Abstract: A system for the dissolution of gas in a large body of liquid comprising an impeller positioned below the surface of the large body of liquid; a floating hood positioned over the impeller and of sufficient size to capture undissolved gas; a conduit for introducing a feed gas stream beneath the floating hood and directly into the large body of liquid; at least one segregation ring positioned under the floating hood and extending below the surface of the large body of liquid such that a first inner region between the ring and the impeller, and a second outer region between the ring and an outer diameter of the floating hood are created, and a back pressure regulator located in the floating hood adjacent to the outer diameter of the floating hood.

Abstract: In order to sparge gas into a liquid or liquid suspension in a tank wherein a principally axial flow pattern downwardly towards the bottom of the tank and then upwardly along the side wall of the tank returning axially downward is established by an axial flow impeller, a disc of a diameter less than the diameter of the impeller is spaced axially therefrom in the direction of the outlet flow towards the bottom of the tank from the impeller so as to turn the axial flow, radially, thereby establishing a pressure gradient which prevents the collection of gas released by a sparge between the disc and the bottom of the tank and flooding of the impeller. The gas is released in the axial flow from the tip region of the impeller thereby facilitating the shearing of the gas into fine bubbles promoting mass transfer of the gaseous phase into the liquid phase in the tank. Since flooding is inhibited, as much as six times the volume of gas (gas rate) can be handled as may be the case without the disc.

Abstract: Oxygen or other gases are dissolved in large bodies of liquid by injection under a baffle for passage into a submerged hollow draft-tube-impeller means assembly for downward passage therein. Liquid containing dissolved gas is dispersed throughout the body of liquid, while any undissolved gas is effectively recovered and recycled.

Abstract: A rotatable apparatus for introducing and dispersing a fluid, such as gas or liquid, in a liquid has outwardly and rearwardly projecting blades about it periphery and air exit ports immediately rearward of said blades. In one embodiment, the apparatus is an aerator having an upper body, a lower body and replaceable blades affixed between the upper and lower bodies. The blades have a body portion positioned between the upper and lower bodies and a projecting portion extending radially outwards. The upper body has an axial bore which is connected to a rotatable hollow tube open to the atmosphere. As the aerator is rotated by rotation of the tube, air is drawn through the tube into the body of the aerator and is ejected through air exit ports between the blades into the liquid. In another embodiment, the aerator has a plurality of radially extending tubes with air exit ports and radially extending blades proximate their outer ends.

Abstract: A mixing system in a tank provides a flotation cell for froth collection of minerals such as metallic ores thereby separating such ores from other materials with which they are mined and enabling a concentrated ore component to be collected. The mixing system maintains particles containing the ores in a circulating liquid suspension in a contact zone where bubbles are discharged. Ore particles are attracted and attached to the bubbles. The bubbles rise and float to the top of the liquid for collection of the concentrated ores. The mixing system includes a radial flow impeller and an axial flow impeller which are attached for rotation on a common shaft, with the axial flow impeller below the radial flow impeller. The radial flow impeller is disposed in a space between a disc, which rotates with the radial flow impeller and another disc which is stationary, and may be a flange of a pipe around the shaft and extending above the surface of the liquid.

Abstract: A mixing device in the form of a centrifugal pump is used to mix gas (typically air) with liquid (typically effluent water, dispersion water, or waste paper pulp suspension, etc.). The pump is provided with a common inlet conduit for both the liquid and the gas so that liquid and gas flow freely and in an arbitrary ratio into the pump, that is there is no controlling or adjusting of the flows. The gas is allowed to either dissolve in the liquid or be mixed as small bubbles with the liquid, and any surplus gas is separated from the mixing device (e.g. by holes in the pump impeller leading to a rear portion of the pump which is attached to a vacuum source, such as a liquid ring pump). The liquid and gas dissolved therein, and small bubbles mixed therein, are discharged from the mixing device at a pressure that is raised from the inlet pressure, due to the action of the impeller, which pressure development enhances the dissolution of gas in the liquid.

Abstract: A turbine installation is adapted for enhancing the level of dissolved gas in water flowing therethrough. The installation comprises a water passageway for containing turbine components including a turbine runner. The water passageway extends from an upper elevation source of water to a lower elevation discharge region. The turbine runner is disposed in the passageway so that water flowing therethrough impinges on the runner. The runner includes a plurality of blades extending from the hub at circumferentially spaced intervals. Each blade is defined by a pressure surface, an oppositely facing suction surface, a leading edge and an spaced apart trailing edge. At least one of the blades has an integrally formed gas passage extending from a gas inlet aperture in the hub to the trailing edge.

Abstract: A fluid mixing system including a liquid mixing device and method for generating and maintaining a substantially uniform, horizontal velocity profile in a liquid circulation system, such as a plug flow reactor, which requires less horsepower than conventional liquid mixing systems without losing mixing effectiveness. The liquid mixing device employs a top-entry, vertically-oriented impeller and a housing that directs the pumped flow in a generally horizontal direction. The liquid mixing module may be positioned in close proximity to an aeration source within a channel.

Abstract: The invention concerns a mixing and aeration unit, especially for waste water treatment and including a submersible axial flow mixer (2), an elongated jet ring (6) with inlet (6a) adjacent the mixer propeller (3) and housing a number of air bubble diffusers (10).

Abstract: A system for dissolved air floatation treatment of a liquid stream where the system includes a pump having an impeller cavity with input and output ports, and an impeller with an eye disposed adjacent the input port. The impeller draws liquid through the input port and drives the liquid toward the output port and creates a subatmospheric pressure zone in the cavity away from the eye. The pump includes an air introduction port opening into the subatmospheric zone to introduce significant quantities of air into the cavity for mixing with the liquid stream. The system also includes a tank adapted to receive the liquid stream from the pump with dissolved air introduced therein.

Abstract: Excessive vibration in industrial mixers such as flotation cells and draft tube mixers is attenuated by connecting a vibration dampening device to a rotor or impeller which is disposed in a mixing tank for pumping a nonhomogeneous fluidic material placed in the tank. In a draft tube mixer, where the rotor is connected to a drive shaft in turn connected to a motor for rotating the rotor, the vibration dampening device is connected to the shaft on a side of the rotor opposite the motor. In a froth flotation cell, if the rotor is hollow, the vibration dampening device is disposed inside a pipe in turn mounted inside the rotor along an axis thereof. The vibration dampening device takes the form of a tuned mass dampener tuned to a resonance frequency of the particular mixing apparatus.

Abstract: An apparatus for selectively aerating a pond. The inventive apparatus preferably includes a first conduit for receiving a fluid from an upper portion of a pond without substantially disturbing a fluid material contained in a lower portion of the pond; a gas delivery conduit for delivering a gas into the apparatus; and a discharge conduit, at least partially positioned in the receiving conduit, for discharging the fluid and the gas into the upper portion of the pond without substantially disturbing the fluid material contained in the lower portion of the pond.

Abstract: The present invention is directed to an apparatus and method for providing absorption of two fluid phases with one another and for the magnetic treatment of the phases for molecular realignment for effective separation of contaminants.

Abstract: A condenser for a carrier recovery apparatus of a liquid imaging system is provided. The condenser for a carrier gas recovery apparatus of a liquid imaging system for recovering a carrier gas as a liquid carrier by collecting and condensing the carrier gas evaporated by a drying unit of the imaging system, includes a bubble generating member provided at a vapor discharging end of a gas duct for inducing the collected carrier gas into the liquid carrier contained in the condenser. The bubble generating member generates bubbles from the carrier gas in the liquid carrier and a rotation member installed in front of the bubble generating member rotates to make the bubbles generated by the bubble generating member into finer bubbles. A rotation driving device rotates the rotation member.

Abstract: The present invention provides for an aquatic environment an aerator having a temperature adjusted air inlet for aerating a quantity of water in a container, where the temperature of air pumped through an aerator may be cooled or heated, the temperature adjusted air entrained with water, and exhausted through an outlet into a bait well or a larger container, such as a pond for raising aquatic livestock. The temperature adjusted air may be supplied from an air conditioning unit in an automobile, a portable or fixed refrigeration unit, or gas flowing through an chilled environment of cooled liquid. In another embodiment, the temperature adjusted air may be drawn through an underground or underwater thermal stabilized conduit, using the natural temperature stability of underlying formations or layers.

Abstract: The present invention generally provides a portable system for maintaining aquatic life that require oxygenated water, such as fish, shrimp, other marine animals, microbial populations, plant life and combinations thereof. The system generally includes a container and a centrifugal pump adapted selectively operate in either an aerating mode to provide oxygen to the aquatic life or a pumping mode in which the water in the tank is replace with fresh water. The pump is designed to be self priming, thereby allowing a system that is substantially self regulating and operating without the necessity of electronic controls.

Abstract: A high efficiency impeller-type aerator designed for aeration of the water supply of aquatic organisms. The aerator design includes a first impeller (booster), a second impeller (main 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 casing water inlet and outlet. The air inlet is positioned advantageously between the first impeller and the second 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: 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. A process, such as fermentation which produces commercial quantities of polysaccharides such as xanthan gum, may be carried out in the 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 may produce 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: A liquid management unit uses a) a shaft mounted disc rotor partially submerged into a liquid for introducing flow-inducing energy and air or treatment gas into the liquid, b) a first baffle for receiving liquid from below the surface of a body of liquid and directing the liquid to the rotor, and c) a second baffle for receiving treated liquid from the rotor and directing the treated liquid below said surface of the body of liquid. The rotor and baffles may be mounted in various orientations including both horizontal and vertical positions. The disc rotor and first and second baffles are mounted on a frame that is supported by pontoons. A shroud placed over the disc rotor and input and output baffles with an air passage through them form a pressurized three-point aeration system in which the input baffle pre-aerates the water to satisfy chemical oxygen demand, the disc rotor transfers additional air to the water, and the output baffle post-aerates the water to satisfy the overall oxygen demand of the liquid.

Abstract: The present invention generally provides a system for maintaining aquatic life that require oxygenated water, such as fish, shrimp, other marine animals, microbial populations, plant life and combinations thereof. The system generally includes a container and a centrifugal pump adapted selectively operate in either an aerating mode to provide oxygen to the aquatic life or a pumping mode in which the water in the tank is replace with fresh water. The pump is designed to be self priming, thereby allowing a system that is substantially self regulating and operating without the necessity of electronic controls.

Abstract: The present invention relates to an aerating fountain for use in aerating water and producing aesthetically appealing water sprays. The fountain has a float with an aperture running through its center. It has an electric motor with an impeller coupled to its shaft. The motor is mounted to the float such that the impeller is adjacent to the float aperture. The fountain has a nozzle plate having a set of nozzles. The nozzle plate is releasably coupled to a top side of the float such that one of the nozzles is disposed directly above the float aperture. The nozzle plate is coupled to the float in such a manner that it may be easily adjusted to bring a different nozzle into alignment with the float aperture.

Abstract: An apparatus and method are provided for mixing gas and liquid. An impeller is rotatably mounted inside a draft tube having a constricted section. Rotation of the impeller draws liquid down through the constricted portion of the draft tube. A gas delivery system introduces gas under the surface of the liquid downstream from the constricted portion of the draft tube to entrain the gas in the liquid by a venturi effect. The impeller creates a turbulent gas-liquid mixing zone and also projects liquid radially into the gas as it enters the draft tube. The gas-liquid venturi mixer is particularly suitable for treating industrial and municipal waste water, as well as various other liquids. Gases such as air, oxygen, hydrogen, and the like are efficiently dissolved in such liquids during operation of the gas-liquid venturi mixer.

Abstract: In order to efficiently mass transfer from gas, particularly air, into liquid or liquid suspensions with enhanced efficiency in terms of the mass of the gas transferred to the liquid, the gas is released or sparged through a plurality of open pipes which are disposed in a space between the bottom of the tank containing the liquid or liquid suspension and an axial flow impeller which creates a flow path downwardly past the outlet ends of the pipes. Turbulence is enhanced even though the air leaves the pipes at low velocity rather than in a jet through the use of a Bernoulli air trapping ring and plates. The ring and plates encounter the flow produced by the axial flow impeller successively. The ring distributes the air and assists in defining a low pressure region below the ring. A low pressure region also is defined by the plates on the underside thereof. The underside of the plates is in the vicinity of the outlets of the pipes.

Abstract: A stirring element (10), especially a gasing stirring element for stirring liquids and introducing a gas, preferably air, to the liquids. The stirring element has a hub (12) for attachment to a stirring shaft and a support disk (14) joined to the hub (12), a plurality of stirring blades (16) being attached to a peripheral edge of the support disk (14). To achieve a low output power coefficient, each stirring blade (16) is made of a wedge-shape that is directed in the direction of rotary motion of the stirring element (10). Preferably, radially inner end sections (22, 24) of two sides (18, 20) of the stirring blade (16) are angled relative to sides (18, 20) outwardly with reference to the direction of rotary motion of the stirring element (10). The stirring element (10) simplifies gas feed and prevents clogs. By providing the support disk (14) with a conical shape having a ring of teeth (26) on its outer edge, a uniform distribution and good dispersion of the gas bubbles is obtainable.

Abstract: An aerator for mixing a gas with a liquid has a motor, fan, rotating central shaft, housing enclosing the shaft, and an air flow pathway between the central shaft and the housing. Rotation of the shaft in the air flow path reduces friction in the flow path and increases efficiency. The shaft may be hollow to provide a second air flow path, also with a rotating shaft in the air flow path to reduce friction, increasing air flow volume and efficiency. A non-lubricated material bearing rotatably mounts the central shaft, and has openings to allow increased air flow through the aerator.

Abstract: In order to reduce the noise made by a foam flotation separator working on the dispersion apparatus principle and maximise the air supply, the foam flotation separator is designed so as to comprise a dispersion pump (2) which draws in water and a gas such as air and/or ozone, a reaction chamber connected on the delivery side, a collector (5) on the upper end of the reaction chamber (4) and an expanded section (15) at the lower, outlet end of the reaction chamber (4).

Abstract: An impeller assembly for agitating a fluid contained in a vessel and dispersing a gas introduced therein. The impeller assembly includes an impeller having a plurality of generally radially extending blades. Each of the blades includes diverging upper and lower sheet-like portions having generally radially extending leading edges. The upper and lower portions are joined to form a generally V-shaped cross-section with a trailing vertex. The width of the upper portion of each blade is greater than the width of the lower portion of the blade such that the upper portion leading edge extends forwardly of the lower portion leading edge, thus producing an upper portion overhang to capture and disperse rising gas bubbles. The impeller assembly further comprises a drive assembly for rotating the impeller assembly.

Abstract: An apparatus is disclosed for rapidly and efficiently dissolving gases in a liquid. A diffuser, having a closed top and an opened bottom, preferably in the form of a conical-shaped frustum having a plurality of openings around the perimeter near the closed top, is submerged in the liquid and rotated at relatively high speeds creating a centrifuge-pump. When the rotating diffuser is located near the surface of the liquid, no additional gas is required in the dissolution process because gas from the surface of the liquid is introduced by cavitation. When the device is submerged substantially below the surface or if a gas other than oxygen is to be dissolved, additional gas must be pumped into the bottom opening of the rotating diffuser or very near the high velocity horizontal liquid jets on the periphery of the diffuser. This device can be used in the oxygenation of treated sewage water, the removal of impurities from liquids, and the oxygenation of horticultural ponds to increase production.

Abstract: An improved aerator, including a removable stator, is disclosed. The aerator includes a submersible motor having a drive shaft which rotates an attached impeller within an aeration zone. The aeration zone includes the removable stator, an upper ring to which the submersible motor is attached and a lower ring. The removable stator engages the upper ring and the lower ring, and is configured to be readily removed from the aeration zone.

Abstract: A method for treating a liquid flow to be cleaned passing through a flow line into a flotation plant including passing a portion of the liquid flow to be cleaned from the flow line along a first branch line into a pump. The suction capacity of the pump is regulated to draw in a direct flow of gas so that the pump sucks the gas as a direct flow. The drawn-in direct flow of gas is then mixed with the liquid flow in the pump and passed along a discharge pipe of the pump into a mixing part wherein the discharge pipe ends in a pressure release. The remaining portion of the liquid flow to be cleaned from the flow line is then passed along a second branch line into the mixing part. A liquid flow is discharged from the pressure release, the liquid flow including gas bubbles containing dissolved gas.

Abstract: An apparatus and method for introducing oxygen into a subsurface stratum of a thermally stratified body of water, while maintaining the thermal stratification thereof substantially undisturbed, comprising a closed flow path wherein water enters an inflow aperture, extends upwardly through an upflow chamber, through a horizontal chamber, downwardly through a downflow chamber, and through an outflow aperture. Both the inflow aperture and the outflow apertures are positioned within the subsurface stratum. Within the conduit is an aerator which introduces oxygen, an impeller which assists the flow of water through the conduit and which mixes water with oxygen, and a collector which collects undissolved gas within the conduit at the horizontal chamber. Outside the conduit, and above the outflow aperture, an interceptor means collects undissolved gas outside of the outflow aperture, and prevents vertical circulation of water discharged from the outflow aperture means.

Abstract: Disclosed is a gas-induced reactor which mainly includes a tank body without inner baffles and a draft tube with inner baffles mounted in the tank body. An upper and a lower turbines are installed in series on a shaft of said tank body and enclosed by the draft tube. The turbines each have six 45.degree. pitched, rectangular, flat blades. When the two turbines rotate at high speed to agitate gas and liquid in the draft tube, a downward regular gas vortex is formed at a center of liquid surface in the tank body above the draft tube. The regular gas vortex is pulled inward to the draft tube and is disturbed by the baffles in the draft tube to become an irregular gas vortex in the draft tube. The irregular gas vortex is broken by the rotating turbines into bubbles which are angularly distributed out of the draft tube and into liquid in the tank body.

Abstract: A dissolved gas flotation tank system is disclosed which is configured to provide educted gas or air into recirculated effluent fluid from the tank which includes a pump system which increases the dissolution rate of gas into the effluent fluid thereby eliminating the need for retention tanks and related equipment which adds to high equipment costs. The dissolved gas flotation tank system of the present invention also provides a pre-contact chamber for assuring immediate and intimate contact between the suspended solids in an influent feed stream and the recirculated effluent fluid in which gas is dissolved, as well as flocculant when used, to produce a better agglomerate structure for improved flotation and separation. The dissolved gas flotation tank of the present invention also provides an improved means of removing and processing float from the tank, and employs a dewatering system enhanced by the addition of chemicals or flocculants into the float removal system.

Abstract: An apparatus for aerating and mixing liquids and gases that includes a hollow housing, at least one rotating object, rotating apparatus for rotating the rotating object, a shaft, and at least one adjustably positioned conduit tube. The hollow housing has a hollow housing first portion and a hollow housing second portion. The hollow housing first portion has a hollow housing first portion wall that contains at least one hollow housing first portion wall inflow port and the hollow housing second portion has a hollow housing second portion wall that contains at least one hollow housing second portion wall outflow port. The at least one rotating object is located in the hollow housing second portion and has a rotating object low pressure side. The rotating apparatus rotates the at least one rotating object and is located in the hollow housing first portion. The shaft connects the at least one rotating object to the rotating apparatus.

Abstract: An aeration device disperses microbubbles into a liquid and maintains efficient transfer of gas to the liquid. The aeration device uses a number of sealed end, hollow fiber membranes that are hydrophobic and provided with pores in the walls of the tubular fibers that range from about 0.01 to 1.0 microns, so that very small bubbles are formed on the outside surface of the hollow fiber membranes. Gas pressures above the bubble point of the fiber membranes are used, and a cloud of microbubbles is expelled into the liquid as it is forced to flow past the fibers. These microbubbles provide a large surface area for the effective dissolution of gases into the liquid. The length of the hollow fiber membranes is controlled in order to obtain efficient small bubble formation.

Abstract: The present invention provides a simple and efficient means for dissolving carbon dioxide gas discharged from sources such as thermoelectric power plants into the seawater and for isolating it at deep sea level. The means comprises an inverted U-shaped gas lift 1 having a shorter gas lift dissolving pipe 2 and a longer descending pipe 3 being connected with each other at the top, said gas lift dissolving pipe 2 is held at shallow sea level, and the lower end of the descending pipe 3 is opened at deep sea level. When carbon dioxide gas is injected in from the lower end of the gas lift dissolving pipe 2, the seawater is introduced from the lower end of the dissolving pipe by gas lift action of the carbon dioxide gas in the dissolving pipe 2, and the carbon dioxide is completely dissolved into the seawater until it reaches the upper end of the dissolving pipe.

Abstract: The invention is directed to an apparatus for providing absorption of two fluid phases with one another. One of the phases made be a gaseous phase, while the other phase may be a liquid phase.

Abstract: Device for introducing a gas into a liquid, of the type which comprises a drive motor, a wind box, a gas intake pipe and a radial diffusion turbine coupled to an agitator turbine, the two turbines being immersed in the liquid mass and the gas being conveyed to the centre of the diffusion turbine and distributed between the vanes thereof, wherein the said diffusion turbine has a plurality of long radial vanes alternating with shorter radial vanes, the latter not extending as far as the shaft of the said turbine so as to leave a clear space between the said shaft and the respective internal edges of the said shorter radial vanes, these two sets of vanes being fixed under a plate driven in rotation by the said shaft and the said radial vanes of the diffusion turbine laterally extend the blades of the agitator turbine as far as a region of relative depression situated behind the turbine.

Abstract: The invention provides for flotation equipment which is locatable inside a container for a pulp to be subjected to a flotation process and a rotor or impeller or agitator rotatable within the container about a substantially vertical axis, the rotor including first means for imparting a radially upward pulp stream movement to pulp particles in the container, the first means being in the form of a set of arcuate surfaces located between the vanes and second means for moving air from atmosphere in a downward direction to below the pulp stream level in the container, the second means comprising a set of arcuate surfaces extending from the top of the rotor to outlets in the peripheral surfaces of the vanes.

Abstract: An aerator designed for aeration of a live bait well and comprising a centrifugal type pump comprising an impeller and an impeller casing having an inlet and an outlet, wherein the inlet is in communication with water from the bait well and also with air via an air conduit. The air conduit is provided with metering means for metering the amount of air entering the impeller and for optimizing the mincing of air in the fluid (which is a different technical phenomena from simply pumping an air/water mixture). The bubbles produced in accordance with the present invention are so fine as to give the water a fogged appearance. The unusually high level of oxygenation makes it possible for the first time to pack two to four times as many bait fish into a live well as had previously been considered possible.

Abstract: A foam fractionator which can create a vortex is utilized to remove proteins from an aquatic environment by skimming. The vortex is created by a propeller arrangement located at the bottom of an internal chamber, centrally located within a main reaction chamber. Air sucked from the atmosphere by the vortex passes down through a central chamber and is dispensed outwardly into the main chamber where air bubbles form and rise to the surface. The air bubbles attract protein deposits which stick thereto which results in the formation of a protein-containing surface foam that is collected within a collection cup.

Abstract: A vertical draft tube submerged turbine mixer/aerator includes an impeller rotatedly disposed within the draft tube above an aerator. A single tiplet extends downwardly from the lower surface of each impeller blade in proximity to the blade tip for improving gas to liquid mass transfer efficiency of the mixer/aerator.

Abstract: Apparatus and process for high speed air dispersion (HSAD) and oxidation of elemental phosphorus in aqueous medium. The HSAD apparatus is an element used in a process designed for treating the highly toxic and hazardous phosphorus sludge wastes with oxygen-containing gas microbubbles at high shear rates in which the elemental phosphorus is quantitatively converted to soluble oxyphosphorus compounds which can be recovered after neutralization as fertilizer by products or disposed of as inert nonhazardous landfill material.

Abstract: A reactor for introducing gas into a fluid comprises a mixing tank (12, 43) for the fluid and a partition means (13,45) for dividing the tank into at least two chambers (21, 89) and (23, 91). The reactor further comprises a first pump means (14, 47) located in one of the chambers for circulating the fluid downwards in one chamber and then upward in the other chamber and an aerator assembly (29, 49) for aerating a sidestream of the fluid and introducing the aerated fluid into the tank for mixing the aerated fluid with the circulating fluid in the tank. The aerator assembly comprises a bank of venturi aerators (38, 57) each having an aerator inlet; an aerator outlet; and a constriction intermediate the aerator inlet and the aerator outlet for creating a region of reduced pressure in the fluid, the constriction being elongate in a section transverse to the direction of flow of the fluid through the constriction; and a means for introducing the gas into the constriction to aerate the fluid.

Abstract: An apparatus for selectively aerating or anaerobically mixing a liquid in a container includes a hollow, star-shaped, multi-vaned rotor (6) arranged in the bottom region of the container (1) for rotation about a vertical axis. The hollow interior of the rotor at one of the two opposite faces thereof is in communication with a gas feed line (15), and each of the vanes (10) at its trailing flank (11), as viewed in the direction of rotation of the rotor, is provided with a respective gas exit opening (12). The inter-vane spaces of the rotor are open at one of its two opposite faces for admitting liquid from the container into those spaces. The rotor is surrounded by a stator (7) providing a plurality of circumferentially spaced flow channels (9) for receiving and guiding away either liquid with admixed gas when gas flows through the gas feed line or liquid without admixed gas when no gas flows through the gas feed line.

Abstract: Improved mixing effectiveness in the mixing of a gas with a liquid suspension is achieved in a batch mixing system having a mixing tank with a hemi-toroidal tank bottom which extends between a radially inner neck portion of the tank to a radially outer cylindrical wall portion of the tank. The hemi-toroidal profile of the tank bottom has a monotonically increasing toroidal radius between the neck and wall portions. Disposed within the tank is an assembly including an axial flow impeller with pitched impeller blades, a stator adjacent to the impeller and having stationary stator blades of a pitch opposite to the pitch of the impeller blades, a shroud surrounding the radial periphery of both the impeller and the stator and a gas sparging means supported by the shroud.

Abstract: Sloped inner and outer conical baffles are provided in a gas-liquid mixing system having a recirculating portion of a body of liquid, separated from a quiescent portion of the body of liquid and an overhead gas phase, precluding the collection of gas under the baffles, eliminating dead zones of gas, and minimizing the passage of gas to the overhead gas phase during normal operation, while facilitating the venting of gases during upset conditions.

Abstract: Apparatus and process for dissolving a gas in a liquid such as a hot edible oil for deodorizing, hydrogenating or other purposes. The invention comprises recirculating the liquid from a closed container, through an eductor and back into the liquid, and connecting the vacuum end of the eductor to the overhead gas space to draw gas down into the liquid. Preferably the apparatus contains an impeller means for sucking gas down from the overhead space, if the liquid is at an operating level.

Abstract: Apparatus including a circulating pump inside a carbonator tank which blends CO.sub.2 with still water and which is started and stopped for predetermined time periods in repetitive cycles having an on/off ratio ranging between 1:10 and 1:20. A timing circuit controls the operating and non operating times of the circulating pump so that sufficient carbonation of the water with CO.sub.2 gas is achieved along with the formation of an ice bank on the cooled wall of the storage tank. During intervening periods when the circulating pump is not operating, the carbonated water arranges itself in layers according to its density so that the relatively warmer water sinks while the colder water together with any ice particles or small pieces of ice floating therein join together, becoming fixed to the ice bank in the upper portion of the carbonator.

Abstract: A mixing device, especially for a fermenter, capable of dispersing gas in a broth therein, in which a number of propeller mixers are provided on a vertically extending shaft. The lower propeller mixer is a gas dispersing mixer having a hollow hub and open channels on the blades extending from this hub and tapering outwardly. At least one intermediate propeller mixer has some blades shorter than others and of reverse flow direction, some blades having baffle bars on trail edges thereof. The upper propeller mixer has the longer blades without channels and flow modifying elements.