JPH043185B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a long-term grain preservation method and apparatus suitable for use in long-term preservation of grains such as soybeans.

[Prior art]

When storing large amounts of grain for a long period of time without deteriorating quality, storage devices such as low-temperature warehouses are generally used.

[Problem that the invention seeks to solve]

However, in storage devices such as low-temperature warehouses, there are problems in that installation of cooling devices and the like requires high equipment costs, and the storage devices are required to have high heat insulation performance. In addition, because the temperature and humidity inside the storage device must always be maintained at a constant level, the cooling and blowing devices must be operated continuously, which has the disadvantage of incurring significant running costs. .

This invention was made in view of the above-mentioned circumstances, and aims to provide a method and device for long-term storage of grain that can significantly reduce equipment costs and running costs, and does not require a high degree of insulation performance in the storage device. There is.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the method according to the present invention provides an airtight structure for the main body of the storage unit for storing grains, and also provides an air intake port and an exhaust port in the main body of the storage unit. In addition, a target change characteristic in which the moisture content target value required to maintain a predetermined quality attenuates with the passage of storage time is set in advance, and data for predicting changes in the moisture content of stored grains is set in advance. Based on this, control characteristics of storage humidity and storage temperature are set so that the moisture content of the stored grain changes in accordance with the target change characteristics, and further, by dehumidifying outside air and blowing it into the air intake port, storage is performed. Humidity and storage temperature are matched to the control characteristics, and
The device according to the present invention includes a storage main body having an airtight structure, an intake port and an exhaust port provided in the main body, a blower device that sends outside air to the intake port, and a space between the blower device and the intake port. an input section into which the initial moisture content and storage time of the stored grain are input; and a moisture content target value and the moisture content necessary to maintain a predetermined quality of the stored grain corresponding to the elapse of the storage time of the stored grain; a storage unit storing a predicted moisture content corresponding to the elapse of storage time due to changes in storage temperature and storage humidity; and a storage unit in which the moisture content of the stored grain is set to the moisture content target value based on the predicted moisture content and the initial moisture content. control characteristic setting means for setting control characteristics of storage humidity and storage temperature so as to match the storage temperature; a sensor for detecting the storage temperature and storage humidity; The air blowing/dehumidifying control means controls the amount of dehumidification of the dehumidifier, thereby making storage humidity and storage temperature match the control characteristics.

[Effect]

By adopting the above method and configuration, the moisture content of stored grain changes in accordance with the target change characteristics, so long-term storage of grain is ensured, and unnecessary running costs are not incurred.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the schematic structure of a grain storage device which is an embodiment of the present invention. In Figure A, 1 is a storage tank with an airtight structure;
An intake port 2 is provided at the bottom, and an exhaust port 3 is provided at the top. Reference numeral 4 denotes a blower device that sends outside air into the air inlet 2, and a dehumidifier 5 is provided between the blower device 4 and the air inlet 2. 6 is a control device that controls the amount of air blown by the air blower 4 and the amount of dehumidification by the dehumidifier 5, and controls the temperature and humidity of the outside air detected by the temperature sensor 7 and the humidity sensor 8, and the temperature sensor 9 and the humidity. The air blowing and dehumidification control is performed based on the temperature and humidity inside the storage tank (hereinafter referred to as storage temperature and storage humidity) each detected by the sensor 10 and a predetermined program that is preset in the control device 6. . FIG. 4B is a block diagram showing an example of the configuration of the control device 6. As shown in FIG. In the figure, 15 is a CPU (central processing unit), 16 is a ROM (read-on memory) in which the management program, moisture content prediction formula (described later), etc. are stored in advance, and 17 is where various data are temporarily stored. RAM (Random Access Memory)
It is. Next, the input unit 18 inputs the interface 1
Various initial value data are input to the CPU 15 via the CPU 9. The temperature sensors 7, 9 and humidity sensors 8, 10 described above each supply data to the CPU 15 via the interface 19, and the CPU 15 also supplies data to the air blower 4 and the dehumidifier via the interface 19. A control signal is supplied to 5 and 5.

Next, the management program in the ROM 16 will be explained, but first an outline will be explained.

For long-term storage of grains, it is extremely effective to lower the moisture content of stored grains. Therefore, in this embodiment, after dehumidifying the outside air, air is blown into the storage tank 1 to lower the moisture content of the stored grains. Since the moisture content changes with the passage of storage time, a target change characteristic of moisture content (target change characteristic) is set in advance, and the moisture content of stored grain is lowered in accordance with the set change characteristic. This aims to reduce running costs. In addition, the storage temperature and storage humidity control characteristics are set in advance to match the target change characteristics using a formula (or table) that predicts changes in the moisture content of stored grains. Humidity and storage temperature are controlled.

Next, details of the management program will be explained.

(1) Setting target change characteristics Figure 2 shows the experimental results of moisture content and mold growth when whole soybeans were stored for one year at various humidity levels (temperature was constant at 30°C). As you can see from this figure, the moisture content is low during the period from 0 to 9 months.
If it is less than 10%, there will be almost no mold growth.
Furthermore, after 9 months, when the moisture content is reduced to 8% or less, there is almost no mold growth. Therefore, in such a case, for example,
Reduce the moisture content from 12% to 10% for 0 to 1.5 months, maintain the moisture content below 10% for 1.5 to 8 months, and reduce the moisture content to 8% after 8 months.
Set the target change characteristics so that If the moisture content of stored grain is controlled in accordance with this target change characteristic, mold will not develop during the 12-month storage period. In addition, in the above example, the "degree of mold growth" was used as a quality standard, but for example, "degree of protein denaturation,""degree of deterioration of extracted oil,""processability of tofu," etc. can also be used as a quality standard. In short, any quality standard may be set depending on the intended use.

FIG. 3 is a graph showing an example of the target change characteristics set as described above. The target change characteristic shown in this figure is that the initial moisture content is M ₀
The target change characteristic is to lower the water content to M ₁ by time P ₁ and converge the water content to M ₂ along the l ₁ or l ₂ curve by storage end point P ₂ .
The period shown in the figure is the period when it is necessary to rapidly reduce the moisture content according to the initial moisture content of the stored grain, and corresponds to the case described above, and is usually 1 to 2 months after the start of storage. . Furthermore, the target moisture content M ₁ at the end of the period is determined by the value of the initial moisture content M ₀ , and the optimal values for the target moisture contents M ₁ and M ₂ are selected depending on the type of grain, storage period, etc. . Next, the third stage is a time when the moisture content is gradually reduced from M ₁ to M ₂ , and depending on the type of grain and storage period, it may be as low as M ₁ M ₂ . In addition, curve l ₁ is a method of gradually lowering the moisture content, and curve l ₂ is a method of lowering the moisture content step by step with time P ₁ ' as a break. Either method can be selected depending on the type of grain, etc. do it. In this case, the period P ₁ -P ₁ ' corresponds to the case described above, and the period P ₁ '-P ₂ corresponds to the case described above.
Further, when the initial moisture content M ₀ is a value that can sufficiently withstand long-term storage, the control in the third stage is not necessary, and it is sufficient to enter the control in the third stage from the start of storage.

As described above, target change characteristics are set depending on the type of grain, initial moisture content, quality standards, storage period, etc.

(2) Setting the control characteristics of storage humidity and storage temperature to match the target change characteristics In order to match the moisture content changes of stored grains to the target change characteristics set in (1) above, it is necessary to A control pattern for storage humidity and storage temperature must be set that changes the storage humidity and storage temperature in accordance with the target change characteristics. Therefore, in this embodiment, the value of storage humidity is determined using a prediction formula for predicting changes in moisture content of stored grains. For example, the following formula: Moisture content (%) = 11.623 − 0.121 × temperature (°C) + 0.094 × humidity (%R・H) + 0.534 × period (month) − 3.283 × √ period (month)……(1) is the moisture content prediction formula for soybeans, and Figure 4 shows this (1)
This is a graph of the formula. Then, by using a prediction equation such as this equation (1), it is possible to obtain temperature and humidity control characteristics to match the target change characteristics. In addition, in order to obtain equation (1), the change in moisture content of stored grain (in this case, soybeans) is actually measured in advance, and
Equation (1) can be derived based on this measured value. In addition, FIG. 5 shows actual measured values of changes in moisture content of stored soybeans used in deriving equation (1). Here, FIGS. 6 and 7 are diagrams showing examples of humidity control characteristics and temperature control characteristics, respectively, for making the moisture content of stored grains match the target change characteristics shown in FIG. 3. As shown in FIGS. 6 and 7, in the period (P ₀ -P ₁ ), the humidity is lowered to H ₁ and the temperature is raised to T ₁ . This is because, as mentioned above, in the third stage, it is necessary to rapidly reduce the moisture content of the stored grain. (See Figure 3) Here, the reason why the storage temperature is raised to T ₁ is that the higher the temperature, the faster the moisture content decreases, and that it is necessary to raise the temperature to lower the relative humidity. by.
Next, in the third period, the storage humidity is increased from H ₁ to H ₂ and the storage temperature is decreased from T ₁ to T ₂ . Possible ways to increase the storage humidity include increasing the storage humidity all at once as in (a), increasing it in steps as in ( _b ), and gradually increasing it as in (c). In addition, methods (d), (e), and (f) can be considered as methods for lowering the storage temperature, as in the case described above. In this case, which method to adopt is determined depending on the target change characteristics. Further, the reason why such control is performed in the third stage is that the water content is gradually lowered in this stage, as shown in FIG. If we assume that the humidity is H ₁ and the temperature is T ₁ as in the third stage, the moisture content will decrease below the target change characteristics, so there will be no negative impact on quality, but it is necessary to maintain these humidity and temperature conditions. This brings about the disadvantage of increased running costs.

As described above, the storage temperature and storage humidity control characteristics are set. Note that the setting method described above was based on a moisture content prediction formula (see formula (1)), but instead of the prediction formula, for example, a table as shown in FIG. 5 may be stored. , based on the data in this table, control characteristics of storage humidity and storage temperature may be set.

The above are the details of the management program. here,
The above-described configuration is shown in FIG. 8 in a functional block diagram. In the figure, a is a target change characteristic setting means for setting a target change characteristic, b is data for predicting the moisture content such as a prediction formula, and c is a target change characteristic for the moisture content of stored grain based on the data for predicting the moisture content. d is a control characteristic setting means for setting the control characteristics of storage temperature and storage humidity so as to change according to and ventilation/dehumidification control means for matching the storage temperature to the control characteristics. In this case, the functions of blocks a to d correspond to the functions of the CPU 15, ROM 16, and RAM 17.

Next, the operation of this embodiment will be explained. FIG. 9 is a flowchart showing the operation of this embodiment,
The operation starts from step SP1 shown in the figure.
When reaching step SP2, the type of grain, initial moisture content, storage period, and purpose of the grain (tolerance of mold) are determined.
Initial values such as , etc. are input. And step SP
3, the CPU 15 inputs each initial value and
(See FIG. 3) to set the target change characteristic based on the data in the ROM 16 (for example, data corresponding to FIG. 2). Next, in step SP4, the CPU 15 sets control characteristics (see FIGS. 6 and 7) corresponding to the set target change characteristics based on the moisture content prediction formula and the management program in the ROM 16. Then move on to step SP5,
Control storage humidity and storage temperature based on set control characteristics. Control in this case is as follows. That is, since the CPU 15 detects the storage temperature and storage humidity based on the output signals of the temperature sensor 9 and the humidity sensor 10, the air blower 4 and dehumidifier 5 are adjusted so that these detected values match the control characteristics. Controls the amount of air blown and the amount of dehumidification. Further, the CPU 15 detects the temperature and humidity of the outside air using a temperature sensor 7 and a humidity sensor 8.
This detected value is also referred to to control the amount of air blown and the amount of dehumidification. Therefore, if it is determined that there is no need for air blowing or dehumidification, the air blower 4 or the dehumidifier 55 is stopped. Thereafter, the processing at step SP5 is continued until the storage period ends and the determination at step SP6 becomes "YES". When the storage period ends, the process moves to step SP7 and the series of processing ends.

Note that the storage tank 1 in the above-described embodiment may be a warehouse (if the grain is packed in bags) or a silo (if the grain is in bulk).

〔Effect of the invention〕

As explained above, according to the present invention, the main body of the storage section for storing grains has an airtight structure, and
The main body of the storage section is provided with an intake port and an exhaust port, and a target change characteristic is set in advance in which the moisture content target value necessary for maintaining a predetermined quality attenuates with the passage of storage time, and Based on data predicting changes in moisture content, control characteristics of storage humidity and storage temperature are set so that the moisture content of the stored grain changes in accordance with the target change characteristics, and furthermore, outside air is dehumidified to By blowing air into the intake port,
Since the storage humidity and storage temperature are made to match the above-mentioned control characteristics, the grain can be stored for a long time, and unnecessary air blowing and dehumidification are not performed.
Running costs can be reduced.
Furthermore, since a cooling device is not required and the main body of the storage unit is not required to have a high degree of heat insulation, it has the advantage of reducing equipment costs.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of a grain storage device that is an embodiment of the present invention, Figure 2 is a graph showing the relationship between the moisture content of whole soybeans and the state of mold growth, and Figure 3 is an example of target change characteristics. Figure 4 is a graph showing the moisture content prediction formula, Figure 5 is the experimental results showing changes in the moisture content of whole soybeans, and Figures 6 and 7 are the control characteristics of storage humidity and storage temperature, respectively. 8 is a functional block diagram showing the functional configuration of the present invention, and FIG. 9 is a flowchart showing the operation of this embodiment. 1...Storage tank (storage unit main body), 2...Intake port,
3...Exhaust port, 4...Blower, 5...Dehumidifier, 15...CPU, 16...ROM, 17...
RAM (15, 16, and 17 are target change characteristic setting means, control characteristic setting means, and ventilation/dehumidification control means).

Claims (1)

[Scope of Claims] 1. The main body of the storage unit for storing grains has an airtight structure, and the main body of the storage unit is provided with an intake port and an exhaust port, and the moisture content target value necessary for maintaining a predetermined quality is maintained in the storage unit. A target change characteristic that attenuates over time is set in advance, and the moisture content of the stored grain changes in accordance with the target change characteristic based on data that predicts a change in the moisture content of the stored grain. Set the control characteristics of storage humidity and storage temperature to
Furthermore, a method for long-term storage of grains, characterized in that storage humidity and storage temperature are made to match the control characteristics by dehumidifying outside air and blowing it into the air intake port. 2. A storage main body having an airtight structure, an air intake port and an exhaust port provided in the main body, a blower device that sends outside air to the air intake port, and a dehumidification device provided between the blower device and the air intake port. and an input section into which the initial moisture content and storage time of the stored grain are input, and a moisture content target value, storage temperature, and storage humidity of the stored grain necessary to maintain a predetermined quality corresponding to the elapse of the storage time of the stored grain. a storage unit that stores a predicted moisture content corresponding to the elapse of storage time due to a change in the moisture content; control characteristic setting means for setting control characteristics of storage humidity and storage temperature; a sensor for detecting the storage temperature and storage humidity; and an air flow amount of the air blower and a dehumidification amount of the dehumidifier based on the output signal of the sensor. 1. An apparatus for long-term storage of grains, characterized in that it comprises an air blowing and dehumidifying control means for controlling storage humidity and storage temperature, thereby making the storage humidity and storage temperature match the control characteristics.