SK13312002A3 - Method for improving the filling ability of tobacco - 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 of increasing the fillability of tobacco, such as cut tobacco leaves, ribs or plant tobacco ingredients having a cellular structure, by treating tobacco material which initially contains 8-16% by weight of moisture with a process gas consisting of nitrogen and / or argon; at pressures of 50 to 1000 bar, either in an autoclave or in cascade shifting in multiple autoclaves, followed by heat treatment of the discharged tobacco after decompression.

BACKGROUND OF THE INVENTION

The expansion of tobacco by inert gases and at high pressures, also known as the INCOM expansion method, has shown its advantages over the pressurized treatment of tobacco with carbon dioxide, ammonia or volatile organic gases, and is known, for example, from U.S. Pat. with a moisture content of more than 20% by weight at operating temperatures in the autoclave between 0 ° C and 50 ° C. The pressure reduction takes place over 0.5 to 10 minutes and, in the examples, about 1.3 minutes, wherein the discharged tobacco is subjected to a heat treatment, for example by saturated steam, while expanding.

According to DE 31 19 330 A1, a tobacco material with a reduced moisture content of 10 to 15% by weight is additionally treated with an operating temperature of less than 50 ° C in order to achieve a stronger cooling of the discharged tobacco material when the pressure is reduced. The pressure reduction time is about 1.3 to 2 minutes.

DE 34 14 625 C2 describes a cascade process in which the impregnation temperature of the tobacco is reduced by cooling the process gas before it is fed into the reactor, cooling the autoclave or using the supercooled and liquefied working gas. The pressure reduction time is 0.5 to 10, in particular 1 to 2 minutes. The lowest temperature of the discharged tobacco should be below 0 ° C.

According to DE 39 35 774 C2, the desired low impregnation temperatures of 25 [deg.] C. and 45 [deg.] C. are also achieved in the cascade expansion process by circulating the process gas through the condenser.

Although these known expansion methods achieve good values in terms of increasing the filler capacity of the tobacco and / or the degree of expansion, they are relatively expensive due to the required cooling of the autoclave or autoclaves and the additional cooling of the process gas.

It is an object of the invention to improve the conventional INCOM process and to achieve equally good or better degrees of expansion, independently of the costly cooling-related measures.

SUMMARY OF THE INVENTION

According to the invention, there is therefore provided a method of the above-mentioned type according to the preamble of the claim, characterized in that the decompression is carried out with at least one holding stage whose pressure corresponds to 3 to 60%, preferably 3 to 30% of the original maximum pressure. The system, which is under residual pressure, is carried out so that the tobacco discharge temperature lies in the range of 10 ° C to 80 ° C after a complete pressure reduction.

Surprisingly, it has been found that, at lower tobacco moisture levels in the range of 8 to 16% by weight, the prior art does not lead to optimum expansion results using a lower processing temperature or lower tobacco discharge temperature. Conversely, by heating the system under residual pressure, surprisingly good values could be achieved in terms of the expansion effect or the filling capability, whereby the method advantageously uses compression heat or does not have to be dissipated, thus eliminating the necessary additional autoclave cooling or autoclaves.

Preferably, the pressure reduction from the respective maximum pressure up to the holding stage pressure is performed in an interval of 20 seconds to 5 minutes, while the residual pressure reduction is performed in a range of 3 seconds to 3 minutes. Furthermore, it is expedient for the temperature of the tobacco to be discharged according to the invention that the temperature rise is achieved by residence time, by circulating the gas under residual pressure, by means of a heat exchanger and / or by passing heated gas from another autoclave.

In a further preferred process variant, the high pressure treatment or the sequence of high pressure treatment and heat treatment is performed several times with the same tobacco material.

Particularly good results are obtained when the output moisture of the tobacco material is in the range of 10 to 14% by weight, and further if the subsequent heat treatment of the tobacco material takes place with saturated steam.

The process according to the invention is explained in the following by means of examples.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

To carry out the process according to the invention as well as for comparative tests, a high pressure treatment with a process gas consisting of nitrogen was carried out in a laboratory autoclave with a 2 L payload, using a jacket allowing circulation of the liquid medium to set the desired operating temperatures. The pressure was increased, or the gas supply to the autoclave was from below, the pressure was reduced, or the gas was discharged from the autoclave upwards. A compressor was used to adjust the final pressure, while the tobacco temperature was measured by a thermocouple in the upper section or in the upper half for tobacco filling.

The laboratory post-heat treatment of the tobacco consisted of a conveyor belt or a wire mesh which was operated at a rate of approximately 5 cm / sec. The tobacco web, guided between the guide plates, was further treated with approximately 10 kg / h of saturated steam under an approximately 160 mm wide steam nozzle with a slot-like outlet of approximately 8 mm. Under the conveyor belt, a steam extraction device was located opposite the steam nozzle.

The tobacco test samples thus treated were spread in flat pans and conditioned at 21 ° C and 60% humidity. The fillerability was determined by a Borgwaldt densimeter and the specific volume in ml / g was converted to a nominal humidity of 12% by weight and a nominal temperature of 22 ° C. From the raw sample and the expanded sample data, a relative improvement in fillerability or degree of expansion is calculated according to the formula:

Δ% = (Fe - F _B ) * 100% / F _B (F _B = raw filler, Fp - expandable filler)

To place the tobacco in the autoclave was a PVC tube with a perforated bottom. The gas supply increased during the pressure increase up to a final pressure of 700 bar. 300 g of Virginia Blend tobacco with a moisture content of 12% were used as tobacco. The results of the tests are shown in the following tables, where Ta is the temperature at the discharge of the tobacco subjected to high pressure. In test 1, two holding stages lasting 2 min at 400 and 100 bar were applied in the pressure reduction, and in tests 2 and 3 only one holding stage lasting 2 min or 4 min at 50 bar, respectively. In comparative test no. 4, the pressure reduction occurred immediately, i. j. without maintenance stage, with a pressure reduction time <1 min.

Table 1: Test results

working temperature 60 80 no. Pressure reduction operation Ta (° C) Δ% T _A (° C) Δ% 1 holding stage for 2 min at 400 and 100 bar 16 83 2 holding stage 2 min at 50 bar 15 93 20 90 3 holding stage 4 min at 50 bar 33 93 41 90 4 no (comparison) -25 80 -3 81

The above tests no. 1 to 3 at different pressure values and holding stage times and at two operating temperatures show the autoclave as compared to test no. 4, with a direct pressure reduction, that the residence time at a preselected holding stage (pressure) provided a marked rise in the discharge temperature from -25 ° C or -3 ° C to up to +33 ° C or +41 ° C, and in contrast By prior art theory, increased refillability improvement despite high discharge temperatures.

Example 2

Analogously to Example 1, 150 g of tobacco were applied under high pressure at an autoclave operating temperature of 40 ° C. During the pressure reduction, test no. 5 the holding stage applied for 2 min at 50 bar, and in the holding stage the gas was circulated by means of a circulation pump through a heat exchanger at 80 ° C. The gas supply at the pressure increase and circulation was from above, this time the gas was removed at the holding stage and the pressure was reduced in line. The sealing ring between the upper boundary of the tobacco container and the autoclave hatch ensured immediate entry of the gas into the tobacco container.

Table 2: Test results

working temperature 40 ° C in c. Pressure reduction operation T _A (° C) Δ% 5 holding stage 2 min at 50 bar, circulation through heat exchanger (82 ° C) 10 79 6 no (comparison) -105 69

Example 3

The procedure was analogous to Example 2, during which the pressure was kept constant at 50 bar with a holding stage of 1 min and the heated gas was fed from a second, donor autoclave into the treatment vessel. The donor had a pressure of 100 bar and a working temperature of 80 ° C at a content of 4 L prior to the leakage.

Table 3: Test results

working temperature 40 ° C no. Pressure reduction operation T _A (° C) Δ% 7 holding stage 1 min at 50 bar, donor discharge, pressure 100 bar, working temperature 60 ° C 16 89

Examples 2 and 3 above show, contrary to Example 1, in which heating due to a residence time of a preselected holding stage or preselected pressure presupposes an elevated working temperature that the circulation of Example 2 via a heat exchanger or gas passage from 7 The burst of Example 3 at a constant holding stage or a constant pressure, even at a gas-trapping operating temperature, as the &quot; acceptor &quot; of the labeled processing vessel, leads from 40 ° C to an elevated discharge temperature. In particular, the discharge variant from the donor tank according to Example 3 leads to a significant increase in the filler performance over Comparative Test No. 3. 6 of Example 2.

To interpret the surprising results, heating of the high-pressure tobacco leads to an overexpansion under the autoclave residual pressure, resulting in additional refillability improvements beyond those known in the art. To confirm this assumption, a pressure treatment was carried out in the following Example 4, now without further saturated steam heat treatment, in order to test a possible pre-expansion effect, with direct conditioning of the test samples to be processed. It is true that the improvement of filler without heat treatment is slight, but the following Example 4 shows the complementary filler effect when heated under residual pressure.

EXAMPLE 4 1550 g of tobacco were subjected to high pressure treatment at an autoclave operating temperature of 60 ° C, whereby the tobacco was not further heat treated after complete pressure reduction. In the reduction of pressure, the holding stage was 1 min at 50 bar with heated gas from the second autoclave analogously to Example 3, the donor having a pressure of 200 bar and a working temperature of 80 ° C before the bleed. In comparative test no. 9, the pressure reduction took place immediately and without the holding stage.

Table 4: Test results

working temperature 60 ° C in c. Pressure reduction operation T _A (° C) Δ% 8, holding stage 1 min at 50 bar, donor discharge, pressure 200 bar, working temperature 80 ° C 19 20 9 no (comparison) -69 8

The above results confirm the presumption of even small pre-expansion before further saturated steam treatment when heating the tobacco subjected to high pressure at the residual pressure occurring.

The following Examples 5 and 6 show a further embodiment of the process according to the invention in which the high-pressure treatment or the high-pressure treatment and the subsequent heat treatment are carried out several times with the same tobacco material.

Example 5

Analogous to Example 3, 150 g of tobacco in the first stage at an autoclave operating temperature of 60 ° C, by passing the heated working gas from the donor at a constant pressure holding stage, was subjected to a high pressure treatment. Donor had a pressure of 300 bar and a working temperature of 80 ° C prior to discharge; the holding stage was set to 1 min at 200 bar.

Tobacco material from the first stage, expanded and conditioned according to test no. 10, was used as a starting material for the next high pressure treatment cycle and subsequent heat treatment. High pressure treatment and an autoclave operating temperature of 60 ° C were carried out on 100 g of tobacco, and a pressure reduction step of 1 min at 100 bar was performed. The donor tank had a pressure of 200 bar at an operating temperature of 80 ° C prior to discharge. Results of this test and test no. 10 shows Table 5.

Table 5: Test results

working temperature 60 ° C no. Pressure reduction operation Ta (° C) Δ% 10 holding stage 1 min at 200 bar, donor discharge, pressure 300 bar, working temperature 80 ° C 26 86 11 holding stage 1 min at 100 bar, donor discharge, pressure 200 bar, working temperature 80 ° C 24 116 (ex- pandemic tobacco from exam 10)

Example 6

The procedure was analogous to Example 5, but in this case two identical pressure treatment cycles followed by heat treatment were carried out in succession. The results are shown in the following table.

Table 6: Test results

working temperature 60 ° C no. Pressure reduction operation T _A (° C) Δ. % 12 holding stage 1 min at 100 bar, donor discharge, pressure 200 bar, working temperature 80 ° C 30 103 Double pressure processing with subsequent thermal treatment)

While the expanded tobacco material of Step 1 of Example 5 was used for the reprocessing in Step 2, in this Example 6, the pressure treatment cycle was performed twice in succession before the pressure-subjected tobacco material was subjected to a subsequent heat treatment. Both processes rely on the principle of multiple expansion by repeating the high pressure treatment and subsequent heat treatment sequence, or only the high pressure treatment and subsequent heat treatment only.

Example 5 shows that the effect of the first expansion stage can be further enhanced by the renewed treatment in step 2 to obtain an extremely high filler tobacco material. Example 6 is simpler due to the discharge of the post-heat treatment step, but does not reach the maximum value of Example 5.

Claims (9)

PATENT CLAIMS A method for improving the fillerability of tobacco, in the form of cut tobacco leaves or ribs, or vegetable tobacco ingredients having a cellular structure, treating tobacco material with 8-16% by weight of initial moisture, a process gas consisting of nitrogen and / or argon at pressures of 50 up to 1000 bar, either in one autoclave or in cascade shifting in several autoclaves, followed by heat treatment of the discharged tobacco material after decompression, characterized in that the decompression is carried out with at least one holding stage whose pressure 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 such that the tobacco discharge temperature after complete pressure reduction is in the range of 10 ° C to 80 ° C. 2.. The method of claim 1, wherein the starting moisture of the tobacco material is in the range of 10 to 14% by weight. · Method according to claim 1 (to 2), characterized in that the temperature increase of the system under residual pressure is caused by a residence time. Method according to claim 1 (to 3), characterized in that the temperature increase is caused by the circulation of the gas under residual pressure through a heat exchanger. Method according to claim 3 (claims 1 to 4), characterized in that the temperature increase of the pressurized system is caused by the passing of the heated gas. Method according to claim 1 (to 5), characterized in that the pressure reduction from the respective maximum pressure up to the pressure of the holding stage is carried out in an interval of 20 seconds to 5 minutes. Method according to claim 1 (to 6), characterized in that the reduction of the residual pressure is carried out at intervals of from 3 seconds to 3 minutes. Method according to claim 1 (to 7), characterized in that the high pressure treatment or the sequence of the high pressure treatment and the heat treatment are carried out several times with the same tobacco material. Method according to claim 1 (to 8), characterized in that the subsequent heat treatment of the tobacco material is carried out with saturated steam.