JP2014069129A - Water treatment device, moving-bed type filter tank, and clarification tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water treatment device, a moving-bed type filter tank, and a clarification tank, for which the closure of a pumping passage due to the bridge formation of a filter material hardly occurs.SOLUTION: An air lift pump P comprises: a water channel wall 26 for forming a pumping passage, through which a filter material can move; a filter material inlet port 32 at the lower end of the pumping passage; a filter material outlet port at an upper portion of the pumping passage; and air supply means 27 for supplying air to the pumping passage. The lower end of the water channel wall 26 forming the outer circumference shape of the filter material inlet port 32 is shaped such that the distance from a bath bottom portion varies, and such that the longest distance Tmax and the shortest distance Tmin have relation of 0≤Tmin/Tmax<1.0.

Description

  The present invention relates to a water treatment apparatus, a moving bed type filtration tank, and a septic tank, which are provided with a water tank, a filler, and an air lift pump that transfers the filler from the bottom of the water tank to the top of the tank.

  As a conventional water treatment apparatus, for example, a moving bed type filtration tank shown in Patent Document 1 is known. Here, the filter medium (an example of the filler) filled in the tank captures (filters) suspended solids (sludge) contained in the water to be treated, and from an air blowing portion provided on the lower side surface of the water channel wall. The air lift pump is operated by blowing air directly to the pumping path, and the filter medium is sucked into the pumping path from the bottom of the tank and circulated to the upper part of the tank, so that the suspended substances attached to the filter medium are peeled off and discharged out of the tank. It is configured.

JP 2003-53110 A

However, in a conventional water treatment device using an air lift pump, a plurality of filter media gathered at the bottom of the tank may form a bridge in the lateral direction near the suction port of the pumping channel, which may block the pumping channel. It was.
An object of the present invention is to provide a water treatment device, a moving bed type filtration tank, and a septic tank that are unlikely to block a pumping channel due to bridge formation of a filler.

  1st characteristic structure which concerns on the water treatment apparatus of this invention is a water treatment apparatus provided with a water tank, a filler, and the air lift pump which transfers the said filler to the tank upper part from the tank bottom part of the said water tank, The said air lift pump is , A water channel wall forming a pumping channel through which the filler can move, a filler inlet at the lower end of the pumping channel, a filler discharge port at the top of the pumping channel, and an air supply for supplying air to the pumping channel And the lower end of the water channel wall constituting the outer peripheral shape of the filler inlet has a shape in which the distance from the tank bottom changes, and the maximum distance Tmax and the minimum distance Tmin are 0. ≦ Tmin / Tmax <1.0.

[Action and effect]
Like this structure, it has the shape from which the distance between the lower end of the channel wall which comprises the outer periphery shape of a filler inflow port and a tank bottom part changes, and the maximum distance Tmax and minimum distance Tmin are 0 <= Tmin / Tmax <. When configured to have a relationship of 1.0, the denseness of the filler staying at the bottom of the tank is broken, and the filler is easily guided to the filler inlet. As a result, bridge formation due to the filler hardly occurs and blockage of the pumping path can be prevented.

  The second characteristic configuration is that the minimum distance Tmin is 0 to 70 mm.

[Action and effect]
According to this structure, the denseness of the filler in the tank bottom becomes easier to collapse.

  The third characteristic configuration is that the maximum distance Tmax is 300 mm or less.

[Action and effect]
According to this structure, regardless of the distance from the filler inlet to the tank bottom, the filler can be prevented from remaining at the tank bottom, and a uniform recirculation of the filler can be expected.

  In a fourth characteristic configuration, the distance between the lower end of the water channel wall and the bottom of the tank is the part related to the minimum distance Tmin at the lower end of the water channel wall from the part related to the maximum distance Tmax at the lower end of the water channel wall. It is in the point which decreases continuously or intermittently.

[Action and effect]
According to this configuration, the opening surface of the filler inlet of the water channel wall is increased, the guidance of the filler into the pumping channel is facilitated, and bridge formation by the filler at the filler inlet is suppressed.

  The fifth characteristic configuration is that a ridge is provided above the outer peripheral side of the filler inlet.

[Action and effect]
According to this configuration, the number of fillers flowing to the bottom of the tank below the filler inlet is restricted by dredging, thereby eliminating excessive stagnation of the filler, thereby clogging with the filler in the pumping channel. Can be prevented.

  The sixth characteristic configuration is that a minimum distance Smin between the lower end of the basket and the tank bottom is smaller than the maximum distance Tmax.

[Action and effect]
According to this configuration, the space is provided between the portion related to the minimum distance Smin at the lower end of the ridge and the portion related to the maximum distance Tmax at the lower end of the water channel wall, thereby moving from the lower end of the ridge to the tank bottom. The number of fillers can be further limited. Thereby, the excessive stagnation of the filler is further less likely to occur, so that the clogging by the filler in the pumping path can be more effectively prevented.

  A seventh characteristic configuration is that an air blowing portion of the air supply means is provided at the bottom of the tank.

[Action and effect]
According to this configuration, since the air blowing portion is provided at the bottom of the tank, the filling material gathered at the bottom of the tank is reliably transferred to the pumping channel by the upward flow of the water to be treated generated by the air supplied from the air blowing portion. Since it is sucked into the tank, it is difficult to stay at the bottom of the tank.

It is a top view which shows the inside of a septic tank. It is a side view which shows the inside of a septic tank. It is the III-III arrow directional view of FIG. It is the IV-IV line arrow directional view of FIG. It is the VV arrow directional view of FIG. It is a perspective view which shows the inside of a support | carrier fluidization tank and a moving bed type filtration tank, Comprising: (a) shows the state which accommodated the filter medium in the moving bed type filtration tank, (b) is the inside of a moving bed type filtration tank. Shows a state where the filter medium is omitted for easy understanding. It is a side view which shows the inside of a moving bed type filtration tank. It is the side view to which a part inside moving bed type filtration tank was expanded. It is a perspective view which shows a transfer amount restriction | limiting part. It is the schematic which shows another form (a)-(c) of a filter medium inflow port. It is the schematic which shows another form of a filter medium inflow port. It is the schematic which shows another form of a filter medium inflow port. It is the schematic which shows another form of a ridge. It is the schematic which shows another form of a ridge. It is the schematic which shows another form of a moving bed type filtration tank. It is the schematic which shows another form of a moving bed type filtration tank. It is the schematic which shows another form of a moving bed type filtration tank.

Embodiments of the present invention will be described below with reference to the drawings.
Embodiment
1 to 5 show a septic tank that purifies domestic wastewater (sewage) as treated water. In addition, in this embodiment, although the example which applies the water treatment apparatus which concerns on this invention to a septic tank is shown, it is not limited to this, The structure which recirculates a filler with an air lift pump and performs water treatment is shown. The present invention can be applied to all devices provided.
As shown in FIGS. 1 and 2, the inside of the septic tank is a biological treatment tank A for biologically treating the treated water, and a moving bed type filtration for filtering the treated water treated in the biological treatment tank A with the filter medium 23. Tank B (an example of a water treatment device), treated water tank C for temporarily storing the treated water filtered in the moving bed type filtration tank B, and disinfection tank D for disinfecting the treated water stored in the treated water tank C It is divided into.

  The biological treatment tank A is divided into a primary treatment tank A1 that receives an treated water (raw water) flowing from the outside and anaerobically treats it, and a carrier fluidized tank A2 as an aerobic treatment tank that aerobically treats the treated water. ing. The primary treatment tank A1 is divided into a precipitation separation tank E1 and an anaerobic filter bed tank E2.

  The treated water (raw water) from the outside flows into the sedimentation separation tank E1 from the inflow part 1, and the treated water sterilized in the disinfection tank D is discharged from the discharge part 2 to the outside.

  The sedimentation separation tank E1 and the anaerobic filter bed tank E2 are divided forward and backward by the first horizontal partition wall 4, and the anaerobic filter bed tank E2, the carrier flow tank A2 and the moving bed type filtration tank B are front and rear by the second horizontal partition wall 5. It is divided into.

  The carrier fluidized tank A2, the moving bed type filtration tank B and the treated water tank C are partitioned on the left and right by the vertical partition wall 7, and the moving bed type filtration tank B and the treated water tank C are partitioned on the front and rear by the partition wall 8, D is defined in the upper part on the inner side of the carrier flow tank A2.

  As shown in FIGS. 3 and 4, the first horizontal partition 4 is provided with a first advection port 11 for advancing water to be treated from the precipitation separation tank E1 to the anaerobic filter bed tank E2. The advection tube 17 and the advection tube 19 are attached.

  As shown in FIG. 5, the second horizontal partition wall 5 is provided with a second advection port 12 for advancing water to be treated from the anaerobic filter bed tank E2 to the carrier flow tank A2.

  As shown in FIG. 6, a third advection port 13 through which the water to be treated flows from the carrier fluid tank A2 to the moving bed type filtration tank B is provided in the partition wall portion of the vertical partition wall 7 near the water surface. It is provided over a position higher than the water surface WL and a lower position.

At the lower end portion of the partition wall 8 between the moving bed type filtration tank B and the treated water tank C, a fourth advection port 14 for moving the treated water from the moving bed type filtration tank B to the treated water tank C is provided.
The third advection port 13 and the fourth advection port 14 are formed with a large number of slit holes so that the fluid carrier 21 and the filter medium 23 accommodated in the carrier fluid tank A2 and the movable bed type filtration tank B do not flow out.
The precipitation separation tank E1 and the anaerobic filter bed tank E2 may have a function as a flow rate adjusting unit that temporarily stores water to be treated at the peak inflow in a time zone such as morning and evening.

  Therefore, the water to be treated which has flowed in from the inflow portion 1 is transferred to the precipitation separation tank E1, the anaerobic filter bed tank E2, the carrier fluidized tank A2, the moving bed type filtration tank B, the treated water tank C, and the disinfection tank D in this order and discharged. It is discharged from the part 2 to the outside.

  The to-be-treated water that has flowed in from the inflow portion 1 is precipitated and separated in the precipitation separation tank E1, guided to the advection pipe 17 and rises along the first horizontal partition 4 and is provided in the first horizontal partition 4. It flows into the anaerobic filter bed tank E2 from one advection port 11. The anaerobic filter bed tank E2 includes an anaerobic filter bed 18 that holds anaerobic microorganisms.

  The water to be treated which has flowed into the anaerobic filter bed tank E2 from the first advection port 11 is guided by the advection pipe 19 and descends along the first horizontal partition wall 4 and passes through the anaerobic filter bed 18 upward to be anaerobically treated. In addition, the water to be treated, in which suspended solids are trapped and solid matter is almost decomposed, is guided to the advection baffle 20 and flows into the upper part of the carrier flow tank A2 from the second advection port 12 provided in the second horizontal partition wall 5. To do.

  As shown in FIG. 6, a large number of fluid carriers 21 carrying aerobic microorganisms are accommodated in the carrier fluid tank A2 so that they can flow together with the water to be treated, and an aeration diffuser 22 is provided at the bottom of the tank. Is provided.

  The water to be treated that has flowed into the carrier fluid tank A2 is aerobically treated with the fluid carrier 21 while being supplied with oxygen by supplying air bubbles from the air diffuser 22, and then, along with the suspended solids (sludge), the vertical partition walls. 7 constantly flows into the moving bed type filtration tank B from the third advection port 13 provided in 7 and the suspended matter (sludge) in the carrier flow tank A2 decreases.

  As shown in FIGS. 6 and 7, a large number of substantially spherical filter media 23 (an example of a filler) having a specific gravity greater than that of water stay in the lower part of the moving bed filtration tank B in a state where they are submerged and stacked. To be filled.

  As shown in FIG. 7, the moving bed type filtration tank B includes a filter medium 23 and an air lift pump P. The air lift pump P includes a water channel wall 26 that forms a pumping channel 25 in which treated water and the filter medium 23 can move, a filter medium inlet 32 at the lower end of the pump channel 25, and a filter medium discharge port 28 at the upper part of the pump channel 25. And an air supply means for supplying air to the pumping path 25. The air lift pump P sucks the water to be treated and the filter medium 23 from the deepest part 50 into the pumping path 25 and transfers it to the upper part of the tank, and repeatedly circulates this to constantly wash the filter medium 23.

  The water channel wall 26 is fixed along the vertical direction at the corner where the second horizontal partition wall 5 and the vertical partition wall 7 intersect (see FIG. 1), and the filter medium discharge port 28 is covered in the moving bed type filtration tank B. It is provided so as to be higher than the liquid level WL of the treated water. By providing the water channel wall 26 at the corner, it is possible to limit the direction in which the water to be treated and the filter medium 23 flow in, and the risk of turbulence is reduced.

  The pumping path 25 is formed inside the channel wall 26, and its cross-sectional shape has a uniform shape over the entire longitudinal direction. In this embodiment, the filter medium discharge port 28 is provided at the upper end of the pumping path 25, but is not limited to this configuration, and provided at any position as long as it is higher than the water surface of the water to be treated. May be.

  As shown in FIG. 8, the distance between the filter medium inlet 32 of the pumping channel 25 and the bottom of the tank is T, and the distance is between 0 ≦ Tmin / Tmax <1.0 from the minimum distance Tmin to the maximum distance Tmax. By changing the shape to be changed, it is possible to further limit the direction in which the water to be treated and the filter medium 23 flow in, and the upward flow of the water to be treated flowing into the filter medium inlet 32 is easily generated. Turbulence generation near 32 is more reliably reduced. As a result, bridge formation by the filter medium 23 is less likely to occur, and blockage of the pumping path 25 can be prevented. In FIG. 5, the lower end portion of the pumping channel 25 is notched obliquely so as to open toward the tank side bottom surface 31, whereby the lower end portion of the pumping channel 25 becomes tapered (tapered) so that the filter medium 23 can pass through. A filter medium inlet 32 is formed. Further, since the water channel wall 26 is in contact with the tank bottom, the minimum distance Tmin is 0 mm. It should be noted that the maximum distance Tmax and the minimum distance Tmin may be measured by the same measurement method regardless of whether the distance is lowered from the filter medium inlet 32 of the pumping path 25 to the tank bottom in the vertical direction or the distance to the tank bottom in the vertical direction. .

  The bottom of the moving bed type filtration tank B has a deepest part 50 arranged just below the pumping channel 25 and two flat tank side bottoms extending from the deepest part 50 to the lower end of the tank inner face 36 obliquely above. 31 and is formed in a downward truncated pyramid shape (see FIG. 6A).

  In the present embodiment, the tank-side bottom surface 31 is formed as a flat inclined surface, but is not limited to this, and may be combined with an arcuate surface, formed into a conical surface, or inclined. You may comprise on a flat surface without doing.

  Above the outer peripheral side of the filter medium inlet 32, there are two flat upper surfaces 29 inclined downward in a direction away from the filter medium inlet 32, and a lower surface 45 inclined in an upward gradient in a direction away from the filter medium inlet 32. A bag 30 is provided. The trough 30 in the present embodiment is fixed to the water channel wall 26. Further, the lower surface 45 of the eaves 30 extends obliquely upward from the lower end of the water channel wall 26 (the upper end of the filter medium inlet 32) toward the lower end of the upper surface 29.

  A hanging wall portion 34 extending vertically downward from the lower end of the upper surface 29 is provided at the end portion of the collar 30. It is desirable that the vertical length of the hanging wall 34 is set to be equal to or greater than the maximum width of the filter medium 23. In the present embodiment, the distance between the lower end of the vertical wall portion 34 and the tank side bottom surface 31 is the minimum distance Smin between the lower end of the basket 30 and the tank bottom portion. The distance between the upper end of the filter medium inlet 32 and the deepest part 50 is the maximum distance Tmax between the filter medium inlet 32 and the tank bottom. The minimum distance Smin and the maximum distance Tmax have a relationship of Smin / Tmax <1. The minimum distance Smin between the lower end of the rod 30 and the bottom of the tank is the maximum distance Tmax, whether it is a distance from the lower end of the hanging wall 34 to the bottom of the tank in the vertical direction or a vertical distance to the bottom of the tank. Any method may be used as long as it is the same as the measurement method.

  In the moving bed type filtration tank B in the present embodiment, since the horizontal cross-sectional area of the inner wall of the moving bed type filtration tank B becomes narrower as it goes downward along the upper surface 29, the filter medium 23 that settles in the tank has an upper surface. It stays in the upper part of 29, forms a staying part, and gradually moves along the upper surface 29 toward the tank inner surface 36 side. Thereby, the speed | rate of the filter medium 23 which flows into the tank bottom part from the trough 30 can be restrict | limited.

  The filter medium 23 in the staying part further sinks, passes between the lower end of the hanging wall part 34 and the tank side bottom face 31, moves to the deepest part 50 side along the tank side bottom face 31, and enters the filter medium inlet. 32 is sucked into the pumping path 25 together with the water to be treated.

  Further, the amount of the filter medium 23 that moves toward the filter medium inlet 32 is limited at a portion of the minimum distance Smin between the lower end of the basket 30 and the tank bottom, and the maximum between the filter medium inlet 32 and the tank bottom. By setting the distance Tmax to satisfy Smin / Tmax <1, a space wider than the space of the minimum distance Smin portion is formed. As a result, the packing density of the filter medium 23 gathered in the vicinity of the filter medium inlet 32 decreases, bridge formation by the filter medium 23 is less likely to occur, and blockage of the pumping path 25 can be further prevented.

  The maximum distance Tmax is preferably equal to or greater than the sum of the minimum distance Smin and the maximum width of the filter medium 23, and more preferably, the minimum distance Smin / maximum distance Tmax <0.85.

  The air supply means includes an air supply pipe 27 connected to an air compressor or the like (not shown), and an air blowing portion 27a that blows out air from the air supply pipe 27. In the present embodiment, the air blowing part 27 a is provided in the deepest part 50. That is, the air blowing part 27 a is provided directly below the filter medium inlet 32 of the pumping path 25, and is configured to blow air from below the filter medium 23 gathered at the deepest part 50. As shown in FIG. 7, the air supply pipe 27 is disposed along the treated water tank C side of the partition wall 8.

  According to the said structure, the filter medium flow of the pumping-up path 25 by the upward flow of the to-be-processed water produced by the air supplied to the deepest part 50 of the moving bed type filtration tank B and the sedimentation sludge from the air blowing part 27a is carried out. Compared to the conventional case in which the air supply pipe 27 is connected to the lower side surface of the water channel wall 26, the filter medium 23 and sludge can be easily prevented from staying in the deepest part 50.

  In the present embodiment, an opening 46 through which air can pass while preventing passage of the filter medium 23 is provided on the lower surface 45 of the bowl 30.

  The opening 46 is a through hole that communicates with the space inside the flange 30, and is formed in the upper end portion of the lower surface 45. The inner diameter of the opening 46 is set so that the air supplied from the air blowing part 27a and the water to be treated are allowed to pass but the filter medium 23 is not allowed to pass.

  Further, a communication portion 47 is formed on the wall surface of the water channel wall 26 near the upper end portion of the eaves 30. The communication part 47 is a through hole that communicates with the pumping path 25 from the space inside the raft 30, and the inner diameter of the communication part 47 allows the air and the water to be treated supplied from the air blowing part 27a to pass therethrough. The filter medium 23 that moves 25 is set not to pass through.

  Of the air supplied from the air blowing portion 27 a, the air that has not entered the filter medium inlet 32 of the pumping channel 25 is guided along the lower surface 45 and flows into the space inside the eaves 30 from the opening 46. To do. And the inflowed air is guided along the back surface of the upper surface 29 of the eaves 30, passes through the communication portion 47, and merges with the pumping path 25.

  According to the above configuration, the filter layer formed by the plurality of filter media 23 staying on the upper surface 29 is not disturbed by the air that has not entered the filter media inlet 32 of the pumping path 25. Furthermore, since the air that has not entered the filter medium inlet 32 of the pumping path 25 can be merged with the pumping path 25, the loss of air supplied to operate the air lift pump P can be minimized. .

  As shown in FIG. 9, on the filter medium discharge port 28 side of the pumping channel 25, a part of the water to be treated discharged from the filter medium discharge port 28 together with suspended solids (sludge) is stored in a tank other than the carrier flow tank A2. Moreover, the transfer part 37 which always transfers to tanks other than the moving bed type filtration tank B is provided.

The air lift pump P and the transfer unit 37 constitute the water to be treated circulating means F, and the air lift in which the water to be treated that has passed through the moving bed type filtration tank B after being treated in the carrier flow tank A2 is disposed in the moving bed type filtration tank B. It transfers to the precipitation separation tank E1 through the pump P and the transfer part 37.
By transferring and circulating the water to be treated from the carrier flow tank A2 to the primary treatment tank A1, the nitrification and denitrification treatment of the water to be treated is promoted.

  As shown in FIG. 9, the transfer unit 37 has a sediment separation tank E1 disposed on the upstream side of the carrier fluidized tank A2 in the treatment tank disposed in the biological treatment tank A for a part of the water to be treated. Is provided with a transfer rod for transfer (return).

  The transfer trough (transfer section) 37 is disposed so that the transfer start end faces the vicinity of the filter medium discharge port 28 of the pumping path 25, is supported by the second horizontal partition wall 5, and is treated water discharged from the filter medium discharge port 28. A part of the water is introduced and transferred to the precipitation separation tank E1.

  The transfer start part of the transfer tank 37 is provided with a transfer amount limiting unit 38 that limits the transfer amount of the water to be treated that can be transferred to the precipitation separation tank E1. The transfer amount limiting unit 38 is configured by providing a weir plate that allows the water to be treated to pass along with the sludge and that is formed with a large number of slit holes 38 a arranged in the slit width direction to prevent the filter medium 23 from passing therethrough. .

  The weir plate (transfer amount limiting portion) 38 is supported at the transfer start side end of the transfer rod 37 by the guide frame 39 provided on the second horizontal partition wall 5 so as to be slidable in the vertical direction. Thus, the transfer amount of the water to be treated to the precipitation separation tank E1 can be adjusted.

  As shown in FIG. 6, water to be treated can be circulated between the carrier fluidized tank A2 and the movable bed type filtration tank B in the vertical partition wall 7 that divides the carrier fluidized tank A2 and the movable bed type filtration tank B. A circulation path 40 is provided. The circulation path 40 has a third advection port 13 as an upper advection port formed in the vertical partition wall 7 and a lower advection port formed in a partition wall portion at a position lower than the third advection port 13 in the vertical partition wall 7. 5 advection ports 41 are provided. The fifth advection port 41 is configured by providing a large number of slit holes that prevent the passage of the filter medium 23.

  In the circulation path 40, the water to be treated in the moving bed type filtration tank B flows into the carrier flow tank A2 from the fifth transfer port 41, and the water to be treated in the carrier flow tank A2 flows from the third flow port 13 into the moving bed type filtration tank. The treated water is circulated in a state of flowing into B.

  The fifth advection port 41 is formed so as to face the staying part of the filter medium 23 in the moving bed type filtration tank B, and the third advection port 13 and the fifth advection port 41 are used for aeration of the carrier fluidized tank A2. It is formed in the partition part facing the diffuser 22 by shifting the position in the vertical direction.

  The treated water filtered in the moving bed type filtration tank B is transferred to the treated water tank C through the fourth transfer port 14 formed in the partition wall 8 and temporarily stored, and then transferred to the disinfection tank D and disinfected. And released to the outside.

[Other Embodiments]
The outer peripheral shape of the filter medium inlet 32 in the above-described embodiment is not limited to the shape as shown in FIG. 8, and the lower end of the water channel wall 26 has a shape in which the distance from the tank bottom changes. And the maximum distance Tmax (see FIG. 12) and the minimum distance Tmin (see FIG. 12) have a relationship of 0 ≦ Tmin / Tmax <1.0. For example, as shown in FIG. 10, the distance between the lower end of the water channel wall 26 and the tank bottom is continuous from the part H related to the maximum distance Tmax at the lower end of the water channel wall 26 toward the part L related to the minimum distance Tmin. It is good also as shapes, such as (a) step shape (b) step shape (c) circular arc shape etc. which reduce automatically or intermittently. The minimum distance Tmin is desirably less than 100 mm in order to maintain the rectifying effect from the tank bottom to the filter medium inlet 32 for loosening the denseness of the filter medium 23 staying at the tank bottom. It is further desirable that it is ˜70 mm. The maximum distance Tmax is 100 to 300 mm in order to prevent clogging of the filter medium 23 due to the rectification effect at the portion H related to the maximum distance Tmax and the tank bottom, and to prevent the filter medium 23 from becoming obvious at the tank bottom. desirable. Further, as Tmin / Tmax becomes smaller than 1.0, the rectification effect increases, and accordingly, turbulent flow generation and blockage of the pumping path 25 are prevented. However, the rectification effect is maintained and these prevention effects are maintained. For more certainty, it is desirable to satisfy 0 ≦ Tmin / Tmax ≦ 0.7, and it is even more desirable that 0 ≦ Tmin / Tmax ≦ 0.5. In the above-described embodiment, the case where the minimum distance Tmin = 0 is illustrated, but more desirably, the minimum distance Tmin> 0 may be used as shown in FIGS. 11 and 12, and in this case, Tmax / Tmin ≦ 3. It is desirable that Moreover, as shown in FIG. 11, the filter medium inlet 32 may be formed by notching the lower end portion of the pumping channel 25 obliquely so as to open to the second horizontal partition wall 5 side. 0.3 ≦ Tmin / Tmax ≦ 0.5 is desirable.

  In the above-described embodiment, the lower surface 45 of the eaves 30 extends obliquely upward from the lower end of the water channel wall 26, but is not limited thereto, and may be configured to extend from the water channel wall 26 in the horizontal direction.

  In the above-described embodiment, the upper surface 29 of the eaves 30 is formed by two flat inclined plates surrounding the water channel wall 26. However, the present invention is not limited to this, and the channel wall is formed by three or more plates. It may be formed so as to surround 26 or may be conical.

  As shown in FIGS. 11 to 14, the bag 30 in the above-described embodiment does not necessarily include the lower surface 45. As shown in FIG. 13, the trough 30 may not be fixed to the water channel wall 26 but may be fixed to the surrounding second horizontal partition wall 5 or the vertical partition wall 7 (see FIG. 1). Or holes 52 may be provided.

  As shown in FIG. 14, the hanging wall 34 may be provided inside the upper surface 29 instead of the lower end of the upper surface 29.

  The shape of the filter medium 23 is not limited to a spherical shape, and may be a polygonal shape. Moreover, when using the spherical filter medium 23, it is desirable that the diameter shall be 10-30 mm.

  As shown in FIGS. 15 to 17, the moving bed type filtration tank does not necessarily need to be provided with the basket 30. The outer peripheral shape of the filter medium inlet 32 is such that the distance between the lower end of the water channel wall 26 and the bottom of the tank is continuous from the portion related to the maximum distance Tmax at the lower end of the water channel wall 26 toward the portion related to the minimum distance Tmin. The shape is such that it decreases intermittently. In particular, if the minimum distance Tmin is 0 to 70 mm, the maximum distance Tmax is 100 to 300 mm, and 0 ≦ Tmin / Tmax ≦ 0.5, the rectifying effect is maintained. The clogging of the pumping path 25 by the filter medium 23 can be prevented.

  The water treatment apparatus according to the present invention is not limited to the moving bed type filtration tank in the septic tank, and can be applied to any apparatus having a configuration in which a filler is circulated by an air lift pump to perform water treatment.

23 Filler (filter material)
25 Pumping channel 26 Water channel wall 27 Air supply pipe (air supply means)
27a Air blowing part (air supply means)
28 Filter media outlet (filler outlet)
29 Upper surface 30 庇 31 Tank side bottom (tank bottom)
32 Filter media inlet (filler inlet)
34 hanging wall 45 lower surface 50 deepest part (tank bottom)
P Air lift pump

Claims (9)

In a water treatment apparatus comprising a water tank, a filler, and an air lift pump for transferring the filler from the tank bottom to the tank upper part of the water tank,
The air lift pump includes a water channel wall forming a pumping channel through which the filler can move, a filler inlet at a lower end of the pumping channel, a filler discharge port at an upper part of the pumping channel, and air to the pumping channel. Air supply means for supplying,
The lower end of the water channel wall constituting the outer peripheral shape of the filler inlet has a shape in which the distance from the tank bottom changes, and the maximum distance Tmax and the minimum distance Tmin are 0 ≦ Tmin / Tmax <1. A water treatment device having a relationship of .0.   The water treatment apparatus according to claim 1, wherein the minimum distance Tmin is 0 to 70 mm.   The water treatment apparatus according to claim 1 or 2, wherein the maximum distance Tmax is 300 mm or less.   The distance between the lower end of the water channel wall and the bottom of the tank is continuously from the portion related to the maximum distance Tmax at the lower end of the water channel wall toward the portion related to the minimum distance Tmin at the lower end of the water channel wall. The water treatment apparatus according to any one of claims 1 to 3, which decreases intermittently.   The water treatment apparatus according to any one of claims 1 to 4, wherein a ridge is provided on an upper peripheral side of the filler inlet.   The water treatment apparatus according to claim 5, wherein a minimum distance Smin between the lower end of the basket and the tank bottom is smaller than the maximum distance Tmax.   The water treatment apparatus according to any one of claims 1 to 6, wherein an air blowing portion of the air supply means is provided at the bottom of the tank.   A moving bed type filtration tank using the water treatment apparatus according to claim 1.   A septic tank provided with the moving bed type filtration tank according to claim 8.

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