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: 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.

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: A multiple hydrocyclone device wherein cyclone units are integrally formed in radial relationship in premolded discs which are mounted in stacked concentric and internested relationship one upon the other within a common housing. The hub portions of the discs provide a central chamber to receive the underflow fraction from the cyclones with the overflow discharged from openings in the periphery of the discs to an outer chamber. Sealing rings are arranged between the internested discs to maintain leak proof integrity of the stacked discs with spring urgent thrust plate means disposed at the top of the stack to permit movement or expansion of the discs in operation of the device without disturbing the sealed relationship.

Abstract: Moist combustible matter is burned in a combustion zone following a drying treatment in which the combustible matter is brought into contact with hot, inert particulates circulated from the combustion zone. The water in the combustible matter is evaporated at a relatively low temperature in the drying zone, thereby conserving heat in the system. The exhaust gas stream from the drying zone is handled separately from the reactor exhaust gases to condense the water vapor therein, the water is removed from the process and the remaining gas is subjected to odor-destroying high temperature.

Abstract: A process for dewatering a suspension of solids in an electric field controllably maintained between opposing electrode structures, causing the solids to migrate relative to the carrier liquid to form a layer or cake on one set of electrode structures while withdrawing carrier liquid under vacuum in the opposite direction through the liqid pervious wall of hollow, counterelectrode structures. A selected electrolyte is pumped through the hollow electrode structure on which the cake is formed to continuously bathe the electrode element therein in said electrolyte. Vacuum is applied to the electrolyte in said electrode structure to remove gases evolved at the electrode element. The cake material is detached from the electrode structure and recovered.

Abstract: A starch wet milling process, in which a series of independent classifications and separations is carried out in the production of starch, employs a Starch Gluten Separation Station having a three-stage centrifugation treatment including passing the entire mill stream through a mill stream centrifuge thickener, followed by primary starch centrifuge separation and gluten centrifuge thickening.

Abstract: A rotary vacuum disc filter having a rotatable center shaft assembly mounting a plurality of filter discs each comprised of a like number of removable filter sectors aligned in horizontal rows, with each row connected to one of a plurality of longitudinally extending filtrate channels in the center shaft assembly wherein the outlet port of a selected channel at one end of the center shaft assembly may be selectively closed by a removable sealing plate to cut off flow from such channel.

Abstract: Flow distribution means for a dewatering screen comprising a nozzle assembly having a rotatable valve and housing assembly extending transversely of the feed end of the screen. Manual or automatically operable actuator means are interconnected to the valve for controlling movement thereof to vary the size of the spout opening of the nozzle and for providing rapid opening of the spout for purging the nozzle assembly.

Abstract: A flow distributor for a fluid bed reactor includes means for decreasing velocity of incoming liquid streams in a uniform, non-turbulent fashion. Inlet ports communicate with fluid portals having divergent walls to slow incoming flow. The fluid portals feed liquid flow to a plurality of diffusing flow paths provided between diffusion baffles positioned at the bottom of the reactor. The diffusion baffles may be prismatic shapes which are trapezoidal in cross-section with the broadest horizontal dimension at the bottom thereof. The diffusion flow paths therefore have divergent walls and act to further slow the liquid flow passing therethrough.