A large chamber curing process suitable for lower grade tobacco

Abstract

The present application relates to the tobacco leaf baking technical field, disclose a kind of large box baking process suitable for lower tobacco, including tobacco box modification, tobacco loading and ignition baking;Ignition baking includes sequentially carried out yellowing period baking, color fixing period baking and dry muscle period baking;Yellowing period baking includes yellowing early stage, yellowing middle stage and yellowing late stage in turn, color fixing period baking includes color fixing early stage, color fixing middle stage and color fixing late stage in turn, dry muscle period baking includes dry muscle early stage and dry muscle late stage in turn.Tobacco loading box is provided with crossbeam area to divide tobacco loading box into multiple layers, with large tobacco loading amount, good internal moisture retention, better chemical composition conversion, while fully ensuring lower tobacco from green to yellow through baking, by scientifically optimizing temperature stabilization and temperature rising time of each temperature section in the baking process, maximumly reduce the consumption of energy by invalid link, optimize tobacco appearance and improve tobacco quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the tobacco leaf roasting technical field, and in particular to a large box roasting process suitable for lower tobacco leaves. BACKGROUND

[0002] The lower tobacco leaves refer to the tobacco leaves grown in the lower part of the tobacco plant, including the lower two leaves and the foot leaves. The leaves in this part are thin, light in color, low in oil content, low in sugar content, total nitrogen and nicotine content, higher in insoluble nitrogen, higher in ash and pH value than the middle tobacco leaves, faster in burning speed, poor in moisture absorption, high in filling power, and light in weight per unit area.

[0003] Yellowing of the lower tobacco leaves after roasting is the most basic appearance feature of high-quality tobacco leaves. At the same time, the coordination of water loss and yellowing during the roasting and conditioning process, the coordination of the internal chemical composition of the tobacco leaves, the excellent physical and economic properties, and the strong industrial usability. The conventional roasting process uses pole roasting. On the one hand, pole roasting requires the lower tobacco leaves to be hung in sequence, which is high in time cost and labor cost. On the other hand, the gap between the hung lower tobacco leaves is large, the air resistance is small, the water is lost quickly, which is not conducive to the internal chemical composition transformation of the lower tobacco leaves, and the large gap causes the lower tobacco leaves to lose flavor quickly in the later period. Therefore, the conventional roasting process will cause the lower tobacco leaves after roasting to have a low sugar-nicotine ratio index and a slightly high protein content, which will produce a large irritation during smoking, and the roasted tobacco leaves will have different degrees of green veins and green leaves. The degree of yellowing is not enough, the internal starch, protein and other substances of the tobacco leaves are not decomposed and transformed enough, the chemical composition is not coordinated, the aroma is poor, the green and miscellaneous smell is heavy, and it is not conducive to improving the industrial usability of the tobacco leaves. SUMMARY

[0004] In order to solve one or more technical problems in the prior art, or at least provide a beneficial alternative, the present application provides a large box roasting process suitable for lower tobacco leaves, which solves the problem that the conventional roasting process causes the lower tobacco leaves to have insufficient yellowing degree, the internal starch, protein and other substances of the tobacco leaves are not decomposed and transformed enough, the chemical composition is not coordinated, the aroma is poor, the green and miscellaneous smell is heavy, and it is not conducive to improving the industrial usability of the tobacco leaves.

[0005] The large box roasting process suitable for lower tobacco leaves disclosed by the present application comprises:

[0006] (1) modification of the tobacco loading box; the large box roasting process uses a tobacco loading box equipped with a fan, the tobacco loading box is provided with a box door, and a cross beam area is further provided to sequentially divide the tobacco loading box from the bottom to the top into a first layer, a second layer, a third layer, a fourth layer and a fifth layer;

[0007] (2) loading tobacco; setting a loading weight, loading tobacco by a special loading machine, the loading machine being provided with a three-stage conveying system to convey tobacco from the ground to a high place and then evenly scatter in the loading box, automatically stop when the loading weight is reached, close the box door, and perform a plug insertion operation, and the loading is completed when the plug insertion is completed;

[0008] (3) firing and baking; including yellowing period baking, color fixing period baking and dry muscle period baking performed in sequence; the yellowing period baking includes yellowing pre-period, yellowing middle period and yellowing post-period in sequence, the color fixing period baking includes color fixing pre-period, color fixing middle period and color fixing post-period in sequence, and the dry muscle period baking includes dry muscle pre-period and dry muscle post-period in sequence.

[0009] Further comprising the following technical features:

[0010] In the yellowing pre-period, the fan is opened at low speed, the dry ball temperature is raised to 36℃, the wet ball is kept at 36℃, the temperature is stabilized for 2-3 hours, the second layer of leaves is in an expanded state, the dry ball temperature is raised to 38℃ at a speed of 1℃ / hour, the temperature is stabilized for 8-10 hours, the wet ball temperature is kept at 38℃ in the first half and kept at 37℃ in the second half, until the second layer of tobacco leaves is heated, the leaf tip is slightly soft, and the leaves are 3-4 yellow.

[0011] In the yellowing middle period, the fan is opened at low speed, the dry ball temperature is raised to 40℃ at a speed of 1℃ / hour, the wet ball temperature is 36℃, the temperature is stabilized for 7-9 hours; deep dehumidification is performed, the wet ball temperature is reduced to 34-34.5℃, maintained for 1.5-3 hours, the dry ball temperature is kept unchanged, the wet ball temperature is raised to 35-35.5℃, and the temperature is stabilized for 8-12 hours, until the second layer of leaves is soft, the main vein is hard and brittle, the third layer of leaf tip and leaf edge is soft, and the leaves are 7 yellow.

[0012] In the yellowing post-period, the fan is opened at high speed, the dry ball temperature is raised to 42℃ at a speed of 0.5℃ / hour, the wet ball temperature is kept at 35℃, the temperature is stabilized for 7-9 hours; the wet ball temperature is reduced to 34-34.5℃, and the temperature is stabilized for 8-10 hours, until the second layer of tobacco leaves is soft, the main vein is unbroken, and the third layer of tobacco leaves is soft, and the leaves are 8 yellow.

[0013] In the color fixing pre-period, the fan is opened at high speed, the dry ball temperature is raised to 45℃ at a speed of 0.3℃ / hour, the wet ball temperature is 34-35℃, the temperature is stabilized for 12-16 hours, until the second layer of tobacco leaves is 9 yellow, 50% of the leaves are dry, the third layer of tobacco leaves is 9 yellow, the leaf tip and leaf edge are dry, and the main vein is soft.

[0014] In the color fixing middle stage, the fan is opened at high speed, the dry ball temperature is increased to 47 DEG C at the speed of 0.5 DEG C / hour, the wet ball temperature is kept at 34.5-35.5 DEG C, and the temperature is kept stable for 15-20 hours; during the temperature keeping, deep moisture removal is carried out once, the wet ball is adjusted to 34 DEG C, and the time is 1.5-2 hours, so that the tobacco leaves of the second layer and the third layer reach the state of yellow sheet and yellow core, and the leaves are completely dry.

[0015] In the color fixing late stage, the fan is opened at high speed, the dry ball temperature is increased to 50 DEG C at the speed of 0.5 DEG C / hour, the wet ball temperature is kept at 35-36 DEG C, the temperature is kept stable for 12-15 hours, the dry ball temperature is increased to 54 DEG C at the speed of 0.5 DEG C / hour, the wet ball temperature is kept at 36-36.5 DEG C, the temperature is kept stable for 14-16 hours, so that at least 1 / 2 of the tobacco core of the tobacco leaves of the second layer is dry, and at least 1 / 3 of the tobacco core of the tobacco leaves of the third layer is dry.

[0016] In the dry core early stage, the fan is opened at low speed, the dry ball temperature is increased to 60 DEG C at the speed of 1 DEG C / hour, the wet ball temperature is kept at 36.5-37 DEG C, and the temperature is kept stable for 8 hours;

[0017] In the dry core late stage, the fan is kept at low speed, the dry ball temperature is increased to 70 DEG C at the speed of 1 DEG C / hour, the wet ball temperature is kept at 38-39 DEG C, and the temperature is kept stable for 15-20 hours, so that the whole furnace is dry.

[0018] The loading box is modified to adopt the size of 2600mm*780mm*1700mm in length* width* height, and directional wheels are installed at the bottom of the loading box.

[0019] The loading weight is calculated according to the water content of the lower tobacco leaves; when the water content is greater than 90%, the loading weight is controlled to be 375-400Kg / box, when the water content is 85%-90%, the loading weight is 400-425Kg / box, and when the water content is less than 85%, the loading weight is 425-450Kg / box.

[0020] The application has the beneficial effects due to the adoption of the above technical scheme:

[0021] The large-box roasting process has the advantage of large smoke loading. Through scientific optimization of the temperature stabilization and temperature rising time of each temperature section in the roasting process, the energy consumption of invalid links is minimized. The large-box roasting process has the advantage of large smoke loading. Through scientific optimization of the temperature stabilization and temperature rising time of each temperature section in the roasting process, the energy consumption of invalid links is minimized. The appearance of the lower tobacco leaf after roasting is improved compared with the conventional roasting process. The structure of the lower tobacco leaf after roasting is more loose, the color is mostly orange, the oil content is increased, the color is enhanced, and the lower tobacco leaf does not need to be hung during the large-box roasting process. The space between the tobacco leaves is small, the air resistance is large, the internal moisture is well maintained, the chemical composition is better converted, the lower tobacco leaf can be fully guaranteed to change from green to yellow after roasting, and the green content of the tobacco leaf after roasting is significantly reduced. At the same time, due to the small space and large air resistance, the aroma loss is small, the aroma quality of the lower tobacco leaf after roasting is higher than that of the conventional roasting process, the amount of miscellaneous gas and the irritability of the lower tobacco leaf are reduced, and the aftertaste is more comfortable. The appearance of the tobacco leaf is optimized, and the quality of the tobacco leaf is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 The figure is a structural schematic diagram of the tobacco loading box in an embodiment of the present application.

[0024] Explanation of reference signs:

[0025] 1-tobacco loading box, 2-directional wheel, 3-cutting steel needle. DETAILED DESCRIPTION

[0026] In order to more clearly explain the overall concept of the present application, the following will be described in detail in an exemplary manner by combining the drawings in the specification.

[0027] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below by combining the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0028] It should be noted that in the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0029] In addition, in the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0030] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0031] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship of two elements. However, it is noted that direct connection means that the connection between the two main bodies does not form a connection relationship through a transition structure, but is connected only through a connection structure to form a whole. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. In the description of the present application, the description referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0033] The specific scheme adopted is: a large box curing process suitable for lower tobacco leaves, (1) modification of tobacco loading box; the large box curing process uses a tobacco loading box and is equipped with a fan, the tobacco loading box is provided with a box door, and in addition, a beam area is provided to sequentially divide the tobacco loading box from the bottom to the top into a first layer, a second layer, a third layer, a fourth layer and a fifth layer;

[0034] (2) Loading tobacco; setting the loading weight, and loading tobacco by a special loading machine, which is provided with a three-stage conveying system to make the tobacco evenly scattered in the loading box after being conveyed from the ground to a high place, and automatically stops when the set loading weight is reached, closes the box door, and performs the inserting operation, and the inserting operation is completed to finish the loading;

[0035] (3) Ignition curing; including sequentially performed yellowing period curing, color fixing period curing, and dry muscle period curing; the yellowing period curing includes, in sequence, pre-yellowing period, mid-yellowing period, and post-yellowing period, the color fixing period curing includes, in sequence, pre-color fixing period, mid-color fixing period, and post-color fixing period, and the dry muscle period curing includes, in sequence, pre-dry muscle period and post-dry muscle period.

[0036] The loading box is adopted, and the loading box is provided with a beam area to divide the loading box into multiple layers, the loading amount is large, and the stable temperature and temperature rising time of each temperature section in the curing process are scientifically optimized to minimize the energy consumption of invalid links. The appearance of the lower tobacco after the large-box curing process is improved compared with the conventional curing process, the structure of the lower tobacco after the large-box curing process is more loose, the color is mostly orange, the oil content is increased, the color is enhanced, compared with the conventional hanging pole curing (fresh tobacco leaves are hung on tobacco poles), the tobacco leaves do not need to be hung during the large-box curing, the labor cost is reduced, at the same time, the space between the tobacco leaves is small, the air flow resistance is large, the internal moisture is well maintained, which is conducive to better chemical composition transformation, can fully ensure that the lower tobacco changes from green to yellow after curing, and significantly reduces the green content of the tobacco leaves after curing. At the same time, due to the small space and large air flow resistance, the aroma loss is small, the aroma quality of the lower tobacco after curing is higher than that of the conventional curing process, the appearance of the tobacco leaves is optimized, and the quality of the tobacco leaves is improved, and the appearance and quality of the tobacco leaves are improved.

[0037] In one embodiment, the ignition curing includes the following steps:

[0038] Pre-yellowing period: the fan is opened at low speed, the dry bulb temperature is increased to 36℃, the wet bulb is maintained at 36℃, and stable temperature is maintained for 2-3 hours, until the second layer of leaves is in an inflated state, the dry bulb temperature is increased to 38℃ at a speed of 1℃ / hour, stable temperature is maintained for 8-10 hours, the wet bulb temperature is maintained at 38℃ in the first half and 37℃ in the second half, until the second layer of tobacco leaves is heated, the leaf tip is slightly soft, and 3-4 yellowing is presented.

[0039] Mid-yellowing period: the fan is opened at low speed, the dry bulb temperature is increased to 40℃ at a speed of 1℃ / hour, the wet bulb temperature is 36℃, stable temperature is maintained for 7-9 hours; deep moisture removal is performed, the wet bulb temperature is reduced to 34-34.5℃, maintained for 1.5-3 hours, the dry bulb temperature is maintained, the wet bulb temperature is increased to 35-35.5℃, stable temperature is maintained for 8-12 hours, until the second layer of leaves is soft, the main vein is hard and brittle, the third layer of leaf tip and leaf edge is soft, and 7 yellowing is achieved.

[0040] Late yellowing stage: the fan runs at high speed, and the dry ball temperature is increased to 42℃ at a rate of 0.5℃ / hour, and the wet ball temperature is kept at 35℃, and the temperature is kept stable for 7-9 hours; the wet ball temperature is decreased to 34-34.5℃, and the temperature is kept stable for 8-10 hours, until the main veins of the second layer of tobacco leaves are unbroken, and the leaves have a silk feel, and the third layer of tobacco leaves is soft, and when the leaves are 80% yellow, the fire is turned to enter the color fixing stage.

[0041] It should be noted that if the leaves do not meet the color fixing standard, they need to be continued to be waited for, and cannot be forcibly turned to enter the color fixing stage.

[0042] Early color fixing stage: the fan runs at high speed, and the dry ball temperature is increased to 45℃ at a rate of 0.3℃ / hour, and the wet ball temperature is kept at 34-35℃, and the temperature is kept stable for 12-16 hours; until the second layer of tobacco leaves reaches 90% yellow, and 50% of the leaves are completely dry, and the third layer of tobacco leaves is 90% yellow, and the leaf tips and edges begin to dry, and the main veins are soft.

[0043] Middle color fixing stage: the fan runs at high speed, and the dry ball temperature is increased to 47℃ at a rate of 0.5℃ / hour, and the wet ball temperature is kept at 34.5-35.5℃, and the temperature is kept stable for 15-20 hours; during the stable temperature period, deep moisture removal is performed once, the wet ball is adjusted to 34℃, and the time is 1.5-2 hours, so that the second layer and the third layer of tobacco leaves reach the state of yellow leaves and yellow veins, and the leaves are completely dry.

[0044] Late color fixing stage: the fan runs at high speed, and the dry ball temperature is increased to 50℃ at a rate of 0.5℃ / hour, and the wet ball temperature is kept at 35-36℃, and the temperature is kept stable for 12-15 hours, and then the dry ball temperature is increased to 54℃ at a rate of 0.5℃ / hour, and the wet ball temperature is kept at 36-36.5℃, and the temperature is kept stable for 14-16 hours, so that at least 1 / 2 of the tobacco veins of the second layer of tobacco leaves are dry, and at least 1 / 3 of the tobacco veins of the third layer of tobacco leaves are dry.

[0045] Early dry vein stage: the fan runs at low speed, and the dry ball temperature is increased to 60℃ at a rate of 1℃ / hour, and the wet ball temperature is kept at 36.5-37℃, and the temperature is kept stable for 8 hours;

[0046] Late dry vein stage: the fan keeps running at low speed, and the dry ball temperature is increased to 70℃ at a rate of 1℃ / hour, and the wet ball temperature is kept at 38-39℃, and the temperature is kept stable for 15-20 hours, so that the whole furnace is dry.

[0047] Among them, before the ignition baking, the fan runs at high speed for 2-3 hours to dredge the air flow channel, so that the moisture on the surface of the lower tobacco leaves is removed, which is beneficial to improve the baking efficiency.

[0048] In addition, during the deep moisture removal operation in the middle yellowing stage, the specific time and the wet ball temperature are adjusted adaptively according to the current moisture content of the lower tobacco leaves, and when the moisture content of the lower tobacco leaves is high, the wet ball temperature is adjusted to be low, and the time is correspondingly lengthened.

[0049]

[0050] Table 1. Intrinsic chemical component content of lower tobacco leaves under different roasting processes

[0051] As can be seen from Table 1, the layered process of large box loading tobacco box can significantly improve the quality of the roasted tobacco leaves. The total sugar and reducing sugar content of the tobacco leaves under the large box roasting process is significantly higher than that under the conventional roasting process, and the starch content is 2.8%, which is 1.54% lower than that under the conventional roasting process, indicating that the starch conversion under the large box roasting process is more sufficient and more in line with the characteristics of high-quality tobacco leaves. In addition, the total nitrogen and nicotine content under the large box roasting process is lower than that under the conventional process, and the sugar-alkali ratio reaches 10.81, which is conducive to maintaining the acid-base balance during smoking and meeting the requirements of high-quality tobacco leaf indicators; while the sugar-alkali ratio under the conventional roasting process is slightly low, and the protein content is slightly high, which will produce greater irritation during smoking, which is not conducive to improving the industrial usability of tobacco leaves.

[0052] In addition, through this embodiment, the appearance of the lower tobacco leaves is improved compared to the conventional roasting process, and the structure of the lower tobacco leaves after roasting under the large box roasting process is more loose, the color is mostly orange, the oil content is increased, and the color is enhanced.

[0053] As shown in Figure 1 In an embodiment, a tobacco loading chamber is provided, which aims to maximize the loading capacity while ensuring the quality of the roasted tobacco. The length of the tobacco loading chamber is 8000mm, and 10 tobacco loading boxes 1 are arranged therein. The tobacco loading box 1 is modified to have a size of 2600mm x 780mm x 1700mm, and is equipped with a steel needle 3 and a directional wheel 2 at the bottom. The bottom layer and the top layer of the tobacco loading box 1 are provided with anti-falling grids. During the roasting process, if the lower tobacco leaves collapse due to water loss, the lower tobacco leaves will be too close to each other due to the collapse, making it difficult for the water to evaporate during roasting, resulting in the roasting of the tobacco leaves. To avoid roasting the tobacco leaves, the steel needle 3 is inserted into the tobacco loading box 1 during the loading process to fix the lower tobacco leaves in the tobacco loading box 1, preventing the lower tobacco leaves from collapsing due to water loss, thereby reducing the proportion of roasting.

[0054] In addition, an observation window is provided on the door of the tobacco loading chamber, and the height of the observation window is set such that at least the second and third layers of the tobacco loading box 1 can be seen outside the tobacco loading chamber. During the ignition and roasting process, the roasting condition of the lower tobacco leaves can be observed through the observation window, or the change of the observation window can be combined to determine whether the lower tobacco leaves enter the next stage of roasting. For example, in the early yellowing stage, in addition to the condition of the lower tobacco leaves, the appearance of water mist in the observation window indicates that the lower tobacco leaves enter the middle yellowing stage.

[0055] In one embodiment, the orientation wheel 2 at the bottom of the tobacco loading box 1 has a diameter of 120 mm and a width of 50 mm. Each tobacco loading box 1 is equipped with 75 insertion steel needles 3, which are made of a national standard round steel with a diameter of 8 mm, each insertion steel needle 3 has a length of 760 mm and a handle length of 80 mm, and the insertion steel needle 3 is made into a 7-shaped form and is horizontally inserted from the front C-shaped beam opening during use. In addition, all the assembly connections of the tobacco loading box 1 are welded, and the materials are all galvanized.

[0056] In addition, when setting the tobacco loading weight, the tobacco loading weight is calculated according to the water content of the lower tobacco leaves. When the water content is greater than 90%, the tobacco loading weight is controlled to be 375-400 Kg / box; when the water content is 85%-90%, the tobacco loading weight is 400-425 Kg / box; and when the water content is less than 85%, the tobacco loading weight is 425-450 Kg / box.

[0057] It should be noted that, in other embodiments, the tobacco loading weight using the tobacco loading box 1 is not more than 500 Kg / box to ensure the baking quality.

[0058] Load (kg / oven) Dry load (Kg / oven) Roasting length (h / oven) Coal consumption (kg / oven) Coal consumption per kg dry load (Kg) Big box roasting process 4419 528.59 173 650 1.23 Conventional roasting process 3251 379.35 161 712 1.88 Comparison 1168 149.24 12 -62 -0.65

[0059] Table 2. Coal consumption statistics under different baking processes

[0060] As can be seen from Table 2, the large-box baking process has the advantage of large tobacco loading capacity, and the temperature stabilization and temperature rising time of each temperature section in the baking process is scientifically optimized. The coal consumption per kilogram of lower dry tobacco is reduced by 0.65 Kg compared with the conventional baking process, which maximally reduces the energy consumption of invalid links.

[0061] Under the large-box baking process, the proportion of superior tobacco (X1F) of the lower tobacco leaves is increased by 3.3%, and the proportion of burnt tobacco is reduced by 2.5%, which improves the baking quality of the lower tobacco leaves and reduces the loss.

[0062] The technical solutions protected by the present application are not limited to the above embodiments. It should be noted that the combination of the technical solutions of any one embodiment with those of one or more other embodiments is within the scope of the present application. Although the present application has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of the present application.

Claims

1. A large-box curing process suitable for lower tobacco leaves, characterized in that, Includes the following steps: (1) Modification of the smoke box; The large box baking process adopts a smoke box equipped with a fan. The smoke box is equipped with a door. In addition, a crossbeam area is set so that the smoke box is divided into the first layer, the second layer, the third layer, the fourth layer and the fifth layer from the bottom to the top. (2) Loading tobacco; Set the loading weight and load tobacco using a special loading machine. The loading machine is equipped with a three-stage conveying system so that the tobacco leaves are conveyed from the ground to a high place and then evenly scattered in the loading box. After the set loading weight is reached, the machine will stop automatically, the box door will be closed, and the insertion of the rods will be carried out. The loading is completed when the rods are inserted. (3) Ignition and baking; including the yellowing period baking, color setting period baking and drying period baking in sequence; the yellowing period baking includes the early yellowing stage, the middle yellowing stage and the late yellowing stage in sequence, the color setting period baking includes the early color setting stage, the middle color setting stage and the late color setting stage in sequence, and the drying period baking includes the early drying stage and the late drying stage in sequence. in, In the early stage of yellowing, the fan is turned on at low speed to raise the dry bulb temperature to 36°C and the wet bulb temperature is maintained at 36°C for 2-3 hours until the leaves of the second layer show signs of expansion. Then, the dry bulb temperature is raised to 38°C at a rate of 1°C / hour and maintained for 8-10 hours. The wet bulb temperature is maintained at 38°C for the first half and 37°C for the second half until the leaves of the second layer of tobacco are warm, the leaf tips are slightly soft, and they show 30-40% yellowing. During the middle stage of yellowing, the fan is turned on at low speed, at a rate of 1℃ / hour, to raise the dry bulb temperature to 40℃ and the wet bulb temperature to 36℃, and maintain the temperature for 7-9 hours; deep dehumidification is then carried out to lower the wet bulb temperature to 34-34.5℃ and maintain it for 1.5-3 hours, keeping the dry bulb temperature unchanged, and then raising the wet bulb temperature to 35-35.5℃ and maintaining the temperature for 8-12 hours, until the leaves of the second layer soften, the midrib hardens and becomes brittle, and the tips and edges of the leaves of the third layer soften, reaching 70% yellowing; During the later stage of yellowing, the fan is turned on at high speed to raise the dry bulb temperature to 42°C at a rate of 0.5°C / hour, while maintaining the wet bulb temperature at 35°C for 7-9 hours. Then, the wet bulb temperature is lowered to 34-34.5°C and maintained for 8-10 hours until the main vein of the second layer of tobacco leaves is unbroken and the leaves have a silky feel, and the leaves of the third layer of tobacco leaves become soft. When the leaves reach 80% yellowing, the fire is switched to enter the color-fixing baking stage. In the early stage of color fixing, the fan is turned on at high speed to raise the dry bulb temperature to 45°C at a rate of 0.3°C / hour, and the wet bulb temperature to 34-35°C, and the temperature is stabilized for 12-16 hours; until the tobacco leaves of the second layer reach 90% yellow and 50% of the leaves are completely dry, and the tobacco leaves of the third layer reach 90% yellow, the leaf tips and edges begin to dry, and the midrib softens; During the color-fixing phase, the fan is turned on at high speed to raise the dry-bulb temperature to 47°C at a rate of 0.5°C / hour, while the wet-bulb temperature is maintained at 34.5-35.5°C for 15-20 hours. During the temperature stabilization period, a deep dehumidification is performed, with the wet-bulb temperature adjusted to 34°C for 1.5-2 hours, so that the tobacco leaves of the second and third layers reach a state of yellow leaves and yellow veins, and the leaves are completely dry. During the later stage of color fixing, the fan is turned on at high speed to raise the dry bulb temperature to 50°C at a rate of 0.5°C / hour, while maintaining the wet bulb temperature at 35-36°C for 12-15 hours. Then, the dry bulb temperature is raised to 54°C at a rate of 0.5°C / hour, while maintaining the wet bulb temperature at 36-36.5°C for 14-16 hours. This process ensures that at least half of the tobacco fibers in the second layer of tobacco leaves are dried, and at least one-third of the tobacco fibers in the third layer of tobacco leaves are shrunk and dried. In the early stage of the drying process, the fan is running at low speed to raise the dry bulb temperature to 60°C at a rate of 1°C / hour, while the wet bulb temperature is maintained at 36.5-37°C for 8 hours. During the later stage of the drying process, the blower operates at a low speed, raising the dry bulb temperature to 70°C at a rate of 1°C / hour, while maintaining the wet bulb temperature at 38-39°C for 15-20 hours to ensure the entire furnace is dry.

2. The large-box drying process for lower tobacco leaves according to claim 1, characterized in that, The modified tobacco filling box has dimensions of 2600mm × 780mm × 1700mm (length × width × height) and is equipped with directional wheels at the bottom.

3. The large-box drying process for lower tobacco leaves according to claim 2, characterized in that, The weight of the tobacco is calculated based on the moisture content of the lower tobacco leaves. When the moisture content is greater than 90%, the weight of the tobacco is controlled at 375-400 kg / box; when the moisture content is 85%-90%, the weight of the tobacco is 400-425 kg / box; and when the moisture content is less than 85%, the weight of the tobacco is 425-450 kg / box.

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