AEROPONICS APPARATUS

Abstract

Aeroponics apparatus is disclosed, which includes a grow bed tray having a base and at least two side-walls, the grow bed tray being able to hold a plant support at a position spaced from the base of the grow bed tray, and a nebulizer for nebulizing nutrient solution, the nebulizer located at the base of the grow bed tray and comprising an ultrasonic transducer and a holder for holding the ultrasonic transducer. Also disclosed is a method for crop production using the aeroponics apparatus by either flowing nutrient solution into the base of the grow bed tray to contact at least the roots of the crops or providing nutrient solution at the base of the grow bed tray and nebulizing the nutrient solution so that the nebulized nutrient solution contacts at least the roots of the crops.

Claims

1. Aeroponics apparatus comprising, a grow bed tray having a base and at least two side-walls, the grow bed tray being adapted to hold a plant support at a position spaced from the base of the grow bed tray, and a nebulizer for nebulizing nutrient solution, the nebulizer located at the base of the grow bed tray and comprising at least one ultrasonic transducer and a fixing portion for fixing the ultrasonic transducer in position.

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. Aeroponics apparatus as claimed in claim 1, wherein the at least one ultrasonic transducer is mounted under the base of the grow bed tray.

7. Aeroponics apparatus as claimed in claim 6, wherein the at least one ultrasonic transducer is held in a holder so that the at least one ultrasonic transducer is in contact with, and compressed against, the base of the grow bed tray.

8. (canceled)

9. Aeroponics apparatus as claimed in claim 7, comprising at least two ultrasonic transducers.

10. Aeroponics apparatus as claimed in claim 7, wherein each grow bed tray comprises one of 2 to 48 ultrasonic transducers, or 4 to 36 ultrasonic transducers, or 6 to 24 ultrasonic transducers.

11. Aeroponics apparatus as claimed in either claim 9, wherein each ultrasonic transducer may be controlled independently.

12. Aeroponics apparatus as claimed in claim 11, wherein each ultrasonic transducer is a piezoelectric transducer.

13. Aeroponics apparatus as claimed in claim 12, wherein each ultrasonic transducer has a resonant frequency in the 200 kilohertz to 100 megahertz range.

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. Aeroponics apparatus as claimed in claim 13, wherein the grow bed tray is adapted to hold a plant support spaced from the base of the grow bed tray, optionally by one or more supports, optionally located on the sidewalls of the grow bed tray.

20. Aeroponics apparatus as claimed in claim 19, wherein one or more of the sidewalls are detachable.

21. Aeroponics apparatus as claimed claim 20, further comprising grow bed tray attachments to attach at least two grow bed trays together.

22. Aeroponics apparatus as claimed in claim 21, comprising a grow bed comprising a plurality of grow bed trays.

23. Aeroponics apparatus as claimed in claim 22, further comprising at least one sensor fixings for fixing sensors in the grow bed tray, optionally further comprising at least one sensors selected from a group consisting of: moisture, light, pH, temperature, carbon dioxide, oxygen, infrared, or ultrasonic, sensors fixed to the sensor fixings.

24. (canceled)

25. (canceled)

26. Aeroponics apparatus as claimed in claim 23, comprising at least one plant support, and nutrient solution covering the nebulizer.

27. Aeroponics apparatus as claimed in claim 26, further comprising crops in the plant support, the roots of the crops, in use, being located in the root space between the plant support and the base of the grow bed tray.

28. A method for crop production, the method comprising, a) providing aeroponics apparatus as claimed in claim 1, b) providing a plant support at the position spaced from the base of the grow bed tray, c) providing crops in the plant support, and c) either: i) flowing nutrient solution into the base of the grow bed tray to contact by immersion at least the roots of the crops, and/or ii) providing nutrient solution at the base of the grow bed tray and nebulizing the nutrient solution so that the nebulized aerosol nutrient solution contacts at least the roots of the crops, optionally in the root space.

29. A method as claimed in claim 28, wherein nebulizing the nutrient solution comprises nebulizing the nutrient solution to provide a controlled droplet size distribution.

30. A method as claimed in claim 29, wherein the droplet size distribution comprises droplets having a diameter in the range 1 to 100 μm.

31. A method as claimed in claim 28, further comprising providing a root density sensor, determining the density of the root bed, nebulizing the nutrient solution to provide a controlled droplet size distribution corresponding to the predetermined optimal droplet size distribution for the density of the root bed.

32. A method as claimed in claim 28, wherein the nutrient solution comprises a by-product of aquaculture.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Embodiment of the invention will now be described with reference to the following figures, in which:

[0065] FIG. 1a) is a perspective view of apparatus according to the invention of a two tray grow bed; FIG. 1b) is a side view; and FIG. 1c) is a section on A-A of FIG. 1b).

[0066] FIG. 2a) shows a perspective view of apparatus according to the invention of a one tray grow bed; FIG. 2b) shows a side view; and FIG. 2c) shows a section on B-B of FIG. 2b).

[0067] FIG. 3 shows a schematic view of apparatus according to the invention.

[0068] FIG. 4 shows a perspective view of a grow bed (single grow bed tray) according to another embodiment of the invention.

[0069] FIG. 5 shows a partially exploded perspective view of a grow bed comprising two grow bed trays connected together.

[0070] FIG. 6a shows a perspective view of a plant support in the form of a plant support tray suitable for use with the grow beds as shown in FIG. 4 and FIG. 5.

[0071] FIG. 6b shows a perspective view of ten plant support trays as shown in FIG. 6a stacked for storage.

[0072] FIG. 7 shows a perspective view of an aeroponic apparatus according to the invention ready-for-use comprising a racked arrangement of three grow beds each grow bed having one grow bed tray and five plant support trays.

DETAILED DESCRIPTION

[0073] FIGS. 1a, 1b and 1c show an apparatus according to the invention of a two tray grow bed 2. The grow bed 2 has two grow bed trays 4, 6, a first grow bed tray 4 and a second grow bed tray 6 connected together at connection 14 by base connectors 16 and side connectors 18. Each grow bed tray has side walls 8, end walls 10, and a base 22. The base 22 has a profile to form a sump 24 for collecting nutrient solution (not shown) and nebulizer port 12 for nebulizer 20 situated in the sump 24 so the nebulizer is conveniently covered with nutrient solution when in use. As seen in the detail in FIG. 1(c), the nebulizer 20 comprises a nebulizer holder with nebulizer holder lower part 30 and nebulizer holder upper part 28 and an ultrasonic transducer 29 comprising a piezoelectric disc. The nebulizer holder 28, 29, 30 is detachably fixed to the base of the grow bed tray at the nebulizer interface 32 on the external surface of the nebulizer port 12.

[0074] The ultrasonic transducers 29 may have resonant frequencies in the kilohertz to megahertz range with the droplet size in the aerosol/mist generated being smaller with higher frequency.

[0075] Each grow bed tray has supports (not shown) on side walls 8 to hold a plant support (not shown) spaced from the base 22 of the grow bed tray 2, forming a root space 26.

[0076] FIGS. 2a, 2b and 2c show a second embodiment of apparatus according to the invention, comprising a single grow bed tray 102 with side walls 108, no end wall (for easier connection to another grow bed tray if desired), six nebulizers ports 112 holding nebulizers 120 distributed over the base 122 of the grow bed tray, each having under-mounted ultrasonic transducers 129 held by nebulizer holders. The nebulizers each comprise nebulizer holder lower part 130, and nebulizer holder upper part 128, and the ultrasonic transducer 129 comprising a piezoelectric disc. The nebulizer holder 128, 129, 130 is detachably fixed to the base of the grow bed tray at the nebulizer interface 132 on the external surface of the nebulizer port 112.

[0077] The ultrasonic transducers 129 may have resonant frequencies in the kilohertz to megahertz range (e.g. 200 kHz to 100 MHz) with the droplet size in the aerosol/mist generated generally being smaller with higher frequency.

[0078] The grow bed tray 102 has supports (not shown) on side walls 108 to hold a plant support (not shown) spaced from the base 122, forming a root space 126.

[0079] FIG. 3 is a schematic of apparatus according to the invention. A grow bed of a single grow bed tray 202 has side walls 210 with supports 237 holding a plant support mat 236 above the base of the grow bed tray to form a root bed space 226. Nutrient solution 234 immerses a nebulizer holder 232 holding an ultrasonic transducer 230. When activated the nebulizer will produce a mist of nutrient solution 234 which disperses throughout the root bed space 226.

[0080] Nutrient solution 234 is supplied through inlet 238 from reservoir 248 and supplied through first conduits 246, low pressure pump 244 and second conduit 242.

[0081] Excess nutrient solution is removed through outlet 240.

[0082] FIG. 4 shows a view of a grow bed according to another embodiment of the invention comprising a single grow bed tray 302 with side walls 308, end walls 310, a plurality of nebulizer shields 320 distributed over the base 322 of the grow bed tray, each having an ultrasonic transducer (not shown) mounted underneath the nebulizer shield 320. The nebulizer shields 320 shield the transducer from the plant roots and otherwise protects them in use. The base 322 of the grow bed tray 302 is otherwise substantially flat and even for easier cleaning, with no sharp comers inside the grow bed tray 302. The grow bed tray 302 comprises a liquid port 312 for inlet and outlet of nutrient solution/waste liquid and a control panel 352.

[0083] FIG. 5 shows an aeroponics apparatus according to an embodiment of the invention comprising a grow bed 402 comprising two grow bed trays. The two grow bed trays are connectable together by removal of the side walls 410 between them and use of attachment fixings (not shown). A plurality of nebulizer shields 420 are distributed over the base 422 of the grow bed trays, each having an ultrasonic transducer (not shown) mounted underneath the nebulizer shield 420. The nebulizer shields 420 shield the transducer from the plant roots and otherwise protect the ultrasonic transducers in use. The base 422 of the grow bed trays are otherwise substantially flat and even for easier cleaning, with no sharp comers. The grow bed trays each comprise a control panel 452.

[0084] The ultrasonic transducers are mounted under the base of the grow bed tray (i.e. are under-mounted) and may be held in a holder so that the ultrasonic transducer is in contact with (and preferably compressed against) the base of the grow bed tray. Generally, this arrangement provides that there is a single layer (usually a relatively thin, single layer) of e.g. plastics or metallic material between the ultrasonic transducer and the nutrient solution, in use. The single layer of e.g. plastics or metallic material provides good acoustic transmission properties.

[0085] The ultrasonic transducer may be mounted into a holder that may be permanently attached to the grow bed tray. The holder usually has a wipe-clean surface/interface, and the ultrasonic transducer is removable from the holder (e.g. may be screwed/compressed into position without removing the holder).

[0086] FIG. 6a shows a plant support in the form of a plant support tray 62 for use with the grow bed trays illustrated in FIG. 4 and FIG. 5. The plant support tray 62 is of a plastics material and comprises a base 64 with apertures 66 to act as supports for crops.

[0087] The plant support tray 62 comprises high side walls 68, 70 and low side walls 72, 74. The tops of the high side walls 68, 70 are shaped to allow convenient stacking with other plant support trays.

[0088] FIG. 6b shows a plurality of plant support trays 62 according to FIG. 6a stacked for storage.

[0089] FIG. 7 shows a perspective view of an aeroponic apparatus according to the invention ready for use. The apparatus comprises racked arrangement 501 of three grow beds 503, 504, 505 each grow bed having a grow bed tray 502 and five plant support trays 62. The grow beds 503, 504, 505 are supported on a shelving rack 507. Each grow bed 503, 504, 505 may be individually controlled by control panels 552. Generally, there may be additional software control system to operate a farming facility.

[0090] The aeroponics apparatus according to the invention is generally for greenhouses and vertical crop production, especially commercial greenhouses and vertical farms. In practice, the apparatus may comprise a hollow grow bed formed of one or more grow bed trays, each grow bed/grow bed tray may have a front end, a back end, a profiled base, and open upper face. The base of a grow bed tray may comprise one or more sumps or a gradient/taper dependent on bed width, in the base of the grow bed tray/grow bed for collecting/directing aqueous nutrient solution in a particular location.

[0091] Generally, each ultrasonic transducer may be controlled independently.

[0092] The apparatus may have standardized interfaces in the grow bed structure for the introduction of sensors and additional modular apparatus. The ends of the grow bed may be detachable and detachably fixed to another grow bed using fixing attachments. The grow bed ends may include T sections for attachment of multiple beds together into a contiguous system, an end section that encloses the internal area and contains interfaces for piping/tubing attachment.

[0093] The apparatus generally includes at least one port that may be an inlet, an outlet or both an inlet and outlet for the nutrient solution. Solution may be provided from a nutrient solution reservoir through pipe/tube/conduits and driven by gravity of a relatively low-pressure pump. There may be other fluid inlets and outlets above the water line for use of gaseous and visual sensory equipment and supply of gases (e.g. air, oxygen and/or carbon dioxide).

[0094] In use, a plant support medium may be arranged across the grow bed tray/grow bed to support growing plants and to reduce the loss of moisture. The plant support may be fibrous. The plant support generally will support the crop plants such that their leaves, crown and fruits are above the plant support and the roots suspended below where the roots can contact the mist generated by the nebulizer. This is useful because it allows space for equipment for harvesting, monitoring, or otherwise tending the crop plants. An additional advantage of a plant support medium is to reduce or prevent the escape of aerosol/mist (and hence moisture) from the root space since it is important to maintain humidity control within the apparatus, especially over the humidity of the root space. The apparatus may therefore have rails or other mechanisms that allow movement or positioning of harvesting, monitoring or other tending devices.

[0095] The apparatus may comprise lighting fixings for suspension of lighting above the grow bed/grow bed trays and may, in use also comprise lighting attached to the lighting fixings.

[0096] The apparatus may have an attachment portion for attachment of a nebulizer at the base of the grow bed tray and may comprise an ultrasonic transducer and an acoustically designed holder for holding the ultrasonic transducer. The ultrasonic transducer will usually comprise one or more piezoelectric devices. The holder will usually be made of acoustically appropriate material (i.e. material with suitable acoustic properties) and will have a suitable form factor for effective dispersion of ultrasonically generated mist. The holder and/or ultrasonic transducer may be detachable from the grow bed/grow bed tray and from each other for maintenance.

[0097] The nebulizer, lighting, sensors where and other powered devices will also have electrical connector for connection to a power supply.

[0098] The aeroponic apparatus allows for a method for vertical hydroponic or aeroponic greenhouse crop production, the method comprising connecting the grow bed to nutrient solution reservoir via tubing and a pump and allows use of both aeroponic production, but also hydroponic production if desired.

[0099] The aeroponic method may comprise pumping nutrient solution from the reservoir into the grow bed through the tubing at sufficient quantity that the troughs (i.e. the grow bed tray or grow bed trays) have sufficient nutrient solution to operate efficiently full, at which point the nutrient solution level is maintained at the optimal level for activation of the ultrasonic transducers. During atomization, usually the troughs will be partially filled. More nutrient solution results in dissipation of energy before it reaches the surface at which the aerosol is generated. Each transducer may therefore have a focal point at which atomization is most effective.

[0100] The ultrasonic transducers are activated at a predetermined frequency and power to control droplet size to ensure the most efficient deposition of nutrient solution on to plant roots. This depends on the stage of growth of the roots and density of the root bed. For example, smaller droplets may be used for dense beds and older plants, larger droplet sizes for less dense beds and younger plants.

[0101] The less preferred hydroponic method may comprise adjusting the height of the plant support in the grow bed tray, to reduce the distance between the support and the base of the grow bed tray grow bed. Usually, however, the grow bed tray would be filled with nutrient solution so that the plant roots are immersed in the nutrient solution, when. Nutrient solution may be pumped from the reservoir into the grow bed tray/grow bed so that the bed is full, at which point the water level is maintained at the optimal level for hydroponic growth of plants.

[0102] The apparatus of the invention is particularly advantageous because it enables the user to exercise greater control over droplet atomization generating a predictable size distribution of droplets, with a characteristic dispersion of aerosol. The invention allows control of droplet size with one or a plurality of ultrasonic transducers by adjusting and controlling the driving frequency. Furthermore, the control of droplet flow rate (speed) and dispersion (velocity) is possible by manipulating the drive circuitry of the transducer. This is controlled by the driving voltage/current. Thus, generally, such control may be achieved by having one or more ultrasonic transducers in the holder. The piezoelectric disc characteristics of the individual transducers are used to select transducers that, when activated, generate droplets of a suitable size and/or speed. The transducers may be arranged in such a way that a predetermined section of the water column within the grow bed is excited to the point of atomization into droplet form. The transducers are mounted in a holder which may conduct the vibrations generated within the nebulizer through the base of the grow bed with minimal dissipation of energy. The holder preferably also provides a protective casing, compression of the piezoelectric materials (especially uniform compression), material that acts as a heat sink, and a structural support to hold the transducers in place.

[0103] The apparatus allows generation of droplets of nutrient solution, of controlled size and behavior, through ultrasonic atomization by activating the ultrasonic transducers with predetermined droplet size.

[0104] The nutrient solution may be prepared using appropriate nutrients dissolved in water or may be a nutrient solution derived from other processes for example fish farming, in particular, aquaponics. A combination of aquaponics and aeroponics/hydroponics of the invention could be advantageous.

[0105] Crops that may be suitable for the apparatus and method of the invention include (but are not limited to) salad crops (for example baby-leaf lettuce, rocket, watercress), herbs (for example basil, coriander), spring onions, root vegetables (for example carrots, radish, wasabi), fruiting crops (for example peppers, strawberries, tomatoes) and micro-greens (for example radish, pea, sunflower, leek).

EXAMPLES

Examples 1 to 8

[0106] A number of crop plants were grown in trials using the aeroponic apparatus according to the invention as illustrated in FIG. 7 for up to 19 days.

[0107] Conditions for the trials are set out in Table 1 together with results of growth rate and yield using the aeroponics apparatus of the invention. The crops were coriander, fennel, leek, pea (Style), radish (Rioja), radish (Sangria), red cabbage and sunflower.

TABLE-US-00001 TABLE 1 Examples under aeroponic conditions according to the invention. Plant Support Seed Harvest Growing Time/ Tray Area/ Yield/ Growth Rate/ Example Crop Weight/g Weight/g Days m.sup.2 g m.sup.−2 g m.sup.−2 day.sup.−1 1 Coriander  60  276 15 0.25 1104  74 2 Fennel  60  237 12 0.25  948  79 3 Leek  89  392 15 0.25 1568 105 4 Pea Style 357  747 16 0.25 2988 187 5 Radish Rioja  56  640 11 0.25 2560 233 6 Radish Sangria  45  747 11 0.25 2988 272 7 Red Cabbage  9  256 12 0.25 1024  85 8 Sunflower 223 1034 13 0.25 4136 318