Abstract: A nozzle type centrifuge having a bottom feed inlet to a main pumping chamber at the base of the machine for injecting the feed slurry to a rotor bowl having separator discs for effecting a two-fraction separation comprising an overflow at the top and an underflow at the peripheral mid portion of the bowl with a portion of the underflow delivered to a return pumping chamber beneath the main pumping chamber and seal means between said chambers to prevent dilution of the underflow fraction.

Abstract: A flotation separation cell is disclosed having a rotor-stator pump assembly wherein a rotor body comprises integrally formed hub, blade and top plate members. These members form a gas chamber in an upper sector of the rotor. The blades are curvilinear and of parabolic or vortex shape. A gas stream which is conveyed to the gas chamber is discharged from the gas chamber in a transverse direction and flows in gas pockets along surfaces of moving blades for dispersion in a slurry.

Abstract: A strong, relatively inert filter cloth is impregnated with an ion exchange resin to provide, for an electrofiltration process, a reinforced solid polymeric electrolyte having ion transport properties and at the same time constituting a positive barrier to mass transport.

Abstract: A cam-actuated stop member in an electrode stripping mechanism prevents any lifting of the electrode away from the hooked lifting elements during lowering of the electrode against the doctor blades and so avoids damaging the electrode and/or lifting elements by dropping the electrode after doctoring.

Abstract: Sulfur-containing atmospheric pollutants are effectively removed from exit gas streams produced in a fluidized bed combustion system by providing a fluidized bed of particulate material, i.e. limestone and/or dolomite wherein a concentration gradient is maintained in the vertical direction. Countercurrent contacting between upwardly directed sulfur containing combustion gases and descending sorbent particulate material creates a concentration gradient across the vertical extent of the bed characterized in progressively decreasing concentration of sulfur, sulfur dioxide and like contaminants upwardly and decreasing concentration of e.g. calcium oxide, downwardly. In this manner, gases having progressively decreasing sulfur contents contact correspondingly atmospheres having progressively increasing concentrations of calcium oxide thus assuring optimum sulfur removal.

Abstract: A system for the comminution of coal, slurry formation and feed of the coal slurry to a fluidized bed reactor.

Abstract: An ultrafiltration step is used in the production of cream cheese to provide a cheese pre-mix which is cultured to form cream cheese without generating whey. The raw materials for this process include whole milk, cream and whey protein solids. The whey protein solids are substituted for the skim milk powder formerly used. Ultrafiltration yields a retentate having the butterfat and non-fat solids content required for cream cheese manufacture.

Abstract: A fluid bed heater or vaporizer unit has a generally cylindrical configuration with its major axis horizontally disposed. A mixture of coal and limestone is fed into the elongated fluidized bed within the unit for combustion; the limestone being present to minimize sulfur emissions due to the sulfur present in the coal. The wall of the unit in the region of the freeboard is lined with horizontally disposed heat exchange tubing. The delivery of air to the fluidized bed is regulated so as to establish a combustion zone of high turbulence and one or more heat transfer zones of lower turbulence. A plurality of heat exchange tubes are located in the heat transfer zone or zones and within the expanded bed level of the fluidized bed but above the region occupied by the slumped bed. Economizer heat exchange coils may be located in the passageway for exhaust gases.

Abstract: In the alkaline digestion of silica-contaminated paper pulp raw material, an addition of aluminum oxide in the form of bauxite ore is made to the liquor, the aluminum oxide being present in the bauxite as a hydrated oxide such as Al.sub.2 O.sub.3.H.sub.2 O or Al.sub.2 O.sub.3.3H.sub.2 O, to insolubilize silica as a sodalite precipitate, and thereby minimize scaling evaporation, avoid undesirable increase in the viscosity of the liquor, as well as assuring recovery of lime by avoiding formation of calcium silicate during causticizing.

Abstract: A corner sweep mechanism for a square shaped settling tank and which mechanism is pivotally connected to the end of a main rotary rake structure and comprises a lightweight buoyant frame structure which includes a rake or sweep arm adapted to be extended into the corner areas of the tank bottom under the control of a tension spring without the use of counterweights during rotation of the main rake structure.

Abstract: A fluidized bed reactor is provided with heat exchange coils for controlling the temperature of the fluidized bed, with only vertically oriented sections of the coils exposed to the erosive conditions in the fluidized bed. The vapor-liquid circuit, of which the heat exchanger coils are a part, is arranged to operate on the principle of natural circulation. At least some of the tuyere elements discharge fluidizing gas at a level substantially above the constriction plate and the bed solids below the level of the tuyere gas discharge constitute a static layer during fluidization in which the lower angle bends of the heat exchange coils are embedded and so shielded from erosion by the fluidized solids of the bed proper. The static layer of bed solids also accommodates thermal expansion of the lower angle bend due to elevated temperatures and insulates the constriction plate from the high temperatures in the reactor.

Abstract: In order to increase or maintain the capacity of fluid bed calciners in the calcination of phosphate rock containng large amounts of organic matter ("hot rocks"), the calciner is modified to permit a pyrolysis reaction to occur in the freeboard zone of the calciner. The hydrocarbons and carbon monoxide gas produced by the pyrolysis reaction are removed from the calciner and burned in an afterburner unit. Dust and fines entrained in the exhaust from the calciner are sent to a dust oxidation chamber outside the calciner for oxidation by addition of air.

Abstract: An electrode assembly for use in dewatering a suspension of solids in which an electric field augments an applied vacuum includes a chamber having ion-pervious walls on which a cake of solids is deposited and an electrode element within the chamber immersed in an electrolyte; the surface area of the ion-pervious walls being substantially greater than the surface area of the electrode element.

Abstract: An ultrafiltration membrane assembly comprising an ultrafiltration membrane, a coarse fabric drainage mat and an impervious backing plate are heat sealed at the edges of the assembly.

Abstract: A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

Abstract: A drainage deck assembly for a rotary vacuum drum filter having filtrate compartments on the outer surface of the drum comprised of premolded interlocked grid sections formed with integral baffle walls for directing the flow of filtrate outwardly of the filtrate compartments and which grid sections are provided with rows of filtrate receptacle trays in the surface thereof having bottom walls formed with filtrate discharge slots located at a position to prevent return flow of filtrate to the receptacle.

Abstract: A sedimentation tank having a central feedwell comprising upper and lower cylindrical channels or raceways for receiving the influent feed in split counter rotative streams wherein an intermediate raceway is provided between the upper and lower channels for receiving a flocculant for mixing with the influent feed in the shear zone where the split streams remerge.

Abstract: An ultrafiltration membrane assembly comprising an ultrafiltration membrane, a coarse fabric drainage mat and an impervious backing plate are heat sealed at the edges of the assembly.

Abstract: An apparatus and method for improving the settling out of suspended solids in a liquor are described. A diffuser of a particular type is used to introduce a liquor containing a flocculant suspension into a sedimentation tank with low turbulence. The diffuser is so shaped that the liquor velocity can be reduced in a controlled manner. Liquid shear conditions are made so low inside the diffuser that excessive break-up of flocs does not occur. The diffuser has a flare angle and a discharge opening to throat dimensional ratio whereby these conditions of low turbulence and formation can be established. Several embodiments of sedimentation apparatus employing such diffuser are described.

Abstract: In order to increase or maintain the capacity of fluid bed calciners in the calcination of phosphate rock containing large amounts of organic matter ("hot rocks"), the calciner is modified to permit a pyrolysis reaction to occur in the freeboard zone of the calciner. The hydrocarbons and carbon monoxide gas produced by the pyrolysis reaction are removed from the calciner and burned in an afterburner unit. Dust and fines entrained in the exhaust from the calciner are sent to a dust oxidation chamber outside the calciner for oxidation by addition of air.