Technical Field
[0001] The present invention relates to a method and an apparatus for expanding tobacco
material. From eg.
EP-A-0 242 873 is a method and a device known wherein tobacco material is moistened and swelled
in an expander and subsequently fed to a cyclone.
Background Art
[0002] Tobacco material (such as stems), which is separated from tobacco leaves, constitutes
20-30% by weight of tobacco leaves. Shreds of stems (cut stems) are used as tobacco
shreds together with cut laminas of tobacco leaves, from which the stems are removed,
for the purpose of utilizing tobacco material. In general, cut stems are obtained
by rolling and shredding stems. The cut stems are subjected to an expanding process
including conditioning and drying, so as to increase filling capacity and combustibility
and soften the smoking taste. Conventional processes of expanding cut stems and techniques
related thereto will be described below.
[0003] Japanese Patent No.
4031115 discloses a method and an apparatus for applying a conditioning agent to tobacco
material. This apparatus has a structure in which nozzles are provided in impeller-like
projections such as carrying pins, including a rotary winnowing roll (hereinafter
referred to as a winnower). According to this method, injection of a conditioning
agent is performed prior to drying, by spraying steam from the nozzles to tobacco
material falling freely, using the above-described apparatus, and then the tobacco
material is conveyed to a drying process section.
[0004] The specification of
U. S. Patent No. 4,766,912 discloses a method and an apparatus for expanding tobacco material. According to
the U. S. patent, the apparatus comprises a steam spraying device including a vibratory
conveyor for conveying tobacco material and conveys the tobacco material by spraying
steam via holes in a lower surface of the vibratory conveyor to the material being
conveyed while vibrating the material, and a fluidized bed dryer, in an attempt to
improve filling capacity of the tobacco material. The specification of
U. S. Patent No. 2,802,334 discloses an apparatus comprising a closed transport duct formed as a vibratory conveyor
including an inlet and an outlet, a supply device for supplying steam or a heated
gas to a bottom of the transport duct, and spraying holes, in relation to the above-mentioned
U. S. Patent.
[0005] Jpn. Pat. Appln. KOKAI Publication No.
62-3778 discloses a method and an apparatus for drying tobacco in which two stages of pneumatic
conveying flush drying process are continuously performed. More specifically, tobacco
material is supplied into a high-temperature gas medium and is transported to a first
separation device via a first duct, where the material and the gas medium are separated
from each other. The high-temperature gas medium is supplied to a second duct, and
the separated tobacco material is supplied to a downstream part of the first separation
device. The tobacco material and the high-temperature gas medium are transported to
the second separation device via the second duct, where the material and the gas medium
are separated from each other. By thus letting the tobacco material pass through two
drying sections, it is possible to (1) reduce the time during which the tobacco material
is continuously exposed to the high-temperature gas medium, (2) solve the problem
that overheating occurs in an excessively intensive manner, and (3) improve drying
efficiency by difference in relative velocity as a result of the tobacco material
being accelerated at two stages. The publication further discloses using a separation
device for reducing the time during which the tobacco material and the high-temperature
gas medium contact each other.
[0006] The above-mentioned conventional techniques, however, have problems as will be described
below.
[0007] In the apparatus disclosed in Japanese Patent No.
4031115, the transit time of the tobacco material and the steam in the apparatus is short,
judging from the descriptions on the velocity of free fall, the effective height of
the apparatus, and the number of revolutions (200 rpm) of the winnower. Since the
tobacco material contacts the steam for a short time, moistening and swelling is not
sufficiently performed. Further, since the winnower includes a rotating part, deterioration
of components is fast. Moreover, the tobacco material easily becomes tangled in the
rotating part. The tangled tobacco material causes a significant effect on the smoking
taste and physical properties.
[0008] U. S. Patent No. 4,766,912 discloses a structure of causing the steam spraying device to convey the material
by vibration and spray steam from the holes in the bottom surface of the vibratory
conveyor. Since deterioration of driving components caused by the vibration is fast,
this structure is inferior in terms of durability. Spraying of steam from the bottom
surface of the vibratory conveyor uses perforations with diameters of as small as
0.8 mm, for example. Accordingly, the perforations are clogged with scale (inorganic
substances such as calcium carbonate) contained in the steam and fine powder of tobacco
material. Clogging of the perforations causes fluctuation in the amount of steam and
makes the quality of processed tobacco material unstable.
[0009] In the technique disclosed in Jpn. Pat. Appln. KOKAI Publication No.
62-3778, since two stages of pneumatic conveying flush drying process are performed using
two separation devices connected in series, drying of tobacco material advances in
each stage. Due to the characteristics of the apparatus, however, the time during
which the tobacco material and high-temperature wet air or a superheated steam flow
contact becomes very short. As a result, it is difficult to sufficiently moisten or
swell the tobacco material. Further, the tobacco material is deposited on a mesh screen
of the separation devices, and thereby an exhaust system is blocked. This obstructs
continuous operation of the separation devices.
Disclosure of Invention
[0010] The present invention provides a method for expanding tobacco material capable of
increasing filling capacity of the tobacco material compared to conventional techniques.
[0011] The present invention provides an apparatus for expanding tobacco material with a
simple structure capable of increasing filling capacity of the tobacco material compared
to conventional techniques and achieving continuous processing and high durability.
[0012] According to a first aspect of the present invention, there is provided a method
for expanding tobacco material, comprising: moistening and swelling tobacco material
by swirling tobacco material together with a steam flow at temperatures of 100-160°C
in contact therewith in a cyclone; and drying the tobacco material after being moistened
and swollen.
[0013] According to a second aspect of the present invention, there is provided an apparatus
for expanding tobacco material, comprising: a cyclone including an inlet, a vent,
and an outlet, the cyclone being configured to moisten and swell tobacco material
by swirling tobacco material together with a steam flow at temperatures of 100-160
degrees Celsius in contact therewith; a supply duct connected to the inlet of the
cyclone; an exhaust duct connected to the vent of the cyclone; a steam supply section
connected to the supply duct; a tobacco material supply section connected to the supply
duct in a position between a connection part of the steam supply section and the inlet
of the cyclone; and a dryer to which tobacco material discharged from the outlet of
the cyclone is conveyed and configured to dry the tobacco material.
Brief Description of Drawings
[0014] FIG. 1 is a schematic diagram illustrating an apparatus for expanding tobacco material
according to an embodiment.
Best Mode for Carrying Out the Invention
[0015] A method for expanding tobacco material according to an embodiment of the present
invention will now be described.
(First Step)
[0016] Tobacco material is moistened and swollen by swirling the tobacco material with a
steam flow at temperatures of 100-160°C in contact therewith.
[0017] Cut stems, for example, can be used as the tobacco material. Cut stems are obtained
by separating rod-like stems from tobacco leaves and rolling and shredding the rod-like
stem material according to a fixed method. More specifically, rod-like stem material
is conditioned to a moisture content of 15-50% by weight, preferably 20-40% by weight,
for example. The conditioned rod-like stem material is rolled by a rolling mill with
0.5 to 1.2 mm roll pitches, for example, and is shredded into 0.1-0.3 mm widths, and
thereby cut stems are produced.
[0018] Steam at temperatures of 100-160°C can moisten and swell the tobacco material without
drying the tobacco material. Preferably, the temperature of the steam should be in
the range of 110-150°C.
[0019] Swirling of tobacco material together with a steam flow is performed by introducing
the tobacco material into a cyclone, for example, together with the steam flow. The
residence time by the swirling should preferably be 0.5-5 seconds.
[0020] By letting the tobacco material contact the steam flow at the above-mentioned temperature
in the above-mentioned residence time, condensation heat transfer of the steam to
the tobacco material occurs. The condensation heat transfer causes increase in moisture
and temperature (goods temperature) of the tobacco material, which makes tobacco tissues
flexible and causes moistening and swelling. When the tobacco material contacts the
steam flow at the above-described temperature in the above-described residence time,
the moistened and swollen tobacco material does not dry and increases in moisture
content to a level equal to a level before contacting the steam flow, or by 5% by
weight or less.
(Second Step)
[0021] The moistened and swollen tobacco material is dried, and thereby expanded.
[0022] Drying can be performed by letting the tobacco material contact a superheated steam
flow or a heated air flow.
[0023] The superheated steam flow should preferably have a temperature higher than the temperature
of the steam of the first step. By thus letting the superheated steam flow have a
temperature higher than the temperature of the steam of the first step, the moistened
and swollen tobacco material can be efficiently dried. The superheated steam flow
should preferably have a temperature higher than the temperature of the steam of the
first step, within the range of temperatures of 160-300°C. When the temperature of
the superheated steam is 160°C, for example, the temperature of the steam of the first
step is set to a temperature less than 160°C, and the temperature of the superheated
steam is set to be higher than the temperature of the steam. Preferably, the temperature
of the superheated steam should be within the range of 180-280°C.
[0024] A variety of existing approaches can be adopted in order to let the moistened and
swollen tobacco material contact the superheated steam flow. In particular, the tobacco
material should preferably be swirled together with the superheated steam flow. Swirling
can be performed using a cyclone, for example. The residence time by the swirling
should preferably be 2-15 seconds.
[0025] After the drying process, the moisture content of the tobacco material can be reduced
to 3-15% by weight, for example.
[0026] According to the above-described method for expanding tobacco material of the present
embodiment, by swirling tobacco material together with a steam flow at temperatures
of 100-160°C in contact therewith, the tobacco material (such as cut stems) can be
made into contact with the steam in a dispersed state without being damaged. As a
result, the tobacco material can be moistened and swollen efficiently. After that,
the moistened and swollen tobacco material is dried. Thereby, expanded tobacco material
(such as expanded cut stems) with high filling capacity, compared to the conventional
one obtained by directly drying conditioned tobacco material, can be obtained. By
letting the moistened and swollen tobacco material contact heated air, preferably
a superheated steam flow (in particular, at a temperature higher than the temperature
of the steam of the preceding step, preferably a superheated steam flow within the
range of temperatures of 160-300°C) during drying of the tobacco material, the filling
capacity of the tobacco material can be further increased. By reducing the moisture
content of the dried tobacco material to a level lower than 12% by weight, expanded
tobacco material with remarkably increased filling capacity can be obtained.
[0027] When the tobacco material swirls together with the steam flow in contact therewith
in the moistening and swelling step, the time required for moistening and swelling
can be arbitrarily controlled by adjusting the amount of steam and the amount of air
discharge. As a result, the filling capacity of the cut stems can be freely controlled
by the drying process.
[0028] An apparatus for expanding tobacco material according to an embodiment will now be
described with reference to FIG. 1.
[0029] A cyclone 1 includes an inlet 2 on a sidewall, a vent 3 at an upper part, and an
outlet 4 at a bottom part. One end of a supply duct 5 is connected to the inlet 2
of the cyclone 1. One end of an exhaust duct 6 is connected to the vent 3 of the cyclone
1. A dryer 7 is arranged adjacent to the cyclone 1.
[0030] A steam supply tube 8 is connected to the other end of the supply duct 5. The steam
supply tube 8 includes an on-off valve 9 which adjusts the amount of supply of steam.
A heater 10 is arranged in the supply duct 5 in a position between a connection part
of the steam supply tube 8 and the inlet 2 of the cyclone 1.
[0031] A tobacco material supply section 11 is connected to the supply duct 5 in a position
between the heater 10 and the inlet 2 of the cyclone 1 via a first air locker 12.
[0032] The outlet 4 of the cyclone 1 is connected to a discharge duct 13, and a second air
locker 14 is interposed in the discharge duct 13. One end of a transportation member,
such as a vibratory conveyor 15, is positioned on the side of the discharge duct 13
of the cyclone 1, and the other end is positioned on the side of the dryer 7. The
vibratory conveyor 15 conveys tobacco material discharged from the cyclone 1 to the
dryer 7. A belt conveyor may be used instead of the vibratory conveyor as the transportation
member. When the dryer is a pneumatic conveying dryer including a duct in which superheated
steam circulates, the discharge duct 13 of the cyclone 1 may be directly connected
to the duct of the dryer.
[0033] A drain separator 16 and an exhaust fan 17 are connected in this order to the exhaust
duct 6 from the vent 3 of the cyclone 1. The other end of the exhaust duct 6 is made
open so as to discharge steam circulating therein to the outside, or connected to
the dryer 7 via a branch duct 18 so as to be reused as a drying source of the dryer
7.
[0034] A diaphragm valve 19 is arranged in the branch duct 18. A pressure gauge 20 is connected
to the branch duct 18 in a position on the side of the dryer 7 from the diaphragm
valve 19. An aperture of the diaphragm valve 19 is controlled on the basis of pressure
detection data (pressure detection signal) from the pressure gauge 20.
[0035] A method for expanding tobacco material using the apparatus for expanding tobacco
material shown in FIG. 1 will now be described.
[0036] Tobacco material (such as cut stems) is prepared. The cut stems are obtained by conditioning
rod-like stem material to a moisture content of 20-40% by weight (wet basis), rolling
the conditioned stem material using a rolling mill with 0.5-1.2 mm roll pitches, and
then shredding the rolled stem material into 0.1-0.3 mm widths.
[0037] Dry saturated steam at a gauge pressure of 1-7 bars is sprayed into the supply duct
5 from the steam supply tube 8. The steam flow is heated by the heater 10 of the supply
duct 5 as necessary. After that, the cut stem s are continuously supplied to the supply
duct 5 from the tobacco material supply section 11 via the first air locker 12. By
driving the discharge fan 17 in advance, the cut stems flow into the cyclone 1 from
the supply duct 5 together with the steam flow at temperatures of 100-160°C, and swirl
together with the steam flow. In this case, the cut stems increase in moisture content
to a level equal to a moisture level before the steam is supplied, or by 5% by weight,
and is sufficiently moistened and swollen. Preferably, the circulation time in the
supply duct 5 and the swirling time in the cyclone 1 should be 0.5-5 seconds, for
example.
[0038] After the swirling, the cut stems are separated from the steam flow. The separated
cut stems are discharged to the vibratory conveyor 15 via the second air locker 14
from the discharge duct 13 connected to the outlet 4 of the cyclone 1. When the exhaust
fan 17 is driven, the steam flow is discharged to the exhaust duct 6 from the outlet
3 of the cyclone 1, from which the steam flow is discharged to the outside. While
the steam flow circulates in the exhaust duct 6, water condensed in the steam flow
is discharged from the drain separator 16.
[0039] The moistened cut stems are conveyed to the dryer (pneumatic conveying dryer, for
example) 7 via the vibratory conveyor 15. The moistened cut stems are dried in the
pneumatic conveying dryer 7, and thereby expanded. Drying in the pneumatic conveying
dryer 7 can be performed using a superheated steam flow or a heated air flow. The
superheated steam flow should preferably have a temperature higher than that of the
steam supplied to the cyclone 1, within the range of temperatures of 160-280°C.
[0040] When the steam exhausted from the cyclone 1 is used as a part of the superheated
steam of the pneumatic conveying dryer 7, an aperture of the diaphragm valve 19 arranged
in the branch duct 18 is controlled on the basis of pressure detection data (pressure
detection signal) from the pressure gauge 20, and a desired amount of steam flow circulating
in the branch duct 18 is introduced into the pneumatic conveying dryer 7.
[0041] The obtained expanded cut stems have a moisture content of 3-15% by weight. The expanded
cut stems have filling capacity of 580-750 cc per 100 g, and can improve the filling
ability by approximately 30-70% compared to the filling capacity (450 cc per 100 g)
of undried cut stems immediately after shredding.
[0042] In a step of drying cut stems in a system of a second cyclone 21 and a second circulation
duct 25, when the moisture content has dropped to 10% or less by weight, for example,
it is permitted to condition the cut stems by a known method, for example, by spraying
water.
[0043] As described above, according to the apparatus for expanding tobacco material of
the present embodiment, by performing moistening of the tobacco material (such as
cut stems) using the cyclone 1 and the supply duct 5 connected to the cyclone 1, the
cut stems can be efficiently contacted with a steam flow in a dispersed state, without
being damaged. Generation of a swirling flow by the cut stems and the steam flow in
the cyclone 1 makes it possible to increase the residence time of the cut stems in
the steam flow even if the apparatus is reduced in size. As a result, the cut stems
can be efficiently moistened and swollen, and by causing the pneumatic conveying dryer
7 to dry the cut stems thereafter, expanded cut stems with increased filling capacity
can be obtained.
[0044] Since the cyclone 1 and the supply duct 5 installed in the expanding apparatus have
an extremely simplified structure which does not require a rotary component or a mesh
screen as in conventional apparatuses, the apparatus is excellent in durability and
is capable of performing the steps of moistening and drying of the cut stems continuously.
[0045] Further, by letting the branch duct 18 divided from the exhaust duct 6 connected
to the vent 3 of the cyclone 1 and connecting the branch duct 18 to the pneumatic
conveying dryer 7 (such as a pneumatic conveying dryer which uses a superheated steam
flow), steam circulating in the branch duct 18 from the cyclone 1 via the exhaust
duct 6 can be efficiently used as a part of superheated steam of the dryer 7, thereby
achieving energy-saving operation.
[0046] The example of the present invention will now be described in detail with reference
to the apparatus for expanding tobacco material shown in FIG. 1.
(Example 1; Comparative Example)
[0047] In Example 1, a drying step was performed using the pneumatic conveying dryer 7 of
FIG. 1.
[0048] Rod-like stem material of flue-cured tobacco of 100% by weight, for example, was
conditioned by a method known to a person skilled in the art, e.g. by spraying water
or steam, to a moisture content of 37% by weight, for example. Cut stems as tobacco
material was prepared by causing a pair of rollers arranged at an interval of 0.8
mm to roll the rod-like stems, and then shredding the stems into 0.2 mm widths.
[0049] The cut stems were continuously introduced into the pneumatic conveying dryer 7 at
a flow quantity of 25 kg/time by wet weight basis. The pneumatic conveying dryer is
formed of a duct measuring approximately 100 mm in diameter and approximately 22 m
in length, and a cyclone measuring approximately 460 mm in diameter and including
a separator with an effective height of approximately 1.4 m. The dried medium circulating
in the duct at a slot of the cut stems is adjusted by supplying 40 kg/time of saturated
steam at a gauge pressure of 2 bars (0.2 MPa), such that the steam ratio becomes 90%
by volume (which can be regarded as being approximately equal to a superheated steam
flow) and the rate of flow becomes 25 m/s. That is, the cut stems circulated in the
duct together with the superheated steam flow at 280°C, swirled and dried in the cyclone
together with the superheated steam flow, and were thereby expanded. The residence
time by the swirling was 5 seconds.
(Examples 2 and 3; Comparative Example)
[0050] Cut stems were dried and expanded in a manner similar to that of Example 1, except
that the temperatures of the superheated steam flow circulating together with the
cut stems were set to 260 and 210°C, respectively, in the duct of the pneumatic conveying
dryer 7.
(Example 4; Embodiment)
[0051] In Example 4, the apparatus for expanding tobacco material shown in FIG. 1 was used.
[0052] Cut stems (37% by weight in moisture content and 0.2 mm in width) subjected to a
process similar to that of Example 1 was prepared.
[0053] Saturated steam at a gauge pressure of 5 bars (0.5 MPa) was injected into the supply
duct 5 (approximately 50 mm in diameter and approximately 0.6 m in length) arranged
in a horizontal state from a nozzle part (3 mm in diameter) of the steam supply tube
8 at a flow quantity of approximately 40 kg/time. The cut stems were continuously
introduced into the supply duct 5 via the first air locker 12 from the tobacco material
supply section 11 at a flow quantity of 36 kg/time by wet weight basis. In this case,
the steam flow circulating in the supply duct 5 was saturated steam at a temperature
of 150°C. By driving the exhaust fan 17 in advance, the cut stems were introduced
into the cyclone 1 (approximately 250 mm in diameter and including a separator with
an effective height of approximately 0.75 m) together with the steam flow from the
supply duct 5, and swirled together with the steam flow, and were thereby moistened
and swollen. The transit time in the supply duct 5 and the cyclone 1 (residence time
was 1.5 seconds) was approximately 1.8 seconds. The moisture content of the moistened
cut stems was 39% by weight, which had increased by 2% by weight from the moisture
content (37% by weight) at the time of conditioning.
[0054] After that, the moistened cut stems discharged from the cyclone 1 were continuously
introduced into the pneumatic conveying dryer 7 via the vibratory conveyor 15, and
the moistened cut stems were dried by a superheated steam flow under conditions similar
to those of Example 1, and thereby expanded. The temperature of the superheated steam
was set to 280°C.
(Example 5; Embodiment)
[0055] Moistened cut stems were dried and expanded in a manner similar to that of Example
4, except that the temperature of the superheated steam flow circulating together
with the cut stems was set to 215°C, in the duct of the pneumatic conveying dryer
7.
[0056] The expanded cut stems obtained in Examples 1-5 were stored (conditioned) for 1 week
in a constant temperature and humidity room at a temperature of 22.0°C and a relative
humidity of 60%. After the equilibrium moisture content was obtained, the filling
capacity was measured.
[0057] The filling capacity indicates the filling ability when the tobacco shreds are filled
in rolling paper so as to be smoked. The measurement was performed using D51 from
Borgwaldt, Germany. The examination was performed by measuring the filling capacity
of the expanded cut stems 5 times repeatedly and calculating an average value.
[0058] The moisture content of the expanded cut stems was obtained as an average value of
5 points calculated from difference in weight before and after drying, after putting
approximately 2 g of expanded cut stems into a weighing bottle and letting the expanded
cut stems dry for 1 hour in a natural convection oven at a temperature of 100°C.
[0059] The filling capacity and the moisture content of the expanded cut stems of Examples
1-5 are shown in Table 1.
Table 1
|
Whether moistening was performed and steam temperature thereof |
Superheated steam temperature (°C) during drying |
Moisture content (% by weight) of cut stems |
Filling capacity (cc/100g) |
During conditioning |
After drying |
Example 1 |
No |
280 |
37.0 |
5.0 |
565 |
Example 2 |
No |
260 |
37.0 |
6.0 |
560 |
Example 3 |
No |
210 |
37.0 |
13.0 |
535 |
|
|
|
During moistening |
After drying |
|
Example 4 |
Yes (150°C) |
280 |
39.0 |
7.0 |
620 |
Example 5 |
Yes (150°C) |
215 |
39.0 |
12.0 |
610 |
[0060] As clear from Table 1, in Examples 4 and 5, in which the conditioned cut stems were
moistened by steam at a temperature of 150°C before being dried by a superheated steam
flow, the filling capacity increases (improves) by 50 cc per 100 g or greater, compared
to Examples 1-3, in which the cut stems were not moistened by a steam flow before
being dried by a superheated steam flow, at every moisture level.
[0061] Improvement in filling capacity by 50 cc per 100 g or greater corresponds to approximately
10% in percentage. Since the filling capacity of unprocessed cut stems before being
dried (after being conditioned and shredded) is 410 cc per 100 g, the expansion coefficient
had increased to 51% in Example 4, for example, which demonstrates that the present
method is an excellent expanding method.
(Example 6; Comparative Example)
[0062] Rod-like stem material obtained by mixing 70% by weight of flue-cured tobacco and
30% by weight of barley tobacco was conditioned to a moisture content of 37% by weight,
by a method known to a person skilled in the art, e.g. by spraying water or steam.
Cut stems as tobacco material were prepared by causing a pair of rollers arranged
at an interval of 0.8 mm to roll the rod-like stems, and then shredding the rolled
stems into 0.2 mm widths.
[0063] A moistening device including a tunnel-type vibratory conveyor and including a plurality
of holes, from which steam was sprayed, in a lower surface of the conveyor was prepared.
External dimensions of this device were 3800 mm in length, 400 mm in width, and 1500
mm in height, and a steam spray section was 2400 mm in length.
[0064] After that, the cut stems were supplied onto the tunnel-type vibratory conveyor of
the moistening device at 320 kg/time by wet weight basis. While the cut stems are
conveyed via the tunnel-type vibratory conveyor, saturated steam at a gauge pressure
of 5 bars (0.5 MPa) at a temperature of 150°C is sprayed toward the cut stems from
a plurality of holes in the lower surface of the conveyor at 130 kg/time (total amount
of steam sprayed in the steam spray section), and thereby the cut stems were moistened
and swollen. The water content in the moistened cut stems was 39.0% by weight, which
had increased by 2% by weight from the water content (37.0% by weight) at the time
of conditioning.
[0065] The conditioned and swollen cut stems were continuously supplied to the pneumatic
conveying dryer with a structure similar to that of Example 1 at the flow quantity
of 25 kg/time by wet weight basis, and were dried and swollen by a superheated steam
flow (at a temperature of 220°C) under conditions similar to those of Example 1.
(Example 7; Embodiment)
[0066] Saturated steam at a gauge pressure of 5 bars (0.5 MPa) was injected into the supply
duct 5 (approximately 50 mm in diameter and approximately 0.6 m in length) arranged
in a horizontal state from a nozzle part (3 mm in diameter) of the steam supply tube
8 at the flow quantity of approximately 40 kg/time. Cut stems (with a moisture content
of 37% by weight) subject to a process similar to that of Example 6 were continuously
introduced from the tobacco material supply section 11 to the supply duct 5 via the
first air locker 12 at the flow quantity of 36 kg/time by wet weight basis. In this
case, the steam flow circulating in the supply duct 5 was saturated steam at the temperature
of 150°C. By driving the exhaust fan 17 in advance, the cut stems were introduced
from the supply duct 5 into the cyclone 1 (approximately 250 mm in diameter and including
a separator with an effective height of approximately 0.75 m) together with the steam
flow, swirled together with the steam flow, and were thereby moistened and swollen.
The transit time in the supply duct 5 and the cyclone 1 (residence time was 1.5 seconds)
was approximately 1.8 seconds. The moisture content of the moistened cut stems was
39% by weight, which had increased by 2% by weight from the moisture content (37%
by weight) at the time of conditioning.
[0067] After that, the moistened cut stems discharged from the cyclone 1 was continuously
introduced into the pneumatic conveying dryer 7 via the vibratory conveyor 15, and
the moistened cut stems were dried and swollen by a superheated steam flow under conditions
similar to those of Example 1. The temperature of the superheated steam was set to
220°C.
[0068] The expanded cut stems obtained in Examples 6 and 7 were stored (conditioned) in
a constant temperature and humidity room at a temperature of 22.0°C and a relative
humidity of 60% for 1 week. After the equilibrium moisture content was obtained, filling
capacity was measured in a manner similar to those of Examples 1-5.
[0069] The moisture content of the expanded cut stems were obtained in a manner similar
to those of Examples 1-5.
[0070] The obtained results are shown in Table 2.
Table 2
|
Steam temperature (°C) during moistening |
Superheated steam temperature (°C) during drying |
Moisture content (% by weight) of cut stems |
Filling capacity (cc/100g) |
During moistening |
After drying |
Example 6 |
150 |
220 |
39.0 |
10.5 |
610 |
Example 7 |
150 |
220 |
39.0 |
11.0 |
635 |
[0071] As clear from Table 2, in Example 7, in which cut stems were moistened and swollen
in a cyclone and dried by a superheated steam flow, the filling capacity can be increased
compared to Example 6, in which cut stems were moistened and swollen by a tunnel-type
vibratory conveyor including a plurality of holes from which steam was sprayed, and
were dried using a superheated steam flow.
1. Verfahren zur Volumenvergrößerung von Tabakmaterial, das Folgendes umfasst:
Befeuchten und Quellen von Tabakmaterial durch Verwirbeln von Tabakmaterial zusammen
mit einem damit in Kontakt stehenden Dampfstrom bei Temperaturen von 100-160 °C in
einem Zyklon, und
Trocknen des Tabakmaterials nach dem Befeuchten und Quellen.
2. Verfahren nach Anspruch 1, wobei Tabakmaterial vor dem Inkontaktbringen mit dem Dampfstrom
auf 15-50 Gewichts-% konditioniert wird.
3. Verfahren nach Anspruch 1, wobei das befeuchtete und gequollene Tabakmaterial einen
Feuchtigkeitsgehalt gleich dem Feuchtigkeitsgehalt hat, den das Tabakmaterial hatte,
bevor es mit dem Dampfstrom in Kontakt kam, oder einen Feuchtigkeitsgehalt hat, der
um maximal 5 Gewichts-% zugenommen hat.
4. Verfahren nach Anspruch 1, wobei die Verweildauer im Wirbelstrom 0,5-5 Sekunden beträgt.
5. Verfahren nach Anspruch 1, wobei das Trocknen des Tabakmaterials ausgeführt wird,
indem das Tabakmaterial mit einem supererhitzten Dampfstrom oder mit erwärmter Luft
in Kontakt gebracht wird.
6. Verfahren nach Anspruch 5, wobei der supererhitzte Dampfstrom eine Temperatur hat,
die höher ist als die Temperatur des Dampfes.
7. Verfahren nach einem der Ansprüche 1 bis 6, wobei es sich bei dem Tabakmaterial um
geschnittene Stängel handelt.
8. Vorrichtung zur Volumenvergrößerung von Tabakmaterial, die Folgendes umfasst:
einen Zyklon (1), der einen Einlass (2), eine Entlüftung (3) und einen Auslass (4)
umfasst,
wobei der Zyklon dafür ausgestaltet ist, Tabakmaterial zu befeuchten und aufzuquellen,
indem das Tabakmaterial zusammen mit einem damit in Kontakt stehenden Dampfstrom bei
Temperaturen von 100-160 °C verwirbelt wird,
einen Zufuhrkanal (5), der mit dem Einlass (2) des Zyklons verbunden ist,
einen Auslasskanal (6), der mit der Entlüftung des Zyklons verbunden ist,
eine Dampfzufuhrsektion, die mit dem Zufuhrkanal verbunden ist,
eine Tabakmaterial-Zufuhrsektion (11), die mit dem Zufuhrkanal an einer Position zwischen
einem Verbindungsteil der Dampfzufuhrsektion und dem Einlass des Zyklons verbunden
ist, und
einen Trockner (7), in den Tabakmaterial, das aus dem Auslass des Zyklons ausgelassen
wurde, transportiert wird, und der dafür umfasst ist, das Tabakmaterial zu trocknen.
9. Vorrichtung nach Anspruch 8, wobei der Auslasskanal in einen Abzweigkanal geteilt
ist, der mit dem Trockner verbunden ist.
1. Procédé d'expansion de matière tabac, comprenant les étapes suivantes :
humidifier et faire gonfler une matière tabac en faisant tourner la matière tabac
conjointement avec un flux de vapeur à des températures de 100 à 160 °C au contact
de celle-ci dans un cyclone ; et
sécher la matière tabac après qu'elle a été humidifiée et qu'elle a gonflé.
2. Procédé selon la revendication 1, dans lequel avant d'être en contact avec le flux
de vapeur, la matière tabac est conditionnée à raison de 15 à 50 % en poids.
3. Procédé selon la revendication 1, dans lequel la matière tabac humidifiée et gonflée
a une teneur en humidité égale à celle de la matière tabac avant d'être en contact
avec le flux de tabac, ou une teneur en humidité qui a augmenté d'au plus 5 % en poids.
4. Procédé selon la revendication 1, dans lequel le temps de séjour du fait de l'agitation
rotative est de 0,5 à 5 seconde(s).
5. Procédé selon la revendication 1, dans lequel le séchage de la matière tabac est réalisé
par mise en contact de la matière tabac avec un flux de vapeur surchauffée ou de l'air
chaud.
6. Procédé selon la revendication 5, dans lequel le flux de vapeur surchauffée a une
température supérieure à la température de la vapeur.
7. Procédé selon l'une quelconque des revendications 1 à 6, dans lequel la matière tabac
consiste en des côtes coupées.
8. Appareil d'expansion de matière tabac, comprenant :
un cyclone (1) présentant une entrée (2), un évent, évent (3), et une sortie, sortie
(4),
le cyclone étant conçu pour humidifier et faire gonfler une matière tabac en faisant
tourner la matière tabac conjointement avec un flux de vapeur à des températures de
100 à 160 °C au contact de celle-ci ;
un conduit d'alimentation (5) raccordé à l'entrée (2) du cyclone ;
un conduit d'échappement (6) raccordé à l'évent du cyclone ;
une section d'alimentation en vapeur raccordée au conduit d'alimentation ;
une section d'alimentation en matière tabac (11) raccordée au conduit d'alimentation
à une position située entre une partie de raccordement de la section d'alimentation
en vapeur et l'entrée du cyclone ; et
un séchoir (7) vers lequel est acheminée la matière tabac évacuée depuis la sortie
du cyclone et conçu pour sécher la matière tabac.
9. Appareil selon la revendication 8, dans lequel le conduit d'évacuation se ramifie
en un conduit secondaire qui est raccordé au séchoir.