JP2020182906A - Inflow part unit and settling tank - Google Patents

Abstract

To provide an inflow part unit and a settling tank capable of restraining reduction of separation performance.SOLUTION: An inflow part unit in an embodiment has an inflow pipe and a storage unit. The inflow pipe is arranged around a rotary shaft for rotating a scrape-up plate of a settling tank. The storage unit is arranged above the inflow pipe, and can store processed water flowing into an inside of the inflow pipe. The storage unit has an inner peripheral wall on an inside of the storage unit in a radial direction of the inflow pipe. The inner peripheral wall has an inner peripheral opening which is at least partially positioned at a point lower than an upper end of an overflow weir of the settling tank.SELECTED DRAWING: Figure 2

Description

Embodiments of the present invention relate to an inflow unit and a settling tank.

Sedimentation tanks that settle and separate suspended solids and the like contained in industrial wastewater are known. It is desired for the settling tank to suppress the deterioration of the settling separation performance.

JP-A-2017-94221 JP-A-9-234465 JP-A-2017-87196

An object to be solved by the present invention is to provide an inflow unit and a sedimentation tank capable of suppressing a decrease in sedimentation separation performance.

The inflow unit of the embodiment has an inflow pipe and an accommodating part. The inflow pipe is arranged around a rotating shaft that rotates the settling plate of the settling tank. The accommodating portion is arranged above the inflow pipe and can accommodate the water to be treated that flows into the inside of the inflow pipe. The accommodating portion has an inner peripheral wall inside the accommodating portion in the radial direction of the inflow pipe. The inner peripheral wall has an inner peripheral wall opening which is at least partially arranged below the upper end of the overflow weir of the settling tank.

A side sectional view of the settling tank of the first embodiment. FIG. 3 is a plan sectional view of the inflow unit of the first embodiment. FIG. 3 taken from arrow III in FIG. The IV arrow view of FIG. The V arrow view of FIG. FIG. 2 is a side sectional view taken along the line VI-VI of FIG. VII arrow view of FIG. The explanatory view of the inflow part unit of the 1st modification of 1st Embodiment. It is explanatory drawing of the inflow part unit of the 2nd modification of 1st Embodiment. FIG. 3 is a plan sectional view of the inflow unit of the second embodiment. FIG. 10 is a side sectional view taken along the line XI-XI of FIG. A side sectional view of the settling tank of the third embodiment. Enlarged view of part XIII of FIG. The plan sectional view of the inflow part unit of 3rd Embodiment. A side sectional view of the settling tank of the first modification of the third embodiment. FIG. 3 is a plan sectional view of an inflow unit of a second modification of the third embodiment. The operation explanatory drawing of the inflow part unit of the 2nd modification of 3rd Embodiment. FIG. 3 is a plan sectional view of an inflow unit of a third modification of the third embodiment.

Hereinafter, the inflow unit and the settling tank of the embodiment will be described with reference to the drawings. In the following description, the same reference numerals are given to configurations having the same or similar functions. Then, the duplicate description of those configurations may be omitted.

FIG. 1 is a side sectional view showing the overall configuration of the settling tank 1 of the present embodiment.
In the present application, the Z direction, the R direction and the θ direction of the polar coordinate system are defined as follows. The Z direction is the axial direction of the inflow pipe 19 and the distribution unit 18. For example, the Z direction is the vertical direction, and the + Z direction (first direction) is the upward direction. The R direction is the radial direction of the inflow pipe 19 and the distribution portion 18, and the + R direction is a direction away from the central axis (outer direction). The θ direction is the circumferential direction of the inflow pipe 19 and the distribution unit 18, and the + θ direction is the rotation direction of the rotating shaft 41. For example, the R direction and the θ direction are horizontal directions.

(First Embodiment)
The first embodiment will be described.
The settling tank 1 of the present embodiment is a settling tank that separates minute SS (suspended solids or suspended solids) contained in the water to be treated such as industrial wastewater from the water to be treated, and is used, for example, by the settling separation method. It is a settling tank.

First, the overall configuration of the settling tank 1 will be described with reference to FIG.
As shown in FIG. 1, the settling tank 1 has a tank body 11, an inflow unit 12, an overflow weir 13, a water discharge unit 14, a scraping unit 15, and a sludge extraction pipe 16. In each figure, the flow of water to be treated is schematically shown by arrows.

The tank body 11 is a container formed in a bottomed tubular shape such as a cylindrical shape or a polygonal tubular shape. The tank body 11 includes, for example, a bottom wall 31 and a peripheral wall 32 that rises upward from the peripheral edge of the bottom wall 31. The tank body 11 has an upper opening 33 at the upper end of the tubular peripheral wall 32. The tank body 11 stores the water to be treated inside and precipitates the flocs. The "flock" means a lumpy substance produced by an agglutinating action or the like, and means, for example, a cotton waste-like lumpy substance formed by adding a flocculant or the like to water to be treated containing suspended solids. The tank body 11 is installed, for example, so that the central axis 11c of the tank body 11 is substantially aligned with the vertical direction. Further, at the central portion of the bottom wall 31 of the tank body 11, a discharge port 31a for discharging the sediment to the outside of the tank body 11 is provided. A sludge extraction pipe 16 is connected to the discharge port 31a.

A coagulation tank (not shown) for pretreating the water to be treated is arranged on the upstream side of the settling tank 1. In the coagulation tank, the coagulant is added to the water to be treated. As a result, specific components in the water to be treated are aggregated to generate flocs. That is, the water to be treated flows into the settling tank 1 in a state containing flocs.

The inflow unit 12 includes, for example, a water supply unit 17 to be treated, a distribution unit (accommodation unit) 18, and an inflow pipe 19. The inflow unit 12 is arranged inside the tank body 11 (that is, inside the settling tank 1). The inflow unit 12 causes the water to be treated, which is supplied from the coagulation tank through the water supply unit 17 to be treated, to flow into the tank body 11 via the distribution unit 18 and the inflow pipe 19.

The water supply unit 17 to be treated is, for example, a supply pipe or an inflow trough extending from the outside of the tank body 11 to the inside of the tank body 11. The term "trough" as used herein means a structure that forms a groove. The water to be treated 17 supplies the water to be treated continuously to the inside of the tank body 11. The water supply unit 17 to be treated is connected to the distribution unit 18 described later to form a water supply port 17a to be treated to the distribution unit 18. The supply port 17a is formed on the inner side surface of the outer peripheral wall 18a of the distribution unit 18 so as to face the central axis 18c of the distribution unit 18. The water to be treated flows in from the supply port 17a toward the central axis 18c of the distribution unit 18.

The distribution unit 18 is also referred to as a "distributed trough" or "inflow pool". The distribution unit 18 has a cylindrical inner peripheral wall 20 inside in the radial direction. The distribution unit 18 has a cylindrical outer peripheral wall 18a on the outer side in the radial direction. The distribution unit 18 has an annular bottom wall 18b on the lower side in the axial direction. The distribution unit 18 is a trough having a predetermined volume formed in a cylindrical shape by the inner peripheral wall 20, the outer peripheral wall 18a, and the bottom wall 18b. The distribution unit 18 may have a shape different from that of a cylinder, for example, a polygonal cylinder. The distribution unit 18 is arranged inside the tank body 11. The central shaft 18c of the distribution unit 18 substantially coincides with the central shaft 11c of the tank body 11. The size of the distribution unit 18 can be appropriately set according to the required treatment amount of the water to be treated and the size of the tank body 11.

The inflow pipe 19 is also referred to as a "center well" or a "feed well", and is formed in a tubular shape such as a cylindrical shape or a polygonal tubular shape. The inflow pipe 19 is arranged below the distribution unit 18. That is, the distribution unit 18 is arranged above the inflow pipe 19. The inflow pipe 19 is arranged at substantially the same position as the inner peripheral wall 20 of the distribution portion 18 in the radial direction. That is, most of the distribution unit 18 is arranged outside the inflow pipe 19 in the radial direction. The distribution unit 18 can accommodate the water to be treated that flows into the inflow pipe 19. As shown in FIG. 1, the central axis 19c of the inflow pipe 19 substantially coincides with the central axis 18c of the distribution unit 18 and the central axis 11c of the tank body 11. The size of the inflow pipe 19 can be appropriately set according to the required treatment amount of the water to be treated and the size of the tank body 11.

The lower end 19a of the inflow pipe 19 is separated from the bottom wall 31 of the tank body 11. That is, a flow path through which the water to be treated is dispersed in the horizontal direction is formed between the lower end 19a of the inflow pipe 19 and the bottom wall 31 of the tank body 11. Further, the lower end 19a of the inflow pipe 19 has an opening (inflow port) 19b that allows the inside of the inflow pipe 19 to communicate with the inside of the tank body 11. The water to be treated, which is supplied from the water to be treated 17 to the inflow pipe 19 via the distribution unit 18, flows downward in the inflow pipe 19 and flows from the opening 19b of the lower end 19a of the inflow pipe 19 to the tank body. It is supplied within 11. The water to be treated supplied from the inflow pipe 19 into the tank body 11 slowly rises between the inner wall surface of the peripheral wall 32 of the tank body 11 and the outer peripheral surface of the inflow pipe 19. For example, in this process, a part of the flocs separates from the water to be treated and precipitates.

The overflow weir 13 is provided above the tank body 11. The overflow weir 13 is provided in a groove shape in the tank body 11 so that the water to be treated overflowing from the upper end 13t of the overflow weir 13 can be accommodated. For example, the overflow weir 13 is provided along the inner wall surface 32a of the peripheral wall 32 of the tank body 11. The overflow weir 13 causes the water to be treated that has been separated and removed from the flocs to flow out to the water to be treated water discharge unit 14.
The water level WL of the water to be treated inside the settling tank 1 coincides with the upper end 13t of the overflow weir 13. The upper ends of the inner peripheral wall 20 and the outer peripheral wall 18a of the distribution portion 18 are arranged above the upper end 13t of the overflow weir 13. The bottom wall 18b of the distribution portion 18 is arranged below the upper end 13t of the overflow weir 13.

The water discharge unit 14 to be treated is, for example, an outflow trough (or a discharge pipe or the like) that communicates with the inside of the overflow weir 13 and extends to the outside of the tank body 11. The water to be treated discharge unit 14 causes the water to be treated overflowing from the upper end 13t of the overflow weir 13 to flow out to the outside of the tank body 11. The water to be treated that has flowed out of the tank body 11 is subjected to further treatment, for example, and is sent to the use point.

The scraping unit 15 includes a rotary shaft 41, a drive motor 42, a support member 43, and a plurality of scraping plates 44. The rotary shaft 41 is arranged at the center of the tank body 11 (the center of the inflow pipe 19). The rotary shaft 41 penetrates the inflow pipe 19 in the axial direction of the central axis 19c of the inflow pipe 19. That is, the inflow pipe 19 is arranged around the rotating shaft 41. The "axial direction of the central axis of the inflow pipe" is a direction substantially parallel to the central axis 19c of the inflow pipe 19. The drive motor 42 is connected to the rotary shaft 41 directly or via a transmission mechanism or the like to rotate the rotary shaft 41. The support member 43 is connected to the lower end of the rotary shaft 41 and extends in the radial direction. The plurality of scraping plates 44 are attached to the support member 43.
That is, the rotating shaft 41 rotates the scraping plate 44 of the settling tank 1. The plurality of scraping plates 44 are provided from the support member 43 toward the bottom wall 31 of the tank body 11. According to the scraping unit 15 having such a configuration, the rotation shaft 41 is rotated by the drive motor 42, so that the support member 43 and the plurality of scraping plates 44 are rotated. As a result, the precipitate settled on the bottom wall 31 of the tank body 11 is scraped toward the central portion of the bottom wall 31. The collected sediment is discharged to the outside of the tank body 11 through the discharge port 31a provided in the central portion of the bottom wall 31 and the sludge drawing pipe 16.

The inner peripheral wall 20 of the distribution unit 18 will be described in detail.
FIG. 2 is a plan sectional view of the inflow unit of the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. As shown in FIG. 2, the inner peripheral wall 20 of the distribution portion 18 has a slit (inner peripheral wall opening) 60. The slit 60 penetrates the inner peripheral wall 20 in the R direction.

FIG. 5 is a view taken along the line V of FIG. The width (angle) of the slit 60 in the θ direction is formed to be constant along the Z direction. The width (angle) of the slit 60 in the θ direction may change along the Z direction. At least a part (lower end) of the slit 60 is arranged below the upper end 13t of the overflow weir 13. As described above, the water level WL of the water to be treated in the settling tank 1 coincides with the upper end 13t of the overflow weir 13. The lower end of the slit 60 is arranged below the water level WL of the water to be treated in the settling tank 1. The water to be treated that has flowed into the distribution unit 18 flows out to the settling tank 1 through the slit 60. The water level WL of the water to be treated in the distribution unit 18 becomes equivalent to the water level WL of the water to be treated in the settling tank 1. The slit 60 is formed from the upper end of the inner peripheral wall 20 to the bottom wall 18b of the distribution portion 18 in the Z direction. As will be described later, the slit 60 may be formed only in a part of the inner peripheral wall 20 in the Z direction.

As described above, flocs are generated in the coagulation tank on the upstream side of the settling tank 1. The water to be treated flows into the settling tank 1 in a state of containing flocs. In a settling tank different from the present embodiment, the water to be treated passes over the upper end of the inner peripheral wall 20 and flows into the inflow pipe 19. In this case, some heavy flocs cannot get over the upper end portion of the inflow pipe 19 and stay in the distribution portion 18. The stagnant flocs are deposited on the bottom wall 18b of the distribution section 18. If the flocs are unevenly deposited, the flow of water to be treated in the distribution unit 18 becomes non-uniform. Therefore, it becomes difficult to evenly flow the water to be treated into the inflow pipe 19 in the θ direction. When the inflow of the water to be treated into the inflow pipe 19 becomes non-uniform, a local high-speed flow of the water to be treated is generated inside the settling tank 1. As a result, the substantial residence time of the water to be treated inside the settling tank 1 is reduced. As a result, the settling separation performance of the settling tank 1 may deteriorate.

In the present embodiment, the inner peripheral wall 20 of the distribution unit 18 has a slit 60. The water to be treated that has flowed into the distribution unit 18 gradually flows out to the settling tank 1 through the slit 60. The slit 60 is formed from the upper end of the inner peripheral wall 20 to the bottom wall 18b of the distribution portion 18. The heavy flocs contained in the water to be treated are pushed by the flow of the water to be treated and discharged from the slit 60. Since the accumulation of flocs is suppressed, the flow of water to be treated in the distribution unit 18 becomes uniform. Along with this, the flow of water to be treated inside the settling tank 1 also becomes uniform. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

As shown in FIG. 2, the slits 60 are formed at a plurality of positions in the θ direction. The slit 60 includes a normal slit 62, a supply port slit 61, and a confluence slit 63.
The inner peripheral wall 20 is divided in the θ direction by the slit 60. The inner peripheral wall 20 usually includes an inner peripheral wall 22, a supply port inner peripheral wall 21, and a confluence inner peripheral wall 23.

The inner peripheral wall 21 of the supply port is arranged in the −R direction of the supply port 17a so as to face the water supply port 17a to be treated. The width of the inner peripheral wall 21 of the supply port in the θ direction is usually larger than that of the inner peripheral wall 22.
The water to be treated that has flowed into the distribution unit 18 from the supply port 17a flows in the −R direction and collides with the inner peripheral wall 21 of the supply port. The inner peripheral wall 21 of the supply port suppresses the water to be treated from directly flowing into the inflow pipe 19 from the supply port 17a. The inner peripheral wall 21 of the supply port divides the water to be treated on both sides in the θ direction. The water to be treated that has flowed through the distribution unit 18 in the + θ direction and the −θ direction is merged at the confluence portion 51c on the opposite side of the supply port 17a in the θ direction.

The inner peripheral wall 23 of the merging portion is arranged in the −R direction of the merging portion 51c. For example, the width of the confluence inner peripheral wall 23 in the θ direction is usually the same as that of the inner peripheral wall 22. The width of the confluence inner peripheral wall 23 in the θ direction may be larger than that of the normal inner peripheral wall 22.
Normally, the inner peripheral wall 22 is arranged between the inner peripheral wall 21 of the supply port and the inner peripheral wall 23 of the merging portion in the θ direction. A plurality of normal inner peripheral walls 22 are arranged side by side at equal angle intervals along the θ direction.

FIG. 3 is a view taken along the line III of FIG.
The supply port slits 61 are formed on both sides of the inner peripheral wall 21 of the supply port in the θ direction. The width of the supply port slit 61 in the θ direction is usually smaller than that of the slit 62.
FIG. 4 is an IV arrow view of FIG.
The merging portion slits 63 are formed on both sides of the merging portion inner peripheral wall 23 in the θ direction. The width of the confluence slit 63 in the θ direction is usually smaller than that of the slit 62.
FIG. 5 is a view taken along the line V of FIG.
The normal slit 62 is formed between the supply port slit 61 and the confluence slit 63 in the θ direction. A plurality of normal slits 62 are formed side by side at equal angle intervals along the θ direction. For example, the width of the normal slit 62 in the θ direction is usually the same as that of the inner peripheral wall 22.

As described above, the water to be treated flows into the distribution unit 18 from the supply port 17a shown in FIG. The water to be treated flows out from the distribution unit 18 through the slit 60.
The supply port slit 61 is arranged near the supply port 17a, and the slit 62 is usually arranged away from the supply port 17a. As described above, the width of the supply port slit 61 in the θ direction is usually smaller than that of the slit 62. Therefore, the outflow amount of the water to be treated from the supply port slit 61 is usually equivalent to the outflow amount from the slit 62.

As described above, the water to be treated divided into the + θ direction and the −θ direction and flowing through the distribution unit 18 merges at the confluence portion 51c.
The merging portion slit 63 is arranged near the merging portion 51c, and the slit 62 is usually arranged away from the merging portion 51c. As described above, the width of the confluence slit 63 in the θ direction is usually smaller than that of the slit 62. Therefore, the outflow amount of the water to be treated from the confluence slit 63 is usually the same as the outflow amount from the slit 62.

In this way, the water to be treated evenly flows out from the distribution unit 18 in the θ direction and flows into the inflow pipe 19. As a result, the water to be treated is evenly distributed at a low speed inside the settling tank 1 without being locally distributed at a high speed. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

As described above, the water to be treated that has flowed in from the supply port 17a is shunted to both sides in the θ direction by the inner peripheral wall 21 of the supply port. On the other hand, a diversion plate (baffle plate) for dividing the water to be treated on both sides in the θ direction may be arranged between the supply port 17a and the inner peripheral wall 20. The water to be treated is distributed substantially evenly in the θ direction by the diversion plate. In this case, the inner peripheral wall 20 may have only a plurality of normal inner peripheral walls 22 arranged at equal angular intervals along the θ direction. Further, the slits 60 may have only normal slits 62 arranged at equal angular intervals along the θ direction.

The position and shape of the slit 60 of the inner peripheral wall 20 can be changed.
FIG. 6 is a side sectional view taken along the line VI-VI of FIG. The inner peripheral wall 20 has a first inner peripheral wall 26 and a second inner peripheral wall 27. The first inner peripheral wall 26 and the second inner peripheral wall 27 are formed of a resin material such as vinyl chloride, a metal material such as aluminum, or the like. The first inner peripheral wall 26 and the second inner peripheral wall 27 are arranged side by side in the R direction. The first inner peripheral wall 26 is arranged in the + R direction, and the second inner peripheral wall 27 is arranged in the −R direction.

A groove 18g is formed at the end of the bottom wall 18b of the distribution portion 18 in the −R direction. The groove portion 18g is formed over the entire circumference in the θ direction. The groove portion 18g accommodates the lower ends of the first inner peripheral wall 26 and the second inner peripheral wall 27, and supports the first inner peripheral wall 26 and the second inner peripheral wall 27.

FIG. 7 is a view taken along the line VII of FIG. The first inner peripheral wall 26 has a first slit (first inner peripheral wall opening) 66. The second inner peripheral wall 27 has a second slit (second inner peripheral wall opening) 67. The first slit 66 and the second slit 67 are formed to have the same size (angle) in the θ direction. The slit 60 is formed by overlapping the first slit 66 and the second slit 67 in the R direction.

The first inner peripheral wall 26 is divided in the θ direction by the first slit 66. The second inner peripheral wall 27 is divided in the θ direction by the second slit 67. The plurality of divided first inner peripheral walls 26 and the second inner peripheral wall 27 can move in the θ direction along the groove portion 18g independently of each other. The first inner peripheral wall 26 and the second inner peripheral wall 27 are formed to have the same size (angle) in the θ direction. The inner peripheral wall 20 is formed by at least one of the first inner peripheral wall 26 and the second inner peripheral wall 27.

When the entire θ direction of the first inner peripheral wall 26 and the second inner peripheral wall 27 overlaps in the R direction, the width M1 of the inner peripheral wall 20 in the θ direction becomes the minimum. At this time, the width N1 of the slits 60 arranged between the adjacent inner peripheral walls 20 in the θ direction becomes maximum. On the other hand, when only a part of the first inner peripheral wall 26 and the second inner peripheral wall 27 in the θ direction overlap in the R direction, the width M2 of the inner peripheral wall 20 in the θ direction becomes large. At this time, the width N2 of the slits 60 arranged between the adjacent inner peripheral walls 20 in the θ direction becomes smaller. The position and shape (size) of the slit 60 can be changed by moving at least one of the first inner peripheral wall 26 and the second inner peripheral wall 27 in the θ direction. The position and shape of the slit 60 are adjusted according to the properties of the water to be treated. As a result, the water to be treated can be evenly flowed from the distribution unit 18 into the inflow pipe 19 in the θ direction.

As described above, the inner peripheral wall 20 is formed by two inner peripheral walls, a first inner peripheral wall 26 and a second inner peripheral wall 27. On the other hand, the inner peripheral wall 20 may be formed by three or more inner peripheral walls arranged side by side in the R direction.

As described in detail above, the inflow unit 12 of the embodiment includes an inflow pipe 19 and a distribution unit 18. The inflow pipe 19 is arranged around a rotating shaft 41 that rotates the scraping plate 44 of the settling tank 1. The distribution unit 18 is arranged above the inflow pipe 19 and can accommodate the water to be treated that flows into the inside of the inflow pipe 19. The distribution unit 18 has an inner peripheral wall 20 inside in the R direction, and the inner peripheral wall 20 has a slit 60 in which at least a part thereof is arranged below the upper end 13t of the overflow weir 13 of the settling tank 1.

At least a part of the slit 60 is arranged below the water level WL of the water to be treated in the settling tank 1. The water to be treated that has flowed into the distribution unit 18 flows out to the settling tank 1 through the slit 60. The heavy flocs contained in the water to be treated are pushed by the flow of the water to be treated and discharged from the slit 60. Since the accumulation of flocs is suppressed, the flow of water to be treated in the distribution unit 18 becomes uniform. Along with this, the flow of water to be treated inside the settling tank 1 also becomes uniform. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

The slit 60 is formed from the upper end of the inner peripheral wall 20 to the bottom wall 18b of the distribution portion 18.
The slits 60 are formed at a plurality of positions in the θ direction.
As a result, heavy flocs are discharged from the slit 60, and accumulation of flocs on the bottom wall 18b of the distribution portion 18 is suppressed.

The inflow unit 12 has a water supply unit 17 to be treated that forms a water supply port 17a for the water to be treated to the distribution unit 18. The inner peripheral wall 20 includes a supply port inner peripheral wall 21 arranged to face the supply port 17a. The width of the inner peripheral wall 21 of the supply port in the θ direction is larger than that of the other inner peripheral wall 20.
The water to be treated that has flowed into the distribution unit 18 from the supply port 17a collides with the inner peripheral wall 21 of the supply port. The inner peripheral wall 21 of the supply port suppresses the water to be treated from directly flowing into the inflow pipe 19 from the supply port 17a. As a result, the water to be treated is evenly distributed at a low speed inside the settling tank 1 without being locally distributed at a high speed.

The slit 60 includes a supply port slit 61 arranged on both sides of the inner peripheral wall 21 of the supply port in the θ direction. The width of the supply port slit 61 in the θ direction is smaller than that of the other slits 60.
The supply port slit 61 is arranged near the supply port 17a, and the other slit 60 is arranged away from the supply port 17a. Therefore, the inflow amount of the water to be treated from the supply port slit 61 to the inflow pipe 19 becomes the same as the inflow amount from the other slits 60. As a result, the water to be treated is evenly distributed at a low speed inside the settling tank 1 without being locally distributed at a high speed. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

The inner peripheral wall 20 can change at least one of the positions and shapes of the slits 60.
According to this configuration, the position and shape of the slit 60 can be adjusted according to the properties of the water to be treated. As a result, the water to be treated can be evenly flowed from the distribution unit 18 into the inflow pipe 19 in the θ direction. Therefore, the accumulation of flocs on the bottom wall 18b of the distribution unit 18 is suppressed.

The inner peripheral wall 20 has a first inner peripheral wall 26 and a second inner peripheral wall 27 that are arranged side by side in the R direction and can move in the θ direction independently of each other. The slit 60 is formed by a first slit 66 formed on the first inner peripheral wall 26 and a second slit 67 formed on the second inner peripheral wall 27.
Thereby, the position and shape of the slit 60 can be changed with a simple configuration.

FIG. 8 is an explanatory diagram of an inflow unit of the first modification of the first embodiment. FIG. 8 is an arrow view similar to that of FIGS. 3 to 5. The slit 68 of the first modification is formed only in the −Z direction (lower half) of the inner peripheral wall 20. The + Z direction of the slit 68 is closed by the inner peripheral wall 20.
The heavy flocs are included in the lower −Z direction of the water to be treated in the distribution unit 18. The heavy flock is discharged from the slit 68 arranged in the −Z direction of the inner peripheral wall 20.

As described above, flocs are generated in the coagulation tank on the upstream side of the settling tank 1. The water to be treated flows into the settling tank 1 in a state of containing flocs. When the water to be treated is supplied to the distribution unit 18, the flocs may be broken and decomposed into fine flocs. The fine flocs are separated from the water to be treated inside the settling tank 1 and are difficult to settle. Therefore, if the fine flocs flow into the inflow pipe 19, the settling separation performance of the settling tank 1 may deteriorate.

The fine flocs are contained in the water to be treated in the distribution unit 18 in the + Z direction. The slit 68 of the first modification is formed only in the −Z direction of the inner peripheral wall 20. Since the + Z direction of the inner peripheral wall 20 is closed, the outflow of the fine flocs from the distribution portion 18 is suppressed. As the residence time of the fine flocs in the distribution unit 18 becomes long, the association frequency of the fine flocs increases. As a result, the fine flocs are aggregated in the distribution unit 18 to promote the regeneration of flocs. The regenerated flocs move in the −Z direction of the distribution unit 18 and are discharged from the slit 68. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

FIG. 9 is an explanatory diagram of an inflow unit of the second modification of the first embodiment. FIG. 9 is an arrow view similar to that of FIGS. 3 to 5. The slit 69 of the second modification is formed only in the + Z direction (upper half) of the inner peripheral wall 20. Even in this case, at least a part (lower end portion) of the slit 69 is arranged below the upper end 13t of the overflow weir 13 of the settling tank 1.
Since the −Z direction of the slit 69 is blocked by the inner peripheral wall 20, the outflow of flocs is suppressed. Normally, by forming a part of the slit 62 with the slit 69, the outflow speed of the flocs can be suppressed.

(Second Embodiment)
FIG. 10 is a plan sectional view of the inflow unit of the second embodiment. FIG. 11 is a side sectional view taken along the line XI-XI of FIG. The inflow unit 212 of the second embodiment is different from the first embodiment in that it has an intermediate wall 220. The description of the second embodiment with respect to the same points as the first embodiment is omitted.

The distribution unit 18 of the inflow unit 212 has an outer peripheral wall 18a, an inner peripheral wall 120, an intermediate wall 220, and a bottom wall 18b. The outer peripheral wall 18a and the bottom wall 18b are formed in the same manner as in the first embodiment.
The intermediate wall 220 is arranged between the outer peripheral wall 18a and the inner peripheral wall 20 in the R direction. The intermediate wall 220 is formed in a cylindrical shape. The water supply unit 17 to be treated forms a water supply port 17a to be treated between the outer peripheral wall 18a and the intermediate wall 220 in the R direction. The supply port 17a is formed on the inner surface of the outer peripheral wall 18a.

The intermediate wall 220 divides the distribution unit 18 into a first flow path 51 and a second flow path 52 in the R direction. The first flow path 51 is outside in the R direction and is formed between the outer peripheral wall 18a and the intermediate wall 220. The second flow path 52 is inside in the R direction and is formed between the intermediate wall 220 and the inner peripheral wall 120. The first flow path 51 and the second flow path 52 are formed in an annular shape when viewed from the Z direction. For example, the widths of the first flow path 51 and the second flow path 52 in the R direction are the same.

The intermediate wall 220 has a slit (intermediate wall opening) 260. The slit 260 penetrates the intermediate wall 220 in the R direction. At least a part (lower end) of the slit 260 is arranged below the upper end 13t of the overflow weir 13. The slit 260 is formed from the upper end of the intermediate wall 220 to the bottom wall 18b of the distribution portion 18 in the Z direction. Similar to the inner peripheral wall 20 of the first embodiment, the intermediate wall 220 can change at least one of the positions and shapes of the slit 260.

The slits 260 are formed at a plurality of positions in the θ direction. Similar to the slit 60 of the first embodiment, the slit 260 includes a normal slit 262, a supply port slit 261 and a confluence slit 263.
The intermediate wall 220 is divided in the θ direction by the slit 260. The intermediate wall 220 includes a normal intermediate wall 222, a supply port intermediate wall 221 and a confluence intermediate wall 223, similarly to the inner peripheral wall 20 of the first embodiment.

The supply port intermediate wall 221 is arranged in the −R direction of the water supply port 17a to be treated. The width of the supply port intermediate wall 221 in the θ direction is usually larger than that of the intermediate wall 222.
The merging portion intermediate wall 223 is arranged in the −R direction of the merging portion 51c. For example, the width of the confluence intermediate wall 223 in the θ direction is usually the same as that of the intermediate wall 222.
Normally, the intermediate wall 222 is arranged between the supply port intermediate wall 221 and the confluence intermediate wall 223 in the θ direction. A plurality of normal intermediate walls 222 are arranged side by side at equal angle intervals along the θ direction.

The supply port slits 261 are formed on both sides of the supply port intermediate wall 221 in the θ direction. The width of the supply port slit 261 in the θ direction is usually smaller than that of the slit 262.
The merging portion slits 263 are formed on both sides of the merging portion intermediate wall 223 in the θ direction. The width of the confluence slit 263 in the θ direction is usually smaller than that of the slit 262.
The normal slit 262 is formed between the supply port slit 261 and the confluence slit 263 in the θ direction. A plurality of normal slits 262 are formed side by side at equal angle intervals along the θ direction. For example, the width of the normal slit 262 in the θ direction is usually the same as that of the intermediate wall 222.

The water to be treated that has flowed into the distribution unit 18 from the supply port 17a flows in the −R direction through the first flow path 51 and collides with the supply port intermediate wall 221. The supply port intermediate wall 221 suppresses the water to be treated from directly flowing into the second flow path 52 from the supply port 17a. The supply port intermediate wall 221 diverts the water to be treated on both sides in the θ direction. The water to be treated, which is divided into two directions in the + θ direction and the −θ direction and flows through the first flow path 51, merges at the confluence portion 51c on the opposite side of the supply port 17a in the θ direction. The water to be treated flows into the second flow path 52 through the slit 260 formed in the intermediate wall 220.

The supply port slit 261 is arranged near the supply port 17a, and the slit 262 is usually arranged away from the supply port 17a. As described above, the width of the supply port slit 261 in the θ direction is usually smaller than that of the slit 262. Therefore, the inflow amount of the water to be treated from the supply port slit 261 to the second flow path 52 is usually equal to the inflow amount from the slit 262.
The merging portion slit 263 is arranged near the merging portion 51c, and the slit 262 is usually arranged away from the merging portion 51c. As described above, the width of the confluence slit 263 in the θ direction is usually smaller than that of the slit 262. Therefore, the inflow amount of the water to be treated from the confluence slit 263 to the second flow path 52 is usually equal to the inflow amount from the slit 262.

In this way, the water to be treated evenly flows from the first flow path 51 into the second flow path 52 in the θ direction. As a result, the untreated water evenly flows into the inflow pipe 19 from the second flow path 52 in the θ direction. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

The inner peripheral wall 120 has a slit 160. Unlike the slit 60 of the first embodiment, the slit 160 usually has only the slit 162. A plurality of normal slits 162 are arranged at equal intervals along the θ direction.
The inner peripheral wall 120 is divided in the θ direction by the slit 160. The inner peripheral wall 120 usually has only the inner peripheral wall 122, unlike the inner peripheral wall 20 of the first embodiment. A plurality of normal inner peripheral walls 122 are arranged at equal intervals along the θ direction.

The water to be treated that has flowed into the second flow path 52 is discharged from the distribution section 18 through the slit 160 formed in the inner peripheral wall 120, and flows into the inflow pipe 19.
As described above, the water to be treated flows evenly from the first flow path 51 into the second flow path 52 in the θ direction. Therefore, even when the slit 160 normally has only the slit 162, the untreated water flows evenly from the second flow path 52 into the inflow pipe 19 in the θ direction. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

Similar to the inner peripheral wall 20 of the first embodiment, the inner peripheral wall 120 may be formed so that at least one of the positions and shapes of the slits 160 can be changed. The position and shape of the slit 160 are adjusted according to the nature of the water to be treated and the distribution condition. As a result, the water to be treated can flow into the inflow pipe 19 more evenly in the θ direction.

The water to be treated that has flowed into the distribution unit 18 flows in the first flow path 51 and the second flow path 52 in order. By flowing through a long flow path, the frequency of fine floc association increases. In particular, when the water to be treated merges at the merging portion 51c, the association of fine flocs becomes remarkable. As a result, the fine flocs are aggregated and the regeneration of flocs is promoted. The regenerated flocs are separated from the water to be treated and settled inside the settling tank 1. Therefore, the deterioration of the quality of the treated water is suppressed.

The intermediate wall 220 divides the distribution unit 18 into a first flow path 51 and a second flow path 52 in the R direction. As a result, the flow path cross-sectional area of the first flow path 51 and the second flow path 52 becomes small. The flow velocity of the water to be treated flowing through the first flow path 51 and the second flow path 52 is so high that floc accumulation does not occur. The flocs pass through the slits 260 and 160 and flow into the inflow pipe 19 without accumulating in the distribution section 18. Since the accumulation of flocs is suppressed, the flow of water to be treated in the distribution unit 18 becomes uniform. The water to be treated evenly flows into the inflow pipe 19 in the θ direction. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

In the second embodiment, one intermediate wall 220 is arranged between the outer peripheral wall 18a and the inner peripheral wall 120 of the distribution unit 18. On the other hand, two or more intermediate walls may be arranged between the outer peripheral wall 18a and the inner peripheral wall 120.

(Third Embodiment)
FIG. 12 is a side sectional view of the settling tank of the third embodiment. FIG. 13 is an enlarged view of part XIII of FIG. FIG. 13 is a side sectional view taken along line XIII-XIII of FIG. The inflow unit 312 of the third embodiment is the first embodiment in that the inner peripheral wall 20 of the distribution unit 18 is arranged in the −R direction of the inflow pipe 19 and the distribution unit 18 has a bottom wall opening 90. It is different from the form. The description of the third embodiment with respect to the same points as the first embodiment is omitted.

As shown in FIG. 12, the inner peripheral wall 20 of the distribution unit 18 is arranged in the −R direction of the inflow pipe 19. The outer peripheral wall 18a is arranged in the + R direction of the inflow pipe 19. The bottom wall 18b straddles the inflow pipe 19 in the R direction and is arranged on both sides of the inflow pipe 19 in the −R direction and the + R direction.
As shown in FIG. 13, the bottom wall 18b of the distribution section 18 has a bottom wall opening 90. The bottom wall opening 90 is formed in the bottom wall 18b arranged in the −R direction of the inflow pipe 19. The bottom wall opening 90 opens inside the inflow pipe 19.

FIG. 14 is a plan sectional view of the inflow unit of the third embodiment. FIG. 14 is a cross-sectional view of a portion corresponding to line II-II in FIG. The bottom wall opening 90 is formed in a circular shape when viewed from the Z direction. The bottom wall opening 90 may be formed in a shape other than a circular shape. The bottom wall opening 90 is formed at an intermediate position between the inner peripheral wall 20 and the inflow pipe 19 in the R direction. The bottom wall opening 90 may be formed near the inner peripheral wall 20 in the R direction, or may be formed near the inflow pipe 19. The bottom wall openings 90 may be formed at a plurality of positions in the R direction.

The bottom wall openings 90 are formed at a plurality of positions in the θ direction. For example, a plurality of bottom wall openings 90 are arranged at equal intervals along the θ direction. The bottom wall opening 90 does not have a supply port bottom wall opening arranged in the −R direction of the supply port 17a. The bottom wall opening 90 has a merging portion bottom wall opening 93 arranged at the merging portion 51c. The bottom wall opening 90 does not have to have the confluence bottom wall opening 93.

Similar to the first embodiment, the flocs contained in the water to be treated flow into the inflow pipe 19 through the slit 60 of the inner peripheral wall 20. In addition to this, in the third embodiment, the flocs flow into the inflow pipe 19 through the bottom wall opening 90. The flocs flow into the inflow pipe 19 through the bottom wall opening 90 without reaching the slit 60. As a result, the accumulation of flocs on the bottom wall 18b is suppressed. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

The bottom wall opening 90 does not have a supply port bottom wall opening arranged in the −R direction of the supply port 17a. The water to be treated that has flowed into the distribution unit 18 from the supply port 17a does not directly flow into the inflow pipe 19. Since the residence time of the water to be treated in the distribution unit 18 becomes long, the frequency of association of fine flocs increases, and the regeneration of flocs is promoted. Therefore, the deterioration of the quality of the treated water is suppressed.

The bottom wall opening 90 has a merging portion bottom wall opening 93 arranged at the merging portion 51c. The flock that has moved to the confluence portion 51c is discharged from the confluence portion bottom wall opening 93 to the inside of the inflow pipe 19. As a result, the accumulation of flocs on the bottom wall 18b is suppressed. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

As shown in FIG. 1, the inner peripheral wall 20 of the distribution unit 18 in the first embodiment is arranged at substantially the same position as the inflow pipe 19 in the R direction. At this time, the outer peripheral wall 18a is arranged away from the inflow pipe 19 in the + R direction. Therefore, the distance A between the outer peripheral wall 18a and the overflow weir 13 becomes small.
On the other hand, the inner peripheral wall 20 of the distribution unit 18 in the third embodiment is arranged in the −R direction from the inflow pipe 19 as shown in FIG. At this time, the outer peripheral wall 18a is arranged near the inflow pipe 19 in the + R direction. Therefore, the distance B between the outer peripheral wall 18a and the overflow weir 13 becomes large. As a result, the flow velocity of the water to be treated between the outer peripheral wall 18a and the overflow weir 13 becomes small. The substantial residence time of the water to be treated inside the settling tank 1 increases. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

FIG. 15 is a side sectional view of the settling tank of the first modification of the third embodiment. In the inflow unit 312a of the first modification, the inner peripheral wall 20 of the distribution unit 18 is arranged near the rotating shaft 41. At this time, the outer peripheral wall 18a is arranged at substantially the same position as the inflow pipe 19 in the R direction. Therefore, the distance C between the outer peripheral wall 18a and the overflow weir 13 becomes large. As a result, the flow velocity of the water to be treated between the outer peripheral wall 18a and the overflow weir 13 becomes small. The substantial residence time of the water to be treated inside the settling tank 1 increases. Therefore, the deterioration of the settling separation performance of the settling tank 1 is suppressed.

FIG. 16 is a plan sectional view of the inflow unit of the second modification of the third embodiment. FIG. 16 is a cross-sectional view of a portion corresponding to line II-II in FIG. In the inflow unit 312b of the second modification, the bottom wall opening 90 is formed in an elliptical shape. The bottom wall opening 90 is formed in an elliptical shape with the R direction as the minor axis direction and the θ direction as the major axis direction. The bottom wall opening 90 has a major axis direction in the θ direction, which is the flow direction of the water to be treated. As a result, the flocs contained in the water to be treated are easily discharged to the inflow pipe 19 through the bottom wall opening 90.

In the second modification, the bottom wall 18b can change the position and shape of the bottom wall opening 90. The bottom wall 18b of the distribution unit 18 has a first bottom wall 86 and a second bottom wall 87. The first bottom wall 86 and the second bottom wall 87 are arranged side by side in the Z direction. The first bottom wall 86 is arranged in the + Z direction, and the second bottom wall 87 is arranged in the −Z direction.

The first bottom wall 86 is formed in an annular shape over the entire circumference in the θ direction. The first bottom wall 86 is fixed to the outer peripheral wall 18a and the inner peripheral wall 20.
The second bottom wall 87 is formed in an arc shape only in a part in the θ direction. The second bottom wall 87 is formed so as to be movable in the θ direction with respect to the first bottom wall 86. The second bottom wall 87 is arranged at each of the formation positions of the plurality of bottom wall openings 90. The plurality of second bottom walls 87 can move in the θ direction independently of each other.

The first bottom wall 86 has a first bottom wall opening 96. The second bottom wall 87 has a second bottom wall opening 97. The first bottom wall opening 96 and the second bottom wall opening 97 are formed in the same shape when viewed from the Z direction. The bottom wall opening 90 is formed by overlapping the first bottom wall opening 96 and the second bottom wall opening 97 in the Z direction.

As shown in FIG. 16, when the entire first bottom wall opening 96 and the second bottom wall opening 97 overlap in the Z direction, the opening area of the bottom wall opening 90 becomes maximum.
FIG. 17 is an operation explanatory view of the inflow unit of the second modification of the third embodiment. When the second bottom wall 87 is moved in the θ direction with respect to the first bottom wall 86, only a part of the first bottom wall opening 96 and the second bottom wall opening 97 overlaps in the Z direction. At this time, the opening area of the bottom wall opening 90 becomes smaller. In this way, the shape (size) of the bottom wall opening 90 can be changed by moving the second bottom wall 87 with respect to the first bottom wall 86 in the θ direction.

As described above, the bottom wall 18b can change the position and shape of the bottom wall opening 90.
Thereby, the position or shape of the bottom wall opening 90 can be adjusted according to the nature of the water to be treated. As a result, the water to be treated can flow into the inflow pipe 19 evenly in the θ direction. Further, the inflow speed of the water to be treated and the flocs from the distribution unit 18 to the inflow pipe 19 can be adjusted.

FIG. 18 is a plan sectional view of the inflow unit of the third modification of the third embodiment. FIG. 18 is a cross-sectional view taken along the line II-II of FIG. The inflow unit 312c of the third modification is different from the first modification in that the distribution unit 18 has an intermediate wall 220. The structure of the intermediate wall 220 is similar to that of the second embodiment.

The water to be treated that has flowed into the distribution unit 18 from the supply port 17a flows in the −R direction through the first flow path 51 and collides with the supply port intermediate wall 221. The supply port intermediate wall 221 suppresses the water to be treated from directly flowing into the second flow path 52 from the supply port 17a. The supply port intermediate wall 221 diverts the water to be treated on both sides in the θ direction. The water to be treated, which is divided into two directions in the + θ direction and the −θ direction and flows through the first flow path 51, merges at the confluence portion 51c on the opposite side of the supply port 17a in the θ direction. The water to be treated flows into the second flow path 52 through the slit 260 formed in the intermediate wall 220.

The water to be treated that has flowed into the second flow path 52 flows into the inflow pipe 19 through the slit 160 formed in the inner peripheral wall 120 and the bottom wall opening 90 formed in the bottom wall 18b. The flocs contained in the water to be treated are discharged from the distribution unit 18 through the slit 60 of the inner peripheral wall 20 and the bottom wall opening 90 formed in the bottom wall 18b. As a result, the accumulation of flocs on the bottom wall 18b is suppressed.

The water to be treated flows in the first flow path 51 and the second flow path 52 in order. By flowing through a long flow path, the frequency of fine floc association increases. As a result, the fine flocs are aggregated and the regeneration of flocs is promoted. The regenerated flocs are separated from the water to be treated and settled inside the settling tank 1. Therefore, the deterioration of the quality of the treated water is suppressed.

According to at least one embodiment described above, the inner peripheral wall 20 of the distribution unit 18 has a slit 60. As a result, the accumulation of flocs on the bottom wall 18b of the distribution unit 18 is suppressed, so that the deterioration of the sedimentation separation performance of the settling tank 1 can be suppressed.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

R ... radial direction, θ ... circumferential direction, 1 ... settling tank, 11 ... tank body, 12 ... inflow unit, 13 ... overflow weir, 13t ... upper end, 17 ... water supply unit to be treated, 17a ... supply port, 18 ... Distributor (accommodation), 18a ... Outer wall, 18b ... Bottom wall, 19 ... Inflow pipe, 20 ... Inner wall, 21 ... Supply port inner wall, 26 ... First inner wall, 27 ... Second inner wall, 41 ... Rotating shaft, 44 ... Scratch plate, 60 ... Slit (inner peripheral wall opening), 61 ... Supply port slit (supply port inner peripheral wall opening), 66 ... 1st slit (1st inner peripheral wall opening), 67 ... 2nd slit (2nd slit) 2 inner peripheral wall opening), 90 ... bottom wall opening, 220 ... intermediate wall, 260 ... slit (intermediate wall opening).

Claims (13)

An inflow pipe arranged around a rotating shaft that rotates the settling plate,
It has an accommodating portion that is arranged above the inflow pipe and can accommodate the water to be treated that flows into the inside of the inflow pipe.
The accommodating portion has an inner peripheral wall inside the accommodating portion in the radial direction of the inflow pipe.
The inner peripheral wall has an inner peripheral wall opening at least partially located below the upper end of the overflow weir of the settling tank.
Inflow unit. The inner peripheral wall opening is formed from the upper end of the inner peripheral wall to the bottom wall of the accommodating portion.
The inflow unit according to claim 1. The inner peripheral wall openings are formed at a plurality of positions in the circumferential direction of the inflow pipe.
The inflow unit according to claim 1 or 2. It has a water supply unit to be treated that forms a supply port for water to be treated to the storage unit.
The inner peripheral wall includes a supply port inner peripheral wall arranged to face the supply port.
The width of the inner peripheral wall of the supply port in the circumferential direction is larger than that of the other inner peripheral walls.
The inflow unit according to claim 3. The inner peripheral wall opening includes the supply port inner peripheral wall openings arranged on both sides of the supply port inner peripheral wall in the circumferential direction.
The width of the inner peripheral wall opening of the supply port in the circumferential direction is smaller than that of the other inner peripheral wall openings.
The inflow unit according to claim 4. The inner peripheral wall can change at least one of the positions and shapes of the inner peripheral wall opening.
The inflow unit according to any one of claims 1 to 5. The inner peripheral wall has a first inner peripheral wall and a second inner peripheral wall which are arranged side by side in the radial direction and can move in the circumferential direction of the inflow pipe independently of each other.
The inner peripheral wall opening is formed by a first inner peripheral wall opening formed on the first inner peripheral wall and a second inner peripheral wall opening formed on the second inner peripheral wall.
The inflow unit according to claim 6. The accommodating portion has an outer peripheral wall on the outer side in the radial direction.
The accommodating portion has an intermediate wall between the outer peripheral wall and the inner peripheral wall in the radial direction.
The intermediate wall has an intermediate wall opening at least partially located below the upper end of the overflow weir.
The inflow unit according to any one of claims 1 to 7. The intermediate wall is capable of changing at least one of the positions and shapes of the intermediate wall openings.
The inflow unit according to claim 8. The inner peripheral wall is arranged inside the inflow pipe in the radial direction.
The inflow unit according to any one of claims 1 to 9. The bottom wall of the accommodating portion has a bottom wall opening that opens inside the inflow pipe.
The inflow unit according to claim 10. The bottom wall is capable of changing at least one of the positions and shapes of the bottom wall openings.
The inflow unit according to claim 11. With the tank body
The inflow unit according to any one of claims 1 to 12;
Settlement tank.

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