JP2023518155A - Method and apparatus for producing reconstituted tobacco - Google Patents

Abstract

1. A method of producing reconstituted tobacco, wherein the solid constituents of tobacco are ground to a particle size of about 20-220 μm, preferably 80-180 μm; mixing with cellulose, at least one binder, and at least one material for forming an aerosol until a slurry is obtained with a liquid content of about 30-50%, preferably about 35-40%; subjecting said mixture to a first lamination in order to obtain a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 m; The strip undergoes a series of further first lamination steps until strips with a remarkably constant thickness of about 90-280 mm, preferably about 140-200 mm are obtained, - said strips are A method characterized in that it is dried to a volume of about 8-15%. [Selection drawing] Fig. 1

Description

The present invention relates to a method and apparatus for the production of reconstituted tobacco, both conventional and non-conventional tobacco, the latter also called HNB (Heat Not Burn).

In general, reconstituted tobacco is obtained using tobacco by-products and processing waste (veins, leaf shreds, powder, etc.), which are mostly powdered and mixed with water, a glycerin binder and other additives. of liquid additives, which makes it possible to obtain a very fluid mixture (slurry) with a liquid content of about 70% by weight, which mixture is then subjected to , is poured onto and over a steel strip and is thereby transported to drying. Evaporation of the liquid fraction of the mixture now takes place, whereby the solid residue forms something like a continuous strip of tobacco with approximately the same width as the steel strip. The strips of the dried mixture are then separated from the steel strip and cut as required into strips of various sizes. These shreds are then transformed into fine filaments which are suitably mixed and fed into conventional cigarette packing machines.

Depending on the raw material used and in particular shredded tobacco by-products with a particle size of up to between 20 μm and 220 μm are used or pulverized with a size of between 5 and 10 mm. Reconstituted tobacco is distinguished as conventional or non-conventional, depending on which tobacco leaves are used.

WO2016/050469, WO2016/050470, WO2016/050471, WO252016/050472 describe known techniques for producing reconstituted tobacco, which known techniques include: Large equipment is required and high energy consumption is involved in bringing the slurry to the consistency of tobacco sheets when the product is rather fluid. Suffice it to point out that drying ovens can reach up to 100 meters in length.

Another drawback of known techniques for the production of reconstituted tobacco using by-products is that the starting product is not homogeneous and its distribution on the steel strip is not uniform, so that sheet formation resulting from a slurry film is rather The point is that it is irregular. The above drawbacks result from the inability to roll or cut reconstituted tobacco sheets in a regular manner.

WO2019/157576 describes a method for the preparation of strips of reconstituted plant material, in which between the pre-layering stage and the final layering stage, pre-layering Re-mixing of the wrought sheets is effected inside the mixer to obtain a homogenous mass, which is then subjected to final lamination.

WO 2020/058814 discloses a method for the preparation of reconstituted tobacco, in which the solid components of shredded tobacco are added to the slurry in a slurry of about 30-50 percent, preferably about 35-50 percent. It is mixed with water, at least one binder, and at least one material to form an aerosol until it has a liquid content of 40 percent.

WO2016/067226 describes a method for preparing reconstituted tobacco, said reconstituted tobacco comprising a first drying unit, a crushing unit, a solid component (i.e. a solid powder of naturally occurring binder) mixing unit for liquid components (i.e. liquid/nanogels containing propylene glycol and glycerin), unit for mixing solid and liquid mixing components, 0.15 Includes 1 to 3 lamination units to obtain ˜0.3 mm membranes and a dryer to reduce the moisture content of the membranes.

It is an object of the present invention to eliminate these drawbacks and to produce conventional and non-conventional reconstituted tobaccos using smaller equipment.

Another object of the present invention is to produce reconstituted tobacco while limiting energy consumption.

Another object of the present invention is to produce reconstituted tobacco using equipment, some of which are already available on the market, even if never used in this particular technical field.

Another object of the present invention is to produce reconstituted tobacco in a manner different from conventional methods.

Another object of the present invention is to produce reconstituted tobacco with suitable properties to meet various market demands.

Another object of the present invention is to produce reconstituted tobacco by operating at low temperatures to preserve all tobacco aroma.

According to the present invention, all these objects, and other objects arising from the following description, are achieved jointly or separately by a method for producing reconstituted tobacco according to claim 1 and a device according to claim 23. be.

Specifically, the method for producing reconstituted tobacco according to the present invention comprises the steps of:
- the solid components of tobacco are ground to a particle size of about 20-220 μm, preferably 80-180 μm;
- the comminutes thus obtained together with water, powdered cellulose, at least one binder and at least one material for forming an aerosol with a liquid content of about 30-50%, preferably about 35-40%; mixing until a slurry is obtained;
- the mixture undergoes a first lamination to obtain a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 m;
- said strip which has already undergone said first lamination, a series of further first lamination steps until a strip having a remarkably constant thickness of about 90-280 mm, preferably of about 140-200 mm is obtained. the process of receiving
- characterized by the fact that said strips comprise continuously performing a step in which they are dried until their liquid content is about 8-15%.

The invention will be further clarified hereinafter in some of its preferred embodiments reported for illustrative and non-limiting purposes only with reference to the accompanying drawings.
1 shows a general schematic diagram of an apparatus for the production of reconstituted tobacco according to the invention; FIG. If the device is intended for the production of conventional reconstituted tobacco, its supply is indicated. If the device is intended for the production of non-traditional (HNB) reconstituted tobacco, its supply is shown. Fig. 3 shows the vein supply of the device; Fig. 2 shows a partial configuration of an apparatus with two separate lines for leaf and tobacco vein preprocessing. Figure 1 shows parts of the equipment for grinding, mixing and storage. 1 shows a schematic diagram of a refiner with a cylinder; FIG. Fig. 2 shows in plan the layered part of the device in different embodiments. Schematically shows the hot air dryer of the device. Fig. 4 schematically shows a hot air dryer of the device in one different embodiment;

As can be seen in these figures, the apparatus for producing reconstituted tobacco according to the present invention transforms the incoming raw material into continuous strips of reconstituted tobacco for subsequent tobacco packaging operations. up to and including several parts designed to work with them.

Specifically, the device according to the invention for the production of reconstituted tobacco comprises:
- a unit for shredding solid tobacco components to a particle size of about 20-220 μm, preferably about 80-180 μm;
- mill 20 and/or grinder 24 and/or pin mill 54;
- supplied with shredded material for metering, water, at least one binder and at least one material for forming an aerosol, a mixture with a liquid content of about 30-50%, preferably about 35-40%; a mixer 80 configured to form
- a first rolling unit 100 for obtaining a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm, from said mixture;
- a rolling line 116 positioned downstream of said first rolling unit for making said continuous strip about 90-280 μm thick, preferably about 140-200 μm thick;
a dryer 122 located downstream of said rolling line 116 for bringing the liquid content of said strips as rolled out of said rolling line 116 to about 8-15%;

Conveniently, the apparatus further comprises a mixture forming unit 92 for the formation of said mixture portions 97, preferably whereby the first rolling unit 100, from said mixture portions 97, It is configured to form a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm.

Preferably, the device according to the invention comprises:
- pre-processing of the starting solid product (tobacco leaves, veins, leaf fragments, powder, etc.) to prepare it for subsequent comminution processing;
- a grinding section and a storage section followed by mixing with a suitable working fluid, said grinding section officially comprising said grinding frame unit;
- a mixing section of solid and liquid materials to obtain a homogeneous mixture with a relatively high density;
- a portion for transforming the mixture, and in particular portions of said mixture, into a continuous strip;
- a rolling line for reducing the continuous strip to the desired final thickness;
- including the drying section of the laminated web.

Conveniently, the preparation and preprocessing sections of the starting solid product are different depending on whether the apparatus is intended to produce conventional (Fig. 2) or non-conventional (Fig. 3) reconstituted tobacco. . Moreover, conveniently, sections for the preparation and preprocessing of tobacco veins can be further provided for use in the production of both conventional and non-conventional reconstituted tobacco (FIG. 4). Further, advantageously, tobacco vein preparation and preprocessing sections may also be provided for use in the production of both conventional and non-conventional reconstituted tobacco (FIG. 4).

Advantageously, when the preparation and preprocessing section is intended to feed a conventional reconstituted tobacco production apparatus (Fig. 2), it comprises a tilter 2 of cartons containing tobacco by-products, The aim is to turn over their contents on the feeder 4 of the vibrating conveyor 6 which separates any heavies from the product to be processed. Heavy loads are collected in suitable containers 8 while the product to be processed is subjected to pneumatic conveying 10, cyclone 12, conveyor belt 14 equipped with metal detector 16 for removal of any metal objects, and pneumatic conveying 18. through, preferably to a low temperature mill 20 .

Advantageously, when a preparation and preprocessing section is provided for the preparation of non-conventional reconstituted tobacco (Fig. 3), it is used for baling tobacco leaves from cartons of about 200 kg (generally containing It includes a feed station that uses a bench 22 to unwrap the granules and transfer them to a grinder 24 .

Conveniently, the outlet of this grinder 24 is connected through an air conveying 26 to a cyclone 28 in which the conveying air is separated from the solid product, which is used to separate the fines from the rest of the product. Vibrating sheave 30 is moved. The fine portion output is directly connected to the cold mill 20 and the product residual portion output feeds a conventional linen levering machine 32 which eliminates any linen not previously removed from the tobacco bale.

The outlet of the linen levering machine 32 feeds into a classification chamber 34 for separating any heavy foreign matter from the crushed tobacco leaves, where air conveying 36, cyclones 38, metal detection to remove any metal objects. A conveyor belt 40 equipped with vessels 42, a weighing system 43 (standard scales), and a pneumatic conveying 44 are moved to a storage and mixing silo 45, where they are fed to the cryogenic mill 20 using another technique of pneumatic conveying 44'. can be transported to These silos 45 are sized to contain the amount of product required to form a batch, depending on the particular recipe being prepared.

Advantageously, when the preparation and preprocessing section is provided for the preparation of tobacco veins used in the production of conventional and non-conventional reconstituted tobacco (Fig. 4), tobacco veins, optionally carton tilters 46 containing vein feeders 48 to a vibrating conveyor 50 for separating the weights of the cartons, and pneumatic conveying 52 for sending them to a pin mill 54 for crushing.

The pin mill 54 has an outlet which in turn is connected to one or more storage silos 60 using air conveying 56 equipped with cyclone filters 58 .

The outlet of the silo or silos 60 is connected by means of a screw conveyor 62 to a weighing system 64 (slave scale), which carries the particular recipe to be prepared before sending it through the pneumatic conveying 44 to the storage and mixing silo 45. Grind the veins to the required percentage in .

As already mentioned, the apparatus according to the invention also includes a mill 20 (FIG. 5), which receives various productions to reach an average particle size of about 20-220 μm, preferably about 80-180 μm. crush things.

Although there are various types of mills that can be used, it is advantageous to use a low temperature pin mill which allows the product to be maintained at a low processing temperature and thus retain tobacco aroma.

Pin mills are themselves conventional, comprising a fixed disc and a rotating or counter-rotating disc in a closed structure and provided with opposed, partially penetrating pins. Being a conventional device per se, shown generally at 20 in FIGS. 5 and 6, its internal construction characteristics, nor its mode of operation, are shown.

Preferably, pin mill 20 is designed to perform cryogenic grinding, ie, grinding in the presence of liquid nitrogen.

As mentioned, in a reconstituted tobacco making apparatus, the cold pin mill 20 has some advantages over conventional mills due to the various methods of processing the product, which is essentially ground. In fact, milling at room temperature can lead to poor quality products, but milling in the presence of liquid nitrogen makes it possible to preserve the physical and chemical and organoleptic properties of the product.

The amount of liquid nitrogen used in the cryogenic grinding process is a key point to consider when investigating the pros and cons of the process and can vary depending on the material being processed. Liquid nitrogen at a temperature of −175° C. is injected into the product in the chamber of the screw conveyor 68 feeding the mill 20 and the residence time in contact with the nitrogen is approximately 2-5 seconds, which is similar to the pin mill. It is also the migration time of the product inside the feeding screw. The temperature of the product leaving the mill 20 is advantageously less than 10° C., so that the nitrogen vapor released almost instantaneously on contact with the tobacco being chilled flows back through the mill's feed system. to provide the desired pre-cooling effect through. The pre-cooling system and liquid nitrogen flow in the mill are controlled by thermocouples, making the cryomind process fully automated.

In summary, the positive factors of cryo-grinding are:
- high yield,
- better quality of the final product without breaking or tearing the molecular structure,
- reduced energy requirements,
- better quality of the final product,
- reduction of waste due to overheating and oxidation,
- a more homogeneous and finer final product,
- A reduction in the amount of material that is reprocessed in the comminution system.

Conveniently, the outlet of the cryogenic pin mill 20 is connected to a fluidized bed sieve 70, which exits the mill itself, and generally from about 0 to 220 μm, necessarily exits from the larger size. , preferably with a mean particle size of about 80-180 μm.

Conveniently, the fluidized bed sieve 70 thus has the function of sorting the product and reintroducing it into the mill 20 with a fraction greater than 220 μm, which through the pneumatic conveying 72 is one or more mixing and after separating the fraction between 20 μm and 220 μm sent to storage silo 74 .

Advantageously, the outlet of the mixing and storage silo 74, using a pneumatic conveying line 76, feeds a cyclone filter 78 which breaks down the dusty air and specifically the dust that is later collected and reintroduced into the cycle. from the air that can be discharged later.

Conveniently, the outlet of cyclone filter 78 feeds mixer 80 through a continuous dosing system, preferably by means of a screw, which can be of many types, for example horizontal slant or vertical spiral.

Mixer 80 is supplied with a measured amount of pulverized tobacco, water, at least one binder, and at least one material to form an aerosol, about 30-50%, preferably about 35-50%. Configured to obtain a mixture with a liquid content of 40%.

More specifically, the liquid or humidity values given herein are intended to be determined according to a weighing system using a wet weight basis. More specifically, the humidity value is defined as the percentage of water contained in the total mass of the corresponding product, in other words the percentage ratio between the amount of water and the total mass of the assembly. Conveniently, these values are based on conventional methods provided in the literature for determining the amount of water in products ("Tobacco Moisture, Water and Oven Volatiles - A status report of common moisture methods used within the tobacco industry"). By Nils Rose ET AL.

Preferably, at least one duct for influent water, a material for forming an aerosol (eg glycerin) and at least one binder are connected to the mixer 80 . Conveniently, one or more inlet ducts may be provided for other additives required by the particular recipe being prepared.

More specifically, the apparatus includes one or more storage tanks 68 for aerosol-forming substances, and one or more premixers 84 containing the materials for forming the aerosol, Preferably, a plurality of additives dosed in the correct proportions to form the liquid introduced into the mixer 80 can be introduced.

The final product is introduced into the mixer 80 along with the other ingredients of the mixer and also powdered cellulose to increase the durability of the final product sheet and at the same time increase the density of the product itself. is preferred. Conveniently, the cellulose powder used is made of organic fibers derived from natural cellulose rather than cellulose-derived compounds.
The powdered cellulose so added preferably has a particle size of 50-100 μm and is preferably present in a proportion comprised between 2-10% by weight relative to the pulverized tobacco.

The added powdered cellulose is mainly or exclusively of natural origin. More specifically, the powdered cellulose added in this way is not synthetic and is not obtained by chemical processing.

Conveniently, the powdered cellulose added in this way does not have a binding function, but does have the function of lowering the specific gravity of the final product and reducing the solids content of the tobacco, thereby making the cellulose less dense than the tobacco. It also costs much less, thus reducing the cost of the final product. Furthermore, the addition of cellulose makes the final product tougher by increasing the tensile strength, making the final product easier to process, which means that the final product is also a pleated sheet. It is particularly useful when it is possible to obtain

The powdered cellulose can be contained in bags or large bags prior to its use and introduced directly into the mixer 80 (FIG. 1), in which case, after being poured into a conventional hopper, the powdered cellulose is fed to a cyclone filter 78' which introduces the powdered cellulose into the mixer 80 as lightened via a continuous dosing system, preferably screw type.

Alternatively, the powdered cellulose can be introduced, again through a cyclone filter 78' and a continuous dosing system, in an air conveying line 44' which feeds the mixing and storage silo. , from this mixing and storage silo line, the powdered cellulose is then transferred to the mill 20 via the pneumatic conveying line 44' along with other components of the mixture present in the line itself (Fig. 5). From mill 20 , the contents of mixing and storage silo 45 are conveyed through conveying line 76 to a metering system located at the inlet of mixer 80 .

Preferred materials for aerosol formation (and more particularly for visible aerosol formation) include, for example, polyhydric alcohols (such as glycerin, propylene glycol, triethylene glycol and tetraethylene glycol), monohydric, bivalent or polyhydric Aliphatic esters of carboxylic acids, such as methyl stearate, dimethyldodecane and dimethyltetradecanoic acid, and mixtures thereof may also be included. Suitably glycerin, propylene glycol, triethylene glycol and tetraethylene glycol can be mixed together to form an aerosol-forming material. Additionally, the aerosol-forming material can be provided as part of a binder (eg, when the binder is propylene glycol alginate). Advantageously, a suitable combination of materials for aerosol formation can also be provided.

Preferably, the at least one binder is roxypropylcellulose supplied, roxypropyl methylcellulose supplied, roxyethylcellulose supplied, microcrystalline cellulose, methylcellulose, carboxymethylcellulose (CMC), corn starch, potato starch, guar gum, locust bean gum, At least one of pectin and alginate (eg, ammonium alginate and sodium alginate).

Preferably, the binder and added powdered cellulose are defined by substances different from each other. Conveniently, the powdered cellulose mainly serves to form a three-dimensional framework, which has a high thickening effect, pseudoplasticity and excellent ability to retain liquids, while the Binders serve exclusively or primarily to bind together the various components to be mixed.

Conveniently, the outlet of the premixer 84 is connected to the inlet of a hydrator 86 which has other inlets for connection to a water supply line 88 and a compressed air supply line 90 .

Preferably, the outlet of said mixer 80 feeds a unit 92 for forming said mixture in order to obtain a plurality of portions 97, the units 92 preferably being lobed and separated from each other. Conveniently, the forming unit 92 comprises a pair of forming cylinders 96, the forming unit 92 exhibiting grooves, preferably parallel to the axis of the cylinders themselves, to direct the mixture at the inlet. It is intended to pick up and deliver said portion 97 at said outlet. Advantageously, said unit 92 is further arranged for roughening said mixture and for this purpose preferably comprises a hopper 94, which contains a block breaker and said It is provided with a pair of forming cylinders 96 at the bottom.

Advantageously, at the exit of said forming unit 92 a conveyor belt 98 is provided for transferring said portion 97 to a first rolling unit 100 .

Preferably, said first rolling unit 100 includes a lobe feeder 102 for homogenizing the mixture formed by said section 97 .

Advantageously, a further metal detector 104 can be provided along the transfer path from the forming unit 92 to the lobe feeder 102, the metal detector 104 being in the mixture and subsequent processing units. It has the ability to remove all metal parts that can be damaged. These metal parts are conveyed along separate paths to the inlet of the lobe feeder 102 and collected in suitable containers 106 .

The lobe feeder 102 includes a series of lobe-type feed rollers between which the portion (exiting the forming rolls 96 of the forming unit 92) is passed 97 so that between a pair of mill rolls 108 The mill rolls are configured to form a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm.

Conveniently, the lobe feeder 102 thus exits the forming unit 92 and causes homogenization of the product, which may have lumps. Advantageously, the lobe feeder 102 further advances the product to force it into an inlet between the pair of laminating cylinders 108 .

Accordingly, the first laminating unit 100 conveniently includes an homogenization module, preferably defined by the lobe feeder 102, which is immediately upstream to the pre-laminating module. positioned, this pre-laminating module is defined by at least one pair of laminating cylinders 108, which at least one pair of laminating cylinders 108 form a continuous strip having a thickness of approximately 1-20 mm, preferably approximately 1-10 mm. configured as Advantageously, the strips thus obtained have greater elasticity.

Conveniently, in a version of the apparatus not shown, the rolling line 116 can be provided directly downstream of the lobe feeder 102 . More specifically, in this case, said rolling line receives a monolayer continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm, the edge of which is provided with said lobe feeder 102 . Out of the first lamination unit 100 . Advantageously, a lamination unit 110 can be provided downstream of the first lamination unit 100 and upstream of the lamination line 116 below. Preferably, the lamination unit 110 is configured to place on several layers a single continuous strip having a thickness of about 1-10 mm, which strip emerges from said first rolling unit 100. , whereby the strip is transformed into a multi-layer belt having a thickness of about 2-20 mm, which is then sent to the inlet of the rolling line 116 .

Preferably, said layering unit 110 comprises an upstream conveyor belt 112 , which functions to lay said product belt on an underlying downstream conveyor belt 114 , preferably attached to said rolling line 116 . and arrange the product belt to be stacked on the downstream conveyor belt 114, for example by multiple folding on itself. Preferably, the upstream conveyor belt 112 is lifted relative to the downstream conveyor belt 114, with forward motion relative to its support structure, and alternating motion continuous motion with its support structure parallel to its longitudinal axis. .

Conveniently, the laminating unit 110 feeds the subsequent lower rolling line 116 and, depending on the type of equipment, the upstream conveyor belt 112 of the laminating unit 110 is parallel or perpendicular to the rolling line 116. can be arranged as follows: More specifically, if the downstream conveyor 114 of the rolling line 116 has a width substantially equal to the width of the product belt exiting the layering unit 110, the upstream conveyor belt 112 may Arranged parallel to the provided downstream conveyor belt 114 (FIG. 1), on the one hand, the downstream conveyor 114 of said rolling line 116 is wider than the product belt present in the lamination unit 110, the upstream conveyor belt 112 is , preferably orthogonal to the downstream conveyor belt 114 provided in the rolling line 116 (FIG. 8). This action allows the product strip to be spread across the useful width of the rolling line 116 .

Conveniently, in either case, the alternating motion of the support structure of the upstream conveyor belt 112 of the stacking unit 110 moves from the first rolling unit 100 to the underlying first downstream conveyor belt 114 of the underlying roll line 116 . Resulting in layering of the overlying product belt and formation of a layered belt having a width substantially equal to the useful width of the rolling line itself.

The rolling line 116 is formed from several rolling stations, each of which includes a pair of cylinders 118, which are spaced apart in order to progressively reduce the thickness of the product strip being processed. Set route boundaries. More specifically, the rolling line 116 is configured to progressively produce a continuous strip with a thickness of 90-280 μm, preferably about 140-200 μm.

Preferably, between each rolling station is a conveyor belt 114, preferably having a length of about 1.5-2 m, which allows the product to rest before going to the next rolling step. It has a function that enables

Advantageously, the roll line 116 is then finished at one or more calibrating stations, each formed by a pair of calibrating laminating rolls 120 .

Advantageously, 118, and possibly calibration roll 120, can be heated so that the drying phase can already begin during lamination. Conveniently downstream of the rolling line 116 is a dryer 122, preferably with air recirculation (FIG. 7), to bring the liquid content of the rolled strip to about 8-15%. be. Advantageously, the dryer 122 can be divided into two units 124, 126, which are arranged in series with each other. More specifically, the upstream unit 124 is provided to carry out the first drying stage and is equipped internally with steel belts or net conveyor belts for conveying the product leaving the rolling line 16 and the downstream unit 126 is provided to carry out a second drying stage and a subsequent cooling stage and is internally equipped with a network conveyor belt.

In addition, the dryer 122 is equipped with sensors 128 at the inlet and outlet, preferably infrared, to monitor the product along its length.

Operation of the apparatus just described for the production of conventional reconstituted tobacco (Fig. 2) is as follows.

Preferably, the tobacco waste container is placed on a tipper 2 which tippers the product onto a feeder 4 which moves the product onto a vibrating conveyor 6 . Here, separation of any weights from the tobacco by-products takes place, the weights are collected in a container 8 and the tobacco by-products are sent upwards by an airflow along a pneumatic conveying line to a cyclone 12 into which a gas and the solid product are separated and the solid product is dropped onto a conveyor for transfer, and the solid product is conveyed through pneumatic line 18 to cryogenic mill 20 .

Preferably, in the production of non-traditional types of reconstituted tobacco (FIG. 3), the carton is instead placed on an undressing bench 22 where individual bales of tobacco containing tobacco are removed from the carton. , and is sent to a grinder 24 which reduces the leaves themselves to a substantially uniform size between approximately 5-10 mm.

Conveniently, the pulverized product is then passed along air conveying 26 to cyclone 28 where it is separated from the air and dropped onto vibrating sieve 30 .

Here, separation from the residual fraction takes place, the fine fraction being sent directly to the cold mill 20 and the residual fraction passing through the yarn levering machine 32 before reaching the classification chamber 34 . Here, any weights are separated from the crushed leaf, which is sent to the cryogenic mill 20 after being exposed to a metal detector 42 so that each step can be viewed enumeratively.

Conveniently, if the recipe calls for it, chopped tobacco veins can also be sent to the same cold mill 20 that is used to produce both conventional and non-conventional reconstituted tobacco.

In this case (FIG. 4) the vessel containing the veins is placed on an overturning device 46 which feeds the veins themselves to a vibrating conveyor 50 for removal of any weights. The veins are then moved through a pneumatic line 52 to a pin mill 54 which shreds the veins down to a size of 5-8 mm.

From here, the shredded veins separated from the conveying air in cyclones 58 are moved to storage silos 60 from which different types of veins from different qualities of tobacco are picked and passed through screw conveyor 62. It is moved to the vein dispenser 64, which prepares the veins according to the recipe to be prepared.

The crushed and dosed leaf veins are transferred to cryogenic mill 20 through pneumatic line 66 .

Advantageously, irrespective of the type of reconstituted tobacco produced and, thus, irrespective of the type of tobacco solids introduced into the shredding unit, the end product averages about 20-220 μm, preferably 80 μm. Resulting in a ground product with a particle size of ˜180 μm. Preferably, the ground product obtained from the flowable bed sieve supplied by cryogenic mill 20 has an average particle size of about 20-220 μm, preferably about 80-180 μm.

Advantageously, the product thus ground is sent to a mixing and storage silo 60 from which it can be removed and moved to the mixer 80 as required.

In addition to pulverized tobacco and cellulose, and generally also the solid product obtained from the mixing and storage silo 45, water, at least one binder and at least one substance for forming an aerosol are all introduced. Advantageously, compressed air and other additives may also be introduced, including more specifically ground cloves.

Conveniently, the whole is then subsequently mixed to form a slurry with a liquid (moisture) percentage of about 30-50%, preferably about 35-40% by wet weight, ie a fairly dense consistency. .

Preferably, the mixture thus obtained is moved to a forming unit 92, from which a plurality of portions 97, preferably shaped like lobes, are obtained.

These portions 97 of the mixture obtained from the forming unit 92 are suitably transferred to the first rolling unit 100, where the first rolling unit 100 homogenizes the mixture and at the outlet about 1-20 mm, It is preferably configured to set a continuous strip having a thickness of approximately 1-10 mm. This continuous strip from the first layering unit 100 is either moved directly to the layering line 116 or is layered by the layering unit on the inlet belt 114 of the rolling line 116 . deposited in a layered fashion

Conveniently, as noted above, stratification is obtained by having a continuous belt fall onto conveyor belt 112, which is advanced relative to its support structure moved by alternating motion. so that it is possible to trim the product belt in several layers on the inlet conveyor belt 114 . Depending on the set-up and direction of alternating motion and the support structure of the conveyor belt 112 immediately downstream of the lamination unit 110, the product belt may be parallel to or perpendicular to the longitudinal axis of the rolling line 116 at some point. Placed on a layer.

Conveniently, on each pass from one station to another of the rolling line 116, the product strip is reduced in thickness to the desired thickness corresponding to the power calibration cylinder 120, It has a significant constant value of about 90-280 μm, preferably about 140-200 μm. Advantageously, furthermore, at the exit from the rolling line 116, the strip has less than 20% or even 15% Has a liquid content.

The product web leaving the rolling line 116 is then dried in a dryer 122 where its liquid content is reduced to about 8-15%.

Preferably, the dryer 122 is air recirculating and has some advantages in terms of production complexity, maximum size, and energy consumption when compared to dryers traditionally used in reconfigured tobacco production facilities. . This is because conventional equipment processes a very fluid, less stable product (slurry), which is processed by the equipment of the present invention in a denser, more stable different from existing products. As a result, while slurry processing equipment requires traditional irradiation and conduction dryers, the equipment of the present invention uses either a network conveyor belt or a steel conveyor belt for the first drying stage and a second drying stage. A recirculating air dryer 122 can be advantageously used which has a system coupled with a net conveyor belt for the stages as well as the cooling stages. In this way reduced dimensions are obtained (approximately 45m compared to over 100m for conventional dryers) while retaining the same performance and lower energy consumption due to the lower amount of water removed. (using about 1000 kg/h of steam/h compared to over 5000 kg/h of steam from conventional dryers).

Conveniently, at the exit of the dryer 122, the product is expected to be reeled or cut into threads of predetermined size for use in tobacco packaging.

Conveniently, in the method according to the invention, the homogenization of the mixture is carried out mainly or exclusively using the lobe feeder 102, and in any case always carried out, and only upstream, preferably , immediately upstream of the pre-rolling module converting the homogenized mixture into continuous strips having a thickness of about 1-20 mm, preferably about 1-10 mm, for delivery to the final rolling line 116. be.

More specifically, once the homogenized mixture has been converted in continuous strips having a thickness of about 1-20 mm, preferably about 1-10 mm, the latter are no longer remixed, In the form of strips, it is sent to rolling line 116 where it is brought to the desired thickness, which is a meaningful constant value of about 90-280 μm, preferably about 140-200 μm. Advantageously, the fact that the rolling line 116 receives strips at the entrance and not a misshapen mixture ensures a constant inflow which increases the accuracy of the sheet thickness in the subsequent rolling process, and the number of lamination cylinders 118 in the same line can also be reduced, thereby reducing the cost and overall size of the equipment.

Conveniently, if the facility is envisioned to produce non-conventional types of reconstituted tobacco, in addition to using different preparation and processing sections than those already described, it may Alternatively, or in addition upstream of this, a cylinder refiner 130 is used which has the task of reducing the solid components of the mixture to a particle size not exceeding 20 μm.

The refiner (FIG. 7) includes a plurality of cylinders 132 arranged in close proximity to each other in sequence to define corresponding grinding slot compartments within a closed vessel.
The lower cylinder 132' is mounted on an axis out of the plane containing the axes of all other cylinders 132 and acts as a feeder for the mixture, which flows between the lower cylinder and the one directly above. It is removed from the bottom of the container and made to stand up in order to pass through and follow all the others. The various pairs of cylinders 132 through which the mixture passes rotate at different speeds, in the sense that the upper cylinder rotates faster than the associated lower cylinder, resulting in a The mixture is stretched during passage, thus reducing the particle size of the mixture itself. In fact, one of the key parameters for the success of the refining process is precisely the various velocities of the various cylinders 132, upon which the total mass flow of the mixture through the milling slots depends. be.

The pressure between the cylinders is hydraulically controlled.

All cylinders 132 are cooled by cold water, which circulates inside each cylinder, thus contrasting the heat generated from the mixture by friction due to both cylinder behavior and product contact. The temperature of the bulk of the product is thus reduced until it reaches 25°C.

Thanks to the refiner 130 just mentioned, the frictional action exerted on the mixture by the latter cylinder 132 develops a considerable binding action of the tobacco, and more specifically the cellulose fibers contained in the veins of the latter, and this This has the dual advantage of eliminating the need to introduce more fiber into the mixture in order to develop the aromatic content of the product and obtain the required binding effect.

The operation of the equipment in this different embodiment leaves the fragmented. Also, the chopped leaves and chopped veins obtained from the preparation and pre-processing station are fed to the cold mill 20 in proportionate doses according to the recipe obtained, from which about 20-220 μm, preferably about 20-220 μm. yields a particle size of 80-180 μm.

The product is then transferred, in the manner previously described, to mixer 80 where a product mixture is formed as described above.

The mixture thus obtained is then fed to a cylinder refiner 130, tasked with reducing the solids content of the mixture to a particle size not exceeding 20 μm. Thus, the frictional action exerted on the mixture by the cylinders 132 of the refiner 130 causes the veins to develop a substantial bonding action of the tobacco, and more specifically the cellulose fibers contained in the veins, which entails a double developmental benefit, on the other hand eliminating the aromatic component of the product, the need to introduce more fiber into the mixture to obtain the required binding effect.

FIG. 1 schematically shows the position of the refiner 130 between the mixer 80 and the forming unit 92, however, in the present invention the refiner 130 can be substituted for the forming unit 92, in which case It is described that the mixture leaves the refiner 130 and is moved directly to the first rolling unit 100 for continuation of the process cycle according to the method already described.

Claims (44)

A method of producing reconstituted tobacco, comprising:
- the tobacco solids are ground to a particle size of 20-220 μm, preferably 80-180 μm;
- the comminute thus obtained, together with powdered cellulose, water, at least one binder and at least one material for forming an aerosol, with a liquid content of about 30-50%, preferably about 35-40%; mixing until a slurry is obtained;
- said slurry undergoes a first layering to obtain a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm;
- Said strip which has already undergone said first lamination undergoes a series of further lamination steps until a strip having a remarkably constant thickness of about 90-280 μm, preferably of about 140-200 μm is obtained. ,
- A method, characterized in that said strips are dried until their liquid content is about 8-15%. 2. The method of claim 1, wherein the dried continuous web is wound or chopped into threads of predetermined dimensions. 3. A method according to any one or more of the preceding claims, characterized in that the solid component is comminuted tobacco by grinding. 4. A method according to any one or more of the preceding claims, characterized in that the solid components of the tobacco are ground using a mill. 5. A method according to any one or more of the preceding claims, characterized in that the solid component is tobacco ground using a cryogenic pin mill (20). 6. Process according to any one or more of the preceding claims, characterized in that powdered cellulose is used which consists of organic fibers obtained from natural cellulose. A method according to any one or more of the preceding claims, characterized in that the slurry is formed with powdered cellulose having a particle size between 50 and 100 µm. A method according to any one or more of the preceding claims, characterized in that the mixture is formed with powdered cellulose in a proportion comprised between 2% and 10% by weight of tobacco. 9. A method according to any one or more of the preceding claims, characterized in that crushed cloves are added to the mixture. 10. A method according to any one or more of the preceding claims, characterized in that the ground tobacco components are mixed with the powdered cellulose before they are used to form said mixture. said mixture formed by pulverized matter, powdered cellulose, water, at least one binder, and at least one material for forming an aerosol,
- a roughening step by passing through at least a pair of grooved cylinders (92) and/or - a refining step by passing through at least a pair of refining cylinders (132, 132') until the particle size of said mixture reaches 20 μm. 11. A method according to any one or more of the preceding claims, characterized in that it is subjected to 12. A method according to any one or more of the preceding claims, characterized in that the mixture undergoes a homogenization and/or shaping step before undergoing the first rolling step. After the mixture has undergone a homogenization and/or forming step to transform it into continuous strips having a substantially constant width of between 100 and 2000 mm and a thickness of between 1 and 10 mm, 13. A method according to any one or more of the preceding claims, characterized in that it undergoes a first lamination step. Claims 1 to 13, characterized in that said mixture is subjected to said first stratification step after undergoing a homogenization and/or forming step in order to be converted into a series of parts (97). The method according to any one or more of 15. Any one of claims 1 to 14, characterized in that said first rolling of said mixture is performed using a unit (100) comprising a lobe feeder (102) and at least a pair of rolling cylinders (108) Multiple methods. Claims 1 to 15, characterized in that said first lamination comprises a homogenization step before obtaining said continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm. The method according to any one or more of Said mixture first undergoes a forming step to be transformed into a series of portions (97), followed by a homogenizing step of said portions (97) in succession, after which it is about 1-20 mm, preferably about 1-20 mm. 17. A method according to any one or more of the preceding claims, characterized in that it undergoes the step of obtaining said continuous strip having a thickness of 10 mm. 18. Any one of claims 1 to 17, characterized in that the mixture is mainly or exclusively homogenized by means of a lobe feeder (102) placed at the inlet of at least one pair of rolling cylinders (108). A method according to paragraph or more. Method according to any one or more of the preceding claims, characterized in that a monolayer tape having a thickness of about 1-10 mm is obtained at the outlet of said first lamination. characterized in that, before a series of further lamination steps, said strip which has already undergone said first lamination undergoes layering until a multi-layer strip having a thickness of about 2-20 mm is obtained, 20. A method according to any one or more of claims 1-19. 21. A method according to any one or more of the preceding claims, characterized in that in a series of further rolling steps the mixture is placed between one layering station and the next layering station. . 22. A method according to any one or more of the preceding claims, characterized in that said lamination is carried out using at least partially heated mating cylinders (118). 23. A method according to any one or more of the preceding claims, characterized by drying the laminated ribbon to pass through a dry air recirculation system (122). A facility for the production of reconstituted tobacco, comprising:
- a unit (20, 24, 54) for grinding tobacco solids to a particle size of about 20-220 μm, preferably 80-180 μm;
- supplied with a measured amount of shredded material, powdered cellulose, water, at least one binder, and at least one material for forming an aerosol, with a liquid content of about 30-50%, preferably about 35-40%; a mixer (80) configured to obtain a mixture in quantity;
- a first rolling unit (100) for obtaining a continuous strip having a thickness of said mixture of about 1-10 mm, preferably about 1-20 mm;
- a rolling line (116) arranged downstream of said first rolling unit (100) to give said continuous strip a thickness of 90-280 μm, preferably 140-200 μm;
- a dryer (122) for bringing the liquid content of the laminated web to about 8-15%; 25. Installation as claimed in claim 24, characterized in that the dryer is air circulating. 26. Equipment according to any one or more of claims 24 to 25, characterized in that the crushing unit comprises a mill (20). 27. Equipment according to any one or more of claims 24 to 26, characterized in that the grinding unit comprises a cryogenic pin mill. 28. An installation as claimed in any one or more of Claims 24 to 27, characterized in that it comprises means for supplying powdered cellulose to the mixer. Claims 24 to 28, characterized in that it comprises, upstream of said mill (20), at least one silo (45) for mixing and storing the solid material comprising pulverized tobacco components and said powdered cellulose. Equipment according to any one or more of the above. 30. The method according to any one or more of claims 24 to 29, characterized in that it comprises a mixture forming unit (92) downstream of said mixer (80) and upstream of said first rolling unit (100). Facility. 31. An installation according to any one or more of claims 24 to 30, characterized in that said mixture forming unit (92) is also arranged to homogenize said mixture. from claim 24, characterized in that said mixture forming unit (92) is arranged to transform said mixture into a continuous belt having a substantially constant width of 100-2000 mm and a thickness of 1-4 mm 31. Equipment according to any one or more of Clauses 31. from claim 24, characterized in that said mixture forming unit (92) is arranged to divide said mixture into a plurality of portions (97) intended to be sent to said first rolling unit (100) 32. The equipment according to any one or more of Clauses 32. An installation characterized in that said mixture forming unit (92) comprises a roughening machine with a refiner having at least a pair of grooved cylinders (96) and/or cylinders (130). said first rolling unit (100) comprising a mixture homogenization module located immediately upstream to a pre-rolling module, said pre-rolling module being defined by at least one pair of stacking rolls (108); 35. According to any one or more of claims 24 to 34, characterized in that the laminating rolls are arranged to form a continuous strip having a thickness of about 1-20 mm, preferably about 1-10 mm. Equipment as described. 36. Equipment according to any one or more of claims 24 to 35, characterized in that the homogenization module comprises a lobe feeder (102). 37. The installation according to any one or more of claims 24 to 36, characterized in that said first rolling unit (100) comprises a lobe feeder (102) and at least one pair of mill rolls (108). . 38. Plant according to any one or more of claims 24 to 37, characterized in that it comprises a lamination unit (110) downstream of said first rolling unit (100). A layering unit (110) comprises an upstream conveyor belt (112) supplied by said first layering unit (100) and having a continuous motion against one of the support structures, said continuous motion preferably comprising 39. Equipment according to any one or more of claims 24 to 38, characterized in that it is provided with an alternating motion to the lower downstream conveyor belt (114) of the rolling line (114). Said rolling lines (116) are separated from each other by a section of conveyor belt (114) of sufficient length to allow placement of the product belt between one lamination station and the next lamination station. 40. An installation according to any one or more of the claims 24 to 39, characterized in that it comprises a plurality of rolling stations arranged together. 41. The installation according to any one or more of claims 24 to 40, characterized in that at least part of the cylinders (118, 120) of the rolling line (116) are heated. Hot air dryers (122) are arranged in a first unit (124) in which a first drying step is performed on the product web leaving the rolling line (116) and in a second unit arranged in series with said first unit. and a unit (126) of said second unit in which a second drying stage is carried out followed by cooling of the already partially dried product web coming from said first unit (124) 42. A facility according to any one or more of claims 24 to 41, wherein the steps are performed. 43. Installation according to any one or more of the claims 24 to 42, characterized in that inside the dryer (122) with hot air, at least one mesh conveyor is used. Said hot air dryer (122) is provided inside said first unit (124) comprising steel belt or net conveyor belt and inside said second unit (126) of network conveyor belt. 44. A facility according to any one or more of claims 24 to 43, wherein

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