DE10006424A1 - Cut tobacco leaf compressed under inert gas and decompressed at defined pressure in a single heated holding stage - Google Patents

Abstract

The invention relates to a method for improving the filling ability of tobacco, such as cut tobacco leaves, or ribs, or plant tobacco additives with a cell structure, whereby the tobacco material, with an initial water content of 8 to 16 wt %, is treated with a gas, comprising nitrogen and/or argon at pressures from 50 to 1000 bar, either in an autoclave, or in a cascade-like series of several autoclaves and, finally, after completion of a decompression, a thermal after-treatment. The invention is characterised in that the decompression is carried out with at least one holding stage, the pressure of which corresponds to 3 to 60 %, preferably, 3 to 30 % of the original maximum pressure and that the heating of the system under residual pressure is carried out, such that the temperature of the tobacco on withdrawal after the complete release of pressure is in the range 10 to 80 DEG C. The elevation of temperature of the system under residual pressure is effected by a holding stage, a circulation over a heat exchanger and/or passing hot gas over the system, whereby the release of pressure from the maximum pressure to the pressure of the holding stage occurs over a period of 20 seconds to 5 minutes and the release of the residual pressure occurs over a period of 3 seconds to 3 minutes.

Description

The invention relates to a method for increasing the Fillability of tobacco materials, such as. B. cut Tobacco leaves, ribs or herbal tobacco additives with cell structure by treatment of 8 to 16% by weight Tobacco material with initial moisture content with a Nitrogen and / or argon existing treatment gas Pressures from 50 to 1,000 bar in either an autoclave or in cascade-like switching in several autoclaves and subsequent thermal aftertreatment of the discharged tobacco material after decompression.

The tobacco expansion with inert gases under high pressures, which is also known as the INCOM expansion process, has its own Advantages over the pressure treatment of tobacco with Carbon dioxide, ammonia or volatile organic gases and is shown for example from US 4,289,148 known that tobacco material with a moisture content of more than 20% by weight at working temperatures in the autoclave between 0 and 50 ° C is treated. The pressure reduction takes place within 0.5 to 10 minutes and in the examples given 1.3 minutes, after which the tobacco discharged one thermal aftertreatment z. B. subjected to saturated steam becomes and inflates itself.

According to DE 31 19 330 A1, the temperature is additionally below 50 ° C lying working temperature with a tobacco material reduced humidity of 10 to 15 wt .-% used to a stronger cooling of the tobacco material to be discharged to achieve while relaxing. The pressure reduction times are here at 1.3 to 2 minutes.  

DE 34 14 625 C2 discloses a cascade process, according to which by cooling the treatment gas before the application the reactor, cooling the autoclave or using a supercooled and liquefied treatment gas low tobacco impregnation temperature. The Pressure reduction times are 0.5 to 10, in particular 1 to 2 Minutes. The minimum temperature of the tobacco discharged should be below 0 ° C.

Similarly, according to DE 39 35 774 C2 at one cascade-like expansion process by circulating the Treatment gas via a cooler the required low impregnation temperatures of 25 or 45 ° C achieved.

Good values for these well-known inflation processes with regard to increasing the filling capacity of tobacco or the degree of swelling are achieved because of the required cooling of the autoclave and or because the additional cooling of the treatment gas relatively expensive.

The invention is based, so far the task INCOM process to improve and independent of elaborate cooling measures equally good or better To achieve swellings.

According to the invention is therefore a method of the beginning mentioned type according to the preamble claim proposed, which is characterized in that the Decompression carried out with at least one holding level whose pressure is 3 to 60%, preferably 3 to 30% of the corresponds to the original maximum pressure and that the  Heating the system under residual pressure in this way is carried out after the tobacco discharge temperature complete pressure reduction in a range from 10 to 80 ° C.

Surprisingly, it has been shown that at low Tobacco moisture in the range of 8 to 16 wt .-% the previous one Teaching, a low treatment temperature or low To provide discharge temperature, not at optimal Results in swelling. Rather, only through the Heating of the system under residual pressure is amazing good values with regard to the blowing effect or Filling ability can be achieved, the procedural Compression heat is advantageously used or not must be dissipated and additional cooling of the or the autoclave is omitted.

The pressure reduction is preferably dependent on the respective Maximum pressure up to the pressure of the holding level in one Interval of 20 seconds to 5 minutes, during the reduction of the residual pressure in an interval of 3 Seconds to 3 minutes. Furthermore, it is to achieve the invention Expedient tobacco discharge temperature that the Temperature increase through a holding time, through circulation of the gas under residual pressure via a Heat exchanger and / or by overflowing heated gas from another autoclave.

In a further preferred method variant, the High pressure treatment or the sequence  High pressure treatment and thermal treatment several times performed the same tobacco material.

Particularly good results are achieved if the Initial moisture content of the tobacco material in the range of 10 to 14% by weight and also when the thermal aftertreatment of the tobacco material is done with saturated steam.

The method according to the invention is described below explained by examples.

example 1

To carry out the method according to the invention as well high pressure treatment was used for the comparative tests with a treatment gas consisting of nitrogen in a laboratory autoclave with a used content of 2 l performed, whereby to set the desired Working temperatures a jacket for circulation liquid media served. The pressure build up or the Gas supply to the autoclave was from below, the Pressure reduction or the gas discharge from the autoclave upwards. A compressor was used to adjust the final pressure used while the tobacco temperature in the upper segment or in the upper half of the tobacco fill with a Thermocouple was measured.

The laboratory device for the thermal aftertreatment of the Tobacco consisted of a permeable conveyor belt or Wire mesh running at a speed of about 5 cm / s was operated. The one guided between baffles Tobacco fleece was placed under an approximately 160 mm wide steam nozzle  with slot-like outlet opening of about 8 mm with about 10 kg / h saturated steam aftertreated. Below the There was a conveyor belt opposite the steam nozzle Vapor extraction device.

The tobacco samples treated in this way were spread out in flat dishes and conditioned at 21.degree. C. and 60% relative humidity. The filling capacities were determined with a Borgwaldt densimeter and the specific volume in ml / g converted at a nominal moisture of 12% by weight and a nominal temperature of 22 ° C. From the data of the untreated comparison and the expanded pattern, the relative improvement in filling capacity or the degree of swelling is calculated according to:

Δ% = (F _E - F _B ). 100% / F _B

(F _B = filling ability untreated, F _E = filling ability expanded)

A PVC pipe with an inserted sieve bottom was used to hold the tobacco in the autoclave. The gas supply during the pressure build-up took place up to a final pressure of 700 bar. 300 g of Virginia blend with an operating moisture content of 12% were used as tobacco. The test results are shown in the following tables, where T _{A means} the discharge temperature of the high-pressure treated tobacco. In test 1, two holding steps of 2 minutes each at 400 and 100 bar were used in the pressure reduction and in tests 2 and 3 only one holding step of 2 minutes and 4 minutes at 50 bar, respectively. In comparative experiment no. 4, the pressure was reduced immediately, that is to say without a holding step, in a pressure reduction time of <1 min.

Table 1

Test results

The above experiments No. 1 to 3 at different pressure and time values of the holding level and two working temperatures of the autoclave show in comparison to experiment No. 4 direct pressure reduction that the holding times at preselected Holding level (pressure) a significant increase in Discharge temperature from -25 ° C or -3 ° C up to + 33 ° C or + 41 ° C and in contrast to the previous technical Teach an increased filling capacity improvement despite high Discharge temperatures resulted.

Example 2

The high pressure treatment with 150 g was analogous to Example 1 Tobacco at an autoclave working temperature of 40 ° C carried out. During the pressure reduction was in the test No. 5 applied a holding step of 2 min at 50 bar and at the holding time the gas with the help of a circulation pump a heat exchanger with a temperature of 80 ° C circulates. The gas supply line when building up pressure and when This time the gas was drained from above  Holding level and pressure reduction down. A sealing ring between the upper limit of the tobacco insert and the autoclave lid ensured the immediate Entry of the gas into the tobacco insert.

Table 2

Test results

Example 3

The procedure was analogous to Example 2, but during Pressure reduction a holding level of 1 min at 50 bar constant regulated and heated gas from a second, as Donator designated autoclave in the treatment vessel was initiated. The donor had before overflowing a pressure of 100 bar and a working temperature of 80 ° C with a content of 4 l. The gas supply line at Pressure build-up and overflow was now from below, the gas discharge at holding level and pressure reduction upwards.

Table 3

Test results

Examples 2 and 3 above show, in contrast to Example 1, in which the heating by holding time at preselected holding level or preselected pressure increased working temperature presupposes that the circulation according to example 2 via heat exchanger or gas transfer from the donor according to Example 3 at a constant holding level or constant pressure even at a working temperature of gas-absorbing, designated as acceptor Treatment vessel from 40 ° C to an elevated Lead discharge temperature. In particular the variant of Overflow from the donor container according to Example 3 leads to a significant increase in Filling capacity improvement compared to the comparison test No. 6 of Example 2.

To interpret the surprising results can be suspected that the warming of the high pressure treated tobacco leads to pre-expansion in the autoclave under residual pressure, which results in additional fillability improvements result that are not with the known procedure let achieve. To confirm this assumption, the following example 4 the pressure treatment now without thermal aftertreatment with saturated steam to to examine a possible effect of a pre-expansion, whereby the treated samples were air-conditioned directly. Though are the fillability improvements without thermal Post-treatment is minor, but is shown below Example 4 an additional filling effect in Heating under residual pressure.  

Example 4

150 g of tobacco were subjected to high pressure treatment at a Subjected to the working temperature of the autoclave of 60 ° C, the tobacco not after the complete pressure reduction was thermally treated. When pressure was reduced a holding level of 1 min at 50 bar with overcurrents of heated gas from a second autoclave analogous to example 3, the donor having a pressure of overflow before 200 bar and a working temperature of 80 ° C. In which Comparative experiment no. 9, the pressure reduction took place immediately and without holding level.

Table 4

Test results

The above results confirm the assumption of an if even slight pre-expansion before thermal Aftertreatment with saturated steam when the bottom is heated Residual pressure standing high pressure treated tobacco.

Examples 5 and 6 below show another Embodiment of the method according to the invention, in which the high pressure treatment or the high pressure treatment and the thermal aftertreatment several times with the same Tobacco material is carried out.  

Example 5

150 g tobacco were in a first stage at a Working temperature of the autoclave of 60 ° C analogous to the example 3 by overflowing heated treatment gas from the Donator at a holding level with constant pressure Subjected to high pressure treatment. The donor had before Overflow a pressure of 300 bar and one Working temperature of 80 ° C; the holding level was 1 min set at 200 bar.

That expanded and conditioned after experiment No. 10 Tobacco material from the first stage was called Starting material for another treatment cycle High pressure treatment and thermal aftertreatment used. The high pressure treatment was 100 g tobacco and at an autoclave working temperature of 60 ° C was carried out and a pressure drop of Provided for 1 min at 100 bar. The donor container had before the overflow a pressure of 200 bar at a Working temperature of 80 ° C. The results of this Experiment 5 and Experiment No. 10 are shown in Table 5.  

Table 5

Test results

Example 6

The procedure was analogous to Example 5, but now two identical pressure treatment cycles in a row and then a final thermal aftertreatment were carried out. The results are as follows.

Table 6

Test results

While the level 1 expanded tobacco material Example 5 used for re-treatment in step 2 in this example 6 is the pressure treatment cycle done twice in a row and only then pressure treated tobacco material of thermal After-treatment has been delivered. Both procedures are based on the principle of multiple expansion  Repeat the sequence of high pressure and thermal Follow-up treatment or just a repeated one High pressure treatment and final thermal Aftercare.

Example 5 shows that the effect of the first Expansion stage through re-treatment in stage 2 can further increase and a tobacco material extremely high Filling capacity is obtained. Example 6 is by the Eliminating a post-treatment step is easier, however does not reach the maximum value of example 5.

Claims (9)

1. A method for improving the filling capacity of tobacco, such as cut tobacco leaves or ribs or vegetable tobacco additives with a cell structure, by treating the tobacco material having 8 to 16% by weight of starting moisture with a treatment gas consisting of nitrogen and / or argon at pressures of 50 up to 1,000 bar in either an autoclave or, in the case of a cascade-like circuit, in several autoclaves and subsequent thermal aftertreatment of the tobacco material discharged after decompression, characterized in that the decompression is carried out with at least one holding stage, the pressure of which is 3 to 60%, preferably 3 to 30% corresponds to the original maximum pressure and that the heating of the system under residual pressure is carried out in such a way that the tobacco discharge temperature is in a range from 10 to 80 ° C. after the pressure has been completely reduced. 2. The method according to claim 1, characterized in that the initial moisture of the tobacco material in the range of 10 up to 14% by weight. 3. The method according to claim 1 to 2, characterized in that that the temperature increase of under residual pressure standing system is caused by a hold time. 4. The method according to claim 1 to 3, characterized in that the temperature increase by circulating the under  Residual pressure of standing gas via a heat exchanger is effected. 5. The method according to claim 1 to 4, characterized in that the temperature increase of under residual pressure system by overflowing heated gas is effected. 6. The method according to claim 1 to 5, characterized in that the pressure reduction from the respective maximum pressure to Printing the hold level in an interval of 20 seconds up to 5 minutes. 7. The method according to claim 1 to 6, characterized in that that the reduction of the residual pressure in an interval of 3 Seconds to 3 minutes. 8. The method according to claim 1 to 7, characterized in that that the high pressure treatment or the sequence out High pressure treatment and thermal treatment several times is carried out with the same tobacco material. 9. The method according to claim 1 to 8, characterized in that the thermal after-treatment of the tobacco material done with saturated steam.