Abstract: A method of separating objectionable particles from host tobacco material which includes fluidizing the tobacco material with a fluidizing air stream to allow heavy unwanted particles to fall, to cause light unwanted particles to rise and be air transported away and to leave a carpet of acceptable material.

Abstract: A process for the expansion of tobacco, wherein in step (a) the tobacco is cooled by being mixed with cold carbon dioxide; (b) the cooled tobacco is impregnated with liquid carbon dioxide through treatment with gaseous carbon dioxide under a predetermined pressure; (c) the liquid carbon dioxide condensed in the tobacco is converted to solid carbon dioxide through pressure reduction; and (d) the tobacco containing solid carbon dioxide is subjected to a hot gas treatment to achieve the expansion. In step (a) the tobacco is cooled to a temperature of -30.degree. C. to -100.degree. C. through expansion of liquid carbon dioxide and the simultaneous mixing of the tobacco therewith.

Abstract: A disinfestation system for agricultural products, for example recovered tobacco, comprises a disinfestation unit which is releasably connected to plural containers. The disinfestation unit supplies a disinfestation gas (CO.sub.2) through the conduit means to the container, and periodically withdraws sample gas from said container. A thermal conductivity detector produces an electrical signal representation of the level of CO.sub.2 in the container, which is supplied, along with a temperature dependent signal, to a computer. The processor controls the introduction of additional CO.sub.2 throughout the process. Preferably, the system also includes heater elements, and the processor generates control signals for controlling temperature in the container. The computer controls the disinfestation process of multiple containers such multiple disinfestation processes can be carried out simultaneously.

Abstract: A method of conditioning tobacco including the steps of: a) vibrating tobacco particles by means of a vibratory conveyor to produce a continuous stream to be transferred along a predetermined path, the conveyor being vibrated in such a manner that the stream of tobacco particles remains in contact with the supporting surface of the conveyor during transportation; b) contacting substantially all of the particles of tobacco with steam by continuously passing steam upwardly through perforations in said conveyor; and c) maintaining said steam at a pressure sufficient to enable the steam to diffuse into the interstices between the particles without causing said stream of tobacco particles to be lifted out of contact with the supporting surface of the conveyor, wherein the steam passing by way of the perforations includes a component of flow parallel with the supporting surface of the conveyor.

Abstract: A process and apparatus for impregnating a cellular material with liquefied gas at a predetermined pressure for subsequent expansion of the impregnated cellular material including the steps of charging the cellular material into an impregnation vessel, purging the impregnation vessel with inert gas, pressurizing the impregnation vessel with inert gas to the predetermined pressure, transferring liquefied inert gas into the impregnation vessel from a process vessel in which the liquefied gas is stored at the predetermined pressure, soaking the cellular material in the liquefied inert gas for a predetermined time period, transferring unabsorbed liquefied gas from the impregnation vessel to the storage vessel, depressurizing the impregnation vessel by venting the inert gas therefrom and removing the impregnated cellular material from the impregnation vessel, the inert gas used to purge and pressurize the impregnation vessel being taken from a source completely independent of the liquefied inert gas contained in t

Abstract: The invention is directed to a process for expanding tobacco wherein tobacco is impregnated with gaseous 1,1,1,2-tetrafluoroethane and thereafter heated in an expansion zone to liberate the 1,1,1,2-tetrafluoroethane and cause expansion of the tobacco. The process of the invention can provide substantial expansion of tobacco cut filler lamina without substantial generation of tobacco fines and employing substantially mild pressures of, for example, less than about 3,000 psi and with minimal effect on tobacco flavor.

Abstract: Process and apparatus for the treatment of tobacco material and other biological materials includes a mechanism comprising a dynamic seal having components having cooperating movable surfaces for sealing a treatment chamber that substantially prevents the passage of fluid at the treatment chamber pressure during movement of the components for introducing material into and removing material from the chamber. The seal components preferably comprise advanced structural ceramic components having a hardness of at least 900 kg/mm.sup.2 and a flatness of at least 70 microinches. The process is preferably conducted at supercritical gaseous conditions.

Abstract: The invention is directed to a process for increasing the filling capacity of tobacco under moderate conditions of temperature and pressure. Tobacco is impregnanted with a low boiling impregnant and thereafter subjected to a pre-expansion treatment. The pre-expansion treatment includes a pre-expansion temperature which is above the atmospheric boiling point of the impregnant and which is at least ten degrees below the critical temperature of the impregnant; and a pressure which is at least five atmospheres above the boiling point pressure of the impregnant at the pre-expansion temperature. Under these conditions, the impregnant is maintained primarily in the liquid phase throughout the pre-expansion treatment. Following the pre-expansion treatment, the pressure of the treated tobacco is rapidly reduced to a pressure below the boiling point pressure of the impregnant to thereby effect tobacco expansion without the need for a separate heating step.

Abstract: The invention is directed to a process for expanding tobacco wherein tobacco is impregnated with sulfur hexafluoride and thereafter heated in an expansion zone to liberate the sulfur hexafluoride and cause expansion of the tobacco. The process of the invention can provide substantial expansion of tobacco cut filler lamina without substantial generation of tobacco fines and employing substantially mild pressure of, for example, less than about 2,000 psi and with minimal effect on tobacco taste. The invention additionally provides an intermediate tobacco product comprising tobacco cut filler lamina impregnated with sulfur hexafluoride in a substantially pliable and unextracted condition.

Abstract: An expanding apparatus of this invention includes a preparatory vessel that is supplied with material of agricultural origin, for example, tobacco material. The tobacco material in the preparatory vessel is supplied to an impregnation vessel through a convey pipe. Carbon dioxide having an impregnation pressure is supplied to the impregnation vessel so as to fill the same. A booster mechanism is associated with the convey pipe to increase the pressure of carbon dioxide around the tobacco material to a pressure substantially equal to the impregnation pressure in the impregnation vessel when the tobacco material is supplied from the preparatory vessel to the impregnation vessel. The tobacco material impregnated in the impregnation vessel is discharged to a blow pipe through a delivery pipe and is expanded by means of a heating medium generated in the blow pipe.

Abstract: The invention is directed to a process for increasing the filling capacity of tobacco wherein tobacco is contacted with a mixture of an inert, normally gaseous expansion agent and about 15-35 weight percent of carbon dioxide at a pressure above the critical pressure of the mixture and a temperature above the critical temperature of the mixture, followed by rapid release of pressure to provide expanded tobacco without a subsequent heating step. Advantageously, the expansion agent is propane.

Abstract: Cigarette rods and filter rods are provided by manufacturing rods from tobacco cut filler and a circumscribing paper wrap, and then subjecting the rods to conditions such that the cut filler undergoes volume expansion while within the paper wrap. For example, the tobacco rods can be exposed to propane under supercritical conditions within a pressure chamber followed by a venting of the gaseous fluid to expand the tobacco cut filler. The resulting rods are very firm, have good integrity, and frequently do not undergo any noticeable visible change. The resulting rods which contain the volume expanded tobacco can be used as smokable rods for cigarettes or as cigarette filters.

Abstract: In a method and apparatus for treating particulate material, the material, when in a mobilization zone bounded by upwardly divergent walls, is subjected to a flow of gaseous mobilizing medium, supplied at a multiplicity of sites of the walls, and preferably also to a simultaneous flow of gaseous accelerating medium supplied in an upward direction from a lower region of the zone. The treatments include drying, moistening, heating, cooling and blending.

Abstract: A method and apparatus for puffing biological material such as fruits and vegetables are provided. The method includes the steps of: (a) placing the material in a pressure chamber; (b) subjecting the material to a puffing gas such as carbon dioxide at an increased pressure between substantially 400 and 1200 psi; (c) quickly releasing the puffing gas pressure in less than 1 second to puff the material; and (d) drying the material after puffing to set it in the puffed state. The material is prepared for puffing by sizing so as to include at least one dimension of between substantially 0.025 and 1.0 inches. The moisture content is also reduced or increased to between substantially 15 and 60% wet basis. Puffing gas usage may be minimized by overpressuring with an inert gas such as nitrogen. The apparatus includes a variable volume pressure chamber that also allows usage of puffing gas to be minimized. More specifically, the volume of the chamber is maintained relatively small during charging with puffing gas.

Abstract: Apparatus for the expansion of tobacco includes a substantially cylindrical container (10), conveyors for feeding tobacco into the container and jet nozzles or slits for introducing a heating medium in the form of steam and/or humid air into the container. The jet nozzles or slits (12) are arranged substantially longitudinally of the container axis serving to direct high pressure steam and/or humid air substantially tangentially to the interior surface of the container (10) to engage the tobacco being fed into the container causing a turbulent mixture of steam, and/or humid air, and tobacco to travel along a helical path and to be maintained by centrifugal force in close proximity to the interior surface of the container as the stream moves axially therein and to maintain the circulation and to provide a succession of repeated high relative velocity, highly turbulent and dispersive contacts between the heating medium and the tobacco.

Abstract: In order to effect expansion of a shredded material, said material is impregnated with an inert organic liquid, which is subsequently vaporized. The major portion of the impregnation agent is removed by separation. In order to eliminate the residual amount of impregnation agent still contained in the material, the material is fed by conveyor belt (31) into a microwave chamber (35). The microwave chamber (35) is provided with microwave energy under continuous control conditions. The vapors are siphoned off and fed into a regenerator for recovery of the impregnation agent. Conditioned, pressurized air is directed at the material in the microwave chamber (35) through discharge nozzles (38) to cause the material to whirl up and become fluidized. The pressurized air serves as a carrier gas for the residual impregnation agent that is to be removed and may simultaneously be used for conditioning the tobacco.

Abstract: A separator for separating tobacco particles from a tobacco/gas mixture comprises a hood, a circular deflection space disposed in the hood, an inlet for the tobacco/gas mixture to be separated opening tangentially into the circular deflection space, a downwardly directed outlet in the deflection space for the tobacco particles, an outlet for the tobacco particles at the lower end of the hood, and an outlet for the gas above the deflection space. The deflection space is formed by an upwardly closed and downwardly open cylinder; the gas is withdrawn from the hood above the deflection space; the size ratio of the area of the deflection space to the area of the inlet lies between 5 and 30; and the size ratio of the area of the hood to the area of the inlet is greater than 50.

Abstract: Extraction means capable of providing a constant feed rate to the inlet of a tobacco expansion pneumatic transport system is provided at the outlet of a tobacco reservoir zone. The extraction means is preferably in the form of a pinned roller capable of metering tobacco, associated with a pinned tobacco opening roller. The extraction means feeds the extracted tobacco into a transport duct as a stream extending across the full width of the duct at a flow rate which is also uniform across the width of the stream.

Abstract: Flue-cured tobacco can be treated with burley tobacco flavor components and subjected to volume expansion conditions. Flavor components are supercritically extracted from burley tabacco and directly applied to the flue-cured tobacco while the extraction fluid is in a supercritical or subcritical state.

Abstract: A tobacco particles separator utilizes turbulent air flow, flow vortices, and a random spread matrix in an air circulation path to separate and singularize tobacco particles. A moving porous web is used to receive and to hold the separated particles which may be retained on the porous web for subsequent analysis.

Abstract: A stream of air is circulated by a blower along an endless path a portion of which is defined by an upright duct having an air inlet at its lower end, an air outlet at its upper end, and an inlet for comminuted tobacco particles intermediate its air inlet and air outlet. The particles of tobacco which are admitted into the duct are classified according to weight by the ascending air stream which advances satisfactory particles toward the outlet where the particles are attracted to a driven foraminous belt conveyor to form a growing tobacco stream. The air inlet of the duct contains a rotary impeller which distributes the inflowing air across the full width of the duct so that the thus formed air stream ensures a predictable classifying action and the formation of a homogeneous shower of satisfactory particles which are advanced toward the stream growing zone.

Abstract: A process and apparatus for improved expansion of tobacco is disclosed wherein tobacco impregnated with a volatile impregnant is treated prior to expansion, in an intermediate stage wherein a gaseous phase containing volatile impregnant vapors is removed and later recovered. The thus treated tobacco is thereafter expanded in a conventional expansion zone by contacting the tobacco with a stream of hot gases. The invention results in more efficient use of volatile impregnant and can provide less residual impregnant in expanded tobacco while not decreasing the degree of tobacco expansion.

Abstract: Comminuted tobacco material expanding apparatus which includes a cellular wheel feeder and an expansion chamber integrated in the cellular wheel feeder. A nozzle opening in a wall of the expansion chamber provides for the introduction of a mixture of air and stream for accelerating the tobacco material under a pressure drop to at least 50 m/s with a residence time of the tobacco material in the expansion chamber of less than about 1/10 s. At least one nozzle opening is located in an end wall of the expansion chamber near the bottom so that an adjustable stream/air mixture moves the tobacco material substantially at a right-angle out of the expansion chamber. The expansion chamber is connected to an acceleration tube with converging cross-section which is connected to a delay tube.

Abstract: Apparatus to expand shredded material, the latter is impregnated with an inert organic liquid which is evaporated subsequently. The substantial portion of the impregnant is separated. To eliminate the residual amount of impregnate still contained in the material, the material is fed in heaps on a conveyor belt (36) to a microwave chamber (39). Upstream and downstream of the microwave chamber, one sluice each (38,40) is provided. The gates (43,44;49,51) of the sluice are synchronized with the drive of the conveyor belt (36). Microwave energy is supplied under continuous control to the microwave chamber (39). The vapors are removed by suction lines (47,55) and fed to a regenerator for recovery of the impregnant.

Abstract: Mobilization apparatus for the treatment, drying for example, of particulate material comprises a mobilization zone bounded by upwardly divergent walls. Particulate material in the zone is mobilized by being subjected to a flow of gaseous mobilizing medium supplied at a multiplicity of sites of the divergent walls. The material is simultaneously subjected to a flow of gaseous accelerating medium supplied in an upward direction from a lower region of the mobilization zone. The obtains in the mobilization zone of circulatory pattern comprising downward flow at the divergent walls and upward flow from a lower region of the zone.In order to discharge the particulate material from the apparatus, a mask extending outwardly from the lower end of an upwardly extending discharge duct is brought to the upper end of the mobilization zone. The result is that the circulatory pattern is destroyed and the material is pneumatically transported up the discharge duct.

Abstract: A process for expanding tobacco includes the steps of adjusting the moisture content of cut tobacco, pressurizing the cut tobacco with or without treatment, releasing the pressurized cut tobacco rapidly into a dryer and reordering the tobacco. The apparatus includes a housing having at least one chamber and preferably a chamber divided into a plurality of isolated sectors. Tobacco is received in the chamber or in each sector and released quickly from the housing following at least the step of pressurization of tobacco by steam. The apparatus may be used for batch and continuous treatment of tobacco. According to the continuous treatment, the sectors are formed by a rotating member, and each sector of the member is filled with tobacco as the member rotates relative to an inlet. The inlet and an outlet through which treated tobacco falls are in vertical alignment.

Abstract: Fragments of tobacco ribs are puffed in an elongated tunnel which is vibrated to advance the particles from the inlet toward the outlet. The particles in the tunnel are contacted by streamlets of supersaturated or superheated steam at such temperature and pressure that the temperature of the particles is raised to between 100.5.degree. and 120.degree. C. To this end, steam is admitted at 2.5 to 25 bar absolute pressure and at a temperature of between 126.degree. and 400.degree. C. The thus heated particles of tobacco ribs are thereupon dried.

Abstract: An improved tobacco treating expansion process involving controlling the moisture content of tobacco and the pre-separator residence time thereof in a treatment of the moisture controlled tobacco under preselected pressures and temperatures so that the tobacco at exit from the drying step of the process has a moisture content in the range of approximately 9% to approximately 15% oven volatiles by weight and fill values at least equivalent to fill values of tobaccos dried to a lower moisture content not exceeding 6% oven volatiles.

Abstract: In a method of expanding tobacco the tobacco is contacted in a first vessel with an expansion agent and, with the vessel being closed and liquid phase expansion agent in the tobacco being at a temperature above the boiling point at a lower, release pressure, the first vessel is connected to a closed second vessel the interior of which is at the release pressure. When the tobacco is contacted in the first vessel with the expansion agent, the tobacco is maintained in a mobilized, particle separated condition by supplying gaseous mobilizing medium to a mobilizing zone of the first vessel via nozzles located at upwardly diverging walls bounding the zone and preferably supplying in addition gaseous accelerating medium to the zone in an upward direction from a lower region of the zone.

Abstract: An improved tobacco treating process for smoking articles including the steps of shredding the tobacco in a disc shredder, controlling the specific energy imparted to the tobacco being shredded to an empirically predetermined value, and processing the shredded tobacco under high humidity drying conditions.

Abstract: Tobacco expansion apparatus comprises a transport duct in which can be established a flow of hot gaseous medium and into an upstream end of which can be fed particulate tobacco. The downstream end of the duct opens into the casing of a tobacco/gaseous medium separator comprising a separation screen.

Abstract: The method for expanding tabacco lamina comprises contacting the tobacco with an organic expansion agent, heating the thus contacted tobacco in a closed first vessel so that the temperature of the agent is above the boiling point of the agent at a lower release pressure, and suddenly venting the first vessel into a second vessel which is at said release pressure prior to the venting. By this means the fill volume of the tobacco is increased by a least 50%.

Abstract: In the expansion of tobacco, the tobacco is entrained in hot gaseous medium, separated from the gaseous medium and re-introduced and re-entrained in the gaseous medium before being once again separated from the medium.

Abstract: An improved tobacco treating process for smoking articles including the steps of introducing tobacco to be dryed into a restricted pressure and flow controllable system to be entrained by pressurized stream for preselected residence time before disentrainment therefrom, the steam being held at preselected minimum pressure and velocity to improve fill value and smoking quality of the tobacco.

Abstract: A method and apparatus for carrying out the volume-expansion (puffing) of disintegrated tobacco, wherein said tobacco is impregnated with an impregnating medium containing water and/or orthophosphoric acid and/or the sodium or ammonium salts thereof and/or ammonium sulphate to an initial moisture content of at least about 35% by weight, and is then reduced to a final moisture content of about 10-13% by weight with the aid of a heating medium containing gaseous water vapor, the overall duration of the method being at least about 10 seconds.

Abstract: A tobacco expansion agent capable of synergistic tobacco expansion comprises a first organic compound which is volatile, non-polar and substantially water insoluble and a second organic compound which is volatile, water soluble, oxygen containing and of a polarity in excess of that of the first compound.

Abstract: An improved tobacco treating process comprising cooling tobacco in a liquid nitrogen bath, impregnating the mixture with carbon dioxide gas under preselected pressure conditions, releasing the pressure and subjecting the so treated tobacco to drying gases with temperatures at least above about 250.degree. F. with wet bulb temperatures in the range of at least about 150.degree. F. with a maximum of 212.degree. F.

Abstract: A method and preferred apparatus for expanding moisture containing tobacco. Tobacco is very rapidly heated by a stream of heated gas, by contacting a high speed downdraft flow of said gas with said tobacco while said tobacco is in transit on a gas porous conveyer. The conveyer is preferably configured as a cylindrical drum with a gas porous cylindrical surface, rotating about its axis.

Abstract: An improved tobacco treating process for smoking articles including the steps of moistening and shredding tobacco stems at a preselected temperature range and drying such shredded stems under high humidity conditions controlled to obtain unexpectedly high fill values.

Abstract: Process for improving the fillability of tobacco, such as cut tobacco leaves or ribs and tobacco additives by treating the tobacco in an autoclave with a containing nitrogen and/or argon at pressures up to 1000 bar, with subsequent decompression and a gas heat treatment. The tobacco or the treatment gas supplied to the reactor and/or the decompression step are carried out in such a way that the discharged tobacco which is thereafter supplied to a subsequent heat treatment has a temperature, at introduction to the heat treatment step, below 0.degree. C. This is achieved by precooling the treatment gas prior to supplying it to the autoclave or cooling the treatment gas while supplying it to the autoclave and/or additionally cooling the autoclave and/or precooling the tobacco and/or injecting subcooled or liquefied treatment gas into the autoclave. The process includes multistage treatment gas whereby supply and decompression steps are carried out in a cascade-like manner.

Abstract: A process and apparatus for producing a smoking tobacco having a low nitrate content includes at least one stage through which a tobacco having a relatively high nitrate content, for example burley tobacco, continuously passes for continuous nitrate removal by dissolution. In the nitrate removal stage, a solvent is added to, for example, the burley tobacco to form a slurry. The free solvent, including dissolved nitrates, is decanted from the slurry leaving saturated burley tobacco. The saturated burley tobacco is subjected to an expression pressure to remove a further amount of solvent and dissolved nitrates therefrom. After the burley tobacco leaves the nitrate removing stage, it is mixed with another tobacco, such as, for example, a flue-cured tobacco. The tobacco mixture is then expanded and dried to a moisture content suitable for use in a smoking article.

Abstract: Methods and apparatus for treating a continuous flow of tobacco under pressure include introducing said tobacco to a pressurized chamber through an entrance lock device, impregnating said tobacco with a pressurized gas or its liquid phase within said chamber, and discharging said impregnated tobacco from said chamber through an exit lock device. Liquid impregnant may be applied as a fine spray within said chamber, and subsequent expansion of said tobacco may be performed by decompression, heating, or by decompression and heating in combination.

Abstract: A fluid pressure treating apparatus including a cylindrical tubular shell with a reciprocal spool assembly mounted for movement between a loading position outside the shell and a treating position within the shell, sealing members on said spool assembly for engaging the shell to form the pressure chamber. Conduits are provided to introduce processing fluid into the pressure chamber.

Abstract: A process for increasing and maintaining the filling power of tobacco, in which an effective amount of at least one cross-linking agent is applied to the tobacco and reacted with various components therein. The cross-linking agent may be applied directly or in the form of a solution, and is preferably employed in conjunction with an expansion treatment of the tobacco.

Abstract: An improved tobacco treating process wherein fill value improvement can be obtained with less energy and less carbon dioxide requirements comprising mixing tobacco with finely divided solid CO.sub.2 at controlled preselected parts by weight, impregnating the mixture with carbon dioxide gas under preselected pressure conditions, releasing the pressure and subjecting the so treated tobacco to drying gases with temperatures at least above 250.degree. F. with wet bulb temperatures in the range of at least about 150.degree. F. to a maximum of 212.degree. F.

Abstract: Increases in filling capacity of 30 to 100% are achieved when tobacco material with a moisture content of 18 to 80% by weight and a temperature of -80.degree. to 100.degree. C. is accelerated to a velocity of at least 20 meters per second by means of a gaseous medium, is subsequently decelerated and is dried in a conventional way. The tobacco material can be accelerated, together with the gaseous medium, in a nozzle of the Venturi type or can be introduced into the fast-flowing gaseous medium.

Abstract: Tobacco ribs, whose moisture content is at least 38 percent and which are heated to a temperature of at least 60 degrees C., are admitted into a cylindrical chamber containing a centrally located nozzle which is surrounded by a driven impeller having arcuate vanes serving to direct tobacco particles at a uniform rate into a high-speed stream of air or steam which issues from the orifice of the nozzle and leaves the chamber through a tapering outlet to pass through a Laval nozzle and into a dryer. The latter is designed to heat a stream of air to a temperature of approximately 350 degrees C. and to mix such air with the stream which admits the particles of tobacco whereby the particles are heated to a temperature of approximately 80 degrees C. and their moisture content is reduced to or below 20 percent.

Abstract: The present invention relates to a process for increasing the filling power of tobacco which comprises heating the tobacco at elevated temperature while maintaining the OV and SV values of the tobacco substantially constant. Preferably, the tobacco is heated at a temperature of at least about 80.degree. C. in a closed system for a time sufficient to increase the CV value of the tobacco.

Abstract: A process for expanding tobacco is provided which employs liquid carbon dioxide as the expansion agent. Tobacco is contacted with liquid carbon dioxide to thoroughly impregnate the tobacco with the liquid carbon dioxide. The carbon dioxide impregnated tobacco is maintained at a temperature no lower than -2.degree. C. and under conditions of temperature and elevated pressure such that all or substantially all of the carbon dioxide which is in contact with the tobacco is in liquid form. After the impregnation has been completed, any excess liquid carbon dioxide which may be present with the tobacco may be removed from the tobacco. The elevated pressure is then reduced in order to convert the liquid carbon dioxide to solid carbon dioxide within the tobacco structure.

Abstract: This invention relates broadly to an improved process for expanding tobacco and involves certain modifications of the basic process for expanding tobacco comprising the steps of (1) contacting the tobacco with liquid carbon dioxide to impregnate the tobacco with the liquid carbon dioxide, (2) subjecting the liquid carbon dioxide-impregnated tobacco to conditions such that the liquid carbon dioxide is converted to solid carbon dioxide and (3) thereafter subjecting the solid carbon dioxide-containing tobacco to conditions whereby the solid carbon dioxide is vaporized to cause expansion of the tobacco. The present invention pertains, in one embodiment, to an improvement in the basic process which involves controlling the moisture content of the tobacco which is employed in the first step of the basic process.