Water stream charging device

Abstract

To provide a water stream charging device which improves charging performance of a filter medium by making a simple configurational modification.SOLUTION: A water stream charging device 10 includes a suction part 40 comprising: a water-permissible transportation part 20 which transports a filter medium 11 being supported from below; a feed section 30 with a nozzle 32 which is arranged above the transportation part 20 and injects water toward the filter medium 11 above the transportation part 20; and a suction device 60 which is arranged below the transportation part 20 and sucks water through a passage constitution part 41 with a suction passage 42 including portions opened upward and extended downward and the suction passage 42. The passage constitution part 41 includes: an opposing face 44 which faces an undersurface of the transportation part 20; a top part 43 with a slit hole 45 which opens to the opposing face 44 and penetrates in a vertical direction; and a body part 46 including a passage body 47 which is communicated with the slit hole 45 and extends downward. An upper limit value of absolute value of vacuum pressure of the suction device 60 is 50 kPa or less. A width of the slit hole 45 is 7 mm or more and 15 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water jet charging device. [Background technology]

[0002] Conventionally, nonwoven fabrics made of ultrafine fibers have been used as filter media for capturing dust particles in the atmosphere, and electret nonwoven fabrics, which are nonwoven fabrics imparted with an electric charge, have been used as filter media with high fine particle collection efficiency.

[0003] As a method for imparting an electric charge to a filter medium made of nonwoven fabric, a water flow charging method is known (see, for example, Patent Document 1). A device that imparts an electric charge to filter media using the water flow charging method (hereinafter referred to as a water flow charging device) charges the filter media using static electricity generated when water sprayed from a nozzle passes through the inside of the filter media. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-131485 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to increase the degree of charging of the filter material, it is preferable to increase the flow rate of water passing through the inside of the filter material. However, there is a limit to increasing the absolute value of the vacuum of the suction device in order to increase the water flow rate. In addition, if a suction device with a large absolute value of the vacuum is used, new problems such as the size of the suction device will arise. [Means for solving the problem]

[0006] The water flow charging device for solving the above problem is a water flow charging device that charges filter material, and includes a water-permeable conveying section that supports and conveys the filter material from below, a supply section located above the conveying section and having a nozzle that sprays water onto the filter material on the conveying section, and a suction section located below the conveying section and having a passageway forming section that has a suction passage that opens upward and includes a portion that extends downward, and a suction device that sucks the water through the suction passage, wherein the passageway forming section includes an opposing surface that faces the underside of the conveying section, a top that has a slit hole that opens into the opposing surface and penetrates in the vertical direction, and a main body section that has a passageway main body that communicates with the slit hole and extends downward, and the upper limit of the absolute value of the vacuum pressure of the suction device is 50 kPa or less, and the width of the slit hole is 7 mm or more and 15 mm or less.

[0007] When the flow velocity of the air sucked into the suction passage slit (hereinafter referred to as suction velocity) is less than 30 m / s, the efficiency of the charged filter media to capture dust in the air (hereinafter referred to as collection efficiency) increases with the increase in suction velocity. On the other hand, when the suction velocity is 30 m / s or more, the efficiency of the atmospheric dust collection does not increase even if the suction velocity increases.

[0008] According to the above configuration, when the width of the slit hole is less than 7 mm, the smaller the width, the greater the pressure loss at the slit hole.Therefore, when the upper limit of the absolute value of the vacuum degree of the suction device is 50 kPa or less, it is difficult to make the suction wind speed 30 m / s or more, and therefore to improve the charging degree of the filter material, that is, the collection efficiency.In addition, when the width of the slit hole is greater than 15 mm, the upper limit of the absolute value of the vacuum degree of the suction device must be greater than 50 kPa, that is, the suction performance must be improved, otherwise the suction wind speed cannot be made 30 m / s or more.

[0009] In this respect, according to the above configuration, the width of the slit hole is 7 mm or more, so the pressure loss at the slit hole can be reduced, and therefore, when the upper limit of the absolute value of the vacuum degree of the suction device is 50 kPa or less, the suction wind speed can be 30 m / s or more.In addition, because the width of the slit hole is 15 mm or less, even if the upper limit of the absolute value of the vacuum pressure of the suction device is 50 kPa or less, the suction wind speed can be 30 m / s or more, and thus the charging performance of the filter material can be improved.

[0010] Therefore, the charging performance of the filter medium can be improved by simply changing the configuration. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a water jet charging device according to one embodiment, focusing on a supply unit, a transport unit, and a suction unit. [Figure 2] FIG. 2 is a plan view of a portion of the conveying section shown in FIG. 1 immediately above the suction section. [Figure 3] FIG. 3 is a plan view of the suction portion of FIG. [Figure 4] FIG. 4 is a front view of the suction unit of FIG. [Figure 5] 5 is a side view of the suction unit of FIG. 3. FIG. [Figure 6] FIG. 6 is a graph showing the relationship between suction wind speed and collection efficiency. [Figure 7] FIG. 7 is a graph showing the relationship between the suction wind speed and the absolute value of the vacuum pressure of the blower for each slit width. [Figure 8] FIG. 8 is a graph showing the relationship between the depth of the slit and the pressure loss at the slit. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of a water jet charging device will be described with reference to the drawings. As shown in FIG. 1, the water flow charging device 10 is a device that charges a filter medium 11 made of nonwoven fabric.

[0013] The water current charging device 10 includes a conveying section 20, a supplying section 30, and a suction section 40. <Conveyor unit 20> 1 and 2, the conveying unit 20 conveys the filter medium 11 while supporting it from below, and has water permeability. The conveying unit 20 of this embodiment is composed of a conveying belt 21 of a belt conveyor device.

[0014] In the following description, the conveying direction of the conveying unit 20 (the left-right direction in FIG. 1) is referred to as a first direction X, and the direction perpendicular to both the first direction X and the up-down direction Z is referred to as a second direction Y. <Supply section 30> As shown in FIG. 1, the supply unit 30 is located above the conveying unit 20 and has a nozzle 32 that sprays water onto the filter medium 11 on the conveying unit 20.

[0015] The nozzle 32 is connected to a pressure-feeding unit 31 that pressure-feeds water toward the nozzle 32. The pressure-feeding unit 31 has a pump. <Suction part 40> As shown in Figure 1, the suction section 40 is located below the conveying section 20 and has a passage forming section 41 having a suction passage 42 that opens upward and includes a portion that extends downward, and a suction device 60 that sucks water through the suction passage 42.

[0016] As shown in FIGS. 1 and 3 to 5, the passage forming portion 41 has a top portion 43 and a main body portion . The top portion 43 has an opposing surface 44 that faces the lower surface of the conveying portion 20 and a slit hole 45 that opens to the opposing surface 44 and penetrates in the vertical direction Z.

[0017] The top portion 43 in this embodiment is plate-shaped. The facing surface 44 is a plane parallel to both the first direction X and the second direction Y. As shown in FIG. 3, the slit 45 has a rectangular shape in a plan view, with a pair of long sides extending along the second direction Y and a pair of short sides extending along the first direction X.

[0018] As shown in FIG. 1, the slit hole 45 is provided at a position that overlaps with the injection port (not shown) of the nozzle 32 in the vertical direction Z. 1, 4 and 5, the main body 46 has a passage body 47 that communicates with the slit hole 45 and extends downward. The slit hole 45 and the passage body 47 form the suction passage 42.

[0019] The main body portion 46 has, in order from above, a gradually changing portion 48, a first straight portion 49, a corner portion 51, and a second straight portion 50. The cross-sectional area of ​​the suction passage 42 in the gradually changing portion 48 gradually increases toward the lower side.

[0020] As shown in FIG. 4, the length of the suction passage 42 in the second direction Y at the gradually changing portion 48 gradually decreases toward the lower side. As shown in FIG. 5, the length of the suction passage 42 in the first direction X at the gradually changing portion 48 gradually increases toward the lower side.

[0021] 1 and 3 to 5, the first straight portion 49 has a cylindrical shape extending in the up-down direction Z. The second straight portion 50 has a cylindrical shape extending in the first direction X. The corner portion 51 connects the first straight portion 49 and the second straight portion 50.

[0022] 1, 4, and 5, a partition wall 52 is provided inside the gradually changing section 48 to separate the suction passage 42 into an inner passage 56 and an outer passage 57. The partition wall 52 is in the shape of a plate extending in both the vertical direction Z and the second direction Y.

[0023] 1 and 5, the inner passage 56 is located on the side of the first straight portion 49 where the second straight portion 50 is located in the first direction X. The outer passage 57 is located on the side of the second straight portion 50 where the first straight portion 49 is located in the first direction X.

[0024] 1, the upper end portion 55 of the partition wall 52 is tapered. More specifically, the entire surface 53 of the partition wall 52 facing the inner passage 56 is flat and extends in both the vertical direction Z and the second direction Y. On the other hand, the entire surface of the partition wall 52 facing the outer passage 57, excluding the upper end portion 55, is flat and extends in both the vertical direction Z and the second direction Y. The upper end portion 55 has an arc-shaped cross section with rounded corners.

[0025] As shown in FIGS. 1 and 5, below the upper end portion 55 of the partition wall 52, the flow path cross-sectional area of ​​the inner passage 56 and the flow path cross-sectional area of ​​the outer passage 57 are preferably the same. The suction device 60 is connected to the second straight section 50. The suction device 60 has an electric blower. The upper limit of the absolute value of the vacuum pressure of the suction device 60 is 50 kPa or less. The absolute value of the vacuum pressure of the blower in this embodiment is 50 kPa. The air volume of the blower in this embodiment is 7.71 m 3 The rotation speed of the blower in this embodiment is 1950 min -1 is.

[0026] The width W of the slit 45 is 7 mm or more and 15 mm or less. In this embodiment, the width W of the slit 45 is 10 mm. The depth D of the slit 45 is 5 mm or more and 7 mm or less. In this embodiment, the depth D of the slit 45 is 6 mm.

[0027] Next, the operation of this embodiment will be described. 6, when the flow velocity of the air sucked into the slit holes 45 of the suction passage 42 (hereinafter referred to as the suction wind velocity) is less than 30 m / s, the efficiency with which the charged filter medium 11 captures dust in the atmosphere (hereinafter referred to as the capture efficiency) increases as the suction wind velocity increases. Also, when the suction wind velocity is 30 m / s or more, the capture efficiency does not increase substantially even if the suction wind velocity increases.

[0028] 7, when the width W of the slit 45 is less than 7 mm, the smaller the width W, the greater the pressure loss at the slit 45. Therefore, when the upper limit of the absolute value of the vacuum degree of the suction device 60 is 50 kPa or less, it is difficult to increase the suction air speed to 30 m / s or more, and therefore it is difficult to increase the degree of charging of the filter medium 11, i.e., the collection efficiency.

[0029] Furthermore, if the width W of the slit hole 45 is greater than 15 mm, the suction wind speed cannot be made 30 m / s or more unless the upper limit of the absolute value of the vacuum degree of the suction device 60 is made greater than 50 kPa, i.e., unless the suction performance is improved.

[0030] In this embodiment, since the width W of the slit 45 is 7 mm or more, the pressure loss at the slit 45 can be reduced, and therefore the suction wind speed can be 30 m / s or more when the upper limit of the absolute value of the vacuum degree of the suction device 60 is 50 kPa or less. Also, since the width W of the slit 45 is 15 mm or less, even if the upper limit of the absolute value of the vacuum pressure of the suction device 60 is 50 kPa or less, the suction wind speed can be 30 m / s or more, and thus the charging performance of the filter medium 11 can be improved.

[0031] Next, the effects of this embodiment will be described. (1) The effects of the above-described embodiment are achieved, and the charging performance of the filter medium 11 can be improved by simply changing the configuration.

[0032] (2) As shown in Fig. 8, when the depth D of the slit 45 is less than 5 mm, the smaller the depth D, the more air is sucked into the slit 45 from various angles, resulting in an increased pressure loss at the slit 45. Furthermore, when the depth D of the slit 45 is greater than 7 mm, the larger the depth D, the greater the pressure loss at the slit 45. For this reason, when the depth D of the slit 45 is less than 5 mm or greater than 7 mm, it is difficult to achieve a suction air velocity of 30 m / s or more when the upper limit of the absolute value of the vacuum pressure of the suction device 60 is 50 kPa or less.

[0033] In this regard, according to this embodiment, the depth D of the slit hole 45 is 5 mm or more and 7 mm or less, so that it is possible to reduce the pressure loss at the slit hole 45. As a result, when the upper limit of the absolute value of the vacuum pressure of the suction device 60 is 50 kPa or less, it is possible to easily make the suction wind speed 30 m / s or more, and therefore to easily increase the degree of charging of the filter medium 11.

[0034] <Modification> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0035] The depth D of the slit hole 45 is not limited to 6 mm, but may be 5 mm or more and less than 6 mm, or may be greater than 6 mm and less than 7 mm. [Explanation of symbols]

[0036] 10...Water flow charging device 11...filter medium 20...Transport unit 21...Conveyor belt 30…Supply section 31...Pumping section 32...Nozzle 40...Suction part 41...Passage component 42...Suction passage 43...Top 44...Opposite surface 45...Slit hole 46...Main body 47...passage main body 48... Gradually changing part 49...First straight section 50...Second straight section 51...Corner 52...Partition wall 53...face 54...face 55...Top end part 56...Inner passage 57…Outside passage 60...Suction device

Claims

1. A water flow charging device for charging a filter medium, A water-permeable conveying section that conveys the filter material while supporting it from below; A supply unit located above the conveying unit and having a nozzle for spraying water onto the filter medium on the conveying unit; a suction unit having a passage forming part located below the conveying part, the passage forming part having a suction passage including a part that opens upward and extends downward, and a suction device that sucks the water through the suction passage; The passage configuration portion is a top portion having an opposing surface facing the lower surface of the conveying portion and a slit hole opening in the opposing surface and penetrating in the vertical direction; a main body portion having a passage body communicating with the slit hole and extending downward, The upper limit of the absolute value of the vacuum pressure of the suction device is 50 kPa or less, The width of the slit hole is 7 mm or more and 15 mm or less. Water flow charging device.

2. The depth of the slit hole is 5 mm or more and 7 mm or less. The water jet charging device according to claim 1 .

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