JPH10272307A - Discharge device in waste-water treating tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent suspended matters from remaining in a waste water treating tank and prevent a large quantity of suspended matters exceeding an allowable value from flowing out together with overflowing water, by discharging treated water utilizing a submerged overflow when the quantity of the suspended matters such as scum exceeds an allowable value. SOLUTION: A movable weir 2 is disposed at a discharge port 11 of a waste water treating tank 1 and by moving the weir 2 in a vertical direction, the opening of the port and the setting position of the weir can be changed. In a normal condition, when the amount of suspended matters W is small, the weir 2 is moved downward to discharge treated water by an upper overflow method. Thus the matters W can be prevented from remaining in the tank 1. In an abnormal condition, when the amount of the matters W is large, the weir 2 is moved upward to discharge the treated water by a submerged flow method. A proper quantity of the matters W remaining in the tank 1 is caused to flow out, little by little, from the upper side of the weir 2 together with overflowing water by operating the weir 2 according to, for example, the treating conditions of a final settling pond of a succeeding process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a drainage device in a sewage treatment tank (including a "sedimentation basin" in the present specification), and more particularly, to a sewage treated in a sewage treatment tank (herein, generally referred to as "sewage treatment tank"). , "Treated water") is discharged through an upper overflow.

[0002]

2. Description of the Related Art A sewage treatment tank such as an oxidation ditch is used for biologically treating sewage. The outlet for discharging the sewage treated in this sewage treatment tank,
Usually, a movable weir for discharging the treated water by the upper overflow is provided. By this, the movable weir is fixed at a fixed position until the predetermined wastewater treatment is completed, and the untreated water is prevented from flowing out to the next process. It discharges by overflow.

[0003]

However, since the movable weir serving as a discharge device in the above-mentioned conventional sewage treatment tank allows only the overflow at the upper part, the generation of suspended matter such as scum in the sewage treatment tank. If the amount exceeds the allowable amount, a large amount of suspended matter such as scum will flow out together with the overflow water, which will hinder the treatment of sewage in the next process. There is a problem that a phenomenon of deterioration of the image occurs.

In order to cope with this problem, it has been proposed to provide a submerged discharge port instead of an upper overflow discharge port as a discharge device in a sewage treatment tank. In this case, there is a problem that suspended matter such as scum stays in the sewage treatment tank and cannot be removed.

The present invention has been made in view of the above-mentioned problems of the conventional drainage device in a sewage treatment tank, and usually, the sewage treatment tank is configured to discharge the treated water in the sewage treatment tank by overflowing the upper part. An object of the present invention is to provide a discharge device in a sewage treatment tank that can also be discharged by a submerged flow.

[0006]

In order to achieve the above object, the present invention provides a discharge device in a sewage treatment tank according to the present invention. , Characterized in that when the amount of floating matter such as scum is larger than the allowable amount, the treated water is discharged by submerging.

[0007] The discharge device in the sewage treatment tank is configured to treat the suspended matter such as scum by an upper overflow method when the amount is small, or by a submerged flow method when the amount is large. The water can be discharged, and thus, by discharging an appropriate amount of suspended matter such as scum together with overflow water, the suspended matter is prevented from staying in the sewage treatment tank, and the suspended matter such as scum is discharged. When the generation amount of the water exceeds the allowable amount, it is possible to prevent a large amount of suspended matter such as scum from flowing out together with the overflow water.

In this case, the weir arranged at the discharge port of the sewage treatment tank can be selectively installed at the upper overflow discharge position and the submerged discharge position.

Thus, it is possible to select the upper overflow method or the submergence method by using a simple mechanism and performing a simple operation.

In addition, a scum prevention wall is provided in a sedimentation basin for introducing the sewage treated in the sewage treatment tank, and an outflow valve is provided at an intermediate portion of the back of the scum prevention wall to allow the treated water to flow upward or upward. A running water trough for discharging as a submerged flow can be provided, and a running water trough for discharging suspended matter such as scum can be provided at the upper end of the back of the scum blocking wall.

As a result, normally, the treated water flows out of a running water trough provided at an intermediate portion behind the scum blocking wall,
If the amount of suspended matter such as scum becomes large, the outflow valve of this water trough is closed, the water level is raised, and the scum or the like floats from the water trough provided at the upper end of the back of the scum blocking wall. After the material is caused to flow out with the overflow water and the suspended matter is removed from the sewage treatment tank, the outflow valve of the flowing water trough is opened, and the treated water can be discharged from the flowing water trough by a submerged flow method.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a discharge device in a sewage treatment tank according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of a discharge device in a sewage treatment tank according to the present invention. The discharge device in the sewage treatment tank has a required capacity and a predetermined shape, and is disposed in a sewage treatment tank 1 such as an oxidation ditch in which a sewage inflow pipe, an aerator, and the like are installed. Tank 1
The weir 2 disposed at the discharge port 11 for discharging the treated water formed at the upper part is movable so that it can be selectively installed at the upper overflow discharge position and the submerged discharge position. .

A movable weir 2 disposed at the outlet 11
The size is determined according to the amount of treated water discharged from the sewage treatment tank 1, and the opening degree and installation thereof are manually or vertically moved by power of a motor, an oil-pneumatic cylinder, or the like. Be able to change the position.

An operation method of the discharge device in the sewage treatment tank will be described. First, during normal times when the amount of suspended matter W such as scum is small, as shown in FIG. 1 (A), a movable weir 2 is moved downward and installed, and treated water is discharged by an upper overflow method. I do. That is, in a sewage treatment tank using activated sludge having a long residence time such as an oxidation ditch, once the amount of suspended matter W such as scum starts to increase, the amount increases at an accelerating rate. Is discharged as quickly as possible by causing an appropriate amount of suspended matter W such as scum to flow out from above the weir 2 together with the overflow water by the upper overflow method. Thereby, the suspended matter W such as scum can be prevented from staying in the sewage treatment tank 1.

Next, in the event of an abnormality in which the amount of suspended matter W such as scum is large, as shown in FIG. 1B, the movable weir 2 is moved upward to be installed, and is processed by a submerged flow method. Drain water. This allows only the treated water not containing the suspended matter W such as scum to flow out from below the weir 2 and
It is possible to prevent a large amount of suspended matter W such as scum from flowing out together with overflow water. By the way, the suspended matter W such as scum stays in the sewage treatment tank 1 due to this, and the suspended matter W such as scum is movable, for example, according to the treatment state of the final sedimentation basin in the next step. Operate the weir 2
From the upper part of the weir 2, an appropriate amount of suspended matter W is caused to flow out together with overflow water.

By measuring the thickness of the floating material W such as scum and moving the movable weir 2 in the vertical direction according to the measured value, the opening degree and the installation position can be automatically changed. You can also do so.

FIGS. 3 and 4 show a second embodiment of the discharge device in the sewage treatment tank according to the present invention. The discharge device in the sewage treatment tank is adapted to be applied to the circular sedimentation basin 1A. A feed well 4 having an inflow pipe 3 is provided at the center of the circular sedimentation basin 1A. An annular scum with an open bottom for preventing scum or the like from passing through the outer periphery of the circular sedimentation basin 1A while supplying sewage into the circular sedimentation basin 1A via the well 4 A scum blocking wall 1 is provided.
An annular running water trough 7 for discharging treated water as either an upper overflow or a submerged flow by connecting an outflow pipe 8 provided with an outflow valve 9 to an intermediate portion on the back of the cylinder 0 and preventing scum An annular running water trough 5 for discharging suspended matter such as scum by connecting a scum discharge pipe 6 is provided at the upper end of the back of the wall 10.

An operation method of the discharge device in the sewage treatment tank will be described. First, during normal times when the amount of suspended matter such as scum is small, the outlet valve 9 of the flowing water trough 7 is opened, and the water level of the circular sedimentation basin 1A is operated at the level L1.
Treated water is discharged from a flowing water trough 7 disposed at an intermediate portion of the back of the scum blocking wall 10 through an outflow pipe 8 provided with an outflow valve 9 by an upper overflow method.

Next, when the amount of suspended matter W such as scum generated is abnormal, the outflow valve 9 of the running water trough 7 is closed to raise the water level, and the water level of the circular sedimentation basin 1A is operated at the level L2. Then, suspended matter such as scum is caused to flow out from the flowing water trough 5 disposed at the upper end of the back of the scum blocking wall 10 together with overflow water, and after the suspended matter is removed from the circular sedimentation basin 1A, the outflow of the flowing water trough 7 is performed. The valve 9 is opened, and the treated water can be discharged from the flowing water trough 7 by a submerged flow method.

The opening / closing operation of the outflow valve 9 can be automatically controlled by timer control.

[0022]

According to the drainage device for a sewage treatment tank of the present invention, depending on the amount of suspended matter such as scum, when the amount is small, the upper overflow method is used. By the submerged flow method, the treated water can be discharged, and thereby, usually, an appropriate amount of suspended matter such as scum is caused to flow out together with the overflow water, thereby preventing the suspended matter from staying in the sewage treatment tank. If the amount of suspended matter such as scum is larger than the allowable amount, prevent a large amount of suspended matter such as scum from flowing out with overflow water,
In the next step, it is possible to prevent a problem from occurring in the treatment of sewage.

In addition, a weir disposed at the discharge port of the sewage treatment tank can be selectively installed at an upper overflow discharge position and a submerged discharge position, so that a simple mechanism can be used. With a simple operation, it is possible to select the upper overflow method or the submerged flow method.

Further, a scum prevention wall is provided in a sedimentation basin for introducing the sewage treated in the sewage treatment tank, and an outflow valve is provided at an intermediate portion of the back of the scum prevention wall to allow the treated water to flow upward or upward. By providing a running water trough that discharges as one of the submerged flows and a running water trough that discharges suspended matter such as scum at the upper end of the back of the scum prevention wall, Treated water is drained from the running water trough located in the middle part of the back, and if the amount of suspended matter such as scum increases, the outflow valve of the running water trough is closed, the water level is raised, and scum is prevented. After the suspended matter such as scum is discharged from the flowing water trough arranged at the upper end of the back of the wall together with the overflow water, and the suspended matter is removed from the sewage treatment tank, the outflow valve of the flowing water trough is opened. Diving treated water It can be discharged by the system.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a discharge device in a sewage treatment tank according to the present invention, wherein (A) shows a state where a weir is moved downward and installed, and (B) shows a state where a weir is moved upward and installed. It is explanatory drawing which shows a state, respectively.

2A and 2B show a first embodiment of a discharge device in a sewage treatment tank according to the present invention, wherein FIG. 2A is a front view and FIG. 2B is a side view.

FIG. 3 is a sectional view showing a second embodiment of the discharge device in the sewage treatment tank of the present invention.

FIG. 4 is a plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewage treatment tank (oxidation ditch) 1A Sewage treatment tank (circular sedimentation tank) 11 Outlet 2 Weir 3 Inflow pipe 4 Feed well 5 Running water trough 6 Scum discharge pipe 7 Running water trough 8 Outflow pipe 9 Outflow valve 10 Scum blocking wall

Claims (3)

[Claims] In a discharge device in a sewage treatment tank configured to discharge sewage treated in a sewage treatment tank through an upper overflow, if a generated amount of suspended matter such as scum becomes larger than an allowable amount, the treatment is performed. A discharge device in a sewage treatment tank, wherein water is discharged by a submerged flow. 2. The dam according to claim 1, wherein the weir disposed at the discharge port of the sewage treatment tank can be selectively installed at an upper overflow discharge position and a submergence discharge position. Discharge device in sewage treatment tank. 3. A scum blocking wall is provided in a sedimentation basin for introducing sewage treated in a sewage treatment tank, and an outflow valve is provided at an intermediate portion on the back of the scum blocking wall to allow treated water to overflow to the top or In addition to arranging a running water trough to discharge as one of the submerged flows, at the upper end of the back of the scum blocking wall,
The discharge device for a sewage treatment tank according to claim 1, further comprising a running water trough for discharging suspended matters such as scum.