Abstract: Substantially the last traces of radon are removed from typical well water at subterranean temperatures prior to significant pressurization of the water by displacement of the radon by a stream of compressed air, such radon mixing with the air vented from the system. Other objectionable gases in well water are removed concurrently with radon.

Abstract: A froth flotation apparatus includes a gas bubble-particle contact unit including a mixing means for breaking a gas into fine bubbles, such as a packed tower packing or mechanical agitation means, and a separate phase separation unit. A conditioned aqueous pulp containing a mixture of hydrophobic and hydrophilic particles and a substantially inert gas, such as air, are introduced into one end of the contact unit and flow concurrently through the mixing means, such that the gas is broken into fine bubbles which intimately contact and become attached to the hydrophobic particles. The resulting gas bubble-particle mixture is introduced into the phase separation unit which is operated under substantially quiescent conditions. A concentrate fraction containing primarily hydrophobic particles and a tailing containing primarily hydrophilic particles are discharged from the upper and lower portions of the phase separation unit, respectively.

Abstract: An apparatus for dissolving a gas, such as oxygen, into a liquid, such as water, having a low concentration of that gas. The apparatus has an inlet, an outlet and a central region therebetween and has walls defining an interior adapted for dissolving the gas in the liquid. The apparatus also has a gas injecting means adapted for maximizing a gas-liquid interface and promoting contact between the gas and the liquid, thereby maximizing the concentration of the gas in the liquid. The apparatus is useful for modifying the liquid for a specific purpose, such as for developing a culture medium. The apparatus can have different internal configurations, depending on the degree of gas linkage and retention required.

Abstract: A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

Abstract: In concepts relating to biotechnology, fermentor and bioreactor apparatus and technology are provided for maximizing aeration for the cultivation and growth of aerobic microorganisms and tissue cells in artificial media such as aqueous growth media. The apparatus comprises a chamber with an impeller assembly for downward peripheral rotary flow under circumferential baffles that are downwardly disposed alongside microporous air sparger tubes. The agitation system preferably comprises a tree-turbine or a spherical-shaped impeller system. The apparatus provides advantages with respect to low shear, low power requirement, and high oxygen absorption rate, the latter being higher than conventional rates by an order of magnitude. In a preferred embodiment for the suppression of headspace foam, the invention comprises an assembly for forcing foam-destructive downdraft air into the headspace as well as stirrer or agitator assembly for stirring and breaking up foam that is present in the headspace.

Abstract: An apparatus for cleaning and aeration of open bodies of water includes a floating structure partially extending above a water surface and having at least one opening in its lower region through which, water flows into the apparatus, and a fan arranged in the upper region of the floating structure for creating vacuum that enables flow of water inside of the floating structure. An air receiving space is defined inside of the floating structure. A perforated plate which is located below a water surface established in the floating structure, limits the air receiving space from above. The air receiving space is connected with atmosphere by a gas conducting conduit.

Abstract: A beverage dispensing system has a valve in a tap controlling dispensing of the beverage through a first passage from a second rigid or flexible container. Air, nitrogen (or other inert gas) or carbon dioxide gas from a passage is introduced into the beverage in the first passage during dispensing for development of a head of froth. The introduced gas flows under pressure (which is preferably adjustable) from the second passage and by way of a capilliary tube restrictor and a non return valve communicating with the tube into the beverage in the first passage. The non return valve has a resilient diaphragm which normally closes that valve and is displaceable under gas pressure to admit the gas to the beverage. A labyrinthine mixer is located in the first passage downstream of the position where the gas is introduced.

Abstract: The present invention comprises tray-like shallow vats placed upside down and horizontally at intervals in a culture tank so as to provide partitioned air spaces in mid water. When gas is sent, via an air supply pipe, into an air space provided at the bottom vat, a good number of artificial environments, in contact with an atmospheric environment in a manner similar to the natural surface of the water, are efficiently provided in the culture tank.

Abstract: A process and any of several pump/circulators provide selective rapid mixing of influent wastewater with the mixed liquor in the channel of an oxidation ditch and thereby provide maximized use of the entire volume of the channel. The pump/circulator is disposed at the beginning of the anoxic zone and preferably receives the influent wastewater. The oxidation ditch is preferably a barrier oxidation ditch or at least a baffle oxidation ditch in order to prevent backmixing.

Abstract: An apparatus for effecting direct contact between a gas and a liquid which has at least one substantially vertical channel, formed for example by a pair of parallel plates, a port for introducing gas at a lower part of the channel, a port for introducing liquid to the channel, and a port for removing gas and liquid at an upper part of the channel, the height of the channel being substantially greater than the distance between the walls which define the channel such that gas at elevated pressure, when introduced into the channel, can cause liquid to move upwardly in the channel and to be removed from the channel. The apparatus may be associated with an electrolytic cell in which a gas is produced by electrolysis. Also, a process for effecting direct contact between a gas and a liquid is disclosed.

Abstract: Diffuser (10) comprising a cylindrical body (11) inside which a helical section (12, 12a) is provided. At the base and at the top, a sparger (13) and a distributor (14) respectively are foreseen. Preferably a second sparger is foreseen at the top, around the distributor (14). Each sparger (13, 13a) consists of a hopper (15) having the major base provided with tongues (16) that radially depart from its periphery. Distributor (14) comprises a truncated-cone portion (24) having the minor base made up of a conical element (25), openings (26, 27) being provided both in the conical element and in the lateral surface of the hopper (15). The diffuser (10) is fixed to a suitable support (22) by means of tie rods (21) held on the protruding edge (18) of the upper sparger (13a).

Abstract: A beverage dispensing system and distributing process with such a system has a flexible bag 1 containing the beverage which may have carbon dioxide dissolved therein. The beverage is drawn off through a pipe 3 (assisted by a pump 8) for dispensing through nozzle 5 having a tap 6. Carbon dioxide, nitrogen (or other inert gas) and/or air gases are introduced into the beverage through a passage 11 by way of a fixed orifice restrictor 12 and a non-return valve 13. The pressure of the gas which is introduced is adjustable at 14 and baffles 15 can provide turbulence in the beverage during dispensing to promote the dissolution of the introduced gas therein.The facility to introduce the gas or gases permits the beverage in the bag 1 to have a low content of carbon dioxide so that the bag collapses under atmospheric pressure while the beverage as dispensed is additionally gasified for the formation of a froth or head.

Abstract: A venturi (eductor) cartridge for injecting and dissolving fluids is installed as a removable insert after a tee, and utilizes an axial aspirator tube and thin-sheet radial diffusion for efficient low-turbulence momentum recovery in a very short distance. The venturi minimizes bubble size and bubble recombination to enable maximum solvation, and is particularly suited for use with corrosive fluids. The venturi exits directly into a tank of fluid or into a standard pipeline.

Abstract: Apparatus for separating contaminant particles from liquid suspension stock, e.g. in the de-inking of used news print, is characterized by one or more of a plurality of features which contribute to increasing the capacity and effectiveness of the apparatus, including the provision of a cell comprising inner and outer annular chambers of substantially equal depth with the inlet and outlet connections for the stock being located adjacent the bottoms of the two chambers to force the stock to travel through the full depth of each chamber, and also the provision of a baffle of substantial width on the top of the wall between the two chambers to spread the stock overflowing that wall into a thin film.

Abstract: A static distributor is provided with a top surface that slopes upwardly from the center port opening through which chlorine dioxide and pulp stock are pumped into a bleaching tower. The upwardly sloping sides of the distributor provide a dish-shaped or concave configuration influencing the flow from the center port opening upwardly and outwardly toward the circumference of the tower. The static distributor is provided with side openings formed by vertical support plates. The vertical support plates are spaced about the circumferences of the concave or dish-shaped flow surface to support the same on a base and change the flow distribution so that a good portion of the flow is radial between the plates rather than vertical. The radial flow is mixed with the flow undergoing upward influence provided by the dish-shaped center portion of the distributor, which causes more complete mixing and the formation of a vortex-type flow in the bleaching tower.

Abstract: A gas bubble generator for mixing or promoting turbulence in a liquid medium, particularly sewage or effluent, comprising a collector for gas which collector is submerged in the medium and has an exit from which leads a pipe with a curved part between the exit and a free end of the pipe from which gas escapes as a bubble to surrounding liquid medium. The free end is spaced laterally from the exit, and curvature of the curved part is such so that there is no obstruction of the pipe by the medium, the curvature forming a circular arc of 135.degree. for example. The exit of the gas collector is preferably aligned with a gas inlet to facilitate cleaning of the pipe in situ (i.e., with the generator submerged) by insertion of a flexible rod-like cleaning tool into the gas supply line, straight through the inlet and the exit, and into the pipe.

Abstract: The gas outlet of a pipe or other sparging device is encompassed by a cover or cap which is located between the gas outlet and the mixing impeller at the bottom of a vessel. The cap is closed at the top and has a side wall so that the gas bubbles disperse around the lower rim of the wall. The wall may be non-symmetric, such as square in cross section, so as to be at different radial positions with respect to the gas outlet. The gas bubbles, even if released in pulses are distributed spatially and in time. The lower rim is preferable serrated (as a saw tooth edge) with the teeth being of different height, thereby further spreading the distribution of the bubbles as they are dispersed. The overlap or distance between the rim and the gas outlet is such that a sufficient quantity of gas is confined around the outlet to damp pressure pulsations when the pressure of the gas at the outlet does not significantly exceed the hydrostatic pressure at the outlet into the liquid.

Abstract: The invention relates to a throttling device for the supply of liquid under high pressure (P.sub.1) having a gas dissolved in it into a liquid of lower pressure (P.sub.O) the device having a supply orifice (2,7) between the high pressure and low pressure side of a dimension which only depends on the required flow capacity as well as downstream of said orifice a free floating body (3,9) of a dimension larger than the orifice (2,7), which body forms a slit (5,10) through which the high pressure flow is deflected into the space of lower pressure, the slit having sufficient length to generate a low flow pressure which, together with the low pressure of the low pressure space, keeps the body in equilibrium with the pressure forces acting at the supply side. The body can have different forms and adjusts itself depending on the circumstances.

Abstract: A gas diffusion system for use in aeration treatment of water, sewage, industrial waste and the like is provided. Gas is released from a lower gas diffuser and rises under the influence of buoyancy and impinges upon an upper gas diffuser having a larger maximum dimension than the lower gas diffuser. In preferred form, a draft conduit is utilized to cause pumping of liquid from the bottom of the liquid tank.

Abstract: The conventional gas scrubbing apparatus includes a tower through which liquid or scrubbing fluid flows in one direction and gas in the opposite direction for contact with the scrubbing fluid. A relatively simple, portable structure includes a casing with a vertical inlet duct in one end thereof for introducing a gas into the bottom of a treatment liquid in the casing; a first inclined baffle extending between the sides of the casing from such one to proximate the other end thereof; a second inclined baffle extending between the sides of the casing from the other end thereof to proximate such one end, the baffles defining a circuitous path for the gas to ensure maximum contact between the gas and the treatment fluid and at least one outlet for the gas in the top of the casing.

Abstract: A gas-liquid mixing process and apparatus having a vessel with an axial flow down-pumping impeller in a draft tube has gas ingestion tubes extending into a body of liquid from a hollow portion of the impeller shaft or other fluid communication means with the overhead gas in the vessel. Upon gas-liquid mixing at liquid levels that interfere with vortex development by the impeller, gas is drawn from the overhead through the ingestion tubes into the body of liquid.

Abstract: A feed gas stream is introduced directly into a recirculating liquid stream so as to facilitate formation and maintenance of gas bubbles in a dispersed form in a recirculating gas bubble-liquid mixture. By the maintaining of a gas-liquid interface and overhead gas phase in conjunction with a quiescent zone of liquid apart from the portion of liquid in which said mixture is maintained in a recirculating flow condition, the loss of appreciable amounts of gas to the overhead gas phase is avoided.

Abstract: Disclosed are methods and apparatus for effecting a selected pattern of fluid flow wherein a first fluid is caused to flow along the surface of a body and a second fluid is caused to flow out of a plurality of holes in the surface of the body. The holes are arranged in a pattern so that the flow of the second fluid creates a baffle to change the direction of flow of the first fluid. The pattern is a grouping of holes wherein the grouping may be a straight line or a helix around a tubular body. The holes are rectangular in cross-section to form a fan-shaped pattern in the fluid passing through the holes. The longitudinal axis of each hole does not intersect the center of adjacent holes.

Abstract: A gas diffuser is provided for water and wastewater treatment. The gas diffuser unit includes a vertical open-bottomed injection pipe extending downwardly and having a plurality of vertical slot-shaped ports adjacent the open bottom. A gas bubble distribution body including a lip portion is located above the open bottom of the injection pipe, and a conical shaped deflector may be mounted on the gas injection pipe above the distribution body. Gas released from the vertical slot-shaped ports forms relatively large diameter bubbles which rise due to buoyancy. The large diameter gas bubbles are broken into smaller diameter gas bubbles and are evenly distributed upon the bottom surface of the gas bubble distribution body above the open bottom of the injection pipe. The lip portion on the gas distribution body promotes turbulence in the rising bubbles, and produces smaller diameter gas bubbles.

Abstract: An aquarium filtration system using airlift to circulate water within the living area to display aquatic organisms, water rising up through the bottom gravel, the gravel providing biological filtration. The living area of the acquarium is free from mechanical obstructions and rising air bubbles. A relatively inexpensive air pump generates the air lift, for circulating water within the living area. Water is removed at the water's surface and thereafter mechanically and chemically filtrated. A protein skimmer device is provided as an integral part of the air lift and mechanical filtration chamber to remove dissolved organic and inorganic compounds.

Abstract: In a water treating device with a water wheel (3) arranged on upper side of an immersion filter bed (4) for performing surface aeration, the immersion filter bed (4) is composed of a plurality of filter bed elements (4a), (4b) including a net-shaped substance (5) as main element, which elements (4a), (4b) are stood in parallel or laminated. In this constitution, the microorganisms are adhered and activated throughout the whole filter bed, and closing due to waste substances is not easily produced, thereby the water treating efficiency is significantly improved.

Abstract: A fermentation vessel comprises an outer shell, and an annular draft tube located within the shell and spaced therefrom to promote continuous circulation of fluids through said draft tube within said shell. The draft tube has an internal cavity located within its walls. The cavity is connected to a fluid supply conduit that extends externally of the shell. A plurality of discrete nozzles are disposed about the circumference of the tube and communicate with the cavity to permit egress of fluids from the cavity to the interior of the shell to promote circulation.

Abstract: An apparatus for aerating water with aeration heads that are fed from a common feed line. In order to achieve an intensive, uniform aeration even when the common line is disposed on an uneven surface, a flexible line is provided as a connection between each aeration head and the common feed line. This connection line can be a rubber hose, and can be relieved from tension by a steel cable.

Abstract: A continuously flowing fluid is processed by being fed to the top of a hydraulic downdraft column (17) which is of a height such that the pressure at the bottom thereof will approximately be at the pressure necessary to create supercritical water conditions. The fluid is conducted to the bottom of the column (17) and received in a reaction chamber (21) in which the majority of the fluid is recirculated around an annular baffle plate (24). The material in the reaction chamber (21) is heated to a temperature above that necessary to create supercritical water conditions by an independent reaction taking place in a heating chamber (32). The result is that the fluid will undergo chemical reactions at the supercritical temperature and pressure range and will be of a lower specific gravity than the unprocessed fluid.

Abstract: A water cooler and carbonator consisting of a water reservoir, apparatus for cooling the reservoir, and a carbonation chamber disposed within the reservoir. Cooled water is transferred to the chamber from the reservoir and a pressure regulated container is used to supply the chamber with carbon dioxide gas, resulting in the production of carbonated water.

Abstract: The tubular arm distributor is provided with at least one tubular arm having metering orifices through which a dispersed phase can be metered and a horizontal box-like element which extends over the metering orifices to define a chamber for receiving the dispersed phase. The box-like element has exit orifices in the form of slots along the side walls to distribute the dispersed phase into the continuous phase.

Abstract: This invention relates generally to the art of gas humidification and more particularly to an improved process for humidifying a gas.

Abstract: An apparatus and method for generating gaseous bubbles in a liquid body comprises a bubble chamber for mixing a pressurized gas with a liquid at a pressure greater than atmospheric and a fine injector tip for releasing the pressurized gas-liquid mixture from the bubble chamber under a high tip velocity and shear. The apparatus is adapted for supplying bubbles to a flotation column for the treatment of mineral ore materials.

Abstract: An improved motionless mixer, referred to herein as a static aerator, for dissolving gases in liquids is disclosed. The static aerator incorporates a helical mixing element in which the pitch of the blade or vane of the helical mixing element decreases continuously along the length of the mixing element. The linear velocity of the flowing liquid is thereby subjected to increasing angular acceleration resulting in centrifugal force against the retaining walls. This additional pressure generated on the liquid increases the amount of gas that may be dissolved in the liquid.

Abstract: A device for continuously introducing a gas into a liquid, in connection with a flotation operation, a deinking unit or the like. The liquid issues from an endless annular gap (6) which does not have any internal obstacles whatever such as boundary walls or the like and, after absorbing the gas, flows into a radial diffuser (14) from which the liquid, enriched with gas bubbles, issues into the treatment container of the apparatus. Therefore, for a treatment tank of circular cross-section, a single gasification device which is disposed centrally in the vicinity of the bottom is sufficient. An optional swirl flow may be produced by suitable deflection in the region of the diffuser or in the chamber for the liquid, which is disposed upstream in the annular gap.

Abstract: A flotation cell featuring a mixing pipe which enters the suspension essentially vertically, follows the point of air intake, and generally receives the entire suspension quantity per flotation cell, the injector of the flotation cell is offset sideways relative to the vertical center axis of the round container cross-section and away from the side on which the foam removal opening and the liquid drain opening are located. The mixing pipe (1) enters the suspension only for a distance such that its discharge opening, mouth (2), is located at least at one-half the height of the level of the overflow edge (7) of the foam removal channel (8), figured from the container bottom. The liquid drain opening (9) is preferably provided in the immediate vicinity of the container bottom, with a cover plate (11) extending across the length of the flotation cell and forming a drain channel (12) into which proceeds the clean liquid through an upper (14) and a lower (13) slot.

Abstract: An orifice device, which includes fluid guidance structure and a flow restriction, for use in a diffused aeration system for treating polluted wastewater is disclosed. The device is inserted directly into the run of a tee-joint which connects a fluid injection pipe to a fluid manifold. The orifice device is provided with fluid guidance structure to reduce fluid turbulence as the flow of fluid changes direction from horizontal to vertical. The orifice device also is provided with an orifice to backpressure fluid and enhance even distribution of fluid among several injection pipes. The upper exterior of the orifice device is threaded to be engageable with the interior of a threaded tee-joint. The orifice device is removeable in order to facilitate cleaning and maintenance of the aeration system.

Abstract: Disclosed is a device for circulating water within a body of water including an inductor and an aspirator disposed inside the inductor. The inductor is partially submerged in the body of water and it has a restricted segment between two open ends. The aspirator is disclosed below the restricted segment in a predetermined position to provide enhanced circulation of water. Specifically, the aspirator provides a cone which fills the restricted segment with a mixture of air and water and the aspirator is positioned relative to the restricted segment so that the point where the cone begins to break apart is at or near this restricted segment.

Abstract: The invention relates to a process and an apparatus for obtaining a gaseous stream containing a compound in the vapor state, more particularly usable for introducing said compound into a vapor phase epitaxy reactor.The process consists of introducing the compound into the first compartment of an enclosure subdivided into first and second compartments by a porous partition, raising to a given temperature the first compound of the enclosure so as to evaporate the compound, circulating within the second compartment a carrier gas able to entrain the evaporated compound and extracting from the second compartment the carrier gas containing the evaporated compound which has diffused into the second compartment by passing through the porous partition.

Abstract: The invention relates to a disperser for a flotation system, in which the stabilizer plates are provided with holes and are offset by a specific angle against the direction of rotation of the agitator relative to a substantially radial position with respect to the agitator. By this arrangement of the stabilizer plates a significant improvement in the selectivity is achieved, particularly in the case of materials which are difficult to prepare.

Abstract: Apparatus for producing and removing dissolved and particulate matter from natural bodies of water and wastewater in situ for the production of organic biomass such as feedstocks, for the removal of pollutants, nutrients, toxins and other substances, and for other purposes. A gas is introduced through a diffuser into a body of water to form bubbles. The bubbles rise within a lifting tube, gathering dissolved and particulate matter on their surfaces. The bubbles produce a foam at the surface of the body of water, the foam being collected in a reservoir, concentrated and drawn off.

Abstract: A continuous ionizer adapted to introduce selected ions into a continually flowing stream of liquid. To ensure that a maximum concentration of ions is incorporated, the continuous ionizer is configured so that turbulent and intimate mixing of the ionizing gas and liquid to be ionized occurs. The flow of ionizing gas is regulated by a liquid level sensor to prevent a gas/liquid mixture from proceeding downstream from the ionizer. The apparatus and method of this invention are particularly suited to situations where deionized water is used in a process which causes undesired static electricity discharges, and clean, ion-possessing water is preferred, such as semiconductor processing.

Abstract: An aerated grit tank is provided having a longitudinally extending control wall dividing the tank into parallel lift and settling chambers. An air discharge apparatus is provided at the bottom of the lift chamber to induce an upward flow of sewage causing a generally helical flow of sewage around the control wall. The control wall is supported in the tank by mechanisms selectively operable to vertically position the wall with a bottom longitudinally extending edge in predetermined spaced relationship to a bottom floor of the tank whereby the velocity of the cross currents may be effectively controlled. One form of the structure has a single control wall unit while a second form of the invention has two wall forming panels with an uppermost panel supported in fixed relationship to the tank and a lowermost panel supported for vertical displacement.

Abstract: In a process for culturing microorganisms in a sealed vessel, the nutrient solution is circulated directionally and the microorganisms are kept in suspension in the moving directional flow. The oxygen-containing gas for aeration of the nutrient solution is run into the solution in such a way that it has a component of motion normal to the direction of flow of the nutrient solution.

Abstract: A method for condensing a gas in a liquid medium to prevent the formation of gas hammer, comprising impinging a gas against a plate at such a velocity so as to cause the gas to fan out in a thin sheet before condensing in the liquid medium.

Abstract: A stripping column is comprised of one or more mixing channels situated in parallel arrangement, each channel in the form of a zigzag strip through which liquid cascades in a series of falls alternating with a corresponding series of pools. Simultaneously, vapor travels upwardly in a counter-current manner, intimately mixing with the liquid when forced through each successive pool. The column is especially useful in separating alcohol from fermented mash. The column is preferably employed with three other identical columns in a parallelogram structure to make a distillation unit of greater efficiency and capacity.

Abstract: Device and method for cleaning waste water, wherein the waste water (19) and oxygen gas (31) are flowing in opposite directions through a cylindrical multireactor (20) having a central rotatable pipe (24), the multireactor comprising a number of bioreactors and at least one separation chamber (75). The average pressure difference between two successive bioreactors is at most seven meter water column. The bioreactors are separated from each other by stationary walls (40, 41, 48, 55, 60), and each bioreactor has its own mixing device (50) for mixing waste water and oxygen gas.

Abstract: An apparatus for contacting fluids combined with solids comprises a cylindrical vessel with a slurry or liquid feed inlet port, a liquid outlet port, a gas inlet port and a gas outlet port. The vessel includes a lower cylindrical baffle which defines a stilling chamber therearound, the main contacting section of the vessel being above the stilling chamber. The lower end of the baffle extends below the liquid outlet port which discharges liquid from the stilling chamber. A cylindrical member is disposed in the cylindrical vessel inwardly of the stilling chamber. It has a lower end which is aligned with the gas inlet port for receiving gas therefrom and an upper end which is higher than a lower edge of the cylindrical baffle. The main contacting section above the cylindrical member has a height which makes a ratio with a length of the cylindrical member having a value within the range between 2 and 50.

Abstract: In the treatment of livestock waste, liquid to be aerated is pumped from a storage container, holding pond or lagoon and drawn through a magnetic air inductor inlet then pumped into a conical chamber towards an outlet port at the narrow end of each of a series of conical chambers. Air is drawn into the chamber by pressure differential and intermingled with the liquid and waste to be treated to hydrolyze the fines as the material passes through the chambers. A conically shaped expansion cone attached as an extension of each chamber outlet port permits further expansion and intermingling of the air and liquid waste mixture. An open-ended sleeve is attached in surrounding relation to the outlet of each discharge cone so that the air/liquid stream from each cone is directed axially through its sleeve, each sleeve having a spiral baffle plate extending along the interior length thereof to further promote agitation of the mixture and most complete aerobic digestion of the fines.

Abstract: Multiphase contacting between gas, solid and liquid phases is effected using a novel apparatus comprising a cylindrical vessel, a draft tube, a conical bottom and a gas-sparger system. Mild and uniform mixing is achieved within the novel apparatus while stagnant zones and zones of high shear within the vessel are eliminated. Gas-liquid mass transfer is achieved at rates comparable to conventional high-shear mechanically-stirred devices while the efficiency of liquid mixing in the vessel is better than conventional low-shear pneumatically-stirred devices. The apparatus is preferably used in fermentation processes.