Abstract: A method and apparatus for supplying dissolved gases (such as oxygen, ozone, chlorine etc.) for chemical and biological processes is described. The methods and apparatus described are particularly suitable for use in the biodegradation of organic matter (such as in municipal and industrial wastewater treatment), and other uses. The apparatus may comprise a dissolved gas supply system.

Abstract: An gas diffusion device for introducing gas into a large body of liquid having at least one diffuser blade that engages over a mounting tube having a spar affixed to its exterior. A passage in the diffuser blade is dimensioned to cooperatively engage over the spar and mounting tube which holds the diffuser blade top surface at a determined angle once so engaged thereover. Changing the position of the spar on the exterior of the mounting tube in relation to the center axis of the mounting tube changes the resulting angle of the diffuser blade top surface. The diffuser blade can be attached to a hub mounted on a mainshaft that automatically cantilevers out of the fluid should compressed gas supplied to the diffuser blade through the mainshaft cease to avoid damage to the diffuser blade and diffuser pad on the blade from particulate in the liquid.

Abstract: The present invention provides an apparatus and method for mass transfer of gas or other fluids into a liquid and/or liquid suspension. The present invention is preferably used in conjunction with waste treatment processes and/or fermentation processes that are commonly carried out in a mixing vessel. In such an arrangement, the mass transfer process is utilized to contact air to liquid in a mixing vessel or aeration basin.

Abstract: A gas charging unit for adding gas to a liquid polyurethane component, in particular a filler-laden polyurethane component of a polyurethane injection molding unit, includes a mixing vessel having an inlet opening and receiving a liquid polyurethane component via the inlet opening. Arranged in the mixing vessel in alignment with the inlet opening and axially adjustable in relation to the inlet opening is at least one movable mixing element to mix the polyurethane component fed into the mixing vessel with gas injected into the polyurethane component via a nozzle.

Abstract: The present invention concerns equipment for the leaching of solid matter from a sludge with the aid of a gas containing oxygen, the said equipment comprising a tall reactor (1) equipped with a central pipe (2) and from the reactor bottom (3), an upward-directed double-action mixer (5). The mixer is situated in the vicinity of the lower edge of the central pipe: the upper blades (13) of the mixer produce a downward suction flow from the central pipe, and the lower blades (14) disperse the gas to be fed into the sludge in the form of small bubbles, thereby preventing the solid matter from settling to the bottom of the reactor.

Abstract: The gas entrainer is a rotodynamic machine for trapping and dispersing bubbles of air into a pool of water. A flat circular disc is mounted for rotation close to and concentric with one end of an open cylindrical tube of equal diameter to form an annular nozzle therebetween. Upon the disc and tube end being immersed in water, the spinning disc draws air down the tube and out through the nozzle to disperse it as fine bubbles into the pool. The faster the disc is spun, the more air bubbles are produced; and this at a considerable depth of water. The disc or rotor employed is without blades or paddles and accomplishes entrainment simply by viscous friction between the disc and water in combination with the closely spaced tube end.

Abstract: The invention relates to a method for the leaching of solid matter from a sludge with the aid of a gas containing oxygen, whereby the solid matter of the sludge is recirculated in a tall reactor equipped with a central pipe in the centre of the reactor and a double-action mixer located in the vicinity of the lower edge of the central pipe. A flow is formed with the aid of the mixer which sucks the sludge from the central pipe downward, and a gas to be conducted into the sludge in the bottom part of the reactor is dispersed in the form of small bubbles into the sludge outside the central pipe and the flow direction of the sludge is turned upwards in the outer casing of the reactor.

Abstract: A floating pump assembly including a compact floatation assembly structured to float on a body of water and supporting a flow pump housing having an inlet, outlet and fluid drive assembly being submerged and wherein at least the outlet is oriented in a predetermined, preferably horizontal orientation during operation and activation. A power assembly is supported on the floatation assembly and is drivingly connected to the fluid drive assembly for powered operation thereof. The predetermined orientation of at least the outlet and particularly the direction of discharge of water issuing from the outlet substantially is such as to eliminate or at least minimize the tendency of the floatation device to become disoriented or unstable at least in terms of being increasingly submerged into a deeper position within the body of water upon activation and operation of the floating pump assembly.

Abstract: The present invention provides an apparatus and method for mass transfer of gas or other fluids into a liquid and/or liquid suspension. The present invention is preferably used in conjunction with waste treatment processes and/or fermentation processes that are commonly carried out in a mixing vessel. In such an arrangement, the mass transfer process is utilized to contact air to liquid in a mixing vessel or aeration basin.

Abstract: The present invention is an improved structure for an oxygen adding and aeration device includes a pump; a two-layer impeller, which is installed on a top of the pump; a pump case, which covers on outside of the two-layer impeller; an air tube, which is installed in impeller inlets of a lower-layer impeller of the two-layer impeller, a top end of the air tube protrudes out of a water level; when starting the pump, the two-layer impeller is then driven to deliver air from the air tube into the lower-layer impeller, partial water is sucked from filter holes into air tube to mix with air becoming an air-water flow, continuously, the air-water injection flow is injected by the lower-layer impeller and the lower-layer outlet of the pump case to form an air-water injection flow, other partial water is sucked from the impeller inlet of the upper-layer impeller into the air tube, continuously, the water passes through the impeller outlet of the upper-layer and the upper-layer outlet of the pump case to form a water i

Abstract: The invention relates to an apparatus for the treatment of contaminated media, comprising a rotatable housing having at least one inlet (28) for gas emerging in the stirrer housing, and at least one suction opening (10; 32) for the medium to be treated. The housing is provided with a plurality of outlet openings (25; 27) arranged along its periphery. A plurality of vanes (22; 23) are arranged in the outlet openings (25; 27). A rotation transferring means (24) is provided to transfer a rotational movement to the stirrer. A method according to the invention comprises generating a vortex in the medium in such a way that an under-pressure occurs in the center of the vortex, and that a nitrogen containing gas is introduced in the center of the vortex.

Abstract: A method and apparatus for producing a liquid compost material. A starter compost material is added to water within a first tank and nutrients are further added. The materials are aerated for a first known time period to facilitate bacterial breakdown until the formation of the liquid compost material or tea is complete whereupon a portion of the tea is removed. Water is added together with nutrients to the remaining tea in the tank and aeration continues for a second and much smaller time period. Liquid compost material is again formed in the tank within the second time period.

Abstract: An apparatus is provided for separation of suspended solid particles from fluids, for separation and mixing of fluids, and for dissolving gases in aqueous fluids. The apparatus employs a grooved ring to divide the fluid stream and impart a high velocity on each of the divided or sub-streams. A grooved ring with any number of grooves that may be spiral in shape is used to create a high velocity circular motion on a divided stream for separation of suspended solid particles by centrifugal force in a cyclone filter and for saturation of liquid with gases in a fluid mixer where gases are introduced through a diffuser. A grooved ring with any number of grooves that may be radial is used in a fluid mixer to divide a stream of fluid, produce a high velocity flow through each groove, introduce a second fluid through an orifice into the first fluid flowing through each groove, and direct the fluid mixture to a center impact zone where the various streams collide to complete the mixing.

Abstract: A high efficiency impeller-type aerator designed for aeration of the water supply of aquatic organisms has a first impeller, a second impeller, and a pump casing having at least one water inlet, one air inlet, and one water outlet. The first and second impellers are disposed between the pump water inlet and outlet, and the pump casing includes constricted portions in association with the first and second impeller to define axial flow direction boundaries. The air inlet is located at the constricted portion, and the axial flow direction boundaries define a channel through which the second impeller urge water to facilitate low pressure that creates a venturi which causes air suction at the pump air inlet.

Abstract: A compost aerator for aerating a compost/liquid mixture. The aerator has a aerator pump located downstream from a liquid inlet. The aerator pump has a plurality of impellers mounted on a rotor which spins within a circular channel though which the liquid flows. The liquid is propelled through the channel by the impellers and, as the area of the channel decreases downstream from the impellers caused by the increase in diameter of the rotor, the velocity of the liquid increases. Air enters the channel upstream from the impellers and is drawn with the liquid through the channel. The diameter of the rotor then decreases significantly thereby causing the area of the liquid carrying channel to increase suddenly downstream of the widest portion of the rotor. Turbulence occurs in this area and bubbles are formed which are released from the outlet of the compost aerator into the compost/liquid mixture to perform aeration for bacterial breakdown.

Abstract: A device for multifoaming expandable plastics, such as, for instance, EPS, EPE, EPP or polymer mixtures, includes at least one storage or supply assembly and a foaming vessel for the discontinuous or batchwise afterfoaming of the prefoamed expandable plastics, whereby precisely adjustable bulk densities are attainable in an afterfoaming procedure while observing tight environmental conditions.

Abstract: A dip aerator for sewage treatment plants is provided with a downwardly directed pump outlet and a pump inlet, which is connected with an air hose. The pump inlet (14) is below the water level (18) in the sewage treatment basin. The air hose (20, 24) starts out from the pump inlet (14) and extends with a specified volume below the water level. In this way, it is achieved that, when the pump is started, water is delivered initially and air is emitted only later. By these means, brief repulsions without input of air become possible.

Abstract: One embodiment of an aerator is disclosed that has a hollow intake housing with a horizontally disposed lip on a lower portion thereof. This intake housing converges a flow of bubbles into a draft tube. These bubbles are injected into a fluid in which the aerator is installed at a location that is directly under the intake housing. A fluid flow is also drawn into this draft tube through the intake housing. Fluid exiting the opposite end of the draft tube is directed into a hollow discharge housing having a divergent inner surface. A wave generator (e.g., a rotating impeller) is mounted within the hollow interior of the discharge housing. The upper end of this discharge housing also includes a horizontally disposed lip to direct a flow out of the aerator at least generally parallel with an upper surface of the fluid.

Abstract: A diffuser for use in a pressurized feed system. The diffuser introduces a carbonic acid solution into water to be treated. The carbonic acid solution within the diffuser is maintained at an elevated pressure. As the carbonic acid solution passes to the exterior of the diffuser, the pressure drop causes an effective mixing of the carbonic acid solution and the water. The carbonic acid solution mixes with the water and the pH of the water is reduced.

Abstract: A reactor for aerating a fluid with a gas comprises a mixing tank (12) for the fluid and a centrally located vertical draft tube (13) submerged in the fluid to divide the mixing tank (12) into an inner chamber (21) and an outer chamber (23). The reactor further comprises a motor driven axial flow impeller (14) located in the draft tube (13) for circulating fluid downwardly through the inner chamber (21) and upwardly through the outer chamber (23). The reactor further comprises an external circuit for withdrawing a portion of the fluid from the mixing tank (12), aerating the fluid, and returning the aerated fluid to the mixing tank (12). The aerator is in the form of a venturi device (17).

Abstract: A diffuser for use in a pressurized feed system. The diffuser introduces a carbonic acid solution into water to be treated. The carbonic acid solution within the diffuser is maintained at an elevated pressure. As the carbonic acid solution passes to the exterior of the diffuser, the pressure drop causes an effective mixing of the carbonic acid solution and the water. The carbonic acid solution mixes with the water and the pH of the water is reduced.

Abstract: A compost aerator for aerating a compost/liquid mixture. The aerator has a aerator pump located downstream from a liquid inlet. The aerator pump has a plurality of impellers mounted on a rotor which spins within a circular channel though which the liquid flows. The liquid is propelled through the channel by the impellers and, as the area of the channel decreases downstream from the impellers caused by the increase in diameter of the rotor, the velocity of the liquid increases. Air enters the channel upstream from the impellers and is drawn with the liquid through the channel. The diameter of the rotor then decreases significantly thereby causing the area of the liquid carrying channel to increase suddenly downstream of the widest portion of the rotor. Turbulence occurs in this area and bubbles are formed which are released from the outlet of the compost aerator into the compost/liquid mixture to perform aeration for bacterial breakdown.

Abstract: A diffuser for use in a pressurized feed system. The diffuser introduces a carbonic acid solution into water to be treated. The carbonic acid solution within the diffuser is maintained at an elevated pressure. As the carbonic acid solution passes to the exterior of the diffuser, the pressure drop causes an effective mixing of the carbonic acid solution and the water. The carbonic acid solution mixes with the water and the pH of the water is reduced.

Abstract: A system for providing improved bulk liquid mixing and effective gas-liquid contacting for mass transfer of the gas to the liquid, especially a non-Newtonian liquid, the viscosity of which decreases when under shearing conditions (shear thinning), in an upright tank. An upright draft tube is mounted within the tank and has a lower end spaced from the tank bottom and an upper end spaced below the surface of the liquid in the tank. A plurality of mixing impellers in the draft tube are sufficiently close to each other to establish a field or pattern of agitation to cause shear thinning and upflow throughout the draft tube and which produces significant turbulence at the liquid surface. A plurality of radially inwardly projecting, circumferentially spaced baffles extend from the draft tube and are proximate the mixing impellers to prevent swirling of the liquid within the draft tube.

Abstract: The device includes a vertical sheath (11) extending in a part of the height of the tank (1), a funnel (14) located around the upper part of the sheath (11), a vertical shaft (19) driving the propeller (20) in rotation, anti-vortex blades (24) located inside the sheath (11), below the propeller (20), a pipe (33) for injecting a gas under pressure in the sheath (11), below the anti-vortex blades (24), and uniquely static stirring obstacles (31, 32) for stirring the liquid (3) by turbulence inside the sheath (11), these obstacles being located below the anti-vortex blades (24). The invention is applicable for example to the treatment of fatty waste products extracted from town sewage effluents or agricultural food industries.

Abstract: An improved method and apparatus for aeration of septic tanks and the like. Because of the interrelationship of the rotating impeller, an air plate and the horsepower of the unit in comparison with the volumetric size of the sludge tank, the unit disperses extremely small reduced pressure microbubbles adjacent the area of the impeller. These reduced pressure microbubbles are thereafter dispersed throughout the wastewater by Brownian movement without agitating the sludge. As a result, there is substantially increased lateral oxygen transfer to replace the oxygen used by the aerobic bacteria. The sludge is therefore efficiently digested without the need for huge, expensive and energy inefficient equipment.

Abstract: A high efficiency impeller-type aerator designed for aeration of the water supply of aquatic organisms has a first impeller, a second impeller, and a pump casing having at least one water inlet, one air inlet, and one water outlet. The first and second impellers are disposed between the pump water inlet and outlet, and the pump casing includes constricted portions in association with the first and second impeller to define axial flow direction boundaries. The air inlet is located at the constricted portion, and the axial flow direction boundaries define a channel through which the second impeller urge water to facilitate low pressure that creates a venturi which causes air suction at the pump air inlet.

Abstract: A high efficiency impeller-type aerator designed for aeration of the water supply of aquatic organisms has a booster impeller, a main mincing impeller, and a pump casing having at least one water inlet, one air inlet, and one water outlet, with the pumping and mincing impellers disposed between the pump casing water inlet and outlet, and wherein the air inlet is positioned advantageously between the booster pump and the main mincing impeller and is in communication with air, and wherein the water-inlet and outlet are in communication with water. The efficiency of the pump is retained while the bubbles produced in accordance with the present invention are advantageously small.

Abstract: An auto-aspirating, rotational dispersion device for gases and liquids with a rotating hollow shaft employed for gas suction and gas channels communicating with said hollow shaft to openings in the gas channels that are positioned at intervals over the circumference of the device, at which openings the gas and liquid are mixed. The device is distinguished by the fact that the gas being dispersed flows in a manner separate from the liquid, from the hollow shaft through the gas channels and is mixed with the liquid outside of the device.

Abstract: A gas/liquid mixing device is provided in which bubbles having such a small diameter as to be invisible to the eye are produced and dissolved in water in a short time, whereby the solubility of gas can be improved. The gas/liquid mixing device has a mixing cylinder, a drive unit, and a gas supply device. In the mixing cylinder, a rotary vane having guide vanes is rotated to compress water in the mixing cylinder and gas supplied into the mixing cylinder so that the water flow containing the bubbles is dispersed outwardly through bubble dispersing holes formed in the wall of the mixing cylinder.

Abstract: An aerating unit includes a container, a submersible motor disposed in the container and having a shaft which is provided with a propeller, an air conduit connected to an air supply at one end and extending into said container at the other end which defines an air outlet adjacent to and facing toward the propeller for introducing air toward the propeller, and a base disposed below and aligned vertically with the propeller in the container and having a curved surface which is convex in a direction toward the propeller for deflecting the air directed from the propeller in radial directions away from the curved surface.

Abstract: In a device (1) for treating waters in a basin, an operating group (8) is immersed in the water, being supported by two upper floats (3) or simply resting on the bottom of the basin. The operating group (8) has, defined inside it, a chamber inside which it is possible to create a pressure drop by means of a propeller (10) rotating outside the chamber. Two suction pipes (6), which lead to the chamber, emerge at the top above the free surface of the water. The operating group (8) is attached to a base structure (12) which is able to rest on the bottom of the basin. The device (1) may be used in particular to aerate and/or oxygenate (by means of movement) the waters contained in a basin, such as for example a tank for aquiculture, a fish-farming basin or an aeration tank of water purification plants.

Abstract: A stirring blade unit includes a perforated cylinder formed around the an internal stirring blade so as to be rotated together with the stirring shaft. The perforated cylinder has perforations which are approximately 30 to 50% of the area of the top and bottom surface of the perforated cylinder. The internal stirring blade unit uses a discharge type stirring blade unit used for gas-liquid mixing of a general fermentation tank. Thus, the gas-liquid flow discharged from the blade unit in the horizontal direction hits the perforated cylinder formed around the blade unit certainly. Due to this hitting of the gas-liquid flow against the perforated cylinder, the pressure of the flow is changed significantly to refine the gas bubbles so that the gas absorption property is improved. The stirring blade unit is suitable for gas-liquid mixing necessary for such as, fermentation, aeration, and reaction (hydrogenation and oxidation) tanks.

Abstract: The aspirator is utilized to introduce air, oxygen, or other gases into a liquid. The advantages of the present design include the ability to inject approximately 30% more air than a conventional current design at 50% of the rotational speed. This reduces the power requirements. Additionally, the 45 degree angle of the aspirator tubes helps to shed debris that might otherwise collect on the aspirator. The aspirator design includes a fin along the aspirator tube, which is formed at a 45 degree angle relative to the aspirator shaft. Superior mixing is provided by the larger profile of the aspirator. The fins along the bottom of the aspirator tubes help to create larger voids in the liquid. This increases the aspirator's capacity to inject air, while minimizing the material requirements of the part.

Abstract: An impeller for use with apparatus to enhance mixing of a gas and a liquid, as used for example in froth flotation apparatus, having a substantially upright portion (11) substantially parallel to the axis of rotation (17), and a plurality of vanes (12) extending outwardly therefrom, at least some of the vanes (12) having an upper part (19) adapted to induce liquid flow generally downwardly towards the impeller and a lower part (20) adapted to induce liquid flow generally upwardly towards the impeller, wherein the impeller further comprises barrier means (14) at least partially dividing the upper and lower parts, and a gas input situated on the same side of the barrier means (14) as the lower part (20). The barrier means (14) may comprise a flange like member in a plane generally perpendicular to the axis of rotation (17) and may intersect, or be integral with at least part of the vanes.

Abstract: Apparatus for facilitating the mixing, absorption and/or retention of carbon dioxide ‘CO2’ in hydrocarbon fuel to economically produce a safety-enhanced and/or improved-combustion fuel. The apparatus includes at least one mixing receptacle having at least one coupling with a controllable inert gas supply; at least one coupling with a controllable hydrocarbon fuel supply; and at least one coupling with a CO2-enriched fuel fuel-line. The mixing receptacle(s) is configured to retain a volume of fuel and a volume of CO2 such that CO2-enriched fuel having a controllable gas-fuel ratio is the product of the mixing receptacle(s) and the gas of the ratio(s) exceeds 0.1 volume of CO2 per volume of fuel and is less than approximately 3 volumes per volume of fuel when conveyed from the receptacle(s). The apparatus controls the exposure of hydrocarbon fuel molecules to an optimal volume of CO2 within the receptacle(s).

Abstract: A mixer for producing a substance mixture includes a rotatable shaft and a body submersible within a first substance. The body includes a first end and a second end. The first end is coupled to the shaft, and the second end includes an outwardly flared opening. The mixer also includes a plurality of apertures disposed on a wall of the body. Rotation of the body draws the first substance and a second substance into an internal area of the body and dispels the substance mixture outwardly through the apertures. The mixer may also include a diverter for diverting the substance mixture toward the apertures. The mixer may further include internally formed vanes to increase a substance flow rate into the mixer. Screens may also be disposed outwardly from the apertures to enhance mixing of the first and second substances.

Abstract: A mixing apparatus comprising a central disc driven by a rotating shaft. A number of mixing plates are stacked above and/or below the central disc. The mixing plates are spaced from and parallel to the central disc. Each plate has a central aperture and the diameter of the central aperture increases progressively away from the central disc to define a space coaxial with the rotating shaft. In operation, fluid is drawn into the space and directed out through the space between the plates. When placed near the surface of a fluid, air is drawn in and the fluid is aerated as well as mixed.

Abstract: A gas/liquid mixing device is provided in which bubbles having such a small diameter as to be invisible to the eye are produced and dissolved in water in a short time, whereby the solution of gas can be improved greatly. The gas/liquid mixing device has a mixing cylinder, a drive unit, and a gas supply means. In the mixing cylinder, a rotary vane having guide vanes is the mixing cylinder and gas supplied into the mixing cylinder so that the water flow containing the bubbles is dispersed outwardly through bubble dispersing holes formed in the wall of the mixing cylinder.

Abstract: An apparatus and method for mixing a gas and a liquid while concomitantly mixing and suspending solids and sludge at the bottom of a deep tank. The present invention includes a gas-liquid aerator which is adapted to be submerged below the surface of wastewater in a deep tank. An expanding high velocity gas-liquid mixture is caused to exit from the bottom of the submerged aerator device with enough force to mix and suspend settling solids and sludge at the bottom of the deep tank.

Abstract: A reactor for aerating a fluid with a gas comprises a mixing tank (12) for the fluid and a centrally located vertical draft tube (13) submerged in the fluid to divide the mixing tank (12) into an inner chamber (21) and an outer chamber (23). The reactor further comprises a motor driven axial flow impeller (14) located in the draft tube (13) for circulating fluid downwardly through the inner chamber (21) and upwardly through the outer chamber (23). The reactor further comprises an external circuit for withdrawing a portion of the fluid from the mixing tank (12), aerating the fluid, and returning the aerated fluid to the mixing tank (12). The aerator is in the form of a venturi device (17).

Abstract: This device includes a drive device (1) arranged above the reactor, provided with a vertical output shaft (2) equipped at its end with an axial-flow mobile assembly such as a propeller (4) immersed in the reactor; the output shaft of the drive device also carries an auto-suction turbine (5) immersed in the reactor and drivable by the output shaft (2), and the latter is enveloped coaxially by a cylinder (6) linked at its upper end to the drive device and whose lower end (6a) opens out into the turbine; in the upper end of the cylinder is drilled an aperture (14) for injecting a gas into an annular gap (15) delimited by the shaft and the cylinder. This device makes it possible to transfer a gas into a liquid efficiently and to ensure agitation whereby particles may be placed in suspension and held there. Application to the biological treatment of industrial effluents.

Abstract: The apparatus of the present invention includes an inverted J-shaped pipe disposed under the sea and including shorter and longer open end portions, and a connecting portion joining them such that the shorter and longer portions extend downward from connecting portion to their respective open ends. An injector nut injecting the carbon dioxide-containing gas into a portion of said short pipe adjacent to said first open end into said shorter pipe. An accumulator is in fluid communication with the connecting portion for collecting gas, which remains undissolved in the seawater during the passage of the carbon dioxide-containing gas through said shorter pipe.

Abstract: An apparatus for conducting aqueous liquid media includes a plurality of static mixers, a gas distributor assembly with a plurality of nozzles, at least one impeller having blades attached thereto and a plurality of static mixer assemblies having flow guide elbows and collectors. The static mixer assemblies are independently and separately mounted to orient to the current leaving the blade tips of the impeller. Swirlers are also described as being utilized in place of the static mixers.

Abstract: An axial flow mixing impeller system for efficient mass transfer by control of size of the bubbles of the fluid which is being dispersed, especially gases and liquids with viscosities greater than the liquid into which dispersion occurs, is obtained by creating passageways through the impeller blades for flow between the suction and pressure sides of the blades which disrupts the flow over the suction sides of the blades thereby reducing the tendency for bubbles to grow or coalesce into large bubbles which instead of being dispersed, rise to the surface without effective mass transfer to the liquid which is pumped by the impeller. The blades of the impeller may be slotted inwardly from the tips thereof to provide the passageways or may be formed from segments, gaps between which provide the flow passageways.

Abstract: An improved method for aeration of septic tanks and the like by drawing atmospheric air into an expansion chamber and from there into agitated sludge to provide low pressure small microbubbles which have long hold times in the sludge material.

Abstract: A waste pond liquid circulator is described in which a plurality of pontoons extend substantially radially from a base and with respect to a central axis passing through the base. A drive mechanism is mounted on the base that is drivingly connected to an impeller for rotating the impeller about the central axis. The base and pontoons are configured to rest on a liquid surface with the pontoons engaging the liquid and forming wedge shaped spaces between successive pontoons. The impeller is rotated by the drive mechanism about the central axis to produce a vortex current of liquid directed toward the it base. The pontoons are configured to receive and direct the current substantially radially away from the base through the wedge shaped spaces.

Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: In a method of and apparatus for producing sub-micron bubbles in liquids, slurries, and sludges, gas is maintained on the interior of the gas permeable partition at predetermined pressure. Relative movement between the gas permeable partition and the surrounding material forms sub-micron sized bubbles in the liquid, slurry, or sludge.

Abstract: A mixing system utilizes up pumping impellers which entrain gas into the liquid both at the surface (the gas liquid interface) and below the surface by induction to draw gas down below the surface where it is dispersed into the circulation produced by the impellers. The impellers are the axial flow type. Tubes disposed on the suction sides of the impeller blades, and providing gas outlets near the tips of the blades, rotate with the impellers. The tubes may extend along the shaft above the surface or into a hollow shaft having a breathing opening above the surface. The rotation of the impeller produces a suction at the tube outlets to draw gas into the liquid while the upward circulation produces surface turbulence for gas entrainment. The entrained gas from the surface and the gas discharged from the tubes is circulated.