JPS60143754A - Moisture-content measurement of grain particle for dryer - Google Patents

Abstract

PURPOSE:To elevate the measuring accuracy in the final drying period by erasing the value of moisture content previously calculated to calculate the moving average anew when the moisture content falls below a specified reference value with the progress of drying. CONSTITUTION:The initial moisture content Mso is measures specified times and after the counting up of the results, data of the moisture content measuring interval time Ta set on a memory 15 is read out to set the counting 16 according to the data. Consequently, a measuring command signal is outputted at an interval of the time Ta to calculate the moisture content Msn by a moving average method with a control section 14. The results are compared with a reference value Msc inputted to the memory 15 previously as data. Then, when the moisture content Msn falls below the reference value Msc as the drying time passes, the results of calculation thus far used are erased and the calculation of moving average is performed again thus removing initial error otherwise added to the water content calculated thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION As a method for measuring changes in the moisture content of grains during drying, a method of periodically operating a moisture content meter and moving average of the measurement output eliminates accidental fluctuations in measurement values, that is, measurement irregularities. However, if a sample whose moisture content is far from the average moisture content is accidentally measured, the influence of the measured value will remain for a long time and reduce the measurement accuracy.

In particular, since the moisture content of grains at the early stage of drying is uneven, the initial measurement results often have a negative effect on the measurement accuracy at the end of drying.

The present invention eliminates the disadvantages that tend to arise from such a moving average method.
It is characterized by once drying to a certain value, the moisture content measured up to that point by the moving average method is once erased, and from then on, the moving average is calculated again from the subsequent measurement output,
This prevents the measurement results from the initial stage of drying, which tend to have uneven water content and therefore cause wide variations in the measurement output of the moisture content meter, to be included in the moving average of the subsequent moisture content. The purpose is to improve measurement accuracy.

The embodiments of the present invention shown in the drawings will now be described.

l is the conditioning chamber C1 of the dryer.A resistance type automatic moisture content meter A is attached to the wall of the dryer.

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

The grains which have been heated and put into the conditioning chamber 1 gradually flow out into the drying chamber 2, and on the way, the surface of the grains is strongly dried by the hot air from the burner 4 which crosses the drying chamber 2.

After the hot air from the eight-cup 4 crosses the drying chamber 2, it is discharged to the outside of the machine by the suction exhaust fan 5.

The rotary valve 6 at the lower end of the drying chamber 2 is slowly rotated to discharge the dried grains to the bottom of the machine.
It is returned to the upper part of the tempering chamber 1 via the elevator 8 and the hull spiral 9.

While the grains are circulated in this way, the moisture inside the grains is diffused to the surface in the conditioning chamber 1, thereby uniformly drying the entire grains.

In the present invention, the measurement output circuit 10 of the moisture content meter A is connected to a first person's port 12 in a central processing unit (CPU) 11 of a microcomputer via an A/D controller 13.

14 is a control section in the central processing section 11, to which a memory 15 and a counter 16 are connected.

Reference numeral 17 denotes an output port in the central processing unit 11, to which a measurement command signal input circuit 19 and an automatic measurement start signal input circuit 20 of the moisture content meter A are respectively connected via a digital output circuit 8.

Reference numeral 21 denotes a second manual port in the central processing unit 11, to which a drying start switch 23 is connected via a digital input circuit 22.

Then, the drying start switch 23 is pressed and closed, and the on signal is read by the control unit 14 via the second human-powered boat 21. Then, specify the address of the time setting data for the initial moisture content measurement interval time TO (for example, TO - 2 minutes) preset in the memory 15, read the data to the control unit 14, and then set the counter 16 to that time. Set the time TO according to the data.

Then, a measurement command signal is outputted from the output port 17 at time intervals of 10, the initial water content is measured by the water content meter A, and 1 is added to the initial measurement counter of the counter 16 for each measurement. The average of the moisture content meter Mso is calculated as M s .

is displayed digitally on a display (not shown).

After measuring the initial moisture content M s o a predetermined number of times (for example, 5 times) and counting up, the memory 5
Moisture content 'A111 fixed interval time Ta(
For example, data of Ta=8 or 4 minutes) is read out and the count 16 is set according to that data. As a result, measurement command signals are output at intervals of time Ta, and the control section 14 calculates the moisture content according to the following moving average method and displays it on the display.

Here, Msn is the moving average water content obtained from the n-th measurement.

Msn-1 is the moving average moisture content obtained from the n-1th measurement, and Msn is the measurement output of the moisture content meter from the n-th measurement.

Then, a predetermined reference value M is stored in the memory 5 as rough data for the moisture content Msn calculated in this way.
sc (eg M sc = 20%).

Then, after the drying time has passed, the moisture content M s n reaches the standard value M
When it becomes less than s c , all the calculation results of the moving average that have been calculated so far are erased (cleared), and the calculation of the moving average is restarted from the above-mentioned step of measuring the initial moisture content M s o.

Therefore, the moisture content at the initial stage of drying, which has many errors, is not included in the moisture content thereafter.

In short, in the present invention, when the moisture content value calculated according to the moving average becomes less than the reference value MSC, all the previously calculated moisture content values are erased, and the moving average is calculated again to calculate the moisture content. This eliminates the negative effects of measurement variations caused by uneven moisture content at the initial stage of drying.
This has the effect of improving the accuracy of measuring moisture content during drying.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of a circulating grain dryer embodying the present invention, Fig. 2 is a cross-sectional plan view taken along the line 11-11, Fig. 3 is a blowing diagram of an embodiment of the invention; Figure 4 is a flowchart. Figure 1 Figure 2 Figure 3 + + + + J - b

Claims (1)

[Claims] In a device in which the moisture content meter is operated periodically and the moisture content of the grain being dried is calculated each time by moving average of the measured output, the calculated moisture content reaches a predetermined reference value as the drying progresses. Moisture content of grains in a dryer characterized in that when the moisture content falls below, the previously calculated moisture content value is deleted, and the measured output of the moisture content meter after deletion is newly averaged to calculate the moisture content. Measuring method.