JP6838438B2 - Algae separator - Google Patents

Description

The present disclosure relates to an algae separator that separates algae from an algae solution containing algae.

In recent years, biofuels (hydrocarbons and biodiesel) and algae (particularly microalgae) capable of producing physiologically active substances have been attracting attention. It is being studied to effectively utilize algae by extracting target substances such as fuel and physiologically active substances from such algae and processing the algae itself into foods, medicines, cosmetics and the like. In order to make effective use of algae, it is necessary to cultivate a large amount of algae in a culture device and separate the cultured algae from the culture solution.

As a technique for separating algae from the culture solution, a technique for coagulating and precipitating algae by adding a flocculant to the culture solution has been developed (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-179586

However, in the technique of adding a flocculant, the cost of the flocculant itself is high, and a treatment for removing the flocculant is required.

In view of such problems, the present disclosure aims to provide an algae separating device capable of separating algae at low cost.

In order to solve the above problems, the algae separation device according to one aspect of the present disclosure has a planar shape in which through holes are formed, has a filter surface portion that is held at an angle with respect to a horizontal plane, and the filter surface portion. An accommodating portion for accommodating an algae solution containing algae and a moving portion for rotating the filter surface portion are provided above.

Further, a bottom surface portion provided below the filter surface portion and having a through hole formed in the center, a side surface portion erected from the bottom surface portion to the filter surface portion side, and a side surface portion provided on the bottom surface portion and from the side surface portion. A liquid discharge portion having a plurality of fins extending to the through hole may be provided.

Further, the screen main body is provided with a screen main body having through holes penetrating from the front surface to the back surface, and an injection portion for injecting the algae solution toward the surface of the screen main body. The accommodating portion includes the screen main body. The algae liquid flowing down from the screen may be contained.

It is possible to separate algae at low cost.

It is a figure explaining the algae separation apparatus. FIG. 2A is a plan view of the screen. FIG. 2B is a sectional view taken along line IIb-IIb in FIG. 2A. It is a figure explaining the 2nd algae separation unit. FIG. 4A is a first diagram illustrating the relative movement of the slurry and the first concentrated algae solution. FIG. 4B is a second diagram illustrating the relative movement of the slurry and the first concentrated algae solution. It is a figure explaining the 2nd algae separation unit of the modification. It is a figure explaining the structure of the liquid discharge part. FIG. 7A is a first diagram illustrating the function of the liquid discharge unit. FIG. 7B is a second diagram illustrating the function of the liquid discharge unit.

The embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding, and the present disclosure is not limited unless otherwise specified. In the present specification and the drawings, elements having substantially the same function and configuration are designated by the same reference numerals, so that duplicate description will be omitted. In addition, elements not directly related to the present disclosure are not shown.

In this embodiment, the algae separating device 100 for separating algae from an algae solution containing algae (algae solution in which algae are suspended) will be described. In addition, Botryococcus as an alga will be described as an example. In addition, Botryococcus may be a wild-type strain, or may be a mutant strain whose particle size is enlarged by gene recombination or induction of mutation.

FIG. 1 is a diagram illustrating an algae separation device 100. In the following figures including FIG. 1, the X-axis (horizontal direction), the Y-axis (horizontal direction), and the Z-axis (vertical direction) that intersect vertically are defined as shown in the figure. As shown in FIG. 1, the algae separation device 100 includes a first algae separation unit 110, a second algae separation unit 120, an algae recovery tank 130, a delivery unit 140, and a drying unit 150. ..

As the first algae separation unit 110, an existing technique, for example, the technique described in JP-A-2016-214151 can be used. For example, the first algae separation unit 110 includes a screen 112 and an injection unit 114.

The screen 112 removes some of the liquid from the algae liquid. FIG. 2 is a diagram illustrating a specific configuration of the screen 112. FIG. 2A is a plan view of the screen 112. FIG. 2B is a sectional view taken along line IIb-IIb in FIG. 2A. In FIG. 2, the slit S is shown larger than it actually is in order to facilitate understanding.

As shown in FIG. 2, the screen 112 includes a screen main body portion 112a and a slit S (through hole). The screen main body 112a is a plate made of a metal such as stainless steel. As shown in FIG. 2B, the screen main body 112a is formed in a curved shape in which the surface 112ad side is recessed. The screen 112 is arranged so that the 112ab on one end side of the screen main body 112a is vertically above the 112ac on the other end side (in the Z-axis direction in FIG. 2).

The slit S is a through hole penetrating from the front surface 112ad of the screen main body 112a to the back surface 112ae. A plurality of slits S extend in the Y-axis direction in FIG. 2 and are provided in a plurality of slits S in the screen main body portion 112a. The width of the slit S in the X-axis direction in FIG. 2 is smaller than the minimum particle size of algae. By setting the width of the slit S to be less than the minimum particle size of the algae, it is possible to avoid a situation in which the algae pass through the slit S. Therefore, it is possible to prevent a decrease in algae recovery efficiency. Since the minimum particle size of algae can be measured with an existing particle size measuring device such as a particle size distribution meter, detailed description thereof will be omitted here. When the algae form colonies, the width of the slit S may be less than the minimum particle size of the colonies.

Returning to FIG. 1, the injection unit 114 sucks the algae liquid from the culture tank 10 and injects the sucked algae liquid onto the surface 112ad of the screen main body 112a. Specifically, the injection unit 114 includes a pipe 114a and a pump 114b. One end of the pipe 114a is immersed in the algae solution stored in the culture tank 10, and the nozzle 114ab is connected to the other end. The nozzle 114ab has a tapered shape in which the cross-sectional area of the flow path gradually decreases from the base end connected to the pipe 114a toward the tip end. The nozzle 114ab is provided so as to face the screen 112 (the surface 112ad of the screen main body 112a). The pump 114b is provided in the pipe 114a.

When the algae liquid is sprayed onto the screen 112 by the injection unit 114, a part of the liquid (culture liquid or the like) in the algae liquid passes through the slit S and falls below the screen 112. Therefore, the algae liquid from which a part of the liquid has been removed (hereinafter referred to as "first concentrated algae liquid") remains on the surface 112ad of the screen main body 112a. Further, when the injection unit 114 injects the algae liquid, the liquid can be efficiently passed through the slit S by the flow of the injection, and the dehydration efficiency of the algae liquid (efficiency of removing the liquid from the algae liquid) is improved. Is possible.

Further, the injection unit 114 injects the algae liquid in the direction from the one end side 112ab of the screen main body 112a toward the other end side 112ac. As a result, the first concentrated algae solution moves in the direction from 112ab on the one end side to 112ac on the other end side due to the impact of the injection. As described above, in the screen main body 112a of the screen 112, the one end side 112ab is arranged vertically above the other end side 112ac. Therefore, the first concentrated algae solution moves from 112ab on one end side to 112ac on the other end side even by its own weight. Therefore, a dedicated power for moving the first concentrated algae liquid becomes unnecessary, and the cost required for the power can be reduced.

The first concentrated algae liquid moves from 112ab on one end side to 112ac on the other end side, and in the moving process, further liquid is further removed through the slit S. Then, the first concentrated algae solution that has reached 112ac on the other end side falls (flows down) under its own weight and is supplied to the second algae separation unit 120. On the other hand, the liquid that has fallen from the screen 112 is stored in the liquid recovery tank 20 provided below the screen 112.

The second algae separation unit 120 further removes the liquid from the first concentrated algae solution to produce a second concentrated algae solution. The specific configuration of the second algae separation unit 120 will be described in detail later.

The algae recovery tank 130 houses the second concentrated algae solution produced by the second algae separation unit 120.

The delivery unit 140 includes a pipe 142 and a pump 144. One end of the pipe 142 is immersed in the second concentrated algae liquid stored in the algae recovery tank 130, and the other end is connected to the drying portion 150. The pump 144 is provided in the pipe 142 and sends the second concentrated algae liquid to the drying unit 150.

The drying unit 150 dries the second concentrated algae solution by natural drying (sun-dried, shade-dried, etc.) to produce dried algae. By using natural drying as the drying unit 150, the cost required for drying can be reduced. The dried algae produced in this way are processed into fuel through a solvent extraction treatment or the like.

(2nd algae separation unit 120)
FIG. 3 is a diagram illustrating the second algae separation unit 120. As shown in FIG. 3, the second algae separation unit 120 includes a storage unit 210 and a moving unit 220.

The accommodating portion 210 includes an outer frame 212, support members 214a and 214b, and a filter surface portion 216. The outer frame 212 is a cylinder made of metal. The support members 214a and 214b are rectangular plate members. Both ends of the support members 214a and 214b are connected to the lower outer peripheral edge of the outer frame 212. The support member 214a and the support member 214b are provided on the outer frame 212 so as to intersect each other. In the present embodiment, the support member 214a and the support member 214b are provided so as to intersect at the center of the outer frame 212 (the center of the filter surface portion 216).

The filter surface portion 216 has a disk shape and is made of a metal such as stainless steel. A plurality of slits S (through holes) are formed in the filter surface portion 216. The slit S has the same shape as the slit S formed in the screen main body 112a. The filter surface portion 216 is arranged on the support members 214a and 214b and covers the lower end opening of the outer frame 212.

The accommodating portion 210 accommodates the first concentrated algae solution on the filter surface portion 216. The liquid in the first concentrated algae liquid contained on the filter surface portion 216 passes through the slit S by its own weight. As a result, the liquid is removed from the first concentrated algae solution.

The moving portion 220 includes a shaft 222 and a motor 224. The shaft 222 is connected to the center of the filter surface portion 216 (where the support members 214a and 214b intersect) and extends in the vertical direction (Z-axis direction in FIG. 3). The shaft 222 holds the accommodating portion 210 by inclining the filter surface portion 216 with respect to the horizontal plane (XY plane in FIG. 3). The inclination angle of the filter surface portion 216 is, for example, about 5 ° to 15 °.

The motor 224 rotates the shaft 222 (indicated by an arrow in FIG. 3). As the motor 224 rotates the shaft 222, the filter surface portion 216 (accommodating portion 210) rotates. The rotation speed of the shaft 222 by the motor 224 is, for example, about 10 rpm to 30 rpm.

As described above, the liquid of the first concentrated algae liquid contained on the filter surface portion 216 is removed as time elapses after being contained. That is, with the passage of time, the concentration of algae in the first concentrated algae solution increases. Then, a slurry composed of a plurality of algae is formed in the first concentrated algae solution. Since the slurry has lower fluidity than the liquid, it may adhere to a part of the filter surface portion 216. If the slurry adheres to the filter surface portion 216, the filter surface portion 216 will be clogged. Therefore, the moving portion 220 rotates the filter surface portion 216 to relatively move the slurry and the first concentrated algae liquid.

FIG. 4A is a first diagram illustrating the relative movement of the slurry and the first concentrated algae solution. FIG. 4B is a second diagram illustrating the relative movement of the slurry and the first concentrated algae solution. In FIGS. 4A and 4B, the first concentrated algae solution is shown by cross-hatching, and the slurry is shown by black circles. In FIGS. 4A and 4B, the support members 214a and 214b are omitted for easy understanding.

At the time ta shown in FIG. 4A, for example, it is assumed that the slurry fixed to the filter surface portion 216 is not immersed in the first concentrated algae solution. Then, when the accommodating portion 210 (filter surface portion 216) is rotated by the moving portion 220, the slurry fixed to the filter surface portion 216 is moved along with the rotation of the filter surface portion 216. Then, after the lapse of time ta + 1, as shown in FIG. 4 (b), the slurry is moved to the place where the first concentrated algae solution is stored. That is, the rotation of the accommodating portion 210 (filter surface portion 216) by the moving portion 220 causes the filter surface portion 216 to continuously come into contact with the first concentrated algae solution.

As a result, the slurry can be washed away with the first concentrated algae solution, and the adhesion between the slurry and the filter surface portion 216 can be released. Therefore, the liquid can be removed from the first concentrated algae solution by the filter surface portion 216 without causing clogging in the filter surface portion 216.

Further, when the shaft 222 tilts and holds the filter surface portion 216, the entire surface of the filter surface portion 216 and the first concentrated algae solution can be relatively moved. This makes it possible to eliminate the portion of the filter surface portion 216 where the slurry adheres. That is, clogging can be prevented on the entire surface of the filter surface portion 216.

As described above, the algae separation device 100 according to the present embodiment has a simple configuration in which the algae solution is stored in the filter surface portion 216 and the filter surface portion 216 and the algae solution are relatively moved to separate the algae from the algae solution. (Concentrate the algae solution). Therefore, it is possible to separate algae at a lower cost as compared with the conventional technique of concentrating algae using a flocculant. Moreover, since it is not necessary to add the coagulant, the treatment for removing the coagulant becomes unnecessary.

(Modification example: Second algae separation unit 320)
FIG. 5 is a diagram for explaining the second algae separation unit 320 of the modified example. As shown in FIG. 5, the second algae separation unit 320 includes a storage unit 210, a moving unit 220, and a liquid discharging unit 330. The components substantially the same as those of the second algae separation unit 120 described above are designated by the same reference numerals and the description thereof will be omitted.

The liquid discharge portion 330 is provided below the filter surface portion 216 of the accommodating portion 210. FIG. 6 is a diagram illustrating the configuration of the liquid discharge unit 330. As shown in FIG. 6, the liquid discharge portion 330 includes a bottom surface portion 340, a side surface portion 350, and a plurality of fins 360.

The bottom surface portion 340 is a disk-shaped member. A through hole 342 is formed in the center of the bottom surface portion 340. The through hole 342 has a circular shape concentric with the outer peripheral edge portion 344 of the bottom surface portion 340. The side surface portion 350 is a cylindrical member erected from the outer peripheral edge portion 344 of the bottom surface portion 340 to the filter surface portion 216 side. The side surface portion 350 is a cylinder concentric with the outer frame 212 of the accommodating portion 210. The upper end of the side surface portion 350 is connected to the lower end of the accommodating portion 210. Therefore, the liquid discharge unit 330 is rotated together with the accommodating unit 210 by the moving unit 220.

The fin 360 is a plate member provided on the bottom surface portion 340 and extending from the side surface portion 350 to the through hole 342. In this embodiment, eight fins 360 are provided. That is, in the liquid discharge portion 330, eight regions A to H partitioned by two adjacent fins 360, a bottom surface portion 340, and a side surface portion 350 are formed.

FIG. 7A is a first diagram illustrating the function of the liquid discharge unit 330. FIG. 7B is a second diagram illustrating the function of the liquid discharge unit 330. At time tb shown in FIG. 7A, it is assumed that the region A is arranged at the lowest position and the area E is arranged at the uppermost position. At this time, at least one fin 360 and the side surface portion 350 that partition the region D, the region E, and the region F are located above the through hole 342. Therefore, among the liquids that have fallen from the slit S formed in the filter surface portion 216 of the accommodating portion 210, the liquids that have fallen into the regions D, E, and F flow downward through the through holes 342.

On the other hand, at the time tb shown in FIG. 7A, at least one fin 360 or the side surface portion 350 for partitioning the region G, the region H, the region A, the region B, and the region C is located below the through hole 342. To do. Therefore, the liquid that has fallen from the slit S is stored in the region G, the region H, the region A, the region B, and the region C (indicated by cross-hatching in FIG. 7A).

Then, the liquid discharging unit 330 (accommodating unit 210) is rotated by the moving unit 220, and after the time tb + 1 elapses from FIG. 7A, the region H is arranged at the lowest position as shown in FIG. 7B. It is assumed that the region D is arranged at the uppermost position. Then, the liquid stored in the region C at time tb flows downward through the through hole 342 (indicated by a white arrow in FIG. 7B). Similarly, a part of the liquid stored in the region B flows downward through the through hole 342 (indicated by a white arrow in FIG. 7B).

As described above, with the configuration including the liquid discharge portion 330, the liquid that has fallen from the slit S of the filter surface portion 216 can be discharged only from the through hole 342. As a result, it is possible to reliably avoid the situation where the liquid separated from the first algae concentrate is mixed in the algae recovery tank 130.

Although the embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to the above embodiments. It is clear to those skilled in the art that various modifications or modifications can be conceived within the scope of the claims, and it is understood that they also naturally belong to the technical scope of the present disclosure. Will be done.

For example, in the above embodiment, the case where the screen 112 and the accommodating portion 210 (outer frame 212, support members 214a, 214b, filter surface portion 216) are made of stainless steel has been described as an example. However, the material of the screen and the accommodating portion (filter surface portion) is not limited. Further, the surfaces of the screen and the accommodating portion (filter surface portion) may be coated to prevent corrosion of the main body portion.

Further, in the above embodiment, a rectangular slit S has been described as an example as a through hole provided in the screen main body 112a. However, the shape of the through hole is not limited. Further, the size of the through hole is preferably smaller than the minimum particle size of the algae (or colonies), but the size of at least one through hole may be smaller than the minimum particle size of the algae.

Further, in the above embodiment, the case where the widths of all the slits S are smaller than the minimum particle size of the algae has been described as an example. However, the width of at least one slit S may be less than the minimum particle size of algae. Further, in the above embodiment, the case where the slit S formed in the screen main body portion 112a and the slit S formed in the filter surface portion 216 have the same shape has been described as an example. However, the two may have different shapes. In any case, the screen main body portion 112a and the filter surface portion 216 may be formed with a plurality of through holes through which algae cannot pass or cannot pass.

Further, in the above embodiment, the case where the filter surface portion 216 has a disk shape has been described as an example. However, the shape of the filter surface portion 216 is not limited. For example, the filter surface portion 216 may have a polygonal planar shape, an elliptical planar shape, or a U-shape.

Further, in the above embodiment, the configuration in which the shaft 222 of the moving portion 220 is connected to the center of the filter surface portion 216 has been described as an example. However, the connection position between the shaft 222 and the filter surface portion 216 is not limited. The moving portion 220 may move the filter surface portion 216 and the algae solution relative to each other by rotating the filter surface portion 216.

Further, the moving portion does not have to rotate the filter surface portion 216. At least the moving portion may move the filter surface portion 216 and the algae liquid relative to each other. For example, the moving portion may reciprocate the filter surface portion 216 in the horizontal direction.

Further, in the above embodiment, the configuration in which the liquid discharge unit 330 is connected to the storage unit 210 (outer frame 212) has been described as an example. However, the liquid discharge unit 330 may be connected to the shaft 222.

Further, in the above embodiment, the configuration in which the algae separation device 100 includes the first algae separation unit 110 has been described as an example. However, the first algae separation unit 110 is not an essential configuration. For example, the algae solution may be directly supplied from the culture tank 10 to the storage unit 210.

Further, in the above embodiment, the configuration in which the algae separation device 100 includes one second algae separation unit 120 has been described as an example. However, the algae separation device 100 may include two or more second algae separation units 120. For example, the algae solution concentrated in one second algae separation unit 120 may be further concentrated in another second algae separation unit 120.

Further, in the above embodiment, Botryococcus as an example of the algae separated by the algae separating device 100 has been described. However, the algae are not limited, and may be, for example, microalgae such as spirulina or algae other than microalgae.

The present disclosure can be used for an algae separator that separates algae from an algae solution containing algae.

S slit (through hole)
100 Algae Separator 112 Screen 112a Screen body 114 Injection 210 Storage 216 Filter surface 220 Moving 222 Shaft 224 Motor 330 Liquid drain 340 Bottom 342 Through hole 350 Side 360 Fins

Claims (3)

It has a planar shape with through holes formed, has a filter surface portion that is held at an angle with respect to a horizontal plane, and has an accommodating portion for accommodating algae liquid containing algae on the filter surface portion.
A moving part that rotates the filter surface part and
Algae separator equipped with. A bottom surface portion provided below the filter surface portion and having a through hole formed in the center, a side surface portion erected from the bottom surface portion to the filter surface portion side, and a side surface portion provided on the bottom surface portion and penetrating from the side surface portion. algae separation apparatus according to claim 1, further comprising a liquid discharge portion having a plurality of fins extending up to the hole, the. A screen body with through holes that penetrate from the front to the back,
An injection unit that injects the algae liquid toward the surface of the screen body, and an injection unit.
With
The algae separation device according to claim 1 or 2 , wherein the algae liquid flowing down from the screen main body is housed in the storage part.

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