JP2022012441A - Microbial culture system - Google Patents

Abstract

To provide systems in which multiple containers are arranged side by side in the height direction of a structure, it is not necessary to have a strong structure that can suppress the hydraulic pressure even if the containers are connected, and it is possible to use inexpensive materials with low strength.SOLUTION: A microbial culture system is installed so as to be adjacent to or next to the outer wall surface or slope of a structure, or to be arranged in the height direction of the structure as the outer wall itself of the structure, and comprises multiple containers (reactors) 10 for accommodating culture medium containing microorganisms, an adjusting tank 11 for adjusting a culture solution to a predetermined condition, and a pump 12 for the adjusting tank that supplies the culture solution adjusted in the adjusting tank to the reactor 10 arranged at the top. Each reactor 10 overflows the culture solution at a predetermined liquid level and supplies the culture solution to the connected reactor 10 one step below or the adjusting tank 11.SELECTED DRAWING: Figure 1

Description

Application for application of Article 30, Paragraph 2 of the Patent Act was announced on July 2, 1991 at IWAlgae 2019 sponsored by The International Water Association.

The present invention relates to a culture system for microorganisms that perform photosynthesis.

Microalgaes known as photosynthetic microorganisms are widely used as health foods, cosmetics, natural colorants, feeds, feeds, fuels, biomaterials and the like. As a culture system (bioreactor) for culturing microalgae, a plate-type bioreactor having a transparent or translucent plate-shaped housing that can be used as an outer wall material of a building is known (see, for example, Patent Document 1). ).

European Patent Application Publication No. 2533627

A structure constructed in a narrow space such as an urban area extends in the height direction, and the above-mentioned plate-shaped plurality of containers (reactors) can be arranged side by side in the height direction of the structure to connect the containers. can.

However, when a plurality of containers are arranged side by side in the height direction of the structure and the containers are connected to each other, the hydraulic load applied to the containers increases as the arranged position becomes lower, resulting in a strong structure that can withstand the hydraulic pressure. There was a problem that I had to.

The present invention is a culture system for microorganisms that perform photosynthesis in view of the above problems.
A plurality of containers that are installed adjacent to or adjacent to the outer wall surface or slope of the structure, or arranged so as to be arranged in the height direction of the structure as the outer wall itself of the structure, and contain a culture solution containing microorganisms.
An adjustment tank for adjusting the culture solution to the specified conditions, and
Including a liquid supply means for supplying the culture liquid prepared in the adjustment tank to the container arranged at the top.
A microbial culture system is provided in which each container overflows the culture solution at a predetermined liquid level and supplies the culture solution to a connected lower container or adjustment tank.

According to the present invention, even if a plurality of containers are arranged side by side in the height direction of the structure and the containers are connected to each other, it is not necessary to have a strong structure in which the hydraulic pressure is suppressed, and the material is low in strength and inexpensive. Can be used.

The figure which showed the structural example of the culture system of microorganisms. The figure which showed the example of the place where the culture system is installed. The figure explaining the flow of the culture medium in each reactor. The figure which showed the example which arranged the Low-E single-layer glass in the front surface of a reactor. The figure which showed the example which arranged the Low-E double glazing in front of the reactor. The figure explaining the method of reversing the direction of the Low-E double glazing. The figure explaining the pipe connecting between reactors. The figure which showed the structure which attached the air filter to the pipe. The figure explaining the method of supplying air from an air pump. The figure which showed the result of the water pressure test. The figure which showed the measurement result of the temperature of the adjustment tank, the temperature, and the temperature in each reactor during the daytime in summer. The figure which showed the structure of the Low-E double glazing. The figure explaining the measurement position of a light intensity and a temperature. The figure which showed the measurement result of the light intensity. The figure which showed the measurement result of the temperature and the absorbance in a reactor.

FIG. 1 is a diagram showing a configuration example of a culture system. The culture system is a system for culturing microorganisms that perform photosynthesis (hereinafter, simply referred to as microorganisms). The culture system includes a plurality of containers (reactors) 10, a adjusting tank 11 for adjusting the culture solution necessary for culturing microorganisms to predetermined conditions, and a adjusting tank pump 12 for supplying the culture solution.

Examples of microorganisms include microalgae and cyanobacteria. Since these microorganisms have a high growth rate, they are attracting attention in the immobilization of CO ₂ and the production of useful substances. Examples of useful substances include health food raw materials, cosmetic raw materials, natural colorant raw materials, feed raw materials, feed raw materials, biofuel raw materials, biomaterial raw materials and the like.

Microalgaes and cyanobacteria are phytoplankton such as chlorella and spirulina. For example, astaxanthin (red pigment) used in cosmetics is industrially produced using hematococcus, which is one of the microalgaes. The blue pigment used in health foods is industrially produced using spirulina, one of the cyanobacteria.

These microorganisms receive sunlight in the culture medium, absorb CO ₂ to perform photosynthesis, and proliferate. The culture broth is a suspension of microorganisms in a medium containing water and nutrients that serve as nutrients for the microorganisms. Nutrients include nitrogen, phosphorus, sulfur, inorganic metal ions (K ⁺ , Mg ²⁺ , Fe ²⁺ , Mn ²⁺ , etc.) and the like.

The culture solution containing microorganisms is supplied with CO ₂ gas in the adjusting tank 11 and adjusted to a predetermined CO ₂ concentration. A CO ₂ cylinder 13 for supplying CO ₂ gas is connected to the adjusting tank 11. The pH of the culture solution can be adjusted to 5 to 10, which is suitable for the growth of microorganisms, by using CO ₂ gas, hydrochloric acid, sodium hydroxide and the like. The oxygen concentration of the culture solution can be adjusted to a concentration suitable for the growth of microorganisms (300% air saturation or less) by aerating a gas such as air.

The culture solution containing the microorganism is adjusted to a predetermined temperature in the adjusting tank 11. The adjusting tank 11 includes a heater 14 and a cooler 15 for adjusting the temperature. The temperature of the culture broth is adjusted to a temperature range (15 to 35 ° C.) suitable for the growth of microorganisms.

The adjusting tank 11 includes a nozzle 16 for blowing air and an air pump 17 connected to the nozzle 16 in order to make the CO ₂ concentration, nutrients and temperature in the culture solution uniform. By blowing air from the nozzle 16, the culture solution is bubbled and stirred. Air agitates the culture medium and removes oxygen that inhibits photosynthesis of microorganisms. The amount of air blown into the adjusting tank 11 can be adjusted by controlling the amount of air discharged from the air pump 17. The oxygen concentration of the culture solution can be adjusted by adjusting the amount of air blown. The air discharge amount can be adjusted by a valve provided in the discharge line of the air pump 17.

The reactor 10 is a thin plate-type reactor composed of a back plate, a transparent or translucent front plate, and four side plates continuous with the back plate and the front plate. The back plate and the side plate may not be transparent or translucent, and may be concrete, a metal plate, or the like. The sizes of the back plate and the front plate may be the same or different. The reactor 10 may be a cylindrical column type or tube type reactor. However, since the column type has a depth, there are some parts where the sunlight does not reach easily, and the tube type has a large flow resistance when the length is long, so a plate type reactor is desirable.

The reactor 10 forms a closed space with a back plate, a front plate, and four side plates, and the culture solution containing microorganisms is housed in the closed space. The reactor 10 is provided with a nozzle 18 and an air pump 19 as in the adjusting tank 11 in order to agitate the contained culture solution, supply CO ₂ and remove oxygen.

The reactor 10 is provided with an air vent valve 20 for discharging the air to the outside because the blown air stays in the upper space and the pressure in the reactor 10 rises.

The plurality of reactors 10 are installed near or adjacent to the outer wall surface of a structure constructed in a narrow space such as an urban area. The structure is a building or the like having an outer wall surface extending in the vertical direction. FIG. 2 shows an example in which a plurality of reactors 10 are hung on a portion protruding from an outer wall surface 70 of a structure such as a building and installed so as to hang down. Here, the building is taken as an example, but the present invention is not limited to this. As shown in FIG. 2, it may be installed near or adjacent to the slope 28 or the roof 29 of a natural structure such as a hill. The plurality of reactors 10 can also be used as the outer wall itself of the structure. Here, it will be described as being installed in the vicinity of the outer wall surface of the structure.

With reference to FIG. 1 again, the plurality of reactors 10 are installed side by side in the height direction of the structure, and the reactors 10 are connected by a pipe 21.

The culture solution in the adjusting tank 11 is appropriately supplied to the uppermost reactor 10 by the adjusting tank pump 12. Therefore, the culture solution is intermittently supplied to the uppermost reactor 10, and it is necessary to repeatedly start and stop the adjustment tank pump 12. If the adjustment tank pump 12 is repeatedly started and stopped, it may cause a pump failure. Therefore, an elevated water tank 22 that acts as a buffer can be installed on the roof of the structure, the culture solution can be supplied to the elevated water tank 22 by the adjusting tank pump 12, and the culture solution can be appropriately supplied from the elevated water tank 22. ..

The elevated water tank 22 is connected to the uppermost reactor 10 by a pipe 21 via a supply valve 23 provided at the bottom of the elevated water tank 22. The elevated water tank 22 appropriately opens the supply valve 23 to supply the culture solution to the uppermost reactor 10. By adjusting the opening degree of the supply valve 23, the amount of the culture solution to be supplied can be adjusted. The frequency of liquid feeding to the elevated water tank 22 can be adjusted based on the liquid level of the elevated water tank 22. A heat insulating material is provided around the elevated water tank 22, and the temperature of the culture solution can be kept constant.

Each reactor 10 is connected to a pipe 21 on the supply side so that the culture solution is supplied downward from the reactor 10 on the upper stage or the elevated water tank 22. Further, in each reactor 10, a pipe 21 on the discharge side is connected so as to overflow the culture solution at a predetermined liquid level and supply it to the reactor 10 or the adjusting tank 11 one step below to be connected.

As a result, one system is formed by passing through the adjusting tank 11, the elevated water tank 22, and each reactor 10 in order and returning to the adjusting tank 11, and the culture solution circulates in the system. The inside of the system is a closed space, and the invasion of other microorganisms from the outside is suppressed.

Microorganisms stay in each reactor 10 for a certain period of time. Since the front plate of each reactor 10 on the side exposed to the sunlight is transparent or translucent, the sunlight is incident into each reactor 10. Therefore, the microorganisms photosynthesize and proliferate in each reactor 10.

A recovery tank 24 is provided one step below the adjustment tank 11. The adjustment tank 11 and the recovery tank 24 are connected via a recovery valve 25, and by opening the recovery valve 25 as appropriate, a part of the culture solution containing the microorganisms that have grown from the adjustment tank 11 to the recovery tank 24 is collected. Microorganisms are separated and recovered from the culture medium using separation processes such as precipitation and filtration.

When a part of the culture solution is recovered in the recovery tank 24, the amount of the culture solution in the adjustment tank 11 decreases. Therefore, a replenishment tank 26 is provided to replenish the reduced amount of the culture solution. The replenishment tank 26 replenishes the adjustment tank 11 with the amount of medium reduced by recovery. The supply tank 26 stores only the medium. A replenishment pump 27 is provided to supply the medium from the replenishment tank 26.

With reference to FIG. 3, how the culture broth flows in each reactor 10 will be described. In FIG. 3, two reactors 10a and 10b arranged in two stages in the height direction of the structure are connected by a pipe 21b. Here, the reactor 10 has two stages for ease of explanation. A tube 21a on the supply side of the culture solution and a tube 21b on the discharge side of the culture solution are connected to the upper reactor 10a. A tube 21b on the discharge side of the upper reactor 10a is connected to the lower reactor 10b as a tube on the supply side of the culture solution, and a tube 21c on the discharge side of the culture solution is connected.

The tube 21a is connected to the side surface adjacent to the bottom of the upper reactor 10a and supplies the culture solution to the bottom of the upper reactor 10a. The tube 21b is connected to the side surface close to the top of the upper reactor 10a, and the culture solution near the liquid surface of the upper reactor 10a is discharged by overflow. The distance from the bottom in the upper reactor 10a to the bottom of the flow path portion of the cross section of the tube 21b is the liquid level height H of the culture solution in the upper reactor 10a.

The culture solution to the upper reactor 10a is appropriately supplied. The pipe 21a extends downward from the side surface of the upper reactor 10a along the side surface of the upper reactor 10a, and the liquid level height in the pipe 21a is substantially the same as the liquid level height in the upper reactor 10a. It becomes the height.

The pipes 21b and 21c are also connected to the lower reactor 10b at the same height as the upper reactor 10a. Therefore, the culture solution overflowing in the upper reactor 10a is supplied to the bottom of the lower reactor 10b through the tube 21b. Then, the culture solution overflowing in the lower reactor 10b is supplied to the lower reactor or the adjusting tank 11 through the tube 21c. The liquid level in the pipe 21b is substantially the same as the liquid level in the lower reactor 10b.

A cavity is formed by air in the pipe 21b connecting the upper reactor 10a and the lower reactor 10b, and the cavity separates the upper reactor 10a and the lower reactor 10b. Therefore, the hydraulic pressure applied to each reactor 10 depends only on the liquid level height H in each reactor 10.

In this system, the liquid level height of each reactor 10a and 10b is lowered to reduce the liquid pressure applied to each reactor 10. As a result, inexpensive members having low pressure resistance such as single-layer glass and plastic bags can be used for high-rise and large-scale reactors configured by arranging them in the height direction.

If it becomes possible to use plastic bags and the like, it will be possible to realize high-rise and large-scale systems with free shapes. In addition, since it can be installed near or adjacent to the outer wall surface or slope of the structure, or used as the outer wall itself, the free shape of the wall surface or slope can be used, and the visual design can be improved. .. Furthermore, since they are installed side by side in the height direction of the structure, it is possible to produce microorganisms using light energy even in a dense area such as an urban area.

In the configuration in which a plurality of reactors 10 shown in FIG. 1 are installed side by side in the height direction of the structure and the reactors 10 are connected to each other, infrared light is also incident on the culture solution in the reactor 10 as light from the sun. .. Then, the infrared light transfers heat to the culture solution, and the temperature of the culture solution rises. Although the adjusting tank 11 is provided with a heater 14 and a cooler 15, it is not possible to sufficiently cool the culture solution in the summer when the sunlight radiation is strong. Further, since the reactor 10 is a plate type, the specific surface area is large and the heat dissipation rate is high. Therefore, in winter when the outside air temperature is low, a large amount of energy is required for temperature control.

Therefore, a special material that selectively transmits only visible light necessary for photosynthesis and reflects or absorbs infrared light that causes heat is used to obtain a heat retaining effect.

FIG. 4 is a diagram showing an example in which a covering member provided with an infrared light reflecting material or an infrared light absorbing material as a special material is arranged on the front surface away from the reactor 10. Hereinafter, an infrared light reflecting material will be used, the infrared light reflecting material will be referred to as a Low-E (Low Emissivity) film, and a transparent or translucent member provided with the Low-E film will be described as glass. The Low-E film portion may be an infrared light absorbing film, and the transparent or translucent member is not limited to glass, and may be an acrylic plate, a film, or the like.

In FIG. 4A, the Low-E single layer glass 30 is arranged in front of the reactor 10. Here, the front surface is the side (outside) of the reactor 10 exposed to the sunlight. The Low-E single-layer glass 30 is arranged with the glass 31 on the outside and the Low-E film 32 facing the reactor 10 and separated from the reactor 10 by a certain distance using a support member or the like.

Sunlight includes infrared light and visible light. Most of the infrared light is reflected by the Low-E film 32, and a part of it is transmitted. Most of the visible light passes through the Low-E film 32. A gap 33 is provided between the reactor 10 and the Low-E single-layer glass 30, and air flows through the gap 33. Since the heat generated by a part of the infrared light transmitted through the Low-E film 32 is transferred to the flowing air, the heat input to the reactor 10 is suppressed.

As the material of the Low-E film 32, silver, chromium, copper, titanium, platinum, gold, zinc, tin oxide and the like can be used. The Low-E film 32 may be a multilayer film in which these metals are laminated. It should be noted that these materials are examples, and are not limited to these materials as long as they can transmit visible light and reflect infrared light. The Low-E single-layer glass 30 can be produced by coating the glass surface with the above-mentioned special metal film such as silver.

In the summer when sunlight radiation is strong, infrared light is reflected and heat input into the reactor 10 is suppressed by the air flow flowing through the gap 33, so that the temperature adjustment by the cooler 15 provided in the adjusting tank 11 is sufficient. The temperature of the culture broth inside can be maintained within a predetermined range.

Further, even in winter when the outside air temperature is low, the Low-E single-layer glass 30 prevents the reactor 10 from coming into direct contact with the outside air, so that heat dissipation from the culture solution in the reactor 10 can be suppressed. As shown in FIG. 4B, a closing member 34 straddling the Low-E single-layer glass 30 and the reactor 10 can be provided to stop the air flow. As a result, a heat retaining effect can be obtained by the air layer 35 interposed between the Low-E single-layer glass 30 and the reactor 10, and heat dissipation from the culture solution in the reactor 10 can be suppressed more effectively. Since the air layer 35 has a low thermal conductivity, it functions as a heat insulating material or a heat insulating material.

The reactor 10 may be provided with a storage portion that allows the closing member 34 to be taken in and out, for example, on the upper surface and the bottom surface. In the summer, the closing member 34 is stored in the storage portion to open the gap 33 so that air can flow. In the winter, the closing member 34 is pulled out from the storage portion and the upper and lower portions of the gap 33 are closed. The air layer 35 can be formed. It should be noted that such a configuration is an example, and any configuration may be used as long as the upper and lower portions of the gap 33 can be opened and closed by the closing member 34.

The culture solution emits infrared light when it dissipates heat. The infrared light is reflected by the Low-E film 32 and returns to the culture solution. Therefore, the heat radiation from the culture solution is also suppressed by the Low-E membrane 32. Since heat is also dissipated from the structure side of the reactor 10, a heat insulating material 36 such as glass wool or rock wool can be provided on the structure side. The heat insulating material 36 may be attached only in winter or may remain attached all year round.

By adopting a configuration in which the Low-E single-layer glass 30 is arranged at a distance from the front surface of the reactor 10, the cost of temperature control can be significantly reduced, and it is possible to realize culture throughout the year. Become. In addition, by adopting this configuration, the applicable range of the installation area can be expanded. Depending on the climate of the installation area, only the summer type without the closing member 34 and the winter type with the closing member 34 may be installed.

Although it is possible to maintain the temperature of the culture solution in the system within a predetermined temperature range even by using the Low-E single-layer glass 30, a configuration for maintaining the temperature more effectively is described with reference to FIG. I will explain.

FIG. 5 is a diagram showing an example in which the Low-E double glazing 40 is arranged in front of the reactor 10 instead of the Low-E single glazing 30 shown in FIG. The Low-E double glazing 40 is provided with a glass 43 facing the Low-E film 42 of the Low-E single glazing 41, and air is provided in a sealed space between the Low-E single glazing 41 and the glass 43. It has a layer 44. Since the air layer 44 has no air flow and low thermal conductivity, it suppresses heat input to the reactor 10 and suppresses heat dissipation from the culture solution to the outside. Since the thermal conductivity increases when a large amount of water is contained in the air, a hygroscopic material such as silica gel is sealed in the air layer 44 in order to reduce the water content in the air.

In the summer, the Low-E film 42 reflects infrared light, so that heat input to the reactor 10 can be suppressed. Further, since the air layer 44 also suppresses heat input, the temperature of the reactor 10 can be more effectively maintained in a predetermined temperature range.

In winter, the outside temperature is low, the plate-type reactor has a large specific surface area, and it is easy to dissipate heat. Therefore, it is desirable to take in infrared light as much as possible. However, the Low-E film 42 reflects infrared light. Infrared light emitted from the reactor 10 escapes to the outside.

Therefore, in winter, the orientation of the Low-E double glazing 40 can be reversed. As a result, the Low-E single-layer glass 41 is located at a position facing the reactor 10, so that it is possible to take in infrared light, and by reflecting the infrared light that escapes to the outside, the temperature of the culture solution even in winter. Can be maintained within a predetermined temperature range.

As a method of reversing the direction of the Low-E double glazing 40, a method of providing a rotation shaft 45 at the center in the width direction of the Low-E double glazing 40 as shown in FIG. 6 and rotating the low-E double glazing 40 around the rotation shaft 45. Can be given as an example. When the Low-E double glazing 40 has a width covering the entire front surface of the reactor 10, it cannot be rotated unless it is arranged away from the reactor 10 because the width is wide.

Therefore, the Low-E double glazing 40 can be divided into a plurality of pieces in the width direction, and the rotation shaft 45 can be provided on each of the divided Low-E double glazing 40s and can be individually rotated. The rotation of the rotating shaft 45 may be performed manually, or may be performed automatically by attaching a motor or the like. Further, the rotation shaft 45 is not limited to the center in the width direction of the Low-E double glazing 40, and may be the center in the height direction.

It should be noted that the Low-E film 42 may be installed on both inner surfaces of the double glazing to realize heat insulation and heat retention in both summer and winter without reversing the orientation.

FIG. 7 is a diagram illustrating a pipe 21 connecting the reactors 10. The tube 21 supplies the overflowing culture medium from the upper reactor 10a to the lower reactor 10b. When a thin tube having a diameter of several mm is used, the air staying in the upper part of the reactor 10 enters the tube, and when the overflowed culture solution flows into the tube, the air remains as bubbles in the tube 21. become.

When the culture solution flows into the tube 21 from the upper reactor 10a as shown in FIG. 7A when the bubble 50 does not exist in the tube 21, the liquid level in the tube 21 rises and the inside of the tube 21 The culture solution flows from the inside of the pipe 21 into the lower reactor 10b so that the liquid level in the lower reactor 10b is almost the same height. That is, when a predetermined amount of the culture solution flows into the tube 21, the same amount of the culture solution flows to the lower reactor 10b. Therefore, the culture solution circulates smoothly in the system.

On the other hand, when the bubbles 50 are present in the tube 21, even if a predetermined amount of the culture solution flows into the tube 21 from the upper reactor 10a as shown in FIG. 7B, the bubbles 50 are deformed and the culture solution is formed. The liquid level does not rise by the amount of flow. More specifically, the buoyancy of air exceeds the flow force of the liquid (a function of weight or resistance), so that the inflow of the liquid is stopped. Therefore, even if the culture solution flows from the inside of the tube 21 into the lower reactor 10b so that the liquid levels in the tube 21 and the lower reactor 10b are the same height, the amount is not a predetermined amount. , Less than this. In this case, the culture solution cannot be circulated smoothly.

Therefore, as shown in FIG. 7C, the diameter of the tube 21 can be increased so that even if air enters the tube 21 and the overflowing culture solution flows into the tube 21, the air escapes from the tube 21. can. When the diameter of the tube 21 is several mm, it can be several cm because air does not escape. The diameter of the tube 21 can be determined according to the amount of the overflowing culture medium.

For example, when the flow rate of the culture solution is 6 to 8 L / min, if the diameter is determined so that the flow rate is 0.4 to 0.6 m / s, air escapes from the inside of the pipe 21 and flows normally. Therefore, if the flow rate is within the above range, for example, a pipe 21 having an inner diameter D of 13 mm can be used as the pipe 21 extending in the vertical direction. Since the portion extending in the vertical direction may be a pipe having an inner diameter of 13 mm, the portion extending in the horizontal direction connected to the reactor 10 may have an inner diameter D smaller than 13 mm, the same diameter, or a larger portion. When pipes having different diameters are connected and used, they can be connected by using a socket. An example thereof is enlarged and shown in FIG. 7 (c).

FIG. 8 is a diagram showing a configuration in which the air filter 51 is attached to the pipe 21. It is desirable that the inside of the system in which the culture solution circulates is a closed space so that other microorganisms and the like existing in the outside air do not invade. The air supplied to each reactor 10 by the air pump 19 is discharged to the outside by the air vent valve 20 after stirring the culture solution in each reactor 10. At this time, since the liquid level sways due to the stirring of the culture liquid, the entire connection portion connected to the tube 21 may be below the liquid level. When the connection portion is below the liquid level, there is no way for air to escape from the pipe 21, so that an air filter 51 can be attached to allow air to escape from the air filter 51. As a result, the flow of the culture solution from the reactor 10 to the tube 21 can be smoothly performed.

In order to let the air escape, only the open portion needs to be provided, but there is a problem that other microorganisms and the like invade from the outside only in the open portion. Therefore, it is possible to install an air filter 51 capable of circulating only air while preventing the invasion of other microorganisms from the outside.

The air filter 51 can be provided on the upper side of the horizontally extending portion of the tube 21 on the discharge side of the culture solution of each reactor 10. Here, an example of attaching to the pipe 21 on the discharge side is shown, but the present invention is not limited to this, and it extends in the vertical direction of the pipe 21 because it may be other than the portion where the culture solution is accumulated in the pipe 21. It may be provided at a position higher than the liquid level of the portion.

FIG. 9 is a diagram illustrating a method of supplying air from the air pump 19. The reactor 10 and the air pump 19 can be connected by using a pipe 52 as shown in FIG. 9A. The same method can be adopted when supplying air from the air pump 17 to the adjusting tank 11.

A check valve 53 is provided in the middle of the pipe 52 on the discharge side of the air pump 19. As a result, the sucked air can be compressed and discharged and supplied to the reactor 10 while suppressing the inflow of the culture solution of the reactor 10 into the air pump 19.

However, if the check valve is damaged for some reason, or if the check valve leaks, the culture solution flows into the air pump 19, and the air cannot be compressed and discharged.

Therefore, as shown in FIG. 9B, the pipe 52 connecting the reactor 10 and the air pump 19 can be formed in a U-shape once raised to a position higher than the liquid level. In the tube 52, since the horizontally extending rising portion 54 at the highest position is located at a position higher than the liquid level in the reactor 10, it is possible to prevent the culture solution from flowing back through the rising portion 54. can. Even when the pipe 52 having such a riser portion 54 is used, the check valve 53 can be used.

Actually, the water pressure applied to each reactor 10 was tested using this system. In the test, water was used instead of the culture solution, and as shown in FIG. 1, a device in which plate-type reactors were arranged in three stages in the height direction and connected to each other by a tube was used. The height of the devices arranged in three stages was about 11 m.

FIG. 10 shows the results of the water pressure test. For comparison, the results of a system in which conventional reactors are simply connected in series in the height direction are also shown. The conventional system is a system in which the bottom of the top reactor and the top of the middle reactor are connected, and the bottom of the middle reactor and the top of the bottom reactor are connected to each other.

The conventional system is indicated by "Direct connection", and the reactor at the top has a head of 2.8 m in which the energy of water is replaced with the height of the water column, and a water pressure of 0.028 MPa is applied. Since the middle-stage reactor is continuous to the water surface of the uppermost reactor, the head is 6.2 m and a water pressure of 0.062 MPa is applied. Since the lowermost reactor is continuous to the water surface of the uppermost reactor via the middle stage reactor, the head is as long as 9.6 m and a water pressure of 0.096 MPa is applied.

On the other hand, this system is indicated by "Overflow", and the head of each of the top, middle, and bottom reactors was 2.8 m, and the water pressure was only about 0.03 MPa. Further, the "Deflection" representing the deflection was about 6 mm, which was sufficiently smaller than 15 to 20 mm, which may be damaged. From this result, even if a plurality of reactors 10 are arranged side by side in the height direction of the structure and the reactors 10 are connected to each other, it is not necessary to form a strong structure, and it is possible to use an inexpensive material having low strength. I was able to confirm that it would be.

The adjusting tank 11 provided with the cooler 15 was operated, and the temperature, the air temperature, and the temperature in each reactor 10 of the adjusting tank 11 during the summer day were measured. FIG. 11 is a diagram showing the measurement results. The horizontal axis shows the measurement date, and the vertical axis shows the measured temperature (° C). The measurement dates are all 2019.

The temperature of the adjusting tank 11 is controlled by the cooler 15 and is kept substantially constant at about 30 ° C. On the other hand, the temperature in the middle reactor and the temperature in the lower reactor exceeded 45 ° C. when the temperature increased. Since microalgae cannot survive above 40 ° C, it was found that some temperature adjustment is required in each reactor 10 in the summer when the temperature is high.

Therefore, the Low-E single glazing 30 and the Low-E double glazing 40 shown in FIGS. 4 and 5 were installed, and the heat shielding effect thereof was verified. For verification, Low-E double glazing 40 having the configuration shown in FIG. 12 was used, chlorella (Chlorella sorokiniana NIES-2173) was used as a microorganism, and C medium was used as a medium. The temperature was room temperature, and two halogen lamps of 500 kW were used as the light source.

In the Low-E double glazing 40, the Low-E film 62 is provided on one of the two glasses 60 and 61, and the glass 60 provided with the Low-E film 62 and the glass 61 are fixed by the spacer 63. Arranged at intervals. Air is sealed between the glass 60 and the glass 61. It is sealed with a sealing material so that air does not escape, and a hygroscopic material 64 is sealed to remove moisture in the air.

The Low-E double glazing 40 used had a transmittance of 70.5% for visible light, 36.9% for solar radiation of all wavelengths including infrared light, and 18.5% for ultraviolet light.

As shown in FIG. 13, the verification was performed with or without the Low-E double glazing 40, and the light intensity of visible light was measured at the positions (1) to (3) and (5) indicated by the arrows. FIG. 14 shows the measurement result of the light intensity. On the front surface (position (1)) of the Low-E double glazing 40, 1350 μmol photos / m ² / s, and on the back surface (position (2)) of the Low-E double glazing 40, 840 μmol photos / m ² / s. Was measured. Further, on the surface of the reactor 10 (position (3)), it was measured as 600 μmol photons / m ² / s. On the other hand, on the surface (position (5)) of the reactor 10 without the Low-E double glazing 40, it was measured as 838 μmol photos / m ² / s. It was confirmed that the low-E double glazing 40 had a lower light intensity of about 30% and a visible light transmittance of about 70%.

FIG. 15 is a diagram showing the temperature measured at the positions of the arrows (1), (3), (4), (5), and (6) shown in FIG. 13 and the absorbance (OD750) at a wavelength of 750 nm. Absorbance is a dimensionless quantity that indicates how much the intensity weakens as light passes through. Absorbance was measured using a spectrophotometer.

When there is the Low-E double glazing 40, the temperature of about 60 ° C. continues on the surface (position (1)) of the Low-E double glazing 40, but the temperature in the reactor 10 (position (4)) is high. It was possible to keep the temperature below 35 ° C throughout 5 days. As shown in the result of OD750, the microalgae had an absorbance of 3 times or more, grew well, and a high specific growth rate of 1d ^-1 or more was obtained. The specific growth rate is a doubling of the unit time.

In the absence of the Low-E double glazing 40, the temperature (position (6)) in the reactor 10 exceeded 45 ° C. in about 2 hours and was maintained at a temperature of about 50 ° C. It was suggested that the microalgae in the reactor 10 became cloudy and died because the temperature exceeded 40 ° C.

From these results, the effectiveness of the infrared reflective material such as Low-E double glazing 40 in culturing microorganisms was shown.

According to this system, the width (horizontal length) of each reactor 10 is increased, the length in the height direction (vertical direction or inclined direction) of the structure is shortened, and they are connected in the height direction. By doing so, it is possible to realize a large-capacity reactor even in a narrow space such as an urban area. In addition, the wall surface of a structure extending in the height direction such as a building can be efficiently used.

Since the hydraulic pressure applied to the reactor 10 is small, the reactor 10 can be formed of a single-layer glass or a plastic bag having a low pressure resistance, and maintenance is facilitated. Further, the front surface of the reactor 10 can be covered with a heat insulating material such as Low-E double glazing 40, so that the reactor 10 is less likely to get dirty and deterioration due to ultraviolet rays can be prevented. Therefore, it is maintenance-free and can be used cleanly for a long period of time as compared with a normal bag reactor. The reactor 10 forms various patterns due to the growth of microorganisms and can be used as a wall surface design.

Although the microorganism culture system of the present invention has been described in detail with the above-described embodiments, the present invention is not limited to the above-mentioned embodiments, and other embodiments, additions, changes, deletions, etc. , It can be changed within the range that can be conceived by those skilled in the art, and it is included in the scope of the present invention as long as the action / effect of the present invention is exhibited in any of the embodiments.

10, 10a, 10b ... Reactor 11 ... Adjustment tank 12 ... Adjustment tank pump 13 ... CO ₂ bomb 14 ... Heater 15 ... Cooler 16, 18 ... Nozzle 17, 19 ... Air pump 20 ... Air vent valve 21, 21a, 21b, 21c , 52, 54 ... Pipe 22 ... Elevated water tank 23 ... Supply valve 24 ... Recovery tank 25 ... Recovery valve 26 ... Supply tank 27 ... Supply pump 28 ... Slope 29 ... Roof 30, 41 ... Low-E single-layer glass 31, 43, 60, 61 ... Glass 32, 42, 62 ... Low-E film 33 ... Gap 34 ... Closing member 35, 44 ... Air layer 36 ... Heat insulating material 40 ... Low-E double glazing 45 ... Rotating shaft 50 ... Bubble 51 ... Air Filter 53 ... Check valve 54 ... Rising part 63 ... Spacer 70 ... Outer wall surface

Claims (10)

It is a culture system for microorganisms that perform photosynthesis.
A plurality of containers that are installed adjacent to or adjacent to the outer wall surface or slope of the structure, or arranged so as to be arranged in the height direction of the structure as the outer wall itself of the structure, and contain a culture solution containing microorganisms.
An adjustment tank for adjusting the culture solution to a predetermined condition, and
A liquid supply means for supplying the culture solution prepared in the adjustment tank to the container arranged at the uppermost portion is included.
A microorganism culture system in which each of the containers overflows the culture solution at a predetermined liquid level and supplies the culture solution to a container one step below to be connected or the adjustment tank. It includes an elevated water tank that is installed on top of the container located at the top and stores the culture solution supplied from the liquid supply means.
The microorganism culture system according to claim 1, wherein the culture solution is supplied from the elevated water tank to a container arranged at the uppermost portion. Each of the plurality of containers is installed so as to cover the outer surface exposed to sunlight, and an infrared light reflecting material that transmits visible light and reflects infrared light or an infrared light absorbing material that absorbs infrared light is used. The microorganism culture system according to claim 1 or 2, which comprises a plurality of covering members provided. The third aspect of the present invention, wherein the covering member has the infrared light reflecting material or the infrared light absorbing material arranged adjacent to the inner surface of one or both of the two transparent members arranged apart from each other. Microbial culture system. The microorganism culture system according to claim 3 or 4, wherein the infrared light reflecting material is a Low-E (Low Emissivity) film. The microorganism culture system according to claim 4, wherein the covering member is reversible. Includes a plurality of connecting pipes connecting each of the above containers.
The microorganism culture system according to any one of claims 1 to 6, wherein the diameter of the connecting tube is determined according to the amount of the culture solution overflowing in each container. A plurality of air supply means for supplying air for stirring the culture solution contained in each container, and
The microorganism culture system according to any one of claims 1 to 7, further comprising a plurality of filter members that discharge air in each container while blocking the inside and the outside of each container. A plurality of air supply pipes connecting each container and each air supply means are included.
The microorganism culture system according to claim 8, wherein each air supply pipe has a rising portion that rises to a position higher than the liquid level height of the culture solution in each container. A gas supply means for supplying carbon dioxide into the adjusting tank and
A temperature adjusting means for adjusting the temperature of the culture solution in the adjusting tank is included.
The microorganism according to any one of claims 1 to 9, which at least adjusts the concentrations of carbon dioxide and oxygen in the culture solution, the pH of the culture solution, and the temperature of the culture solution in the adjustment tank. Culture system.

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