance D increases, the amount of overlap decreases. It is therefore believed that the percentage of tobacco chunks that pass through the drum rake 26 without being broken by the rotating rake 18 and the drum rake 26 is increased, thereby reducing the crushing of the impregnated minced tobacco.

[0057] As a result, the degree to which the tobacco chunks are subdivided, ie, the average particle size of the impregnated minced tobacco, depends on the spacing D, ie, the distance between the rotating rake 18 and the drum rake 26, at a desired level. Can be easily maintained.

[0058] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0059] The rotary rake 18 and the drum rake 26 of the secondary declamper 10 may be independently rotated by separate electric motors.

As shown in FIG. 9, the secondary declamper can use a conveyor type movable rake wall instead of the drum rake 26. In this case, the movable rake wall includes a conveyor 58 disposed below the pair of rotating rakes 18 and a plurality of rake rows 60 provided on the conveyor 58. These rake rows 60 are arranged at predetermined intervals in the width direction of the conveyor 58, and have a large number of rake pins 62 arranged at intervals in the traveling direction of the conveyor 58.

[0061] Accordingly, when the conveyor 58 is run, each rake train 60 passes through the center between the rake pins 24 of the rotating rake 18. Further, similarly to the drum rake 26 described above, the height level and the traveling speed of the conveyor 58 can be adjusted respectively.

According to the above-described movable rake wall of the conveyor type, when the conveyor 58 travels, each rake row 60 passes between the rake pins 24 of the rotary rake 18, whereby the rake row 60 becomes the rake pin row 22. Work with to subdivide tobacco chunks.

Claims

The scope of the claims

[1] A device for subdividing a tobacco cake for a chopped tobacco swelling treatment system, wherein the swelling treatment system impregnates the cut tobacco with liquid nigari carbon in an impregnator. After that, the tobacco cake of the impregnated chopped tobacco taken out of the impregnator is supplied to the shredding device,

The subdivision device,

A primary declamper that receives the tobacco cake, subdivides the received tobacco cake into tobacco loafs, and sends out these tobacco loaf;

A secondary declano that receives the tobacco loaf from the primary declamper and subdivides the received tobacco loaf;

The secondary declamper is

A pair of rotating rakes, horizontally spaced apart from each other, subdividing the tobacco loaf into tobacco chunks and delivering these tobacco chunks downwards;

The tobacco chunk is disposed below the pair of rotating rakes, moves to one side force of the rotating rake and overlaps the rotating rake in the vertical direction, and moves the tobacco chunk in cooperation with the rotating rake. With a movable rake wall that subdivides it into

including.

[2] The device of claim 1,

The movable rake wall overlaps with the pair of rotating rakes.

[3] The device of claim 2,

The secondary declamper further includes a lap adjusting device for adjusting an overlap between the rotating rake and the movable rake wall.

[4] The apparatus of claim 2,

The secondary declamper further includes a speed adjusting device for adjusting a rotation speed of the rotary rake and a moving speed of the movable rake wall.

[5] The apparatus of claim 2,

Each of the rotating rakes includes a rotatable roller and a plurality of rake rows provided on an outer peripheral surface of the roller.

[6] The device of claim 5,

The plurality of rake rows are arranged at intervals in the circumferential direction of the roller, and have a large number of rake pins arranged at intervals along the axis of the roller.

[7] The device of claim 6, wherein

The rake pin is arranged between the pair of rotary rakes and is arranged in the same phase with respect to the axial direction of the roller. The rail array is disposed between the pair of rotary rakes and in the circumferential direction of the roller. They are arranged in different phases.

[8] The apparatus of claim 7,

The movable rake wall is disposed below the pair of rotary rakes and at a center between the rotary rakes, and includes a rotary shaft extending in parallel with the rotary rake, and a plurality of rake disks provided on the rotary shaft. Including

The rake disks are arranged at intervals in the axial direction of the rotating shaft, and are positioned between rake pins of the rotating rake.

[9] The apparatus of claim 7,

The movable rake wall includes a conveyor disposed below the pair of rotating rakes and extending in a direction crossing the rotating rakes, and a plurality of rake rows provided on the conveyor.

[10] The apparatus according to claim 9,

The plurality of rake rows are arranged at intervals in the width direction of the conveyor, and have a large number of rake pins arranged at intervals in the traveling direction of the conveyor, and the conveyor is run. At this time, the rake train passes between the rake pins of the rotating rake.