JP6872282B1 - Filtration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filtration device capable of cleaning a filter material with energy saving.
SOLUTION: A filtration device 100 includes a filter material storage container 10, a filter material 1 housed in the filter material storage container 10, and a cleaning control device C for controlling cleaning of the filter material 1. The filter material storage container 10 includes an inflow pipe 12, an outflow pipe 23, and a vent pipe 33 for discharging circulating water from the filter material storage container 10. After executing the outflow pipe closing control for closing the outflow pipe 23, the cleaning control device C executes the air blow control for driving the blower B that sends air to the circulating water accumulated inside the filter medium accommodating container 10.
[Selection diagram] Fig. 6

Description

The present invention relates to a filtration device.

Conventionally, various types of filter media such as coral pieces (sand), oyster shells, hydrophilic ceramics, and effervescent glass have been used in the circulation breeding of seafood. Such a filter medium is used as an aggregate in which a plurality of particles are collected.
However, as time passes in the conventional filter medium, the voids (pores) formed inside the particles constituting the filter medium may become clogged with dirt, and the voids may be blocked. In this case, in order to remove the blockage of the filter material, it is necessary to take out the filter material from the container containing the filter material, rub and wash it, spray high-pressure water, etc., which requires appropriate labor and energy. I needed it.

Japanese Patent No. 6270006

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a filtration device capable of cleaning a filter medium with energy saving.

In order to achieve the above objectives, it is grasped by the following configuration.
(1) The filtration device of the present invention is a filtration device that filters circulating water circulated by a pump via a water tank, and includes a filter material storage container, a filter material housed in the filter material storage container, and the above. A cleaning control device for controlling the cleaning of the filter material is provided, and the filter material has ^{a density of 0.9 g / cm 3} or more and 1.1 g / cm ³ or less, and has granular elasticity formed in a plurality of porous materials. The filter medium containing the body includes an inflow pipe that communicates with the water tank and flows the circulating water from the water tank into the filter material storage container, and the filter material containing container that communicates with the water tank. The cleaning control device has an outflow pipe for discharging the circulating water to the water tank and a vent pipe for discharging the circulating water from the filter medium accommodating container, and the cleaning control device executes an outflow pipe closing control for closing the outflow pipe. After that, the air blow control for driving the blower that sends air to the circulating water accumulated inside the filter medium containing container is executed, and before the air blow control is executed, the pump stop control for stopping the drive of the pump is performed. After a predetermined time has elapsed from the execution and the execution of the air blow control is started, the vent pipe opening control for opening the vent pipe is executed, and a predetermined time has elapsed since the execution of the vent pipe opening control is started. Alternatively, after the water level in the filter medium accommodating container becomes equal to or lower than a predetermined water level, the vent pipe closing control for closing the vent pipe is executed, the vent pipe closing control is executed, and then the filter medium accommodating container is operated by the pump. The circulating water is allowed to flow into the filter medium, and the water storage control for storing the circulating water in the filter medium storage container is executed. After the water storage control is executed, the outflow pipe control valve of the outflow pipe is opened. A filtration device characterized by performing outflow pipe opening control.
(2) In the above (1), the pump may be controlled so that the linear velocity of the circulating water is 60 m / h or more.
(3) In the above (1) or (2), the filter material storage container has the inflow pipe and the outflow pipe so as to branch from the inflow pipe and the outflow pipe and bypass the filter material storage container. The outflow pipe closing control may include closing the inflow pipe and the outflow pipe, and at the same time executing the bypass pipe opening control for opening the bypass pipe.
(4) In any of the above (1) to (3), the cleaning control device is a series of the outflow pipe closing control, the air blow control, the vent pipe opening control, the vent pipe closing control and the water storage control. The cleaning sequence control of the above may be executed a specified number of times.
(5) In the above (4), the cleaning control device has elapsed a predetermined time since the previous cleaning sequence control was executed, the circulating water overflows from the filter medium accommodating container, or the circulating water. The cleaning sequence control may be executed again with the transparency of the above value being equal to or less than the specified value as a trigger.

According to the present invention, it is possible to provide a filtration device capable of cleaning a filter medium with energy saving.

It is an overall schematic diagram of a circulation breeding system. It is explanatory drawing of the filtration apparatus. It is a view of arrow A of FIG. It is a control flow diagram. It is explanatory drawing of the filtration apparatus in the outflow pipe closing control. It is explanatory drawing of the filtration apparatus under air blow control. It is explanatory drawing of the filtration apparatus after the vent pipe open control. It is explanatory drawing of the filtration apparatus in the water accumulation control after the vent pipe closing control. It is explanatory drawing of the filtration apparatus after the bypass pipe open control.

(Embodiment)
Hereinafter, embodiments for carrying out the present invention (hereinafter, embodiments) will be described in detail with reference to the drawings.
In the following, an example of applying the filtration device 100 of the present invention to the ring water channel of the circulation breeding system S will be described. However, the filtration device 100 of the present invention is not limited to the circulation breeding system S, and may be applied to a free-flowing breeding system.

(Circulation breeding system)
FIG. 1 is an overall schematic view of the circulation breeding system S.
The circulation breeding system S is used to circulate circulating water in the waterway to breed aquatic organisms such as seaweeds and seafood.
As shown in FIG. 1, the circulation breeding system S mainly receives the aquarium 200 for breeding aquatic organisms and the circulating water (hereinafter, also referred to as breeding water) flowing out from the aquarium 200 once. A foam separation device 300 for removing suspensions containing small particles, and a filtration device 100 for filtering circulating water (including either ammonia nitrification, biological filtration, or physical filtration) flowing out of the foam separation device 300. And the circulating water sterilizing device 400 that sterilizes the circulating water flowing out from the filtration device 100 and flows out to the water tank 200.
In FIG. 1, the circulation breeding system S provides a ring water channel which is a circular flow path of circulating water indicated by a water tank 200, a foam separation device 300, a filtration device 100, a circulating water sterilizer 400, and an arrow connecting them. I have.
Further, the circulation breeding system S includes a pump P, which is provided in the ring water channel and supplies power to circulate the circulating water. The pump P is not limited to being arranged between the foam separation device 300 and the filtration device 100, and may be arranged at any place on the ring water channel.

The circulating water flowing through the ring channel of the circulating breeding system S may be seawater or freshwater.
Circulation breeding is a method of reusing purified circulating water for breeding, closed circulation breeding (without replenishment of circulating water other than evaporation) and semi-circulating breeding (part of circulating water). It is a method of reuse and is classified into two types (one that involves some water change). The circulation breeding system S may be applied to either closed circulation breeding or semi-circulation breeding.

The aquarium 200 is a tank for storing circulating water for breeding aquatic organisms. Water lost due to evaporation or the like may be appropriately poured into the water tank 200, and a part of the circulating water may be drained from the water tank 200 as appropriate.

The foam separator 300 removes suspensions containing small particles. The foam separation device 300 is applied when the circulating water is seawater. The foam separation device 300 is not required when the circulating water is fresh water.
The circulating water sterilizer 400 sterilizes the circulating water by irradiating the circulating water with ultraviolet rays or the like. The circulating water sterilizer 400 is optional and does not have to be provided in the circulating breeding system S.

(Filtration device)
Next, the filtration device 100 applied to the ring water channel of the circulation breeding system S will be described.
FIG. 2 is a cross-sectional view of the filtration device 100 according to the present embodiment. In the present embodiment, the flow direction of the circulating water will be described as going from the inflow pipe 12 to the outflow pipe 23 as shown by an arrow in FIG. 2, but the opposite flow direction, that is, the outflow pipe 23. It may be from to the inflow pipe 12.
The filtration device 100 filters the circulating water circulated by the pump P via the water tank 200. The filtration includes either biological, chemical or physical filtration such as ammonia nitrification.
As shown in FIG. 2, the filtration device 100 includes a filter medium storage container 10, a filter medium 1 housed in the filter medium storage container 10, and an inflow pipe 12 for supplying circulating water into the filter medium storage container 10. It includes an outflow pipe 23 for flowing out circulating water from the inside of the filter material storage container 10, and a vent pipe 33 for discharging sewage mainly after cleaning the filter material 1 from the inside of the filter material storage container 10. The filtration device 100 has a plurality of filtration materials 1 having a total bulk volume, which is a predetermined ratio with respect to the capacity of the water tank 200, in the filtration material storage container 10. The filter medium 1 is preferably formed in a porous manner. The filter medium 1 may be for physical filtration, may be for biological filtration, and may be used for both physical filtration and biological filtration. The filter medium 1 will be described later.

Further, the filtration device 100 includes a blower B and a cleaning control device C.
The blower B sends air to the circulating water collected inside the filter medium accommodating container 10. The blower B has an air supply unit 41 in which the blower B and the filter material storage container 10 are communicated with each other and an air ejection port 41a is provided which opens inside the filter material storage container 10. The air supply unit 41 is provided at the lower part of the storage space of the filter medium storage container 10 so that the air ejection port 41a faces upward. When the blower B is driven, the air compressed by the blower B passes through the air supply unit 41 and is sent out from the air ejection port 41a. The air sent out from the air ejection port 41a rises from the lower part to the upper part in the circulating water collected inside the filter material storage container 10, and thus has the effect of raising the filter material 1. Then, the air acts to separate the deposits such as dust adhering to the filter material 1 from the filter material 1 while providing a flow in which the filter material 1 is convected inside the filter material storage container 10. , The deposits can be peeled off from the filter material 1, and the filter material 1 can be efficiently cleaned.

The cleaning control device C has an output including driving and stopping of the blower B, an opening / closing operation of the outflow pipe control valve 23c, an opening / closing operation of the vent pipe control valve 33c, an output including driving and stopping of the pump P, and an inflow pipe control valve as appropriate. It is a control device that controls the opening / closing operation of 12c and the bypass pipe control valve 50c, respectively. The cleaning control device C includes a timer for measuring the output timing of the control signal and a counter for counting the number of repetitions of the purification sequence control.
As shown in FIG. 2, the cleaning control device C is electrically connected to each of the blower B, the outflow pipe control valve 23c, the vent pipe control valve 33c, and the pump P. The cleaning control device C is electrically connected to the inflow pipe control valve 12c and the bypass pipe control valve 50c as appropriate.
As described above, since the filtration device 100 includes the cleaning control device C capable of automatically cleaning the filtration material 1, the physical filtration function of the filtration material 1 can be effectively maintained. Then, in order to ensure the function of separating bubbles from the circulating water by the foam separating device 300, the load of a physical filter usually provided on the upstream side of the foam separating device 300 in the circulation path for removing coarse dust and the like can be reduced. , The installation of the physical filter itself can be omitted. That is, the filtration device 100 can be provided as an alternative to the physical filter normally provided on the upstream side of the foam separation device 300 in the circulation path. Further, since the filtration device 100 can effectively filter bubbles in addition to coarse dust and the like, it can be provided as a substitute for the foam separation device 300 and the physical filter in the circulation path.

(Filter material storage container)
As shown in FIG. 2, the filter medium storage container 10 has a container body 11, a first upper flange 13 provided on the upper part of the container body 11, and a container body 11 in the center provided on the lower part of the container body 11. It has a first lower flange 14 having an opening hole 14a having substantially the same diameter as the inner diameter. The first upper flange 13 is fixed to the upper part of the container body 11, and the first lower flange 14 is fixed to the lower part of the container body 11 in a watertight state by welding, bolts, or the like.

The filter material storage container 10 may appropriately include a bypass pipe 50 that branches from the inflow pipe 12 and the outflow pipe 23 and communicates the inflow pipe 12 and the outflow pipe 23 so as to bypass the filter material storage container 10.

The container body 11 has rigidity that can withstand the water pressure of circulating water, and may be made of vinyl chloride, for example. The container body 11 may be made of transparent acrylic or translucent vinyl chloride so that the internal state such as the degree of dirtiness of the filter material 1 can be confirmed. The container body 11 is preferably cylindrical.

The filter material accommodating container 10 has an inflow pipe 12 in which circulating water flows in from the upstream side of the ring water channel in the upper part of the container body 11, and an outflow pipe in which the circulating water flows out to the downstream side of the ring water channel in the lower part of the container body 11. 23 and a vent pipe 33 for discharging the circulating water accumulated inside the filter material accommodating container 10 are provided below the container main body 11.

The inflow pipe 12 and the outflow pipe 23 are directly or indirectly connected to the water tank 200 outside the filtration device 100, and the circulating water in the water tank 200 is allowed to flow into the inside of the filtration device 100, and the circulation obtained after filtration is performed. It has a function of allowing water to flow downstream from the filtration device 100.

The inflow pipe 12 may have an inflow pipe control valve 12c capable of switching the opening and closing of the flow path of the inflow pipe 12 as appropriate. The inflow pipe 12 is preferably provided on or near the ceiling surface (lower surface of the first upper flange 13) of the filtration device 100. As shown in FIG. 2, the inflow pipe 12 may be provided on the side wall of the container body 11, and may be erected from the upper surface of the first upper flange 13, for example. The inflow pipe control valve 12c is, for example, an electric valve, and may be controlled so as to switch the flow path of the inflow pipe 12 between an open state and a closed state in response to a control signal from the cleaning control device C.

The outflow pipe 23 has an outflow pipe control valve 23c that can switch the opening and closing of the flow path of the outflow pipe 23. The outflow pipe 23 is provided below the trap plate 25 in the filtration device 100. As shown in FIG. 2, the outflow pipe 23 may be provided on the side wall of the base member main body 26. The outflow pipe control valve 23c is, for example, an electric valve, and is controlled so as to switch the flow path of the outflow pipe 23 between an open state and a closed state in response to a control signal from the cleaning control device C.

The filter material storage container 10 has an overflow pipe 13a communicating with the inside of the filter material storage container 10 at the upper part. The overflow pipe 13a may communicate with any of the ring water channels including the water tank 200. As a result, the circulating water overflowing from the filter medium accommodating container 10 can be returned to the ring water channel.

The overflow pipe 13a is a filter material, for example, when dust or the like is clogged in a gap formed between adjacent filter materials 1 and the flow path through which the circulating water passes through the filter material storage container 10 is narrowed. It is a pipe that communicates with the inside and outside of the filter medium storage container 10 so that the circulating water can be discharged when the water level of the circulating water in the storage container 10 becomes high. The overflow pipe 13a is normally in an open state. As a result, the overflow pipe 13a does not increase the internal pressure of the filter medium accommodating container 10 even if the filter medium 1 is clogged, the amount of water flowing through the overflow pipe 13a decreases, and the water level of the filter medium accommodating container 10 rises. Damage to the filter medium storage container 10 can be prevented.

The vent pipe 33 has a vent pipe control valve 33c that can switch the opening and closing of the flow path of the vent pipe 33. The vent pipe 33 is preferably provided near the bottom surface (upper surface of the second lower flange 22). The vent pipe control valve 33c is, for example, an electric valve, and is controlled so as to switch the flow path of the vent pipe 33 between an open state and a closed state in response to a control signal from the cleaning control device C.

The first lower flange 14 has a fastening hole 14b for connecting to the fastening hole 21b of the second upper flange 21 of the base member 20, which will be described later, by a fastening member (not shown) such as a bolt and a nut.

The bypass pipe 50 is a pipe that branches from the inflow pipe 12 and the outflow pipe 23 and communicates the inflow pipe 12 and the outflow pipe 23 so as to bypass the filter medium accommodating container 10. The bypass pipe 50 includes a bypass pipe control valve 50c. The bypass pipe control valve 50c is electrically connected to the cleaning control device C. The bypass pipe control valve 50c is controlled so as to switch the flow path of the bypass pipe 50 between an open state and a closed state in response to a control signal from the cleaning control device C.

In addition, the inflow pipe control valve 12c and the bypass pipe control valve 50c are integrated, and the A state in which the inflow pipe 12 is closed and the bypass pipe 50 is opened at the same time, and the A state in which the inflow pipe 12 is opened and the bypass pipe is opened at the same time. The first switching valve 50c1 may have a function of switching between the B state and the B state in which the 50 is closed. Similarly, the outflow pipe control valve 23c and the bypass pipe control valve 50c are integrated, and the C state in which the outflow pipe 23 is closed and the bypass pipe 50 is opened at the same time, and the C state in which the outflow pipe 23 is opened and bypassed at the same time. The second switching valve 50c2 may have a function of switching between the D state in which the pipe 50 is closed.

The bypass pipe control valve 50c is in a closed state during normal times other than during cleaning (during cleaning sequence control), and responds to a control signal instructing outflow pipe closing control (B1) from the cleaning control device C. It is controlled to be in the open state. As a result, even if the inflow pipe 12 or the outflow pipe 23 is closed, the bypass pipe 50 is opened, so that the filter material 1 housed in the filter material storage container 10 can be washed while the circulating water is flowing through the ring water channel.

The base member 20 has a base member main body 26, a second upper flange 21, and a second lower flange 22. The second upper flange 21 and the second lower flange 22 are fixed to the upper end portion and the lower end portion of the base member main body 26 by means such as welding, respectively.
The second upper flange 21 is attached to the first lower flange 14 of the filter medium accommodating container 10 via the trap plate 25.
The second lower flange 22 is fixed to a structure such as the ground or the floor of a factory by an anchor (not shown).

Further, the base member 20 includes an outflow pipe 23 for flowing out the circulating water obtained after filtration from the inside of the filter material storage container 10 and a vent pipe 33 for discharging the circulating water from the inside of the filter material storage container 10 to the outside of the ring water channel. Have.

The vent pipe 33 is provided on the side surface of the base member 20 that is closer to the bottom surface (upper surface of the second lower flange 22) than the outflow pipe 23. The water flow state of the vent pipe 33 is controlled by opening and closing the vent pipe control valve 33c provided in the vent pipe 33.

The trap plate 25 is arranged so as to be sandwiched between the first lower flange 14 and the second upper flange 21. Watertightness is ensured between the trap plate 25 and the first lower flange 14 and between the trap plate 25 and the second upper flange 21 by appropriate sealing means.
The trap plate 25 has a plurality of water passage holes 25h having a size that allows circulating water to pass through but cannot pass through the filter medium 1.
The trap plate 25 prevents the filter medium 1 from moving downward (downstream side). On the other hand, the circulating water can pass through the water passage hole 25h in the trap plate 25 and reach the outflow pipe 23 provided on the downstream side of the trap plate 25.
The filtration device 100 may include a perforated plate (not shown) arranged so as to partition the flow path of the overflow pipe 13a and the filtration material 1 housed inside the container main body 11. The perforated plate has a plurality of water passage holes having a size that allows circulating water to pass through but cannot pass through the filter medium 1. The perforated plate has the same structure as the trap plate 25, and is a disk having a plurality of water passage holes penetrating in the vertical direction (plate thickness direction of the plate) and having an outer shape slightly smaller than the inner shape of the container body 11. It is a shaped body or a reticulated body. If there is a perforated plate, even if the circulating water overflows from the filter medium storage container 10, it is possible to prevent the filter medium 1 from being clogged with the overflow pipe 13a or flowing out from the overflow pipe 13a. Further, if there is a perforated plate, when the circulating water flows into the filter material accommodating container 10, the circulating water is rectified by a plurality of water passage holes provided in the perforated plate, and the filter material accommodating container 10 is rectified. It is possible to keep the flow rates in the cross section. Therefore, it is possible to prevent the filter medium 1 from being unevenly arranged in the filter medium storage container 10 due to the impact that the circulating water falls directly from the inflow pipe 12 and concentrates on a part of the filter medium 1. it can.

(Air blow mechanism)
The base member 20 has an air blow mechanism 40 that ejects air into the filter medium accommodating container 10. As a result, the filter medium storage container 10 and the filter medium 1 in the filter medium storage container 10 can be effectively cleaned by the direct action of the ejected air and the action of the water flow generated by the ejection of the air.
As shown in FIGS. 2 and 3, the air blow mechanism 40 has an air supply unit 41 provided with an air ejection port 41a and a blower B communicating with the air supply unit 41 to send out air. .. The blower B may be, for example, an air pump provided with an electric air compressor.

Specifically, the air supply unit 41 has a plurality of pipes in parallel with which one end communicates with the pipe connected to the blower B and the other end is closed. A plurality of air outlets 41a are provided in each pipe. Each pipe penetrates the base member main body 26. Note that FIGS. 2 and 3 show a case where two air supply units 41 are provided. Since the air supply unit 41 has a plurality of pipes provided with the air outlet 41a, the filter medium 1 filters the air when the air is ejected from the air outlet 41a, as compared with the case where the air supply unit 41 has a single pipe. Accumulation can be suppressed at the corners inside the material storage container 10, particularly at the peripheral edge of the upper surface of the trap plate 25.

The air outlet 41a is provided at a position eccentric from the center of the filter medium accommodating container 10 in a plan view. The air outlet 41a may be provided upward. By providing the air outlet 41a at a position eccentric from the center, when air is ejected from the air outlet 41a, it is possible to create a vortex that extends to the corners inside the filter medium accommodating container 10, and the filter medium 1 can be used. The filter medium 1 can be largely moved inside the filter medium storage container 10 while suppressing the accumulation in the corner inside the filter medium storage container 10, particularly the peripheral edge of the upper surface of the trap plate 25, and the filter medium can be moved significantly. The aggregate of 1 can be washed without any gap. Further, as shown in FIG. 3, when two air supply units 41 are provided, one air supply unit 41 is provided with an air outlet 41a facing upward, and the other air supply unit 41 is provided with an air outlet 41a. It may be provided downward. As a result, when air is ejected from the respective air ejection ports 41a, it is possible to easily create a vortex by generating a moment in the water inside the filter medium accommodating container 10 due to the ejection outputs of the two airs having different directions. ..

(Filter material)
The filter medium 1 is an elastic body formed porously and has a granular (lumpy) shape. More specifically, it has a substantially cubic shape. Then, the plurality of filter media 1 are housed in the filter media storage container 10 of the filter device 100. Here, the filter medium 1 may be used in a state of being compressed and deformed. Here, the elastic body has mechanical properties such that it is remarkably deformed by applying a force corresponding to the fluid pressure due to the flow of circulating water having a linear velocity of about 60 m / h, and returns to the original shape when the force is removed. It means that the rigidity is relatively low as compared with sand and the like. Then, due to its structural characteristics, the filter material 1 performs physical filtration and biological filtration on the circulating water.

The filter medium 1 is formed of, for example, polyvinyl alcohol (hereinafter, may be referred to as “PVA”), and has an ability to adsorb bacteria and SS (Suspended Solids, dust in water) that grow in water. It has a high water filtration function and is excellent in water filtration function. The filter medium 1 contains polyvinyl alcohol as a main component, and may contain impurities as long as it does not interfere with physical filtration and biological filtration by nitrifying bacteria.

The filter medium 1 is formed to be porous. Since the filter medium 1 is porous, the ratio of the surface area per weight can be increased, and the bulk volume and the filtration processing capacity per weight of the filter medium 1 can be improved.

Cells are formed as voids (pores) inside and on the surface of the filter medium 1. The porosity of the filter medium 1 is preferably 90% or more and 95% or less.

Further, the average diameter of the cells in the filter medium 1 (hereinafter, may be referred to as "average cell diameter") is preferably 1200 μm or more and 1900 μm or less. When the average diameter of the cells in the filter medium 1 is in this range, the efficiency of physical filtration can be improved. The method for measuring the average diameter of the cells in the filter medium 1 is not particularly limited. For example, on the cut surface that appears by cutting the filter material 1 on an arbitrary surface, ^{an area of about 20 mm 2} is observed with an electron microscope or the like, and the maximum length of the opening in each cell existing in the observation field is measured. , The average value obtained by arithmetically averaging the measured maximum lengths can be used as the average diameter of the cells.

The filter material 1 preferably has a specific surface area (unit: m ² / m ³ ), which is the surface area per unit volume, of 3000 m ² / m ³ or more and 5000 m ² / m ³ or less. If the specific surface area of the filter medium 1 ^{is smaller than 3000 m 2} / m ³ , the surface area for physical filtration is small and the area where nitrifying bacteria settle is also small. Therefore, when circulating water is filtered, physical filtration and organisms are used. The total filtration processing capacity combined with filtration may not be effectively exhibited. Further, if the specific surface area of the filter material 1 ^{is larger than 5000 m 2} / m ³ , the pores of the filter material 1 may be easily clogged. The method for measuring the specific surface area of the filter material 1 is not particularly limited, and the specific surface area of the filter material 1 can be measured using a commercially available specific surface area measuring device.

The density of the filter medium 1 is preferably smaller than ^{1.0 g / cm 3.} When the density of the filter material 1 is 1.0 g / cm ³ or more, when the circulating water is passed through the filter material storage container 10 containing the filter material 1, the filter material 1 is filtered without floating in the water. It is deposited on the bottom of the material storage container 10. On the other hand, when the density of the filter material 1 ^{is smaller than 1.0 g / cm 3} , the filter material 1 easily floats in the water and easily moves along with the flow of the cleaning water due to the air ejection during cleaning, and the cleaning efficiency. Is improved. Further, the filter medium 1 having a density smaller than 1.0 g / cm ³ has a light weight per volume and is excellent in handling. The lower limit of the density of the filter medium 1 is not particularly limited, but the density of the filter medium 1 ^{is preferably 0.01 g / cm 3} or more. The method for measuring the density of the filter medium 1 is not particularly limited, and for example, the density can be obtained by measuring the mass and volume of the filter medium 1 and calculating the mass / volume.
Further, the filter medium 1 preferably has a density of 0.9 g / cm ³ or more and 1.1 g / cm ³ or less. As a result, since the density of the filter medium 1 is close to the density of water, it is compressed by the flow of circulating water, and when the circulating water passes through the gap formed between the adjacent filter media 1, the filter medium 1 and the filter medium 1 are used. The area of contact with the circulating water is increased to improve the filtration efficiency, and the washing efficiency can be improved because it becomes easier to move in water during washing.

Further, it is more preferable ^{that the density of the filter medium 1 is less than 1.0 g / cm 3 in} a state where the nitrifying bacteria are fixed on the surface. If the density of the filter medium 1 in the state where the nitrifying bacteria are fixed on the surface ^{is less than 1.0 g / cm 3} , the filter medium 1 easily floats in the water, and the flow of the cleaning water by air ejection during cleaning. As a result, it becomes easier to exercise and the cleaning efficiency is improved.

The shape and size of the filter medium 1 are not particularly limited. The filter medium 1 is usually a granular body having a size that can be used with one hand. Specific examples of the shape of the filtering material 1 include a spherical shape, a cylindrical shape, a prismatic shape, a truncated cone shape, and a truncated cone shape, a conical shape, a polygonal pyramid shape, and the like. The shape of the filter medium 1 is particularly preferably spherical or polygonal columnar, and most preferably cubic. When the shape of the filter material 1 is a cube shape, the gap between the plurality of filter materials 1 can be reduced, and the filter material 1 can be accommodated at a high density in the filter device 100. It is particularly preferable that the size of the filter medium 1 having a cubic shape is 0.5 cm or more and 3.5 cm or less on one side of the cube. The filter medium 1 has, for example, a cubic shape having a side of about 1 cm, about 1.5 cm, about 2 cm, or about 3 cm. Further, the size of the spherical filter material 1 is particularly preferably such that the diameter of the sphere is 0.5 cm or more and 3.5 cm or less. If the diameter of the sphere or one side of the cube is smaller than 0.5 cm, the gap between the filter media 1 becomes too small when the filter media 1 is filled, which causes clogging when circulating water is passed through. It may be easier. Further, if the diameter of the sphere or one side of the cube is larger than 3.5 cm, the gap between the filter media 1 becomes large when a plurality of filter media 1 are accommodated, and the gap between the filter media 1 is circulated in a short time. When water is allowed to pass through, the contact efficiency between the circulating water and the surface of the filter medium 1 may decrease. When the size of the filter medium 1 having a cubic shape is a cube shape with a side of about 1.5 cm or about 2.0 cm, it becomes easy to move with the flow of cleaning water due to air ejection during cleaning, and cleaning is performed. The efficiency is good.

By the way, in order to improve the filtration efficiency of the circulating water, the capacity of the filter material 1 in the filter material storage container 10 and the circulation water velocity in the inflow pipe 12 and the outflow pipe 23 pass through, for example, the filter material storage container 10. It is adjusted as appropriate based on the spatial velocity of the circulating water. Space velocity is also commonly abbreviated as "SV". The higher the space velocity SV, the higher the filtration performance of circulating water, which is preferable. The space velocity SV is a numerical value indicating the ratio of the volume of the circulating water to be filtered to the bulk volume of the filter material 1 housed in the filter material storage container 10 per unit time.

(Filtration method)
Next, a method for filtering circulating water will be described.
FIG. 2 is an explanatory diagram of the filtration device 100. FIG. 3 is a view taken along the arrow A of FIG.

(A1) First, as shown in FIG. 1, a filtration device 100 as shown in FIGS. 2 and 3 is installed in the ring water channel of the circulation breeding system S. At this time, as shown in FIG. 2, in the filtration device 100, the aggregate of the filter material 1 is housed in the filter material storage container 10 and arranged on the trap plate 25. After that, the filter medium 1 may be appropriately compressed.

(A2) Subsequently, circulating water is supplied to the ring canal.

(A3) Next, the pump P provided in the ring water channel of the circulation breeding system S is operated. That is, the cleaning control device C executes the normal control (B0) described later. Then, the circulating water circulates in the ring water channel by the power of the pump P.
(A4) Then, aquatic organisms such as seafood are released into the aquarium 200 and bred as appropriate. The aquarium 200 may already be bred with aquatic organisms such as seafood.
In this way, the filter material 1 is used to filter the circulating water circulating in the ring water channel.

(How to clean the filter media)
Next, a method of cleaning the filter medium 1 will be described.
FIG. 4 is a control flow diagram. FIG. 5 is an explanatory view of the filtration device 100 during the outflow pipe closing control (B1). FIG. 6 is an explanatory diagram of the filtration device 100 during the air blow control (B2). FIG. 7 is an explanatory view of the filtration device 100 after the vent pipe open control (B3). FIG. 8 is an explanatory view of the filtration device 100 during the water retention control (B5) after the vent pipe closing control (B4). FIG. 9 is an explanatory view of the filtration device 100 after the bypass pipe opening control (D1).
The cleaning method of the filter medium 1 is automatically executed as follows according to the control flow diagram shown in FIG. 4 by the cleaning control by the cleaning control device C.
When the bypass pipe opening control (D1) and the bypass pipe closing control (D2), which will be described later, are not executed, the filtration device 100 may not include the bypass pipe 50.

(B0) In the normal operating state in which the circulating water is circulated, the inflow pipe 12 is in the open state of the cleaning control device C, the drive of the pump P is controlled to be ON, and the vent pipe is used. Normal control (B0) is executed in which the control valve 33c is controlled to be in the closed state, the outflow pipe control valve 23c is controlled to be in the open state, and the drive of the blower B is controlled to be OFF. When the filtration device 100 includes the bypass pipe 50, the cleaning control device C controls the bypass pipe control valve 50c of the bypass pipe 50 in the closed state in the normal control (B0).

(B1) In performing cleaning control by the cleaning control device C, first, as shown in FIG. 5, the outflow pipe closing control (B1) for closing the outflow pipe 23 is executed. Specifically, the cleaning control device C sends a control signal to the outflow pipe control valve 23c to control the outflow pipe control valve 23c so as to be in the closed state. As a result, the circulating water can be prevented from flowing into the filter medium containing container 10 from the ring water channel, and the circulating water can be prevented from flowing out from the filter material containing container 10 into the circulating water channel. Therefore, the circulating water in the filter material containing container 10 can be prevented from flowing out. Can be partitioned from the waterway.
The timing of executing the outflow pipe closing control (B1) is such that the timer provided in the cleaning control device C is activated at the same time as the normal control (B0) is executed, and the elapsed time measured by the timer is set in advance (for example,). It may be 60 minutes, 24 hours, etc.). At this time, the preset time (for example, 60, 24 hours, etc.) is set experimentally (for example, the time until the filter medium 1 is clogged and cleaning is required by trial running the normal control (B0). , The time is artificially determined in advance by measuring (by measuring the time from the start of execution of the normal control (B0) until the circulating water overflows from the overflow pipe 13a of the filter medium accommodating container 10). Good.
At this time, the drive of the pump P may be stopped (pump stop control) by sending a control signal for stopping the drive to the pump P from the cleaning control device C. That is, the cleaning control device C may execute the control of closing the outflow pipe 23 and stopping the driving of the pump P (pump stop control).

(B2) After that, as shown in FIG. 6, the air blow control (B2) for driving the blower B that sends air to the circulating water collected inside the filter medium accommodating container 10 is executed. Specifically, the cleaning control device C sends a control signal to the blower B to control the blower B to be driven.
As a result, the air extruded from the blower B is ejected upward from the air outlet 41a (see FIGS. 2 and 3) of the air blow mechanism 40. Therefore, in the partitioned filter medium storage container 10, the filter medium storage container 10 is used. The circulating water accumulated inside and the filter medium 1 can be convected. In FIG. 6, the white arrow drawn inside the filter medium accommodating container 10 indicates the air ejection direction.
Then, as shown by the solid line arrow drawn inside the filter material storage container 10 in FIG. 6, a flow is generated in the circulating water of the filter material storage container 10 due to the ejection of air, and the filter material is accompanied by the flow of the circulating water. 1 exercises. Then, due to the friction between the flow of circulating water and the moving filter material 1, substances such as dust and SS that cause clogging adhering to the filter material 1 can be efficiently removed. Therefore, the filter medium 1 can be easily washed without removing the filter medium 1 from the filter medium storage container 10 without replacing the filter medium 1, and the filtration efficiency can be improved.
More specifically, in the air supply unit 41, for example, an on-off valve a for preventing the circulating water collected inside the filter medium accommodating container 10 from flowing back toward the blower B when the blower B is stopped, and a blower. An on-off valve b for releasing the air discharged from the blower B when the on-off valve a is closed when B is stopped is provided. The on-off valve a is provided between the filtration accommodating container 10 and the blower B in the air supply unit 41. The on-off valve b is provided in the air supply unit 41 in a pipeline branched from between the on-off valve a and the blower B. Both the on-off valve a and the on-off valve b may be solenoid valves. The on-off valve a is a normally closed type that is opened when energized, and the on-off valve b is a normally open type that is closed by electromagnetic waves. At the start of cleaning, the cleaning control device C first opens the on-off valve b, then drives the blower B, then opens the on-off valve a, and finally closes the on-off valve b. Further, when the cleaning is stopped, the cleaning control device C first opens the on-off valve b, then closes the on-off valve a and closes the blower B.

(B3) As shown in FIG. 7, the cleaning control device C executes the vent pipe opening control (B3) for opening the vent pipe 33 after a predetermined time has elapsed from the start of the execution of the air blow control (B2). Specifically, the cleaning control device C sends a control signal for driving the blower B to the blower B, and at the same time, activates a timer included in the cleaning control device C, and the elapsed time measured by the timer is a preset time (for example). 1 minute), a control signal is sent to the vent pipe control valve 33c to control the vent pipe control valve 33c to be in the open state. Then, while the filter material 1 remains in the filter material storage container 10, the circulating water in the filter material storage container 10 is discharged from the vent pipe 33, and the water level drops. As a result, the circulating water collected in the filter medium storage container 10, which is sewage containing dust and the like peeled off from the filter medium 1 by cleaning, can be discharged to the outside of the ring water channel. The blower B may or may not be stopped during drainage. When the blower B is stopped during drainage, specifically, the cleaning control device C sends a control signal to the blower B to stop the blower B immediately before or at the same time as controlling the vent pipe control valve 33c to be in the open state. send.

(B4) After that, as shown in FIG. 8, the cleaning control device C has elapsed a predetermined time from the start of execution of the vent pipe opening control (B3), or the water level in the filter medium storage container 10 is predetermined. After the water level falls below the water level, the vent pipe closing control (B4) for closing the vent pipe 33 is executed. Specifically, the cleaning control device C sends a control signal for opening the vent pipe control valve 33c to the vent pipe control valve 33c, and at the same time, activates a timer included in the cleaning control device C, and the progress measured by the timer. When the time reaches a preset time (for example, 20 seconds), a control signal is sent to the vent pipe control valve 33c to control the vent pipe control valve 33c to be in the closed state. Alternatively, when the cleaning control device C has a water level of circulating water in the filter medium accommodating container 10 detected by a measuring instrument such as a water level gauge or a water pressure gauge included in the cleaning control device C becomes a preset lower limit water level Lb or less. Then, a control signal is sent to the vent pipe control valve 33c to control the vent pipe control valve 33c so as to be in the closed state.

(B5) After that, as shown in FIG. 8, the cleaning control device C causes the circulating water to flow into the filter medium accommodating container 10 by the pump P, and the circulating water is accumulated in the filter medium accommodating container 10 up to the upper limit water level Lt. Control (B5) is executed. Specifically, the cleaning control device C executes the pump drive control for driving the pump P to allow the circulating water to flow into the filter medium accommodating container 10. Then, a control signal is sent to the pump P, the driving of the pump P is continued until a predetermined time elapses, and after the predetermined time elapses, a control signal for stopping the driving of the pump P is sent to the pump P. Alternatively, the cleaning control device C considers that the water level has reached the upper limit water level Lt when the input value reaches a predetermined value based on the input value detected by a sensor (not shown) such as a water level gauge or a water pressure gauge, and pumps. A control signal for stopping the driving of the pump P is sent to P.
Then, the circulating water flows into the filter medium accommodating container 10 through the inflow pipe 12 by the pump P. Since the outflow pipe 23 and the vent pipe 33 are in the closed state, the water level in the filter medium accommodating container 10 rises, and the circulating water collects. As a result, the circulating water can be stored in the filter medium storage container 10. In this way, the pump P that circulates the circulating water can also be used as a power source for water injection (reservoir control (B5)) when cleaning the filter medium 1.
If the pump stop control is not performed in the outflow pipe closing control (B1), the pump P has already started, so that the pump drive control is unnecessary.
When the bypass pipe opening control (D1) described later is performed, the cleaning control device C executes the inflow pipe opening control for controlling the inflow pipe 12 to the open state, and at the same time, closes the bypass pipe 50 as appropriate. The closing control (D2) is executed. As a result, the path of the circulating water can be switched from the path passing through the bypass pipe 50 to the path passing through the inflow pipe 12, and the circulating water can be made to flow into the filter medium accommodating container 10 by the pump P. In this way, the circulating water may be caused to flow into the filter medium accommodating container 10 by the pump P, and the reservoir control (B5) for accumulating the circulating water up to the upper limit water level Lt in the filter medium accommodating container 10 may be executed.

(B6) After that, as appropriate, a series of cleaning sequences of the above-mentioned outflow pipe closing control (B1), air blow control (B2), vent pipe opening control (B3), vent pipe closing control (B4) and water retention control (B5). Control (C1) is executed a specified number of times. Specifically, the cleaning control device C counts the number of times the cleaning sequence control (C1) is executed by the counter provided in the cleaning control device C, and performs the cleaning sequence control (C1) until the number of executions reaches the specified number of times. Execute. The specified number of times may be one time, may be two or more times, and is preferably three times from the viewpoint of cleaning efficiency per time and electric power.

(B7) Then, after executing the series of cleaning sequence control (C1) a predetermined number of times, the cleaning control device C executes the outflow pipe opening control (B7) as shown in FIG. Specifically, the cleaning control device C sends a control signal to the outflow pipe control valve 23c to control the outflow pipe control valve 23c so as to be in the open state. As a result, the section of the circulating water in the filter material containing container 10 can be released, and the circulating water in the filter material containing container 10 can communicate with the ring water channel. Therefore, it is possible to continue breeding of aquatic organisms by using the washed filter medium 1 without taking out the filter medium 1 housed in the filter medium storage container 10 in the water ring channel from the filter medium storage container 10. .. Therefore, it is possible to suppress energy and manual labor related to cleaning the filter medium 1. When the bypass pipe open control (D1) described later is performed, the cleaning control device C closes the bypass pipe 50 at the same time as the inflow pipe open control and the outflow pipe open control (B7) (D2). To execute.

(C1) Further, in the cleaning control device C, a predetermined time has passed since the previous cleaning sequence control (C1) was executed, the circulating water overflows from the filter medium accommodating container 10, or the transparency of the circulating water becomes high. The cleaning sequence control (C1) may be executed again with the value becoming equal to or less than the specified value as a trigger. As a result, even if the filter medium 1 is clogged with the lapse of the breeding time, the filter medium 1 can be automatically cleaned at a timing according to the need for cleaning the filter medium 1. Therefore, it is possible to suppress the burden of manual monitoring regarding the cleaning of the filter medium 1.
For a predetermined time after the previous cleaning sequence control (C1) is executed, specifically, at the same time as the previous cleaning sequence control (C1) is executed, the timer provided in the cleaning control device C is activated, and the timer is activated. The elapsed time measured by the timer may be a preset time (for example, 60 minutes, 24 hours, etc.). The transparency may be a measured value detected by a sensor (not shown) provided in the water channel.

(D1) By the way, in the above-mentioned cleaning method (cleaning sequence control (C1)), the cleaning control device C executes the outflow pipe closing control (B1) for closing the outflow pipe 23 while the pump P is still being driven. Immediately before or at the same time, the bypass pipe opening control (D1) for opening the bypass pipe 50 connecting the inflow pipe 12 and the outflow pipe 23 so as to branch from the inflow pipe 12 and the outflow pipe 23 and bypass the filter material storage container 10 is performed. You may do it.
Specifically, as shown in FIG. 9, the cleaning control device C sends a control signal to the inflow pipe control valve 12c and the outflow pipe control valve 23c, and closes the inflow pipe 12 and the outflow pipe 23, respectively. At the same time, the bypass pipe control valve 50c is controlled to be in the open state.
As a result, the filter medium 1 housed in the filter medium storage container 10 can be washed while the pump P is being driven, that is, the circulating water is circulated in the ring water channel. Therefore, while the cleaning method of the filter medium 1 is being carried out (cleaning sequence control (C1) is being executed), changes in the flow velocity, flow rate, or linear velocity of the circulating water passing through the water tank 200 can be suppressed. When the filtration devices 100 are installed in parallel in the circulation path, when the above-mentioned cleaning method (cleaning sequence control (C1)) is performed in any of the filtration devices 100, the filter material is accommodated in the other filtration device 100. By using the container 10 as a bypass path for circulating water, changes in the linear velocity and the flow rate in the other filter medium accommodating container 10 can be suppressed. Therefore, the effect of filtration can be maintained even when the above-mentioned cleaning method (cleaning sequence control (C1)) is performed. In this way, a plurality of filtration devices 100 can be installed in parallel in the same circulation path. When a plurality of filtration devices 100 are installed in parallel in the same circulation path, each filtration device 100 may have a cleaning control device C, and each filtration device 100 shares a single cleaning control device C. You may. Further, while the cleaning method of the filter medium 1 is being carried out, other functions on the circulation breeding system S such as the aquarium 200, the foam separation device 300, and the circulating water sterilizer 400 can be prevented from being stopped.

Although the preferred embodiment of the present invention has been described in detail above, the filtration device 100 according to the present invention is not limited to the above-described embodiment, but is within the scope of the gist of the present invention described in the claims. , Various deformations and changes are possible.
For example, the filter medium 1 has ^{a density of 0.9 g / cm 3} or more and 1.1 g / cm ³ or less, and contains a plurality of porous granular elastic bodies, and the pump P draws circulating water. It may be circulated at a speed of 60 m / h or more. Here, the linear velocity (LV) is the velocity of circulating water passing through the minimum cross-sectional area of the circulation path formed inside the filtration device 100 per unit time (for example, unit: m / h). , The flow rate (m ³ / h) of circulating water passing through the minimum cross-sectional area (for example, unit: m ² ) of the circulation path formed inside the filtration device 100 per unit time divided by the minimum cross-sectional area. Is.
Specifically, the linear velocity (m / h) of the circulating water flowing inside the filter medium storage container 10 under normal control (B0) is 60 or more, preferably 80 or more, and more preferably 100 or more. Pump P (current or voltage) may be controlled. When the linear velocity is 60 or more, the force toward the downstream direction due to the flow of circulating water acting on the filter material 1 is superior to the buoyancy toward the upstream direction, and the excess material 1 is the lower part of the container body 11 (the upper part of the trap plate 25). ), And in that state, the filter medium 1 is compressionally deformed. Then, when the circulating water passes through the gap formed between the adjacent filtering materials 1, the area where the filtering material 1 and the circulating water come into contact with each other increases, and the filtration efficiency can be improved. Moreover, since the density of the filter medium 1 is close to the density of water, it becomes easy to move in water during cleaning, so that the cleaning efficiency can be improved. Further, the pump P that circulates the circulating water can also be used as a power source for water injection (reservoir control) into the filter medium accommodating container 10 when cleaning the filter medium 1.
Further, for example, the time interval of the cleaning sequence control (C1) is set to an experimental value (after the filtration is started, the filter medium 1 is clogged and the linear velocity of the circulating water in the filter medium storage container 10 decreases, so that the overflow pipe 13a It may be set in advance based on the measured value of the time until the circulating water overflows, etc., but for example, the line of circulating water depends on the amount of circulating water overflowing from the filter medium storage container 10 (or the presence or absence of overflow). The pump P (current or voltage) may be controlled to reduce the speed. Then, the filtration device 100 executes the cleaning sequence control (C1) according to the linear velocity of the circulating water (rotational speed of the pump P, etc.), for example, when the rotational speed of the pump P becomes equal to or less than a predetermined value. You may. Thereby, the cleaning of the filter material 1 can be automatically performed according to the degree of contamination of the filter material 1.
Further, for example, the cleaning control device C is triggered by the operator issuing a cleaning start command to the cleaning control device C by pressing a cleaning start switch or the like provided on the filtration device 100, as described above. Cleaning sequence control (C1) may be executed.

The filtration device 100 according to the present embodiment is a filtration device 100 that filters circulating water circulated by a pump P via a water tank 200, and is a filtration material storage container 10 and a filter housed in the filter material storage container 10. It includes a material 1 and a cleaning control device C that controls the cleaning of the filter material 1. Here, the filter medium storage container 10 communicates with the water tank 200 to flow the circulating water from the water tank 200 into the filter material storage container 10, and communicates with the water tank 200 to circulate the water from the filter material storage container 10. It has an outflow pipe 23 that flows out to the water tank 200, and a vent pipe 33 that discharges the circulating water from the filter medium accommodating container 10. Then, the cleaning control device C executes the outflow pipe closing control (B1) that closes the outflow pipe 23, and then drives the blower B that sends air to the circulating water accumulated inside the filter medium accommodating container 10 (B2). ) Is executed. Therefore, the filter medium 1 housed in the filter medium storage container 10 can be automatically cleaned. Therefore, it is possible to provide the filtration device 100 which can save energy and labor and can clean the filter medium 1 at low cost.

1 Filter material 10 Filter material storage container 100 Filter device 11 Container body 12 Inflow pipe 12c Inflow pipe control valve 13 First upper flange 13a Overflow pipe 14 First lower flange 14a Opening hole 14b Fastening hole 20 Base member 200 Water tank 21 Second upper Flange 21b Fastening hole 22 Second lower flange 23 Outflow pipe 23c Outflow pipe control valve 25 Trap plate 25h Water flow hole 26 Base member body 300 Foam separation device 33 Vent pipe 33c Vent pipe control valve 40 Air blow mechanism 400 Circulating water sterilizer 41 Air Supply unit 41a Air outlet 50 Bypass pipe 50c Bypass pipe control valve B Blower C Cleaning control device Lb Lower limit water level Lt Upper limit water level P Pump S Circulation breeding system

Claims (5)

A filtration device that filters circulating water circulated by a pump via a water tank.
A filter material storage container, a filter material housed in the filter material storage container, and a cleaning control device for controlling cleaning of the filter material are provided.
The filter medium has ^{a density of 0.9 g / cm 3} or more and 1.1 g / cm ³ or less, and contains a plurality of porous granular elastic bodies.
The filter material storage container has an inflow pipe that communicates with the water tank and flows the circulating water from the water tank into the filter material storage container, and the circulating water from the filter material storage container that communicates with the water tank. It has an outflow pipe that flows out to the water tank and a vent pipe that discharges the circulating water from the filter medium storage container.
After executing the outflow pipe closing control that closes the outflow pipe, the cleaning control device
An air blow control for driving a blower that sends air to the circulating water accumulated inside the filter medium storage container is executed .
Before executing the air blow control, the pump stop control for stopping the driving of the pump is executed, and the pump stop control is executed.
After a predetermined time has elapsed from the start of execution of the air blow control, the vent pipe open control for opening the vent pipe is executed.
After a predetermined time has elapsed from the start of execution of the vent pipe opening control, or after the water level in the filter medium accommodating container becomes equal to or lower than the predetermined water level, the vent pipe closing control for closing the vent pipe is executed.
After executing the vent pipe closing control, the circulating water is made to flow into the filter material accommodating container by the pump, and the water storage control for accumulating the circulating water in the filter material accommodating container is executed.
A filtration device characterized in that after executing the pool water control, an outflow pipe open control for controlling the outflow pipe control valve of the outflow pipe to be in an open state is executed. The filtration device according to claim 1 , wherein the pump is controlled so that the linear velocity of the circulating water is 60 m / h or more. The filter material storage container includes a bypass pipe that branches from the inflow pipe and the outflow pipe and communicates the inflow pipe and the outflow pipe so as to bypass the filter material storage container.
The filtration according to claim 1 or 2 , wherein the outflow pipe closing control includes executing a bypass pipe opening control for opening the bypass pipe at the same time as closing the inflow pipe and the outflow pipe. apparatus. The cleaning control device claims, characterized in that the outflow pipe closing control, the air blow control, the vent pipe opening control, defining the number of executing the series of cleaning sequence control of the vent pipe closing control and the accumulated water control The filtration device according to any one of claims 1 to 3. In the cleaning control device, a predetermined time has elapsed since the previous cleaning sequence control was executed, the circulating water overflows from the filter medium accommodating container, or the transparency of the circulating water becomes a specified value or less. The filtration device according to claim 4 , wherein the cleaning sequence control is executed again with the above-mentioned trigger.

Images