Abstract: A method for drying at least one unfired columnar honeycomb formed body comprising a raw material composition containing at least one raw material of ceramics, water and at least one heat-gelling binder, and cells defined by partition walls comprising flow paths from a first end surface to a second end surface. The method comprising drying the honeycomb formed body by passing hot gas satisfying 0.8?T2/T1?3.3, where T1 represents a gelation temperature of the binder (° C.) and T2 represents a wet-bulb temperature of the hot gas (° C.) through the flow paths from the first end surface and out the second end surface, while surrounding the honeycomb formed body with a correction mold to correct the shape of the honeycomb formed body during drying.

Abstract: A system and methodology facilitates the handling of oilfield materials in a space efficient manner. The oilfield materials are delivered without blowers to at least one modular silo. Each modular silo comprises an outer housing defining an enclosed interior. A vertical conveyor is positioned within the enclosed interior and is used to lift the oilfield material from a silo inlet to an upper portion of the modular silo without utilizing airflow to carry the oilfield materials. Once the oilfield materials are disposed within the upright modular silo, the outflow of oilfield materials through a silo outlet may be controlled so as to selectively release the desired amount of material into a blender or other suitable equipment.

Abstract: Methods and apparatuses for drying electronic devices are disclosed. Embodiments include methods and apparatuses that heat and decrease pressure within the electronic device. Some embodiments increase and decrease pressure while adding heat energy, such as by using a heated platen in contact with the electronic device or by supplying a gas (e.g., air), which may be heated, into the interior of the electronic device.

Abstract: The present disclosure relates to a method and apparatus for performing a dry plasma procedure, while mitigating internal contamination of a semiconductor substrate. In some embodiments, the apparatus includes a semiconductor processing tool having a dry process stage with one or more dry process elements that perform a dry plasma procedure on a semiconductor substrate received from an input port. A wafer transport system transports the semiconductor substrates from the dry process stage to a wet cleaning stage located downstream of the dry process stage. The wet cleaning stage has one or more wet cleaning elements that perform a wet cleaning procedure to remove contaminants from a surface of the semiconductor substrates before the semiconductor substrate is provided to an output port, thereby improving wafer manufacturing quality.

Abstract: A method for phytochemical extraction includes providing a distillation vessel, providing a mixture of solvent and plant extract to the distillation vessel, placing the distillation vessel on a heat source, coupling the distillation vessel with a collector configured to collect condensed solvent, selecting an initial distillation temperature and outputting heat from the heat source at a heat source initial target temperature to heat the distillation vessel to a distillation vessel initial target temperature and boil the mixture in the distillation vessel at the initial distillation temperature and at an initial heat flux. With a vacuum pump, a distillation vessel initial target pressure is set within the distillation vessel.

Abstract: An apparatus for a lithography device is provided, which includes a laser-based particle eliminating component and a particle collector. The laser-based particle eliminating component includes a laser emitter and a laser absorbing member. The laser emitter is configured to emit laser beams for irradiating particles in a space near a photomask of the lithography device. The laser absorbing member is disposed opposite to the laser emitter for absorbing the laser beams. The particle collector is configured for collecting the irradiated particles.

Abstract: Methods and apparatuses for drying electronic devices are disclosed. Embodiments include methods and apparatuses that heat and decrease pressure within the electronic device. Some embodiments increase and decrease pressure while adding heat energy, such as by using a heated platen in contact with the electronic device or by supplying a gas (e.g., air), which may be heated, into the interior of the electronic device. Embodiments include heating the gas supplied into the interior of the electronic device with pump used to decrease pressure within the electronic device and/or a separate heater. Still other embodiments include controlling the temperature of the gas supplied into the electronic device. Still further embodiments automatically control, such as by using an electronic processor, some or all aspects of the drying of the electronic device.

Abstract: Methods and apparatuses for drying electronic devices are disclosed. Embodiments include methods and apparatuses that heat and decrease pressure within the electronic device. Some embodiments increase and decrease pressure while adding heat energy, such as by using a heated platen in contact with the electronic device or by supplying a gas (e.g., air), which may be heated, into the interior of the electronic device. Embodiments include heating the gas supplied into the interior of the electronic device with pump used to decrease pressure within the electronic device and/or a separate heater. Still other embodiments include controlling the temperature of the gas supplied into the electronic device. Still further embodiments automatically control, such as by using an electronic processor, some or all aspects of the drying of the electronic device.

Abstract: A control apparatus is configured to control an operation of a substrate processing apparatus configured to place at least a monitor substrate therein. The control apparatus controls the operation of the substrate processing apparatus based on a difference between a processing result of the monitor substrate processed by the substrate processing apparatus and a predictive result so as to optimize the monitor substrate loading frequency.

Abstract: The present invention relates to a method for controlling a laundry treating apparatus including a drum for holding laundry, a connection duct for exhausting air from an inside of the drum, an exhaust duct provided parallel to a length direction of the drum connected to the connection duct, a filter assembly with a filter unit provided to the exhaust duct for filtering the air and a brush for removing foreign matter from the filter unit, a brush drive unit for making the brush to reciprocate a section of the filter unit, and a position sensing unit for sensing a position of the brush.

Abstract: According to the present invention, a condensing dehumidifier includes: a main body having a space for receiving an object to be dried, and an inlet and an outlet formed at the top and bottom, respectively, of the receiving space; a drying unit for supplying heated air through the main body inlet to the receiving space; a condensing unit for cooling and condensing the heated air discharged through the main body outlet and separating the air into condensed water and dry air; a first pipe connecting the main body outlet and the condensing unit to each other, and transferring the heated air discharged through the main body outlet to the condensing unit; a second pipe connecting the condensing unit and the drying unit to each other, and transferring the dry air separated by the condensing unit to the drying unit; and an intermediate pipe one end of which is branched from the first pipe, and the other end of which is connected to the second pipe, wherein a portion of the heated air discharged through the main body

Abstract: A coalescing dryer passes air downwardly through items to be dried in a container. The air can be diverted to change direction following passage of the air through the items to be dried. The moving air causes liquid on the surface of items to be dried to coalesce and travel downwardly and from the items being dried. A vacuum dryer applies a vacuum to the container of items to be dried when placed in a vacuum chamber after pre-drying by the coalescing dryer so as to evaporate liquid in the items to be dried that has not been removed by the coalescing dryer.

Abstract: A method and an apparatus to protect a reticle against particles and chemicals in an actinic EUV reticle inspection tool are presented. The method and apparatus utilizes a pair of porous metal diffusers in the form of showerheads to provide a continual flow of clean gas. The main showerhead bathes the reticle surface to be inspected in smoothly flowing, low pressure gas, isolating it from particles coming from surrounding volumes. The secondary showerhead faces away from the reticle and toward the EUV illumination and projection optics, supplying them with purge gas while at the same time creating a buffer zone that is kept free of any particle contamination originating from those optics.

Abstract: A continuous drying kiln (CDK) design, in which two sets of carriages carrying spaced stacks of lumber travel in opposite directions through a sequence of chambers in which green lumber is exposed to heated air to dry the lumber to desired conditions. The continuous drying kiln using fans in each chamber to circulate air across the stacked lumber on the two sets of carriages, orthogonal to the direction of carriage travel, in either a first circulation direction or in a second circulation direction. As a carriage moves from chamber to chamber, the circulation direction is reversed.

Abstract: An apparatus for thermo-transformation of wood planks comprises a chamber delimited by upright perforated walls, a top wall and end walls and having a closable entry for receiving wood planks into the chamber. A shell surrounds the chamber and is spaced therefrom to define a first vertical plenum with the first perforated wall, a second vertical plenum with the second perforated wall, and a horizontal plenum with the top wall. A ventilation system is in fluid communication with the plenums to produce a flow of heated air in the plenums. Vanes are actuatable to close/open access to the vertical plenums, to allow heated air into at least one of the vertical plenums, through the chamber via the perforated walls, and out from at least the other of the vertical plenums, to return to the ventilation system. A method for the thermo-transformation of wood is also provided.

Abstract: A coating apparatus includes modular interfaces and substrate receptors for accommodating various shapes and sizes of monolith substrates when coating layers are applied onto the monolith substrates. The monolith substrates are laterally surrounded by an elastically deformable sleeve that prevents lateral leakage of a vacuum out of the monolith substrate when a vacuum is applied to opposing ends of the monolith substrate, thereby eliminating needs for bulky vacuum chambers. The coating apparatus also includes valves and control apparatus that enable excess precursor liquid to be drained from monolith channels in-situ, without the use of additional spin-drying steps. Coating methods for using the coating apparatus are provided.

Abstract: Methods and apparatuses for drying electronic devices are disclosed. Embodiments include methods and apparatuses that heat and decrease pressure within the electronic device. Some embodiments increase and decrease pressure while adding heat. Other embodiments include a desiccator for removing moisture from the air being evacuated from the electronic device prior to the air reaching an evacuation pump. Further embodiments detect humidity within the low-pressure chamber and determine when to increase and/or decrease pressure based on the humidity. Still further embodiments determine that the device is sufficiently dry to restore proper function based on the detected humidity, and in some embodiments based on the changes in humidity while pressure is being increased and/or decreased. Still further alternate embodiments automatically control some or all aspects of the drying of the electronic device. Additional embodiment disinfect the electronic device.

Abstract: A method of controlling and enhancing the nucleation of product in a freeze dryer, wherein the product is maintained at a predetermined temperature and pressure in a chamber of the freeze dryer, and a predetermined volume of condensed frost is created on an inner surface of a condenser chamber separate from the product chamber and connected thereto by a vapor port. The condenser chamber has a predetermined pressure that is greater than that of the product chamber. The opening of the vapor port into the product chamber creates gas turbulence that breaks down the condensed frost into ice crystals that rapidly enter the product chamber for even distribution therein to create uniform and rapid nucleation of the product in different areas of the product chamber.

Abstract: A coalescing dryer passes air downwardly through items to be dried in a container. The air can be diverted to change direction following passage of the air through the items to be dried. The moving air causes liquid on the surface of items to be dried to coalesce and travel downwardly and from the items being dried. A vacuum dryer applies a vacuum to the container of items to be dried when placed in a vacuum chamber after pre-drying by the coalescing dryer so as to evaporate liquid in the items to be dried that has not been removed by the coalescing dryer.

Abstract: Methods and apparatuses for drying electronic devices are disclosed. Embodiments include methods and apparatuses that heat and decrease pressure within the electronic device. Some embodiments increase and decrease pressure while adding heat energy, such as by using a heated platen in contact with the electronic device or by supplying a gas (e.g., air), which may be heated, into the interior of the electronic device. Embodiments include heating the gas supplied into the interior of the electronic device with pump used to decrease pressure within the electronic device and/or a separate heater. Still other embodiments include controlling the temperature of the gas supplied into the electronic device. Still further embodiments automatically control, such as by using an electronic processor, some or all aspects of the drying of the electronic device.

Abstract: A low pressure dryer for granular or powdery material includes a plurality of canisters rotatable about a common vertical axis serially among material heating, vacuum drying and material inventory discharge positions; pneumatic piston-cylinder means for rotating the canisters about said axis among said heating, vacuum drying and inventory discharge positions; means for heating contents of a canister at said heating position; means for sealing and drawing vacuum within a canister at said vacuum drying position and means for selectably permitting downward flow of dried granular or powdery material out of a canister at said discharge position where said canisters move collectively and unitarily one with another.

Abstract: A coalescing dryer passes air downwardly through items to be dried in a container. The air can be diverted to change direction following passage of the air through the items to be dried. The moving air causes liquid on the surface of items to be dried to coalesce and travel downwardly and from the items being dried. A vacuum dryer applies a vacuum to the container of items to be dried when placed in a vacuum chamber after pre-drying by the coalescing dryer so as to evaporate liquid in the items to be dried that has not been removed by the coalescing dryer.

Abstract: Systems and methods are described for conductively heated vacuum-based drying of portable electronic devices. For example, a portable electronic device that has been exposed to excessive liquid is placed inside a drying chamber. The drying chamber is closed and a drying routine commences. During the drying routine, the chamber is pressurized to a vacuum level sufficient to gasify liquids inside the device, and the device is conductively heated at least to replace latent heat of vaporization lost during the pressurization. Some embodiments include techniques relating to payment processing, monitoring and feedback control, decontamination, and/or other functionality.

Abstract: The present invention relates to an apparatus for removing liquid from a suspension. More particularly, the present invention relates to a filtration apparatus using vacuum pressure, compressed air and radiant heat to facilitate extraction of water from a suspension and an air flow within the vacuum chamber to remove the evaporate as a cost-efficient and resource-efficient means of filtering and drying solids in large volumes of suspension to remove interstitial and chemically bound liquids, resulting in up to 100% total solids.

Abstract: An evacuation method which can reduce evacuation time without causing moisture-related problems. In a vacuum processing apparatus including a vacuum processing chamber, during the evacuation for the vacuum processing chamber, the pressure in the vacuum processing chamber is maintained at a pressure lower than or equal to the atmospheric pressure but higher than or equal to 6.7×102 Pa (5 Torr).

Abstract: A method for improving the manufacture and reliability of new, remanufactured, repaired or reconditioned Fire Control Radar APG-68 tactical radar systems (FCR) utilized in military aircraft and providing such units with extended useful life expectancies equivalent to or better than new of the FCR APG-68 unit high frequency, high voltage dual mode radar transmitters that are deployed in over 1000 state-of-the-art military aircraft such as the F-15, F-16 and F-18 fighter aircraft, and B-1 bombers. The novel method extends the mean lifetime of previously repaired and repairable FCR APG-68 tactical radar units and radar units and ageing transmitters from about 100 to a few hundred hours to about five hundred or more hours by the step of removing embedded moisture and absorbed moisture from the heterogeneous electronic components in the FCR APG-68 tactical radar unit.

Abstract: Methods and apparatuses for drying electronic devices are disclosed. Embodiments include methods and apparatuses that heat and decrease pressure within the electronic device. Some embodiments increase and decrease pressure while adding heat. Other embodiments include a desiccator for removing moisture from the air being evacuated from the electronic device prior to the air reaching an evacuation pump. Further embodiments detect humidity within the low-pressure chamber and determine when to increase and/or decrease pressure based on the humidity. Still further embodiments determine that the device is sufficiently dry to restore proper function based on the detected humidity, and in some embodiments based on the changes in humidity while pressure is being increased and/or decreased. Still further alternate embodiments automatically control some or all aspects of the drying of the electronic device. Additional embodiment disinfect the electronic device.

Abstract: A wood kiln system and method that sequentially cures and dries layers of stacked wood during which each layer of wood is heated to 125 to 170 deg. F. as the kiln container is evacuated to approximately 13 inches of Hg for 8 to 12 hrs. After the wood has been cured, drying stage is commenced as the wood is continuously heated by evacuating the kiln container to 0.35 to 3 inches of Hg for 6 to 12 hrs. During the drying stage, a cold water bath is formed in the bottom of the kiln container. A condensation tank located between the vacuum pump and the kiln is used to continuously remove the water and water vapor from the kiln container. In one embodiment, the vacuum pump includes a primary vacuum pump serially connected to an auxiliary vacuum pump that allows the air to be continuously and gradually reduced in the kiln container.

Abstract: A method of manufacturing a liquid discharge head including a flow path member for forming a flow path communicating with a discharge port discharging a liquid includes forming a mold of the flow path made of a positive photosensitive resin on a substrate; applying a coated layer on the mold for forming the flow path member, which coated layer includes a solvent, an epoxy resin, and a curing agent of the epoxy resin; removing the solvent from the coated layer at a normal temperature under substantially 1 atm. so that the weight of the coated layer may become 93% or less of that thereof at a time of applying of the coated layer, and then further removing the solvent from the coated layer under a depressurized condition; curing the coated layer; and removing the mold to form the flow path.

Abstract: The removal of moisture from an object to be sterilized is provided through at least the steps of placing the load in the chamber, reducing the pressure within the chamber to increase the rate of evaporation of moisture from the load, monitoring over a predetermined period of time the increase in the quantity of vapor within the chamber resulting from evaporation of moisture from the load, admitting gas into the chamber and repeating the steps following placing the load into the chamber.

Abstract: An apparatus and method for quickly drying porous materials. A sealable chamber is connected to a cold trap which is connected to a vacuum pump. A sample is placed inside the sealable chamber. The vacuum pump is turned on and air is evacuated through the cold trap to the vacuum pump. Because evaporation may lower the temperature inside the sealable chamber, an infrared lamp may be used to heat the chamber and sample therein directly or heated air may be allowed to enter the sealable chamber in response to the vacuum created by the vacuum pump. Air may be drawn directly from the sealable chamber to the vacuum pump bypassing the cold trap. A load cell may be placed in the bottom of the sealable chamber to monitor the weight of a sample to determine if the drying process is complete. Other parameters could be used, including the degree of vacuum achieved in the chamber.

Abstract: Methods and systems are disclosed for drying a material or, more generally, flash evaporating a target substance having a vapor pressure threshold. The methods and systems include a conveyor conduit that receives material. The material moves through the conveyor and is expelled into a pressure drop zone created by one or more venturi nozzles. As the material encounters the pressure drop zone, the targeted substance in the material experiences a rapid and extreme pressure drop and simultaneously a rapid temperature increase. This causes the target substance in the material to flash evaporate virtually immediately. The resulting vapor is separated from the remaining material and the now dry material is collected for further processing or use. The vapor can be collected, condensed, exhausted, or otherwise treated depending upon the goals of a particular installation or process.

Abstract: A method for drying a wet semiconductor substrate includes the steps of immersing the substrate in a drying liquid in a drying chamber; removing the substrate from the drying liquid within the drying chamber; purging the drying chamber with inert gas; exposing the substrate to vacuum pressure within the drying chamber; and backfilling the drying chamber with the inert gas to substantially achieve atmospheric pressure. A system for drying a semiconductor substrate includes a drying chamber, a drying liquid reservoir in fluid communication with the drying chamber, a liquid pump, an inert gas supply in fluid communication with the drying chamber, and a vacuum pressure source in fluid communication with the drying chamber.

Abstract: A method for reconditioning Fire Control Radar APG-68 tactical radar systems (FCR) utilized in military aircraft and returning them to operation with extended useful life expectancies equivalent to or better than new of the FCR APG-68 unit high frequency, high voltage dual mode radar transmitters that are deployed in over 1000 state-of-the-art military aircraft such as the F-15, F-16 and F-18 fighter aircraft, and B-1 bombers. The novel method extends the mean lifetime of previously repaired and repairable FCR APG-68 tactical radar units and radar units and ageing transmitters from about 100 to a few hundred hours to about five hundred or more hours by the step of removing embedded moisture and absorbed moisture from the heterogeneous electronic components in the FCR APG-68 tactical radar unit.

Abstract: An apparatus and method for quickly drying porous materials. A sealable chamber is connected to a cold trap which is connected to a vacuum pump. A sample is placed inside the sealable chamber. The vacuum pump is turned on and air is evacuated through the cold trap to the vacuum pump. Because evaporation may lower the temperature inside the sealable chamber, an infrared lamp may be used to heat the chamber and sample therein directly or heated air may be allowed to enter the sealable chamber in response to the vacuum created by the vacuum pump. Air may be drawn directly from the sealable chamber to the vacuum pump bypassing the cold trap. A load cell may be placed in the bottom of the sealable chamber to monitor the weight of a sample to determine if the drying process is complete. Other parameters could be used, including the degree of vacuum achieved in the chamber.

Abstract: The removal of moisture from an object to be sterilized is provided through at least the steps of placing the load in the chamber, reducing the pressure within the chamber to increase the rate of evaporation of moisture from the load, monitoring over a predetermined period of time the increase in the quantity of vapor within the chamber resulting from evaporation of moisture from the load, admitting gas into the chamber and repeating the steps following placing the load into the chamber.

Abstract: A process is provided for recovering polymer solids from a polymerisation reactor effluent. The process comprises extracting the polymerisation effluent from a polymerisation reactor; passing the effluent, or a part thereof, to a flash vessel for flashing liquid in the effluent to vapour, and removing said vapour from said flash vessel; passing the polymer solids from the flash vessel to a transfer apparatus which comprises a transfer vessel; passing the polymer solids from the transfer vessel to a purging means for removing residual liquid from the polymer solids; wherein the polymer solids are passed from the flash vessel to the purging means in a continuous flow such that a quantity of polymer solids is maintained in the transfer vessel. An apparatus for performing the process is also provided.

Abstract: Embodiments disclosed herein relate to an apparatus for and method of protecting a reticle in a lithography system from particle deposition using thermophoresis, but still allowing a high vacuum area for the photo-optics.

Abstract: A synthesis process of trans-1,4-polyisoprene, using bulk precipitation polymerization of isoprene catalyzed by supported titanium catalyst TiCl4/MgCl2. The process includes prepolymerizing carried out in a prepolymerization reactor with an anchor agitator; polymerizing carried out in a polymerization reactor with a helical ribbon agitator; and devolatilizing and drying carried out in a vacuum rake dryer. Not only does the process require lower energy consumption and thus a lower production cost, but it also eliminates the emission of three wastes.

Abstract: A process for removing water and solutes from the lumens of green wood, while leaving the cell walls throughout the wood uniformly fully swollen, comprises subjecting the green wood to supercritical carbon dioxide.

Abstract: A laundry room machine and a drying method thereof are provided. The laundry room machine may includes a payment device for collecting a payment for operation of the laundry room machine. The laundry room machine performs drying of laundry items for a preset dry time corresponding to a selected drying course. The drying method includes determining a condition of the laundry items by measuring a humidity level, and either sustaining the preset dry time or resetting a hot air supplying time and cooling time based on the determined condition of the laundry items.

Abstract: A vacuum drying apparatus and method to dry and cure paint is disclosed. The method provides a substantially particle free environment that shortens drying time, reduces cost and improves surface finish. The apparatus includes an enclosed drying tunnel that is maintained at a reduced pressure relative to ambient conditions. Heat lamps with the drying tunnel aid in curing and provide the desired particle free environment.

Abstract: An evacuation method which can reduce evacuation time without causing moisture-related problems. In a vacuum processing apparatus including a vacuum processing chamber, during the evacuation for the vacuum processing chamber, the pressure in the vacuum processing chamber is maintained at a pressure lower than or equal to the atmospheric pressure but higher than or equal to 6.7×102 Pa (5 Torr).

Abstract: A method of controlling the pressure within a chamber (12) of a drying apparatus (10) from which air and vapour is removed by a pump (30), which is operated continuously during the drying process. If both of a vent valve (18) and a pressure control valve (32) is opened, air at atmospheric pressure is drawn by the pump (30) directly from the pressure control valve (32), and via the chamber (12) and a non-return valve (26) from the vent valve (18). When the pressure in the chamber (12) is to be reduced both vent and pressure control valves (18, 32) are closed to allow the pump (30) to remove air, gas and vapor from the chamber (12) via the non-return valve (26). After a required chamber pressure has been reached, the pressure control valve (32) is opened while the vent valve (18) remains closed.

Abstract: An apparatus capable of performing consecutively, independently and/or simultaneously the processes of quick freezing and/or freeze drying of produce. The apparatus is characterized by a central vacuum system operating over one or more independent vacuum chambers (10,11,12,13,14); said vacuum system being composed of at least two vacuum subsystems (40,50), connected to the chambers by means of independent manifolds (400,500). One vacuum subsystem (40) evacuates air from any of the chambers from atmospheric pressure to a pressure slightly above that of the triple point of water, and the other vacuum subsystem (50) further quickly evacuates any of the chambers from said pressure slightly above the triple point of water to the pressure corresponding to the thermodynamic equilibrium of ice and water vapor at a desired freezing temperature, in a desired freezing time.

Abstract: A processing apparatus includes a first detection unit for detecting a temperature of an inner wall of the vacuum vessel, a second detection unit for detecting a temperature of the processing unit, and a first control unit for controlling a temperature of the gas. The first control unit controls the temperature of the gas based on a temperature gradient between the temperatures of the inner wall and the gas or a temperature gradient between the temperatures of the processing unit and the gas. A method for removing particles from a processing apparatus includes a first detection step for detecting a temperature of an inner wall of the vacuum vessel, a second detection step for detecting a temperature of the processing unit, a first control step for controlling a temperature of the gas, and a gas introduction step for introducing the gas into the inner space of the vacuum vessel.

Abstract: A vacuum dryer and method for drying granular or powdery material including at least one canister for holding said material being movable among a series of locations including material heating and vacuum drying locations, means for moving said canister among said locations, and means for directing heating air to a canister for delivery to said canister at a selected position on said canister for heated air passage though material in said canister in a selected direction corresponding to the selected position at which said heated air is delivered to said canister.

Abstract: A method of conditioning an organic substrate is described The method involves heating the substrate using RF energy under desired pressure conditions in a constrained environment At a desired time point, the pressure is rapidly reduced causing any water present in the substrate to rapidly boil and convert to steam.

Abstract: A lithographic mask is placed in a chamber which is then sealed. The gas pressure in the chamber is reduced to dislodge contaminant particles on the mask surface.

Abstract: A low pressure dryer for granular or powdery material includes a plurality of hoppers rotatable about a common vertical axis serially among material filling and heating, vacuum drying and material discharge positions; pneumatic piston-cylinder means for rotating the hoppers about said axis among said filling and heating, vacuum drying and discharge positions; means for heating contents of a hopper at said filling and heating positions; means for sealing a hopper at said vacuum and drying positions; means for drawing vacuum within a hopper at said vacuum drying position and means for selectably permitting downward flow of dried granular or powdery material out of a hopper at said discharge position where said hoppers move collectively and unitarily one with another.