JP7594992B2 - Carrier separation device, carrier separation method, and processing system - Google Patents

Description

The present invention relates to a carrier separation device, a carrier separation method, and a treatment system, and in particular proposes technology that contributes to improving the ability to treat treated water containing carriers.

Anaerobic treatment, in which the organic wastewater is passed through a reaction tank that holds a non-biological carrier and biologically treated by anaerobic microorganisms attached to the carrier, is widely used as a method for treating wastewater containing organic matter (organic wastewater). In particular, this anaerobic treatment method allows for high-load, high-speed treatment by placing granular sludge or the above-mentioned carrier in the reaction tank and flowing the organic wastewater upward.

However, in the method using a fluid non-living carrier, microorganisms adhere to the carrier, forming a biofilm on the surface of the carrier, and a reaction that generates gas inside the biofilm progresses. The generated gas adheres to the carrier, causing the apparent specific gravity of the carrier to decrease, causing the carrier to float up in the reaction tank and flow out together with the separated treated water. This problem can be alleviated by using a carrier with a high specific gravity and a high settling rate. However, a carrier with an excessively high specific gravity and an excessively high settling rate has poor contact efficiency with the water to be treated, making it difficult to obtain sufficient treatment efficiency, and there are also problems such as solids accumulating in the sedimentary layer of the settled carrier, clogging the flow path. On the other hand, when a carrier that does not have such problems is used, it is difficult to avoid the carrier floating up and flowing out due to the generated gas described above.

JP 2012-110820 A JP 2014-237102 A

In response to such problems, for example, the devices described in Patent Documents 1 and 2 propose a device that allows the carriers flowing out from the reaction tank to be stored in a separate tank (treated water tank) outside the reaction tank, and the carriers separated there to be returned to the reaction tank via circulation piping or the like. In this device, not only the treated water tank but also additional equipment for treating the bubbles (methane gas) separated from the carriers was required outside the reaction tank. Therefore, this device has problems in that it requires many components as a treatment device for organic wastewater and requires a large installation area, and is not sufficient in terms of easily separating solids in the treated water.

In response to this, the present inventors have proposed a carrier separation device that separates the carriers in the treated water using a screen installed inside the device as a device external to the reaction tank, and that is configured to be capable of generating a swirling flow inside the device. With this carrier separation device, even if the device structure is simplified, it is possible to easily separate the carriers from the treated water containing the carriers while preventing the carriers from clogging the screen.
However, the treated water that is treated in the reaction tank and contains carriers may also contain impurities that are more likely to float in the treated water than the carriers. If the treated water containing such floating impurities flows into the inside of the carrier separation device, the impurities will not be caught in the swirling flow of the treated water, and will float at the top of the tank of the carrier separation device, or the accumulated impurities will adhere to the screen. In such a situation, the separation efficiency of the carrier by the screen will decrease, and the treatment of the treated water may be hindered.

The present invention aims to provide a carrier separation device and a carrier separation method capable of efficiently separating carriers from treated water even when the treated water contains floating impurities, and a treatment system capable of efficiently treating wastewater.

The carrier separation device of the present invention is a carrier separation device for separating carriers from treated water,
The carrier separation device includes a separation tank, a partition section that partitions the inside of the separation tank into an inner tank and an outer tank, a screen that is provided in the partition section and separates the carriers and allows the treated water to pass from the inner tank to the outer tank, an inflow section that allows the treated water containing the carriers to flow into the inner tank, and an outflow section that allows the treated water from which the carriers have been separated to flow out of the outer tank,
The partition section includes a curved swirl flow forming section for generating a swirl flow of the treatment water in the inner tank, and a side wall section located on a side of the swirl flow and on which the screen is disposed,
The carrier separation device includes an impurity discharge mechanism that discharges impurities from the inner tank and further discharges the impurities from the separation tank when the impurities are contained in the treatment water,
When the space within the inner tank formed by the swirling flow forming section and the side wall section is defined as a swirling flow forming space, the impurity discharge mechanism is characterized in having a first discharge section that opens at the top of the swirling flow forming space in the vertical direction or above the top in the vertical direction, for discharging impurities from the inner tank, and a second discharge section that further discharges the impurities discharged by the first discharge section from inside the separation tank.

The carrier separation method of the present invention is a carrier separation method for separating carriers from treated water using the above-mentioned carrier separation device,
The method includes a step of flowing treated water containing carriers into the inner tank from the inlet, separating the carriers with the screen, flowing the treated water from which the carriers have been separated into the outer tank, and then flowing the treated water in the outer tank out from the outlet,
When the treated water flowing in from the inlet contains impurities, the method includes a step of discharging the impurities from the inner tank via the first discharge part of the impurity discharge mechanism, and further discharging the impurities from the separation tank via the second discharge part.

The treatment system of the present invention is a treatment system for treating water to be treated,
The treatment system includes a reaction tank that treats the water to be treated with a carrier that retains microorganisms;
The carrier separation device according to the present invention includes a carrier discharge unit formed at a lower portion in the vertical direction within the inner tank, the carrier discharge unit being configured to discharge the carrier from the inner tank;
A connection part connecting the reaction tank and the carrier discharge part;
Equipped with.

The present invention provides a carrier separation device and a carrier separation method capable of efficiently separating carriers from treated water even when the treated water contains floating impurities, and a treatment system capable of efficiently treating wastewater.

1 is a schematic diagram showing a processing system including a carrier separation device according to an embodiment of the present invention. FIG. 2 is a transparent perspective view that typically illustrates the carrier separation device of FIG. 1. FIG. 2 is a perspective view showing the carrier separation device of FIG. 1 in a state where a part of the configuration of the carrier separation device is removed. FIG. 2 is a transparent perspective view that typically illustrates an inner tank of the carrier separation device of FIG. 1 . FIG. 2 is a perspective front view showing the carrier separation device of FIG. 1 . FIG. 2 is a perspective plan view showing a schematic view of the carrier separation device of FIG. 1 . FIG. 2 is a perspective view showing a schematic diagram of a carrier separation apparatus shown in FIG. 1 in which carriers are separated from treated water. FIG. 2 is a perspective plan view that illustrates a first modified example of the carrier separation device of FIG. 1. FIG. 3 is a perspective plan view that illustrates a second modified example of the carrier separation device of FIG. 2.

Hereinafter, an embodiment of the present invention will be described in detail.
The carrier separation device 1 of the present embodiment is a device that can be used in, for example, a treatment system 4 as shown in FIG. 1, and is used to separate carriers from treatment water that contains carriers.
Specifically, the treatment system 4 that can be equipped with the carrier separation device 1 of this embodiment is a treatment system 4 that can perform anaerobic treatment by contacting organic wastewater containing organic matter, such as manufacturing wastewater from food factories, organic wastewater from chemical factories, general sewage, etc., with anaerobic microorganisms, and passes the organic wastewater through a reaction tank 41 that holds non-living carriers to biologically treat it with the anaerobic microorganisms attached to the carriers. The carrier separation device 1 of this embodiment can be used to separate carriers from treated water that has been treated in the reaction tank 41 in the treatment system 4 as described above, since the treated water may contain carriers.
The carrier separation device 1 of this embodiment is not limited to application to the treatment system 4 for anaerobic treatment as shown in Fig. 1, and can be used in applications for separating carriers and solids from treated water. The treatment system will be described in detail later in this embodiment.

2, the carrier separation device 1 of this embodiment includes a separation tank 10, a partition section 13 that partitions the separation tank 10 into an inner tank 12 and an outer tank 11, a screen 14 that is provided in the partition section 13 and separates the carrier and allows the treated water to pass from the inner tank 12 to the outer tank 11, an inlet section 15 that allows the treated water containing the carrier to flow into the inner tank 12, and an outlet section 16 that allows the treated water from which the carrier has been separated to flow out from the outer tank 11. In addition, in the carrier separation device 1 of this embodiment, the partition section 13 includes a curved swirling flow forming section 132 for generating a swirling flow of the treated water in the inner tank 12, and a side wall section 131 located to the side of the swirling flow and on which the screen 14 is arranged, and the carrier separation device 1 includes an impurity discharge mechanism 18 that discharges impurities from the inner tank 12 and further from the separation tank 10 when impurities are contained in the treated water. Furthermore, in the carrier separation device 1 of this embodiment, when the space in the inner tank 12 formed by the swirling flow forming portion 132 and the side wall portion 131 is the swirling flow forming space S1, the impurity discharge mechanism 18 has a first discharge portion 181 that opens at the top of the swirling flow forming space S1 in the vertical direction or above the top in the vertical direction to discharge impurities from the inner tank 12, and a second discharge portion 182 that further discharges the impurities discharged by the first discharge portion 181 from inside the separation tank 10.

The carrier separation device 1 of this embodiment has such a configuration, and by generating a swirling flow in the treated water containing carriers, it is possible to prevent the carriers from clogging the screen 14 and to easily separate the carriers from the treated water containing carriers. In addition, the carrier separation device 1 is provided with an impurity discharge mechanism 18, which prevents impurities accumulated in the inner tank 12 from adhering to the screen 14 and reducing the separation efficiency of the carriers by the screen 14. Therefore, according to the carrier separation device 1 of this embodiment, even if the treated water containing carriers contains floating impurities, the carriers can be efficiently separated from the treated water.

More specifically, in the carrier separation device 1 of this embodiment, an inner tank 12 and an outer tank 11 are formed inside the separation tank 10 by a partition section 13, and a screen 14 is provided in the partition section 13, thereby enabling the separation of carriers in the treatment water.
In this case, since the carrier separation device 1 of this embodiment has a curved swirling flow forming part 132 as the partition part 13 that partitions the inner tank 12, as shown in Fig. 7, after the treated water containing carriers flows into the inner tank 12, a swirling flow of the treated water can be generated in the inner tank 12, and the carriers in the treated water can be easily biased to the outside (outer periphery) of the swirling flow by the centrifugal force when the treated water is swirling. In addition, since the screen 14 is arranged on the side wall part 131 located on the side of the swirling flow in this carrier separation device 1, the carriers that may be biased to the outside of the swirling flow are less likely to adhere to the screen 14 and become clogged, and the treated water can easily pass through the screen 14 with the carriers separated. In addition, the generation of the swirling flow can also prevent the carriers from floating up to the water surface in the inner tank 12.
Therefore, in the carrier separation device 1 of this embodiment, a swirling flow is generated in the treatment water containing the carrier, which prevents the carrier from clogging the screen 14 and makes it possible to easily separate the carrier from the treatment water containing the carrier.

However, the treated water containing the carriers may contain impurities that are more likely to float in the treated water than the carriers themselves. If the treated water contains such impurities, even if the treated water forms a swirling flow, the impurities may not be caught up in the swirling flow and may drift at the top of the inner tank, or the accumulated impurities may adhere to the screen.
In contrast, in the carrier separation device 1 of this embodiment, even if the treated water flows into the inner tank 12 while containing floating impurities, the first discharge section 181 provided in the impurity discharge mechanism 18 opens at the top in the vertical direction of the swirling flow forming space S1 or above the top in the vertical direction, so that impurities that tend to float above the swirling flow formed by the treated water can be discharged from the inner tank 12 via the first discharge section 181.
Furthermore, since the impurity discharge mechanism 18 is equipped with the second discharge section 182 , the impurities discharged by the first discharge section 181 can be further discharged from inside the separation tank 10 .
Therefore, since the carrier separation device 1 of this embodiment is equipped with the impurity discharge mechanism 18, it is possible to prevent impurities that may accumulate in the inner tank 12 from adhering to the screen 14, thereby preventing a decrease in the separation efficiency of the carrier.
Furthermore, as described above, the carrier separation device 1 of this embodiment does not have many components, so it has a simple and uncomplicated structure, can be a space-saving device, and can be easily maintained, such as by cleaning.

Here, in this embodiment, the treated water is wastewater (which may contain wastewater in the middle of treatment) obtained by, for example, anaerobic treatment of organic wastewater containing organic matter as described above, for example, methane fermentation water. The treated water contains suspended sludge and biofilms detached from the carriers, and if it is not discharged outside the system, it will accumulate in excess in the reaction tank 41, which may reduce the fluidity of the carriers and cause the treatment to deteriorate. The treated water flowing into the carrier separation device 1 contains carriers that hold microorganisms, and there are no particular limitations on the composition or concentration of the treated water.

There are no particular limitations on the carrier that can be used as long as it can support microorganisms and allow the microorganisms to grow on the carrier surface.
The shape of the carrier may be any shape, such as spherical, cylindrical, rectangular, hollow, etc., but a spherical shape is particularly preferred, taking into consideration the amount of microorganisms supported, the contact efficiency between the propagated microorganisms and the organic wastewater, and the amount of carrier held in the anaerobic reaction tank.
The average size of the carrier (median diameter d50 in the case of spherical particles, and the arithmetic average of the maximum and minimum dimensions in the case of other shapes) is preferably 0.1 mm to 20 mm, more preferably 2 mm to 10 mm.
The carrier is preferably a porous carrier having pores to which microorganisms can easily adhere, and the pore size is preferably from 1 μm to 100 μm, and more preferably from 5 μm to 50 μm.
In addition, from the viewpoint of allowing the carrier to flow well within the anaerobic reaction tank, it is preferable that the expansion rate (carrier height when water is passed through relative to the carrier height at the time of introduction) be 105% or more and 150% or less when fresh water is passed through an 80 mm diameter cylindrical column packed with unused carrier at an upward linear velocity (LV) of 1 m/h or more and 20 m/h or less, and that the expansion rate be 110% or more and 130% or less when water is passed through at an LV of 2 m/h or more and 15 m/h or less.
The carrier may be made of any material as long as anaerobic microorganisms can adhere to it. In particular, activated carbon, polyvinyl alcohol, ethylene glycol, etc. are preferred because they satisfy the above-mentioned requirements.
The specific gravity of the carrier is preferably 1.001 or more and 1.5 or less, and more preferably 1.01 or more and 1.5 or less. In this way, it is desirable for the carrier to have a relatively large specific gravity because the carrier is likely to settle in the inner tank 12 of the carrier separation device 1.

In this embodiment, impurities refer to solid matter with a relatively low specific gravity that may be contained in the treated water, such as floating solid matter, or solid matter that has accumulated or accumulated, including granular sludge with a low specific gravity. Impurities tend to be larger than the mesh size of the screen 14. Impurities also include impurities that have become more floating due to the treatment in the reaction tank 41.

Next, the structure of the carrier separation device 1 of this embodiment will be described in more detail.
The carrier separation device 1 of this embodiment includes a separation tank 10 as shown in Fig. 2. The separation tank 10 may be buried underground or installed above ground. As shown in Fig. 3 with some parts such as a partition 13 described below removed, the separation tank 10 may be in the shape of a substantially rectangular parallelepiped box defined by a bottom 111 and a side 112, and has a space therein for introducing treated water containing carriers.
A recess 113 can be formed in the bottom 111, and as will be described later, this has a shape that makes it easy to lead the carrier within the inner tank 12 to the carrier discharge portion 17.
In the illustrated example, the recess 113 has a truncated cone shape (a funnel shape) with its side inclined so that the opening of the recess 113 widens from the bottom to the top in the vertical direction of the figure. The recess 113 defines a part (lower part) of the inner tank 12 within the separation tank 10, and therefore also functions as a part of the partition section 13 described below.
In addition, the separation tank 10 has an opening at the top, and the opening can be closed with a removable lid (not shown).
In the illustrated example, the separation tank 10 is formed in a rectangular parallelepiped shape, but the shape may be any desired shape.
In this embodiment, the up-down direction and the lateral direction of the carrier separation device 1 can be the vertical direction and the horizontal direction.

The separation tank 10 is preferably made of a corrosion-resistant material, and can be made of, for example, concrete, a metal such as stainless steel, FRP (fiber reinforced plastic), or a resin such as polyethylene. Alternatively, the separation tank 10 can be made by forming the outer frame of the separation tank 10 from concrete, and forming the inner surface from the above-mentioned metal, FRP, or resin.

As shown in Fig. 2, the carrier separation device 1 includes an inlet 15 for allowing treated water containing carriers from, for example, the reaction tank 41 to flow into the inner tank 12 of the separation tank 10. As shown in Fig. 3, the inlet 15 may be a pipe extending from the outside of the separation tank 10 and opening at the side 112 of the separation tank 10, but it may also be a pipe extending from the outside of the separation tank 10 through the side 112 of the separation tank 10 or above the side 112 to the inside of the separation tank 10 (extending to the inside of the inner tank 12).
Furthermore, although not shown, the inflow section 15 may have an inflow adjustment section such as a pump or a valve capable of adjusting the inflow rate of the treatment water containing the carrier.
The inlet portion 15 is preferably formed from a corrosion-resistant material, and can be formed from a metal such as stainless steel.

As shown in Fig. 2, the carrier separation device 1 includes an outlet 16 for allowing the treated water from which the carriers have been separated to flow out from within the outer tank 11 of the separation tank 10. As shown in Fig. 3, the outlet 16 may be a pipe that opens into the side 112 of the separation tank 10 and extends to the outside of the separation tank 10, but it may also be a pipe that opens within the separation tank 10 (in the outer tank 11) and penetrates the side 112 of the separation tank 10 or extends above the side 112 to the outside of the separation tank 10.
Furthermore, although not shown, the outflow section 16 may have an outflow adjustment section such as a pump or a valve capable of adjusting the outflow rate of the treated water containing the carrier.
The outflow portion 16 is preferably formed from a corrosion-resistant material, and can be formed from a metal such as stainless steel.

2, the carrier separation device 1 can include a carrier discharge section 17 provided at the bottom 111 of the inner tank 12 for discharging the carriers separated by the screen 14 from the inner tank 12 to the outside. By providing the carrier discharge section 17, the carriers that do not permeate from the screen 14 to the outer tank 11 and are collected by the swirling flow can be easily discharged to the outside of the device. In this case, there is no need to provide a separate tank for settling and collecting the carriers.
As shown in FIG. 3 , the carrier discharge section 17 can be formed in the bottom 111 of the separation tank 10, more specifically, in a recess 113, and can be a pipe having an opening in the bottom 111 of the separation tank 10 and extending to the outside of the separation tank 10.
Moreover, the carrier discharge portion 17 is preferably formed from a material having corrosion resistance, and can be formed from a metal such as stainless steel.

As shown in FIG. 2 , a partition 13 is provided inside the separation tank 10, thereby dividing the interior of the separation tank 10 into an outer tank 11 and an inner tank 12. In the example shown, the outer tank 11 is formed so as to accommodate a portion of the inner tank 12 therein.
The inner tank 12 has therein a swirling flow forming space S1 (mainly an area surrounded by a dashed line with reference symbol S1 in FIG. 5 ) which is a space formed by the swirling flow forming portion 132 and the side wall portion 131. Specifically, the swirling flow forming space S1 is a space in which the treatment water containing carriers that has flowed in through the inlet portion 15 can exist, and is a space in which a swirling flow is mainly formed by the treatment water.
Furthermore, the inner tank 12 may have within it a carrier recovery space S2 (mainly the area surrounded by a dashed line with the symbol S2 in FIG. 5 ) which is a space formed by a partition 13 (in the illustrated example, a recess 113) specifically in a lower portion of the swirling flow forming space S1 or in a portion lower than the space S1, and the carrier recovery space S2 is a space which can collect and recover carriers which are settling or carriers flowing downward with the swirling flow.
In Figure 5, the swirling flow forming space S1 and the carrier recovery space S2 are adjacent to each other and are shown by dashed lines, but these spaces are not strictly divided as spaces that perform different roles, and some of them may overlap.

The outer tank 11 also has a space formed therein in which treated water containing carriers in the inner tank 12 is stored after passing through a screen 14 (described later), and the treated water in the outer tank 11 can be discharged to the outside from the outlet 16. As shown in FIG. 5, the outlet 16 can be positioned lower in the vertical direction than the inlet 15, or can be positioned at the same vertical direction as the inlet 15.

In this embodiment, specifically, as shown in Figures 2, 4, 5 (views of the separation tank 10 from the front), 6 (views of the separation tank 10 from above), and 7, the partitioning section 13 includes a curved swirl flow forming section 132 and a side wall section 131 for generating a swirl flow of the treatment water containing the carrier inside the inner tank 12. Furthermore, in the illustrated example, the partitioning section 13 further includes a guide plate section 133 for appropriately guiding the treatment water containing the carrier flowing in from the inlet section 15 into the inner tank 12. The guide plate section 133 is a section extending from the edge of an opening formed in the upper part (upper part in the vertical direction) of the swirl flow forming section 132 and the side wall section 131, which leads to the swirl flow forming space S1.
The partition 13 is preferably made of a corrosion-resistant material, and may be made of a metal such as stainless steel or may be made of a plurality of materials. In addition, when a part of the partition 13 is a part of the separation tank 10, such as the recess 113, the partition 13 may be made of the material that forms the separation tank 10.

4, 6, 7, etc., the side wall portion 131 may be a pair of portions whose surfaces extend in a vertical direction along the extension direction of the inlet portion 15. More specifically, the side wall portion 131 is located away from the side portion 112 of the separation tank 10, defines the swirling flow forming space S1 in the inner tank 12 from the side, and exists mainly as a plate-shaped portion in the illustrated example.
Since the surface of the side wall portion 131 extends in a direction along the extension direction of the inlet portion 15, it can function to support the treatment water containing carriers from the side to form a swirling flow when it flows into the inner tank 12 from the inlet portion 15 (if the overall shape of the swirling flow is assumed to be cylindrical, the flow direction of the swirling flow will be along the curved surface of the cylinder, and the side of the swirling flow will be the bottom side of the cylinder).
5, the screen 14 is located in the center of the side wall 131. A part of the side wall 131, here the lower part (the part in the vertical direction) forms a recess 113 in the bottom 111 of the separation tank 10.

Note that the surface of the side wall 131 extending in a "direction along the vertical direction" and in a "direction along the extension direction of the inlet" does not mean that the direction in which the surface of the side wall 131 extends needs to be strictly the same as the vertical direction or the extension direction of the inlet 15. For example, a deviation of about an angle of 15° or less is acceptable, and preferably 7° or less. Furthermore, the extension direction of the inlet 15 can be a direction parallel to the opening direction of the inlet 15 into the separation tank 10.
In the illustrated example, the screen 14 is provided inside the side wall portion 131 , but in this embodiment, the side wall portion 131 may be entirely formed of the screen 14 .
In addition, while the side wall portion 131 includes a pair of plate-shaped portions in the illustrated example, for example, when the inner tank 12 is positioned close to one side of the side portion 112 of the separation tank 10, the side wall portion 131 can also be a single plate-shaped portion and the side portion 112 of the separation tank 10 (i.e., the side portion 112 of the separation tank 10 can also be used as the side wall portion 131 of the partition portion 13).

As shown in FIG. 4 and other figures, the swirling flow forming section 132 is a section adjacent to the side wall section 131, and in the illustrated example, it is a section adjacent to each of the pair of side wall sections 131. More specifically, the swirling flow forming section 132 is located away from the side section 112 of the separation tank 10, and is provided so that its surface is perpendicular to the side wall section 131. As shown in FIG. 6, the surface of the swirling flow forming section 132 extends in a direction perpendicular to the extension direction of the inlet section 15 when viewed from above (the front-to-rear direction when viewed from the front in FIG. 5). As shown in FIG. 5, the swirling flow forming section 132 is provided in a position that extends generally in the vertical direction when viewed from the front, and in the illustrated example, it exists mainly as a plate-shaped section.

4 and the like, the swirling flow forming section 132 may be a pair of swirling flow forming sections 132, specifically having a first swirling flow forming portion 1321 whose surface forming the swirling flow extends in a direction opposite to and intersecting with the extending direction of the inlet section 15, and a second swirling flow forming portion 1322 whose surface forming the swirling flow faces the first swirling flow forming portion 1321. More specifically, the pair of swirling flow forming sections 132 (the first swirling flow forming portion 1321 and the second swirling flow forming portion 1322) are curved plates having a circular or elliptical arc shape, as shown in FIG.
The swirling flow-forming space S1 defined by such a pair of mutually opposing swirling flow forming sections 132 has an approximately circular or elliptical shape in a front view, and as shown in Figure 5, the lateral length of the swirling flow-forming space S1 (the lateral length from the surface of one swirling flow forming section 132 (first swirling flow forming portion 1321) to the surface of the other swirling flow forming section 132 (second swirling flow forming portion 1322)) gradually increases from the upper and lower ends of the inner tank 12 downward, reaches a maximum length, and then gradually decreases.
The pair of swirling flow forming sections 132 have different radii of curvature of the arcs, and of the pair of swirling flow forming sections 132, the swirling flow forming section 132 located in front of the inflow direction of the treated water containing carriers from the inlet section 15 has a larger radius of curvature than the swirling flow forming section 132 located behind the inflow direction, but they can also be made the same.
Further, a part of the swirl flow forming portion 132 , here the lower part, forms a recess 113 in the bottom 111 of the separation tank 10 .

In addition, when the surface of the swirling flow forming section 132 is "perpendicular to the side wall section" or "extends in a direction perpendicular to the extension direction of the inlet section," it is not necessary that they are strictly perpendicular; for example, a deviation of an angle of about 15° or less is acceptable, and preferably 7° or less.
The swirling flow forming section 132 is formed of an arc-shaped curved plate (curved surface R-shaped), and thus has the effect of smoothing the flow of treated water in the inner tank 12 and forming a good swirling flow. However, in the case of the conventional technology in which the inner tank 12 is configured as a rectangular parallelepiped or a flat plate is used to form a swirling flow, stagnation of the flow occurs in the corners, reducing the swirling flow speed and reducing the cleaning effect of the screen 14, making it prone to clogging.
Furthermore, by making the swirling flow forming section 132 a curved surface, the carrier hits and comes into contact with the curved surface during swirling flow, softening the impact and reducing damage to the carrier, and also having the effect of suppressing excessive detachment of the biofilm attached to the carrier, reducing excessive collisions with the wall surface and preventing excessive detachment of the biofilm attached to the carrier.

In the inner tank 12 of the separation tank 10, as described above, a swirling flow can be formed by the treated water containing carriers that has flowed in from the inlet portion 15. The swirling flow can be formed by the swirling flow forming portion 132, and specifically, as shown in Fig. 7, the treated water containing carriers that has flowed in hits the surface of the swirling flow forming portion 132, and the treated water containing carriers is induced to swirl, thereby forming the swirling flow.
In this embodiment, the shape and the like of the swirling flow forming section 132 are not particularly limited as long as it is capable of forming a swirling flow in the treatment water containing the carrier.

In the illustrated example, the recess 113 in the separation tank 10 forms part of the partition 13, which partitions a part of the swirling flow forming space S1 and the carrier recovery space S2. However, in this embodiment, the recess 113 can be replaced by a funnel-shaped recovery plate portion (not shown) formed, for example, from a metal plate.
It is preferable that the portion of the partition 13 that partitions and forms the carrier recovery space S2 is connected to a carrier discharge part 17 for discharging the carrier to the outside. Specifically, as shown in Fig. 3, in the illustrated example, the carrier discharge part 17 is formed at the bottom part 111 of the recess 113. Furthermore, the carrier discharge part 17 can be connected to the reaction tank 41 as shown in Fig. 1, for example, so that the carrier discharged by the carrier discharge part 17 can be used again for treating the waste liquid.

2 and other figures, the carrier separation device 1 includes a screen 14 that is provided in the partition section 13 to separate the carriers and to allow the treated water containing the carriers to pass from the inner tank 12 to the outer tank 11. Specifically, the screen 14 is provided in the partition section 13 so as to be disposed to the side of the swirling flow, and in the illustrated example, is provided in the center of the side wall section 131.
The size of the screen 14 can be determined arbitrarily depending on the operating conditions of the apparatus, the size of the carriers to be separated in the treated water containing the carriers, etc. In the illustrated example, a pair of screens 14 are provided, but only one of them may be provided.

The screen 14 is not particularly limited, and any type of screen can be used, such as punched metal, wedge wire, wire mesh, etc. The screen 14 preferably has openings smaller than the size of the carrier, specifically, 25 to 90% of the size of the carrier, and more preferably 40 to 80%.
Moreover, the screen 14 is preferably made of a corrosion-resistant material, such as stainless steel.

In the illustrated example, as shown in Figures 2, 4, and 7, the guide plate portion 133 is provided to appropriately guide the treated water containing carriers flowing in from the inlet portion 15 to the swirling flow forming space S1 in the inner tank 12, and has a horizontal plate portion 135 extending in a horizontal direction from the edge of the opening formed in the upper part of the side wall portion 131 and the swirling flow forming portion 132, and a pair of vertical plate portions 134 extending in a direction along the extension direction of the inlet portion 15 and along the vertical direction. The horizontal plate portion 135 and the vertical plate portion 134 prevent the treated water containing carriers in the inner tank 12 and the outer tank 11 from mixing with the treated water from which the carriers have been separated, and can guide the treated water containing carriers flowing in from the inlet portion 15 to the opening formed in the upper part of the side wall portion 131 and the swirling flow forming portion 132.

Here, in this embodiment, as described above, since the treatment water containing the carrier may contain impurities that are more likely to float in the treatment water than the carrier, the carrier separation device 1 of this embodiment is equipped with an impurity discharge mechanism 18 that discharges the impurities from the inner tank 12 and further from the separation tank 10.
In detail, in this embodiment, the impurity discharge mechanism 18, as shown in FIG. 2, opens at the top in the vertical direction of the swirling flow forming space S1 or above the top in the vertical direction, and has a first discharge section 181 for discharging impurities from the inner tank 12, and a second discharge section 182 for further discharging the impurities discharged by the first discharge section 181 from inside the separation tank 10.
Therefore, in this embodiment, while separating the carriers in the treated water, impurities that tend to float above the swirling flow formed by the treated water are discharged from the inner tank 12 via the first discharge section 181, and further, the impurities discharged by the first discharge section 181 can be further discharged from the inside of the separation tank 10 via the second discharge section 182.

In the example shown in Figure 2, the first discharge section 181 opens into the inner tank 12 above the upper and lower upward ends of the first swirling flow forming portion 1321 as the swirling flow forming section 132, and the second discharge section 182 is connected to the first discharge section 181 and can have a flow path section 183 extending from the first discharge section 181 to the outside of the separation tank 10.
2, the first discharge section 181 is partitioned by the upper and lower improved ends of the first swirling flow forming portion 1321 of the swirling flow forming section 132 and a pair of vertical plate sections 134 as the above-mentioned guide plate section 133, and includes an opening that opens into the inner tank 12 so as to face the extending direction of the inlet section 15. In this way, the first discharge section 181 opens into the inner tank 12 above the upper and lower improved ends of the first swirling flow forming portion 1321, so that the impurities floating above the swirling flow can be discharged from the inner tank 12 by the first discharge section 181 while reducing entrainment of treated water, and further, by arranging the first discharge section 181 to face the extending direction of the inlet section 15, the impurities can be discharged by using the flow of treated water from the inlet section 15 to be pushed out of the inner tank 12.

In the illustrated example, the first discharge section 181 is an opening section partitioned by the upper and lower end of the first swirling flow forming portion 1321 of the swirling flow forming section 132 and a pair of vertical plate sections 134 as the above-mentioned guide plate section 133. However, for example, the partition section 13 may have a second vertical plate section as the guide plate section 133 above the first swirling flow forming portion 1321 of the swirling flow forming section 132, which extends in the vertical direction and in a direction perpendicular to the extension direction of the inlet section 15, and the first discharge section 181 may be an opening section that opens into the second vertical plate section, or the first discharge section 181 may be an opening section of a flow path section such as a pipe that penetrates the second vertical plate section and extends into the inner tank 12.

From the viewpoint of facilitating efficient discharge of impurities from the inner tank 12, it is preferable that the first discharge section 181 opens into the inner tank 12 vertically lower than the opening of the inlet section 15, in other words, that the vertical lower end of the opening of the first discharge section 181 is positioned vertically lower than the upper and lower upper ends of the opening of the inlet section 15.

2 may have a converging portion 1835 in the middle of the flow path portion 183, where the flow paths converge from the first discharge portion 181 toward the outside of the separation tank 10. The converging portion 1835 may extend in a downward, up-down direction from the first discharge portion 181 toward the outside of the separation tank 10.
do.
Impurities have a low density and tend to be difficult to discharge to the outside of separation tank 10, but by providing convergent portion 1835 in this manner, the discharge speed of impurities can be improved, so that impurities can be discharged more efficiently. Furthermore, by extending convergent portion 1835 in a direction along the downward vertical direction, impurities can be caused to fall while rotating downward (while generating a vortex), so that the discharge speed is improved, and even if the amount of impurities accumulated in convergent portion 1835 is small, they can be discharged more effectively.

In the example shown in Figure 2, the flow path section 183 of the second discharge section 182 is more specifically formed to include a first flow path portion 1831 formed to include a flow path bottom 1832 extending laterally from the first discharge section 181 and a pair of flow path side portions 1833, and a tubular second flow path portion 1834 connected to the first flow path portion 1831 and extending in a direction along the downward vertical direction.
Furthermore, the second flow path portion 1834 can be connected to a discharge pipe that penetrates the bottom 111 of the separation tank 10 and extends into the outer tank 11. Since the flow path portion 183 includes the tubular second flow path portion 1834, it is possible to prevent treated water present in the outer tank 11 from being mixed into the flow path portion 183 when the carrier separation device 1 is in use. In addition, since the second flow path portion 1834 extends downward in the vertical direction, impurities in the flow path portion 183 can be transported to the outside of the separation tank 10 more vigorously by gravity.
In addition, the converging portion 1835 can be provided at the connection portion of the second flow path portion 1834 to a piping provided at the bottom 111 of the separation tank 10, and can be a portion whose cross-sectional area gradually decreases in a direction perpendicular to the extension direction of the flow path portion 183 from the first discharge portion 181 toward the outside of the separation tank 10.

The second flow path portion 1834, including the converging portion 1835, may be a tube having a truncated cone shape and a square cross section as shown in FIG. 2, but the entirety or a part of it (for example, only the converging portion 1835) may be a tube having a circular or elliptical cross section.
In addition, the entire second flow path portion 1834 can be shaped so that the flow path converges from the first discharge section 181 toward the outside of the separation tank 10 (in other words, the second flow path portion 1834 can be the converging section 1835).
Furthermore, from the viewpoint of effectively rotating the impurities downward (generating a vortex) within the converging portion 1835, the flow rate, etc. can be set within the range of the Reynolds number being 100<Re<1500.

As shown in FIG. 2, the extension direction of the flow path portion 183 of the second discharge portion 182 is from the first discharge portion 181 toward the outside of the separation tank 10, with the first flow path portion 1831 extending horizontally and the second flow path portion 1834 extending vertically downward. Note that the extension direction along the horizontal direction and the extension direction along the vertically downward direction do not need to be strictly the same direction as the horizontal direction or the vertical direction; for example, a deviation of about 15° or less is acceptable, and preferably 7° or less.

Furthermore, in the impurity discharge mechanism 18 according to the illustrated example, a valve can be provided in the piping of the second discharge section 182 in order to improve the efficiency of discharge of the impurities. As a result, for example, when a certain amount of impurities has accumulated in the flow path section 183 (particularly the second flow path portion 1834) of the second discharge section 182 with the valve closed, the impurities that have a low density and are difficult to discharge can be discharged all at once by opening the valve.
In this case, whether a certain amount of impurities has accumulated in the flow path portion 183 (particularly the second flow path portion 1834) can be detected by a sensor or by visual inspection by an operator. Alternatively, the valve can be a valve that opens and closes based on the mass of the contents including the impurities accumulated in the flow path portion 183 (particularly the second flow path portion 1834).

When a sensor is provided in the flow path portion 183, a control portion can be provided that opens the valve based on a signal sent by the sensor indicating that a certain amount of impurities has accumulated.
As the sensor, for example, a water level gauge can be used. Also, image data obtained by an imaging device can be used instead of the sensor, or these can be used in combination.

Also, in the illustrated example, the flow path section 183 of the second discharge section 182 can be cylindrical as a whole, and specifically, the upper part of the flow path section 183 is not covered with a lid except for the second flow path portion 1834, but can also be covered with a lid.
Furthermore, in this embodiment, the size of the separation tank 10 can be adjusted by adjusting the length in the extension direction of the first flow path portion 1831 of the second discharge section 182 and the arrangement position of the second flow path portion 1834.

In this embodiment, the impurity discharge mechanism 18 (and the impurity discharge mechanisms 28 and 38 described below) is preferably made of a corrosion-resistant material, and can be made of a metal such as stainless steel.

While the above describes the example of the impurity discharge mechanism 18 shown in Figure 2, in this embodiment, the impurity discharge mechanism is not particularly limited as long as it opens at the top in the vertical direction of the swirling flow forming space S1 or above the top in the vertical direction and has a first discharge section 181 for discharging impurities from the inner tank 12, and a second discharge section 182 for further discharging the impurities discharged by the first discharge section 181 from inside the separation tank 10.
As an example of the impurity discharge mechanism of this embodiment, a first modified example will be described below. Components common to the impurity discharge mechanism 18 of the example illustrated in Fig. 2 and the impurity discharge mechanism 28 of the first modified example illustrated in Fig. 8 are given the same reference numerals and will not be described.

The first discharge parts 181 of the impurity discharge mechanism 18 of the example shown in FIG. 2 and the impurity discharge mechanism 28 according to the first modified example have the same configuration as shown in FIGS.
In contrast, the converging portion 1835 of the flow path portion 183 of the second discharge portion 182 of the impurity discharge mechanism 18 in the example shown in Figure 2 above extends in a downward, up-down direction from the first discharge portion 181 toward the outside of the separation tank 10, whereas the converging portion 2835 of the flow path portion 283 of the second discharge portion 282 of the impurity discharge mechanism 28 in the first modified example extends in a horizontal direction from the first discharge portion 181 toward the outside of the separation tank 10, as shown in Figure 8.
In this way, in the first modified example, the convergent portion 2835 extends in the lateral direction, which makes it easier to adjust the volume of the outer tank 11 and allows the separation tank 10 to be relatively small, thereby saving space. Specifically, the length of the flow path portion 283 in the extension direction (the lateral position of the convergent portion 2835) and the length of the convergent portion 2835 in the extension direction can be set appropriately, and for example, the position of the convergent portion 2835 can be brought closer to the inner tank 12, or further, all or part of the convergent portion 2835 can be positioned directly above the swirl flow forming portion 132 of the inner tank, thereby allowing the separation tank 10 to be relatively small.
In the first modified example, the converging portion 2835 extends in the lateral direction, so that impurities can be efficiently discharged when a comparatively large amount of treated water flows into the carrier separation device 1 .

Specifically, in the second discharge section 282 of the impurity discharge mechanism 28 relating to the first modified example, as shown in FIG. 8, the flow path section 283 is formed to include a flow path bottom section 2832 extending laterally from the first discharge section 181 and a pair of flow path side sections 2833.
8, the flow path 283 of the second discharge part 282 can be connected to a discharge pipe that opens into the side wall 131 of the separation tank 10. In this manner, since the second discharge part 282 has the flow path 283, impurities can be discharged from the inside to the outside of the separation tank 10 without being mixed into the outer tank 11.

The converging portion 2835 can be provided at the connection portion of the flow path portion 283 to the piping provided in the side wall portion 131 of the separation tank 10, and can be a portion where the width of the flow path bottom portion 2832 of the flow path portion 283 and the height of the pair of flow path side portions 2833 become smaller in the direction from the first discharge portion 181 toward the outside of the separation tank 10.

The extension direction of the flow path section 283 of the second discharge section 282, including the extension direction of the convergence section 2835, is along the horizontal direction from the first discharge section 181 toward the outside of the separation tank 10, as shown in FIG. 8. Note that the extension direction along the horizontal direction does not necessarily have to be in the exact same direction as the horizontal direction; for example, a deviation of about 15° or less is acceptable, and preferably 7° or less.

In the first modified example, the flow path section 283 of the second discharge section 282 can be cylindrical. Specifically, as shown in FIG. 8, the upper part of the flow path section 283 is not covered with a lid except for the converging section 2835, but it can be covered with a lid. Also, as shown in FIG. 8, the upper part of the converging section 2835 is covered with a lid. At the converging section 2835, there is a risk that impurities may spill out of the flow path section 283 and fall into the outer tank 11 due to the convergence of the flow path. By doing so, it is possible to prevent such impurities from falling.

In the first modified example, as in the example shown in FIG. 2, a valve can be provided in the piping of the second discharge section 282 to adjust the discharge of impurities accumulated in the flow path section 283. The valve can be opened and closed, for example, by a sensor provided in the flow path section 283, or by image information from an imaging device or visual inspection by an operator.

Next, a second modification of the impurity discharge mechanism of this embodiment will be described. Components common to the impurity discharge mechanism 18 of the example shown in Fig. 2 and the impurity discharge mechanism 38 according to the second modification shown in Fig. 9 are given the same reference numerals and will not be described.
The first discharge section 181 of the impurity discharge mechanism 18 in the example shown in Figure 2 above opens into the inner tank 12 above the upper and lower upward ends of the first swirling flow forming portion 1321, whereas the first discharge section of the impurity discharge mechanism 38 in the second modified example is located above the upper and lower upward ends of the screen 14 of the side wall portion 131 as shown in Figure 9, and is an opening section that opens from the inner tank 12 to the outer tank 11.
Further, while the second discharge section 182 of the impurity discharge mechanism 18 in the example shown in FIG. 2 above has a flow path section 183, the second discharge section 382 of the impurity discharge mechanism 38 according to the second modified example opens into the outer tank 11 vertically above the position at which the outflow section 16 opens into the outer tank 11, as shown in FIG.

According to the second modified example, the first discharge section 381 is an opening that opens from the inner tank 12 to the outer tank 11 above the upper and lower improved ends of the screen 14, so that impurities that may be floating in the inner tank 12 can be effectively discharged from the inner tank 12 to the outer tank 11 via the first discharge section 381 without adhering to the screen 14. At this time, since a swirling flow is formed in the inner tank 12, the carriers tend to be unevenly distributed around the swirling flow and settle due to gravity. Therefore, even if the first discharge section 381 exists, the carriers are unlikely to reach the first discharge section 381, and it is possible to prevent the carriers from flowing out from the inner tank 12 to the outer tank 11. Furthermore, impurities tend to float near the surface of the treated water in the outer tank 11, but since the second discharge section 382 opens into the outer tank 11 at a position vertically above the position at which the outflow section 16 opens into the outer tank 11, impurities floating in the outer tank 11 can be discharged from the second discharge section 382 while being prevented from flowing out from the outflow section 16. Note that even if the carrier flows out from the inner tank 12 to the outer tank 11 at this time, the carrier tends to settle in the outer tank 11, so that it is possible to prevent the carrier from being discharged from the outflow section 16 or the second discharge section 382.
Therefore, according to the second modified example of this embodiment, while separating the carriers in the treated water, impurities that tend to float above the swirling flow formed by the treated water are discharged from the inner tank 12 via the first discharge section 381, and further, the impurities discharged by the first discharge section 381 can be further discharged from the inside of the separation tank 10 via the second discharge section 382.

Here, in the second modified example, the position of the first discharge section 381 is not particularly limited as long as it is located above the upper and lower improved ends of the screen 14 of the sidewall section 131, but from the viewpoint of effectively discharging impurities floating in the swirling flow, it is preferable that the first discharge section 381 is located in the swirling flow forming space S1 above the upper and lower improved ends of the screen 14 of the sidewall section 131. Moreover, from the viewpoint of more efficiently removing impurities that may adhere to the screen 14, it is more preferable that the first discharge section 381 is formed adjacent to and above the upper and lower improved ends of the screen 14 of the sidewall section 131.
The first discharge section 381 is not particularly limited in its horizontal position or length, but its horizontal center position can be the same as the horizontal center of the screen 14, and its horizontal length LL1 can be 0.5 to 1.5 times the horizontal length LL2 of the screen 14. The horizontal length LL1 of the first discharge section 381 is preferably 0.8 times or more, more preferably 0.9 times or more, the horizontal length LL2 of the screen 14. The horizontal length LL1 of the first discharge section 381 is preferably 1.2 times or less, more preferably 1.0 times or less, the horizontal length LL2 of the screen 14. The horizontal length LL1 of the first discharge section 381 is most preferably 1.0 times the horizontal length LL2 of the screen 14.

The size of the opening of the first discharge section 381 (area of the opening) is not particularly limited, but can be smaller than the size of the screen 14 arranged on the side wall section 131 (area of the screen 14), and is preferably 0.4 times or less, and more preferably 0.3 times or less. If the size of the opening of the first discharge section 381 is too small, the effect of discharging impurities may decrease, so it is preferably 0.05 times or more the size of the screen 14, and more preferably 0.1 times or more.

Furthermore, in the illustrated example, the carrier separation device 1 has a pair of screens 14, and the above-mentioned first discharge sections 381 can also be disposed above the pair of screens 14, respectively.
In addition, in the illustrated example, above the first swirling flow forming portion 1321 of the swirling flow forming section 132, the partition section 13 has a second vertical plate section 136 that extends upward in the vertical direction as the guide plate section 133 and extends in a direction perpendicular to the extension direction of the inlet section 15.

The second discharge section 382 of the impurity discharge mechanism 38 according to the second modified example may be a pipe that penetrates the side wall section 131 from the outside of the separation tank 10 and opens into the outer tank 11, as shown in the figure, or may have a pipe and a discharge section (not shown) with an enlarged opening area from the opening of the pipe. Also, it is preferable that the opening of the second discharge section 382 into the outer tank 11 opens in the horizontal direction, as shown in the figure.

The vertical position at which the second discharge section 382 opens into the outer tank 11 is not particularly limited as long as it is located vertically above the position at which the outflow section 16 opens into the outer tank 11 (in other words, the vertical lower end of the opening of the second discharge section 382 into the outer tank 11 is located vertically above the upper and lower upper ends of the opening of the outflow section 16 into the outer tank 11), but it is preferable that it is located at the same position as the opening of the inflow section 15 into the inner tank 12 or vertically below that position (in other words, the upper and lower upper ends of the opening of the second discharge section 382 into the outer tank 11 are located at the same vertical position as the upper and lower upper ends of the opening of the inflow section 15 into the inner tank 12 or vertically below that upper end).

9, it is preferable that the bottom of the outer tank, which defines the lower side of the outer tank 11 in the vertical direction, has a recess 385, and the impurity discharge mechanism 38 further has a third discharge part 384 that opens at the bottom of the recess 385. By doing so, even if the carrier flows out from the inner tank 12 to the outer tank 11, the flowed-out carrier can be taken out of the separation tank 10 via the third discharge part 384.
In the illustrated example, the bottom of the outer tank is included in the bottom 111 of the separation tank 10, and therefore in this example, the bottom 111 of the separation tank 10 has a recess 385. As illustrated, the recess 385 can be formed by sloping from one end toward the center in the lateral direction of the bottom 111 of the separation tank 10 and also sloping from the other end toward the center. Alternatively, although not illustrated, the recess 385 can be formed into a truncated cone shape (a funnel-like shape) from the bottom of the recess 385.

The third discharge section 384 may be a pipe that opens at the bottom of the recess 385 as shown in the figure, and may also be provided with a valve so that carriers that may accumulate in the outer tank 11 can be discharged as necessary. Furthermore, the third discharge section 384 may be merged with the carrier discharge section 17.

In addition, in this specification, the impurity discharge mechanism 18 and the first and second modified impurity discharge mechanisms 28, 38 are described separately, but the carrier separation device 1 can be provided with an impurity discharge mechanism in which at least two forms of impurity discharge mechanisms 18, 28, 38 are combined with each other, for example, a combination of the impurity discharge mechanism 18 and the impurity discharge mechanism 38, or a combination of the impurity discharge mechanism 28 and the impurity discharge mechanism 38. In the case of such a combined impurity discharge mechanism, the drain discharge section 19 can also be merged with the carrier discharge section 17.

In the present embodiment, the carrier separation apparatus 1 can be provided with a drainage section 19 at the bottom 111 of the separation tank 10, as shown in Figures 2 and 3, etc., whereby it is possible to drain treated water from which residual carriers have been separated when the operation of the carrier separation apparatus 1 is stopped to clean or inspect the inside of the separation tank 10. The drainage section 19 can be a pipe made of a metal such as stainless steel, which has an opening at the bottom 111 of the separation tank 10 and extends to the outside of the separation tank 10.
Although FIG. 9 does not show the drainage section 19 as shown in FIG. 2 or FIG. 3, for example, in the example shown in FIG. 9, the third drainage section can also be used as the drainage section.

Although not shown, the carrier separation device 1 can be provided with a sensor capable of measuring the water level in the separation tank 10. Specifically, the sensor can be provided in the inner tank 12 of the separation tank 10. The carrier separation device 1 of this embodiment has a feature that the screen 14 is not easily clogged, but clogging may occur due to the state of the biofilm on the carrier surface, the inflow of foreign matter, or impurities. Therefore, by measuring and monitoring the water level, it is possible to prevent the treated water containing the carrier from overflowing from the inner tank 12. In addition, when the water level rises, it is possible to perform control to release the clogging on the screen 14 surface, close the inflow part 15, etc.
In the illustrated example of the carrier separation device 1, during normal operation, the water level can be positioned at the height of the vicinity of the opening formed by the side wall portion 131 and the swirl flow forming portion 132 of the partition portion 13.

Although not shown, the carrier separation device 1 may further include a discharge adjustment unit that adjusts the discharge amount of the treated water containing the carrier in the inner tank 12. Specifically, the discharge adjustment unit may be provided in the carrier discharge unit 17. In this case, the discharge amount of the treated water containing the carrier from the carrier discharge unit 17 may be adjusted by a pump or a valve as the discharge adjustment unit. Alternatively, the carrier discharge unit 17 may be provided with a drain pipe branching from the carrier discharge unit 17 and a valve for adjusting the opening and closing of the drain pipe as the discharge adjustment unit, and the discharge amount of the treated water containing the carrier from the carrier discharge unit 17 may be adjusted by controlling the valve. Alternatively, although not shown, a drain pipe opening into the inner tank 12 and a valve for adjusting the opening and closing of the drain pipe may be provided as the discharge adjustment unit below the inner tank 12 in the vertical direction, specifically, in the part of the bottom 111 of the separation tank 10 located within the inner tank 12, and the discharge amount of the treated water containing the carrier in the inner tank 12 may be adjusted by controlling the valve.

In this way, by providing the carrier separation device 1 with a discharge adjustment unit, for example, when the screen 14 becomes clogged with carriers, the screen 14 can be cleaned. Specifically, for example, while the carrier separation device 1 is in operation, the discharge adjustment unit can be used to increase the discharge of treated water containing carriers, thereby reducing the amount of treated water containing carriers present in the inner tank 12. This reduces the amount of treated water containing carriers that permeates from the inner tank 12 to the outer tank 11 through the screen 14, or the treated water from which the carriers have been separated flows back from the outer tank 11 to the inner tank 12, allowing the carriers that have clogged the screen 14 to be removed.

Next, the method for separating the carrier according to this embodiment will be described.
The carrier separation method of this embodiment is a carrier separation method for separating carriers from treated water using the carrier separation device 1 of the above-mentioned embodiment of the present invention, and includes the steps of: causing treated water containing carriers to flow from the inflow section 15 into the inner tank 12, separating the carriers with the screen 14 and causing the treated water from which the carriers have been separated to flow into the outer tank 11, and then causing the treated water in the outer tank 11 to flow out from the outflow section 16. The carrier separation method of this embodiment includes the steps of, when the treated water flowing in from the inflow section 15 contains impurities, discharging the impurities from the inner tank 12 via the first discharge section 181 of the impurity discharge mechanism 18, and further discharging them from the separation tank 10 via the second discharge section 182.
In the carrier separation method of the present embodiment, by including the above steps, clogging of the screen 14 with the carrier can be prevented and the carrier can be easily separated from the treated water containing the carrier. Furthermore, when the treated water contains impurities, the impurities can be discharged from the separation tank 10 while being prevented from adhering to the screen 14.

In addition, the step of discharging the impurities from the separation tank 10 may include, for example, a step of opening the valve in the case where the second discharge section 182 of the impurity discharge mechanism 18 has a valve capable of adjusting the discharge of the impurities, based on a signal that the impurities have accumulated detected by a sensor or based on an operation by an operator. In this way, by opening the valve that was closed when the impurities had accumulated, the accumulated impurities can be discharged all at once, and even impurities that have a low density and tend to float can be discharged.
The step of opening the valve can also be carried out periodically by setting a timer or the like.

Incidentally, in the carrier separation method of this embodiment, the adhesion and clogging of the carriers and impurities to the screen 14 can be reduced by the above steps, but the method may also include a cleaning step as described below.
Specifically, in the washing step, an inflow adjustment section (not shown) capable of adjusting the inflow rate of the treated water containing the carrier is provided in the inflow section 15, and the inflow rate of the treated water containing the carrier is temporarily reduced or stopped by the inflow adjustment section. The carriers and impurities that are clogged in the screen 14 are clogged by the water pressure when the treated water containing the carrier passes through the screen 14, but by temporarily reducing or stopping the inflow rate, the permeation flow rate at the screen 14 and the associated water pressure caused by the permeation of the treated water are reduced, and the carriers and impurities that have clogged the screen 14 can be removed from the screen 14 and the screen 14 can be washed.
Furthermore, instead of or in addition to the adjustment by the inflow adjustment unit, the carrier separation device 1 is provided with a discharge adjustment unit capable of adjusting the discharge amount of the treated water containing carriers in the inner tank 12, and the discharge adjustment unit adjusts the discharge amount of the treated water containing carriers to increase. This makes it possible to reduce the permeation flow rate at the screen 14 and wash the screen 14, similar to the case where the inflow amount of the treated water containing carriers is adjusted to temporarily decrease or stop by the inflow adjustment unit.
The adjustment in the discharge adjustment section can be performed by adjusting a pump or a valve provided in the carrier discharge section 17 as a discharge adjustment section, or by providing, in the carrier discharge section 17, a drain piping branching off from the carrier discharge section 17 and a valve for adjusting the opening and closing of the drain piping as a discharge adjustment section and controlling said valve, or by providing, vertically below the inner tank 12, specifically, in a portion of the bottom 111 of the separation tank 10 that is located within the inner tank 12, a drain piping that opens into the inner tank 12 and a valve for adjusting the opening and closing of the drain piping as a discharge adjustment section and controlling said valve, etc.

In this embodiment, the cleaning process can be performed periodically by setting a timer, or can be performed when the water level reaches or exceeds a predetermined level using a sensor capable of measuring the water level.

Next, the processing system of this embodiment will be described.
The treatment system 4 of this embodiment is a system for treating water to be treated, such as organic wastewater, as shown in FIG. 1. Specifically, the treatment system 4 is a system for performing anaerobic treatment of organic wastewater containing organic matter, such as manufacturing wastewater from food factories, organic wastewater from chemical factories, and general sewage, by bringing the organic wastewater into contact with anaerobic microorganisms.
More specifically, the treatment system 4 of this embodiment includes a reaction tank 41 that treats the water to be treated with carriers that retain microorganisms, the carrier separation device 1 that includes the carrier discharge part 17 formed in the vertically lower part of the inner tank 12 and that discharges the carrier from the inner tank 12, and a connection part that connects the reaction tank 41 and the carrier discharge part 17. In addition, the treatment system 4 can optionally include an acid fermentation tank 42 that decomposes organic matter that may be contained in the water to be treated.
In the treatment system 4 of this embodiment, the carrier separation device 1 may be the carrier separation device 1 of the embodiment of the present invention described above, which is provided with a carrier discharge part 17 provided on the bottom 111 of the inner tank 12 and which discharges the carrier separated by the screen 14 to the outside. Furthermore, in the treatment system 4 of this embodiment, the carrier discharge part 17 and the reaction tank 41 are connected to each other by a connection part (connection line (lines L5 and L4 in the illustrated example)).

In this embodiment, specifically, the acid fermentation tank 42 can be a tank for decomposing organic matter contained in water to be treated, such as waste liquid, to obtain acid-fermented water, and can also be used as a tank for performing pretreatment for the treatment in the reaction tank 41, and can decompose organic matter (polymers) that may be contained in the wastewater down to low-molecular-weight organic acids such as acetic acid and propionic acid.
The acid-fermented water obtained in the acid fermentation tank 42 is discharged into the reaction tank 41 through a line L4 connecting the acid fermentation tank 42 and the reaction tank 41.

In the reaction tank 41, the water to be treated (wastewater or acid fermentation water in the case where the above-mentioned acid fermentation tank 42 is provided) is introduced, and the water to be treated is treated with a carrier that holds microorganisms, specifically, anaerobically treated, to obtain treated water containing the carrier. Although not particularly limited, the reaction tank 41 contains granular sludge and a carrier in the reaction tank 41, and organic wastewater is passed upward to perform high-load, high-speed treatment. In the anaerobic reaction tank 41 (methane fermentation tank), biogas (methane gas) generated by the anaerobic reaction rises in the anaerobic reaction tank 41 and is discharged to the outside from the top of the anaerobic reaction tank 41 and collected. At this time, the carrier holding the microorganisms also rises together and may flow out of the anaerobic reaction tank 41 as overflow.
As shown in FIG. 1, the reaction tank 41 may be provided with a circulation line L1 connecting the upper and lower parts of the reaction tank 41 for circulation.
The reaction tank 41 can be a complete mixing tank using mechanical or gas agitation, an upflow anaerobic sludge blanket (UASB), an expanded granular sludge bed (EGSB) as an improved version of the UASB method for high loads, or a reaction tank equipped with a gas collector, guide walls, and baffles therein that have an efficient fluidization state.

The carrier separation device 1 is the carrier separation device 1 according to the embodiment of the present invention described above, and treated water containing carriers after wastewater has been treated in the reaction tank 41 or during treatment passes through a line L2 and flows into the separation tank 10 via the inlet part 15 of the carrier separation device 1. Then, in the carrier separation device 1, the carriers in the treated water are separated, and the treated water from which the carriers have been separated flows out from the outlet part 16, and the separated carriers (treated water in which the carriers are concentrated) are discharged from the carrier discharge part 17.
Furthermore, the impurities are discharged from the separation tank 10 via the second discharge part 182 by the impurities discharge mechanism 18 of the carrier separation device 1. The impurities discharged from the second discharge part 182 are carried out from the carrier separation device 1 through the line L7, and although not shown in the figure, the mixed treated water can be further separated as necessary and disposed of, or further treated in the reaction tank 41.
The treated water from which the carriers have been separated and discharged from the outlet 16 of the carrier separation device 1 can be transported to the outside of the treatment system 4 through a line L3. In addition, a part of the treated water from which the carriers have been separated and passing through the line L3 can be returned to the acid fermentation tank 42 again through a line L6.

In the treatment system 4 of this embodiment, the carrier discharge part 17 of the carrier separator 1 and the reaction tank 41 are connected by a connection part (connection line). Specifically, in the example of Fig. 1, the line L5 extending from the carrier discharge part 17 of the carrier separator 1 merges with the line L4, thereby connecting the carrier discharge part 17 of the carrier separator 1 and the reaction tank 41.
In the treatment system 4 of this embodiment, the treatment system 4 includes the carrier separation device 1, and the carrier discharge part 17 of the carrier separation device 1 is connected to the reaction tank 41 by a connection line, so that wastewater treatment can be performed efficiently. Specifically, when wastewater is treated using a carrier, the carrier may also flow out from the reaction tank 41 together with the treated water, but since the treatment system 4 includes the carrier separation device 1, the carrier can be easily separated and discharged. The discharged carrier can be quickly returned to the reaction tank 41 and can be used again for wastewater treatment. In addition, the carrier separation device 1 makes it easy to obtain treated water from which the carrier has been separated, so that treated water from which the carrier has been anaerobically treated can also be easily obtained.
Furthermore, in the treatment system 4 of this embodiment, even if the treatment water containing the carrier contains impurities that are more likely to float than the carrier, the impurities can be discharged from the separation tank 10 by the impurity discharge mechanism 18 possessed by the carrier separation device 1, so that separation of the carrier in the carrier separation device 1 can be performed more efficiently.

Although an embodiment of the present invention has been described above with reference to the drawings, the carrier separation device, carrier separation method, and processing system of the present invention are not limited to the above examples and can be modified as appropriate.

The present invention provides a carrier separation device and a carrier separation method capable of efficiently separating carriers from treated water even when the treated water contains floating impurities, and a treatment system capable of efficiently treating wastewater.

1: Carrier separation device 10: Separation tank 11: Outer tank 111: Bottom 112: Side 113: Recess 12: Inner tank 13: Partition 131: Side wall 132: Swirling flow forming section 1321: First swirling flow forming section 1322: Second swirling flow forming section 133: Conducting plate section 134: Vertical plate section 135: Horizontal plate section 136: Second vertical plate section 14: Screen 15: Inlet section 16: Outlet section 17: Carrier discharge section 18, 28, 38: Impurity discharge mechanism 181, 381: First discharge section 18 2, 282, 382: second discharge section 183, 283: flow path section 1831: first flow path section 1832, 2832: flow path bottom section 1833, 2833: flow path side section 1834: second flow path section 1835, 2835: convergence section 384: third discharge section 385: recess 19: drainage section 4: treatment system 41: reaction tank 42: acid fermentation tank L1: circulation lines L2 to L7: line S1: swirl flow formation space S2: carrier recovery space LL1, LL2: lateral length

Claims (10)

A carrier separation device for separating a carrier from treated water, comprising:
The carrier separation device includes a separation tank, a partition section that partitions the inside of the separation tank into an inner tank and an outer tank, a screen that is provided in the partition section and separates the carriers and allows the treated water to pass from the inner tank to the outer tank, an inflow section that allows the treated water containing the carriers to flow into the inner tank, and an outflow section that allows the treated water from which the carriers have been separated to flow out of the outer tank,
the partition section includes a swirling flow forming section having a curved first swirling flow forming section and a second swirling flow forming section facing the first swirling flow forming section for generating a swirling flow of the treatment water in the inner tank, and a side wall section located to the side of the swirling flow and on which the screen is disposed;
The carrier separation device includes an impurity discharge mechanism that discharges impurities from the inner tank and further discharges the impurities from the separation tank when the impurities are contained in the treatment water,
a first discharge section that opens above an upper end of the first swirling flow forming section or above an upper end of the screen , for discharging impurities from the swirling flow forming space, and a second discharge section that further discharges the impurities discharged by the first discharge section to the outside of the separation tank, when the space within the inner tank formed by the swirling flow forming section and the side wall section is defined as a swirling flow forming space. The carrier separation device according to claim 1 , further comprising: a carrier discharge section formed in a lower portion of the inner tank for discharging the carrier from the inner tank. The swirl flow forming portion has a surface that forms a swirl flow extending in a direction intersecting with an extension direction of the inlet portion ,
The carrier separation apparatus according to claim 1 , wherein the second discharge section is connected to the first discharge section and has a flow path section extending from the first discharge section to an outside of the separation tank. The carrier separation device according to claim 3, wherein the flow path section of the second discharge section has a converging section in the middle of the flow path section where the flow path converges from the first discharge section toward the outside of the separation tank. The carrier separation apparatus according to claim 4 , wherein the converging portion extends in a downward direction from the first discharge portion toward an exterior of the separation tank. The carrier separation device according to claim 4, wherein the converging portion extends in a lateral direction from the first discharge portion toward the outside of the separation tank. The first discharge portion is an opening portion located above an upper end of the screen of the side wall portion and opening from the inner tank to the outer tank,
The carrier separation device according to claim 1 or 2, wherein the second discharge portion opens into the outer tank at a position above a position where the outlet portion opens into the outer tank. The outer tank bottom, which defines the lower side of the outer tank, has a recess,
The carrier separation device according to claim 7 , wherein the impurity discharge mechanism further comprises a third discharge portion that opens at a bottom of the recess. A carrier separation method for separating carriers from treated water using the carrier separation device according to any one of claims 1 to 8,
The method includes a step of flowing treated water containing carriers into the inner tank from the inlet, separating the carriers with the screen, flowing the treated water from which the carriers have been separated into the outer tank, and then flowing the treated water in the outer tank out from the outlet,
A method for separating carriers, comprising the steps of, when the treatment water flowing in from the inlet contains impurities, discharging the impurities from the swirling flow forming space via the first discharge part of the impurity discharge mechanism, and further discharging the impurities from the separation tank via the second discharge part. A treatment system for treating water to be treated, comprising:
The treatment system includes a reaction tank that treats the water to be treated with a carrier that retains microorganisms;
9. The carrier separation apparatus according to claim 1, further comprising: a carrier discharge unit formed in a lower portion of the inner tank for discharging the carrier from the inner tank;
A connection part connecting the reaction tank and the carrier discharge part;
A processing system comprising: