JPS63198857A - Method for measuring moisture in grain for grain dryer or the like - Google Patents

Abstract

PURPOSE:To prevent interruption of moisture measurement even if the actual moisture value of a sample grain is extremely low by using a preset value as a detected value when the detected value does not exceeds the threshold for the prescribed time during the moisture measurement. CONSTITUTION:The sample grains taken out of the mid-point of the grain circulation of a dryer are let off by each piece to the spacing between electrode rolls 22 by a stationary conveyance plate 27 and a let-off roll 26 having spiral hollow flights 25 which can fit one piece of the grains. The sample grain 50 is crushed between electrode rolls 22 which rotate in opposite directions at different speeds. The electric resistance thereof is inputted through a resistance-voltage converter 29 and an AD converter 30 to a CPU 31. The CPU 31 regards that the sample 50 arrives at the rolls 22 every time when the resistance between said rolls falls to the predetermined threshold or below. Then, the CPU calculates the moisture value thereof and estimates the grain moisture value by averaging the moisture values of the 32 grains. The CPU calculates the moisture value by using the preset value when the resistance does not fall to the threshold or below for the prescribed time. The interruption of the measurement is then obviated even if the moisture value of the sample grains is extremely low.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a method for measuring grain moisture in grain driers and the like.

[Problems to be solved by the prior art and the invention] For example, each sample grain is guided between a pair of electrode rolls and crushed, and the electrical resistance of the crushed grains is converted into a voltage to determine the moisture content. In a moisture measuring device that converts into a value, a common calculation method is to continuously measure a predetermined number of grains and calculate the average value thereof.

However, some of the sample grains had extremely low moisture values, and because they could not reach the threshold level, the average value could not be calculated.In the past, the dryer burner was stopped after assuming that the rice was clogged. It was controlled and switched to a safe ventilation drying state. In other words, the drying time was unnecessarily prolonged in order to assume an abnormal condition and interrupt the hot air control.

[Means for solving the problem of bad luck] For this reason, the present invention sequentially takes in test grains from the middle of the grain circulation path, obtains an electrical output for each unit grain, converts it into a moisture value, and calculates the moisture content of a predetermined grain unit group. In the grain moisture measurement method that calculates the average value by combining multiple average values, if the electrical output does not rise for a predetermined period of time during moisture measurement output, the average value "calculation" is calculated using a preset value. This is the configuration of a grain moisture measurement method such as a grain dryer used as one data.

[Operations and Effects of the Invention] During drying, when a measurement signal is output, each part of the moisture meter is activated, and for each unit sample grain that is guided, for example, an electrode roll outputs an electric signal for moisture conversion, and the Process the signal and calculate the moisture value. When a predetermined number of grains is reached, the electrical signals that are continuously output for each unit grain are averaged to calculate an average moisture value.

The average values of these predetermined grain number groups are further averaged and estimated as the grain moisture value during drying. During such moisture measurement, if the electrical signal cannot exceed a predetermined level within a predetermined time, that is, if it is outside the processable range, it will interfere with the averaging process, and in this case, the data of the measured particle group will be This is to estimate the value to a preset value and perform averaging processing.

Therefore, even if the actual moisture value of the sample grains to be processed is extremely low and electrical signals cannot be continuously received, steady drying can be carried out without fear of interrupting the normal operation of the dryer because it is presumed to be clogged. The control state can be continued.

[Example] An embodiment of this invention will be described based on the drawings.

Reference numeral 1 denotes a grain dryer frame, which is vertically arranged with a storage tank 2 at the top, a drying chamber 3 at the middle, and a grain collection chamber 4 at the bottom. An elevator 5 for lifting and returning the collected grains to a holding tank 2 is installed on one side. Note that the drying chamber 3 has a downstream passage 10. This is a known configuration in which the vA grains passing through the flow passage 10.10 are dried by being exposed to hot air.

The elevator 5 has a belt 11 that runs between the upper and lower driving pulleys and driven pulleys, and buckets 1 to 12, 12, . . . are arranged on the belt 11 at regular intervals.

These buckets L-12, 12... scoop up the grains transferred to one side by a transfer spiral 13 installed horizontally at the lower part of the grain collection chamber 4, transfer them upward, and transfer them on the outward journey. It is configured to spring out from the terminal end to the throwing spout 14. Reference numeral 15 designates an upper transfer spiral that receives and horizontally transfers the splashed grains, 16 a diffusion plate disposed at the center of the upper part of the storage tank 2 to rotate around the vertical axis, and 17 and 17 a delivery valve.

The elevator 5 is provided with a moisture meter 18.

This moisture meter 18 includes a funnel-shaped grain intake part 20 communicating with a side wall opening 19 of the elevator 5, a main body part 23 having a grain feeding device 21, a pair of electrode rolls 22, 22, etc. and a return section 24 that returns the inside of the elevator 5. Among these, the -grain feeding device 21 has a spiral groove 25 on one circumferential surface into which one grain can fit, and approaches a feeding roll 26 that rotates in a certain direction in the tangential direction of this feeding roll 26. It is composed of a fixed conveyor plate 27, and is configured to receive one grain between the four spiral stripes 25 and the conveyor plate 27 and convey it in the axial direction of the feed roll 26. The transfer start end of the feed roll 26, which extends into the grain intake section 18, is formed to have a large diameter so that the test grains can be deposited thereon, and the portion from the middle portion to the transfer end portion is formed to have a small diameter to remove excess. It is configured to eject the grain downward.

The electrode rolls 22, 22 are located below the transfer end of the grain dispensing device 21 and rotate in opposite directions at different circumferential speeds.

Reference numeral 28 denotes a motor that rotationally drives the feed roll 26 and the electrode rolls 22 and 22.

FIG. 5 shows a block circuit diagram, in which the electrode roll 22.
The electrical resistance value of the sample grains crushed between 22 and 22 is converted into a voltage value by a resistance-voltage converter 29, and this output voltage ER
is input to the CPU 31 via the A/D converter 3o,
The CPU 31 mainly has the following functions. That is, (1) a moisture measurement signal is output at predetermined intervals (for example, 5 minutes), and the motor 28 is output in reverse for 1 minute. (2) Next, a normal rotation signal of the motor 28 is output. ■The output voltage due to crushing of the test grain is increased every 60 milliseconds from the time when the threshold value α is exceeded.
A/D conversion is performed for seconds. ■Using the maximum value ER from this A/D conversion, calculate the moisture value using the following calculation formula (% formula %) (where Mo, A are constants, and TG is the grain temperature), and use it as the moisture value of the sample grain. Remember. ■Similarly, the output voltage for a preset number of grains (for example, 32 grains) is continuously captured, the moisture value is calculated by simply averaging the respective moisture equivalent values, and the average moisture value Mn of 32 grains is calculated. Find the average value Mn. ■Outputs a moisture measurement end signal.

The motor 28 is controlled to stop. (2) Calculates the drying rate from the difference from the average moisture content, compares it with a preset drying rate, and outputs an increase/decrease signal for fuel supply to the furnace. (2) The average moisture value Mn is compared with a preset finished moisture value Ms, and if it is less than this, a drying end signal is output. etc. Also,
CI) U31 converts the voltage value ERo when the electric signal ER value cannot exceed the threshold α set for noise removal (for example, a voltage value ER equivalent to 10% in terms of moisture). 10% is estimated as the moisture value for averaging the moisture value Mn. That is, every time the set time of 3 seconds for A'/D conversion of the sample grains that are continuously taken in elapses, the timer mechanism built into the CPU 31 measures a predetermined time t, for example, 2 minutes, and within this time, the threshold value is reached. If the value α is not exceeded continuously (Fig. 7b), the above average value Mn in moisture
As one data for finding the voltage value ER, (10%)
is used. In addition, in order to deal with the case where the sample grains cannot reach the threshold value α immediately after the start of measurement, the above-mentioned predetermined time setting is such that timing is initially started based on the generation of the normal rotation output signal of the motor 28. .

32 is a digital display section that displays the above-mentioned average moisture value Mn.

A grain temperature sensor such as a thermistor (not shown) for detecting the grain temperature TG is embedded in the sample grain group in a space corresponding to the transport plate 27 on the transfer start end side of the feed roll 26. There is.

The action of the upper side will be explained.

A predetermined amount of grain is loaded from a loading hopper into a storage tank 2 using an elevator 5. Next, the grain type, finishing moisture, etc. are set, and drying work is started. The grains in the storage tank 2 are exposed to hot air while flowing down the drying room 3 and reach the grain collection room 4.

The grain is transferred to one side by the lower transfer spiral 13, fried by the packets 12, 12, etc. of the elevator 5, reaches the storage tank 2 again, and is subjected to a tempering action for a while.

During such drying work, the motor 28 of the moisture meter 18 is operated at preset measurement intervals to measure moisture content and control the temperature of the hot air while monitoring the drying loss rate. Then, when the average moisture value Mn reaches the moisture value MS, the drying operation ends.

When a measurement signal is input to the moisture meter 18, the motor 28 is activated to rotate the feed roll 26 and the electrode rolls 22, 22 in the normal direction. Moisture meter 18 continuously from opening 18 of elevator 5
The grains taken into the interior are transported by a feeding roll 26 and a conveying plate 26.
While a plurality of grains are deposited on the transfer start end side of the feed roll 26, one grain that fits into the spiral groove 25 is received as a test grain by the conveyor plate 27, and the grain is directed toward the terminal end side. be transported. While crushing the test grains that are fed out sequentially at 3 to 4 second intervals with the electrode rolls 22 and 22, the output "city pressure ER" is converted into a moisture value, and a predetermined grain, for example, 32 grains of MrL-Z is
The simple average value of r'%-5 12 柚竪;mi、赫;=4 is taken as the average moisture value, and is used as a numerical value for drying rate control and digital display.

The above moisture measurement is carried out continuously for each unit grain, but during the measurement, after the previous output voltage drops and becomes below the threshold value α, the moisture value of the next sample grain becomes extremely low. threshold α
In some cases, the level is not reached even after the predetermined time has elapsed, but in this case, the output voltage is set to Elo, that is, in this embodiment, 10% is used as data corresponding to 32 grains, and the CPU 31 averages the data. Therefore, the moisture calculation is not interrupted and there is no problem in continuing the drying operation.

Note that if paddy clogging actually occurs at the entrance of the moisture meter 18 or in the sample grain transportation system within the moisture meter 18, the output voltage ER=O will continue as shown in the output example in Figure 7C, and the above-mentioned condition will continue. As in the case of a low moisture value, the threshold level will not be reached for a predetermined period of time, but if the output voltage is in a form that can distinguish between the state of ER=O and the low moisture output as shown in Figure 7. It is convenient because it allows troubleshooting due to paddy clogging. As a specific example of how to distinguish between the two, if the output voltage has an inflection point at approximately constant intervals, it can be determined that low-moisture grains are being supplied, and if ER = O continues, it is paddy clogged. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is an overall front view, Fig. 2 is a sectional view thereof, Fig. 3 is a front view of main parts, Fig. 4 is a side view thereof, and Fig. 5 is a side view. is a block diagram, FIG. 6 is a flowchart, and FIGS. 7a and b. C is a diagram showing an example of output voltage. In the figure, 18 is a moisture meter, 19 is an opening, and 21 is a unit grain (-
grain) feeding device 5, 25 is a spiral groove, 26 is a feeding roll,
27 is a transport plate, and 31 is a CPU.

Claims (2)

[Claims] (1) Sequentially take in the test grains from the middle of the grain circulation path,
In a grain moisture measurement method, an electrical output is obtained for each unit grain, converted to a moisture value, and a plurality of average values of a predetermined grain unit group are collected to obtain an average value @Mn@.
A method for measuring grain moisture in a grain dryer, etc., in which a preset value is used as one data for calculating an average value @Mn@ when the electrical output does not rise continuously. (2) The grain moisture measuring method for a grain dryer or the like according to claim 1, wherein the preset setting value is the converted moisture value ER_0 at the threshold value α.