JP5619108B2 - Solid-liquid separation system - Google Patents

Description

  The present invention relates to a solid-liquid separation system that separates solids from raw water containing solids by water treatment such as waste water treatment and water purification treatment.

  In conventional water treatment, floc formation is performed by injecting a flocculant and a coagulant aid as shown in FIG. 12 for solid separation such as suspended matter and turbidity components, and sedimentation using a gravity sedimentation tank. A solid-liquid separation system 1 combined with separation is often used.

  In the solid-liquid separation system 1 shown in FIG. 12, the raw water to be processed is fed to the mixing tank 11 by the raw water pump 10. In the mixing tank 11, the raw water and the flocculant injected by the flocculant injection device 12 are mixed by the mixing device 111. The raw water mixed with the flocculant in the mixing tank 11 is sent to the reaction tank 13. In the reaction tank 13, raw water and the coagulation aid injected by the coagulation aid injection device 14 are mixed by the mixing device 131. The raw water mixed with the coagulation aid in the reaction tank 13 is sent to the floc forming tank 15. In the floc forming tank 15, the flocculator 150 promotes aggregation and grows floc. The raw water containing the flock formed in the flock forming tank 15 is sent to the gravity settling tank 18. By retaining the raw water in the gravity settling tank 18 for a predetermined time or more, a solid floc having a large specific gravity is settled due to a difference in specific gravity between the floc and water to separate the floc from the raw water. Moreover, in the solid separation system 1, the clear supernatant liquid after floc settles is used as treated water.

  In the conventional solid-liquid separation system 1 using gravity settling as shown in FIG. 12, the suspended solids contained in the raw water are enlarged as flocs by the flocculant and the specific gravity difference with water is used, and the specific gravity is higher than that of water. After the flocs are settled with a large suspended substance, the supernatant is obtained as treated water, so that the raw water is separated into solid (suspended substance) and liquid (treated water) (gravity sedimentation). Here, in the solid-liquid separation system 1, it is necessary to retain the raw water in the gravity sedimentation tank 18 for a time necessary for the floc to settle. Therefore, the gravity settling tank 18 needs to have a large capacity.

  On the other hand, in recent years, for the purpose of reducing the capacity of the gravity sedimentation tank 18 and improving the separation efficiency, a method of increasing the processing speed using an inclined tube or an inclined plate is also used, but the processing speed is shortened. There was a limit to the reduction in the capacity of the gravity sedimentation tank 18.

  As an effective means for solving the problems of shortening the processing speed by using the gravity sedimentation and reducing the capacity of the gravity sedimentation tank, there is a centrifugal separator such as a hydrocyclone (for example, see Patent Document 1). In the centrifugal separator, raw water containing sand is swirled inside, and a solid having a predetermined particle diameter or more is separated from the raw water using centrifugal force. In such a centrifugal separator, a centrifugal force having a higher acceleration than that of gravity is used, so that sand that is solid can be separated in a shorter time than when gravity is used, and the capacity of the centrifugal separator is increased. It is possible to reduce the capacity of the gravity sedimentation tank.

JP 11-333320 A

  However, in centrifugal separators, raw water is swirled at high speed to obtain centrifugal force, but if flocs with low binding force are swung at high speed, the flocs once formed may break up and become finer. The device could not be used. Therefore, in order to separate easily fragile substances such as floc from raw water, it is inevitable to use a gravity settling tank having a high processing speed and a large capacity.

  Therefore, an object of the present invention is to provide a solid-liquid separation system that forms flocs that are difficult to split or miniaturize, reduces the installation space of the system, and improves the efficiency of solid-liquid separation.

  In order to solve the above-described problems, the present invention provides a solid-liquid solution that separates raw water into solids and treated water by injecting chemicals that form solids into flocs into the raw water when raw water containing solids is introduced. A separation system, in which a plurality of shelves are arranged in parallel, and when raw water flows in, the raw water that flows in is cut between the two shelves and at the end of the shelves and the inner wall of the floc forming tank When the raw water that flows out of the flock formation tank flows into the flock formation tank that flows out the raw water including the flock formed by the diversion water path, A solid-liquid separator that separates flocs, which are solid substances, using centrifugal force.

  The present invention can form a floc that is difficult to be split or refined from a solid contained in raw water, thereby reducing the installation space of the system and improving the efficiency of solid-liquid separation.

It is the schematic explaining the solid-liquid separation system which concerns on 1st Embodiment. It is sectional drawing explaining the flock formation tank of the solid-liquid separation system of FIG. It is a figure explaining the side wall and shelf board which the flock formation tank of the solid-liquid separation system of FIG. 1 has. It is a figure explaining the flock formation tank of the solid-liquid separation system which concerns on 2nd Embodiment. It is a figure explaining the flock formation tank of the solid-liquid separation system which concerns on 3rd Embodiment. It is a figure explaining the modification of the flock formation tank of FIG. It is a figure explaining the flock formation tank of the solid-liquid separation system which concerns on 4th Embodiment. It is a figure explaining an example of the small piece utilized in the flock formation tank of FIG. It is a figure explaining the modification of the flock formation tank of FIG. It is a figure explaining the flock formation tank of the solid-liquid separation system which concerns on 5th Embodiment. It is a figure explaining the flock formation tank of the solid-liquid separation system concerning a 6th embodiment. It is a figure explaining the conventional solid-liquid separation system.

  Hereinafter, a solid-liquid separation system according to each embodiment of the present invention will be described with reference to the drawings. In the solid-liquid separation system according to the present invention, as in the conventional solid-liquid separation system 1 described above with reference to FIG. 12, in water treatment such as wastewater treatment and water purification treatment, solids such as suspended substances and turbidity components are removed. It is a device that separates raw water containing it into solid and liquid. In the following description, the same components are denoted by the same reference numerals and description thereof is omitted.

<First Embodiment>
As shown in FIG. 1, the solid-liquid separation system 1 a according to the first embodiment of the present invention includes a mixing tank 11 into which raw water to be treated is introduced by a raw water pump 10, and a flocculant in the raw water in the mixing tank 11. A flocculant injection device 12 for injecting the flocculant, a reaction tank 13 into which the raw water stirred with the flocculant in the mixing tank 11 flows, and a flocculant auxiliary injection device 14 for injecting the coagulation aid into the raw water in the reaction tank 13 When the raw water stirred with the coagulation aid flows into the reaction tank 13, a floc forming tank 15 a for growing solids contained in the raw water into flocs, and raw water containing flocs grown in the flock forming tank 15 a by the water supply pump 16 are introduced. And a solid-liquid separator 17 for separating the floc as a solid and the treated water as a liquid.

  The flocculant injection device 12 injects a flocculant for aggregating the solid contained in the raw water. The flocculant injecting device 12 includes an appropriate type selected from inorganic flocculants such as polyaluminum chloride, aluminum sulfate, ferric chloride, sulfuric acid band, and polyiron sulfate according to the solid contained in the raw water. Inject the amount of flocculant.

  The mixing tank 11 has a mixing device 111 for mixing the raw water inside and the flocculant. By stirring the raw water and the flocculant with the mixing device 111, the flocculant in the raw water is uniformly mixed to facilitate the growth of flocs in the floc forming tank 15a.

  The agglomeration aid injection device 14 injects a coagulation aid that forms flocs in a property that is strong or easily collectable. This coagulation aid injection device 14 is provided with an appropriate type and amount of coagulation aid selected from organic polymer coagulants such as polyacrylamide and inorganic polymer coagulants such as polysilica according to the solid contained in the raw water. inject.

  The reaction tank 13 has a mixing device 131 that mixes the raw water inside and the coagulation aid. By stirring the raw water and the coagulation aid with the mixing device 131, the coagulation aid in the raw water is uniformly mixed so that the floc can be easily collected in the floc forming tank 15a.

  The flock formation tank 15a is, for example, a rectangular shape, and has a plurality of shelf plates 152 that are obstacles to the raw water as shown in FIG. 2, and the raw water flowing from the reaction tank 13 is bypassed along the shelf plates 152. A diversion channel that flows (meanders) is formed inside. Specifically, as shown in FIG. 2, each shelf plate 152 is disposed so as to contact only one of the first side wall 151a and the second side wall 151b in the flock formation tank 15a. Has been. At this time, each shelf 152 is different in the side wall 151 (151a, 151b) in contact with the adjacent shelf 152. That is, since the plurality of shelf boards 152 are installed so as to alternately contact the first side wall 151a and the second side wall 151b, a certain shelf board 152 is in contact with the first side wall 151a and the second side wall 151b. When it is not in contact with the shelf, the shelf plate 152 positioned next to it is in contact with the second side wall 151b and is not in contact with the first side wall 151a. Accordingly, the raw water flowing in from the inlet 153 collides alternately with the second side wall 151b and the first side wall 151a and proceeds to the outlet 154 between the plurality of shelves 152 while diverting in the left-right direction.

  As shown in FIG. 2, the flow velocity increases in the gap portion between the end portion of the shelf plate 152 and the side wall 151 in the flock forming tank 15 a in which the plurality of shelf plates 152 are arranged. As a result, separation occurs when the raw water flows between the two shelf boards 152, the flow meanders, and the number of collisions of the flocks formed in the raw water with the shelf board 152 increases. When the number of times the floc collides with the shelf board 152 increases, the formed floc gap is tightened and the strength of the floc increases. Further, when the number of times the floc collides with the shelf plate 152 increases, the density of the floc formed also increases, and the separation efficiency in the solid-liquid separator 17 is improved.

  As shown in FIG. 3, one end of the shelf 152 is installed at a predetermined distance from the first side wall 151a or the second side wall 151b, but the number of times the flock collides with the shelf 152 is increased. In order to increase the strength of the floc, it is preferable that the interval (pitch) b between the shelf plates 152 is larger than the interval (gap length) a between the shelf plate 152 and the side wall 151 (a <B). Further, the number of necessary shelf boards 152 is not limited. However, when the number of shelf boards 152 is larger, the number of turns of the raw water increases and the number of times the flock collides with the wall surfaces (side walls 151 and shelf boards 152) increases. For this reason, it is preferable that the number of the shelf boards 152 is larger than a small number.

  Further, by coating the inside of the flock forming tank 15 or selecting a material for forming the flock forming tank 15, it is possible to prevent the flock from adhering to the side wall 151 and the shelf board 152 or to increase the effect of forming the flock. Can be raised. For example, when the polymer flocculant is injected by the flocculant injection device 12, ionic bonds are generated due to the aggregation effect. Since ionic bonding has the principle that it has adhesion to structures in water, flocs may easily adhere to the side wall 151, the shelf board 152, and the like. For example, if the side wall 151 or the shelf board 152 is damaged, a flock may be easily attached to the damaged part. Therefore, by forming or coating the inside of the flock formation tank 15 with an inert material, it is possible to prevent adhesion due to ionic bonding and adhesion at a scratched portion. For example, it is preferable to use Teflon (registered trademark), polyvinyl chloride, amorphous carbon, ceramic, glass, titanium oxide or the like as a material for forming the flock forming tank 15 or a material for coating.

  Here, the inlet 153 is provided above the flock forming tank 15a, the outlet 154 is provided below, and the flowing water flows from the upper side of the flock forming tank 15a to the left and right while flowing under the flock forming tank 15a. Explained as a thing. However, the raw water flowing in from the inlet provided on the left side (or right side) of the flock forming tank may flow up to the outlet provided on the right side (or left side) of the flock forming tank while diverting up and down.

  The solid-liquid separator 17 rotates the raw water flowing inside to generate a centrifugal force. This centrifugal force gives the floc an acceleration larger than gravity, and sinks the floc while increasing the sedimentation speed to treat the raw water with the treated water. And separate into floc. For example, a liquid cyclone can be used for the solid-liquid separator 17. In the solid-liquid separator 17, the raw water that flows in swirls at a speed at which it is easy to form a floc, and swirls at a speed at which the floc can be easily separated from the high-speed raw water.

  The water feed pump 16 may feed the raw water with such strength that when the raw water is fed to the solid-liquid separation device 17, the solid-liquid separation device 17 can obtain the swirl speed necessary for forming the floc and separating the floc. desirable.

  As described above, in the solid-liquid separation system 1a according to the first embodiment, the strength of the floc formed in the flock forming tank 15a can be increased, the strength of the flock can be increased, and the density can be increased. Therefore, in the solid-liquid separation system 1a according to the first embodiment, it is possible to use the solid-liquid separation device 17 that uses a centrifugal separation that is more compact than the gravity sedimentation device, thereby reducing the installation space of the system. be able to.

  Further, in the solid-liquid separation system 1a, the solid-liquid separation device 17 can sediment the flocs using gravity as well as centrifugal force. Therefore, in the solid-liquid separation system 1a according to the first embodiment, the flocs are settled in a short time compared to the case of using only gravity, so that the separation efficiency can be improved.

<Second Embodiment>
Compared with the solid-liquid separation system 1a according to the first embodiment described above with reference to FIG. 1, the solid-liquid separation system according to the second embodiment of the present invention is shown in FIG. It differs in the point provided with the flock formation tank 15b shown. Fig.4 (a) shows sectional drawing of the flock formation tank 15b, FIG.4 (b) has shown the perspective view of the shelf board 152b which the flock formation tank 15b has.

  The floc forming tank 15b shown in FIG. 4 includes a plurality of shelf boards 152b to form a bypass water channel, but the shape and installation method of the shelf boards 152b are the same as those described above with reference to FIGS. It is different from 15a. In the flock formation tank 15a described above with reference to FIGS. 2 and 3, when one end of the shelf plate 152 contacts the first side wall 151a, the other end of the shelf plate 152 does not contact the second side wall 151b. A predetermined interval (gap) is maintained. On the other hand, in the flock formation tank 15b shown in FIG. 4, both ends of the shelf board 152b are in contact with the side walls 151. Moreover, the notch part 152c is provided in the end of the shelf board 152b of the flock formation tank 15b, and the some shelf board 152b is contacted with each side wall 151 so that the notch part 152c may be located in a staggered direction. In the flock formation tank 15b shown in FIG. 4, since raw water flows from the cut portion 152c of the shelf board 152b, the raw water passes through between the plurality of shelf boards 152b from the inlet to the outlet similarly to the flock formation tank 15a. To do.

  In the flock formation tank 15b, the flow of the raw water becomes non-uniform by passing through the cut portion 152c, a rotational flow component is generated with the flow direction as an axis, the number of collisions on the shelf board 152b is increased, and the density of the flock is increased. increase. In addition, it is preferable that the space | interval (pitch) between the notch parts 152c is about twice the space | interval of the shelf boards 152, or a multiple of about 2 times.

  The shape of the cut portion 152c is not limited to the concave shape shown in FIG. 4B, and may be a triangle or a curved shape such as a semicircle.

  Also, in the flock formation tank 15b, the material for forming the flock formation tank 15b is selected in the same manner as the flock formation tank 15a or the inside is coated to prevent the flock from adhering to the side wall 151 or the shelf board 152b. The effect of forming a flock can be obtained.

  As described above, even in the solid-liquid separation system according to the second embodiment, the floc strength is increased and the floc density is increased by increasing the number of times the floc collides with the shelf plate 152b in the floc forming tank 15b. Therefore, it is possible to reduce the installation space of the system and improve the efficiency of solid-liquid separation by using a solid-liquid separation device by centrifugation.

<Third Embodiment>
Compared with the solid-liquid separation system 1a according to the first embodiment described above with reference to FIG. 1, the solid-liquid separation system according to the third embodiment of the present invention is shown in FIG. The difference is that a flock forming tank 15c is shown. Fig.5 (a) shows sectional drawing of the flock formation tank 15c, and FIG.5 (b) has shown the perspective view of the shelf board 152 which the flock formation tank 15c has.

  The flock forming tank 15c shown in FIG. 5 is different from the flock forming tank 15a described above with reference to FIGS. 2 and 3 in that the shelf plate 152 has a baffle plate 155. Specifically, the shelf plate 152 of the flock forming tank 15 c shown in FIG. 5 includes a baffle plate 155 at one end that is not in contact with the side wall 151. The installation direction of the baffle plate 155 is the same as the flow direction (turn direction) of the raw water. In the flock formation tank 15c, the flow of raw water becomes non-uniform by the baffle plate 155, and a swirling flow with the flow direction of the existing water as an axis is generated. The floc that cannot follow the swirl flow increases the number of times it collides with the shelf plate, so that the gap of the floc is tightened and the strength of the floc can be increased.

  The shape of the baffle plate 155 is not limited to the triangle shown in FIG. 5B, and may be a quadrangle or a curved shape such as a semicircle.

  Here, since the size of the swirl flow vortex depends on the interval between the shelves 152, as shown in FIG.5 (b), when a plurality of baffle plates 155 are installed at the ends of the shelves 152, The interval (pitch) c between the baffle plates 155 provided at the same end is preferably about twice the interval (pitch) b between the shelf plates 152 or a multiple of about 2 (c≈2b).

  Also, in the flock forming tank 15c, the material for forming the flock forming tank 15c is selected similarly to the flock forming tank 15a or the inside is coated to prevent the flock from adhering to the side wall 151 or the shelf board 152. The effect of forming a flock can be obtained.

  As described above, the solid-liquid separation system according to the third embodiment also increases the strength of the flock by increasing the number of times the flock collides with the shelf plate 152 by the baffle plate 155 in the flock formation tank 15c. Since the density of flocs can be increased, the efficiency of solid-liquid separation can be improved.

<Modification>
FIG. 6 is an example of a flock forming tank 15d of a solid-liquid separator according to a modification of the third embodiment. FIG. 6A shows a cross-sectional view of the flock forming tank 15d, and FIG. 6B shows a perspective view of the shelf plate 152 included in the flock forming tank 15d.

  The shelf plate 152 of the flock formation tank 15c shown in FIG. 5 has a baffle plate 155 that is the same as the flow direction (turn direction) of the raw water at one end not in contact with the side wall 151. On the other hand, the shelf plate 152 of the flock forming tank 15d shown in FIG. 6 also has a baffle plate 155 installed in a direction opposite to the baffle plate 155 installed at one end not in contact with the side wall 151.

  Here, since the size of the swirl flow vortex depends on the interval between the shelf plates 152, as shown in FIG. 6B, when a plurality of baffle plates 155 are installed in the vertical direction of the shelf plate 152, The interval (pitch) c between the baffle plates 155 provided on the same shelf plate is preferably about twice or a multiple of about 2 times the interval (pitch) b of the shelf plate 152 (c≈2b).

  As described above, even when this flock formation tank 15d is used, increasing the number of times the flock collides with the shelf board 152 can increase the strength of the flock and increase the density of the flock. The efficiency of liquid separation can be improved.

<Fourth Embodiment>
Compared with the solid-liquid separation system 1a according to the first embodiment described above with reference to FIG. 1, the solid-liquid separation system according to the fourth embodiment of the present invention is shown in FIG. It differs in the point provided with the flock formation tank 15e shown. Fig.7 (a) is sectional drawing of the flock formation tank 15e, FIG.7 (b) is a perspective view of the shelf board 152 which the flock formation tank 15e has.

  The flock forming tank 15e shown in FIG. 7 is different from the flock forming tank 15a described above with reference to FIGS. 2 and 3 in that the shelf plate 152 has small pieces 156. A plurality of small pieces 156 facing the raw water flow are arranged in parallel on the shelf board 152. In the flock forming tank 15e, the small piece 156 increases the number of times the flock collides with the shelf board 152 by generating a swirling flow with the flow direction of the raw water as an axis between the two shelf boards 152 (gap part). Can be made.

  Here, since the size of the swirl flow vortex depends on the interval between the shelf plates 152, the interval (pitch) d between the adjacent small pieces 156 is about twice or about 2 times the interval (pitch) b between the shelf plates 152. It is preferably a multiple (d≈2b). In this case, the interval between the small pieces 156 is based on the center of gravity of the small pieces 156.

  Moreover, it is preferable that the space | interval (pitch) of the small piece 156 which has a front-back relationship on the basis of the flow direction of raw | natural water is substantially equal to the space | interval (gap length) of the shelf board 152 and a side wall.

  The shape of the small piece 156 is not limited to the rectangular parallelepiped shown in FIG. 7, and may be a shape as shown in FIG. By making the shape as shown in FIG. 8, retention of solids such as floc in the small piece 156 can be prevented.

  Also, in the flock formation tank 15b, the material for forming the flock formation tank 15b is selected in the same manner as the flock formation tank 15a or the inside is coated to prevent the flock from adhering to the side wall 151 or the shelf board 152b. The effect of forming a flock can be obtained.

  As described above, even when this flock formation tank 15e is used, increasing the number of times the flock collides with the shelf plate 152 can increase the strength of the flock and increase the density of the flock. The efficiency of liquid separation can be improved.

<Modification>
FIG. 9 is an example showing a modification of the flock forming tank 15e of the solid-liquid separation system according to the fourth embodiment. In the flock formation tank 15e shown in FIG. 7, a plurality of small pieces 156 are arranged on the shelf board 152 in the same direction in accordance with the flow direction of the raw water. On the other hand, as shown in FIG. 9, the longitudinal direction of the small piece 156 is shifted from the flow direction of the raw water and installed on the shelf board 152. As shown in FIG. 9, by setting the angle at which the longitudinal direction of the small piece 156 and the flow direction of the raw water do not coincide with each other, solids such as flocs in the small piece 156 can be prevented. Further, instead of giving the adjacent small pieces 156 the same angle, it is possible to easily generate a swirling flow of the raw water by alternately arranging the rows of small pieces 156 perpendicular to the flow direction of the raw water.

  Here, since the size of the swirl flow vortex depends on the interval between the shelf plates 152, the interval (pitch) d between the adjacent small pieces 156 is about twice or about 2 times the interval (pitch) b between the shelf plates 152. It is preferably a multiple (d≈2b).

  As described above, even when the longitudinal direction of the small piece 156 and the flow direction of the raw water are angled, by increasing the number of times the floc collides with the shelf board 152, the floc strength is increased and the floc density is increased. Since it can increase, the efficiency of solid-liquid separation can be improved.

<Fifth Embodiment>
Compared with the solid-liquid separation system 1a according to the first embodiment described above with reference to FIG. 1, the solid-liquid separation system according to the fifth embodiment of the present invention is replaced with the flock formation tank 15a in FIG. It differs in the point provided with the flock formation tank 15f shown.

  The flock forming tank 15f shown in FIG. 10 includes a first flock forming portion 157a and a second flock forming portion 157b. Both the first flock forming portion 157a and the second flock forming portion 157b have shelf plates 152, but the interval (pitch) b1 between the shelf plates 152 in the first flock forming portion 157a and the second flock forming portion 157b The interval (pitch) between the shelves 152 is different from b2.

  In general, the wider the interval between the shelves 152, the slower the flow rate of the raw water, and the less frequent the flocs in the raw water collide with the shelf plate 152. The smaller the interval between the shelves 152, the faster the raw water flow rate. The number of times the underwater flock collides with the shelf board 152 increases. If the number of times of collision with the shelf board 152 is increased before the floc becomes hard, the floc may be destroyed by the impact of the collision of the floc with the shelf board 152. Accordingly, after the floc is gradually collided with the shelf 152 by the first flock forming portion 157a and the floc is gradually increased, the number of times the floc is collided with the shelf 152 by the second flock forming portion 157b is increased. Strengthen the flock.

  In the flock forming tank 15f shown in FIG. 10, there are two flock forming parts having a gap between the shelf plates 152, a first flock forming part 157a having a distance b1 between the shelf boards 152 and a second flock forming tank 157b having a distance b2. However, the interval between the shelf boards is not limited to two types. Further, the ratio of the flock forming portions 157a and 157b having shelf boards with different intervals is not limited. For example, the first 1/4 may be formed with a slow floc forming portion, and the remaining 3/4 may be formed with a rapid floc forming portion. Alternatively, the flocs may be formed repeatedly with the slow floc forming portion, the rapid floc forming portion, the slow floc forming portion and the rapid floc forming portion. Further, the flock may be formed by gradually changing from a slow speed.

  Also, in the flock forming tank 15f, the material for forming the flock forming tank 15b is selected similarly to the flock forming tank 15a or the inside is coated to prevent the flock from adhering to the side wall 151 or the shelf board 152b. The effect of forming a flock can be obtained.

  As described above, even when this flock formation tank 15f is used, increasing the number of times the floc collides with the shelf board 152 can increase the strength of the flock and increase the density of the flock. The efficiency of liquid separation can be improved. In addition, since the floc can be formed large by a slow water flow and the floc can be formed hard by a rapid water flow, the floc can be formed into a large and hard floc that can be easily separated by the solid-liquid separator 17.

<Sixth Embodiment>
Compared with the solid-liquid separation system 1a according to the first embodiment described above with reference to FIG. 1, the solid-liquid separation system according to the sixth embodiment of the present invention is replaced with the flock formation tank 15g in FIG. The difference is that a flock forming tank 15g is provided. Fig.11 (a) shows sectional drawing of the flock formation tank 15g, FIG.11 (b) has shown the perspective view of shelf board 152b, 152c which the flock formation tank 15g has.

  The flock forming tank 15g shown in FIG. 11 is cylindrical, the first shelf 152c is donut-shaped, and is circular with the second shelf 152d. The diameter of the first shelf plate 152c is the same as the diameter of the flock forming tank 15g. The diameter of the second shelf plate 152d is smaller than the diameter of the flock forming tank 15g. Since both the first shelf plate 152c and the second shelf plate 153d are supported by the support column 157, they have support column openings h1 and h2.

  Inside the flock forming tank 15g, the first shelf plate 152c and the second shelf plate 152d are alternately supported by the support columns 157. The raw water flowing into the flock forming tank 15g passes through the hole inside the first shelf 152c and passes outside the second shelf 152d. Thereafter, the raw water alternately passes through the inside of the first shelf board 152c and the outside of the second shelf board 153d.

  Here, the area (gap area) formed by the area (gap area) S1 of the hole provided in the center of the first shelf plate 152c, the inner frame of the flock forming tank 15g, and the outer frame of the second shelf plate 152d. ) By making S2 the same (S1 = S2), the flow rate of the raw water from the first shelf 152c to the second shelf 152d and the raw water from the second shelf 152d to the first shelf 152c It is possible to make the flow velocity moving to the same. The intervals (pitch) between the shelf plates 152c and 152d may all be the same, or the flow rate may be changed by changing the interval as described above in the fifth embodiment.

  Also in the case of such a cylindrical floc forming tank 15g, a swirling flow is generated in the raw water inside, and the flocs collide with the shelf plates 152c and 152d and are formed to be large and hard. Furthermore, in the case of a cylindrical shape, the pressure resistance is easier than that of a general rectangular parallelepiped flock forming tank, and the effect that the thickness of the container may be thin can be obtained.

  As described above, even when this flock formation tank 15f is used, increasing the number of times the floc collides with the shelf board 152 can increase the strength of the flock and increase the density of the flock. The efficiency of liquid separation can be improved. In addition, since the flock forming tank 15f is cylindrical, the design of the flock forming tank 15f can be facilitated particularly in a use environment under pressure.

DESCRIPTION OF SYMBOLS 1a ... Solid-liquid separation system 10 ... Raw water pump 11 ... Mixing tank 111 ... Mixing apparatus 12 ... Coagulant injection apparatus 13 ... Reaction tank 131 ... Mixing apparatus 14 ... Coagulation assistant injection apparatus 15a-15e ... Flock formation tank 151 ... Side wall 152 ... shelf board 152b ... shelf board 152c ... notch 155 ... baffle board 156 ... small piece 16 ... water pump 17 ... solid-liquid separator

Claims (3)

A solid-liquid separation system that separates raw water into solids and treated water by injecting chemicals that form solids into flocs into the raw water when raw water containing solids is introduced.
When the raw water flows in, a mixing tank that stirs and mixes the raw water and the flocculant injected from the flocculant injection device that aggregates the solid contained in the raw water,
When the raw water that has flowed out of the mixing tank flows in, a reaction tank in which the coagulant auxiliary agent that is injected from the coagulant auxiliary agent injection device and that forms flocs is easily collected is stirred and mixed,
When a plurality of shelves are arranged in parallel and the raw water flowing out from the reaction tank flows in, the raw water that flows in is diverted between the two shelves and between the end of the shelves and the inner wall of the floc forming tank. A floc forming tank that has a diverted water channel that causes the raw water including the flock formed in the diverted water channel to flow out,
A solid-liquid separation device that separates flocs, which are solids from raw water, using centrifugal force when raw water that has flowed out of the flock formation tank flows in,
The shelves may have a plurality of baffles having a flow direction perpendicular to the plane of the raw water to the end,
The interval between each of the plurality of adjacent baffle plates is twice or a multiple of 2 times the interval between the shelf plate on which the baffle plate is installed and the shelf plate and the shelf plate forming the bypass water channel. Solid-liquid separation system.   When the baffle plate is installed at the end of the opposite shelf plate, the baffle plate is perpendicular to the shelf plate and the inner wall surface of the flock forming tank facing the shelf plate The solid-liquid separation system according to claim 1, wherein the solid-liquid separation system is arranged so as to be in parallel with each other. In the flock forming tank, a plurality of intervals between the shelf plates are set, and the interval between the shelf plates forming the bypass water channel close to the inlet is set wider than the interval between the shelf plates forming the downstream bypass water channel. The solid-liquid separation system according to claim 1 or 2 .

Images