JPH1043508A - Scum scraping method for circular settling basin and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scum scraping method for a circular settling basin capable of efficiently scraping the sum floating on the entire water surface of this settling basin to a scum discharge section and a device therefor. SOLUTION: This device has a revolving shaft which exists at the center of a settling basin body 10 and an arm 30 which is mounted toward the radial direction of the settling basin body 10 in its upper part. This arm is provided with a stationary scraping board 31 which is fixed toward the swiveling direction of the arm 10 and a movable scrapping board 33 which is constituted to make its scraping surface movable toward the radial direction of the settling basin body. The movable scrapping board 33 is mounted at a bar-shaped member suspended at the arm in a horizontally movable state. The bottom end of this bar-shaped member is engaged in a state of allowing its horizontal movement and a state of prohibiting its upward movement with an annular guide rail 34 which is disposed at the level lower than the arm 30 and forms a loop reaching the neighborhood of a scum discharge port 14 in the peripheral part enclosing a center well 12 of the central part of the settling basin body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for scraping scum floating on the water surface of a sedimentation basin to a scum discharge part when sedimentation and separation of sludge in sewage treatment and the like, and an apparatus for implementing the method. About.

[0002]

2. Description of the Related Art In sewage treatment, scum is generated during the treatment and rises to the surface of the water, so scum is removed. Scum is scraped into a sedimentation basin for sedimentation and separation of sludge in the treated water. There is a device for discharging.

Various devices have been proposed for discharging scum, one of which is shown in FIGS.
There is a device shown in FIG. 6 is a plan view showing a state in which a conventional scum scraping device is provided in a circular sedimentation basin, and FIG. 7 is a sectional view thereof.

6 and 7, reference numeral 10 denotes a circular sedimentation basin main body, 11 denotes a raw water inflow pipe, 12 denotes a center well, and 13 denotes a center well.
Is a baffle plate for preventing the scum floating on the water surface from flowing out, 14 is a scum outlet, 15 is an overflow weir of treated water, and 16 is a drain of treated water.

Reference numeral 17 denotes a rotary shaft disposed at the center of the sedimentation tank main body 10, 18 denotes a driving device for the rotary shaft, and 50 denotes an arm mounted on the upper part of the rotary shaft 17 in the radial direction of the sedimentation tank main body 10. Numeral 51 denotes a pulling plate fixed with the scraping surface directed substantially in the turning direction of the arm 50. The pulling plate 51 is attached from the central portion of the sedimentation basin body 10 to the peripheral portion thereof. As described above, the scum scraping device includes the rotating shaft 17, the driving device 18 for the rotating shaft, the arm 50, and the fixed shifting plate 51. The fixed shift plate 51 is attached to the arm 50 at an appropriate angle α, and its scraping surface is directed slightly outward with respect to the turning direction. In the figure, 19
The reference numeral 20 denotes a rake for scraping the settled sludge to the center, and 20 denotes a support member for the center well 12.

When raw water containing sludge is supplied to the sedimentation basin provided with the above-described scum scraper, the sludge is settled and separated, and supernatant water (treated water) is produced. At this time, scum is generated and floats on the surface of the treated water, but the scum is prevented from flowing out by the baffle plate 13. And
The treated water goes under the baffle plate 13, overflows the overflow weir, and is discharged from the drain 16.

On the other hand, the scum floating on the water surface is
Fixed approaching plate 5 that rotates together with arm 50 with the rotation of
1 at this time.
The scum that floats on the arm 50 can be adjusted by turning the scraping surface of the arm 50 slightly obliquely outward with respect to the turning direction.
Along with the turning, the scraping surface of the fixed gathering plate 51 is slid and is sequentially sent out from the center to the peripheral portion to be collected and scraped to the scum discharge port 14.

[0008]

The rotating shaft 17 of the sedimentation basin is provided with a rake 19 for collecting mud, so its rotation speed is very low. Is extremely slow (about 3 m / min).

For this reason, in the above-mentioned prior art, even if the scraping surface of the shift plate 51 is directed obliquely outward with respect to the turning direction, most of the scum turns together with the shift plate 51. It will not be sent from the center to the periphery. For this reason, the scum in the peripheral part is discharged,
There is a problem that the scum in the central portion is not sent to the peripheral portion but remains as it is.

It is an object of the present invention to provide a method and an apparatus for scraping a scum of a circular sedimentation basin capable of efficiently scraping scum floating on the entire surface of the sedimentation basin to a scum discharge part.

[0011]

In order to achieve the above object, a method for scraping a scum according to the first aspect of the present invention is to scrape a scum floating on the water surface in a circumferential direction of a sedimentation tank body. The scum scraped in the circumferential direction is scraped in the radial direction of the sedimentation basin body and collected in the peripheral portion, and the scum collected in the peripheral portion is scraped to the discharge portion.

The scum scraping device according to the second aspect of the present invention has a rotating shaft positioned at the center of the sedimentation tank main body, and an arm mounted on the upper part thereof in a radial direction of the sedimentation tank main body. The arm has a fixed gathering plate fixed with the scraping surface facing substantially the turning direction of the arm and a movable gathering plate with the scraping surface oriented in the radial direction of the sedimentation tank body.
Two movable plates are provided, and the movable movable plate is mounted on a rod-like member suspended from an arm in a horizontally movable state, and a lower end of the rod-like member is provided at a level below the arm, and a sedimentation basin is provided. It is engaged with a loop-shaped guide rail extending from the center to the periphery of the main body in a horizontally movable state and in a state where upward movement is prevented. The sedimentation basin is configured to move in the radial direction of the sedimentation tank body along with the guide rail.

[0013] In order to scum floating on the surface of the water and discharge the scum to the discharge portion, it is necessary to collect the scum in the peripheral portion. Therefore, in the scum scraping method of the present invention, the operation of scraping the scum on the water surface from two directions is performed in parallel, and the scum is collected in the peripheral portion. That is, first, when the scum on the water surface is raked in the circumferential direction, the scum is raked and accumulated so as to close the fan. Next, the scum on the water surface is accumulated in the peripheral portion if the scum that has been raked as described above is pushed toward the peripheral portion.

In order to carry out the above method, in the scum scraping device of the present invention, the scraping surface is oriented substantially in the turning direction of the arm, and the scraping surface is formed in the radial direction of the sedimentation basin body. Are provided, and by moving these two parallel plates in parallel, the scum on the water surface is scraped in the circumferential direction by one of the parallel plates, The other side plate pushes out to the periphery.

[0015]

FIG. 1 is a plan view showing an embodiment of a scum scraping device according to the present invention provided in a circular sedimentation basin, and FIG. 2 is a sectional view thereof. 1 and 2, the same components as those in FIGS. 6 and 7 are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, an arm 30 is attached to the upper part of the rotating shaft 17 in the radial direction of the sedimentation tank main body, and the scraping surface of the arm 30 is oriented substantially in the turning direction of the arm. A fixed fixing plate 31 fixed,
A movable pulling plate 33 that is configured so that the scraping surface is directed in the radial direction of the sedimentation tank body and is movable.

The movable pulling plate 33 is attached to a bar 32 suspended from the arm 30.
Is in a state where it can move horizontally along the longitudinal direction of the arm 30. Therefore, the movable approach plate 33 can be moved from the central portion to the peripheral portion.

The rod-like member 32 suspended from the arm 30 has a lower end provided below the arm 30 in a state in which it can be moved horizontally and in a state where it is prevented from moving upward. 34, and the arm 30 and the guide rail 34 are connected by the rod-shaped member 32. The guide rail 34 is provided at a level lower than the upper end of the baffle plate 13 with a constant level difference from the arm 30. The guide rail 34 has a loop shape and surrounds the center well 12 in the central part of the sedimentation basin body 10, and surrounds the scum discharge port 14 in the peripheral part.
Is formed in the vicinity of. Reference numeral 35 denotes a mount for the guide rail 34.

FIGS. 3 and 4 show details of a movable portion of the scum scraping device shown in FIGS. 1 and 2, FIG. 3 is a side view, and FIG. 4 is a sectional view. 3 and 4, reference numeral 30 denotes an arm, reference numeral 34 denotes a guide rail, reference numeral 32 denotes a rod-shaped member, and reference numeral 33 denotes a movable approach plate. The arm 30 and the guide rail 34 are formed of lip channel steel or the like, and the arm 30 is attached with the lip 36 on the lower side and the guide rail 34 with the lip 39 on the upper side.

The upper end of the rod-shaped member 32 is located on the inner surface side of the arm 30, and the upper end is fixed to the upper plate 37. Further, four wheels 38 are provided below the upper plate 37, and the upper plate 37 is mounted on the lip portions 36, 36 of the arm via the wheels 38. For this reason, the bar-shaped member 32 having the movable shift plate 33 is suspended from the arm 30 via the upper plate 37 and the wheel 38, and is movable in the longitudinal direction of the arm 30 by the wheel 38.

The lower end of the rod-shaped member 32 is located on the inner surface side of the guide rail 34, and the lower end is fixed to the lower plate 40. Two wheels 41 are provided on the upper side of the lower plate 40, and the wheels 41 are arranged at positions close to or in contact with the lip portions 39 of the guide rail. For this reason, the lower end of the rod-shaped member 32 having the movable pulling plate 33 can be moved in the longitudinal direction of the guide rail 34, and the rod-shaped member 32 is moved upward by the wheels 41 even when a pulling force acts upward. Movement to is blocked. However, even in the state where the pulling force is acting on the rod-shaped member 32, the movement along the guide rail 34 is possible because the wheels 41 are provided.

The wheels 4 provided on the lower plate 40
1 has the same structure as a free-form caster whose direction can be freely changed. For this reason, the lower end of the rod-shaped member 32 can move in any direction, and even if the engaged guide rail 34 is formed in an annular shape,
It can move along the guide rail 34.

A sleeve 42 is loosely fitted on the upper and lower portions of the rod-shaped member 32.
2 moves, the rod-shaped member 32 and the lip 3
6 or contact with the lip 39 of the guide rail,
The rod-shaped member 32 can move smoothly.

Next, the operation of the movable shift plate 33 will be described with reference to FIG. In FIG. 5, reference numeral 10 denotes a sedimentation basin main body, 33 denotes a movable approach plate, and 34 denotes a guide rail. As described above, the rod-shaped member to which the movable shift plate 33 is attached is suspended from the arm 30, and the lower end thereof is engaged with the guide rail 34 in a state where it is prevented from moving upward. The part of the guide rail 34 where the lower end is located is located directly below the part of the arm 30 where the upper end is located, and the distance between the two parts is always constant. For this reason, when any one end of the rod-shaped member is moved, the other end also moves, and the portion of the guide rail 34 where the lower end exists is located directly below the portion of the arm 30 where the upper end exists. It is adjusted to be the position.

The above operation will be specifically described. Arm 3
When 0 turns, the movable approach plate 33 cannot turn while drawing a concentric circle. If movable plate 3
If 3 draws a concentric circle as it is, the rod-shaped member to which the movable approaching plate 33 is attached becomes oblique, and the distance between the upper and lower ends must be longer than the length of the rod-shaped member. For this reason, when the arm 30 turns, the positional relationship between the upper and lower ends of the bar-shaped member is not normal, and the upper and lower ends are slightly moved relative to each other, and the positional relationship returns to the original state.

For example, when the arm 30 turns and a₁Position of
From a_TwoIf you move to the position of b ₁Possible
The lower end of the rod-shaped member having the moving approach plate 33 is a guide rail.
34, the arm 30 moves in the turning direction of the arm 30.
Occasionally, the upper end of the rod-shaped member extends radially of the arm 30.
Move towards. As a result, b₁Movable in the position of
The approach plate 33 is b_TwoReach the position. Thereafter, in the same manner,
The movable shift plate 33 is b_TwoFrom the location toward the periphery
B_ThreeTo position b and b_ThreeScum from position
B close to outlet 14_FourMove to the position. During this time, movable
The scraping surface of the gathering plate 33 extends in the radial direction of the
Because it is facing, as the arm 30 turns,
Scum is sequentially pushed toward the periphery.
Then, the scum collected around the periphery has
Fixed scraping plate (shown in FIG.
) And is squeezed to the scum discharge port 14 and discharged.
Is done.

[0027] The position movable shifting plate 3 which has moved up to b ₄
3 then moves to the center along the guide rail 34 and repeats the movement to the periphery again.

[0028]

According to the present invention, while the scum floating on the surface of the water is scraped in the circumferential direction, the scum being scraped is scraped to the peripheral portion. The accumulated scum can be accumulated in the peripheral portion so as to be pushed out, and can be scraped to the scum discharge portion.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state in which an example of a scum scraping device of the present invention is provided in a circular sedimentation basin.

FIG. 2 is a sectional view of the apparatus of FIG.

FIG. 3 is a side view showing details of a movable section according to an example of the scum scraper of the present invention.

FIG. 4 is a cross-sectional view showing details of a movable portion of the scum scraping device of FIG. 3;

FIG. 5 is an explanatory view showing the movement of a shift plate.

FIG. 6 is a plan view showing a state in which a conventional scum scraping device is provided in a circular sedimentation basin.

FIG. 7 is a sectional view of the apparatus of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Settlement pond main body 11 Raw water inflow pipe, 12 Center well 13 Baffle plate 14 Scum discharge port 15 Overflow weir 16 Drain port 17 Rotary shaft 18 Rotary shaft drive device 30 Arm 31 Fixed closing plate 32 Bar-shaped member 33 Movable closing plate 34 Guide Rail 36 Arm lip 37 Upper plate 38 Wheel 39 Guide rail lip 40 Lower plate 41 Wheel

Claims (2)

[Claims] 1. A method of scraping scum floating on the water surface of a circular sedimentation basin to a scum discharge part, while sweeping scum floating on the water surface in the circumferential direction of the sedimentation basin body. Scum scraped in a circular sedimentation basin, wherein the scum gathered in the settling basin is scraped in the radial direction of the sedimentation basin body and collected in the peripheral portion, and the scum collected in the peripheral portion is scraped to the discharge portion. . 2. A scum scraping device for scraping scum floating on the water surface of a circular sedimentation basin to a scum discharge part, wherein a rotating shaft located at the center of the sedimentation basin main body and a radial direction of the sedimentation basin main body above the rotation axis. An arm attached to the arm, and a movable pulling plate fixed to the arm with the scraping surface directed substantially in the turning direction of the arm and a movable pulling plate directed to the radial direction of the sedimentation tank body. Two movable plates are provided, and the movable movable plate is attached to a bar-like member suspended from an arm in a horizontally movable state, and the lower end of the bar-like member is at a level below the arm. And is engaged with a loop-shaped guide rail extending from the central portion to the peripheral portion of the sedimentation tank main body in a horizontally movable state and in a state where upward movement is prevented. Board A scum scraping device for a circular sedimentation basin, wherein the scum scraper is configured to move along the arm and in the radial direction of the sedimentation basin body along the guide rail.