Patent Publication Number: US-2020275622-A1

Title: System And Method For Forced Induction By Condensation On Plant Roots Using Temperature And Pressure

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of hydroponics and aeroponics, and more specifically to an apparatus and method for the growing of plants and/or other organisms in a substantially water and air based environment. 
     BACKGROUND OF THE INVENTION 
     Plant roots require three main inputs for healthy growth: air, water, and nutrients. As long as these inputs are adequately provided, the root system does not need to be placed in soil to thrive. The growing of plants in a nutrient rich water based solution is known as hydroponics. The growing of plants in a nutrient rich air and mist environment is known as aeroponics. 
     Such physical soil-less systems typically house the plant and provide its roots with a nutrient solution, water, and air. Using such a system aids growth due to the ability to optimize the provision of water, air, and nutrients to the roots. Another advantage of such systems is the ability to have greater control over pathogens and other microorganisms, either in terms defense or in terms of introducing beneficial microorganisms to encourage symbiosis or neutrality. Such systems also can provide greater flexibility over the location of the plant growth, either in terms of indoor versus outdoor, smaller quarters, and/or places with unusable soil. 
     A system using a nutrient solution in a fluid stage can be better controlled to balance nutrients, oxygen and other conditions, such that improved growth characteristics can be obtained compared to soil-grown plants. With soil-less methods, dense and fine root structures can be developed by the plant, thereby optimizing and facilitating transport through the xylem. Moreover, the addition of adequate oxygen to a nutrient solution or the use of aerosol prevents the respiratory death of cells in the root and prevents root rot and pathogenesis, by maintaining healthy root immune systems. 
     A primary concern with many commercial and domestic hydroponic and aeroponic applications is maximizing plant growth in the shortest time possible. In order to achieve this aim, various systems have been developed attempting to optimize uptake of the nutrient solution into the plant. However, such systems are complex, noisy, require frequent filter changes, require extensive maintenance, include many moving parts that tend to break, utilize nozzles that clog, require repeated cleaning, and require constant timing adjustments. These systems are not user friendly, lack longevity, and are excessively costly to make, store, transport, set up, and operate. Still other systems attempt to use heat from ultrasonic units which tend to be too much for the roots and system components to handle. Temperature control devices used to remove heat from such systems tend to expend it in a fashion that is wasted. 
     It is therefore an object of the present invention to solve the aforementioned problems and to provide an aeroponic system which is simpler to manufacture, transport and store, easier to use, requires less maintenance, consists of fewer moving parts, does not use nozzles that clog, minimizes required maintenance, and avoids using filters that require periodic changing. It is a further object of the invention to optimize the water/root interface, increase transpiration of leaves, and recapture the water from the plants for the purpose of water re-use and conservation. 
     BRIEF SUMMARY OF THE INVENTION 
     The aforementioned problems and needs are addressed a plant growing system that includes a chamber having a plurality of holes through which plant stalks can extend, a heating device in fluid communication with the chamber and configured to receive a liquid solution from the chamber, to vaporize the received liquid solution to create a vapor, and to supply the vapor to the chamber to create a first pressure inside the chamber that is greater than a second pressure immediately outside the chamber. 
     A method of growing plants includes providing a chamber having a plurality of holes, providing plants each having a stalk extending through one of the holes, wherein each of the plants has roots disposed inside of the chamber and leaves disposed outside of the chamber, vaporizing a liquid solution using a heating device to create a vapor, and supplying the vapor to the chamber to create a first pressure inside the chamber that is greater than a second pressure immediately outside the chamber. 
     Other objects and features of the present invention will become apparent by a review of the specification, claims and appended figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of the plant growing system of the present invention. 
         FIG. 2  is a side cross-sectional view of the growing chamber of the present invention. 
         FIG. 3  is a perspective view of the growing chamber of the present invention. 
         FIG. 4  is a side view of the growing chamber of the present invention. 
         FIG. 5  is a side view of the growing chamber of the present invention with the input lines. 
         FIG. 6  is a partial, exploded side view of the top of one of the cylindrical sub-chambers. 
         FIG. 7  is a side view of the top of one of the cylindrical sub-chambers. 
         FIG. 8  is a side cross-sectional view of the growing chamber of the present invention, illustrating the vapor in the sub-chambers and liquid nutrient solution in the main chamber. 
         FIG. 9  is a side view of the top of one of the cylindrical sub-chambers with a UV light source. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a plant growing system  10  as shown in  FIG. 1 . The system  10  includes a growing chamber  12 , a reservoir  14 , a heating device  15 , and valve  20 , all interconnected as shown with lines  22   a - 22   e.  Lines  22   a - 22   e  can be flexible tubing, rigid pipes, or a combination of the two. 
     Reservoir  14  is a container that holds a water based nutrient solution. As a non-limiting example, the nutrient solution can include the following (per gallon of water base): 6.0 gram of Ca(NO3)2, 2.09 grams KNO3, 0.46 grams K2SO4, 1.39 grams KH2PO4, 2.42 grams MgSO4 7H20, and 0.4 grams of 7% Fe Chelated trace elements (where Fe Chelated trace elements can include 7% iron, 2% manganese, 0.4% zinc, 0.1% copper, 1.3% boron and 0.06% molybdenum). 
     The nutrient solution passes from reservoir  14 , through line  22   a,  through a back flow preventer valve  24  (which prevents any reverse flow of the nutrient solution), through line  22   b,  and into heating device  15 . The heating device  15  preferably includes a chamber  16  for receiving the nutrient solution, and a heating element  18  that provides sufficient heat to vaporize the received nutrient solution to create a heated nutrient vapor (mist). A non-limiting example for heating element  18  is a glow plug (similar to those used in diesel engines) or its equivalent, which provides heat up to 1200 degrees Celsius. Preferably, heating element  18  generates a nutrient vapor that is preferably heated to at least 800 degrees Celsius for several reasons. First, that temperature is the minimum temperature required to liquefy the salt component of the nutrient solution, and to prevent the salt component from accumulating on apparatus surfaces inside the system as it is delivered to the roots of the plants. Second, this high temperature efficiently generates vapor molecules of the various nutrients in solid or liquid form suspended in water vapor) allowing greater control of micron droplet formation, which is ideal for root absorption as further described below. This is in contrast with vapor generation techniques such as ultrasound, which typically generates mist molecules around 5 microns in size (which are too small). Third, the high temperature serves to self-clean the system because it effectively kills contaminants. Fourth, this temperature effectively generates the positive pressure necessary to drive the nutrient vapor through line  22   c,  through valve  20 , through line  22   d,  and into growing chamber  12 , and to positively pressurize growing chamber  12  as further explained below. The flow of the nutrient vapor and therefor the pressure inside grow chamber  12  can be controlled by valve  20 . 
     Growing chamber  12  is best shown in  FIGS. 2-6 , and includes a main chamber  26  and a plurality of sub-chambers  28  extending up from and in fluid communication with the main chamber  26 . See  FIGS. 2-3 . In a non-limiting embodiment shown in the figures, main chamber  26  is rectangular shaped, and each sub-chamber  28  is a cylinder extending up from the top of main chamber  26  and in fluid communication therewith via openings  30 . Main chamber  26  and sub-chambers  28  collectively form a sealed growing chamber  12 . 
     Each sub-chamber  28  includes an opening  32  (see  FIGS. 3-4 ) in its side wall to which the line  22   d  connects (see  FIG. 5 ), so that the nutrient vapor is supplied directly to each of the sub-chambers  28 . The top of each sub-chamber  28  include a membrane  34  installed therein that seals the top of the sub-chamber  28 . The membrane  34  is preferably made of neoprene or any other appropriate material that absorbs, blocks and/or otherwise prevents the nutrient vapor from escaping the sub-chamber  28 , but preferably does allow air to flow there through by stripping the nutrient molecules from the air passing there through). Membrane  34  can include a small hole  36  through which the plant will grow. The hole  36  will preferably expand with plant growth, and therefore make an air seal with the plant stalk. Underneath the membrane  34  is a root cage assembly  38  that provides a cage structure to physical support of the roots of the plant.  FIG. 7  shows a plant with its stalk  40  growing through hole  36  of membrane  34 , its leaf structure  42  above membrane  34  and outside of sub-chamber  28 , and its root structure  44  below membrane  34  and inside of sub-chamber  28 . As used herein, the area immediately above the membrane  34  outside the sub-chamber  28  is referred to as the leaf zone (where the plant&#39;s leaf structure  42  grows), and the area immediately below the membrane  34  inside the sub-chamber  28  is referred to as the root zone (where the plant&#39;s root structure  44  grows). As shown in  FIG. 8 , condensation of the nutrient vapor  70  back into a nutrient solution  72  is captured by the main chamber  26 , where the nutrient solution is then fed back to the reservoir  14  by line  22   e  so the nutrient solution can be vaporized again into a nutrient vapor for re-insertion into the sub-chambers  28 . 
     The growing chamber  12  includes one or more temperature sensors  46  to measure the temperature of the nutrient vapor inside the growing chamber  12 , and preferably inside one or more of the sub-chambers  28  of the growing chamber  12 . The growing chamber  12  also includes a pressure sensor  48  to measure the pressure inside the growing chamber  12 . 
     An air pump  50  provides a cooling air flow for the growing chamber  12 . The cooling air flow can be simply blown on the growing chamber  12  to cool the nutrient vapor and/or nutrient solution therein. An optional secondary chamber  52  can be positioned around the growing chamber  12  to contain the cooling air around the growing chamber  12 . An optional cooling chamber  54  and cooling element  56  can be used to cool the air flow from pump  50 . One example of the cooling element  56  is a thermoelectric cooler (TEC). An optional air valve  58  can be used to control the amplitude of the air flow onto the growing chamber  12 . By providing a separate sub-chamber  28  for each plant, a greater cooling effect and efficiency can be achieved (by increasing the surface area of the growing chamber  12  portion dedicated to each plant). 
     A controller  60  containing control circuitry is connected to the various system components for monitoring and control. Specifically, the controller  60  receives the outputs of temperature sensor  46  and pressure sensor  48 , and controls the operation of the heat element  18  and valve  20 , the air pump  50 , cooling element  56  and valve  58  in response, to achieve and maintain the desired temperature and pressure inside the growing chamber  12 . 
     It has been discovered by the present inventor that providing the nutrient vapor to the root zone at a pressure greater than 1 atmosphere (1 ATM) accelerates the growing process of most plants. Specifically, maintaining the root zone of the growing chamber  12  to a pressure of approximately 0.5 PSI to 5 PSI above 1 ATM, with the leaf zone at 1 ATM, causes a forced induction of the water and nutrients in the nutrient vapor into the roots, accelerating plant growth. The pressure differential of 0.5 PSI to 5 PSI between the root zone and the leaf zone is easiest to achieve by providing a pressure above 1 ATM at the root zone, and a 1 ATM pressure at the leaf zone, so there is no need for a pressure chamber or other apparatus for holding the leaf zone at a pressure other than 1 ATM. However, the pressure differential could optionally be achieved at least partially by manipulating the pressure at the leaf zone to something other than 1 ATM. 
     It has also been discovered that the temperature of the root zone significantly affects the rate at which the roots absorb the water based nutrients. It has been determined that the ideal temperature of the root zone for most blooming plants is approximately 75 degrees Celsius, and for most non-blooming plants is approximately 67 degrees Celsius, both of which are well below the initial vapor temperature of 800 degrees Celsius or more. These ideal temperatures can vary not only based on the particular plants being grown, but also with the differential pressure used in operation between the root and leaf zones. Therefore, cooling of the growth chamber  12  is preferable to maintain these root zone temperatures. Separate sub-chambers for different plants provides more efficient conduction cooling (i.e., increased growth chamber surface area for each root zone for increased heat conduction). While ambient cooling using still air may be possible, using circulating cooling air (from pump  50 ) to extract the necessary heat from the system to achieve and maintain the desired root zone temperatures is advantageous for those applications that would otherwise require placing the leaf zone in a frigid ambient air temperature that is not ideal for plant growth. Moreover, the circulating air can be used to transfer the heat from the root zone to the leaf zone, further promoting plant growth. 
       FIG. 9  illustrates the addition of an optional UV light source  62  attached to the sub-chamber  28  for illuminating the root zone with UV light. The UV light promotes root growth and directionality of growth. Preferably, the UV light source  62  is activated in intervals of  15  minutes or less. When the roots are exposed to UV light, they begin “escape tropism,” which caused the plant to focus its energy on growing the roots away from the light. Therefore, in the present case, the UV light will cause the plants to grow in a ordered fashion. The UV light can be used to better utilize space in the root zone. For example, when growing plants with large roots, the UV light source could be placed below the roots to keep them from overtaking the bottom of the sub-chamber  28  and the main chamber  26 , and instead force the roots to grow and crowd a smaller space adjacent the top of the sub-chamber  28 . 
     The present invention has many advantages. The system provides pressure enhanced fusing of water, nutrients and air into roots, greatly increasing plant growth rates and allowing crop harvest in shorter growing cycles. The air flowing through membrane  34  (without accompanying water and nutrients which are blocked) is beneficial to the leaves in the leaf zone, increases the transpiration process. Providing a separate sub-chamber  28  for each plant means that vapor flow, temperature, air flow and even pressure can be customized dependent on plant type and/or growth cycle. 
     The system and method of the present invention provides a platform for rapid crop growth with a small form factor, allowing for indoor use in otherwise harsh climates. The system can be used in more seasons and in locations closer to consumer markets (reducing shipping costs and time, and allowing produce to be both locally grown and consumed). The size of the system and its crop production can be effectively scaled in size to meet the needs of the user (individual residential use versus industrial applications). The system is self-cleaning and requires relatively little maintenance. The system produces little noise given that the vapor pressure is generated by the same heat source used to vaporize the nutrient solution, making it ideal for indoor and residential use. The use of liquid or vapor pumps, liquid filters, and oxygenating systems required by typical hydroponic devices is avoided. Also avoided is the use of mist or vapor jets, which can clog and require routine maintenance. 
     The system provides pressurized nutrient vapor at the root zone with a range of ideal molecule sizes (e.g., 40 to 80 microns). Roots with a smaller size provide less surface area for vapor condensation, so molecules at the lower end of the size range condense onto and are driven into the root. As roots grow to larger sizes, they provide a larger surface area so that molecules at the higher end of the size range condense onto and are driven into the root. Therefore, the roots self-select the ideal molecule size given the root&#39;s size, enhancing growth. In addition to this self-selection, the controller  60  can be programmed to modify pressure and/or temperature conditions over the growing cycle of the plants, to fine tune the molecule condensation and infusion. For example, the pressure and/or temperature in the root zone can be changed as the roots change in size or consistency as they grow (e.g., stringy versus hairy) to maximize vapor condensation on and infusion into the roots. 
     It is to be understood that the present invention is not limited to the embodiment(s) described above and illustrated herein, but encompasses any and all variations falling within the scope of any claims. For example, references to the present invention herein are not intended to limit the scope of any claim or claim term, but instead merely make reference to one or more features that may be covered by one or more of the claims. Materials, processes and numerical examples described above are exemplary only, and should not be deemed to limit the claims. Certain components could be combined for simplicity or reduced cost. For example, the reservoir  24  can be eliminated, whereby the bottom of the grow chamber  12  can be used to hold the nutrient solution that is fed to the heating element. The cooling chamber  54  and cooling element  56  can be eliminated for those applications in which the source of air for pump  50  is already sufficiently cool (e.g., cold air climates). Valve  20  can be a plurality of valves (one for each sub-chamber  28  for individual control either manually or by the controller), or can be eliminated for those applications in which adequate flow and pressure control is attainable from the heating device  15 .