Abstract: A fluidized bed process heater with a reaction chamber of toroidal configuration is provided with radially-oriented bed coils in the reaction chamber in which steam is generated or other process fluids are heated. The inner wall of the toroidal reaction chamber is water-cooled and the bed coils in the reaction chamber are removable. The return bends of the coils are protected against erosion from particulate bed solids.

Abstract: Porous, moisture-containing materials are dried in a fluidized bed reactor. The moisture content of both the underflow and carryover products from the dryer are controlled by introducing hot gases into the freeboard region above the fluidized bed. One or more tuyeres of extended length with ports at a level above the fluidized bed in the freeboard regin may be employed to admit hot gases directly into the freeboard region from the reactor windbox without traversing the fluidized bed. Alternatively, a valved conduit may be employed extending through the refractory dome or gas distributor to regulate gas flow between the windbox and the freeboard region.

Abstract: Beneficiation of phosphate rock containing limestone is accomplished by calcining, cooling, slaking and separation of the slaked lime from the phosphate rock product. The cooling, slaking and separation operations are conducted in a fluid bed reactor.

Abstract: A refractory constriction dome for a fluidized bed reactor is constructed to resist the upward thrust of pressure in the windbox as well as the weight of the fluidized bed. A reverse arch of refractory brick or tiles, forming the upper surface of the dome, is the structural feature which functions to resist upward thrust.

Abstract: A nozzle type centrifugal machine designed for two-fraction separation of feed slurry, wherein the rotor has a light fraction overflow at the top, while feed slurry as well as underflow return slurry from the nozzles are introduced into the rotor from below into respective feed accelerating pumping chambers, and wherein improvements in the pumping chambers results in reduced power requirement and in improved overall performance of the machine.

Abstract: Sedimentation apparatus which employs an agitator-equipped mixing tank for a feed suspension and a flocculating agent or flocculant, which mixing tank is located within the central feed well of a continuously operating sedimentation tank, and wherein the flocculant-treated feed suspension overflows the top end of the mixing tank, then to continue along a downward path in the surrounding feed well of the tank.

Abstract: Alumina-cryolite waste from aluminum pot lines is subjected to oxidation in a fluidized bed reactor to remove carbon and organic contamination. Agglomeration of the alumina-cryolite product occurs in the fluidized bed and a pellet product suitable for return to the aluminum pot lines is produced.

Abstract: In a continuously operating square settling tank, the provision of scum skimming devices wherein a pivotally mounted corner exploring skimmer member is swingable in a predetermined horizontal plane, while kept in contact with the peripheral scum baffle during rotation of the supporting rake structure. This skimmer member forms with the scum baffle a scum collecting pocket whereby when the thus collected scum is pushed up along the slope of a ramp, it is trapped and thereby contained on the ramp for delivery into a receiving box connected to the ramp.The scum collecting effectiveness of the skimmer member may be enhanced by the additional provision of a directional skimmer blade cooperatively so related to the swingable skimmer member, that floating scum material is thereby guided into said collecting pocket.

Abstract: A method of, and a system for, processing or treating raw sugar juice wherein raw sugar juice produced in a crushing mill is delivered to a first section of a partitioned surge chamber from which section it is withdrawn and subjected to a degritting process in one or more cyclone separators, the juice which is relatively free of heavy solids being subsequently delivered to a second section of the partitioned surge chamber from which section it is withdrawn for clarification in a clarifier and from which clarifier mud is withdrawn for subsequent treatment in one or more centrifugal separators, the removal of heavy solids, such as dirt and grit, during the degritting process being such as to reduce wear and erosion of the components in the centrifugal separators for processing the clarifier mud.

Abstract: A fluidized bed incinerator is provided with feed pipes which are downwardly directed or vertically oriented and have access to the reaction chamber. Secondary air is introduced into the reaction chamber at a point above the fluidized bed through pipes which are concentric with the feed pipes and spaced therefrom in surrounding relation to define annular air passageways. Air passing into the reaction chamber through these passageways provides an air shield about the feed pipes.

Abstract: A fluidized bed waste incinerator is operated with a space rate such that essentially the entire reactor chamber is occupied by a dilute fluidized bed. Particulate solids elutriated with the exhaust gases are returned to the reactor chamber to thereby conserve the heat generated in the reactor chamber.

Abstract: Heat exchanger tubes exposed to high-temperature gases from which dust or scale is deposited on the tubes are subjected to forces applied at the resonant frequency of the tube array to remove deposits on the tube surfaces.

Abstract: Phosphate rock is calcined under conditions calculated to completely oxidize the carbon and sulfur in the rock. Calcination is also conducted at elevated temperature to eliminate cadmium metal, a poisonous substance in fertilizers, from the calcined rock product. A fluid bed system for eliminating cadmium metal in the calcination of phosphate rock involves a two-vessel system in which an independent cadmium removal vessel served by a separate fluidizing air stream carries out volatilization of cadmium, while preheating, precalcining and cooling is conducted in another multi-bed reactor which is served by a separate fluidizing air stream.

Abstract: A process and apparatus for economically removing algae producing phosphorus, from sewage by separating sludge from the sewage, recirculating the sludge, mixing into this the lime needed to bring the pH up to 11.0 or more and then mixing the limed sludge with the raw feed to a pH of 10.5 or under to precipitate more phosphorus from the total flow than would result from an equal amount of lime fed directly into the total flow. This result is also obtained by splitting the feed and heavily dosing one part with lime before returning it to the remainder of the feed.The high pH reached in the heavily dosed part also produces a water softening effect, which makes the sludge easier to dewater and the effluent more acceptable for discharge or reuse. Additional precipitation is economically secured by mixing polyvalent metal salts or polyelectrolytes with the lime treated waste material before separation of the lime sludge from the waste material effluent.

Abstract: A continuously operating Sedimentation Tank having a Rotary Rake Structure equipped with sludge engaging blade means constructed and arranged so as to induce thin sludge or supernatant from an upper or superjacent zone to enter the bottom zone of a bed of packed sludge solids, thereby reducing friction between the mass being moved by the blades and a layer underneath of residual material on the tank bottom, thereby reducing the torque requirement of the rake structure for moving the sludge.

Abstract: A nozzle type centrifugal machine with provision for light and heavy phase overflow delivery from top and bottom respectively of the rotor bowl, and equipped with control devices operable for correctively shifting the location of the interface within the limits of the centrifugal separating zone located within the area surrounded by a stack of separating discs.

Abstract: Continuously operating sedimentation tank wherein a load yieldable composite rotary rake arm structure is constructed and arranged to conform to the compound slope of the tank bottom, while being dragged over the tank bottom by draft means connecting it to a driving arm spaced upwardly from the rake arm structure.

Abstract: Hot gases for fluidizing the preheat compartment of a multi-bed fluid bed reactor are cooled by injection of water, or cool air and water, to reduce scaling of the ducts, hot cyclone, hot windbox and the tuyeres in the constriction dome separating the hot windbox from the preheat compartment.

Abstract: Apparatus for removing grit and fiber from waste activated sewage sludge prior to introduction into a centrifuge for further separation. Grit removal is accomplished by hydrocyclones and fiber removal is carried out on a 300.degree. screen. The hydrocyclones and screen, together with connecting conduits, are conveniently mounted on a supporting frame for facilitating transportation of the unit and for maintaining the predetermined structural relationships of the various members.

Abstract: In a membrane separation device means for mounting a semi-permeable membrane separation unit on the sidewall of a casing including a plug member and releasable interlocking means for interconnecting the plug and separation unit to the sidewall with the plug member including permeate outlet means for discharging permeate from the separation unit.