Abstract: A heater for a grain bin is attached to the inlet flange of a centrifugal inline blower and comprises a housing having a vertical front wall attached to the inlet flange of the blower and a parallel vertical rear wall. The front wall has an opening aligned with the opening into the blower. The rear wall has an opening aligned with the opening in the front wall so that the majority of the air entering the blower passes straight through the housing from the rear wall to the front wall. A sleeve surrounds the opening in the rear wall and induces some flow from the housing to mix with the flow into the blower. The combustion chamber is attached to the rear wall through an opening in the rear wall above the sleeve. The housing has two side walls converging to an open top through which air can escape. When heated air is required an air flow is induced from the combustion chamber to mix with the air flow through the housing to heat the total air flow.

Abstract: A method for providing higher yielding seed corn comprising a single-pass, reversing, high air velocity process. Another aspect of the invention concerns a conversion panel for converting a dual-pass seed corn drying system into a single-pass system.

Abstract: A method and apparatus for treating cullet before use as a raw material in a glass manufacturing process is disclosed. The method includes providing a bed of cullet; passing hot gases through the bed, the quantity and temperature of gases being sufficient to pyrolyze odor creating impurities within the bed of cullet; entraining volatile products of pyrolysis into gases leaving the moving bed; heating the gases leaving the bed to oxidize odor creating impurities; and discharging the gases to the atmosphere. The apparatus includes a housing containing a moving bed of cullet; a source of hot gases which permits the gases to pass through the moving bed of cullet to pyrolyze odor creating impurities within the cullet and entrain volatile products of pyrolysis into gases leaving the moving bed; and an incinerator to remove odor creating impurities from gases leaving the moving bed.

Abstract: A substrate drying apparatus includes a process bath having an object containing region for containing an object to be treated, a treatment liquid containing region for containing a volatile treatment liquid, and heating member for evaporating the treatment liquid, a receiving container, provided below the object containing region, for receiving water removed from the object with use of the evaporated treatment liquid, an exhaust pipe, attached to the container, for exhausting the water from the container to the outside of the process bath, and a cooling device, provided above the object containing region of the process bath, for condensing the evaporated treatment liquid, wherein the exhaust pipe has a valve and a branch pipe branched from the exhaust pipe such that the branch pipe is closer to the container than the valve is.

Abstract: A flowable solid material, such as wet-milled corn germ, is continuously fed into the upper portion of a large vessel having a cylindrical shell with a vertical axis and a series of vertically spaced horizontal decks. Each deck has concentrically spaced annular zones of holes or perforations, and heated air from a set of blowers and a gas-fired or steam heat exchanger is forced countercurrently or upwardly through the perforations to produce a recirculating bed of material above each deck with an upward spouting flow of the material above the zones of perforations and a downward flow of material between the zones of perforations. The recirculating material forming the lower beds is also heated by cylindrical steam heat exchangers which extend vertically between the zones of perforations, and the material is fed progressively downwardly through the vessel to form the beds and for discharge from the lowermost bed.

Abstract: A flowable solid material, such as wet-milled corn germ, is continuously fed into the upper portion of a large vessel having a cylindrical shell with a vertical axis and a series of vertically spaced horizontal decks. Each deck has concentrically spaced annular zones of holes or perforations, and heated air from a set of blowers and a gas-fired or steam heat exchanger is forced countercurrently or upwardly through the perforations to produce a recirculating bed of material above each deck with an upward spouting flow of the material above the zones of perforations and a downward flow of material between the zones of perforations. The recirculating material forming the lower beds is also heated by cylindrical steam heat exchangers which extend vertically between the zones of perforations, and the material is fed progressively downwardly through the vessel to form the beds and for discharge from the lowermost bed.

Abstract: An apparatus for drying a moist particulate material having a nonuniform particle size with superheated steam, which apparatus comprises a cylindrical vessel (2) comprising a number of parallel, substantially vertical elongated chambers (6) located in ring form, one or more of the chambers (7) having a closed bottom and the remaining chambers having a steam-permeable bottom (8), wherein means for emitting flows of superheated steam substantially parallel to the chamber bottom (8) are located at the lowermost portion of at least some of the chambers (6) having steam-permeable bottoms (8).

Abstract: An apparatus for drying a moist particulate material having a non-uniform particle side with superheated steam includes a cylindrical part wherein a number of parallel, substantially vertical elongated chambers is located in ring form, one or more of the chambers having a closed bottom and the remaining chambers having a steam-permeable bottom, the adjacent chambers being interconnected, and an upper conical part which is also divided into chambers and which at a lower end is connected with the chambers of the cylindrical part of the apparatus, the chambers of the conical part of the apparatus being divided into smaller chambers by inclined guide plates, wherein at least part of each of the inclined guide plates in the conical part of the apparatus is hollow and can be heated by supplying superheated steam hereto.

Abstract: An apparatus for drying bulk materials such as plastic granules which includes a substantially cylindrical hopper having a funnel-shaped bottom, a filler spout for feeding bulk material to the hopper, an air inlet with an injector tube for introducing heated dry air into bulk material situated in the hopper, a bulk material withdrawal system with a conveying duct connected to it through which the bulk material is carried to further processing, a temperature measuring system is disposed in the cylindrical portion of the hopper which measures the temperature of the bulk material, and a device which, when the measured temperature falls below a predetermined limit, either sounds an alarm or decreases or interrupts the discharge of bulk material to prevent discharge of inadequately dried material.

Abstract: The application describes a drying process and a fully electric drying device consuming from 80 to 140 KWH of electricity per ton of water evaporated. One and the same drying fluid (air, gas or steam) saturated with steam at a temperature of .THETA.0 rises, gradually becoming laden with steam, after each of the numerous fluidized drying stages for granulous products descending in the opposite direction. Between each drying stage, the drying fluid is superheated by crossed tubes (14) maintained at a temperature .THETA.2 approximately 20.degree. C. greater than .THETA.0 by condensation (at 28) of the same steam compressed from .THETA.0 to .THETA.2, or by the condensation of auxiliary steam evaporated at .THETA.0-5.degree. C. by condensation of the vapors formed by the drying process.

Abstract: A grain column dryer which includes two concentric, cylindrical pervious walls and a pervious cone on top of the inner pervious wall, utilizes an impervious, heat insulated, cylindrical outer wall spaced outwardly from the pervious walls. A heater/blower assembly is supported on a substantially airtight impervious bulkhead in the center of the dryer to force heated air into an upper heated plenum and out through the concentric pervious walls and the pervious top cone, and to thereby draw air through lower portions of the pervious walls. A hottest air recycle collar is attached to the outer pervious wall above the bulkhead baffle and extends, in spaced relation to the outer pervious wall and to the outer impervious wall, to position well below the bulkhead baffle.

Abstract: A method, apparatus and system for use in drying particulate matter employing a drier comprising a cylindrical upper section, a frustoconical lower section, a rotatable shaft extending substantially the entire length of the interior of the drier, a plurality of axially spaced arrays of circumferentially spaced, radially extending stirring arms appended to the shaft, and at least two perforated frustoconical separators mounted within the drier in fixed, inverse and spaced apart relation to each other, and means for introducing a heated gas into the drier for contacting and drying the particulate matter, the stirring arms and separators cooperating to retard agglomeration of the particulate matter.

Abstract: Liquid is evaporated from a particulate solid material by passing the material through a row of upwardly open, elongated interconnected cells and introducing superheated steam into the cells at their lower ends in a manner so as to impart to the particles a whirling movement. Dried particles are lifted out of the cells and into a common transfer zone and from said zone down into a discharge cell which has no steam supplied thereto. The dried material thus introduced into the discharge cell is discharged together with material which has passed the row of cells.The invention eliminates the need for effecting an initial disintegration of the solid particulate material.

Abstract: A food warming apparatus is provided with a cabinet defining a food treatment space and a food storage space above the food treatment space and in communication therewith. A wall at the bottom of the food treatment space supports a supply of food. Structure is provided to gain access to the food storage space to introduce a food supply and separate structure is provided to gain access to the food in the food treatment space for removal of the treated food. Heat is directed in a circulating path upwardly through food at one portion of the treatment space and downwardly through food in another portion of the treatment space.

Abstract: The present invention relates to an improved method and system for properly and uniformly distributing fluids in upright vessels commonly called vertical shaft kilns or retorts. The distributors disclosed have a unique shape to facilitate movement of particulate matter passing by them and in addition have orifices which are recessed to keep each orifice free of solids with varying sized orifices as needed to provide the flow distribution uniformly across the lateral extent of the retort. Further the distributors are supported at each end by and protrude through nozzles built into the vessel shell to supply connection for external piping. The supports are so formed as to provide for thermal expansion through fluid-tight closures during high temperature operation.

Abstract: The invention relates to a method and means for cooling lump material in which the material in a vertical, gas-tight cooler (1) is subjected in a furst step to a transverse cooling flow (at 9) and in a second step to counter-flow cooling (at 20). Optimal cooling effect is obtained by a distribution of the cooling gas between transverse and counter-flow cooling in such a way that maximum temperature is obtained in the cooling gas leaving through the outlet (13).

Abstract: An apparatus for drying and powdering liquid radioactive wastes produced in radioactive material treating plants such as nuclear power stations comprising a vessel having liquid material inlet and outlet ports for liquid wastes, a support plate arranged in the vessel, a great number of spherical bodies piled in layers on the support plate, stirring means having stirring blades for rolling the spherical bodies, and heating means for heating the spherical bodies. An induction heating coil may be used as the heating means, when the spherical bodies are conductive. If electric resistance heating means is used, the spherical bodies are non-conductive. Hot air can be used for heating the spherical bodies. The electric resistance heating means consists of a plurality of resistance heaters one above the other around the vessel. The support plate is formed with slits concentric to each other and the stirring means is provided with pins rotating therewith and extending into the slits.

Abstract: An improved hopper drier for drying granular material of synthetic resin to supply it to a molding machine. The hopper drier includes two dehumidifying columns which are arranged such that dry air dehumidified in one of the dehumidifying columns at a lower temperature is delivered to a heating pipe spirally wound round the heating column disposed adjacent to the hopper drier housing. After air is preheated in the heating pipe, it is mixed with waste air coming from the hopper drier housing and the mixture is then heated in the heating column. While the one dehumidifying column is operated under normal working conditions, the other dehumidifying column is supplied with a part of the dehumidified air flowing from the one dehumidifying column so as to dry dehumidifying material held in the other dehumidifying column.

Abstract: Method for drying damp material by vapor recompression. The vapor (8) released by the damp material (4) circulating on the heating elements (2) of a vertical dryer is recompressed by means of a motor-compressor (9) so as to provide the heat-conveying fluid to the heating elements (2) of the dryer. Application to the drying of damp vegetables.

Abstract: In order to ensure, in a method for extracting gases and vapors from plastics granules and powders which are being pre-heated and dried in a drying hopper by a stream of dry air flowing into the lower region of the hopper while the outlet air is extracted from the hopper above the granules, that also that part of the plastics granules which is in the lowermost region of the drying hopper is reliably dried and warmed, the method provides that a portion of the stream of dry air is guided in a direction opposite to that of the main stream and is extracted at the lowermost point of the hopper. A drying hopper for plastics granules is suitable for carrying out the method according to the invention which has in its upper part a feeding opening for the granules and an air outlet pipe, and further has a lower outlet port for the granules and an air inlet pipe which ends inside the hopper in an air distributing opening, wherein a second air outlet pipe is mounted in the hopper near the outlet port.

Abstract: The exhaust air from a bulk material drying hopper is conveyed through a chamber filled with an adsorbing medium and the air is fed back to the drying hopper in a closed circuit. The chamber is regenerated at intervals by a counterflow of drying gas. The frequency of regenerating the chamber is controlled as a function of the temperature of the exhaust air.

Abstract: The object of the present invention is a modular drier.Each module comprises two fans each supplying a common diffusion chamber (14) disposed between two columns of a group of columns (12, 13). Said chambers (14) adjoin a perforated wall of said columns comprising vertical deflectors, with the opposite wall of these columns, likewise perforated, communicating with a common chamber (15) for exhausting the air used for drying.The invention relates to a modular drier for drying grains, in which gravity draws the grain down in parallel sheets within vertical columns crossed horizontally by the drying air.

Abstract: A method and apparatus for cooling hot bulk material in a cooling bunker by passing cooling gas streams therethrough in a manner such that the bulk material is cooled in a uniform manner while avoiding temperature fluctuations of the outflowing heated cooling gas. The cooling gas is passed through the hot bulk material in at least two gas streams, one of which is directed through a core zone of the hot bulk material and another of which is passed through a peripheral zone thereof. The flow rates of the respective cooling gas streams are regulated according to the temperature of the outflowing heated cooling gas which may be sensed by the temperature of a fluid flowing through heat exchanger over which the heated cooling gas passes.

Abstract: The exhaust air from a bulk material drying hopper is conveyed through a chamber filled with an absorbing medium and the air is fed back to the drying hopper in a closed circuit. The chamber is regenerated at intervals in a second circuit. The air throughput through the hopper is controlled as a function of the temperature of the exhaust air.

Abstract: A grain drier system is disclosed which includes means for collecting heated air which has passed through grain and conducting it to the inlet of the burners which supply the heated gas to dry the grain. The collected air is introduced into the inlet of the burner at the periphery of the air stream to the burner in an area where the contact between the collected air and the flame of the burner is minimized. This procedure enables the heat of the collected air to be utilized without the likelihood of subjecting any entrained material to the action of the flame of the burner.In order to further minimize the possibility of fire, prior to being conducted to the burner, the collected air is passed into a plenum where the velocity of the stream of collected air is decreased and its direction of movement changed so that a substantial portion of entrained dust and organic material is caused to fall out of the air stream.

Abstract: A cross flow grain drying and conditioning apparatus having an improved grain column configuration wherein the thickness is narrower at the top and bottom thereof than at an intermediate portion thereof for optimumly confining the grain to be dried. A single blower operates to force heated drying air through a first zone of the column of grain and to pull cooling air through a second zone or alternatively to push heated air through both the first and second zones by opening or closing a plenum divider which can be closed to define the zones or opened to combine the zones.

Abstract: In apparatus and method for treating granular product within a cylindrical chamber as the product, by the force of gravity, falls through a plurality of regions maintained at varying temperature and pressure. Structure formed by at least a pair of collectors is connected tangentially to a housing surrounding the regions to withdraw gas from and reintroduce gas to the cylindrical chamber. Particularly gas is withdrawn from a lower region, treated by heating and dilution with flue gases prior to reintroduction. Movement of gas is provided by a ventilator which serves to draw fresh air into the cylindrical chamber from the vicinity of the lower region. The flow of gas, the temperature of the gas, and the pressure within the regions result in granular product first moving counter to the flow of gas, then with the flow of gas, and then counter to the flow of gas. The granular product is heated, maintained at a heated temperature, and cooled within these flows.

Abstract: Structure is provided defining a flow path for granular materials to be dried and laterally through which drying air may be passed. The flow path includes inlet and outlet end portions and supply means is provided for supplying granular material to the inlet end portion and discharge means is provided for discharging granular material from the outlet end portion. Air passage structure is provided including means for passing heated drying air laterally through the inlet end portion of the flow path and cooled drying air laterally through the outlet end portion of the flow path. The air passage structure includes a substantially closed loop circuit and pump structure for pumping air through the circuit.

Abstract: There is a disclosed a process and apparatus wherein a solvent-enriched material is introduced into a desolventizer-toaster tower to form a desolventized material which is introduced into a dryer and heated in the absence of air to form a dried material and a vapor steam including solvent which is compressed and passed to the desolventizer-toaster tower to provide all or a portion of the sparger steam requirements therefor.

Abstract: An apparatus for preheating and drying a granulate (43) comprises an inlet (61), a discharge (3a, 3b), a blower (10), air guide pipes (9, 15, 16, 19, 23, 24, 25, 31), a valve (11), and a heater. For creating three air circuits, an adjustable, multiport valve and a reversible blower (10) are provided. In each position, air from the blower passes in two directions through said multiport valve (11). The apparatus comprises a heat accumulator (161). The first circuit dries the granulate (43), the second circuit regenerates a humidity adsorbing material, and the third circuit transports material to the drier. The accumulator (161) preheats air during the regeneration, re-uses accumulated heat from said regeneration during the granulate drying cycle. The multiport valve is adjustable to various positions, gas in each position being directed along two paths through the valve.

Abstract: A plenum drying hopper for granular material includes a housing enclosing a plenum chamber, an upper material inlet for introducing a flow of granular material into the plenum chamber, and a perforate diffuser cone, located in the lower portion of the plenum chamber, that directs the granular material from the plenum chamber into a material outlet. The perforations in the diffuser cone are large enough to permit ready passage of gas therethrough but small enough to preclude passage of all but the finest particles of the granular material. A gas inlet extends into the lower portion of the housing for introducing a drying gas (air) into the plenum chamber; a gas outlet discharges the gas from the upper part of the housing. Heaters are provided for heating the gas prior to its entry into the plenum chamber.

Abstract: This invention relates to an apparatus for effecting the uniform pre-heating of thermoplastic parisons of the type that are introduced into a blow molding machine for fabrication into a blow molded article. The invention provides a hopper which is intermittently supplied with batches of parisons and through which the parisons move by gravity. A convection heating zone is provided in the hopper to uniformly heat each parison passing therethrough, and a temperature equalization zone is provided adjacent to the heating zone. The parisons are removed from the temperature equalization zone by a continuously moving parison conveyor which forms part of the temperature equalization zone.

Abstract: A grain drying and conditioning apparatus having a housing with an outer pervious skin with impervious end walls, air inlet, grain inlet, grain outlet and air exhaust duct structures connected thereto has air pervious walls which are spaced within the structure for confining a column of grain to be dried. A blower and heater mechanism is also connected to the housing for causing heated air to be forced through a first zone of the column of grain in one direction to heat and extract moisture therefrom and simultaneously causing air for cooling the grain to be pulled through a second zone of the grain column in an opposite direction, or, by simple adjustments, to be pushed in the same direction as the flow of the heated air.

Abstract: A recycle control is provided for grain dryers of the type which have a drying column area with heating and cooling zones and a recirculating air blower. During a recirculating mode of the grain dryer, the recirculating blower draws in a mixture of cooling air and heating air from the cooling and heating zones respectively and forces the mixture after additional heating back into the heating zone. The recycle control includes an inlet duct and adjustable louver arrangement which during partial recirculating mode selctively flows outside air into the mixture of cooling air and heating air at an intake portion of the recirculating blower to regulate the extent of dryer recirculation, and control grain drying. During a non-recirculating mode the recirculating blower draws in only outside air.

Abstract: An inlet duct is provided for recirculating grain dryers of the type which have a drying column area, and a recirculating blower mounted in a room portion of the dryer, with an open side of the room communicating with the drying column area. The inlet duct is connected with an intake portion of the recirculating blower, and has an open end thereof disposed adjacent to the open side of the room, whereby during a full recirculating condition of the grain dryer, air is drawn into the recirculating blower substantially wholly from the drying column area. The inlet duct has an aerodynamically streamlined interior shape with walls which taper inwardly toward the blower intake portion for efficiently guiding the flow of air from the drying column area directly into the recirculating blower intake.

Abstract: A grain dryer having upright grain passages defined by perforate walls confining grain columns therein, the grain passages having offset portions and common inlets and outlets and vertically spaced plenum chambers, and a duct with a fan and burner drawing air from the lower plenum and applying the air in the upper plenum, a pair of upright imperforate plates lying along the exterior of the grain passages and directing a portion of the air emerging from the upper plenum to be recycled by again passing inwardly through the column and into the lower plenum.

Abstract: A method of producing abrasion resistant coke from brown coal briquets in a shaft furnace comprises charging the coke briquets into the top of the furnace and removing coke from the bottom of the furnace while directing inert hot combustion gases into the furnace and through the briquets at a plurality of vertically spaced levels throughout the height of the shaft furnace. Gases are directed at temperatures to effect and successively lower stages of the furnace the preheating, predrying, carbonization, and cooling of the charge. Gases are collected in each of the preheating and predrying stages by the use of a tubular suction arm which extends substantially across the width of the furnace and includes a performated bottom and sidewalls which extend partly below the bottom and are provided with a saw-tooth configuration so as to withdraw the gases through the space below the bottom and through the perforations of the bottom and to effect entrainment of dust from the charge in so doing.

Abstract: A process and apparatus for drying wet solid material are provided. The process comprises introducing material into a dryer, bringing it into contact with one side of a plurality of heated surfaces located therein and vaporizing liquid in the material. The liquid is withdrawn from the dryer, compressed to a pressure greater than in the dryer and returned to the other side of the heated surfaces where, upon condensation, latent heat energy is released therefrom and used to vaporize liquid in material on the opposite side of the heated surfaces, withdrawing the condensate from the heated surfaces and substantially dried solids from the dryer.The apparatus comprises a housing having entrance and exit openings and means for delivering material into and dried material therefrom located in the openings and isolating the dryer interior from the outside atmosphere. A plurality of hollow heat exchange means connected to an external heat source and to atmosphere are disposed in the interior of the dryer.

Abstract: A regeneration equipment for spent activated carbon comprises a regeneration reactor provided vertically through a vertical heating furnace and an integrated body of a longitudinal series of numerous spiral elements fixedly provided almost throughout the length of said regeneration reactor. Steam ducts are provided so that they are inserted in said regeneration reactor at about the middle portion thereof. On the outside surface of the wall of said regeneration reactor, fixedly provided are exhaust chambers, each of which communicates at its bottom portion with the inside of said regeneration reactor through exhaust holes provided in the wall of said reactor, and is filled with heat-resisting balls piled up in three layers so that the balls in the top and bottom layers are larger in diameter than said exhaust holes and those in the middle layer are similar in diameter to activated carbon particles.

Abstract: Granular solid material is dried in a vertically extending annular chamber formed between inner and outer cylindrical walls by a current of high temperature inert drying gas of high humidity passed downward through the material. Material enters the chamber under gravity through a slot in the inner wall, which slot extends round the full periphery of the inner wall, and is removed from the bottom of the chamber by a variable speed discharge system, the rate of entry through the slot being governed by the rate of discharge from the bottom of the chamber so that the top of the column of material is of frusto-conical form. The spent drying gas stream, less a quantity which is discharged, is used to dilute the products of a fuel in air, the high temperature mixture thus formed constituting the drying gas. The quantity discharged has a mass equal to that of the fuel and air forming the products of combustion. An upward current of cooling air may be passed through the lower portions of the column of material.

Abstract: A concurrent-countercurrent flow type grain dryer is described having an improved wet grain-drying air contacting arrangement. The dryer is in the form of a tower, with the grain passing from top to bottom by gravity flow. The tower has a wet grain bin at the top with intermediate drying zones and metering grain outlets at the bottom for controlling the rate of movement of grain through the tower. The drying zone is divided into several sections including at least two concurrent flow hot air drying zones with a steeping zone between each pair of concurrent flow hot air drying zones, followed by a countercurrent flow cooling zone. The use of two or more concurrent flow drying zones with intermediate steeping zones have been found to remarkably improve both the rate of flow of grain through the dryer and the moisture removal efficiency. Still greater efficiencies have been achieved by recycling the outlet drying air from one drying zone to the inlet drying air of a subsequent drying zone.

Abstract: In a dry type quenching facility for red hot coke wherein an operation pressure at the upper portion of the quenching station is set up within the range of 0 to +10 mmH.sub.2 O, red hot coke is charged into said station under a reduced pressure of 0 to -30 mmH.sub.2 O, to prevent escape of dust and smoke from said station and thereby prevent polluting of the environment.

Abstract: An installation for the burning and/or sintering and cooling of cement clinker, lime, magnesite, dolomite and similar materials in granular or crushed form, especially adapted as a small-scale cement mill or lime mill, having two movable materials carrying platforms arranged inside a burn chamber, in a staggered relationship, and an intermediate wall subdividing the burn chamber into a forehearth for the upper platform and a main hearth for the lower platform. Blowers supply combustion air, draw the used burn gases through air permeable back walls above the platform, recirculate them into the changing shaft to dry and preheat the materials, and cool the sintered materials in the cooling shaft. An aftersinter platform or rotating aftersinter kiln may be arranged between the lower platform and the cooling shaft.

Abstract: A concurrent-countercurrent air flow grain dryer of the type having an enclosed bin with a wet grain inlet at the top and a dry grain outlet at the bottom includes means for introducing hot air near the top of the bin to serve as a drying medium for the grain in a flow concurrent with the grain. Means are provided at the bottom of the bin to introduce cool air which flows countercurrent to the grain flow. An exhaust is provided intermediate where the hot and cool air are introduced. A manifold for the exhaust directs parts of the exhaust air through the hot air inlet portion of the dryer. In this manner, at least a portion of the exhaust air is recycled prior to ultimate exhaust from a vent associated with the exhaust manifold.

Abstract: Improved process and apparatus for drying are disclosed whereby a moist granular material is dried by contact with a heated gas and is then cooled by contact with a cooler gas. The cooling gas is supplied to the cooling zone at a pressure which exceeds atmospheric pressure. During passage through the cooling zone, the temperature of the cooling gas is increased, and all of it is then circulated to the heating zone in order to reuse the heat thus absorbed for drying still more granular material. Fuel utilization and drying cost can be substantially reduced, and the invention is especially suitable for use with recirculating grain dryers.

Abstract: An improved concurrent flow, counterflow continuous type grain dryer includes bottom cold air inlet ducts for counterflow of cold air, a first and second set of upper horizontal hot air inlet ducts connected with a common hot air manifold for concurrent flow of hot air, intermediate exhaust ducts transverse to the inlet ducts and connected with the hot air manifold for recycling of exhaust air through the inlet ducts, and separate upper, transverse exhaust ducts vented to the atmosphere.

Abstract: Method and apparatus are described for the production of solid fuel and steam by drying moisture-containing solids, such as refuse and sludge cakes, in a multi-stage heating zone by using the moisture-containing solids as the feed-water in a direct contact countercurrent flow pressurized boiler. After vaporizing the bulk of the moisture in the heating zone of the boiler, the solid residue is further dried in a multi-stage flashing zone. From the upper end of the heating zone is removed a nearly saturated steam including the water vapor evaporated from the moisture-contained solids by the heat of cooling of the introduced superheated steam. A portion of the removed steam equal to the vaporized moisture is heated and then directed to a turbine, generating all the power required to operate the system. The bulk of the removed steam equal to the introduced superheated steam is compressed, reheated and recycled through the heating zone.

Abstract: A dryer for particulate material combines the drying effect of a stream of heated gas circulated by a blower in a closed duct system with that of a radiator structure which is in the drying chamber and is in a heat pump circuit. The condenser of the heat pump circuit is in the duct system where it condenses moisture from the gas which has passed through the particulate material. The heat pump compressor is driven by an internal combustion engine which is in a compartment in heat exchange relationship with the duct system. The engine cooling system radiator is immediately downstream from the condenser and the engine exhaust system includes a heat exchanger which is in the duct downstream from the engine cooling radiator.