JPH0627633B2 - Burner combustion control device for grain dryer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a burner combustion control device in a grain flow dryer, and more particularly to a burner combustion control device for controlling a burner combustion control device according to a change in temperature or humidity of outside air during a drying operation. The present invention relates to a control device that performs optimum drying by changing the hot air temperature of the burner to be used.

(Prior art) Generally, if the grain is dried rapidly in a short time, cracking will occur and the quality will deteriorate. Conversely, if it is dried slowly over a long period of time, it will take a long time to complete the drying and the efficiency will decrease. .

Therefore, when a burner is used as the drying heat source, it is necessary to adjust the hot air temperature of the burner so that the grains dry in an optimum time without being too early or too late. By the way, the drying capacity of the hot air is determined by the difference between the saturated water vapor amount of the hot air and the actual water vapor amount contained in the hot air if the air amount is constant. Here, the saturated water vapor amount of the former is determined by the hot air temperature, and the water vapor amount of the latter is nothing but the amount of water vapor contained in the outside air, and therefore is determined by the outside air humidity (relative humidity) at the outside air temperature at that time. Therefore, in order to maintain the drying ability of the hot air constant and perform drying in the optimum time, it is necessary to appropriately correct the hot air temperature by following the fluctuations of the outside air temperature and the outside air humidity during the drying operation.

Therefore, it is conventionally known that a dryer is provided with an outside air temperature sensor and an outside air humidity sensor and burner combustion control is performed based on the outputs of both sensors so that the burner dries at an optimum time.In that case, if the sensor fails Since proper combustion control cannot be executed, the dryer was stopped during operation at the same time as the failure.

(Problems to be solved by the invention) However, since it usually takes a long time of about 10 hours until the drying of the grains is completed, most of the workers do the drying work at night, and the workers are far from the dryer, so that the operation is not possible. If it is interrupted, not only will the discovery be delayed and a considerable amount of time will be wasted until the operation is restarted, not only will the efficiency be reduced, but there is also the risk that the grain inside the machine will become damp and the quality will deteriorate.

The present invention has been made in view of such circumstances, and when the outside air temperature sensor or the outside air humidity sensor fails in the middle, the hot air temperature is automatically adjusted to a predetermined stability according to the amount of grains stuck at that time. By lowering the temperature and continuing the drying operation without interruption, it is an object to avoid a decrease in efficiency and quality deterioration due to the interruption of the operation, and to prevent the danger due to abrupt drying and perform the drying safely.

(Means for Solving the Problems) In order to achieve the above object, the present invention sets the hot air of a burner so as to perform drying in an optimum time following changes in the outside air temperature and / or outside air humidity during a drying operation. In a grain dryer that automatically corrects the temperature, failure detection means of an outside air temperature sensor and / or an outside air humidity sensor, and when the sensor fails based on the output of the detection means, the hot air set temperature is set as the amount of grain stuck. A hot air temperature correction means for decreasing the temperature to a predetermined safety temperature according to the temperature, and a fuel control means for controlling the fuel flow rate of the burner based on the output of the correction means.

(Operation) If either or both of the outside air temperature sensor and the outside air humidity sensor have failed during the drying operation, the failure detection means detects this and the hot air set temperature differs according to the amount of swelling at that time. Switch to safe temperature. After that, combustion control is continued so that the hot air temperature of the burner reaches this safe temperature.

(Example) Next, the present invention will be described based on an example shown in the drawings.

1 and 2 show a so-called suction exhaust type circulating grain dryer, 1 is a pair of left and right drying chambers communicating with the bottom of the grain storage chamber 2, the inner and outer surfaces of which are like nets or perforated plates. Consists of a ventilation plate.

3 is a grain collecting room looking into the lower end discharge port of the drying chamber 1, and the sending end of the grain collecting spiral 4 which is laterally placed in the central concave groove is connected to the lower end intake of the grain raising machine 5 arranged in parallel with the dryer main body. Then, the upper outlet of the grain elevator 5 is connected to the starting end of the grain feeding helix 6 which is mounted along the ceiling of the grain storage chamber 2. Reference numeral 7 denotes a diffusion blade that hangs in the center of the ceiling of the grain storage chamber 2, and the end of the grain feeding spiral 6 is opened above the diffusion blade.

Then, the burner B is installed toward the hot air supply port 8a of the hot air chamber 8 surrounded by the ventilation plates inside the left and right drying chambers 1, 1 and the ventilation plates outside the drying chambers 1, 1 and the dryer are installed. A suction fan 1 is provided at the outlet side of the exhaust chambers 9 surrounded by the outer wall.
Install 0.

11 is a shield for closing the hot air chamber 8 on the side opposite to the hot air supply port 8a, 12 is a grain inlet communicating with the lower end intake of the grain raising machine 5, and 13 is a shaft at the lower end outlet of the drying chamber 1. This is a grain discharge valve.

The outside air heated by the burner B, that is, hot air, is sucked into the hot air chamber 8 through the hot air supply port 8a and enters the drying chamber 1 because the suction fan 10 causes a negative pressure inside the machine. Then, the moisture of the grains flowing down to the drying chamber 1 from the grain storage chamber 2 is removed to strongly dry the surface layer of the grain, and then exhausted air containing moisture is produced. Exhaust to the outside of the machine.

With the rotation of the grain discharge valve 13, the grains in the drying chamber 1 gradually fall into the grain collecting chamber 3 and are rotated by the diffusion blades 7 that rotate through the grain collecting spiral 4, the grain raising machine 5, and the feeding shell spiral 6. Return to the grain storage chamber 2 evenly. Then, in the grain storage chamber 2, moisture in the core portion of the grain is diffused to the surface layer for conditioning, and then dried again 1
And then gradually dried while circulating inside the machine.

FIG. 3 is a block diagram of the combustion control device of the burner B. An outside air temperature sensor 14 (for example, a thermoelectric thermometer or a thermistor thermometer) and an outside air humidity sensor 15 mounted on the outer wall of the dryer.
A hot air temperature sensor 16 (for example, a thermistor thermometer) mounted in the drying chamber 8 (for example, a dry and wet bulb electric hygrometer) is connected to a first input port 18 of a CPU (central processing unit) 17 of a microcomputer, respectively. The connection is made via the / D converter 19.

20 is a drying timer that sets the drying time from the start to the end of drying, 21 is a swelling amount switch that sets the grain swelling amount, 22 is a hot air temperature range that switches the hot air set temperature, and these are digital input circuit 23 To the second input port 24 of the CPU 17 via.

Reference numeral 25 is a calculation control unit of the CPU 17, 26 is a memory, and 27 is a counter.
Connect.

An electromagnetic fuel injection valve V for controlling the fuel of the burner B is connected to an output port 29 of the CPU 17 via a power circuit 30.
Connect.

Then, as shown in the flow chart of FIG. 4, first, the drying time is set to an appropriate time by the drying timer 20, and then the drying switch (not shown) is closed.
Is ignited and the dry operation is started.

After the ignition, until the combustion of the burner B becomes stable, the valve U is fully opened for a fixed time (for example, 2 minutes and 45 seconds), which is called initial combustion. When the initial combustion is completed and the counter 27 counts up, the routine proceeds to the steady combustion process.

In the steady combustion process, the signals of the amount of swelling and the hot air temperature range set before starting the drying operation and the signals of the outside air temperature sensor 14 and the outside air humidity sensor 15 are set to C
After being read by the arithmetic control unit 25 of the PU 17, the address of the hot air set temperature data set in the memory 26 is designated and the data is read to the arithmetic control unit 25,
Combustion control of the burner B is performed while comparing the output of the hot air temperature sensor 16 so that the hot air reaches the set temperature by narrowing the valve V according to the read data.

FIG. 5 shows a set temperature table of hot air in the case of paddy when the outside air temperature is 25 ° C. and the outside air temperature is 70%.
4 stones, hot air temperature range “4”, outside air temperature 25 ° C., outside air humidity 70%, hot air temperature 49 ° C. according to the table in FIG.
Set to.

Here, the hot air temperature range is appropriately selected from the range 22 from "1" to "8" by the range 22 in consideration of the variety of grain, cropping pattern, harvest time, and the like.

The memory 26 also stores the other outside air temperature and outside air humidity in the fifth range.
Write the hot air preset temperature data in advance according to the table in the figure.

If the outside air temperature or the outside air humidity fluctuates during the drying operation, the set temperature is corrected based on the output of the sensors 14 and 15 according to the correction value data written in the memory 26 in advance.

FIG. 6 shows a table of the correction values of the hot air temperature due to the fluctuation of the outside air temperature when the outside air temperature is 25 ° C., and FIG. 7 shows the changes in the outside air humidity when the outside air humidity is 60 to 80%. The table of the correction value of the hot air temperature according to is shown.

For example, at the start of operation, the outside temperature is 25 ° C and the outside humidity is 70%.
At this time, when the outside air temperature reaches 30 ° C during operation, the set temperature 49 ° C is corrected by + 1 ° C to 50 ° C. Similarly, when the outside air humidity exceeds 80%, the set temperature is corrected by + 1 ° C. It goes without saying that if both the outside temperature and the outside humidity fluctuate, only the sum of the respective correction values is corrected.

However, during the drying operation, the outside air temperature sensor 14 or the outside air humidity sensor 15 may be short-circuited or disconnected, and
When an abnormal value such as 0% is output from ℃ and deviates from the range of normal value, this is detected by comparing the sensor output with the upper and lower limit values of the normal value. The set temperature is lowered to a predetermined safe temperature, for example, a reference temperature of outside air or a minimum temperature that can be corrected at outside humidity, and the drying operation is continued.

For example, if the pull-in amount is 24 stones and the reference outside air temperature is 25 ° C. and the outside air humidity is 70%, if the outside air temperature sensor 14 has a failure such as a wire breakage, the sensor output is set to 0 ° C. Correct the temperature by -5 ° C according to Fig. 6 and lower it to 44 ° C. Also, if the outside air humidity sensor 15 fails, the sensor output is set to 60% or less so that the set temperature is 49 ° C.
Is adjusted to -1 ° C according to Fig. 7 and lowered to 48 ° C. When both the outside air temperature sensor 14 and the outside air humidity sensor 15 fail, the set temperature of 49 ° C. is set to −6 (° C.) (= −5 + −).
1) Correct and drop to 43 ° C.

If the amount of paddy rice is 16 stones, the hot air temperature range is “4”, the outside air temperature is 25 ° C., and the outside air humidity is 70%, the hot air temperature is set to 43 ° C. according to the table of FIG. At this time, if a failure such as a wire breakage occurs in the outside air temperature sensor 14, the sensor output is set to 0 ° C., and the set temperature 43 ° C. is set according to FIG.
Correct to 5 ° C and drop to 38 ° C. Also, the outside air humidity sensor 1
If 5 fails, the sensor output is set to 60% or less, whereby the set temperature 43 ° C. is corrected by −1 ° C. according to FIG. 7 and dropped to 42 ° C.

If the outside air temperature sensor 14 and the outside air humidity sensor 15 fail in this way during the drying operation, a predetermined amount according to the amount of stake and the hot air temperature range at that time is thereafter irrespective of the actual outside air temperature and outside air humidity. Since the hot air temperature is lowered to the safe temperature and the drying operation is performed, even if the drying timer 20 times out, the grain does not finish to the initial moisture, but the worker returns to the dryer when the time is up. There is no hindrance. If the sensor failure is indicated by a sensor abnormality indicator such as a lamp, it is convenient for the worker who returns to the dryer to know the failure and immediately repair it.

(Effect of the invention) In summary, according to the present invention, in the grain dryer that corrects the hot air set temperature of the burner so as to dry in an optimum time by following the fluctuations of the outside air temperature and the outside air humidity during the drying operation. A failure detection means for the outside air temperature sensor and / or the outside air humidity sensor is provided, and when the sensor fails based on the output of the detection means, the hot air temperature is set to a predetermined safety temperature according to the amount of grain swelling at that time. Since it descends and continues the drying operation, it is not only safe without the risk of overdrying, but also
There is no risk of quality deterioration such as grain stuffiness due to operation interruption.

Furthermore, even if the outside air temperature sensor and / or the outside air humidity sensor fails, the drying can be continued at a predetermined safe temperature according to the amount of grain stuck. There is an effect of improving.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a grain dryer in which the present invention is implemented, FIG. 2 is a cross-sectional plan view thereof, FIG. 3 is a block diagram of a burner combustion control device of the present invention, and FIG. 4 is a control procedure thereof. Flow chart, FIG. 5 is a set temperature table of hot air in the case of paddy at an outside air temperature of 25 ° C. and an outside air humidity of 70%, and FIG. 6 is a correction value table of the hot air temperature associated with the change of the outside air temperature at the reference outside air temperature of 25 ° C. FIG. 7 shows a correction value table of the hot air temperature according to the fluctuation of the outside air humidity at the reference outside air humidity of 60 to 80%.

Claims (1)

[Claims] 1. A grain flow dryer that automatically corrects a hot air set temperature of a burner so as to dry in an optimum time by following a change in outside air temperature and / or outside air humidity during a drying operation. Humidity sensor failure detection means, and hot air temperature correction means for lowering the hot air set temperature to a predetermined safe temperature according to the amount of grain infiltration when the sensor fails based on the output of the detection means, and the correction means. A burner combustion control device comprising: a fuel control means for controlling the fuel flow rate of the burner based on the output of the means, and a dry operation.