Wet Powder Storage Tank

Abstract

To provide a wet powder storage tank capable of suppressing exudation of a solvent from wet powder.SOLUTION: A wet powder storage tank 1 includes a tank body 100 capable of storing wet powder WP containing powder and solvent. The tank body 100 has: an upper storage part 110 having a supply port 112 for supplying wet powder WP; a lower storage part 120 located below the upper storage part 110 and having a discharge port 122 for discharging the wet powder WP; and a bridge forming part 130 that is provided between the upper storage part 110 and the lower storage part 120, and that promotes a formation of a bridge BR by wet powder WP so as to block wet powder WP from falling from the upper storage part 110 to the lower storage part 120.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wet powder storage tank. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 7-265782 discloses a storage tank for supplying powder, which includes a tank body, a rotary bar, and an air outlet. The tank body is capable of storing powder. A powder inlet is provided at the top of the tank body, and a powder outlet is provided at the bottom of the tank body. The rotary bar agitates the powder in the tank body. Rotation of the rotary bar prevents caking and blocking of the powder. The air outlet is provided above the outlet. Air is discharged from the air outlet, causing the powder to be discharged from the outlet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-265782 Summary of the Invention [Problem to be solved by the invention]

[0004] When a wet powder containing powder and a solvent is stored in a storage tank such as that described in JP-A-7-265782, the wet powder stored at or near the bottom of the tank body experiences a relatively large compressive stress due to the weight of the wet powder stored above it. As a result, there is a concern that the solvent may seep out of the wet powder stored at or near the bottom of the tank body, causing deterioration of the wet powder (such as a decrease in ductility).

[0005] An object of the present disclosure is to provide a wet powder storage tank that can suppress the seepage of a solvent from the wet powder. [Means for solving the problem]

[0006] A wet powder storage tank according to one aspect of the present disclosure includes a tank body capable of storing wet powder containing powder and a solvent, the tank body having an upper storage section having a supply port for supplying the wet powder, a lower storage section disposed below the upper storage section and having a discharge port for discharging the wet powder, and a bridge forming section provided between the upper storage section and the lower storage section and forming a bridge using the wet powder to block the wet powder from falling from the upper storage section to the lower storage section. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a wet powder storage tank that can suppress the seepage of solvent from the wet powder. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating a wet powder storage tank according to an embodiment of the present disclosure. [Figure 2] FIG. 10 is a schematic diagram showing a modified example of the wet powder storage tank. [Figure 3] FIG. 10 is a schematic diagram showing a modified example of the wet powder storage tank. [Figure 4] FIG. 10 is a schematic diagram showing a modified example of the wet powder storage tank. [Figure 5] FIG. 1 is a schematic diagram of a wet powder storage tank used in the examples of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram of a wet powder storage tank used in comparative examples in relation to the examples. [Figure 7] FIG. 1 is a schematic diagram of an apparatus for evaluating the spreadability of a wet powder. [Figure 8] 1 is a table showing various evaluation results in Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] 1 is a cross-sectional view schematically illustrating a wet powder storage tank according to an embodiment of the present disclosure. This wet powder storage tank 1 is suitable for use in storing wet powder used in, for example, electrode sheets of energy storage cells.

[0011] The wet powder storage tank 1 includes a tank body 100 and a crushing member 200.

[0012] The tank body 100 can store a wet powder WP containing a powder and a solvent. The solid content of the wet powder WP is, for example, 70% or more and 84% or less. The solid content is measured, for example, by a dry weight method. The wet powder WP may be granular, flaky, or clay-like. The particle size of the wet powder WP is, for example, 4 mm or less. The tank body 100 of this embodiment can store the wet powder WP in a state where it is separated into upper and lower halves. The tank body 100 has an upper storage section 110, a lower storage section 120, and a bridge-forming section 130.

[0013] The upper storage section 110 has a supply port 112 for supplying the wet powder WP. The supply port 112 opens upward. The upper storage section 110 is formed in a cylindrical shape. More specifically, the upper storage section 110 is formed in a cylindrical shape.

[0014] The lower storage section 120 is disposed below the upper storage section 110. The lower storage section 120 has a discharge port 122 for discharging the wet powder WP. The discharge port 122 opens downward. The lower storage section 120 is formed in a cylindrical shape. More specifically, the lower storage section 120 is formed in a cylindrical shape. The central axis of the lower storage section 120 is located on an extension of the central axis of the upper storage section 110. In other words, the upper storage section 110 and the lower storage section 120 are formed in a cylindrical shape having a central axis extending in a direction connecting the upper storage section 110 and the lower storage section 120 (the up-and-down direction in FIG. 1 ).

[0015] A supply port 124 may be provided at the top of the lower storage section 120 for supplying the wet powder WP.

[0016] The bridge forming portion 130 is provided between the upper storage portion 110 and the lower storage portion 120. The bridge forming portion 130 promotes the formation of a bridge BR (see FIG. 1 ) by the wet powder WP so as to block the wet powder WP from falling from the upper storage portion 110 to the lower storage portion 120. In other words, the bridge forming portion 130 forms a space S between the wet powder WP stored in the upper storage portion 110 and the wet powder WP stored in the lower storage portion 120.

[0017] The bridge-forming portion 130 has a connecting portion 132 that connects the upper storage portion 110 and the lower storage portion 120. In this embodiment, the connecting portion 132 has a constricted portion 132a. The cross-sectional area of ​​the constricted portion 132a in a plane perpendicular to the central axis is smaller than the cross-sectional area of ​​the lower end portion 111 of the upper storage portion 110 in the plane perpendicular to the central axis, and is also smaller than the cross-sectional area of ​​the upper end portion 121 of the lower storage portion 120 in the plane. The constricted portion 132a may have a shape that is curved so as to be convex toward the central axis.

[0018] The crushing member 200 crushes the bridges BR formed inside the tank body 100. In this embodiment, an agitator is used as the crushing member 200. The agitator has a rotating shaft 202, an upper stirring section 210, and a lower stirring section 220.

[0019] The rotating shaft 202 is fixed to the tank body 100 so as to be aligned along the central axis. The rotating shaft 202 is rotatable around the central axis relative to the tank body 100. The rotating shaft 202 has a shape that extends from the upper end of the upper storage section 110 to the bottom of the lower storage section 120.

[0020] The upper agitating section 210 is connected to a portion of the rotary shaft 202 that is located inside the upper storage section 110. The upper agitating section 210 agitates the wet powder WP inside the upper storage section 110.

[0021] The lower agitator 220 is connected to a portion of the rotary shaft 202 that is located inside the lower storage unit 120. The lower storage unit 120 agitates the wet powder WP inside the lower storage unit 120.

[0022] As described above, in the wet powder storage tank 1 of this embodiment, the bridge-forming portion 130 is provided between the upper storage portion 110 and the lower storage portion 120, so that the wet powder WP stored in the upper storage portion 110 and the wet powder WP stored in the lower storage portion 120 are vertically separated. This prevents the weight of all the wet powder WP in the tank body 100 from acting on the wet powder WP stored at or near the bottom of the lower storage portion 120, thereby preventing the solvent from seeping out from the wet powder WP.

[0023] In the above embodiment, as shown in FIG. 2, the constricted portion 132a may be configured as an inclined surface whose diameter gradually decreases downward.

[0024] 3, the connecting portion 132 in the bridge-forming portion 130 may be formed in a cylindrical shape having the same diameter as the upper storage portion 110 and the lower storage portion 120. In this example, the surface roughness of the inner surface of the connecting portion 132 (the portion indicated by the thick line in FIG. 3) is smaller than the surface roughness of the inner surface of the upper storage portion 110.

[0025] In this embodiment, the surface roughness of the inner surface of the connecting portion 132 is smaller than the surface roughness of the inner surface of the upper storage portion 110, so that the contact area between the wet powder WP and the connecting portion 132 is larger than the contact area between the wet powder WP and the inner surface of the upper storage portion 110. Therefore, friction generated between the wet powder WP and the inner surface of the connecting portion 132 is large, and a bridge BR is effectively formed at the connecting portion 132.

[0026] 4, the bridge forming portion 130 may have a connecting portion 132 and a solvent supplying portion 134 that supplies a solvent toward the inner surface of the connecting portion 132. The solvent supplying portion 134 sprays the solvent onto the inner surface of the connecting portion 132 while rotating around the central axis relative to the tank body 100.

[0027] Furthermore, in the above embodiment, an agitator was exemplified as the crushing member 200, but the crushing member 200 may also be an air supply unit capable of blowing air against the bridge BR inside the tank body 100, or an energy applying unit (such as a knocker) that applies impact energy to the bridge forming portion 130 in the tank body 100 or a portion nearby from outside the tank body 100.

[0028] The exemplary embodiments described above are examples of the following aspects.

[0029] The wet powder storage tank in the above embodiment comprises a tank body capable of storing wet powder containing powder and a solvent, and the tank body has an upper storage section having a supply port for supplying the wet powder, a lower storage section arranged below the upper storage section and having a discharge port for discharging the wet powder, and a bridge forming section provided between the upper storage section and the lower storage section and forming a bridge made of the wet powder so as to block the wet powder from falling from the upper storage section to the lower storage section.

[0030] In this wet powder storage tank, a bridge-forming section is provided between the upper and lower storage sections, which vertically separates the wet powder stored in the upper and lower storage sections, thereby preventing the weight of all the wet powder in the tank body from acting on the wet powder stored at or near the bottom of the lower storage section, thereby preventing the solvent from seeping out of the wet powder.

[0031] The upper and lower reservoirs may each be formed in a cylindrical shape having a central axis extending in a direction connecting the upper and lower reservoirs. In this case, the bridge-forming portion may have a constricted portion. The cross-sectional area of ​​the constricted portion in a plane perpendicular to the central axis is smaller than the cross-sectional area of ​​the lower end of the upper reservoir in the plane perpendicular to the central axis, and is also smaller than the cross-sectional area of ​​the upper end of the lower reservoir in the plane.

[0032] In this embodiment, a constricted portion is formed between the upper storage portion and the lower storage portion, so that the wet powder stored in the upper storage portion and the wet powder stored in the lower storage portion are effectively separated in the vertical direction.

[0033] In this case, it is preferable that the constricted portion has a shape that is curved so as to be convex toward the central axis.

[0034] This prevents the wet powder from getting caught in the constricted portion.

[0035] The bridge-forming portion may also have a connecting portion that connects the upper reservoir portion and the lower reservoir portion, in which case the surface roughness of the inner surface of the connecting portion is smaller than the surface roughness of the inner surface of the upper reservoir portion.

[0036] In this embodiment, the surface roughness of the inner surface of the connecting part is smaller than that of the inner surface of the upper reservoir part, so that the contact area between the wet powder and the connecting part is larger than the contact area between the wet powder and the inner surface of the upper reservoir part, and therefore friction between the wet powder and the inner surface of the connecting part is large, effectively forming a bridge at the connecting part.

[0037] The bridge forming portion may also have a connecting portion that connects the upper storage portion and the lower storage portion, and a solvent supply portion that supplies the solvent toward an inner surface of the connecting portion.

[0038] In this embodiment, the ratio of the solvent in the wet powder increases at the connecting portion, so that a bridge is effectively formed at the connecting portion.

[0039] Preferably, the wet powder storage tank further includes a crushing member for crushing the bridge formed in the tank body.

[0040] In this embodiment, the bridge can be crushed by the crushing member, which makes it easier to drop the wet powder from the upper storage section to the lower storage section.

[0041] For example, the disintegrating member includes an agitator capable of stirring the wet powder in the tank body. The agitator preferably has an upper stirring portion that stirs the wet powder in the upper storage portion and a lower stirring portion that stirs the wet powder in the lower storage portion.

[0042] In this embodiment, it is possible to achieve both the collapse of the bridge by the upper agitating section and the promotion of the discharge of the wet powder from the discharge port by the lower agitating section. [Example]

[0043] Next, the evaluation results of the wet powders in both the examples of the above embodiment and the comparative examples will be described with reference to Figures 5 to 8. The wet powders used contained an active material, conductive particles, a resin, and a solvent.

[0044] Figure 5 is a schematic diagram of a wet powder storage tank used in Examples and Figure 6 is a schematic diagram of a wet powder storage tank used in Comparative Examples.

[0045] As shown in FIG. 5, in the embodiment, similar to the example shown in FIG. 2, a tank body 100 having a constricted portion 132a formed of an inclined surface whose diameter gradually decreases downward was used.

[0046] 6, in the comparative example, a tank body 100B formed in a cylindrical shape with a bottom was used. An agitator 200B was provided inside this tank body 100B.

[0047] Fig. 7 is a schematic diagram of an apparatus for evaluating the spreadability of a wet powder WP. As shown in Fig. 7, this apparatus has an upper plate 11, a lower plate 12 disposed below the upper plate 11, and an intermediate plate 13 disposed between the upper plate 11 and the lower plate 12 so as to be in contact with the upper surface of the lower plate 12.

[0048] The spreadability of the wet powder WP was evaluated as follows: That is, as shown by the arrow in Figure 7, an intermediate plate 13 was inserted between an upper plate 11 and a lower plate 12, and the spreadability was evaluated based on the distance h between the upper plate 11 and the intermediate plate 13 when a specified shear load was generated by the wet powder WP sandwiched between the intermediate plate 13 and the upper plate 11. The upper surface of the lower plate 12 and the lower surface of the intermediate plate 13 in contact with the upper surface are inclined so that the distance between the upper plate 11 and the intermediate plate 13 becomes smaller as the intermediate plate 13 is inserted.

[0049] Various evaluations including spreadability were performed on the wet powder WP stored in the bottom A of the tank body 100 of the example and the wet powder WP stored in the bottom B of the tank body 100B of the comparative example. Figure 8 shows the evaluation results.

[0050] As shown in Figure 8, the wet powder WP stored in the bottom part A of the example did not ooze out of the solvent and had good spreadability (no deterioration occurred). Furthermore, when this wet powder WP was formed into a film by the MPS film formation method, no film defects were observed.

[0051] On the other hand, the wet powder WP stored in the bottom B of the comparative example had poor spreadability (deterioration occurred) due to the seepage of the solvent. Furthermore, when this wet powder WP was formed into a film by the MPS film formation method, film formation defects were observed.

[0052] It should be noted that the embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the description of the above embodiments and examples, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0053] 1 wet powder storage tank, 100 tank body, 110 upper storage section, 120 lower storage section, 130 bridge forming section, 132 connecting section, 132a constricted section, 200 crushing member, 202 rotating shaft, 210 upper stirring section, 220 lower stirring section, BR bridge, WP wet powder.

Claims

1. a tank body capable of storing a wet powder containing a powder and a solvent; The tank body is an upper reservoir having a supply port for supplying the wet powder; a lower storage section disposed below the upper storage section and having a discharge port for discharging the wet powder; a bridge forming portion provided between the upper storage portion and the lower storage portion, which promotes the formation of a bridge by the wet powder so as to block the wet powder from falling from the upper storage portion to the lower storage portion, the bridge forming portion has a connecting portion connecting the upper reservoir portion and the lower reservoir portion, A wet powder storage tank, wherein the surface roughness of the inner surface of the connecting portion is smaller than the surface roughness of the inner surface of the upper storage portion.

2. The upper storage section and the lower storage section are formed in a cylindrical shape having a central axis extending in a direction connecting the upper storage section and the lower storage section, The bridge forming portion has a constricted portion, 2. The wet powder storage tank according to claim 1, wherein a cross-sectional area of ​​the constricted portion in a plane perpendicular to the central axis is smaller than a cross-sectional area of ​​a lower end of the upper storage portion in a plane perpendicular to the central axis, and is smaller than a cross-sectional area of ​​an upper end of the lower storage portion in the plane.

3. 3. The wet powder storage tank according to claim 2, wherein the constricted portion has a shape that is curved convexly toward the central axis.

4. 4. The wet powder storage tank according to claim 1, wherein the bridge forming portion further comprises a solvent supply portion that supplies the solvent toward an inner surface of the connecting portion.

5. 5. The wet powder storage tank according to claim 1, further comprising a crushing member for crushing the bridge formed in the tank body.

6. the crushing member includes an agitator capable of stirring the wet powder in the tank body, The agitator is an upper stirring section that stirs the wet powder in the upper storage section; 6. The wet powder storage tank according to claim 5, further comprising: a lower agitator for agitating the wet powder within the lower storage section.

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