JP4386337B2 - Automatic drying method of leaf tobacco using automatic drying program - Google Patents

Description

  The present invention relates to an automatic drying method for leaf tobacco using an automatic drying program used when a drying process of leaf tobacco is controlled by a computer.

  Leaf tobacco is dried mainly by a bulk dryer. This bulk drying apparatus is equipped with a leaf tobacco storage chamber (hereinafter referred to as a drying chamber), a hot air generator, a blower, an outside air intake and exhaust port for ventilation, an air circulation duct, and the like. Is dried by blowing air. Conventionally, drying of leaf tobacco has been carried out by the five senses of an operator with reference to a drying temperature table, but in recent years, it is common to control a bulk drying apparatus with a computer storing a drying program.

In the drying of leaf tobacco, not only dehydration drying, but also through a curing process that promotes scientific changes in the content components in order to bring out the color choices and flavors peculiar to tobacco, followed by dehydration of the mesophyll part and the middle bone part It is important to apply drying. Therefore, the drying process is roughly divided into three stages: a fermentation period and a yellowing period that keep the water content of leaf tobacco moderately, a color selective fixation period that mainly dehydrates the mesophyll, and a middle bone drying period that dries the bone. Drying proceeds.

  Specifically, in accordance with the progress of drying, the temperature is increased from about 38 ° C. to 2 ° C. to 3 ° C. over a certain period of time, and the middle bone is dried at a final temperature of 68 ° C. On the other hand, the humidity is controlled by the wet bulb temperature, but the yellowing period and the color selective fixation period are in the range of about 36 ° C to 38 ° C, and the final drying is performed at 40 ° C. When the drying state is adjusted to relative humidity, the yellowing period is set to about 95 to 75%, and the middle bone drying period is set to about 50 to 20%. Thus, conventionally, a method of drying while gradually reducing the humidity from the start to the end of drying has been adopted.

  Then, as a drying control method for performing the above drying process satisfactorily, the wet bulb temperature in the drying chamber is maintained at a constant value (for example, 38 ° C.) throughout the entire drying process or for each step, and the dry bulb temperature is kept constant. A drying method has been developed and implemented step by step with a predetermined value as the drying time elapses (see, for example, Patent Document 1).

JP-A-57-74079 (pages 2 to 3 and FIG. 2)

  However, in the above-described conventional method, the dry bulb temperature is raised for a preset time, so no matter how hard the time setting is, the dry bulb temperature rise time may not be compatible with the drying progress of the leaf tobacco being dried. In many cases, the actual state is not necessarily appropriate as an automatic drying control method for leaf tobacco. That is, at a constant temperature, the temperature does not penetrate to the inside of the tobacco tobacco suspension rack. If the temperature is raised stepwise, only a certain period of fermentation is possible. It is necessary to determine in each temperature zone of yellowing state and dry state. Condensation may occur due to rapid temperature rise inside the rack. The damper is indeterminate and there is a problem that it is difficult to grasp the dry state.

Therefore, the heating control of the heating device in the drying chamber in which the leaf tobacco of the present invention is accommodated, and the intake / exhaust control into the drying chamber, the temperature increase or decrease of the dry bulb temperature in the drying chamber and the temperature increase or decrease of the wet bulb temperature The automatic drying method of leaf tobacco using the automatic drying program that controls the temperature drop is the fermentation period of the leaf tobacco drying process , from the end of fermentation to the early stage of yellowing, and from this end of yellowing period to the color selection fixation period and the color selection fixation period. The operation of switching the temperature of the dry bulb and the temperature of the wet bulb in each stage from the transition to the dry stage of bone and the switching operation of the temperature of the wet bulb is performed smoothly and gradually. The first feature is that the working time is shortened. In addition, the dry bulb / wet bulb temperature for checking the dry state from this yellowing period to the color selection fixed period, from this color selection fixed period to the color selection fixed period, and from the color selection fixed period to the middle bone dry period performs control, the damper opening degree changes and / or via an on-off state to allow a determination of the drying degree as a second aspect, further, during this蒸酵period, dry bulb in accordance with the properties of the leaf tobacco The third feature is that the draining operation to raise the temperature is set to be interruptible . Furthermore, in order to avoid the uneven humidity and dehydration that occur during this yellowing period, the leaf tobacco is sufficiently warmed to diffuse inside. The fourth feature is that the operation for promoting the above is set to enable the interrupt operation . In addition, at the end of the middle bone dry period, the fifth feature is that the stage in which the transition of the damper opening is maintained in the fully closed state for a predetermined time is the end of drying, and it is determined that all of the leaf tobacco drying process is completed. .

  According to the present invention, it is possible not only to eliminate the waste of drying time of leaf tobacco, to improve the operation rate by improving the dewaterability of leaf tobacco, but also to easily and labor-saving confirmation of the dry state, quality Can get good dry leaves.

Next, embodiments of the present invention will be described based on examples shown in the drawings.
FIG. 1 is a schematic diagram of a drying apparatus for carrying out the leaf tobacco drying method according to the present invention, FIG. 2 is a block diagram showing a control unit, FIG. 3 is a drying process diagram according to the present invention, and FIGS. 4 and 5 are according to the present invention. It is a temperature table | surface for implementing the drying program of leaf tobacco.

The leaf tobacco drying method according to the present invention is carried out in a bulk drying apparatus as shown in FIG.
In FIG. 1, A is a drying chamber, B is a hot air generator, and these drying chamber A and hot air generator B are provided integrally adjacent to each other, and are opened at the lower part of the partition wall 1 that divides them. The hot air blowing port 2 and the circulation port 3 established in the upper part of the partition wall 1 communicate with each other.

  The hot air generator B includes a blower a, a furnace 4 constituting a heating device b, a heat exchanger 5 and the like, and a ceiling wall 6 is provided with an intake port 8 provided with a damper 7. The drying chamber A is provided with a floating floor 10 having a gap with the floor 9 at the same level as the upper edge of the warm air outlet 2 or slightly above it. A space between them is a hot air introduction space 11. A large number of straightening holes 12 are formed in the floating floor 10 over the entire surface. In the drying chamber A, an exhaust port 14 is formed at the upper portion of one of the side walls 13.

  Then, the warm air generated by the warm air generator B is blown into the warm air introduction space 11 between the drying chamber A floor 9 and the floating floor 10 through the warm air outlet 2, and is passed through the rectifying holes 12 of the floating floor 10. The air flows into the drying chamber A and spreads upward and flows uniformly. A part of the air is discharged from the exhaust port 14 to the outside, and the rest returns to the hot air generator B from the circulation port 3 and is newly supplied from the intake port 8. Then, it is heated again together with the outside air sucked in, and sent to the drying chamber A again. That is, the drying chamber A is configured such that warm air circulates and flows inside. Further, in this dryer, a dry bulb temperature sensor 17 and a wet bulb temperature sensor 18 are provided in the drying chamber A, and these sensors 17 and 18 communicate with a control unit C including a computer 21.

  In the leaf tobacco dryer, the leaf tobacco T is suspended on the leaf tobacco suspension 15 and suspended on the shelf rail 16 in the drying chamber A in two stages, upper and lower, and the temperature and humidity in the drying chamber A are controlled. , Curing and drying. That is, the temperature control is performed by comparing the set value with the dry bulb temperature detected by the dry bulb temperature sensor 17 and controlling the on / off of the heating device b (burner) of the furnace 4, and the humidity control is performed by the wet bulb temperature sensor. The wet bulb temperature detected by 18 is compared with a set value, and the damper 7 is subjected to P · PI or PID control according to the deviation.

  The heating device b is a heat generation source of a hot air generator B that generates hot air and circulates the hot air into the drying chamber A. The heating device b opens and closes an electromagnetic valve 26 provided in the heating device b, an ignition device, and the like. The damper 7 controls the intake of outside air into the drying chamber A, and the opening degree is varied by forward / reverse rotation of the motor 27.

  The temperature and humidity are controlled by the heating device b and the damper 7 by the computer 21 stored in the control unit C based on the basic drying program. And the warm air generator B is operated based on this basic program, and gradually increases in temperature with the passage of time. As shown in FIG. 3, the fermentation process (step S1), the yellowing process (step) S2), the color fixation process (step S3), and the intermediate bone drying process (step S4) are sequentially performed.

  For temperature control and humidity control, for example, a digital program controller capable of storing 8 × 5 patterns of 15 steps per pattern was used. A temperature sensing resistor was used as the temperature sensor, and the wet bulb temperature sensor 18 was covered with gauze and the moisture bulb temperature sensor 18 was covered with gauze, and was placed in the vicinity of the outlet.

  As shown in FIG. 2, the control unit C includes a computer 21, and a temperature increase command signal is sent from the output unit 20 by a drying program stored in advance in the ROM 24 of the computer 21 to operate the heating device b. The operation of automatically increasing the set value of the dry bulb temperature is performed, the temperature is about 3 ° C. during the yellowing period from the start of drying throughout the entire drying time, the temperature is about 2 ° C. to 10 ° C. during the color selection fixing period, Further, during the middle bone fixation period, the temperature is raised again by 2 ° C. to 15 ° C. Also, a damper opening / closing control signal for opening / closing the damper 7 is sent from the output unit 20. Then, in drying the leaf tobacco T accommodated in the drying chamber A, the wet bulb temperature setting is set to a constant temperature (for example, 38 ° C.), and the dry bulb set temperature is set to the initial temperature (for example, 35 ° C.) to start drying. To do. In the figure, reference numeral 25 denotes a display unit that visually shows the elapsed time, the dry bulb temperature, the change in the wet bulb temperature due to the elapsed time, the change in the damper opening, and the like.

  Changes in the wet bulb temperature and the dry bulb temperature in the drying chamber A are detected by the dry bulb temperature sensor 17 and the wet bulb temperature sensor 18, and the signal is sent to the control unit C via the input unit 19. The damper 7 and the heating device b which is a heat source of the hot air generator B are controlled so as to maintain the dry bulb temperature and the wet bulb temperature set in advance by the program. When the dry bulb temperature in the drying chamber A decreases by a certain value (for example, 40 ° C. to 39 ° C.), the signal is sent to the RAM 22 via the input unit 19, and the temperature raising command signal is sent from the CPU 23 to the dry bulb. The temperature sensor 17 is automatically operated to increase the measured temperature. Therefore, the dry bulb temperature in the drying chamber is increased by a predetermined value, and the leaf tobacco T is increased in dehydration rate and drying proceeds again. At the same time, a damper open / close signal is sent, so that the damper 7 automatically adjusts the opening degree of the intake port 8 so that the wet bulb temperature in the drying chamber A is constant or rises / falls to a set value (for example, 38 ° C.). Adjust. The dry bulb temperature and the wet bulb temperature are increased or decreased by one step by the same operation as described above every time the dry program temperature rises from the time when the dry bulb temperature is raised, and this is repeated until the drying is completed.

Drying based on a table (hereinafter, simply referred to as a temperature table) showing temperature and humidity changes depending on the dry bulb temperature and the elapsed time of the wet bulb temperature as shown in FIG. Drying was controlled using a program.
The temperature rise value and the drying time in each drying stage are controlled by a drying program stored in advance in the ROM 24 of the computer 21. First, the fermentation period in the leaf tobacco drying process is a time for increasing the drying efficiency of the leaf tobacco T (making the subsequent drainage good), and the damper 7 is fully closed and the relative humidity in the drying chamber A is This is a step of maintaining the amount of water in the leaf tobacco T and the drying chamber A for a certain period of time so as to be in a state of 100%, and once the water content in the drying chamber A is in an equilibrium state, and the fermentation time varies depending on the sweating amount of the leaf tobacco T . The wet bulb temperature is gradually decreased from 40 ° C. to 38 ° C. while maintaining the dry bulb temperature at 40 ° C. by the heating of the heating device b (indicated on the temperature table by a descending gradient line). Take control. Thereby, a fermentation time will be automatically adjusted according to the sweating amount of the accommodated leaf tobacco T. FIG. That is, for example, as the humidity in the drying chamber A is lower than 100%, the start of opening of the damper 7 is delayed, and thus the start of opening of the damper 7 is automatically determined so that the fermentation period naturally becomes longer. Therefore, waste of the fermentation time can be eliminated. That is, conventionally, since the time from the start of the fermentation to the start of the opening of the damper 7 has been controlled by arbitrarily determining the time at which the fermentation is expected to be completed, it is necessary to set the fermentation time longer. However, this is not only corrected but can be shortened, and the visual confirmation of the exposed state, which was necessary in the past, becomes unnecessary.

  Then, from the end of the fermentation period to the early stage of the yellowing period (exhaust increases with the damper 7 open, and the temperature of the dry bulb is raised to 43 ° C in the process of gradually yellowing from the leaf tip to the leaf base) As the drying conditions, the dry bulb temperature and the wet bulb temperature in the drying chamber A are raised or lowered by a predetermined temperature, respectively. Specifically, the dry bulb temperature is maintained at 40 ° C. for 3 hours to 10 hours, and the wet bulb temperature is gradually decreased from 40 ° C. to 38 ° C. for 3 hours to 10 hours. Next, the drying conditions from the end of yellowing to the initial stage of the color selection fixing stage (in the process of further heating and drying to raise the dry bulb temperature to 53 ° C.) are as follows: the dry bulb temperature is 40 ° C. to 43 ° C. The temperature is gradually increased over 3 to 15 hours (indicated by a rising gradient line on the temperature table) and the wet bulb temperature is gradually increased over 3 to 15 hours between 40 ° C. and 37 ° C. (Indicated on the temperature table by a descending gradient line).

  Next, from the color selection fixation stage to the middle bone dry stage (the dry bulb temperature is raised from 48 ° C. to 53 ° C. where the mesophyll is dried up to 68 ° C. where the drying of the middle bone is completed) The bulb temperature is gradually increased from 43 ° C. to 53 ° C. over 20 hours to 70 hours, and the wet bulb temperature is gradually decreased between 37 ° C. and 35 ° C. over 20 to 70 hours. The dry bulb temperature was gradually increased from 53 ° C. to 68 ° C. over 15 to 60 hours, and the wet bulb temperature was increased from 35 ° C. to 39 ° C. The temperature is controlled to gradually decrease over 60 hours.

  Here, as can be seen from the temperature table of FIG. 4, in the automatic drying program of the present invention, the constant temperature for confirming the dry state from the end of yellowing to the color selection fixed period and from the color selection fixed end period to the middle bone dry period. By performing the control (indicated by a horizontal line in the temperature table), the degree of dryness of the leaf tobacco T can be confirmed, and this confirmation is made by the transition of the damper opening displayed on the display unit 25 (displayed on the display unit 25). Compared to the transition of the damper opening from a certain time before the start, the drying degree is delayed if the opening of the damper 7 changes in the opening direction after the start of the constant temperature control, and the drying becomes dry if it changes in the closing direction. It indicates that the degree is too advanced) and the leaf tobacco T is visually recognized. In other words, it is only necessary to carry out the dry state confirmation work that has been frequently performed in the past twice, thus saving labor. Furthermore, at the end of the middle bone dry period, if the change of the opening degree of the damper 7 is maintained in a fully closed state for a predetermined time (for example, about 3 hours), it can be considered that the drying is finished, and the whole process of leaf tobacco drying is completed. It can be determined that the drying operation can be automatically stopped.

  Furthermore, as shown in FIG. 2, in the automatic drying program of the present invention, the dry bulb temperature is increased by about 5 ° C. during the fermentation period according to the properties (rain leaves and dew leaves) of the harvested leaf tobacco T. The draining operation program is set to allow interrupt operation, and can be arbitrarily drained (Step T1) with a single touch, and enough leaf tobacco T is used to avoid uneven humidity and dehydration during the yellowing period. A stretching operation program for warming up and promoting internal diffusion is provided, and this can be arbitrarily performed by one touch (step T2). The extension operation is performed by closing the damper 7 and sealing the inside of the drying chamber A to raise the temperature, and controlling the relative humidity to 85% to 90% (dry wet bulb difference of 1 to 2 ° C.). The temperature and humidity changes due to the elapsed time of the dry bulb temperature and the wet bulb temperature in the above two operations were measured, respectively, and the results are shown in the temperature table of FIG.

  In addition, the gist of the present invention is conventionally the temperature increase control at each stage of the leaf tobacco drying process from the end of the fermentation to the early yellowing, from the yellowing end to the color selection fixing period and from the color selection fixing period to the middle bone drying stage. The operation that was performed by switching the temperature stepwise in a stepwise manner is to switch smoothly and gradually, and the constant temperature control part for confirming the dry state is not necessarily required, and the desired effect is obtained be able to.

  According to the present invention, the drying work time of the leaf tobacco can be shortened, and since the degree of drying (change in the damper opening displayed on the display unit 25) can be determined by the constant temperature control, it is possible to save labor for human work. Time and human allowance in a series of work schedules from leaf tobacco harvesting to dry leaf shipment can be obtained, and the economic efficiency is improved.

It is a schematic diagram of the drying apparatus which implements the leaf tobacco humidification method concerning this invention. It is a block diagram which shows a control part. It is a drying process figure concerning the present invention. It is a temperature table for implementing the drying program of leaf tobacco concerning the present invention, Comprising: The interruption operation of the draining operation program and the extension operation program is explained. It is a temperature table for carrying out the drying program for leaf tobacco according to the present invention, and the operation that is performed by switching the temperature in each step in the step-up temperature control or the temperature-down control is gradually and gradually changed. It explains the state performed in.

A Drying room B Hot air generator C Controller a Blower b Heating device 1 Bulkhead 2 Hot air outlet 3 Circulation port 4 Furnace 5 Heat exchanger 6 Ceiling wall 7 Damper 8 Air inlet 9 Floor surface 10 Floating floor 11 Hot air introduction space 12 Rectification hole 13 Side wall 14 Exhaust port 15 Leaf tobacco hanger 16 Shelf rail 17 Dry bulb temperature sensor 18 Wet bulb temperature sensor 19 Input unit 20 Output unit 21 Computer 22 RAM
23 CPU
24 ROM
25 Display Unit 26 Solenoid Valve 27 Motor T Leaf Cigarette

Claims (5)

The heating control of the heating device in the drying chamber in which the leaf tobacco is accommodated and the intake / exhaust control into the drying chamber are used to control the temperature increase / decrease of the dry bulb temperature and the temperature increase / decrease of the wet bulb temperature. each step of utilizing an automatic drying program, to migration and蒸酵life of the leaf tobacco drying process, the yellowing and early蒸酵end, the middle bone dry period from this yellowing end from the color択固periodically and color択固regular The automatic operation is designed to shorten the drying operation time of the tobacco leaf by switching the temperature increase or decrease of the dry bulb temperature and the operation of switching the temperature increase or decrease of the wet bulb temperature smoothly and gradually. A method for automatically drying tobacco leaves using a drying program ,
( 1) In the fermentation period, while the dry bulb temperature is maintained at 40 ° C. by heating of the heating device, the wet bulb temperature is gradually lowered from 40 ° C. to 38 ° C., and
(2) From the end of the fermentation period to the yellowing period, the dry bulb temperature is maintained at 40 ° C. for 3 hours to 10 hours and the wet bulb temperature is gradually decreased from 40 ° C. to 38 ° C. for 3 hours to 10 hours. Control to
(3) From the end of yellowing to the color selection fixing period, the dry bulb temperature is gradually increased from 40 ° C. to 43 ° C. over 3 to 15 hours and the wet bulb temperature is set between 40 ° C. and 37 ° C. And a control for gradually decreasing the temperature over 3 to 15 hours,
(4) From the color selection fixing period to the intermediate bone drying period, as a drying condition, the dry bulb temperature is gradually increased from 43 ° C. to 53 ° C. over 20 hours to 70 hours and the wet bulb temperature is set to 37 ° C. Control to gradually decrease the temperature between ˜35 ° C. over 20 to 70 hours,
(5) The drying conditions from the initial drying of the intermediate bone to the completion of the intermediate bone drying are gradually increased from 53 ° C. to 68 ° C. over 15 to 60 hours, and the wet bulb temperature is set to 35 ° C. to 39 ° C. Control to gradually decrease the temperature to 15 ° C. over 15 to 60 hours;
An automatic drying method for leaf tobacco using an automatic drying program consisting of An automatic drying method for leaf tobacco using the automatic drying program according to claim 1,
Dry bulb / wet bulb temperature control for checking the dry state from this yellowing period to the color selection fixed period, from this color selection fixed period to the color selection fixed end period, and from the color selection fixed period end to the middle bone dry period A method for automatically drying leaf tobacco using an automatic drying program configured to enable the determination of the degree of drying through the change of the damper opening and / or the open / closed state. An automatic drying method for leaf tobacco using the automatic drying program according to claim 1,
An automatic drying method of leaf tobacco using an automatic drying program characterized in that a draining operation for increasing the dry bulb temperature according to the properties of the leaf tobacco during the fermentation period is set to be interruptible . An automatic drying method for leaf tobacco using the automatic drying program according to claim 1,
In order to avoid humidity unevenness and dehydration unevenness that occur during this yellowing period, use an automatic drying program characterized by enabling the interrupting operation to sufficiently warm the leaf tobacco and promote internal diffusion Automatic drying method for dried tobacco. An automatic drying method for leaf tobacco using the automatic drying program according to claim 1 or 2,
The stage in which the transition of the damper opening degree is maintained in a fully closed state for a predetermined time in the middle bone dry end stage is determined to be the end of drying, and it is determined that all of the leaf tobacco drying process is completed. 2. An automatic drying method of leaf tobacco using the automatic drying program according to 2.

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