JPS6147562B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides efficient precipitation and separation of suspended solids (hereinafter referred to as SS) such as inorganic solids and organic solids from various types of suspended water (hereinafter referred to as raw water). The present invention provides a precipitation device for obtaining clear water.

That is, the precipitation apparatus of the present invention, as shown in FIGS. 1 and 2, includes an upper tank 1 and a lower tank 2. A divided multi-stage inclined sedimentation layer 4, a raw water supply vertical channel 5 communicating with the upper end inlet of the multi-stage inclined precipitation layer 4, a downward flow channel 6 communicating with the lower end outlet of the multi-stage inclined precipitation layer 4, and a lower end thereof. An ascending channel 7 is provided, the opening of which is adjacent to the lower end opening of the descending channel 6, and the lower tank 2 communicates with the lower end openings of the descending channel 6 and the ascending channel 7. It is equipped with a funnel part 8 for collecting sediment and a water collector 9 that opens above the funnel part 8, and a discharge pipe 10 for discharging the sediment together with raw water is connected to the bottom of the funnel part 8. Clear water is made to overflow and discharge from the upper end of the channel 7 and the upper end of the rising water pipe 11 communicating with the water collector 9.

Hereinafter, the specific structure will be explained in more detail based on an embodiment shown in FIGS. and an overflow pipe 14, and a water supply pipe 16 for supplying raw water to the upper end of the raw water supply vertical channel 5 in the upper tank 1 via a water supply valve 15 is connected to the lower part. In this embodiment, the upper tank 1 and the lower tank 2 are cylindrical, and as shown in FIGS. The plate 3b is a circular umbrella-shaped plate having a through hole in the center that forms the raw water supply vertical flow path 5, and the lowermost inclined plate 3a is a base plate that forms the bottom of the raw water supply vertical flow path 5. 17 and a bottom plate 18 that seals the lower side of the inclined plate 3a. The truncated conical body 19 forming the lowermost inclined plate 3a is supported at a plurality of peripheral points on the inner upper side of the lower tank 2 via the bracket 20, and the other umbrella-shaped inclined plates 3b are supported by the lower inclined plates 3a,
It is supported by the lower inclined plates 3a and 3b by a weir plate 21 interposed radially between the upper surface (upper surface) of the lower inclined plate 3b. As shown in FIGS. 1 and 2, a covered cylindrical body 22 that seals the upper end of the raw water supply flow path 5 projects from the center of the uppermost inclined plate 3c, and inside this covered cylindrical body 22. The water supply pipe 16 is inserted into.

The descending flow path 6 and the ascending flow path 7 have a circular cylindrical shape, and 23 is a covered inner cylinder that partitions the two flow paths 6 and 7, and the upper end is sealed at the position of the covered cylinder body 22. As shown in FIG. 4, it is supported on the peripheral wall of the upper tank 1 by vertical support plates 24 at multiple locations in the circumferential direction. The upper end of the ascending flow path 7 is open,
An annular clear water receiving tank 25 for receiving overflow water from the ascending channel 7 is provided on the outside thereof. 26 is the clear water from the clear water receiving tank 25 and the rising water pipe 1
This is a flow rate regulating tank that receives clear water from 1, and is equipped with an overflow weir 27 and a discharge pipe 28. 2
Reference numeral 9 indicates a flow rate adjustment valve interposed in the rising water pipe 11, and reference numeral 30 indicates a discharge valve interposed in the discharge pipe 10.

Next, to explain the usage and function, raw water flows into the water level adjustment tank 12 from the raw water pipe 13, and the overflow pipe 1
4, the raw water enters the raw water supply vertical channel 5 through the water supply pipe 16 at a water supply amount adjusted by the water supply valve 15, and flows downward. If the SS discharge valve 30 is closed, the raw water will fill up to the upper end of the upper tank 1, and if the water is continuously fed, the raw water flowing from the raw water supply vertical flow path 5 will continue to flow from the upward flow path 7. The raw water rises, and most of the raw water overflows from the upper end of the rising channel 7 and flows into the flow rate regulating tank 26 via the clear water receiving tank 25 on its outer periphery. A portion of the raw water passes through the water collector 9 in the lower tank 2, ascends the rising water pipe 11, and enters the flow rate adjustment tank 26.

Since the flow rate adjustment tank 26 is in communication with the clear water receiving tank 25, the rising water level of the rising water pipe 11 is the same as the overflow water level from the rising channel 7. The flow rate ratio between the overflowing water volume from the rising water channel 7 and the rising water volume in the rising water pipe 11 is approximately equal to the ratio of the cross-sectional areas of both water channels, so if the ratio of the cross-sectional areas of both water channels is determined according to the nature of the raw water, good. Specifically, the flow rate of the rising water is adjusted by a flow rate regulating valve 29 installed in the rising water pipe 11, thereby adjusting the flow rate ratio between the overflowing water from the rising flow passage 7 and the rising water volume of the rising water pipe 11. It can be adjusted. The water discharged from the flow rate regulating tank 26 is controlled by the overflow weir 27 and then discharged from the discharge pipe 28.

Although the raw water flows roughly as described above, the flow of the raw water filling the upper tank 1 will be explained in more detail based on FIG. 5. In Fig. 5, black dots indicate SS in the raw water, and arrows indicate the flow of the raw water. The raw water that enters the raw water supply vertical channel 5 and flows downward flows into the inclined sedimentation layer 4 of each stage from the upper end inlet, flows downward (outward) along the surface of each inclined plate 3a, 3b, and during this period. The SS in the raw water is successively tilted plates 3a and 3.
It settles on the surface of b. This sedimentation separated SS
slides down on the inclined plates 3a and 3b under the influence of gravity and the flow of raw water in the inclined sedimentation layer 4, and is located at an inner position ( position near the lower edge of the inclined plates 3a, 3b)
It descends vertically through the raw water due to gravity. Most of the raw water that has undergone the sedimentation and separation action of SS in this way is
From the lower end opening of the descending channel 6 to the lower end opening of the ascending channel 7 located outside thereof, it makes a U-turn at a position closer to the outside, ascends the ascending channel 7 as primary clear water, and as described above clear water It will flow into the receiving tank 25.

On the other hand, the raw water with increased SS concentration that further descends from the U-turn portion of the raw water immediately below the lower end openings of the descending flow path 6 and the rising flow path 7, that is, from the separating portion 31 at a position closer to the inside, is transferred to the lower tank 2. and undergoes a second SS sedimentation separation action. That is, this raw water descends vertically from the separation section 31 and then makes a U-turn toward the water collector 9 above the center, so that the high concentration of SS in this raw water
sediments on the funnel part 8 of the lower tank 2 and is collected at the center bottom of the funnel part 8. Then, the raw water introduced into the water collector 9 rises through the rising water pipe 11 as secondary clear water,
It is released together with the primary clear water. The SS collected at the center bottom of the funnel part 8 is connected to the discharge valve 3.
By opening 0, the raw water flowing out from the discharge pipe 10 is discharged to the outside of the tank. This discharge pipe 1
SS discharge work from 0 can be performed continuously or periodically. In the case of continuous operation, the opening degree of the discharge valve 30 may be adjusted so that the amount of raw water discharged from the discharge pipe 10 together with the SS is sufficiently small compared to the amount of raw water supplied.

In addition, in the above-mentioned SS precipitation separation action, the flow velocity of raw water in the raw water supply vertical channel 5 reaches the highest flow velocity at the location corresponding to the uppermost inclined sedimentation layer 4, and as The flow rate decreases and reaches the lowest flow velocity (maximum flow velocity ÷ number of inclined precipitation layers 4) at the lower end corresponding to the lowest inclined precipitation layer 4. The flow rate of raw water flowing into each inclined sedimentation layer 4 is approximately equal, and the flow rate of raw water within each inclined sedimentation layer 4 spreads radially toward the lower end exit of the sloped sedimentation layer 4, so the raw water flow rate on the raw water supply vertical channel 5 side It gradually decreases from the upper end inlet to the lower outlet on the downward flow path 6 side (experimental example, 0.230 to 0.083 cm/
seconds). The raw water flow velocity in the descending channel 6 reaches its lowest flow velocity at a location corresponding to the uppermost slanted sedimentation layer 4, increases as it descends, and reaches a minimum flow velocity at a location corresponding to the lowermost slanted sedimentation layer 4. Maximum flow velocity (minimum flow velocity ×
(number of stages of inclined sedimentation layer 4). Of course, the maximum flow velocity at the lower end of the downward flow path 6 is sufficiently lower than the maximum flow velocity at the upper end of the raw water supply vertical flow path 5.

The flow rate of raw water flowing into the ascending channel 7 via the separation section 31 directly below the lower end opening of the descending channel 6 and the lower end opening of the ascending channel 7 depends on the nature of the raw water, the SS concentration, and the required clarity. For example, 2/3 of the raw water supply amount can be made to flow into the ascending channel 7. The flow velocity in the separation section 31 is necessarily lower than the flow velocity in the descending channel 6 and ascending channel 7, but it is lower than the standard flow velocity in sedimentation tanks of general waterworks (experimental example, 0.453 cm/sec). It is desirable to do so. The flow velocity of raw water in each inclined sedimentation layer 4 is lower than the flow velocity in the separation section 31 (experimental example, average 0.1226 cm/sec)
It is something that should be taken seriously.

Since the raw water in the inclined sedimentation layer 4 flows downward along the surfaces of the inclined plates 3a and 3b, the flow velocity when flowing into the downward flow path 6 is as shown in the figure.
When the inclination angle of plate 3b is 60 degrees, it becomes 1/2, and the SS that slides down from the lower ends of the inclined plates 3a and 3b is quickly turned vertically downward by the downward flow in the downward flow path 6, and inside the downward flow path 6. Since the water flows at the offset position, clear water can be easily separated in the separating section 31.

6 to 8 show other embodiments of the present invention, and parts corresponding to the embodiment shown in FIGS. 1 to 4 are given the same reference numerals. In this example,
The upper tank 1 and the lower tank 2 have a rectangular cross section, and a raw water supply vertical channel 5 is formed in the center of the upper tank 1 over the entire width. A sloped sedimentation layer 4 partitioned by rectangular sloped plates 32 is formed in a symmetrical shape, and further adjacent to the lower end of the sloped sedimentation layer 4, descends over the entire width of both opposite sides of the upper tank 1. The flow path 6 and the ascending flow path 7 are
It is formed by vertical partition plates 33. In addition, the lower space 34 of the rectangular inclined plate 32 at the lowest stage is the water collector 9.
A water collecting porous pipe 35 communicating with the rising water pipe 11 is installed at the top of this space 34. Since the funnel portion 8 of the lower tank 2 has a rectangular planar shape, its central bottom is configured in the shape of an inclined gutter, and a porous discharge pipe 36 communicating with the discharge pipe 10 is disposed within this gutter-like bottom portion 8a. ing.

Further, the clear water receiving tank 25 is formed in the shape of a gutter over the entire width within the upper tank 1 so that the upper end of the vertical partition plate 33 also serves as an overflow weir for clear water from the upper end of the ascending channel 7. A raw water distribution gutter 36 is provided at the upper end of the horizontally long raw water supply vertical channel 5 to evenly distribute the raw water supplied from the water supply pipe 16 over the entire horizontal length of the raw water supply vertical channel 5. ing. 37 is an overflow weir for keeping the raw water level in the gutter 36 constant, and the overflow water is discharged to the outside of the tank.

In the illustrated structure, two sets of sedimentation devices are installed side by side, so the upper tank walls adjacent to each other are omitted, and a common ascending channel 7 is arranged in the adjacent portion.

The usage and operation of the rectangular precipitation apparatus of this embodiment are basically the same as the usage and operation of the circular precipitation apparatus shown in FIGS. 1 to 4, so a description thereof will be omitted.

The precipitation apparatus of the present invention can be implemented and used as in the above embodiments, and its characteristics include an upper tank and a lower tank, and the upper tank has multiple stages of inclined plates. A vertical flow path for supplying raw water communicating with the upper end inlet of the multi-stage inclined sedimentation layer, a downward flow path communicating with the lower end outlet of the multi-stage inclined sedimentation layer, and a downward flow path of the downward flow path. An ascending channel having a lower end opening is provided adjacent to the lower end opening, and the lower tank communicates with the lower end openings of the descending channel and the ascending channel. a water collector that opens above the funnel part, a discharge pipe for discharging sediment together with the raw water is connected to the bottom of the funnel part, and a rising water pipe that communicates with the upper end of the ascending channel and the water collector. The point is that clear water is allowed to overflow and discharge from the upper end of the pipe.

That is, according to the present invention, in the upper tank, the inclined sedimentation layers in which the flow direction of the raw water and the flow direction of the SS on the inclined plate are the same are stacked in multiple stages in the vertical direction, so that the unit of the device is The sedimentation area per installation area increases, and the cross-sectional area of the sloped sedimentation layer (raw water flow path) on the sloped plate increases, so the flow rate of raw water in the sloped sedimentation layer decreases for a constant raw water supply amount. In addition to extending the settling time, the thickness of the raw water layer on the inclined plate is reduced to shorten the settling distance of SS, and the settling and separation of SS in the raw water can be carried out extremely efficiently. Moreover, in the descending flow path, the raw water with extremely high SS concentration is biased toward the inside, and the raw water flows down, and at the separation part where the lower end of the descending flow path and the lower end of the outer ascending flow path are adjacent, the raw water is biased toward the inside. flows down in layers
It is possible to effectively separate the clear water flowing in layers near the outer side from the raw water with a high SS concentration, and take out the clear water from the ascending channel as primary clear water.
The remaining raw water with a high concentration of SS flows into the lower tank, and when the raw water makes a U-turn toward the water collector above the funnel in the lower tank, the SS is sedimented and separated, resulting in secondary clear water. can be taken out from a rising water pipe communicating with the water collector.

As described above, the precipitation device of the present invention can be implemented as a compact device that occupies a small installation area, and yet can very efficiently precipitate and separate SS in raw water and extract it as clear water with the required clarity. It is something that can be done. Furthermore, the sediment collected at the bottom of the lower tank funnel can be fluidly discharged out of the apparatus using raw water within the apparatus, and no special power is required to discharge the sediment.

In addition, as shown in the example, when the weir plate 21 that supports the upper stage inclined plate is interposed between the inclined plates forming the inclined sediment layer of each stage, this weir plate 21 is
It can function as a rectifying plate for the raw water flowing in the inclined sedimentation layer 4, and can prevent the raw water from becoming a short-circuit flow or a drifting flow in the inclined sedimentation layer 4.

Further, in the embodiment, the primary clear water overflowing from the ascending flow path 7 and the secondary clear water overflowing from the ascending water pipe 11 are taken out together, but it is also possible to take out each separately.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view showing the first embodiment, FIG. 2 is a plan view of the same, and FIG. 3 is an enlarged vertical side view of the same main part.
Figure 4 is an enlarged cross-sectional plan view of the main part, Figure 5 is the SS
An explanatory diagram showing the state of separation action and the state of flow of raw water, FIG. 6 is a vertical cross-sectional side view showing the second embodiment, and FIG.
The figure is a longitudinal sectional front view of the same, and FIG. 8 is a sectional plan view of the same. 1... Upper tank, 2... Lower tank, 3a to 3c... Circular umbrella-shaped inclined plate, 4... Inclined sedimentation layer, 5... Raw water supply vertical channel, 6... Downward channel, 7... rising flow path,
8... Funnel part for collecting sediment, 9... Water collector, 10
... Discharge pipe, 11 ... Rising water pipe, 12 ... Water level adjustment tank, 13 ... Raw water pipe, 14 ... Overflow pipe, 16 ...
... Water supply pipe, 21 ... Weir plate, 23 ... Covered inner cylinder, 2
4...Support plate, 25...Clear water receiving tank, 26...Flow rate adjustment tank, 28...Discharge pipe, 31...Separation section, 3
2... Rectangular inclined plate, 33... Vertical partition plate, 35...
...Porous pipe for water collection, 36...Porous pipe for discharge.

Claims (1)

[Claims] 1.Equipped with an upper tank and a lower tank, the upper tank includes a multi-stage inclined sedimentation layer partitioned by multiple stages of inclined plates, and a raw water supply vertical channel communicating with the upper end inlet of these multi-stage inclined sedimentation layers. , a descending channel communicating with the lower end outlet of the multi-stage inclined sedimentation layer, and an ascending channel having a lower end opening adjacent to the lower end opening of the descending channel, and the lower tank is connected to the descending channel and the ascending channel. It communicates with the opening at the lower end of the channel, and is provided with a sediment collecting funnel part and a water collector opening above the funnel part;
A discharge pipe for discharging sediment together with raw water is connected to the bottom of the funnel part, and clear water is overflowed and discharged from the upper end of the ascending flow path and the upper end of the ascending water pipe communicating with the water collector. precipitation equipment.