JP4894243B2 - Pressure levitation device - Google Patents

Description

  The present invention relates to a pressurized flotation device for flotation-separating a suspended substance from water containing the suspended substance, and in particular, supplying a mixed water of raw water and pressurized water into a tank body by a rotating distributor. It is related with the pressurized levitation device.

A distributor is provided in a cylindrical tank so as to be able to swivel, and while the distributor is swiveled, a mixed water of raw water and pressurized water is flowed out from the distributor into the tank, and suspended substances are floated and separated in the tank. There exists a thing of Unexamined-Japanese-Patent No. 2000-93942 as a pressurization levitation | floating apparatus. In this pressurized levitation device, the mixed water of raw water and pressurized water flows from the opening of the distributor toward the downstream side in the swirling direction of the distributor. Then, bubbles generated from the pressurized water adhere to the suspended material, and the suspended material floats on the water surface to form a floating scum.
JP 2000-93942 A

  The pressurized levitation device disclosed in Japanese Patent Application Laid-Open No. 2000-93942 causes the mixed water of raw water and pressurized water to flow out from the distributor to the downstream side in the swirling direction of the distributor. Compared to the case, the flow of the mixed water is less disturbed, the bubbles are difficult to separate from the suspended matter, and the floating separation efficiency is good.

  However, in the pressurized flotation device of the same publication, since the centrifugal force due to the turning of the distributor is applied to the mixed water flowing out from the distributor, the mixed water flowing out from the distributor is in the radial direction (on the peripheral wall of the tank body). Try to flow in the direction of approach. Moreover, since this centrifugal force increases toward the distributor tip side, the radial flow velocity differs between the mixed water flowing out from the opening on the distributor tip side and the mixed water flowing out from the opening on the swivel center side. The mixed water tends to be slightly disturbed. Moreover, the mixed water flow is slightly disturbed by the mixed water flowing out from the front end side of the distributor hitting the peripheral wall of the tank body. If the mixed water flow is disturbed as described above, the floating separation efficiency of the suspended substance may be lowered.

  An object of the present invention is to solve the above problems and to provide a pressurized flotation device with very good flotation separation efficiency of suspended solids.

  A pressurized levitation device according to the present invention includes a tank body having an annular peripheral wall, a distributor extending radially from a central portion of the tank body, and capable of turning in the tank body around the central portion. And means for supplying mixed water of raw water and pressurized water into the distributor, an opening for flowing out of the mixed water that is provided in the distributor and opens toward the downstream side in the rotational direction, and a scum that floats in the tank body In the pressurization levitating apparatus comprising a clearance for scraping the water toward the peripheral wall side of the tank body, and a scum discharge part provided on the peripheral wall of the tank body, the plate surface is set in the vertical direction, and A guide plate is provided for guiding the outflow water from the opening to the downstream side in the rotational direction, extending toward the downstream side in the rotational direction.

  In the pressurized levitation device of the present invention, the mixed water of the raw water and the pressurized water flows out from the opening of the distributor toward the downstream side in the swirling direction of the distributor. Then, bubbles generated from the pressurized water adhere to the suspended substance, and the suspended substance floats on the surface of the water to form a floating scum, which is scraped by the gap and sent to the scum discharge part. In the present invention, since the guide plate having the plate surface in the vertical direction is extended from the distributor to the downstream side in the rotation direction, the mixed water flowing out from the distributor is suppressed from flowing in the radial direction, and the mixed water flows. Disturbance is less likely to occur. As a result, the floating separation efficiency of the suspended substance is improved.

  By providing a plurality of guide plates as in claim 2, the disturbance of the mixed water is further reduced, and the floating separation efficiency is improved.

  As described in claim 3, by providing the first scraping plate for scraping the floating scum on the front side in the rotational direction of the distributor to the peripheral wall side, the floating scum is prevented from hitting the distributor, As the scum is discharged quickly, the floating separation efficiency is improved.

  As described in claim 4, the first scraping plate extends along the front surface side in the rotational direction of the distributor, or faces from the radial front end side of the distributor toward the front in the rotational direction of the distributor and away from the peripheral wall. By extending the scum, the floating scum can be quickly discharged.

  As described in claim 5, by providing a second scraping plate for scraping the levitated material to the peripheral wall side, extending from the distal end side of the distributor in the direction of the downstream direction of rotation and approaching the peripheral wall, The floating scum is prevented from flowing around the distal end side of the distributor and flowing into the downstream side in the rotational direction, so that the scum discharge efficiency is improved.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a pressure levitation apparatus according to an embodiment, and FIG. 2 is a plan view thereof. 3 is a cross-sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a perspective view showing the configuration of the distributor. In FIG. 4, the scraping plate is not shown.

  The tank body 1 has a cylindrical shape whose axial direction is a vertical direction. A cylindrical partition wall 2 is provided along the inner peripheral surface of the peripheral wall 1 a of the tank body 1. The lower end of the partition wall 2 is located above the bottom portion 1 b of the tank body 1. The treated water in the tank body 1 is configured to flow around the lower end of the partition wall 2 and flow out to the treated water trough 4 through the ascending flow path 3 between the partition wall 2 and the peripheral wall 1a. The treated water trough 4 is provided so as to project outward from the upper part of the tank body 1. The treated water trough 4 is provided with a treated water outlet 5.

  A scum box 6 is provided at the upper side of the tank body 1 on the side opposite to the treated water trough 4, and a scum discharge port 7 is provided in the scum box 6. The scum box 6 has an open upper surface, and an upper edge protrudes slightly above the water level of the tank body 1.

  A mud pipe 9 with a mud valve 8 is connected to the bottom 1b of the tank body 1 as a countermeasure when scum settles. In addition, in FIG. 1, although the bottom part 1b of the tank body 1 is flat, you may make it the funnel shape (inverse cone shape) which becomes a bottom position toward the center.

  A rotary drive device 10 such as a motor is installed above the central portion of the tank body 1. The rotation drive device 10 is supported by the tank body 1 via a support member (not shown). A drive shaft 11 extends vertically downward from the rotary drive device 10. A cylindrical center cage 12 is attached to the drive shaft 11. The center cage 12 is arranged with the axial direction as a vertical direction, and is supported rotatably with respect to the tank body 1 via a bearing member (not shown). The upper surface of the center cage 12 is sealed with a top plate, and the drive shaft 11 is connected to the top plate.

  A bottom plate is provided on the bottom surface of the center cage 12, and a supply pipe 14 of mixed water of raw water and pressurized water is connected to a water receiving tube 13 inserted in the center of the bottom plate. The receiving cylinder 13 is a lidless, bottomed cylindrical member that is open at the top and closed at the bottom. The receiving cylinder 13 is inserted into an insertion hole in the center of the bottom plate of the center cage 12. The gap between the outer circumference of the receiving cylinder 13 and the inner circumference of the insertion hole is extremely small, and the mixed water is configured not to flow out of the gap.

  A distributor 15 extends from the upper part of the center cage 12 in the radial direction. In this embodiment, two distributors 15 are provided in the diameter direction, but one or three or more (for example, 3 to 8) may be provided. In order to balance the weight of the center cage 12, it is preferable that a plurality of distributors 15 are arranged equally in the circumferential direction.

  The distributor 15 is rotated (turned) around the drive shaft 11 by the drive device 10. The distributor 15 is provided with an opening 16 that opens toward the downstream side in the rotational direction. In this embodiment, the opening 16 is composed of one long hole extending in the longitudinal direction of the distributor 15, but a plurality of openings such as a circle or the like are provided at intervals in the longitudinal direction of the distributor 15. It may be provided.

  The distributor 15 is disposed so as to be immersed in water.

  The distributor 15 has a plurality of guide plates 17 extending toward the downstream side in the rotational direction. A plurality of guide plates 17 are provided in the longitudinal direction of the distributor 15 with the plate surface in the vertical direction (vertical direction in this embodiment). In this embodiment, the guide plate 17 is provided along the edge of the opening 16 on the distal end side and the proximal end side of the distributor, and one guide plate 17 is provided between the guide plates 17 and 17 on both end sides. Is provided. However, the number of guide plates 17 may be larger than this, and when the opening 16 is small, only two guide plates 17 may be provided across the opening 16. In some cases, only the guide plate 17 on the tip side of the opening 16 may be provided.

  A scraper plate is attached to the upper part of the distal end side of the distributor 15. The scraping plate includes a first scraping plate 21 extending from the distal end of the distributor 15 in the forward direction of the distributor 15 and in a direction away from the peripheral wall 1a, and the rearward and peripheral wall of the distributor 15 from the distal end of the distributor 15. And a second scraping plate 22 extending in a direction approaching 1a. In this embodiment, the first scraping plate 21 and the second scraping plate 22 are made of a single piece of a structure in which one long plate is bent halfway, but may be separated. .

  The scraping plates 21 and 22 have a lower part that is submerged in water and an upper part that protrudes upward from the water surface.

  In this embodiment, a rod-like support member 23 that rises from near the center of the upper surface portion of the center cage 12 to above the water surface and then extends outward is provided, and a clearance 24 is provided at the tip of the support member 23. Is provided. The clearance 24 rotates integrally with the center cage 12 along the inner periphery of the peripheral wall 1a. The clearance 24 is attached to the support member 23 so as to be movable up and down or tiltable in the moving direction of the clearance 24. The lower portion of the gap 24 is submerged in the water of the tank body 1, and the upper portion projects upward from the water surface. When the clearance 24 rotates with the rotation of the center cage 12 and reaches the scum box 6, the clearance 24 rides on the scum box 6 and passes while sliding on the upper surface thereof. At this time, the scum scraped by the gap 24 gets over the upper edge of the scum box 6 and falls into the scum box 6.

  Next, the operation of the pressure levitation apparatus configured as described above will be described.

  The center cage 12, the distributor 15 and the skimmer 24 are all rotated (turned) in the direction of the arrow θ in FIG.

  Mixed water of raw water and pressurized water (water that has been melted so as to be supersaturated by pressurizing air or the like) is introduced from the supply pipe 14 into the center cage 12 and flows out from the opening 16 of the distributor 15 to the downstream side in the rotational direction. To do. Since the guide plate 17 protrudes from the distributor 15 in the wake direction, the mixed water flowing out from the opening 16 is suppressed from flowing toward the peripheral wall 1a, and is stationary in the tank body 1 with almost no disturbance. Or slowly flows in the circumferential direction. Then, bubbles generated from the pressurized water adhere to the suspended material, and the suspended material floats on the water surface to form a floating scum. The floating scum is scraped to the vicinity of the peripheral wall 1 a by the scraping plates 21 and 22, then dropped into the scum box 6 by the skimmer 24 and discharged from the discharge port 7. The treated water from which suspended substances have been removed descends in the tank body 1, rises in the ascending flow path 3 from the lower end of the partition wall 2, flows into the treated water trough 4, and flows out of the tank body 1 from the outlet 5. leak.

  In this embodiment, as described above, since the first scraping plate 21 is provided in front of the distributor 15 in the rotation direction, the lifted scum is smoothly scraped to the vicinity of the peripheral wall 1 a without hitting the distributor 15. . In addition, since the second scraping plate 22 is provided, the scum that has passed through the distal end side of the distributor 15 is prevented from turning around to the downstream side of the distributor 15. For this reason, the scum is efficiently dropped into the scum box 6 by the clearance 24.

  In the embodiment described above, the first scraping plate 21 is provided so as to obliquely cross the distributor 15, but the first scraping plate may be provided along the front surface of the distributor 15.

  In addition, suitable constituent materials or dimensions of the apparatus of the present invention will be described below.

  The height from the bottom of the tank body 1 to the water surface is preferably about 2 to 10 m, particularly about 4 to 5 m. The diameter of the tank body 1 is preferably 1 m or more, for example, about 1 m to 30 m, but may be larger than that. The constituent material of the tank body 1 can be, for example, a steel plate with a corrosion-resistant coating, but can be formed with a structure that can withstand strong agitation without being affected by the substance contained in the treatment target by filling it with water. Any material may be used, and a reinforcing material for strength and shape retention may be included.

  The rising speed of water in the center cage 12 is preferably about 0.03 to 0.3 m / sec.

  The distributor 15 may have the same diameter from the proximal end to the distal end, or may have a tapered shape with a smaller diameter toward the distal end. The length of the distributor 15 is preferably such that the distance between the tip of the distributor 15 and the scum box 6 is 20% or less, for example, 5 to 20% of the radius of the tank body 1. The flow rate of water in the distributor 15 is preferably about 0.03 to 0.3 m / sec. The outflow speed of water from the opening 16 of the distributor 15 to the rear is preferably about 0.03 to 0.3 m / sec. The opening area of the opening 16 is preferably 20% or more, for example, about 20 to 80% of the projected area of the distributor 15 in the turning direction. The number of revolutions of the distributor 15 is preferably about 0.05 to 0.5 rpm.

  The guide plate 17 preferably has a vertical plate surface, but may be slightly inclined. The guide plate 17 may have a flat plate shape, or may be curved so that the shape in plan view has a substantially equal radius with respect to the center of the tank body 1.

  The vertical width of the guide plate 17 is preferably about 0.5 to 1.5 times the vertical dimension (for example, diameter) of the distributor 15. The horizontal length of the guide plate 17 is preferably 50 mm or more, and is preferably half or less of the radius of the tank body. When a plurality of guide plates 17 are provided, the interval is preferably 30% or more of the length of the distributor 15. This interval may be constant or not constant. The thickness of the guide plate 17 is preferably 50 mm or less, for example, about 5 to 50 mm. The guide plate 17 may be a rigid plate such as a stainless steel plate that does not deform with respect to the flow of mixed water or the floating scum. In order to make the flow smooth, a natural rubber plate that naturally deforms may be used. The material of each guide plate 17 may be different.

  The vertical width of the scraping plates 21 and 22 is preferably about 100 to 500 mm. The scraping plates 21 and 22 are preferably installed so that the vicinity of the center in the vertical direction is the water surface. The scraping plates 21 and 22 may be fixed to the distributor 15 and may be positionally adjustable in the vertical direction. The distance in the vertical direction between the lower edge of the scraping plates 21 and 22 and the upper edge of the opening 16 is preferably about 0 to 500 mm.

  The angle of intersection between the first scraping plate 21 and the distributor 15 is preferably 45 ° or less, particularly 30 ° or less. The length of the first scraping plate 21 is preferably such that the length when the first scraping plate 21 is projected onto the distributor 15 is 2/3 or more of the total length of the distributor 15.

  The length of the second scraping plate 22 is preferably 10 mm or more. As described above, the first scraping plate 21 and the second scraping plate 22 are preferably formed by bending one long plate. The shape of the bent portion is arbitrary, and for example, it may be bent in a step shape or may be bent.

  The material of the scraping plates 21 and 22 is preferably a steel plate or the like having a corrosion resistance coating, for example, having a strength that does not cause deformation due to water resistance caused by its own turning or floating scum.

  The vertical width of the gap 24 is preferably 100 mm or more, for example, about 100 to 300 mm. It is preferable that the gap 24 is installed close to the second scraping plate 22 so that the gap is as small as possible.

  The material of the gap 24 has a strength that does not cause deformation due to water resistance caused by swirling, floating scum, and interference with the scum box 6. For example, steel with a corrosion-resistant coating may interfere with the scum box. What protected the part with natural rubber etc. is good.

  The above embodiment is an example of the present invention, and the present invention may take forms other than those shown in the drawings. For example, in the present invention, as shown in FIGS. 5 and 6, a substantially horizontal rectifying plate 30 may be extended rearward from the distributor 15 so as to straddle the guide plate 17. Providing this rectifying plate 30 prevents the water flowing out from the opening 16 from rising immediately, thereby further improving the floating separation efficiency.

  In the present invention, the partition wall 2 may be omitted, and a treated water may be taken out by providing a water collecting pipe at the lower part in the tank body 1 instead.

  In the present invention, only the upper part of the center cage 12 may be rotatable, and a distributor may be attached to this upper part.

It is sectional drawing of the pressurization levitating apparatus which concerns on embodiment. It is a top view of the pressurization levitation device concerning an embodiment. It is the III-III sectional view taken on the line of FIG. It is a perspective view of the distributor of the pressurization levitation device concerning an embodiment. It is a perspective view of the distributor of the pressurization levitating device concerning another embodiment. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tank body 2 Partition 3 Ascending flow path 4 Processed water trough 6 Scum box 10 Rotation drive device 12 Center cage 15 Distributor 16 Opening 17 Guide plate 21 1st scraping plate 22 2nd scraping plate 24 Clearance

Claims (5)

A tank body having an annular peripheral wall;
A distributor extending in a radial direction from the central portion of the tank body, and capable of swiveling the tank body around the central portion;
Means for supplying mixed water of raw water and pressurized water into the distributor;
An opening for mixing water outflow provided in the distributor and opening toward the downstream side in the rotational direction;
A gap for scraping the scum that has floated in the tank to the peripheral wall side of the tank;
A scum discharge portion provided on the peripheral wall of the tank body;
In a pressurized levitation apparatus comprising:
A guide plate is provided to guide the effluent water from the opening to the downstream side in the rotational direction, the plate surface being in the vertical direction and extending from the distributor toward the downstream side in the rotational direction. Pressurized levitation device.   2. The pressurized levitation apparatus according to claim 1, wherein a plurality of the guide plates are provided at intervals in the longitudinal direction of the distributor.   3. The pressurized levitation device according to claim 1, wherein the distributor is provided with a first scraping plate for scraping the levitation scum on the front side in the rotational direction of the distributor toward the peripheral wall.   4. The first scraping plate according to claim 3, wherein the first scraping plate is extended along the front side in the rotational direction of the distributor, or from the radial front end side of the distributor to the front in the rotational direction of the distributor and away from the peripheral wall. A pressure levitation device characterized by extending toward the surface.   5. The second scraping plate for scraping the floating scum toward the peripheral wall side, which extends from the distal end side of the distributor in the direction of the downstream in the rotational direction and in the direction of approaching the peripheral wall. A pressure levitation device characterized by the above.

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