WO2004093527A1

WO2004093527A1 - Hydroponic production system

Info

Publication number: WO2004093527A1
Application number: PCT/AU2004/000534
Authority: WO
Inventors: David Jonathan Moore; Terrence Dean Colless
Original assignee: Collmoore Fodder Pty Ltd
Priority date: 2003-04-24
Filing date: 2004-04-23
Publication date: 2004-11-04

Abstract

Hydroponic system (1) to allow automatic production of fodder crops includes frame (2) supporting pairs of superimposed tracks (5-6) which are oppositely inclined and carry rollers to allow movement of trays (7) under gravity therealong. Trays (7) pass from upper track (5) to lower track (6) by sliding onto the platform of transfer station (8) which then pivots down, due to the overcoming of the tension of a spring, so as to align with lower track (6) onto which tray (7) slides. At the end of the bottom track, trays (7) may be inverted, to tip out the crop for harvesting, and for washing of trays (7) which may then be reseeded.

Description

HYDROPONIC PRODUCTION SYSTEM

FIELD OF THE INVENTION The present invention relates to a method and apparatus for the hydroponic growth of plants.

BACKGROUND ART Whilst the present invention has particular application in the growth of animal fodder, the present invention may be used in the hydroponic growth of a variety of other plants. It will be appreciated that the present invention is described with reference to the production of crops for human consumption or animal fodder, the features, principles and applications of the present invention will be readily applicable to the growth of other plants, particularly the growth of plants for commercial use. Animal fodder is generally grown as a broad acre crop, harvested and transported to the stock for which it is intended. The growth of animal fodder as a broad acre crop is economic and readily mechanised. However, a large area of arable land is required along with sufficient rainfall in order to successfully grow commercial quantities of animal fodder, h many regions, the amount of arable land is limited and it is impractical to utilise broad acre farming processes.

Intensive farming processes have been used in the production of animal fodder. It has been known to produce animal fodder hydroponically. Typically the hydroponic production of animal fodder and other crops is conducted in trays or channels that are racked to provide many layers of production and thereby reduce the footprint of the hydroponic production system.

Hydroponic production systems based on trays stored in racks are labour intensive in that the trays periodically have to be removed. Trays used for the production of animal fodder are large in size and difficult to handle. Forklifts and other lifting machines are required to remove trays from the racks and to replace the trays. Hydroponic production systems are generally organised such that trays of germinating seeds are grouped together so that conditions for germination and initial growth may be optimised. For example, light and nutrient supply may be controlled for optimal growth. Once these seeds have germinated and the desired stage of growth has been achieved the trays of these seeds may be removed to another area within the hydroponic production system to optimise the growth of the plants. Trays also need to be removed from the racks for harvesting of the plants and reseeding the trays with the next crop of plants.

It is an object of the present invention to provide a hydroponic production system that reduces the need for the handling of trays containing crops at various stages of development. It is desirable that the hydroponic production system overcomes or ameliorates one or more of the disadvantages described above, or which at least provides the consumer with a useful choice.

SUMMARY OF THE INVENTION

In one broad form, the present invention provides a hydroponic production system comprising a race and a plurality of hydroponic growing trays wherein the race comprises at least two tracks, and said tracks being spaced apart vertically, the race further comprising transfer stations for transferring hydroponic growing trays from one track to the track immediately below.

The hydroponic production system of the present invention allows hydroponic growing trays to move along the race during the growing period such that on reaching the end of the race the crop is ready for harvest. Crops suitable for production in the hydroponic system of the present invention include barley, wheat, oats, corn, alfalfa, bean, for example.

Seeds maybe presoaked prior to use to reduce germination time and reduce the growth of mould on the seeds. The presoaked seeds may be collected in a seeder for seeding the trays. The seeder may include a sorter to distribute seeds along a hopper, a hopper to contain the seeds until required and a feeder so that a number of seeds may be planted onto trays, as required.

The sorter may consist of a tube along with the length of the hopper with holes along its length. The holes may be large enough to allow the flow of a number of seeds therethrough into the hold of the hopper. When the stored seeds pile up in the hold and reach the height of the sorter, the associated hole in the sorter is blocked or plugged so the incoming seeds move along the length of the sorter to any remaining unplugged holes. When all of the holes are plugged the hopper may register as being full. The feeder may consist of two overlapping plates having a number of alignable holes so that when the holes are in alignment at least one seed is encouraged to drop through each pair of aligned holes onto the trays below.

The flow rate of the seeds to be planted may be controlled by hole size or the duration at which the holes are aligned. The plates may be formed so that at rest, the holes are not aligned. Further one plate may be slidable so that it can slide relative to the other fixed plate to align the holes. A resilient means such as a spring may be used to return the plate to a resting condition with the holes being out of alignment. In this way the seeds may only flow through the holes when the plates are so aligned.

The holes in the slidable plate may be driven into alignment with holes in the fixed plate by a mechanical or electrical drive. For example a spring could be placed between a wall of the hopper and the sliding plate so that the spring may be compressed by applying force to the sliding plate until the holes of each plate align. Once seeded, the trays may pass through a submersion reservoir which fills each tray with water to provide nourishment for the seeds. The submersion reservoir maybe large enough to accommodate the width of the trays, so the trays may be filled with water. Further the submersion reservoir may include a drain. The duration of soaking is controlled for instance by a PLC, relays, a CPU or other logic device. Once each tray has soaked for the requisite time it is moved along the race to the next station.

Once seeds are planted on the trays, the hydroponic production system of the present invention allows the trays to move along the race during the growing period such that upon reaching the end of the race the crop is ready for harvest. The hydroponic growing trays may be of any convenient configuration.

It is preferred that the hydroponic growing trays are shallow trays of sufficient size to accommodate the desired quantity of grown plants for harvest. Preferably the growing trays will be in the range of from 50 mm to 150 mm, more preferably 70 mm in depth, in the range of from 200 mm to 2 m, more preferably 235 mm in width and in a range of from 4 m to 8 m, more preferably 6 m in length.

The trays may be mounted directly on the race or may be mounted on a bogey that engages the race. It is desirable that the base of the trays, on which the seed is grown, is maintained in a generally horizontal plane notwithstanding the race comprises a number of tracks. The race may be comprised of slides or rollers to facilitate movement of the trays along the race. The slides or rollers may be driven mechanically for instance using pneumatics or hydraulic drives or electrically.

In one embodiment of the invention, the tracks are maintained at a relatively slight inclination and the base of the trays have a relatively high friction surface whereby the angle of inclination does not unduly affect the distribution of seed and plants within the tray.

The race includes at least two tracks. The number of tracks will depend upon the area available, the required harvest and the growing period. For example, where a relatively large area is available only two tracks may be required.

For similar production, in a smaller area a greater number of tracks may be required.

It is generally desirable to limit the number of tracks as each transfer station increases the cost of the race thus it is generally desirable to limit the number of transfer stations employed. In a typical configuration four tracks will be required. Because each tray is relatively large in size a preferred configuration of the race includes each alternate track being oriented directly below the previous track.

The trays may move backwards and forwards as they pass down the race, or alternatively in one direction only along the race.

An even or odd number of tracks may be used dependent upon whether it is desired that the trays for harvest reach the end of the race on the same side or opposite side the trays entered the race and the direction of travel.

The tracks may be of any convenient configuration. The tracks may be in the form of a pair of spaced apart rails, a series of rollers mounted on a platform (the rollers may be suitably wide such that only a single series of rollers may be required or a pair of spaced apart sets of rollers may be used).

The tracks may be substantially horizontal and disposed in vertical alignment so that the bogies of the tracks conveniently engage the next set of tracks. h one embodiment we have found that by using pairs of spaced apart oppositely inclined rails for the track we can laterally offset the rails of each alternate track such that the rails of every second track are aligned. By doing this we are able to mount the trays on bogies having two opposing pairs of inclined slides matching the angle of inclination of the tracks. In this way, the tray is maintained substantially horizontal whether it is travelling down a left-handed or right-handed track. The transfer stations may be of any convenient configuration. We have found that in one form, a suitable transfer station may be simply constructed with a platform aligned with the end of the track such that the tray is able to slide or otherwise be readily transferred onto the platform. A torsion spring may be used to retain the platform in alignment with the upper track and once the trays is positioned on the platform, the weight of the tray causes the platform to rotate about a pivot such that the platform aligns with the start of the lower track. The tray is able to slide or be readily transferred from the platform to the lower track.

In another form a suitable transfer station will comprise a pneumatic or hydraulic lift and transfer system to move the trays from one platform to an adjacent, typically lower platform. It would be understood by a person skilled in the art that other mechanical or electrical equivalents could be employed to move the trays between platforms.

A selectively operable stop maybe provided on the upper track proximate the transfer station such that only one tray, or a predetermined number of trays, may slide or be transferred onto the transfer station. The selectively operable stop may preferably be operated by the position of the transfer station, whereby when the transfer station is in position to receive one or more trays from the upper track the stop is disengaged and when the transfer station is moving the trays to the lower track the stop is engaged.

A nutrient supply for the trays may be mounted to the framework of the hydroponic production system or may be mounted to the track above tray to be fed.

The hydroponic production system of the present invention may be automated such that the trays are harvested, cleaned and reseeded automatically. The trays to be harvested may be removed from the bottom of the race, or may simply be inverted and in the case of the production of animal fodder, simply be inverted to harvest the plant material. The plant material may be tipped onto a conveyor belt for collection and distribution. The inverted trays may then be washed, while still inverted, encouraging dirty water to run downward into a drain. The washed trays may be reseeded and returned to the top of the race.

In one embodiment of the present invention, the hydroponic production system may be additionally provided with a loader arm. The loader arm may be to set for rotation halfway between the beginning and end of the race. The loader arm may include a bucket at the end of the arm for receiving a tray. Suitably the pivot may be positioned such that the bucket is aligned with the angle of inclination of the tracks and the beginning and end of the race.

The loader arm in a first position may receive a full tray of plant material to be harvested from the end of the race in the bucket. Rotation of the loader arm about the pivot may move the bucket containing the tray of plant material to a collection position where the bucket is pivoted such that the plant material is tipped from the tray.

The loader arm may rotate to a second position where the plants may be harvested or the tray may be washed. A washing station may be provided integrally with the bucket or may be mounted on the hydroponic production system adjacent to the second position.

The loader arm may rotate to a loading position adjacent the start of the race where the tray may be reseeded and released onto the race. In order that the invention may be more fully understood and put into practice, preferred embodiments thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1 to 5 are digital photographs of the hydroponic production system according to one aspect of the invention.

Figure 1 shows the framework 2 of the hydroponic production system

1. The framework 2 includes a base 3 on which a race 4 is mounted. The race 4 includes two pairs of tracks 5 and 6 respectively. The tracks 5 and 6 respectively include a series of rollers to allow the easy movement of trays 7.

In one embodiment the respective tracks 5 and 6 may be oppositely inclined such that a tray 7 when placed on the top track 5 will move to the transfer station 8, to be transferred to the lower track 6 for harvesting. Figure 3 shows the transfer station 8 which has a platform 9 onto which the trays slide from upper rails 5. The platform 9 is mounted on a rotatable shaft 10 driven by a motor 11 that operates to rotate the platform so it aligns with the lower tracks 6 and allows the tray to pass thereon. At the bottom of the lower track 6 is provided a loader arm 20 that is rotatably mounted on the frame 2 on a shaft 21. The shaft 21 is rotated using a motor 22. The loader arm 20 can receive the tray on forks 23. The tray is retained on the forks 23 as the loader arm 20 rotates from the receiving position shown in Figure 4 the forks 23 rotate to tip the plant material from the trays and present the trays to a washing station and once washed to the start of the race where they may be filled with new seed for another growth cycle.

Figure 5 shows the tray 7 mounted on the loader arm 20. A motor 24 is mounted on the loader arm 20 to rotate the forks 23. Figure 6 shows a side, top, bottom and perspective view of the seeder of the invention. The seeder 30 is shown to have a sorter 31 at the top, a feeder 32 at the base and a hopper 35 therebetween. The walls 36,37 of the seeder 30 taper narrowing from the sorter 31 to the feeder 32 so that seeds are thinned out and automatically fed onto the trays one row at a time, due to the geometry of the hopper 35.

Figure 7 shows the sorter according to one aspect of the invention and the seeder Seeds enter the hopper 35 though the sorter 31 and are distributed along the length by passing through holes 40 in the sorter 31 to be collected in the hopper 35. When the height of seeds collected in the hopper 35 reaches the height of the sorter 31, the associated holes 40 are blocked stopping further seeds passing therethrough. Seeds then filter to the next unblocked hole in the sorter 31 until the hopper 35 is full. The seeds are collected in a hopper 35 having walls 36 and 37 that taper narrowing to a thin base where seeds are fed into the feeder 32.

The feeder consist of 2 plates 33,34 lying on top of each other overlappingly. One plate is fixed while the other plate is slidable relative to the fixed plate. Both plates have holes 38 therein said holes 38 may be large enough to allow one or more seeds to pass therethrough. The holes may be formed equally spaced so that the plates and associated holes may be aligned to allow seeds to pass through both plates. At rest, the plates may be positioned such that the holes are out of alignment to stop seeds passing through the holes in the lower plate 3.

The alignment of the holes may be controlled by including a bias on the sliding plate so that the sliding plate has a resting condition with the holes out of alignment containing the seeds in the hopper and second condition to place the holes in alignment allowing seed to pass therethrough. A force may be applied to the sliding plate sufficient to overcome the bias and align the holes 38 for long enough to allow seeds to pass therethrough. The plate may resile back to the resting condition when the force is removed from the sliding plate 34. Force may be applied directly to the sliding plate or to a lever or other activation device.

Figure 8 shows the path of the trays 7 along the track 5 being seeded by the seeder 30, then soaking in the submersion reservoir 50. As shown the race may be inclined so that the trays travel over a graduated slope into the submersion reservoir to fill with water and leave via an upward slope in the track. Figure 9 shows a 4 tiered race. In this system trays are seeded, watered then slowly progress along each platform to the transfer station at which point they are moved between platforms to the lower tier. In the lowermost tier the plants are harvested by tipping the trays upside down remaining in this position to be washed before returning to the seeding platform to be replanted. The tracks are shown having 3 rollers across the width of the track for transporting the trays therealong.

Persons skilled in the art will appreciate that the invention described above may be subject to improvements and modifications that will be apparent without departing from the spirit and scope of the invention described herein.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A hydroponic production system comprising a race and a plurality of hydroponic growing trays wherein the race comprises at least two tracks, and said tracks being spaced apart vertically, the race further comprising transfer stations for transferring hydroponic growing trays from one track to the track immediately below.

2. A hydroponic production system according to claim 1 wherein the tracks are oriented in alternating directions where by the trays move backwards and forwards through the race.

3. A hydroponic production system according to claim 1 wherein the tracks are formed from a pair of spaced apart rails.

4. A hydroponic production system according to claim 1 wherein the tracks compromise a series of rollers mounted on a platform.

5. A hydroponic production system according to claim 1 wherein the tracks are formed from pairs of spaced apart oppositely inclined rails wherein the rails of each alternate track are laterally offset whereby the rails of every second track are aligned.

6. A hydroponic production system according to claim 1 wherein the race consists of four tracks.

7. A hydroponic production system according to claim 1 wherein the transfer station comprises a platform aligned with an end of the track, which platform is retained in alignment with the end of the track by a torsion spring wherein the weight of a tray on the platform causes the platform to rotate about a pivot such that the platform aligns with the start of a lower track.

8. A hydroponic production system according to claim 1 wherein the transfer station comprises a pneumatic or hydraulic lift and transfer system to move the trays from one platform to a lower platform.

9. A hydroponic production system according to claim 1 wherein the hydroponic growing trays are shallow trays to accommodate the desired quantity of grown plants for harvest.

10. A hydroponic production system according to claim 4 wherein the trays are mounted on bogeys.

11. A hydroponic production system according to claim 5 wherein the trays are mounted on bogies having two opposing pairs of inclined slides matching the angle of inclination of the tracks whereby the fray is maintained substantially horizontal whether it is travelling down a left-handed or right-handed track.

12. A hydroponic production system according to claim 1 further comprises a loader arm set for rotation midway between a vertically offset beginning and end of the race wherein the loader arm includes a bucket at the end of the arm for receiving a tray and includes a pivot positioned such that the bucket is aligned with the angle of inclination of the tracks and the beginning and end of the race.

13. A hydroponic production system according to claim 12 wherein the loader arm in a first position receives a full tray of plant material to be harvested from the end of the race in the bucket whereby rotation of the loader arm about the pivot may move the bucket containing the tray of plant material to a collection position where the bucket is pivoted such that the plant material is harvested from the tray.