JP2535164B2 - Drying control method for grain dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention corrects the stopped moisture value so that the desired moisture value is obtained at the time of hulling, in consideration of the variation of the moisture value of the dried paddy rice after the drying is stopped. The present invention relates to a drying control method for a grain dryer.

[Prior Art] The moisture value of the sample paddy rice collected from the grain dryer is measured,
A drying control method of a grain dryer for controlling the drying operation to stop when the moisture value reaches a preset stop moisture value is disclosed before the application of the present application, for example, in Japanese Examined Patent Publication No. 60-16575. It has become a technology.

[Problems to be Solved by the Invention] By the way, in the conventional drying control method as described above, the drying operation is performed immediately when the moisture value of the dried unhulled rice reaches a preset stop moisture value. However, various inconveniences occurred after the drying was stopped due to the nature of the dried paddy rice.

In other words, the dried paddy rice is stored in the storage tank inside the grain dryer or the storage tank outside the grain dryer for the predetermined time from the stop of the drying operation until the start of hulling because of the legal cooling. However, there was a "phenomenon" in which the water content of paddy rice varied in various ways during this storage time.

That is, as shown in FIGS. 4 and 5, the drying operation is stopped when the moisture value measured for the target of dried rice becomes a predetermined low moisture value (for example, stop moisture value), and thereafter, a predetermined storage is performed. It is a graph which shows the fluctuation | variation of the moisture value (M) measured after progress of time (T). In the figure, A shows a moisture value (hull moisture value A) using paddy as a measurement sample, and B shows a moisture value (brown rice moisture value B) with brown rice obtained by hulling paddy as a measurement sample. And, according to FIG. 4, the so-called "remaining heat drying" state in which the moisture value A of paddy increases and the moisture value B of brown rice gradually decreases after a few hours immediately after the stop of the drying operation is shown. . This is due to the phenomenon of "moisture transfer" caused by the difference in water content between the unhulled rice and brown rice immediately after the stoppage of the drying operation, and the water transfer from the high-moisture-valued brown rice to the low-humidity rice husks. Is the main cause.

On the other hand, according to FIG. 5, the paddy moisture value A increases after a few hours immediately after the stop of the drying operation, while the brown rice moisture value B tends to decrease once but gradually increase with the passage of time. A so-called "return" state is shown. This is because the phenomenon of "moisture transfer" inside the unhulled rice described above appears in the early stage, and then the water moves from other high-moisture-valued immature grains that are mixed in the dried hulled rice to the low-moisture-sized unhulled rice. The cause is.

Due to such a phenomenon, when the hulling work is started after a predetermined time has passed since the drying was stopped, the dried rice to be dried becomes overdried rice, or conversely, the high water content value makes the hulling work impossible. As a result, various inconveniences have occurred in terms of work efficiency and quality improvement.

Therefore, when dried paddy rice having various properties of paddy rice is dried by a grain dryer, a change in the moisture value due to the above-mentioned "phenomenon" is predicted before reaching the stop moisture value, and the stop set by the operator is set. It was also considered that the water content could be adjusted by changing it up and down. However, the above-mentioned fluctuations are not always constant due to various paddy rice properties [cropping, thickness of rice husks, grain beam (quality of fertilizer), mixing ratio of immature grains], etc. It was practically difficult to appropriately adjust the stopped water value each time the above procedure was performed.

[Object of the Invention] Therefore, an object of the present invention is to automatically correct the stop moisture value in consideration of the variation characteristics of the moisture value of the paddy rice after the drying operation is stopped, and to obtain a desired moisture value at the specified paddying time. Accordingly, it is an object of the present invention to provide a drying control method for a grain dryer, which prevents the above-mentioned inconvenience from occurring.

[Means for Solving the Problems] In order to achieve this object, the present invention measures the moisture content of dried rice collected from a grain dryer, and the moisture content is set to a preset stop moisture content. When the drying operation is stopped and controlled when the value becomes a value, the moisture fluctuation characteristics at a predetermined storage time (T) after the drying of the dried rice having various paddy properties is stopped by experiments in advance. The difference between the moisture value of paddy (Mm) and the moisture value of brown rice (Mg) immediately after the drying was stopped (△
M) as a function F _T (ΔM) in advance, and during the actual drying operation, the paddy water content (Mm) and brown rice water content (Mg) are measured to obtain the difference (ΔM). The water content at the storage time (Ta) is calculated from the function F _T (ΔM) selected by the storage time (Ta) from the set drying stop to the start of hulling and the calculated difference (ΔM). The fluctuation value (△ m) is calculated, and this water fluctuation value (△
The stop moisture value is corrected by m).

[Operation] The present invention focuses on the fact that the variation of the moisture value of the dried rice after the drying is stopped can be predicted by the difference between the paddy moisture value immediately after the drying is stopped and the brown rice moisture value. From the experimentally determined function F _T (ΔM) of the moisture fluctuation characteristics at the predetermined storage time, select the function F _T (ΔM) corresponding to the set storage time (Ta) from the drying stop to the start of hulling, Using this function F _T (ΔM), the moisture fluctuation value (Δm) is calculated by the difference (ΔM) calculated from the paddy moisture value (Mm) measured during the drying operation and the brown rice moisture value (Mg). Calculate,
Since the stop moisture value is corrected by this moisture fluctuation value (Δm), the drying operation can be controlled so that the moisture value of the dried rice becomes a desired moisture value at the set hulling time.

[Example] The principle of the drying control method of the present invention based on the drawings,
And, the embodiments will be described in detail and specifically.

First, as described above, it is predicted that the phenomenon of "moisture transfer" such as "remaining heat drying" and "return" is deeply related to the moisture difference (difference) between the paddy moisture value and the brown rice moisture value immediately after the drying operation is stopped. Since it was done, I pursued the relationship by experiment.

That is, what is presented in FIG. 1 is a graph prepared based on a certain experimental result, and the vertical axis shows the moisture value (M) of brown rice obtained by hulling dried paddy rice, and the horizontal axis shows the moisture content of the rice collected immediately after the drying is stopped. Value (Mm) and brown rice moisture value (Mg) (Δ
M), and every predetermined storage time (T) (for example, A,
(B, C, D hours) A part of the sample unhulled rice that has been stored is hulled, and the moisture variation characteristics of the brown rice moisture value (M) measured at that time after the drying is stopped are shown.

In this experiment, first, a predetermined amount of paddy rice was collected from a grain dryer that is drying the dried paddy rice every predetermined time, and the moisture content (Mm) of the paddy just after the collection and the moisture content of brown rice (Mg) are measured by an electric resistance-type moisture. The drying operation is stopped when the moisture value (Mg) of brown rice at that time reaches a predetermined moisture value (M ₀ ). This water content value (M ₀ ) is a value in the set range (for example, 13% to 16.5%) of the stop water content value that is the drying target. Next, every time a predetermined storage time elapses (for example, A = 2, B = 4, C = 24, D =
For 48 hours, the brown rice moisture value (M) of the dried unhulled rice stored and stored in the grain dryer is measured, and the brown rice moisture value at each time point (for example, m1, m2, m3, m4) is obtained.

Next, the difference (ΔM) between the paddy moisture value (Mm) immediately after the collection and the brown rice moisture value (Mg) is calculated, and the brown rice is plotted at the graph coordinate on the horizontal axis corresponding to the difference (ΔM1) at that time. Plot the water content (m1, m2, m3, m4). Then, such an experiment was carried out on dried paddy rice having various properties of paddy rice, and a large number of plot values were obtained.

The results shown in Fig. 1 are the experimental results. According to this graph, the sample paddy rice having a moisture value of brown rice (M ₀ ) immediately before the stop of the drying operation was the paddy moisture value (Mm) collected immediately after the stop. Difference (ΔM) between water content of brown rice and brown rice (Mg) and storage time (T)
A function F _T (ΔM) that indicates the characteristic of water fluctuation with p as a variable
It turned out that it can be expressed as

In addition, the function F _T (ΔM) indicating the moisture fluctuation characteristic is the difference in various properties of the paddy rice as long as it is the dried rice which has a moisture value close to the moisture value (M ₀ ) when the drying operation is stopped. It was found to have water content variation characteristics that correspond to any of the above functions F _T (ΔM) regardless of the above.

From the above-mentioned point, when drying the unhulled rice having various properties of the unhulled rice with the grain dryer, the above-mentioned moisture fluctuation characteristics of the unhulled rice to be dried are shown in the drying process before reaching the stopped moisture value (mt). When the function F _T (ΔM) is known, it is possible to predict what moisture value of the brown rice will change when the storage time (T) after the drying operation is stopped elapses.

That is, during the drying operation, the moisture content of paddy (Mm) and the moisture content of brown rice (M
g) and the difference (ΔM) is calculated, and if the storage time (Ta) until the start of hulling in the subsequent process is set, the corresponding function F _T (ΔM) indicating the moisture fluctuation characteristic is specified. Then, the moisture value (M ₁ ) at the start of hulling can be obtained from the function F _T (ΔM).

Then, a moisture variation value (Δm) is calculated from the obtained moisture value (M ₁ ) and the moisture value (M ₀ ) and the moisture variation value (Δm) is calculated.
If the stop moisture value (mt) for stopping the drying operation is corrected by m), a method (dry control method) of always performing dry control so that a predetermined brown rice moisture value is obtained at the start of hulling is realized.

Hereinafter, this drying control method will be described based on the embodiment shown in FIGS.

In FIG. 2, 1 is an automatic moisture measuring device, and 2 is a circulation type grain dryer. The automatic moisture measuring device 1 includes a sampling unit 3, a distributing unit 4, a hulling unit 5, a measuring unit 6, a measuring unit 7,
It is composed of a display unit 8 and a calculation control unit 9. The sampling unit 3 has a function of automatically collecting sample paddy rice from the grain dryer 2 and supplying the sampled paddy rice to the distribution unit 4, and the distribution unit 4 supplies the supplied test paddy rice to the hulling unit 5 and the measuring unit 6 at a predetermined timing. Has a function of supplying to. The hulling unit 5 hulls the supplied sample rice as a brown rice sample and supplies it to the measuring unit 6. The measuring unit 6 detects the electric resistance values of the paddy sample and the brown rice sample supplied from the distributing unit 4 and the hulling unit 5, measures the respective water content values, and outputs the measurement results to the control unit.
The setting unit 7 switches the storage moisture value (mt) of the drying operation and the storage time (Ta) from the stop of drying to the start of hulling, and outputs it to the arithmetic control unit 9. The display unit 8 is a calculation control unit 9
It is composed of a display MD that displays the moisture value output from the display and a display TD that displays the waiting time (TW) from the stop of the drying operation to the start of hulling.

The arithmetic control unit 9 is, for example, a micro computer (CPU),
It is composed of a read-only memory (ROM) and a random access memory (RAM) that temporarily stores various data. The arithmetic and control unit 9 outputs a control signal to a mechanical unit (not shown) in the measuring unit 6 to control the drive, and at the same time, the sampling unit 3, the distributing unit 4, the hulling unit 5, the measuring unit 6,
The display unit 8 and the like are drive-controlled at a predetermined timing. Further, the arithmetic control unit 9 stores a function F _T (ΔM) indicating the water content variation characteristics corresponding to various types of paddy rice properties, which are obtained in advance by experiments, and stores the function F _T (ΔM) and the start of hulling. Water storage value (Δ
Then, a drying control program (described later) for calculating m) and correcting the stopped moisture value (mt) is executed.

Next, the operation of the drying control program, which is the drying control method of the present invention, will be described with reference to FIG. First, when the drying operation of the grain dryer 2 is started, the measurement program stored in the arithmetic control unit 9 is started (S100).

First, the sampling unit 3 samples a predetermined amount of sample rice from the grain dryer 2, supplies half of the sample rice to the hulling unit 5, and stores the other half (S101). Next, the hulling section 5 supplies the brown rice sample obtained by hulling the sample hulled rice to the measuring section 6 (S102). Next, the measuring unit 6 detects the electric resistance value of the supplied brown rice sample and measures the brown rice moisture value (Mg) (S103).

Next, it is determined (S104) whether or not the brown rice moisture value (Mg) measured in (S103) is equal to or lower than a predetermined value (M _S ). This predetermined value (M _S ) is set to be slightly higher (for example, about + 2%) than the stopped moisture value (mt) set in the above-mentioned setting range of the drying target. When it is determined to be NO in (S104) above,
The remaining sample paddy rice stored in the distribution unit 4 in (S101) is returned to the grain dryer 2 and jumps to (S101).

If YES is determined in (S104), the measured brown rice moisture value (Mg) is stored in the RAM of the arithmetic control unit 9 (S10).
5) Do. The determination in (S104) is not limited to one time, and may be performed a plurality of times. next,
The remaining sample hull rice stored in the distribution unit 4 in the above (S101) is directly supplied to the measuring unit 6 without passing through the hulling unit 5 to measure the hull moisture value (Mm) (S106). Next, the measured paddy moisture value (Mm) is stored in the RAM of the arithmetic control unit 9 (S10
7) Do.

Next, from the brown rice moisture value (Mg) and the paddy moisture value (Mm) during the drying operation thus obtained, the difference (ΔM) =
(Mm)-(Mg) is calculated (S108). Next, the hulling start timing set by the switch in the setting unit 7, that is, the corresponding storage time (Ta) is input and stored in the RAM in the arithmetic control unit 9 (S10).
9).

Next, the arithmetic control unit 9 uses the stored stored data of the storage time (Ta) as a function F _T indicating the corresponding moisture fluctuation characteristic.
Select (ΔM) (S110). That is, according to FIG. 1, when the storage time (Ta) at the start of hulling is set to 24 hours, the function F _T (ΔM) to be selected is (C).

Next, the moisture value (M ₁ ) at the start time of hulling is calculated from the selected function F _T (ΔM) and the calculated difference (ΔM), and this is substituted into the following calculation formula to calculate the moisture fluctuation value (Δm).
Is calculated (S111).

Δm = M ₁ −M ₀ (1) Next, the stop moisture value (mt) set in the setting unit 7 is input and stored (S112), and the input stop moisture value (mt) is also stored.
The calculated moisture fluctuation value (Δm) is substituted into the following calculation formula to obtain the corrected stop moisture value (MT ₀ ). (S11
3) MT ₀ = mt− (Δm) (2) Similar to (S101), the sampling unit 3 includes the grain dryer 2
A sample of unpolished rice is sampled from the inside (S114), and then hulled (S115) through the distribution unit 4 and the hulling unit 5, and then the measuring unit 6 measures the moisture value (M) of unpolished rice (S116). In addition, the hulling in (S115) is omitted, and in (S116), the moisture value of paddy is measured, and the obtained measured value is substituted into a predetermined "paddy-brown rice conversion formula" to obtain a brown rice moisture value (M). May be requested.

Next, it is determined whether or not the brown rice moisture value (M) measured in (S116) is less than or equal to the corrected stop moisture value (MT ₀ ) (S11).
7) Do. If NO is determined, the process jumps to (S114) again, and after a predetermined time, sampling is again performed (S114),
Hulling (S115) and moisture measurement (S116) are performed. (S11
If YES is determined in 7), the arithmetic control unit 9 outputs a drying stop signal to the grain dryer 2 to stop the drying operation (S118).
To do. Next, the arithmetic control unit 9 calculates the remaining time until the start of hulling, that is, the hulling waiting time (TB) from the storage time (Ta) data until the hulling start time stored in (S109), and displays this. It is displayed on the display TD of the unit 8 every moment (S119). Next, it is determined whether or not the calculated hulling waiting time (TB) has become zero (S120). If NO is determined, the process jumps to (S119), and if YES is determined, all measurements are performed. Stop the program (S121).

The present invention is not limited to the above-mentioned embodiment, and various application modifications are possible.

For example, in the embodiment of the present invention, the moisture value (M ₀ ) was made to match the same predetermined value when the function F _T (ΔM) showing the moisture fluctuation characteristic was created and when it was selected later. The moisture value (M ₀ ) does not necessarily have to be the same as long as the function F _T (ΔM) to which the unhulled rice belongs can be identified by experimental data or the like. Further, in the present embodiment, the difference (ΔM) is calculated by one measurement, but the difference (ΔM) may be calculated from a plurality of measurements and the average value thereof. Alternatively, brown rice samples may be selected and measured as refined brown rice (immature rice is removed). However, in this case RO
A function F that shows the moisture fluctuation characteristics that must be stored in M
_It is necessary to create _T (ΔM) based on the experimental data using purified brown rice as a sample. Further, instead of setting the switch of the storage time (Ta) from the stop of drying to the start of hulling in the setting unit 7, a predetermined storage time (Ta) required to start hulling is stored in the ROM of the arithmetic control unit 9 in advance. You may leave it set.

[Effects of the Invention] As is clear from the above description, according to the present invention,
Measure the moisture value of the dried rice collected from the grain dryer,
In a case where the drying operation is stopped and controlled when the moisture value reaches a preset stopped moisture value, a predetermined storage time after the drying of the dried rice having various paddy properties is stopped by experiments ( The moisture fluctuation characteristic in _T ) is obtained as a function F _T (ΔM) having a variable (ΔM) between the moisture value (Mm) of unhulled rice and the moisture value (Mg) of brown rice immediately after the drying of the dried rice is stopped. During the actual drying operation, the above-mentioned paddy moisture value (M
m) and brown rice moisture content (Mg), and the difference (△ M)
And the function F selected by the storage time (Ta) from the set dry stop to the start of hulling
A moisture variation value (Δm) at the storage time (Ta) is calculated from _T (ΔM) and the calculated difference (ΔM), and the stopped moisture value is corrected by this moisture variation value (Δm). By controlling the drying operation, it is possible to control the dry moisture so that the desired brown rice moisture value can be obtained at the specified hulling time, and at the start of the hulling work after a predetermined time has passed since the drying was stopped, The dried rice becomes excess dried rice,
On the contrary, it is possible to prevent inconveniences such as a high moisture content that makes hulling work impossible, and work efficiency and quality can be improved.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a diagram showing a function F _T (ΔM) showing moisture fluctuation characteristics of brown rice moisture value of dried paddy rice in various rice grain properties, and FIG. FIG. 3 is a block diagram of an automatic moisture measuring device incorporating a drying control method as a drying control program, FIG. 3 is a flowchart showing the operation of the drying control program, and FIGS. 4 and 5 are brown rice moisture values (M) of dried unhulled rice after drying is stopped. 3] is a graph showing the variation characteristics of () with respect to the storage time (T). 1 is an automatic moisture measuring device, 2 is a grain dryer, 3 is a sampling unit, 5 is a hulling unit, 6 is a measuring unit, 8 is a display unit, and 9 is an arithmetic control unit.

Claims (1)

(57) [Claims] 1. A method for measuring a moisture value of dried rice collected from a grain dryer and controlling the drying operation to stop when the moisture value reaches a preset stop moisture value, According to an experiment, the moisture fluctuation characteristics of the dried rice having various paddy properties at a predetermined storage time (T) after the drying was stopped were evaluated as follows: the moisture content (Mm) of the paddy immediately after the drying was stopped and the moisture content of the brown rice (Mg). ) Function F _T (△
M), and during the actual drying operation, the paddy moisture value (Mm) and the brown rice moisture value (Mg) are measured to calculate the difference (ΔM), and the paddying is started from the set drying stop. From the function F _T (ΔM) selected according to the storage time (Ta) up to and the calculated difference (ΔM), a moisture fluctuation value (Δm) during the storage time (Ta) is calculated. A drying control method for a grain dryer, wherein the stopped moisture value is corrected by a moisture fluctuation value (Δm).