SK281909B6 - Process for adjusting the moisture content of 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

SK 281909-6

Technical field

The invention relates to a method of increasing the moisture content of organic materials such as pharmaceutical and agricultural products, fruits, vegetables, cereals, coffee and tea.

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 material products. 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 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 easily crumbled at such low humidity. In addition, the structure of expanded tobacco collapses when the moisture is treated, i.e.. j. 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 US 4,178,946.

However, none of these 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 expanded tobacco to any gaseous environment in which condensation, such as steam or high-saturated air, occurs, leads to the breakdown of its structure.

A method that bypasses these difficulties is to equalize the humidity of the initially dry expanded tobacco in a chamber that contains air of equilibrium moisture with the tobacco of the desired humidity and allows dry expanded tobacco to slowly equalize its humidity with the environment in 24 and 48 hours. The air through the chamber is very low, usually not higher than about 127 mm / s ² . This procedure leads to little or no deterioration in the properties of tobacco caused by the disintegration of its structure. However, the long contact times required limit the applicability of this method to the laboratory.

We have attempted to reduce the residence time required for such an equalization process by increasing the flow rate. This approach was unsuccessful because the fillers of laboratory processed tobacco could not be achieved. The size of the conveyors which 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.

Generally, 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 shredded 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. In addition, 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 to prevent diffusion of the internal moisture in the tobacco onto 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 introduced a number of constraints.

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

SUMMARY OF THE INVENTION

These drawbacks are overcome by the method of increasing the moisture content of the organic material of the present invention, which consists in the steps of forming an organic material substrate by applying the organic material to a multi-level screw conveyor, then contacting the organic material on the substrate with a stream of air having a relative humidity close to equilibrium conditions of the organic material, wherein the air flows from the tray to the tray in a substantially counter-flow path relative to the path of the substrate of the organic material along the plurality of trays and subsequently increasing the relative humidity of the air stream contacting the organic material on the substrate to increase the moisture content of the organic material so that the relative humidity of the stream The air contacting the organic material is maintained near the equilibrium conditions of the organic material until the desired moisture content in the organic material is reached. the air stream gradually dehydrates, and the organic material is gradually humidified as the air flows on a substantially counter-flowing path relative to the path of the substrate of the organic material.

In a preferred embodiment, when contacting the organic material, the air flow has a relative humidity close to or lower than the equilibrium conditions of the organic material substrate, and the relative humidity of the air contacting the organic material decreases until the moisture content of the organic material decreases so that the relative humidity of the air contacting the organic material is maintained close to or below the equilibrium conditions of the organic material until the desired moisture content in the organic material is achieved, thereby gradually dehydrating the organic material and gradually streaming the air stream as the air flows on a road substantially opposite to the organic material substrate.

Preferably, the temperature of the organic material is below 38 ° C and has an initial moisture content of 1.5% to 13% prior to contacting it with an air stream, the organic material has an initial moisture content of 1.5 to 6% and the air stream has a relative humidity from 30% to 64% at 21 ^° C to 49 ° C.

In another preferred embodiment, the organic material is tobacco, which may be selected from the group consisting of expanded or unexpanded tobacco, whole tobacco leaves, cut or chopped tobacco, stems, reconstituted tobacco, or a combination thereof

The step of contacting the organic material with the air stream can be performed either by directing the air stream down or up through the organic material substrate or by directing the air stream down and up.

Preferably, the air temperature is such that no heat treatment is performed.

It is also preferred that the organic material is a hygroscopic organic material that is selected from the group consisting of fruits, vegetables, cereals, coffee, pharmaceuticals, tea, and any combination thereof.

In carrying out the process, it is advantageous if a screw conveyor is used as the storage conveyor and the air flows through the substantially accumulated material successively through successive trays.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the method will be further described with 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 humidifying the hygroscopic organic material of the present invention using air with time-varying relative humidity, RH;

Fig. 3 is a view of an exemplary device with a cut-away portion 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 over time of the tobacco surface; was obtained when humidified in the apparatus of FIG. Third

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method 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, speed 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)

Tobacco filling weighing 20 g unless expanded and 10 g if expanded is placed in a 6 cm diameter densitometer cylinder. DD-60, designed by Heinf. Borgwald GmbH, Schnackenburgallee 15, Postfach 540722, 2000 Hamburg 54 Germany. A tobacco with a diameter of 5.6 cm and a weight of 2 kg is placed on the tobacco for 30 seconds. The resulting compressed tobacco volume is read and divided by the tobacco sample weight. 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. If 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 according to the Ideal Gas Behavior Act. Throughout this application, unless otherwise stated, the term specific volume is used for

286 values determined on the same sample on which the moisture content was determined to be 0 V, t. j. tobacco dried in a circulating air oven 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. The determination of volatile matter OV is a simple determination of the weight loss of tobacco by weighing after drying for 3 hours in a circulating oven at 100 ° C. The loss in percent of initial weight is the volatile matter content determined by drying in an OV oven.

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 in the case of unexpanded tobacco and 100 ± 10 g in the case of expanded tobacco shall be placed in a sieve shaker. The shaker uses a 30.5 cm diameter sieve set (and are manufactured by WS Tyler Inc., A Subsidiary of Combustion Engineering Inc. Screenib Division, Mentor, Ohio 44060), which meets ASTM standards (American Society for Testing Materials ⁸ ). Typical mesh apertures are 6; 12; 20 and 35 mesh corresponding to 4.2 mm; 2.11 mm; 1.27 mm; 0.73 mm. The shaker has a lift 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, a successful humidification of humid air must operate at a relatively low speed with good control of the relative air humidity, air temperature and flow rate 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 at 23.9 ° C applicable to 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, the balanced tobacco will have an equilibrium 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 represents an alternative relative humidity profile RH which was also judged to be 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 of 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 of RH to a volatile content of 11.7% that would be in equilibrium with an air with a relative humidity of about 60% %, can be achieved better by exposing the tobacco to air whose humidity is gradually increased from 40% to about 60% than when exposed to air directly 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 an 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 great, without adversely affecting the tobacco filler. . It is also important that for tobacco containing volatile OV ingredients between

7.5 and 11.5%, the humidity of the air used for humidification may be about 2 to 8% higher than the relative humidity of the air that is in equilibrium with tobacco, with a greater deviation of five for tobacco with lower volatile constituents, to adversely affect tobacco filler.

When this process was applied to tobacco drying, there was no decrease in the cylindrical volume of tobacco. It 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. j. 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 the tobacco of the present invention.

The present invention can be applied to both batch and continuous processes. When carried out as a batch humidification process, the relative humidity of the airflow 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 inside the chamber. Tests were performed in which the dry expanded tobacco was humidified from an initial OV value (volatile constituents) of 2% to a final 11.0% using air with gradually increasing relative humidity values from an initial value between 30% and 52% to a final value between 59 and 65% over a period of 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% over a period of less than about 40 minutes, provided a moistened tobacco with a fully maintained CV value, such as This 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 speed of 24 to 48 hours. Gradual change was successful as long as the humid air velocities were up to 1.016 m / s and the temperature was from about 23.9 ° C to 32.2 ° C. Expanded tobacco moistened in this manner had 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, is transported by the unit 10 spirally from the bottom of the spiral container at the top, as shown, and exits through the tobacco outlet after moistening. The humidified air is blown downwardly through the tobacco from the humid air inlet 15 to the bottom of the spiral container 14, where it exits through the humid air outlet 16, substantially flowing countercurrent to the tobacco movement direction, i. j. most of the moist air flows from the top of the inserted tobacco up 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. 3 a. 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 21 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 tobacco advances upwardly through the spiral feeder 14. The major portion of the air 20, which is substantially countercurrent to the tobacco pathway, is directed by the levels of the tobacco layer 21a and comes into contact with the tobacco at a level immediately below it. This portion of the air stream 22 may later pass through the layer of tobacco 21.

The key to a successful demonstration of the present invention, in the case of humidification, is the means for permanently increasing the relative humidity of the air in contact with the tobacco, depending on the increased humidity expressed by the OV value 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. By supplying tobacco from below and air from above 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, ie, similar conditions to the batch experiments, the results of the batch humidification experiment can be approximated in a continuous configuration. To moisten 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 an air flow rate of from about 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.

A relative humidity recorder over time, such as the 29-03 RH / Temperature recorder (manufactured by Rustrak Instruments Co. E. Greenwich, RI), was attached to the Frigoscandia unit during tobacco humidification. This device showed a sustained increase in relative humidity when transferred over a spiral container with an initial relative humidity value of about 35 to 45% at the bottom of the device where the tobacco is drier, to about 62% at the top of the device where the tobacco is already completely moistened.

Fig. 6 is a typical relative humidity vs. time curve recorded by the Rustrak unit. The relative air humidity percentages of the tobacco layer versus time are shown in FIG. 6. Tobacco with an initial OV humidity of about 3% that enters the spiral humidification unit and has been in contact with air with a relative humidity of about 43% (point A of Figure 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 had no significant cylinder volume loss.

In order to realize the present invention, other methods can be used to effect gradual changes in the relative humidity of the air, as shown in FIG. 4. According to FIG. 4, the tobacco enters the feeder 43 through the tobacco inlet 40 and exits the tobacco outlet 41. The air of increasing humidity is supplied so as to blow up or down the tobacco layer 42 in several zones 44 and thus reproduce the effect of the progressive moisture in the apparatus of FIG. This progressive effect can also be achieved by moving the air from one source that follows 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, chopped 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 aforementioned 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 countercurrently modified spiral dryer with a feeder, Frigoscandia, from a tobacco humidity of from about 21 to about 15% in about 1 hour. . In this case, air entered the top of the unit at about 29.5 ° C and 58% RH and exited at 25 ° C and 68% humidity. Drying was carried out with little or no heat treatment of the tobacco.

SK 281909-6

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 no. 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 OV content of the tobacco fill was

3.4%. It was calculated that about 1.98 g of water would be needed to increase the OV content to 11.5%. This amount of water was placed in a small glass container 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%. By this is meant tobacco before it has been equilibrated with air at 60% relative humidity and a temperature of 23.9 ° C for 24 to 48 hours. This straightening procedure is generally used as a means of achieving a standard tobacco state before measuring the cylinder CV volume and specific CV volume as well as before the crosslinking tests. After this standard alignment, the tobacco moistened in the desiccator had a cylindrical volume, CV, of ca.

9.5 cm ³ / g and a specific volume 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 volatile content, OV, was 11.3% and the CV and SV values were successively 9.4 cm ³ / g and 2.7 cm ³ / respectively. g. A third sample of expanded tobacco packing was moistened in a spray column so that the volatile content was about

11.5%. After equalizing this sample, the CV had 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 data in Table 1, the tobacco moistened slowly in the desiccator had a significant improvement in the CV and SV equilibrium values compared to the values for the sample that had been sprayed. This sample also had a slight improvement in CV and SV values over the sample that was directly leveled in the equalization chamber.

Table 1

sample as such balanced ον μ) SVlceVqJ in L * J CV [atr i / g j SV [cn / g | Výetup 3.4 3.A 11.3 9.4 2.7 towers wetted 11.S I.E 11.6 8.5 1.9 in the cylinder Desiccator 11.s 2.7 11.5 9.5 2.9

A second set of experiments was performed in a buffer chamber for humidifying the tobacco fill. 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 controlled elevation of ¹⁰ conditions within the chamber.

Experiment no. 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 Table 2 and show that for the 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 roller containers. However, it was found that the greatest benefit was achieved by escalating in a time as short as one hour.

Table 2 sample as such aligned in the equalization chamber

0V IM SV (CB / g) UVjcm / gj output 3.1 from the tower 3.6 11:33 9.71 spray 11.51 container 1.61 11:37 8.61 graded- 10.83 no 1 h 1.85 11:38 9.72 11.44 step 3 h 1.88 11:36 9.81 step 11.45 6h 1.90 11:30 9.88 stupňová- 11.41 1.97 11:27 9.89

12 hours

Experiment no. 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 carried out with tobacco impregnated with carbon dioxide and expanded in an expansion tower at 288 ° C. The expanded tobacco was moistened in the following ways:

1. Equalizing 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 / sec.

SK 281909-6

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

3. Spray with water up to 7.5% OV, and then final wetting in a spray cylinder.

4. Spray water at about 7.5% OV, and then using gradually varying relative humidity from 46 to 60%.

5. Grading the 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:

1st step times: 30, 60 and 90 minutes

2. air temperatures of 23,8 ° C and 35 ° C,

3. successive air speeds upwards through a layer of tobacco of about 13 m / s and downwards through a layer of tobacco of 89 cm / s; and

4. Tobacco layer thickness: 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 from 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 step-humidification conditions. Data for these test kits are shown in Tables 3 to 3e.

Table 3c aligned as is

sample OV [%] SVfcm / g] OV [ ») CVfcm / g] X output 1.81 from tower 2.78 11:37 9.23 B at 10.91 vito 60 min. (46-60 RH, 35 ') 1.86 C) 11:47 8.86 C atup 10.53 vito 60 nin. (46-60 4 RB, 23 2.2 .9 ’C) 11:28 9.20 D degree 10.84 vito 90 in. (46-60 t RH, 35 1.99 • C) 11:45 8.90 B only 5.39 spray 2:37 11:25 8.71 F apray and 10.80 directly inserted at 30 nin. up to 60 t RH, 35 ’C 1.81 11:27 8:39 G apray and 10.66 degrees 60 nin. (46-60 4 1.85 RB, 35'C) 11:23 8.65 H apray a 10.76 degree 90 min. (46-60 * 1.82 RH, 35 ’C) 11:24 8.62 I apray and 10.65 degrees 60 nin. (46-60% 1.90 RB, 23.9 ° C) 11:23 8.75 J apray and 10.57 degrees 90 nin. (46-60 * 1.87 RH, 23.9 ° C) 11:38 8.74 K apray and 10.73 directly on 30 siin. up to 60 8 RH, 1.87 23.9 ’C 11:22 8.64 L apray and 10.98 and cylinder 1.60 11:39 8.28

Table 3a

same as me balanced sample OV [t] SV (cm / g] 0 V [4] CVLC / g] X output with towers 3:43 2.3 11:31 4.9 With just spray B.06 2.14 11.68 B.66 C spray and cylinder 11:53 1.81 11:59 8:59 F spray and graded 90 ^u mines. 11:27 1.87 11:51 1.9 (46 to 01 RB, 23.9 * C | H spray and stepwise 90 min. 10.96 1.98 11:36 9:48 (46 to 60% RH, 23.9 * C) I sample H hold- 11:54 1.95 11:56 9:40 15 sdn-pri 60 S RH, 23.9 ° C J spray and stepped 60 eln · 10:37 2:38 11:28 9:58 (46 to 60 t RB, 23.9 ’c) K sample J held 15 siin. at 62 4 RB and 35 ° C 11:17 2.26 11:22 9.88

Table 3d

Table 3b as aligned

sample OV (I) SV [cm ^, / g] OV ( "I CVÍon ¹ /,] X get off 3.01 8 towers 2:58 11:34 9.23 8 only 7.51 spray 2.13 11:39 8.87 C spray 11. B6 and cylinder 1:59 11.64 7.8 P spray and 10.55 degree 60 minutes (46-60 * RK, 23.9 * C) 1:54 11:45 8.86 G sample F 11.56 held 15 nin.pri 60 »RH, 23.9 ´C 1:54 11:42 6.61 --------------- n

as it is balanced sample OV ll] SV l «’ / g] OV [»] cv [c '/ gj TI output from the tower 2.83 1.3 11.92 9:46 T2 inserted at 30 nin.to RH 60 * at 23.9 ° C 11:24 2.27 11.77 8.9 T3 gradually 30 to 60 4 RB, 23.9 ’C 11.8 2.24 11.83 9.29 T4 gradually 90 in ,. 30 to 60 * RB, 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 strict at 30 nin.de 60 1 RH, 23.9 * C 11:10 2.19 11.64 8.89 S3 spray and gradually 90 nin.46 to 60 t RB, 23.9 * 'C 10:54 2.25 11:27 5.9 84 spray and gradually 60 nin. 46 to 60 4 RB, 23.9 * 'C 10:56 2.22 11.73 3.9 SS spray and gradually 30 min. 46 to 60 4 RH, 23.9 ' 'C 9.74 2.29 11.67 9.19 C spray and vAlec 10:48 1.95 11.81 8.80

spray and 10.28 1.97 11.27 8.99 degree nin. (46 to * RH,

23.9 ’C)

1 sample H 11.73 held 15 stin. at 62 1 RH, 23.9 ’C 1.82 11:25 8.61

SK 281909-6

Table 3e

podnlanky tupAovania as well as j  balanced Itar speed fiat temperature RH OV SV OV CV OV [8 | Výduch («C) ros / Í »1 (c «/ 9) Í »J c «/ gj {· / ·) • ah TOWER SOCKET -9.2 0.79 11.B6 5.5 OUTPUT t TOWERS 3:44 2.82 11.72 9:49 OUTPUT L. . SPRAYING SPRAY 5.6 * 3.72 11.82 9:40 OUTPUT B CYLINDER CONTAINERS 10.3 « 3.0 * 11.66 9.28 A 3.9 119 60 23 » 30-51 6.67 2:39 11.65 9.76 5.6 Β » 60 23.9 30/58 8:44 2:45 11.B2 9.91 C 3.9 97 60 23.9 * 5-58 7.83 3.25 11.65 9:57 D 5.6 97 60 23.9 «5-58 8th ** 2:39 11.79 9.66 E 3.9 97 60 23.9 17-62 11:10 2:33 11.7 * 10.2 F 5.6 B9 60 23.9 * 7-62 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 «0 23.9 30-62 9:41 3:41 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 * 7-6 * 10:18 2.13 11.94 9.13 K 3.9 91 60 23.9 35-64 7.9 2.23 11.99 9:51 L 3.9 91 60 32.2 35-60 B.65 2.1? 9.12 8:59 M 3.9 91 60 32.2 «5-60 10:11 2:39 11.92 10.2 K 5.6 91 60 32.2 «5-60 8.10 2:39 11.93 10.2 0 3.9 122 60 32.2 «7-64 10.88 2.31 11.96 9:51 P 3.9 122 60 32.2 * 7-64 11:30 3:33 11.95 9.30

The data presented in Table 3a to 3e show a gain in CV values ranging from 0.5 to about 1 cm ³ / g and a gain in SV values from about 0.3 to about 0.4 cm ³ / g, which may be achieved by gradually varying the RH of air when humidifying cold tobacco, i.e., tobacco temperature from about 23.9 ° C to about 35 ° C, compared to spraying in a cylindrical vessel used to humidify hot tobacco leaving the 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 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 of from about 89 to about 119 cm / s, or upward at speeds of about 23 cm / s without observing significant differences in SV and CV values. Additionally, it was found that successive humidification yielded 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 ° C in a buffer chamber. Finally, it was found that water spraying leading to an increase in volatile matter OV to 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 cylinder.

Experiment no. 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 ³ / 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 placed inside the equalizing chambers. The 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 upward air flow direction immediately above, and for downstream measurement under the sample layer.

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 / sec. Small air channels were then formed and the tobacco settled. Due to the channels present, the flow rate is very inhomogeneous 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 channeling became more pronounced, and at flows above 22.9 cm / s, significant abduction and blowing of tobacco was observed, followed by significant channeling of the layer.

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 compaction of the layer was about half that at 97.5 cm / sec and the air flow through the tobacco was much less reduced.

Table 4

IMPACT OF LAYER COMPACTITY TO THE AIR FLOW FLOW Initial air velocity [ca / s] layer thickness beginning the end change (8) beginning the end of en * * (8) 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 wetted 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 at a rate of up to 22.9 or downward at about 112.7 cm / sec.

Experiment no. 5

Approximately 65.25 kg per hour of the blend of burley ¹⁴ tobacco which has been impregnated with carbon dioxide as described in commonly-assigned and commonly accepted Cho et al., SN 17/717 167, and expanded as described in the examples. was passed through a cooling conveyor to lower 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 feedstock 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 humidification process, in other words: no statistically significant analysis was found by standard variance analysis. loss of filling capacity. In addition, the sieve test did not show a measurable decrease in tobacco particle size due to the humidification process.

Experiment no. 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 / hr. tobacco in relation to the moistened tobacco mass was moistened in the modified Frigoscandia spiral unit described in experiment no. 5. The temperature of the air entering the humidifier was adjusted to about 29.4 ° C and the relative humidity to about 62%. The air exiting the humidification unit 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 had no decrease in filling capacity.

Table 5

balanced Type foku temperature OV OV CV OV CV □ In tobacco e. towers vatup výa- vatup vatup výa- výa- apos; c] [*] tup c »%] [ »] tup tup ( »| [ »] [*) Bright * FO 20SC 287 2.70 11:16 9.93 11.87 9:40 12:00 FO 205A 321 2.11 11:38 10:41 11:57 10.83 11:56 FO 205B 329 1.87 9.99 11:30 11:30 10.90 11:50 Briqht * FO 206A 304 2:47 11.9 10:00 12:34 10:20 11.74 PO 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 dysca processed tobacco avatlý tobacco from Kentucky

Experiment no. 7

About 90.6 kg of smoke-treated tobacco per hour with an OV of 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% O in a residence time of about 60 minutes using air having an inlet temperature of about 35 ° C and a RH humidity of about 35%. The air leaving the drying unit was about 28.3 ° C and had a humidity of 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 the 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.

PATENT CLAIMS

Claims (23)

Method for increasing the moisture content of organic material, characterized in that the steps are: a) forming a substrate of organic material by applying organic material to a screw conveyor containing a number of trays, b) contacting the organic material on the substrate with a stream of air having a relative humidity close to the equilibrium conditions of the organic material, the air flowing from the tray to the tray in a substantially counter-directional way relative to the tray path of the organic material along a number of trays; c) increasing the relative humidity of the air stream contacting the organic material on the substrate to increase the moisture content of the organic material so that the relative humidity of the air stream contacting the organic material is maintained near the equilibrium conditions of the organic material until the desired moisture content in the organic material is reached; the air stream gradually dehydrates and the organic material is gradually humidified as the air flows on a substantially counter-flowing path relative to the path of the organic material substrate. Method for reducing the moisture content of organic material, characterized in that the steps are: a) forming a substrate of organic material by applying organic material to a screw conveyor containing a number of trays, (b) contacting the organic material with the air flowing from the tray to the tray by a substantially counter-current path relative to the path of the tray of organic material along the plurality of trays, the air flow having a relative humidity close to or below the equilibrium conditions of the tray (c) reducing the relative humidity of the organic material air stream until the moisture content of the organic material decreases such that the relative humidity of the organic material air stream is maintained near or below the equilibrium conditions of the organic material until the desired moisture content in the organic material is reached; whereby the organic material is gradually dehydrated and the air stream is gradually humidified as the air flows on a path substantially opposite to the path of the substrate of the organic material. The method of claims 1 or 2, wherein the temperature of the organic material is below about 38 ° C (100 ° F) before contacting it with the air stream. 4. The method of claim 1 or 2, wherein before the step of contacting the organic material with the air stream, the organic material has an initial moisture content of from about 1.5% to about 13%. The method of claim 4, wherein prior to the step of contacting the organic material with the air stream, the material has an initial moisture content of from about 1.5% to about 6%. The method of claim 1, wherein the air stream contacting the organic material has a relative humidity of from about 30% to about 64% at a temperature of from about 21 ° C (70 ° F) to about 49 ° C (120 ° F). . Method according to claim 1 or 2, characterized in that the organic material is tobacco. The method of claim 7, wherein the tobacco is expanded tobacco. The method of claim 7, wherein the tobacco is cut tobacco. The method of claim 7, wherein the tobacco is selected from the group consisting of expanded or unexpanded tobacco, whole tobacco leaves, cut or chopped tobacco, stems, reconstituted tobacco, or any combination thereof. The method of claim 2, further comprising the step of preheating the organic material to a temperature of about 38 ° C (100 ° F) to about 121 ° C (250 ° F) prior to step (a). The method of claim 2, wherein the temperature of the organic material is below about 121 ° C (250 ° F) prior to the step of contacting the organic material with the air stream. The method of claim 1, wherein the desired moisture content in the organic material after step (c) is from about 11% to about 13%. 14. The method of claim 2, wherein before the step of contacting the organic material with the air stream, the organic material has a moisture content of from about 11% to about 40%. The method of claim 2, wherein the air stream contacting the organic material has a relative humidity of from about 20% to about 60% at a temperature of from about 21 ° C (70 ° F) to about 49 ° C (120 ° F). . 16. The method of claim 2 wherein the airflow temperature is from about 24 [deg.] C (75 [deg.] F) to about 121 [deg.] C (250 [deg.] F). The method of claim 1 or 2, wherein the step of contacting the organic material with the air stream is performed using an air stream with a velocity of from about 0.23 m / s to about 1.22 m / s. A method according to claim 1 or 2, characterized in that the step of contacting the organic material with the air stream is carried out by directing the air stream either down or up over the organic material substrate or by directing the air stream simultaneously down and up through the organic material substrate. Method according to claim 1 or 2, characterized in that the temperature of the air stream is selected so as to ensure the desired heat treatment. Method according to claim 1 or 2, characterized in that the temperature of the air stream is selected so that no heat treatment is carried out. Method according to claim 1 or 2, characterized in that the organic material is a hygroscopic organic material. 22. The method of claim 21, wherein the hygroscopic organic material is selected from the group consisting of fruits, vegetables, cereals, coffee, pharmaceuticals, tea, and any combination thereof. Method according to claim 1 or 2, characterized in that the storage conveyor is a screw conveyor and the air flows through the substantially accumulated material successively through successive trays.