AU2012101593A4 - A system for growing one or more biological organisms - Google Patents

Abstract

A SYSTEM FOR GROWING ALGAE Described herein is a system 1 for growing algae. The system includes a substantially enclosed chamber (3) for defining an isolated, controllable environment having conditions that are favourable for growing algae. A substrate, in the form of a continuous fabric belt (5), is provided for supporting the algae during a predetermined growth period. A conveyor, in the form of a series of interconnected and generally parallel guiding rollers (7), is configured for moving the belt along a predetermined conveying path (9) through chamber (3) to expose the algae to light, carbon dioxide and nutrients under appropriate temperatures for promoting growth of the algae. The system is also configured for harvesting algae grown on the belt. (FIG. 1) I-M

Description

AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT ORIGINAL Name of Applicants: Brian Hutchings and Kevin Murphy Address for Service is: SHELSTON IP 60 Margaret Street Telephone No: (02) 9777 1111 SYDNEY NSW 2000 Facsimile No. (02) 9241 4666 CCN: 3710000352 Attorney Code: SW Invention Title: A system for growing one or more biological organisms Details of Associated Provisional Application No(s). 2011904761 (dated 15 Nov 2011) The following statement is a full description of this invention, including the best method of performing it known to us : File: 72350AUP00 2 A System for Growing one or more Biological Organisms FIELD OF THE INVENTION (0001] The present invention relates to a system and a method for growing one or more biological organisms. [0002] The invention has been developed primarily to facilitate the growth of algae and will be described herein with reference to that application. Moreover, in the preferred embodiments, the growth of the algae is, in part, to assist with the absorption of carbon dioxide from power stations and other carbon dioxide producing facilities, and for the production of bio-fuels and other products derivable from algae. While some embodiments will be described herein with particular reference to those technical applications, it will be appreciated that the invention is not limited to such a field of use, and is applicable in broader contexts including the growth of other biological organisms such as bacteria. BACKGROUND [0003] Any discussion of the background art throughout the specification should in no way be considered as an admission that such art is widely known or forms part of common general knowledge in the field. [0004] It has been known that micro and macro algae species have an ability to grow quickly and produce high protein mass and lipids. These resulting products can be used in the manufacture of pharmaceuticals, human food supplements and oil for the production of bio-diesel. As early as 1948, some commentators predicted that algae would have applications as a food source for human consumption to reduce the incidence of famine. [0005] Micro and macro algae species inhabit most marine environments, lakes, rivers and surface water reservoirs and, under certain conditions, cause contamination of those water bodies. For example, it is known for an algal species to "bloom" and dominate the flora and fauna of a river or other waterway. During a bloom, the elements present allow the algae to multiply at a very fast rate.

3 [0006] Current techniques to grow algae species attempt to replicate these environmental conditions which cause the algae to bloom and rapidly multiply. Examples of current commercial means for growing algae include open race ponds and photo bioreactors. Open Race ponds [0007] Algae species have been grown in open raceway type ponds for the past 50 years using both freshwater species and salt water species. These ponds contain water that is treated with nutrients and carbon dioxide either initially or over time to encourage the growth of the algae. [0008] Disadvantageously, the water in the open ponds is exposed to contamination by airborne bacteria, other varieties of algae, intruding flora and fauna, and additional water added to the ponds to replace the evaporative losses that occur over time. Also, the temperature of the water in the open ponds can fluctuate widely between night time and day time temperatures. This fluctuation can slow the growth of the algae and, in extreme cases, can even cause the entire algae species in the pond to die. Because of the varying conditions referred to above, open ponds require constant monitoring by qualified staff to maintain the conditions necessary to grow the algae. [0009] Algae require the infusion of carbon dioxide to sustain growth. During daylight hours, the algae utilise photosynthesis to convert sunlight and carbon dioxide into the necessary building blocks to maintain their development and growth. During this process, oxygen is produced as a waste product. [0010] Many attempts have been made to introduce other life forms into the ponds to assist with the nutrient balance such as catfish and shrimp, whereby the waste products from these creatures is used to assist with the supply of nutrients and carbon dioxide to the growing of the algae. However, these introduced life forms also require regular monitoring, can contaminate the pond, and come at an added cost to the producer. [0011] Another issue associated with the growing of algae in open ponds is the difficulty in harvesting the mature algae from the ponds. Algae can grow to a population of 200 parts per million in these ponds, which means there is approximately 200 kilograms of algae in 1 million litres of water. The removal of the algae from the water is therefore energy and resource intensive. To qualify this, to harvest 200 4 kilograms of algae from an open pond, 99.998 % of the water has to be separated through filtration of the water or by chemical flocculation. This process involves high capital and running costs, including pumps, filters, power consumption, labour and chemicals. [0012] Whilst algae will survive in a vast array of environments, the concentration of the algae will remain low unless the environment is favourable. Accordingly, to grow algae in commercially sustainable quantities stringent requirements must be met to provide the ideal conditions for them to grow consistently and quickly. The open pond system described above does not provide the ideal conditions required by algae due to contamination, environmental conditions and the required constant supply of nutrients and carbon dioxide. Photo Bio Reactors [0013] Over recent years much research has been employed to provide the perfect growing conditions to grow algae consistently and quickly in alternative technologies such as bio reactors. [0014] These devices are variable in shape and size but all of these devices encompass a singular approach: to isolate the algae from the prevailing environmental conditions. Photo bio reactors, as the name implies, are systems which provide correct amounts of light when required by the algae through natural and artificial illumination. They provide carbon dioxide, which is sparged or bubbled through the growing media. They also provide nutrients and control of temperature under certain circumstances all in the effort of producing consistent growing conditions for the algae. [0015] The bio reactors are usually formed as tubes and orientated along a vertical or a horizontal plane. The tubes circulate water that is loaded with the necessary nutrients to sustain algae growth. These bio reactors can also be formed using opposing plates of transparent or partially transparent glass which contain circulating liquid in a container between the sheets of glass. The transparency of the glass allows external light to reach the contained liquid. Bio reactors can be realised in a number of other configurations, all of which serve to achieve the ideal growing conditions required by the algae. [0016] Bio reactors are expensive to build and require large investment in resources, machinery and monitoring. Further, once the algae are grown and ready for harvesting, 5 similar difficulties are encountered in separating the algae from the water, as found with open pond systems. [0017] Overall, known systems are often too expensive to install and operate and too space intensive to be commercially viable for other than a very small number of sites. SUMMARY OF THE INVENTION [0018] It is an object of the invention, in its preferred form to provide an improved or alternative system for growing one or more biological organism. [0019] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [0020] In accordance with a first aspect of the present invention there is provided a system for growing one or more biological organisms, the system including: a substantially enclosed chamber for defining a growth zone; a substrate for supporting the one or more biological organisms during a predetermined period; and a conveyor for moving the substrate through the zone during the predetermined period to thereby promote growth of the one or more biological organisms. [0021] In an embodiment, the one or more biological organisms include at least one species of algae. [0022] In an embodiment, the one or more biological organisms include at least one species of bacteria. [0023] The substrate is preferably moveable along a predetermined conveying path through the growth zone for exposing the algae to one or more of light, carbon dioxide and a nutrient source. The conveying path preferably traverses predefined sub-zones within the growth zone, including: an illumination zone wherein the substrate is exposed to light; a first applicator zone wherein the substrate is exposed to a first treatment fluid; and 6 a second applicator zone wherein the substrate is exposed to a second treatment fluid. [0024] The system preferably also includes a harvesting zone within the chamber through which the conveying path passes, wherein, in the harvesting zone, algae are selectively extracted and collected from the substrate. [0025] The substrate is preferably defined by one or more fabric belts releasably engagable with the conveyor. The conveying path is preferably a loop and the substrate includes a belt extending continuously along the conveying path. The conveyor preferably includes a series of interconnected rollers for supporting the belt and urging the belt along the conveying path. At least one of the rollers is preferably mechanically driven. The at least one mechanically driven roller is preferably either: chain driven; or hydraulically driven. [0026] The conveyor preferably includes upper and lower vertically separated arrays of horizontally staggered rollers and wherein the conveying path extends between staggered rollers of the respective arrays. The lower array of rollers is preferably disposed within the first applicator zone. [0027] The first applicator zone preferably includes a reservoir of the first treatment fluid in liquid form and the conveying path passes through the reservoir thereby at least partially immersing the belt in the first treatment fluid. The lower array of the rollers is preferably at least partially submerged within the reservoir such that the belt passes through the reservoir after traversing each roller of the lower array. [0028] The upper array of rollers is preferably disposed within the second applicator zone. The second applicator zone preferably includes a plurality of fluid applicators for spraying the second treatment fluid onto the belt at locations adjacent the upper array of rollers. At least one of the first and second treatment fluids preferably include nutrients for promoting growth of algae. [0029] The illumination zone is preferably disposed between the upper and lower arrays of rollers. The chamber preferably includes one or more at least partially transparent windows for allowing light external to the chamber to illuminate the substrate in the illumination zone. The system preferably includes one or more LEDs 7 disposed within the chamber for selectively illuminating the substrate in the illumination zone. [0030] The harvesting zone preferably includes: an algae displacer for displacing algae from the substrate; and an algae collector for collecting algae displaced from the substrate. [0031] The algae displacer preferably includes a pair of opposing counter-rotating brushes disposed on either side of the substrate for scouring algae from the substrate. The algae displacer also preferably includes a pair of scraping blades positioned on opposing sides of the substrate for scraping algae from the substrate. The algae collector preferably includes at least one receiving aperture in communication with a receptacle, the aperture having a negative pressure gradient for urging removed algae through the aperture to the receptacle for collection. [0032] The system preferably includes a temperature controller for controlling temperature in the growth zone. The system also preferably includes a humidity controller for controlling humidity in the growth zone. The system further preferably includes one or more gas monitors for generating a monitor signal indicative of the level of carbon dioxide within the chamber and one or more actuators responsive to the monitor signal for selectively adjusting the level of carbon dioxide in the chamber. [0033] In accordance with a second aspect of the present invention, there is provided a method of growing algae including: defining a growth zone substantially isolated from a surrounding environment; providing a substrate for supporting the algae during a predetermined period; and moving the substrate through the zone during the predetermined period to thereby promote growth of the algae. [0034] In an embodiment, the method includes the additional step of the one or more biological organisms being selected from at least one species of algae. [0035] In an embodiment, the method includes the additional step of the one or more biological organisms being selected from at least one species of bacteria.

8 [0036] In accordance with a third aspect of the present invention there is provided a processing system including: an inlet for receiving the one or more biological organisms grown in the system of the first aspect of the invention; a processor for processing the one or more biological mechanisms and for providing at least a product and a by-product; and a first outlet and a second outlet for expelling the product and the by-product respectively from the processor. [0037] In an embodiment, the one or more biological organism is selected from at least one species of algae and the product is a vegoil algae product and the by-product is algal cake. [0038] In accordance with a fourth aspect of the present invention there is provided a product produced by the processing system of the third aspect. [0039] In accordance with a fifth aspect of the present invention there is provided a method of processing including the steps of: providing an inlet for receiving the one or more biological organisms grown in the system of the first aspect of the invention; processing the one or more biological mechanisms and providing at least a product and a by-product; and providing a first outlet and a second outlet for expelling the product and the by product respectively. [0040] In an embodiment, the one or more biological organism is selected from at least one species of algae and the product is a vegoil algae product and the by-product is algal cake. [0041] In accordance with a sixth aspect of the present invention there is provided a product produced by the method of processing of the fifth aspect. BRIEF DESCRIPTION OF THE DRAWINGS [0042] Preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: 9 FIG. 1 is a perspective view of a system for growing algae according to one aspect of the present invention; FIG. 2 is conceptual flow chart illustrating various functional zones within the system of Fig. 1; FIG. 3 is a sectional side view of the system illustrating the configuration of rollers and conveying belt within the system; FIG. 4 is a sectional side view of the system illustrating the positioning of nozzles for applying treatment fluid to the belt; FIG. 5 is a sectional side view of the system illustrating the positioning of LEDs for illuminating the belt as it moves between the rollers; FIG. 6 is sectional side view of the system illustrating a harvester for displacing and collecting algae grown on the belt; FIG. 7 is another sectional side view of the system; FIG. 8 is a schematic process flow diagram illustrating process control between a climate control system and sensors and actuators within the chamber of the system; and FIG. 9 is a functional flow chart outlining the main steps in a method according to an aspect of the present invention. DETAILED DESCRIPTION [0043] Referring initially to Fig. I there is provided a system I for growing algae. The system includes a substantially enclosed chamber 3 for defining an isolated, controllable environment having conditions that are favourable for growing algae. A substrate, in the form of a continuous fabric belt 5, is provided for supporting the algae during a predetermined growth period. A conveyor, in the form of a series of interconnected and generally parallel guiding rollers 7, is configured for moving the belt along a predetermined conveying path 9 through chamber 3 to expose the algae to light, carbon dioxide and nutrients under appropriate temperatures for promoting growth of the algae. The system is also configured for harvesting algae grown on the belt.

10 [0044] Chamber 3 is defined by interconnected metal panels II of a shipping container and is portable. Panels 11 each include an inwardly disposed temperature insulating layer (not shown) and are opaque to visible electromagnetic radiation. In some embodiments, one or more of panels I I defining at least one window for allowing light to penetrate into chamber 3. In one embodiment, every panel II is transparent to allow external light to penetrate into chamber 3. In another embodiment, a subset of the panels 11, or defined regions within panels 11, defines transparent windows to allow light to penetrate chamber 3 at specific locations. [0045] The operation of system I requires the maintenance of a gaseous growing environment in combination with the ingress and egress of various materials into and from chamber 3. With the exception of those materials, chamber 3 is sufficiently sealed in practical terms to prevent any large movements of air and other contaminants into the chamber while still maintaining a relatively stable gaseous growing environment. [0046] Chamber 3 is portable, generally rectangular and has dimensions of about 6 m in length, 2.5 m in height and 2.5 m in width. In another embodiment, chamber is defined within a warehouse of dimensions 65 m long, 50 m wide and 10 m high. In this latter embodiment, chamber 3 is defined by transparent polyethylene film and has no panels. It will be appreciated by those skilled in the art that in other embodiments, chamber 3 has other forms, is of varying sizes and is fixed. In one further embodiment, chamber 3 is defined within a fixed warehouse or building structure being at least partially sealed to the external environment. [0047] In the illustrated embodiment, the conveyer is defined by rollers 7 and the substrate is a continuous fabric belt extending along the length of conveying path 9 about the rollers. Rollers 7 are about 2 m long and 50 mm in diameter. Belt 5 is about 2 m in width. In another embodiment, the conveyer is defined by rollers 7 and a continuous connecting belt extending between rollers 7. In this latter embodiment, the substrate is defined by one or more fabric mats releasably engagable with the connecting belt. In a further embodiment, the mats are engagable with the belt by way of an adhesive such as glue or Velcro. In another further embodiment, the mats are engaged with the belt by clamps disposed at spaced locations along the belt. In a still further embodiment, the conveyer includes attachment rails extending between the rollers for securely receiving the one or more mats or belt and supporting them during I1 movement along the conveying path. In other embodiments, belt 5 is formed of other materials besides fabric. [0048] Referring now to Fig. 2, system I provides a series of functional zones within chamber 3. In traversing conveying path 9, the algae, supported on belt 5, are passed sequentially through: a growth zone 13, including a first applicator zone 15 where the algae are exposed to a first treatment fluid; an illumination zone 17 where the algae are exposed to light; and a second applicator zone 19 where the algae are exposed to a second treatment fluid. After one or more repetitions of the sequence, the algae are then passed through a harvesting zone 21, where the algae are selectively extracted and collected from belt 5. [0049] Path 9 is a convoluted loop and provides an iterative process of growth and harvesting of algae are established in system 1. Belt 5 extends continuously along conveying path 9 so that the process of growth and harvesting is substantially continuous. The harvesting process is configured to retain some residual algae on belt 5 to make further growth of algae possible during passage of growth zone 13 in the next cycle. As will be explained, the particular order and location of zones 15, 17 and 19 within growth zone 13 is variable and repeatable within a single cycle. In some embodiments, harvesting zone 21 is disposed within growth zone 13 and growth of algae on belt 5 continues through the harvesting process. In other embodiments, belt 5 is provided by two separate belts, and the algae are transferred between the belts. [0050] Turning now to Fig. 3, rollers 7 are arranged in upper and lower vertically separated arrays 23 and 25 and rollers 7 are horizontally staggered. In one embodiment, upper array 23 and lower array 25 are separated by a height of about 10 m and rollers 7 of each array are spaced apart by a distance of about 100 mm. Belt 5 extends between staggered rollers of arrays 23 and 25, passing over the tops of rollers in upper array 23 and under the bottom of rollers in lower array 25. Between each roller 7, belt 5 extends substantially vertically. Rollers 7 are generally cylindrical in shape having an axial width that is great enough to laterally support belt 5. In one embodiment, belt 5 has a width that is smaller than the axial width of rollers 7, while in another embodiment, belt 5 has a width that is greater than the axial width of rollers. In this latter embodiment, the outer regions of belt 5 do not contact rollers 7. In still other 12 embodiments, rollers 7 have other shapes and profiles such as an elongate polygon profile to reduce the contact of the rollers with the surface of belt 5. [0051] Rollers 7 of upper array 23 are mounted for rotation about respective substantially horizontal axles 27 and are engagable with a drive chain 29, which is mechanically driven by an electric motor (not shown), to move belt 5 along the conveying path. Chain 29 is engagable with like sprockets or cogs (not shown) fixedly mounted to respective axles 27 of each roller of upper array 23 for substantially uniformly rotatably driving the axles and corresponding rollers to provide linear motion of belt 5 along conveying path 9. In one embodiment, chain 29 and the sprockets are connected to an electric motor and reduction gearbox installed outside chamber 3 and connected through a connecting chain which passes through the insulated exterior wall of the chamber. [0052] Axles 27 of upper array 23 are rotatably supported by bearings (not shown) attached to the structure of chamber 3. In another embodiment, axles 27 are fixedly mounted to the bearings and chain 29 is engagable with sprockets on rollers 7 to rotatably move rollers 7 with respect to axles 27. [0053] Rollers 7 of lower array 25 are passive free-rotating rollers for guiding belt 5 and are engaged to a fixed support 31 by respective pairs of tension springs 33. Support 31 is mounted to the adjacent panel 11 of chamber 3 by tension bolts 35 and 36 and corresponding nuts 37 and 38. Tension springs 33 provide the tension needed to drive belt 5 along conveying path 9 under and over respective rollers 7. [0054] In another embodiment, only one roller is mechanically driven and the remaining rollers are passive free-rotating rollers. In a further embodiment, one or more rollers are mechanically driven hydraulically by a hydraulic power source. [0055] Referring still to Fig. 3, zone 15 is defined by a reservoir 39 for containing a first treatment liquid 41. As shown, rollers 7 of lower array 25 are partially submerged within reservoir 39 such that belt 5 travels through liquid 41 after passing each lower roller. In this embodiment, liquid 41 is a solution of water and liquid nutrients that are favourable for promoting algae growth. In other embodiments, liquid 41 is water only or liquid nutrients only.

13 [0056] In a further embodiment, liquid 41 is temperature controlled within reservoir 39 for additionally promoting growth of algae. [0057] In other embodiments, reservoir 39 is segmented into a plurality of sub reservoirs that contain respective treatment liquids. This allows for the use of different liquids at different points in the growth cycle. [0058] Reservoir 39 is preferably fed by an inlet pipe (not shown) to replenish the level of liquid 41 within reservoir 39 without the need to further unseal chamber 3. [0059] Referring to Fig. 4, a plurality of nozzles 43 are disposed above rollers 7 of upper array 23 for directing a second treatment fluid 45 toward belt 5 as the belt passes by each upper roller. Nozzles 43 source fluid 45 from a supply pipe 46 in fluid connection with a source (not shown). In other embodiments, fluid 45 is directed toward belt 5 by other form of fluid applicator. The area of application of fluid 45 defines zone 19. Nozzles 43 are configured to apply treatment fluid 45 to the algae on belt 5 in the form of a mist, vapour or atomized droplets. Such droplets have a large surface area and are capable of dissolving a larger amount of carbon dioxide into the water and nutrient being atomised. Treatment fluid 45 is preferably a solution of nutrients and water. The nutrients may be the same or different to the nutrients contained in liquid 41. In other embodiments, liquid 41 includes only nutrients or only water. Further, in some embodiments, nozzles 43 deliver fluid 45 at a predetermined temperature and/or at selectively variable rates. [0060] In this embodiment fluid 45 is a liquid containing a combination of nutrients. In other embodiments, fluid 45 is a gas. In further embodiments, fluid 45 is a combination of a liquid and a gas. In still further embodiments, fluid 45 includes one or more solids that are entrained in the liquid and/or gas. [0061] Referring now to Fig. 5, a plurality of light emitting diodes (LEDs) 47 are mounted on laterally extending elongate support rails 49 that are disposed intermediate array 23 and array 25. LEDs 47 emit electromagnetic radiation at wavelengths in one or more of the visible, ultraviolet or infrared ranges. This emitted radiation is incident upon the algae on belt 5 to stimulate or promote growth of algae and initiate photosynthesis. The locations where belt 5 is irradiated by LEDs 47 define or partially 14 define zone 17. LEDs 47 are independently or collectively controllable to adjust the output intensity and wavelength of radiation, and to be switched on or off. [0062] In one embodiment, chamber 3 includes one or more spaced apart transparent windows for allowing radiation external to chamber 3 to illuminate algae on belt 5 in zone 17. In this embodiment, belt 5 is illuminated by light from both LEDs 47 and light transmitted through the one or more windows. In one embodiment, the windows are configured to be selectively opened and closed by corresponding actuators for assisting with the regulation of the gaseous environment contained within chamber 3. [0063] In one embodiment, control of LEDs 47 is provided by one or more light sensors (not shown) and an associated feedback circuit (not shown). The sensors generate a sensor signal indicative of the intensity of light irradiating belt 5 and the feedback circuit is responsive to the sensor signal to selectively adjust the output intensity and/or output wavelength of LEDs 47. In embodiments where chamber 3 includes windows, the adjustability of LEDs 47 allows the overall intensity of light incident onto belt 5 to be maintained at a relatively constant level even as the external light received through the windows varies. For example, in one embodiment, selective adjustment of LEDs 47 is used to compensate for a diurnal variation in sunlight intensity. In another embodiment, LEDs 47 are controlled by an electronic timing device. [0064] In one embodiment, the combined light intensity from the windows and from LEDs 47 is monitored and the LED output intensity is controlled to continuously output light at an intensity level of about 2,500 to 5,000 Lm (lumens) for twenty four hours per day to activate the Calvin cycle or photosynthesis of the algae. [0065] Once sufficient algae growth has occurred on belt 5, the algae must be extracted for later use. In this embodiment, the later use includes being converted into one or more of the following: algal oil; algal cake; and other by-products. Referring to Fig. 6, system I includes a harvester 51 for removing and collecting algae from belt 5. Harvester 51 is located at one end of chamber 3 in an enclosed area defining zone 21. As shown in Fig. 6, belt 5 is directed through harvester 51 by a set of directing rollers 53, 55, 57, 59 and 61.

15 [0066] Harvester 51 includes a pair of opposing counter-rotating brushes 63 and 65, disposed on either side of belt 5 for scouring algae from belt 5. As algae is able to grow on both sides of belt 5, scouring both sides of belt 5 ensures more efficient removal of algae. Brushes 63 and 65 have a width that is equal to or greater than the width of belt 5 and are disposed horizontally relative to each other while belt 5 is passed vertically downwardly between the brushes. Brushes 63 and 65 include semi-flexible or rigid bristles that are urged against belt 5 counter to the direction of travel of the belt to scour the algae growing on belt 5. [0067] Harvester 51 further includes a pair of scraping blades 67 and 69 that are positioned on opposing sides of belt 5 immediately below brushes 63 and 65. That is, the blades are downstream of the brushes. Blades 67 and 69 are rigid or semi-rigid and have tips that engage belt 5 at an upward and inwardly directed angle. As belt 5 moves between blades 63 and 65, their tips scrape algae from belt 5. [0068] Harvester 51 also includes a pair of receiving apertures 71 and 73 connected to a receptacle (not shown) by one or more vacuum tubes (not shown). Apertures 71 and 73 are disposed to receive algae scoured from belt 5 by brushes 63 and 65 and/or scraped from belt 5 by blades 67 and 69. Apertures 71 and 73 are located on opposite sides of belt 5 to collect displaced algae from both sides of the belt. A negative pressure gradient, provided by a vacuum pump (not shown), is established between chamber 3 and the receptacle to urge loose algae through apertures 71 and 73 to the receptacle for collection. In one embodiment, the receptacle includes a centrifuge for removing water and moisture from the algae to produce products such as B100 Bio Diesel and algal cake. [0069] Apertures 71 and 73 are disposed below brushes 63 and 65 and blades 67 and 69 to capture algae falling under gravity after being scoured and scraped from belt 5. In another embodiment, a receiving tray is provided adjacent apertures 71 and 73 for catching scoured algae prior to or in addition to being urged through apertures 71 and 73 to the receptacle. In one embodiment, a return tube is provided between the receptacle and chamber 3 to return the exhausted vacuum gas, containing an enriched atmosphere of carbon dioxide, to chamber 3.

16 [0070] The positioning of blades 67 and 69 and brushes 63 and 65 are selectively laterally adjustable to set the amount of contact with belt 5 and to remove more or less algae. However, in other embodiments, blades 67 and 69 and brushes 63 and 65 are fixed with respect to belt 5. In some embodiments, blades 67 and 69 and brushes 63 and 65 are selectively moveable vertically along belt 5. It will be appreciated that, in other embodiments, harvester 51 is provided with only one of blades 67 and 69 or brushes 63 and 65. That is, in these other embodiments, removal of algae from belt 5 is provided solely by brushes 63 and 65 or solely by blades 67 and 69. [0071] Referring to Fig. 6 and 7, after removal of algae, belt 5 travels along a return path section 75 of path 9 to once again enter zone 13 to begin the growth stage again. As shown in Fig. 7, path 75 extends through reservoir 39 below array 25 of rollers 7 and is returned to arrays 23 and 25 by a lower roller 77 within reservoir 39. Harvester 51 is configured to leave a small amount of algae on belt 5 to initiate growth during the next cycle through the growth zone 13. [0072] In another embodiment, system 1 includes no harvester and algae are collected manually from belt 5. In this embodiment, internal access to chamber 3 is provided through a door, window, access panel or the like. In some embodiments, belt 5 is selectively removable from rollers 7 for separately removing algae and replacement belts are able to be installed on rollers 7. [0073] With reference now to Fig. 8, system I includes a climate control system 79 for controlling temperature, humidity and carbon dioxide levels within chamber 3. Fig. 8 illustrates schematically the signal process flow between climate control system 79 and chamber 3. Sensors 81, 83 and 85, which include thermostats, humidity monitors and gas monitors, located within chamber 3 measure respectively the temperature, humidity and carbon dioxide levels within chamber 3 and transmit respective signals to climate control system 79. System 79 processes these signals and transmits signals to respective actuators 87, 89 and 91 for selectively controlling the parameters within chamber 3. System 79 includes a processor and a database. The processor processes input sensor signals and produces output actuator control signals. The database stores data indicative of optimum temperature, humidity and carbon dioxide levels for growing algae.

17 [0074] Actuators 87, 89 and 91 control respective devices for modifying the respective temperature, humidity and carbon dioxide in chamber 3. Referring to Fig. 1, temperature and humidity are controlled by an air conditioner 93 disposed in a side of chamber 3. Air conditioner 93 draws gasses from within chamber 3, selectively modifies the temperature of the gasses, if necessary, and returns those gasses to the interior of the chamber. Air conditioner 93 is also configured to control the relative humidity inside chamber 3. Specifically, as the temperature is raised or lowered, the "dew point" of condensation of excessive moisture in chamber 3 is varied. [0075] Control of carbon dioxide within chamber 3 is provided by an inlet (not shown) connected to an external source of carbon dioxide, such as a gas cylinder. The inlet is selectively actuated by carbon dioxide actuator 87 from system 79. If an increase in carbon dioxide is required, actuator 87 opens the inlet to allow more carbon dioxide to enter chamber 3. The inlet has a non return valve which restricts the passage of carbon dioxide gas to the input direction only. In one embodiment, chamber 3 also includes a vent (not shown) for venting carbon dioxide gas if the gas level becomes too high. This vent is also selectively actuatable by the carbon dioxide actuator signal from climate control system 79. [0076] In one embodiment, system 79 is also configured to control the output intensity and wavelength of LEDs 47 through respective sensors and actuators. Further, in some embodiments, climate control system 79 is also configured to selectively control the output rate of liquid 41 from nozzles 43. [0077] In one embodiment, system 79 is configured to selectively control the speed of one or more circulation fans located within chamber 3. The fans actuate to keep the atmosphere in a mixed state. Due primarily to the density of carbon dioxide, stratification of layers of dense and lighter gasses may occur. By providing regular circulation, this stratification of gasses is substantially reduced. [0078] In some embodiments, system 79 is configured to only control these parameters in a subregion of chamber 3, such as in growth zone 13. In other embodiments, the temperature, humidity and carbon dioxide levels are controlled independently by separate monitors and controllers not configured through system 79. In some 18 embodiments, system 79 is provided as an integrated unit together with chamber 3. In other embodiments, system 79 is provided separately to chamber 3. [0079] The concentrated carbon dioxide within the atmosphere of chamber 3 can be harmful to humans. Therefore, in some embodiments, chamber 3 includes safety devices to prevent the chamber from being opened while in operation. In one particular embodiment, an electronic locking system is provided that is responsive to inputs from a gas monitor or system 79 to selectively prevent access to chamber 3 while the carbon dioxide measured to be above a predetermined threshold level. [0080] Referring now to Fig. 9, there is illustrated a process diagram of a method of growing algae according to an aspect of the present invention. At step 100, algae, supported on a substrate, such as belt 5 described above, is progressed through zone 13. This includes, at sub-step 102, immersing the substrate in a liquid treatment fluid, at sub-step 104, irradiating the substrate with light, at sub-step 106, spraying a second treatment fluid onto the substrate, and at sub-step 108, exposing the substrate to carbon dioxide. At optional step 110, sub-steps 102 to 108 are able to be repeated a predetermined number of times until a desired amount of algae growth occurs on the substrate. For example, in system 1 described above, each return pass of belt upward and downward between arrays 23 and 25 of rollers 7 represents a completion of sub steps 102 to 108. It will be appreciated that the particular order of sub-steps 102 to 108 is interchangeable without departing from the scope of the invention. [0081] Once sufficient algae growth has occurred, at step 112, the substrate is passed through a harvesting zone. At sub-step 114 in the harvesting process, algae are displaced from the substrate, for example, by brushes 63 and 65, and by blades 67 and 69 described above. At sub-step 116, the displaced algae are collected for later use, for example, by receiving apertures 71 and 73, and the receptacle described above. [0082] After harvesting a small amount of algae remains on the substrate. At step 118, the substrate is then returned to the growth zone for further growing algae from the remaining algae on the substrate. CONCLUSIONS [0083] It will be appreciated that the illustrated system for growing algae provides an improved or alternative means for growing algae. The present invention allows for 19 efficient growing of large quantities of algae suitable for pharmaceuticals, bio diesel and high protein animal feed stock. The present invention produces algae using a smaller carbon footprint than bio reactors and has much smaller land requirements than open ponds. [0084] The present invention provides other advantages in growing algae over the known methods of open ponds and bio reactors, including: > High efficiency in production of algae. One estimate, assuming a 3,000 square meter warehouse sized chamber, places algal production at about 4,000 kg per day. > Close emulation of ideal growing conditions for algae by moving the algae laden substrate or belt through varying conditions, including exposure to light, moisture, nutrients and carbon dioxide at suitable temperatures. > Easy extraction of algae from the substrate. The internal harvesting system of the present invention makes removing and collecting grown algae easy and efficient, compared to that of open ponds and bio reactors. > A smaller carbon footprint compared to bio reactors. The carbon dioxide input to the present system is efficiently circulated and recycled until it is absorbed by the algae. > Reduction in the land area required for open ponds. INTERPRETATION [0085] Throughout this specification, use of the term, "light" is intended to mean electromagnetic radiation in one or more of the ultraviolet, visible and infrared wavelength regions. [0086] Throughout this specification, use of the term "element" is intended to mean either a single unitary component or a collection of components that combine to perform a specific function or purpose. [0087] Reference throughout this specification to "one embodiment", "some embodiments" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases "in one 20 embodiment", "in some embodiments" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. [0088] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. [0089] In the claims below and the description herein, any one of the terms comprising, comprised of or which comprises is an open term that means including at least the elements/features that follow, but not excluding others. Thus, the term comprising, when used in the claims, should not be interpreted as being limitative to the means or elements or steps listed thereafter. For example, the scope of the expression a device comprising A and B should not be limited to devices consisting only of elements A and B. Any one of the terms including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising. [0090] It should be appreciated that in the above description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, Fig., or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

21 [0091] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the disclosure, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. [0092] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. [0093] Similarly, it is to be noticed that the term coupled, when used in the claims, should not be interpreted as being limited to direct connections only. The terms "coupled" and "connected," along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression a device A coupled to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. "Coupled" may mean that two or more elements are either in direct physical, electrical or optical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. [0094] Thus, while there has been described what are believed to be the preferred embodiments of the disclosure, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the disclosure, and it is intended to claim all such changes and modifications as fall within the scope of the disclosure. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present disclosure.

Claims (43)

1. A system for growing one or more biological organisms, the system including: a substantially enclosed chamber for defining a growth zone; a substrate for supporting the organisms during a predetermined period; and a conveyor for moving the substrate through the zone during the predetermined period to thereby promote growth of the organisms.

2. A system according to claim I wherein the one or more biological organisms include at least one species of algae.

3. A system according to claim I wherein the one or more biological organisms include at least one species of bacteria.

4. A system according to claim 2 wherein the substrate is moveable along a predetermined conveying path through the growth zone for exposing the algae to one or more of light, carbon dioxide and a nutrient source.

5. A system according to claim 4 wherein the conveying path traverses predefined sub zones within the growth zone, including: an illumination zone wherein the substrate is exposed to light; a first applicator zone wherein the substrate is exposed to a first treatment fluid; and a second applicator zone wherein the substrate is exposed to a second treatment fluid.

6. A system according to claim 4 or claim 5 including a harvesting zone within the chamber through which the conveying path passes, wherein, in the harvesting zone, algae are selectively extracted and collected from the substrate.

7. A system according to claim 5 or claim 6 wherein the substrate is defined by one or more fabric belts releasably engagable with the conveyor. 23

8. A system according to claim 7 wherein the conveying path is a loop and the substrate includes a belt extending continuously along the conveying path.

9. A system according to claim 8 wherein the conveyor includes a series of interconnected rollers for supporting the belt and urging the belt along the conveying path.

10. A system according to claim 7 wherein at least one of the rollers is mechanically driven.

11. A system according to claim 10 wherein the at least one mechanically driven roller is either: chain driven; or hydraulically driven.

12. A system according to any one of claims 9 to 11 wherein the conveyor includes upper and lower vertically separated arrays of horizontally staggered rollers and wherein the conveying path extends between staggered rollers of the respective arrays.

13. A system according to claim 11 wherein the lower array of rollers is disposed within the first applicator zone.

14. A system according to claim 3 wherein the first applicator zone includes a reservoir of the first treatment fluid in liquid form and the conveying path passes through the reservoir thereby at least partially immersing the belt in the first treatment fluid.

15. A system according to claim 4 wherein the lower array of the rollers is at least partially submerged within the reservoir such that the belt passes through the reservoir after traversing each roller of the lower array.

16. A system according to any one of claims 12 to 15 wherein the upper array of rollers is disposed within the second applicator zone.

17. A system according to claim 166 wherein the second applicator zone includes a plurality of fluid applicators for spraying the second treatment fluid onto the belt at locations adjacent the upper array of rollers. 24

18. A system according to any one of claims 12 to 17 wherein at least one of the first and second treatment fluids include nutrients for promoting growth of algae.

19. A system according to any one of claims 12 to 18 wherein the illumination zone is disposed between the upper and lower arrays of rollers.

20. A system according to claim 19 wherein the chamber includes one or more at least partially transparent windows for allowing light external to the chamber to illuminate the substrate in the illumination zone.

21. A system according to claim 19 or claim 20 including one or more LEDs disposed within the chamber for selectively illuminating the substrate in the illumination zone.

22. A system according to claim 6 wherein the harvesting zone includes: an algae displacer for displacing algae from the substrate; and an algae collector for collecting algae displaced from the substrate.

23. A system according to claim 22 wherein the algae displacer includes a pair of opposing counter-rotating brushes disposed on either side of the substrate for scouring algae from the substrate.

24. A system according to claim 22 or claim 23 wherein the algae displacer includes a pair of scraping blades positioned on opposing sides of the substrate for scraping algae from the substrate.

25. A system according to claim 23 or claim 24 wherein the algae collector includes at least one receiving aperture in communication with a receptacle, the aperture having a negative pressure gradient for urging removed algae through the aperture to the receptacle for collection.

26. A system according to any one of the preceding claims including a temperature controller for controlling temperature in the growth zone.

27. A system according to any one of the preceding claims including a humidity controller for controlling humidity in the growth zone. 25

28. A system according to claim 4 including one or more gas monitors for generating a monitor signal indicative of the level of carbon dioxide within the chamber and one or more actuators responsive to the monitor signal for selectively adjusting the level of carbon dioxide in the chamber.

29. A method of growing one or more biological organisms, the method including: defining a growth zone substantially isolated from a surrounding environment; providing a substrate for supporting the one or more biological organisms during a predetermined period; and moving the substrate through the zone during the predetermined period to thereby promote growth of the one or more biological organisms.

30. A method according to claim 29 wherein the one or more biological organisms are selected from at least one species of algae.

31. A method according to claim 29 wherein the one or more biological organisms are selected from at least one species of bacteria.

32. A method according to claim 30 wherein the substrate is moved along a predetermined conveying path through the growth zone such that the algae are exposed to one or more of light, carbon dioxide and a nutrient source.

33. A method according to claim 32 wherein the conveying path traverses predefined sub-zones within the growth zone, including: an illumination zone wherein the substrate is exposed to light; a first applicator zone wherein the substrate is exposed to a first treatment fluid; and a second applicator zone wherein the substrate is exposed to a second treatment fluid.

34. A method according to claim 31 including the step of passing the substrate through a harvesting zone within the chamber, wherein, in the harvesting zone, algae are selectively extracted and collected from the substrate. 26

35. A method according to claim 31 wherein the conveying path is a loop and the substrate extends substantially continuously along the length of the conveying path.

36. A method according to claim 32 wherein the substrate is moved along the conveying path by a series of interconnected rollers.

37. A method according to claim 36 wherein at least one of the rollers is mechanically driven.

38. A method according to any one of claims 32 to 37 wherein, in the first applicator zone, the substrate is passed through a reservoir of the first treatment fluid.

39. A method according to any one of claims 32 to 38 wherein, in the second applicator zone, the second treatment fluid is sprayed onto the substrate.

40. A method according to any one of claims 32 to 39 including the step of controlling the temperature within the growth zone.

41. A method according to any one of claims 32 to 40 including the step of controlling the humidity within the growth zone.

42. A method according to any one of claims 32 to 41 including the step of circulating air and carbon dioxide within the growth zone.

43. A system or method for growing algae substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.