SK119393A3 - Process of treatment of moisture inside of the tobacco and in other organic materials - Google Patents

Abstract

Process consists of creating basis of the organic material by applying organic material on worm carrier containing number of etages. It is followed by contacting the organic material on the basis with the air stream with relative humidity closed to balanced conditions of organic material. The air flows from etage to etage in the way in principle contrary to the way of basis of organic material along the number of etages and subsequently is increased relative humidity of the air stream contacting org anic material on the basis to increas humidity contents of organic material so that relative humidity of the air stream contacting the organic material is sustained near the balanced conditions of organic material to reach the required humidity content in organic material. By this the air stream is gradually anhydrated and organic material is gradually moistened as the air flows on the way in principle contrary to the way of the basis of organic material.

Description

Technical field

The present invention relates to methods for treating moisture, i. processes for increasing the moisture content and drying of tobacco and other hygroscopic organic substances, such as pharmaceutical and agricultural products, including but not limited to fruits, vegetables, cereals, coffee and tea. In particular, it relates to the use of humidity-controlled air for humidifying or drying these materials.

BACKGROUND OF THE INVENTION

The need for moisture management of various organic materials, including tobacco, has long been recognized in this field. For example, the moisture content of the tobacco that has been processed into a useful product has been varied many times. Each processing step e.g. the shredding, chopping, blending, flavoring, expansion and preparation of the cigarette filler requires a certain optimum amount of moisture, which must be carefully controlled to ultimately achieve top quality tobacco or other hygroscopic organic materials. In addition, the way in which the moisture content of the tobacco is altered can have a lasting effect on the physical, chemical and subjective properties of the final product. This shows the meaning of the method and procedure used to treat the moisture of tobacco or other organic material.

The moisture treatment of the expanded tobacco is particularly demanding. Typically, the moisture content of the tobacco coming from the expansion device is less than 6% and often less than 3%. The tobacco is very easy to crumble at such low humidity. In addition, the structure of expanded tobacco is collapsed in the moisture treatment, i. partially or completely returns to its unexpanded state. This degradation of the structure reduces the filler and abolishes the benefits of tobacco expansion.

Various methods are used to treat the moisture of the expanded tobacco. The most common method is spraying with water when turning tobacco in a rotating roller. Another method uses saturated steam as a humidifying environment. Yet another method uses high humidity air that passes through a web of tobacco moving on the belt, as shown in U.S. Pat. No. 4,178,946.

However, none of the above methods is fully satisfactory in the processing of expanded tobacco. Direct contact with liquid water results in the breakdown of the tobacco structure. Steam humidification will also cause the tobacco structure to break down. This can be partly attributed to high temperatures in the vapor environment, but also exposure of the expanded tobacco to any gaseous environment in which condensation such as steam or high-saturated air takes place leads to the breakdown of its structure.

The method that circumvents these difficulties lies in the alignment of moisture initially dry expanded tobacco in a chamber containing air equilibrium moisture content in tobacco desired moisture and allows to dry slowly expanded tobacco, for 24 and 48 hours, compared to its moisture with the environment ^first The successive air velocity through the chamber is very low, usually not higher than about 127 mm / s. This procedure leads to little or no deterioration in the properties of tobacco caused by the breakdown of its structure. However, the long contact times required limit the applicability of this method to the laboratory only.

We have attempted to reduce the residence time required for such an equalization process by increasing the flow rate. This approach was not successful because the fillers shown by laboratory processed tobacco could not be achieved. The size of the conveyors that must be filled with tobacco to achieve the desired long residence time, the unevenness of the moisture content of the tobacco product coming from such devices and the occurrence of fires in such units are described in U.S. Pat. No. 4,202,357.

The use of drying to control moisture in tobacco processing is as important as moistening it. When drying tobacco, physical and chemical changes can occur that affect the physical and subjective quality of the product. Therefore, the tobacco drying process is also of utmost importance.

In general, two types of drying equipment are used in the tobacco industry: rotary driers and belt or apron driers. Pneumatic dryers are sometimes used. A particular type of dryer was selected for the desired drying operation. For example, a belt or apron drier is normally used for stripped tobacco, while rotary driers are used for cut or chopped tobacco. Both rotary and belt dryers are used for drying stems.

In the belt dryer, the tobacco is spread on a perforated belt and air is conveyed up or down through the belt and the layer of tobacco.

Uneven drying of tobacco is a consequence of the channels that are created by the air flow in the layer and which allow the drying air to bypass the tobacco. - ........................... .............

Most rotary driers in the tobacco industry are lined with steam snakes and can work as indirect or direct driers, depending on whether the heat is supplied by the jacket or whether it is heated directly inside the tobacco drier. Moreover, these dryers can be operated in co-flow, i.e.. j. the tobacco and air streams move in the same direction or countercurrent as they move in opposite directions. Rotary drying must be carefully controlled to avoid drying, which causes both chemical changes and unnecessary crumbling of the tobacco during rotation. In addition, with too fast drying, an impermeable layer may be formed on the surface of the tobacco, which prevents diffusion of the internal moisture in the tobacco to the surface. The formation of such a layer slows the drying rate and causes uneven drying.

The use of rotary or belt dryers for tobacco drying can mean heat treatment that causes chemical and physical changes in tobacco. These are not always undesirable changes and are due to the fact that water is removed from tobacco. In typical tobacco applications, the need to dry the tobacco in a limited time determines the resulting heat treatment in a drying step. Due to the dependence of the heat treatment on drying, it is not possible to optimize the heat treatment separately from the drying which has introduced a number of constraints.

The present invention is defined by the independent claims to which reference is made.

SUMMARY OF THE INVENTION

Embodiments of the invention are characterized in that they preferably treat the moisture of hygroscopic materials such as fruits, vegetables, cereals, coffee, tea, even brittle tobacco emerging from the expansion process, and not only these; these can be dried or humidified without _; fragmentation. Furthermore, the method is advantageous in that it allows the moisture of the expanded tobacco to be treated with little or no damage to the tobacco structure and allows the tobacco or other suitable hygroscopic materials to be dried at approximately atmospheric pressure, e.g. without the use of vacuum and at a selected temperature, the heat treatment induced in this process can be controlled to an extent that conventional methods of tobacco drying do not allow.

In a preferred embodiment of the invention, changes in the moisture content of the tobacco or other organic material are affected by the contact of the tobacco with air having a relative humidity carefully controlled above or below the equilibrium relative humidity of the organic material with which it is in contact. The relative humidity is continually increased or decreased as necessary during processing to maintain a controlled difference between the relative humidity of the organic material with which it is in contact. Careful continuous control of the relative humidity makes it possible to control the humidity of the moisture transfer between the organic material and its surroundings so that changes in the tobacco structure are minimized. The use of relative humidity as the primary driving force for moisture transfer allows independent control of the heat treatment. This process can be carried out batchwise or continuously. In addition, it can be carried out without the use of rotary rollers ³ which cause crumbling ⁴ .

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the process and preferred embodiments will be described by reference to the accompanying drawings, in which:

Fig. 1 shows the relative air humidity (RH), expressed as a percentage, as a function of the moisture content of the tobacco determined as volatile (OV);

Fig. 2 is a diagram of a laboratory apparatus for reordering hygroscopic organic material according to the invention using the air with time-varying relative humidity _of RH;

Fig. 3 is a perspective view of an exemplary cut-off device for implementing the present invention in a continuous manner;

Fig. 3a is a cross-sectional view of a portion of the spiral belt container shown in FIG. 3 showing the air flow path relative to the path of the hygroscopic organic material;

Fig. 4 is a diagram of an alternative device suitable for implementing the present invention in a continuous manner;

Fig. 5 is a flow chart illustrating the application of the present invention to humidification; and

Fig. 6 is a typical relative air humidity profile _from which it is at the tobacco surface as a function of time;

was obtained when humidified in the apparatus of FIG. Third

The present invention relates to a process for adjusting the moisture content of tobacco or other suitable hygroscopic organic materials, such as pharmaceutical and agricultural products, including but not limited to fruits, vegetables, cereals, coffee and tea, which comprises ⁵ to minimizing the crumbling remains physically structure, nor does it induce unwanted thermal changes in the chemical composition of the processed tobacco. In particular, it relates to the use of humidity-controlled air to moisten or dry tobacco or other suitable hygroscopic organic material. The moisture content of the tobacco or other suitable hygroscopic material is either increased or decreased by gradually increasing or decreasing, as appropriate, the relative humidity of the air in contact with the tobacco or other suitable hygroscopic organic material. This is how moisture transmission is controlled. Other process characteristics such as temperature, velocity and air pressure can be optimized separately.

Two commonly used methods for characterizing the physical structure of tobacco are cylinder volume (CV) and specific volume (SV). These measurements are particularly valuable in assessing this tobacco humidification process.

Cylinder volume (CV)

20 g unless expanded and 10 g, if expanded, is placed in a 6 cm densitometer cylinder, Model No. 1, Densitometer cylinder. DD-60, designed by Heinf. Borgwald GmbH, Schnackenburgallee 15, Postfach 540722, 2000 Hamburg 54 Germany. A tobacco of 5.6 cm diameter and 2 kg weight is placed on the tobacco for 30 seconds. The resulting volume of compressed tobacco is read and divided by the tobacco sample. This gives a value of ⁶ (CV) in cm ³ / g. This test determines the apparent volume of tobacco fill per unit weight. The test is performed under standard conditions of 23.9 ° C and 60% relative humidity. Unless otherwise specified, the sample is left in this environment for 24 and 48 hours.

Specific volume (SV)

The term specific volume is a unit of measurement of volume occupied by solid objects e.g. tobacco, as determined by the Archimedes Extrusion Act. The specific volume of an object is determined as the reciprocal of the actual density. The specific volume is expressed in cm ³ / g. Both mercury porosimetry and helium pycnometry are suitable for these measurements. Their results were found to correlate well with each other. When helium pycnometry is used, the weighed tobacco sample, either as it is or dried at 100 ° C for 3 hours, or leveled, is placed in a measuring chamber of the pycnometer (Quantachrome Penta Pycnometer Model 2042-1, manufactured by Quantachrome Corporation, 5 Aerial Way , Syosset, New York). The chamber is further flushed and filled with helium. The volume of helium extruded by tobacco is compared to the volume of helium required to fill an empty chamber. The volume of tobacco is determined in accordance with the Ideal Gas Behavior Act. In this application, unless otherwise stated, the term specific volume is used for values determined on the same sample on which the moisture content OV has been determined, ie tobacco dried in a circulating air dryer at 100 ° C for 3 hours.

As used herein, the moisture content can be considered identical to the volatile matter content of ⁷ OV, since not more than 0.9% by weight of the tobacco are volatile substances other than water. Determination of the volatile matter is a simple measurement of tobacco weight loss after 3 hours in a circulating air oven at 100 C ^much loss in percentage of the original weight of the volatile je'obsah oven-IP.

The net test is a method of measuring the length distribution of pieces in a sample of chopped tobacco filling. The test is often used as an indicator of the degradation of the length of tobacco fill particles during processing. The tobacco filler weighing 150 ± 20 g for unexpanded tobacco and 100 + 10 g for expanded tobacco shall be placed in a sieve shaker. The shaker uses a set of 30.5 cm diameter sieves (and are manufactured by W.S. Tyler Inc., A Subsidiary of Combustion Engineering Inc. Screenib Division, Mentor, Ohio 44060), which conforms to ASTM standards. Typical mesh apertures are 6; 12; 20 and 35 mesh, corresponding to 4.2 mm; 2.11 mm; 1.27 mm; and 0.73 mm. The shaker has a pitch of about 12.5 to 25 mm and a shaking rate of about 350 ± 5 oscillations per minute. The shaker sieves the tobacco for 5 minutes and separates the sample into different size classes. Each size class is weighed and the ordered result set represents the particle size distribution in the sample.

Laboratory experiments have shown that attempts to moisten tobacco rapidly by exposure to high humidity air result in cylinder volume losses, CV. It has also been shown that loss of CV value occurs when the tobacco is moistened or when water condenses on it. This occurs when the moist air comes into contact with tobacco whose temperature is below the dew point of the moist air. Moistening occurs when moisture differences within the tobacco layer are created due to uneven exposure to humid air. Thus, successful humid air humidification must operate at a relatively low speed with good control of air relative humidity, air temperature and air flow and air pressure through the tobacco bed. This is best achieved by gradually increasing the humidity of the air passing through the tobacco layer so that the tobacco is in contact with an air stream that is substantially in equilibrium with the tobacco.

According to FIG. 1, line ABC is an isotherm for 23.9 ´C for typical expanded tobacco. This isotherm refers to the volatile matter content of the OV tobacco to the relative humidity of the air surrounding it at equilibrium at a given temperature. Thus, point B shows that at 23.9 ° C and 60% relative humidity, RH will have a balanced tobacco balance of about 11.7% volatile matter OV. The DEF lines in FIG. 1 represents a typical RH profile for tobacco that has been wetted according to the present invention. The GEF line in FIG. 1 shows an alternative moisture profile RH which has also been considered satisfactory. Line HF in FIG. 1. Represents a typical path that represents prior art humidification methods in the equilibrium chamber at very low air speeds. Line IJ in FIG. 1 illustrates an application according to the present invention for drying tobacco.

Fig. 1 shows that a humidification of tobacco with a volatile content of about 6.5% that would be in equilibrium with a 30% relative humidity RH, to a volatile content of 11.7% that would be in equilibrium with an air with a relative humidity of about 60%, could be achieved better by exposing the tobacco to air whose humidity is gradually increased from 40% to about 60% than when exposed to air at 60% RH. If the humidification is carried out under these slowly changing conditions, then the transfer of moisture from the air stream to the tobacco is relatively slow, since the driving force is low and thus the expanded tobacco structure is not damaged. Humidification of the expanded tobacco without losing the CV volume values can be achieved by exposing the tobacco to air whose moisture is increased by small steps lasting a certain time from 40% RH to 62% RH for about 60 min. This reduces the total time required for humidification without significantly altering the expanded tobacco structure. Thus, the lines DEF and GEF in FIG. 1 represent effective embodiments of the present invention in the humidification of tobacco.

In FIG. 1 shows conditions close to the equilibrium segments EF and ABC lines relating to the air and tobacco flow. Significantly, for tobacco with a volatile OV content of less than about 7%, the difference between the relative humidity of the air in equilibrium with the tobacco and the relative humidity of the humidified air stream used for humidification is considerable, without adversely affecting the filler tobacco. It is also important that for tobacco with an OV content of between 7.5 and 11.5%, the humidity of the air used for humidification can be about 2 to 8% higher than the relative humidity of the air that is in equilibrium with the tobacco, with a larger deviation tobacco with a lower content of volatile ingredients OV, without adversely affecting tobacco

When this process was applied to tobacco drying, there was no decrease in the cylindrical volume of tobacco. This has also been found in cases where the relative humidity of the air used for drying was significantly less than the relative humidity of the air in equilibrium with the tobacco, i. the relative humidity of the drying air was lower than the equilibrium conditions of the tobacco. Therefore, it is important that line 11 in FIG. 1 represents only one of many routes that can be used to dry tobacco according to the present invention.

The present invention can be applied to both batch and continuous processes. If it is carried out as a batch humidification process, the relative humidity of the air by-pass of the tobacco increases with time to ensure the continuous growth of moisture in the tobacco. This can be achieved in the buffer chamber - shown in FIG. 2. The tobacco to be moistened is placed in a layer of about 5 cm thickness on floors with a mesh bottom inside the buffer chamber so that the controlled humidity air flow can pass down the tobacco layer. Chambers that may have a volume of 0.560 to 2.250 m ³ (manufactured by Parameter Generation and Control, Inc. 1104 Old US 70, West Black Mountain, NC 28711) have been used in many studies. The equalization chambers were equipped with microprocessors to allow controlled gradual changes in humidity within the chamber. Tests were conducted in which the dry expanded tobacco was moistened from an initial OV value (volatile components) of 2% to a final 11.0% using air with a gradually increased relative humidity value from an initial value between 30% and 52% to a final value between 59 and 65% over a period between 30 and 90 minutes. Air velocities ranged between about 0.254 and 1.016 m / s. Relative humidity and temperature measurements were monitored with a Thunder model 4A-1 manufactured by Thunder Scientific Corp., 623 Wyoming, SE, Albuquerque, New Mexico 87123. Air velocities were 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 velocity was gradually changed from initial values of 52% to final values of about 62% in a time that was less than about 40 min, provided a moistened tobacco with a fully maintained CV volume value , such as was achieved in a comparative experiment with similar tobacco moistened in a buffer chamber with air maintained at 60% RH and at 23.9 ° C, passing through the tobacco at a low rate of 24 to 48 hours. Gradual change was successful when the humid air speeds were up to 1.01'6 m / s and the temperature was from about 23.9 ° C to 32.2 ° C. Expanded tobacco moistened in this manner exhibited minimal, if any, loss of cylindrical volume when compared to expanded tobacco moistened in the buffer control space.

The present invention can be practiced as a continuous process most effectively in the Frigoscandia, which is a spiral feeder for self-leveling tobacco on a conveyor belt as shown in FIG. 3. This equipment is a specially modified Model GCP 42 Spiral Freezer as supplied by Frigoscandia Food Process Systems AB of Helsingborg, Sweden. The dry tobacco to be moistened enters the unit 10 on the feeder

13, it is transported by the unit 10 along the spiral from the bottom of the spiral container on top, as shown, and exits through the tobacco outlet after wetting. The humidified air is blown down through the tobacco from the humid air inlet 15 to the bottom of the scroll container

14, where it exits the humid air outlet 16, substantially flowing countercurrent to the direction of tobacco travel, i. most of the moist air flows from the top of the inserted tobacco to the floors of the tobacco layer, while the tobacco moves upward and follows the spiral movement of the entrainer. A small amount of wet air flows down the top of the carrier container spiral path in a true countercurrent way. These streams are shown in FIG. 3a. It has been found that this arrangement effectively duplicates the stepwise changes in relative humidity that can be produced in the apparatus of FIG. Second

In FIG. 3a, which is a cross-sectional view of a portion of the spiral tab of the inserted tobacco 14 shown in FIG. 3, the direction of the air flow 20 and 22 relative to the path of the tobacco layer 2.1 is shown. As shown in FIG. 3a, directs the air flow from top to bottom over the tobacco supply in the dryer. The tobacco movement is directed downwards by the unit and is illustrated as a right-to-left movement in FIG. 3a, as the tobacco passes through the helical feeder-14. A major portion of the air 20 that is substantially upstream of the tobacco pathway is directed through the floors of the tobacco layer 21 and comes into contact with the tobacco at a level immediately below, while a small portion of the airflow 22 passes through the tobacco layer. later pass through the layer of tobacco 21.

The key to a successful demonstration of the present invention, in the case of humidification, are means to provide a constant increase in the relative humidity of the air in contact with the tobacco, depending on the increased humidity expressed by the OV of the tobacco. The self-leveling of the inserted tobacco in the Frigoscandia dryer on a spiral feeder, by its design, permits most of the air flowing down the feeder floors (the feeder supply) that carry the tobacco. As the tobacco is supplied from below and the air from the top of the dryer, the air and tobacco streams are substantially countercurrent. This, essentially countercurrent, provides a natural continuous gradient of RH (relative humidity) of the air that is in contact with the tobacco, as the air passes gradually over the floors of the moistened tobacco. By sensitively selecting tobacco feed rate, air and tobacco velocity, controlling the temperature and relative humidity of the humidified air, i. Under similar conditions to the batch experiments, the results of the batch humidification experiment can be approximated in a continuous configuration. To moisturize about

65.25 kg of tobacco containing 3% OV per hour the following conditions were found: belt speed corresponding to a residence time of about 40 to 80 minutes, an inlet air temperature of about 28 to 35 ° C with an inlet relative humidity of about 61 to about 64%, and air flow and from 28.3 to about 70.8 m ³ / min. When a Frigoscandia GCP 42 spiral unit was used, there was no loss of CV or measurable crushing.

Relative humidity recorders over time, such as the 29-03 RH / Temperature recorder (manufactured by Rustrak Instruments Co. E. Greenwich, RI), were connected to the Frigoscandia unit during the entire time of tobacco humidification. This device showed a steady increase in relative humidity when transferred over a spiral container with an initial relative humidity of from about 35 to 45% at the bottom of the device where the tobacco is dryest to about 62% on top of the device where the tobacco is already completely wetted.

Fig. 6 is a typical time relative humidity curve recorded by the Rustrak unit. The relative air humidity percentages of the tobacco layer versus time are shown in FIG.

6. A tobacco with an initial moisture content of about 3% OV that enters the spiral humidifier unit of the unit and has been in contact with air of about 43% relative humidity (point A of Fig. 6). Fig. 6 shows that the relative humidity of the air increases from about 43% to about 62% as it exits the unit as the tobacco progresses through the spiral humidification unit (point B of FIG. 6). The OV-containing tobacco exits the unit. The relative humidity of the RH air entering the spiral humidifier was controlled so that the outgoing tobacco did not exhibit a significant cylinder volume loss.

In order to realize the present invention, other methods may be used to effect gradual changes in the relative humidity of the air, such as the unit shown in FIG. 4. Referring to FIG. 4, the tobacco enters the feeder 43 through the tobacco inlet 40 and exits the tobacco outlet 41 ♦ The gradually increasing humidity is supplied so as to blow up or down through the tobacco layer 42 in several zones 44 and thus reproduce the effect of the progressive humidity in the device. . 2. This gradual effect can also be achieved by moving the air from one source following the serpentine pattern from right to left in FIG. 4, which essentially represents the upstream movement of air to the movement of tobacco. Thus, the air exiting from a certain zone becomes the incoming air for the adjacent zone on the left.

In order to carry out the process according to the invention, it is possible to process whole smoke-treated tobacco leaf, cut or cut tobacco, either expanded or unexpanded, or selected portions of tobacco, such as stems or reconstituted tobacco. The process may be applied to any of the above-mentioned species, including flavored tobacco. In a particular case of tobacco drying, it has been found that the unexpanded tobacco filler can be dried continuously at substantially room temperature in a substantially countercurrent modified spiral dryer with a feeder, Frigoscandia, from a tobacco humidity of from about 21 to about 15% for about 1 hour. In this case, air entered the top of the unit at about 29.5 ° C and a RH of 58% and exited at 25 ° C and a 68% humidity. Drying was carried out with little or no heat treatment of the tobacco.

Alternatively, the process of the invention may be used to dry tobacco having a temperature significantly higher than room temperature, e.g. tobacco at 93.3 ° C to 121 ° C. When the tobacco is dried at this high temperature, the temperature and the relative temperature of the drying air are adjusted so as to create suitable conditions to demonstrate the process of the invention.

Analogous to the humidification of tobacco, it has been found that drying is best accomplished in a minimum amount of time by setting the final air humidity level lower than that corresponding to preparing the tobacco at the desired final humidity, thereby increasing the air-tobacco humidity gradient and accordingly, the driving force causing drying. However, unlike the humidification process, the air stream can be maintained at a level much lower than that which is in equilibrium with the tobacco having the desired OV content after drying.

Experiment 1

To demonstrate the benefits of the dry expanded tobacco humidification process in which water is dosed more slowly than the spray method in a cylindrical vessel, we placed 20 g of tobacco filling in a sealed desiccator. This sample was impregnated with liquid carbon dioxide and expanded in an expansion tower at 288 ° C. The content of volatile matter OV in this tobacco filler was 3.4%. It was calculated that about 1.98 g of water would be required to increase the OV content to 11.5%. This amount of water was placed in a small glass jar with a rubber stopper with a glass tube with an inside diameter of 3.2 mm passing through the stopper. This vessel was also sealed in a desiccator. After nine days, all water was adsorbed by tobacco. Its subsequent analysis revealed a volatile matter, OV, of about 11.5%. Here we mean tobacco before it has been equilibrated with air at 60% relative humidity and a temperature of 23.9 ^e C for 24 to 48 hours. This straightening procedure is generally used as a means to achieve a standard tobacco state before measuring the cylinder volume CV and specific CV volume as well as before the screening tests. After this standard straightening, the tobacco moistened in the desiccator had a cylindrical volume, CV, of about 9.5 cm ³ / g and a specific volume of SV of about 2.9 cm ³ / g with a volatile matter content, OV of about

11.6%. For comparison, if a sample of the same tobacco was placed directly inside the buffer chamber under standard conditions, then the equilibrium content of the OV was 11.3% and the CV and SV values were successively 9.4 cm ³ / g and 2.7 cm ³ / g respectively. A third sample of expanded tobacco plug was moistened in a spray column so that the volatile content was about 11.5%. After equalizing this sample, the CV showed about 8.5 cm ³ / g and an SV of about 1.9 cm ³ / g at an equilibrium OV of about 11.6%.

As can be seen from the TAB data. 1, the tobacco moistened slowly in the desiccator showed a significant improvement in the CV and SV equilibrium values compared to the values for the sample that had been sprayed. This sample also showed a slight improvement in CV and SV values over the sample that was directly leveled in the equalization chamber.

ΤΑΒ. 1

sample than so balanced OV (%) SV [cm ³ / gj dP> O CV [cm '/ g] SV [cm '/ g) Output 3.4 3.0 11.3 9.4 2.7 towers wetted 11.5 1.8 11.6 8.5 1.9 in the cylinder Desiccator 11.5 2.7 TTLG 9.5 2.o

A second set of experiments was performed in a buffer chamber at. moistening of the tobacco filling. A PGC (Parameter Generation and Control) chamber ⁹ was used for this purpose. This chamber was equipped with a Micro-Pro 2000 microprocessor from Parameter Generation and Control Inc., which allowed a controlled escalation of ¹⁰ conditions inside the chamber.

Experiment 2

Approximately 1359 g of smoke treated ¹¹ tobacco impregnated with liquid carbon dioxide and expanded under conditions similar to those described in Experiment No. 1 was placed on a screen in a layer about 5 cm high. The sieve had firm edges and the bottom was mesh. The sieve was placed in a buffer chamber. The sample was humidified for 1 hour in air at a temperature of about 23.9 ° C with an initial relative humidity of about 36%, which was stepwise increased to a final relative humidity of about 60%. The downward movement of the air through the tobacco layer was about 23 cm / sec. This experiment was repeated at intervals of 3, 6 and 12 hours. The results are shown in TAB. 2 and show that, for periods of degrees up to about 6 hours and under these experimental conditions, it does not affect the wetting rate of CV and SV tobacco. The slower the speed, the higher the CV and SV values were found. In addition, the humidification of the present invention gives CV values of at least 1 cm ³ / g and SV values of at least 0.2 cm ³ / g higher than those achieved with tobacco humidified in spray cylinder containers. However, it was found that the greatest benefit was achieved by escalating in a time as short as one hour.

TAB. 2

sample than so aligned in the equalization chamber % ’OV SV (cm ³ / g) OVLcm '/ GJ CV [cm3 / g] exit from the tower 3.1 3.6 11:33 9.71 spray container 11:51 1.61 ....... ... 11:37 ........ 8.61 escalation 1 h 10.83 1.85 11:38 9.72 grading 3 h 11:44 1.88 11:36 9.81 grading 6 h 11:45 1.9Ό 11:30 9.88 stupňová- 11:41 1.97 11:27 9.89

12 hours

Experiment 3

A laboratory study was conducted on the effect of humidification rate and temperature on tobacco CV and SV values. Seven sets of experiments were performed with carbon-impregnated tobacco and expanded in an expansion tower at 288 ° C. The expanded tobacco was moistened in the following ways:

1) Equalization for 24 hours in a buffer chamber at 60% relative humidity and 23.8 ° C at an air velocity of tobacco bed of about 12.7 cm / s;

2) Spraying with water to increase the OV content to about 7.5% and then leveling for 24 hours as in Method (1);

3 / Spraying water up to 7.5% OV and then final wetting in a spray cylinder;

4 / Spraying water at about 7.5% OV and then using a gradually varying relative humidity from 46 to 60%;

5 / Increasing air humidity from RH 46 to 60%.

Humid air humidification was performed inside a PGC buffer chamber equipped with a microprocessor to control the gradation at selected intervals. The following conditions were selected:

1 / step times: 30, 60 and 90 minutes;

2 / air temperature 23.8 ° C and 35 ^e C

3) successive air velocities up through the tobacco bed of about 13 m / s and down through the tobacco bed of 89 cm / s; and

4 / thickness of the tobacco layer: 51 mm.

The tobacco used in all humidifiers, except that which passed through the cylindrical spray canister, was removed at the exit of the tower after expansion and sealed in a double plastic bag prior to humidification. Therefore, the tobacco had to be cooled to room temperature of 93 ° C prior to humidification, which is the temperature at the exit of the expansion tower. The tobacco, still enclosed in the bag, was sufficiently heated prior to humidification with a stepped humidity at 35 ° C to prevent condensation of water on the tobacco when contacted with humid air under the stepped humidification conditions. The data for these test sets are shown in TAB.3a to 3e.

TAB. 3a so how is a balanced sample 0V [%] SV [cm ³ / g] OV [%] CV [cm ³ / g] X exit from tower 3.43 2.3 11:31 4.9 S spray only 8.06 2.14 11.68 8.66 C spray and cylinder 11.53 1.81 11:59 8:59 F spray and step 11.27 9 9 ¹² min (46 to 60% RH, 23.9 ° C) 1.87 11:51 1.9 H spray and 10.96 grade 90 min (46 to 60% RH _r 23.9 ° C) 1.98 11:36 9:48 Sample H was held at 11.54 for 15 min at 60 RH, 23.9 ^e C 1.95 11:56 9:40 J spray and Grade 10.37 in 60 min (46 to 60% RH, 23.9 ’C) 2:38 11:28 9:58 K sample J held for 11 min at 15 min 62% RH and 35 ° C 2.26 11:22 9.88 •

TAB. 3b as aligned

sample 0V [%] SV [cm ³ / g] 0 V [%] CV [cm ³ / g] X output 1.3 2:58 11:34 9.23 from the tower With only 7:51 2.13 11:39 8.87 spray C spray 11.86 1:59 11.64 7.8 and cylinder F spray a 10:55 1.64 11:45 8.86

graded min (46-60% RH,

23.9 ’C)

G sample F 11.56 1.64 11.42 8.61 held for 15 min at 60% RH, 23.9 ° C -------------------------------- -------------------------------- H spray a 10.28 1.97 11.27 8.99 degree min (46 to% RH,

23.9 ’C)

I sample H 11.73 held for 15 min at 62 ° C % RH, 23.9 ’C 1.82 11:25 8.61

TAB. 3c

so such as balanced sample 0 V [%] SV [cm ³ / g] 0 V [%] CV [cm ³ / g] X output 1.81 2.78 11:37 9.23 from the tower B degree- 10.91 1.86 11:47 8.86

vito 60 min (46-60 RH, 35 ° C)

C degree-10.53 vito 60 min (46-60% RH, 2.2 23.9 ’C) 11:28 9.20 D degree - 10.84 yarn 90 'min (46-60% RH, 1.99 35 ’C) 11:45 8.90 E only 5.39 spray 2:37 11:25 8.71 F spray and 10.80 1.81 11:27 8:39

directly pasted for 30 min to 60% RH, 35 ’C

G spray and 10.66 graduated 60 min (46-60 1.85 11:23 8.65 % RH, 35 ’C) H spray and 10.76 1.82 11:24 8.62 stupňovi- to 90 min (46—60 % RH, 35 ’C) I spray and 10.65 1.90 11:23 8.75 stupňovi- - to 60 min (46-60 % RH, 23.9 ’C) J spray and 10.57 1.87 11:38 8.74 stupňovi- to 90 min (46-60 % RH, 23.9 ’C) K spray and 10.73 1.87 11:22 8.64 directly to 30 min to 60% RH 23.9 ’C L spray and 10.98 1.60 11:39 8.28 and cylinder

TAB. 3d

as it is balanced sample OV [%] SV [cm ³ / g] 1 1 1 1 1 1 1 1 · "> 1 1> <M> 1 0 - i 1 1 1 1 1 1 1 1 CV [Cm '/ g] TI output from the tower 2.83 1.3 11.92 9:46 T2 inserted directly for 30 min at RH 60% at 23.9 ´C 11:24 2.27 11.77 8.9 T3 gradually 90 min, 30 to 60% RH, 23.9 ´C 11.8 2.24 11.83 9.29 T4 gradually 90 min, 30 to 60% RH, 23.9 ’C 9.77 2.24 11.85 9:43 SI just spray 4.78 2.82 11.66 8.98 S2 spray and directly for 30 min to 60% RH, 23.9 ’C 11:10 2.19 11.64 8.89 S3 spray and pos- tupne 90 min 46 up to 60% RH, 23.9 ’C 10:54 2.25 11:27 5.9 S4 spray and pos- tupne 60 min 46 up to 60% RH, 23.9 ’C 10:56 2.22 11.73 3.9 S5 Spray and Post- tupne 30 min up to 60% RH, 23.9 ’C 9.74 2.29 11.67 9.19 C spray and cylinder 10:48 1.95 11.81 8.80

Table 3

W2

conditions escalation as it is balanced Start speed time temperature RH OV SV OV cv ₃ OV [%] Výduch [mini [° C] roz / [%] [cm / g] [% J cm / g] [Sm / s] sah injections » TO THE TOWER -9.2 0.79 11.86 5.5 OUTPUT FROM TOWERS 3.94 2.82 11.72 9:49 OUTPUT 1 . SPRAYING SPRAY 5.64 2.72 11.82 9:48 OUTPUT FROM CYLINDER CONTAINERS 10:36 2.4 11.66 9.28 A 3.9 119 60 23.9 30-58 6.67 2:39 11.65 9.76 5.6 89 60 23.9 - - : -30/58 8:44 2:45 ... 11.82 9.91 C 3.9 97 60 23.9 45-58 7.83 2.25 11.65 9:57 D 5.6 97 60 23.9 45-58 8:44 2:39 11.79 9.66 E 3.9 97 60 23.9 17-62 11:10 2:33 11.74 10.2 F 5.6 89 60 23.9 47-62 10:10 2:41 11:59 8.10 G 3.9 91 60 23.9 30-62 8.13 2.20 11.89 9.63 H 5.6 89 60 23.9 30-62 9:41 2:41 11.79 10:11 I 3.9 102 60 23.9 47-62 10:21 2.15 11.76 8.98 J 3.9 91 60 23.9 47-64 10:18 2.13 11.94 9.13 K 3.9 91 60 23.9 35-64 7.9 2.23 11.90 9:51 L 3.9 91 60 32.2 35-60 8.65 2.17 9.12 8:59 M 3.9 91 60 32.2 45-60 10:11 2:39 11.92 10.2 N 5.6 91 60 32.2 45-60 8.10 2:39 11.93 10.2 0 3.9 122 60 32.2 47-64 10.88 2.31 11.96 9:51 P 3.9 122 60 32.2 47-64 11:30 2:33 11.95 9.30

The data in Tables 3a to 3e show the gain in values

CV, which is in the range of 0.5 to about 1 cm ³ / g and gain in values

SV of about 0.3 to about 0.4 cm / g, which can be achieved by gradually changing RH of air in the humidification cool the tobacco, i.e., tobacco at from 23.9 ° C to about 35 ^e C, as compared to cylinder spray reordering of hot tobacco leaving expansion tower. The volatile matter content, OV, achieved by using incremental humidification directly at the tower exit proved to be more advantageous than in the first tobacco spraying to increase the OV value to about 7%, followed by incremental humidification. There was no significant difference in SV and CV values for tobacco successively humidified by using humid air with an initial RH of about 46% compared to tobacco successively humidified with an initial RH of about 30% or tobacco successively humidified for either 60 or 90 minutes. It has also been observed that tobacco can be wetted either by moving the air downward at speeds from about 89 to about 119 cm / s or upward at speeds up to about 23 cm / s without observing significant differences in SV and CV values. Additionally, it was found that successive humidification gave equivalent or better CV and SV values than tobacco after expansion in an expansion chamber humidified by direct exposure to 60% RH at 23.9 ^e C in the buffer chamber. Finally, it was found that water spraying leading to an increase in volatile matter OV of about 7.5% and subsequent gradual humidification with humid air gave better CV and SV values than spraying followed by final wetting in a spray cylindrical vessel.

Experiment 4

Attempts have been made to determine the effect of air flow and its velocity on the abduction, channeling, and compaction of tobacco. These tests were performed using two PGC buffer chambers. In both chambers the actual air flow was approximately 14.16 m / min. The air flowed through a layer of tobacco upwardly in one chamber and downwardly in the other chamber. Tobacco samples in a 51 mm thickness layer were placed inside a 124 x 145 mm top-open sieve with a mesh at the bottom and a fixed edge of 102 mm. These sieves were located inside the equalization chambers. Air was forced to flow through the samples by covering the unoccupied floor area with cardboard and sealing all gaps with tape. The air velocity was varied by changing the number of sample screens that were loaded into the chamber. Tobacco for these experiments was impregnated with carbon dioxide and expanded at about 288 ° C. Tobacco was moistened in the first stage by spraying with water to about 8% OV immediately after expansion. The conditions inside the test chamber were controlled at 23.9 ° C and 60% RH. Both a blade anemometer (Airflow Instrumentation, MOdel LCA 6000, Frederick, Maryland) and a hot pin ¹³ anemometer (Alnor Instrument Company, Skokie Illinois, Thermometer Model 8525) were used to measure air velocity. These instruments were placed for measurement in the upstream direction of air flow immediately above, and for downstream measurements of the sample bed.

Upon moving the air, light tobacco lifting was observed immediately after switching on the average flow rate, even at speeds as low as 13.2 cm / s. Small air channels were then formed and the tobacco settled. Due to the channels present, the flow rate is very non-genogenic, from 11.2 cm / s to 22.86 cm / s for an average flow rate of about 13.2 cm / s. By increasing the average air flow, the canalization became more apparent, and at flows above 22.9 cm / s, significant abduction and blowing of tobacco was observed, followed by significant channel ducting.

By moving the air downwards, some compaction of the layer was observed and a corresponding decrease in the air velocity through the layer was observed at all speeds studied. This is shown in Table 4. At an initial velocity of about 97.5 cm / s, the tobacco layer was compacted by 28% and as a result the air velocity of the layer was reduced to about 72 cm / s. At an initial velocity of about 72 cm / sec or less, the densification of the layer was about half that at 97.5 cm / sec and the air flow through the tobacco was much less reduced.

ΤΑΒ.4

INFLUENCE OF LAYER COMPACTION ON LAYER AIR FLOW

Initial air velocity [cm / s] layer thickness mm beginning the end change(%) beginning end change(%) 97.5 71.6 27 51 39.1 28 81.8 73.2 11 51 41.9 18 71.6 67.6 6 51 43.2 15 52.8 49.8 6 51 45.7 10 21.8 20.8 5 51 48.3 5

Based on these experiments, it has been determined that expanded tobacco can advantageously be moistened by a sequential method in the following methods:

(a) time: from about 60 to 90 minutes;

(b) RH: from an initial RH of from about 30 to 45% to a final RH of from about 60 to 64%;

(c) temperature: from about 23.9 to about 35 ° C;

(d) air flow: upward to 22.9 or downward to about 112.7 cm / s.

Pokus č.5

Approximately 65.25 kg per hour of a blend of smoke-treated burley ¹⁴ which has been impregnated with an oxide, carbon dioxide process as described in commonly-assigned and commonly-accepted Cho et al., SN 17/717 167, and expanded as described in the above examples was passed through a cooling conveyor to reduce the temperature from about 93.3 to about 29.4 ° C before being introduced into the Frigoscandia Model GCP 42 spiral unit. Tobacco passes through the spiral unit from bottom to top. The air flows from the top to the bottom, essentially creating a countercurrent flow of tobacco and air. This arrangement allows the tobacco to be gradually moistened as a result of the continuous dehydration of tobacco air. Tobacco enters the process with about 3% and comes out with 11% OV. The CV value of the equilibrated feed material was about 10.53, while the CV value of the equilibrated moistened material was 10. 46 cm ³ / g, indicating no significant loss of tobacco filler capacity in the humidifier process, in other words: a statistically significant filler loss was found by standard analysis. skills. In addition, the sieve test did not show a measurable decrease in tobacco particle size due to the humidification process.

Pokus č.6

Numerous experiments have been carried out on tobacco expanded at different tower temperatures in which the tobacco has been moistened by the process of the present invention. In each experiment, about 68 kg / h of tobacco relative to the moistened tobacco mass was moistened in the modified Frigoscandia spiral unit described in Experiment 5. The temperature of the air entering the humidifier unit was set to about 29.4 ° C and the relative humidity to about 62%. The air exiting the unit humidifier had a typical temperature of about 32.2 to 35 ° C and a relative humidity of about 40 to 45%. As shown in Tab. 5, the tobacco moistened according to the present invention showed no decrease in filling capacity.

ΒΑΒ.5 balanced

CV

OV

OV

temperature

attempt

Type

OV OV CV

tobacco Λ no. towers [° C] input high- input; cm ³ / g] input [%] output [%] will output%] [%] tup | [%] Bright * FO 205C 287.8 2.70 11:16 9.93 11.87 9:40 12:00 FO 205A 321 2.11 11:58 10:41 11:57 10.83 11:56 FO 205B 329 1.87 9.99 11:30 11:30 10.90 11:50 Bright * FO 20 6A 304 2:47 11.9 10:00 12:34 10:20 11.74 FO 217 321 2:59 10.86 10:49 11.79 10:51 11.63 Burley ** FO 206B 248 3.11 10.75 12:39 10.91 12:31 10:52 FO 206C 271 2.95 10:22 8.12 10.85 12:41 10:40 FO 214 271 3:00 10.4 11.3 10.4 11.2 10.4

smoked tobacco light tobacco from Kentucky

Experiment no. 7

About 90.6 kg of smoke treated tobacco per hour with OV about

21.6% were fed to the modified Frigoscandia unit described in experiment no. 5 working as a drying room. The tobacco stream on the spiral conveyor of the drying unit was oriented from bottom to top. Air flowed from above to the bottom of the unit, creating a substantially countercurrent flow of tobacco relative to the air. The tobacco was successfully dried to about 12.2% OV at a residence time of about 60 minutes using air having an inlet temperature of about 35 ° C and a RH humidity of about 35%. Air existing the drying unit was about 28.3 C, and ^E, humidity 62% RH. The tobacco entering and leaving the unit was cold to the touch with an estimated temperature of about 23.8 ° C, indicating that no heat treatment of the tobacco took place. There was no change in the CV value of the balanced tobacco due to drying. This particular drying experiment was designed to minimize heat treatment. Similar drying results can be achieved using higher temperatures in controlled heat treatment.

Although the invention has been particularly described in connection with preferred embodiments, it is to be understood that various changes in the process and details may be made without departing from the spirit and scope of the patent.

Claims (36)

PATENT CLAIMS 1. A process for increasing the humidity of an organic material having the following steps: (a) contacting the organic material with an air stream with a relative humidity close to the equilibrium conditions of the organic material, and (b) increasing the relative humidity of the air stream in contact with the organic material to increase the moisture content of the organic material in such a way contact with the organic material is maintained near the equilibrium conditions of the organic material until the background moisture of the organic material is attained. 2. The process of claim 1, wherein the CV value of the balanced organic material after step (b) is not significantly less than the CV value of the organic material before step (a). 3. The procedure for increasing the humidity of organic material, which comprises the steps of: (a) forming an organic material layer by depositing it on a conveyor; (b) contacting the organic material with an air stream flowing substantially upstream of the organic material; and (c) implementing these conditions in which a portion of the air stream moisture content passes into the organic material that the relative humidity of the air stream in contact with the organic material is maintained near the equilibrium conditions of the organic material, causing a gradual dehydration of the air stream, and the organic material is progressively hydrated at substantially countercurrent airflow relative to the organic material flow until the desired moisture of organic material. 4. The process defined in claim 13 ¹⁵ wherein the CV of the balanced sample of the organic material after step (c) is significantly less than the balanced value CV of the organic material prior to step (b). 5. The process of any one of Claims 1 to 4, wherein the temperature of the organic material is below 38 ^e C before contact with the air stream. 6. The process of any one of claims 1 to 5, wherein before the step of contacting the organic material with an air stream, the initial moisture content of the material is in the range of 1.5-13%. 7. The process of claim 6, wherein the initial moisture content of said organic material is in the range of 1.5% to 6% prior to the step of contacting said organic material with an air stream. 8. The process of clause 3, wherein the desired humidity of the organic material after step (c) is in the range of about 11 to about 13%. 9. The process of any preceding claim, wherein the air stream coming into contact with the organic material has a relative humidity of about 30 to 64% and a temperature of about 21 to 49 ° C. 10. A method according to any one of the preceding claims, wherein the temperature of the air stream is selected to provide thermal treatment of the organic material while the relative humidity of the air stream is selected to humidify. Process according to any one of the preceding claims, characterized in that the material to be processed is tobacco. 12. The process of any of the preceding claims, wherein the treated material is expanded tobacco. 13. The method of claim 11, wherein the tobacco is selected from the group consisting of expanded and unexpanded tobacco, cellular tobacco, cut or chopped tobacco, stems, recombined tobacco, and any combination thereof. .. - .......... 14. A process for reducing the moisture content of an organic material comprising the steps of: (a) contacting the organic material with an air stream ¹⁶ having a relative humidity close to or less than the equilibrium conditions of the organic material; and, (b) reducing the relative humidity of the contact with the organic material while reducing the moisture content of the organic material in such a way the humidity of the air stream in contact with the organic material is maintained near or below the equilibrium conditions of the organic material until the desired humidity of the organic material is achieved. 15. The process of clause 14, wherein the CV value of the balanced organic material after step (b) is not significantly lower than the CV value of the balanced organic material before step (a). 16. A process for reducing the moisture content of an organic material comprising the steps of: (a) forming an organic material layer by depositing it on a conveyor, (b) contacting the organic material with an air flow stream substantially countercurrent to the organic material layer, and (c) implementing these conditions wherein part of the moisture content of the air stream passes into the organic material that the relative humidity of the air stream in contact with the organic material is maintained near the equilibrium conditions of the organic material, causing a gradual hydration of the air stream, and the organic material is gradually dehydrated at a substantially countercurrent flow of airflow relative to the organic material flow until the desired moisture of organic material. 17. The process of clause 16, wherein the CV value in the aligned organic material sample after step (c) is not significantly less than the equalized CV value of the organic material prior to step (b). 18. The process of any one of items 14 to 17, further comprising the step of heating the organic material from about 38 ° C to about 121 ° C prior to step (a). 19. The process of any one of Claims 14 to 18, wherein the temperature of the organic material is less than 121 ° C prior to the air flow contact step. 20. The process of clause 19, wherein the temperature of the organic material is below 38 ° C prior to the air flow contact step. 21. The process of Claims 14 to 20 wherein the organic material has a moisture content of from about 20% to about 20% before the step of contacting said air stream. 11 to 40%. 22. The process of paragraphs 14 to 20, characterized in that the air stream before the step of, when in contact with organic material, a relative humidity of about 60% and a temperature of about ^21E C to 49 ° C. 23. The process of any one of Claims 14 to 22, wherein the temperature of the air stream is selected to provide the necessary heat treatment. 24. The process of any one of Claims 14 to 22, wherein the temperature of the air stream is selected so as not to cause substantially any heat treatment. 25. The process of any one of claims 14 to 24, wherein the temperature of the air stream is in the range of about 24 to 121 ° C. 26. The process of any one of claims 14 to 25, wherein the organic material is tobacco. 27. The method of claim 26, wherein the tobacco is cut tobacco. 28. The method of clause 26, wherein said tobacco is selected from the group consisting of expanded or unexpanded tobacco, cellular tobacco, cut or chopped tobacco, stems, recombined tobacco, and any combination thereof. 29. The process of any preceding claim, wherein the step of contacting the organic material and the air stream is carried out in a continuous manner using a spiral conveyor wherein the air flow flows in a direction substantially countercurrent to the flow direction of the organic material. 30. The process of any preceding claim, wherein the step of contacting the organic material a. of the air stream, is carried out in a continuous manner using a linear conveyor. 31. The process of clause 30, wherein the linear conveyor is designed to form a series of multiple zones of increasing humidity. 32. The process according to any one of the preceding claims, wherein the step of contacting the organic material and the air stream is performed so that the air stream has a velocity of from about 0.23 m / s to about 1.22 m / s. 33. A method according to any one of the preceding claims, wherein the step of contacting the organic material with the air flow is carried out in such a way that the air flow is directed either downwards or upwards and passes through the organic material. 34. The process of any one of items 1 to 10 and 15 to 25, wherein the organic material is a hygroscopic organic material; 35. The method of clause 29, wherein the hygroscopic organic material is selected from the group consisting of fruits, vegetables, cereals, coffee, pharmaceuticals, tea, and any combination thereof. 36. The process of clause 29, wherein the spiral conveyor consists of a reservoir that has multiple floors and the air essentially flows through the supply sequentially through the individual floors. Fig. First y-axis: OV content in tobacco [%] x-axis: relative humidity [%] Fig. Second Water source for humidification Air inlet Microprocessor control of constant increase of relative humidity with time. sensor Relative humidity control Tobacco layer Perforated floor Air outlet Fig. Third Fig. 3a. Fig. 4th The air Low RH (relative humidity) Higher RH Fig. 5th Tobacco from the expansion process 95 ° C, 3% OV. Cooling air 23.8 ’C, RH <52% Tobacco cooler 26.6 ’C, 4% OV Tobacco from the tobacco cooler Humidifier air 29.4 ° C, 62% RH Spiral humidification unit Tobacco from the humidification unit 29.4 ’C, 11.5% OV Fig. 6th y-axis:% RH of air just above the tobacco layer X-axis: time And the entrance to the spiral humidification unit B output from spiral humidification unit