Charging device

Abstract

To provide an electrostatic charge device which improves charge efficiency of a filter material.SOLUTION: A conveyance part 20 of an electrostatic charge device 10 conveys a filter material 11 in a state that the filter material 11 is placed thereon. A nozzle part 30 is provided above the conveyance part 20, and water W is injected downward. A suction part 40 is provided below the conveyance part 20. The suction part 40 has a base part 41, a suction hole 44, and a suction passage 43. The base part 41 extends in a conveyance direction X of the filter material 11 according to the conveyance part 20. The suction hole 44 penetrates a portion facing the conveyance part 20 in the base part 41, in a vertical direction Z. The suction passage 43 suctions water W through the suction hole 44. In the suction passage 43, one end is constituted by the suction hole 44, whereas the other end communicates with a suction device 45 for suctioning water W. A portion on a side of the suction hole 44 in the suction passage 43 is shaped such that a channel cross-section area gradually increases when alienating from the suction hole 44.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a charging device for charging a filter material.

Background Art

[0002] Conventionally, in order to improve the dust collection efficiency of a filter material (for example, a non-woven fabric) provided in a filter device, a charging device for charging the filter material has been proposed (for example, see Patent Document 1).

[0003] Patent Document 1 describes a device that sprays a fluid (specifically, water) from a nozzle onto a filter material conveyed by a conveying unit such as a conveying conveyor as a charging device. Patent Document 1 also describes a charging device that sucks a fluid through a suction unit (specifically, a slit-shaped suction hole) provided below the filter material immersed in the fluid. In any of the devices, the filter material is charged by utilizing the static electricity generated when the fluid passes through the inside of the filter material. <000001​​​​​​​​​​​​​​​​​​​​​​​​​However, in this case, the fluid flow path within the suction section widens at the downstream end of the suction hole. As a result, separation vortices may be generated in the downstream portion of the suction hole within the suction section, potentially reducing the fluid velocity within the suction section. This can lead to a decrease in the fluid velocity passing through the filter material. In this respect, the above-mentioned charging device still has room for improvement. [Means for solving the problem]

[0007] A charging device for solving the above problems comprises: a transport section for transporting a filter material with the filter material placed on it; a nozzle section provided above the transport section for spraying a fluid downward; a suction section provided below the transport section and having a base section extending in the direction of transport of the filter material by the transport section; a suction hole penetrating the portion of the base section facing the transport section in the vertical direction; and a suction passage having one end formed by the suction hole and the other end connected to a suction device for sucking the fluid, and sucking the fluid through the suction hole, wherein the portion of the suction passage on the side of the suction hole has a shape in which the cross-sectional area of ​​the flow path gradually increases as it moves away from the suction hole.

[0008] In the above configuration, the fluid injected from the nozzle passes through the filter material transported by the transport unit and is also drawn into the suction passage through the suction hole of the suction unit. In the above configuration, the cross-sectional area of ​​the suction passage expands downstream of the suction hole. However, in the above configuration, the cross-sectional area of ​​the suction passage expands gradually downstream of the suction hole. Therefore, compared to a configuration where the cross-sectional area of ​​the suction passage expands abruptly at the downstream end of the suction hole, the generation of separation vortices within the suction passage can be suppressed. As a result, the decrease in fluid velocity within the suction passage can be suppressed, and thus the decrease in fluid velocity passing through the filter material can be suppressed, and the fluid velocity can be increased. Therefore, according to the above configuration, the charging efficiency of the filter material by the charging device can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side cross-sectional view of a charging device according to one embodiment. [Figure 2] This is a plan view of the filter material, the transport section, and the suction section. [Figure 3] This is a plan view of the suction section. [Figure 4] This is a view of the suction section from the perspective of arrow 4 in Figure 3. [Figure 5] This is a view of the suction section from the perspective of arrow 5 in Figure 3. [Figure 6] This is a side cross-sectional view showing a magnified view of the upper end portion of the partition wall and its surrounding area. [Figure 7] This is a side cross-sectional view showing a magnified view of the suction port and its surrounding area in the suction section. [Modes for carrying out the invention]

[0010] The following describes one embodiment of the charging device with reference to Figures 1 to 7. As shown in Figure 1, the charging device 10 of this embodiment is a device for charging a filter material 11 by utilizing the static electricity generated when a fluid (water W in this embodiment) passes through the inside of the filter material 11. The filter material 11 is made of a nonwoven fabric that has breathability and water permeability. The charging device 10 has a transport unit 20, a nozzle unit 30, and a suction unit 40.

[0011] <Conveying Section> As shown in Figures 1 and 2, the conveying unit 20 is composed of a belt conveyor device. The conveying unit 20 has a conveyor belt 21. The conveyor belt 21 is permeable to air and water. The filter material 11 is placed on the conveyor belt 21. When the conveying unit 20 is operated, the conveyor belt 21 moves in one direction (to the right in Figure 1) with the filter material 11 on it. The conveying unit 20 conveys the filter material 11 with the filter material 11 placed on the conveyor belt 21.

[0012] <Nozzle section> As shown in Figure 1, the nozzle section 30 is located above the conveying section 20. When the charging device 10 charges the filter material 11, water W is sprayed downward from the nozzle section 30.

[0013] A fluid passage 31 extending in the vertical direction Z is provided inside the nozzle section 30. One end of the fluid passage 31 (the upper end in Figure 1) is connected to the pumping section 32. The pumping section 32 is composed of a pump that pumps water W. The other end of the fluid passage 31 (the lower end in Figure 1) is an injection port 33 for spraying water W. In this embodiment, the water W supplied from the pumping section 32 to the nozzle section 30 is sprayed downward from the injection port 33 of the nozzle section 30 (specifically, toward the transport section 20 and the filter material 11).

[0014] <Suction part> The suction unit 40 is located below the transport unit 20. When the filter material 11 is charged by the charging device 10, water W is drawn in by the suction unit 40. The suction unit 40 has a base unit 41 and a suction passage 43.

[0015] <Base section> As shown in Figures 1 and 2, the base portion 41 extends in the direction X (left-right direction in Figure 1) of the conveying direction 20 for the filter material 11. The base portion 41 is a substantially rectangular flat plate that extends substantially parallel to the conveying belt 21 of the conveying section 20. In this embodiment, the upper surface of the base portion 41 and the lower surface of the conveying belt 21 are facing each other.

[0016] A suction hole 44 is provided in the base portion 41. The suction hole 44 is a through hole that penetrates the base portion 41 in the vertical direction Z. The suction hole 44 opens to the lower surface of the conveyor belt 21. The suction hole 44 is a slit that extends linearly in the orthogonal direction Y (vertical direction in Figure 2), which is perpendicular to the conveying direction X. The cross-sectional shape of the suction hole 44 is rectangular, with the orthogonal direction Y as its longitudinal direction.

[0017] In this embodiment, the injection port 33 of the nozzle unit 30 and the suction hole 44 of the base unit 41 are arranged so as to be aligned in the vertical direction Z. Then, the injection of water W by the nozzle unit 30 is performed in a manner in which the water W spreads fan-shaped in the orthogonal direction Y from the injection port 33. In this embodiment, the nozzle unit 30 and the suction hole 44 are arranged so that the water W injected from the injection port 33 of the nozzle unit 30 is sprayed onto the entire opening of the suction hole 44.

[0018] <Suction passage> As shown in FIGS. 1, 3 to 5, the suction passage 43 has a tubular shape through which water W passes inside. The suction passage 43 extends below the base unit 41. One end (the upper end in FIG. 1) of the suction passage 43 is constituted by the suction hole 44. That is, the suction passage 43 extends in such a manner that the suction hole 44 is the upper end opening of the suction passage 43. The other end (the lower end in FIG. 1) of the suction passage 43 is communicated with the suction device 45. The suction device 45 is constituted by a suction pump that sucks water W. The suction passage 43 constitutes a passage for sucking water W through the suction hole 44.

[0019] The portion of the suction passage 43 on the side of the suction hole 44, that is, the upper portion 43A of the suction passage 43, has a shape in which the flow path cross-sectional area gradually increases as it moves away from the suction hole 44. The inner surface of the upper portion 43A of the suction passage 43 is constituted by a surface without a step. As shown in FIG. 5, the upper portion 43A of the suction passage 43 has a tapered shape in which the passage width W1 of the suction passage 43 in the short side direction (the left-right direction in FIG. 5) of the slit gradually increases as it moves away from the suction hole 44 formed by the slit. As shown in FIG. 4, the upper portion 43A of the suction passage 43 has a tapered shape in which the passage width W2 of the suction passage 43 in the longitudinal direction (the left-right direction in FIG. 4) of the slit gradually decreases as it moves away from the suction hole 44 formed by the slit.

[0020] As shown in Figures 1, 3 to 5, the portion of the suction passage 43 that is spaced away from the suction hole 44, i.e., the lower part 43B of the suction passage 43, is cylindrical. The lower part 43B of the suction passage 43 has a bent portion 51 and a downstream portion 52, starting from the upstream side in the flow direction of the water W (hereinafter, upstream side). The bent portion 51 starts from the lower end of the upper part 43A and extends in one direction (to the left in Figure 1) in a manner that bends the suction passage 43 at a predetermined angle (90 degrees in this embodiment). The downstream portion 52 extends in a straight line in the conveying direction X.

[0021] <Partition wall> As shown in Figures 1, 4, and 5, a partition wall 55 is provided at the upper part 43A of the suction passage 43, dividing the interior of the suction passage 43 into two passages (an inner passage 53 and an outer passage 54). The partition wall 55 is substantially flat and extends in the vertical direction Z and the orthogonal direction Y. In this embodiment, the partition wall 55 divides the interior of the suction passage 43 into an inner passage 53, which is on the inside in the bending direction of the bent portion 51 (left side in Figure 1), and an outer passage 54, which is on the outside in the bending direction (right side in Figure 1).

[0022] As shown in Figures 1 and 6, the upper end portion of the partition wall 55 has a tapered shape. More specifically, the first surface 56 of the partition wall 55 on the inner passage 53 side is composed of planes extending in the vertical direction Z and the orthogonal direction Y. On the other hand, the second surface 57 of the partition wall 55 on the outer passage 54 side has a so-called R shape with rounded corners at its upper end portion 57A. Furthermore, the portion of the second surface 57 of the partition wall 55 other than the upper end portion 57A is composed of planes extending in the vertical direction Z and the orthogonal direction Y. In this embodiment, by making the upper end portion of the partition wall 55 the tapered shape described above, the flow path cross-sectional area S1 at the upstream end 54A (Figure 6) of the outer passage 54 is larger than the flow path cross-sectional area S2 at the upstream end 53A of the inner passage 53.

[0023] As shown in Figures 1, 4, and 5, in this embodiment, the partition wall 55 is provided in such a manner that the flow path cross-sectional area of ​​the downstream side (hereinafter referred to as the downstream side) of the inner passage 53 and the flow path cross-sectional area of ​​the downstream side of the outer passage 54 are the same. Specifically, the upper part 43A of the suction passage 43 has a plane-symmetric shape with a plane extending in the vertical direction Z and the orthogonal direction Y as the plane of symmetry. The partition wall 55 is provided on this upper part 43A of the suction passage 43 in such a manner that it extends along the plane of symmetry. In this embodiment, the downstream side of the inner passage 53 and the downstream side of the outer passage 54 have the same shape, more specifically, a plane-symmetric shape with a plane extending in the vertical direction Z and the orthogonal direction Y as the plane of symmetry.

[0024] <Operating mode of the charging device 10> The operation of the charging device 10 of this embodiment will be described below. When the filter material 11 is charged by the charging device 10, the filter material 11 is placed on the conveyor belt 21, and the conveying unit 20 begins to transport the filter material 11. At the same time, the pumping unit 32 starts pumping water W and the suction unit 40 starts sucking water W.

[0025] As a result, water W is sprayed from the nozzle opening 33 of the nozzle section 30, and this water W is blown from above onto the filter material 11 that is being transported on the conveyor belt 21.

[0026] The water W sprayed onto the filter material 11 passes downward through the inside of the filter material 11. At this time, the filter material 11 is charged by utilizing the static electricity generated when the water W flows through the inside of the filter material 11 (more specifically, on the surface of the nonwoven fabric fibers).

[0027] The water W that has passed through the filter material 11 passes downward along the conveyor belt 21 and is then sucked up by the suction unit 40. As a result, the water W, along with the surrounding air A, flows into the suction passage 43 through the suction holes 44 of the base unit 41. The water W and air A then flow through the upper part 43A, the bent part 51 of the lower part 43B, and the downstream part 52 of the suction passage 43 in that order, and are sent downstream.

[0028] <Effects and Effects> The following describes the effects and benefits of the charging device 10 of this embodiment. (1) In the charging device 10 of this embodiment, the water W supplied by spraying from the nozzle section 30 passes through the inside of the filter material 11 that is transported by the transport section 20 and is sucked into the inside of the suction passage 43 through the suction hole 44 of the suction section 40. As shown in Figure 7, in this embodiment, the cross-sectional area of ​​the flow path of the suction passage 43 is structured to expand downstream of the suction hole 44.

[0029] A charging device in which the cross-sectional area of ​​the suction passage 43 increases sharply at the downstream end of the suction hole 44 is referred to as the "comparative device." In the comparative device, a portion of the flow of water W or air A bends sharply in the downstream portion of the suction passage 43 below the suction hole 44, making it easy for separation flow and separation vortices to occur. When separation vortices occur in this portion, there is a risk that the flow velocity of water W in the suction passage 43 will decrease as a result.

[0030] As shown in Figure 7, in the charging device 10 of this embodiment, the upper part 43A of the suction passage 43 has a shape in which the flow path cross-sectional area gradually increases as it moves away from the suction hole 44. The charging device 10 of this embodiment has a structure in which the flow path cross-sectional area of ​​the upper part 43A of the suction passage 43 gradually increases in the portion downstream of the suction hole 44.

[0031] By adopting this structure, the occurrence of a phenomenon in which a portion of the flow of water W and air A bends significantly in the downstream portion of the suction hole 44 (an example is shown by arrow F1 in Figure 7) can be suppressed. Therefore, according to this embodiment, the generation of separation vortices in the downstream portion of the suction hole 44 can be suppressed compared to the apparatus of the comparative example. As a result, the decrease in the flow velocity of water W and air A in the upper part 43A of the suction passage 43 can be suppressed, and the decrease in the flow velocity of water W passing through the filter material 11 located upstream of the suction passage 43 can be suppressed, and the flow velocity can be increased. Consequently, the charging efficiency of the filter material 11 by the charging device 10 can be improved.

[0032] (2) The inner surface of the upper part 43A of the suction passage 43 is made up of a surface without steps. Therefore, compared to the case in which steps are formed on the inner surface of the upper part 43A of the suction passage 43, water W and air A can flow more smoothly through the suction passage 43, and thus the decrease in the flow velocity of water W and air A inside the suction passage 43 can be effectively suppressed.

[0033] (3) The upper part 43A of the suction passage 43 is provided with a partition wall 55 that divides the inside of the suction passage 43 into an inner passage 53 which is on the inside in the bending direction of the bent portion 51 and an outer passage 54 which is on the outside in the bending direction. In this embodiment, the flow path cross-sectional area S1 at the upstream end 54A of the outer passage 54 is larger than the flow path cross-sectional area S2 at the upstream end 53A of the inner passage 53.

[0034] As shown in Figures 1 and 6, according to this embodiment, the opening area of ​​the inlet portion of the outer passage 54 (the above-mentioned flow path cross-sectional area S1) can be made larger than the opening area of ​​the inlet portion of the inner passage 53 (the above-mentioned flow path cross-sectional area S2). This makes it possible to create a structure in which water W and air A drawn into the suction passage 43 through the suction hole 44 can flow more easily into the outer passage 54 than into the inner passage 53. Therefore, more water W and air A can flow into the outer passage 54 compared to the inner passage 53.

[0035] Furthermore, by making the opening area of ​​the inlet portion of the outer passage 54 larger than the opening area of ​​the inlet portion of the inner passage 53, a flow F2 (shown by the white arrow in Figure 6) is formed at the upper part 43A of the suction passage 43, which actively draws air A into the outer passage 54. Here, because air A has a small mass, once a flow is established in one direction, it tends to follow that flow and flow in the same direction. In this embodiment, the air A flowing into the suction passage 43 through the suction hole 44 follows the flow F2 and flows in the same direction. As a result, most of the air A flowing into the suction passage 43 through the suction hole 44 flows into the outer passage 54.

[0036] As shown in Figure 1, the air A that passes through the outer passage 54 mainly flows through the portion of the bent section 51 where the outer passage 54 is continuous, i.e., the portion of the bent section 51 that is on the outside in the bending direction (hereinafter referred to as the first portion Ao). Similarly, the air A that passes through the inner passage 53 mainly flows through the portion of the bent section 51 where the inner passage 53 is continuous, i.e., the portion of the bent section 51 that is on the inside in the bending direction (hereinafter referred to as the second portion Ai). Therefore, in this embodiment, the majority of the air A passing through the bent section 51 flows through the first portion Ao that is on the outside in the bending direction.

[0037] In the bent portion 51 described above, the degree of curvature of the air A flow in the first portion Ao on the outer side in the bending direction is smaller than the degree of curvature of the air A flow in the second portion Ai on the inner side in the bending direction. Therefore, the pressure loss tends to be smaller in the first portion Ao on the outer side in the bending direction compared to the second portion Ai on the inner side in the bending direction.

[0038] According to this embodiment, by providing a partition wall 55, a large portion of the air A flowing through the suction passage 43 can be directed to the first portion Ao on the outer side of the bent portion 51 in the bending direction, i.e., the portion where pressure loss tends to be small. Therefore, water W and air A can be directed downstream of the suction passage 43 having the bent portion 51 while suppressing pressure loss. This effectively suppresses the decrease in the flow velocity of water W and air A inside the suction passage 43.

[0039] (4) In this embodiment, the partition wall 55 is provided in such a manner that the flow path cross-sectional area of ​​the downstream portion of the inner passage 53 is the same as the flow path cross-sectional area of ​​the downstream portion of the outer passage 54.

[0040] Here, if the flow path cross-sectional area of ​​the inner passage 53 is increased and the flow path cross-sectional area of ​​the outer passage 54 is decreased, air A will flow more easily into the second portion Ai on the inside in the bending direction of the bent portion 51, thus increasing the pressure loss. Also, if the flow path cross-sectional area of ​​the inner passage 53 is decreased and the flow path cross-sectional area of ​​the outer passage 54 is increased, air A will flow more easily into the first portion Ao on the outside in the bending direction of the bent portion 51, thus reducing the pressure loss. However, in this case, the flow velocity of air A flowing through the second portion Ai on the inside in the bending direction of the bent portion 51 increases by the amount that the flow path cross-sectional area of ​​the inner passage 53 decreases, thus increasing the pressure loss in the second portion Ai.

[0041] According to this embodiment, the flow path cross-sectional area of ​​the downstream portion of the inner passage 53 is the same as the flow path cross-sectional area of ​​the downstream portion of the outer passage 54. Therefore, it is possible to increase the flow rate of air A in the first portion Ao on the outside of the bending direction of the bending portion 51 while suppressing an increase in the flow velocity of air A in the second portion Ai on the inside in the bending direction of the bending portion 51. This makes it possible to suppress the pressure loss throughout the suction passage 43 in a balanced manner. Consequently, it is possible to suitably suppress the decrease in the flow velocity of water W and air A inside the suction passage 43.

[0042] (5) The suction hole 44 is a slit extending in the orthogonal direction Y. The upper part 43A of the suction passage 43 has a shape in which the passage width W1 of the suction passage 43 in the short direction of the slit gradually increases as it moves away from the slit-shaped suction hole 44. The upper part 43A of the suction passage 43 has a shape in which the passage width W2 of the suction passage 43 in the longitudinal direction of the slit gradually decreases as it moves away from the slit-shaped suction hole 44. According to this embodiment, by adopting this structure, the shape of the suction passage 43 can be changed to a shape that gradually changes from a slit shape in which the pressure loss is large to a cylindrical shape in which the pressure loss is small.

[0043] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0044] The inner surface of the upper part 43A of the suction passage 43 is not limited to being a smooth surface; it can be made up of any shape, such as a stepped surface or a wave-shaped surface. In short, the upper part 43A of the suction passage 43 should have a shape in which the flow path cross-sectional area gradually increases as it moves away from the suction hole 44.

[0045] If the flow path cross-sectional area S1 at the upstream end 54A of the outer passage 54 is greater than the flow path cross-sectional area S2 at the upstream end 53A of the inner passage 53, the shape of the upper end portion of the partition wall 55 can be arbitrarily changed. For example, the upper end portion of the partition wall 55 can be made to have a protrusion that projects toward the inner passage 53, or to have a curved shape toward the inner passage 53.

[0046] The partition wall 55 may be provided in such a manner that the flow path cross-sectional area of ​​the downstream portion of the inner passage 53 and the flow path cross-sectional area of ​​the downstream portion of the outer passage 54 are not identical. For example, the partition wall 55 can be made into a curved shape, or the shape of the upper part 43A of the suction passage 43 can be made into a shape that is not symmetrical.

[0047] • The partition wall 55 can be omitted. The suction hole 44 may be a slit extending in a direction that intersects the transport direction X at an angle.

[0048] The cross-sectional shape of the suction port 44 can be arbitrarily changed, such as by making the cross-section circular or elliptical. • As the filter material to be charged by the charging device, in addition to the filter material 11 made of nonwoven fabric, filter materials made of woven fabric or knitted fabric can also be used.

[0049] The above embodiment of the charging device is not limited to the charging device 10 which uses water W as the fluid for charging the filter material 11, but can also be applied to charging devices which use liquids other than water W (for example, oil) or charging devices which use gases such as air.

[0050] <Note> The above embodiment includes the configuration described in the following appendix. [Note 1] A charging device comprising: a transport section for transporting a filter material with the filter material placed on it; a nozzle section provided above the transport section for spraying a fluid downward; a suction section provided below the transport section and having a base section extending in the direction of transport of the filter material by the transport section; a suction hole penetrating the portion of the base section facing the transport section in the vertical direction; and a suction passage having one end formed by the suction hole and the other end connected to a suction device for sucking the fluid, and sucking the fluid through the suction hole, wherein the portion of the suction passage on the side of the suction hole has a shape in which the cross-sectional area of ​​the flow path gradually increases as it moves away from the suction hole.

[0051] [Note 2] The charging device according to [Note 1], wherein the inner surface of the portion of the suction passage on the side of the suction hole is formed by a surface without steps. [Note 3] The charging device according to [Note 1] or [Note 2], wherein the suction passage has a bent portion that curves and extends in one direction, and has a partition wall provided upstream of the bent portion in the direction of fluid flow that divides the inside of the suction passage into an inner passage on the inside of the bent portion in the direction of bending and an outer passage on the outside of the direction of bending, and the flow path cross-sectional area at the upstream end of the outer passage in the direction of flow is larger than the flow path cross-sectional area at the upstream end of the inner passage in the direction of flow.

[0052] [Note 4] The charging device according to [Note 3], wherein the flow path cross-sectional area of ​​the portion downstream in the direction of fluid flow in the inner passage is the same as the flow path cross-sectional area of ​​the portion downstream in the direction of fluid flow in the outer passage.

[0053] [Note 5] The suction hole is a slit extending in a direction intersecting the transport direction, and the portion of the suction passage on the side of the slit has a shape such that the passage width of the suction passage in the short direction of the slit gradually increases as it moves away from the slit, and the passage width of the suction passage in the longitudinal direction of the slit gradually decreases as it moves away from the slit, as described in any one of [Note 1] to [Note 4]. [Explanation of symbols]

[0054] 10. Charging device 11 Filter material 20 Conveying section 21 Conveyor belt 30 Nozzle section 31 Fluid passage 32 Pressure feeding section 33 Nozzle 40 Suction part 41 Base section 43 Suction passage 43A Upper 43B lower part 44 Suction hole 45 Suction device 51 Bending section 52 Downstream 53. Medial pathway 53A end 54 Lateral pathway 54A end 55 Shi Qiebi 56 Page 1 57 Page 2 57A Upper part

Claims

1. A conveying unit that transports the filter material with the filter material placed on it, A nozzle section is provided above the aforementioned transport section and sprays fluid downwards, The system includes a suction unit provided below the transport unit for sucking up the fluid that has passed through the filter material, The suction section is A base portion extending in the direction of transport of the filter material by the transport unit, It consists of a slit extending in a direction intersecting the aforementioned transport direction, and a suction hole that penetrates vertically through the portion of the base facing the transport section, It has a suction passage at one end which is formed by the suction hole and at the other end which is connected to a suction device that sucks up the fluid, The suction passage includes an upper portion which is connected to the suction hole and is on the side of the suction hole, and a bent portion which is located downstream of the upper portion in the fluid flow direction and extends in a curved manner in the conveying direction. A partition wall is provided upstream of the bent portion in the suction passage in the direction of fluid flow. The partition wall extends in the direction of fluid flow and the intersecting direction, and divides the interior of the suction passage into an inner passage on the inside of the bending direction of the bend and an outer passage on the outside of the bending direction, such that the fluid flows more easily into the outer passage than into the inner passage. In the portion between the suction hole and the partition wall in the upper part, the flow path cross-sectional area gradually increases as it moves away from the suction hole, and the inner surface is composed of a surface without steps. A charging device.

2. The portion of the suction passage on the side of the slit has a shape such that the width of the suction passage in the short direction of the slit gradually increases as it moves away from the slit, and the width of the suction passage in the long direction of the slit gradually decreases as it moves away from the slit. The charging device according to claim 1.

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