VERTICAL-FLOW AGITATION SYSTEM FOR MICROALGAE CULTIVATION TANKS

Abstract

The present invention relates to the cultivation of microalgae for the production of biofuels. In this scenario, the present invention provides a vertical flow agitation system for microalgae culture tanks comprising: a source of energy generation (1); an energy storage device (2); a control system (3); an electric motor (4); at least one end of travel sensor (5); an agitation plate (6); a torque transmission system (7); and at least two lateral drive elements (8).

Claims

1. A vertical flow agitation system for microalgae culture tanks, wherein it comprises: a source of energy generation (1); an energy storage device (2); a control system (3); an electric motor (4); at least one end of travel sensor (5); an agitation plate (6); a torque transmission system (7); and at least two lateral drive elements (8).

2. A system as claimed in claim 1, wherein the source of energy generation (1) is at least one of: a photovoltaic energy generator, and a wind energy generator.

3. A system as claimed in claim 2, wherein the energy storage device (2) is at least one battery, or at least one supercapacitor, or a combination thereof.

4. A system as claimed in any one of the claims 1 to 3, wherein the control system (3) is adapted to execute the control of the direction of movement of the autonomous vertical flow agitation system, wherein the control system (3) is composed by at least one of: microcontrollers, programmable logic controllers, and relays.

5. A system as claimed in any one of the claims 1 to 4, wherein the end of travel sensors (5) are adapted to detect when the agitation system reaches the end of the culture tank in a given direction.

6. A system as claimed in any one of the claims 1 to 3, wherein the torque transmission system (7) is adapted to transmit the torque generated by the motor (4) to the drive elements (8), wherein the transmission system (7) comprises a set of gears and shafts.

7. A system as claimed in any one of the claims 1 to 6, wherein the drive elements (8) are adapted to drive the agitation system along the culture tank, wherein the drive elements (8) are positioned laterally in relation to the agitation plate (6), wherein the drive elements (8) comprise at least one of: lateral rails, lateral belts connected to toothed shafts, and lateral wheels, and wherein the drive elements (8) are supported and move upon a lateral rim of the culture tank.

8. A system as claimed in any one of the claims 1 to 7, wherein the agitation plate (6) comprises a format substantially respecting the format of the cross-section of the culture tank, wherein the sides of the agitation plate (6) are positioned in a precise manner in relation to the lateral walls of the tank, and the inferior region of the agitation plate (6) maintains a given distance from the bottom of the tank such that the passage of fluid is permitted past the inferior region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The detailed description presented in the following section makes reference to the appended FIGURES and the respective reference numbers thereof.

[0030] FIG. 1 illustrates a view of an optional configuration of the autonomous vertical flow agitation system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0031] In a preliminary manner it is emphasized that the description which follows arises from a preferential embodiment of the invention. As will however be obvious to anyone skilled in the art the invention is not limited to this particular embodiment.

[0032] FIG. 1 illustrates a view of a particular configuration of the autonomous vertical flow agitation system of the present invention.

[0033] As may be observed in FIG. 1, in a specific configuration of the invention herein described, the system comprises: a source of energy generation 1; an energy storage device 2; a control system 3; an electric motor 4; at least one end of travel sensor 5; an agitation plate 6; a torque transmission system 7; and at least two lateral drive elements 8.

[0034] The source of energy generation 1 is preferentially an autonomous generation source providing all the energy required for the operation of the system. Diverse sources of energy generation 1 may be adopted, wherein an autonomous source is preferred.

[0035] Optionally, the source of energy generation 1 is of the renewable type and may be of any type known in the state of the art such as, inter glia, photovoltaic or wind energy generators.

[0036] In FIG. 1 a configuration is illustrated wherein the source of energy generation 1 is a photovoltaic plate positioned above the autonomous vertical flow agitation system. In this configuration solar energy could be transformed into electrical energy to supply the entire system.

[0037] The invention furthermore anticipates a combination of different sources of energy, consequently, should the environmental conditions not be favorable for one type of source of energy generation 1 others may be used, not compromising the overall operation of the system.

[0038] The energy storage device 2 is optionally adopted to store the excess energy generated by the source of energy generation 1. The energy storage device 2 adopted may be any known in the state of the art, such as at least one battery, at least one supercapacitor, or the interaction of these latter, among others.

[0039] Optionally, as illustrated in FIG. 1, the energy storage device 2 is incorporated into the assembly of the vertical flow agitation system. In alternative configurations, however, the energy storage device 2 may be fixed at a point external to the system and connected to the same by electrical wiring.

[0040] Optionally, there is also adopted a control system 3 executing the control over the direction of movement of the autonomous vertical flow agitation system. This control system 3 may be composed by microcontrollers or by programmable logic controllers, or by relays, or by the interaction of these latter, among others.

[0041] Furthermore, when adopted, the control system 3 may be affixed to the assembly of the vertical flow agitation system. Nevertheless, in alternative configurations, the control system 3 may be fixed at a point external to the system, wherein the communication between the control system 3 and the elements controlled may be realized in wireless form.

[0042] The end of travel sensors 5 are adopted to detect when the agitation system reaches the end of the culture tank in one direction. When this occurs, the end of travel sensor 5 sends data to the control system 3 which will reverse the movement of the agitation system, it being displaced in the opposite direction, that is to say towards the other extremity of the culture tank.

[0043] It is emphasized that the control system 3 is responsible for controlling all the elements of the agitation system, wherein the communication between the control system and the other elements may be realized in any known manner, such as by electrical wiring or wireless connections.

[0044] The motor 4 is the device which will transform the electrical power received from the generating source 1, or from the storage device 2, into mechanical work to actually drive the agitation system, in particular, the agitation plate.

[0045] For this purpose, the invention comprises a transmission system 7 to transmit the torque generated by the motor 4 to the drive elements 8.

[0046] The transmission system 7 adopted may be any known in the state of the art. In the optional configuration illustrated, the transmission system 7 comprises a set of gears and shafts transmitting the required torque to the drive elements 8.

[0047] The drive elements 8 responsible for moving the agitation system, in particular the agitation plate 6, along the culture tank. Optionally, the drive elements 8 are positioned laterally in relation to the agitation plate 6, in this manner they also assist in the physical equilibrium of the system.

[0048] It is emphasized that, in spite of the fact that the lateral drive elements 8 illustrated in FIG. 1 comprise two wheels, each one positioned at each lateral extremity of the agitation plate 6, other configurations may be adopted.

[0049] For example, the drive elements 8 may comprise lateral rails or lateral belts connected to toothed shafts, or any other configurations permitting the driving of the agitation system along the culture tank.

[0050] Optionally, the drive elements 8 may be supported and be moved upon a lateral rim of the culture tank.

[0051] The agitation plate 6 is the element responsible for actually realizing the agitation of the liquid (and, consequently, of the microalgae) in the culture tank, such that the microalgae cells may be always exposed to the light.

[0052] The agitation plate 6 adopted is of the type commonly adopted in the state of the art. Consequently, the agitation plate 6 has lateral dimensions approximately equal to the internal lateral dimensions of the culture tank such that the minimum flow of culture is permitted to pass the sides of the agitation plate 6.

[0053] In addition, the agitation plate 6 extends vertically from a position above the water line of the culture tank to a region proximate to the bottom of the tank.

[0054] In this manner, the agitation plate 6 may present different formats, wherein the format adopted must substantially respect the format of the cross-section of the culture tank, wherein the sides of the agitation plate 6 must be located as proximately as possible to the walls of the tank, and the inferior region of the agitation plate 6 must maintain a given distance from the bottom of the tank such as to permit the passage of fluid past the inferior region.

[0055] Consequently, the operation of the vertical flow agitation system of the present invention may be summarized as described below.

[0056] The source of energy generation 1 furnishes the energy for the entire system and directs at least part of the energy to the storage device 2, to the motor 4 and to the control system 3. The motor 4 furnishes the mechanical torque to the transmission system 7 which transmits torque to the drive elements 8 and moves the system.

[0057] The control system 3 defines the direction of movement of the whole assembly shown in FIG. 1, that is to say when the same reaches one of the extremities of the tank the end of travel sensor 5 detects the position thereof and sends a signal to the control system 3 in order for the same to reverse the rotation of the motor 4. The assembly is then displaced in the contrary direction, in this manner executing a periodic movement, travelling along the entire tank in the longitudinal direction.

[0058] In this manner, whilst the system is being displaced in the culture, the agitation plate 6, being in direct contact with the same, executes the agitation of the microalgae, exposing the same to the light.

[0059] Consequently, the invention provides an autonomous vertical flow agitation system through the utilization of a photovoltaic generation unit to furnish all the energy required to execute the agitation of the culture, generating a reduction in the cost of electrical energy.

[0060] By means of all that set out it is clear that the vertical flow agitation system of the present invention demonstrates a series of advantages in relation to the models of the state of the art, they being: reduction in the unit cost of production of biomass from microalgae; automation of the agitation system, rendering it capable of operation even in remote areas whereat the offer of electrical energy is non-existent; low maintenance system, by virtue of the fact that the devices comprising it possess high durability; and facility of adaptation of the current culture systems to this invention.

[0061] Innumerable variations affecting the scope of protection of the present application are permissible. In this manner, the fact is reinforced that the present invention is not limited to the aforedescribed specific configurations and embodiments.