An automatic continuous culture device for seawater microalgae

Abstract

The application discloses a kind of seawater microalgae automatic continuous culture device, including liquid tank and pump, two ends of double-row pipeline are connected with liquid tank respectively, the pump is used to pump liquid into pipeline so that liquid circulates and flows between liquid tank and pipeline, the liquid tank includes liquid outlet and water replenishing port, water replenishing port is connected with seawater storage tank, after collecting microalgae, seawater in seawater storage tank after disinfection is replenished into liquid tank.The photo-bioreactor of the application can continuously cultivate, and is easy to use.

Description

Technical Field

[0001] This invention relates to an automated continuous culture device for marine microalgae. Background Technology

[0002] Microalgae or their processed products are high-quality food sources for shellfish breeding in aquatic organisms, such as diatoms and spirulina. Microalgae used as food are typically cultured in a three-stage process: first, in Erlenmeyer flasks; then transferred to culture tanks for expansion; and finally, in a secondary culture tank for tertiary culture. In recent years, some aquaculture farms have also used tubular photobioreactors for secondary culture, which offers advantages such as small footprint, high culture concentration, sterile culture, and immunity to external climate interference. However, the disadvantage is that the above culture process cannot be carried out continuously, making it somewhat inconvenient to use. Summary of the Invention

[0003] To address the aforementioned shortcomings, the present invention aims to provide an automated continuous culture device for marine microalgae for continuous cultivation of food microalgae.

[0004] Therefore, the present invention provides an automated continuous cultivation device for seawater microalgae, comprising a spirally arranged double-row pipe, a liquid tank, and a pump. The two ends of the double-row pipe are respectively connected to the liquid tank. The pump is used to pump liquid into the pipe so that the liquid circulates between the liquid tank and the pipe. The liquid tank includes an outlet and a water inlet. The water inlet is connected to a seawater storage tank. After the microalgae are collected, disinfected seawater from the seawater storage tank is added to the liquid tank.

[0005] Furthermore, it also includes a sleeve located outside the pipe, wherein a light-emitting device is provided inside the sleeve, the incident light intensity of the light-emitting device is adjustable, and several light-emitting devices are arranged spirally around the straight pipe.

[0006] Furthermore, the sleeve includes a light-reflecting layer disposed on the inner side, the light-reflecting layer being used to guide diffused light to the surface of the pipe.

[0007] Furthermore, the sleeve also includes a heat insulation layer, which is disposed outside the light reflection layer. The sleeve has caps at both ends, and a central through hole for the pipe to pass through is provided in the middle of the cap. The cap is also provided with an openable and closable ventilation interface, which is suitable for connecting to the air outlet of the temperature control device.

[0008] Furthermore, the pipe includes a straight pipe, and the sleeve on the outside of the straight pipe is formed by a combination of semi-cylinders. The semi-cylinders are fixed on a connecting rod, and the connecting rod can drive the semi-cylinders to move along the length of the connecting rod so that the light-emitting device is away from the surface of the straight pipe.

[0009] Furthermore, the dual-row pipes are equipped with a mixer, which is used to remix the algal solution entering the mixer.

[0010] Furthermore, the mixer has several shaped guide plates inside, an inlet connection at the top, and an outlet at the bottom. The algal liquid flows into the mixer through the inlet and flows out of the mixer through the outlet.

[0011] Furthermore, the mixer is equipped with an impeller inside. The algal liquid flows through the impeller, causing the impeller to rotate and thus remixing the algal liquid before it passes through the mixer.

[0012] The beneficial effects of this invention are as follows:

[0013] (1) An automated continuous culture device for seawater microalgae according to the present invention includes a spirally arranged double-row pipe, a liquid tank connected to both ends of the pipe, and a pump connected to the pipe. The pump pumps the algal solution from the liquid tank into the pipe. The algal solution flows in the pipe and receives light. After 3-5 days of culture, when the concentration of microalgae in the reactor reaches 6 million to 10 million / ml, the microalgae are collected from the outlet. A seawater ionization disinfection device ionizes seawater to generate hypochlorite ions to disinfect the seawater. The disinfected seawater is stored in a seawater storage tank and sodium thiosulfate is added to eliminate the remaining hypochlorite ions. The deionized seawater and other nutrients required for microalgae culture are added to the collected liquid tank. After 3-5 days of culture, the collection is repeated, and the above process is repeated to achieve continuous culture of microalgae.

[0014] (2) In a specific embodiment of the present invention, a sleeve is provided on the outside of the pipe, and a light-emitting device and a light-reflecting layer are provided in the sleeve to improve the light utilization rate of the photobioreactor and reduce energy consumption.

[0015] (3) The sleeve consists of two semi-cylinders. The semi-cylinders can move away from the pipe, which facilitates the heat dissipation of the light-emitting device and controls the pipe temperature within a suitable range. The sleeve is equipped with ventilation ports at both ends. The warm or cold air from the temperature control device can be introduced into the sleeve through the ventilation ports to regulate the pipe temperature.

[0016] (4) In the tubular photobioreactor, the flow velocity of the algal solution is greater than 0.5 m / s. The algal solution mainly flows axially with very little radial disturbance. After cultivation, the concentration of microalgae in the algal solution increases significantly. Since microalgae are phototropic and the microalgae near the pipe surface can receive more light, their growth rate is faster, resulting in a higher concentration of microalgae on the pipe surface facing the light, which affects light transmittance and inhibits the growth of microalgae inside the pipe. The pipe is equipped with a mixer, which remixes the algal solution flowing into it before sending it back into the pipe. After being mixed by the mixer and pumped back into the pipe, the radial distribution of the algal solution in the pipe is changed, so that the algal solution in the middle of the pipe and the algal solution on the pipe surface are mixed, reducing the growth inhibition of the algal solution in the middle of the pipe. Attached Figure Description

[0017] Figure 1 A schematic diagram illustrating a specific embodiment of the present invention;

[0018] Figure 2-1 This is a side view of a double-row pipe system.

[0019] Figure 2-2 Side view of a double-row pipe with a mixer

[0020] Figure 3 This is a schematic diagram of the cross-section of the sleeve;

[0021] Figure 4 This is a schematic diagram of the sleeve after it has been virtually unfolded.

[0022] Figure 5 This is a schematic diagram of the cover.

[0023] Figure 6 A schematic diagram showing the relationship between the liquid tank, pipelines, and pump;

[0024] Figure 7 This is a cross-sectional schematic diagram of Embodiment 1 of the mixer;

[0025] Figure 8 This is a cross-sectional schematic diagram of Embodiment 2 of the mixer.

[0026] Explanation of reference numerals in the attached drawings: 1. Double-row pipe; 101. Straight pipe; 102. Bend; 2. Liquid tank; 3. T-joint; 4. Inlet pipe; 5. Outlet; 6. Mixer; 601. Guide plate; 602. Frame; 603. Impeller; 604. Inlet; 605. Outlet; 7. Pump; 8. Air inlet pipe; 9. Water supply pipe; 10. Valve; 11. Sleeve; 111. Light-emitting device; 112. Light-reflecting layer; 113. Semi-cylinder; 114. Connecting rod; 115. Rack; 116. Gear; 117. Groove; 118. Support rod; 119. Insulation layer; 12. Cover; 121. Central through hole; 122. Ventilation interface; 13. Seawater storage tank; 14. Seawater ionization disinfection equipment. Detailed Implementation

[0027] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0028] Reference Figure 1 , Figure 2-1 , Figure 6As shown, an automated continuous culture device for seawater microalgae according to the present invention includes a double-row pipe 1 arranged in a longitudinal three-dimensional spiral and a liquid tank 2 connected to both ends of the double-row pipe 1. The bottom of the liquid tank 2 is funnel-shaped, and a three-way pipe 3 is connected to the bottom of the liquid tank 2. The three-way pipe 3 is connected to the liquid inlet pipe 4 of the double-row pipe 1. One end of the liquid inlet pipe 4 leads to the double-row pipe 1 of the photobioreactor, and the other end is connected to the liquid outlet 5 of the algal liquid. The liquid outlet 5 can be used to harvest microalgae or for sampling and testing. In this embodiment, a control valve 10 and an auxiliary pipe are also provided. The auxiliary pipe includes a CO2 inlet pipe 8, an exhaust pipe for reducing dissolved oxygen, and an addition pipe for other substances needed by microalgae. The inlet pipe 8 and the addition pipe can be installed on the liquid inlet pipe 4. The exhaust pipe can be installed on the liquid tank 2 or on the pipe entering the liquid tank 2. The top of the liquid tank 2 is also connected to a water supply pipe 9. The water supply pipe 9 is connected to the seawater storage tank 13 disinfected with hypochlorous acid. A valve 10 is provided on the liquid outlet 5. The seawater ionization disinfection device 14 disinfects the seawater by generating a high concentration of hypochlorite ions through seawater ionization. The disinfected seawater is stored in the seawater storage tank 13. Sodium thiosulfate is added to the seawater storage tank 13 to eliminate the remaining hypochlorite ions in the seawater for later use. Of course, disinfection can also be carried out by directly adding hypochlorous acid to the seawater. The elimination method can also be to remove calcium hypochlorite ions by aeration. However, aeration is prone to causing seawater to be re-polluted. Therefore, in this embodiment, the elimination is carried out by adding chemical agents. In this embodiment, an artificial light source can be used, and a special culture room is set up, with a temperature regulation device installed in the culture room to regulate the temperature inside.

[0029] In the above embodiments, reference is made to Figure 1 , Figure 3 and Figure 4As shown, it also includes a sleeve 11 provided outside the straight pipe 101 of the pipeline, and a light-emitting device 111 provided inside the sleeve 11. The incident light intensity of the light-emitting device 111 is adjustable, and several light-emitting devices 111 are spirally arranged around the pipeline. When an artificial light source is used in a photobioreactor, the light source is usually located in the middle of the two rows of pipes in the photobioreactor. This results in only one side of the pipe receiving direct light, while the other side receives weaker diffused light. The concentration of microalgae is higher on the side of the pipe directly facing the light. In this embodiment, a light-emitting device 111 is installed in the sleeve 11. On the one hand, this can improve the utilization rate of light. On the other hand, the light-emitting device 111 is spirally arranged around the pipe. When the algal solution receives light from the light-emitting device 111 and grows rapidly on the surface of the pipe directly facing the light, the positions of adjacent light-emitting devices 111 are different, and the positions of the pipe surfaces are also different. The next sequential light-emitting device 111 can irradiate the pipe surface with a lower concentration of microalgae, allowing the light to penetrate the inside of the pipe better. Due to the phototaxis of microalgae, the concentration of microalgae on the pipe surface with a higher concentration of microalgae will decrease to a certain extent after losing the favorable position for receiving light. When the position is directly facing the light again, its light transmittance is improved to a certain extent. After repeating a certain number of times or a predetermined number of times, the algal solution enters the mixer 6. Combined with the mixing effect of the mixer 6, this embodiment effectively reduces the growth inhibition effect. Furthermore, in the early stages of cultivation, the concentration of microalgae in the bioreactor is low, and excessive light can limit microalgae production. Therefore, this embodiment employs a light-emitting device with adjustable incident light intensity. Adjustable intensity light sources are existing technology, typically using silicon controlled rectifiers (SCRs) for adjustment. The aforementioned light-emitting device 111 can also employ a light guide system to introduce natural light from the outside.

[0030] In the above embodiments, reference is made to Figure 3 and Figure 4 As shown, the sleeve 11 includes a light-reflecting layer 112 disposed on the inner side. The light-reflecting layer 112 is used to guide diffused light to the surface of the pipe. This embodiment can improve the utilization rate of light and save energy.

[0031] In the above embodiments, reference is made to Figure 3 , Figure 5As shown, the sleeve 11 also includes a heat insulation layer 119, which is disposed outside the light reflective layer 112. The straight tube 101 of the sleeve 11 has caps 12 at both ends, which are threadedly connected to the sleeve 11. A central through hole 121 for a pipe to pass through is provided in the middle of the cap 12. The cap 12 also has an openable and closable ventilation port 122, which is suitable for connecting to the ventilation duct of a temperature control device. Microalgae growth requires a suitable temperature; therefore, a temperature control device needs to be installed in the greenhouse or room where the photobioreactor is located. The temperature control device consumes a significant portion of the energy. In this embodiment, by providing channels for connecting the temperature control device on the caps 12 at both ends of the sleeve 11, the space required for temperature adjustment is significantly reduced, effectively saving energy. In addition, the photobioreactor is mainly composed of straight pipes 101. The purpose of setting up the bend pipe 102 is only to connect the straight pipes 101 distributed in the space. Its length is very short, and the algal liquid maintains a flow rate of more than 0.5 m / s. The main component of the algal liquid is water, which has a large specific heat. The temperature of the algal liquid in the area of ​​the bend pipe 102 will not drop significantly. Therefore, it is appropriate to adjust and keep the temperature only on the straight pipe 101. In addition, a corresponding sleeve can also be set in the bend part of the pipe, and a heat insulation layer can be set in the sleeve to reduce heat loss.

[0032] In the above embodiments, reference is made to Figure 3 and Figure 4 As shown, the sleeve 11 is formed by assembling a semi-cylinder 113, which is fixed to a connecting rod 114. The connecting rod 114 is connected to a rack 115, which has a groove 117 inside. A support rod 118 is provided on the bracket, and the support rod 118 engages with the groove 117. The rack 115 engages with a gear 116, which, driven by a motor, causes the connecting rod 114 to move the semi-cylinder 113, moving the light-emitting device 111 away from the surface of the straight pipe. Artificial light sources typically generate heat, causing the pipe temperature to rise. This heat is beneficial when the ambient temperature is low, as it helps maintain the pipe at a suitable growth temperature, typically 20–35°C. However, when the ambient temperature is high, this heat is harmful. In this embodiment, by moving the movable semi-cylinder 113 away from the pipe, the heat generated by the light-emitting device 111 can be quickly dissipated.

[0033] In the above embodiments, reference is made to Figure 2-2Depending on the length of the double-row pipe 1, one or more mixers 6 can be connected within the double-row pipe 1. The algal solution passes through the mixers 6 and is remixed before entering the double-row pipe 1, causing a radial redistribution of the algal solution within the double-row pipe 1. Firstly, microalgae exhibit phototaxis, meaning they can move to and maintain a more favorable position for light exposure. Secondly, microalgae grow faster on the pipe surface where they receive sufficient light. Thirdly, the flow velocity of the algal solution in a tubular photobioreactor typically needs to be greater than 0.5 m / s, thus requiring a smooth flow path within the pipe. For example, using an α-tube instead of a U-shaped bend can reduce the Reynolds number of the fluid. The algal solution within the pipe primarily flows axially, with radial disturbances being negligible. These factors lead to a higher concentration of microalgae on the pipe surface. This high concentration of microalgae on the pipe surface reduces light penetration, concentrating the bright area of ​​the pipe only on the surface facing the light source, thus inhibiting the growth of microalgae inside the pipe. When the algal solution enters the double-row pipe 1 of this invention, the microalgae rapidly multiply and grow. After flowing through a certain length of pipe, the number of microalgae on the pipe surface is higher than that inside the pipe. At this point, the algal solution enters the mixer 6. After mixing in the mixer 6, the concentration of microalgae in the algal solution tends to be uniform. The algal solution is then sent back into the double-row pipe 1, and the growth inhibition of microalgae is improved. The mixer 6 can be a mixing tank, and an agitator, such as a motor-driven impeller 603, can be used inside the tank. The agitator is suitable for a slower rotation speed. A pump 7 can be installed on the pipe outside the mixing tank according to the actual situation to pump the liquid in the tank to the double-row pipe 1.

[0034] In the above embodiments, reference is made to Figure 7 and Figure 8 As shown, the mixer 6 may also include the following two specific embodiments. In embodiment 1, the mixer 6 has several guide plates 601 arranged in a Z-shape inside. The upper part of the mixer 6 has an inlet 604, and the lower part of the mixer 6 has an outlet 605. The algal liquid flows into the mixer 6 through the inlet 604 and flows out of the mixer from the outlet 605. The guide plates 601 cause the fluid to turbulent and self-mix. The surface of the guide plates may have wavy protrusions to generate vortices and improve the mixing effect. In embodiment 2, the mixer 6 has one or more frames 602 inside. Each frame 602 is connected to a freely rotating impeller 603. The impeller 603 is made of lightweight plastic. The liquid entering the mixer 6 has a flow velocity of more than 0.5 m / s. The flowing liquid drives the impeller 603 to rotate. The rotation of the impeller 603 causes radial turbulence in the fluid, and the fluid re-mixes itself in the mixer.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An apparatus for the automated continuous cultivation of marine microalgae comprising a double row of spirally arranged pipes, characterized in that: The device comprises a liquid tank and a pump, two ends of a double-pipe are connected with the liquid tank respectively, the pump is used for pumping liquid into the double-pipe to make the liquid flow between the liquid tank and the double-pipe, the liquid tank comprises a liquid outlet and a water supplementing port, the water supplementing port is connected with a seawater storage tank, after collecting microalgae, seawater in the seawater storage tank is supplemented into the liquid tank after sterilization; The device further comprises a sleeve arranged outside the double-pipe, the sleeve is provided with light emitting devices, the incident light intensity of the light emitting devices is adjustable, and the light emitting devices are arranged in a spiral around the straight pipe; The double-pipe is provided with a mixer, the mixer is used for mixing the algal liquid again after entering the mixer; The light emitting devices are arranged in a spiral around the double-pipe, positions of adjacent light emitting devices are different, and positions of the double-pipe surface are also different, the next light emitting device in sequence irradiates the double-pipe surface with lower microalgae concentration, after the double-pipe surface with higher microalgae concentration loses the favorable light receiving position, the microalgae concentration is reduced, and the light transmission performance is improved, after repeating a predetermined number of times, the algal liquid enters the mixer, and the growth inhibition effect is reduced in combination with the mixing effect of the mixer; The sleeve comprises a light reflection layer arranged on the inner side, and the light reflection layer is used for guiding the diffused light to the double-pipe surface; The sleeve further comprises a heat insulation layer, the heat insulation layer is arranged on the outer side of the light reflection layer, the double-pipe comprises a straight pipe, the sleeve outside the straight pipe is formed by a half-cylinder combination, the half-cylinder is fixed on a connecting rod, and the connecting rod can drive the half-cylinder to move along the length direction of the connecting rod so that the light emitting devices are away from the surface of the straight pipe.

2. The device for the automated continuous culture of marine microalgae according to claim 1, characterized in that: The inside of the mixer is provided with a plurality of flow guide straight plates in a "Z" shape, the upper part of the mixer is provided with an inlet connection, and the lower part of the mixer is provided with an outlet, the algal liquid flows into the mixer through the inlet and flows out of the mixer through the outlet.

3. The device according to claim 1, wherein the device is characterized by: The inside of the mixer is provided with an impeller, the algal liquid flows through the impeller to drive the impeller to rotate so that the algal liquid is mixed again and then passes through the mixer.

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