Abstract: Apparatus for feeding doses of fluidisable materials comprising one upper Intel pipe (1?, 1?), one lower outlet pipe (2?, 2?) and a Pausing (6?,6?). and a fluidising element (5?,5?) for controlling outflow of materials through the outlet pipe (2?, 2?), The apparatus further comprising a control volume constituted by a chamber (3?,3?) between the Intel pipe (1?, 8?) and the outlet pipe (2?,2?) and a fluidising element (4?, 4?) for controlling inflow of materials Into the chamber (3?, 3?). A diverter (7?,7?) la arranged between the Inlet pipe (1?, 8?) and the outlet pipe {2?, 2?) defining said chamber (3?, 3?) between said Inlet pipe (1?,8?) diverter (7?,7?) the housing (6?, 6?) and the fluidising element (5?,5?). The Invention also relates to a method for feeding doses of fluidisable materials by the apparatus.

Abstract: Apparatuses include a laser cutter positioned within an enclosure that is capable of cutting printed sheets; however, this cutting produces debris made up of airborne dust of the sheet material and marking material. An air duct is capable of drawing an air stream of air and the debris out of the enclosure. A dispenser is positioned within the air duct where the air duct connects to the enclosure. The dispenser is capable of dispensing a dry powder of calcium carbonate into the air stream. The dry powder attaches to the debris. The combination of the dry powder and the debris forms waste, and a filter device (that is connected to the air duct) filters the waste. The filter device is capable of separating the air from the waste, to collect the waste and release the air free of the waste to areas outside the filter device.

Abstract: An aeration apparatus to ease the emptying of a mass of powdered material from any kind of container. The apparatus comprises a vibrating membrane coupled to a device for pulling and fastening it to the container wall, so that said membrane adheres to the inner surface of the container wall. The apparatus is characterized in that the inner surface of membrane has a number of grooves shaped as radial recesses formed only on the lower half of the inner surface of the membrane itself. Each radial section of any radial recess is advantageously venturi-shaped.

Abstract: The invention relates to a powder supply device for a powder coating system having at least one powder container (24), which has a powder chamber (22), and having at least one powder dispensing device, which is connected or can be connected to a powder dispensing channel (13) opening into the powder chamber (22) via a powder dispensing opening (36), in order to extract coating powder from the powder chamber (22) during powder coating operation of the powder coating system. In order to achieve as homogeneous and effective a powder conveyance as possible using the powder supply device according to the invention, the at least one powder dispensing device is designed as a powder dense flux pump (4), in particular as a single-chamber powder dense flux pump (200).

Abstract: A mechanically-controlled vacuum throttle for a continuous dense phase pneumatic conveying system and related method is provided. The system includes a pneumatic conveyance line, a particulate material insertion assembly, a positive displacement blower, a transport fluid intake assembly, and a vacuum throttling assembly. The vacuum throttling assembly is configured to control the flow of air mass density into the blower and through the conveyance line. A portion of the vacuum throttling assembly is tied in to the conveyance line pressure downstream of the blower and adjusts the air mass density flow depending on the downstream pressure. Preferably, the vacuum throttling assembly includes an obstruction element and an opening collar, where the obstruction element is moveable relative to the opening collar and the air mass density flow is adjusted depending on the amount of movement of the obstruction element relative to the opening collar.

Abstract: A singulating and counting device includes a bulk housing for storing a plurality of substantially identical articles, an exit channel, and in the exit channel, forwardly- and rearwardly-directed jet apertures, each of which is fluidly connected to a positive pressure source. A forwardly-directed jet generated by the positive pressure source through the forward jet aperture can accelerate singulated articles in the exit channel, thereby increasing the interval between individual articles and rendering them more easily and accurately counted. A rearwardly-directed jet generated by the positive pressure source through the rearwardly-directed jet aperture can cause articles in the exit channel to return to the housing.

Abstract: Methods, processes, and apparatuses for the large scale synthesis of carbon nanostructures are provided. Metal catalysts having small diameter and narrow distribution of particle sizes are prepared and continuously injected as aerosols into a reactor. The metal catalysts are supported on supports that are substantially free of carbon. The metal catalyst, in the form of a powder, is placed in an injector that is shaken vertically. The powder is aerosolized, and the powder entrailed in the gas is passed through a conduit that is bifurcated where one portion delivers the powder to the reactor while the other portion connects back to the ejector that is located in between the gas source and the top part of the container.

Abstract: The invention pertains to a vessel (1) for storing particulate matter, such a pulverized coal or fly ash, comprising a main part (2) and, at its bottom portion, at least one discharge device (3), which comprises a converging outer shell (10) and a permeable, converging inner shell (14) positioned in the outer shell (10), the discharge device (3) being connected to the main part (2) by means of a first flange (9) at or near the lower rim of the bottom portion of the main port (2) and a second flange (11) at or near the upper rim of the outer shell (10). The inner shell (14) is secured to the inner wall of the outer shell (10) of the discharge device (3), preferably to the inner wall of the second flange (11). Thus the number of gaskets is reduced an/or the positioning of the inner shell becomes less critical.

Abstract: With a device for discharge, particularly of a very fine-grained solid material or solid material mixture, from a container having a discharge funnel in the direction of gravity, underneath the main container part, a solution is to be created, with which the disadvantages of double-wall cone designs, particularly also at high system pressures, are avoided, with a simple, versatile design. This is achieved in that a part (3) of the discharge funnel in the upper region that faces the container (2) is formed partly by the container wall itself, which makes a transition into a cylindrical lower container part (4), while the further part that carries the discharge adapter (14) is formed by a separate cylinder element (9) with funnel part (11), which element is installed in the cylindrical lower container part (4).

Abstract: An elongate container (7) for the transport of bulk powders is provided along its base with a longitudinally sloping membrane support. A gas permeable membrane (11) is mounted on the support and the support is itself unsupported relative to the container between its longitudinal and transverse ends. A method of conveying bulk powder using such a container is also described.

Abstract: An apparatus for conveying fluidized high temperature finely divided dry material by gravity utilizes a multi-layered, gas permeable gas distributor member comprising (i) an upper layer a flat, rigid gas permeable, porous medium capable of withstanding temperatures up to about 2900° F. through which gas to fluidize the material will pass; (ii) a middle layer comprised of a gas permeable insulation material that maintains its physical integrity when exposed to temperature differentials ranging from about 500° F. to about 2900° F.; and (iii) a lower layer that supports the top and middle layers comprising a substantially flat plate having a plurality of openings therethrough through which fluidizing gas can pass.

Abstract: A reservoir for powdery media, in particular powder coating, comprises a housing having at least one inlet and at least one outlet for the powdery medium. A fluidising floor of porous, air-permeable material is located in the interior of the housing at a distance from its base. A pressure chamber which is chargeable with compressed air is located between the fluidising floor and the base of the housing. The outlet has the shape of an upwardly open funnel which is located in the lower partial zone of the housing adjacent to the fluidising floor. In this way well-mixed powdery medium the grain-size distribution of which corresponds to the maximum extent to that of the fluidised powdery medium inside the reservoir is always withdrawn.

Abstract: This invention is a method for operating fluidized beds, such as used to convey powdered material, wherein the fluidizing gas flows are pulsed or vibrated to help initiate and maintain fluidization. The invention maintains the fluidization effects by preventing channeling or ‘rat-holing’ in a powder bed by oscillating gas pulse frequencies in the 0.5 to 300 hertz range. The invention further is directed to efficient conversion of the energy contained in the pressurized gas flow to vibrational energy. The invention describes devices capable of feeding one or more fluidized-beds from a compressed (pressurized) gas supply, thus conserving energy and increasing mass transfer within the beds.

Abstract: A reservoir for powdery media, in particular powder coating, comprises a housing having at least one inlet and an outlet. A fluidising floor of porous, air-permeable material is located in the interior of the housing at a distance from its base. In this way a pressure chamber which is chargeable with compressed air is formed between the fluidising floor and the base of the housing. In order to reduce the quantity of compressed air required for fluidising and to keep low the mechanical stress imposed on the powdery medium when in the fluidised state, the cross-section of the housing narrows downwardly towards the fluidising floor. In addition, this shape of the housing generates turbulence in the fluidised powdery material.

Abstract: A device for introducing poorly flowing bulk material into a feed line includes a swirl chamber connectable to a feed line so as to form an inlet aperture in a side wall of the swirl chamber. The device further includes a diffuser plate through which a loosening fluid may be introduced into the swirl chamber. The diffuser plate is arranged in the vicinity of the inlet aperture in the side wall of the swirl chamber. A device for producing a gas flow is also provided inside the swirl chamber, the gas flow being directed in the direction of the inlet aperture.

Abstract: An apparatus and method for supplying multi-color powder paint material to an applicator in which at least one canister is used. This invention can be utilized with multiple or with a single color of powder paint material. The preferred system includes two canisters that alternate in supplying powder to the applicator. While one canister supplies powder to the applicator, the other canister is purged of the previous material and filled with the next material to be sprayed. The canister has an interior sized to store a predetermined quantity of powder material. During operation, a powder transfer pump and a color changer transfer powder material from a storage container/hopper to the canister interior. A venturi pump then supplies the applicator with powder. After the object is painted, purge air is opened and the canister is purged of the previous material. The canister is then ready to start another cycle.

Abstract: This invention relates to a system and a process for the removal of bulk material from a container, in particular, from a box-shaped transport container. In order to be able to suction the bulk material off in a simple and reliable manner out of the transport container, one first of all attaches to an outlet area of container (10) a removal instrument (23) that has a conveyance device. This conveyance device conveys the bulk material in the removal instrument (23) essentially against its direction of outflow out of container (10) into a discharge area of the removal instrument (23) out of which bulk material is sectioned off by means of an off-suctioning device (39) that is connected thereto. To support the off-suctioning of the bulk material, air—by means of an air supply device (17, 19, 20′)—is so piped into the bulk material located in container (10) that the bulk material is fluidized.

Abstract: An arrangement for spreading material, comprising at least one container (1) for holding the material (6) and having a conveyor duct (2), which is connected to the container (1) and is designed to accommodate an air flow for conveying the material (6) from the container (1) to at least one dispensing element (12). The conveyor duct (2) is provided with a venturi-like constriction (18) and the container (1) is connected to the conveyor duct (2) by the said constriction (18), so that the material (6) is fed from the container (1) to the conveyor duct (2) by means of the venturi effect.

Abstract: A fluidizing method transports particulates by gravity flow but passes the particulates through a fluidizer which is partitioned by a porous distributor plate to form first and second chambers and wherein the particulate materials pass through said first chamber which is in gaseous communication with said second chamber via the porous distributor plate. Gas is delivered to the second chamber at a pressure sufficient to generate a gas bearing between the porous distributor plate and the particulate material. The gas is permitted to migrate through the particulate material, but it is then vented to the surrounding atomosphere without causing substantial turbulence in the particulate material and to reduce tendencies for dusting and separation of the particulates into sizes.

Abstract: The method according to the invention is suitable for determining a powder quantity in a container and for determining a change in powder quantity, i.e. the powder quantity that is supplied from the container(s). The powder is fluidized in the container, the pressure of the fluidized powder in the container is measured to determine the pressure of the fluidized powder or the change of the pressure between two measurements, wherein the powder quantity in the container, or which was supplied from the container between two measurements is calculated from the pressure or the change in pressure. By the method according to the invention it is possible by a simple pressure measurement to determine the powder quantity which is supplied per time unit from the container and which is sprayed by the coating apparatus, and therefore to determine the supplied powder mass flow.

Abstract: The present invention is directed to a system and a method to unload bulk powders from large bulk containers. The system and method are particularly useful for unloading bulk cohesive powders.

Abstract: An apparatus for emptying powder from a container, such as an original shipping box includes a support having a vibrating unit for loosening the powder within the container. A powder pick-up tube and an attached powder pump draw powder from the container and transfer the powder to a powder spray gun. The lower end of the pick-up tube includes a positively pressurized fluidization unit for locally fluidizing the powder at the pick-up tube inlet. The pressurized fluidization unit primarily assists in providing a consistent draw of powder up the pick-up tube.

Abstract: This invention relates to an improved apparatus for treating the surface of particles by plasma-activated gas species to modify the particle surfaces.

Abstract: A conveyor comprises perforation bands arranged in the floor of a storage space. Some of the bands emit an air stream that in quantity or pressure differs from the air stream in the remaining bands and have apertures with a larger flow area than the apertures in the remaining bands. The larger apertures are provided: along with a first perforation band placed in the middle of a sector of the floor and extending across the entire sector; along one further band arranged on one side of the first band with a shorter extension than in the first band; and in portions of bands which portions are closest to the walls of the storage space.

Abstract: A powder metering apparatus for making available a powder, in particular for powder coating, and which comprises a metering pump with a rotatably driven metering disk arranged between two lateral plates. The metering pump includes an inlet, through which it receives a powder-air mixture, and an outlet that connects via a suction tube to an injector pump. From the outlet, the powder-air mixture conveyed by means of the metering disk to the outlet is sucked out by a vacuum flow that is generated in the injector pump and enters the metering pump via a suction inlet opening, and the powder-air mixture is then supplied to a consumer.

Abstract: In a powder coating material feeding apparatus, a lid section is mounted onto an opening of a metal drum containing powder coating material, and a support unit holds the metal drum in its upside-down or tilted position. An air distribution panel supplies carrier air into a conveying hose via a carrier air supply port, opens a pinch valve, activates a vibrator, and supplies fluidizing air into an air chamber in the lid section to fluidize the powder coating material in the metal drum. With this arrangement, the powder coating material is drained into the conveying hose through a drain port in the lower end of the metal drum in its upside-down position, and is then transferred to a powder tank by the carrier air.

Abstract: A method and an apparatus for powder spraying can be used, for example, for electrostatic enameling. In order to achieve an easily regulatable high powder output rate, it is proposed to fluidize powder in a closed container, extract it in the region of the fluid bed and cause it to emerge through a nozzle on the container. The container is subdivided by a frit into a first chamber to which air is fed and a second chamber which contains the powder and out of which air is discharged through a valve. A powder output rate can be regulated by the regulation of air pressures.

Abstract: In a coating plant, the powder feed device is cooled permanently in order to avoid the deterioration of the powder which could be caused by an excessively high temperature. The air for the fluidization of the powder contained in the reservoir (1) is cool, dry air. A heat exchanger (30) supplies a closed loop circuit which includes an annular cooling chamber (32) and a coil (33) arranged in the path of the powder. The shaft of the worm screw may also be cooled.

Abstract: A powder feeding device for feeding powder at a constant rate has a container for storing a powdered material and a discharge device mounted in the container at a lower portion thereof for discharging the powdered material from the container at a constant rate. A vibrator is mounted on the container or on a wire net mounted in the container to separate air from the powder. The powder may be supplied from a powder tank to the powder container.

Abstract: A method for dosing and particularly for mixing substances, particularly for mixing at least one granular or powdery solid matter with a liquid. A first substance, particularly the granular or powdery solid matter is liquidized by means of a gas fed continuously or pulsatingly, and after that this homogenized gas/matter mixture is brought together in a time stable, dosed manner and mixed with a second substance, particularly a liquid. For dosing the homogenized gas/matter mixture, there is additionally supplied to it gas prior to the mixing with the second substance, with this gas being supplied to the gas/matter stream in a sheathing way and parallel to its direction of flow.

Abstract: An injector-conveyor device for the pneumatic conveying of powder, particularly powdered coating material, in order to measure the amount of powder conveyed, measures indirectly the vacuum produced in an injector (4) by having a stream of air measured with respect to its amount of flow or pressure drop in a throttled measurement channel (30) which places the outside atmosphere (32) in fluid communication with the vacuum chamber (10) of the injector (4). In order to avoid errors in measurement due to pressure variations in a powder suction channel (8), an equalization air inlet (56) is provided by means of which a small amount of equalization air is introduced into the powder suction channel (8) in order to make the pressure variations occurring therein of higher frequency and smaller with respect to the amplitudes of variation.

Abstract: A fluidized type paint powder tank has a fluidizing chamber for fluidizing paint powder and a storage chamber into which the paint powder in the fluidizing chamber is fed to keep it still. There is also provided a paint supply device for an electrostatic painting apparatus that includes a paint tank for containing paint powder and a painting gun coupled to the paint tank through an injector and a hose. The device includes a discharge member for discharging the paint powder from the paint tank and a hopper for receiving the paint powder discharged by the discharge member. A screw feeder is provided under the hopper. With this arrangement, the paint powder supplied at a uniform rate by the screw feeder is fed into the injector.

Abstract: A feed system for flame spray guns is provided that comprises a hopper with a powder storage chamber, a pressurized gas source separated from the powder storage chamber by a gas distributor board, at least one flow line providing fluid communication for the pressurized air and entrained powder between the storage chamber and a flame spray gun, a powder outlet valve on each flow line for controlling the flow of pressurized gas and entrained powder from the storage chamber into the flow line, and a purge line delivering pressurized gas to the flow line downstream of the powder outlet valve for clearing powder from the flow line after the valve is closed.

Abstract: The invention is directed to a method and apparatus for establishing and maintaining a uniform mass flow rate of particulate solids and gas mixture from a container to a receiving reactor. A preferred embodiment utilizes an aeration tube suspended in the particulate mixture and serving as a fluidic valve to maintain a uniform mass flow rate. A portion of the aeration gaseous fluid may be directed upward in aid of such flow.

Abstract: The invention is directed to a method and apparatus for establishing and maintaining a uniform mass flow rate of particulate solids and gas mixture from a container to a receiving reactor. A preferred embodiment utilizes a plurality of porous inserts in the walls of the container through which a gaseous fluid is forced thereby contacting particulate solids within said container and enhancing the flow of said solids.

Abstract: An improved fluidized bed discharge bin comprising a removable closure covering an opening in the bottom of the bin. The closure is of an inverted pyramidal shape having a square base and an offset nadir. A discharge opening is positioned adjacent to the nadir on the side wall toward which the nadir is offset. An air-permeable member overlies the interior of the closure and is retentively secured between the bin opening and the closure. Positioned at the approximate midsection of each wall is a spacer which prevents the air-permeable member from being compressed in complete surface-to-surface contact with the interior surfaces of the closure. Aeration is introduced into the enclosure through an air inlet correspondingly positioned adjacent to the spacer on one wall of the enclosure.

Abstract: A self acting pressure air pulse control valve for use with fluidizing and pneumatic conveying systems for dry particulate material comprises a housing having a chamber in which a plate type closure member and an actuating piston are disposed and interconnected by an elongated actuating rod. A spring engages the actuating rod through a pivotally supported lever and biases the closure member toward a closed position. Pressure air acts across the face of the closure member to allow the valve to crack open whereupon pressure air acting on the larger actuating piston face snaps the valve to the fully open and unrestricted flow position. A reduction in pressure of the air flowing through the valve allows the biasing spring to reclose the valve to repeat its operating cycle.

Abstract: A porous filter pad for use in conjunction with a fluid pressure conveying system is disclosed. The porous filter pad includes a rigid, self-supporting molded plastic body having a predetermined elongated shape with opposed walls. Openings of a predetermined porosity are provided along one wall and openings of a predetermined smaller porosity are provided along the other wall. Inner tortuous pathways within the molded plastic body interconnect the openings between the opposed walls. The molded plastic body includes a plurality of molded and bonded particles which are formed in close proximity to one another at least along the wall having the openings of predetermined smaller porosity and are compressed into a more compact and dense relationship as a coherent mass with the openings of predetermined smaller porosity therein.

Abstract: A powder feed hopper includes a housing which mounts a porous plate adapted to support particulate powder material and receive an upwardly directed flow of fluidizing air to form an air-entrained fluidized bed in the housing above the porous plate. In order to improve fluidization, a baffle plate is mounted beneath the porous plate in the path of the pressurized air discharged from one or more air nozzles to create a circulating flow of air-entrained particulate powder material within the fluidized bed in which the flow moves upwardly along the wall of the housing and then inwardly and downwardly toward the center of the porous plate. Additionally, stirrer blades are located immediately above the porous plate to create turbulence and reduce the formation of concentrated channels of air atop the porous plate.

Abstract: An aeration device to facilitate the flow and discharge of bulk material granules through a discharge opening in a bulk material container is disclosed. The aeration device includes at least one self-supporting molded plastic hollow body which is adapted to overlie an air inlet in the bulk material container at a predetermined distance above the discharge opening thereof. Each of the molded plastic hollow body aeration devices include an inner arched wall which is adapted to face the air inlet in the bulk material container and an outer arched wall facing away from the air inlet. The molded plastic hollow body is formed in a porous construction having a plurality of openings of predetermined porosity along the inner arched wall, a plurality of openings of predetermined smaller porosity along the outer arched wall, and inner tortuous pathways ending between the openings in the inner and outer arched walls.

Abstract: A sifter-screening machine for loose material, especially flour, including an inlet for the material, downstream thereof a screen through which the material can be conveyed via an air stream, and downstream thereof an outlet for screened material. Disposed in the conveying route of the material, downstream of the screen, is a zone of reduced static pressure followed in the conveying direction by a conveying zone having an increasing cross-sectional configuration. The weight of the material just upstream of the outlet is at least nearly equal to the oppositely directed pressure of compressed air below an air-permeable element for supplying the material to the outlet.

Abstract: A dry pesticide applicator is disclosed. The applicator includes a fluidizing medium secured within a housing. A blower mechanism generates a flow of air through the fluidizing medium to establish a fluidized bed within the housing. This fluidized bed is drawn into a dusting by means of a venturi to create a powdered stream. Whenever the dispensing mechanism is inoperative, the fluid flow which creates the powdered stream (by drawing the fluidized bed through a powder inlet) is directed into the housing through the powder inlet to purge any accumulation of powdered material therein.

Abstract: Injection of gas into a bed of solids contained in a hopper is compartmentalized to allow independent control of gas to be vented upward and gas and solids to be discharged.

Abstract: The invention is directed to a method and apparatus for establishing and maintaining a uniform mass flow rate of particulate solids and gas mixture from a container to a receiving reactor. A preferred embodiment utilizes an aeration tube suspended in the particulate mixture which, in conjunction with a second independent aeration device, serves as a fluidic valve to maintain a uniform mass flow rate.

Abstract: A hopper system comprising a hopper having a side wall sloping downwardly and radially inwardly from the inlet at the top of the hopper to the outlet at the bottom of the hopper. Secured to the inside of the hopper is a membrane having a shape generally conforming to the inside of the hopper and closely overlying the conical side wall of the hopper. The membrane is permeable to air but generally impermeable to fluent material in the hopper and has a plurality of pockets for receiving stay bars. The upper and lower cylindric ends of the membrane are clamped to clamping assemblies mounted on the inside of the hopper adjacent its upper and lower ends, respectively, without the use of fasteners extending through holes in the ends of the membrane or other means of attachment to the hopper. The clamping assemblies are removable from the hopper without first unclamping the membrane whereby the clamping assemblies and membrane may be readily installed in and removed from the hopper.

Abstract: An apparatus and method for continuously dispensing particulate material utilizes a transfer vessel which may be placed at a location spaced below and apart from a dispensing vessel. Particulate material may be transferred from the transfer vessel to the dispensing vessel by aerating the particulate material and pneumatically transferring the material to the dispensing vessel through a suitable pipeline. Valving on the dispensing vessel and the transfer vessel prevents loss of pressure from the system during operation. The air supply for transfer and dispensing may be provided by one source. The dispensing unit may continuously dispense material through repeated cycles of transfer of material from the transfer vessel.

Abstract: A pressure-reducing device in a pneumatic transport system for particulate material having a first and a second transport channel which are arranged so that, at the transition between the two channels, the gas/particulate flow is bent through 180.degree.. After the bend, a throttling means is arranged. The throttling means consists of an annular nozzle, the inlet side thereof being rounded with an arcuate profile in radial section. The pressure-reducing device may be included in a transportation system for feeding particulate material out from a pressurized container to a container under a lower pressure, for example for removing dust from a dust separator in a PFBC plant to a collecting container.

Abstract: A method of recovering powder, for example in a powder-coating installation, uses processing plant adapted to operate at a pressure different to atmospheric pressure. Powder accumulating in a receptacle communicating with the processing plant is fluidized and a pressure head of fluidized powder is created to compensate the pressure difference imposed by the processing plant. A corresponding powder recovery device comprises processing plant adapted to operate at a pressure different to atmospheric pressure, a receptacle for the powder, a substantially vertical column through which this receptacle communicates with the processing plant, and structure for fluidizing at least the powder in this column. The processing plant may comprise a cyclone type separator, in which case the column is a pipe extending the cyclone downwardly. Alternatively, the processing plant may comprise a box having an air inlet and an air outlet and filters between the air inlet and the air outlet.

Abstract: A method and apparatus for improved in-car slurrying of dry bulk powder in hopper cars is disclosed. The individual hopper car compartments have ports in the bottom therein for admitting air under pressure and water to form the slurry. The apparatus of this invention includes an open mesh disposed across the upper portion of the hopper car at about the level of the dry material. When air and water are pumped into the bottom of the hopper car compartment, the pumping action causes the dry material to impact the mesh whereby clumps thereof break up and become wetted. Air passes upwardly through the mesh then but clumps of unwetted powder do not. A central port is provided in the mesh for filling the compartment with dry bulk powder.

Abstract: A plenum chamber for an air slide conveyer is provided with two air chambers one within the other. The inner chamber communicates with a medial strip of the membrane which separates the chambers from the rest of the duct through which the material passes when fluidized by air from the plenum chamber. The central air duct also serves to support the membrane which is drawn over it and then clamped between the two halves of the duct. The supply of air to either the outer or inner chamber may be separately shut off. The lower half may be removed as a unit for repair or replacement of the membrane. A novel seal is provided for preventing the edges of the membrane from becoming wet and acting as a wick to moisten and clog the central portions of the membrane.