GB2137464A - Apparatus for use in growing plants - Google Patents

Abstract

A plant development and growth system comprises a plurality of modular plant growth and development units each including a housing (50) formed of a thermal insulating material and having a liquid communications connection (72), heating apparatus (74) and a plant tray support; elongate members (80) can join a plurality of modular units together, enabling displacement as a whole. The system includes means (40) for movably supporting the modular units. Each module may have a tent (90) on it. <IMAGE>

Description

SPECIFICATION Apparatus for use in growing plants This invention relates to apparatus for use in growing plants under controlled conditions.

In recent years there has been a rapid development in greenhouse growing techniques, particularly in the area of early plant development. Various hydroponic and airoponic techniques are described in the patent literature and are known on the marketplace.

Various types of growing bench systems for greenhouse use have been proposed. One exampie is the Ro-Flo Benching System manufactured by Rough Brothers, Inc, of P.O.B. 16010, Cincinatti, Ohio 45216 U.S.A. This system incorporates floating aisles and bearing mounted growing pallets.

Growing systems employing rolling tables are also manufactured by Intransit product handling systems of de hondert margen 6, postbus 87. 2678 ZH delier, Holland. These systems employ rolling rods for providing sidewise movement of the individual tables. Growing systems of a similar type having built in watering and bottom tubular hot water heating systems are also produced by Bosman, b.v. of Jac. Takkade 3, 1432 Aalsmeer, Holland.

Electrical bottom heating apparatus for plant development is well known and is manufactured by GeBall Pacific, Inc. of P.O.B. 9055, Sunnyvale, California, U.S.A.

Most greenhouse systems, including the advanced systems described above, suffer from a number of important disadvantages. These may be summarised as follows: 1. They are extremely energy intensive in terms of the maintenance of a desired environmental temperature. This disadvantage limits the types of plants that it is economical to grow on such systems, the seasons of the year that such growth can be undertaken, and the geographical locations suitable for such growth.

2. The advanced systems are extremely expensive and require a very expensive infrastructure.

3. The advanced systems are extremely complex and require costly and high level maintenance attention continuously. They are not user maintainable.

4. The advanced systems are designed and built only for large scale operations and are unsuitable for reasons of complexity, capital cost and maintenance for average and small scale operations.

5. The conventional systems including the advanced systems are not designed so as to limit disease propagation within the system structure.

In accordance with a first feature of the present invention there is provided a modular plant growth and development unit including a housing formed of a thermal insulating material and having a liquid communications connection, heating means and a plant tray support. The invention further provides a plant development and growth system including a plurality of such units, elongate means for joining the plurality of modular units together for aisplace- ment thereof as a whole and means for movably supporting the modular units.

Such plant growth and development apparatus may be designed to be convenient to use and may be relatively simple and inexpensive to manufacture, and require only relatively low operating costs.

Preferably the housing is made of a foamed plastics material. The housing may be of a rectangular or even square overall configuration, with side walls, a bottom wall and structural members for supporting plant trays. The modular unit may also include a moulded liquid drain plate which is arranged with sloped surfaces to provide substantially complete drainage thereof when desired.

The heating means is preferably an electrical heating element. This heating element preferably contains ribbon type conductor which operates at low voltage and provides heating inside the housing whether or not the conductor is surrounded by water. It is appreciated that when the conductor contacts water, a desired vapor environment underneath the plants is provided. Preferably the ribbon type conductor is woven though a large grid mesh, such as that provided by conventional plastics fencing.

Such a ribbon type conductor may be operative to provide heat transfer primarily by radiation. It is preferably formed of aluminium foil of thickness of about 0.1 mm.

A tent may be selectably associated with each modular plant development unit to provide a separate micro-environment for the plants growing therein. By suitable ventilation of the tent, desired separate environments may be provided for the root portions and for the upper structure of the plants in each modular unit.

The provision of a tent in association with the plant development unit has significant economic benefits as it enables the required heated environment to be limited to the volume of the tent(s) and enables the remainder of the location of the units, e.g. of a greenhouse, to be maintained at a much colder temperature. This greatly reduces energy costs, while permitting the use of much less substantial greenhouse structures.

Preferably the elongate means for joining the modular units together comprises a specially designed profile, typically extruded from aluminium, which not only joins the modular units but provides a mechanically strong outer edge therefor. Preferably such a profile has at least one bearing surface upon which a wheeled cart can travel. The profile may also have a bearing surface upon which the joined modular units may be moved relative to a movable or stationary support.

The means for movably supporting the joined modular units preferably comprises bearing supports attached to the support apparatus for rollably enagaging bearing surfaces inside slots formed in the undersides of the unit housings of some of the joined units. Additional slots may be formed transverse to these inside slots for permitting displacement of the joined units along an axis at 90 degrees to the direction of the inside slots. This enables rectangular, non square units to be coupled together for common movement in two alternative width configurations.

The invention is illustrated, by way of example, with reference to the accompanying drawings, in which: Figures 1A and 18 are pictorial illustrations of two systems according to the present invention; Figure 2 is a sectional illustration of a preferred plant growth and development unit according to the present invention; Figures 3 is a sectional illustration taken along lines 3 - 3 of Figure 2; Figures 4A, 4B and 4C are respective top, side and detailed cut away pictorial illustrations of a housing forming part of the plant growth and development unit of Figure 2; Figure 5 is a multiple cut away top view illustration of the plant growth unit of Figure 2; Figure 6 is a sectional side view illustration taken along the lines 6 - 6 appearing in Figure 5;; Figure 7 is a top view illustration of the liquid drain surface employed in the growth unit of Figure 2; Figure 8 is a partially cut away side view of a movable bearing mount for the growth unit illustrated in Figure 2; Figures 9A and 9B are respective side view and top view illustrations of a movable cart arranged for engagement with a single joining profile associated with the modular units of Figure 2; Figures 10A and 10B are respective side and bottom views of a movable cart arranged for en gagementwith the modular units of Figure 2; Figure 11 is a plan view of the electrical heating element employed in the modular unit of Figure 2; Figure 12 is a pictorial illustration of the electrical connections to the electrical heating element at the modular unit of Figure 2;; Figure 13 is a sectional illustration of the elongate joining profile employed to join the modular elements shown in Figure 2 and Figures 14A and 148 are respectively a bottom pictorial view and a detailed partial sectional view of the tent illustrated in Figure 2.

Figures 1 A and 1 B illustrate two alternative typical greenhouse layouts. In Figure 1A, a layout suitable for use with a building having one row of central supports 10 is provided. Banks 12 of typically ten growing units 13 are provided and are arranged for movement as a unit in the direction indicated by arrows 14 so as to provide a movable and selectable aisle 16 between banks. it will be appreciated that by shifting the positions of the banks 12 of growing units 13, access may be had to each of the growing units from at least two sides.

Main and subsidiary movable carts 18 and 19 are shown in association with the growing units both in the aisles 16 and alongside the central passage 20.

Figure 1 B illustrates an alternative greenhouse layout in which two rows of spaced building supports 22 are provided. Here banks 24 of growing units 26 are arranged for movement in the directions indicated by arrows 28 into and out of the main passage 30. In the main passage, the bank 24 may be further transported by a suitable cart to a different location, indicated by reference numeral 32. Fixed aisles 34 are provided in this embodiment.

Figure 2 illustrates in section, a preferred growing unit in accordance with the present invention. It comprises a stationary base 40 including legs 42 and a cross bar 44. The legs 42 are provided with conventional screw type leveling devices 46.

Mounted directly on legs 42 and lying directly thereover are support bearings 48 which movably support a growing unit housing 50. The location of support bearings 48 directly over the legs 42 is a particular feature of the present invention since it enables the legs to support the weight of the movable housing 50 directly, thus requiring much less structure, weight and cost in the design of the stationary base 40, as compared with prior art constructions which employ a rolling rod which requires transverse supports over the width of the base.

The movable housing 50 is a modular unit, typically of rectangular or even square overall outside configuration and formed of a thermally insulative material, such as foamed polystyrene. The housing 50 is integrally moulded to define side wall portions 52 of generally uniform cross sectional configuration. The underside 54 of the movable housing 50 has an arrangement of transverse slits 56 and 58 arranged at right angles to one another. Slits 56 serve to engage support bearings 48, and are reinforced with metal or other hard lining 60, as seen in Figure 3. Figure 3 also illustrates stop members 62 which are fixed to the underside 54 of housing 50 and engage respective legs 42 to limit the range of motion of housing 50 relative to base 40 in the directions of arrows 64.

Slits 58 are arranged for permitting motion of the housing 50 along an axis perpendicular to the axis indicated by arrows 64, as by engagement of support bearings in a manner illustrated in Figure 8.

This enables rectangular, non square units to be coupled together for common movement in two alternative width configurations.

Housing 50 is also moulded with structural supports 66 which support a liquid drain surface 68.

Associated with liquid drain surface 68 is a water supply and drainage unit 70 which communicates with a liquid connection 72 in a side of the housing 50. Disposed above drain surface 68 is an electrical heating unit 74 and disposed above heating unit 74 are plant growth containers 76 which may be of any desired size and configuration, as suitable. The arrangement of the apparatus associated with housing 50 is shown clearly also in Figures 5,6 and 7, from which it is also seen that the drain surface 68 is formed with one or more liquid supply inlets 75 which communicate with an arrangement of inclined drain recesses 78 which lead to a liquid return filter 79 which serves to trap spurious material, so as not to clog the system. The outlet of filter 79 communicates with a liquid outlet 81. Filter 79 may be any suitable ty0e of filter and may include a biological filter. The liquid systems of the individual housings 50 may be isolated, or instead, as is usual, they may be joined in banks, as the housings are mechanically joined. This absolute or relative isolation acts to control the spread of disease or other contamination.

A joining member 80, typically an extruded profile formed of aluminium, engages a portion of the side edges of each of a plurality of housings 50. The joining member 80 has a number of functions.

Principally, when applied to both opposite side edges of housings 50, it serves to join a plurality of housings 50, typically up to 10 or more in number, together as a unit. Secondarily, it provides a mechanically stronger and wear resistant edge surface for the combined unit. Additonally it provides one or more bearing surfaces 82 upon which carts or other elements may be supported and travel. Such carts are described hereinbelow.

The overall structure of the housing 50 is illustrated in Figures 4A, 4B and 4C. Figures 4A and 4B illustrate the sub-structure of the lower portion 84 of the housing, while Figure 4C illustrates the configuration of the side wall portions 52 of the housing and their location offset upwardly from the lower portion 84 of the housing.

Disposed in sealing relationship above housing 50 is a tent 90 which provides a controllable microenvironment for the upper structure of the plants which are supported in the housing tent 50. Tent 90 is also illustrated in Figures 14A and 14B. Tent 90 is typically formed of a plastics sheet 92 which is supported on a pair of curved cross pieces 94 which are joined by a central coupling member 96. According to a preferred embodiment of the invention, the curved cross pieces 94 also serve as gas conduits leading from a source of pressurized gas, such as cooled air (not shown) coupled via a supply conduit 98. In this embodiment, a multiplicity of outlets 99 is provided from the cross pieces 94 to the interior of the tent. In this way, the environment and temperature inside the tent may be varied without requiring removal or replacement of the tent.Alternatively, circulation of cooling air or other cooling means within the controllable microenvironment may be provided by other means.

Figures 9A and 9B illustrate a cart 100 which is mounted for travel along a bearing surface 82 of the elongate profile joining element 80. Such a chart is useful for collection or distribution of plants from or onto the housing units. Mounting of the cart 100 is normally achieved by the provision of a mounting bracket 102 on the underside of the cart. Rotatably mounted on bracket 102 is a grooved wheel 104 which engages surface 82 and an underside wheel 106 which engages a second indented bearing surface 108 of joining element 80.

Figures 10A and lOB illustrate a cart 110 similar to cart 100 but arranged to travel and be supported on the bearing surfaces 82 of two adjacent spaced joining members 80 associated with adjacent banks of growing units.

The electrical heating unit and its electrical connection are illustrated in Figures 11 and 12. The heating unit comprises a ribbon type conductor 112, which is commercially available aluminium foil of typical thickness 0.1 mm. In accordance with a preferred embodiment of the present invention, the ribbon type conductor 112 is woven into an insulative grid, such as plastics fencing grid which is commercially available. A free end of the conductor 112 is coupled via a contact terminal 114 to a low voltage, typically 12 volt, power supply via a conduc toll6.

It is a particular feature of the present invention that the heating unit 74 provides heat to the plant growth containers 76 both by conduction and convection when liquid is present thereabout and primarily by radiation, when no liquid is present, i.e.

between irrigation cycles.

The apparatus of the present invention may be based on sub-irrigation techniques whereby an intermittent supply of water is supplied to the roots of the plants in the plant growth containers 76 through openings therein. Between waterings, the water is drained completely insofar as practicable from the drain surface 68. Alternatively the apparatus of the present invention may be used in connection with any other suitable growing technique.

Figure 13 is a sectional illustration of the joining element 80, showing some of its particular features.

Joining 80 has convex and concave bearing surfaces 82 and 108. It also has stop members 120 and 122 which are provided to position a joining plate (not shown) for joining two elongate lengths of element 80 end to end to form a continuous length.

Claims (25)

1. A modular plant growth and development unit comprising: a housing formed of a thermal insulating material and having a liquid communications connection; heating means; and a plant support.

2. A unit according to claim 1 wherein the housing is formed of a foamed plastics material and is of rectangular overall configuration, having side walls, a bottom wall and structural members for supporting plants.

3. A unit according to claim 1 or 2 and including a moulded liquid drain plate arranged with sloped surfaces to provide substantially complete drainage thereof when desired.

4. A unit according to claim 3 wherein the moulded liquid drain plate is provided with at least one liquid inlet located at the top of the sloped surfaces and at least one liquid outlet located at the bottom of the sloped surfaces.

5. A unit according to claim 4 and comprising a filter located in liquid communication with the at least one liquid outlet.

6. A unit according to any one of the claims 3 to 5 wherein the moulded liquid drain plate also has a flat support surface.

7. A unit according to any one of claims 1 to 6 wherein the heating means comprises an electrical heating element providing bottom heating for plants disposed thereabove.

8. A unit according to claim 7 wherein the electrical heating element comprises a ribbon type conductor which operates at low voltage and provides bottom heating whether or not the conductor is surrounded by water.

9. A unit according to claim 8 wherein the ribbon type conductor is woven through a supportive insulative grid mesh.

10. A unit according to any one of claims 1 to 9 wherein each modular unit comprises a tent which provides a separate microenvironmentforthe plants growing therein.

11. A unit according to claim 10 and the comprising means for providing a selected gas environment to the microenvironment.

12. A unit according to claim 11 and wherein the means for providing the selected gas environment comprises means for providing a cooled gas for cooling the microenvironment.

13. A unit according to claim 11 or 12 wherein the means for providing a selected gas environment comprises gas conduits in structural supports for the tent.

14. A unit according to any one of claims 1 to 13 wherein the housing is formed at its underside with first and second pairs fo slots arranged perpendicularly to each other to permit displacement of the unit in two perpendicular directions.

15. A modular plant growth and development unit substantially as illustrated in any of the Figures 2 to 11,12, and 14B of the accompanying drawings.

16. A moulded liquid drain plate having sloped surfaces to provide substantially complete drainage thereof when desired.

17. A moulded liquid drain plate according to claim 16 and provided with at least one liquid inlet located at the top of the sloped surfaces and at least one liquid outlet located at the bottom of the sloped surfaces.

18. A moulded liquid drain plate according to claim 17 and comprising a filter located in liquid communication with the at least one liquid outlet.

19. A moulded liquid drain plate substantially as shown and described with reference to Figures 5 to 7 of the accompanying drawings.

20. A plant development and growth system comprising: a plurality of modular plant growth and development units according to any one of claims 1 to 15, elongate means for joining the plurality of modular units together for displacement thereof as a whole; and means for movably supporting the modular units.

21. A system according to claim 20 wherein the elongate means for joining the modular units together comprises a profile which joins the modular units and provides a mechanically strong outer edge therefor.

22. A system according to claim 21 wherein the profile defines at least one bearing surface upon which a wheeled cart can travel.

23. A system according to claim 22 wherein the profile also defines a bearing surface upon which the joined modular units may be moved relative to a stationary or movable support.

24. A system according to any one of claims 20 to 23 wherein the means for movably supporting the joined modular units comprises bearing supports attached to the support apparatus for rollably engaging bearing surfaces defined inside slots formed in the undersides of the unit housings of some of the joined units.

25. A plant development and growth system substantially as hereinbefore described with reference to any of Figures 1A, 1 B, 8, 9A, 9B, 10A, 10B and 13 of the accompanying drawings.