JPH0650220B2 - Equipment for measuring moisture content of grain in grain dryer - Google Patents

Description

TECHNICAL FIELD The present invention relates generally to grain dryers, and more particularly to a moisture content measuring device for grains in grain dryers.

[Technical background and problems] In the grain dryer, in order to dry the grains to the desired moisture content without excess or deficiency, it is necessary to stop the dryer properly at the time of drying to the moisture content. For that purpose, it is necessary to measure the present value of the water content which changes from moment to moment accurately at all times.

By the way, since the dried grains circulate inside the dryer during the drying operation, it is not possible to measure the water content without unevenness. Therefore, the measured water content varies.

Therefore, various proposals have been conventionally made to improve the measurement accuracy of the water content. For example, one of the methods is to operate the water content measuring device at a constant cycle, obtain a moving average of the measured values, and use this as the current water content measured value.

However, it has been difficult to improve the measurement accuracy of the water content in the conventional water content measuring device of the grain dryer in the conventional grain dryer due to the influence of green rice, rice cake, etc. mixed in the dried grain.

[Object of the Invention] The present invention was created in order to improve the above-mentioned problems of the prior art, and an object thereof is a grain dryer capable of improving the measurement accuracy of the moisture content of dried grains. To provide a moisture content measuring device for grains in the above.

[Configuration of the Invention] A feature of the present invention for achieving the above object is a grain dryer that automatically stops when a measured moisture value of a dried grain measured by an automatic moisture meter reaches a target moisture value, The n-th calculated moisture value sn is calculated from the measured moisture value Ms output from the automatic moisture meter according to the average moisture value, and this calculated moisture value sn is several% of the target moisture value ML.
In the apparatus for measuring the moisture content of grains in a grain dryer, which is provided with a means for calculating the calculated moisture value by excluding the measured moisture value Ms that deviates from the preset moisture value range after reaching the value obtained by adding .

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

1 is an overall perspective view of a grain dryer according to an embodiment of the present invention, FIG. 2 is a front sectional view of a grain dryer according to an embodiment of the present invention, and FIG. 3 is a control according to an embodiment of the present invention. FIG. 4 is a block diagram of the apparatus, and FIG. 4 shows a flowchart of the configuration of FIG.

In FIG. 1, the grain dryer 1 has an operation box 3 containing a control unit (not shown) and an automatic moisture meter 5. The operation box 3 includes a target moisture content setting switch 7 for setting a target moisture content, that is, a target moisture value,
A target hot air temperature setting switch 9 for setting the target hot air temperature, a drying switch, a grain type switch, an operation switch 11 such as a sticking amount switch, and the like are provided.

As shown in FIG. 2, the grain dryer 1 has a storage chamber 13
The grains that have been stretched out are gradually discharged to the flow-down passage 15, and the surface of the grain is dried by the hot air of the burner 17 that crosses the flow-down passage 15 on the way. This grain is discharged from the lower end of the flow-down passage 15 into the grain collection chamber 21 via the discharge amount control valve 19.
It is sent to the elevator 25 by the lateral feed spiral 23, and is fed from the upper outlet thereof to the upper center of the storage chamber 13 by the tension spiral 27 and diffused into the storage chamber 13 by the diffusion blade 29.

While slowly circulating the grains in this way, the storage chamber 13
Inside, the moisture inside the grain is diffused to the surface, and the whole grain is dried uniformly.

FIG. 3 is a block diagram of a control unit built in the operation box 3 described above. The microcomputer 31 includes a CPU 101, a memory 103,
Input port 105, input port 107, output port 10
Have 9.

The CPU 101 performs arithmetic logic operation and comparison operation.
The input information of the CPU 101 is digital input circuit 33, input port 105 and A / D conversion circuit 35, input port 1
It is given via 07. Information provided to the CPU 101 via the digital input circuit 33 includes target moisture value setting information 37, target hot air temperature setting information 39, and operation information 41.
There is timer input information from the timer 43. The target moisture value setting information 37 is output from the target moisture value setting switch 7. The target hot-air temperature setting information 39 is a target hot-air temperature setting switch 9 in which the target hot-air temperature is automatically set by setting a scale according to the type and amount of dried grains circulating in the dryer 1. Is output from. Operation information 41
Is supplied from the operation switch 11 for starting / stopping the drive system 45 of the dryer 1 and igniting the combustion system 47. The CPU 101 calculates the target moisture value ML for the dried grain based on the target moisture value setting information 37, and stores the result in the memory 103.

The information provided to the CPU 101 via the A / D conversion circuit 35 includes the measured moisture value information 49 and the actual hot air temperature information 51.
There is. The measured moisture value information 49 is given from the automatic moisture meter 5. The CPU 101 takes in the measured moisture value Ms at predetermined time intervals, performs arithmetic processing, and then stores it in the memory 103.
The water content value in the memory 103 is updated every predetermined time. The actual hot air temperature information 51 is the hot air temperature detection sensor 5
Given from 3.

The drive command signals for the drive system 45 and the combustion system 47 of the dryer 1 provided from the CPU 101 are provided via the output port 109 and the digital output circuit 55.

The CPU 101 takes in the measured moisture value Ms given from the automatic moisture meter 5 and temporarily stores it in the memory 103 as an average value sn by averaging. The CPU 101 extracts a value obtained by adding 2 to the target moisture value ML stored in the memory 103 and the measured average moisture value sn, and performs a comparison calculation. As a result of this comparison operation, the CPU 101 causes sn ≦ ML
When it is determined to be +2, the CPU 101 determines the measured moisture value Ms.
Further, arithmetic logic operations such as least squares method operation, standard deviation operation, and frequency distribution operation are performed, and the operation value m _n1 or m _n0 +
k is temporarily stored in the memory 103. CPU 101
Is the ML and m _n1 or m stored in the memory 103.
_n0 + k is taken out and compared, and the end of drying is determined.

The memory 103 contains a control program and the like and stores necessary data.

The control operation of the above configuration will be described with reference to the flowchart of FIG.

Prior to the start of the drying operation, the operator sets the target hot air temperature setting switch 9 to a predetermined scale and the target moisture value setting switch 7 to the target moisture value ML according to the type and amount of dried grains. Then, when the operation switch 11 is turned on, it is used as the operation information 41 by the CPU via the digital input circuit 33 and the input port 105.
Given to 101. The CPU 101 uses the operation information 41
When it is recognized that the operation switch 11 is turned on (step 111), a drive command signal is output to the drive system 45 and the combustion system 47 via the output port 109 and the digital output circuit 55 (step 113). CPU 101
Takes in the amount of the dried grain as the operation information 41 via the digital input circuit 33 and the input port 105 (step 115). The CPU 101 calls the target hot air temperature setting data stored in the memory 103, compares the actual hot air temperature information 51 fetched through the A / D conversion circuit 35 and the input port 107 with the target hot air temperature setting data, and calculates the hot air temperature. (Step 117), CPU 1
01 takes the first measured moisture value Ms ₁ measured by the automatic moisture meter 5 through the A / D conversion circuit 35 and the input port 107 and temporarily stores it in the memory 103 (step 119). The CPU 101 calls the measured water content value Ms ₁ stored in the memory 103 and calculates the first average value s ₁ (s ₁ = Ms ₁ ) (step 12).
1). Then, the timer 43 is set, for example, for 4 minutes (step 123). The CPU 101 takes in the target moisture value ML given from the target moisture value setting switch 7 via the digital input circuit 33 and the input port 105,
It is stored in the memory 103 (step 125). CPU1
01 controls the hot air temperature in the same manner as in step 117 (step 127). When the CPU 101 determines that the timer set in step 123 has timed out (step 129), the CPU 10
1 is a memory 1 for fetching the moisture value Ms measured by the automatic moisture meter 5 through the A / D conversion circuit 35 and the input port 107.
03 (step 131). CPU 101
The average moisture value sn at the time of the n-th measurement of this time is calculated according to the following relational expression (step 133).

sn = a * s (n-1) + (1-a) Msn Here, s (n-1) is the average water content at the time of the last measurement, a is a constant (integer) experimentally obtained, and n Is an integer greater than 1.

If the CPU 101 does not determine in step 129 that the timer has timed out, the process returns to step 125, and this operation is repeated until the time is up.

The CPU 101 calls the value obtained by adding 2 to the target moisture value ML stored in the memory 103, and executes the above step 1
A comparison calculation is performed with the average moisture value sn calculated in 33 (step 135). As a result of this comparison operation, the CPU 10
If 1 determines that sn ≦ ML + 2, the CPU 101
Calculates the first least-squares approximated water content value m _n0 of the n-th measurement value of this time according to the following relational expression (step 137).

m _n0 = An ² + Bn + C Here, A, B, and C are constants, and n is an integer greater than 1.

The CPU 101 calculates the difference between the moisture value Msn measured for the nth time by the automatic moisture meter 5 and the least-squares approximate moisture value m _n0 calculated in step 137, that is, Msn-mn ₀ (step 139). When the calculation result of step 139 is Msn-m _n0 > 1, the measured water content value Msn is removed (step 141), and the second least-squares approximate water content value m _n1 is calculated from the remaining measured water content value Msn. Calculate (step 143).

m _n1 = Dn ² + En + F Here, D, E, and F are constants, and n is an integer greater than 1.

The CPU 101 calls the target moisture value ML stored in the memory 103, and compares it with the least-squares approximate moisture value m _n1 calculated in step 143 (step 145). As a result of this comparison operation, the CPU 101
When it is determined that _n1 ≦ ML, the CPU 101 stops the drive system 45 and the combustion system 47 of the grain dryer 1 via the output port 109 and the digital output circuit 55 (step 147).

In step 135, if sn> ML + 2, the process returns to step 123, and under the control of the CPU 101, the automatic moisture meter 5 repeats the measurement any number of times until sn ≦ ML + 2 is obtained.

If m _n1 > ML in step 145, the process returns from step 149 to step 137 under the same control of the CPU 101 as in steps 123 to 131 and returns to step 137.
Under the control of 1, the automatic moisture meter 5 can repeat the measurement any number of times until m _n1 ≦ ML is obtained.

FIG. 5 shows a flowchart of the second embodiment. In this embodiment, the standard deviation value δ is obtained from the value of Msn-m _n0 calculated in step 139 of the first embodiment, and the subsequent control is performed based on this standard deviation value δ. . That is, in step 159 shown in FIG. 5, the CPU 101 calculates the standard deviation value δ according to the following relational expression.

Here, n is an integer greater than 1.

The CPU 101 calls the correction value k corresponding to the standard deviation value δ calculated in step 159 from the memory 103 (step 161) and corrects the least squares approximate moisture value m _n0 calculated in step 137 (step 16).
3). The correction value k is an experimentally obtained constant and is stored in the memory 103 in advance.

As a result of the above correction operation, the CPU 101 causes m _n0 + k ≦ ML
CPU 101 determines that the output port 109,
The drive system 45 and the combustion system 47 of the grain dryer 1 are stopped via the digital output circuit 55 (step 165).

When m _n0 + k> ML in step 163,
After the operations from step 149 to step 157 similar to those in the above-described first embodiment, the process returns to step 137, and the CPU 10
Under the control of 1, the automatic moisture meter 5 is allowed to repeat the measurement until m _n0 + k ≦ ML is obtained.

FIG. 6 shows a flowchart of the third embodiment. In this embodiment, the frequency distribution is obtained from the value of Msn-m _n0 calculated in step 139 of the first embodiment, and the subsequent control is performed based on this frequency distribution. That is, in step 167 shown in FIG.
The CPU 101 divides the value of Msn-m _n0 into series at constant intervals (for example, 0.2 intervals), performs the frequency distribution calculation, and divides this by the measurement number n to obtain the relative frequency value (step 169). ).

The CPU 101 calls the correction value k corresponding to the relative degree value calculated in step 169 from the memory 103 (step 171), and corrects the least-squares approximate moisture value m _n0 calculated in step 137 (step 1).
73). The correction value k is an experimentally obtained constant and is stored in the memory 103 in advance.

As a result of the above correction operation, the CPU 101 causes m _n0 + k ≦ ML
CPU 101 determines that the output port 109,
The drive system 45 and the combustion system 47 of the grain dryer 1 are stopped via the digital output circuit 55 (step 175).

If m _n0 + k> ML in step 173,
After the operations from step 149 to step 157 similar to those in the above-described first embodiment, the process returns to step 137, and the CPU 10
Under the control of 1, the automatic moisture meter 5 is allowed to repeat the measurement until m _n0 + k ≦ ML is obtained.

FIG. 7 shows a flowchart of the fourth embodiment. This embodiment uses the CPU 10 in step 135 of the first embodiment described above.
When it is determined that 1 is sn ≦ ML + 2, step 17
The process moves to 7 and the measurement of the moisture value is started from the first time. Then, when the CPU 101 recognizes that the fifth moisture measurement is completed in step 187 through the steps 179 to 185, the CPU 101 measures the measured moisture value M five times.
A simple average moisture value is calculated from s ₁ , Ms ₂ ... Ms ₅ (step 189).

The CPU 101 calls the target moisture value ML stored in the memory 103, and compares it with the simple average moisture value calculated in step 189 (step 19).
1). When the CPU 101 determines that ≦ ML as a result of this comparison calculation, the CPU 101 determines that the output port 109,
The drive system 45 and the combustion system 47 of the grain dryer 1 are stopped via the digital output circuit 55 (step 193).

When sn> ML + 2 in step 135, the process returns to step 123 and the automatic moisture meter 5 repeats the measurement under the control of the CPU 101 as many times as necessary until sn ≦ ML + 2 is obtained.

If it is recognized in step 187 that the fifth moisture measurement has not been completed, the process returns to step 179 to repeat the measurement.

Further, if> ML in step 191, the process returns to step 177, and the automatic moisture meter 5 repeats the measurement under the control of the CPU 101 as many times as possible until ≦ ML is obtained.

[Effects of the Invention] As described above, according to the present invention, the moving average moisture value of the n-th time is obtained from the measured moisture value output by the automatic moisture meter, and the moving average moisture value is added to the target moisture value by several%. Once it reaches the specified value, it is decided to calculate the calculated moisture value by excluding the measured moisture value that is out of the preset moisture value range, so it is possible to significantly improve the measurement accuracy of the moisture content of the dried grain. It is possible to provide a grain moisture content measuring device in a grain dryer capable of performing the above.

[Brief description of drawings]

1 is an overall perspective view of a grain dryer according to an embodiment of the present invention, FIG. 2 is a front sectional view of a grain dryer according to an embodiment of the present invention, and FIG. 3 is a control according to an embodiment of the present invention. FIG. 4 is a block diagram of the apparatus, FIG. 4 is a flowchart of the configuration of FIG. 3, FIG. 5 is a flowchart according to the second embodiment of the present invention, FIG. 6 is a flowchart according to the third embodiment of the present invention, and FIG. 7 is a flowchart according to a fourth embodiment of the invention. (Explanation of symbols showing main parts of the drawing) 1 ... Grain dryer, 5 ... Automatic moisture meter, 31 ... Microcomputer

Claims (1)

[Claims] 1. In a grain dryer that automatically stops when the measured moisture value of dried grains measured by an automatic moisture meter reaches a target moisture value, an average is obtained from measured moisture values Ms output by the automatic moisture meter. The calculated moisture value sn is calculated in accordance with the moisture value and the calculated moisture value sn is calculated.
A grain is provided with a means for calculating a calculated moisture value by excluding a measured moisture value Ms out of a preset moisture value region after reaching a value obtained by adding several% to the target moisture value ML. An apparatus for measuring the moisture content of grains in a dryer.