JP7270051B2 - sewage filtration equipment - Google Patents

Description

One embodiment of the present invention relates to a sewage filtration system.

2. Description of the Related Art Biological filtration devices using aerobic microorganisms and anaerobic microorganisms are conventionally known as filtration devices used for purifying human waste, domestic wastewater, and the like. Such a biological filter usually has a filter layer formed by filling a treatment tank with small filter media that float on water, and the sewage is purified by passing the sewage through the filter layer. For example, in the biological filtration device described in Patent Document 1, sludge containing aerobic or anaerobic microorganisms is adhered to the filtration layer. Therefore, the above-mentioned biological filtration device can simultaneously perform decomposition processing of organic contaminants and separation processing of suspended solids by supplying sewage into the filtration layer.

In the filter device having the above-described structure, as the purification process continues, part of the contaminants and suspended solids gradually adhere to the inside of the filter layer, resulting in a decrease in the processing capacity of the filter layer. Therefore, periodic cleaning of the filter media is necessary to maintain the throughput of the filter layer. Therefore, the biological filtration apparatus described in Patent Document 1 has a structure in which air is accumulated in the lower part of the treatment tank and the air is removed instantaneously to generate a rapid downward water flow in the treatment tank. . The downward water flow generated in the treatment tank causes the filtration layer in the treatment tank to descend rapidly. The descending filter layer separates into individual filter media from above and rises while repeating vigorous movements. As a result, some of the contaminants and suspended substances adhering to the individual filter media separate from the filter media and settle toward the bottom of the treatment tank.

JP-A-8-132082

In the filtration device described in Patent Document 1, a raw water supply pipe that supplies sewage into the treatment tank and a washing drain pipe that removes precipitated pollutants (sludge) from the treatment tank are separately provided. , the structure becomes complicated and the size of the apparatus is increased. In addition, since the above filtering device has only one cleaning drainage pipe, there is room for improvement in the sludge discharge performance.

An object of one embodiment of the present invention is to provide a sewage filtering apparatus that has a simple structure and improves the performance of discharging sludge in a treatment tank.

A sewage filtration device in one embodiment of the present invention comprises a treatment tank, a sewage treatment unit provided inside the treatment tank, and a sewage treatment unit provided in the sewage treatment unit, and has a specific gravity of 0.1 or more and 0.3 or less with respect to water. A filter layer composed of a floating filter medium (e.g., foaming filter medium), an air holding unit provided below the sewage treatment unit, an air supply pipe communicating with the air holding unit, and the sewage treatment unit a first air lift pump that extends from above through the filter layer to reach the air holding section; and a water sealing section that is provided inside the air holding section and communicates with the first air lift pump. . The first air lift pump serves as a raw water supply pipe, an air discharge pipe and a sludge discharge pipe.

The sewage filtering device further includes a second air lift pump extending from above the sewage treatment section through the filtration layer to reach the air holding section. The second airlift pump may be a sludge discharge pipe.

The sewage filtering device may further include a metering device (specifically, a gas-liquid separation metering device) connected to the first airlift pump and the second airlift pump.

The sewage filtration device includes a partition member having an outer edge connected to the inner wall of the treatment tank and partitioning the sewage treatment section and the air holding section, and the partition member through an opening provided in the partition member. and a cylindrical member extending toward the bottom of the processing bath. At this time, the sewage treatment section and the air holding section may communicate with each other through a plurality of slits provided in the lower portion of the tubular member.

The plurality of slits may be positioned below a break point of the water sealing portion. Further, an end portion of the first air lift pump within the processing tank may be positioned below a break point of the water sealing portion.

The air retaining section may be a space having an outer edge defined by an inner wall of the processing tank.

The bottom of the processing tank may have an inclined surface that rises inwardly from the outer edge.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the sewage treatment apparatus of 1st Embodiment. It is a figure which shows the structure of the biological filtration chamber in the sewage treatment apparatus of 1st Embodiment. It is a figure which shows the structure of the weighing device in the biological filtration chamber of 1st Embodiment. FIG. 4 is a diagram for explaining a filter medium cleaning process in the biological filtration chamber of the first embodiment; FIG. 4 is a diagram for explaining a filter medium cleaning process in the biological filtration chamber of the first embodiment; FIG. 4 is a diagram for explaining a filter medium cleaning process in the biological filtration chamber of the first embodiment; FIG. 4 is a diagram for explaining a filter medium cleaning process in the biological filtration chamber of the first embodiment; FIG. 4 is a diagram for explaining a filter medium cleaning process in the biological filtration chamber of the first embodiment; FIG. 4 is a diagram for explaining the behavior of filter media in the filter media cleaning process of the first embodiment; FIG. 4 is a diagram for explaining the behavior of filter media in the filter media cleaning process of the first embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in various aspects without departing from the gist thereof, and should not be construed as being limited to the description of the embodiments illustrated below. In the drawings, in order to make the description clearer, the width, thickness, shape, etc. of each part may be schematically represented compared to the actual embodiment, but this is only an example and limits the interpretation of the present invention. not something to do. In this specification and each drawing, elements having the same functions as those described with respect to the previous drawings are denoted by the same reference numerals, and redundant description may be omitted.

(First embodiment)
[Configuration of sewage treatment equipment]
FIG. 1 is a diagram schematically showing the configuration of a sewage treatment apparatus 100 of the first embodiment. As shown in FIG. 1 , the sewage treatment apparatus 100 of this embodiment includes a first anaerobic filter bed chamber 110 , a second anaerobic filter bed chamber 120 , a biological filtration chamber 130 and a treated water chamber 140 . However, the example shown in FIG. 1 is only an example, and is not limited to this example. For example, although illustration is omitted in FIG. 1 for convenience of explanation, each processing chamber is provided with a pump or the like for adjusting the amount of water or the flow rate.

The first anaerobic filter bed chamber 110 is an anaerobic treatment chamber through which sewage supplied from the raw water supply port 105 first flows. The first anaerobic filter bed chamber 110 comprises a first anaerobic filter bed 111 . The sewage that has flowed in from the raw water supply port 105 passes through the first anaerobic filter bed 111 in a downward flow. In the first anaerobic filter bed 111, solids in the sewage are removed, and organic substances contained in the sewage are decomposed by anaerobic microorganisms. The insoluble solids and the like removed here are accumulated in the first anaerobic filter bed chamber 110 as sludge or scum.

The first anaerobic filter bed chamber 110 communicates with the second anaerobic filter bed chamber 120 through an opening 115 a provided in the partition plate 115 . The sewage that has passed through the first anaerobic filter bed chamber 110 flows into the second anaerobic filter bed chamber 120 through the opening 115a.

The second anaerobic filter bed chamber 120 is an anaerobic treatment chamber that performs a secondary filtration process to further purify the sewage that has undergone the primary filtration treatment by the first anaerobic filter bed chamber 110 . The second anaerobic filter bed chamber 120 comprises a second anaerobic filter bed 121 . Sewage that has flowed from the first anaerobic filter bed chamber 110 through the opening 115a passes through the second anaerobic filter bed 121 in an upward flow. In the second anaerobic filter bed 121, solid matter in the sewage is removed, and organic substances contained in the sewage are decomposed by anaerobic microorganisms. Insoluble solids and the like removed here are accumulated in the second anaerobic filter bed chamber 120 as sludge or scum.

The sewage that has passed through the second anaerobic filter bed chamber 120 is supplied to the raw water inlet 125 via a flow control pump (not shown) and flows into the biological filtration chamber 130 . The biological filtration chamber 130 is a processing chamber for performing a tertiary filtration process to further purify sewage that has been subjected to a secondary filtration process by the second anaerobic filter bed chamber 120 . The biological filtration chamber 130 includes a filtration layer 131 composed of an aggregate of filter media (specifically, floating filter media). The biological filtration chamber 130 also includes a first airlift pump 132 and a second airlift pump 133 . A water seal portion 134 communicates with the first air lift pump 132 .

The sewage that has flowed into the biological filtration chamber 130 from the second anaerobic filter bed chamber 120 through the raw water inlet 125 is sent downward through the piping of the first airlift pump 132 and then flows upward. It passes through the filter layer 131 . In the filtration layer 131, solids in the sewage are removed, and organic substances contained in the sewage are decomposed by microorganisms. The insoluble solid matter removed here and the surplus sludge separated from the filter layer 131 are discharged by the first air lift pump 132 and the second air lift pump 133 . A specific configuration and operation of the biological filtration chamber 130 will be described later.

The treated water that has passed through the filtration layer 131 flows into the treated water chamber 140 from a treated water outlet 135 provided above the biological filtration chamber 130 . The treated water that has flowed into the treated water chamber 140 is discharged from the discharge port 145 after being disinfected in a disinfection chamber (not shown). Although not shown in FIG. 1, the treated water in the treated water chamber 140 is adjusted to the water level of the first anaerobic filter bed chamber 110 and/or the second anaerobic filter bed chamber 120 using an air lift pump and a flow rate regulator. Can be used for adjustment.

[Configuration of biological filtration device]
FIG. 2 is a diagram showing the configuration of the biological filtration chamber 130 in the sewage treatment apparatus 100 of the first embodiment. The biological filtration chamber 130 shown in FIG. 2 is an example of a sewage filtration device in the sewage treatment device 100 of this embodiment.

As described above, the biological filtration chamber 130 of this embodiment includes the raw water inlet 125, the filter layer 131, the first air lift pump 132, the second air lift pump 133, the water seal portion 134, and the treated water outlet 135 described above. Furthermore, the biological filtration chamber 130 of this embodiment includes a treatment tank 30 , an air supply pipe 31 , a partition member 32 , a cylindrical member 33 , a filter medium stopper 34 and a weighing device 35 .

The processing tank 30 is a cylindrical housing made of steel plate or synthetic resin. The treatment tank 30 corresponds to the outer frame of the biological filtration chamber 130 of this embodiment. A partition member 32 and a cylindrical member 33 connected to the partition member 32 through an opening 32 a provided in the partition member 32 are arranged inside the processing tank 30 .

The partition member 32 has an outer edge connected to the inner wall of the processing bath 30 . That is, the partition member 32 has a role of separating the inside of the processing bath 30 into an upper portion and a lower portion. The tubular member 33 is a cylindrical member extending from the partition member 32 toward the bottom portion 30 a of the processing bath 30 . Specifically, the tubular member 33 has one end connected to the opening 32 a of the partition member 32 and the other end connected to the bottom portion 30 a of the processing tank 30 . A plurality of slits 33 a are provided along the outer periphery of the tubular member 33 at the lower portion of the tubular member 33 .

The interior of the treatment tank 30 is divided into a sewage treatment section 40 and an air holding section 50 by the partition member 32 and the cylindrical member 33 described above. The sewage treatment unit 40 is provided with a filtration layer 131 inside, and is a region where filtration processing is performed. The air retaining part 50 is a region that retains air supplied from the air supply pipe 31 in the filter material cleaning process, which will be described later.

A filtering medium stopper 34 is provided in the sewage treatment section 40 . The filter medium stopper 34 is a disk-shaped member, and has a plurality of slits (not shown) provided on the entire surface thereof. Therefore, the filter medium stopper 34 allows the treated water that has flowed from below to pass through the filter layer 131 . On the other hand, the filter media stop 34 serves to stop floating of the plurality of floating filter media constituting the filter layer 131 . That is, the plurality of floating filter media constitutes the filter layer 131 with a predetermined thickness (for example, 500 mm or more and 1500 mm or less) by being prevented from floating by the filter media stopper 34 .

Thus, the filter layer 131 of the present embodiment is composed of a plurality of floating filter media (for example, a plurality of foaming filter media). The plurality of floating filter media are porous media each having a specific gravity of 0.1 or more and 0.3 or less with respect to water. In this embodiment, the filter layer 131 is configured using a floating filter medium having a particle size of 1 mm or more and 30 mm or less (preferably 1 mm or more and 15 mm or less). Specifically, porous materials such as foamed polystyrene, urethane resin, pumice, and shirasu balloons can be used as the floating filter medium. It should be noted that the floating filter medium is preferably spherical in consideration of fluidity in sewage and sludge releasability.

In the biological filtration chamber 130 of the present embodiment, the treated water that has passed through the filter layer 131 and the filter medium stop 34 and reaches the upper portion of the treatment tank 30 overflows the treated water outlet 135 and flows into the adjacent treated water chamber 140. .

The air holding section 50 is provided below the sewage treatment section 40 and is a space formed by the inner wall of the treatment tank 30 , the bottom portion 30 a of the treatment tank 30 , and the partition member 32 . That is, the air holding part 50 is a space whose outer edge is the inner wall of the processing tank 30 . The air holding section 50 communicates with the sewage treatment section 40 through the plurality of slits 33 a of the cylindrical member 33 . Specifically, the air holding section 50 communicates with the inner region of the cylindrical member 33 (the region forming part of the sewage treatment section 40) through a plurality of slits 33a. Further, the air supply pipe 31 communicates with the air holding portion 50 below the partition member 32 . Therefore, the air holding part 50 can hold air inside the processing tank 30 in a range from the partition member 32 to the upper ends of the plurality of slits 33a.

The first air lift pump 132 and the second air lift pump 133 extend from above the sewage treatment section 40 through the filtration layer 131 to reach the air retention section 50 . Strictly speaking, the first air lift pump 132 and the second air lift pump 133 pass through the filter medium stop 34 , the filter layer 131 and the partition member 32 from above the sewage treatment section 40 to reach the air retaining section 50 . The lower ends of the first air lift pump 132 and the second air lift pump 133 are positioned near the bottom 30 a of the processing tank 30 . As a result, the sludge deposited on the bottom portion 30a of the treatment tank 30 can be discharged using the first air lift pump 132 and the second air lift pump 133 in the filter medium cleaning process, which will be described later.

The bottom 30a of the processing bath 30 has an inclined surface that rises inwardly from the outer edge. Therefore, the sludge that has separated from the filter layer 131 and descended during the filter medium washing process tends to collect near the outer edge of the bottom 30a of the treatment tank 30 along the inclined surface. This makes it possible to improve the discharge efficiency when the sludge deposited on the bottom 30 a of the treatment tank 30 is discharged using the first air lift pump 132 and the second air lift pump 133 .

A water sealing portion 134 is provided inside the air retaining portion 50 . Specifically, the water seal portion 134 communicates with a portion of the first air lift pump 132 located in the air retaining portion 50 . Although the specific structure of the water sealing portion 134 will be described later, the water sealing portion 134 is a structure having a curved flow path. Normally, the inside of the water sealing portion 134 is filled with sewage. However, when the amount of air held in the air holding portion 50 exceeds a certain amount (exceeds a break point 53, which will be described later), the water seal of the water sealing portion 134 is broken, and the air held in the air holding portion 50 is instantaneously released. 1 air lift pump 132 to the outside. In this embodiment, this phenomenon is utilized in the cleaning process of the filter medium.

Both the first air lift pump 132 and the second air lift pump 133 described above communicate with the metering device 35 . In this embodiment, a gas-liquid separation weighing device is used as the weighing device 35 . In this embodiment, the metering device 35 is provided with a raw water inlet 125 leading from the second anaerobic filter bed chamber 120 . That is, the sewage sent from the second anaerobic filter bed chamber 120 first flows into the weighing device 35 . After that, sewage that has flowed in from the raw water inlet 125 is sent through the first air lift pump 132 to the vicinity of the bottom 30 a of the treatment tank 30 .

FIG. 3 is a diagram showing the configuration of the weighing device 35 in the biological filtration chamber 130 of the first embodiment. Specifically, FIG. 3A is a cross-sectional view of the weighing device 35 as seen from above. FIG. 3(B) is a cross-sectional view of the weighing device 35 taken along line A-A' shown in FIG. 3(A). FIG. 3(C) is a cross-sectional view of the weighing device 35 taken along line B-B' shown in FIG. 3(A). The weighing device 35 includes a housing 21 , a first pumping chamber 22 , a second pumping chamber 23 , a sludge discharge port 24 and a lid member 25 . The housing 21 is made of synthetic resin or the like, and has a top surface covered with a lid member 25 .

The first pumping chamber 22 is a chamber that communicates with the first air lift pump 132 . A bottom portion of the first pumping chamber 22 communicates with the first air lift pump 132 . That is, air or sludge sent from the treatment tank 30 through the first air lift pump 132 flows into the first pumping chamber 22 . Further, the first pumping chamber 22 is provided with a raw water inlet 125 connected to the second anaerobic filter bed chamber 120 . Sewage that has flowed in from the raw water inlet 125 flows into the first air lift pump 132 and is sent to the vicinity of the bottom 30 a of the treatment tank 30 .

The second pumping chamber 23 is a chamber that communicates with the second air lift pump 133 . A side portion of the second pumping chamber 23 communicates with the second air lift pump 133 . That is, the sludge sent from the treatment tank 30 through the second air lift pump 133 flows into the second pumping chamber 23 . The sludge that has flowed into the first pumping chamber 22 flows over the rectifying plate 26 a and flows into the second pumping chamber 23 . That is, the sludge sent from the first air lift pump 132 and the sludge sent from the second air lift pump 133 join in the second pumping chamber 23 . Furthermore, the second pumping chamber 23 is provided with a plurality of rectifying plates 26b to 26d to rectify the sludge that has flowed therein. The sludge that has passed through the straightening plates 26b to 26d is discharged from the sludge discharge port 24 of the second pumping chamber 23. As shown in FIG.

The current plate 26d described above has a metering notch 27 having a predetermined angle (.theta.), as shown in FIG. 3(C). A scale 27a is provided near the metering notch 27. As shown in FIG. In this embodiment, the sludge can be weighed by reading the amount of sludge passing through the weighing notch 27 from the scale 27a. The predetermined angle is set to 60 degrees, 90 degrees, or the like, for example.

As described above, in the metering device 35 of the present embodiment, since the first airlift pump 132 serves both as the raw water supply pipe and the sludge discharge pipe, one room (first pumping chamber 22) is provided with the raw water inlet 125 and the first airlift. It has a structure in which both outlets of the pump 132 are in communication. In addition, since the weighing device 35 of the present embodiment uses both the first air lift pump 132 and the second air lift pump 133 to discharge the sludge after washing the filter media, the first air lift pump 132 communicates with the first pumping chamber 22. , and the second air lift pump 133 communicates with the second pumping chamber 23 . The biological filtration chamber 130 of this embodiment can measure the sludge and control the flow rate with a simple structure by using the weighing device 35 having the structure described above.

As described above, in the biological filtration chamber 130 of the present embodiment, the first air lift pump 132 serves as a raw water supply pipe (sewage supply pipe), an air discharge pipe in the filter medium cleaning process, and a sludge discharge pipe after filter medium cleaning. plays a role. On the other hand, the second air lift pump 133 has a role as a sludge discharge pipe after washing the filter media. That is, in this embodiment, the first air lift pump 132 is used for a plurality of purposes, and both the first air lift pump 132 and the second air lift pump 133 are used to discharge the sludge that has settled on the bottom 30a of the treatment tank 30. can be done. Therefore, according to the present embodiment, it is possible to provide a sewage filtering apparatus having a simple structure and improved sludge discharge performance in the treatment tank.

[Configuration of filter media washing process]
Next, the filter media cleaning process will be described. The filtering medium cleaning process is a process of cleaning the filter layer 131 that is periodically performed. Specifically, by rapidly moving water from the sewage treatment unit 40 to the air holding unit 50 inside the treatment tank 30, the individual filter media (the above-described floating filter media) constituting the filtration layer 131 are washed. It refers to a series of processes to

4 to 8 are diagrams for explaining the filter medium cleaning process in the biological filtration chamber 130 of the first embodiment. Specifically, FIG. 4 shows the normal state of the filter media cleaning process. FIG. 5 shows the first step (air supply step) of the filter media cleaning process. FIG. 6 shows the second step (air evacuation and washing steps) of the filter media washing process. FIG. 7 shows the third step (settle and sedimentation steps) of the filter media cleaning process. FIG. 8 shows the fourth step (sludge discharge step) of the filter media cleaning process.

As shown in FIG. 4, in a normal state, that is, in a state in which sewage filtration is being performed, the inside of the treatment tank 30 is filled with sewage. However, the area above the filter layer 131 is filled with treated water purified by the filtration process, and when the treated water exceeds a certain amount, it is continuously discharged from the discharge port 145 . In FIG. 4, the diagonal lines in the area below the filter layer 131 indicate that the area is filled with sewage. In the normal state shown in FIG. 4 , an upward flow is always generated, and sewage continues to be supplied via the first air lift pump 132 .

In the first step shown in FIG. 5, the inflow of sewage from the raw water inlet 125 is stopped, and air is supplied from the air supply pipe 31 into the treatment tank 30 . Therefore, an air reservoir 50 a is formed in the air holding portion 50 . At this time, as the air reservoir 50a is formed, the sewage inside the air holding section 50 passes through the plurality of slits 33a provided in the cylindrical member 33 and flows into the sewage treatment section 40. As shown in FIG. As a result, the water surface 51 of the sewage drops in the air holding section 50 and the amount of treated water in the sewage treatment section 40 increases. However, since the treated water is discharged from the discharge port 145 by the increased amount, the position of the water surface 52 of the treated water does not change. Also, although the amount of sewage passing through the filter layer 131 increases, the position of the filter layer 131 does not change because the filter medium stop 34 is provided.

Here, as shown in FIG. 5, as the volume of the air reservoir 50a increases, the water surface 51 of the sewage in the air holding portion 50 descends, and the water surface 51 of the sewage inside the water sealing portion 134 also descends. In the example shown in FIG. 5, the water sealing portion 134 includes a plurality of partition plates 134a and 134b, which are combined to form a curved flow path. At this time, when the water surface 51 exceeds (falls below) the edge (break point 53) of the partition plate 134b of the water sealing portion 134, the air in the air reservoir formed in the air retaining portion 50 instantly is released to the outside through In this manner, when the water surface 51 of the sewage in the air retaining portion 50 exceeds the break point 53 of the water sealing portion 134, the filtering medium cleaning process shifts to the second step shown in FIG. By making the partition plate 134b detachable and preparing a plurality of partition plates 134b having different lengths, it is possible to change the break point 53 to an arbitrary position.

The biological filtration chamber 130 needs to hold air in the air holding section 50 until the water seal of the water seal section 134 is broken. Therefore, the plurality of slits 33 a of the tubular member 33 are positioned below the break point 53 of the water sealing portion 134 . For the same reason, the ends of the first air lift pump 132 and the second air lift pump 133 in the processing tank 30 are located below the break point 53 of the water sealing portion 134 .

In the second step shown in FIG. 6, the air in the air holding section 50 is instantaneously released to the outside, and the sewage stored in the sewage treatment section 40 is discharged through the plurality of slits 33a of the cylindrical member 33 into the air holding section. Flow into 50. As the sewage flows into the air holding section 50, the water level 51 of the sewage in the air holding section 50 rises, and the water level 52 of the treated water in the sewage treatment section 40 falls. At this time, the treated water stored above the filter layer 131 is instantaneously drawn downward (in the direction in which the cylindrical member 33 is positioned) of the sewage treatment section 40 . At that time, a plurality of filter media constituting the filter layer 131 are also pulled downward of the sewage treatment section 40 together. After that, due to the buoyancy of the filter media, the individual filter media move upward in the sewage treatment section 40 while repeating motion.

In the third step shown in FIG. 7, the inside of the treatment tank 30 is maintained in a state in which the supply and discharge of sewage is stopped until the filter layer 131 moves again above the sewage treatment section 40 (immediately below the filter medium stop 34). be done. Filtration layer 131 actually floats as individual filter media constituting filtration layer 131 float while repeating vigorous movements. As the individual filter media vigorously move in this way, the sludge adhering to the surface of the filter media is peeled off and settled down to the bottom 30 a of the treatment tank 30 as surplus sludge 71 .

In the fourth step shown in FIG. 8, the surplus sludge 71 deposited on the bottom 30a of the treatment device 30 is discharged to the outside of the biological filtration chamber 130 using the first air lift pump 132 and the second air lift pump 133 . In this embodiment, since the first air lift pump 132 and the second air lift pump 133 are provided at positions facing each other with the tubular member 33 interposed therebetween, the excess sludge 71 can be efficiently discharged.

In this embodiment, the first to fourth steps described with reference to FIGS. 5 to 8 form one cycle, and this cycle is repeated 3 to 4 times to obtain individual filter media constituting the filter layer 131. A cleaning process is performed.

9 and 10 are diagrams for explaining the behavior of the filter media in the filter media cleaning process of the first embodiment. Specifically, FIG. 9A shows the behavior of the filter medium in the first step. FIG. 9(B) shows the behavior of the filter medium in the second step. 10(A) and 10(B) show the behavior of the filter medium in the third step.

As shown in FIG. 9A, when sewage flows into the sewage treatment unit 40 from the air holding unit 50 in the first step, the amount of sewage stored in the air holding unit 50 decreases and is stored in the sewage treatment unit 40. Sewage volume increases. At this time, since the individual filter media 131a constituting the filter layer 131 are blocked by the filter media stopper 34 and do not move upward, the position of the filter layer 131 does not change.

After that, as shown in FIG. 9(B), when the sewage instantaneously flows from the sewage treatment unit 40 into the air holding unit 50 in the second step, the amount of sewage stored in the sewage treatment unit 40 rapidly decreases, and the air The amount of sewage stored in the holding portion 50 increases sharply. At this time, as shown in FIG. 9(B), the individual filter media 131a constituting the filter layer 131 move downward in the sewage treatment section 40 all at once.

If the interior of the processing tank 30 is maintained as it is in the state of FIG. 9B, the plurality of filter media 131a are individually separated and floated as shown in FIG. 10A. At that time, the filter media 131a repeat, for example, a violent spiral movement and float while colliding with each other. Therefore, the sludge adhering to each filter medium 131a is peeled off and aggregated to precipitate. In the present embodiment, this separated aggregate of sludge is referred to as surplus sludge 71 .

Separation of the filter layer 131 into individual filter media 131a progresses from above the filter layer 131 as shown in FIG. proceed. The separated individual filter media 131 a reassemble directly below the filter media stop 34 to form the filter layer 131 when floating is interrupted by the filter media stop 34 . By such behavior, the filter medium 131a constituting the filter layer 131 is entirely washed.

As described above, in the biological filtration chamber 130 of the present embodiment, the cleaning process of the filter layer 131 is performed by stirring the filter media 131a as water moves inside the treatment tank 30 . At this time, since the plurality of filter media 131a are washed by the treated water drawn downward in the second step, there is no need to separately prepare water for cleaning the filter media 131a, and the sewage treatment apparatus 100 can be downsized. can be done.

[Control of biological filtration device]
A control unit (not shown) for controlling the cleaning time and cleaning timing is connected to the biological filtration chamber 130 of the present embodiment. The controller determines the cleaning time and cleaning timing by monitoring the water level fluctuations in the biological filtration chamber 130 . The controller uses AI (Artificial Intelligence) to determine the cleaning time and the cleaning timing. Specifically, the control unit performs calculation based on a machine learning model using the speed of water level fluctuation, cleaning time, and cleaning timing as input parameters, and provides the cleaning time and cleaning timing as output parameters.

The rate of water level fluctuation is used as a parameter for predicting the degree of clogging of the biological filtration chamber 130 . For example, the clogging of the biological filtration chamber 130 is caused by deterioration of the filter layer 131 . In this embodiment, a sensor is provided inside the first pumping chamber 22 of the weighing device 35, and the speed of water level fluctuation is measured by measuring the time required for water level fluctuation between arbitrary two points. The cleaning time is the time required for one cleaning. In the case of this embodiment, the cleaning time corresponds to the number of times the cycle from the first step to the fourth step is repeated. Cleaning timing is the frequency at which the cleaning process is performed. For example, cleaning timing may correspond to the number of times a day is performed or the period of time between cleaning processes.

In the present embodiment, the control unit controls the speed of water level fluctuation immediately after the cleaning process (hereinafter referred to as "first fluctuation speed") and the speed of water level fluctuation immediately before executing the cleaning process (hereinafter referred to as "second fluctuation speed"). ) are compared, and the cleaning time and/or cleaning timing are determined based on the result. For example, when the second fluctuation speed is smaller than the first fluctuation speed (water level fluctuation is slow), the controller increases the washing time or controls the washing process to shorten the washing timing. That is, the control unit increases the processing time or processing frequency of the cleaning process when the water level fluctuation is slow and clogging is expected to occur in the biological filtration chamber 130 . At this time, the control unit performs control so that the difference between the first fluctuation speed and the second fluctuation speed is almost eliminated (for example, the difference is within ±5%) by calculation based on the machine learning model described above.

As described above, the control unit of the biological filtration chamber 130 of the present embodiment monitors the water level fluctuation of the biological filtration chamber 130 (specifically, the first pumping chamber 22) and inputs the value into the machine learning model. Therefore, an appropriate cleaning time and cleaning timing are determined. Further, the control unit causes the determined cleaning time and cleaning timing to be machine-learned again using deep learning or the like, and reflects them in the aforementioned machine-learning model. As described above, in this embodiment, the control unit uses AI to determine appropriate cleaning time and cleaning timing, and manages the biological filtration chamber 130 to operate normally.

(Modification 1)
In this embodiment, in addition to the first air lift pump 132, an example in which the second air lift pump 133 is provided as a sludge discharge pipe is shown, but not limited to this example, more air lift pumps (for example, two or more air lift pumps ) may be provided as a sludge discharge pipe. In this case, the speed of sludge discharge is improved, so the time required for the filter medium washing process can be shortened.

(Modification 2)
In this embodiment, an example in which the second airlift pump 133 is provided as a sludge discharge pipe has been shown, but the second airlift pump 133 may also serve as a raw water supply pipe without being limited to this example. In this case, the rate of raw water supply is improved, so the throughput of the biological filtration chamber 130 per unit time can be improved.

The embodiments of the present invention and their modifications can be implemented in appropriate combinations as long as they do not contradict each other. Based on the sewage filtration device and filter medium cleaning process of the embodiment described above, those skilled in the art may appropriately add, delete, or change the design of components, or add, omit, or change the conditions of steps. , are included in the scope of the present invention as long as they have the gist of the present invention.

In addition, even if there are other effects different from the effects brought about by the aspect of the embodiment described above, those that are obvious from the description of this specification or those that can be easily predicted by those skilled in the art are of course to the present invention.

21 ... housing, 22 ... first pumping chamber, 23 ... second pumping chamber, 24 ... sludge discharge port, 25 ... lid member, 26a to 26d ... rectifying plate, 27 ... weighing notch, 27a ... scale, 30 ... treatment tank , 30a... Bottom part 31... Air supply pipe 32... Partition member 32a... Opening 33... Cylindrical member 33a... Slit 34... Filter medium stopper 35... Weighing device 40... Sewage treatment unit 50... Air retention Part 50a... Air reservoir 51, 52... Water surface 53... Break point 71... Excess sludge 100... Sewage treatment device 105... Raw water supply port 110... First anaerobic filter bed chamber 111... First anaerobic filter Floor 115 Partition plate 115a Opening 120 Second anaerobic filter bed chamber 121 Second anaerobic filter bed 125 Raw water inlet 130 Biological filtration chamber 131 Filter layer 131a Filter medium 132 First air lift pump 133 Second air lift pump 134 Water seal portion 134a, 134b Partition plate 135 Treated water outlet 140 Treated water chamber 145 Outlet

Claims (8)

a treatment tank;
a sewage treatment unit provided inside the treatment tank;
A filter layer provided in the sewage treatment unit and made up of a floating filter medium having a specific gravity to water of 0.1 or more and 0.3 or less;
an air holding section provided below the sewage treatment section;
an air supply pipe communicating with the air holding part;
a first air lift pump extending from above the sewage treatment unit through the filtration layer to reach the air holding unit;
a water seal portion provided inside the air holding portion and communicating with the first air lift pump;
with
The first air lift pump serves as a raw water supply pipe, an air discharge pipe and a sludge discharge pipe, in a sewage filtering device. further comprising a second air lift pump extending from above the sewage treatment unit through the filtration layer to the air retention unit;
2. The sewage filtration system of claim 1 , wherein said second airlift pump is a sludge discharge pipe. 3. The sewage filtration system of claim 2 , further comprising a metering device coupled to said first airlift pump and said second airlift pump. a partition member having an outer edge connected to the inner wall of the treatment tank and partitioning the sewage treatment section and the air holding section;
a tubular member connected to the partition member through an opening provided in the partition member and extending toward the bottom of the processing tank;
further comprising
The sewage filtration device according to any one of claims 1 to 3 , wherein said sewage treatment section and said air holding section communicate with each other through a plurality of slits provided in a lower portion of said tubular member. The sewage filtering device according to claim 4 , wherein the plurality of slits are positioned below a break point of the water sealing portion. The sewage filtration device according to any one of claims 1 to 5 , wherein an end portion of said first air lift pump in said treatment tank is located below a break point of said water sealing portion. The sewage filtering device according to any one of claims 1 to 6 , wherein the air holding portion is a space whose outer edge is the inner wall of the processing tank. 8. The sewage filtering apparatus according to any one of claims 1 to 7 , wherein the bottom of said treatment tank has an inclined surface that rises inwardly from the outer edge.

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