Nanobubble Generator

Abstract

The nanobubble generator includes an elongated housing defining an internal cavity adapted to receive a liquid carrier, a liquid inlet, and a liquid outlet; a gas permeable member disposed at least partially within the internal cavity of the housing, the gas permeable member including a first end adapted to receive a pressurized gas, a second end, and a porous sidewall; and an electrical conductor adapted to generate a magnetic flux parallel to an outer surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet. The housing and gas permeable member are configured such that a flow rate of the liquid carrier flowing parallel to the outer surface of the gas permeable member is greater than a turbulence threshold of the liquid for creating a turbulent flow condition, thereby allowing the liquid to shear the gas from the outer surface of the gas permeable member to form nanobubbles in the liquid carrier. TIFF2024506941000002.tif52155

Description

[Technical Field]

[0001] Priority claims This application claims priority to U.S. Provisional Patent Application No. 63 / 150,973, filed February 18, 2021, the entire contents of which are incorporated herein by reference.

[0002] Technical Field The present invention relates to the generation of nanobubbles in a liquid carrier. [Background technology]

[0003] background Nanobubbles are stable in liquid carriers for extended periods of time and can be transported in liquid carriers without coalescence. These properties make nanobubbles useful in a variety of areas, including water treatment, plant growth, aquaculture, and sterilization. Summary of the Invention

[0004] overview In a first aspect, an apparatus for generating a composition comprising nanobubbles in a liquid carrier is described, comprising: (a) an elongated housing having a first end and a second end and defining a liquid inlet, a liquid outlet, and an interior cavity adapted to receive a liquid carrier from a liquid source; (b) a gas permeable member disposed at least partially within the interior cavity of the housing, the gas permeable member including a first end adapted to receive pressurized gas from a gas source, a second end, and a porous sidewall extending between the first and second ends, the gas permeable member defining an interior surface, an exterior surface, and a lumen; and (c) at least one electrical conductor adapted to generate a magnetic flux parallel to the exterior surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet. The housing and gas permeable member are configured such that when the liquid carrier from the liquid source flows parallel to the outer surface of the gas permeable member from the liquid inlet to the liquid outlet, the flow velocity is greater than the turbulence threshold of the liquid to create turbulent flow conditions, thereby allowing the liquid to shear the gas from the outer surface of the gas permeable member to form nanobubbles in the liquid carrier.

[0005] In some embodiments, the gas permeable member is electrically conductive. The electrical conductor may be an electromagnetic coil (e.g., a stator) or a wire. In some cases, the device includes a pair of electrical conductors, one of which is a gas permeable member and the other of which is, for example, an electromagnetic coil or wire.

[0006] In some embodiments, the device includes a helical member adapted to rotate the liquid carrier as it flows from the liquid inlet to the liquid outlet. The helical member may be in the form of a pattern integral with the gas permeable member, the housing, or both. In other embodiments, the helical member includes an electromagnetic coil adapted to generate a magnetic flux parallel to the outer surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet. In the latter case, the helical member also serves as a conductive member.

[0007] The electrical conductors may be located on the exterior of the housing, within the interior cavity of the housing, or on the exterior surface of the gas permeable member. The electrical conductors may also be located downstream or upstream of the gas permeable member.

[0008] The device may further include a hydrofoil located within the interior cavity of the housing. The hydrofoil may be located upstream or downstream of the gas permeable member. In some embodiments, the hydrofoil is physically attached to the gas permeable member. The hydrofoil rotates the liquid carrier as it flows past the hydrofoil.

[0009] In a second aspect, a second apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier is described. The apparatus includes: (a) an elongated housing having a first end and a second end and defining a liquid inlet, a liquid outlet, and an interior cavity adapted to receive a liquid carrier from a liquid source; (b) a gas permeable member disposed at least partially within the interior cavity of the housing, the gas permeable member including a first end adapted to receive pressurized gas from a gas source, a second end, and a porous sidewall extending between the first and second ends, and defining an interior surface, an exterior surface, and a lumen; (c) one or more electrodes, one of which is an electromagnetic coil adapted to generate a magnetic flux parallel to the exterior surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet; (d) a helical member adapted to rotate the liquid carrier as it flows from the liquid inlet to the liquid outlet; and (e) a hydrofoil positioned within the interior cavity of the housing. The housing and gas permeable member are configured such that when the liquid carrier from the liquid source flows parallel to the outer surface of the gas permeable member from the liquid inlet to the liquid outlet, the flow velocity is greater than the turbulence threshold of the liquid to create turbulent flow conditions, thereby allowing the liquid to shear the gas from the outer surface of the gas permeable member to form nanobubbles in the liquid carrier.

[0010] In some embodiments, the helical member comprises an electromagnetic coil.

[0011] In a third aspect, a method is described for producing a composition comprising nanobubbles dispersed in a liquid carrier using the apparatus described in the first and second aspects of the invention. The method includes the steps of: (a) introducing a liquid carrier from a liquid source into the interior cavity of the housing through a liquid inlet at a flow rate that creates turbulence above a turbulence threshold at the exterior surface of the gas permeable member; (b) applying a magnetic flux parallel to the exterior surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet; and (c) introducing pressurized gas from a gas source into the lumen of the gas permeable member at a gas pressure selected so that the pressure in the lumen is greater than the pressure in the interior cavity of the housing, thereby forcing the gas through the porous sidewall and forming nanobubbles on the exterior surface of the gas permeable member. The liquid carrier flowing parallel to the exterior surface of the gas permeable member from the liquid inlet to the liquid outlet picks up nanobubbles from the exterior surface of the gas permeable member to form a composition comprising the liquid carrier and nanobubbles dispersed therein.

[0012] In some embodiments, the flow velocity is at least 2 m / s.The method may include applying an oscillating magnetic flux, for example, a high frequency oscillating magnetic flux.

[0013] In a fourth aspect, a third apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier is described, comprising: (a) an elongated housing having a first end and a second end, further comprising an internal cavity and a gas inlet adapted to introduce pressurized gas from a gas source into the internal cavity; (b) a gas permeable member disposed at least partially within the internal cavity of the housing, the gas permeable member including a liquid inlet adapted to receive liquid from the liquid source, a liquid outlet, and a porous sidewall extending between the liquid inlet and the liquid outlet, the gas permeable member defining an inner surface, an outer surface, and a lumen through which the liquid flows; and (c) at least one electrical conductor adapted to generate a magnetic flux parallel to the inner surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet. The housing and gas permeable member are configured such that when the liquid carrier from the liquid source flows parallel to the inner surface of the gas permeable member from the liquid inlet to the liquid outlet, the flow velocity is greater than the turbulence threshold of the liquid to create turbulent flow conditions, thereby allowing the liquid to shear the gas from the inner surface of the gas permeable member to form nanobubbles in the liquid carrier.

[0014] In a fifth aspect, a method is described for producing a composition comprising nanobubbles dispersed in a liquid carrier using the apparatus described in the fourth aspect of the invention. The method includes the steps of: (a) introducing a liquid carrier from a liquid source into the internal cavity of the gas permeable member through a liquid inlet of a housing at a flow rate that creates turbulence above a turbulence threshold at the outer surface of the gas permeable member; (b) applying a magnetic flux parallel to the internal surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet; and (c) introducing pressurized gas from a gas source into the internal cavity of the housing at a gas pressure selected such that the pressure within the internal cavity of the housing is greater than the pressure inside the gas permeable member, thereby forcing the gas through the porous sidewall and forming nanobubbles on the internal surface of the gas permeable member. The liquid carrier flowing parallel to the internal surface of the gas permeable member from the liquid inlet to the liquid outlet picks up nanobubbles from the internal surface of the gas permeable member to form a composition comprising the liquid carrier and the nanobubbles dispersed therein.

[0015] In some embodiments, the flow velocity is at least 2 m / s.The method may include applying an oscillating magnetic flux, for example, a high frequency oscillating magnetic flux.

[0016] In each of the above-described devices and methods, configuring the device so that the flow velocity of the liquid carrier from the liquid source is greater than the liquid turbulence threshold for creating turbulent flow conditions when the liquid carrier flows parallel to the inner or outer surface of the gas permeable member from the liquid inlet to the liquid outlet minimizes nanobubble coalescence. Including at least one electrical conductor for generating a magnetic flux (e.g., a high-frequency oscillating magnetic flux) parallel to the inner or outer surface of the gas permeable member when the liquid carrier flows from the liquid inlet to the liquid outlet enhances both nanobubble generation and the rate of nanobubble generation. Measurement of changes in the resistance of the electrical conductor may be used to detect the presence of nanobubbles in the fluid.

[0017] The helical member further enhances nanobubble generation and nanobubble generation rate by imparting angular velocity to the liquid carrier, causing vortexing and thereby increasing the efficiency of nanobubble capture at the interface between the gas permeable member and the liquid stream. The hydrofoil further enhances nanobubble generation and nanobubble generation rate by creating a region of high turbulence in the fluid flowing through the device based on the surface of the hydrofoil and by creating a turbulent trailing edge downstream of the hydrofoil.

[0018] The above-described devices and methods can be used in a variety of applications. An example is water treatment, such as wastewater treatment, for example, to oxygenate and / or remove contaminants from a body of water. Another example is aquaculture and plant growth, where the compositions of the present invention can be used to deliver oxygen or other nutrients. Still other examples include cleaning and sterilization, for example, to minimize or eliminate the use of chemicals such as chlorine in hot tubs or spas.

[0019] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the appended claims. [Brief explanation of the drawings]

[0020] [Figure 1A] FIG. 1 is a top view of an exemplary apparatus for producing a composition comprising nanobubbles dispersed in a liquid carrier. [Figure 1B] FIG. 1B is a side cross-sectional view of the device of FIG. 1A. [Figure 1C] FIG. 1B is an exploded view of the device of FIG. 1A. [Figure 2] Figure 2A is a top view of an exemplary apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier, and Figure 2B is a side cross-sectional view of the apparatus of Figure 2A. [Figure 3]Figure 3A is a top view of an exemplary apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier, and Figure 3B is a side cross-sectional view of the apparatus of Figure 3A. [Figure 4] Figure 4A is a top view of an exemplary apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier, and Figure 4B is a side cross-sectional view of the apparatus of Figure 4A. [Figure 5] Figure 5A is a top view of an exemplary apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier, and Figure 5B is a side cross-sectional view of the apparatus of Figure 5A. [Figure 6] Figure 6A is a top view of an exemplary apparatus for generating a composition comprising nanobubbles dispersed in a liquid carrier, and Figure 6B is a side cross-sectional view of the apparatus of Figure 6A. [Figure 7] FIG. 1 is a top view of an exemplary apparatus for producing a composition comprising nanobubbles dispersed in a liquid carrier. [Figure 8] FIG. 1 is a top view of an exemplary apparatus for producing a composition comprising nanobubbles dispersed in a liquid carrier. [Figure 9A] FIG. 1 is a perspective view of an exemplary hydrofoil. [Figure 9B] FIG. 9B is a side view of the hydrofoil of FIG. 9A. [Figure 9C] FIG. 9B is a top view of the hydrofoil of FIG. 9A. [Figure 10] Figure 10A is a top view of an exemplary mount coupled to the hydrofoil of Figure 9A. Figure 10B is a cross-section of the mount of Figure 10A, excluding the hydrofoil for illustrative purposes. Figure 10C is a cross-section of the mount of Figure 10A coupled to the hydrofoil of Figure 9A. [Figure 11] 1 is a schematic diagram of an exemplary permeable member. [Figure 12] FIG. 1 is a schematic diagram of an exemplary device.

[0021] Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE INVENTION

[0022] Detailed Description The present disclosure describes an apparatus for generating nanobubbles in a liquid carrier. The nanobubbles have a diameter of less than 1 micrometer (μm). In some embodiments, the nanobubbles have a diameter of less than or equal to 500 nanometers (nm). In some embodiments, the nanobubbles have a diameter of less than or equal to 200 nanometers (nm).

[0023] The devices and methods described herein selectively apply a combination of supercavitation, vorticity, and / or magnetic fields (preferably high frequency oscillating magnetic fields) in addition to shear to form nanobubbles in a liquid carrier.

[0024] 1A and 1B are schematic diagrams illustrating a top view and a cross-sectional side view, respectively, of an exemplary device 100. FIG. 1C is a schematic diagram illustrating an exploded view of device 100, with the components of device 100 shown separated from one another. Device 100 includes a housing 101, a permeable member 103, and an electrical conductor 105. Elongated housing 101 is defined by a first end 101a, a second end 101b, and an interior cavity adapted to receive a liquid carrier from a liquid source. Housing 101 includes an inlet and an outlet. First end 101a may be the inlet, and second end 101b may be the outlet.

[0025] Device 100 includes a gas permeable member 103 at least partially disposed within the interior cavity of housing 101. Permeable member 103 defines an interior surface, an exterior surface, and a lumen. Permeable member 103 may include a first end 103a adapted to receive pressurized gas from a gas source, a second end 103b, and a porous sidewall 103c extending between first and second ends 103a, 103b. First end 103a of permeable member 103 may be open, and second end 103b of permeable member 103 may be closed.

[0026] The housing 101 and permeable member 103 may be arranged such that when the liquid carrier from the liquid source flows parallel to the outer surface of the permeable member 103 from the liquid inlet to the liquid outlet, the flow velocity is greater than the turbulence threshold of the liquid to create turbulent flow conditions, thereby allowing the liquid to shear gas from the outer surface of the gas permeable member to form nanobubbles in the liquid carrier.

[0027] 1A-C, device 100 includes an electrical conductor 105 in the form of a helical member (e.g., a helical electrode) located within the interior cavity of housing 101. Electrical conductor 105 is adapted to generate a magnetic flux parallel to the outer surface of permeable member 103 as the liquid carrier flows from the liquid inlet to the liquid outlet of housing 101. Preferably, electrical conductor 105 is adapted to generate a high frequency oscillating magnetic flux.

[0028] The electrical conductor 105 may be located on an outer surface of the permeable member 103. The electrical conductor 105 may surround at least a portion of the permeable member 103. The electrical conductor 105 may also be implemented in other forms. For example, in some embodiments, the electrical conductor 105 comprises a wire. In some embodiments, the electrical conductor 105 comprises one or more electrodes. In some embodiments, the electrical conductor 105 is in the form of an electromagnetic coil (e.g., a stator). In some embodiments, the permeable member 103 may serve as the electrical conductor 105.

[0029] In some embodiments, device 100 is connected to a liquid source that provides a liquid carrier (e.g., water). In some embodiments, the liquid source is a water container or body connected to a pump via a suction line. In some embodiments, the pump is a variable speed pump. In some embodiments, the pump is connected to device 100 via a discharge line with a control valve. In some embodiments, the discharge line is in fluid communication with housing 101. For example, the liquid carrier flows from the pump, through the control valve, through the discharge line, and to first end 101a. The opening rate of the control valve may be adjusted to control the pressure and flow rate of the liquid carrier into device 100.

[0030] The apparatus 100 may optionally include a hydrofoil 150 shaped to induce rotation in the liquid carrier flowing through the apparatus 100. In some embodiments, the hydrofoil 150 is shaped (e.g., with a tapered and / or curved surface) to induce supercavitation in the liquid carrier flowing through the apparatus 100. For example, the hydrofoil 150 may be shaped to create a region of high turbulence in the fluid flowing through the apparatus 100 based on the surface of the hydrofoil 150 and to create a turbulent trailing edge downstream of the hydrofoil 150. In this disclosure, the terms "downstream" and "upstream" refer to the general direction of flow of the liquid carrier, for example, through the apparatus 100. For example, in FIGS. 1A-B, the general direction of flow of the liquid carrier through the apparatus 100 is from left to right, so "downstream" correlates to "to the right of" and "upstream" correlates to "to the left of."

[0031] 1B, the hydrofoil 150 may be located within the internal cavity of the housing 101. At least a portion of the hydrofoil 150 may be located upstream of the permeable member 103. The hydrofoil 150 may be physically attached to the permeable member 103. Other hydrofoil embodiments are also contemplated. For example, in some embodiments, at least a portion of the hydrofoil 150 may be located downstream of the permeable member 103. The hydrofoil 150 and one or more other components (such as the helical member and / or the electrical conductor 105) may cooperatively induce rotation in the fluid flowing through the device 100.

[0032] In some embodiments, the device 100 may optionally include a mount 151. A mount may serve to connect two or more components together within the device. As shown in FIGS. 1A-B , the permeable member 103 and, optionally, the hydrofoil 150 may be connected to the mount 151. The housing 101 may be connected to the mount 151, for example, by connecting a first end 101 a of the housing 101 to the mount 151. Various means for connecting components together may be employed. For example, the first end 101 a of the housing 101 may engage an internal bore of the mount 151. The mount 151 may provide fluid inlet and / or outlet ports into the component connected thereto. For example, the mount 151 may define a port 151 a in fluid communication with the first end 103 a of the permeable member 103. The port 151 may be used to introduce gas into the permeable member 103.

[0033] The device 100 is connected to a gas source. As described above, the gas source may be connected to a port 151a (defined by a mount 151) that is in fluid communication with the first end 103a of the permeable member 103. The gas may flow into the first end 103a of the permeable member 103 and into the lumen. As the gas flows from the lumen of the permeable member 103 through the pores, nanobubbles may be formed and may be sheared from the outer surface of the permeable member 103 by the liquid carrier flowing across the outer surface of the permeable member 103 at a flow velocity above the turbulence threshold of the liquid.

[0034] In some embodiments, the liquid carrier containing the nanobubbles formed by device 100 exits device 100 (e.g., from second end 101b) and flows into an outlet line. In some embodiments, the liquid carrier containing the nanobubbles formed by device 100 exits device 100 and flows into a selectable number of outlet lines (e.g., into a water container or body of water).

[0035] 2A and 2B are schematic diagrams of an exemplary device 200. Device 200 includes one or more of the same features as device 100 (e.g., transparent member 103, mount 151), but some differences also exist. For example, device 200 includes a segmented housing 201. The segments of housing 201 may be connected by mount 151. Mount 151 may be located between first end 201a and second end 201b of housing 201.

[0036] 2A-B also includes a plurality of electrical conductors 205, 207. The electrical conductor 205 is an electromagnetic coil (e.g., a stator) located on the exterior of the housing 201 downstream of the permeable member 103. The electrical conductor 205 is a helical member 207 (e.g., a coil electrode) located within the interior cavity of the housing 201 upstream of the permeable member 103. The helical member 207 may include a helical baffle (or coiled wire) positioned along the inner circumferential wall of the housing 201. The helical member 207 may be adapted to rotate the liquid carrier as it flows through the device 200 (e.g., from the liquid inlet to the liquid outlet). Similar to the electrical conductor 105 of the device 100, the helical member 207 may also serve as an electromagnetic coil adapted to generate a magnetic flux (e.g., a high-frequency oscillating magnetic field) parallel to the outer surface of the permeable member 103 as the liquid carrier flows through the device 200 (e.g., from the liquid inlet to the liquid outlet).

[0037] In some embodiments, the helical member 207 may be a feature integral with the permeable member 103 or the housing 201, or both, that causes the liquid carrier to rotate. For example, the helical member 207 may include one or more surface features on the walls of the permeable member 103 or the housing 201, or both, that cause the liquid carrier to rotate as it flows near the surface. The surface features may include cavities and / or protrusions on the walls. For example, the helical member 207, in some embodiments, may include a helical-shaped surface formed along the interior wall of the housing.

[0038] The devices provided herein may include a variety of conductor configurations. In some embodiments, one or more conductors (e.g., conductor 205 or helical member 207) are separate components of device 200. For example, conductor 205 and helical member 207 may be separate components directly coupled to housing 201 (as shown in FIGS. 2A-B) or spaced apart from housing 201 (as shown in FIGS. 1A-B). For example, helical member 207 may be in the form of a helical baffle coupled to and disposed around the outer surface of permeable member 103. In some embodiments, at least a portion of one or more electrodes may be positioned upstream, downstream, or generally at the same location as permeable member 103.

[0039] 3A and 3B illustrate another exemplary device 300. While device 300 includes some of the same features (e.g., permeable member 103) as previously described devices (e.g., devices 100, 200), this section focuses on differences present in device 300. For example, device 300 has multiple electrical conductors located within housing 301, including electrical stator 305 located upstream of permeable member 103 and helical member 307 surrounding at least a portion of permeable member 103. Helical member 307 may be sized as desired. For example, helical member 307 of device 300 is longer than permeable member 103 such that a portion of helical member 307 extends downstream of permeable member 103. In some embodiments, helical member 307 may be longer, shorter, or approximately the same length as permeable member 103 along the longitudinal direction.

[0040] 4A and 4B illustrate another exemplary device 400. While device 400 includes some of the same features (e.g., permeable member 103) as previously described devices (e.g., devices 100, 200, 300), this section focuses on differences present in device 400. For example, device 400 includes electrical conductor 405 in the form of a helical member (e.g., a helical electrode) located on the exterior of housing 401. For example, electrical conductor 405 may include a coiled wire (or simply a coil) directly coupled to and disposed around the exterior of housing 401. The electrical conductor 405 of device 400 is located upstream of the permeable member 103. In some embodiments, at least a portion of the electrical conductor 405 may be located downstream of or generally co-located with the permeable member 103. In some embodiments, the electrical conductor may be disposed on a mount 405.

[0041] 5A and 5B illustrate another exemplary device 500. While device 500 includes some similar features (e.g., permeable member 103) to previously described devices (e.g., devices 100, 200, 300, 400), this section will focus on differences present in device 500. Device 500 includes a conductor 505 in the form of a helical member (e.g., a helical electrode) located on the exterior of housing 501 and positioned generally downstream from permeable member 103 near the outlet end 501b of housing 501.

[0042] 6A and 6B illustrate another exemplary device 600. While device 600 includes some similar features (e.g., permeable member 103) to previously described devices (e.g., devices 100, 200, 300, 400, 500), this section focuses on differences present in device 600. Electrical conductor 605 of device 600 includes an electromagnetic coil (e.g., a stator) located on the exterior of housing 601, upstream of permeable member 103 and near housing inlet 601a.

[0043] 7 shows another exemplary device 700. Device 700 includes electrical conductors 705 in the form of electromagnetic coils (e.g., stators) located on the exterior of housing 701. Electrical conductors 705 of device 700 are generally co-located with and surround a portion of permeable member 103.

[0044] FIG. 8 shows another exemplary apparatus 800 that includes an electrical conductor 105 that is an electromagnetic coil (eg, a stator) located on the exterior of a housing 801 downstream of a permeable member 103 .

[0045] An exemplary hydrofoil 150 is shown in Figures 9A-C. The hydrofoil includes an asymmetric shape configured to create turbulence in the flow of fluid (e.g., a liquid carrier) downstream of the hydrofoil 150. The shape of the hydrofoil 150 may include curved wings (a pair of tapered ends) offset from one another to induce rotation in the fluid flowing around the hydrofoil. The hydrofoil 150 optionally includes a coupling element (e.g., an internally threaded portion in the diffuser mount shown in Figure 9A) that can be coupled to the first end 103a of the permeable member 103. The shape of the hydrofoil 150 may induce rotation in the fluid flowing through the device 100, causing the fluid to swirl (e.g., in a spiral manner) around the permeable member 103 of Figures 1A-B. Although the hydrofoil 150 has been described above with respect to the device 100, the same concepts are applicable to any of the devices 200, 300, 400, 500, 600, 700, or 800 described herein.

[0046] 10A-C illustrate an exemplary mount 151 that may optionally be included in the devices described herein. As mentioned above, the mount may be coupled to one or more components of the devices described herein, such as, for example, the hydrofoil 150 of FIGS. 1A-B.

[0047] FIG. 11 is a schematic diagram of an exemplary gas permeable member 103 that may be implemented in any one of the devices described herein. The permeable member 103 defines a plurality of pores through which gas can pass to generate nanobubbles. Each of the pores may have a diameter equal to or less than 50 μm. In some embodiments, each of the pores has a diameter that is in the range of 200 nm to 50 μm. The pores may be of uniform size or may vary in size. The pores may be uniformly or randomly distributed across the surface (e.g., outer surface) of the permeable member 103. The pores may have any regular (e.g., circular) or irregular shape. In some embodiments, the permeable member 103 is electrically conductive and serves as an elongated electrode.

[0048] As liquid flows around the exterior surface of the permeable member 103, gas may be flowed into the permeable member 103 such that the gas flows from the lumen of the permeable member 103 through the pores to generate nanobubbles along the surface of the permeable member 103. The fluid flowing around the permeable member 103 shears nanobubbles from the permeable member, resulting in a nanobubble-enriched liquid.

[0049] 12 is a schematic diagram of an exemplary device 1200. Unlike the previously described exemplary devices, device 1200 includes a housing 1201 adapted to receive a gas from a gas source and a permeable member 1203 adapted to receive a liquid carrier from a liquid source. Permeable member 1203 may be substantially similar to permeable member 103 (shown in FIG. 11 ). In device 1200, a liquid is flowed into permeable member 1203, and a gas flows around the outer surface of permeable member 1203. The gas flows through pores into the lumen of permeable member 1203, generating nanobubbles that are sheared and dispersed into the liquid flowing through permeable member 1203.

[0050] The housing 1201 of the device 1200 includes a first end 1201a and a second end 1201b that are closed ends. Gas flows from a gas source through a port 1201c defined by the housing 1201 and into the interior cavity of the housing 1201. Although shown in FIG. 12 as being located near the center of the housing 1201, the port 1201c may be located at any point on the housing 1201, so long as the port 1201c provides an entrance for the gas to enter the interior cavity of the housing 1201.

[0051] The permeable member 1203 has a first end 1203a that may serve as a liquid inlet adapted to receive a liquid carrier. The permeable member 1203 includes pores that allow gas to pass through its wall. The permeable member 1203 is enclosed within the interior cavity of the housing 1201 such that gas within the housing flows across the wall of the permeable member 1203. Pressure is applied to force gas through the pores of the permeable member 1203 and into the lumen of the permeable member 1203. Nanobubbles are formed as the gas flows through the pores of the permeable member 1203. As the nanobubbles are formed, the liquid carrier flowing through the lumen of the permeable member 1203 shears them from the interior surface of the permeable member 1203. A second end 1203b of the permeable member 1203 may be an open end or outlet for discharging the liquid carrier carrying the formed nanobubbles.

[0052] 12 includes an electrical conductor 1205 in the form of an electromagnetic coil (e.g., a stator) located on the exterior of housing 1201. Electrical conductor 1205 surrounds at least a portion of permeable member 1203 and is located upstream of port 1201c. As described in the previous sections, the electrical conductor or conductors may be implemented in a variety of ways.

[0053] Device 1200 may optionally include a component (e.g., a helical member and / or a hydrofoil) for inducing rotation in a fluid flowing through permeable member 1203, as described previously herein. The optional component may be located within an interior cavity of housing 1201. For example, the optional component may be coupled to permeable member 1203. In some embodiments, the optional component is integral with permeable member 1203. For example, the optional component may be a helical member comprising a helical baffle or coil disposed near the interior surface of permeable member 1203. In some embodiments, at least a portion of the optional component is located upstream or downstream of permeable member 1203. In some embodiments, device 1200 includes a hydrofoil, a helical member, and / or an electrical conductor 1205 that may cooperatively induce rotation in a fluid flowing through device 1200.

[0054] Any of the devices and methods described herein include generating nanobubbles in a liquid volume having an average diameter of less than 1 μm. In some embodiments, the nanobubbles have an average diameter ranging from about 10 nm to about 500 nm, from about 75 nm to about 200 nm, or from about 50 nm to about 150 nm. The nanobubbles in the composition may have a unimodal distribution of diameters, with the average bubble diameter being less than 1 μm. In some embodiments, any of the compositions generated by the devices and methods described herein include nanobubbles, but are free of microbubbles.

[0055] Although specific aspects of the subject matter have been described, it should be understood that various modifications, substitutions, and alterations may be made.

Claims

1. (a) an elongated housing having a first end and a second end, defining a liquid inlet, a liquid outlet, and an interior cavity adapted to receive a liquid carrier from a liquid source; (b) a gas permeable member at least partially disposed within the interior cavity of the housing, the gas permeable member having a first end adapted to receive pressurized gas from a gas source, a second end, and a porous sidewall extending between the first and second ends, the gas permeable member defining an inner surface, an outer surface, and a lumen; (c) at least one electrical conductor adapted to generate a magnetic flux parallel to the outer surface of the gas permeable member when the liquid carrier flows from the liquid inlet to the liquid outlet. Equipped with the housing and gas permeable member are configured such that when the liquid carrier from the liquid source flows parallel to the outer surface of the gas permeable member from the liquid inlet to the liquid outlet, the flow velocity is greater than a turbulence threshold of the liquid for creating turbulent flow conditions, thereby allowing the liquid to shear gas from the outer surface of the gas permeable member to form nanobubbles in the liquid carrier; An apparatus for producing a composition comprising nanobubbles dispersed in a liquid carrier.

2. 10. The device of claim 1, wherein the gas permeable member is electrically conductive.

3. 10. The apparatus of claim 1, wherein the electrical conductor comprises an electromagnetic coil.

4. 4. The apparatus of claim 3, wherein the electromagnetic coil comprises a stator.

5. 10. The device of claim 1, wherein the electrical conductor comprises a wire.

6. a helical member adapted to rotate the liquid carrier as it flows from the liquid inlet to the liquid outlet; 10. The device of claim 1, comprising:

7. 7. The device of claim 6, wherein the helical member is in the form of a pattern integral with the gas permeable member, the housing, or both.

8. 8. The device of claim 7, wherein the helical member comprises an electromagnetic coil adapted to generate a magnetic flux parallel to the outer surface of the gas permeable member when the liquid carrier flows from the liquid inlet to the liquid outlet.

9. 10. The device of claim 1, wherein the electrical conductors are located on the exterior of the housing.

10. 10. The device of claim 1, wherein the electrical conductor is located within an internal cavity of the housing.

11. 10. The device of claim 1, wherein the electrical conductor is located on an exterior surface of the gas permeable member.

12. 10. The device of claim 1, wherein the electrical conductor is located downstream of the gas permeable member.

13. 10. The device of claim 1, wherein the electrical conductor is located upstream of the gas permeable member.

14. The apparatus of claim 1 , further comprising a hydrofoil located within the interior cavity of the housing.

15. 15. The apparatus of claim 14, wherein the hydrofoil is located upstream of the gas permeable member.

16. 15. The apparatus of claim 14, wherein the hydrofoil is located downstream of the gas permeable member.

17. 10. The device of claim 1, wherein the hydrofoil is physically attached to the gas permeable member.

18. (a) an elongated housing having a first end and a second end, defining a liquid inlet, a liquid outlet, and an interior cavity adapted to receive a liquid carrier from a liquid source; (b) a gas permeable member at least partially disposed within the interior cavity of the housing, the gas permeable member having a first end adapted to receive pressurized gas from a gas source, a second end, and a porous sidewall extending between the first and second ends, the gas permeable member defining an inner surface, an outer surface, and a lumen; (c) one or more electrical conductors, one of which comprises an electromagnetic coil adapted to generate a magnetic flux parallel to the outer surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet; (d) a helical member adapted to rotate the liquid carrier as it flows from the liquid inlet to the liquid outlet; and (e) a hydrofoil located within the internal cavity of the housing; Equipped with the housing and gas permeable member are configured such that when the liquid carrier from the liquid source flows parallel to the outer surface of the gas permeable member from the liquid inlet to the liquid outlet, the flow velocity is greater than a turbulence threshold of the liquid for creating turbulent flow conditions, thereby allowing the liquid to shear gas from the outer surface of the gas permeable member to form nanobubbles in the liquid carrier; An apparatus for producing a composition comprising nanobubbles dispersed in a liquid carrier.

19. 20. The device of claim 18, wherein the helical member comprises an electromagnetic coil.

20. 19. A method for producing a composition comprising nanobubbles dispersed in a liquid carrier using the device of claim 1 or claim 18. (a) introducing a liquid carrier from a liquid source into an interior cavity of the housing through a liquid inlet of the housing at a flow rate that creates turbulence at an exterior surface of the gas permeable member that exceeds a turbulence threshold; (b) applying a magnetic flux parallel to the outer surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet; and (c) introducing pressurized gas from a gas source into the lumen of the gas permeable member at a gas pressure selected such that the pressure within the lumen is greater than the pressure within the interior cavity of the housing, thereby forcing gas through a porous sidewall to form nanobubbles on the exterior surface of the gas permeable member. Including, the liquid carrier flowing parallel to the outer surface of the gas permeable member from the liquid inlet to the liquid outlet picks up nanobubbles from the outer surface of the gas permeable member to form a composition comprising the liquid carrier and the nanobubbles dispersed therein; method.

21. 21. The method of claim 20, comprising applying an oscillating magnetic flux parallel to an exterior surface of the gas permeable member.

22. 22. The method of claim 21, comprising applying a high frequency oscillating magnetic flux parallel to the exterior surface of the gas permeable member.

23. (a) an elongated housing having a first end and a second end, further comprising an internal cavity and a gas inlet adapted to introduce pressurized gas from a gas source into the internal cavity; (b) a gas permeable member at least partially disposed within the interior cavity of the housing, the gas permeable member including a liquid inlet adapted to receive liquid from a liquid source, a liquid outlet, and a porous sidewall extending between the liquid inlet and the liquid outlet, the gas permeable member defining an inner surface, an outer surface, and a lumen through which liquid flows; (c) at least one electrical conductor adapted to generate a magnetic flux parallel to the inner surface of the gas permeable member when a liquid carrier flows from the liquid inlet to the liquid outlet; Equipped with the housing and gas permeable member are configured such that when the liquid carrier from the liquid source flows parallel to the inner surface of the gas permeable member from the liquid inlet to the liquid outlet, the flow velocity is greater than a turbulence threshold of the liquid for creating turbulent flow conditions, thereby allowing the liquid to shear gas from the inner surface of the gas permeable member to form nanobubbles in the liquid carrier; An apparatus for producing a composition comprising nanobubbles dispersed in a liquid carrier.

24. 24. A method for producing a composition comprising nanobubbles dispersed in a liquid carrier using the device of claim 23, comprising: (a) introducing a liquid carrier from a liquid source into an interior cavity of a gas permeable member through a liquid inlet of a housing at a flow rate that creates turbulence at an exterior surface of the gas permeable member that exceeds a turbulence threshold; (b) applying a magnetic flux parallel to the inner surface of the gas permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet; and (c) introducing pressurized gas from a gas source into the interior cavity of the housing at a gas pressure selected such that the pressure within the interior cavity of the housing is greater than the pressure inside the gas permeable member, thereby forcing gas through a porous sidewall to form nanobubbles on the interior surface of the gas permeable member. Including, a liquid carrier flowing parallel to the inner surface of the gas permeable member from the liquid inlet to the liquid outlet entrains nanobubbles from the inner surface of the gas permeable member to form a composition comprising the liquid carrier and the nanobubbles dispersed therein; method.

25. 25. The method of claim 24, comprising applying an oscillating magnetic flux parallel to an interior surface of the gas permeable member.

26. 26. The method of claim 25, comprising applying a high frequency oscillating magnetic flux parallel to the interior surface of the gas permeable member.

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