Abstract: A molded stationary induction apparatus is provided with: a winding the surface of which is covered with resin or an insulating material containing resin; a closed vessel in which the winding is housed and air having pressure exceeding atmospheric pressure is sealed; and a heat exchanger which cools the air in the closed vessel.

Abstract: A reaction vessel in the form of a box is sized to closely contain electrode elements or core cell elements of a lithium-based or sodium-based battery or capacitor for contacting of the electrode material, placed in the reaction vessel, with a flowing gaseous stream of an inert carrier gas and vapor of an organic solvent of water for removing residual water from the porous electrode material elements which are to be infiltrated with a non-aqueous electrolyte solution. Complementary equipment is provided for delivering the gaseous stream to the reaction vessel with predetermined portions of carrier gas and organic vapor at a predetermined temperature, pressure, and flow rate.

Abstract: A vacuum assisted dehydration system including a vacuum chamber, a gas compressor, a heating coil, and a vacuum pump is provided. A sealing member removably attached to an opening of the vacuum chamber is opened to introduce one or more instruments into the vacuum chamber. The gas compressor, in fluid communication with the vacuum chamber, recirculates a pressurized gas into the vacuum chamber. The heating coil within the vacuum chamber heats the recirculating gas, which contacts the instruments positioned therein and transfers heat energy into interstitial cavities and to surfaces of the instruments or onto other moist components, for example, hands to vaporize moisture present therein. The vacuum pump, in fluid communication with the vacuum chamber, creates a negative gas pressure in the vacuum chamber to exhaust the vaporized moisture entrained in the heated recirculating gas from the vacuum chamber to dehydrate the instruments or the moist components.

Abstract: The invention concerns a method for the recovery of thermal energy from a steam dryer 2 with a closed circulation 2.1 that produces excess steam SS characterised in that the excess steam SS is condensed to an unclean condensate UC in a steam regeneration unit 3 and in that thermal energy in the unclean condensate UC is recovered by being transferred to a district heating medium HW in a heat exchanger 4 for district heating. The invention concerns also a system for the recovery of thermal energy from a steam dryer 2 with a closed circulation 2.1.

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 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: An apparatus for preserving wood product comprising, in one embodiment, a treatment space sealable in medium-tight manner; a vacuum pump connected to the treatment space; a steam source connected to the treatment space; a heating device which is in thermal contact with the treatment space; a dispenser for adding predetermined amounts of either a base or an acid to the treatment space; pH measuring device for determining the pH value of steam in the treatment space; and measuring and control equipment adapted to monitor at least the pH temperature and pressure inside the treatment space and to control the vacuum pump, the steam source and the heat source, and the pH by dispensing either a base or an acid. Also disclosed is a method for preserving wood. The preservation process has a relatively short process time, wherein a good preservation is realized while the mechanical strength of the wood is largely retained. The amount of waste wood material is greatly reduced.

Abstract: A hygienic razor blade dryer is provided that comprises a housing having an interior, a razor blade holder disposed within the interior that is adapted to receive a razor blade, a dryer for drying a razor blade received in the razor blade holder, and a vacuum for evacuating the air within the interior to prevent moisture buildup in the air and on the razor blade and to inhibit oxidation on the blade surfaces. A sanitizer may also be provided to sanitize the razor blade before, during or after the dryer operation.

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: Methods that increase the overall rate of heat transfer between a substrate and a heat sink or source, e.g., in a loadlock are provided. According to various embodiments, the methods involve varying the heat transfer coefficient of a heat transfer gas in the loadlock or other chamber. The heat transfer coefficient is varied to reduce the time-dependent variation of the rate of heat transfer. As a result, the overall rate of heat transfer is improved. In certain embodiments, the methods involve varying the gas pressure of a chamber in order to affect the rate of heat transfer to a wafer within a system. By manipulating the gas pressure accordingly, the rate of heat transfer is controlled throughout the heating or cooling cycle.

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: 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: 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: 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: The present invention relates to a method for screening of polycondensation catalysts, wherein at least two polycondensation catalysis reactions are performed simultaneously under substantially equivalent conditions in at least two reaction cells which are present in one and the same room, using a sample comprising material to be polycondensated and a catalyst to be screened, and wherein the performances of the catalysts are analyzed. The present invention further relates to an apparatus suitable for performing the method.

Abstract: A method of pasteurizing dewatered sludge into valuable soil conditioners is provided. Unpasteurized dewatered sludge is introduced into a first end of an dryer and maintained under vacuum pressure. Moisture is removed using a condenser and knock out tank while a boiler provides heat to treat the dewatered sludge. An auger moves the sludge to an outlet.

Abstract: In wire cross-linking process, after microwave is launched into the inside of the waveguide coaxial converter, the coated wire is inserted into the wire insertion pipe. The coated wire is cross-linked by high frequency heat and a coating insulator is adhered well to an electric conductor by heat shrinking.

Abstract: A wire processing apparatus includes a microwave generator, a microwave transmitter, a waveguide coaxial converter and a wire insertion pipe, and the wire insertion pipe is disposed in the wireguide coaxial converter. In wire recycling process, after a tip end of a coated wire is inserted into the wire insertion pipe, microwave is launched into the inside of the waveguide coaxial converter. The tip end of the coated wire is separated into a decomposed coating insulator and a molten electric conductor by microwave. In wire cross-linking process, after microwave is launched into the inside of the waveguide coaxial converter, the coated wire is inserted into the wire insertion pipe. The coated wire is cross-linked by high frequency heat and a coating insulator is adhered well to an electric conductor by heat shrinking.

Abstract: A web coating machine for coating a web of material having first and second faces and a web travel path, the web coating machine including a tension zone in a portion of the web travel path, a fixed port structure over which the web travels, and a web positioning device including at least one gas flow port in the port structure capable of generating a vacuum that brings the first face of the web of material into contact with a portion of the port structure immediately surrounding one of more of the gas flow ports and reduces, retards or arrests longitudinal travel of the web of material through the web coating machine.

Abstract: Object for the invention is a method for treatment and drying of wood, in which at the first phase wood is warmed up over to the temperature close of the boiling point of water, and wood is compressed with a variable pressure between moisture permeable pressing elements, the temperature of the wood is increased so quickly, that the moisture existing in the wood does not have time to evaporate essentially before the temperature of the wood has increased around the boiling point of water. According to the invention when the surface layers of the timber have reached the temperature close the boiling point of the water the pressure is increased, and at the pressing phase the temperature of wood is kept at the temperature range close the boiling point of the water under that higher pressure.

Abstract: A method for performing multiple cleaning and vacuum drying operations in enclosed vessels uses cleaning and vacuum drying apparatus, low-dissolved-air cleaning solution, and drain-to-vacuum process to produce vacuum in a cleaning vessel, so that influence of air pressure on the operations is minimized. The method utilizes physical features that boiling points of general liquids lower with reduced pressure, that liquid saturated vapor pressure reduces with lowered temperature, and that two vacuum vessels of different working temperatures would have a pressure differential between their saturated vapor pressures, and uses heat control units and heat egress units to regulate temperature and pressure in the vacuumized cleaning vessel, so that wet clean, dry clean, vacuum heat drying, and vacuum freeze drying can be performed on the same apparatus, and low-pressure gas used in the dry clean and cleaning solution and waste solution can be recovered to achieve environment protection and energy saving.

Abstract: Disclosed is a method of drying timbers loaded in a drying chamber, which comprises the steps of heating the drying chamber by a heating system up to a temperature of 80 to 100° C., subjecting the timbers to vacuum blowing by connecting the inside of the drying chamber with a vacuum chamber (receiver) evacuated by a rotary pump until the inside pressure of the drying chamber drops to 1 to 10 mmHg, disconnecting the inside of the drying chamber from the vacuum chamber, connecting the drying chamber with the atmosphere. When the inside of the drying chamber is connected with the vacuum chamber, the moisture content of the timbers is sharply reduced, so that their temperature sharply drops. Thereafter, when it is disconnected from the vacuum chamber, and connected with the atmosphere, the inside temperature of the drying chamber is again increased. Meanwhile, the heating system is worked during the whole process.

Abstract: A method of and an apparatus for drying a wafer using the Marangoni effect quickly forms an isopropyl alcohol layer on a cleaning liquid in which the wafer is submerged. The isopropyl alcohol is first heated and then supplied in a fluid state onto the cleaning liquid. The isopropyl alcohol liquid thus diffuses rapidly to form the isopropyl alcohol layer. The wafer is thoroughly dried by removing it from the cleaning liquid through the isopropyl alcohol while only supplying more of the heated nitrogen gas into the ambient above the cleaning liquid.

Abstract: A process for the heat treatment of lignocellulosic material where the material is perheated and dried at a temperature close to the vaporization temperature of water, heated in a reducing atmosphere and cooled by the injection of water vapor.

Abstract: A processing method for processing a substrate has a vertical thermal processing furnace 4 having a bottom and an opening 4a provided at the bottom. A boat 3 holding substrates W in vertical multistairs can be placed on a first lid 17, and the first lid 17 can open and close the opening 4a of the vertical thermal processing furnace 4 with the boat 3 placed thereon. The processing unit also has a boat-placing portion 19 on which the boat 3 and another boat 3 can be placed and a boat conveying mechanism 21 for conveying the two boats 3 alternatively between the boat-placing portion 19 and the first lid 17. A second lid 18 hermetically closes the opening 4a of the vertical thermal processing furnace 4 when the first lid 17 opens the opening 4a but no boat 3 passes through the opening 4a.

Abstract: The present invention provides a drying method for removing a residual solution from a semiconductor wafer. The semiconductor wafer is placed into a chamber, and then the air pressure of the chamber is lowered from atmospheric pressure to a lower pressure. Next, an inert gas with a predetermined pressure is injected into the chamber to exchange with the dissolved oxygen in the residual solution. The pressure in the chamber is reduced to 0.5˜100 torr so as to lower the boiling point of the solution and to remove the displaced oxygen. Finally, a heating process is performed to completely evaporate the residual solution on the semiconductor wafer.

Abstract: A dryer for use with chemical compounds employs controlled vacuum, elevated temperature and dry, inert gas to dry the chemical compounds. The dryer includes a vacuum chamber into which trays containing the compounds are placed. The chamber includes heating elements which elevate the temperature of chemical samples placed within the chamber. Supplying and evacuating manifolds, each with a plurality of orifices for supplying and evacuating dry inert gas, provide a substantially laminar flow of dry inert gas just above the trays of chemical compounds which are to be dried. The laminar gas flow removes the unwanted vapor which tends to form above the tray of chemical compound, thus accelerating the drying process.

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.

Abstract: A dryer for use with chemical compounds employs controlled vacuum, elevated temperature and dry, inert gas to dry the chemical compounds. The dryer includes a vacuum chamber into which trays containing the compounds are placed. The chamber includes heating elements which elevate the temperature of chemical samples placed within the chamber. Supplying and evacuating manifolds, each with a plurality of orifices for supplying and evacuating dry inert gas, provide a substantially laminar flow of dry inert gas just above the trays of chemical compounds which are to be dried. The laminar gas flow removes the unwanted vapor which tends to form above the tray of chemical compound, thus accelerating the drying process.

Abstract: A steam re-compression vacuum dryer includes a vacuum tank for accommodating waste; a first steam duct for removing steam from the vacuum tank; a steam compressor for compressing steam removed from the vacuum tank via the first steam duct and for producing a vacuum pressure in the vacuum tank; a steam condenser disposed in and/or thermally coupled to the vacuum tank; a non-condensing gas exhausting device for automatically exhausting non-condensing gas from the steam condenser; and a condensation water exhausting device for automatically exhausting condensation water from the steam condenser. If desired, a gas heater can be provided on the first steam duct to heat gas withdrawn from the tank through this duct. This gas heater may use steam discharged from the steam compressor as a heat source. The steam condensing device can be disposed in the vacuum tank, or it can be integral with an outer surface of the vacuum tank (e.g., the tank wall may have a double wall construction).

Abstract: In a method for the cleaning of oil- and water-containing roll scale sludge, the roll scale sludge is introduced to a heatable treatment region 10 for a first drying step. In addition to the first drying step, a second drying step is provided for with which the roll scale sludge is subjected to a vacuum drying 14, 15. For this reason, the purification of the oil- and water-containing roll scale sludge is improved without additional auxiliary materials using only pure thermal energy in an effective manner which is applicable to large-scale commercial applications.

Abstract: A method of drying a coated monolithic substrate by imposing a vacuum at one end of the substrate to draw volatilized constituents out of the channels and by delivering a gas stream through the other end of the substrate during the drying process.

Abstract: A method and apparatus for drying of a material containing a volatile component, in which the material is disposed in a bed in a drying zone which is in communication with a closed circuit in which a gaseous drying medium is circulated. Associated with the drying gone is a closed heat pump system including a compressor, at least one condenser in the drying zone, a super heat exchanger and a working medium. The drying zone is supplied with super heat from the super heat exchanger, and the condenser is supplied with working medium from a super heat exchanger, thereby increasing the temperature in the drying zone.

Abstract: The invention provides a method and an apparatus for vacuum drying of a material, particularly timber or the like. The apparatus comprises a drying chamber (1), a vacuum producing unit (6) coupled with the drying chamber, a cooler structure (2,4), and devices for heating the drying chamber (1). The cooler structure (2,4) and the drying chamber (1) are coupled together by a compression unit (9) that may be placed substantially within the drying chamber (1). The cooler structure (2,4) is placed at least partially in a heat transfer connection with the drying chamber (1).

Abstract: The present invention is a method and apparatus for the dynamic cleaning of semiconductor fabrication equipment and particularly quartzware with thermally activated nitrogen trifluoride wherein the cleaning effluent is safely removed and cleaning by-products isolated or diluted to provide for efficient cleaning and rapid restarts of fabrication equipment so cleaned.

Abstract: A method for feeding metalorganic gas from solid raw materials in MOCVD and its device provides an absorption reagent consisting of porous grains into which a solid metalorganic material is absorbed and the passing of the carrier gas among the absorptive porous grains in the container under a high thermal condition. The mixture gas including the metalorganic gas at a constant density is obtained in stability for a long time.

Abstract: A process for drying water-containing materials in a closed-circuit system using a vertical drying tower having inlets located at a lower portion of the tower, the inlets circulating superheated steam in countercurrent to the water-containing materials descending through the vertical drying tower thereby drying the water-containing materials, the improvement being:(a) providing an auxiliary fluid having a temperature below that of the superheated steam entering into the vertical drying tower;(b) providing a double jacket having a permeable inner wall wherein the double jacket surrounds the lower portion of the vertical drying tower below the inlets; and(c) introducing the auxiliary fluid through the permeable inner wall of the double jacket and into the vertical drying tower in a tangential or radial direction relative to the permeable inner wall.

Abstract: Material containing organic substances including rubber, plastic, and lacquer is heated in a vacuum process chamber at subatmospheric pressure in a nonreactive atmosphere to a temperature of at least 200.degree. C., the gases and vapors thus formed are condensed in a condensate separator, and the condensate is captured and made available for reuse or disposal. The embrittled residues formed from these substances are crushed and the crushed residues are collected and made available for recycling or disposal. If metals are contained in the material, the residues are loosened, collected, and crushed. The process and the apparatus are suitable for recycling insulted wire, metal bonded to rubber, plastic containers decorated with pigments, motor vehicle steering wheels, workpiece hangers and tools coated with lacquer, poorly lacquered metal parts, tires and rubber pads of track-laying vehicles, and seals.

Abstract: An article is dried in a vacuum and sublimation is prevented by controlling both the heat applied to the article and the heat lost through evaporation. The article is placed in a vacuum chamber having a plurality of infrared lamps disposed around the interior of the chamber and the chamber is heated to a predetermined temperature prior to evacuation. Heat loss is controlled by maintaining the pressure above approximately 5 torr, which controls the rate of evaporation. The drying cycle also cleans the article.

Abstract: A process and a device for evacuating a drying room filled with one or more evaporable fluids or one or more non-evaporable fluids or mixtures thereof. The device includes a turbo engine, a liquid seal pump and a condensor. The pressure of the fluids or mixture of fluids is raised by the turbo engine, the resulting volume flow is reduced by condensation in the condensor, and the resulting reduced volume flow is pumped off with the pump.

Abstract: The invention relates to a process for the regulation of lyophilization in which the evaporative flux--that is to say, the output of evaporated water transferred on the trap (4)--is measured in a continuous manner, and action is carried out at the temperature of the racks (2) in order to reach, as close as possible, a predetermined optimal flux.

Abstract: A vacuum creating method comprising preparing a chamber for forming a space which can be made so atmospheric and vacuous as to allow a substrate to be directly or indirectly carried in and out of the space, exhausting the chamber, filling the space in the chamber with a CO.sub.2 gas whose vapor pressure becomes larger than 1 atm at ambient temperature but smaller than 10 Torr at a temperature lower than the ambient temperature, carrying the substrate into the chamber, cooling the CO.sub.2 gas to solidify, thereby making an internal pressure in the chamber highly vacuous, carrying the substrate out of the chamber, and heating the solidified dry ice to vaporize thereby returning the internal pressure in the chamber to atmospheric pressure.

Abstract: Method and apparatus for generating and delivering a gas that contains vapor produced by subliming a solid for use in chemical vapor deposition processes such as Metal Organic Molecular Beam Epitaxy (MOMBE) and Organometallic Vapor Phase Epitaxy (OMVPE). The method includes generating a gas saturated with the vapor and subsequently diluting the gas with an inert gas to obtain an uniform non-saturated gas. The apparatus includes a vessel for containing a sublimable solid, a heater for maintaining the vessel at a desired temperature, tubes and valves for introducing a gas into the vessel and for discharging a gas that is saturated with the vapor of the solid from the vessel, and a tube and a valve for diluting a gas discharged from the vessel.

Abstract: A vacuum drying apparatus characterized by a means for pre-heating a product by hot air, provided to a vacuum container having a heater housed therein.

Abstract: An improved method and apparatus are provided for subliming solid precursors, and especially organometallic precursors, for use in a chemical vapor deposition (CVD) process. The sublimation apparatus includes a sealed vessel having a vacuum chamber. A quantity of the solid precursor is mixed with a loosely packed particulate material, such as ceramic beads, placed within the vacuum chamber. The vacuum chamber and particulate material are heated. A supply of a carrier gas is directed through the particulate material (particularly through pockets formed in the particulate material) to sublime the precursor which coats the individual particles of particulate material. By agitating the particulate material, a relatively constant sublimation area is maintained. Agitation of the particulate material may be with a mechanical stirrer or by directing an a.c. field through a piezoelectric particulate material.

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.

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.