FR2568106A1 - IMPROVED TOBACCO SWELLING METHOD - Google Patents

Abstract

IMPROVED PROCESS FOR THE TREATMENT OF TOBACCO TO INFLATE IT, IN WHICH THE HUMIDITY LEVEL OF TOBACCO AND THE DURATION OF TOBACCO STAY IN A PRE-SEPARATOR UNDER PRESELECTED PRESSURE AND TEMPERATURE CONDITIONS AS TOBACCO AT THE EXIT FROM THE DRYING STAGE HAS A HUMIDITY LEVEL BETWEEN APPROXIMATELY 9 AND 15 BY WEIGHT OF OVEN PULLED PRODUCTS.

Description

2S68106

  The present invention relates to an improved process

  tobacco treatment, and more particularly a

  improved to inflate tobacco, wherein the tobacco

  is maintained at a relatively high humidity level.

  There are known in the art a number of

  processes in which tobacco is swollen by impregnating

  using a liquefied gas, such as carbon dioxide, under pressure to incorporate the gas as a liquid in the tobacco; when the pressure on the thus impregnated tobacco is reduced, the liquefied gas is transformed into a solid

  and the tobacco is then inflated when the solid is

  porisé. For example, U.S. Patent Nos. 4,336,814 and 4,340,073, as well as a number of prior patents and publications teach or suggest wholesale such methods. In addition, there are known in the art a number of patent applications which describe

  structural arrangements to implement the

  In one embodiment of the present invention, the present invention relates to impregnated tobacco swelling in conduit systems and associated drying chambers, for example, US Pat. Nos. 3,357,436, 3,786,573 and 4,366,825 and a number of prior patents. In addition, US Patent Application Serial Nos. 391,882 and 541,752 each disclose structural arrangements that can be used to inflate impregnated tobacco in ducting systems and communicating drying chambers; in addition, each of these applications describes a tobacco feeding device

  disposed substantially at the entrance of a separate device

  to introduce tobacco to dry and swell in

  the conduit at the inlet to the separator device.

  In view of certain disadvantages of prior methods for inflating tobacco, the present invention

  provides an improved method for inflating tobacco by

  the losses in glycerin, alkaloids and sugar. In addition, the method of the present invention allows a decrease in the temperature of the tobacco at the outlet of the dryer, while allowing a high swelling of the particles and an increase in the moisture content of the dryer.

  tobacco at the exit of the dryer, from which it follows that

  holds larger and less friable particles. Since it results from the present invention that the moisture content of the tobacco is higher at the exit of the dryer, the necessary reprocessing, if necessary, to bring the inflated tobacco to the final desired moisture content is minimized and the cooling required is less and as a result, it takes less energy to bring

  tobacco on exit to an acceptable storage temperature

  table. In addition, as no additional treatment

  tobacco or possibly minimal treatment is

  necessary to bring the inflated product to the final desired moisture content, the amount of water to be added is low or

  null, and as a result, the loss of power to

wise is very small. -

  More particularly, the present invention provides an improved method of treating tobacco, in

  which brings the tobacco to a preselected humidity level

  sufficient to obtain at the exit a rate of humidity

  between 9% and 15% of products are

  baking (hereinafter simply baked volatile products, as determined by weight loss

  dried sample in a forced draft oven

  heated at 110 C for 3.25 hours) and

  filling at least equivalent to the values of

  If the tobaccos are dried at a lower moisture content, the tobacco thus treated is impregnated with a liquefied gas under a given pressure and at a given temperature and the pressure is sufficiently reduced to form a solid inside the tobacco and subjected to the impregnated tobacco solid at pressure and temperature conditions for a pre-selected limited residence time in a pre-separator of less than about 0.1 sec., whereby the solid is vaporized and inflates the tobacco so to obtain at the outlet a tobacco having a moisture content of between approximately 9 and 15% of volatile products in the oven and with filling values at least equivalent to the tobacco filling values

  dried in a lower range of moisture

  with a longer residence time in a pre-separator.

  In carrying out the process according to the invention

  tion, it is understood that one can use

  One of several structural arrangements known in the art, including some of the arrangements described in the aforementioned patents and patent applications for inflating impregnated tobaccos in conduit systems and associated associated dryer chambers. Therefore, to be more brief, we will not describe here the details of these structural arrangements, being well

  understood that the structural arrangement used in the

  Prior conventional method leading to a compilation of the comparative data shown in Table 1 below is similar to that described in FIG. 4 of the aforementioned pending patent application Serial No. 541,752 and that the structural arrangement used in carrying out the process according to the invention leading to a compilation of the data shown in Tables 2, 3 and 4 below. is similar to that described in FIG. 5 of the above-mentioned pending patent application

series 541 752.

  In general, the tobacco to be treated by the process of the invention is brought with a mixture, by

  example of water and glycerin, at a higher moisture content

  better than conventional cutting moisture. In this regard,

  the treatment of tobacco to bring it to levels of

  conventional cuttings gives tobaccos with

  volatile oven fuels as defined above of about 20% by weight. According to the present invention, this first stage of treatment is set to obtain a tobacco having a moisture content higher than these conventional cutting moisture levels, preferably in a range of moisture content by weight of about 22 to 26%, and advantageously about 25%. The tobacco thus treated in the process of the invention is then cut to about 12 cuts per centimeter and is impregnated with liquid carbon dioxide under pressure; pressure

  is then reduced sufficiently to form the

  smoke of solidified carbon dioxide. The tobacco impregnated with carbon dioxide solidified with the above-mentioned moisture content is then treated in a volume expansion (or swelling) device, at a time of

  extremely short stay, by opting for the

  Conventional swelling agents with longer residence times under pressure and temperature conditions

  preselected so that solid carbon dioxide

  dified sublimates or vaporizes to cause swelling

  tobacco and produce at the outlet an inflated tobacco having a moisture content of between about 9% and 15% by weight, which is higher than the range of 1 to 6% volatile oven normally encountered. As can be seen in Tables 2 to 4 below, this higher moisture content at the outlet improves the particle size, because the particles are less brittle and less friable, and reduces losses of glycerin, alkaloids and total sugar, because the temperature of the tobacco is lower, which results from the combination of a higher moisture content and a residence time in the smoking device.

  relatively short swelling.

  To illustrate the improvements brought by the

  implementation of the present invention, the following will be

  after four examples with an attached Data Table

2568 106

  for each example, Table 1 of Example 1 indicates

  as for data relating to residence times in an almost conventional pre-separator. In this respect, it should be noted that the residence time reduced by 0.7 sec. in Table 1 and 0.06 sec. in Tables 2, 3 and 4 is obtained in the examples given mainly by the reduction of the residence time in the pre-separator, the residence time in the separator being practically

  the same for all the examples given below. Usual-

  Also, the residence time in the separator itself is about 1.4 sec. It should be noted that

  results of the Borgwaldt test on the power of

  pleating, indicated in the Tables below, are obtained by compressing a defined weight of tobacco samples in a cylinder under a load (falling in free fall) of 3 kg for a period of 30 seconds. The weight of

  the sample and the height of the tobacco column

  awarded are used to calculate the filling power expressed in cc / g. For the particle size distribution data in the tables, these data are usually obtained

  placing a weighed amount of tobacco on the top sieve

  of a "Ro-tap" device (particle size measurement method), and sieving it through a series of successive Tyler screens with the dimensions of

  preselected meshes indicated.

EXAMPLE 1

  In this example, a tobacco mixture of 50% flue-cured and 50% burley is packaged and brought to the moisture content shown in Table 1 (A-F). The thus treated tobacco is then cut to 12 slices per centimeter and impregnated with liquid carbon dioxide at relative pressures of about 2,550 kPa to 2930 kPa and temperatures of about -10 to -5 ° C. At the end of the impregnation, the pressure is dropped, which transforms the liquid carbon dioxide inside the tobacco into solid. The frozen tobacco is then agglomerated and passed through packets through an intermediate storage device where it is supplied in a continuous stream to a conveyor-weigher

  up to a combined swelling and separating device

  tangential drying. As described in FIGS. 3 and 4 of the current application serial number 541 752,

  the supply of frozen tobacco from the drying system is

  by means of a rotating air lock which

  in a horizontal duct. The duct is then rotated 90 to bring it to the vertical, it is

  rotates another 90 and connects it to a separate

  tangential factor. The length of stay in the conduit is

  about 0.7 seconds. The length of stay in the

  The typical duration is about 1.4 seconds. The swollen tobacco is then transported to a reprocessing cylinder, in which the moisture content is adjusted to about 12% by weight of volatile products in the oven,

  by a water spray at 10-15 C and a cooling

in the air at 21 C.

  As can be seen from the following Table 1 data collected in Example 1, with the relatively longer residence time in the separator, 0.7 sec. humidity levels at the entrance of the dryer, even high and of the order of about 25% by weight, do not significantly increase the moisture content at the outlet of the dryer. In addition, we can see little improvement,

  if there are any, in the distribution of the

  in Tables A and F of Table 1 with Tests B and C in Table 2 and Tests B in Tables 3 and 4 which correspond to a relatively shorter residence time of 0.06 sec . and relatively high humidity levels at the entrance to the dryer, of about 25% by weight. In addition, there is no significant improvement in the D, E and F tests of Table 1 when compared to Tests B and C in Table 2 and the tests in Tables 3 and 4 for

  the reduction of the percentage of losses in gly-

ceria, alkaloids and sugar. -

(000 T 1 X)

  TE 61 VZ EZ tZ EZ (%) wm 8'I peTiBTel -

  L9 ES zE Sb ztp (%) um z Op OTtTvm +: ggTmea-x TeuT qTnpo2d np eTilos eI V saonOT1ud sap suoTsuOMTp sap uoTnqTxSTa 99 LL - Z9 68 Z8 (%) uawaTguoD bZ'L S8'9 - Z6'9 6Z ' L 9Tvx; ax TeuT3 qTnpold np salos eI V 9ú'9 L8'E _ 9'9 58'ú 60'9 luama4ex np 092quaT V xnm ap% 9T V 6 / oo): pPlvmixoE OebssTT4dax XToAnod Z 'O,' E ' E 8 'Z 9'1 xn8' InaeTes np xe, p its np Tajos and v The .Z 8''z 8'SE 9'ZZ The ZZ úTEuso np 0; uaT y: (sPFod ua%) 9fTpTulnq xnvi IES 8651 86SI SSeT 9rST 08v1 (8anoq / Des * bX) sOpTios op Iq9C Ns XS> EWs 1tu W'E Ws' E tS'bExXS '% E * w5' rE (aznOq / bX) ze6 BOp qTqa 6ZE: 6ZE ZEEg 6ZE 6Zú7 LZE (Do) sgz4ueT e ze6 sap sxnvx9gduma The 0 The 0 L "0 L" 0 The 0 The 0 (s) xzneqledpsgxd and Suep mno gs Op sdmal: xTOqDOs np soeuuoca

--- 3 -... - -

  d 3. 9, 8 V I n2q 1 TABLE 1 (continued)

A B C D E F

  Glycerin (kg glycerin / kg dry tobacco): & treatment input 3.8 3.1 5, 6 6.7 4.3 at the output of the final reprocessed product 2.4 2.2 - 4.0 3, 8 3.3 loss (%) 37.0 29.0 - 29.0 43.0 23.0 Alkaloids (%):

  at the treatment entrance 3.13 3.13 3.13 - -

  at the exit from the final restated product 1.93 1.93 1.93 - - -

loss (%) 38.0 38.0 38.0 - -

Total sugar (%):

  at process input 6.8 6.8 6.8 - - -

  at the end of the final product 5.5 5.5 5.5 - - -

loss (%) 19.0 19.0 19.0 - - -

Ln o> Co osb

EXAMPLE 2

  The tobacco is treated as in Example 1 except that the frozen tobacco is brought into the drying line immediately before the tangential separator. As a result, the residence time in the pre-separator is 0.06 seconds, compared to 0.7 sec. of example 1,

  Table 1. It is understood that such times of

  shorter days can advantageously be understood

between about 0.01 and 0.1 seconds.

  As can be seen in Table 2, below,

  tests 2A are processed to achieve a moisture content

  Approximately 20% of oven-by-weight volatile products, while 2B, 2C are treated to bring them to a moisture content of about 25% by weight of volatile products in the oven. Tests 2A, 2B and 2C use several inlet gas temperatures

  of the dryer. We must note the increase in the rate of humidity

  at the separator outlet for tests 2B and 2C, compared to tests 2A. The increase in Borgwaldt filling values should also be noted, comparing tests 2B and 2C with tests 2A. In addition, improvements in particle size distribution should be noted, comparing tests 2B to

  tests 2A. It should also be noted that the reduction of losses in gly-

  when comparing Tests 2B and 2C with Tests 1A, 1B, 1D, 1E and 1F of Table 1 and the reduction in alkaloid and sugar losses when comparing

  tests 2B and 2C in tests 2A. We must note the diminu

  of the reprocessing spray requirements when comparing the tests in Table 2C and Table 2A, as well as decreases in tobacco temperatures when comparing the tests in Tables 2B and 2C with

Table 2A tests.

TABLE 2

A B C

  Dryer data: Time in the pre-separator (s) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 Inlet gas temperature (C) 264, 4,296.7 328.9 264.4 329.4 329.4 268.3 305.4 341.7 Gas flow rate (kg / hour) 34.5M 34.5M 34.5M 34.5M 34.5M 34, 5M 34.5M 34.5M 34.5M Solids flow (kg.sec / hour) 1398 1398 1398 1317 1317 1317 1680 1680 1680 Reprocessing data: Total water spray (ú / hour) 83 129 155 - - - 23 87 136 Pulverized unit water (kg.water / T tobacco) 60 92 111 - - - 14 52 81 Tobacco temperature (C) at the outlet of the airlock of the separator. 79.3 87, 8 90.06 68.3 73.9 79.3 71.1 76.7 77.8 Moisture content (% by weight): at the beginning of treatment 20.3 20.2 20 , 2 24.7 24.7 24.7 24.8 24.8 24.8 at the outlet of the separator airlock 9.3 7.1 3.5 10.1 8.7 6.3 14, 5 10.2 7.2 Borgwaldt filling capacity (cc / g at 14% of inhinitis rate): at the beginning of the treatment 4.61 4.61 4.61 4.52 4.52 4.52 4.50 4.50 4.50 at the outlet of the final reprocessed product 7.80 8.05 8.15 7.75 8.05 8.25 7.44 8.05 8.39% swelling 69.0 75.0 77 , 0 71.0 78.0 83.0 65.0 79.0 86.0 - o tn N m m O'O'0 0 O O O O O O O O O O O; o 9'9 Z 'ZL S'L 8'I The 9'9''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' Ipoxd np a; o; s and V'L''l E'L 814 48'L 8'1 L'L L'L, ppDOrld np es;, uaT V: (%) Tu; o; aorn O'LI 0'6 O'L O ', 0'Ci 0'6 O'Z O'L O'S (%) Oad LV'Z 69'Z 9L'Z EE'Z 9S'Z 89'Z Tp' Zb'Z 9t> 'Za TWeaVeUT .; WFnpoxd np e6os ut v L6 '6' 'L6'Z S6' S6SS6Z56'Z T6'Z T16'Z p6'o 9pPDOdI np B9auO, 1 V s I: (%) septotot 0'1 0'9 O'E 0 8 0'0 0 -%) ed cE'z L6'Z 9o'E t9'Z 8L'Z E6'1 - - -Z_; Tu_ T FU; qFnPoxd Inp eFqOs uT V LI 'L'E L8' L8'Z L8'Z _ _- 9pPotd np ea; uaT V: (oas oDqe; B // auTZoKAiT6 5) auT29OATD

  L 8 T OZ 9Z s0 (%) CE8 'amTIem -

  Es Os 6V Lr T9 (E) mm Z aTT M + 9IzTez; x TuuT; qTnpoed np eT $ aos uT: BaTnOT-4ced sap suoosueuap sap uoTU4nq $ 2sqa m S '

EXAMPLE 3

  The tobacco is treated as in Example 2. As can be seen in Table 3 below, the tests 3A are brought to an approximate moisture content by weight of 21.5% of volatile products in the oven, while that tests 3B are brought to an approximate moisture content by weight

  25%. As in Example 2, we should note the increase

  of the moisture content at the outlet of the separator and the decrease of the exit moisture content of the separator by comparing the tests 3B to the tests 3A. The increase in Borgwaldt filling values should also be noted by comparing tests 3B to tests 3A. Finally, the reduction in glycerin losses, alkaloid losses and total sugar losses should be noted by comparing

tests 3B at tests 3A.

TABLE 3

A B

  Dryer data Residence time in the pre-separator (s) 0.06 0.06 0.06 0.06 Inlet gas temperature (C) 327.8 332.8 298.9 306.6 Gas flow ( kg / hour) 34.5M 34.5M 34.5M 34.5M Solids flow (kg dry / hour) 1843 1843 1916 1798 Reprocessing data: Total water spray (ú / hour) 197 208 125 118 Unit water sprayed ( kg.water / T tobacco) 107 113 65 65 Temperature of the tobacco (C) at the outlet of the airlock of the separator. 82.2 79.3 71.1 75.6 Moisture content (% by weight): at the treatment inlet 21.6 21.6 24.9 24.9 at the outlet of the airlock of the separator 5,9 4,5 9,3 9,1 Borgwaldt filling capacity (cc / g at 14% moisture content): & treatment input 4.82 4.82 4.27 4.27 at the outlet of the restated final product 7.72 7.94 6.96 7.11% swelling 60.0 65.0 63.0 67.0 TABLE 3 (continued)

A B

  Glycerine (kg glycerin / kg dry tobacco): at the beginning of the process 2,38 2,38 3, 35,35 at the outlet of the final product reprocessed 2,09 2,07 3,11 3,13 loss (% ) 12.0 13.0 7.0 7.0 Alkaloids (%): at process input 2.93 2.93 2.87 2.87 at the outlet of the final reprocessed product 2.47 2.42 2 , 72 2.69 loss (%) 16.0 17.0 5.0 6.0 Total sugar (%): at process input 8.7 8.7 8.5 8.5 at product release Final restated 9.2 8.4 9.1 9.4 Loss (%) 0 3.0 0 0,,%

EXAMPLE 4

  The tobacco is treated as in Examples 2 and 3.

  As can be seen in Table 4 below, the tests 4A are reprocessed to arrive at a moisture content of about 22% by weight of volatile products in the oven, while the tests 4B are brought to a rate of Approximate moisture of 24.5% by weight of volatile products in the oven. Comparing the 4B tests with those of 4A, improvements in the particle size distribution and in the swelling and reduction of glycerine, alkaloid and total sugar losses, as well as the decrease in temperatures at the airlock outlet of the separator and quantities

  required for pulverized liquid for retirement purposes-

is lying.

TABLE 4

A B

  Dryer data: Residence time in the pre-separator (s) 0.06 0.06 0.06 0.06 Inlet gas temperature (C) 321.1 332.8 287.8 304.3 Gas flow rate (kg / hour) 34.5M 34.5M 34.5M 34.5M Solids flow (kg dry / hour) 1771 1771 1816 1816 Reprocessing data: Total water spray (Z / hour) 50 53 13 22 Unit water sprayed (kg.water / T tobacco) 107 113 27 46 Tobacco temperature (C) at the outlet of the airlock of the separator. 79.3 79.3 65.6 71.1 Moisture content (% by weight): at the treatment inlet 21.8 21.8 24.5 24.5 at the outlet of the airlock of the separator 6.7 5,6 11,5 10,6 Borgwaldt filling capacity (cc / g at 14% moisture content): at the treatment inlet 4.91 4.91 4.42 4.42 at the outlet of the final product reprocessed 8,34 8,51 7,68 8,06% swelling 70,0 74,0 74,0 82,0% swelling C cn TABLE 4 (continued)

A B

  Particle size distribution: at the outlet of the reprocessed final product + mesh 2 mm (%) 38 - 43 44 - mesh 1,18 mm (%) 28 - 22 23 Glycerine (kg glycerin / kg dry tobacco): & l process input 2.36 2.36 2.06 2.06 & final reprocessed product output 2.19 2.19 1.99 1.93 loss (%) 7.0 7.0 3.0 6.0 Alkaloids (%): & process input 3.05 3.05 3.01 3.01 at the output of the restated final product 2.56 2.48 2.81 2.69 loss (%) 16.0 19 , 0 7.0 11.0 Total sugar (%): at the beginning of the process 9.5 9.5 9.4 9.4 at the end of the final product reprocessed 8.5 8.5 8.8 9, 1 loss (%) 11.0 11.0 6.0 3.0 O .. Co Thus, above examples and respective data tables, being noted that all inflated products are brought back to a humidity level Final 12% of volatile products in the oven, we can easily see that the process of the invention is a tobacco treatment process to better control losses of glycerin, alkaloids and total sugar, ameliori add particle size and fill values

  tobacco, while requiring only a lower

  water and less cooling to bring

  tobacco with ideal storage conditions.

Claims (13)

  1. Improved process for the treatment of tobacco,   characterized in that the tobacco is brought to a preselected humidity level sufficient to obtain an output moisture content of between about 9% and 15% of volatile products in the oven, and filling values of at least equivalent to the filling values of dried tobaccos in a range of higher moisture content   weak, the tobacco thus treated is impregnated with di-   liquid carbon monoxide under a certain pressure and at a certain temperature and the pressure is sufficiently reduced to form solidified carbon dioxide inside the tobacco, and the tobacco impregnated with solidified carbon dioxide is subjected to pressure conditions   and temperature during a limited residence time pre-   selected less than 0.1 seconds in a pre-separator, whereby the solidified carbon dioxide is vaporized and causes the tobacco to swell, providing at the outlet a tobacco with a moisture content of between about 9 and 15% by weight of volatile products in the oven and filling values at least equivalent to the filling values of dried tobacco in a lower moisture content range with a residence time   higher in the pre-separator.   2. Method according to claim 1, characterized in   what this treatment is done with a mixture of gly- ceria and water.   3. Method according to claim 1, characterized   in that the tobacco is treated to have a moisture content about 25% by weight.   4. Method according to claim 1, characterized in that the tobacco is a mixture of 50% flue-cured and 50% burley by weight.   5. Process according to claim 1, characterized in that the stage of impregnation of liquefied carbon dioxide is carried out at a pressure of between approximately 2550 and 2930 kPa and temperatures of between approximately 10 and -5 ° C. 6. Method according to claim 1, characterized   in that at the exit the tobacco has a moisture content of   Viron 11% of volatile products in the oven.   7. Method according to claim 1, characterized in that the tobacco impregnated with solid carbon dioxide is subjected to a vaporization in a pre-separator and   in a separator, the residence time in the pre-sepa-   the amount being between about 0.01 and 0.1 sec.   8. Method according to claim 1, characterized in that the tobacco impregnated with solid carbon dioxide is subjected to a vaporization in a pre-separator and   in a separator, the residence time in the pre-sepa-   of about 0.06 seconds and the residence time   in the separator being about 1.4 seconds.   9. Method according to claim 1, characterized in that the tobacco thus treated is cut at about 12 cuts to the centimeter.   10. Process according to claim 1, characterized in that the inflated tobacco is reprocessed if necessary to bring it to a moisture content of at least 12% by weight of volatile products in the oven.   11. The method of claim 1, characterized in that the tobacco has at the inlet a moisture content of about 22 to 26% by weight before the impregnation with carbon dioxide. liquid carbon.   12. Improved process for the treatment of tobacco,   in that it comprises a treatment of tobacco with a mixture of glycerin and water bringing the moisture content of the tobacco to about 25% by weight, the treated tobacco is impregnated with liquid carbon dioxide at a pressure between about 2550 and 2930 pKa, and at a temperature between about -10 and -5 ° C., the pressure is then sufficiently reduced to form solid carbon dioxide inside the tobacco, and the impregnated tobacco is subjected to solid carbon dioxide   spray in a pre-separator and separator   the residence time in the pre-separator is between about 0.01 and 0.1 seconds, to provide at the outlet a tobacco having a moisture content of about   11% of volatile products in the oven and   pleating at least equivalent to filling values   of dried tobacco in a range of lower moisture   with a longer residence time in the pre- separator.   13. Improved process for the treatment of tobacco,   in that the tobacco is treated to a preselected moisture content sufficient to give the output a tobacco moisture content of between about 9 and 15% oven volatile and   filling at least equivalent to the values of   If the tobacco is treated with a liquefied gas under a certain pressure and at a certain temperature, the pressure is reduced enough to form a solid inside the tobacco. and the solid impregnated tobacco is subjected to pressure conditions   and temperature during a limited residence time pre-   selected less than about 0.1 seconds, from where   As a result, the solid is vaporized to cause the gon-   tobacco with a moisture content of between 9 and 15% of volatile products in the oven and filling values at least equivalent to the filling values of dried tobacco in a range of lower humidity with a time   stay higher in the pre-separator.