A cage-type stirring device suitable for microalgae cultivation

Abstract

This invention discloses a cage-type stirring device suitable for microalgae cultivation, belonging to the field of microalgae stirring. It includes a stirring tank with an open top; a horizontal plate fixed to the upper wall of the stirring tank, with a gap between the horizontal plate and the tank; multiple guide rods fixed to the upper wall of the horizontal plate, with mounting plates simultaneously fitted onto the guide rods, the mounting plates being movable along the axes of the guide rods; a stirring motor fixed to the upper wall of the mounting plate, with a long rod fixed to the shaft of the stirring motor; the long rod passing through the mounting plate and the horizontal plate; a spring fitted onto the long rod; an outer sleeve fixed to the lower wall of the horizontal plate; a middle sleeve fitted onto the long rod, the outer sleeve fitted onto the middle sleeve, the middle sleeve being rotatably mounted on the outer sleeve via a bearing; the long rod being movable vertically relative to the middle sleeve; a first cage-type stirring device and a second cage-type stirring device respectively mounted on the middle sleeve and the long rod; and a lifting device mounted on the horizontal plate. This device does not require an aeration device, has a simple structure, and can meet the oxygen requirements of the microalgae solution.

Description

Technical Field

[0001] This invention belongs to the field of microalgae stirring technology, specifically relating to a cage-type stirring device suitable for microalgae cultivation. Background Technology

[0002] Microalgae are a type of autotrophic plant that is widely distributed on land and in the ocean. They are rich in nutrients and have high photosynthetic efficiency. The polysaccharides, proteins, pigments and other substances produced by cell metabolism make them promising for development in the fields of food, medicine, genetic engineering and liquid fuels.

[0003] Authorization announcement number CN207811737U discloses a mobile stirring microalgae cultivation device. In this prior art, the stirring wheel is raised and lowered along with the support rod, and the stirring wheel can stir the microalgae liquid while simultaneously agitating the microalgae liquid up and down.

[0004] The drawback of this patent is that multiple stirring wheels are fixed to the support rod along its axis. If the support rod rises or falls, all the stirring wheels will rise and fall synchronously. Since the upper layer of microalgae solution is the only part that can come into contact with oxygen, the oxygen in the middle and lower layers comes from the agitation of the upper layer. Only by agitating the upper layer can sufficient oxygen be guaranteed. However, in this patent, when the stirring wheels descend with the support rod, the stirring blades that were originally agitating the upper layer will agitate the middle layer, and the stirring blades that were originally agitating the middle layer will agitate the lower layer. The lack of agitation in the upper layer reduces its contact with oxygen, leading to oxygen deficiency. Once the upper layer is oxygen-deficient, even if the middle and lower layers are continuously agitated, they will also become oxygen-deficient. To prevent oxygen deficiency in the middle and lower layers of microalgae solution, the existing technology incorporates an aeration device. When the middle and lower layers are agitated but the upper layer is not, the aeration device provides oxygen to these layers to prevent oxygen deficiency in both the middle and lower layers due to reduced oxygen contact with the upper layer. However, adding the aeration device increases structural complexity.

[0005] If the support rod is equipped with three stirring wheels to simultaneously agitate the upper, middle and lower layers of microalgae liquid, the three stirring wheels increase the structural complexity. During lifting and lowering, the additional stirring wheel will occupy more space, further increasing the overall structural complexity. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a cage-type stirring device suitable for microalgae cultivation. This device can achieve agitation of the upper, middle, and lower layers of microalgae solution while ensuring the oxygen content of the upper, middle, and lower layers of microalgae solution without adding an aeration device or setting up three stirring wheels.

[0007] To achieve the above objectives, the present invention provides a cage-type stirring device suitable for microalgae cultivation, comprising a stirring tank with an open top; a horizontal plate fixed to the upper wall of the stirring tank, the horizontal plate not sealing the open top, with a gap between the horizontal plate and the stirring tank; multiple guide rods fixed to the upper wall of the horizontal plate, the axes of the guide rods being vertically oriented, and mounting plates simultaneously fitted onto the multiple guide rods, the mounting plates being movable along the axes of the guide rods; a stirring motor fixed to the upper wall of the mounting plate, the axis of the stirring motor's rotating shaft being vertically oriented, and a long rod fixed to the rotating shaft of the stirring motor, the axis of the long rod being aligned with the axis of the stirring motor. The assembly consists of a long rod passing through a horizontal plate; a spring fitted on the long rod, with one end of the spring abutting against the lower surface of the mounting plate and the other end abutting against the upper surface of the horizontal plate, the spring being in a compressed state; an outer sleeve fixed to the lower surface of the horizontal plate; a middle sleeve fitted on the long rod, the outer sleeve fitted on the middle sleeve, the middle sleeve being rotatably mounted on the outer sleeve via bearings; the long rod being movably locked onto the middle sleeve, allowing it to move vertically relative to the middle sleeve; a first cage-type stirring device and a second cage-type stirring device are respectively installed on the middle sleeve and the long rod; a lifting device is installed on the horizontal plate, used to raise and lower the stirring motor, mounting plate, and long rod as a whole along the axis of the long rod.

[0008] The first cage-type agitator continuously stirs the upper layer of microalgae solution, allowing outside air to contact the solution through gaps, thus ensuring sufficient oxygen in the upper layer. The first cage-type agitator remains stationary while the second cage-type agitator is raised and lowered via a stirring motor, mounting plate, and long rod. Simultaneously, the second cage-type agitator rotates, agitating the middle and lower layers of microalgae solution. The middle layer obtains oxygen from the upper layer, and the lower layer obtains oxygen from the middle layer. This avoids the situation in existing technologies where both the first and second cage-type agitators move downwards simultaneously. If both cage-type agitators move downwards at the same time, the upper layer of microalgae solution will not be agitated, resulting in oxygen deficiency throughout the entire mixing tank.

[0009] Furthermore, the first cage-type stirring device and the second cage-type stirring device have the same structure; the second cage-type stirring device includes multiple stirring rods, which are made of silicone and are arched. The two ends of the stirring rods are fixed to a long rod, one above the other, and the stirring rods are arranged in a circular array along the axis of the long rod; the stirring rods of the first cage-type stirring device are fixed to the outer wall of the middle sleeve.

[0010] The stirring rod is made of silicone. During rotation, the rod deforms, reducing the shear force on the microalgae solution and preventing damage to the microalgae cells. The cage-type stirring device easily generates negative pressure in its central part, causing the microalgae solution to flow towards the center and then descend from the outer edge of the long rod or the middle sleeve, circulating repeatedly to achieve uniform mixing.

[0011] Furthermore, the second cage-type stirring device also includes a blasting plate, which is made of silicone and is disc-shaped; the blasting plate is sleeved on a long rod and fixedly connected to the long rod; the axis of the blasting plate coincides with the axis of the long rod, and the outer edge of the blasting plate abuts against the stirring rod.

[0012] Because the linear velocity in the middle of the stirring rod is greater than that at both ends, the middle part of the stirring rod is more prone to deformation. By setting a throbbing plate to support the middle of the stirring rod, the stirring rod has a considerable plasticity and will not be completely bent and deformed during the rotation of the stirring rod.

[0013] Furthermore, the agitator plate is thin in the middle and thick at the edges.

[0014] When the second cage-type stirring device is raised and lowered, the agitator plate is thin in the middle and thick at the edges. As the second cage-type stirring device is raised and lowered, the agitator plate will fold continuously, thereby agitating the microalgae liquid above and below to achieve exchange and improve the mixing of the microalgae liquid above and below.

[0015] Furthermore, the lifting device includes a mounting frame fixed on a horizontal plate, a lifting motor is mounted on the mounting frame, a cam is fixed on the rotating shaft of the lifting motor, and a stop plate is fixed on the non-rotating shaft end of the stirring motor, with the outer edge of the cam abutting against the stop plate.

[0016] Furthermore, the stirring tank is equipped with a thermostatic heater for controlling the temperature of the microalgae solution, which is used to agitate the microalgae solution to a suitable temperature.

[0017] Furthermore, a slider is fixed on the long rod, and a groove is provided on the inner wall of the middle sleeve, in which the slider is movably engaged.

[0018] The groove and slider ensure that when the long rod and the middle sleeve rotate as a whole relative to the outer sleeve, the long rod and the middle sleeve will not have relative displacement, thus maintaining a high degree of rotational consistency between the long rod and the middle sleeve.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The first cage-type agitator continuously stirs the upper layer of microalgae solution, ensuring its oxygen supply. The second cage-type agitator then continuously rises and falls, directly or indirectly obtaining oxygen from the upper layer. In existing technologies, the first and second cage-type agitators rise and fall simultaneously, resulting in simultaneous stirring of the middle and lower layers of microalgae solution. Due to the lack of stirring of the upper layer, the entire microalgae solution is more prone to oxygen deficiency. Therefore, this solution avoids oxygen deficiency, eliminates the need for an aeration device, and simplifies the apparatus.

[0020] 2. An agitation plate is installed, which is thin in the middle and thick at the edges. During the continuous raising and lowering of the second cage-type stirring device, the middle part of the agitation plate is more easily deformed, thereby causing the agitation plate to continuously agitate, making it easier for the upper and lower microalgae liquids to mix, and achieving the purpose of uniformly mixing the upper and lower layers of microalgae liquids. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the device.

[0022] Figure 2 This is a schematic diagram showing the connection relationship between the first cage-type mixing device, the second cage-type mixing device, and the long rod.

[0023] 1. Mixing tank; 2. Horizontal plate; 3. Gap; 4. Guide rod; 5. Mounting plate; 6. Anti-loosening nut; 7. Mixing motor; 8. Long rod; 9. Spring; 10. Outer sleeve; 11. Middle sleeve; 12. Bearing; 13. Sliding block; 14. Slide groove; 15. Mixing rod; 16. Agitator plate; 17. Mounting bracket; 18. Lifting motor; 19. Cam; 20. Support plate. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 , 2 As shown, a cage-type stirring device suitable for microalgae cultivation includes a stirring tank 1. In this embodiment, the stirring tank 1 is a cylindrical tank with an open top. A horizontal plate 2 is fixed to the upper wall of the stirring tank 1, but the horizontal plate 2 does not seal the open top of the stirring tank 1. A gap 3 is left between the horizontal plate 2 and the stirring tank 1.

[0026] Multiple guide rods 4 are fixed on the horizontal plate 2. In this embodiment, there are two guide rods 4, and their axes are arranged vertically. A mounting plate 5 is simultaneously fitted onto the multiple guide rods 4, meaning that the multiple guide rods 4 pass through the mounting plate 5 at the same time. The mounting plate 5 has holes for the guide rods 4 to pass through. The mounting plate 5 is horizontally arranged and can move along the axis of the guide rods 4. The top ends of the multiple guide rods 4 are threaded with anti-loosening nuts 6. The inner diameter of the anti-loosening nuts 6 is larger than the diameter of the holes on the mounting plate 5 for the guide rods 4 to pass through. Therefore, due to the restriction of the anti-loosening nuts 6, the mounting plate 5 cannot detach from the upper end of the guide rods 4.

[0027] The upper surface of the mounting plate 5 is provided with a stirring motor 7. The non-rotating shaft end of the stirring motor 7 is fixed on the upper surface of the mounting plate 5. The rotating shaft of the stirring motor 7 is downward and passes through the mounting plate 5. The rotating shaft axis of the stirring motor 7 is set vertically. The mounting plate 5 is provided with a hole for the rotating shaft of the stirring motor 7 to pass through. The rotating shaft of the stirring motor 7 can rotate relative to the mounting plate 5.

[0028] A long rod 8 is fixed to the shaft of the stirring motor 7, and the axis of the long rod 8 coincides with the axis of the shaft of the stirring motor 7. The lower end of the long rod 8 passes through the horizontal plate 2 and extends into the mixing tank 1. The horizontal plate 2 has a hole for the long rod 8 to pass through, and the long rod 8 can rotate relative to the horizontal plate 2. A spring 9 is fitted on the long rod 8. One end of the spring 9 abuts against the lower surface wall of the mounting plate 5, and the other end abuts against the upper surface wall of the horizontal plate 2. The spring 9 is in a compressed state.

[0029] A sleeve 10 is fixed to the lower wall of the horizontal plate 2. The end face of the sleeve 10 is annular, and the axis of the sleeve 10 coincides with the axis of the long rod 8. The sleeve 10 is fitted onto the long rod 8. A middle sleeve 11 is rotatably connected to the inner wall of the sleeve 10 via a bearing 12. The end face of the middle sleeve 11 is annular, and the axis of the middle sleeve 11 coincides with the axis of the sleeve 10. The sleeve 10 is fitted onto the middle sleeve 11. The inner ring of the bearing 12 is fixedly connected to the outer wall of the middle sleeve 11, and the outer ring of the bearing 12 is fixedly connected to the inner wall of the sleeve 10. The middle sleeve 11 is fitted onto the long rod 8.

[0030] A groove 14 is provided on the inner wall of the middle sleeve 11, and a slider 13 is fixed on the outer wall of the long rod 8. The slider 13 is movably engaged in the groove 14, and the long rod 8 is movably engaged on the middle sleeve 11 by means of the slider 13 and the groove 14. The long rod 8 can move relative to the middle sleeve 11 along the axis of the middle sleeve 11.

[0031] The lower end of the aforementioned middle sleeve 11 is lower than the lower end of the outer sleeve 10, and the lower end of the long rod 8 is lower than the lower end of the middle sleeve 11. A cage-type stirring device is installed on the outer wall of the middle sleeve 11 and the outer wall of the long rod 8, respectively referred to as the first cage-type stirring device and the second cage-type stirring device. The second cage-type stirring device includes: Multiple stirring rods 15, each arched in shape and made of silicone, are fixed at both ends of a long rod 8, one above the other. The stirring rods 15 are arranged in a circular array along the axis of the long rod 8. The stirring rods 15 deform when rotated, reducing the shear force on the microalgae.

[0032] The agitator plate 16, made of silicone, is disc-shaped and placed horizontally, fitted onto the long rod 8 and fixedly connected to it. The axis of the agitator plate 16 coincides with the axis of the long rod 8. The agitator plate 16 is thin in the middle and thick at the edges, making it prone to longitudinal twisting when moving up and down. This twisting reduces shear force, thus protecting the microalgae cells. Furthermore, the longitudinal twisting exerts a force on the upper and lower layers of microalgae solution, facilitating mixing. The outer edge of the agitator plate 16 abuts against the stirring rod 15.

[0033] The first cage-type mixing device and the second cage-type mixing device have the same structure. The difference is that both ends of the mixing rod 15 of the first cage-type mixing device are fixed on the middle sleeve 11; and the agitator plate 16 of the first cage-type mixing device is sleeved on the middle sleeve 11 and fixedly connected to the middle sleeve 11.

[0034] The mounting plate 5 is also equipped with a lifting device for driving the stirring motor 7, the long rod 8, and the second cage-type stirring device on the long rod 8 as an overall lifting mechanism. The lifting device includes: Mounting bracket 17 is fixed to the upper surface of horizontal plate 2.

[0035] The non-rotating shaft end of the lifting motor 18 is fixed to the upper surface of the mounting bracket 17, and the rotating shaft of the lifting motor 18 is set horizontally.

[0036] Cam 19 is sleeved on the rotating shaft of lifting motor 18 and is fixedly connected to the rotating shaft of lifting motor 18.

[0037] The abutment plate 20 is fixed to the non-rotating shaft end of the stirring motor 7, and the abutment plate 20 is set horizontally. The cam 19 is located above the abutment plate 20, and the outer edge of the cam 19 abuts against the upper surface wall of the abutment plate 20.

[0038] A thermostatic heater (not shown) for controlling the temperature of the microalgae solution is placed in the stirring tank 1.

[0039] Usage process: Pour the microalgae solution into the mixing tank 1 through gap 3; When the stirring motor 7 is turned on, the stirring motor 7 drives the long rod 8 to rotate. Since the middle sleeve 11 and the long rod 8 can only move relative to each other in the vertical direction, the middle sleeve 11 cannot rotate relative to the long rod 8 around the axis of the long rod 8. Therefore, the middle sleeve 11 and the long rod 8 rotate as a whole with the rotating shaft of the stirring motor 7.

[0040] Since the middle sleeve 11 and the outer sleeve 10 rotate relative to each other through the bearing 12, the middle sleeve 11 and the long rod 8, as a whole, rotate relative to the outer sleeve 10 around the axis of the outer sleeve 10.

[0041] Turn on the lifting motor 18, which drives the cam 19 to rotate. The cam 19, by abutting against the abutment plate 20, causes the stirring motor 7 to rise and fall. The stirring motor 7, mounting plate 5, and long rod 8 move vertically as a whole. Because the long rod 8 and the middle sleeve 11 can move vertically relative to each other, and the middle sleeve 11 cannot move vertically relative to the outer sleeve 10, the stirring motor 7, mounting plate 5, and long rod 8 can move vertically relative to the middle sleeve 11 as a whole. Since the second cage-type stirring device is fixed on the long rod 8, it can move vertically as the long rod 8 rotates. Because the first cage-type stirring device is fixed on the middle sleeve, it can only rotate with the middle sleeve 11 and cannot move vertically. The stirred microalgae liquid is poured out from the gap 3.

[0042] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A cage-type stirring device suitable for microalgae cultivation, characterized in that, Includes a mixing tank (1), with an opening at the top; a horizontal plate (2) is fixed to the upper surface of the mixing tank (1), the horizontal plate (2) does not seal the opening, and a gap (3) is left between the horizontal plate (2) and the mixing tank (1); multiple guide rods (4) are fixed to the upper surface of the horizontal plate (2), the axis of the guide rods (4) is set vertically, and mounting plates (5) are simultaneously fitted on the multiple guide rods (4), and the mounting plates (5) can move along the axis of the guide rods (4); A stirring motor (7) is fixed on the upper surface of the mounting plate (5). The shaft axis of the stirring motor (7) is set vertically. A long rod (8) is fixed on the shaft of the stirring motor (7). The axis of the long rod (8) coincides with the axis of the stirring motor (7). The long rod (8) passes through the horizontal plate (2). A spring (9) is sleeved on the long rod (8). One end of the spring (9) abuts against the lower surface of the mounting plate (5), and the other end abuts against the upper surface of the horizontal plate (2). The spring (9) is in a compressed state. The lower surface of the horizontal plate (2) is fixed with an outer sleeve (10); a middle sleeve (11) is fitted on the long rod (8), and the outer sleeve (10) is fitted on the middle sleeve (11). The middle sleeve (11) is rotatably mounted on the outer sleeve (10) via a bearing (12); the long rod (8) is movably mounted on the middle sleeve (11), and the long rod (8) can move vertically relative to the middle sleeve (11); a first cage-type stirring device and a second cage-type stirring device are respectively installed on the middle sleeve (11) and the long rod (8); a lifting device is installed on the horizontal plate (2) to make the stirring motor (7), the mounting plate (5) and the long rod (8) rise and fall as a whole along the axis of the long rod (8).

2. The cage-type stirring device suitable for microalgae cultivation according to claim 1, characterized in that, The first cage-type stirring device and the second cage-type stirring device have the same structure; the second cage-type stirring device includes multiple stirring rods (15), the stirring rods (15) are made of silicone, the stirring rods (15) are arched, and the two ends of the stirring rods (15) are fixed on the long rod (8) one above the other, and each stirring rod (15) is arranged in a circular array along the axis of the long rod (8); the stirring rods (15) of the first cage-type stirring device are fixed on the outer wall of the middle sleeve (11).

3. A cage-type stirring device suitable for microalgae cultivation according to claim 2, characterized in that, The second cage-type stirring device also includes a blasting plate (16), which is made of silicone and is disc-shaped. The blasting plate (16) is sleeved on the long rod (8) and the blasting plate (16) is fixedly connected to the long rod (8). The axis of the blasting plate (16) coincides with the axis of the long rod (8), and the outer edge of the blasting plate (16) abuts against the stirring rod (15).

4. A cage-type stirring device suitable for microalgae cultivation according to claim 3, characterized in that, The agitator plate (16) is thin in the middle and thick at the edges.

5. A cage-type stirring device suitable for microalgae cultivation according to claim 1, characterized in that, The lifting device includes a mounting bracket (17) fixed on a horizontal plate (2), a lifting motor (18) is provided on the mounting bracket (17), a cam (19) is fixed on the shaft of the lifting motor (18), and a stop plate (20) is fixed on the non-shaft end of the stirring motor (7), with the outer edge of the cam (19) abutting against the stop plate (20).

6. A cage-type stirring device suitable for microalgae cultivation according to claim 1, characterized in that, The mixing tank (1) is equipped with a thermostatic heater for controlling the temperature of the microalgae solution.

7. A cage-type stirring device suitable for microalgae cultivation according to claim 1, characterized in that, A slider (13) is fixed on the long rod (8), and a groove (14) is provided on the inner wall of the middle sleeve (11). The slider (13) is movably locked in the groove (14).

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