JP2010172872A - Muddy water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small muddy water treatment apparatus of high performance that quickly removes suspended solids. <P>SOLUTION: A perforated plate 10 with a plurality of water passage holes 9 is installed horizontally or tilted toward the side in a treatment vessel designed so that muddy water flows upward. An upward cylindrical rising edge 11 is attached to the edge of each water passage hole 9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a muddy water treatment apparatus for removing suspended substances in muddy water.

In areas where upward filter ponds are installed as small-scale water purification devices that use mountain stream water and valley water as raw water, the water supply will be drastically increased due to abnormal rainfall such as thunderstorms, torrential rains and typhoons in summer Sudden increase in turbidity (turbidity is defined by JIS K0101) frequently occurs, which causes a problem that the filter bed of the filter basin is clogged.
The main component of this muddy water is an inorganic substance, and most of it is mountain soil and sand.
The inflow duration of muddy water in the upstream area of such a river is often several hours at most, unlike the middle and downstream areas.

In order to solve such a problem, there is no method other than removing suspended substances in muddy water or preventing inflow of muddy water.
As means for removing suspended substances, a sedimentation tank (for example, see Patent Document 1) and a sedimentation tank (for example, see Non-Patent Document 1) are known.
Non-Patent Document 1 stipulates that the turbidity of the raw water in the slow filtration basin is approximately 10 degrees or less. However, it is said that precipitation treatment or primary filtration equipment can be added to the turbidity increase of the raw water before the slow filtration. In addition, the residence time in a normal sedimentation tank or a sedimentation tank is about 8 hours.
However, sedimentation basins and sedimentation tanks require a large area, and many small-scale water purification facilities in mountainous areas are not installed due to restrictions on topography and area.

As a means for preventing the inflow of turbid water, there is one that prevents the clogging of the filtration basin by performing control such as stopping the inflow of raw water at the time of high turbidity by a high turbidity sensing system.
With this means, since the inflow of raw water stops, clean water cannot be obtained during that time. In order to avoid the water outage, a large reservoir for storing the purified water is required, but the time during which high turbidity continues does not deviate from the estimated range, so it is difficult to plan this size. In addition, the high turbidity detection system and the control device require a large amount of construction cost and are difficult to manage, so that they are rarely used in small-scale water purification facilities.

JP 2008-229437 A

“Water Supply Facility Design Guidelines 2000” published by Japan Water Works Association

  In order to recover the clogging of the filtration bed in the filtration basin and maintain the purification function, the washing work of the filtration bed is indispensable. The standard frequency of cleaning the upward filtration pond is 1-2 times a year, but depending on the inflow of high turbidity raw water such as thunderstorms, typhoons, and torrential rains, several times a year or every month Once, sometimes it may be necessary to carry out every rain. In an emergency cleaning operation, it is necessary to urgently dispatch cleaning personnel and to secure the amount of cleaning water. In addition, depending on the balance between the amount of water stored in the reservoir that stores the purified water and the amount of water used, which is the amount of water used, it is also predicted that there will be a situation where water must be cut off during the cleaning operation.

  By installing a muddy water treatment apparatus having an effective turbidity function according to the inflow mode of muddy water in front of the new and existing water purification apparatus, obstacles are avoided and anxiety is eliminated. Moreover, since this muddy water treatment apparatus is often installed in a narrow place, it is desirable that it can be miniaturized.

  In view of the above situation, an object of the present invention is to provide a muddy water treatment apparatus that is small in size, high in performance, and capable of quickly removing suspended substances.

According to the present invention, the above problem is solved as follows.
(1) In a treatment tank in which muddy water flows upward, a perforated plate having a plurality of water passage holes is disposed so as to be inclined horizontally or laterally. An upright cylindrical standing edge is provided at the edge of the skirt.

With such a configuration, when turbid water passes upward through each water passage hole of the perforated plate, the flow velocity temporarily increases, and at the side thereof, the pressure is reduced according to Bernoulli's theorem, A vortex flow is generated in a radial direction centering on the passing flow, and suspended substances in muddy water ride on this vortex flow and stay on the outer periphery of the water passage hole on the upper surface of the perforated plate.
Suspended matter staying on the upper surface of the perforated plate tends to move toward the water passage hole due to the vortexing action, but the edge of the water passage hole is provided with an upright cylindrical standing edge. Therefore, the suspended substance continues to stay on the upper surface of the perforated plate without joining the turbid water passing through the water passage holes.
Therefore, after the turbid water passes through each water passage hole, the suspended substance quickly settles on the perforated plate, so that the removal efficiency of the suspended substance can be improved and the permeated plate has a large number of standing edges. By providing the holes, it is possible to reduce the size and improve the performance.

  (2) In the above item (1), a plurality of perforated plates are arranged in a multistage manner in the treatment tank.

  With such a configuration, further miniaturization and higher performance can be achieved.

  (3) In the above item (1) or (2), the height of the standing edge is 3 to 7 mm.

With such a configuration, the suspended matter staying on the upper surface of the perforated plate is moved toward the water passage hole by the vortexing action, and it is reliably prevented from joining the muddy water passing through the water passage hole. can do.
Note that the height of the rising edge may be appropriately determined within the above range based on the amount of suspended solids expected to stay on the upper surface of the porous plate.

  (4) In any one of the above items (1) to (3), the perforated plate is provided in the treatment tank so as to be inclined to the side, and the precipitate is led to the sediment retaining portion on the lower end side of the perforated plate. Provide a streamer.

  With such a configuration, the processing operation can be continued for a long period of time, and the number of removal operations by washing of the suspended substance retained on the perforated plate can be reduced.

  (5) In any one of the above items (1) to (4), an upward flow filtering means is disposed in the upper part of the treatment tank.

  With such a configuration, the turbid water treatment device of the present invention can be integrated into the upward flow filtration device as its pretreatment means, reducing installation space, reducing installation costs, and treating efficiency. Improvements can be made.

  (6) In any one of the above items (1) to (5), a drain pipe is connected to the lower end portion of the treatment tank, and the precipitate retained on the porous plate is located above the porous plate in the treatment tank. A cleaning device for cleaning is provided.

  With such a configuration, when the amount of suspended matter retained on the perforated plate becomes large, the turbid water treatment operation is temporarily stopped, and the retained suspended matter is quickly washed, and the drain tube It can be discharged more.

  According to the present invention, it is possible to provide a muddy water treatment apparatus that is small in size, high in performance, and capable of quickly removing suspended substances.

It is a typical longitudinal section front view of a 1st embodiment of a muddy water treatment device of the present invention. It is an enlarged vertical front view of a part of the porous plate for explaining the operation. It is an enlarged vertical front view similar to FIG. 2, showing a comparative example. It is a typical vertical front view of 2nd Embodiment of the muddy water processing apparatus of this invention. It is a typical vertical front view of the experimental apparatus for demonstrating the effect of the muddy water processing apparatus of this invention, and the raw | natural water supply apparatus to it.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a first embodiment when a muddy water treatment apparatus 1 according to the present invention is used as a pretreatment apparatus for a purification apparatus (not shown) for purifying raw water into clean water.
As shown in FIG. 1, this muddy water treatment apparatus 1 includes a treatment tank 3 in which raw water 2 that has become suspended due to inflow of suspended substances flows upward.

The bottom surface 3a of the processing tank 3 has a funnel shape that is inclined downward toward the center, and a drain pipe 5 including a drain valve 4 is provided at the center.
An inflow pipe 8 connected to the raw water supply source 6 and provided with an inflow valve 7 is provided at the lower part of the treatment tank 3, and the tip of the inflow pipe 8 opens at the lower center of the treatment tank 3. .

  In the treatment tank 3, as shown in FIG. 2, a plurality of perforated plates 10 each having a plurality of water passage holes 9 formed in a predetermined pattern are horizontally arranged in upper and lower stages. Has been.

As shown in FIG. 2, an upward cylindrical standing edge 11 is provided at the edge of each water passage hole 9 in each porous plate 10.
The material of the porous plate 10 is not particularly limited, and can be formed of metal or synthetic resin.
The height of the standing edge 11 is preferably 3 to 7 mm.

  The hole diameter of the water passage holes 9 of the perforated plate 10 in each stage, the interval between the water passage holes 9, the height of the standing edge 11, etc. are made different from each other, for example, the lower one is made larger. May be.

  On the upper side surface of the treatment tank 3 above the uppermost porous plate 10, when the water level of the raw water 2 in the treatment tank 3 is equal to or higher than a predetermined water level, the muddy water-treated raw water 2 overflows. An outflow pipe 12 is provided.

  Further, at the upper part of the treatment tank 3, there is provided a water spray pipe 14 that is connected to the raw water supply source 6 or other water source via a cleaning valve 13 and forms a cleaning device. A large number of watering nozzles 14a are provided.

  An observation window 15 formed by liquid-tight fitting a transparent glass plate or the like may be provided on any side wall 3b of the processing tank 3 as necessary.

A first switching valve 17 that selectively supplies the raw water 2 of the raw water supply source 6 to the inflow pipe 8 and the sprinkling pipe 14 side and the bypass pipe 16 side is provided at the outlet portion of the raw water supply source 6. .
The outlet end of the bypass pipe 16 and the outlet end of the outflow pipe 12 are connected to the raw water inflow pipe 19 in the purification device (not shown) via the second switching valve 18, and pass through the bypass pipe 16. The raw water 2 that has been sent and the raw water 2 that has been subjected to muddy water treatment through the muddy water treatment device 1 can be selectively supplied to the raw water inflow pipe 19.

  Although all the valves such as the first and second switching valves 17 and 18, the drain valve 4, the inflow valve 7, and the cleaning valve 13 may be opened and closed manually, the control device schematically shown in FIG. It is preferable to be opened and closed by 20 commands.

  In particular, when the turbidity of the raw water 2 of the raw water supply source 6 is equal to or lower than a predetermined turbidity, the first and second switching valves 17 and 18 are all controlled by the control device 20 so that all of the raw water 2 passes through the bypass pipe 16. The turbidity detection device (not shown) that is controlled to pass and detects the turbidity of the raw water 2 of the raw water supply source 6 detects a predetermined turbidity, or the raw water 2 of the raw water supply source 6 is visually detected. When it is confirmed that the turbid water treatment device 1 is manually input to the control device 20 after confirming that it is cloudy, the control device 20 simultaneously switches the raw water 2 to be supplied to the turbid water treatment device 1 side. It is better to do so.

Next, the operation and handling of the muddy water treatment apparatus 1 will be described.
When an operation command for the muddy water treatment device 1 is input to the control device 20, the drain valve 4 and the cleaning valve 13 are closed, and the inflow valve 7 is opened. It is preferable that the opening degree of the inflow valve 7 at this time can be adjusted as appropriate.

When the inflow valve 7 is opened, the raw water 2 of the raw water supply source 6 is supplied into the treatment tank 3 through the inflow pipe 8, and the water level of the raw water 2 in the treatment tank 3 gradually rises.
When the raw water 2 in the treatment tank 3 passes upward through the water passage holes 9 of the perforated plates 10 in each stage, as shown in an enlarged view in FIG. The flow velocity is greater than that of the surroundings, and at the outer periphery of the passage flow A, the pressure is reduced according to Bernoulli's theorem, and a vortex B is generated in the radial direction centering on the passage flow A. Rides on the vortex B and stays in the outer peripheral portion of the water passage hole 9 on the upper surface of each porous plate 10.

  The suspended substance C staying on the upper surface of the perforated plate 10 tends to be moved toward the water passage hole 9 by the entrainment action of the vortex B, but the edge of the water passage hole 9 has an upward cylindrical shape. Since the standing edge 11 is provided, the suspended substance C continues to stay on the upper surface of the porous plate 10 without joining the passing flow A.

  Therefore, when the raw water 2 rises in the treatment tank 3, that is, each time it passes through each porous plate 10, the suspended matter C is gradually removed, and when it overflows the outflow pipe 12, most of the suspended water C is suspended. After the turbid substance C is removed and purified, the turbid substance C is supplied to the raw water inflow pipe 19 of the purification device.

FIG. 3 shows a comparative example in which the standing edge 11 is not provided at the edge of the water passage hole 9 in the perforated plate 10.
In this case, the suspended substance C staying on the upper surface of the perforated plate 10 is moved toward the water flow hole 9 by the entrainment action of the vortex B, merges with the through flow A, and is wound up again. The removal efficiency of the turbid substance C is extremely poor.

  When it is confirmed by visual recognition from the observation window 15 that the height of the suspended substance C staying on any of the perforated plates 10 has approached the height of the standing edge 11, the inflow valve 7 is closed, While stopping the supply of the raw water 2 from the inflow pipe 8 and opening the drain valve 4 and the cleaning valve 13, the raw water 2 and the suspended matter C in the treatment tank 3 are discharged from the drain pipe 5, and the water spray pipe 14 is sprayed to wash away suspended matter C retained on each porous plate 10.

In order to facilitate cleaning of the perforated plate 10 at this time, it is preferable to provide a gap without an upstanding edge between the entire peripheral edge of each perforated plate 10 or a part thereof and the inner surface of the treatment tank 3.
Further, the sprinkling pipe 14 may be provided not only at the upper part in the treatment tank 3 but also at the intermediate part or above each porous plate 10.
Further, each porous plate 10 is simply placed on a bracket 10 a provided on the inner surface of the treatment tank 3, and can be easily removed from the porous plate 10 so that it can be cleaned. Each of the perforated plates is pivoted to the inner surface of the processing tank 3 with a horizontal axis (not shown), and the bracket 10a supporting the other side end is removed from the inner surface of the processing tank 3 or moved. 10 may be inclined downward from the horizontal axis to facilitate cleaning.

  After the perforated plate 10 is cleaned, the drain valve 4 and the cleaning valve 13 are closed, and the inflow valve 7 is opened, so that the suspended substance C can be removed from the raw water 2 again.

FIG. 4 is a schematic longitudinal sectional front view of the second embodiment of the muddy water treatment apparatus of the present invention.
In this embodiment, a horizontal receiving plate 22 having a large number of water permeable holes 21 is provided in the middle portion in the vertical direction of the treatment tank 3, and the crushed stone is the same as that in the conventional upward flow filtration device. By providing the upward flow filtration means 23 composed of a filtration layer in which gravel, sand and the like are sequentially refined from below to above, the muddy water treatment apparatus 1 is used as a pretreatment means for the upward flow filtration apparatus 24. It is assumed that it is integrally formed.

  Below the horizontal receiving plate 22 in the treatment tank 3, a plurality of mountain-shaped perforated plates 25 inclined downward from the center toward both sides above the inflow pipe 8 are provided in multiple stages in the vertical direction. At both ends of each perforated plate 25, there are provided flow-down tubs 26 for guiding the precipitate to a precipitate retention portion (not shown).

The height of the cylindrical standing edge 27 provided at the edge of the plurality of water passage holes 26 drilled in each of the mountain-shaped perforated plates 25 is higher as it is at a lower slope. Suspended substance C (see FIG. 2) deposited on the surface of the suspended material C climbs over the rising edge 27 at a low slope so as not to join the passing flow A (see FIG. 2) passing through the water passage hole 26.
Other configurations are the same as those of the first embodiment.

According to the second embodiment, the suspended substance C precipitated on each porous plate 25 is slowly fluidized along the inclination of each porous plate 25 by the same action as in the first embodiment. Then, it is guided to the sediment retaining portion along the downflow basin 26.
Therefore, it is not necessary to perform the cleaning operation of the porous plate 25 over a long period of time, and the number of cleaning operations can be reduced.

FIG. 5 is an experimental apparatus for grasping the effectiveness of the turbidity effect by the muddy water treatment apparatus of the present invention.
In the raw water tank 30, a stirring device 31 and a pump 32 are provided, and Kanuma soil is introduced, the raw water 2 is stirred by the stirring device 31, and the raw water 2 pumped up by the pump 32 is flowed in the flow rate adjusting tank 33. And the turbidity are adjusted so as to have the following specifications, and are supplied into the treatment tank 3 from the inflow pipe 8.
Various conditions of this experimental apparatus are as follows.
Size of the processing tank 3: length 285 mm × width 285 mm × height 850 mm
Residence time of raw water 2 in treatment tank 3: 1.13 liters / minute ... 1.62 m3 / day Upward flow velocity of raw water 2 in treatment tank 3: 20 m / day ... 0.83 m / hour perforated plate Inner diameter and interval of 10 water passage holes: Diameter 7 mm x interval 15 mm, diameter 5 mm x interval 15 mm
Number of perforated plates 10: diameter 7 mm × 2 and diameter 5 mm × 5 perforated plates 10 in the vertical direction: 75 mm
Initial turbidity of raw water 2: about 80 degrees Experiment duration: 6-8 hours

  The average turbidity of mountain stream water and valley water in normal times is 5 or less, but the turbidity increases rapidly to around 50 when it rains, and often exceeds this when it rains abnormally. Since the maximum turbidity of raw water in a conventional upward flow filtration apparatus is generally 50 degrees, the experiment was conducted at a turbidity of about 80 degrees higher than this.

  The experiment duration was set to 6 to 8 hours. In the case of mountain stream water and valley water, the turbidity rise at the beginning of the rain was large, but the turbidity was relatively lowered after several hours even if the rain continued. Is taken into account.

In order to confirm the effectiveness of the turbidity-eliminating effect of this experimental apparatus, using the same experimental apparatus, all the perforated plates 10 were removed, all other conditions were the same, and the empty operation was carried out only by natural sedimentation separation. The degree change was observed. The results are as shown in Tables 1 and 2.

  As is apparent from the experimental results, the removal rate of turbid matter in the idling operation is 5.7%, whereas the removal rate of turbid matter is 35.3 when the porous plate 10 is used. %. This difference indicates that the turbid water treatment apparatus of the present invention has a large turbidity-removing action.

  Since the average value of the turbidity of the treated water is 50.20, this experimental apparatus can be used almost as it is as a pretreatment apparatus of a conventional upward flow filtration apparatus.

From the measurement result of the turbidity of the intermediate water collected from the intermediate data collection position in the treatment tank 3, it can be seen that the turbidity is different depending on the number of installation stages of the porous plate 10.
It is expected that the turbid content captured below the intermediate data collection position and the turbid content captured similarly above will differ to some extent, but it will match the turbid content in the raw water 2 to be collected. Thus, it is presumed that a more efficient turbidity effect can be obtained by determining the number of installation stages of the perforated plate 10, the inner diameter and the interval of the water passage holes 9, and the like.

  Since almost the same removal rate was obtained during the 8 hours of the experiment, the device of the present invention was effectively used in the first few hours of the rain when it was predicted that high turbid water would actually continue. Proven to be available.

  After the experiment is completed, after draining and draining from the bottom of the treatment tank 3, when clear water is sprinkled from above, turbid components deposited on the perforated plates 10 fall from the upper water passage holes 9. It was washed with washing water to be discharged and discharged to the outside of the treatment tank 3 in a few minutes.

The treatment tank 3 used in the above-mentioned experiment corresponds to about 1/4 of the area of the conventional upward flow filter and 1/2 of the height (depth of the tank). Further, with this volume, the raw water 2 having a turbidity of 80 can be deturbed to a turbidity of about 50 degrees with an upward flow rate of 20 m / day and a residence time of 1 hour.
This treatment time is 1/8 compared to the sedimentation time of 8 hours in the normal sedimentation basin.
Therefore, it can be effectively installed in a narrow space as a pretreatment device for a water purification device in a mountainous area.

1 Muddy water treatment device 2 Raw water (turbid water)
DESCRIPTION OF SYMBOLS 3 Treatment tank 3a Bottom surface 3b Side wall 4 Drain valve 5 Drain pipe 6 Raw water supply source 7 Inflow valve 8 Inflow pipe 9 Water flow hole 10 Perforated plate 10a Bracket 11 Standing edge 12 Outflow pipe 13 Washing valve 14 Sprinkling pipe 14a Watering nozzle (cleaning device) )
15 observation window 16 bypass pipe 17 first switching valve 18 second switching valve 19 (purifier) raw water inflow pipe 20 controller 21 water permeation hole 22 horizontal receiving plate 23 upward flow filtration means 24 upward flow filtration device 25 perforated plate 26 Water flow hole 27 Standing edge 30 Raw water tank 31 Stirrer 32 Pump 33 Flow rate adjusting tank

Claims (6)

  In a treatment tank in which muddy water circulates upward, a perforated plate having a plurality of water passage holes is horizontally or laterally inclined and disposed at the edge of each water passage hole. A muddy water treatment apparatus provided with an upward cylindrical rising edge.   The muddy water treatment apparatus according to claim 1, wherein a plurality of perforated plates are arranged in a multistage manner in the treatment tank.   The muddy water treatment apparatus according to claim 1 or 2, wherein the height of the standing edge is 3 to 7 mm.   The turbid water according to any one of claims 1 to 3, wherein a perforated plate is provided in the treatment tank so as to be inclined to the side, and a falling gutter is provided on the lower end side of the perforated plate to guide the precipitate to the sediment retaining portion. Processing equipment.   The muddy water treatment apparatus according to any one of claims 1 to 4, wherein an upward flow filtration means is disposed at an upper portion of the treatment tank.   The drain apparatus is connected to the lower end part of a processing tank, and the washing | cleaning apparatus which wash | cleans the deposit which stayed on the porous board was provided above the porous board in a processing tank. Turbid water treatment equipment.

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