JP2003200006A - Slurry gravitationally concentrating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slurry gravitationally concentrating apparatus contrived for improving the efficiency when a group of suspended particles is concentrated. <P>SOLUTION: This slurry gravitationally concentrating apparatus is provided with a gravitationally concentrating tank 1, a rotary shaft 3 arranged vertically in the central part of the tank 1, a plurality of water passage forming bar fixing blades 10 fitted radially to the shaft 3 horizontally and a plurality of water passage forming bars 11 fitted vertically to each of the blades 10 at the prescribed intervals in the longitudinal direction of each of the blades 10. The bars 11 are moved horizontally by rotating the shaft 3 slowly so that negative pressure can be generated just at the rear of each of the moved bars 11, and consequently, a vertical water passage can be formed through which the liquid in the tank 1 is made to pass easily along each of the bars 11. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravity concentrating device for slurry, and more particularly to a gravity concentrating device for increasing the number density of suspended particle groups in a slurry.

[0002]

2. Description of the Related Art Conventionally, for the treatment of sewage / drainage purification process, slurry generated in civil engineering construction work, industrial process, etc., the slurry is conventionally put into a concentrating tank and the suspended particle group is simply naturally settled by gravity. A gravitational concentration method is used to achieve concentration.

In this conventional gravity concentration method, a group of suspended particles settles in a liquid due to its own weight and is concentrated,
It is a very energy-saving method. But in this case
Since the sedimentation velocity of the particle group depends on the liquid passage resistance in the particle group gap, the liquid passage resistance increases and the particle group sedimentation velocity decreases in the particle group gap that gradually narrows as the particle settles. . Therefore, there has been a problem that the efficiency of concentration deteriorates with the lapse of processing time, and it is difficult to increase the number density of particle groups to a level much higher than when the particles are put into a concentration tank. In order to deal with such a problem of the gravity concentrating method, a mechanical concentrating method tends to be frequently used, especially in the case of concentrating a hard-to-concentrate slurry. However, such a mechanical concentration method has a problem that it requires a lot of power and chemicals.

In view of the above-mentioned problems, the present inventors of the present applicant have found that a vertical water channel (mizumichi) in the slurry.
It was found that by interposing a rod (hereinafter, referred to as a water channel rod) that forms a flow path, the passage resistance of the liquid in the gap between the particle groups can be relaxed and the sedimentation velocity of the particle group due to gravity can be increased. Then, a water channel rod is installed vertically in the direction in which gravity acts in the gravity concentration tank, and by laterally moving the water channel rod to form a water channel, the sedimentation speed of the particle group consisting of an organic substance or an inorganic substance is increased, and Japanese Patent Application No. 2000-1 describes a gravity concentration method for a slurry, which is characterized by concentration.
Patent application was filed as No. 45894.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gravity concentrating device for a slurry, which has been devised in order to improve the concentration efficiency of suspended particle groups by carrying out the invention of the above method. It is a thing.

[0006]

In order to achieve the above object, the invention of claim 1 provides a gravity concentrating tank, a rotary shaft vertically provided at a central portion of the concentrating tank, and the rotary shaft. A plurality of laterally-fixed water channel rod fixed vanes are provided in a radial direction, and a plurality of vertically-oriented water channel rods at predetermined intervals on the fixed vanes. Is configured such that the rotary shaft is slowly rotated and laterally moves so that the immediate vicinity of the rear portion of the moved rod has a negative pressure, and a vertical water channel along which the liquid easily passes can be formed. Is characterized by.

According to a second aspect of the present invention, in the first aspect, the water channel rods are provided at a close interval in a portion close to the rotation axis of the fixed blade, and a sparse interval in a portion on the tip side of the portion. Characterize. According to the invention of claim 3, in claim 2,
The water channel rods provided at close intervals are characterized by having a height higher than that of the water channel rods provided at sparse intervals.
According to a fourth aspect of the present invention, in any one of the first to third aspects, a tubular body having upper and lower ends opened and fitted into the rotary shaft, and a fixed arm for fixing the tubular body to the rotary shaft. Is provided around the upper part of the rotating shaft.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a plurality of scraper blades are provided laterally so as to be radial with respect to the rotating shaft, and the water channel rod is provided in the longitudinal direction of the scraper blades. The gravity concentrating tank has a plurality of vertically arranged vertical walls, and the bottom wall of the gravity concentrating tank inclines downward from its outer peripheral portion toward the central portion having the rotation axis. An extraction section is provided, and a scraper is provided below the scraper blade to scrape suspended particle groups that settle on the bottom wall of the concentrating tank and guide them to the concentrated solution extracting section.

According to a sixth aspect of the present invention, in the first aspect, the fixed blades for the water channel rod are provided at intervals above and below the rotating shaft,
A waterway rod is installed vertically between the upper fixed blade and the lower fixed blade, and the bottom of the gravity concentration tank is formed into a funnel-shaped portion so that the tip opening faces the funnel-shaped portion. A concentrated liquid extraction pipe is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic vertical sectional front view of the gravity concentration tank shown in the embodiment, and FIG. 2 is a schematic transverse plan view of the same. In both figures, 1 is a cylindrical gravity concentrating tank with an upper opening,
A column 2 is provided vertically at the center of the concentration tank. The lower end of the pillar 2 is open, and the upper end of the strut 2 is an inwardly facing annular collar 3
A hollow rotary shaft 3 having a is provided rotatably by engaging the flange portion with the upper end surface of the column 2. Since the rotating shaft 3 is immersed in the slurry in the concentration tank 1, it is desirable that the rotating shaft 3 be made of a corrosion resistant material. A rotary shaft drive motor 5 is installed on a management jetty 6 installed laterally on the upper end of the column 2, and transmits rotary drive force to the rotary shaft 3 via a gear mechanism (not shown). The bottom wall of the concentrating tank 1 is formed on an inclined surface 1a that is gradually and downwardly inclined from the outer peripheral edge toward the central portion where the supporting column 2 is provided, and a concentrating liquid extracting section 7 is provided near the supporting column 2. .

A plurality of (one pair) scraper blades 8 formed in a truss shape are provided in the lower part of the rotary shaft 3 in a lateral direction with their tips positioned near the peripheral wall of the concentrating tank 1. The scraper blades 8 are provided so as to face each other with respect to the rotating shaft 3, and have a lateral width that is large on the base end side when viewed from the plane and gradually narrows toward the tip end side. A scraper 9 is provided at the lower end of each scraper blade 8 to scrape the particles that settle on the bottom wall of the concentrating tank 1 into the concentrated liquid extracting section 7. Further, a plurality of (6 in the drawing) fixed blades 10 for water channel rods are provided in the lower part of the rotary shaft 3 in a lateral direction with their tips positioned close to the peripheral wall of the concentration tank 1 like the scraper blades 8. There is. Fixed wing 10
Are provided at the same height as the scraper blades 8 so that the adjacent blades form an angle of 45 ° with the scraper blades 8 in a plan view and become radial.

On the upper surfaces of the scraper blade 8 and the fixed blade 10, a plurality of water channel rods 11 are vertically provided at predetermined intervals in the lengthwise direction (not shown in FIG. 2). The water rod 11 is installed in a direction in which gravity acts, that is, in a vertical direction.
As shown in Fig. 4, when the rod is laterally moved in the vertical direction in the direction of the arrow, a negative pressure is immediately applied to the rear portion of the moved rod, and a vertical water channel 12 in which the liquid easily passes along the water channel rod 11 can be formed in the slurry. ing. Reference numeral 13 denotes the interface of the slurry (suspended particle group). The water channel rods 11 have a narrow interval (for example, 20 cm) at a distance L1 from the rotary shaft 3 to an intermediate position in the longitudinal direction.
At a distance L2 from the middle position to the tip, the spaces are installed at wide intervals (for example, 25 cm) and the heights are unbalanced.

That is, the water channel rods 11 provided at a narrow interval at the distance L1 have the highest height except for the slurry charging section 17 described later, and the upper end thereof is located near the upper end of the concentrating tank 1, and at the distance L2. In the waterway rods 11 provided at wide intervals, the height of the scraper blade 8 is the highest and the height of the waterway rod 11 is lower by about 1 m, and the height is 1.5 m. It is getting lower. The height of the fixed blade 10 is about 1 m lower than that of the highest height, and the height at the tip is even lower, about 1.5 m. The reason why the heights of the water channel rods 11 are made unbalanced in this way is that the particle groups are to be quickly submerged in the portions of the water channel rods 11 that are densely provided at narrow intervals. In the portions of the water channel rods 11 that are sparsely arranged at wide intervals, natural subsidence proceeds, and the water channel rods 11 are not required to be dense. The water channel rod 11 around the rotary shaft 3 is
The upper end is lower than the upper end of the concentrating tank 1 by about 2 m, and the upper end of the concentrating tank 1 is fixed by a fixed arm 16 in which a predetermined number of cylindrical bodies 15 having upper and lower end openings are circumferentially arranged in the lowered gap. It is fixed so as to project slightly, and this portion is formed in the slurry feeding portion 17. The water channel rod 11 is preferably made of a resin such as SUS or PVC because it does not apply an excessive load to the scraper blades 8 and the fixed blades 10 and needs to be resistant to corrosion. The water rod 11 may have any shape as long as it is rod-shaped.

In the gravity concentrating device as described above, the rotary shaft 3 is always rotated by the drive motor 5 and the water channel rod 11 is slowly moved laterally at a speed of, for example, about 0.5 to 3 m / min. On the other hand, in the concentration tank 1, the slurry charging unit 1
The slurry is charged from No. 7, and the automatic concentration operation state is achieved at the optimum liquid level as shown in FIG. In this state, when the water channel rod 11 placed vertically in the slurry is laterally moved as it is, a negative pressure is generated in the vicinity of the rear portion of the moved water channel rod, and along the water channel rod 11 there, as shown in FIG. A vertical water channel 12 through which liquid can easily pass is formed. As a result, the passage resistance of the liquid in the gap between the particle groups is locally greatly reduced. Then, since a large number of such waterway rods 11 simultaneously act, the passage resistance in the system is relatively reduced and the sedimentation velocity of the particle group is increased.

In the above, if the lateral movement speed of the water channel rod 11 is too fast, a large turbulent vortex is formed in the immediate vicinity of the rear portion thereof, and as a result, it becomes a rod for stirring the slurry, which acts in the opposite manner to the purpose. become. On the other hand, the water channel 12 is not formed at all when the moving speed is zero.

The optimum lateral moving speed of the water rod 11 is as follows.
It depends on the viscosity of the slurry in question, which in turn is governed by the ease with which the liquid moves through the interstices of the set of particles. In general, in the case of a particle group that is difficult to settle and concentrate, a moderate speed that does not stop the water channel rod 11 is good.

The water rods 11 are arranged in a plane in the concentrating tank 1 in accordance with the type and properties of the slurry and the temporal operation target for concentration. In general, if the number of arrangements per unit area is large, the effect manifestation can be achieved with a short settling and concentration time. However, if it is too much, it will be greatly affected by the viscous resistance of the slurry in the sedimentation process, and the water rod 11 and the particles in the sedimentation process will move laterally as a unit, and no effect will be exhibited. .

The conventional slurry (suspended particle group) interface and the slurry (suspended particle group) interface of the present invention will be compared and described with reference to the concentration phenomenon explanatory view shown in FIG. As shown in FIG. 4, the slurry interface in the conventional method exists near the liquid surface as shown by the solid line, and is high in the central portion of the concentration tank 1,
It tends to gradually decrease toward the outer periphery of the tank. Here, what is important is that the flow of liquid or slurry is from the central part of the tank toward the outer peripheral side, so how quickly the slurry interface is lowered in the central part, in other words, how quickly it is concentrated. . Here, the point is to effectively act the water channel rod 11. To this end, FIG.
As shown in FIG. 3, the water channel rods 11 are densely arranged near the central portion, and the length of the water channel rods 11 is such that it reaches from near the bottom of the concentrating tank 1 to near the liquid surface. As a result, the slurry interface is formed deeper than the liquid surface as compared with the conventional case, as shown by the dotted line in FIG. This is because the slurry thickens in a short time. In FIG. 4, arrow B indicates a range of particular importance for enrichment.

As a result of the experiment, the concentration effect was 2 w / v-% in the conventional concentration method, but it was 3.
It was confirmed that it was improved to 5 to 4 w / v-%. At the same time, regarding the energy saving effect, it was confirmed that the present invention can achieve energy saving of 1/10 to 1/100 as compared with the mechanical concentration technology.

5 and 6 show another embodiment. Whereas the above-described embodiment is suitable for large / medium-scale facilities, this embodiment is suitable for relatively small-scale facilities, that the concentrating tank has a square tube shape with an upper opening, and the scraper is It is basically different from the above embodiment in that it is not provided.

At the center of the bottom wall of the concentrating tank 31, a rotating shaft 33 is rotatably erected with its lower end supported by a lower bearing 34. The upper end of the rotary shaft 33 has a flange coupling 3
It is connected to the shaft of a rotary shaft driving motor 37 installed on the motor base 36 via 5 and receives a rotary drive from the motor. The motor base 36 is mounted on a mounting plate 38 installed so as to cover the upper end opening of the concentrating tank 31 substantially in half. In the lower part of the rotary shaft 33, a plurality of (8 in the drawing) fixed blades 40 for waterway rods are provided laterally with their tips positioned near the peripheral wall of the concentration tank 31. The fixed blades 40 are provided so that adjacent blades form a radial angle of 45 ° when viewed from a plane. The rotary shaft 33 above the fixed blade 40 is also provided with the fixed blade 41 for a waterway rod. A plurality of waterway rods 43 are provided at predetermined intervals between the lower fixed blade 40 and the upper fixed blade 41, are vertically oriented, and are vertically attached by U bolts. The height of the water channel rod 43 is unbalanced as shown.

Also in the case of this embodiment, as in the case of the above-mentioned embodiment, the water channel rod 43 around the rotary shaft 33 is provided above the rotary shaft 33.
Has its upper end lower than the highest one, and the lowered portion is formed in a void, and the slurry supply pipe 45 is installed in the void with its tip opening facing downward. Reference numeral 46 is a concentrated liquid extraction pipe, and the tip opening is provided with the concentrated tank 31.
It is located so as to face the central part of the bottom wall of the. Concentration tank 31
The bottom part of the is formed to be an inclined surface 47 that is gently inclined downward from the outer peripheral edge toward the center part where the rotating shaft 33 is located, and a rectangular funnel-shaped portion 48 is formed by these inclined surfaces.

Also in the case of this embodiment, the drive motor 3
When the rotary shaft 33 is rotated by 7, the fixed blades 4 in the upper and lower stages are
The channel rod 43 fixedly supported by 0, 41 and vertically placed in the slurry is slowly laterally moved as a result, and as a result, a negative pressure is generated near the rear part of the moved channel rod and along the channel rod 43. A vertical water channel is formed through which the liquid can easily pass, whereby the passage resistance of the liquid in the interstices of the particle groups is locally greatly reduced. The settled particles are collected by the funnel-shaped portion 48 at the center of the bottom surface of the concentration tank 31, and extracted from the tip opening of the concentrated liquid extraction pipe 46. As described above, it is possible to expect the same effects as the above-described embodiment.

In this embodiment, the water channel rods 11, 43 are used.
Although the heights are arranged unbalanced as shown in FIGS. 1 and 5, and are densely arranged near the rotation shafts 3 and 33 and sparsely arranged outside thereof, this is only a preferable example, and in practice, It is possible to set various variations. In addition, it goes without saying that the detailed configuration of each embodiment such as the configuration of the rotating shaft portion and the configuration of the drive portion thereof can be variously changed and modified during the implementation.

[0025]

As described above, the invention as set forth in claims 1 to 6 is similar to that described above, and the water rod is also vertically provided through the fixed blades by the rotation of the vertically provided rotary shaft in the gravity concentration tank. By slowly moving laterally, a negative pressure was created in the immediate vicinity of the rear part of the moved rod, and a vertical water channel was formed along the rod so that the liquid in the tank could easily pass through it. The efficiency can be improved. Moreover, it is possible to perform concentration of the slurry with substantially the same concentration efficiency as that of the mechanical concentration method with much less power as compared with the mechanical concentration method. Therefore, there is an excellent effect that the patent application of the applicant's prior application can be effectively implemented.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional front view of a gravity concentration tank showing an embodiment of the present invention.

FIG. 2 is a schematic transverse plan view of the above.

3A and 3B are views for explaining the action of the water channel rod, in which FIG. 3A is a transverse sectional view thereof, and FIG. 3B is a longitudinal sectional view thereof.

FIG. 4 is a diagram illustrating a concentration phenomenon.

FIG. 5 is a schematic vertical sectional front view of a gravity concentrating tank according to another embodiment.

6 is a cross-sectional plan view taken along the line AA of FIG.

[Explanation of Codes] 1 Cylindrical gravity concentrating tank 2 Support 3 Rotating shaft 5 Driving motor 7 Concentrated liquid extraction unit 8 Scraper blade 9 Scraper 10 Water channel rod fixed blade 11 Water channel rod 12 Water channel 15 Cylindrical body 16 Fixed arm 17 Slurry charging Part 31 Square tube type concentration tank 33 Rotating shaft 37 Drive motors 40, 41 Fixed blades for water channel rod 43 Water channel rod 45 Slurry supply pipe 46 Concentrated liquid extraction pipe 47 Inclined surface 48 Funnel-shaped portion

Claims (6)

[Claims] 1. A gravity concentrating tank, a rotating shaft vertically provided at a central portion of the concentrating tank, and a plurality of fixed blades for a waterway rod provided laterally so as to be radial on the rotating shaft. And a plurality of vertically arranged water channel rods at predetermined intervals on the fixed blade, the water channel rods being moved laterally by slowly rotating the rotation shaft. A gravity concentrating device for a slurry, characterized in that a negative pressure is applied near the rear part of the rod, and a vertical water channel is formed along the rod to facilitate passage of liquid. 2. The gravity concentrating device for a slurry according to claim 1, wherein the water channel rods are provided at a dense interval in a portion close to the rotation axis of the fixed blade and at a sparse interval in a portion on the tip side of the portion. 3. The gravity concentrating apparatus for slurry according to claim 2, wherein the water channel rods provided at close intervals have a height higher than that of the water channel rods provided at sparse intervals. 4. A slurry charging section comprising a cylindrical body having upper and lower ends opened and fitted into the rotary shaft and a fixed arm for fixing the cylindrical body to the rotary shaft is provided around the upper part of the rotary shaft. The gravity concentrating device for a slurry according to any one of claims 1 to 3, which is provided in. 5. A plurality of scraper blades are provided laterally so as to be radial with respect to a rotating shaft, and a plurality of water channel rods are provided longitudinally at predetermined intervals in the lengthwise direction of the scraper blades.
Further, the bottom wall of the gravity thickening tank is inclined downward from the outer peripheral portion toward the central portion where the rotating shaft is located, the concentrated liquid extracting portion is provided on the bottom wall near the end of the inclination, and at the bottom of the scraper blade. The gravity concentrating device for slurry according to any one of claims 1 to 4, further comprising a scraper that scrapes a set of suspended particles onto the bottom wall of the concentrating tank and guides the suspended particle group to the concentrated liquid extracting section. 6. Water channel rod fixed blades are provided at intervals above and below the rotating shaft, and water channel rods are provided vertically between the upper fixed blades and the lower fixed blades, and gravity concentration is performed. 2. The gravity concentrating apparatus for slurry according to claim 1, wherein the bottom of the tank is formed into a funnel-shaped portion, and the concentrated liquid extraction pipe is provided so that the tip opening faces the funnel-shaped portion.