Kneader

Abstract

This kneader (1) comprises: a barrel (2); a screw (4) that is inserted into an internal space (8) of the barrel (2) and that transfers a material (M) while kneading the same; and a jacket (6) which covers the barrel (2) and through which a heat medium flows. The jacket (6) has one or a plurality of first charging holes (24) into which the material (M) is charged. The barrel (2) has one or a plurality of second charging holes (26) connected to the first charging holes (24) and the internal space (8). At least one of the second charging holes (26) has: a material inlet (32) connected to the first charging hole (24); a material outlet (34) connected to the internal space (8) at a position shifted in at least one among the axial direction and the circumferential direction of the screw (4) with respect to the material inlet (32); and a material flow path-forming structure (36) for communicating the material inlet (32) and the material outlet (34).

Description

Kneading machine

[0001] The present disclosure relates to a kneader.

[0002] Patent Document 1 describes a continuous mixer that produces an active material mixture for an electrode of a power storage device by mixing a paste containing a binder and a conductive agent with an active material.

[0003] Japanese Patent Application Laid-Open No. 2017-22052

[0004] In order to adjust the temperature of the material flowing inside the barrel of a kneader, the outer periphery of the barrel is sometimes covered with a jacket. A heat transfer medium flow path is provided inside the jacket, and the temperature of the material is adjusted by heat exchange between the heat transfer medium and the material inside the barrel. When the barrel is covered with a jacket, the material to be kneaded is introduced into the barrel through a linear introduction hole that penetrates from the outer surface of the jacket to the inner surface of the barrel. The introduction hole needs to be provided in a partition wall that separates the heat transfer medium flow path so that the heat transfer medium in the jacket does not leak out. For this reason, in kneaders in which the barrel is covered with a jacket, the connection position between the internal space of the barrel and the introduction hole, i.e., the position where the material is released into the internal space, is limited.

[0005] The present disclosure has been made in light of these circumstances, and one of its objectives is to provide a technology that increases the degree of freedom in the position at which material is discharged into the internal space of the barrel.

[0006] One aspect of the present disclosure is a kneader. The kneader includes a cylindrical barrel that is long in one direction, a screw that is inserted into the interior space of the barrel and feeds materials from one end to the other end of the barrel while kneading them, and a jacket that covers the barrel and through which a heat transfer medium flows. The jacket has one or more first input holes that communicate between the interior and exterior of the jacket and through which materials are input. The barrel has one or more second input holes that communicate between the interior and exterior of the barrel and are connected to the first input hole and the interior space. At least one second input hole has a material inlet connected to the first input hole, a material outlet connected to the interior space at a position offset from the material inlet in at least one of the axial direction and circumferential direction of the screw, and a material flow path forming structure that communicates between the material inlet and the material outlet.

[0007] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure.

[0008] According to the present disclosure, the degree of freedom in the position at which material is discharged into the internal space of the barrel can be increased.

[0009] Fig. 1 is a cross-sectional view along the longitudinal direction of a kneader according to an embodiment; Fig. 2 is a cross-sectional view along the lateral direction of the kneader; Fig. 3 is a schematic view of the internal structure of a jacket in a kneader as seen from above; Fig. 4 is a cross-sectional view along the longitudinal direction of a kneader according to a modified example; Fig. 5 is a cross-sectional view along the lateral direction of the kneader;

[0010] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0011] FIG. 1 is a cross-sectional view taken along the longitudinal direction X of a kneader 1 according to an embodiment. FIG. 2 is a cross-sectional view taken along the transverse direction Y of the kneader 1. FIG. 3 is a schematic diagram of the internal structure of a jacket 6 in the kneader 1 as viewed from above. Note that FIG. 1 corresponds to the cross-sectional view taken along line B-B in FIG. 2 and the cross-sectional view taken along line C-C in FIG. 3. FIG. 2 corresponds to the cross-sectional view taken along line A-A in FIG. 1. FIG. 1 schematically illustrates the screw 4. For ease of explanation, FIG. 1 illustrates the first input hole 24 projected onto the cross section taken along line B-B. The internal structure of the jacket 6 is omitted from FIG. 2. The first input hole 24 is omitted from FIG. 3.

[0012] The kneader 1 includes a barrel 2, a screw 4, and a jacket 6. The barrel 2 is a cylindrical body that is long in one direction, that is, a cylinder. As an example, the barrel 2 is oriented so that the longitudinal direction X extends horizontally. In this embodiment, the direction that is perpendicular to the longitudinal direction X and extends horizontally is defined as the lateral direction Y. Furthermore, the direction that is perpendicular to the longitudinal direction X and the lateral direction Y and extends vertically is defined as the thickness direction Z. Note that the orientation of the kneader 1 is not limited to this. The internal space 8 of the barrel 2 is a space in which the material M, which will be described later, is kneaded and transported. Therefore, the barrel 2 functions as a container in which the material M to be kneaded is placed. The internal space 8 is defined by the inner surface of the barrel 2. Therefore, the inner surface of the barrel 2 corresponds to the internal space forming structure.

[0013] The screw 4 is inserted into the internal space 8 of the barrel 2 and feeds the material M from one end of the barrel 2 or the internal space 8 to the other while mixing the material M. The screw 4 has a rotating shaft 10, screw blades 12, and paddles 14. The rotating shaft 10 is rotatably supported with respect to the barrel 2, and one end is connected to a drive unit (not shown). The drive unit includes a motor or the like and rotates the rotating shaft 10 in the screw 4 or the circumferential direction of the rotating shaft 10. For example, the axial direction of the screw 4, i.e., the direction in which the rotating shaft 10 extends, is the same as the longitudinal direction X of the barrel 2.

[0014] The screw blade 12 is spiral-shaped and fixed to the circumferential surface of the rotating shaft 10. The screw blade 12 rotates together with the rotating shaft 10, thereby mainly functioning as a transport mechanism for the material M. In the axial direction of the screw 4, the screw blade 12 is provided in a partial region of the rotating shaft 10. The paddle 14 is fixed to the circumferential surface of the rotating shaft 10 where the screw blade 12 is not provided. The paddle 14 rotates together with the rotating shaft 10, thereby mainly functioning as a kneading mechanism for the material M.

[0015] As an example, the kneader 1 is equipped with two screws 4. That is, the kneader 1 is a twin-screw kneader. The two screws 4 are aligned in the short-side direction Y of the barrel 2. The rotation directions of the two screws 4 may be the same as or opposite to each other. Furthermore, the rotation speeds of the two screws 4 may be the same as or different from each other. The kneader 1 may be a single-screw kneader equipped with one screw 4, or a multi-screw kneader equipped with three or more screws 4.

[0016] The jacket 6 covers the outer surface of the barrel 2. The kneader 1 has, as an example, two jackets 6. The two jackets 6 sandwich the barrel 2 in the thickness direction Z. Therefore, one jacket 6 covers the upper surface of the barrel 2, and the other jacket 6 covers the lower surface of the barrel 2. The two jackets 6 may also sandwich the barrel 2 in the short direction Y. The jacket 6 has, for example, a flat housing with a hollow structure. A recess into which half of the barrel 2 fits is provided on one main surface of the housing.

[0017] Each jacket 6 has a heat medium flow path forming structure 16 therein through which the heat medium HM flows. The heat medium HM is, for example, water adjusted to a predetermined temperature. The heat medium flow path forming structure 16 includes an inner surface of a housing constituting the jacket 6 and partition walls 18 that regulate the flow of the heat medium HM. As an example, the heat medium flow path forming structure 16 has a plurality of partition walls 18. Each partition wall 18 extends in the longitudinal direction X and is arranged at intervals from each other in the lateral direction Y. Furthermore, of two adjacent partition walls 18, one partition wall 18 has one end in the longitudinal direction X separated from the inner surface of the housing, and the other partition wall 18 has the other end in the longitudinal direction X separated from the inner surface of the housing. This forms a serpentine flow path within the jacket 6.

[0018] An inlet 20 for the heat medium HM is connected to one end of this flow path. An outlet 22 for the heat medium HM is connected to the other end of this flow path. The inlet 20 and the outlet 22 are connected to an external temperature regulator (not shown), such as a chiller. The heat medium HM adjusted to a predetermined temperature by the temperature regulator flows from the inlet 20 into the heat medium flow path forming structure 16, exchanges heat with the material M while passing through the serpentine flow path, and flows out from the outlet 22 and is returned to the temperature regulator.

[0019] The jacket 6 has one or more first input holes 24 that communicate between the inside and outside of the jacket 6. The jacket 6 in this embodiment has multiple first input holes 24. More specifically, the upper and lower jackets 6 each have multiple first input holes 24. Each first input hole 24 is provided at a position overlapping with the partition wall 18 and passes through the partition wall 18. The first input holes 24 are also arranged offset from each other in the axial direction of the screw 4. Note that only one of the jackets 6 may have a first input hole 24. Also, the kneader 1 may have only one first input hole 24 in its entirety.

[0020] The barrel 2 has one or more second input holes 26 that communicate between the inside and outside of the barrel 2 and are connected to the first input hole 24 and the internal space 8. Each second input hole 26 extends from the outer surface to the inner surface of the barrel 2. The barrel 2 preferably has the same number of second input holes 26 as the first input holes 24, and the first input holes 24 and the second input holes 26 are connected in a one-to-one relationship. This forms an input path for the material M in the kneader 1 that passes through the main body wall of the jacket 6 and the main body wall of the barrel 2, connecting the outside of the barrel 2 and the internal space 8. The first input holes 24 and the second input holes 26 may be connected in a one-to-multiple or multiple-to-one relationship.

[0021] The material M is, for example, an electrode slurry S for a secondary battery. An example of the electrode slurry S contains an electrode active material, a solvent, a binder, and a conductive material. In the case of a typical lithium-ion secondary battery, the electrode active material is, for example, lithium cobalt oxide or lithium iron phosphate for the positive electrode, and graphite for the negative electrode. The solvent for the negative electrode is water; alcohols such as ethanol; N-methylpyrrolidone (NMP); toluene; dimethyl carbonate (DMC); ethyl methyl carbonate (EMC); etc.; and for the positive electrode, amine-based solvents such as N,N-dimethylaminopropylamine; ether-based solvents such as tetrahydrofuran; ketone-based solvents such as methyl ethyl ketone; ester-based solvents such as methyl acetate; amide-based solvents such as dimethylacetamide; etc. The binder is, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), etc. The conductive agent is, for example, graphite, carbon black, acetylene black, etc. The material M is not limited to the electrode slurry S of the secondary battery.

[0022] Each of the first input holes 24 aligned in the direction of transport of the material M receives one or a mixture of two or more of an electrode active material, a solvent, a binder, and a conductive material. The components fed into each of the first input holes 24 may be the same or different, as long as all components are ultimately fed. The material M fed into each of the first input holes 24 passes through the second input holes 26 and is discharged into the internal space 8. The materials M discharged into the internal space 8 are mixed with each other and transported downstream by the rotation of the screw 4. In this way, an electrode slurry S is formed.

[0023] The jacket 6 has a first discharge hole 28 at its downstream end in the direction of transfer of the material M, which connects the inside and outside of the jacket 6. The barrel 2 has a second discharge hole 30 which connects the inside and outside of the barrel 2 and is connected to the first discharge hole 28 and the internal space 8. The first discharge hole 28 and the second discharge hole 30 form a discharge path for the electrode slurry S, which penetrates the main body wall of the jacket 6 and the main body wall of the barrel 2 and connects the outside of the barrel 2 to the internal space 8. The electrode slurry S that has reached the downstream of the internal space 8 is sent out of the barrel 2 via this discharge path. The material M is continuously supplied to the internal space 8 and mixed while moving through the internal space 8 to form the electrode slurry S. The obtained electrode slurry S is continuously discharged from the barrel 2. Therefore, the kneader 1 of this embodiment is a so-called continuous kneader.

[0024] In this embodiment, at least one second input hole 26 has a material inlet 32, a material outlet 34, and a material flow path forming structure 36. The material inlet 32 ​​is provided on the outer surface of the barrel 2 and is connected to the first input hole 24. The material outlet 34 is provided on the inner surface of the barrel 2 and is connected to the internal space 8. The material outlet 34 is provided at a position offset from the material inlet 32 ​​in at least one of the axial direction and circumferential direction of the screw 4. The material flow path forming structure 36 communicates the material inlet 32 ​​and the material outlet 34. In other words, the at least one second input hole 26 is routed in at least one of the longitudinal direction X and lateral direction Y of the barrel 2.

[0025] The material M introduced into the first input hole 24 flows from the material inlet 32 ​​into the second input hole 26, passes through the material flow path forming structure 36 to the material outlet 34, and is released from the material outlet 34 into the internal space 8. Because the second input hole 26 has the above-mentioned routing structure, the position of the material outlet 34 can be determined without being restricted by the internal structure of the jacket 6. Therefore, compared to when the first input hole 24 and the second input hole 26 extend linearly, the degree of freedom in the release position of the material M into the internal space 8 can be increased. This makes it possible to introduce the material M at a more appropriate timing, making it easier to improve the quality of the electrode slurry S.

[0026] In this embodiment, as an example, the second input hole 26 connected to the second most upstream first input hole 24 in the upper jacket 6 has a wiring structure. The other second input holes 26 extend linearly. The arrangement and number of second input holes 26 having a wiring structure are not particularly limited. For example, the second input holes 26 having a wiring structure may be provided only on the upper side of the barrel 2, only on the lower side of the barrel 2, or on both the upper and lower sides.

[0027] The material flow path forming structure 36 in this embodiment is entirely embedded in the barrel 2. In other words, holes formed in the main body wall of the barrel 2 constitute the material flow path forming structure 36. In this case, the material flow path forming structure 36 does not contact the jacket 6. Therefore, the sealing structure for the gap between the barrel 2 and the jacket 6 can be simplified compared to when the material flow path forming structure 36 contacts the jacket 6, as in the modified example described below.

[0028] Furthermore, the second input hole 26 in this embodiment has multiple material outlets 34 for one material inlet 32. In other words, multiple material outlets 34 are connected to one material inlet 32 ​​via a material flow path forming structure 36. This increases the amount of material M discharged per unit time into the internal space 8. As shown in FIG. 1 , the multiple material outlets 34 are offset from one another in the axial direction or longitudinal direction X of the screw 4. In this case, for example, some of the material outlets 34 can be plugged with screws or the like to limit the material outlets 34 from which material M is discharged. This configuration allows for easy switching of the material outlets 34 from which material M is discharged. Therefore, the discharge position of material M into the internal space 8 can be easily shifted in the transport direction of material M. This makes it easier to use the kneader 1 to produce a wider variety of kneaded products.

[0029] 2, the multiple material outlets 34 are offset from one another in the circumferential direction or the short-side direction Y of the screw 4. This makes it possible to suppress uneven supply of the material M to the kneaded material present in the internal space 8. This further improves the quality of the electrode slurry S. The material inlets 32 and the material outlets 34 may be in one-to-one correspondence. The multiple material outlets 34 may also be offset from one another only in the axial direction or only in the circumferential direction.

[0030] As described above, in this embodiment, at least one of the second input holes 26 provided in the barrel 2 has a routing structure. In other words, the material inlet 32 ​​and the material outlet 34 are offset in at least one of the axial and circumferential directions of the screw 4, and are connected to each other by the material flow path forming structure 36. This allows the material outlet 34 to be located at any position, even if the placement of the material inlet 32 ​​is restricted by the jacket 6. This increases the degree of freedom in the release position of the material M into the internal space 8.

[0031] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the invention defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Furthermore, any combination of components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0032] (Modification) Figure 4 is a cross-sectional view taken along the longitudinal direction X of the kneader 1 according to a modification. Figure 5 is a cross-sectional view taken along the lateral direction Y of the kneader 1. The material flow path forming structure 36 of the embodiment is entirely embedded in the barrel 2. On the other hand, at least a portion of the material flow path forming structure 36 of this modification is formed as a groove provided on the outer surface of the barrel 2. In other words, at least a portion of the material flow path forming structure 36 is exposed on the outer surface of the barrel 2.

[0033] Even with this configuration, the degree of freedom in the position at which the material M is discharged into the internal space 8 can be increased, as in the embodiment. Furthermore, compared to the case in which the entire material flow path forming structure 36 is embedded in the barrel 2 as in the embodiment, the material flow path forming structure 36 can be formed more easily. This reduces the manufacturing cost of the kneader 1. Note that when the grooves constituting the material flow path forming structure 36 and the material inlet 32 ​​are continuous, the portion overlapping with the first input hole 24 when viewed from the stacking direction of the barrel 2 and jacket 6 becomes the material inlet 32.

[0034] The embodiments and modifications may be specified by the following items: [First Item] A kneading machine including a cylindrical barrel (2) that is long in one direction, a screw (4) that is inserted into an internal space (8) of the barrel (2) and feeds a material (M) from one end to the other end of the barrel (2) while mixing the material (M), and a jacket (6) that covers the barrel (2) and through which a heat transfer medium (HM) flows, the jacket (6) having one or more first input holes (24) that communicate between the inside and outside of the jacket (6) and through which the material (M) is input, the barrel (2) having one or more second input holes (26) that communicate between the inside and outside of the barrel (2) and that are connected to the first input hole (24) and the internal space (8), A kneader (1), wherein at least one second input hole (26) has a material inlet (32) connected to the first input hole (24), a material outlet (34) connected to the internal space (8) at a position offset in at least one of the axial direction and circumferential direction of the screw (4) from the material inlet (32), and a material flow path forming structure (36) communicating the material inlet (32) and the material outlet (34). [Item 2] The kneader (1) according to Item 1, wherein the material flow path forming structure (36) is entirely embedded in the barrel (2). [Item 3] The kneader (1) according to Item 1, wherein at least a portion of the material flow path forming structure (36) is formed by a groove provided on the outer surface of the barrel (2). [Item 4] The kneader (1) according to any one of Items 1 to 3, wherein the second input hole (26) has multiple material outlets (34) for one material inlet (32). [Item 5] The kneader (1) according to Item 4, wherein the plurality of material outlets (34) are offset from one another in the axial direction. [Item 6] The kneader (1) according to Item 4 or Item 5, wherein the plurality of material outlets (34) are offset from one another in the circumferential direction.

[0035] The present disclosure can be used in a kneader.

[0036] REFERENCE SIGNS LIST 1 kneader, 2 barrel, 4 screw, 6 jacket, 8 internal space, 24 first input hole, 26 second input hole, 32 material inlet, 34 material outlet, 36 material flow path forming structure.

Claims

1. A kneader comprising: a cylindrical barrel that is long in one direction; a screw that is inserted into the internal space of the barrel and feeds material from one end to the other end of the barrel while kneading it; and a jacket that covers the barrel and through which a heat transfer medium flows, wherein the jacket has one or more first input holes that communicate between the inside and outside of the jacket and through which the material is input, and the barrel has one or more second input holes that communicate between the inside and outside of the barrel and are connected to the first input hole and the internal space, and at least one of the second input holes has a material inlet connected to the first input hole, a material outlet connected to the internal space at a position offset from the material inlet in at least one of the axial and circumferential directions of the screw, and a material flow path forming structure that communicates between the material inlet and the material outlet.

2. The kneader according to claim 1, wherein the material flow path forming structure is entirely embedded in the barrel.

3. The kneader according to claim 1, wherein the material flow path forming structure is at least partially constituted by a groove provided on the outer surface of the barrel.

4. The kneader according to any one of claims 1 to 3, wherein the second input hole has a plurality of the material outlets for one of the material inlets.

5. The kneader according to claim 4, wherein the material outlets are offset from one another in the axial direction.

6. The kneader according to claim 4, wherein the material outlets are offset from one another in the circumferential direction.

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