JPS623372B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This is an invention of a moisture content measuring device using a resistance type moisture content meter.

A resistance-type moisture content meter sends an electric current through the crushed grains with the tip of an electrode rod, and measures the moisture content from the resistance value. Therefore, unless the grains are crushed reliably, the correct moisture content cannot be measured even if an electric current is applied.

However, when a moisture content meter is installed inside the dryer and the grains are crushed and measured in the dryer without being taken out of the machine, there is no need to take the grain out of the machine and it is convenient for automation, but on the other hand, the crushing of the grains fails. Moreover, since failures cannot be seen from the outside, the operation of the dryer must be controlled based on the erroneous measured values, resulting in the disadvantage that grains cannot be dried to the desired moisture content.

The present invention eliminates this drawback.

This will be explained based on the embodiment shown in the drawings. Reference numeral 1 denotes a conditioning chamber of a dryer, and a resistance type moisture content meter A is attached to the wall 1a of the dryer.

A downstream passage 2 communicates with the bottom of the tempering chamber 1 and is formed by two parallel perforated plates 3.

Then, the grains packed in the conditioning chamber 1 gradually flow out into the downstream passage 2, and the surface of the grains is strongly dried by the hot air from the burner 4 that crosses the passage 2 on the way.

The grains are discharged from the lower end of the flow path 2, sent to the elevator 6 by a cross-feeding helix 5 at the bottom of the dryer, and returned to the upper center of the tempering chamber 1 from the upper outlet by a tensioning helix 7.

While slowly circulating the grains in this way, the moisture inside the grains is diffused to the surface in the conditioning chamber 1, and the whole grains are uniformly dried.

A motor 9 capable of forward and reverse rotation is installed in the case 8 of the water content meter A, and gears 11 and 1 are attached to the output shaft 10 of the motor 9.
The rotary cylinder 13 is connected via 2. 14 is a bearing for the rotating cylinder 13.

A key groove 15 is carved inside the rotary tube 13, and the base end of the electrode rod 17 is slidably connected to the rotary tube 13 via a key 16 that fits into the key groove 15.

18 is an extruded metal that moves only in the left and right direction, and is screwed into a screw 19 carved in the center of the electrode rod 17.
An expansion spring 20 interposed between the extruded metal 18 and the bearing 14 urges the electrode rod 17 toward its tip.

Reference numeral 21 denotes a gutter-like plate vertically fixed to the inner surface of the machine wall 1a, and its upper edge is tilted low toward the inside of the tempering chamber 1 to reduce the resistance of grains flowing down. A receiving plate 22 having an uneven surface is attached to the inner surface of the gutter-like plate 21 so as to face the tip of the electrode rod 17.

Reference numeral 23 is a threaded rod having bearings at both left and right ends, and connects the gear 24 to the gear 12.

A movable metal 25 is screwed into the screw rod 23, and this metal 25 is connected to a key groove 27 carved into the lower surface of the machine frame 26.
Key join to.

A shutter plate 28 extends freely in and out below the gutter-like plate 21, and is urged toward the inside of the tempering chamber 1 by a contraction spring 29. A locking piece 28a is erected at the center of the upper surface of the shutter plate 28, and limit switches Sa and Sb are installed near both left and right ends of the screw rod 23, respectively. Reference numeral 28b indicates a stopper formed by bending the end of the shutter plate 28, and 28c indicates a connecting rod for the spring 29 installed on the lower surface of the shutter plate.

Moisture content meter A operates as follows.

First, the motor 9 begins to rotate forward, thereby rotating the rotary cylinder 13 and the threaded rod 23, and the electrode rod 17 and the shutter plate 28 are respectively projected into the tempering chamber 1 by the extruded metal 18 and the moving metal 25.
When the moving metal 25 comes into contact with the limit switch Sa, the motor 9 is turned off, and the electrode rod 17 is locked at a position with a slight gap from the receiving plate 22 as shown by the solid line, and its tip flows into the gutter-like plate 21. The grains are crushed, a current is passed through them, the moisture content is measured from the resistance, and a data voltage Er is output.

After a certain period of time (for example, 10 seconds) has elapsed after the start of locking, the motor 9 reverses and the moving metal 25 moves backward.
When this comes into contact with the limit switch Sb, the motor is cut off, which causes the electrode rod 17 and the shutter plate 18 to
Store it in its original position.

According to the present invention, the moisture content meter A is connected to the calculator C, and the display D and operating mechanisms such as the valve of the burner 4 and the power switch of the motor 9 (not shown) are connected to the output side of the meter.

Calculator C then determines whether the electrode rod 17 is locked, that is, whether the moisture content meter A is measuring, based on the presence or absence of the data outputting flag, and if so, erases the flag, and then
The determination unit C1 compares the data voltage Er output by the moisture content meter A with a predetermined lowest voltage Eo. The minimum voltage Eo is determined to be a value lower than the data voltage during excessive drying (in the case of rice, moisture content of less than 14% is excessive drying).

Therefore, if grains are clogged above the moisture content meter A and grains do not flow into the inside of the gutter-like plate 21, grains remain between the electrode rod 17 and the receiving plate 22 even if current is applied. Therefore, the data voltage Er becomes abnormally low and falls below the minimum voltage Eo.

In this manner, when the data voltage Er is lower than the lowest voltage Eo, the determination section C1 does not output the voltage Er, but outputs the timer set signal t1 to the control section C2. As a result, the control unit C2 measures whether or not N minutes have elapsed, and outputs a measurement command signal a to the moisture content meter A when N minutes have elapsed. Here, N is 10 or 4, which means the operating cycle of the moisture content meter A, in which measurements are taken every 10 minutes during the first half of the drying process, and every 4 minutes during the second half of the drying process.

The measurement command signal a causes the motor 9 of the moisture content meter A to rotate forward again, and the electrode rod 17 and shutter plate 28 move forward.

As a result, the grains flow into the gutter-like plate 21 without clogging, and the shutter plate 28 also protrudes into a fixed position.
While the electrode rod 17 is moving forward, the grains are pushed in all directions and are supported on the upper surface of the shutter plate 28, so that when the electrode rod 17 accurately pinches and crushes the grains between the receiving plates 22, the grains containing moisture are removed. Rate meter A outputs a data voltage Er with a value exceeding the minimum voltage Eo.

In this case, the data voltage Er is output from the discrimination unit C1 to the conversion unit C3, where the data voltage Er
is converted into the digital quantity measured moisture content Ms.

Next, in the calculation unit C4, it is determined whether this measured moisture content Ms is the first measurement value, and if it is the first measurement value, that value is used as the calculated moisture content s, and if it is the second or subsequent measurement value, s←4 The calculated moisture content s is calculated according to the relational expression ×Ms+Ms/5. In this relational expression, s on the right side is the previous calculated moisture content, and s on the left side is the current calculated moisture content.

Then, the target moisture content Ml (14.5% in the case of paddy) is set, and after the setting is completed, the calculation section C4 compares and calculates the magnitude of both s and Ml+2.
As a result, if s is large, that is, if the grain is still moist in the early stage of drying, the timer set signal t sets the operating cycle of moisture content meter A to 10 minutes.
If s is small, that is, if the grain is dry in the late stage of drying, a timer set signal t3 is output to set the time to 4 minutes. In either case, the numerical value of s is displayed on the display D.

In summary, in the present invention, the moisture content meter A
By comparing the data voltage Er with the lowest voltage Eo, it is confirmed whether the electrode rod 17 has compressed the grain, and only the data voltage when the electrode rod 17 has definitely crushed the grain is processed. Since the moisture content is calculated using
The measurement accuracy is improved, and therefore, if the dryer is automatically operated based on the measurement results, it is possible to accurately dry the grains to the desired moisture content.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a part of a grain dryer embodying the present invention, Fig. 2 is an enlarged sectional view of its main parts, Fig. 3 is its block diagram, and Fig. 4 is its flowchart. It is.

Claims (1)

[Claims] 1 Install the resistance type moisture content meter A in parallel to the dryer, let the grains in the machine flow between the receiving plate 22 of the moisture content meter A and the electrode rod 17, and move the electrode rod 17 forward toward the receiving plate 22. In devices that crush grains and measure their moisture content, a calculator C is connected to the output side of moisture content meter A, and only when the data voltage Er of moisture content meter A is higher than the predetermined minimum voltage Eo, A moisture content measuring device for grains in a dryer that calculates the moisture content by calculating the data voltage Er.