JPH08187500A - Sludge stirring device - Google Patents

Abstract

PURPOSE: To perfectly stir the sludge in a cut-off frame without generating stirring residue by making the outer shape of the locus of the tip of a blade polygonal. CONSTITUTION: An internal gear 31 is arranged above a cut-off frame 11 whose horizontal cross section is polygonal and meshed with a planetary gear 32. When the number of the corners of the cut-off frame 11 is set to (n), the number-of-tooth ratio of the internal gear 31 to the planetary gear 32 is set to n:1. The center of rotation of a rotary shaft 12 is made eccentric with respect to the center of rotation of the planetary gear 32. The internal gear 31 and the planetary gear 32 are made synchronous so that the center of the rotary shaft 12 is positioned outside the center of the rotation of the planetary gear 32 on the straight line connecting the center of the cut-off frame 11 and one corner thereof when the center of rotation of the planetary gear 32 is positioned on the straight line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to sludge from rivers and lakes for improving the environment, especially sludge that is difficult to dehydrate and has a large fluidity and is difficult to handle. The present invention relates to a sludge agitator used for injecting and stirring and solidifying the same.

[0002]

2. Description of the Related Art As a device of this kind, a water stop frame having a rectangular horizontal cross section for preventing the sludge from diffusing so as not to be buried in sludge and pollute the entire river or lake, and the center of the water stop frame. It is known that a plurality of radial stirring blades are provided at the lower end of a vertical rotation shaft having a matched center of rotation and a plurality of radial stirring blades that stir the sludge in the water blocking frame.

[0003]

In the above device, the outer diameter of the locus drawn by the tip of the blade is circular. Therefore, even if the blades are rotated in the water blocking frame, the sludges at the four corners of the water blocking frame have dead spaces in which they are not stirred. This dead space accounts for 21.5% of the total water blocking frame. Since the sludge in such dead space is not solidified, when it is lifted from the water, it flows out and diffuses into the water to pollute the entire water of rivers and lakes, or it flows out during transportation to post-treatment and the nearby Contamination, deterioration of the performance of the dehydration treatment, contamination of various natural environments, and post-treatment work will be hindered.

An object of the present invention is to provide a sludge agitator capable of agitating sludge in a water blocking frame completely without causing agitation residue.

[0005]

A sludge agitator according to the present invention comprises a water stop frame having a polygonal horizontal cross section and a plurality of radial agitating blades provided at the lower end of a vertical rotary shaft. In the device, an internal gear disposed above the water-stop frame and having a center coinciding with the center of the water-stop frame, and a planetary gear that is meshed with the internal gear and is rotatably connected to the rotary shaft. And a drive means for driving the planetary gear to revolve while rotating on its own axis. When the number of corners of the water-stop frame is n, the tooth ratio of the internal gear and the planetary gear is n: 1. The rotation center of the rotation shaft is eccentric with respect to the rotation center of the planetary gear, and the rotation center of the planetary gear is located on the straight line connecting the center of the water blocking frame and one corner of the water blocking frame. Sometimes the center of rotation is more than the center of rotation of the planetary gears on the same line. Is characterized in that the internal gear and the planetary gear to be is positioned on the side are synchronized.

Further, the driving means is provided on the support frame fixed to the upper end of the water blocking frame, the elevating frame provided on the supporting frame, and the center of the internal gear provided on the elevating frame. A driving rotating body having a rotation center and a driven rotating body having a rotation center provided on the driving rotation body and matched with the center of the planetary gear,
It is preferable that the internal gear is fixed to the lifting frame, and the planetary gear and the rotation shaft are fixed to the driven rotating body.

Another agitator according to the present invention is a sludge agitator having a water stop frame having a polygonal horizontal cross section and a plurality of radial agitating blades provided at the lower end of a vertical rotating shaft. An internal gear arranged above the frame and having a center coinciding with the center of the water blocking frame; a planetary gear meshed with the internal gear and connected to the rotary shaft so as to be rotationally transmittable; and a planetary gear. And a drive means for driving so as to revolve while rotating on its own axis. When the number of corners of the water blocking frame is n, the ratio of the number of teeth of the internal gear and the planetary gear is n: 1, and the rotation shaft The rotation center of is aligned with the rotation center of the planetary gears, the number of blades is m, and the angle formed by the two straight lines connecting the two adjacent corners of the water-stop frame When the angle equally divided by a number equal to the number is α, When the straight line connecting one corner of the water frame is the first line and the m-1 line sequentially separated from the first line by an angle α is the 2nd to mth line, the center of the water stop frame From the distance from 1 to m where the 1st to mth lines intersect the inside of one side of the water blocking frame and the lines extending along it, respectively, the distance obtained by sequentially reducing the revolution radius of the planetary gears and the rotation axis. The length of the blade is changed so that the distance from the center of rotation of the blade to the tip of the blade becomes equal, and the center of rotation of the planetary gear is aligned with the straight line connecting the center of the water blocking frame and one corner of the water blocking frame. It is characterized in that the internal gear and the planetary gear are synchronized so that the longest blade is located outside the center of rotation of the planetary gear on the same line when it is positioned.

Further, the drive means is provided on the support frame fixed to the upper end of the water blocking frame, the elevating frame provided on the support frame, and the center of the internal gear provided on the support frame. A driving rotating body having a rotation center and a driven rotating body having a rotation center provided on the driving rotation body and matched with the center of the planetary gear,
The internal gear is fixed to the support frame, the planetary gear is fixed to the driven rotating body, and the rotating shaft is connected to the elevating frame so as to be freely rotatable but restricted in axial movement. It is preferable.

[0009]

In the sludge agitator according to the present invention, the internal gear, which is disposed above the water blocking frame and has a center coinciding with the center of the water blocking frame, can be meshed with the internal gear and rotationally transmitted to the rotary shaft. And a drive means for driving the planetary gear to revolve while rotating on its own axis. When the number of corners of the water blocking frame is n, the internal gear and the planetary gear are provided. Has a tooth ratio of n to 1, the center of rotation of the rotating shaft is eccentric with respect to the center of rotation of the planetary gear, and the planetary gear is on a straight line connecting the center of the water blocking frame and one corner of the water blocking frame. The internal gear and the planetary gear are synchronized so that the center of the rotation axis is located outside the center of rotation of the planetary gear on the same line when the center of rotation of the planetary gear is positioned. When rotating while revolving, the rotating shaft is almost similar to the water stop frame Order to be moved along a polygonal, the outer shape of the trajectory of the blade tip becomes polygon.

Further, the driving means is provided on the support frame fixed to the upper end of the water blocking frame, the elevating frame provided on the supporting frame, and the elevating frame and the center of the internal gear. A driving rotating body having a rotation center and a driven rotating body having a rotation center provided on the driving rotation body and matched with the center of the planetary gear,
When the internal gear is fixed to the elevating frame and the planetary gear and the rotating shaft are fixed to the driven rotating body, the drive means is moved together with the water stop frame.

In another agitator according to the present invention, an internal gear, which is disposed above the water blocking frame and has a center coinciding with the center of the water blocking frame, is meshed with the internal gear and rotationally transmitted to the rotary shaft. The planetary gears are connected so that the planetary gears and the drive means for driving the planetary gears to revolve while rotating on their own axis. When the number of corners of the water blocking frame is n, the internal gear and the planetary gears are provided. The gear tooth ratio is n to 1, and the rotation center of the rotating shaft is made to coincide with the rotation center of the planetary gear,
When the number of blades is m and the angle formed by two straight lines connecting the center of the water blocking frame and two adjacent corners of the water blocking frame is equally divided by the number equal to the number of blades, α The straight line connecting the center of the water frame and one corner of the still water frame is defined as the first line, and the m-1 line sequentially separated from the first line by the angle α is 2 to
When the m-th line is defined, from the center of the water-stop frame, the distance from the center of the water-stop frame to the point of 1-m at which the 1-m-th line intersects the line extending along the inside of one side of the water-stop frame, The length of the blades is changed so that the distance from the rotation center of the rotating shaft to the tip of the blades is sequentially equalized by sequentially reducing the revolution radius of the planetary gears. When the rotation center of the planetary gear is located on the straight line connecting one angle, the internal gear and the planetary gear are synchronized so that the longest blade is located outside the rotation center of the planetary gear on the same straight line. Therefore, if the planetary gear is revolved while revolving, the rotating shaft will move along the revolution circle of the planetary gear, but during the movement, as the rotating shaft moves away from one side of the water stop frame, the rotating shaft will move. Due to the rotation of the The blade that was on one side of the frame moves away, and the next blade rotates and approaches toward the one side of the water-stopping frame that has moved due to the revolution.By repeating this, the outer shape of the trajectory of the blade tip becomes polygonal. Become.

Further, the drive means is provided on the support frame fixed to the upper end of the water blocking frame, the elevating frame provided on the support frame, and the center of the internal gear provided on the support frame. A driving rotating body having a rotation center and a driven rotating body having a rotation center provided on the driving rotation body and matched with the center of the planetary gear,
The internal gear is fixed to the support frame, the planetary gear is fixed to the driven rotating body, and the rotating shaft is connected to the elevating frame so as to be freely rotatable but restricted in axial movement. Then, the drive means is moved together with the water stop frame.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1> Referring to FIG. 1, a sludge agitator comprises a water stop frame 11 having a square horizontal cross section, and four radial agitating blades 13 provided at a lower end portion of a vertical rotary shaft 12. ing.

The water stop frame 11 is suspended by a crane (not shown) mounted on a barge and is hidden in sludge at a treatment site. The top of the water blocking frame 11 is covered with a slit screen 36. The slit screen 36 is for confining the sludge water in the water blocking frame 11 and for replacing water and air when the water blocking frame 11 is thrown in and pulled up.
Further, although not described in detail, the slit screen 36 is provided with a slit through which the rotary shaft 12 is inserted.

A lower coagulant passage 14 is provided at the axis of the rotary shaft 12. The upper end of the lower coagulant passage 14 is opened to the upper end surface of the rotary shaft 12. A spout 15 is provided near the lower end of the rotary shaft 12, and the lower end of the lower coagulant passage 14 is in communication therewith.

At the upper end of the water blocking frame 11, a rectangular tubular support frame 21 having a cross section substantially the same as the cross sectional shape of the water blocking frame 11 is fixed. On the top wall of the support frame 21, a vertically downward fluid pressure cylinder 22 is equipped so that the piston rod projects into the support frame 21.

A vertical guide rod 23 is provided along the side wall of the support frame 21, and a hollow hermetically elevated frame 24 is provided on the vertical guide rod 23.
Is slidably penetrated. A driving rotor 25 is supported at the center of the bottom wall of the lifting frame 24. The driving rotor 25 has a vertical rotation axis that is aligned with the center of the water blocking frame 11. A driven rotating body 26 is supported at a predetermined distance from the center of rotation of the driving rotating body 25. The driven rotor 26 is
It has a vertical center of rotation parallel to the center of rotation of the driving rotor 25.

A fluid pressure cylinder is mounted on the top wall of the lifting frame 24.
22 piston rods are connected. Lifting frame 24
A vertical downward hydraulic motor 27 is provided at the end of the top wall so that its output shaft projects downward from the top wall. A drive gear 28 is fixed to the output shaft. A driven gear 29 meshed with the drive gear 28 is fixed to the driving rotor 25.

An internal gear 31 is fixed to the elevating frame 24 in the vicinity of the outer periphery of the driving rotor 25. The center of the internal gear 31 is made to coincide with the rotation center of the driving rotor 25, and is therefore made to coincide with the center of the water blocking frame 11. The driven rotating body 26 is integrally provided with a planetary gear 32 that meshes with the internal gear 31. The rotation center of the planetary gear 32 is matched with the rotation center of the driven rotary body 26. The tooth number ratio of the internal gear 31 and the planetary gear 32 is 4: 1.

An upper coagulant passage 33 is provided vertically through the driven rotor 26. The upper coagulant passage 33 is formed in a substantially S shape, the upper end opening of which is aligned with the rotation center of the driven rotor 26, and the lower end opening of which is offset from the rotation center of the driven rotor 26 by a distance ε. There is. Upper coagulant passage
One end of a coagulant supply pipe 35 is connected to the upper end opening of 33 through a rotary seal 34.

The driven rotor 26 is arranged so that the upper end opening of the lower coagulant passage 14 and the lower end opening of the upper coagulant passage 33 are communicated with each other.
A rotary shaft 12 is eccentrically fixed to a lower end surface of the eccentric member by a distance ε.

While the fluid pressure cylinder 22 is actuated to raise and lower the elevating frame 24, the hydraulic motor 27 is actuated to rotate the driving rotor 25. When the driving rotor 25 is rotated, the planetary gear 32 revolves while revolving in a state where the internal gear 31 and the planetary gear 32 are meshed with each other, and accordingly, the driven rotor 26 also revolves while revolving. When the driven rotating body 26 revolves around its axis while rotating, the rotating shaft 12 revolves around the driven rotating body 26 while rotating the driven rotating body 26.
Can be rotated while drawing a circle corresponding to the eccentricity amount ε around the rotation center of. When the blade 13 is rotated according to the rotating shaft 12, the outer shape of the trajectory drawn by the tip of the blade 13 becomes a square that is almost close to the square of the water-stop frame 11, and
The sludge in the water blocking frame 11 is completely agitated without being left behind.

Next, the trajectory of the rotating blade will be described in detail with reference to FIG.

In FIG. 2, the center of the water blocking frame 11 is set at the origin (0, 0) of the (x, y) coordinates. When R1 is the pitch circle radius of the internal gear 31, and R2 is the pitch circle radius of the planet gear 32, a predetermined distance R from the center of rotation of the planet gear 32
The locus P of the center of rotation of the blade (center of rotation of the rotation axis) separated by 3 (amount of eccentricity ε) is expressed by the following equation.

X = R2. (N-1) cos .theta. + R3.c
os (n-1)? y = R2. (n-1) sin? -R3.sin (n-
1) θ n is the number of polygonal corners of the still water frame 11, where n =
It is 4. The ratio of the number of teeth of the internal gear 31 and the planetary gear 32 (R1 to R
2) is n: 1, and therefore is 4: 1, so that every time the planetary gear 32 revolves 90 degrees along the internal gear 31, the planetary gear 32 rotates 360 degrees. The four blades 13 are of equal length l and are equally spaced. The length l of the blade 13 needs to reach the center of the water blocking frame 11.

Here, R1 = 200, R2 = 50, R3
= 20, the numerical value of (x, y) is obtained, and the plotted value is shown in FIG. 2 by a square C1 having rounded four corners.

In the above, R2 / R3 = 50/20
However, if the ratio is set to be larger than 0.4, the straight line portion of the square C becomes concave, and if it is set to be small, the straight line portion of the square C1 becomes convex.

When the locus of the point P is determined as described above, the outer shape of the locus of the tip of the blade 13 that revolves around the point P while revolving becomes a quadrangle similar to the square C1. Therefore, when the point P is, for example, on the x-axis and is located outside the center of rotation of the planetary gear 32, the internal gear 31 and the planetary gear 32 are arranged so that the corners of the water blocking frame 11 are on the x-axis. If you synchronize,
The tips of the blades 13 move as a fit to the inner surface of the water blocking frame 11.

FIG. 3 is a diagram in which all loci of the blade 13 when the blade 13 is moved on the point P are obtained and plotted. The display angle is every 3 degrees. According to this, the dead space at the four corners of the water blocking frame 11 is 4%, which is
Compared with the numerical value of 21.5% of the conventional device described at the beginning,
It is a great improvement.

<Embodiment 2> Referring to FIG. 4, the sludge agitator comprises a water blocking frame 41 with a slit screen 83 and a square horizontal cross section, and four radial agitating blades provided at the lower end of a vertical rotary shaft 42. It has 43 and.

The rotary shaft 42 has a coagulant passage 44 and a spout 45 as in the first embodiment.

A rectangular tubular support frame 51 is provided at the upper end of the water-stop frame 41.
Has been fixed. The support frame 51 includes a lower frame 51A having substantially the same shape as the water blocking frame 41 and an upper frame 51B larger than the lower frame 51A.

A vertical screw shaft 52 is provided along the side wall of the upper frame 51B. A driven sprocket 53 is provided on the upper end of the screw shaft 52. On the side opposite to the screw shaft 53 across the side wall, a vertical upward hydraulic motor 54 for operating the lifting frame is installed.
Is equipped. A drive sprocket 55 is fixed to the output shaft of the hydraulic motor 54. A chain 56 is wound around the driven sprocket 53 and the drive sprocket 55.

In the central portion of the lower frame 51A, a driving rotor is provided.
61 are supported. The driving rotator 61 has a vertical rotation axis that is aligned with the center of the water blocking frame 41. Prime mover
The lower driven rotary body 62 is supported at a predetermined distance from the center of rotation of 61. The lower driven rotary body 62 has a vertical rotation center parallel to the rotation center of the driving rotary body 61. Driving body 61
An elevating frame 63 is arranged above. An upper driven rotating body 64 is supported on the elevating frame 63. The upper driven rotator 64 has a vertical rotation axis aligned with the center of the water blocking frame 41. A nut 65 screwed to the screw shaft 52 is fixed to the elevating frame 63.

A vertically downward hydraulic motor 66 for activating the rotating body is provided on the upper frame 51B in the vicinity of the outer periphery of the upper end of the driving rotating body 61. A drive gear 67 is fixed to the output shaft of the hydraulic motor 66. Driven gear 68 meshed with drive gear 67
Is fixed to the driving rotor 61.

An internal gear 71 is fixed to the lower frame 51A in the vicinity of the outer periphery in the middle of the height of the driving rotor 61.
The center of the internal gear 71 is made to coincide with the rotation center of the driving rotor 61, and is therefore made to coincide with the center of the water stop frame 41. The lower driven rotary body 62 is integrally provided with a planetary gear 72 meshed with the internal gear 71. The rotation center of the planetary gear 72 is matched with the rotation center of the lower driven rotary body 62. The tooth number ratio of the internal gear 71 and the planetary gear 72 is 4: 1.

At the center of the shaft of the lower driven rotor 62, the rotary shaft 42 is free to move in the axial direction in the middle of its length.
The rotation is penetrated so as to be restrained. Rotating shaft 42
The upper end of the is connected to the upper driven rotating body 64 so as to be free to rotate but to be restrained from moving in the axial direction.

One end of a coagulant supply pipe 82 is connected to the upper end opening of the coagulant passage 44 via a rotary seal 81.

The lifting frame 63 is moved up and down by the lifting frame actuating hydraulic motor 54. While raising and lowering the lifting frame 63, the driving rotor 61 is rotated by the operation of the rotating body operating hydraulic motor 66. When the driving rotor 61 is rotated, the planetary gear 72 is revolved while revolving in a state where the internal gear 71 and the planetary gear 72 are meshed with each other, and accordingly, the lower driven rotor 62 is also revolved while revolving. . When the lower driven rotating body 62 is rotated while revolving,
While the 42 is revolving along the lower driven rotary body 62, it is rotated about the rotation center of the lower driven rotary body 62.

Next, the length of the blade 43 will be described in detail with reference to FIG.

In FIG. 5, a circle C2 centered on the center O of the water blocking frame 41 is the center of rotation of the blade 43 (center of rotation of the planetary gear).
Is the trajectory of. The radius R of the circle C2 is R1-R2.

The number m of blades 43 is four. Four wings 43
Are evenly spaced. The lengths of the four blades 43 are l1, l2, l3 and l4 in the order of the rotation direction.

The angle between the center O of the water-stop frame 41 and the two straight lines connecting the two adjacent corners of the water-stop frame 41 is 90 degrees, which is equally divided by four blades 43. Is α. A straight line connecting the center O of the water-stop frame 41 and one corner of the water-stop frame 41 is defined as the first line L1, and from this, lines separated by an angle α are sequentially set to the second line L2 and the third line. Let line L3 and the fourth line L4. On the other hand, a line S is drawn from one side of the water blocking frame 41 with a predetermined gap inward. 1st to 4th lines L
The intersections of 1-L4 and the line S are A1-A4. Then, from the distance from the center O of the still water frame 41 to the point A1, the circle C2
The length obtained by subtracting the radius R of is the length l1 of the longest blade 43. Similarly, the remaining blade 43 has a length obtained by subtracting the radius of the circle C2 from the distance from the center O of the water blocking frame 41 to the points A2 to A4.
Has a length of l2 to l4. Here, l2 = l4. The longest length 43 of the blade 43 is required to reach the center of the water blocking frame 41. When the rotation center of the blades 43 is positioned on a straight line connecting the center of the water blocking frame 41 and one corner of the water blocking frame 41, the longest blade 43 is located outside the rotation center on the same straight line. Internal gear 71 to be made
And the planet gear 72 are synchronized.

FIG. 6 shows the ratio of the lengths of the above-mentioned four blades 43 as l1: l2: l3: l4 = 1: 0.7: 0.5:
The value is 0.7, and all loci of the blade 43 when the blade 43 is moved are obtained and plotted. Display angle is 3
It is a step. According to this, the dead space in the water blocking frame 41 which is not agitated by the blade is 1.4%, which is a further improvement as compared with the case of the first embodiment.

In the above embodiment, the water blocking frame has a quadrangular cross section, but it may have a triangular shape, a pentagonal shape, a hexagonal shape or the like. For example, when the cross section of the water blocking frame is triangular, the tooth ratio between the internal gear and the planetary gear is 3: 1.

[0047]

According to the invention of claim 1 or claim 3, since the outer shape of the locus of the blade tips is polygonal, the sludge in the water blocking frame is completely stirred without causing a stirring residue. can do.

According to the invention of claim 2 or 4,
Since the drive means can be moved together with the water stop frame, for example, the drive means can be a simple mechanism as compared with the case where the drive means is equipped on a ship with the water stop frame suspended. Significant cost improvement can be achieved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a stirring device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a rotation operation of blades of the stirring device.

FIG. 3 is an explanatory diagram of a locus of blades of the stirring device.

FIG. 4 is a vertical vertical sectional view of a stirring device according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a rotation operation of blades of the stirring device.

FIG. 6 is an explanatory diagram of a locus of blades of the stirring device.

[Explanation of symbols]

 11 Water stop frame 12 Rotation shaft 13 Blade 31 Internal gear 32 Planet gear 41 Water stop frame 42 Rotation shaft 43 Blade 71 Internal gear 72 Planet gear

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ishige 2-1-9 Sellobori, Nishi-ku, Osaka City Ataka Industrial Co., Ltd. In the company

Claims (4)

[Claims] 1. A water blocking frame 11 having a polygonal horizontal cross section, and a plurality of radial stirring blades 13 provided at the lower end of a vertical rotating shaft 12.
In the sludge agitator including, an internal gear 31 arranged above the water-blocking frame 11 and having a center coinciding with the center of the water-blocking frame 11, and a rotary shaft 12 meshed with the internal gear 31. It is provided with a planetary gear 32 that is rotatably connected and a drive unit that drives the planetary gear 32 to revolve while rotating on its own axis. When the number of corners of the water blocking frame 11 is n, , The ratio of the number of teeth of the internal gear 31 and the planetary gear 32 is n: 1, the rotation center of the rotating shaft 12 is eccentric to the rotation center of the planetary gear 32, and the center of the water blocking frame 11 and the water blocking When the center of rotation of the planetary gear 32 is located on a straight line connecting one corner of the frame 11, the center of the rotation shaft 12 is located outside the center of rotation of the planetary gear 32 on the same line. A sludge agitator characterized in that a gear 31 and a planetary gear 32 are synchronized. 2. The drive means includes a support frame 21 fixed to the upper end of the water blocking frame 11, an elevating frame 24 provided on the support frame 21, and an internal gear 31 provided on the elevating frame 24. A driving rotor 25 having a center of rotation coincident with the center, and a planetary gear 32 provided on the driving rotor 25 and a planetary gear 32.
Driven rotor 26 having its center of rotation coincident with the center of
The sludge agitator according to claim 1, further comprising an internal gear 31 fixed to the elevating frame 24, and the planetary gear 32 and the rotary shaft 12 fixed to the driven rotor 26. 3. A water blocking frame 41 having a polygonal horizontal cross section, and a plurality of radial stirring blades 43 provided at the lower end of a vertical rotating shaft 42.
In the sludge agitator including, an internal gear 71 arranged above the water-blocking frame 41 and having a center coinciding with the center of the water-blocking frame 41, and a rotary shaft 42 meshed with the internal gear 71. It is provided with a planetary gear 72 that is rotatably connected and a drive means that drives the planetary gear 72 to revolve while rotating on its own axis. When the number of corners of the water blocking frame 41 is n, , The ratio of the number of teeth of the internal gear 71 and the planetary gear 72 is n: 1, the center of rotation of the rotary shaft 42 is matched with the center of rotation of the planetary gear 72, the number of blades is m, and the water-stop frame is
When the angle formed by the two straight lines connecting the center of 41 and two adjacent corners of the still water frame 41 is equally divided by the number equal to the number m of blades 43, the center of the still water frame 41 And still water frame 41
The straight line connecting one corner of the line is defined as the first line L1 and the m-1 lines sequentially separated by the angle α from the first line L1 are
When the m-th line L2 to Lm is set, the 1st to mth lines L1 to Lm intersect with the line S extending along the inside of one side of the water-stop frame 41 from the center of the water-stop frame 41, respectively. Of the blades 43 such that the distance from the points A1 to Am of the point m to m is successively reduced by the revolution radius R of the planetary gear 72 and the distance from the center of rotation of the rotary shaft 42 to the tips of the blades 43 becomes equal. Length l
When the rotation center of the planetary gear 72 is positioned on a straight line connecting the center of the water blocking frame 41 and one corner of the water blocking frame 41 when 1 to 1 m is changed, the longest blade 43 is on the same line. A sludge agitator in which an internal gear 71 and a planetary gear 72 are synchronized so as to be positioned outside the rotation center of the planetary gear 72. 4. The drive means includes a support frame 51 fixed to the upper end of the water blocking frame 41, an elevating frame 63 provided on the support frame 51, and an internal gear 71 provided on the support frame 51. A driving rotor 61 having a center of rotation matched with the center, and a planetary gear 72 provided on the driving rotor 61.
Driven rotor 62 having its center of rotation coincident with the center of
The internal gear 71 is fixed to the support frame 51, the planetary gear 72 is fixed to the driven rotor 62, and the rotary shaft
The sludge agitator according to claim 3, wherein 42 is connected to the elevating frame 63 so as to be freely rotatable but restrained from moving in the axial direction.