Patent Application
20230255150
The present invention is directed towards a system and method for circulating air to a vertical gardening system.
Vertical farming is the practice of producing food and medicine in vertically stacked layers, vertically inclined surfaces and/or integrated in other structures such as warehouses and other structures that can accommodate growing plants. Vertical farming use indoor farming techniques and controlled-environment agriculture (CEA) technology, where all environmental factors can be controlled. These facilities utilize artificial control of light and watering. Prior methods for circulating air are accomplished using wall mounted oscillating fans and ceiling mounted HVAC systems. However, this air circulation method is ineffective in a vertical growing configuration and most vertical gardens are too compact for these environmental control methods to be efficient.
Prior methods for carbon dioxide dispersion use piping a plastic line to the back of a wall mounted fan or a carbon dioxide generator mounted at the ceiling in the room. Both methods do not allow for a controlled direction of carbon dioxide. Prior methods of filtering air have been through large “can filters” attached to a fan on the intake side. However, these large can filters occupy a large volume of space.
Prior methods are also generally silent on transpiration of the plants subjected to air circulation. Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97 to 99.5% is lost by transpiration and guttation. Leaf surfaces are dotted with pores called stomata, and in most plants they are more numerous on the undersides of the foliage. The stomata are bordered by guard cells and their stomatal accessory cells (together known as stomatal complex) that open and close the pore. Transpiration occurs through the stomatal apertures, and can be thought of as a necessary “cost” associated with the opening of the stomata to allow the diffusion of carbon dioxide gas from the air for photosynthesis. Transpiration also cools plants, changes osmotic pressure of cells, and enables mass flow of mineral nutrients and water from roots to shoots. Water vapor is removed quickly by air movement, speeding up diffusion of more water vapor out of the leaf. However, if there is no wind, the air around the leaf may not move very much, raising the humidity of the air around the leaf. Wind will move the air around, with the result that the more saturated air close to the leaf is replaced by drier air.
It would be desirable to provide a system which improves the circulation of air, may improve the distribution of carbon dioxide, and may use smaller filters that occupy less space, as well as improves transpiration.
The present invention is directed towards a system and method for circulating air and which may circulate carbon dioxide and provide light to a vertical gardening system. Traditional methods of wall mounted fans do not properly circulate air. The present invention eliminates the problem of stagnant air pockets created in indoor vertical farming where space is limited. Carbon dioxide may be dispersed directly onto each row of crops growing on a different shelf of a rack assembly. This process insures that each plant receives an equal quantity of carbon dioxide, as opposed to common methods of releasing carbon dioxide into a large general area with non-uniform distribution. The invention may also provide a compact air filtration system, eliminating the need for large can filters commonly used.
In one aspect, a flow distribution assembly provides air circulation to a rack-based vertical gardening system. The distribution assembly includes a housing having air inlet and outlet portions, and defining a plenum therebetween. At least one elongated duct has an end fluidly coupled to housing's air outlet portion, the duct adapted to extend along a shelf of the rack, to an opposite end thereof. A fan is fluidly coupled to the housing's air inlet portion and is supportable by the rack so that it can direct ambient air into the air inlet portion. The duct has a plurality of openings arranged to direct air at a plant growing area of the gardening system when the distribution assembly is mounted on a rack system. Optionally, the air inlet portion is positionable laterally outboard of plant growing regions of the vertical gardening system.
Embodiments of the invention may differ from traditional methods by having the filters on the supply side of an air circulation system. This allows for the air coming out of the fan to be disrupted, eliminating the spiral motion and pressurizes the low profile duct evenly on either side. The inventive system creates air movement inside each rack of plants where wall fans can't adequately reach and space does not allow for. The new invention may allow carbon dioxide to be plumbed into the plenum and dispersed directly to the plants. The new invention utilizes a fan or fans, optionally with a filter to clean the air as well as circulating the air. This allows for less space to be used, lower energy costs, and the benefit of being able to change disposable filters more often at a much lower cost than “can filters”.
The inventive system can be used with a vertical plant growing system to disperse air, and may disperse carbon dioxide gas, to a plurality of stacked shelves that are arranged vertically in a rack placed in a room or a building. An air distribution system can be mounted over each shelf of the rack so several air distribution systems can be used with each rack. The air distribution system can perform various functions including: circulate air around each of the plants, provides an even distribution of air, and optionally carbon dioxide, to each of the plants and filters the recirculating air. A lighting system can also be attached to the bottom of the air distribution system that can provide continuous grow light exposure to the plants.
With reference to
With reference to
Many conventional distribution systems utilize multiple fans due to uneven air distribution over a plant canopy. In a typical example, two 75 W fans may be placed every eight linear rack feet along a row of crops so that a 32 foot rack would utilize eight fans total resulting in a total of 600 W of power usage. The distribution system described herein may utilize a single fan, e.g., 242 W, for the same 32 foot rack. The same configuration may be applied to longer rack lengths. For instance, a conventional fan configuration for a 40 foot rack would require ten fans, a 48 foot rack would require twelve fans, and a 64 foot rack would require sixteen fans. However, each of the increased rack lengths could utilize a single fan with the distribution systems as described herein resulting in reduced power usage and lower costs.
The distribution system may be attached via one or more structural elements 114 such as braces, retaining brackets, etc. which allow for the distribution system to be slidingly secured or removed from the rack system 200, as shown. If desired, a second distribution system may be secured to the top of the rack system 200 so that air and/or carbon dioxide may be distributed upon any plants placed upon the first shelf 110 below the second distribution system.
The shelves in any of the embodiments described herein may vary in the number of shelves utilized per rack and may also vary in size. For example, one variation of the one or more shelves may each range in length from, e.g., 8 ft. to 64 ft., and in width from, e.g., 2 ft. to 4 ft. Various configurations of the shelf may range, e.g., 4 ft.×8 ft.; 3 ft.×8 ft.; 2 ft.×8 ft.; 4 ft.×4 ft.; 4 ft.×3 ft.; 4 ft.×2 ft., etc.
Additionally, the vertical distance between each shelf of a rack may be adjusted depending upon various factors, e.g., desired number of shelves or spacing between each shelf, growth phase of plant, etc. For instance, the distance between each shelf may be varied from, e.g., 12 in. to 48 in. when the plants are in their vegetative cycle, 36 in. to 96 in. when the plants are in their flower cycle, etc.
The racks as well as shelves may be constructed from various materials, e.g., powder coated square steel, aluminum, etc. Additionally and/or alternatively, one or more of the shelves may be configured to define a slope towards one specified corner or edge relative to horizontal for facilitating drainage of water or other liquids from the plants positioned upon the shelves.
With reference to
With reference to
The filters 111 can trap particulates from the plants, which can be beneficial when the plants being grown are very aromatic. Terpenes are a group of organic molecules derived from isoprene that are present in fruits, vegetables and vegetation. Terpenes are derived bio synthetically from units of isoprene and the basic molecular formula is (CsHs). These terpenes cause the specific odors for example: limonene in citrus fruit, pinene in pine tree. Marijuana is also a plant that produces terpenes. Because the smell of terpenes can be a nuisance to the surrounding areas, it can be highly beneficial to remove the marijuana terpenes that have been released into the air by the cannabis plants. In an embodiment, the filters used with the system can be terpene filters that remove terpenes from the circulating air in the plant grow building. By removing terpenes from the air, the odor generated by the building where the plants are grown can be greatly reduced so that the building is not a nuisance to the surrounding community. When the terpenes saturate the filters 111, the door to the filter housing 101 can be opened and the filters 111 can be removed and replaced with clean filters 111. The used filters 111 can be placed in sealed bags so that the odors are contained.
When the air enters the plenum through the fan 105, the air must passes through the air filters 111. In an embodiment, the filters 111 can have the dimensions, 12″×20″×1″. This process disrupts the spiraling air flow created by the fan 105 and allows both sides of the supply runs to pressurize and distribute even amounts of air through the 1.125″ duct exit holes. This was unachievable with a direct fan to supply run configuration. The process also eliminates the need for a separate fan and carbon filter to be installed in the room.
In an embodiment, a pressure sensor(s) 121 can be mounted in the filter housing 101 to measure static pressure and a differential pressure across the filters 111. This information can be used to determine the flow resistance through the filter 111 and the flow rate through the system. If a first pressure sensor 121 is mounted in the filter housing 101 upstream of the filter 111 and a second pressure sensor 121 is mounted in the filter housing 101 downstream of the filter 111, the differential pressure across the filters 111 can be measured. A clean filter 111 will allow air to more easily flow through the filter 111 and will have a lower differential pressure than a dirty filter 111. In an embodiment the system can have a processor 123 that is coupled to the pressure sensors 121 that monitor the differential pressure and the processor 123 can issue notifications when the differential pressure exceeds a predetermined value. The operator will then know that the filter(s) 111 need to be replaced.
In another embodiment, the system sensor 121 and processor 123 can monitor the static pressure of the pressure up stream of the filter 111. This monitoring system can depend upon the air input providing a constant power or flow rate into the system. As the filter(s) 111 becomes dirty, the static pressure upstream of the filter(s) 111 will increase and when the upstream static pressure exceeds a predetermined value, the monitoring system can inform the operator who will then know that the filter(s) 111 need to be replaced. Conversely, the system can monitor the static pressure of the pressure downstream of the filter(s) 111. As the filter(s) 111 becomes dirty, the static pressure downstream of the filter 111 will decrease and when the downstream static pressure falls below a predetermined value, the monitoring system can inform the operator who will then know that the filter(s) 111 need to replaced.
With reference to
With reference to
The distribution ducts 117 can be a metal duct system made from aluminum or galvanized sheet metal. The distribution ducts 117 can be designed to be as thin as possible while still providing desired flow rate of optional carbon dioxide and velocity of air movement over a vertical gardening application. This can be accomplished by using a thin cross section distribution duct 117 so that the ducts consume very little vertical space. For example, the ducts 117 can have a cross section that is about 3 inches high and about 16 inches wide. This height to width (H/W) ratio can be known as the aspect ratio. In this example, the aspect ratio is 3/16=0.1875. In an embodiment, the aspect ratio of the ducts 117 is less than 0.25. The flow rate of the air and optional carbon dioxide can be quantified with a flow rate metric such as cubic feet per minute (CFM). The carbon dioxide and airflow eliminates warm pockets of air by providing concentrated air movement, carbon dioxide dispersion, and filtration.
As described herein, the fan 105 can be mounted outside of the pallet rack volume on an end of the pallet rack. In one embodiment, the fan 105 flow rate can output 1,000 CFM while in other embodiments, the system may output between, e.g., 5.5 to 8 CFM at a rate of, e.g., 600 to 800 ft./min. The output CFM may be obtained at a distance of, e.g., 4 to 6 inches, above the plant canopy to provide adequate air movement without overstressing the underlying plants. A controller may be used to adjust the volume and velocity depending on, e.g., the distance between the distribution system and the plants. The distribution system and flow rates may be configured so that the flow exiting the openings 136 along the ducts 117 is balanced along the length of the ducts 117. For instance, the flow rate from a proximal location as compared to the flow rate from a distal location along the ducts 117 may vary within, e.g., 1 to 2 CFM, and, e.g., 100-200 ft./min, along racks up to, e.g., 56 feet in length.
With the flow parameters configured with the distribution system, transpiration in plants treated with the distribution system may improve. For instance, a 30 to 40% increase in transpiration may result.
Instead of a uniform distribution pattern, the openings may be defined in alternative patterns. For instance,
Additionally and/or alternatively, the ducts 117 may also be varied in height to adjust for the parameters such as pressure, flow rates, etc. relative to the length of the duct.
Furthermore, any of the features in one embodiment may be combined with another feature from another embodiment depending upon the desired flow characteristics, e.g., pressure, flow rate, etc. For instance, the tapered height of the ducts 117 may be combined with openings 136 which are uniform in distribution or varied in distribution patterns and/or size of the openings. Other combinations are intended to be within the scope of the disclosure.
In addition to providing optional carbon dioxide to the plants on the rack system, embodiments of the present invention incorporate grow lights that emit light that is directed towards the plants. With reference to
With reference to
In an embodiment with reference to
The Air exiting the filter housing 250 is directed towards the gas distribution ducts as described above. In the example, air is forced through a fan housing 103 and a pre-filter 251 into a light exposure space between the pre-filter 251 and a secondary filter 253. When the air is in between the pre-filter 251 and the secondary filter 253 the air is exposed to short-wavelength ultraviolet (UV-C) light, which results in ultraviolet germicidal irradiation (UVGI) of particles in the air. The UVGI is a disinfection method that uses UV-C light to kill or inactivate microorganisms by destroying nucleic acids. UVGI devices can produce strong enough UV-C light in circulating air systems to make them inhospitable environments to microorganisms such as bacteria, viruses, molds and other pathogens. UVGI can effectively provide air purification to the inlet air.
UV light is electromagnetic radiation with wavelengths shorter than visible light. UV can be separated into various ranges, with short-wavelength UV (UVC) considered “germicidal UV”. At certain wavelengths, UV is mutagenic to bacteria, viruses and other microorganisms. Particularly at wavelengths around 250 nm-270 nm, UV breaks molecular bonds within microorganism DNA, producing thymine dimers that can kill or disable the organisms. In an embodiment, the system can have three 33 inch long, 120V, 25 Watt UV-C lamps that each produce a light intensity of 302 μW/cm2. The lights are mounted in the plenum that eliminates surface bacteria, mold, and viruses from the system.
In different embodiments, various different types of lights can be used for the UVGI disinfectant air processing. For example, mercury-based lamps emit UV light at the 253.7 nm line, Ultraviolet Light Emitting Diodes (UV-C LED) lamps emit UV light at selectable wavelengths between 255 and 280 nm, and Pulsed-xenon lamps emit UV light across the entire UV spectrum with a peak emission near 230 nm.
The effectiveness of germicidal UV can depends on the length of time a microorganism is exposed to UV, the intensity and wavelength of the UV radiation, the presence of particles that can protect the microorganisms from UV, and a microorganism's ability to withstand UV during its exposure. In many systems, redundancy in exposing microorganisms to UV is achieved by circulating the air repeatedly. This ensures multiple passes so that the UV is effective against the highest number of microorganisms and will irradiate resistant microorganisms more than once to break them down.
The effectiveness of this form of disinfection depends on line-of-sight exposure of the microorganisms to the UV light. The lights 255 are placed in a direct line of sight for optimum for disinfection of the air. In an embodiment, the effectiveness and UV intensity can be achieved by using reflection. The interior surface of the filter housing 250 can have reflective surfaces so that the UV light can reflect back into the vent housing and expose more air to UV light. Aluminum can have a polished high reflectivity surface, which can improve the UVGI processing.
In air disinfection applications the UV effectiveness is estimated by calculating the UV dose which will be delivered to the microbial population. The UV dose is calculated through the equation: UV dose μWs/cm2=UV intensity μW/cm2× Exposure time (seconds). The UV intensity is specified for each lamp at a distance of 1 meter. In the air duct application, the exposure time is short so the UV intensity must be high and output by multiple UV lamps. The UV lights are located in a straight duct section with the lamps perpendicular to the air flow to maximize the exposure time. The UV dose is the amount of germicidal UV energy absorbed by a microbial population over a period of time. UVGI can be used to disinfect air with prolonged exposure. Disinfection is a function of UV intensity and time.
The pre-filters can keep dust particles out of the ducts of the system and prevent dust particles from being placed on the plants. The secondary filters can slow the air flow through the filter housing, giving the UV light more time to eliminate pathogens in the air. The pre-filter and the secondary filter are positioned to prevent light escaping the filter housing, which would be harmful to plants and people. The pre-filter and secondary filter can be carbon activated to reduce odors. The pre-filter and secondary filter can be black in color and absorb the light output by the UV light. The pre-filter and secondary filter can be opaque and the light output by the UV light from being transmitted through the pre-filter and secondary filter. The pre-filter and secondary filter does not reflect light which can prevent the UV light from escaping the filter housing.
With reference to
The air system can be configured to maintain a specific level of carbon dioxide in a grow room. For example, in an embodiment, the system may be configured to maintain the carbon dioxide level at approximately 1,500 ppm. The system can include carbon dioxide sensors 221 coupled to a controller 225 that controls flow control values 135 coupled to the carbon dioxide source 131. By altering the positions of the control valves 135, the flow rates of carbon dioxide to the air distribution systems can be adjusted. The controller 225 can control the flow rate to maintain an optimum carbon dioxide level and prevent the carbon dioxide level from becoming dangerous. When the carbon dioxide level is too high (for example, above, 2,000 ppm), the sensors 221 can detect this excess carbon dioxide and reduce the flow rate of carbon dioxide into the distribution system. Conversely, if the carbon dioxide level is detected as being lower than 1,000 ppm, the controller 225 can open the control vales 135 to increase the carbon dioxide levels through the air distribution system. If the carbon dioxide source 131 is a tank, a pressure sensor 137 can be mounted to the tank. If the pressure in the tank drops below a predetermined level, the system can inform the operator that the carbon dioxide tank should be replaced.
If the carbon dioxide level exceeds a level of 3,000, the system can issue a warning indicating that there can be a carbon dioxide control problem and the control system should be inspected. If the carbon dioxide level exceeds a level of 5,000, the system can issue a warning indicating that the carbon dioxide level exceeds the workplace exposure limit and warning people not to enter the room. With reference to Table 1 below a listing of carbon dioxide levels and the human reaction to exposure to the carbon dioxide gas.
The ducts 117 can run along the length of the rack shelves 201 and the light bars 145 can extend across the width of the shelves 201. In this embodiment, the light bars 145 can be suspended with wires or other supports below the ducts. In other embodiments, the light bars 145 can be mounted directly to the bottom of the ducts 117. In an embodiment, the height of the light bars 145 over the plants 211 can be adjustable. The light bars 145 can be positioned so that the LED lights may be 12-18 inches above the plants 221. As the plants 211 grow, the vertical positions of the light bars 145 may be adjusted to provide the optimum grow light exposure to the plants 211.
While the openings distributed along the bottom of the ducts 117 may be varied in size, pattern, etc., additional features may be incorporated to further enhance the flow of air through the openings. One example is shown in the perspective view of
One embodiment of a flow diverter 260 is shown in the partial cross-sectional side view of
In one example of use, the flow diverter 260 may be secured to the duct 117 so that the platform 261 extends at least partially into the channel interior CI so that a portion of the airflow AF encounters the flow surface 262 and is forced through the opening 136 as diverted flow DF.
While the platform 261 may extend transversely, e.g., at 90°, into the channel interior CI relative to the duct 117 when the diverter 260 is secured for use, the platform 261 may be configured so that the platform 261 presents an angled flow surface 262 relative to the channel interior CI and duct surface. One embodiment is shown in the side view of
Another embodiment is shown in
It is intended that any of the flow diverters 260 may be used with any of the different distribution systems described herein and with any of the variations of the openings as well.
In another embodiment, the ducts may be configured to provide the flow diversion rather than attaching a separate mechanism.
In yet another variation, rather than utilizing racks which are separate from the ducts, the ducts 117 may be integrated directly with the racks to form a combined rack and air distribution system, as shown in the perspective view of
The braces supporting the rack 300 may also be configured to allow for the 15 placement of the ducts 117 with minimal interference to the shelf platforms so that access to the shelves 301, 302 remains unhindered. In one embodiment, the braces may be configured into a diagonal cross-brace 304 between the rack supports while a second cross-brace 303 may extend horizontally between the rack supports relative to a surface of the shelf and positioned at a distance from the shelf surface so as to provide unhindered access to the shelf.
With this embodiment or any of the other rack and distribution systems described herein, any of the racks may be placed upon a floor or platform or secured in place upon the floor or platform. Alternatively, any of the racks may be configured to be mobile to allow for positioning or re-positioning of the racks relative to one another in order to facilitate access to multiple racks. An example of one embodiment is shown in the perspective view of
Each of the racks (or a select number of the racks) may be mounted upon a respective carriage 313 configured to slide or roll upon one or more tracks 314. Each of the racks may be positioned directly next to one another during use and when access to a particular rack is needed, the actuation mechanism 312 of a rack may be actuated to create a space 321 between the respective racks to provide sufficient access space. The racks may be moved individually or several at a time accordingly depending upon which rack is accessed.
The present disclosure, in various embodiments, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present disclosure after understanding the present disclosure. The present disclosure, in various embodiments, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and/or reducing cost of implementation. Rather, as the flowing claims reflect, inventive aspects lie in less than all features of any single foregoing disclosed embodiment.
The application is a continuation of U.S. patent application Ser. No. 17/012,322, filed Sep. 4, 2020, which is a continuation of U.S. patent application Ser. No. 16/122,077, filed Aug. 24, 2018, now U.S. Pat. No. 10,806,099, issued Oct. 20, 2020, which is a continuation-in-part of U.S. patent application Ser. No. 15/730,659, filed Oct. 11, 2017, now U.S. Pat. No. 10,694,682, issued Jun. 30, 2020, which claims the benefit of U.S. provisional application, Ser. No. 62/549,919, filed Aug. 24, 2017; and said U.S. patent application Ser. No. 16/112,077, filed Aug. 24, 2018, claims the benefit of U.S. provisional applications, Ser. No. 62/549,919, filed Aug. 24, 2017 and 62/712,675, filed Jul. 31, 2018, all of which are hereby incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 62549919 | Aug 2017 | US | |
| 62549919 | Aug 2017 | US | |
| 62712675 | Jul 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17012322 | Sep 2020 | US |
| Child | 18305891 | US | |
| Parent | 16112077 | Aug 2018 | US |
| Child | 17012322 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15730659 | Oct 2017 | US |
| Child | 16112077 | US |
