RO111821B1 - Process for the raising or lowering of the moisture content of an organic material - Google Patents

Abstract

A process for reordering tobacco, which results in no significant decrease in equilibrium tobacco CV or significant tobacco degradation, is provided. Tobacco to be reordered is contacted with an air stream having a relative humidity near the equilibrium conditions of the tobacco. As the ov content of the tobacco increases, the relative humidity of the air stream contacting the tobacco is increased to affect reordering of the tobacco. Also provided is a process for drying tobacco, which results in no significant change in equilibrium tobacco CV or significant tobacco degradation. Tobacco to be dried is contacted with an air stream having a relative humidity near or below the equilibrium conditions of the tobacco. As the OV content of the tobacco decreases, the relative humidity of the air stream contacting the tobacco is decreased to affect drying of the tobacco. It has been found that tobacco can be reordered or dried successfully in a continuous manner using a self-stacking spiral conveyor. <IMAGE>

Description

The present invention relates to a process for increasing or decreasing the moisture content of hygroscopic organic materials, such as pharmaceuticals and agricultural products, including tobacco, fruits, vegetables, cereals, coffee and tea. In particular, this invention relates to the controlled use of air humidity to moisten or dry these materials.

In the field, it has long been recognized the need to control the moisture content of various organic materials, including tobacco. For example, the moisture content of tobacco that has been processed as a useful product has changed many times. Each processing step, for example, removing the stalk, cutting, mixing the components, adding flavorings, expanding and manufacturing them in the form of cigarettes, requires certain optimum levels of humidity that must be carefully controlled to ensure the top quality of tobacco and tobacco. other products from hygroscopic organic materials. Moreover, the manner in which the moisture content of the organic material is modified can have a lasting effect on the physical, chemical and subjective characteristics of the final product. Therefore, the methods for making changes in the moisture content of tobacco or other organic materials are important.

Rearranging expanded tobacco is a particularly demanding process. Typically, the tobacco obtained from the expansion process will have a moisture content below 6%, and often less than 3%. At such low moisture content, tobacco is highly susceptible to crushing. In addition, the expanded tobacco structure can be compressed upon rearrangement, meaning it suffers a full or partial return to its unexpanded state. This compression results in a loss of filling capacity, thus decreasing the profit derived from the expansion process.

Various means were used to rearrange the expanded tobacco. The most common method is to subject the tobacco to a spray of water, usually, while the tobacco is rolled into a cylinder. Another method is to use saturated steam as a rearrangement medium. An additional method is to blow high humidity air through a moving tobacco bed on a carrier, as shown in US 4,178,946.

None of the above methods is considered completely satisfactory for use in expanded tobacco. Rolling the tobacco into a spray cylinder can result in the shattering of expanded tobacco, which is fragile. Direct contact with liquid water tends to lead to deflation of the expanded tobacco structure. Steam rearrangement also leads to the deflation of the expanded tobacco structure. While this may be partly attributed to the high temperature in the steam environment, exposure of expanded tobacco to any gaseous environment in which water condensation, such as steam or a high humidity air environment, may lead to collapses (compression). .

One method, which has been used to avoid these difficulties, is to place the expanded, dry tobacco in a room containing air with a desired moisture level and allow the tobacco to balance in the room over a period of 24 hours. at 48 h. The air velocity per room is kept very low, usually not more than 7.6 m / min. This process leads to a slight if not non-existent deflation of the expanded tobacco structure. However, the long periods of time required, 24 to 48 hours, limited its application to laboratory purposes.

Attempts have been made to reduce the time required for such a balancing process by increasing the air speed. Such attempts were not successful, due to an inability to reproduce the maintenance of filling power observed in slow laboratory balances, the size of the carriers required for the transport of tobacco to match the required length of stay, the uniformity of the moisture content. of the tobacco product, which emerges from such trans

EN 111821 Carriers, and the incidence of ignitions in such units, as described in US

4202357

The use of drying, as a means of controlling the moisture content during the processing of tobacco, is of equal importance to that of rearrangement. When the tobacco is dry, both chemical and physical changes can occur, which can affect the physical and subjective quality of the product. Therefore, the method of drying tobacco is of particular importance.

There are generally two types of drying equipment, used in the tobacco industry: rotary dryers, and conveyor or ramp dryers. Pneumatic dryers are also used sometimes. The type of dryer is chosen according to the drying operation required. Conveyor or ramp dryers, for example, are normally used for striped tobacco, while rotary dryers are used for cut tobacco. For drying the stems, both rotary and conveyor dryers are used.

In a conveyor dryer, the tobacco is spread on a perforated conveyor belt and the air is directed either up or down through the conveyor belt and the tobacco bed. Due to the channels formed by the tobacco bed, it is often the uneven drying of the tobacco, because thus the drying air penetrates the tobacco locally.

Most rotary dryers, used in the tobacco industry, are lined with steam coils and can operate either as indirect or direct heat dryers depending on the location of heat outside or inside the coat of the dryer containing tobacco. Moreover, they can be operated either in co-current when the tobacco and air flow in the same direction or in the counter current when the tobacco and air flow in opposite directions. Rotary dryers must be carefully controlled to avoid overheating, which causes, through the rotary movement, both chemical changes and unnecessary crushing.

In addition, if the drying occurs too quickly, on the outer surface of the tobacco, an unforeseen layer may form, making it difficult to spread the internal moisture of the tobacco to the surface. The formation of such a layer slows the drying rate and leads to uneven drying.

The use of the rotary dryer or conveyor to dry the tobacco can lead to heat treatment that can lead to physical and chemical changes in tobacco, which although not always desired, requires the removal of tobacco water.

In typical tobacco applications, the requirement of dry tobacco within a limited time period dictates a result of the heat treatment from the drying step, which prevents the optimization of the heat treatment separated by the constraints of the drying process.

The technical problem, which the invention solves, consists in adjusting the moisture content of a hygroscopic organic material to a predetermined final moisture content, without breaking or modifying its physical structure or chemical composition.

The process of increasing or decreasing the moisture content of a hygroscopic organic material, selected from food, tobacco, tea and coffee, up to a predetermined final moisture content comprising the steps:

(a) forming a bed of hygroscopic organic material by depositing the hygroscopic organic material on a conveyor:

(b) the transport of the hygroscopic organic material deposited on the conveyor along the troughs of a spiral conveyor, from the inlet portion to the outlet portion of the conveyor; and (c) contacting the hygroscopic material with an air stream, as opposed to the bed of hygroscopic organic material, consists in the fact that (d) the air stream is introduced during the transport stage on the exit portion of the conveyor, has a relative humidity approximately equal to the initial relative equilibrium humidity: and

EN 111821 Bl (e) is maintained in the conveyor together with the hygroscopic organic material near the equilibrium conditions such that as it passes countercurrently over the organic material bed, the airflow is dehydrated or progressively hydrated, and the hygroscopic organic material is hydrated or dehydrated, progressively, until the desired moisture content of the material is reached.

In this process, the equilibrium volume (CV) at equilibrium of the organic material after step (d) is insignificantly smaller than (CV) at equilibrium of the organic material before step (b), (CV) at equilibrium of the organic material after the step (e) is insignificantly smaller than (CV) at equilibrium of the organic material before step (c). The temperature of the organic material is below about 38 ° C before its contact with the air stream 1.5 ... 6%.

Prior to the step of contacting the organic material with the air stream, the organic material has an initial moisture content of about 1.5 ... 13%.

In a variant embodiment of the process prior to the step of contacting the organic material with the air stream, the organic material has an initial moisture content of about 1.5 ... 6%. The desired moisture content of the organic material after step (s) is approximately

11 ... 14%. The air flow that contacts the organic material has a relative humidity of about 30 ... 64%. at a temperature of about 21 ... 49 ° C. The temperature of the air stream is chosen to provide the desired heat treatment of the organic material, while the relative humidity of the air stream is chosen to ensure the rearrangement of the material. In other embodiments, for the purpose of decreasing the moisture content, the organic material, which has a temperature of about 38 ° C, is possibly preheated to about 121 ° C, before step (b). The temperature of the organic material is below about 121 ° C, before the step of contacting the organic material with an air flow, the organic material has a moisture content of approximately 11 ... 40%, or the air flow that contacts the organic material has a relative humidity of about 20 ... 60%, at a temperature of about 21 ... 49 ° C. The temperature of the airflow is about

24 ... 121 ° C.

When the organic material whose moisture content is regulated is tobacco, it can be expanded tobacco and is chosen from the group consisting of expanded or non-expanded tobacco, whole tobacco leaves, chopped or crushed, stems, reconstituted tobacco or any combination of them.

The step of contacting the organic material with an air stream is carried out continuously in a linear conveyor, provided with a plurality of areas with increasing relative humidity. The step of contacting the organic material with an air stream is carried out using an air stream with a velocity of about 0.23 ... 1.22 m / s and is carried out by directing the air stream, either from top to bottom, either from the bottom, up through the bed of organic material, or by directing the airflow both downward and upward, downward through the bed of organic material.

In another embodiment, the spiral conveyor has a stack with a plurality of troughs and the air stream passes through the stack sequentially through the successive troughs.

The invention has the advantage that suitable hygroscopic and agricultural products, including, but not limited to fruits, vegetables, cereals, coffee and tea, can be dried with little or no crushing, and even fragile tobacco that comes from the expansion process. . The process also has the advantage of rearranging the expanded tobacco with little or no loss of the expanded tobacco structure and allows drying of tobacco or other hygroscopic organic materials of the same nature, approximately at atmospheric pressure, for example without the use of vacuum and at a selected temperature where the heat treatment made can be controlled during the process to an extent that cannot be achieved in the conventional processes of

RO 111821 Drying of tobacco.

Changes in the moisture content of tobacco or other suitable organic materials are affected by contacting tobacco with air that has a carefully controlled relative humidity, below or above the relative equilibrium humidity of the organic material it is in contact with. The relative humidity of the air is continuously increased or decreased, as appropriate, during processing to maintain a controlled difference between the relative humidity of the air and the relative equilibrium humidity of the organic material with which it is in contact. Careful, continuous control of the relative humidity allows the control of the mass transfer rate of moisture between the organic material and its environment so that the changes in structure of the material are reduced. The use of relative humidity as the primary driving force for moisture mass transfer allows independent control of heat treatment. This process can be carried out either in batches or continuously. Moreover, the process can be carried out without the use of rotary cylinders, which has the consequence of breaking the material.

The following are 7 examples of embodiments of the invention, with reference to the accompanying figures, which represent:

- Fig. 1, the graph of the relative humidity of the air (UR) in percent relative to the moisture content of the tobacco or OV;

- Figure 2, a schematic diagram of a laboratory apparatus for rearranging the hygroscopic organic material, according to this invention, by increasing the air in time:

- Fig. 3, a cut-out view of an exemplary apparatus for carrying out this invention continuously;

-fig.3a, sectional view of a portion of the spiral conveyor with stacking in fig. 3, which shows the trajectory of the air flow versus the trajectory of the hygroscopic organic material;

-fig. 4, schematic diagram of an alternative apparatus suitable for carrying out the invention continuously;

-fig.5, the block diagram illustrating the application of the present invention in a rearrangement process and

FIG. 6, the typical UR profile of the air adjacent to the tobacco over time, obtained during the use of the apparatus of FIG. 3.

Example 1. The present invention relates to a process for adjusting the moisture content of tobacco or other hygroscopic organic material, such as pharmaceutical or agricultural products, including but not limited to diminished fruits, vegetables, cereals, coffee and tea. crushing, changes of physical structure or changes entailed by the thermal path in the chemical composition of the material to be treated. In particular, the present invention relates to the use of controlled air humidity for the purpose of either rearrangement or drying of tobacco or other hygroscopic organic materials. The moisture content of tobacco or other hygroscopic organic materials is either increased or decreased by the gradual and continuous increase or decrease, as appropriate, of the relative humidity of the air contacting tobacco or other suitable hygroscopic organic materials. In this way, the humidity transfer is controlled, allowing the separate optimization of other process variables, such as temperature, air speed and air pressure.

□ Eggs commonly used to characterize the physical structure of tobacco are cylindrical volume (CV) and specific volume (SV). These measurements are particularly valuable in determining the benefits of this process in rearranging tobacco.

cylindrical volume (CVI

Filling tobacco weighing 20 g if unexpanded or 10 g, if expanded, is placed in a 6 cm diameter drum, Model No. 11-60, designed by Heinr.Borgwaldt Company, Heinr. Borgwaldt GmbH, Schnackenburgallee Nr. 15, Postfack 54 07 02, 2000 Hamburg 54 Germany. On tobacco, in the cylinder, a piston of 2 kg, with a diameter of 5.6 cm is placed for 30 s. The resulting volume of tobacco com

RO 111821 Primate Bl is read and divided by the weight of the tobacco sample to give the cylindrical volume with cm ³ / g. The test determines the apparent volume of a given weight of tobacco filling. The resulting volume of the filling is reported as cylindrical volume. This test is performed under standard environmental conditions of 23.9 ° C (75 ° F) and 60% RH; conventionally, unless otherwise stated, the sample is preconditioned in this environment for

24 ... 48 h.

Specific Volume (SV)

The term Specific Volume is a unit for measuring the volume occupied by solid objects, for example tobacco, using Archimedes' principle of fluid displacement. The specific volume of an object is determined by taking the inverse of its actual density. The specific volume is expressed in cm ³ / g. Both mercury porosity and helium picnometry are suitable methods for performing these measurements, and the results have been found to correlate. When using helium picnometry, a sample weighed with tobacco as such, dried at 100 ° C for 3 hours or equilibrated, is placed in a cell in a Quantachrome Penta Picnometer Model 2042-1 (manufactured by Quantachrome Corporation, 5 Aerial Way, Syosset, New York). The cell is then purged and pressurized with helium. The volume of helium displaced by tobacco is compared with the volume of helium required to fill an empty sample cell. Tobacco volume is determined based on the fundamental principles of the ideal gas law. As used throughout this description, unless otherwise specified, the specific volume was determined using the same sample of tobacco used to determine the OV, i.e., dry tobacco after exposure for 3 hours in an oven with circulating air controlled at 100 ° C.

As used below, the moisture content can be considered equivalent to the volatile content in the oven (OV) as no more than about 0.9% by weight of tobacco is represented by volatiles other than water. The determination of the volatiles in the oven is a simple measurement of the weight loss of the tobacco after exposure for 3 hours in an oven with circulating air, controlled at 100 ° C. Weight loss as a percentage of the initial weight is the volatile content in the oven.

The test of the sieve refers to a method of measuring the distribution of the length of fragments from a sample of cut filling. This test is frequently used as an indicator of the degradation of fragment length during processing. The tobacco filling weighing 150 ± 20 g if not expanded or 100 ± 10 g if expanded, is placed on a shaker. The stirrer uses a series of 0.30 m diameter round trays (manufactured by WS Tylor, Inc. a subsidiary of Combustion Engineering Inc., Screening Division, Mentor, Ohio 44060) that meets ASTM (American Society of Testing Materials). The normal sizes of mesh trays are 2.4; 4.8; 7.9 and 13.8 stitches / cm. The device has a stirring distance of about 0.0254 ... 0.0127 m, and a stirring speed of 350 ± 5 rpm. The agitator shakes the tobacco for 5 minutes to separate the sample into different particles.

Each quantity in a particle size range is weighed, thus obtaining the particle size distribution of the sample.

Laboratory experiments have shown that attempts to rearrange tobacco quickly, by exposing it to high humidity, lead to loss in CV. CV leakage has also been shown to occur when either condensation or overfeeding occurs in an expanded tobacco bed. Condensation occurs when humid air contacts the tobacco that is below the mist point of moist air. Overgrowth can occur when humidity variations in the tobacco bed are created due to uneven exposure to wet air. Therefore, a humid air rearrangement system must operate at relatively low speed, with good control of the relative humidity of air, air temperature, air flow and pressure through

RO 111821 Blank tobacco bed. This is best accomplished by gradually increasing the moisture content of the moist air passing through the tobacco, so that the tobacco is exposed to an air stream that is close to the balance with the tobacco.

Referring to FIG. 1, line ABC is an isotherm of - 23, O ° C for typically expanded open tobacco. This isotherm relates the OV of the tobacco to the UR of the air surrounding it at equilibrium for a given temperature. Thus point B indicates that at ~ 23.9 ° C and 60% RH, this expanded tobacco sample will have an OV of approximately 11.7% compared to balancing. The DEF line represents a typical UR profile for tobacco that is rearranged according to this invention. The GEF line in fig. 1 represents an alternative UR profile that was also found satisfactory. The HF line in fig. 1 represents a typical trajectory of the field as well as the laboratory rearrangement at room equilibrium at very low air speeds. Line IJ of FIG. 1 is the application of this invention to the drying of tobacco.

Fig. 1 represents that the rearrangement of tobacco from an OV of about 6.5%, where it could be in balance with the air that has 30% UR, to an OV of about 11.7% where it could be in balance with the air that has 60% RU, could occur by exposing it to air whose humidity is increased from about 40% RU with small increases over a period of time until it reaches about 60% RU, rather than being exposed directly to the air with 60% UR. When it occurs under these slowly changing conditions, the mass transfer between airflow and tobacco occurs relatively slowly because the driving force is small and the expanded tobacco structure is maintained. The rearrangement of expanded tobacco without loss of CV can occur by exposing the tobacco to air, whose humidity is increased from about 40% RH with small increases over a period of about 40 to 60 min, until it reaches RU of approximately 62%. This reduces the total time required to complete the rearrangement process without significantly changing the structure of the rearranged tobacco. Thus, the lines DEF and GEF of fig. 1 represents each embodiment of the present invention for rearranging tobacco.

Referring to FIG. 1, the conditions close to the balance between airflow and tobacco are illustrated by the line segment EF and the line ABC. It is estimated that at an OV of tobacco below 7%, the difference between the relative humidity of the air in balance with the tobacco and the relative humidity of the humid air stream, used for rearrangement, can be quite large without affecting the loading power of the tobacco. It is also appreciated that at a tobacco OV of about 7.5 to about 11.5%, the relative humidity of the damp air stream used for rearrangement can be from about 2 to about 8% above the relative humidity of the air in balance with tobacco, the largest deviation from the balance corresponding to the lowest OV of the tobacco, without affecting the loading power of the tobacco.

When the present invention is used for drying tobacco, no measurable loss of tobacco CV is observed. This is the case even when the relative humidity of the drying air stream is significantly below the relative humidity of the air in equilibrium with the tobacco, that is, the relative humidity of the drying air stream is below the equilibrium conditions of the tobacco. Accordingly, it is appreciated that line IJ of Fig. 1 illustrates only one of the many possible trajectories that can be used for drying tobacco according to the present invention.

When it takes the form of a rearrangement in batches, the relative humidity of the air that comes in contact with the tobacco is increased over time to provide for a continuous increase in the humidity of the tobacco. This can take place in a room under normal conditions, as illustrated in fig.2. The tobacco to be rearranged is placed at a bed depth of approximately 0.0308 m, in compartments based on the site, in a room with normal conditions, so that an air flow with controlled humidity

EN 111821 Bl can pass down through tobacco. Rooms approximately 0.567 m ³ ... 2.27 m ³ (manufactured by Parameter Generation and Control, lnc., 1104 01 d US7D, WestBIach Mountain NC28711) are used in a number of studies. The rooms with normal conditions are equipped with microprocessors that allow the control of the humid air conditions in the room. There have been tests in which dry, expanded tobacco is rearranged from initial OV levels, about 2% to final OV levels of about 11.5% by increasing UR from low initial levels of about 30% UR and raised by about 2% UR for periods between about 30 to about 90 minutes, to final levels of UR, between about 99 and about 65% use air speeds between about 15.25 and about 61 m / min. UR and temperature measurements are monitored with a Thunder 4A-1 model instrument (manufactured by Thunder Scientific Corp. 623 Wyoming, SE Albuquerque, New Mexico 87123). Air speeds are measured with an Alnor Thermo Anemometer model 8525 (manufactured by Alnor Instrument Co., 7555 N. Linder Ave, Skokie, Illinois 60066). Tests in which the relative humidity goes from initial values of about 52% to final values of UR of about 62% in a short time of about 40 minutes, resulting in tobacco rearranged with complete CV retention, compared to similar tobacco rearranged in a room controlled from the point of view of the conditions with an air maintained at 60% RH and - 23.9 ° C passing through tobacco at a low speed for 24 to 48 h. This type of passage achieved success with high humid air velocities in about 61 m / min and temperatures from about 23.9 to about 32 ° C. Expanded tobacco, rearranged in this way, presents minimal CV losses, if there were, compared to expanded tobacco, rearranged in a room controlled from the point of view of conditions.

The present invention can take place as a continuous process more efficiently in a machine with a spiral conveyor belt that gathers alone Frigoscandia, such as the one shown in FIG. 3. This appliance is a specially modified Spiral Fridge Model GCP 42, supplied by Frigoscandia Food Process Systems AB of Helsingborg, Sweden. The dry tobacco to be rearranged enters unit 10 on a conveyor belt 13, is transported through unit 10 in a spiral geometry from the base to the top of the spiral stack 14, as shown and exits via the tobacco exit 11, after rearrangement. The humidified air is blown down through the tobacco through the inlet of the moist air 15 at the base of the spiral stack 14, where it exits through the outlet of the moist air 16, essentially passing in the counter current in the direction of the tobacco stream, that is, the majority of the air flow. wet is from the tip of the stack down through the layers of the tobacco bed, while the tobacco moves upward following the spiral path of the conveyor belt. A small portion of moist air follows the spiral trajectory of the carrier with the stack from tip to base on a true countercurrent path. These types of air flow are shown in fig.3a. This arrangement was found to effectively reproduce the passage of the UR obtained in the apparatus in fig.2.

Referring to FIG. 3a, which is a cross-sectional view of a portion of the stacked spiral conveyor, shown in FIG. 3, the trajectory of air flow 20 and 22 is illustrated with respect to the trajectory of the tobacco bed 21. As shown shown in Fig. 3a, the air flow 20 and 22 is from the top of the stack down, the tobacco stream is from the base to the top of the unit and is illustrated as moving from the right side to the left side of Fig. 3a, as it progresses. up the stacked spiral conveyor 14. The major portion of the air stream 20, which is essentially counter-current to the tobacco path, is directed through the layer of the tobacco bed 21 and contacts the tobacco bed at the level immediately below, while a small portion of air stream 22 passes over the bed

EN 111821 Tobacco blast 21 in counter current to the trajectory of the tobacco bed 21. This portion of air stream 22 may later pass through the tobacco bed 21.

The key to the successful implementation of this invention, in the case of rearrangement, provides means of continuous increase of the relative humidity of the air, in contact with the tobacco, while the tobacco OV increases the Spiral Conveyor which is stacking alone in Frigoscandia, by virtue of its design. stacking, alone, channels most of the airflow down through the multiple layers of the conveyor (the stacked conveyor), which carries the tobacco. By supplying tobacco to the base of the stacked and humidified air carrier at the top of the stack, the total air and tobacco flow is essentially counter current. The same flow, essentially countercurrent, provides a continuous natural UR that rises in the air that contacts the tobacco, because the air is progressively dehydrated, while moving down through the layers of tobacco that support the rearrangement process. By judiciously selecting the speed of the conveyor belt, the speeds of air and tobacco flow and controlling the temperature and the air of the incoming air, conditions such as those entering the furnace laboratories, the rearrangement experiments can be approximated on a continuous basis. For rearrangement of approximately 1.95 kg / h of expanded tobacco with 3% OV, transport speeds requiring residence time from about 40 to about 80 minutes and air conditions from about 24 to about 35 ° C, with the entry of relative humidities from about 61 to about 64% at air currents from about 28 to about 70 m ³ / min, it was found that they provide a total rearrangement without significant loss of CV or measurable crushing of tobacco, using the spiral unit Frigoscandia GOP 42 amended.

Devices for recording relative humidity over time, such as Model

2903 RH / Temperature recorder (manufactured by Rustrak Instruments Cc.of E.Greenwich,

Rl), they went through the unit Frigoscandia during the rearrangement of tobacco. These devices showed a continuous increase in the relative humidity of the air, while the device is transported up the spiral stack, with initial HR recordings of from about 35 to about 45% at the base of the stack, where tobacco is the driest. , up to about 62% at the tip of the stack, where tobacco is better rearranged.

Fig. 6 is a typical curve compared to the time obtained with the Rustrak unit. The percentage of RU of the air adjacent to the tobacco bed in comparison with the time is shown in fig.6. Tobacco with an initial OV of about 3% in the rearrangement spiral unit and contacts the air with an UR of about 43% (Point A in fig.6). Fig. 6 shows that, as the tobacco progresses through the spiral rearrangement unit, the UR of the air adjacent to the tobacco increases from about 43 to about 62% upon exiting the unit (Point B in Fig. 6). Tobacco has an OV of about 11% when exiting the rearrangement spiral unit. The UR of air entering the rearrangement spiral unit was controlled to produce rearranged tobacco without significant loss of OV.

Other means for predicting the RU of the air, such as the unit shown in FIG. 4, can also be used to drive this invention on a continuous basis. Referring to FIG. 4, the tobacco enters the unit through the tobacco inlet port 40 on the carrier 43, and exits through the tobacco outlet 41. Air whose relative humidity is continuously increased is blown upstream or downstream, through the tobacco bed 42 in a multiplicity of zones 44 to reproduce the storm effect in the apparatus of Fig. 2. This storm effect can be obtained by moving the air from a single source, in the form of a coil, from right to left in Fig. 4, providing for essential air flow in the counter current in the direction of the tobacco movement. Thus, the air coming out of a given area will become the air entering the adjacent area on the left.

RO 111821 Bl

In order for the process of the present invention to occur, the whole tobacco leaf may be treated, cut or chopped tobacco, expanded or non-expanded tobacco or selected parts of tobacco, such as reconstituted tobacco or strains. The process can be applied to any or all of the above, with or without addition. For the specific case of tobacco drying, it was found that the non-expanded cut content can be continuously dried at ambient temperature, essentially by countercurrent flow, mainly by the Frigoscandia self-propelled spiral conveyor modified from a moisture of the tobacco. about 21 to about 15% OV in about one hour. In this case, the air enters the top of the unit at about 29.5 ° C and about 58% RH and exits at about 25 ° C and about 68% RH. Drying occurs with little or no heat treatment of tobacco.

Alternatively, the process of the present invention can be used to dry tobacco having a temperature significantly above ambient temperature, for example tobacco at about 93 to about 121 ° C. When the tobacco between these temperature levels is dry, the UR and the temperature of the drying air are adjusted to provide appropriate conditions for conducting the process of the present invention.

Analogously with the rearrangement of tobacco, it has been found that drying occurs better in a minimum amount of time by establishing the final humidity of the lower air than will be necessary to bring the tobacco to the final humidity level of the desired air, increasing the humidity of the tobacco and the air and consequently the driving force of the drying. Other than in the rearrangement process, the final humidity of the air stream can be maintained at a much lower level than that in balance with tobacco at the desired level of OV after drying.

To demonstrate the benefit of rearranging dry tobacco, expanded by the measured addition of water, slowly, compared to rearranging with spray cylinder, place a sample of 20 g of tobacco fill in a sealed dryer. This sample was impregnated with liquid carbon dioxide and expanded into an expanding tobacco at 288 ° C. The OV of this expanded tobacco filling is 3.4%. It was calculated that approximately 1.89 g of water is needed to increase the OV of this sample to 11.5%. This amount of water was placed in a small glass stopper with a rubber stopper, having a glass tube with an inner diameter of 0.3 cm passing through it. The glass is also sealed in the dryer. After nine days, all the water was adsorbed by tobacco. Tobacco was then analyzed and found to have an OV of about 11.5%. As used herein, it refers to tobacco before being equilibrated in a room with normal conditions, with air maintained at 60% RH and 24 ° C, passing through it at a low speed over a period of 24 to at 48 h. This balancing process is generally used as a means of bringing tobacco to standard conditions before CV, SV and sieve are measured. After this standard balancing, the dry-rearranged tobacco has a CV of about 9.5 cm ³ / g and an SV of about 2.9 cm ³ / g at an SV of about 11.6%. By comparison, when a second sample of dry tobacco is placed directly in the balancing chamber and rearranged by balancing under standard conditions, the balanced OV was about 11.3% and the CV and SV values were about 9 , 4 cm ³ / g and approximately 2.7 cm ³ / g respectively. A second sample of expanded tobacco is rearranged in a spray cylinder to an OV of approximately 11.5%. After balancing, this sample has a CV of about 8.5 cc / g and an SV of about 1.9 cc / g at an equilibrium OV of about 11.6%. As can be seen from Table 1, the tobacco sample that was rearranged in the dryer by a slight controlled addition of water, shows a significant improvement in the balance of CV and SV, compared to the sample that was rearranged by spray. -ere. This sample also shows a slight improvement in CV and SV compared to the directly balanced sample in the balancing room.

RO 111821 Bl

20

Table 1

Sample As such Balanced 0V (%) SV (cm ³ / g) 0V (%) CV (cm ³ / g] SV (cm ³ / g) Exit tobacco 3.4 3.0 11.3 9.4 2.7 Rearrangement with cylinder 11.5 1.8 11.6 8.5 1.9 Dryer 11.5 2.7 11.6 9.5 2.9

A second set of experiments takes place using a room with normal conditions to rearrange expanded tobacco. For this purpose, a Parameter Generation and Control (PGC) camera was used. This room is equipped with a 15 Micro-Pro 2000 microprocessor provided by Parameter Generation and Control Inc., which allows control of room conditions.

Example 2. About 4 g of open tobacco, impregnated with 20 carbon dioxide and expanded under conditions similar to those described in example 1, are placed at a bed depth of about 5 cm, inside a compartment. The compartment, which has solid sides and a 25 sieve base, is placed inside a room with normal conditions. The sample is then rearranged within one hour, using air of about 24 ° C with an initial RH of about 36%, passed to a final RH of about 60%. The movement of the air takes place in a downward direction through the tobacco bed, with a speed of approximately 12.2 m / min. This experiment is then repeated at time intervals of 3, 6 and 12 h. The results, presented in table 2, indicate that for the transition periods up to about 6 h, the rearrangement rate affects the CV and the SV of tobacco. , under these experimental conditions. The lower the rearrangement rate, the higher the CV and SV. Furthermore, the rearrangement according to the present invention results in CVs at least 100 / g larger and SVs at least 0.2 cc / g higher than those found for tobacco rearranged in spray cylinder. However, it was found that the highest efficiency is obtained at the passage of at least 1 h.

Table 2

As such 0V (%) Balanced in a room under normal conditions SV (cm ³ / gm] 0V (%) 0V (cm ³ / gm) Exit speed 3.10 3.06 11.33 9.71 Spray cylinder 11.51 1.61 11.37 8.61 The passage after 1 h 10.83 1.85 11.38 9.72 Passing after 3 h 11.44 1.88 11.36 9.81 Passing after 6 h 11.45 1.90 11.30 9.88 Passing after 12 h 11.41 1.97 11.27 9.89

RO 111821 Bl

Example 3. A laboratory study is conducted based on the rearrangement speed and the temperature on the CV and SV of the tobacco. Seven sets of experiments are conducted using carbon dioxide impregnated tobacco and 5 expanded in an expansion tower at about 288 ° C. Expanded tobacco is rearranged by the following methods:

- (1) by balancing for 24 hours in a room with normal conditions at 60% at one UR and 24 ° C with a movement of air through tobacco at a speed of about 7.6 m / min;

- (2) by spraying with water to increase the OV to about 7.5%, then 15 balancing at 60% RH and 24 ° C for 24 h as in (1);

- (3) by spraying with water to increase the OV to about 7.5%, finally rearranging in a spray cylinder; 2 o

- [4] by spraying with water up to about 7.5% OV, then using humid air passed from the initial UR of about 46% to the final UR of about 60%, and

- (5) by passing humid air from 25 to about 46% RU to about 60% RU.

Wet air rearrangement takes place in a room with normal PGC conditions equipped with a microprocessor for controlled passage at selected time intervals. The following conditions are selected:

- (1) pass times: 30, 60, and 90 min;

- (2) air temperatures: 24 and 35 ° C

- (3) air speeds up through the tobacco bed by approximately 13.7 m / min and down through the tobacco bed by approximately 53.4 m / min; and

- (4) the thickness of the tobacco bed: 5 cm.

The tobacco used for all rearrangements, except for the one with the spray cylinder, is collected in the expansion tower after expansion and sealed in double plastic bags, before being rearranged. Consequently, the tobacco cooled to about 94 ° C, the temperature of the tobacco at the exit of the expansion tower, at the ambient temperature before rearrangement. When re-packing occurs at about 35 ° C, the tobacco, while still in sealed bags, is preheated enough to prevent condensation from contact with moist air before being exposed to the conditions. The data of these experiments are presented in tables 3a to 3e.

Table 3a

Sample As such Balanced 0V (%) SV (cm ³ / g) □ V (%] CV (cm ³ / g) X Exit tower 3.43 3.02 11:31 9.04 S Only through sprays 8.06 2.14 11.68 8.66 C By Spray + cylinder 11.53 1.81 11.59 8.59 F By spray + flushing 90 min (46 to 60% RH, 24 ° C 11.27 1.87 11.51 9.01 H By spray + flushing 90 min (46 to 60% RH, 24 ° C 10.96 1.98 11.36 9.48 I Sample H held 15 min at 60% RH, 24 ° C ' 11.54 1.95 11.56 9.40 J By spray + flushing 60 min (45 to 62% RH, 35 ° C 10.37 2.38 11,28 9.85 K Probe J held 15 min at 62% RH, 35 ° C ' 11.17 2.26 11.22 9.88

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24

Table 3b

Sample As such Balanced □ V (%) SV (cm ³ / g) □ V (%) CV (cm ³ / g) X Exit tower 3.01 2.58 11.34 9.23 S Only by spray 7.51 2.13 11.39 8.87 C By spray + cylinder 11.86 1.59 11.64 8.07 F By spray + stirring 60 min (46 to 60% RH, 24 ° C 10.55 1.64 11.45 8.86 G Sample F held for 15 min at 60% RH, 24 ° C 11.56 1.64 11.42 8.61 H By spray-age + flushing 30 min (46 to 60% RH, 24 ° C) 10.28 1.97 11.27 8.99 I Sample H held for 15 min at 60% RH, 24 ° C 11.73 1.82 11.25 8.61

Table 3c

Sample 3rd such Balanced 0V (%) SV (cm ³ / g) CV (%) CV (cm ³ / g Exit Tower 1.81 2.78 11.37 9.23 B 60 min (46 to 60% RH, 35 ° C) 10.91 1.86 11.47 8.86 C Hunting 60 min (46 to 60% RH, 24 ° C) 10.53 2.02 11,28 9.20 D Hunting 90 min (46 to 60% RH, 35 ° C] 10.84 1.99 11.45 8.90 E Through sprayers 5.39 2.37 11.25 8.71 F By sprayers + direct application 60% RH, 35 ° C, 30 min 10.80 1.81 11.27 8.39 G Through sprayers + stirring 60 min (46 to 60% RH, 35 ° C) 10.66 1.85 11.23 8.65 H By spray + bake 90 min (46 to 60%, 35 ° C) 10.76 1.82 11.24 8.62 I By spraying + flushing 60 min (46 to 60% RH, 24 ° C) 10.65 1.90 11.23 8.75 J Through sprayers + flushing 90 min (46 to 60% RH, 24 ° C] 10.57 1.87 11.38 8.74 K By spray + 60% RH, 24 ° C, 30 min. 10.73 1.87 11.22 8.64 L Through sprayers and cylinder 10.98 1.60 11.39 8.28

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Table 3d

Sample C 3rd such Balanced 0V (%) SV (cm ³ / g) OV (%) CV (cm ³ / g) T1 Exit speed 2.83 3.01 11.92 9.46 T2 Direct setting at 60% RH, 24 ° C, 30min 11.24 2.27 11.77 9.08 T3 Hunting 90 min (46 to 60% RH, 24 ° C) 11.08 2.24 11.83 9.29 T4 Hunt 90 min (30 to 60% RH, 9.77 2.39 11.85 9.43 S1 Through sprayers 4.78 2.82 11.66 8.98 S2 By spray and direct application at 60% RH, 24 ° C, 30 min 11.10 2.19 11.64 8.89 S3 Spraying and flushing 90 min (46 to 60% RH, 24 ° C) 10.54 2.25 11.27 9.05 S4 By spraying and flushing 60 min (46 to 60% RH, 24 ° C 10.56 2.22 11.73 9.03 S5 By spray and flushing 30 min (46 to 60% RH, 24 ° C) 9.74 2.29 11.67 9.19 0 Through sprayers and cylinder 10.48 1.95 11.81 8.80

CD \ ω E a > Oh cn CD 9.48 9.28 CD rx cri 9.91 9.57 9.66 with an o 00 O O 9.63 r ~ «ro 8.98 9.03 9.51 I 8.59 10.02 WITH A A in cri 9.30 o ^x > o 11.72 11.82 11.66 11.65 with ω on CD 11.79 11.74 CD cn CD 00 V 11.79 11.76 CD 11.90 12.09 with CD 11.93 CD CD 11.95 CD X co And the > ω 5.05 2.82 2.72 O with 2.39 in with 2.25 2.39 co 00 cu 2.41 2.20 2.41 2.15 2.13 2.23 2.17 2.39 CD 09 WITH 2.31 09 09 WITH θ ' > o 11.86 3.94 ___________j 5.64 10.36 6.67 8.44 7.83 8.44 11.10 A A 8.13 9.41 10.21 00 a rx or cry on CD oo ' □ 00 o A 10.88 11.30 Balanced UR% 0.79 30-58 30-58 45-58 45 - 58 47 - 62 47 - 62 30 - 62 30-62 with CD and Γχ CD 1 rx st 'and CD 1 in 00 35 - 60 45 - 60 45 - 60 47 - 64 47 - 64 As such Q_ Ie 15.40 with with sr with 24 ^ r with 24 ST CU with with with with 32 32 WITH 09 with 09 with CD Time (min) 09 09 the CD The CD 60 60 09 The CD the CD 09 60 09 09 09 09 The CD Jites for hunting Average air speed (m / min) c u • 1 Exit tower Stage I spray output 72 53.5 00 in 58 58 53.5 55 53.5 co 55 55 55 55 55 73.2 73.2 beginning OV (%) Powered in you Cylinder outlet CD cri 5.6 3.9 5.6 3.9 5.6 3.9 CD so-called 3.9 CD cri 3.9 CD CD CD cri CD in 3.9 3.9 c o ω < m ω □ LU LL ω I - z a 0-

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The data presented in tables 3. , .3e shows that the increase from about 0.5 to about 1 cm ³ / g in CV and from 0.3 to about 0.4 cm ³ / g in SV, can be obtained by re-arranging the hinges of dry tobacco, that is, tobacco from about 24 to about 35 ° C, compared to the rearrangement by spray spray of hot tobacco coming out of the expanding tobacco. Rearranging with hinges directly at the exit of the tower is preferable to first spraying tobacco, to increase the content in DV up to about 7%, followed by rearrangement with hogging. No significant difference is observed between CV or SV of rearranged tobacco using wet air as an initial RU of about 46% compared to tobacco resurfaced from an initial RU of about 30% over a period of time. for about 90 min. It is also noted that tobacco can be rearranged by moving the air directed down through the tobacco bed, with speeds from about 53.5 to about 72 m / min or with the air directed up through the tobacco bed and up to 13, 8 m / min without significant differences of CV or SV. In addition, it is observed that the rearrangement with the result results in better CVs and SVs compared to the rearranged tobacco by placing it directly in a room with normal conditions at 60% RH and 24 ° C after exiting the expansion tower. . Finally, it was observed that spraying with water to increase the QV to about 7.5%, followed by humid air supply, gives better CVs and SVs compared to spraying followed by the final rearrangement in a spray cylinder.

Example 4. Tests were performed to determine the effect of air flow trajectory and air velocity on tobacco feed, sewerage and compaction. These tests were conducted using two rooms with normal PGC conditions. In both chambers, the air movement was approximately 14 mc / mm. The air movement was directed upward through the tobacco bed in one of the PGC rooms, and downward through the tobacco bed in the other room. Tobacco samples, 5 cm deep, are placed inside trays (compartments) open at the top 12.5 x 5 1.8 cm with sieve at the bottom and with 10 cm high solid walls. These compartments are placed on shelves, in the room with normal conditions. The air is forced through these samples by covering the unoccupied shelf with cardboard and by covering with tape each crack. Air velocity varies by changing the number of sample containers through which air passes. The tobacco used for these tests is impregnated with carbon dioxide and expanded to about 288 ° C. Tobacco was rearranged at an early stage by spraying water at about 8% OV, immediately after expansion. The conditions inside the chambers during the tests were controlled at about 24 ° C and about 60% RH. A valve anemometer (Airflow Instrumentation, Model LGA 6QD0, Frederick, Maryland) and a hot filament anemometer (Alnor Instrument Company, Skokie, Illinois, Thermometer Model 8525) were used to measure air velocities. These instruments are placed directly above or below samples for the movement of air in the upward or downward direction respectively.

As the air moves upward, there is a slight movement of the tobacco immediately after the air has been returned with average low speeds of approximately 8 m / min. Then small channels are formed, and the tobacco stabilizes. As a result of these channels, the airflow path is very uneven along the tobacco bed (about 6.7 to about 13.8 m / min for an average flow of about 8 m / min). □ with the increase of the average current flow, the sewerage is clearer, and at 13.8 m / min an expansion of the tobacco is observed, followed by the significant sewerage of the bed.

□ as the air moves downward, a compaction is observed

RO 111821 Bl and corresponding reduction of air velocity through beds, at all studied speeds. These things are shown in table 4. At an initial velocity of about 58.5 m / min, the depth of the 5 bed of tobacco is compacted by approximately 28%, day, as a result, the air speed through the bed is reduced to about 43 m / min. At initial air velocities of about 43 m / min or less, the compaction of the tobacco bed is about half as compared to that observed at about 58.5 m / min, and the air passage through the tobacco bed is much reduced.

Table 4

The effect of bed compaction on the speed of air through the bed

Speed with (m / min) Bed depth (cm)

beginning The end % Change beginning End% Change 58.5 43 27 5 3.6 28 49 44 11 5 4.1 18 43 40.5 6 5 4.25 15 31.7 30 6 5 4.5 10 13 12.5 5 5 4.75 5

Based on the experiments above 25, it was determined that expanded tobacco can be rearranged by hunting under the following conditions:

- (a) for about 60 minutes to about 90 minutes; 3o

- (b) RU: from the initial RU of about 30 to about 45% to a final RU of, from about 60 to about 64%;

- (c) the temperature from about 35 24 to about 35 ° C;

- (d) air flow: ascending at speeds up to about 13.8 m / min or descending with speeds up to about 71.6 m / min. 40

Example 5. Approximately 0.195 kg / h of open and large tobacco mixture, which was impregnated with carbon dioxide, according to the process described in the patent application S.N. 07 / 717.067, 45 and expanded as described in the examples above, are passed through a cooling conveyor to reduce the temperature from about 93 to about 29 ° Before feeding 50 in a self-propelled spiral unit Frigoscandia Model GCP 42, amended. Tobacco flow through the spiral unit is made from the base to the tip. The air flow is from the tip to the base, so the tobacco flows counter-current with the air. This arrangement provided for the re-arrangement by flushing with a result of the continuous dehydration of the air by tobacco. Tobacco enters this process with about 3% OV and comes out with about 11%. The balanced CV of the fed material was about 10.53 cc / g, while the CV of the rearranged material was about 10.46 cc / g, indicating no significant loss of tobacco filling capacity during the processing process. rearrangement, that is, no statistically significant loss of filling capacity, as determined by the standard analysis of the variation procedure. In addition, there is no measurable reduction in the size of the tobacco particle, as determined by the sieve test, during the rearrangement process.

Example 6. A series of experiments were conducted using different types of expanded tobacco, at different temperatures of the tobacco, in which the tobacco is rearranged according to the process of the present invention.

In each experiment, about 0.195

EN 111821 Bl kg / h of tobacco, based on the rearranged tobacco mass, is rearranged in the modified Frigoscandia self-propelled spiral unit, described in Example 5. The air inlet in the rearrangement unit was set at about 5 ° C, with a relative humidity. of about 62%. The air exiting the rearrangement unit generally has about 32 to about 35 ° C, with a relative humidity of about 40 to about 45%. As shown in Table 5, the tobacco rearranged according to the process of the present invention does not exhibit any significant loss of filling capacity.

Table 5

balancing Tobacco Type Nr. Temp. (° C) OV in (%) OV out OV in [cm ³ / g) Sheep (%) OV out OV out Open FO 2050 288 2.70 11.16 9.93 11.87 9.40 12.00 FO 2O5A 321 2.11 11.58 10.41 11.57 10.83 11.56 FO 205B 329 1.87 9.93 11.30 11.30 10.90 11.50 Open FO 206A 304 2.47 11.09 10.00 12.34 10.20 11.74 FO 217 321 2.59 10.86 10.49 11.79 10.51 11.63 Great FO 206B 249 3.11 10.75 12.39 10.91 12.31 10.52 FO 2060 271 2.95 10.22 10.08 10.85 12.41 10.40 FO 214 271 3.00 10.4 11.3 10.4 11.2 10.4

Example 7. Approximately 0.26 kg / h 3 5 of tobacco opened with an OV of about 21.6% is fed to the modified Frigoscandia self-propelled unit described in Example 5, which operates as a drying unit. The flow of tobacco 4o through the drying unit is made from the base to the tip. Air flow is made from the tip to the base of the unit, the tobacco flowing counter-current to the air. The tobacco is dried to about 45 12.2% OV in about 60 minutes of standing time, using air with an inlet temperature of about 35 ° C and an inlet UR of 35%. The air coming out of the drying unit was about 28 ° C and about 62% RH. Tobacco entering and leaving the drying unit is cold to the touch, with an estimated temperature of about 24 ° C, indicating that no tobacco treatment takes place. As a result of the drying process, there is no change in the balanced CV of tobacco. This drying experiment was designed to reduce heat treatment. Similar drying results can be obtained using a higher temperature to provide a controlled degree of heat treatment.

Claims (22)

claims 1. Process for increasing or decreasing the moisture content of a hygroscopic organic material, selected from food, tobacco, tea and coffee, up to a predetermined final moisture content, comprising the steps: - (a) formation of a bed of hygroscopic organic material by depositing the hygroscopic organic material on a conveyor; - (b) the transport of the hygroscopic organic material, deposited on the conveyor along the troughs of a spiral conveyor, from the inlet portion to the outlet portion of the conveyor; and - (c) contacting the hygroscopic material with an air stream, in countercurrent with the bed of hygroscopic organic material, characterized in that, - (d) the airflow is introduced during the transport phase to the exit portion of the conveyor, has a relative humidity and approximately equal to the initial relative equilibrium humidity; and - (e) is maintained in the conveyor together with the hygroscopic organic material near the equilibrium conditions, so that as it passes countercurrently over the bed of organic material, the airflow is dehydrated or progressively hydrated, and the hygroscopic organic material is hydrated, respectively dehydrated progressively until the desired moisture content of the material is reached. Process according to claim 1, characterized in that the equilibrium volume (CV) at equilibrium of the organic material after step (d) is insignificantly smaller than (CV) at equilibrium of the organic material before step (b). Process according to claim 1, characterized in that, (CV) at equilibrium of the organic material after step (e) is insignificantly smaller than (CV) at equilibrium of the organic material before step (c), 4. Process according to the claims 1 ... 3, characterized in that the temperature of the organic material is below about 38 ° C before its contact with the air stream. 5. Process according to the claims 1 ... 4, characterized in that, before the step of contacting the organic material with the air stream, the organic material has an initial moisture content of about 1.5 ... 13%. 6. Process according to claims 1 ... 4, characterized in that, before the step of contacting the organic material with an air stream, the organic material has an initial moisture content of about 1.5 ... 6%. Process according to the claims 1 .. .4, characterized in that the desired moisture content of the organic material, after step (s), is about 11 ... 14%. Process according to the claims 1 .. .7, characterized in that the air stream that contacts the organic material has a relative humidity of about 30 ... 64%, at a temperature of about 21 ... 49 ° C. 9. Process according to the claims 1 .. .7, characterized in that the temperature of the air stream is chosen to provide the desired heat treatment of the organic material, while the relative humidity of the air stream is chosen to ensure the rearrangement of the material. 10. Process according to claims 1 ... 7, characterized in that, for the purpose of decreasing the moisture content, the organic material, which has a temperature of about 38 ° C, is possibly preheated to about 121 ° C, before the step (b ). Process according to claim 1, characterized in that the temperature of the organic material is below about 121 ° C, prior to the step of contacting it with the air stream. Process according to claim 1, characterized in that, before the contact step of the organic material with air flow, the organic material has a moisture content of approx. 11 .. .40%. RO 111821 Bl Process according to claim 1, characterized in that the air stream contacting the organic material has a relative humidity of approximately 20 .. .60%, at a temperature of about 21 .. .49 ° C. Process according to Claim 1, characterized in that the temperature of the air stream is about 24 ... 121 ° C. Process according to claim 1, characterized in that the organic material is tobacco. 16. Process according to claims 1 and 15, characterized in that the tobacco is expanded tobacco. 17. Process according to claims 1 ... 15, characterized in that the tobacco is selected from the group consisting of expanded or non-expanded tobacco, whole leaves of tobacco, chopped or crushed, stems, reconstituted tobacco or any combination thereof. The process according to claim 1, characterized in that the step of contacting the organic material with an air stream is carried out continuously in a linear conveyor. Process according to claim 18, characterized in that the linear conveyor is provided with a plurality of areas with increasing relative humidity. Process according to claims 1 ... 17, characterized in that the step of contacting the organic material with an air stream is carried out using an air stream with a velocity of about 0.23 ... 1.22 m / s. Process according to Claims 1.20, characterized in that the step of contacting the organic material with air flow is carried out by directing the air stream, either from top to bottom or from bottom to top through the bed of organic material. 22. Process according to claim 1, characterized in that the spiral conveyor has a stack with a plurality of troughs and the air stream passes sequentially through the successive troughs.