JP4593543B2 - Flocculator - Google Patents

Description

  The present invention relates to a flocculator.

  In water purification facilities, flocculants are added to raw water such as river water to aggregate turbidity to form flocs, and the raw water containing these flocs is slowly stirred with a slow stirrer called a flocculator. The raw water is purified by separating the coarse floc from the raw water by, for example, sedimentation separation.

  As the flocculator, a rotating shaft provided with a large number of stirring blades is disposed sideways in a flock forming tank in which flocs are grown, and the rotating shaft is supported by an underwater bearing so that the rotating shaft is rotated. Of these, a configuration in which the mixture is stirred at a low speed is frequently used.

  An example of such a flocculator is disclosed in Non-Patent Document 1. This flocculator is called a float type flocculator, and uses a hollow shaft made of a steel pipe or the like as a rotating shaft and attaches a float to the shaft to reduce the load applied to the bearing as much as possible. The float type flocculator is applied to a large floc forming tank because the weight of the rotating shaft is light and the rotating shaft can be elongated.

On the other hand, when the treatment tank is large, an expansion section is often provided as an earthquake countermeasure. This expansion part divides a processing tank into two tank parts, and when a divided tank part shifts in the case of an earthquake, distortion of the tank by an earthquake is absorbed and destruction of the whole tank is prevented. Further, a mechanism that allows the tank to be displaced is also studied on the rotating shaft of the flocculator. In Patent Document 1, a pair of bearing bases are provided on the bottom of the tank with the expansion portion interposed therebetween. The connection structure which divides | segments a rotating shaft in between and connects the divided | segmented rotating shafts is disclosed.
JP-A-11-197482 “Water Supply Facility Design Guidelines 2000”, Japan Waterworks Association, p.574-575

  However, the above flocculator has a problem in that the long shaft, which is an advantage of the float type flocculator, is hindered because the tank is allowed to shift due to the connecting structure provided by dividing the rotating shaft.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a flocculator capable of making the rotation axis longer while allowing the tank to be displaced due to an earthquake or the like.

  The flocculator according to the present invention is a flocculator having a rotating shaft having a connecting portion formed by coaxially connecting a driving shaft and a hollow shaft, and the connecting portion of the rotating shaft is on the hollow shaft side of the driving shaft. An inner ring portion having a spherical sliding surface provided at one of the end portion and the drive shaft side end portion of the hollow shaft, and an inner ring portion provided at the other of the drive shaft side end portion of the hollow shaft and the hollow shaft side end portion of the drive shaft Limit the relative slidable range of the inner ring portion with respect to the outer ring portion so that the crossing angle formed by the outer ring portion that accommodates the outer ring portion and the axis of the hollow shaft and the axis of the drive shaft is less than a predetermined angle. And an end portion different from the drive shaft side end portion of the hollow shaft is supported by a spherical bearing.

  In this way, one end of the hollow shaft is supported by the spherical bearing, and the other end is connected to the drive shaft via the connecting portion. The slidable range of the inner ring portion and the outer ring portion of the connecting portion is limited by the slide limiting means so that the intersection angle formed by the axis of the hollow shaft and the axis of the drive shaft is less than a predetermined angle. While transmitting torque to the hollow shaft, it is possible to allow the displacement of the hollow shaft in the tilt direction, and to allow the displacement of the tank due to an earthquake or the like. Further, since the hollow shaft is provided without being divided in the middle, the hollow shaft can be elongated and the rotating shaft can be elongated.

  Here, as the sliding limiting means that preferably exhibits the above-described action, specifically, a loose fitting convex portion protruding outward from the spherical sliding surface of the inner ring portion and a concave portion on the sliding surface of the outer ring portion are provided. And a loose fitting concave portion for loosely fitting the loose fitting convex portion. If it does in this way, the slidable range of an outer ring | wheel part or an inner ring | wheel part can be easily set by forming a loose fitting convex part and a loose fitting recessed part with a suitable dimension.

  Further, the inner ring portion has a ring-shaped member fitted to the outer peripheral surface of one end of the drive shaft, and the loose fitting convex portion has an end portion of a rod-shaped member that penetrates the drive shaft and the inner ring portion in the axial radial direction. It is preferable to include. According to this configuration, the loose fitting convex portion formed at the end portion of the rod-shaped member does not have a bent portion that easily concentrates stress during the operation of the flocculator, so that the rigidity of the loose fitting convex portion is increased. Further, even when the loose fitting convex portion is deformed, an appropriate slidable range can be maintained by exchanging the rod-shaped member.

  According to the flocculator of the present invention, it is possible to make the rotation axis longer while allowing the tank to be displaced due to an earthquake or the like.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described. 1st embodiment demonstrates the case where the flocculator which concerns on this invention is applied to the flock formation tank of a water-purification process equipment.

  First, with reference to FIG. 1 thru | or FIG. 10, the structure of the flocculator concerning 1st embodiment is demonstrated. FIG. 1 is a plan view showing a flocculator 1 according to the first embodiment, FIG. 2 is a front view of a main part of the flocculator shown in FIG. 1, and FIG. 3 is a side sectional view of the flocculator shown in FIG. 4 is a side sectional view showing a state where the rotating shaft is supported by the underwater bearing, FIG. 5 is a sectional view showing a section along the line VV of the rotating shaft shown in FIG. 4, and FIG. FIG. 7 is an enlarged side view of the connecting portion of the rotating shaft, and is a cross-sectional view showing a cross section taken along the line VI-VI shown in FIG. 7, and FIG. 7 is a cross section taken along the line VII-VII of the connecting portion shown in FIG. FIG. 8 is a perspective view showing the outer ring, FIG. 9 is a perspective view showing the inner ring and the rod-like member, and FIG. 10 is a diagram showing a state where the rod-like member is loosely fitted in the loose fitting hole.

  Referring to FIG. 1, a flocculator 1 is a rotary shaft formed by coaxially connecting a submerged bearing 4, a support base 6, a spherical bearing 7, a paddle 60, a hollow shaft 10 and a drive shaft 30 in a flock formation tank 2. It is configured with.

  Referring to FIGS. 1 and 3, in the water purification treatment facility, an inflow tub 20 is provided in the front stage of the flock formation tank 2, and treated water is supplied through an inflow port 22. A sedimentation tank 21 that facilitates sedimentation of the formed floc is provided at the subsequent stage of the floc formation tank 2. A plurality of floc-forming tanks 2 are usually provided between the inflow tank 20 and the settling tank 21, and the respective flock-forming tanks are connected through water holes 23 (see FIG. 3).

  Referring to FIG. 2, the flock formation tank 2 is composed of two tank parts whose bottom part is divided by an expansion part 8. Above the expansion section 8, a rotation shaft is horizontally mounted along the bottom surface of the flock formation tank 2. At the time of an earthquake, these two tank parts move independently with the expansion part 8 as a boundary, and the flock formation tank 2 is displaced with respect to the expansion part 8.

  On the bottom surface of the flock formation tank 2, two support bases 6 are provided to support the rotating shaft, and the underwater bearing 4 and the spherical bearing 7 are provided on the two support bases 6, respectively. ing.

  The underwater bearing 4 is a sliding bearing having a cylindrical sliding surface, and surrounds the driving shaft 30 by the bearing upper portion 4a and the bearing lower portion 4b to support the driving shaft 30. On the other hand, the spherical bearing 7 is a spherical sliding bearing having a spherical sliding surface, and accommodates the end of the hollow shaft 10 formed in a spherical shape as shown in FIG. Supports an end different from the end. The underwater bearing 4 and the spherical bearing 7 are located on both end sides with the hollow shaft 10 in between.

  Referring to FIG. 2, the rotating shaft is a shaft member in which the hollow shaft 10 and the drive shaft 30 are coaxially connected by a connecting portion 40. A shaft portion 10 f is provided at the end of the rotary shaft on the hollow shaft side, and this shaft portion 10 f is pivotally supported by the spherical bearing 7 described above. A spherical sliding surface is provided on the outer peripheral surface of the end portion of the shaft portion 10 f and is slidably fitted to the spherical bearing inner ring 7 a of the spherical bearing 7. As a result, the displacement of the hollow shaft 10 in the drive axis X direction can be allowed. The drive shaft side of the rotary shaft extends out of the flock formation tank 2 via a shaft seal water device (not shown) such as a gland packing type, and is connected to a drive source 13 via a thrust bearing 9 and a speed reducer 11. ing.

  During the operation of the flocculator 1, as shown in FIG. 2, the drive source 13 drives the drive shaft 30, and the drive shaft 30 transmits rotational torque to the hollow shaft 10. The hollow shaft 10 rotates the paddle 60 fixed in the axial direction of the rotating shaft by the transmitted rotational torque. As shown in FIG. 1, the paddle 60 has two fixed arms 5 arranged in parallel, and stirring blades 3 arranged at one end side of the fixed arms 5 in a hook shape at regular intervals. .

  As shown in FIGS. 4 and 5, the hollow shaft 10 is a cylindrical body made of stainless steel or the like, and the peripheral wall of the cylindrical body is formed as thin as possible within a range where necessary strength can be maintained. ing. Thus, when the flocculator 1 is operated, sufficient buoyancy is generated, and a load is applied to the bearing upper portion 4a by the buoyancy. In the hollow portion of the hollow shaft 10, a watertight partition wall 10b is provided. FIG. 4 shows a state in which the hollow portion is divided into three sections 10c, 10d, and 10e in the longitudinal direction by two watertight partition walls 10b. When the flocculator 1 is in operation, the water to be treated flows into the hollow sections 10d and 10e through the opening 10a, and the hollow sections 10d and 10e can pass water.

  6 and 7, the connecting portion 40 of the rotating shaft includes, for example, a two-piece flange member 45 formed in a cylindrical shape, and is fixed to the drive shaft side of the hollow shaft 10 by bolting or the like. ing. The connecting portion 40 includes an inner ring (inner ring portion) 41, an outer ring (outer ring portion) 42, and a rod-like member 43 that constitutes a sliding restricting means inside the flange member 45.

  The outer ring 42 slidably accommodates an inner ring 41 which will be described later, and is provided at the end of the hollow shaft 10 on the drive shaft side. For example, as shown in FIG. 8, the outer ring 42 has a spherical inner peripheral surface 42 c that surrounds a spherical sliding surface 41 a of the inner ring 41 described later, and projects the cylindrical outer ring fastening hole 42 b outward. An annular member provided. For example, as shown in FIG. 6, the outer ring 42 and the flange member 45 are fixed by an outer ring set screw 44 through an outer ring fastening hole 42 b.

  Moreover, the outer ring | wheel 42 has a loose fitting recessed part which loosely fits the loose fitting convex part mentioned later. This loose fitting recess is, for example, a loose fitting hole 42a as shown in FIG. 10, and allows an axis Y1 inclined at an allowable inclination angle θ around an inclination center O with respect to an axis Y of a rod-like member 43 described later. To have a volume to Moreover, it is preferable that the opening of the loose fitting hole 42 a is a frustoconical hole having an allowable inclination angle θ extending outward in the axial radial direction of the outer ring 42. In this way, when the axis of the rod-shaped member 43 is inclined to the axis Y1, the outer circumferential surface of the rod-shaped member 43 and the inner circumferential surface of the loose fitting hole 42a are in contact with each other, so the rod-shaped member 43 and the loose fitting hole 42a. The wear of the contact portion with is reduced.

  Referring again to FIGS. 6 and 7, the inner ring 41 has a ring-shaped member that has a spherical sliding surface 41 a and is fitted to the outer peripheral surface of the drive shaft 30 on the hollow shaft side. For example, as shown in FIG. 9, the inner ring 41 is an annular member having an opening surrounding the outer peripheral surface of the drive shaft 30, and the inner ring 41 and the drive shaft 30 are fixed by, for example, a rod-shaped member 43.

  Further, the inner ring 41 has a loose fitting convex portion that protrudes outward from the spherical sliding surface 41a. In FIG. 9, the loose fitting convex portion is formed by an end portion 43 a of a rod-like member 43 that penetrates the drive shaft 30 and the inner ring 41 in the axial radial direction. By this end portion 43a and the above-described loose fitting hole 42a in which the end portion 43a is loosely fitted, the slidable range in which the inner ring 41 slides relative to the spherical inner peripheral surface 42c of the outer ring 42 is limited. A sliding limiting means is configured. Therefore, the sliding angle of the inner ring 41 is limited to the allowable inclination angle θ of the loose fitting hole 42a of the outer ring 42 described above.

  When the flocculator 1 is operated, as shown in FIG. 10, when the rotation angle of the drive shaft 30, that is, the sliding angle of the inner ring 41 reaches the allowable inclination angle θ, the outer peripheral surface of the end 43 a of the rod-shaped member 43 is loosely fitted. The inner ring 41 is pressed against the inner wall surface of the hole 42a and the sliding of the inner ring 41 with respect to the rotation direction of the drive shaft 30 is restricted. Therefore, the rotational torque of the drive shaft 30 is transmitted to the hollow shaft 10. Further, at the time of an earthquake, the crossing angle of the hollow shaft 10 with respect to the drive axis, that is, the sliding angle in the tilt direction with respect to the drive axis is limited to the allowable tilt angle θ or less of the loose fitting hole 42a.

  Next, the operation of the flocculator 1 according to the first embodiment will be described.

  When the flocculator 1 is operated, referring to FIG. 1 and FIG. 4, the inlet 22 provided so that the inlet 20 can be opened and closed is opened, and the water to be treated flows into the flock formation tank 2. When the inflow water level reaches near the height of the hollow shaft 10, an upward load is applied to the bearing upper portion 4 a by the buoyancy of the hollow shaft 10. When the inflow water level exceeds the installation height of the hollow shaft 10, the water to be treated flows into the hollow section 10d and 10e through the opening 10a, and the hollow section 10d and 10e can pass water.

  During the operation of the flocculator 1, the drive source 13 drives the drive shaft 30 as shown in FIG. When the rotation angle of the drive shaft 30, that is, the sliding angle of the inner ring 41 reaches the allowable inclination angle θ of the loose fitting hole 42 a as shown in FIG. 10, the outer peripheral surface of the end 43 a of the rod-shaped member 43 is loosely fitted. The inner ring 41 is pressed against the inner wall surface of 42 a and the sliding of the inner ring 41 with respect to the rotation direction of the drive shaft 30 is restricted.

  When the sliding of the inner ring 41 is restricted, the rotational torque of the drive shaft 30 is transmitted to the hollow shaft 10 as shown in FIG. At the time of this torque transmission, since the rod-shaped member 43 has a shape without a bent portion, there is no local concentration of stress. As shown in FIG. 3, the hollow shaft 10 rotates the paddle 60 fixed in the axial diameter direction of the hollow shaft 10 by the transmitted rotational torque.

  In the event of an earthquake, as shown in FIG. 2, as the ground shakes, the flock formation tank 2 moves independently from the expansion section 8, and the flock formation tank 2 moves the expansion section 8. Deviation occurs at the border. This deviation is absorbed by the inclination of the hollow shaft 10 with respect to the drive axis X by the spherical bearings 7 and the connecting portions 40 provided at both ends of the hollow shaft 10.

For example, as shown in FIG. 11, a case is considered where the deviation of the flock formation tank 2 is absorbed by the inclination of the crossing angle α with respect to the drive axis X of the axis X1 of the hollow shaft 10. The sliding of the inner ring 41 stored in the flange member 45 is limited by the allowable inclination angle θ of the loose fitting hole 42a of the outer ring 42. Therefore, if the crossing angle α is equal to or smaller than the allowable inclination angle θ of the loose fitting hole 42a. The tank shift is absorbed. If the relative displacement amount Δ between the end portions is generated in the hollow shaft 10 having the length L1 due to the deviation of the flock forming tank 2, the crossing angle α is given by sin ⁻¹ (Δ / L1). Therefore, the allowable inclination angle θ of the loose fitting hole 42a may be sin ⁻¹ (Δ / L1) or more.

  To give a specific numerical example, for example, in order to allow the displacement of the floc forming tank 2 with the relative displacement amount Δ = 350 mm between the end portions of the hollow shaft 10 with the hollow shaft length L1 = 10 m, The allowable inclination angle θ of 42a may be about 2 degrees or more. In this case, if the dimension of the rod-shaped member 43 is 150 mm in length and the shaft diameter is 25 mm, the loose fitting hole 42a may be an opening diameter of 30.5 mm.

Next, the operation and effect of the flocculator 1 according to the first embodiment will be described.
According to the flocculator 1 of the present embodiment, one end of the hollow shaft 10 is supported by the spherical bearing 7, and the other end is connected to the drive shaft 30 via the connecting portion 40. The slidable range of the outer ring 42 of the connecting portion 40 is limited by the rod-shaped member 43 so that the sliding angle is equal to or smaller than the allowable inclination angle θ. Accordingly, it is possible to allow the displacement of the hollow shaft 10 in the tilt direction while transmitting torque from the drive shaft 30 to the hollow shaft 10, and to allow the displacement of the flock formation tank 2 due to an earthquake or the like. Moreover, since the hollow shaft 10 is provided without being divided in the middle, the hollow shaft 10 can be elongated and the rotation shaft can be elongated.

  Here, the loose fitting convex portion of the sliding limiting means is constituted by the rod-like member end portion 43a, and the loose fitting concave portion is constituted by the loose fitting hole 42a. Therefore, the slidable range of the outer ring 42 or the inner ring 41 can be easily set by forming the rod-like member end portion 43a and the loose fitting hole 42a with appropriate dimensions.

  Further, the loose fitting convex portion is the end portion 43a of the rod-shaped member 43 that penetrates the drive shaft 30 and the inner ring 41 in the axial radial direction. In this way, the loosely fitting convex portion formed by the end portion 43a of the rod-like member 43 does not have a bent portion that tends to concentrate stress during the operation of the flocculator, so that the rigidity of the loosely fitting convex portion is increased. Even when the rod-shaped member end portion 43a is deformed, an appropriate slidable range can be maintained by replacing the rod-shaped member 43.

  In addition, embodiment mentioned above shows an example of the flocculator based on this invention. The flocculator according to the present invention is not limited to this, and the above-described embodiment may be modified so as not to change the gist of the present invention.

  For example, with regard to the connecting portion 40, in the above embodiment, the inner ring 41 is fixed to the drive shaft 30 and the outer ring 42 is fixed to the hollow shaft 10, but as shown in FIG. 10 and the outer ring 42 may be fixed to the drive shaft 30.

  In the above embodiment, the outer ring 42 is configured as a separate member from the flange member 45. However, the outer ring 42 may be formed integrally with the inner peripheral surface of the flange member 45. Similarly, the inner ring 41 may be formed integrally with the drive shaft 30 or the hollow shaft 10. Moreover, the opening of the loose fitting hole 42 a may be a cylindrical shape that does not have an allowable inclination angle θ extending outward in the axial radial direction of the outer ring 42. Further, the spherical bearing 7 may be slidably installed on the support base 6. If the size of the flock forming tank is larger than the hollow shaft length, a hollow shaft 12, an underwater bearing 4 and a support base 6 are added to sandwich the expansion portion 8 as shown in FIG. A configuration may be employed in which the connecting portion 40 and the spherical bearing 7 are provided at both ends of the hollow shaft 12 supported by one support base 6, and the underwater bearing 4 is attached to both ends of the other hollow shaft 10.

It is a top view which shows the flocculator which concerns on 1st embodiment. It is a principal part front view of the flocculator shown in FIG. It is a sectional side view of the flocculator shown in FIG. It is a sectional side view which shows a mode that a rotating shaft is supported by the underwater bearing. It is sectional drawing which shows the cross section along the VV line of the rotating shaft shown in FIG. It is an enlarged side view of the connection part of a rotating shaft, and is a figure which shows the cross section along the VI-VI line shown in FIG. It is sectional drawing which shows the cross section along the VII-VII line of the connection part shown in FIG. It is a perspective view which shows an outer ring | wheel. It is a perspective view which shows an inner ring | wheel and a rod-shaped member. It is a figure which shows a mode that a rod-shaped member loosely fits in a loose fitting hole. It is a figure explaining the inclination of the rotating shaft at the time of an earthquake. It is a sectional side view which shows the other example of the connection part of a rotating shaft. It is a principal part front view which shows the modification of a flocculator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Floculator, 2 ... Flock formation tank, 3 ... Stirring blade, 4 ... Underwater bearing, 4a ... Bearing upper part, 4b ... Bearing lower part, 5 ... Fixed arm, 6 ... Support stand, 7 ... Spherical bearing, 7a ... Spherical bearing Inner ring, 8 ... expansion section, 9 ... thrust bearing, 10, 12 ... hollow shaft, 10a ... opening, 10b ... watertight partition, 10c, 10d, 10e ... hollow section, 11 ... speed reducer, 13 ... drive source, 20 DESCRIPTION OF SYMBOLS ... Inflow tank, 21 ... Precipitation tank, 22 ... Inlet, 23 ... Water flow hole, 30 ... Drive shaft, 40 ... Connection part, 41 ... Inner ring, 41a ... Spherical sliding surface, 42 ... Outer ring, 42a ... Free fitting hole (Free fitting recess), 42b ... outer ring fastening hole, 43 ... rod-shaped member, 43a ... rod-shaped member end (free fitting convex portion), 44 ... outer ring set screw, 45 ... flange member, 60 ... paddle.

Claims (2)

In a flocculator having a rotating shaft having a connecting portion formed by coaxially connecting a drive shaft and a hollow shaft,
The connecting portion of the rotating shaft is
An inner ring portion having a spherical sliding surface provided at one of the hollow shaft side end portion of the drive shaft and the drive shaft side end portion of the hollow shaft;
An outer ring portion that is provided at the other of the drive shaft side end portion of the hollow shaft and the hollow shaft side end portion of the drive shaft and slidably accommodates the inner ring portion;
The crossing angle to the axis forms the drive shaft and the axis of the hollow shaft to a predetermined angle or less, a slide limiting means for limiting the relative sliding range of the inner ring relative to the outer ring portion The sliding restricting means includes a loose fitting convex portion projecting outward from the spherical sliding surface of the inner ring portion and a loose fitting convex portion recessed on the sliding surface of the outer ring portion. Sliding limiting means having a loosely fitting recess
Have
An end portion different from the drive shaft side end portion of the hollow shaft is supported by a spherical bearing. The inner ring portion has a ring-shaped member fitted to the outer peripheral surface of one end of the drive shaft, and the loose fitting convex portion is a rod-shaped member that penetrates the drive shaft and the inner ring portion in the axial radial direction. The flocculator according to claim 1 , further comprising an end portion.

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