Patent Application
20180368466
The present invention relates to an apparatus and method for conditioning tobacco after curing.
Once tobacco plants have been harvested the leaves are removed, separated and placed into a barn for drying and curing. After curing, the leaves are subsequently conditioned and then packed into bundles or bales for storage or transportation to industry for manufacture into products such as cigars or cigarettes.
The above processing of tobacco is often carried out under humid weather conditions. One benefit of the humidity is that it tends to soften the leaves, which can make them more pliant, i.e. less brittle and liable to damage, during the handling of the tobacco. Indeed, a common procedure for many producers is to spray water onto the leaves as part of the processing if they lack the desired softness.
On the other hand, an excess of moisture may impair the quality and conservation of the tobacco leaves. For example, an excess of moisture may result in serious damage to the final product quality including: fermentation, mould, loss of aroma and distinctive taste, and other chemical changes in the tobacco. The Brazilian Ministry of Agriculture has issued an Ordinance that recommends a moisture level of no more than approximately 17%. However, processed tobacco may end up exceeding this recommended moisture level, for example, because the tobacco has been processed in air of high relative humidity, and/or because additional water has been sprayed onto the tobacco, especially if the amount of sprayed water is high, and/or if the spraying has not been uniform.
Aspects of the invention are defined in the accompanying claims.
According to a first aspect there is provided an apparatus for conditioning of tobacco leaves including a tobacco chamber for storing cured tobacco leaves for conditioning; and an air processing facility. The air processing facility includes a ventilation system for creating an airflow through the apparatus, a heater for adding heat to the airflow; and a humidity generator for adding moisture to the airflow. The airflow is drawn into the air processing facility, passes from the air processing facility into the tobacco chamber, and subsequently exits the apparatus. The apparatus is thus able to condition the tobacco leaves in the chamber to a desired moisture level by using the heater to add heat to the airflow if the moisture level of the tobacco leaves in the chamber is above said desired moisture level, and to add moisture to the airflow if the moisture level of the tobacco leaves in the chamber is below said desired moisture level.
According to a second aspect there is provided a method for conditioning of tobacco leaves including the steps of: introducing tobacco leaves to a tobacco chamber; using a ventilation system to draw air into an air processing facility and pass the air from the air processing facility through the tobacco chamber; heating the airflow if the moisture level of the tobacco leaves in the chamber is above a desired moisture level and using a humidity generator to add moisture to the airflow if the moisture level of the tobacco leaves in the chamber is below the desired moisture level.
The present disclosure helps to control accurately the moisture content of tobacco during conditioning, which is generally performed after curing but before baling, thereby avoiding a situation where, on the one hand, the tobacco which has been dried is overly brittle, resulting in the tobacco being very difficult to handle and bale for transportation, or on the other hand, the tobacco retains too much moisture, and therefore is susceptible to problems such as mould or fermentation.
The present teachings will now be described by way of example only with reference to the following figures in which like parts are depicted by like reference numerals:
While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description of the specific embodiments are not intended to limit the invention to the particular forms disclosed. On the contrary, the invention covers all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims.
In one example, the tobacco chamber 20 is typically 10 m long, 2 m wide and 1.3 m high, but the skilled person will be aware of many other possible sizings. The tobacco chamber 20 is formed of a housing containing one or more racks 22 for supporting tobacco leaves 06 that have been cured. The tobacco leaves 06 may be introduced into the apparatus 100 in the form of individual (separate) tobacco leaves, bundles of tobacco leaves or whole tobacco plants, dependent upon how the previous processing has been performed. An access door may be provided in one wall of the tobacco chamber 20 to allow tobacco 06 to be introduced and removed from the tobacco chamber 20.
The one or more racks 22 are positioned in a central portion of the tobacco chamber 20, and often extend across the entire tobacco chamber 20 to provide the maximum amount of space for the tobacco 06. Each rack 22 is typically formed of a wooden grid or mesh for supporting the tobacco 06, the mesh being sized such that the tobacco does not fall through the holes in the mesh. In alternative examples the racks 22 may be formed of a wire mesh.
The ceiling or roof of the tobacco chamber 20 includes at least one outlet or vent or hole 24 for allowing air to escape out of the tobacco chamber 20, typically into the external environment. In the example shown in
At least one air inlet is provided in the wall 26 separating the tobacco chamber 20 from the air processing chamber 30. The one or more air inlet(s) are positioned in the wall 26 such that they are generally below the tobacco rack(s) 22. In other words, the one or more air inlets in wall 26 open into the area between the floor and the tobacco rack(s), while the outlets 24 are provided in the ceiling above the tobacco rack(s).
In one example, the air processing chamber 30 is typically 2 m long, 0.6 m wide and 1.8 m high, but again the skilled person will be aware of many other possible sizings. The air processing chamber includes at least one air inlet 01 located in one wall of the air processing chamber 30. In the illustrated example, the air inlet 01 is located near the ceiling of the air processing chamber 30. An air outlet is provided near the base of the air processing chamber in the wall 26 adjacent to the tobacco chamber 20. In particular, this air outlet from the air processing chamber 30 connects to the corresponding air inlet into the tobacco chamber 20, thereby providing a connecting passage that allows air to pass through from the air processing chamber 30 into the tobacco chamber 20.
A temperature sensor may be provided at the air outlet of the air processing chamber 30 in order to detect the temperature of air as it passes into the tobacco chamber 20.
A ventilation system 02 is provided in the air processing chamber 30 to draw air into the air processing chamber 30 through air inlet 01 and to expel the air from the air processing chamber 30 into the tobacco chamber 20 via the air outlet in the dividing wall 26. The ventilation system 02 typically includes an electrical engine or motor and a propeller or fan arranged to push air through the air processing chamber 30.
A heater 03 is also provided in the air processing chamber 30. As shown in
A heat exchanger 11 is located between the duct 32 and the chimney 07. This heat exchanger comprises multiple U-shaped pipes which are connected in parallel to receive heated air and exhaust gases from the furnace 10 via duct 32. These heated gases then pass along one leg-of a U-shaped pipe before returning back to the chimney 07 along the other leg of the U-shaped pipe. By having multiple such pipes, the surface area of the heat exchanger 11 is enlarged in order to provide increased heat transfer from the heated gases produced by the furnace (and flowing in the heat exchanger pipes) to the airflow that passes the heat exchanger en route from the air inlet 01 to the air outlet into the tobacco chamber 20.
The air processing chamber 30 also includes a humidity generator 04, which is linked via a connecting pipe 34 to a water reservoir 13 and a submersion pump 12. The water reservoir 13 is provided as a source of water for providing humidity (moisture) to the tobacco leaves 06. In some implementations, the water reservoir 13 may be provided inside the air processing chamber 30, in other implementations, the water reservoir may be provided outside the air processing chamber 30 (as shown in
A submersion pump 12 is provided in the water reservoir 13 to pump water out of the water reservoir 13, through the connecting pipe 34, and then to be dispersed via a nebuliser or atomizer nozzle(s) into the airflow through the air processing chamber 30. In other words, the atomizer nozzle is arranged to release atomized water into the air processing chamber 30 for supply into the tobacco chamber 20.
In operation, air is drawn into the air processing chamber 30 through the inlet 01 by the ventilation system 02. The ventilation then creates an airflow which passes through the air processing chamber 30 and dividing wall 26 into the lower portions of the tobacco chamber 20. In passing through the air processing chamber 30, the airflow passes both the heater 03, in particular the heat exchanger 11, and the humidity generator 04. As described in more detail below, the apparatus 100 controls the heater 03 and the humidity generator 04 to add heat and/or humidity respectively into the airflow. For example, the atomiser nozzle of the humidity generator 04 may introduce water particles into the airflow.
The airflow, with the added heat and/or moisture as appropriate, then passes out of the air processing chamber 30 into the tobacco chamber 20 through the connecting passage in the dividing wall 26. The air enters the tobacco chamber 20 below the one or more racks 22 and passes up through the holes in the rack(s) to the outlets 24 in the ceiling of the tobacco chamber 20. Note that this air therefore does not circulate within the apparatus 100, or within the tobacco chamber 20 or air processing chamber 30, but rather just makes a single pass through the apparatus 100, passing firstly through the air processing chamber 30 and then through the tobacco chamber 20 before exiting the apparatus 100.
As the air passes over the tobacco leaves 06, the tobacco leaves may be heated and/or moistened as appropriate (depending on the moisture and temperature of the air). In particular, if the airflow has added moisture, this will tend to increase the moisture level of the dried tobacco, hence making it easier to handle. Conversely, if the airflow is heated, this will tend to decrease the moisture level of the tobacco (by evaporating moisture from the tobacco).
The apparatus 100 is therefore able to maintain the tobacco leaves at a desired level of moisture (e.g. approximately 17%) by heating the airflow into the tobacco chamber 20 if the current moisture level of the tobacco leaves 06 is too high, for example when the tobacco moisture level exceeds 18%. Alternatively the apparatus is able to increase the moisture level of the tobacco leaves by adding moisture from the humidity generator if the current moisture level of the tobacco leaves 06 is too low. In this manner the apparatus is able to condition the cured tobacco to the optimum moisture level before it is baled and stored.
The assessment of the current moisture level may be made by a skilled human operator, who may then set the heater and the humidity generator to introduce heat or moisture into the airflow accordingly. Alternatively, some or all of this measurement and control procedure may be automated. For example, the tobacco chamber 20 may be provided with one or more humidity sensors (not shown in
By keeping the air at a desired moisture level between curing and baling, the apparatus 100 therefore conditions the tobacco leaves to help optimise the quality of the tobacco. In particular, the moisture level can be maintained at a level which is low enough to avoid problems such as fermentation or mould, but which is still high enough for the leaves to retain an appropriate degree of softness for ease of handling. Furthermore, by controlling the moisture level to a desired (e.g. standardised) amount, the tobacco which is input to the baling process is more consistent and predictable in terms of quality, softness, etc, which can assist in developing a more efficient and reliable baling process.
In conclusion, in order to address various issues and advance the art, this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and to teach the claimed invention(s). It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claims. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc other than those specifically described herein. The disclosure may include other inventions not presently claimed, but which may be claimed in future.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1522277.1 | Dec 2015 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2016/053630 | 11/22/2016 | WO | 00 |
