JP2013244522A - Powder granulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder granulator for forming grains by compressing powder capable of increasing quality of granular products.SOLUTION: A powder granulator 100 includes a first roll 110, a second roll 120, a first pocket 10 formed on the circumferential surface of the first roll 110, and a second pocket 20 formed on the circumferential surface of the second roll 120. The first roll 110 rotates in one direction around the axis thereof. The second roll 120 is arranged in parallel to the first roll 110. The second roll 120 rotates in an opposite direction of the first roll 110 around the axis thereof. The second pocket 20 forms granular products 50 by compressing powder in cooperation with the first pocket 10. In the powder granular 100, the surface area of the bottom of the second pocket 20 is smaller than the surface area of the bottom of the first pocket 10.

Description

  The present invention relates to a powder granulating apparatus that performs granulation by compressing powder.

  As a powder granulating apparatus that performs granulation by compressing powder, an apparatus having a pair of cylindrical rolls is known. The pair of rolls are arranged such that their central axes are arranged in parallel so that their peripheral surfaces are in line contact with each other, and rotate in opposite directions around the respective central axes. A recess called a pocket is formed on the peripheral surface of at least one of the rolls, and a granular product (hereinafter referred to as a granular product) is obtained by compressing the powder taken into the pocket between the pair of rolls. ) Is formed.

For example, in Patent Documents 1 and 2, a powder having a first pocket formed in one roll and a second pocket formed in the other roll and forming a granular product in cooperation with the first pocket. A body granulator is described. In the powder granulators of Patent Documents 1 and 2, the first pocket and the second pocket have the same shape and size.
In Patent Document 2, it is described that concave portions having a plurality of diameters are formed in each roll, but the diameters of the concave portions that form the granular product in cooperation with each other are equal to each other.

Japanese Patent Laid-Open No. 11-123598 JP 10-34394 A

  There is a demand for improving the quality of a granular product with respect to a powder granulating apparatus in which pockets are formed in each of a pair of rolls as in Patent Documents 1 and 2.

  This invention is made | formed in view of said subject, and provides the powder granulation apparatus which can improve the quality of a granular product.

The present invention includes a first roll that rotates in one direction around an axis;
A second roll disposed in parallel with the first roll and rotating in a direction opposite to the first roll around an axis;
A first pocket formed on the peripheral surface of the first roll;
A second pocket formed on a peripheral surface of the second roll and forming a granular product by compressing powder in cooperation with the first pocket;
Have
Provided is a powder granulating apparatus in which the surface area of the bottom surface of the second pocket is smaller than the surface area of the bottom surface of the first pocket.

According to this powder granulator, the surface area of the bottom surface of the second pocket is smaller than the surface area of the bottom surface of the first pocket. Thus, after the powder is compressed to form the granular product, when the granular product is peeled off from the first roll and the second roll, in most cases, from the second pocket which is the pocket having the smaller surface area. The granular product can be peeled off first. As a result, high quality stability of the granular product can be obtained.
In addition, since the surface area of the bottom surface of the second pocket is smaller than the surface area of the bottom surface of the first pocket, the depth of the second pocket can be easily made smaller than the depth of the first pocket. Can be made gentler than the angle of the bottom surface of the first pocket. As a result, since the shear component acting on the granular product from the second pocket can be reduced and cracking of the granular product can be suppressed, the quality of the granular product can be improved.

  According to the present invention, the quality of the granular product can be enhanced.

It is a typical front sectional view of a powder granulation device concerning an embodiment. It is a figure which shows a 1st roll and a 2nd roll. It is typical front sectional drawing which shows a mode that a granular product is produced | generated by the powder granulation apparatus which concerns on embodiment. It is a figure for demonstrating the shape of the 1st pocket of a 1st roll, and the 2nd pocket of a 2nd roll. It is a figure for demonstrating the shape of the 1st pocket of a 1st roll, and the 2nd pocket of a 2nd roll. It is a figure for demonstrating the shape of the 1st pocket of a 1st roll, and the 2nd pocket of a 2nd roll. It is a figure for demonstrating the shape of the 1st pocket of a 1st roll, and the 2nd pocket of a 2nd roll. It is a figure for demonstrating the shape of the 1st pocket of a 1st roll, and the 2nd pocket of a 2nd roll. It is a figure for demonstrating the mechanism of embodiment. 6 is a diagram for explaining a mechanism of Comparative Example 1. FIG. It is a figure for demonstrating a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 1 is a schematic front sectional view of a powder granulating apparatus 100 according to an embodiment.
FIG. 2 is a view showing the first roll 110 and the second roll 120. 2 (a) is a front view of the first roll 110, FIG. 2 (b) is a side view of the first roll 110 (a view of the first roll 110 seen from the direction of arrow A in FIG. 2 (a)), FIG.2 (c) is sectional drawing along the BB line of FIG.2 (b). 2 (d) is a front view of the second roll 120, FIG. 2 (e) is a side view of the second roll 120 (view of the second roll 120 from the direction of arrow C in FIG. 2 (d)), and FIG. 2 (f) is a cross-sectional view along the line DD in FIG. 2 (e).
FIG. 3 is a schematic front cross-sectional view showing how the granular product 50 is generated by the powder granulator 100.
4 to 8 are views for explaining the shapes of the first pocket 10 of the first roll 110 and the second pocket 20 of the second roll 120. FIG. 4 is a front sectional view showing a contact portion between the first roll 110 and the second roll 120 and a portion in the vicinity thereof. 5 to 8 show a part of FIG. 4 in an enlarged manner.
FIG. 9 is a diagram for explaining the mechanism of the embodiment. FIG. 10 is a diagram for explaining the mechanism of the first comparative example.

  The powder granulation apparatus 100 according to the present embodiment includes a first roll 110, a second roll 120, a first pocket 10 formed on the peripheral surface of the first roll 110, and a peripheral surface of the second roll 120. A second pocket 20 formed. The first roll 110 rotates in one direction around its axis. The second roll 120 is disposed in parallel with the first roll 110. The second roll 120 rotates in the opposite direction to the first roll 110 around its axis. The second pocket 20 forms the granular product 50 by compressing the powder 60 (FIG. 3) in cooperation with the first pocket 10. In the powder granulator 100, the surface area of the bottom surface of the second pocket 20 is smaller than the surface area of the bottom surface of the first pocket 10. Details will be described below.

  The powder granulation apparatus 100 according to the present embodiment is preferably a briquetting machine (also referred to as a briquetting machine) that generates briquettes as the granular product 50 by compressing powdered coal, for example. It is an example. However, the powder granulating apparatus 100 may perform compression molding of the powder 60 of various materials other than coal. Examples of materials other than coal include ores other than coal, metals, resins, chemicals, and other chemical substances.

  As shown in FIG. 1, the powder granulator 100 has a pair of rolls, that is, a first roll 110 and a second roll 120, a screw casing 130, a feed hopper 140, a screw 150, and a motor 160. doing.

  The first roll 110 and the second roll 120 are each formed in a cylindrical shape. The first roll 110 and the second roll 120 are arranged such that their respective central axes are parallel so that their peripheral surfaces are almost in line contact with each other. In other words, the first roll 110 and the first roll 110 are arranged so that a circular cross section orthogonal to the axial direction of the first roll 110 and a circular cross section orthogonal to the axial direction of the second roll 120 are circumscribed. Two rolls 120 are arranged. For example, the central axes of the first roll 110 and the second roll 120 are arranged horizontally and at the same height.

  Hereinafter, a portion where the first roll 110 and the second roll 120 are in line contact with each other may be referred to as a meshing portion.

  The first roll 110 and the second roll 120 are rotationally driven around their respective central axes by an actuator such as a motor (not shown). The rotation direction of the 1st roll 110 and the 2nd roll 120 is a direction which extrudes below, after compressing the powder 60 supplied from the screw casing 130 arrange | positioned above them. The rotation direction of the first roll 110 is the direction of arrow A in FIG. 1, and the rotation direction of the second roll 120 is the direction opposite to the rotation direction of the first roll 110, that is, the direction of arrow B in FIG.

  For example, the outer diameters of the first roll 110 and the second roll 120 are set to the same size, and the first roll 110 and the second roll 120 rotate in opposite directions at the same rotational speed. ing.

  The screw casing 130 and the feed hopper 140 are, for example, tapered cylindrical bodies each having a diameter reduced downward. Of the screw casing 130 and the feed hopper 140, the screw casing 130 is disposed on the pair of rolls, that is, the lower side, and the feed hopper 140 is disposed on the side far from the pair of rolls, that is, the upper side. The upper end portion of the screw casing 130 and the lower end portion of the feed hopper 140 are connected to each other, and the internal space of the feed hopper 140 and the internal space of the screw casing 130 communicate with each other.

  The feed hopper 140 stores the powder 60 inside and causes the powder 60 to flow down to the screw casing.

  The screw 150 is disposed inside the screw casing 130 so that the axial direction of the screw 150 is the vertical direction. The lower end portion of the connecting shaft 170 is connected to the upper end portion of the screw 150 so that the connecting shaft 170 is positioned on the axial extension of the screw 150.

  The motor 160 is disposed on the upper side of the feed hopper 140, for example. A drive shaft (not shown) of the motor 160 is connected to the connecting shaft 170 via a drive conversion mechanism (not shown). When the drive shaft of the motor 160 rotates in one direction, the rotational force is transmitted to the screw 150 via the drive conversion mechanism and the connecting shaft 170, and the screw 150 rotates in one direction. The direction of rotation of the screw 150 is set to a direction in which the powder 60 in the screw casing 130 is discharged downward from the lower end of the screw casing 130 (in the direction of arrow C in FIG. 1).

  The lower end of the screw casing 130 is disposed above the meshing portion between the first roll 110 and the second roll 120. Therefore, the powder 60 discharged below the screw casing 130 is supplied to the upper part of the meshing portion.

  As shown in FIG. 2, a first pocket 10 is formed on the cylindrical peripheral surface of the first roll 110, which is a recess that is recessed toward the center side of the first roll 110. On the other hand, a second pocket 20 is formed on the cylindrical peripheral surface of the second roll 120, which is a recess that is recessed toward the center side of the second roll 120. The bottom surface 11 of the first pocket 10 and the bottom surface 21 of the second pocket 20 have, for example, a mortar-shaped (saddle-shaped) concave curved surface. For example, a plurality of first pockets 10 are formed on the first roll 110, and a plurality of second pockets 20 are formed on the second roll 120. As shown in FIGS. 2B and 2E, the shape and size of the opening of the first pocket 10 are equal to the shape and size of the opening of the second pocket 20. Further, the arrangement interval (pitch) of the first pockets 10 in the circumferential direction of the first roll 110 is equal to the arrangement interval (pitch) of the second pockets 20 in the circumferential direction of the second roll 120. In the case of the present embodiment, since the outer diameters of the first roll 110 and the second roll 120 are equal to each other and the rotation speeds of the first roll 110 and the second roll 120 are equal to each other, the first pocket 10 and the second pocket 20 are , One-to-one correspondence. As shown in FIGS. 2B and 2E, the first pocket 10 and the second pocket 20 are arranged in a staggered pattern, respectively.

  In the process in which the first roll 110 and the second roll 120 rotate, the first pocket 10 and the second pocket 20 corresponding to each other gradually approach each other toward the meshing portion, and face each other at the meshing portion. When crossing the part, they are separated from each other.

  As shown in FIG. 3, in the process of rotating the first roll 110 and the second roll 120, the first pocket 10 and the second pocket 20 in which the powder 60 is taken inside are in a one-to-one relationship at the meshing portion. The powder 60 is compressed by the cooperation of the first pocket 10 and the second pocket 20 by facing each other. Thereby, the granular product 50 of the shape equivalent to combining the 1st pocket 10 and the 2nd pocket 20 in the mutual opening end is produced | generated. Thereafter, in the process in which the first pocket 10 and the second pocket 20 are separated from each other, the granular product 50 is peeled off from the first pocket 10 and the second pocket 20, and the granular product 50 falls.

  Hereinafter, the shapes of the first pocket 10 and the second pocket 20 will be described in detail with reference to FIGS. 4 to 8.

  First, the surface area of the bottom surface 21 of the second pocket 20 is smaller than the surface area of the bottom surface 11 of the first pocket 10. However, as described above, the shapes and dimensions of the openings of the first pocket 10 and the second pocket 20 are equal to each other. For this reason, the second pocket 20 is formed shallower than the first pocket 10 (details will be described later).

  More specifically, the inclination angle of the bottom surface 21 of the second pocket 20 with respect to the peripheral surface of the second roll 120 is smaller than the inclination angle of the bottom surface 11 of the first pocket 10 with respect to the peripheral surface of the first roll 110 (however, (Excluding the central portion of the bottom surface 21 of the second pocket 20 and the central portion of the bottom surface 21 of the first pocket 10)

  The following description based on FIG. 4 thru | or FIG. 8 is all description in the plane orthogonal to the axial direction of the 1st roll 110 and the 2nd roll 120. FIG.

  FIG. 4 is a diagram illustrating a portion in the vicinity of the meshing portion in the cross section of the first roll 110 and the second roll 120 orthogonal to the axial direction of the first roll 110 and the second roll 120. Note that hatching is omitted in FIG. In FIG. 4, the gradient α <b> 1 is the gradient of the bottom surface 11 of the first pocket 10 with respect to the peripheral surface of the first roll 110 at the end of the first pocket 10 on the side opposite to the rotation direction of the first roll 110. Further, the gradient β1 is a gradient (tilt angle) of the bottom surface 21 of the second pocket 20 with respect to the peripheral surface of the second roll 120 at the end of the second pocket 20 on the opposite side to the rotation direction of the second roll 120. is there. The gradient β1 is smaller than the gradient α1.

  FIG. 4 will be further described. The tangent L11 is a tangent to the peripheral surface of the first roll 110 at the end of the first pocket 10 on the side opposite to the rotation direction of the first roll 110. The tangent L12 is a tangent to the bottom surface 11 of the first pocket 10 at the end of the first pocket 10 on the side opposite to the rotation direction of the first roll 110. The gradient α1 is an angle formed by the tangent line L11 and the tangent line L12.

  Similarly, the tangent L <b> 21 is a tangent to the peripheral surface of the second roll 120 at the end of the second pocket 20 on the side opposite to the rotation direction of the second roll 120. The tangent line L <b> 22 is a tangent line to the bottom surface 21 of the second pocket 20 at the end of the second pocket 20 on the side opposite to the rotation direction of the second roll 120. The gradient β1 is an angle formed by the tangent line L21 and the tangent line L22.

  FIG. 5 is an enlarged view of a part of FIG. In FIG. 5, the gradient α <b> 2 is the bottom surface 11 of the first pocket 10 with respect to the circumferential surface of the first roll 110 at a position 1/5 from the end of the first pocket 10 opposite to the rotation direction of the first roll 110. Is the gradient. Further, the gradient β2 is the gradient of the bottom surface 21 of the second pocket 20 with respect to the peripheral surface of the second roll 120 at a position 1/5 from the end of the second pocket 20 opposite to the rotation direction of the second roll 120. It is. The gradient β2 is smaller than the gradient α2.

  FIG. 5 will be described in more detail. The line segment L31 (first line segment) is the end of the first pocket 10 in the rotation direction of the first roll 110 from the end E11 (first end) of the first pocket 10 on the opposite side to the rotation direction of the first roll 110. This is a line segment connecting up to E12 (second end). Let the length of the line segment L31 be l. The point P31 is a point 1/5 from the end E11 in the line segment L31. That is, the distance from the end E11 to the point P31 is 1/5. The straight line L32 (first straight line) passes through the point P31 and is orthogonal to the line segment L31. A point P32 (first intersection) is an intersection between the straight line L32 and the bottom surface 11 of the first pocket 10. The tangent line L <b> 33 is a tangent line at the point P <b> 32 with respect to the bottom surface 11 of the first pocket 10. A point P33 (second intersection) is an intersection between the straight line L32 and the circumferential surface of the first roll 110. The tangent line L34 is a tangent line at the point P33 with respect to the circumferential surface of the first roll 110. The gradient α2 is represented by an angle formed by the tangent line L33 and the tangent line L34.

  Similarly, the line segment L41 (second line segment) is the second pocket in the rotation direction of the second roll 120 from the end E21 (third end) of the second pocket 20 on the side opposite to the rotation direction of the second roll 120. This is a line segment connecting up to 20 ends E22 (fourth end). The length of the line segment L41 is the same as the length of the line segment L31. The point P41 is a point 1/5 from the end E21 in the line segment L41. That is, the distance from the end E21 to the point P41 is 1/5. The straight line L42 (second straight line) passes through the point P41 and is orthogonal to the line segment L41. A point P <b> 42 (third intersection) is an intersection between the straight line L <b> 42 and the bottom surface 21 of the second pocket 20. The tangent line L43 is a tangent line at the point P42 with respect to the bottom surface 21 of the second pocket 20. A point P43 (fourth intersection) is an intersection between the straight line L42 and the circumferential surface of the second roll 120. The tangent line L44 is a tangent line at the point P43 with respect to the circumferential surface of the second roll 120. The gradient β2 is represented by an angle formed between the tangent line L43 and the tangent line L44.

  FIG. 6 is an enlarged view of a part of FIG. In FIG. 6, the average gradient α <b> 3 is an average gradient with respect to the circumferential surface of the first roll 110 in the half of the bottom surface 11 of the first pocket 10 on the side opposite to the rotation direction of the first roll 110. The average gradient β3 is an average gradient with respect to the circumferential surface of the second roll 120 in the half of the bottom surface 21 of the second pocket 20 opposite to the rotation direction of the second roll 120. The average gradient β3 is smaller than the average gradient α3.

  6 will be described in more detail. The point P51 is an intermediate point of the line segment L31 (that is, an intermediate point between the end E11 (first end) and E12 (second end)). Therefore, the distance from the end E11 to the point P51 is l / 2. The straight line L51 (third straight line) passes through the point P51 and is orthogonal to the line segment L31 (first line segment). A point P <b> 52 (fifth intersection point) is an intersection point between the straight line L <b> 51 and the bottom surface 11 of the first pocket 10. The straight line L52 passes through the end E11 and the point P52. A point P53 (sixth intersection) is an intersection between the straight line L51 and the circumferential surface of the first roll 110. The straight line L53 passes through the end E11 and the point P53. The average gradient α3 is represented by an angle formed by the straight line L52 and the straight line L53.

  Similarly, the point P61 is an intermediate point of the line segment L41 (that is, an intermediate point between the end E21 (third end) and E22 (fourth end)). Therefore, the distance from the end E21 to the point P61 is l / 2. The straight line L61 (fourth straight line) passes through the point P61 and is orthogonal to the line segment L41. A point P62 (seventh intersection) is an intersection between the straight line L61 and the bottom surface 21 of the second pocket 20. The straight line L62 passes through the end E21 and the point P62. A point P63 (eighth intersection) is an intersection between the straight line L61 and the circumferential surface of the second roll 120. The straight line L63 passes through the end E21 and the point P63. The average gradient β3 is represented by an angle formed by the straight line L62 and the straight line L63.

  Hereinafter, the depth of the first pocket 10 and the second pocket 20 will be described in detail.

  FIG. 7 is an enlarged view of a part of FIG. As shown in FIG. 7, the maximum depth d2 (MAX) of the second pocket 20 is shallower than the maximum depth d1 (MAX) of the first pocket 10.

  As shown in FIG. 5, the depth d2 (1/5) of the second pocket 20 at the position 1/5 from the end E21 opposite to the rotation direction of the second roll 120 is the first pocket 10. The depth d1 (1/5) is shallower than the end E11 opposite to the rotation direction of the first roll 110 at a position 1/5. For example, the depth d1 (1/5) is represented by the distance from the point P33 to the point P32, and the depth d2 (1/5) is represented by the distance from the point P43 to the point P42.

  FIG. 8 is an enlarged view of a part of FIG. As shown in FIG. 8, the average depth d2 (AVE) of the second pocket 20 is shallower than the average depth d1 (AVE) of the first pocket 10.

  Next, the mechanism will be described.

  First, the mechanism of Comparative Example 1 will be described with reference to FIG. The configuration of the powder granulating apparatus according to Comparative Example 1 is that the shape and dimensions of the second pocket 20 are the same as the shapes and dimensions of the first pocket 10 in the embodiment. Different from the grain device 100. In the comparative example 1, the production | generation of the granular product 50 advances in order of Fig.10 (a), FIG.10 (b), FIG.10 (c). FIGS. 10A, 10 </ b> B, and 10 </ b> C each show a cross section orthogonal to the axial direction of the first roll 110 and the second roll 120.

  As shown in FIG. 10 (a), the granular product 50 compression-molded by the cooperation of the first pocket 10 and the second pocket 20 is usually out of the first pocket 10 and the second pocket 20. It is thought that it peels off from either one of the pockets first.

  However, in the case of the comparative example 1, since the surface areas of the first pocket 10 and the second pocket 20 are equal to each other, it is not stable from which pocket the granular product 50 is peeled first, and the quality of the granular product 50 is improved. There was room for improvement in stability.

  Further, the granular product 50 starts to expand from the moment when it is released from the compressed state by both the pockets 10 and 20.

  In the example of FIG. 10, the granular product 50 is peeled off first from the second pocket 20 out of the first pocket 10 and the second pocket 20. The expansion line 70 shown in FIG. 10 is an example of the position of the outline of the granular product 50 in a state where the granular product 50 has expanded when it is assumed that the second pocket 20 (second roll 120) does not exist. Show. That is, since the granular product 50 released from the compressed state by both the pockets 10 and 20 tends to expand to the expansion line 70, the granular product 50 generates the reaction force F20 shown in FIG. Received from the bottom surface 21 of the two pockets 20.

  The reaction force F20 is divided into a component force F21 and a component force F22 whose directions are orthogonal to each other. Of these, the direction of the component force F21 is assumed to be parallel to the straight line connecting the end E11 and the end E12 of the first pocket 10. That is, the component force F21 is a force for shearing the granular product 50 along a line connecting the end E11 and the end E12.

  In the case of the comparative example 1, compared with the case of embodiment, component force F21 is large. In the case of Comparative Example 1, this is because the gradients β1, β2 and the average gradient β3 are the same as the gradients α1, α2, and the average gradient α3, respectively (see FIGS. 4 to 6).

  In Comparative Example 1, as a result of such a large component force F21 acting on the granular product 50, as shown in FIG. 10 (c), a crack 51 is generated at the center of the granular product 50, etc. The phenomenon that it breaks may occur.

  Next, the mechanism of this embodiment will be described with reference to FIG. In this embodiment, the production | generation of the granular product 50 advances in order of Fig.9 (a), FIG.9 (b), FIG.9 (c). FIGS. 9A, 9 </ b> B, and 9 </ b> C each show a cross section orthogonal to the axial direction of the first roll 110 and the second roll 120.

In the case of this embodiment, as shown in FIG. 9A, the granular product 50 compression-molded by the cooperation of the first pocket 10 and the second pocket 20 is usually the periphery of the second roll 120. It is thought that it will peel off from the surface first. This is because the bottom surface 21 of the second pocket 20 has a smaller surface area than the bottom surface 11 of the first pocket 10. Thereby, compared with the case of the comparative example 1, the quality of the granular product 50 can be stabilized.
Moreover, since the surface area of the bottom surface 21 of the second pocket 20 is smaller than the surface area of the bottom surface 11 of the first pocket 10, the depth of the second pocket 20 can be easily made shallower than the depth of the first pocket 10. The angle of the bottom surface 21 of the two pockets 20 can be made gentler than the angle of the bottom surface 11 of the first pocket 10. As a result, since the shear component (component force F21 (FIG. 9B)) acting on the granular product 50 from the second pocket 20 can be reduced and cracking of the granular product 50 can be suppressed, the quality of the granular product 50 is improved. Can be increased.

  The configuration of the present embodiment will be described from another viewpoint. Since the maximum depth d2 (MAX) is shallower than the maximum depth d1 (MAX), the surface area of the bottom surface 21 of the second pocket 20 can be easily increased. A configuration smaller than the surface area of the bottom surface 11 of one pocket 10 can be realized.

  In the case of the present embodiment, the surface area of the bottom surface 21 of the second pocket 20 can be easily increased even when the depth d2 (1/5) is shallower than the depth d1 (1/5). A configuration smaller than the surface area of the bottom surface 11 can be realized.

  In the case of the present embodiment, the surface area of the bottom surface 21 of the second pocket 20 can easily be reduced by the surface depth of the first pocket 10 even when the average depth d2 (AVE) is shallower than the average depth d1 (AVE). A structure smaller than the surface area of 11 can be realized.

  In the present embodiment, the gradient β1 is smaller than the gradient α1 (see FIG. 4). For this reason, the magnitude of the component force F21 (FIG. 9B) of the reaction force F20 is smaller than that of the comparative example 1. For this reason, in the case of this embodiment, compared with the comparative example 1, the crack of the granular product 50 can be suppressed.

  In the case of the present embodiment, the magnitude of the component force F21 of the reaction force F20 is smaller than that of the comparative example 1 because the gradient β2 is smaller than the gradient α2 (see FIG. 5). Generation | occurrence | production of the crack of the granular product 50 in embodiment can be suppressed compared with the comparative example 1. FIG.

  In the case of the present embodiment, the magnitude of the component force F21 of the reaction force F20 becomes smaller than that in the comparative example 1 also because the average gradient β3 is smaller than the average gradient α3 (see FIG. 6). The occurrence of cracks in the granular product 50 in this embodiment can be suppressed as compared with Comparative Example 1.

  Here, in the case of the present embodiment, since the maximum depth d2 (MAX) is shallower than the maximum depth d1 (MAX), a configuration in which the gradient β1 is smaller than the gradient α1, and the gradient β2 is easily obtained. A configuration smaller than the gradient α2 and a configuration where the average gradient β3 is smaller than the average gradient α3 can be realized.

  Further, in the case of the present embodiment, the configuration in which the gradient β1 is smaller than the gradient α1 can be easily achieved even when the depth d2 (1/5) is shallower than the depth d1 (1/5). A configuration in which β2 is smaller than the gradient α2 and a configuration in which the average gradient β3 is smaller than the average gradient α3 can be realized.

  Further, in the case of the present embodiment, even when the average depth d2 (AVE) is shallower than the average depth d1 (AVE), the configuration in which the gradient β1 is smaller than the gradient α1 and the gradient β2 are easily set. A configuration smaller than the gradient α2 and a configuration where the average gradient β3 is smaller than the average gradient α3 can be realized.

  Moreover, in the present embodiment, the protruding amount of the granular product 50 from the peripheral surface of the first roll 110 is smaller than that in the case of Comparative Example 1. Also from this, in the case of this embodiment, compared with the comparative example 1, the crack of the granular product 50 can be suppressed.

  According to the powder granulation apparatus 100 of the embodiment as described above, the quality of the granular product 50 can be improved. More specifically, for example, cracks in the granular product 50 can be suppressed.

<Modification>
FIG. 11 is a diagram illustrating a modification of the embodiment. As in the modifications described below, any one or more of the various conditions described above may not be satisfied.

  In the example of FIG. 11A, the condition of gradient α1> β1 is not satisfied, and other conditions (gradient α2> gradient β2, average gradient α3> average gradient β3, maximum depth d1 (MAX)> maximum depth. Depth d2 (MAX), depth d1 (1/5)> depth d2 (1/5), average depth d1 (AVE)> average depth d2 (AVE)).

  In the example of FIG. 11B, the condition of gradient α1> β1 and the condition of depth d1 (1/5)> depth d2 (1/5) are not satisfied, and other conditions are satisfied. Satisfies.

  In the example of FIG. 11C, the condition of gradient α2> gradient β2 is not satisfied, and other conditions are satisfied.

  In the example of FIG. 11D, the condition of average gradient α3> average gradient β3 and the condition of maximum depth d1 (MAX)> maximum depth d2 (MAX) are not satisfied, and other conditions Meet.

  Even if it is not shown in FIG. 11, the condition that the surface area of the second pocket 20 is smaller than that of the first pocket 10 may be satisfied. That is, it is sufficient that the granular product 50 is easily peeled off from the second pocket 20 as compared with Comparative Example 1.

  Alternatively, the condition of gradient α1> β1, the condition of gradient α2> gradient β2, and the condition of average gradient α3> average gradient β3 so that the magnitude of the component force F21 is smaller than that of Comparative Example 1. It is sufficient to satisfy at least one of the conditions.

In addition, the following invention is disclosed by the said embodiment.
(Appendix 1)
A first roll rotating in one direction around an axis;
A second roll disposed in parallel with the first roll and rotating in a direction opposite to the first roll around an axis;
A first pocket formed on the peripheral surface of the first roll;
A second pocket formed on a peripheral surface of the second roll and forming a granular product by compressing powder in cooperation with the first pocket;
Have
In a plane perpendicular to the axial direction of the first roll and the second roll,
Than the angle formed by the tangent to the peripheral surface of the first roll and the tangent to the bottom surface of the first pocket at the end of the first pocket on the side opposite to the rotation direction of the first roll,
Powder having a small angle formed by the tangent to the peripheral surface of the second roll and the tangent to the bottom surface of the second pocket at the end of the second pocket on the side opposite to the rotation direction of the second roll Granulator.
(Appendix 2)
A first roll rotating in one direction around an axis;
A second roll disposed in parallel with the first roll and rotating in a direction opposite to the first roll around an axis;
A first pocket formed on the peripheral surface of the first roll;
A second pocket formed on a peripheral surface of the second roll and forming a granular product by compressing powder in cooperation with the first pocket;
Have
In a plane perpendicular to the axial direction of the first roll and the second roll,
The first pocket is orthogonal to the first line segment that connects the first end, which is the end opposite to the rotation direction of the first roll, to the second end, which is the end on the rotation direction side of the first roll. A straight line passing through a point 1/5 from the first end of the first line segment when the length of the first line segment is 1,
The intersection of the first straight line and the bottom surface of the first pocket is defined as a first intersection,
The intersection of the first straight line and the peripheral surface of the first roll is a second intersection,
In the second pocket, orthogonal to the second line segment connecting from the third end, which is the end opposite to the rotation direction of the second roll, to the fourth end, which is the end on the rotation direction side of the second roll. A straight line passing through a point that is 1/5 from the third end of the second line segment when the length of the second line segment is 1,
The intersection point of the second straight line and the bottom surface of the second pocket is a third intersection point,
When the intersection of the second straight line and the peripheral surface of the second roll is a fourth intersection,
Than the angle formed by the tangent at the first intersection with the bottom surface of the first pocket and the tangent at the second intersection with the peripheral surface of the first roll,
A powder granulating apparatus having a small angle formed by a tangent line at the third intersection point with respect to a bottom surface of the second pocket and a tangent line at the fourth intersection point with respect to a peripheral surface of the second roll.
(Appendix 3)
A first roll rotating in one direction around an axis;
A second roll disposed in parallel with the first roll and rotating in a direction opposite to the first roll around an axis;
A first pocket formed on the peripheral surface of the first roll;
A second pocket formed on a peripheral surface of the second roll and forming a granular product by compressing powder in cooperation with the first pocket;
Have
In a plane perpendicular to the axial direction of the first roll and the second roll,
The first pocket is orthogonal to the first line segment that connects the first end, which is the end opposite to the rotation direction of the first roll, to the second end, which is the end on the rotation direction side of the first roll. A straight line passing through an intermediate point between the first end and the second end is a third straight line,
The intersection point of the third straight line and the bottom surface of the first pocket is a fifth intersection point,
The intersection of the third straight line and the peripheral surface of the first roll is a sixth intersection,
In the second pocket, orthogonal to the second line segment connecting from the third end, which is the end opposite to the rotation direction of the second roll, to the fourth end, which is the end on the rotation direction side of the second roll. A straight line passing through an intermediate point between the third end and the fourth end is a fourth straight line,
The intersection point of the fourth straight line and the bottom surface of the second pocket is a seventh intersection point,
When the intersection of the fourth straight line and the peripheral surface of the second roll is the eighth intersection,
Than an angle formed by a straight line passing through the first end and the fifth intersection and a straight line passing through the first end and the sixth intersection,
A powder granulation apparatus having a small angle formed by a straight line passing through the third end and the seventh intersection and a straight line passing through the third end and the eighth intersection.

10 First pocket 11 Bottom surface 20 Second pocket 21 Bottom surface 50 Granular product 51 Crack 60 Powder 70 Expansion line 100 Powder granulator 110 First roll 120 Second roll 130 Screw casing 140 Feed hopper 150 Screw 160 Motor 170 Connection Shaft E11 end E12 end E21 end E22 end F20 reaction force F21 component force F22 component force α1 gradient α2 gradient α3 average gradient β1 gradient β2 gradient β3 average gradient d1 (MAX) maximum depth d2 (MAX) maximum depth d1 (1 / 5) Depth d2 (1/5) Depth d1 (AVE) Average depth d2 (AVE) Average depth

Claims (7)

A first roll rotating in one direction around an axis;
A second roll disposed in parallel with the first roll and rotating in a direction opposite to the first roll around an axis;
A first pocket formed on the peripheral surface of the first roll;
A second pocket formed on a peripheral surface of the second roll and forming a granular product by compressing powder in cooperation with the first pocket;
Have
A powder granulating apparatus, wherein a surface area of a bottom surface of the second pocket is smaller than a surface area of a bottom surface of the first pocket. In a plane perpendicular to the axial direction of the first roll and the second roll,
Than the angle formed by the tangent to the peripheral surface of the first roll and the tangent to the bottom surface of the first pocket at the end of the first pocket on the side opposite to the rotation direction of the first roll,
The angle formed by the tangent to the peripheral surface of the second roll and the tangent to the bottom surface of the second pocket at the end of the second pocket on the side opposite to the rotation direction of the second roll is small. 2. The powder granulator according to 1. In a plane perpendicular to the axial direction of the first roll and the second roll,
The first pocket is orthogonal to the first line segment that connects the first end, which is the end opposite to the rotation direction of the first roll, to the second end, which is the end on the rotation direction side of the first roll. A straight line passing through a point 1/5 from the first end of the first line segment when the length of the first line segment is 1,
The intersection of the first straight line and the bottom surface of the first pocket is defined as a first intersection,
The intersection of the first straight line and the peripheral surface of the first roll is a second intersection,
In the second pocket, orthogonal to the second line segment connecting from the third end, which is the end opposite to the rotation direction of the second roll, to the fourth end, which is the end on the rotation direction side of the second roll. A straight line passing through a point that is 1/5 from the third end of the second line segment when the length of the second line segment is 1,
The intersection point of the second straight line and the bottom surface of the second pocket is a third intersection point,
When the intersection of the second straight line and the peripheral surface of the second roll is a fourth intersection,
Than the angle formed by the tangent at the first intersection with the bottom surface of the first pocket and the tangent at the second intersection with the peripheral surface of the first roll,
3. The powder granulation according to claim 1, wherein an angle formed between a tangent line at the third intersection point with respect to a bottom surface of the second pocket and a tangent line at the fourth intersection point with respect to a peripheral surface of the second roll is small. apparatus. In a plane perpendicular to the axial direction of the first roll and the second roll,
The first pocket is orthogonal to the first line segment that connects the first end, which is the end opposite to the rotation direction of the first roll, to the second end, which is the end on the rotation direction side of the first roll. A straight line passing through an intermediate point between the first end and the second end is a third straight line,
The intersection point of the third straight line and the bottom surface of the first pocket is a fifth intersection point,
The intersection of the third straight line and the peripheral surface of the first roll is a sixth intersection,
In the second pocket, orthogonal to the second line segment connecting from the third end, which is the end opposite to the rotation direction of the second roll, to the fourth end, which is the end on the rotation direction side of the second roll. A straight line passing through an intermediate point between the third end and the fourth end is a fourth straight line,
The intersection point of the fourth straight line and the bottom surface of the second pocket is a seventh intersection point,
When the intersection of the fourth straight line and the peripheral surface of the second roll is the eighth intersection,
Than an angle formed by a straight line passing through the first end and the fifth intersection and a straight line passing through the first end and the sixth intersection,
The powder according to any one of claims 1 to 3, wherein an angle formed by a straight line passing through the third end and the seventh intersection and a straight line passing through the third end and the eighth intersection is small. Granulator.   The powder granulation apparatus according to any one of claims 1 to 4, wherein a maximum depth of the second pocket is shallower than a maximum depth of the first pocket. Than the depth at the position of 1/5 from the end of the first pocket opposite to the rotation direction of the first roll,
The powder granulation apparatus according to any one of claims 1 to 5, wherein a depth of the second pocket at a position 1/5 from an end opposite to a rotation direction of the second roll is shallow.   The powder granulator according to any one of claims 1 to 6, wherein an average depth of the second pocket is shallower than an average depth of the first pocket.

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