SYSTEM

Technical Field

[0001] The present disclosure relates to a valve assembly and associated system for allowing a container to be filled with a liquid and consequently drained, in particular for use in growing plants through a fill and drain method.

Background of the Disclosure

[0002] Many applications exist where it is advantageous for a container, or series of containers to be successively filled and drained with a liquid. One such application is in the field of hydroponics, where a common method of providing water to the plants or crops being grown is through a flood/drain system, which is also commonly referred to as an ebb/flow or a fill/drain system. For ease of understanding, the term flood/drain will be used throughout this specification.

[0003] Unlike other hydroponic methods such as nutrient film technique or deep water culture where the roots of the plants being grown are constantly submerged in water, flood/drain systems leave the roots of the plants exposed to air. This allows the plants to be sufficiently oxygenated without the need to artificially oxygenate the water system. To provide the required water to the plants, flood/drain systems rely on a two phase system. In the first "flood" phase, a grow tray containing the plants is filled with liquid (water or a nutrient solution) to a predetermined height as quickly as possible. Once the "flood" phase is over, the "drain" phase begins, wherein water is quickly drained from the tray. The quick draining has the secondary effect of pulling oxygen towards the root structure as the water drains, further promoting healthy roots and oxygenation of these roots.

[0004] Typical flood/drain systems work by providing a holding tank below the grow tray and using a pump to fill the tray through a flush-mounted port on the bottom of the grow tray. An overflow port is also provided in the grow tray to set the height to which the grow tray is filled to. This overflow port redirects excess water back to the holding tank. Once the pump is stopped, the remaining water in the grow tray returns through the flush-mounted port back to the holding tank, draining the tray. A timer is used to periodically turn on and off the pump, the frequency and duration of which are chosen depending on the plants being grown. [0005] Flood/drain systems are comparatively simpler and in many cases produce healthier plants than other hydroponic systems, and accordingly, they have been studied with some interest with a view to adapting or creating flood/drain systems for large scale or commercial use. A big hurdle however, in the development of these systems is that these larger scale hydroponic set-ups require a number of vertically stacked grow trays to achieve optimum space usage. These systems may also be referred to in the art as multi-tiered systems. Currently, flood/drain systems pose an issue as they require a number of plumbing connections between each vertically stacked tray, which adds to the complexity of the system as well as the difficulty in removing trays for harvesting etc.

[0006] Similar problems exist in other non-vertically stacked operations where the grow trays are moved along conveyor belts or similar to maximize automation of the process. In these instances, the required connections to the holding tank make such a system unfeasible.

[0007] Additionally, there exists a need to maximize the number of trays or containers in these systems to increase the crop yield and thus the efficiency of the system as a whole.

[0008] Embodiments of the present invention seek to at least partially overcome these problems, enabling use of a flood/drain system on larger scale growing operations, in particular but not limited to those using grow trays that are vertically stacked and/or moved/transported by automated or semi-automated means such as through a conveyor belt, chain or rollers. Embodiments of the present invention may also be advantageous for other systems in which containers or irrigation channels require filling and draining.

Summary of the Invention

[0009] In a first broad aspect, there is provided a valve assembly for allowing filling and draining of a container with a liquid, comprising: a reservoir movably connected to a valve body, the reservoir being configured to hold liquid when in a first position and to drain liquid in a second position; a sealable opening in the valve body in fluid communication with the reservoir; a biasing member; and an overflow inlet in fluid communication with the reservoir, the overflow inlet extending from the valve body; wherein the reservoir can be moved between the first position in which the sealable opening is sealed preventing fluid flow into the reservoir and the second position in which the sealable opening enables fluid flow into the reservoir; wherein the biasing member acts to retain the reservoir in the first position unless a force is applied above a predetermined value. [0010] In some embodiments, the reservoir is located beneath the valve body.

[0011] In some embodiments, the reservoir is movably connected to the valve body by a hinge.

[0012] In some embodiments, a catch is provided on an opposing end of the valve body to the hinge, the catch holding the reservoir in the second position.

[0013] In some embodiments, the reservoir contains at least one opening to drain liquid in the second position, the catch being configured to cover the at least one opening in the reservoir when in the first position.

[0014] In some embodiments, the overflow inlet includes at least one inlet opening at a predetermined height above the valve body.

[0015] In some embodiments, the overflow inlet extends upwardly from the top surface.

[0016] In some embodiments, the predetermined value is chosen based on the weight of liquid in the reservoir.

[0017] In some embodiments, the valve assembly further comprises a sealing member on an interior of the reservoir, wherein the sealing member seals the sealable opening when the reservoir is in the first position.

[0018] In some embodiments, the biasing member is in the form of at least one magnet.

[0019] In some embodiments, the overflow inlet has a conical or rounded cover.

[0020] In some embodiments, the overflow inlet is adapted to be adjustable such that the maximum height that the container can be filled with liquid to can be changed by a user.

[0021] In some embodiments, the valve body has a rectangular or partially rectangular shape.

[0022] In some embodiments, the valve body includes a means of attachment to the container.

[0023] In some embodiments, the sealable opening is located in a central part of the valve body. [0024] In some embodiments, the valve body is shaped to direct water towards the sealable opening.

[0025] According to a second aspect, there is provided a container including a valve assembly according to the first aspect.

[0026] According to a third aspect, there is provided a system for filling and draining containers, comprising: a plurality of vertically arranged containers, each container including a valve assembly comprising a reservoir movably connected to a valve body, the reservoir being configured to hold liquid when in a first position and to drain liquid in a second position; a sealable opening in the valve body in fluid communication with the reservoir; a biasing member; and an overflow inlet in fluid communication with the reservoir, the overflow inlet extending from the valve body; wherein the reservoir can be moved between the first position in which the sealable opening is sealed preventing fluid flow into the reservoir and the second position in which the sealable opening enables fluid flow into the reservoir; wherein the biasing member acts to retain the reservoir in the first position unless a force is applied above a predetermined value; a holding tank containing a liquid; a conduit for allowing the flow of the liquid from the holding tank to fill an uppermost container; and wherein the containers and/or valve assemblies are arranged such that liquid that drains from one container flows to fill a lower container.

[0027] In some embodiments, the valve assembly is a valve assembly according to the first aspect.

[0028] In some embodiments, the system is configured to allow a user to insert and/or remove containers from the system, and the containers are arranged so that when a container is removed, liquid that would otherwise fill that container is instead conveyed to another container located below the removed container.

[0029] In some embodiments, the system is for growing plants and the containers contain plants.

[0030] According to a fourth aspect, there is provided a method for filling and draining containers, comprising: providing a plurality of vertically arranged containers, wherein each container includes a valve assembly according to the first aspect; wherein each the plurality of containers are vertically arranged to allow at least one of: draining liquid from the reservoir in the second position of the associated valve assembly towards another container; or receiving liquid drained from the reservoir in the second position of the valve assembly of another container; conveying liquid into the opening of an uppermost container for predetermined periods at predetermined intervals so as to fill the plurality of containers.

Brief Description of the Figures

[0031] The present disclosure will become better understood from the following detailed description of various non-limiting embodiments thereof, described in connection with the accompanying figures, wherein:

[0032] FIGURE 1 shows a system of vertically stacked grow trays according to the prior art.

[0033] FIGURE 2 shows a previous fast filling valve assembly created by the same inventors.

[0034] FIGURE 3 shows a perspective view of an embodiment of the fast filling valve according to the present invention.

[0035] FIGURE 4 shows a side view of an embodiment of the fast filling valve of FIGURE

3.

[0036] FIGURE 5A shows a view of the reservoir of an embodiment of the fast filling valve in a first 'flooding' position.

[0037] FIGURE 5B shows a view of the reservoir of an embodiment of the fast filling valve in a second 'draining' position.

Detailed Description

[0038] FIGURE 1 shows a conventional flood/drain system 100 in which a series of grow trays 101 for growing plants 102 are arranged vertically. A holding tank 103 is positioned under the grow trays 101 and includes a pump 104 and a conduit 105 which is connected to each grow tray. There is a check valve (not shown) between the conduit and each tray except the uppermost tray. This check valve prevents liquid from entering the tray from the conduit, as well as prevents liquid from leaving the tray while the pump is active due to the pressure exerted by the pump. Each grow tray is also provided with an overflow outlet 106 which is connected to the grow tray below, with the exception of the bottommost tray which is connected to the reservoir 103.

[0039] The flooding/draining of the grow trays 101 is carried out in this system through the following method. The pump 104 is turned on, conveying liquid from the holding tank 103 up through the conduit 105 as shown by the arrow in FIGURE 1. The liquid is prevented from entering all but the uppermost tray by the check valves. The uppermost tray is filled to a predetermined height set by the height of the overflow outlet 106. As liquid continues to enter the uppermost tray, it is directed through the overflow outlet into the tray below which then fills with liquid until the height set by the overflow outlet is reached, wherein liquid flows into the next tray, and so on until liquid returns to the holding tank via the overflow outlet of the bottommost tray. When the pump is turned off, liquid drains from each tray through the conduit, the check valves now allowing liquid to flow in the opposite direction, leaving each tray and returning to the holding tank.

[0040] Such a system requires at least one connection between the conduit and each tray, if not a further connection between adjacent trays in the form of the overflow outlet. This limits the adaptability of the system, as the addition or removal of trays requires connecting or disconnecting trays from the conduit, and hinders the ability of a user to remove the trays for planting or harvesting. This is particularly a problem in larger scale operations where it may be advantageous to automate or semi-automate the planting/harvesting processes. In these operations, the ability of a user or autonomous/semi-autonomous vehicle to remove the tray and deliver it to a location for planting/harvesting by workers or machinery is complicated by the need to disconnect and reconnect these connections. Currently, this is only possible for nutrient film technique or deep water culture systems, which provide less healthy crops and reduced yield compared to those grown by flood/drain systems but which do not require these connections.

[0041] The present invention seeks to provide a valve and associated system which may overcome these issues by providing a system wherein no direct connections are required between the growing trays and/or a source of water. This is accomplished by the use of a novel valve assembly configured to both fill and drain the container. This valve assembly may further convey liquid into the valve assembly of another container when draining to create a multi tiered system.

[0042] The inventors previously designed a valve assembly which is capable of providing a fill/drain system without direct connections, which is shown in FIGURE 2 in place in a container.

[0043] This assembly is shown in place in a container 200 and includes a filling catchment 201 connected to a plugging member 202 and an arm 203 connected to a pivot 204 at an opposing end to the filling catchment. The filling catchment is shaped such that a lower internal surface proximate the location of plugging member 202 on the opposing side is provided at a distal end of the filling catchment to the pivot 204. The internal side surfaces are sloped so that any liquid which enters the catchment is directed towards this lower surface. A drainage orifice 205 is provided in the lower surface of the filling catchment. The plugging member is in the form of a partially fmsto-conical rubber stopper, and has an internal channel 206 which is connected to the drainage outlet. The internal channel 206 allows for the water in the filling catchment to drain through the drainage outlet. The pivot may be in the form of protrusions on the arm 203 or catchment 201 which cooperate with corresponding recesses or openings in a base 207 to provide the pivoting function.

[0044] This assembly also includes an adjustable overflow outlet 208 which is located on the base 207 which also is connected to the pivot 204. The adjustable overflow outlet 208 includes an internal overflow channel in fluid communication with the overflow outlet at a first end 209 and an exterior of the container at a second end 210. The first and second ends of the channel are offset such that liquid is conveyed towards the same location as the drainage outlet. The base 207 can be attached to a container through any known methods, such as by screws or bolts 211. The adjustable overflow outlet 208 may be adjusted, for example, by the use of a castle nut. The overflow outlet acts to create a maximum height within the container for a liquid to fill to. A grate or mesh 212 is also provided in the filling catchment located over the drainage orifices to prevent any solids (such as soil particles) from blocking the drainage orifices.

[0045] This valve assembly operates in the following manner: The pivot causes the filling catchment and the plugging member to be movable in an arc-like motion from a first 'upper' position to a second 'lower' position, wherein a drainage outlet in the container is sealed by the plugging member in the second position. A biasing member in the form of a compression spring located at a distal end of the base to the pivot is provided to bias the filling catchment and plugging member into the first position unless a force is applied to overcome it. The force required to move the filling catchment may be balanced against the weight of liquid within the filling catchment, such that the catchment moves from the first position to the second position when the catchment is partially or substantially filled with water, and/or the force required to overcome the biasing member may be balanced against the force exerted by water entering the filling catchment from a height, preferably where the height is the distance between the drainage outlet of the container above and the filling catchment of the valve assembly.

[0046] In use, this valve assembly functions in the following manner. Water is directed towards the filling catchment, causing it to pivot into a lowered position where the drainage outlet is covered. The internal channel in the plugging member has a small diameter so water leaves the filling catchment through the internal channel slower than the catchment is being filled. This results in the filling catchment overflowing and filling the container with water up to the height of the overflow outlet. Any further water travels through the overflow outlet and is directed to the drainage outlet. Once water stops being directed towards the filling catchment, the filling catchment drains through the internal channel and returns to its raised position in which the plugging member does not cover the drainage outlet. Water in the container then drains through the drainage outlet, achieving the desired flood/drain process. In systems of vertically stacked containers, the drainage outlet of a first container can be positioned over the filling catchment of a second container, repeating the process for the next tray down.

[0047] While this valve assembly allows for a physical connectionless water supply, the inventors found that the valve assembly was ill-suited for systems with large numbers of containers. This is attributed to the water loss through the system. In essence, the design of the valve assembly in FIGURE 2, where the drain stage of the flood/drain process is facilitated by enough water passing out of the filling catchment through the internal channel to return the filling catchment to the first position, requires more water than is feasible in order to maintain a flood/drain process through the entire set of vertically stacked containers in a system when a large number of containers are used. Otherwise stated, the time required for the filling catchment to drain and return to the first position is too long to enable large numbers of containers in the system.

[0048] To overcome these issues, and to provide a fast filling/draining valve which enables higher numbers of containers to be used in a system. This allows larger systems to be constructed, with the associated benefits. For example, in a hydroponic system, where each container is a grow tray containing plants, the crop yield can be greatly increased, and the system made more efficient, by use of this new valve assembly.

[0049] An embodiment of the new valve assembly is shown in FIGURE 3. The assembly 300 consists of a valve body 301, and a reservoir 302 which is connected to the valve body in this embodiment by means of a hinge 303 to enable the reservoir to move in an arc-like fashion from a first position where the lengthways direction of the reservoir is substantially parallel to the lengthways direction of the valve body to a second position wherein the lengthways direction of the reservoir is angled relative to the lengthways direction of the valve body. This embodiment includes a sealable opening 304 in the valve body which allows fluid communication through to the reservoir when the latter is in the second position. It will be appreciated that in other embodiments, multiple sealable openings may be provided, or a sealable opening with a different position or shape, provided that it allows fluid communication from the container to the reservoir when in the second position.

[0050] The valve assembly also includes an overflow inlet 305 which in this embodiment is in the form of a pipe with openings at a set height 306. The overflow inlet 305 extends from the valve body 301, and enables fluid communication between the openings 306 and the reservoir 302. In some embodiments, the overflow inlet may be adjustable so that the set height of the openings may be changed, as the height of the openings will define the volume of liquid to which the container may be filled. In this embodiment, the overflow inlet also includes a cover to prevent liquid directed towards the container from entering the overflow inlet before the desired volume of liquid has filled the container. In this embodiment, the cover is conically shaped so as to prevent liquid from pooling on the cover and to direct it towards the interior of the container.

[0051] Otherwise stated, the reservoir of the valve assembly can be in a first 'flooding' position, wherein the sealable opening is sealed and liquid, such as water, is able to fill the container until the height of the liquid in the container reaches the height of openings. Any further liquid which enters the chamber is directed through these openings into the reservoir. In this position, the container can be flooded with liquid to a desired height. The reservoir can also be in a second 'draining' position. In this position, the sealable opening is unsealed and liquid can drain through the sealable opening and into the reservoir, quickly draining the container. The reservoir has an opening or openings which enable liquid to leave the reservoir, these openings are configured such that they only allow draining to occur when the reservoir is in the second 'draining' position.

[0052] A biasing member, such as one or more magnets, is provided to bias the reservoir towards the first position. In preferred embodiments, the biasing force provided by the magnet or other biasing means is balanced such that it is able to overcome the force from liquid above the sealable opening, but not enough to overcome the gravitational force of the reservoir when it is partially or fully filled with liquid. When the reservoir fills to a predetermined amount, the biasing force is overcome and the reservoir moves to the second position. Liquid flowing through the sealable opening and into the reservoir as it drains provides a force to keep the reservoir in the second position. The container is then able to substantially or fully drain before the biasing member returns the reservoir to the first 'flooding' position.

[0053] In this embodiment, the valve body 301 is shaped so that the sealable opening 304 is provided in a depression, so that liquid in the container is directed towards the opening. The valve body 301 also includes a peripheral flange 307 including holes 308 through which the valve assembly can be attached to a container. It will be understood that in other embodiments, other attachment means may be used, or the valve assembly may be partially formed within the container.

[0054] FIGURE 4 shows a side view of the same embodiment with valve body 401, reservoir 402, hinge 403, sealable opening 404, and overflow inlet 405, From this view it can be seen that there is also a sealing member 409 within the reservoir which, when the reservoir is in the first position, acts to seal the sealable opening 404. From this view, it is also possible to see that the overflow inlet 405 extends through the valve body 401. It is also possible to see catch 410 on an opposing end of the valve body to the hinge 403 which acts to limit the extent of rotation of the reservoir 402, in effect setting the second position of the reservoir.

[0055] FIGURES 5A and 5B show the reservoir of an embodiment of the present invention in a first 'filling' position and a second 'draining' position respectively, as seen from below the container. The reservoir 502 is attached by hinge 503 to the valve body 501. A catch 510 is provided on an opposing side of the valve body to the hinge 503. In this embodiment, the reservoir includes a drainage outlet 511 which is shaped to correspond with the catch 510 so that the catch covers the outlet when the reservoir is in the first position. As a result, when the reservoir is in the first position, liquid cannot leave the reservoir through the drainage outlet, and when the reservoir is in the second position, liquid can drain from the reservoir. In this embodiment, the catch is in the form of a hooked tab and the outlet in the form of a rectangular slot which is sized to be smaller in width than the width of the hooked tab. It will be appreciated that, in other embodiments, other catches and openings may be used, and/or multiple catches and openings may be used.

[0056] This design allows for a smaller profile compared to existing designs, and enables a system of vertically stacked containers with a higher number of containers in the system relative to the valve shown in FIGURE 2. This is both because the system has less water loss and a reduced profile, enabling a higher number of containers in the same space. The containers can be stacked on top of each other, with liquid poured into the uppermost container filling to the predetermined level before draining out through the sealable opening and the reservoir when the latter moves to the second position. The liquid leaving the drainage outlet of the reservoir can be directed to the next container beneath the first, which can then fill and drain to further containers in the same manner. Unlike the design in FIGURE 2, the liquid leaving a container does not need to be directed to a filling catchment or similar, instead it may simply flow into the container. This provides greater flexibility in design as the valves do not have to be placed directly above one other in order to provide this cascading effect. The design also enables the quick removal and reinsertion of containers from the system. Due to the absence of any physical connections between containers in the system, if a container is removed, the liquid which would otherwise fill the container will instead flow into another container below the location of the removed container. The system as a whole is thus able to be easily scaled up or down. This is particularly advantageous when the application is in hydroponic crop growing, with each container being a tray containing plants. Each tray can be slid out for inspection, planting, or harvesting without disrupting the watering schedule for the other trays in the system. Further, if plants require different watering schedules at different stages of growth, then trays may be removed and inserted in another system adapted to this second watering schedule as they mature and grow.

[0057] While the embodiments above have been described in reference to vertically stacked growing trays, it will be appreciated that the valve assembly may be used in any sort of hydroponic operation where trays are removed/replaced for harvesting/planting. For instance, this valve may be particularly suited to operations which utilize a conveyor belt for easy harvesting, as no connections are required between a grow tray and a reservoir and a nozzle for dispensing water or other nutrient solution may be provided above the conveyor belt for supplying liquid to the grow trays.

[0058] In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose.

[0059] In this specification, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of’. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.

[0060] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0061] In addition, the foregoing describes only some embodiments of the invention(s), and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.

[0062] Furthermore, invention(s) have described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention(s). Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment.