HU219164B - Process for increasing or decreasing the moisture content of hygroscopic organic materials - 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 adjusting, i.e. increasing or decreasing, the moisture content of tobacco and other hygroscopic organic substances, preferably pharmaceutical active ingredients, agricultural products, preferably fruits, vegetables, cereals, coffee and tea. More particularly, the present invention relates to a process in which the above materials are wetted or dried using controlled humidity air.

The need to control the moisture content of various hygroscopic organic materials, such as tobacco, has long been recognized in the literature. For example, the moisture content of tobacco processed into a usable product changes several times during processing. Each processing step, such as steam treatment, cutting, mixing of ingredients, adding of flavors, expanding tobacco and converting it into a cigarette, requires a certain optimum moisture content, which must be carefully controlled to obtain very good quality tobacco or very good quality. other products made of hygroscopic organic materials. In addition, the process by which the moisture content of the tobacco is changed can have a lasting effect on the physical, chemical and organoleptic characteristics of the final product. Therefore, the quality and the form of the methods used to reduce the moisture content of tobacco or other hygroscopic organic matter are of great importance.

Restoring the moisture content of expanded tobacco is a particularly demanding task. Typically, the tobacco obtained from the expansion process has a moisture content of less than 6% by weight and very often less than 3% by weight. With such a low moisture content, tobacco breaks very easily. In addition, the expanded tobacco structure very often loses the expanded structure during the restoration of moisture, i.e., the tobacco is partially or completely returned to the unexpanded position. If this structure collapses, the filling capacity of the tobacco will be reduced and thus no advantage will be gained from the previous expansion process.

Various methods have been used to adjust the moisture content of expanded tobacco. The simplest process is usually the tobacco is sprayed with water, typically by centrifugation in a rotating cylinder. Alternatively, the moisture is restored to saturated steam. A third method involves passing or bubbling high moisture air through a tobacco bed moving on a conveyor belt, as described in U.S. Patent 4,178,946.

None of the above procedures are completely satisfactory for carrying out expanded tobacco operations. Tobacco centrifugation in the spray roller results in the breakage of the sensitive expanded tobacco. Direct contact with liquid water results in the expanded tobacco structure being eliminated and the former state is restored. Adjusting the moisture content with the steam also causes the expanded tobacco structure to collapse. This is partly due to the high temperature in the vapor circuit, but in the expanded tobacco, when exposed to any gaseous environment where water condensation occurs, such as steam or very high humidity air, the expanded structure collapses.

One method used to overcome these disadvantages is to place the dry expanded tobacco in a chamber containing air having the desired moisture content and to allow the tobacco to equilibrate in the chamber for a period of 24 to 48 hours. The air velocity in the chamber was kept very low, typically not more than 0.76 m / min. The process achieves very little or no damage to the expanded tobacco structure. The disadvantage of this process is that it requires 24 to 48 hours and is therefore limited to laboratory use.

Attempts have been made to shorten the required residence time in such equilibrium processes by increasing the air velocity. These attempts were unsuccessful because they failed to double the water uptake efficiency created by the slow laboratory equilibrium process, and the size of the tobacco conveyor belts for the required long residence time cannot be achieved, moreover, such conveyors do not have the same moisture or equipment, as is described in U.S. Patent 4,202,357.

The drying process used to control the moisture content of tobacco processing is as important as the moisture recovery process. If tobacco is dried, physical and chemical changes occur which alter the physical and / or organoleptic characteristics of the product. Therefore, tobacco drying processes are very important.

Two types of drying equipment are used in the tobacco industry: rotary dryers and belt or conveyor dryers. Occasionally pneumatic dryers are also used. The particular dryer is selected according to the drying task to be performed. Belt dryers or conveyor dryers are generally used to dry strip tobacco and rotary dryers are used to dry cut tobacco. Rotary and conveyor drying is used to dry tobacco from the stems.

In the conveyor dryer, the tobacco is distributed on a perforated conveyor belt and is vented either upstream or downstream which passes through the tobacco and the conveyor belt. Very often, the drying of tobacco is not uniform due to the formation of channels in the tobacco bed due to air blowing, which allow the

164 Β shake air should pass through the area without contacting the tobacco.

Most rotary dryers used to dry tobacco have a vapor coating and can act as an indirect or direct heated dryer depending on whether the heat is inside or outside the tobacco-containing dryer. In addition, the devices may be operated in direct current, in which case the direction of tobacco and air flow are the same, or in countercurrent, if the direction of tobacco and air flow are opposite. Rotary drying must be carefully controlled to avoid overdrying which causes chemical change and / or breakage due to rotational movement. In addition, if drying occurs too quickly, an impermeable layer may be formed on the outer surface of the tobacco, which makes it difficult for moisture to escape from the tobacco interior. The formation of such a layer generally slows down the drying rate or results in uneven drying.

Rotary or conveyor drying of tobacco can result in a thermal treatment that produces chemical and physical changes in the tobacco. These changes are not always detrimental, but they are done to remove moisture from tobacco. For typical tobacco uses, the need to dry tobacco for a limited time results in a heat treatment during the drying step, which prevents optimization of the heat treatment independent of drying.

The present invention relates to a process which has the advantage that tobacco or other suitable hygroscopic and agricultural products, which may be preferably dried or moistened in fruits, vegetables, cereals, coffee and tea, can be carried out with very little damage or breakage. even for highly sensitive expanded tobacco. A further advantage of the process of the invention in the rehydration of the expanded tobacco is that the expanded tobacco structure is very slightly damaged or unaffected, and the method allows the tobacco or other suitable hygroscopic organic material to be dried at about atmospheric pressure, e.g. and drying may be carried out at a temperature of your choice where the heat treatment associated with the drying can be controlled during the process to an extent that could not be achieved by prior conventional tobacco drying processes.

According to a preferred method of the invention, the moisture content of the tobacco or other hygroscopic organic material is altered by contacting the tobacco with air having a very well controlled relative humidity and above or below the equilibrium relative humidity of the hygroscopic organic material in contact. The relative humidity of the air is continuously increased or decreased during the process as required, in order to maintain a controlled difference between the relative humidity of the air and the equilibrium relative humidity of the hygroscopic organic material that it comes into contact with. Careful control of the relative humidity enables the rate of moisture transfer between the hygroscopic organic material and the environment to be controlled so as to minimize the structural changes in the tobacco. The use of relative humidity as a control factor for the primary moisture mass transfer allows independent control of the thermal treatment. The process can be performed in batches or as a continuous process. In addition, the process can be performed without the use of rotary rollers, thus avoiding the fracture resulting from the use of such an apparatus.

The invention and the preferred embodiment thereof are illustrated in detail in the following figures, wherein: Figure 1 shows the relative humidity (RN) of the air as a function of tobacco moisture or volatile matter (V);

Figure 2 is a view showing a laboratory apparatus adapted to adjust the humidity of the hygroscopic organic material according to the process of the invention by reducing the relative humidity of the air over time;

Figure 3 is a sectional view of a device used to carry out the method of the invention in a continuous manner;

3a. Figure 3 is a sectional view of a portion of the spiral conveyor horn shown in Figure 3, which also illustrates the air flow in relation to the flow of the hygroscopic organic material;

Figure 4 is a schematic diagram of another apparatus for performing the process of the invention in a continuous manner; Figure 5 is a block diagram of a process for adjusting the water content of the process of the present invention; and Figure 6 illustrates the typical relative humidity evolution over time in the immediate vicinity of the tobacco in the humidity adjusting device shown in Figure 3.

The present invention relates to a process for adjusting the moisture content of tobacco or other suitable hygroscopic organic material, such as a pharmaceutical active ingredient or agricultural product, preferably fruit, vegetable, cereal, coffee and tea, by minimizing fracture in the treated tobacco, thermal changes that may occur in the chemical structure of the treated tobacco. More particularly, the present invention relates to a process for increasing the moisture content of tobacco or other suitable hygroscopic organic material.

Or drying such material using controlled humidity air. The moisture content of the tobacco or other suitable hygroscopic organic material may be increased or decreased by gradually and continuously increasing or decreasing the relative humidity of the air in contact with the tobacco or other suitable hygroscopic organic material. By this method, the moisture transfer is controlled and allows other process features such as temperature, air velocity and / or air pressure to be optimized in a separate process.

Two common methods used to characterize the physical structure of tobacco are the determination of cylinder volume (CV) and specific volume (SV) characteristics. These two measurements are particularly suitable for demonstrating the advantage of the method of the present invention in increasing the moisture content of the tobacco. Hereinafter, the term "%" means weight%, unless otherwise noted.

Cylinder capacity (CV)

When an expanded tobacco weighing 20 grams, if expanded, weighing 10 grams, is placed in a 6 cm diameter Densimeter roller, the apparatus is a Model No. DD-60 Density Meter from Heinr, Borgwaldt Company, Heinr. Product of Borgwaldt GmbH (Schnackenburgallee No. 15, Postfack 54 07 02, 2000, Ganbzrg 54 West Germany). A 5.6 cm diameter piston weighing 2 kg is placed on the tobacco in the cylinder for 30 seconds. The volume of pressed tobacco is read and then divided by the weight of the tobacco sample to give a cylinder volume of cubic centimeters / g. The test test shows the apparent volume of a tobacco fill of a given weight. The resulting volume is called the cylinder cylinder volume. The test assay is performed under standard ambient conditions at a relative humidity of 24 ° C and 60%. Unless otherwise noted, the sample is conditioned for 24-48 hours under these conditions.

Specific volume (SV)

The "specific volume", which is the unit that measures the volume occupied by a solid object (such as tobacco) according to the Archimedes Principle or displaces liquids. The specific volume of a given object is determined by taking the reciprocal of the true density. The specific volume is cm ³ / g. Either the mercury porosity method or the helium pycnometry method are suitable for the measurement and the results are well correlated. When using a helium pycnometer, a weighed tobacco sample is placed either at 100 ° C after drying for 3 hours or in equilibrium, in a cell, in a Quantachrome Penta-Pycnometer Model 2042-1, a Quantachrome Corporation (5 Aerial Way, Syosset). , New York). The cell is then purged with helium and pressurized with helium. The volume of helium which the tobacco replaces is measured and compared with the volume of helium required to fill the empty cell. The volume of tobacco is determined according to the rules of the ideal gas law. In the present specification, unless otherwise indicated, the specific volume is measured for the same sample of tobacco as that used for the volatile determination, i.e., the tobacco is dried in an oven containing 100 ° C for 3 hours.

As used herein, the moisture content is considered to be equal to the volatile matter content (OV) since only about 0.9% by weight of the tobacco is non-water volatile matter. The determination of the volatile matter content is a simple measurement of the weight loss of the tobacco after heating it to 100 ° C in a circulating air oven for 3 hours. The percentage weight loss calculated on the original mass is the volatile matter content.

A "sieve test" is a method of measuring the length distribution of cut tobacco pieces. This measurement is very often used to determine the amount of tobacco piece length reduction during processing. Place 150 ± 20 g of unexpanded tobacco or 100 ± 10 g of expanded tobacco in a shaker. The shaker incorporates a series of trays with 366 cm diameter holes (WS Tyler, Inc., a subsidiary of the Screening Division of Combustion Engineering Inc., Mentor, OHIO 44060) and complies with ASTM (American Society of Testing Materials) The screen sizes on the trays are 2.5 mm (6 mesh), 1.68 mm (12 mesh), 0.841 mm (20 mesh), and 0.42 mm (35 mesh) .The shaking stroke length of the apparatus is approximately 4 cm, shaking rate 350 ± 5 rpm The tobacco is shaken for 5 minutes on a shaker to separate the sample into different particle size classes, and the mass of each particle size group is determined to obtain a particle size distribution of the sample.

Laboratory experiments have shown that restoring the moisture content of the tobacco, if it is to be done quickly by contacting the tobacco with high humidity air, results in a decrease in CV (roll volume). It has also been shown that CV (cylinder volume) reduction occurs when the expanded tobacco bed is subjected to condensation or over-wetting conditions. Condensation occurs when wet air comes into contact with tobacco that is below the dew point of wet air. Over-moistening occurs when the inside of the tobacco bed changes in moisture due to the fact that the tobacco is not evenly exposed to moist air. Therefore, a successful wet air humidity recovery system should operate at a relatively low rate, with good control by precisely controlling the relative humidity of the air, the air temperature, the air flow and the pressure across the tobacco bed. This can best be achieved by gradually increasing the moisture content of the air passing through the tobacco so that the tobacco is always in contact with an air stream that

21 approximately equilibrium with the actual moisture content of the tobacco.

The ABC curve of Figure 1 is an isothermal curve of 24 ° C for a typical expanded light tobacco. The isotherm refers to the volatile content of tobacco and the relative humidity of the surrounding air at equilibrium at a given temperature. B. indicates that at 24 ° C and 60% relative humidity, the expanded tobacco sample tested has a volatile content of 11.7% by weight. Figure 1 is a DEF curve of a typical relative humidity profile for tobacco re-wetted according to the present invention. The GEF curve in Figure 1 is another relative humidity profile which is also of satisfactory quality. The HF curve in Figure 1 is a representative pathway described in the prior art, such as a laboratory rehydration process in a very low air velocity equilibrium chamber. The IJ curve in Figure 1 illustrates the use of the method of the present invention for drying tobacco.

The result of Figure 1 shows that rehydration of tobacco starting from a volatile content of 6.5 wt.%, With air in equilibrium with the starting material, having a relative humidity of 30% to a volatile content of 11.7 wt. Equilibrated with air having a relative humidity of 60%, it can be accomplished by contacting the tobacco with air of increasing humidity, wherein the relative humidity of the air is 40%, and increasing the humidity in small increments until the 60% relative humidity is reached. The result is much more achievable with this process than if the tobacco were treated directly with air having a relative humidity of 60%. If the humidification of the tobacco is carried out under the above slowly and gradually changing conditions, the air flow and the mass transfer between the tobacco are relatively slow, since the respective driving force is low and the expanded tobacco structure is maintained if this method is used. Rehydration of expanded tobacco without loss of CV (cylinder volume) can also be accomplished by treating the tobacco with an increasing humidity air having an initial relative humidity of 40% and increasing this humidity gradually over a period of 40-60 minutes until reaches a relative humidity of 62%. This process reduces the time required for the entire rehydration process without substantially altering the expanded tobacco structure. Therefore, the DEF and GEF lines of Figure 1 illustrate an effective form of the process of the present invention when used to rehydrate tobacco.

Figure 1 shows close equilibrium states between tobacco and airflow on line EF and line ABC. It can be seen that for tobacco with a volatile content below 7% by weight, the relative humidity of the air in equilibrium with the tobacco and the relative humidity of the humid air used for rehydration can be quite large without adversely affecting the filling characteristics of the tobacco. It is also observed that the relative humidity of the moist air used to rehydrate the tobacco in the range of 7.5 to 11.5% by weight of the volatile material may be 2 to 8% higher than the relative humidity of the air equilibrated with the tobacco. the difference can be applied to tobacco with lower volatile content without adversely affecting the filling characteristics of the tobacco.

When the method of the present invention is used for drying tobacco, no reduction in tobacco roll volume (CV) is measured. This is also found to be the case when the relative humidity of the drying air stream is significantly lower than the relative humidity of the air in equilibrium with the tobacco, i.e., the relative humidity of the drying air stream below the equilibrium conditions of the tobacco. Therefore, the IJ curve shown in Figure 1 is only one of many possible routes that can be used for drying tobacco according to the process of the invention.

The process of the invention may also be carried out in batch or continuous mode. When the process is carried out in a rehydration form per serving, the relative humidity of the air stream in contact with the tobacco is increased over a period of time, thereby ensuring a continuous increase in the moisture content of the tobacco. This can be accomplished by means of the chamber shown in Figure 2. The tobacco to be wetted is placed on trays 23 having a suitable screen size, in a layer about 5 cm thick. The trays 23 are located inside the chamber so that a stream of humidified air entering the air inlet 25, controlled by a water source 27 and a microprocessor 28, passes downward through the tobacco and exits the air outlet 26. The chambers have a size of about 560-2240 m ³ (product of Parameter Generation and Control, Inc. (1104Old US 70, West, Black Mountain, NC 28711)) and have been used in numerous experiments. The chambers are equipped with 28 microprocessors, which allow controlled rising humid air to enter the chambers, which is controlled by 24 relative humidity controls. The tests were carried out by rehydrating dry expanded tobacco starting from 2% by weight of volatile material to a final volatile content of 11.5% by weight, with an initial relative humidity of 30% or even 52% relative humidity for 30-90 minutes. below, to a final relative humidity of 59% and 65%. The air velocity was 1525-6100 cm / min. Relative humidity and temperature were measured on a Thunder 4A-1 model (Thunder Scientific Corp., 623 Wyoming, SE, Albuquerque, New Mexico 87123). The air velocity was measured using an Alnor Thermo Anemometer Model 8525 (Alnor Instrument Co., 7555 N. Linder Ave., Skokie, Illinois 60066). In a test where the initial relative humidity of 52% was raised to a relative humidity of 62 %5

In 40 minutes, that is, in a relatively short period of time, a re-wetted tobacco of similar quality to the re-wetted tobacco wetted in a controlled environment using 60% relative humidity and 24 ° C air, which is the air in the tobacco, is obtained. it runs at slow speed for 24-48 hours and retains its total cylinder volume (CV). This increase in relative humidity is successful even at humid air velocities such as 6000 cm / min and the air temperature can be between 24 ° C and 194 ° C. Expanded tobacco rehydrated by such a process exhibits minimal CV (cylinder volume) loss, if any, when compared to environmentally controlled controlled room rehydrated expanded tobacco.

The process of the invention is most preferably and most efficiently carried out on a Frigoscandia self-horn spiral conveyor, such as that shown in Figure 3, as a continuous process. The equipment is a specially modified GCP 42 model spiral freezer, manufactured by Frigoscandia Food Process Systems AB of Helsingborg, Sweden. The dry tobacco to be wetted enters unit 10 through conveyor 13 through inlet 12 and passes unit 10 through conveyor 13 according to spiral geometry; from the bottom up; and then exits through the tobacco evacuator 11 after wetting. The tobacco is blown with wet air from the wet air inlet 15, which enters the bottom of the spiral chimney 14 and exits the wet air outlet 16 and moves in a direction substantially opposite to the tobacco movement. That is, most of the wet air stream flows downward from the top of the chimney through a series of tobacco heaps, while tobacco follows the spiral conveyor path from the bottom up. Air flows of this type are shown in Fig. 3a. 4A. This arrangement has been shown to double the rate of increase in relative humidity obtained in the apparatus shown in Figure 2.

3a. 3A, a sectional view of a portion of the spiral horn 14 shown in FIG. 3 illustrates the path of the air stream 20 and 22 relative to the tobacco bed 21. As in Figure 3a. As shown in FIGS. 2A and 4B, air flows 20 and 22 travel from the top of the chimney to the bottom of the chimney. The tobacco flow from the bottom of the unit to the top is shown as shown in FIG. 3a. 5a, moving from the right to the left of the FIG. The main stream of air stream 20, which is substantially transverse to the tobacco, passes through and directly below the tobacco bed 21 while a small portion of the air stream 22 passes over the tobacco bed 21 in the opposite direction to the tobacco bed 21. This air stream portion 22 may later pass through the tobacco bed 21.

A key aspect of the process of the present invention for its use is the use of the process for rehydration to provide a means for providing a steady and constant increase in the relative humidity of the air in contact with the tobacco as the volatile content of the tobacco increases. Frigoscandia self-horn spiral conveyor belt, due to its self-horn design, directs much of the air stream 20 down through multiple layers of conveyor belt 13 (conveyor belt 13) which conveys tobacco. When the tobacco is fed to the conveyor 13 at the bottom of the spiral horn 14 and the humidified air is applied at the top of the horn, the entire flow of air and tobacco is reversed. This substantially countercurrent material stream provides a natural continuous relative humidity gradient in the air (which is in contact with the tobacco) as the air gradually loses its moisture content as it travels downward through the tobacco layers subjected to the wetting process. By appropriately weighing the conveyor speed, air and tobacco flow rates, and controlling the inlet air temperature and relative humidity, the same conditions as those used in the laboratory for increasing humidity in a portion-wise and . Preferably, 80 kg / h of expanded tobacco containing 3% by weight of volatile material is desired to be rehydrated using a conveyor speed of 40 to 80 minutes and air at 24 to 35 ° C with a relative humidity of 61 to 64% and 20 to 22%. air flow between 28.3-71 m ³ / min. This process achieves complete re-wetting without significant cylinder volume (CV) reduction or measurable tobacco refraction when using the modified Frigoscandia GCP 42 spiral apparatus.

The time dependence of the relative humidity can be made using a Model 29-03 relative humidity / temperature meter (Rustrak Instruments Co. E. Greenwich, RI) operated in a Frigoscandia apparatus while the tobacco is rehydrated. The gauges show a constant and steady increase in the moisture content of the air as the gauge is moved upwardly on the conveyor belt in the spiral horn 14. The initial relative humidity at the bottom of the spiral chimney is generally between 35-45% where the tobacco is the driest and 62% at the top of the spiral chimney 14 where the tobacco is substantially completely wetted.

Figure 6 shows a representative relative humidity versus time curve measured with a Rustrak unit. Figure 6 shows the relative humidity of the air in the tobacco bed over time. The initial 3% volatile tobacco entering the spiral rehumidifying unit 10 is contacted with air having a relative humidity of 43% (Figure 6A). Figure 6 shows that as the tobacco passes through the spiral rehumidifying unit 10, the relative humidity of the air adjacent to the tobacco increases from 43% to 62%, which is the outlet of the unit (Figure 6B). The tobacco has 11% by weight of volatile material at the point where it leaves the spiral rehumidifying unit 10. The relative humidity of the air entering the spiral rehumidifier unit 10

21 so that the re-wetted tobacco does not show a significant decrease in the roll volume (CV).

Devices can be used to carry out the process according to the invention in a continuous manner, which ensure an increase in the relative humidity of the air having a relative humidity. An example of such a device is the device shown in Figure 4. In the apparatus shown in Figure 4, tobacco enters the tobacco inlet 40 through the conveyor belt 43 and exits the tobacco outlet 41. A steadily increasing relative humidity air is directed through either the top-down or bottom-up tobacco bed 42 through zone 44 to reproduce the relative humidity increase in the direction of the dashed arrow provided in the apparatus of Figure 2. This effect of increasing the moisture content can be achieved by moving the air from a single source in a serpentine manner from the right side of Figure 4 to the left side, thereby providing a substantially countercurrent air flow against the tobacco movement. The air exiting a particular zone becomes the intake air in the next adjacent left zone.

Figure 5 is a block diagram of a method according to the invention. The expanded tobacco enters the tobacco cooler 51 at a temperature of 93 ° C, with a volatile content of 3% by weight, into which cooling air 52 of 24 ° C with a relative humidity of 52% is introduced. The cooled tobacco having a temperature of 27 ° C and a relative humidity of 4% is introduced from the tobacco cooler 51 into a spiral rehumidifier unit 53, into which a rehydration air 54 of 29 ° C and a relative humidity of 62% is introduced. The tobacco 55 leaving the spiral rehumidification unit 53 has a temperature of 29 ° C and a volatile content of 11.5% by weight.

In accordance with the process of the invention, whole treated tobacco leaves, cut or shredded tobacco, either in expanded or non-expanded form, or certain parts of the tobacco, such as tobacco stems or reconstituted tobacco, may be treated. The process can be applied to any or all of the above cases, provided they are flavored with or without flavoring. In some cases of tobacco drying, it has been found that the unexpanded cut filler can be continuously dried at substantially room temperature using a substantially countercurrent air stream in a modified Frigoscandia self-horn spiral conveyor, so that the moisture content of tobacco is from 21% by weight to hours. In this case, the inlet air at the top of the unit is 29 ° C and 58% relative humidity, and the outlet air is 25 ° C and 68% relative humidity. The drying is carried out without heat treatment on the tobacco or with very little heat treatment.

Alternatively, the process of the present invention is suitable for drying tobacco which is substantially higher than room temperature; for example, for drying tobacco having a temperature of 93-121 ° C. If tobacco is dried between such temperature limits, the relative humidity and temperature of the drying air are adjusted to provide the conditions of the process of the invention.

Similar to the tobacco rehydration process, it has been found that drying is best accomplished in a minimal amount of time when the final air humidity is lower than that needed to convert the tobacco to the desired final air humidity. This increases the air-tobacco moisture gradient and, consequently, the driving force that drives the drying forward. In contrast to the rehydration process, the final moisture content of the air stream can be maintained at a level much less than that which would be in equilibrium with the desired volatile tobacco content after drying.

Example 1

The advantage of the method of wetting dry expanded tobacco is to add water to the tobacco at a slow rate compared to spray or cylindrical rewetting. For this purpose, 20 g of tobacco filler is placed in a sealed desiccator. The sample was impregnated with liquid carbon dioxide and expanded in a expansion tower at 287 ° C. The expanded tobacco filler has a volatile content of 3.4% by weight. We calculated that approx

Water (89 g) is needed to increase the volatile content of the sample to 11.5% by weight. This amount of water is poured into a small glass jar, which is sealed with a rubber stopper pierced by a glass tube of 0.3 cm internal diameter. The glass container is also placed in a sealed desiccator. After 9 days, the tobacco adsorbs all water. The tobacco sample was then analyzed and found to have a volatile content of 11.5% by weight. As used herein, tobacco is understood to be a substance that is in equilibrium prior to equilibration in a chamber in which air having a relative humidity of 60% and a temperature of 24 ° C is passed through at low speed for a period of 24 to 48 hours. The above equilibration procedure is generally used to modify the tobacco to standard conditions prior to measuring cylinder volume, specific gravity, and screen size. In the standard equilibration or equilibration procedure, the desiccator has a CV (roll) value of 9.5 cm ³ / g and a specific gravity (SV) value of 2.9 cm ³ / g, while having a volatile matter content

II, 6% by weight. For comparison, a second sample of the same tobacco is placed directly in the equilibrium chamber and rewetted using an equilibration process under standard conditions. In this case, the volatile matter content of the equilibrated material was 9.3% by weight and the cylinder volume (CV) and specific volume (SV) were 9.4 or 2.7 cm ³ / g. A third expanded tobacco filler sample is rewetted in a spray roller so that after wetting, the volatile content is 11.5% by weight. After equilibration, this sample has a cylindrical volume (CV) of 8.5 cm ³ / g and a specific gravity (SV) of 1.9 cm ³ / g.

EN 219 164 Β, the smoothing volatile content is 11.6 wt. gel again. This sample also shows, as shown in Table 1, a significant improvement in cylinder volume (CV) and specific volume tobacco, which in a desiccator is repeated by slow addition of water (SV), even when wet. shows equilibrium equilibrium with the sample, which is directly moistened in CV and SV in a equilibration equilibrium chamber.

Table 1

Sample Pattern features Characteristics of the smoothed sample OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) SV (cm ³ / g) tower Output 3.4 3.0 11.3 9.4 2.7 Moistened in a roller 11.5 1.8 11.6 8.5 1.9 Desiccated in a desiccator 11.5 2.7 11.6 9.5 2.9

A second set of experiments was conducted using an ambient chamber to rehydrate the expanded tobacco filler. To this end, a Parameter Space Generation and Control (PGC) chamber is used.

The chamber is equipped with a Micro-Pro 2000 microprocessor, a product of Parameter Generation and Control Inc., which allows the conditions inside the chamber to be increased in a controlled manner.

Example 2

1.35 kg of light tobacco are impregnated with liquid carbon dioxide and expanded under conditions similar to those described in Example 1. The tobacco is then placed on a tray 5 cm thick.

The sides of the tray are solid, while the bottom has a sieve with appropriate openings. Place the tray in an environmental chamber. The sample is then re-wetted with air at 24 ° C, initially 36% relative humidity, for 1 hour, and the humidity is raised to a final relative humidity of 60%. The air stream is directed downward through the tobacco bed and air velocity is 13.7 meters / min. This experiment is then repeated for 3 hours, 6 hours and 12 hours. The results are shown in Table 2. The results show that increasing the moisture content for about 6 hours under the conditions used will affect the CV (roll volume) and SV (specific gravity) of the tobacco. At a lower rate of re-wetting, higher CV (cylinder volume) and SV (specific volume) values are observed. For reordering method according to the invention also as compared to spray cylinder reordering tobacco can achieve at least 1 cm ³ / g, a value larger cylinder volume (CV) and at least 0.2 cm ³ / g, more fajlagostérfogat- value (SV) values were. In contrast, it has been found that this advantageous change can be achieved primarily by increasing the moisture content within up to 1 hour.

Table 2

The product The product is equilibrated in an environmental chamber OV (% by weight) SV (cm ³ / g) OV (% w / w) CV (cm ³ / g) tower Output 3.10 3.06 11,33 9.71 Cylinder spray 11.51 1.61 11.37 8.61 Raise within 1 hour 10.83 1.85 11.38 9.72 Raise within 3 hours 11.44 1.88 11.36 9.81 Raise within 6 hours 11.45 1.90 11.30 9.88 Raise within 12 hours 11.41 1.97 11.27 9.89

Example 3

A laboratory study was conducted to investigate the effect of rehydration rate and temperature on tobacco roll volume (CV) and specific volume (SV). Seven assays were performed using tobacco impregnated with carbon dioxide, followed by 60 extensions of the impregnated mixture in an extension tower at 287 ° C. The wetted tobacco is rehydrated by the following procedure:

(1) Equilibrium position using tobacco at ambient temperature for 24 hours at 60% relative humidity and 24 ° C

21 by introducing air through the tobacco at a speed of 7.6 m / min;

(2) water is sprayed onto the mixture to increase the volatile matter content to 7.5% by weight and the resulting material is equilibrated for 1 hour at 60% RH with air at 167 ° C. bring;

(3) spraying water to increase the volatile matter content to 7.5% by weight and then final wetting in a spray roller;

(4) water was sprayed to maintain the volatile content at 7.5% by weight and humidified air was used which increased the relative humidity from an initial 46% to a final 60%; and (5) increasing the humidity of the moist air from 46% to 60%.

Wet air rehydration is carried out in a PGC ambient chamber equipped with a microprocessor so that the microprocessor is capable of increasing the moisture content at selected times. The following conditions apply.

(1) Moisture increase times: 30, 60 and 90 minutes;

(2) air temperature: 167 ° C and 203 ° C;

(3) air velocity: upward flow through the tobacco bed at 13.7 m / min and down through the tobacco bed at 53.4 m / min; and (4) tobacco bed thickness: 5 cm.

The tobacco used in the rehydration experiments, except for the sample used in the spray roller, was collected at the outlet of the expansion tower and then sealed in a double plastic bag before rehydration. As a result of storage, the tobacco was cooled to a temperature of 93 ° C, which cooled the expansion tower to outlet tobacco temperature, to room temperature, before rehydration was performed. If the humidification is carried out at a temperature of about 35 ° C during rehydration while the tobacco remains in the sealed bag, this can be accomplished so as to avoid condensation due to the humid air before the tobacco comes into contact with the air having a higher moisture content. The results of the assays are shown in Tables 3a-3e.

Table 3a

Sample The pattern itself Equilibrium pattern OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) X Output Tower 3.43 3.02 11.31 9.04 S Through Sprayers (Exceptional Case) 8.06 2.14 11.68 8.66 C Through sprayer and roller 11.53 1.81 11.59 8.59 F With humidifier and within 90 minutes increase in humidity (from 46% RH to 60% RH at 24 ° C) 11.27 1.87 11.51 9.01 H With sprayer and within 90 minutes relative humidity increase (from 46% relative humidity to 60% relative humidity at 167 ° C) 10.96 1.98 11.36 9.48 I AH sample maintained at 167 ° C for 60 minutes in air having a relative humidity of 60% 11.54 1.95 11.56 9.40 J Increased relative humidity for sprays and 60 minutes (from 46% RH to 62% RH, At 35 ° C) 10.37 2.38 11.28 9.85 Sample K J held for 15 minutes in air at 62% RH at 35 ° C 11.17 2.26 11.22 9.88

Table 3b

Sample The pattern itself Equilibrium pattern OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) X Output Tower 3.01 2.58 11.34 9.23 S Through Sprayers (Exceptional Case) 7.51 2.13 11.39 8.87

HU 219 164 Β

Table 3b (continued)

Sample The pattern itself Equilibrium pattern OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) C Through sprayer and roller 11.86 1.59 11.64 8.07 F With humidifier and within 90 minutes increase in humidity (from 46% RH to 60% RH at 24 ° C) 10.55 1.64 11.45 8.86 G sample H held for 15 minutes in air having a relative humidity of 60% at 24 ° C 11.56 1.64 11.42 8.61 H With sprayer and within 30 minutes increase in relative humidity (from 46% RH to 60% RH, At 24 ° C) 10.28 1.97 11.27 8.99 I AH sample maintained for 15 minutes in air having a relative humidity of 60% at 24 ° C 11.73 1.82 11.25 8.61

Table 3c

Sample The pattern itself Equilibrium pattern OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) The Output Tower 1.81 2.78 11.37 9.23 B Increase in humidity within 60 minutes (from 46% relative humidity to 60% relative humidity at 35 ° C) 10.91 1.86 11.47 8.86 C Increase in humidity within 60 minutes (from 46% RH to 60% RH at 24 ° C) 10.53 2.02 11.28 9.20 D Increase in relative humidity within 90 minutes (from 46% RH to 60% RH at 35 ° C) 10.84 1.99 11.45 8.90 E Through the spray equipment 5.39 2.37 11.25 8.71 F Spray + directly at 60% relative humidity placed in air at 35 ° C for 30 minutes 10.80 1.81 11.27 8.39 G Increased humidity through spray equipment for 60 minutes (from 46% RH to 60% RH at 35 ° C) 10.66 1.85 11.23 8.65 H Increased humidity through spray equipment and 90 minutes (from 46% RH to 60% RH at 35 ° C) 10.76 1.82 11.24 8.62 I Increased humidity through spray equipment for 60 minutes (from 46% RH to 60% RH at 24 ° C) 10.65 1.90 11.23 8.75 J Increased humidity through spray equipment and 90 minutes (from 46% RH to 60% RH at 24 ° C) 10.57 1.87 11.38 8.74

HU 219 164 Β

Table 3c (continued)

Sample The pattern itself Equilibrium pattern OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) K Sprayed and placed directly in a 60% relative humidity environment at 24 ° C for 30 minutes 10.73 1.87 11.22 8.64 L Through spray equipment and roller 10.98 1.60 11.39 8.28

3d table

Sample The pattern itself Equilibrium pattern OV (% by weight) SV (cm ³ / g) OV (% by weight) CV (cm ³ / g) TI Output Tower 2.83 3.01 11.92 9.46 T2 With a direct relative humidity of 60%, Place in air at 24 ° C for 30 minutes 11.24 2.27 11.77 9.08 T3 increase in humidity for 90 minutes (from 46% RH to 60% RH at 24 ° C) 11.08 2.24 11.83 9.29 T4 Increase in relative humidity for 90 minutes (from 30% RH to 60% RH at 24 ° C) 9.77 2.39 11.85 9.43 Ski Through Spray Equipment 4.78 2.82 11.66 8.98 S2 Spray gun and placed directly in a 60% relative humidity environment at 24 ° C for 30 minutes 11.10 2.19 11.64 8.89 Increased relative humidity through S3 Sprayer and 90 minutes (from 46% RH to 60% RH at 24 ° C) 10.54 2.25 11.27 9.05 S4 Spraying Equipment and Increased Relative Humidity (46%) for 60 minutes from Relative Humidity to 60% Relative Humidity at 24 ° C) 10.56 2.22 11.73 9.03 S5 Increased relative humidity through a sprayer for 30 minutes (from 46% RH to 60% RH at 24 ° C) 9.74 2.29 11.67 9.19 C Via spray equipment and roller 10.48 1.95 11.81 8.80

Table 3e

Conditions for increasing moisture content The pattern itself Balanced sample initial DEFEND (Volatile substances, crowd%) Average air speed (M / min) Time (minute) tem- ture (° C) Relative Humidity,% DEFEND (crowd%) SV (cm ³ / g) DEFEND (crowd%) CV (cm ³ / g) Material fed into the tower 15.40 0.79 11.86 5.05 Out of the tower material 3.94 2.82 11.72 9.49

HU 219 164 Β

Table 3e (continued)

Conditions for increasing the moisture content The pattern itself Balanced sample initial DEFEND (Volatile substances, crowd%) Average air speed (M / min) Time (minute) tem- ture (° C) Relative Humidity,% DEFEND (crowd%) SV (cm ³ / g) DEFEND (crowd%) CV (cm ³ / g) 1 spray position 5.64 2.72 11.82 9.48 Output roller 10.36 2.04 11.66 9.28 THE 3.9 71.6 60 24 30-58 6.67 2.39 11.65 9.76 B 5.6 53.3 60 24 30-58 8.44 2.45 11.82 9.91 C 3.9 57.9 60 24 45-58 7.83 2.25 11.65 9.57 D 5.6 57.9 60 24 45-58 8.44 2.39 11.79 9.66 E 3.9 57.9 60 24 47-62 11.10 2.33 11.74 10.02 F 5.6 53.5 60 24 47-62 10.10 2.41 11.59 10.08 G 3.9 54.8 60 24 30-62 8.13 2.20 11.89 9.63 H 5.6 53.3 60 24 30-62 9.41 2.41 11.79 10.11 I 3.9 60.9 60 24 47-62 10.21 2.15 11.76 8.98 J 3.9 53.3 60 24 47-64 10.18 2.13 11.94 9.03 K 3.9 53.3 60 24 35-64 9.07 2.23 11.90 9.51 L 3.9 53.3 60 35 35-60 8.65 2.17 12.09 8.59 M 3.9 53.3 60 35 45-60 10.11 2.39 11.92 10.02 N 5.6 53.3 60 35 45-60 10.08 2.39 11.93 10.02 SHE 3.9 73.2 60 35 47-64 10.88 2.31 11.96 9.51 P 3.9 73.2 60 35 47-64 11.30 2.33 11.95 9.30

It is apparent from Figures 3a-3e defined data tables, that in comparison escaping the expansion tower spray reordering of hot tobacco cylindrical procedure of a temperature of the cooled tobacco, i.e., 24-35 ° C for 40 to vei Reordering tobacco gradually increased air humidity of 0.5 cm ³ / A CV (cylinder volume) gain of g1 cm ³ / g and a specific gravity gain of 0.3 cm ³ / g to 0.4 cm ³ / g SV can be achieved. If tobacco obtained directly from the outlet of the tower is re-wetting, it has been found advantageous to first treat the tobacco with a spray to increase the tobacco's volatile content to 7% by weight, and then to re-wipe with high humidity air 50 The CV (roll volume) of the re-wetted tobacco - or There should be no significant difference in SV (Specific Volume) m, then rehydration is performed with an initial 46% humidity air, or an initial 30% humidity air in a roller process or in the case of tobacco where the rehydration process is performed for 60 minutes or 90 minutes. In addition, it has been observed that the tobacco can be rewetted when the air flow is downwardly through the tobacco bed at a rate of 53-71 m / min, or if the air is upward, up to 13 m / min. In such cases, there is no significant difference in CV (cylinder volume) or SV (specific gravity). In addition, it has been observed that re-wetting with incremental air humidity results in tobacco having the same or better CV (Roll Volume) and SV (Specific Volume) values than tobacco re-wetted by placing it in an environmental chamber and directly at 60%. air at a relative humidity of 24 ° C (after leaving the expansion tower). Finally, it has been observed that spraying with water to increase the volatile matter content to 7.5% by weight, followed by gradual treatment with humidified air, results in better CV (roll volume) and SV (specific volume) tobacco than tobacco produced by spray treatment in a spray roll for final rehydration.

Example 4

Testing was performed to determine the effect of airflow and air velocity on the filling, filing and compaction characteristics of tobacco. Testing it12

The enclosure was performed using PGC ambient chambers and two chambers were used in the experiments. Air velocity in both chambers was 500 CFM (1415 L / min). In one of the PGC chambers, the air movement is upward through the tobacco bed, and in the other chamber the air flow is downward through the tobacco bed. The 5 cm tobacco samples are placed on a top side open tray system of 150 cm χ 170 cm (5 ″ χ 5 3/4 ″), with trays with a mesh bottom and with 10 cm high side panels. The trays are placed on shelves which are inside the ambient chamber. Air is passed through the samples by covering the uncoated area of the shelf with cardboard and sealing the openings or any break line with adhesive tape. The air velocity is varied by varying the number of sample containers through which air is passed. The tobacco used in the experiments was impregnated with carbon dioxide and expanded at 290 ° C. The tobacco is wetted again by spraying with water in the first step to achieve a volatile content of 8% by weight immediately upon expansion. During the test, the conditions in the chamber were set at 24 ° C and 60% relative humidity. The wet air velocity was measured using a paddle air velocity meter (Airflow Instrumentation, Model LCA 6000, Frederick, Maryland) and a hot-wire air velocity meter (Alnor Instrument Company, Skokie, Illinois, Thermometer Model 8525). Devices are placed directly above or below the samples, depending on whether the air flow is upward or downward.

When the upward air flow is used, a slight increase in tobacco is observed immediately after the air reaches an average speed of up to 8 m / min. Small air ducts are formed and, as a result, the tobacco settles in its original position. Due to the resulting channels, it was found that the airflow through the tobacco bed was not even at all (6.7-13.7 m / min, mean 7.9 m / min). If the average airflow is increased, many more channels are apparently formed and, at a flow rate above 13 m / min, significant movement or "boiling" occurs in the tobacco, followed by significant channel formation in the bed.

When using a downward flow of air, there is compaction in the bed and consequently a decrease in air velocity at any of the air velocities tested. This is shown in Table 4. At an initial air velocity of 58.5 m / min, the thickness of the tobacco bed is reduced by 28% due to compaction, resulting in a velocity of air passing through the bed to 43 m / min or less. When using an initial air velocity of 43 m / min or less, about half of the bed compaction experienced at the above 58 m / min is achieved and the air flow rate through the tobacco bed is much reduced.

Table 4

Effect of air velocity passing through tobacco bed on compaction of bed

air Speed (M / min) bed Height (Cm) Kiin- examined by chromium release End- point %-ancestor change Kiin- examined by chromium release End- point %-ancestor change 58 43 27 5 3.62 28 49 44 11 5 4.12 18 43 40 6 5 4.3 15 31 30 6 5 4.5 10 13 12 5 5 4.7 5

From the above experiments, it can be established that expanded tobacco can be rehydrated by the process of the present invention preferably under the following growth conditions.

(a) Duration: 60 minutes to 90 minutes;

(b) relative humidity: initial humidity between 30% and 45% and final relative humidity between 60% and 64%;

(c) temperature: 24 ° C to 35 ° C;

(d) airflow rate: upward velocity up to 13.7 m / min or downward air velocity up to 71.6 m / min.

Example 5

6.8 kg / h light and raw tobacco blend was fed into a modified Frigoscandia GCP 42 model self-horn spiral device. Prior to feeding, the tobacco mixture is impregnated with carbon dioxide. The tobacco sample is then passed through a heat sink to cool its temperature from 93 ° C to 29 ° C before being fed into the above apparatus. The direction of the air flow is from the top of the device to the bottom, thereby providing a substantially countercurrent air flow to the direction of the tobacco flow. The arrangement ensures that the tobacco is rehydrated with air of increasing humidity as the air is continuously and continuously dehydrated by the tobacco. The tobacco introduced into the apparatus has a volatile content of 3% and the tobacco leaving the apparatus has a volatile content of 11%. The equilibrated CV (roll volume) of the feed material is 10.53 cm ³ / g and the equilibrated CV (roll volume) of the rehydrated material is 10.46 cm ³ / g, indicating that during rehydration, there was no significant change in the filling characteristics of the tobacco, that is, there was no statistically significant decrease in the filling characteristics as determined by the standard variance analysis. In addition, there is no measurable reduction in tobacco particle size, which is analyzed by a sieve test during the rewetting process.

HU 219 164 Β

Example 6

A series of experiments is carried out by expanding different types of tobacco using different tower temperatures and then rehydrating the tobacco according to the process of the invention. For each experiment, 6.8 kg / hr of tobacco is used, based on the weight of the re-moistened tobacco, and this amount of tobacco is rehydrated in a modified Frigoscandia self-horn spiral apparatus as described in Example 5. Inlet air characteristics of the rehumidification unit: temperature 29 ° C, relative humidity 62%. The air leaving the rehumidification unit has a temperature of 32-35 ° C and a relative humidity of 40% -45%. As shown in Table 5, tobacco rehydrated by the process of the present invention does not show a significant reduction in its filling properties.

Table 5

tobacco Type Experiment number Toronyhő- moderation (° C) Tobacco- volatile matter input (crowd%) Tobacco- volatile matter output (%, By weight) Cylinder tooth inlet (cm ³ / g) He brought me into balance volatile matter input (crowd%) Cylinder volume (cm ³ / g) lllóanyag- output (crowd%) Clear FO 205C 142 2.70 11.16 9.93 11.87 9.40 12.00 FO 205A 160 2.11 11.58 10.41 11.57 10.83 11.56 FO 205B 166 1.87 9.99 11.30 11.30 10.90 11.50 Clear FO 206A 153 2.47 11.09 10.00 12.34 10.20 11.74 FO217 160 2.59 10.86 10.49 11.79 10.51 11.63 Crude FO 206B 120 3.11 10.75 12.39 10.91 12.31 10.52 FO 206C 132 2.95 10.22 12.08 10.85 12.41 10.40 FO214 132 3.00 10.4 11.3 10.4 11.2 10.4

EXAMPLE 7 PATENT CLAIMS

At a rate of 90.8 kg / h, light tobacco having a volatile content of 21.6% by weight is fed into a modified Frigoscandia self-horn apparatus described in Example 5 which functions as a drying apparatus. The tobacco flows through the spiral dryer from the bottom to the bottom, thereby ensuring that a substantially countercurrent flow of air and tobacco occurs.

The tobacco was dried to a volatile content of 12.2% by weight, with a residence time of 60 minutes, using air having an inlet temperature of 35 ° C and a relative inlet humidity of 35%. The air leaving the dryer unit has a temperature of 28 ° C and a relative humidity of 62%.

Tobacco entering and exiting the dryer seems to be cold to the touch and has an estimated temperature of 45 to 24 ° C, indicating that the tobacco has not been substantially heat-treated. There was no change in the CV value of the tobacco at equilibrium during the drying process. This drying process has been carried out in order to minimize the thermal heat treatment during drying. Similar drying procedures can be performed at higher temperatures and a controlled heat treatment value can be achieved.

The subject matter of the invention is illustrated in detail in the examples with preferred embodiments, however, as will be appreciated by one of ordinary skill in the art, various modifications are included and any modifications which do not alter the spirit of the invention are encompassed.

Claims (21)

A method for increasing the moisture content of an hygroscopic organic material, comprising: (a) forming a bed of the hygroscopic organic material by depositing the hygroscopic organic material on a spiral horn conveyor having more than one level; (b) contacting the hygroscopic organic material on the bed with an air stream that is substantially countercurrent to the hygroscopic organic material bed, and that the relative humidity of the air stream contacting the hygroscopic organic material is close to the equilibrium increasing the relative humidity of the air stream in contact with the material to increase the moisture content of the hygroscopic organic material and maintaining the relative humidity of the air stream in contact with the hygroscopic organic material at in countercurrent flow, the air stream is continuously dehydrated and the hygroscopic organic material is moisten it well. A method for reducing the moisture content of an hygroscopic organic material, comprising (a) forming a bed of the hygroscopic organic material by depositing the hygroscopic organic material on a spiral horn conveyor belt having more than one level; EN 219 164 b (b) contacting the hygroscopic organic material with an air stream on the bed which is substantially countercurrent to the hygroscopic organic material bed, and the relative humidity of the air stream contacting the hygroscopic organic material is less than or equal to c) decreasing the relative humidity of the air stream in contact with the hygroscopic organic material to reduce the moisture content of the hygroscopic organic material and each time maintaining the relative humidity of the air stream in contact with the hygroscopic organic material at or below the desired during which the air stream is streamed when the air stream is countercurrently flowing through the bed of the hygroscopic organic material hydrate and continuously dehydrate the hygroscopic organic material. The process according to claim 1 or 2, characterized in that the temperature of the hygroscopic organic material is kept below 38 ° C prior to contact with the air stream. A process according to claim 1 or 2, characterized in that the hygroscopic organic material is used which has a moisture content of between 1.5% and 13% by weight prior to contact with the air stream. The process of claim 4, wherein said hygroscopic organic material has an initial moisture content of between 1.5% and 6% by weight prior to contact with the air stream. 6. The method of claim 1, wherein said stream of air is contacted with said hygroscopic organic material having a relative humidity of 30% to 64% and a temperature of 21 ° C to 49 ° C. The process according to claim 1 or 2, wherein the hygroscopic organic material is tobacco. 8. The method of claim 7, wherein the tobacco is expanded tobacco. 9. The method of claim 7, wherein the tobacco is cut tobacco. The method of claim 7, wherein the tobacco is expanded or non-expanded tobacco, whole leaf tobacco, cut or comminuted tobacco, tobacco stems, reconstituted tobacco or any combination thereof. 11. A method for reducing the moisture content of a hygroscopic organic material comprising: (a) heating said hygroscopic organic material to a temperature of from 38 ° C to 121 ° C; (b) forming a bed of the hygroscopic organic material by depositing the heated hygroscopic organic material on a spiral horn conveyor having more than one level; (c) contacting the hygroscopic organic material on the bed with an air stream that is substantially countercurrent to the hygroscopic organic material bed, and the relative humidity of the air stream contacting the hygroscopic organic material is less than or equal to the equilibrium of the hygroscopic organic material; lowering the relative humidity of the air stream in contact with the hygroscopic organic material to reduce the moisture content of the hygroscopic organic material, and at least maintaining the relative humidity of the air stream in contact with the hygroscopic organic material at or below during the countercurrent flow of the hygroscopic organic material on the bed, the air stream is continuously cooled and continuously dehydrating the hygroscopic organic material. The process of claim 1, wherein the moisture content of the hygroscopic organic material after step c) is adjusted to 11-13% by weight. 13. The method of claim 2, wherein said contacting air stream is a hygroscopic organic material having a moisture content of 11% to 40% by weight. 14. The method of claim 2, wherein said hygroscopic organic material is in contact with an air stream having a relative humidity of 20% to 60% and a temperature of 21 ° C to 49 ° C. 15. The process of claim 2, wherein the air stream is at a temperature between 24 ° C and 121 ° C. The method of claim 1 or 2, wherein the hygroscopic organic material and the air stream are contacted at an air flow rate of 0.23 m / s and 1.22 m / s. 17. The method of claim 1 or 2, wherein the hygroscopic organic material is contacted with the air stream by passing an air stream downstream or upstream on the bed of the hygroscopic organic material or the air stream downwardly at a time upstream. also applied to the hygroscopic organic material in bed. The process according to claim 1 or 2, characterized in that the heat treatment is carried out with an air stream having a temperature of at least 60 ° C. A process according to claim 1 or 2, characterized in that an air flow of up to 60 ° C is used. 20. The method of claim 1 or 2, wherein the hygroscopic organic material is selected from the group consisting of fruits, vegetables, cereals, coffee, the pharmaceutical active ingredient tea, and any combination thereof. A method according to claim 1 or 2, characterized in that the air is passed through the chimney through successive conveyor belts.