Filtration device

Abstract

The object of the present invention is to solve the problems of the prior art, that is, to provide a filtration device that can clean the filter media with a simpler structure and at a lower cost compared to the prior art. [Solution] The present invention is a filtration device in which a filter media layer made of powdered filter media is installed in a filtration tank, and is equipped with a water supply means and a water inlet pipe. The water inlet pipe, which is located below the filter media layer, is a means for injecting cleaning water supplied from the water supply means into the filter media layer from the inlet. The water inlet pipe is positioned along the side wall of the filtration tank and with its axial direction approximately horizontal. The cleaning water injected from the inlet rotates and rises within the filter media layer, thereby cleaning the filter media in the filter media layer.

Description

Technical Field

[0001] The present invention relates to a technology for filtering raw water, and more specifically, to a filtering device capable of cleaning powder filter media installed in a filtering tank.

Background Art

[0002] For example, drip irrigation is sometimes implemented to supply water to agricultural crops. This drip irrigation, also called trickle irrigation, is a method in which irrigation water pumped from a water source by a pump or the like is conveyed through a pipeline, and then literally dripped directly onto agricultural crops like droplets to supply water.

[0003] When water is pumped from a water source by a pump or the like, facilities such as screens are provided to prevent trash from mixing in, but the mixing of fine trash such as sediment and plant fragments is unavoidable. The mixed trash is problematic because it causes clogging of the nozzles of drip irrigation, and in particular, in recent years, it has been regarded as a problem that invasive alien organisms are carried over a wide range along with irrigation water. Therefore, it is common to install a filtering device to filter the conveyed irrigation water.

[0004] Among these filtering devices, those using sand as filter media (sand filters) are well known. More specifically, the filtering device comprises a "filtering tank" and a "filter medium layer" provided in the filtering tank, and the filter medium layer is formed of sand. An extremely fine wire mesh is installed inside the filtering tank, and a filter medium layer can be formed by depositing a predetermined amount of sand on this wire mesh.

[0005] Filtration systems remove debris and other contaminants from irrigation water, and therefore, with continuous use, debris naturally accumulates in the filter media layer. To maintain filtration functionality, the filter media layer must be cleaned as needed. Traditionally, the most common method for cleaning the filter media layer was "backwashing," which involved pressurizing water in the opposite direction to the water flow during filtration, that is, vertically upward from the bottom of the filter media layer. However, with backwashing, if the filter media is a powder such as sand, the likelihood of water flowing throughout the entire filter media layer is low, and the flow tends to concentrate in specific water channels, meaning only a portion of the filter media can be cleaned. Furthermore, because the filter media does not move significantly during cleaning, the cleaning effect is low.

[0006] Against this backdrop, various technologies have been proposed to more effectively clean filter media. For example, Patent Document 1 proposes a sand washing device equipped with a washing tank, a stirring tank, and a screw conveyor that rotates within the stirring tank. Non-Patent Document 1 also discloses a filtration device that utilizes the technology disclosed in Patent Document 1. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 10-109051 [Non-patent literature]

[0008] [Non-Patent Document 1] https: / / genryo.co.jp / water / st / [Overview of the project] [Problems that the invention aims to solve]

[0009] The technology disclosed in Patent Document 1 and Non-Patent Document 1 involves cleaning filter media using a screw conveyor consisting of fins shaped like a spiral staircase. The screw conveyor, installed in a stirring tank, rotates electrically, and the fins perform a circumferential motion, causing the filter media placed in the tank to move upward little by little. As the filter media rises, friction between the filter media cleans the media itself, and at the same time, a water flow is created from below to above, allowing suspended debris to be discharged from above.

[0010] However, the technologies described in Patent Document 1 and Non-Patent Document 1 require the rotation of a screw conveyor to clean the filter media, which consumes electricity. Furthermore, manufacturing the filtration device described in Patent Document 1 requires numerous parts to be prepared and assembled, resulting in considerable manufacturing costs. Moreover, such devices generally require regular maintenance, making operational and upkeep costs unavoidable.

[0011] The object of the present invention is to solve the problems of the prior art, that is, to provide a filtration device that can clean the filter media with a simpler structure and at a lower cost compared to the prior art. [Means for solving the problem]

[0012] The present invention relates to a filtration device in which a filter media layer made of powdered filter media is installed in a "filtration tank," and is equipped with a water injection pipe for washing the filter media. The water injection pipe, located at the bottom of the filter media layer, is a means for injecting washing water supplied from a water supply means such as a pump into the filter media layer from an injection port. The water injection pipe is positioned along the side wall of the filtration tank, and its axial direction is approximately horizontal (including horizontal). The washing water injected from the injection port rotates as it rises within the filter media layer, that is, the washing water becomes a helical flow (swirling flow), thereby washing the filter media in the filter media layer.

[0013] The filtration device of the present invention may also be equipped with an air intake pipe in the water inlet pipe. In this case, as the washing water flows through the water inlet pipe, outside air flows into the water inlet pipe through the air intake pipe. The filter media is then washed by the washing water and air injected from the water inlet.

[0014] The filtration device of the present invention may also be configured such that an air intake pipe is provided in the water inlet pipe. However, in this case, the water inlet pipe does not need to be positioned along the side wall of the filtration tank, nor does it need to be positioned so that its axial direction is approximately horizontal (including horizontal). In this case, as the washing water flows through the water inlet pipe, outside air flows into the water inlet pipe through the air intake pipe. The filter media is then washed by the washing water and air injected from the water inlet.

[0015] The filtration device of the present invention may also be equipped with two or more water inlet pipes located in different places. These two or more water inlet pipes are all arranged to inject water in the same circumferential direction.

[0016] The filtration device of the present invention may further include an inclined plate installed in front of the water inlet (however, in the direction of water injection). In this case, the washing water injected from the water inlet is guided by the inclined plate and moves upward. [Effects of the Invention]

[0017] The filtration device of the present invention has the following effects: (1) By spraying cleaning water from the side, a spiral flow can be generated within the filter media layer. As a result, the filter media can be cleaned more effectively than with conventional technology. (2) The power for injecting cleaning water from the water supply pipe is water pressure, and does not require electricity or other energy sources. In other words, it is possible to reduce the cost of power and save energy compared to conventional technology. (3) Because efficient cleaning of the filter media can be achieved with relatively simple equipment, frequent maintenance is not required, which means that labor can be saved in operation and maintenance. (4) When an air suction pipe is provided on the water injection pipe, air is also injected together with the washing water, so that dust trapped in the filter medium can be floated by fine bubbles and then removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] [Figure 1] A front view schematically showing the filtration device of the present invention. [Figure 2] (a) is a horizontal cross-sectional view schematically showing a situation where washing water injected from a water injection port forms a swirling flow and moves through a filter medium layer, and (b) is a vertical cross-sectional view schematically showing a situation where washing water injected from a water injection port forms a swirling flow and moves through a filter medium layer. [Figure 3] A horizontal cross-sectional view schematically showing a filtration device in which three water injection pipes are arranged so as to inject water in the same circumferential direction. [Figure 4] (a) is a horizontal cross-sectional view schematically showing a filtration device provided with a J-shaped water injection pipe in plan view, and (b) is a vertical cross-sectional view schematically showing a filtration device provided with water injection pipes arranged to have a gentle gradient. [Figure 5] A vertical cross-sectional view schematically showing a filtration device in which an air suction pipe is provided on a water injection pipe. [Figure 6] (a) is a horizontal cross-sectional view schematically showing a filtration device provided with an inclined plate, and (b) is a vertical cross-sectional view schematically showing a filtration device provided with an inclined plate. [Figure 7] (a) is a plan view schematically showing a filtration device in which an air suction pipe is provided on a water injection pipe arranged substantially perpendicular to a side wall, and (b) is a vertical cross-sectional view schematically showing a filtration device in which an air suction pipe is provided on a water injection pipe arranged to rise toward a filtration tank. MODE FOR CARRYING OUT THE INVENTION

[0019] An example of an embodiment of the filtration device of the present invention will be described with reference to the drawings. The present invention is capable of washing the filter medium of a filtration device, and functions particularly effectively in cases of washing powder filter media such as sand filter media (that is, sand filters).

[0020] Figure 1 is a schematic front view (however, the inside of the filtration tank is shown as a cross-sectional view) of the filtration device 100 of the present invention. As shown in this figure, the filtration device 100 of the present invention filters raw water and is therefore composed of elements for filtering raw water, specifically comprising a "filtration tank 120" and a "filter media layer 130" installed inside the filtration tank 120. The filter media layer 130 can be formed by depositing a predetermined amount of filter media on an extremely fine mesh wire 140 installed inside the filtration tank 120. In addition to the function of filtering raw water, the filtration device 100 of the present invention also has a function of washing the filter media (for example, sand), and is therefore equipped with a water inlet pipe 110. When filtering raw water, it is necessary to close the water inlet pipe 110, so this water inlet pipe 110 is provided with an on / off valve.

[0021] The filtration tank 120 is a so-called tank that houses the filter media layer 130 and the raw water to be filtered, and its interior is enclosed by side walls 121. When filtering raw water using the filtration device 100 of the present invention, raw water is introduced from the upper opening 122 at the top of the filtration tank 120 and filtered as it passes through the filter media layer 130. The raw water, from which debris and other impurities have been removed by filtration, is then discharged from the lower opening 123 at the bottom of the filtration tank 120.

[0022] In contrast, when cleaning the filter media layer 130 (i.e., the filter media) using the filtration device 100 of the present invention, the water injection pipe 110 is used. Cleaning water can be supplied to this water injection pipe 110 from a water supply means PM, such as a pump. Of course, when supplying cleaning water to the water injection pipe 110, the on / off valve is left open.

[0023] Meanwhile, a water inlet pipe 110 is positioned below the filter media layer 130. This water inlet pipe 110 is a hollow pipe with open ends. The water inlet pipe 110 is attached to the filtration tank 120 so as to penetrate the side wall 121, with a portion (left side in the diagram) inserted into the filter media layer 130 and the remaining portion (right side in the diagram) protruding to the outside of the filtration tank 120.

[0024] The cleaning water supplied from the water supply means PM flows into the water supply pipe 110 from the opening on the outside of the water supply pipe 110 (right side in the figure) and is injected into the filter media layer 130 from the opening on the inside of the water supply pipe 110 (left side in the figure) (hereinafter referred to as "water inlet 111"). As shown in Figure 1, the water supply pipe 110 is positioned so that its axis is approximately horizontal (including horizontal), so the cleaning water injected from the water inlet 111 also moves from the water inlet 111 with a gentle slope that is close to horizontal. When cleaning the filter media, the water outlet is the upper opening 122, so the water moves upward through the filter media layer 130.

[0025] The mechanism by which the filter media layer 130 (i.e., the filter media) is cleaned by the filtration device 100 of the present invention will be described below with reference to Figure 2. Figure 2 is a schematic diagram showing how the cleaning water injected from the water inlet 111 of the water inlet pipe 110 moves through the filter media layer 130 as a spiral flow (swirling flow), where (a) is a cross-sectional view of the filtration tank 120 cut in the horizontal plane, and (b) is a cross-sectional view of the filtration tank 120 cut in the vertical plane.

[0026] As shown in Figure 2(a), the water inlet pipe 110 is positioned along the side wall 121 of the filtration tank 120. More specifically, the water inlet pipe 110 is positioned so as to be roughly tangential to the point where it penetrates the side wall 121. Therefore, when viewing the movement of the cleaning water injected from the water inlet 111 in plan view, as shown in Figure 2(a), it moves through the filter media layer 130 while rotating roughly around the vertical axis.

[0027] Furthermore, when cleaning the filter media (for example, sand), since the water outlet is the upper opening 122, the cleaning water injected from the inlet 111 of the nearly horizontally positioned water injection pipe 110 moves upward. As a result, as shown in Figure 2(b), the cleaning water moves through the filter media layer 130 in a way that rotates and rises, as if in a vortex. Also, due to the viscosity of the water, the cleaning water injected from the inlet 111 moves in a vortex-like manner, as shown in Figure 2(a), faster near the side wall 121 and slower farther away. Thus, the cleaning water injected from the inlet 111 is considered a "swirling flow" that rotates and rises, and flows through the filter media layer 130 in a way that covers the entire area.

[0028] The filtration device 100 of the present invention can have one water inlet pipe 110 or two or more water inlet pipes 110. However, when two or more water inlet pipes 110 are arranged, they are arranged so that each inlets water in the same circulating direction. For example, in Figure 3, three water inlet pipes 110 are arranged, and the washing water injected from each inlet 111 is arranged to circulate clockwise. Of course, as long as the circulating direction is the same, the water inlet pipes 110 can be arranged so that they all circulate counterclockwise, not just clockwise as shown in Figure 3.

[0029] The water inlet pipes 110 shown in Figures 2 and 3 are straight pipes, but it is not limited to straight pipes; water inlet pipes 110 with a curved horizontal alignment (i.e., curved pipes) can also be used. For example, in Figure 4(a), water inlet pipes 110 are arranged in a "J" shape when viewed from above. In this case, it is best to arrange the water inlet pipes 110 so that the water inlet 111 faces inward. Furthermore, although it has been explained that the water inlet pipes 110 are arranged so that their pipe axis is approximately horizontal (including horizontal), they can also be arranged to have a gentle slope that is close to horizontal, as shown in Figure 4(b). For example, the water inlet pipes 110 can be arranged with a gentle slope such that the vertical angle with respect to the horizontal plane is 1° to 5°. However, in this case, the water inlet pipes 110 are arranged so that the water inlet 111 is higher.

[0030] As shown in Figure 5, an air intake pipe 150 can also be provided in the water injection pipe 110. This air intake pipe 150 is, so to speak, a vent pipe that allows outside air to flow into the water injection pipe 110, and for this reason, a hollow, small-diameter pipe with open ends is used. The air intake pipe 150 is installed so as to penetrate a part of the pipe wall of the water injection pipe 110, and is positioned so that one opening (on the right in the figure) is exposed to the outside air, and the other opening (on the left in the figure) is inside the water injection pipe 110.

[0031] Furthermore, the air intake pipe 150 should be positioned so as to be inclined inward toward the water inlet 111. For example, the air intake pipe 150 shown in Figure 5 is positioned above the water inlet 110 and is inclined downward toward the inside of the water inlet 110 from the outside air side.

[0032] As the cleaning water supplied from the water supply means PM flows through the water inlet pipe 110, the water passage cross-section inside the water inlet pipe 110 narrows, creating negative pressure. This means that outside air flows into the water inlet pipe 110 through the air intake pipe 150 due to the aspirator effect. As a result, as shown in Figure 5, bubbles are ejected from the water inlet 111 in addition to the cleaning water. This allows the swirling flow of the cleaning water to remove debris from the filter media layer 130 (filter media), and the removed debris can be made to float by the fine bubbles.

[0033] As shown in Figure 6, the filtration device 100 of the present invention may also be equipped with an inclined plate 160. This inclined plate 160 is a plate-shaped fin that guides the cleaning water injected from the water inlet 111 upwards. Therefore, as shown in Figure 6(a), the inclined plate 160 is installed in front of the cleaning water that is being injected from the water inlet 111, that is, in front of the water inlet 111 when viewed in the direction of water injection. Furthermore, as shown in Figure 6(b), the inclined plate 160 may be installed at the same height as (or slightly lower than) the bottom of the water inlet pipe 110, and in a position close to the water inlet 111. In addition, to guide the cleaning water further upwards, the front of the inclined plate 160 (forward in the direction of water injection) can be formed to be inclined upwards. For example, in Figure 6(b), the rear (right side in the figure) in the direction of water injection is approximately horizontal, but the front (left side in the figure) in the direction of water injection has a gentle upward slope.

[0034] Up to this point, we have described an example in which the washing water injected from the water inlet 111 of the water injection pipe 110 moves through the filter media layer 130 as a swirling flow, that is, an example in which the water injection pipe 110 is arranged along the side wall 121 of the filtration tank 120 and is approximately horizontal. However, the filtration device 100 of the present invention can also arrange the water injection pipe 110 in any orientation. For example, the water injection pipe 110 in the filtration device 100 shown in Figure 7 is arranged approximately perpendicular to the side wall 121 of the filtration tank 120 and is arranged to rise toward the filtration tank 120. Figure 7(a) is a schematic plan view showing a filtration device 100 in which an air intake pipe 150 is provided on a water injection pipe 110 arranged approximately perpendicular to the side wall 121, and Figure 7(b) is a schematic vertical cross-sectional view showing a filtration device 100 in which an air intake pipe 150 is provided on a water injection pipe 110 arranged to rise toward the filtration tank 120. In Figure 7(a), the water inlet pipe 110 is positioned approximately perpendicular to the side wall 121, but it is not limited to this arrangement; the water inlet pipe 110 can also be positioned at any angle to the side wall 121.

[0035] Thus, if the water inlet pipe 110 is not positioned in a specific orientation (along the side wall 121 of the filtration tank 120 and approximately horizontal), the cleaning water injected from the water inlet 111 may not form a swirling flow but instead move within the filter media layer 130. Therefore, in this example, it is advisable to provide the air intake pipe 150 shown in Figure 5 to the water inlet pipe 110. This will cause air bubbles to be injected from the water inlet 111 in addition to the cleaning water, resulting in the cleaning water removing debris from the filter media layer 130 (filter media) and the removed debris being lifted by the fine air bubbles. Even when the water inlet pipe 110 is positioned in any orientation, it is possible to use one water inlet pipe 110 or two or more water inlet pipes 110. When using two or more water inlet pipes 110, they can be arranged so that each injects water in the same circumferential direction. Furthermore, even when the water inlet pipe 110 is positioned in any orientation, it is possible to use a water inlet pipe 110 whose planar alignment is curved (i.e., a bent pipe) as shown in Figure 4, or to position the inclined plate 160 in front of the water inlet 111 as shown in Figure 6. [Industrial applicability]

[0036] The filtration device of the present invention can be used not only for irrigation water but also in various technical fields where filtration is performed, such as in the water supply and industrial water sectors. According to the present invention, filtration can be performed efficiently, labor can be saved in operation and maintenance, and as a result the production of agricultural products can be promoted, it is an invention that can be expected to make a significant contribution not only to industry but also to society. [Explanation of Symbols]

[0037] 100 Filtration device of the present invention 110 (Water inlet pipe of the filtration system) 111 (Water inlet of the filtration device) 120 (Filtering device) filter tank 121 Side wall (of the filtration tank) 122 (Top opening of the filtration tank) 123 Lower opening (of the filtration tank) 130 (Filter media layer of the filtration device) 140 (Filtration device) wire mesh 150 (Air intake tube of filtration device) 160 (Inclined plate of the filtration system) PM water supply means

Claims

1. A filtration device in which a filter media layer made of powdered filter media is installed inside a filtration tank, The filter media layer is located below the filter media layer and includes a water inlet pipe for injecting cleaning water into the filter media layer from a water inlet, The water inlet pipe is positioned along the side wall of the filtration tank and with its axial direction horizontal or approximately horizontal. The cleaning water injected from the water inlet rises while rotating within the filter material layer, thereby cleaning the filter material in the filter material layer. A filtration device characterized by the following features.

2. The water supply pipe is provided with an air intake pipe. As the cleaning water flows through the water inlet pipe, outside air flows into the water inlet pipe through the air intake pipe. The filter material is cleaned by the cleaning water and air injected from the water inlet. The filtration apparatus according to claim 1, characterized by the features described above.

3. A filtration device in which a filter media layer made of powdered filter media is installed inside a filtration tank, The filter media layer is located below the filter media layer and includes a water inlet pipe for injecting cleaning water into the filter media layer from a water inlet, The water inlet pipe is provided with an air intake pipe. As the cleaning water flows through the water inlet pipe, outside air flows into the water inlet pipe through the air intake pipe. The filter material is cleaned by the cleaning water and air injected from the water inlet. A filtration device characterized by the following features.

4. The system includes two or more of the aforementioned water inlet pipes located in different places, The two or more water inlet pipes are all arranged to inject water in the same circumferential direction. A filtration apparatus according to claim 1 or 3, characterized by the features described herein.

5. The system further includes an inclined plate installed in front of the water inlet in the direction of water injection, The cleaning water poured in from the water inlet moves upward as it is guided by the inclined plate. A filtration apparatus according to claim 1 or 3, characterized by the features described herein.

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