Atmospheric water harvesting apparatus

An atmospheric water harvesting apparatus includes a post, a water capturing unit, a drive bearing, a motor, a water collecting member, and a power source. The water capturing unit comprises a cylindric wall. The cylindric wall is positioned concentrically with the post. The cylindric wall comprises an inner surface and an outer surface. The cylindric wall forms an air passageway having an air inlet and an air outlet. The inner surface of the cylindric wall is coated with a layer of triboelectric material. The drive bearing is rotatably mounted about the post. The drive bearing is provided with a plurality of radial bars. The water collecting member is located beneath the water capturing unit to collect water captured by the water capturing unit. The power source is electrically connected to the motor.

FIELD OF THE INVENTION

The present invention relates generally to water harvesting from the atmosphere. More specifically, the present invention is an apparatus for harvesting water from surrounding air. The present invention provides improved energy efficient extraction of water from air, particularly in outdoor settings and over a range of relative humidity.

BACKGROUND OF THE INVENTION

Worldwide, the shortage of freshwater has increased exponentially due to population growth, climate change and contamination of available water, especially in water tables that provide water for general consumption. There are vast regions of Africa, India, and the Pacific Ocean where there is real water scarcity.

Over the 20th century and into the 21st century, the global population has increased by 300%, while water consumption has increased by 600%. Freshwater is becoming a scarce commodity as climate change, man-made pollutants entering the water system, and over-withdrawal of existing aquifers place enormous strain on freshwater supplies. The distribution of freshwater around the globe is highly uneven, leading to regional shortages or excesses of water resources. Based on the Falkenmark Stress Indicator (FSI) index, the United Nations has predicted that 48 countries will experience water stress or scarcity by 2025. Four billion people in the world face at least one month of water scarcity every year. The water crisis has or will soon turn into food crisis in many areas of the world. To avert the looming water-food crisis, certain measures should be adopted, including, but not limited to i) water conservation, ii) reducing pollutants entering the water system, iii) upgrading current infrastructure, and iv) improving freshwater generation technologies. With an estimated 12,800 trillion liters of renewable water available in the atmosphere, atmospheric water harvesting has the potential to be a viable solution to address some of the global needs for freshwater, especially in locations where even saline and/or brackish water is not available. Combining these facts and considering the challenges and shortcomings of existing centralized water provision and delivery systems, the idea of decentralized atmospheric water harvesting (AWH) systems has emerged and been followed by a number of researchers and manufacturers during the last few decades. A conventional AWH operates using vapor compression refrigeration (VCR) unit to condensate water from ambient air by cooling it below its dew point temperature.

However, several drawbacks are associated with the existing AWH systems. For example, the existing AWH systems are expensive to manufacture, and/or are not conducive to operation in arid climates, and/or are not suitable for reliable production of potable water in significant quantities, and/or cannot be implemented in compact units, and/or require large amounts of energy per quantity of water produced, and/or have geographical location requirements.

Therefore, it is an objective of the present invention to provide an atmospheric water harvesting apparatus that overcomes the problems set forth above.

SUMMARY OF THE INVENTION

The present invention discloses an atmospheric water harvesting apparatus that comprises a post, a water capturing unit, a drive bearing, a motor, a water collecting member, and a power source. The post comprises a first end and a second end. The water capturing unit comprises a cylindric wall. The cylindric wall is positioned concentrically with the post. The cylindric wall comprises an inner surface and an outer surface. The cylindric wall forms an air passageway having an air inlet and an air outlet. The inner surface of the cylindric wall is coated with a layer of triboelectric material. The drive bearing is rotatably mounted about the post. The drive bearing is provided with a plurality of radial bars. Each of the plurality of radial bars comprises a proximal end connected to the drive bearing and a distal end attached to the inner surface of the cylindric wall. The motor is mounted adjacent to the drive bearing to rotatably drive the drive bearing about the post. The water collecting member is located beneath the water capturing unit to collect water captured by the water capturing unit. The power source is electrically connected to the motor.

DETAIL DESCRIPTIONS OF THE INVENTION

Other technical advantages may become readily apparent to one of ordinary skill in the art after review of the following figures and description. It should be understood at the outset that, although exemplary embodiments are illustrated in the figures and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the drawings and described below.

Unless otherwise indicated, the drawings are intended to be read together with the specification and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up”, “down” and the like, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, “radially”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly,” “outwardly” and “radially” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate. As used herein, the term “proximate” refers to positions that are situated close/near in relationship to a structure. As used in the following description, the term “distal” refers to positions that are situated away from positions.

The present disclosure includes many aspects and features. Moreover, while many aspects and features relate to, and are described in the context of atmospheric water harvesting apparatuses, embodiments of the present disclosure are not limited to use only in this context.

The present invention is an atmospheric water harvesting apparatus that is designed to harvest water from air. It is an aim of the present invention to provide an efficient, low-cost atmospheric water harvesting apparatus that can operate virtually anywhere including low humidity or arid areas. It is another aim of the present invention to provide an atmospheric water harvesting apparatus that is simple in structure, inexpensive to manufacture, and easy to use. It is another aim of the present invention to provide a compact atmospheric water harvesting apparatus that only occupies a small footprint.

Referring now to the figures of the present disclosure.FIG.1is a perspective view of the present invention. The atmospheric water harvesting apparatus of the present invention comprises a post100, a water capturing unit200, a drive bearing300, a motor400, a water collecting member500, and a power source600.

The post100is configured to install thereto the components of the present invention. It should be noted that the post100can be of any shape, size, material, features, type or kind, orientation, location, quantity, components, and arrangements of components that would allow the present invention to fulfill the objectives and intents of the present invention. In a preferred embodiment, the post100is a cylindric post comprising a first end102and a second end104. In one embodiment, the second end104of the post100may be fixed to ground with the post100being vertically oriented. In another embodiment, the post100may comprise a wire guiding member120having at least one aperture122formed therethrough. Preferably, the wire guiding member120is located above the water capturing unit200.

In reference toFIGS.1-4, the water capturing unit200is configured for electrostatic precipitation of moisture in the air. The efficiency of electrostatic precipitation (or Electrostatic Water Air Nucleation) of water from the air has been theoretically analyzed and the inherent limitations are known. Water drops below a certain minimum size cannot be extracted from the air since they either cannot be charged, or their charge is insufficient for precipitation. Values of the minimal and effective radiuses of drops have been analytically determined. Enlarging the drops is proposed to increase the efficiency of precipitation. Another key aspect of the improved precipitation efficiency is the centrifugal force of the water capturing unit200that flings the small water droplets toward the high static field on the wall of the water capturing unit200. The combination of

The key principles of electrostatic precipitation for moisture in the air comprises three main independent stages:Ionization of air molecules;Charging of water drops in the air by the ion;Centrifugal force that flings water outward; andPrecipitation of the water drops using a static electric field.

One of the most effective methods of ionization and subsequent charging of the particles in the air is the use of crown (or corona) discharge. This method involves passing the gas in between ionized electrodes. When the atoms or molecules meet the surface of the metal electrodes, they lose or gain a charge subject to the polarity of the electrode. The electric field density must be as high as a few kV/m to initiate ionization.

The water capturing unit200of the present invention may comprise a cylindric wall202. The cylindric wall202may be positioned concentrically with the post100. The cylindric wall202may be conductive and may have a charge thereon so as to enhance the attraction of the charged water droplets. The cylindric wall202may comprise an inner surface204and an outer surface206. In one embodiment, the cylindric wall202of the water capturing unit200forms an air passageway210having an air inlet212and an air outlet214. Preferably, the air inlet212is located at the top of the cylindric wall202, while the air outlet214is located at the bottom of the cylindric wall202. The inner surface204of the cylindric wall202is preferably coated with a layer of triboelectric material216. The cylindric wall202is able to rotate about the post100by means of the drive bearing300, which will be described in more detail hereinafter. In an alternative embodiment, the post100, instead of the cylindric wall202, may be rotated by the motor400. The cylindric wall202may be made of any suitable material. Preferably, the cylindric wall202is made of sailcloth, waterproof fabric, polyvinyl chloride, or aluminum.

The cylindric wall202of the present invention creates a high static electricity potential between the interior of the cylindric wall202and the outer surface206of the cylindric wall202. This is caused by the friction of the rotating cylindric wall202with the air and the optimization of high negative turboelectric materials. The rotation of the cylindric wall202initially moves water microdroplets in the air passageway210outwards. The water microdroplets are consolidated into bigger droplets that accelerate toward the inner surface204of the cylindric wall202. Then the bigger droplets hit the inner surface204of the cylindric wall202and are captured by the layer of triboelectric material216coated on the inner surface204of the cylindric wall202.

Air coming from the air inlet212goes down the inner surface204of the cylindric wall202with a large velocity differential to the inner surface204of the cylindric wall202. In a preferred embodiment, air can be sucked in via an air suction device (e.g., a fan, etc.), which may be attached to the air inlet212of the air passageway210. Friction with inner surface204of the cylindric wall202causes the air to match the high static potential inner rotating surface velocity, such that the same friction triboelectrically charges the inner surface204of the cylindric wall202. The charged inner surface204acts upon the incoming water droplets so that the water droplets are rapidly attracted to the inner surface204of the cylindric wall202. Moreover, due to gravitation, the water droplets will bead up and move down to the bottom of the cylindric wall202. To facilitate water collection, the inner surface204can be coated with a hydrophobic coating. The hydrophobic coating may be disposed on the layer of triboelectric material216.

The cylindric wall202can also be electrically charged to further enhance the triboelectric effect. This can be implemented via a fine wire mesh embedded in the cylindric wall202such that the charge can be tuned up or down via the microcontroller700based on atmospheric conditions and available power.

In reference toFIG.4, the cylindric wall202may comprise at least one circular batten220to reinforce the cylindric wall202. The circular batten220may be built in the cylindric wall202or attached to the inner surface204or outer surface206of the cylindric wall202. In a preferred embodiment, the cylindric wall202may comprise at least one vertical rib222to help water droplet flow down to the bottom of the cylindric wall202. The at least one vertical rib222may also be built in the cylindric wall202or attached to the inner surface204or outer surface206of the cylindric wall202. In a preferred embodiment, the diameter to height ratio of the cylindric wall202may range from 1:3 to 1:8. For instance, the cylindric wall202may be 1 meter in diameter and 3-8 meters in height. In another preferred embodiment, the water capturing unit200further comprises a flared inlet duct218attached to the cylindric wall202, preferably at the air inlet212, in order to reduce air pressure and facilitate air intake. In one embodiment, the air suction device may be attached to the flared inlet duct218.

In reference toFIGS.5and6, the drive bearing300is configured to rotate the water capturing unit200. The drive bearing300may be rotatably mounted about the post100. Further, the drive bearing300may be provided with a plurality of radial bars or wires302. Each of the plurality of radial bars302may comprise a proximal end304connected to the drive bearing300and a distal end306attached to the inner surface204of the cylindric wall202. In a preferred embodiment, the distal end306of each of the plurality of radial bars302is attached to the circular batten220of the cylindric wall202. This will facilitate improving the stability and stiffness of the apparatus when the water capturing unit200is rotated at a relatively high speed (e.g., 500-4,000 rpm). In another preferred embodiment, the drive bearing300further comprises a circular hub member310. The circular hub member310may be positioned concentrically with the drive bearing300. The plurality of radial bars302travels through the circular hub member310to enhance the structural integrity. Therefore, when the drive bearing300is rotated, the plurality of radial bars302will cause the water capturing unit200to rotate about the post100.

In a preferred embodiment, the atmospheric water harvesting apparatus of the present invention further comprises an idle bearing320. The idle bearing320may be similar to the drive bearing300in structure. Particularly, the idle bearing320may be provided with a plurality of radial bars322. Each of the plurality of radial bars322may comprise a proximal end324connected to the idle bearing320and a distal end326attached to the inner surface204of the cylindric wall202. In a preferred embodiment, the distal end326of each of the plurality of radial bars302is attached to the circular batten220of the cylindric wall202. Preferably, the idle bearing320is located adjacent to the air outlet214of the air passageway210, while the drive bearing300is located adjacent to the air inlet212of the air passageway210. Although only one idle bearing300is illustrated in the drawings, it should be noted that more than one idle bearing300may be utilized.

The drive bearing300is preferably driven by the motor400. In one embodiment, the motor400may be mounted below the drive bearing300to rotatably drive the drive bearing300about the post100. The motor400may be mounted onto the post100via any suitable mechanisms (e.g., U-bolt mounting bracket, etc.). The motor400provided can be a brushed motor or a brushless motor either AC or DC. In a preferred embodiment, the motor400drives the drive bearing300via a belt-pulley power transmission system. In this system, the motor400comprises a driving pulley404attached to an output shaft402of the motor400, and the drive bearing300comprises a driven pulley312attached thereto. An endless belt406is wound around the driving pulley404and the driven pulley312. The endless belt406is tensioned such that the rotation of the driving pulley404can be transmitted to the driven pulley312via the endless belt406.

In reference toFIGS.7and8, the water collecting member500is configured to collect the water captured by the water capturing unit200. Preferably, the water collecting member500is a circular member concentrically connected to the post100. In one embodiment, the water collecting member500is connected to the post100via a plurality of radial bars502. In one embodiment, the water collecting member500comprises a circumferential groove504. The bottom edge of the cylindric wall202may be located inside the circumferential groove504, such that the water captured by the water capturing unit200is collected in the circumferential groove504. The water collecting member500may further comprise a water outlet506that is in fluid communication with the circumferential groove504. The collected water may be directed to a storage device (e.g., a bucket, a tank, etc.) via the water outlet506.

The power source600can be any type of power source, including a battery, a direct current (DC) voltage source, a wind turbine, a solar panel, a fuel cell, or any other type of power source. Preferably, the power source comprises a solar panel602, as shown inFIGS.1and2. Preferably, the solar panel602is mounted at the first end102of the post100. In one embodiment, the present invention further comprises a linear actuator604. The linear actuator604may be mounted to the post100, adjacent to the first end102of the post100. The linear actuator604is connected to the solar panel602to adjust a tilt angle of the solar panel602. The solar panel602may be electrically connected to the motor400to directly supply power thereto. Alternatively, the solar panel602may be electrically connected to one or more energy storage devices606(e.g., rechargeable batteries, etc.) for transmitting the electric energy generated by the solar panel602to the energy storage device for later use.

Now referring toFIG.9, which illustrates the control system of the present invention. The abovementioned components of the present invention are preferably controlled by the control system to work typically during the late evening and early morning, in order to ensure maximum water extraction from higher humidity atmosphere. Specifically, the present invention may comprise a microcontroller700that is electrically connected to the linear actuator604and the motor400. Moreover, the present invention may comprise a temperature sensor702and a humidity sensor704. In a preferred embodiment, the present invention further comprises a wind sensor703and a barometric pressure sensor705. The sensors may transmit collected data to the microcontroller700. The microcontroller700may be configured to adjusts a rotation speed of the motor400based on the data collected from the temperature sensor702, the wind sensor703, the humidity sensor704, and/or the barometric pressure sensor705. The microcontroller700may be enclosed in a control box706. In one embodiment, the microcontroller700may be connected to an external device (e.g., a desktop computer, a laptop computer, a server, a cellphone, etc.) via a wired or wireless network, such that the atmospheric water harvesting apparatus of the present invention can be controlled remotely. Moreover, the microcontroller700may control the operation of the present invention in accordance with weather forecasts. In one embodiment, any radio signal can serve as inputs to the microcontroller700in order to control the apparatus of the present invention.

It is envisioned that the sizes of the components forming the present invention such as the post100, the water capturing unit200, the water collecting member500, etc. can vary based on design requirements. Additionally, a plurality of the atmospheric water harvesting apparatuses can be grouped into clusters and work independently or in tandem.