JPH0222006Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a supernatant liquid discharge device for discharging only the supernatant liquid of a sedimentation tank to the outside of the tank.

(Prior art) A conventional supernatant liquid discharge device is, for example,
As described in Publication No. 5702 and Japanese Utility Model Publication No. 59-21850, a liquid collector is floated slightly below the liquid level, and a retractable pipe and a discharge pipe are opened at the bottom of the liquid collector. The supernatant liquid that has flowed into the liquid collector is discharged to the outside of the tank via the valve. Furthermore, a filter is installed around the liquid collector,
It is constructed to prevent lightweight floating objects such as scum from getting mixed into the supernatant liquid flowing into the liquid collector.

The above-mentioned conventional supernatant liquid discharge device has a problem in that the filter is easily clogged by lightweight floating objects, and the filter requires periodic cleaning, which is troublesome. Therefore, if the mesh size of the filter is made larger to prevent clogging, lightweight floating objects are likely to be mixed into the supernatant liquid to be discharged, which may also cause clogging of the discharge valve. In particular, in the batch activated sludge method, which has attracted attention as a small-scale sewage treatment system in recent years, in which aeration and precipitation are carried out in one tank, the aeration and precipitation processes are carried out in a single treatment tank, and the scum generated during the aeration process is floats to the top of the supernatant. In order to remove this scum, the filter must be made extremely fine, which easily clogs and requires frequent cleaning.
Moreover, it is difficult to reliably remove scum from the supernatant liquid using a filter.

In addition, in Japanese Utility Model Publication No. 56-12975, a liquid collector is floated slightly below the liquid level, and a weir is provided in the liquid collector so that the sliding part has a watertight structure and the vertical position can be controlled freely. are listed.

With such a supernatant liquid discharge device, by controlling the position of the weir upward or downward, the supernatant liquid can be caused to flow into or out of the liquid collector, and a discharge valve is not required. However, the scum floating on top of the supernatant liquid must be removed by a filter, which is problematic in that it is likely to become clogged.
Further, there is a problem that the watertight structure of the sliding contact portion is likely to deteriorate.

Therefore, in the microfilm of Utility Model Application No. 57-200836 (see Utility Model Application No. 59-106505), a liquid collector is fixed to the center inside the frame-shaped float, and an air tank is provided, and the buoyancy of this air tank is It is described that the position of the float and the entire liquid collector can be freely controlled in the vertical direction with respect to the liquid level by adjusting the .

(Problem to be solved by the invention) The technology described in the microfilm of Utility Application No. 1983-200836 controls the position of not only the liquid collector but also the float in the vertical direction, so the relative movement of the device is There are no parts, the structure is robust, and maintenance is easy. However, a large buoyancy force is required to raise the float in the vertical direction, which requires a large volume of the air tank, resulting in a large device. In addition, the air tank is placed below the liquid collector, making the device unstable. Furthermore, when the liquid collector is controlled to the upward position, the depth at which the float is immersed in the liquid becomes shallow or becomes above the liquid level, making it easy for lightweight floating objects such as scum to enter the inside of the float. Then, when the liquid collector is next controlled to the lower position and the supernatant liquid is discharged, there is a problem in that the scum and the like that have entered the inside of the float are also discharged at the same time.

The purpose of this invention was to solve the above-mentioned problems with the conventional supernatant liquid discharge device, and without using a filter, it does not mix lightweight floating substances such as scum into the discharged supernatant liquid. Moreover, it is an object of the present invention to provide a supernatant liquid discharge device that is easy to maintain and manage.

(Means for Solving the Problems) In order to achieve the above object, the supernatant liquid discharge device of the present invention has a vertically long cylindrical circumferential wall whose upper end opening protrudes above the liquid surface and whose lower end opening protrudes above the liquid surface. is immersed in the liquid to the depth of the lower part of the device and floated, and an upwardly facing bucket-shaped liquid collector is installed on the inside of the peripheral wall by a guide provided on at least one of the liquid collector or the peripheral wall. is provided so as to be able to control its position in the vertical direction relative to the peripheral wall, one end of a telescopic tube communicating with the outside of the tank is opened at the bottom of the liquid collector, and the liquid collector is connected to the peripheral wall. By controlling the position in the vertical direction relative to the surrounding wall, the supernatant liquid surrounded by the peripheral wall is configured to flow into or not flow into the liquid collector.

(Function) A vertically long cylindrical peripheral wall is floated with the upper end opening protruding above the liquid surface and the lower end opening immersed in the liquid to the depth of the bottom of this device, and a liquid collector is installed inside this peripheral wall. The supernatant liquid surrounded by the surrounding wall passes under the surrounding wall, which is deeply immersed in the liquid, and flows into the inner side of the surrounding wall. Clear liquid does not contain light floating substances such as scum. In addition, since the position of the liquid collector is controlled in the vertical direction relative to the surrounding wall, the surrounding wall is floated at an approximately constant position relative to the liquid surface using a float, and the attitude of the surrounding wall is stable. .

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a longitudinal sectional view of an embodiment of the supernatant liquid discharge device of the present invention, and FIG.
FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 is a view with the liquid collector in the upper position in FIG. 1.

In Figures 1 to 3, three floats 2, 2, 2 are integrally arranged inside a vertically long cylindrical peripheral wall 1 on a concentric circle at equal intervals in the circumferential direction, and the peripheral wall 1 is The upper end opening projects above the liquid level 3, and the lower end opening is immersed in the liquid to the depth of the lower part of the device, so that it is floating. Also, by means of guide rollers 4, 4, . It is arranged so as to be movable up and down relative to the other hand. A bottom plate 5a is provided in the middle of the cylinder frame 5 in the vertical direction, and when the cylinder frame 5 is lowered, the bottom plate 5a
Liquid collecting ports 5b, 5b, . Furthermore, a flange-shaped stopper 5c is provided at the upper end of the cylinder frame 5 to engage with the upper ends of the floats 2, 2, . . . . Further, a discharge port 5d is bored in the center of the bottom plate 5a, and one end of the telescopic tube 6 is opened from below into the discharge port 5d. The other end of this telescopic tube 6 is connected to a drain pipe 7 that communicates with the outside of the tank. Further, one end of an air pipe 8 is opened at the bottom surface of the bottom plate 5a by penetrating the bottom plate 5a from above, and the other end of this air pipe 8 is communicated with a three-way valve 9 via a telescopic tube. In this operation, the air pipe 8 is shut off or communicated with either the air source 10 or the atmosphere.
Note that an upward bucket-shaped liquid collector 11 is formed by the bottom plate 5a and the cylindrical frame 5 above the bottom plate 5a.
A and the cylindrical frame body 5 below this form a downward-facing bucket-shaped air storage chamber 12.

In this configuration, as shown in FIG. 3, when the three-way valve 9 is operated to connect the air source 10 to the air pipe 8, compressed air flows into the air storage chamber 12 under the bottom plate 5a of the cylinder frame 5. The buoyancy causes the cylinder frame body 5 to rise relative to the peripheral wall 1. Then the surrounding wall 1
On the other hand, since the liquid level 3 is at a substantially constant position, the liquid collecting ports 5b, 5b, . next,
As shown in FIG. 1, when the three-way valve 9 is operated to connect the air pipe 8 to the atmosphere, the compressed air in the air storage chamber 12 is released into the atmosphere, and the cylinder frame 5 is lowered by its own weight and the stopper 5c is moved. It is stopped at a position where it engages with the upper end of the floats 2, 2.... In this state, the liquid collection port 5
b, 5b... are located below the liquid level 3, and the supernatant liquid inside surrounded by the peripheral wall 1 flows into the liquid collector 11 and is discharged to the outside of the tank via the telescopic pipe 6 and the drain pipe 7. be done. Here, the supernatant liquid inside the peripheral wall 1 has passed under the peripheral wall 1 which is deeply immersed in the liquid and has flowed into the inside, and the light floating objects 13 such as scum floating on the liquid surface 3 are It is blocked by the peripheral wall 1 and cannot flow inward. Therefore, the lightweight floating objects 13 are not mixed into the supernatant liquid that flows into the liquid collector 11 and is discharged. In addition, in order to adjust the height of the liquid collection ports 5b, 5b... from the liquid level 3, the air pipe 8 is shut off with the three-way valve 9 when the compressed air in the air storage chamber 12 has an appropriate buoyancy. good.

4 and 5 show other embodiments of the supernatant liquid discharge device of the present invention. FIG. 4 is a longitudinal sectional view of another embodiment of the supernatant liquid discharge device of the present invention, and FIG.
The figure is a plan view of FIG. 4. Figures 4 and 5
In the drawings, the same or equivalent members as in FIGS. 1 to 3 are given the same reference numerals, and redundant explanations will be omitted.

In FIGS. 4 and 5, a float 2 is integrally arranged on the entire inner circumferential surface of a rectangular cylindrical circumferential wall 1 long in the vertical direction, and the circumferential wall 1 has an upper end opening protruding above the liquid level 3 and a lower end thereof. The opening is deeply immersed in the liquid at the bottom of the device and is floated. In addition, guide rollers 4, 4 protruding from the inner wall of the float 2
..., the rectangular tube-shaped cylinder frame 5 is attached to the peripheral wall 1 by providing an appropriate gap around the central position when viewed from the plane of the peripheral wall 1.
It is arranged so that it can move up and down relative to it.
This cylindrical frame body 5 has a bottom plate 5a, a liquid collection port 5b,
5b...and stoppers 5 protruding on both sides
c and 5c are provided in the same manner as in the embodiment shown in FIGS. 1 to 3, and a telescopic tube 6 and an air tube 8 are connected to the bottom plate 5a, and an upwardly facing bucket-shaped liquid collector 11 and a downwardly facing bucket-shaped liquid collector 11 are connected to each other. An air reservoir chamber 12 is formed. Further, a telescopic guide 15 is inserted into the telescopic tube 6 and is vertically provided on the tank bottom 14 . In addition, support columns 16, 16, .
It is held in place by 8... In addition, 19, 19...
are stoppers provided on the supports 16, 16, . . . to limit the lowering of the support frames 17, 17, .

In the embodiment shown in FIGS. 3 and 4, the up and down movement of the peripheral wall 1 due to changes in the liquid level 3 is
6..., the peripheral wall 1 is moved vertically in a stable posture. Also, stopper 19,
Since the descending of the peripheral wall 1 is restricted by 19...,
When the liquid level 3 falls below a predetermined height, the supernatant liquid is prevented from flowing into the liquid collector 11. Furthermore, since the telescopic guide 15 is inserted into the telescopic tube 6, it is possible to prevent the telescopic tube 6 from being bent and blocked when the liquid collector 11 is lowered.

In the above embodiment, the float 2 is arranged integrally inside the peripheral wall 1, but the present invention is not limited to this, and the float 2 can be arranged outside the peripheral wall 1, or the peripheral wall 1 and the float 2 can be constructed separately. Also good. In addition, the buoyancy of the air reservoir chamber 12 is adjusted appropriately, and the cylinder frame body 5
If the position of the liquid surface 3 can be controlled within a predetermined range, it is not necessary to provide the stopper 5c. Furthermore, the operation of the three-way valve 9 is controlled by a liquid level detection switch provided in the tank, and the operation of the three-way valve 9 is controlled according to the inflow of processing liquid and the precipitation processing time in the processing process of the sedimentation tank in which the supernatant liquid discharge device of the present invention is used. The operation of the three-way valve 9 may also be controlled by the controller. Further, the vertical position control of the liquid collector 11 is not limited to the buoyancy of the air reservoir chamber 12, and the liquid collector 11 is placed on the float 2.
1 may be provided with a driving means that can appropriately control the vertical movement. Further, the relative vertical movement of the liquid collector 11 with respect to the peripheral wall 1 is not limited to that guided by the guide rollers 5, 5, etc., but can be performed simply by combining a vertical slide groove and a protrusion whose tip slides within this groove. Of course, the guide may have a simple structure.

(Effect of the invention) As explained above, in the supernatant liquid discharge device of the present invention, the supernatant liquid surrounded by the surrounding wall passes under the surrounding wall that is deeply immersed in the liquid and flows into the inside of the surrounding wall. This prevents lightweight floating substances such as scum from being mixed into the supernatant liquid that flows into the liquid collector and is discharged. Moreover, since no filter is used to remove scum, etc., there is no need for cleaning or other effort. In addition, since the liquid collector is controlled in the vertical position relative to the peripheral wall, the peripheral wall is floated at a substantially constant position relative to the liquid surface by the float, and the posture of the peripheral wall is stable.
By controlling the position of only the liquid collector in the vertical direction relative to the peripheral wall, the position of the liquid collector is controlled with respect to the liquid level, so the position of the entire device can be controlled in the vertical direction with respect to the liquid level. Compared to conventional devices of this type, the force required to raise the liquid collector is smaller, and the mechanisms such as the air trap chamber can be made smaller accordingly. Furthermore, there is no sliding contact part of the watertight structure, and an excellent effect is achieved in that maintenance management is easy.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the supernatant liquid discharge device of the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 4 is a longitudinal cross-sectional view of another embodiment of the supernatant liquid discharge device of the present invention; FIG.
FIG. 5 is a plan view of FIG. 4. 1: Peripheral wall, 2: Float, 3: Liquid level, 4: Guide roller, 6: Expandable tube, 8: Air tube, 9: Three-way valve, 10: Air source, 11: Liquid collector, 12: Air reservoir chamber .

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A vertically long cylindrical peripheral wall is floated by having the upper end opening protrude above the liquid surface and the lower end opening being immersed in the liquid to the depth of the bottom of the device. , the position of an upwardly facing bucket-shaped liquid collector is controlled in the vertical direction relative to the peripheral wall by providing a gap inside the peripheral wall by a guide provided on at least one of the liquid collector or the peripheral wall; The liquid collector is freely arranged, one end of an extendable tube communicating with the outside of the tank is opened at the bottom of the liquid collector, and the position of the liquid collector is controlled in the vertical direction relative to the peripheral wall. A supernatant liquid discharge device characterized in that the supernatant liquid surrounded by a peripheral wall is configured to flow into or not flow into the liquid collector. (2) An air reservoir is provided at the bottom of the liquid collector, and this air reservoir is communicated with an air source through a valve, and the buoyancy of the air reservoir causes the liquid collector to move upward and downward with respect to the liquid surface. The supernatant liquid discharge device according to claim (1) of the utility model registration claim, characterized in that the supernatant liquid discharge device can be freely controlled in position. (3) A downward bucket-shaped air reservoir is provided at the bottom of the liquid collector, and the air pipe communicating with the air reservoir is configured to be shut off by a three-way valve or communicated with either the air source or the atmosphere. A supernatant liquid discharge device according to claim (2) of the utility model registration claim.