JPS6357089B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention is applicable to various types of wastewater (domestic wastewater, industrial wastewater,
The present invention also relates to a method for separating sludge in a settling tank in a treatment device for treating wastewater from agricultural and fishery industries, livestock wastewater, etc.), industrial water, or tap water.

``Prior Art'' The conventional method for sedimentation and separation of sludge in the above-mentioned settling tank is as illustrated in FIG.
A center well 5 is provided in the center of the sedimentation tank 1 with its lower end facing the bottom 3, and sludge water 11 is allowed to flow in from the center well 5, and the sludge component 12 in the sludge water 11 is settled on the bottom 3. At the same time, the supernatant water 13 is discharged from the overflow part 4, and the sludge 12 that has settled in the bottom part 3 is sucked up and discharged by the sludge pipe 10 that passes through the center of the center well 5 and reaches the bottom part 3, and the sludge water 11 is This method separates the sludge into a sludge component 12 and supernatant water 13.

"Problems to be Solved by the Invention" In the conventional method described above, sludge water 1
Because of the sedimentation method in which sludge 1 flows in intensively and settles directly into the bottom 3, for example, when a large amount of sludge water temporarily flows in, the sludge 12 that has settled in the bottom 3 is rolled up first. This may cause a turbulent flow and impede the sedimentation separation action, and the moisture in the sludge water 11 flowing in from the center well 5 causes a short-circuit flow that rises from the slope 3' of the bottom part 3 along the inner wall of the settling tank 1. This tends to create a stagnant water area 14 around the center well 5 where water does not flow.

Therefore, the settling performance of sludge is generally poor;
High-quality supernatant water may not be produced. - The residence time of sludge water becomes longer in some areas, and microorganisms in the sludge water die and rot, resulting in foamy sludge floating to the surface. - Highly concentrated sludge water It is often difficult to separate the sediment, and the sedimentation tank function may not function properly. There are various performance problems such as.

It is an object of the present invention to solve the problems in the prior art described above.

``Means for Solving the Problems'' The present invention achieves the above-mentioned objects. The sludge water is guided from the center of the tank to a radial introduction pipe that extends generally horizontally toward the inner wall of the settling tank, and then is dispersed from the tip of the introduction pipe along the slope of the mortar-shaped bottom. The sludge is separated into sludge and supernatant water by letting it flow out and letting it settle naturally.

"Example" and "Operation" The structure and operation of the present invention will be explained in detail below with reference to a settling tank of an example using the method of the present invention.

FIG. 1 shows a settling tank 1 of one embodiment. In the figure, a sedimentation tank 1 has a mortar-shaped bottom part 3 connected to the lower end of a hollow cylindrical main part 2, and an overflow part 4 for supernatant water near the upper end of the main part 2. A center well 5 is provided upright in the center of the main portion 2 to allow the sludge water 11 to flow in, and the center well 5 is closed at its lower end by a bottom plate 6. A group of 7 introduction pipes extending generally horizontally from the lower end of the center well 5 toward the inner wall of the main portion 2 is provided radially (in the illustrated embodiment, there are eight introduction pipes 7 arranged equally). At the tip of the tube 7, a dispersion tube 8 that extends in the circumferential direction along the inner periphery of the main part 2 and has a closed tip is attached.
The outflow holes 9 are arranged so as to face the upper end of the slope 3' of the bottom part 3. In addition,
10 in the figure is a sludge pipe that sucks up and discharges the sludge 12 that has settled on the bottom 3.

In the settling tank 1 described above, the sludge water 11 is distributed and guided from the center well 5 to the introduction pipe 7, and distributed and flows out from the outflow hole 9 to the upper end position of the slope 3' of the bottom part 3 via the distribution pipe 8. The supernatant water 13 is raised and separated by uniformly flowing down along the circumferential surface of the sludge 3', and the sludge component 12 with a heavy specific gravity is allowed to settle and accumulate on the bottom 3 to separate solids and water.

Then, the supernatant water 13 gradually rises and is discharged from the overflow part 4, and the sludge portion 12 is discharged to the outside of the tank through the sludge pipe 10.

According to the above-described sedimentation separation method of the present invention, the sludge water 11 flowing through the horizontally extending inlet pipe 7 has upper and lower layers of supernatant water with a light specific gravity and sludge with a heavy specific gravity, so that the sludge component and the sludge component during the flow. There is an effect that the separation from the supernatant water progresses, and the sludge water in a state where the separation has progressed is dispersed and flowed out to the upper end of the slope 3' of the bottom part 3.
The sludge component 12 naturally flows down the slope 3', continues to separate the supernatant water 13, and quickly settles and accumulates on the bottom 3. Immediately after the supernatant water 13 comes out of the discharge hole 9, the separated portion rises in the introduction pipe 7, and the sludge portion 12 slides down the slope 3' and settles to the bottom 3. Separation rises,
Separation between the supernatant water 13 and the sludge component 12 is greatly promoted, and the separation performance is improved.

Since the supernatant water 13 rises sequentially from the slope 3' of the bottom part 3, the flow of rising water in the sedimentation tank 1 becomes uniform, and there is no stagnant water that does not flow as in the conventional method.
Corruption due to long-term retention in the tank can be prevented. Furthermore, according to the method of the present invention, the sludge water 11 is uniformly dispersed and flowed down along the inner circumference of the settling tank 1, so that a turbulent flow that stirs up the sedimented sludge 12 is not generated, and high-quality sludge is maintained. It has the effect of separating and producing a supernatant liquid and increasing the sedimentation rate of the sludge component 12. Even if a large amount of sludge water 11 is temporarily introduced, the sedimentation separation effect will not be confused or deteriorated thereby, and a stable sedimentation separation effect can be maintained.

"Effects of the Invention" As explained above, the sludge water sedimentation separation method of the present invention improves the separation accuracy and separation speed of sludge water and supernatant water, and quickly produces high-quality supernatant water in a stable manner. It has an excellent effect of separating and generating.

[Brief explanation of drawings]

Figure 1: Shows a settling tank of an embodiment used in the method of sedimentation and separation of sludge water of the present invention, A is a front view showing its basic structure, B is a cross-sectional view along line AA of A, Figure 2: Sedimentation according to the prior art FIG. 3 is a front view showing the basic structure of the tank. Main symbols: 1...Sedimentation tank, 2...Main part, 3...
Bottom, 4...Overflow part, 5...Center well, 6...Bottom plate, 7...Introduction pipe, 8...Distribution pipe, 9...Discharge hole, 11...Sludge water, 12...Sludge content, 13 ...Super clear water.

Claims (1)

[Claims] 1. When sludge water is introduced into a sedimentation tank having a mortar-shaped bottom and separated into sludge and supernatant water by sedimentation, the sludge water is introduced into an introduction pipe that extends radially from the center of the sedimentation tank in a generally horizontal manner. , and then,
Sedimentation of sludge in a settling tank characterized in that the sludge water is dispersed and flowed out from the tip of the introduction pipe, and is allowed to settle naturally along the slope of the mortar-shaped bottom to separate the sludge into sludge and supernatant water. Separation method.