JPS58214775A - Controller for temperature of hot air of cereal drier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel hot air temperature control device for a grain dryer,
In detail, the hot air temperature is controlled with high precision according to the detected value of the hot air temperature, which changes from moment to moment, to perform stable drying, and to prevent the displayed value of the hot air temperature from changing unnecessarily violently, so as to disturb the administrator. It is an object of the present invention to provide a new hot air temperature control device for a grain dryer that does not give a necessary sense of anxiety.

Generally, grain driers for drying grains such as rice use ventilation thermal dryers that blow hot air onto the grains.

Figure 1 shows an example of a circulation-type grain dryer (a) that circulates and dries grain, in which b is a storage section, C is a drying section, d is a hot air generator equipped with a burner, and e is an exhaust air generator. Showing a wind machine. In this type of grain dryer a, the grains are not tempered in the storage section C.
When passing through this drying section C, it is dried by being exposed to the hot air flowing from the hot air generator d to the exhaust fan e, and then transferred to the aging storage section, and this process is repeated to reach the target moisture content. Once it reaches that point, it will be taken out of the aircraft.

In drying grains performed in this manner, controlling the temperature of the hot air to be supplied is extremely important. I mean,
In order to achieve the target degree of dryness as quickly as possible without deteriorating the quality of the grain, it is necessary to maintain the grain at a temperature that matches the change in drying rate over time, and the temperature of the hot air must be adjusted to match the temperature of the hot air. This is because it is an important factor that determines grain temperature together with air volume.

For this reason, in general, an appropriate hot air temperature sensor f is installed in the hot air flow path.
is installed to detect the temperature of the hot air every moment, and on the one hand, the detected hot air temperature is fed back to an appropriate control circuit g to automatically control the combustion amount in the burner, etc., and on the other hand, the detected hot air temperature is By displaying the temperature on an appropriate display h digitally or with a pointer, etc., when the hot air temperature changes abnormally, the administrator can promptly deal with the abnormality and keep the grain dryer operating normally. I'm trying to make it possible.

By the way, this momentary detection value of the wind 1 temperature is determined by the 1ljl iJj circuit g that automatically controls eight-stroke combustion.
When feeding back to the control circuit G, it is almost impossible to manually input the control circuit G as it changes from moment to moment. Manual input to the display device may cause inconveniences if it sharpens the sensor sensitivity of the detector f used to detect the degree of discomfort (particularly if it gives unnecessary anxiety to the administrator). This is detected!Vx la degree, for example, during the stable period of combustion, fluctuates frequently with predetermined temperature peaks and peaks relative to the set temperature number, so these frequent fluctuations are displayed as they are. The rapid fluctuations in the displayed values make managers feel uneasy. Figure 2 shows the detected fluctuations in hot air temperature. Curve i in the figure has a time constant of 20 seconds (wind speed 2 m) as its sensor sensitivity.
Line j shows the transition when the hot air temperature is automatically controlled using a detector with a speed of
This curve shows the transition when using a detector (seconds), and the line shows the target set temperature.
If a highly sensitive detector is used, the transition period until the hot air temperature enters the stable period is extremely short compared to the transition period m in curve j, and furthermore, the fluctuations n after entering the stable period are frequent. Since the temperature changes to a small value, the error with respect to the set temperature is kept small and the hot air temperature can be controlled well.

However, on the other hand, if the hot air temperature that frequently repeats hunting is detected and input to the display, the displayed value will change in accordance with the frequent changes in the hot air temperature. Moreover, fluctuations in the hot air temperature are not simply caused by changes in the eight-gas combustion amount; there are also variations in the temperature distribution in the hot air flow path, large hunting occurs when the air volume is changed, and other Disturbance factor 1 For example, the pulsation of the burner flame due to the blowing of yellow wind into the outside air intake of the hot air generator d, the density difference in the flow of grain in the drying section C, or the blowing of gusts of wind into the exhaust fan e. Hunting can also occur due to temporary changes in air volume due to factors such as airflow, etc., so a detector with high sensor sensitivity will sensitively detect even the slightest hunting caused by these various causes. The detected temperature is displayed on the display every moment. Therefore, managers who pay close attention to this display are attacked by a sense of unreasonable anxiety.
In extreme cases, if the monitoring of other displayed numbers, machine operation, and grain are neglected, or if it becomes difficult to leave the hot air temperature display, stop the machine operation and check for malfunctions. Unreasonable drying management was forced. However, if a detector with low sensor sensitivity is used, the hot air temperature will slowly repeat hunting O, which is significantly different from the target set temperature, so the display will be stable, but the drying efficiency will decrease and the temperature will change immediately after control starts. This is also undesirable because it has fatal drawbacks such as thermal damage due to overheating of the grain. It is also possible to attach hot air stirring blades to the hot air generator to make the temperature distribution within the hot air flow path uniform and thereby reduce hunting, but this would increase the cost and increase the size of the equipment. This has disadvantages and is not practical.

Therefore, the present invention uses a temperature detector with as high a sensitivity as possible to detect the hot air temperature, and controls the hot air temperature with high precision according to the detected value of the hot air temperature that changes every moment to perform stable drying. The present invention aims to provide a new hot air temperature control device for a grain dryer that prevents the displayed value of the hot air temperature from changing unnecessarily and violently, thereby avoiding causing unnecessary anxiety to the administrator. , and a hot air temperature sensor installed in the hot air flow path leading to the drying section through which the grain passes.

It consists of a dryer control circuit that receives at least a detection signal from the hot air temperature detector as one input, a hot air generator whose generated heat is controlled by the control circuit, and a display that displays the hot air temperature. The machine control circuit samples the hot air temperature from the hot air temperature detector at approximately constant intervals, processes the detected value of the sampled hot air temperature every time each sampling is completed, calculates the amount of heat to be generated, and calculates the amount of heat to be generated. The amount of heat generated by the hot air generator is controlled according to the calculation result, and the average value of the same number of hot air temperature detection values obtained by sampling a predetermined number of times is calculated, and the average value is displayed as the hot air temperature. The display device is characterized in that the display device is controlled as follows.

The details of the invention will now be described in accordance with the embodiments illustrated in the accompanying drawings.

FIG. 3 shows an example 1 of a grain dryer equipped with a hot air temperature control device according to the present invention.The main body 2 of this grain dryer 1 includes a storage section 3, a drying section 4. Consisting of a grain collecting section 5, there is a lower conveying means 6 such as a screw conveyor in the grain collecting section 5, and the delivery end of the lower conveying means 6 is connected to the lower part of a grain lifting machine 7 provided outside the main body. . 8 is a hopper. An upper conveying means 9 such as a screw conveyor is connected to the upper part of the grain lifting machine 7, with a delivery end facing the medium heat section on the upper side of the main body 2. 10
1 is a heat R generator installed at the front of the drying section 4, and 11 is an exhaust fan installed at the back of the drying section 4. 12 is a motor that drives the grain lifting machine 7 and the upper conveying means 9; 13 is a motor that drives the lower conveying means 6; 14 is a motor that drives the exhaust fan; for example, a motor that can change the number of poles is used;
Adjust the amount of hot air by changing the fan rotation speed.

Further, 15 is a dryer control panel provided on the front panel of the main body 2, and is equipped with a control circuit, etc. of the hot air temperature control device of the present invention.61
Reference numeral 6 denotes a moisture meter whose detection end is inserted below the storage section 3 to measure and display the moisture value of the grain.

In the grain dryer 1 thus constructed, the grains put into the hoisting machine 8 are lifted up by the grain lifting machine 7, and are evenly distributed from the upper central part of the main body to the storage part 3 by the upper conveying means 9. From there, it flows down the drying section 4 one after another. During this flow, the grains are sucked into the hot air generator lO by the exhaust fan 11.
The amount of hot air from the grain is exposed and dried, and then guided to the grain collection section 5, transferred to the lower part of the lower conveyance means 7, and written and written by the grain lifting machine 7 (
The cycle of being lifted up is repeated over and over again.

FIG. 4 shows the hot air generator 10, in which 17 is a casing, 18 is an evaporative oil heater, and 19 is a heat sink 18.
This is a combustion tube placed horizontally on top. Further, 20 is a temporary air fan, 21 is a driving motor for the fan 20, and 22 is an oil nozzle. , 23t1 is an electromagnetic pump that transports oil from the tank 24 to the above-mentioned Nohena 184, and is driven so as to be electromagnetically driven using an iM dynamic pump such as a plunger pump. 25 is a hot air temperature detector consisting of a thermoelectric conversion element such as a thermistor provided in the hot air flow path 26 which passes from the hot air generator 10 to the drying section 4;
Approximately 1 electrical connection is made to 8. In addition, the electromagnetic pump 23 is activated by the command from the hot air temperature control section 28.
This system controls the amount of oil fed to the tank, thereby controlling the temperature of the hot air.

FIG. 5 shows the details of the dryer control panel 15, including an OK monitor display 29 that displays the operating status of each part of the grain dryer 1, an operation switch 30. Stop switch 31, target moisture a1a setting switch 32, grain input amount setting switch 3
3, a hot air temperature indicator 34, and so on.

FIG. 6 shows a block tire dram of the dryer control circuit 27 configured by integrally incorporating the hot air temperature control section 28 into the circuit.

In the figure, 16 is a moisture meter, 25 is a hot air temperature detector, 3
Reference numeral 2 designates a target moisture value setting switch 30 as a dryer operation switch, and 31 as a dryer operation stop switch, which are provided in the dryer a1 and the control panel 15 described above. Further, 35 is an outside air temperature sensor attached to the vicinity of the grain dryer l, preferably near the outside air intake of the hot air generator 10, and 36 is various safety switches installed on the control panel 15, such as a fire extinguisher activation switch, Grain lifting machine safety switch.

This is a group of switches such as fuel overflow switches.

37 is a clock oscillator, which generates a synchronization signal (clock, pulse signal) to match the progress of input/output and arithmetic processing operations.
38 is an A/D conversion circuit, which converts analog information signals from the outside air temperature sensor 35, moisture meter 16, and hot air temperature detector 25 into digital signals;
39 is an encoder, and the target moisture value setting switch 32
This is a device that encodes the setting values of the grain input amount setting switch 33 and inputs the encoded values to an input data buffer 42, which will be described later.

The ROM is a beam-only memory and can store various calculation programs, such as the average value of hot air temperature.

It contains arithmetic expressions for changing the burner combustion amount, tables for changing the burner combustion amount, and programs for instructing the operating procedures of each part. R
AM is a random access memory, which is a readable and writable memory having a storage section for temporarily storing, for example, a detected value of hot air temperature, other input data, or a calculation result of the CPU. CPU is the central processing unit, R
According to the above program written in the OM, it has a calculation unit that calculates the side input value of the hot air temperature written in, for example, the random access memory RAM, and also performs various operations on the read-only memory ROM and random access memory RAM. This is a device that performs the function of storage control or output control. 40 is a timer interrupt control circuit, and the central processing unit CPU
a timer circuit whose time can be set according to the command of the
It consists of a circuit that issues an interrupt command to the central processing unit CPU to indicate the completion of the timer operation. 41 is an interrupt control circuit that issues an A/D conversion start command to the A/D conversion circuit 38 according to the Iu command of the central processing unit CPU, and a circuit that issues an A/D conversion start command to the A/D conversion circuit 38, and a circuit that issues an A/D conversion start command to the CPU.
It consists of a circuit that issues an interrupt command. Reference numeral 42 denotes an input data transfer, which transfers data from the A/D conversion circuit 38, encoder 39, various switches 3o, 31.
7 has a register function.

Reference numeral 43 denotes a display control circuit, which includes a decoder for decoding output data etc. sent from the central processing unit CPU via an output data path 44 (to be described later), and the above-mentioned OK monitor display and display 34.
It consists of a driver that operates the . 45 is an output data buffer, which transfers the output data from the central processing unit CPU to the output data buffer 44.
The output data sent via C is also sent to the central processing unit C.
It has a register function for temporarily storing a command sent from the PU via a control signal line 46, which will be described later.

Each of the above-mentioned devices shown surrounded by a dashed line in FIG.
The CPU functions as a control microcomputer.

Further, the OK monitor display 29 displays the safe state of the drying plate. A display 34 provided on the control panel 15 alternately digitally displays the average value of, for example, six detected values detected by the hot air temperature detector 25 at each sampling time and the moisture value obtained from the moisture meter 16. 48 is a burner drive circuit, and 49 is a motor drive circuit, which drive the respective loads according to the data from the output data buffer 45. That is, the /hener drive circuit 48 includes the ignition heater 5o and the ignition valve 51.
, the electromagnetic pump 23, and the temporary air fan motor 21 of the burner. In addition, the motor drive circuit 49 includes the fan motor 14 of the exhaust fan, the upper 74811 & the feeding means 9.
and the motor 12 of the grain lifting machine 7, and the motor 13 for the lower conveying means.
, and controls and drives the moisture meter motor 52.

In this embodiment, the electromagnetic pump 23 uses a reciprocating pump such as the above-mentioned re-plunger pump that is electromagnetically driven, and as described later, the plunger of the pump is driven by a pulse signal, and the width and narrowness in the pulse signal is change proportionally to
Although the method is used to control the amount of oil fed, it is of course possible to use a method in which the drive cycle of the plunger is changed by changing the frequency of the pulse signal to control the amount of oil fed.

FIG. 7 is a flowchart showing the operation program of the dryer control circuit 27 shown in FIG. executed in steps. Before starting this procedure, set the amount of grain to be fed into the grain dryer 1, the target moisture value, etc. by operating the dials on the grain input amount setting switch 33 and target moisture value setting switch 32 provided on the control panel 15. and set it in advance. This flowchart will be explained step by step below.

(a) When the operation switch 30 is turned on, the program in the ROM is started to "start drying", and the various motors 12, 13 and 52 of the motor drive circuit 49 are activated.

(b) Next, the eight drive circuit 48 is activated, the ignition heater 50 is turned on, the ignition valve 51 is opened for a predetermined time, and the electromagnetic pump 23 drives the burner fan motor 21 while supplying oil to the 7 henna 18. do.

(c) Next, compare the moisture value of the grain obtained from the moisture meter 16 with the target moisture value, and if the moisture value does not reach the target, step (
Proceed to step e), and if the moisture value or target value number has been reached, step
Proceed to step (d).

(d) If the water content has reached the target value in step (C) above, outputs the "/hener stop" command to stop the burner 18, and also outputs the "motor stop" command to stop the various motors. Remove and finish drying.

(e) If the moisture value has not reached the target value in step (C), the hot air temperature Tb detected by the hot air temperature detector 25 is read.

(f) Next, a calculation is performed to obtain the average value Th of the hot air temperature. The average value Th of the hot air temperature is determined by calculating the sum of the detected value Tb detected this time and the five detected values Tb obtained from the previous five detections, and dividing the sum by six. In addition, at the stage where the number of detections of the hot air temperature Tb is less than 6, the average value T
h is calculated, and when the first detection is completed immediately after the start of program execution, one detected value Tb becomes the average value Th.

(g) The average value Th obtained in step (f) is sent to the display control circuit 43, and then the moisture value obtained from the moisture meter 16 in step (C) is also sent to the display control circuit 43. The display control circuit 43 has a function of causing the display 34 to display the hot air temperature and moisture value alternately, for example, for 5 seconds each as shown in FIG. 8, so that the display 34 displays the hot air temperature. During the period, the average value Th input in this process (g) is digitally displayed.

(h) The detected value Tb of the hot air temperature input in step (e) above, the outside air temperature detected by the outside air temperature sensor 35, the moisture value from the moisture meter 16, and the amount of grain input from the grain input amount setting switch 30 or 31. The temperature TC of the hot air to be supplied is set based on the signal indicating the temperature. The setting of the temperature of the hot air is carried out because, as described above, it is necessary to keep up with the drying progress of the grains and readjust the appropriate temperature value of the hot air to be supplied every moment. This hot air temperature setting is an example.

This may be done by storing a table in advance in the storage unit in which the set temperature is determined based on each of the above-mentioned human power values, and reading out the set temperature Te by comparing the input values with the table. Alternatively, various methods can be applied, such as substituting each input value into a predetermined calculation formula and calculating each time.

(1) Hot air temperature Tb and set hot air temperature Tc 1Tc
- It is determined whether or not Tbl≦1, and if the absolute value is greater than or equal to 1, that is, greater than l'O, proceed to step (D), and if it is below 1 °C, proceed to step (k). Control of the oil supply amount using the drive pulse having the pulse width Tw determined in the previous routine is performed as is.

(j) Determine whether or not Tc-Tb>O, and if yes, branch to step (L); if no, branch to step (nn). That is, if the hot plate temperature Tb is too high than the set temperature Tc, the amount of oil fed is decreased, and if the hot plate temperature Tb is too low, the amount of oil fed is increased.

(L) Judge whether Tc-1>Tb≧Tc-4 or not, and if the judgment result is YES, branch to step (n) and pulse lil T W of the pump drive pulse to 61
Increase by minute. Conversely, if it is know, step (0)
The drive pulse pulse fil T w is branched to 2Δ
The power is increased by τ.

(m) Determine whether Tc+4≧Tb≧Tc+1, and if yes, branch to step (p) and reduce the pulse width Tw of the pump drive pulse by △τ (minimum variable pulse [1 pulse)] let If the judgment result is NO, branch to step (q) and pump drive pulse tt]Tw is changed by 2Δ
Decrease by τ.

(r) Steps (k), (n), (p), (q
), the pulse width of the pump drive pulse for driving the electromagnetic pump 23 is set to the value determined by that step to control the amount of oil fed. Also, along with that, eight-
Control the fan motor 21 to exhaust air! The fan motors 14 of a, it, the motors 12 and 12 of the upper conveying means 9, and the motor 13 of the lower conveying means 6 are controlled respectively.

(S) Check whether the various safety switches 36 are operating.

(1) If a YES judgment result is obtained in step (S) above, that effect is displayed on the OK monitor display 29, and the error processing routine is called and the process proceeds to the subroutine Cu). When the error handling subroutine (U) is completed, the process jumps to step (C) asking "Is the moisture value OK?".

(V), ), If a negative judgment result is obtained in step (5), that is, if there is no problem, check whether the ring timer Ts has timed out or not. If not, the program jumps to step (r) again and repeats this routine until Ts exceeds the set time. When the time has elapsed, the routine jumps to step (C) and repeats this routine starting from checking the moisture value.

When the moisture value finally reaches the set value, the drying process is completed through the above-mentioned step (d).

According to the hot air temperature control device of the present invention, the hot air temperature can be minutely controlled moment by moment in accordance with the progress of grain drying, and in particular, the hot air temperature can be displayed extremely stably. 9th
Figures (A) and CB) show changes in the detected hot air temperature value Tb and the displayed average value Th of the hot air temperature. This figure (A)
As is clear from the above, the actual hot air temperature detection value Tb fluctuates frequently and the range of fluctuation is large. Therefore, if this is displayed as it is on the display 34, the administrator who monitors it as described above will be able to determine the display shake detection value T.
However, as shown in the same figure (B), the average value Th of the hot air temperature displayed by the display 34 has a small fluctuation frequency and a small fluctuation range. , there is little risk of causing unnecessary anxiety due to the display. In other words, although the hot air temperature detection value Tb repeatedly rises and falls relatively sharply, it is not necessary to grasp the change status of the hot air temperature in short cycles of several seconds, but it is necessary. L, this is an understanding of the change in hot air temperature over a comparatively long period of about several seconds. Since the 3F average value Th of 4rt4 is displayed, it is possible to grasp the changes in the board temperature for a long circumference (IJ), and to detect the hot air temperature of the same cycle (for changes in lliTb). It is possible to completely avoid the risk of being misled and having unnecessary anxiety in management.Therefore, there is less risk of management errors occurring, and more stable drying can be performed.

In the above embodiment, the average value Th is calculated every time the hot air temperature is sampled, and the average value Th is
is sent to the display 34 for the ship where the calculation is made.

However, every time the hot air temperature is pumped a certain number of times, for example six times, an average (+iTh) is calculated by calculating the six detected values and displayed.

For example, the displayed value of the hot air temperature may not change during the 6 sample cycle period. Figure 1O shows the case when the method is carried out in this way, and the detected hot air temperature value Tb is the 9th.
8 Wind temperature display value when changing as shown in the figure, that is, Th
This shows the transition of As is clear from this figure, according to this embodiment, the frequency of fluctuations in the displayed value of the hot air temperature is reduced, and the need for the administrator to feel unnecessary anxiety is reduced.

5 In the program described above, six detected values are used as data to calculate the average value of hot air temperature, but this is not limited to six, and an appropriate number of detected values can be used as data. The cycle of each sampling is not limited to 10 seconds, and an appropriate cycle time may be set.

Regarding the control of the burner combustion amount, in the above embodiment, the oil feed amount is corrected every sampling period of the hot air temperature, and the number of times per unit time of the sampling operation and the oil feed amount correction operation, that is, the frequency The program is simplified by making the correction operations consistent with each other, and always taking correction operations when necessary at the completion of sampling. However, there is no need to match the number of times of sampling and the number of corrections.

As described above, the hot air temperature control device for a grain dryer of the present invention includes a hot air temperature sensor provided in a hot air flow path leading to a drying section through which grains pass, and at least a detection signal from the hot air temperature sensor. The dryer control circuit includes a dryer control circuit that takes two inputs, a heat generator whose heat generation is controlled by the control circuit, and a display that displays the hot air temperature. The temperature is sampled at approximately constant intervals, and each time the sampled hot air temperature is finished, the detected value of the sampled hot air temperature is processed to calculate the amount of heat to be generated. In addition to controlling the amount of heat generated, an average value of the same number of hot air temperature detection values obtained by sampling a predetermined number of times is calculated, and the display is controlled so that the average value is displayed as the hot air temperature. The feature is that the hot air temperature is displayed as the average value of multiple detected values of hot air temperature within a certain period of time, so even if the detected value of hot air temperature changes little by little, The frequency and range of fluctuations in the displayed values are small. However, since the displayed value reflects changes in the hot air temperature over a relatively long cycle, the administrator can operate the grain dryer normally without feeling unnecessary anxiety. In addition, since a stable display can be made using the average value in this way, a detector with high sensitivity can be used for detecting the hot air temperature.This allows for highly accurate measurement of the hot air temperature. By detecting this and finely changing the burner combustion amount based on this detected value, it is possible to supply efficient and appropriate hot air that follows the drying progress of the grain, and to display and control the hot air temperature. can also be done properly.

[Brief explanation of the drawing]

Figure 1 is a side view schematically showing a general grain dryer, Figure 2
The figure is a curve diagram showing the transition of hot air temperature detected by a hot air temperature detector, and FIGS. 3 to 9 are for explaining an example of implementation of the hot air temperature control device for a grain dryer according to the present invention. Fig. 3 is a perspective view showing the grain dryer, Fig. 4 is an enlarged vertical side view showing the main part B6 of the hot air generator, Fig. 5 is a front view of the dryer control panel, and Fig. 6 is the dryer control circuit. Block tire diagram, Figure 7 is a flowchart showing the control program of the control device, Figure 8 is a time chart showing the display timing of hot air temperature and moisture value, and Figure 9 is the transition of the detected value of hot air temperature and the displayed value. A time chart showing the changes in correspondence, where (A) shows the changes in the detected value of hot air temperature, and (B)
FIG. 1O is a tie 1 chart showing the transition of the displayed value of hot air temperature in another embodiment of the hot air temperature control device of the present invention. Explanation of symbols 1...Grain dryer, 4...Drying section, 10...φ hot air generator, 27...Dryer control circuit, 34...Display 1-i Figures 1 and 2 3 figures 4 figures 4 33 62

Claims (1)

[Claims] (1) A hot air temperature detector installed in the hot air flow path leading to the drying section through which the grain passes, a dryer control circuit that receives at least a detection signal from the hot air temperature detector as one input, and the amount of heat generated by the control circuit. The dryer control circuit includes a hot air generator that is controlled, and a display that displays the hot air temperature, and the dryer control circuit samples the hot air temperature from the hot air temperature detector at a period of about -1 feet. After each sampling, the detected value of the sampled hot air temperature is processed and the amount of heat to be generated is determined by calculation, and the amount of heat generated by the hot air generator is controlled according to the calculation result, and the amount of heat generated by the hot air generator is controlled according to the calculation result. The grain is characterized in that the average value of the same number of hot air temperature detection values obtained through sampling is determined by calculation, and the display device is controlled so that the average value is displayed as the hot air temperature. Dryer hot air temperature control device.