JPH0627634B2 - Grain dryer - Google Patents

Description

TECHNICAL FIELD The present invention relates generally to grain dryers, and more particularly to grain dryers that perform combustion control by pulse controlling the drive system and combustion system of the dryer.

[Prior Art] Generally, this type of grain dryer has a control box containing electronic circuit control means such as a microcomputer and two types of temperature sensors, that is, a sensor for detecting the outside air temperature and a sensor for detecting the hot air temperature. And the combustion control is performed in the procedure described below. That is, the CPU of the microcomputer constituting the electronic circuit control means is
Sensor information (T
Captures _A), drying target temperature is set according to Chokomi amount to be dried grain dryer by Chokomi amount knob (T _C)
Is corrected by the outside air temperature (T _A ), and the correction value is compared with the actual dryer internal temperature (T _B ) given from the hot air temperature detection sensor. The CPU outputs an on-time variable fuel supply amount control pulse signal to the valve drive circuit to control the fuel supply system based on the comparison. At the same time, the CPU also outputs a predetermined drive command signal to the fan drive circuit so as to control the ventilation system that supplies the outside air ventilation to the dryer so that combustion can be performed at an appropriate air-fuel ratio.

The CPU controls the combustion of the dryer in the above procedure.

Meanwhile CPU when performing combustion control in such the above-described procedure, recognized temperature difference between the drying target temperature set value (T _C) and the hot air temperature detection value (T _B) is greater than a preset reference value At times, it was judged that an abnormality had occurred in the dryer, and the drive of the dryer was stopped.

Therefore, the reason why the differential temperature is larger than the reference value is, for example, due to a temporary abnormal state during mere operation such as non-uniform temperature distribution in the dryer or blowing of outside air ventilation or an abnormality due to misfire, It was not possible to distinguish whether the cause was a continuous abnormal condition such as a failure that occurred in the control box or various safety sensors.
Further, since it is impossible to distinguish between the temporary abnormal state and the continuous abnormal state as described above, the work efficiency is remarkably lowered because the driving of the dryer is stopped every time the CPU recognizes the abnormal state. There was a problem.

[Object] Therefore, the modified invention improves the above-mentioned problems of the conventional technology, and an object thereof is to identify whether or not the detected abnormal condition is such that the driving of the dryer needs to be stopped. The purpose is to provide a grain dryer that does not reduce work efficiency.

[Configuration] A feature of the present invention for achieving the above object is that a target drying temperature setting unit that sets a target drying temperature according to the amount of grains to be dried that are loaded into the dryer, and a unit that detects the outside air temperature. And having an actual temperature detecting means for detecting the hot air temperature in the dryer,
The temperature difference between the hot air temperature detection value and the outside air temperature detection value is compared with a preset reference value, and when the ratio of the temperature difference value to the reference value exceeds a predetermined rate, it is determined to be abnormal. The grain dryer is provided with arithmetic control means for stopping the combustion system and / or the drive system of the dryer.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall perspective view of a grain dryer according to the first and second embodiments of the present invention, FIG. 2 is a block diagram according to the first embodiment of the present invention, and FIG. 3 is of the configuration of FIG. A flow chart, FIG. 4 is a block diagram according to the second embodiment of the present invention, and FIG. 5 is a flow chart of the configuration of FIG. The first
In FIG. 2, FIG. 2 and FIG. 4, reference numerals having the same reference numerals indicate the same.

In FIG. 1, the dryer 1 has an operation box 3 containing a control unit (not shown) and a burner combustion system 5. The operation box 3 is a fuel setting device 7 for setting the fuel supply amount to the burner combustion system 5 in multiple stages,
Adjustment completion switch 9, fan adjustment device 11 that adjusts the rotation speed of a fan that supplies outside air into dryer 1, adjustment lamp 13, and operation switch 15 such as a drying switch, a grain type switch, and a set moisture switch A quantity switch 69 is provided.

The burner combustion system 5 includes a fuel tank 17 mounted on the wall of the dryer 1, a fuel pipe 2 communicating with the combustion chamber 23 via the fuel tank 17, the electromagnetic pump 19, and the electromagnetic valve 21.
5 and a ventilation tube 27 having a combustion chamber 23 therein, which is provided with a means for supplying outside air ventilation such as a fan (not shown). One of the electromagnetic pump 19 and the electromagnetic valve 21 is opened / closed by a fuel supply amount control pulse signal output from the control unit (not shown) to control the amount of fuel flowing from the fuel tank 17. . In the embodiment according to the present invention, the electromagnetic valve 21 is so-called on-time controlled as will be described later.

FIG. 2 is a block diagram of the control unit built in the operation box 3 described above. The microcomputer 10 includes a CPU 101, a memory 103,
Input port 105, input port 107, output port 10
8 and an output port 109.

The CPU 101 performs arithmetic logic operation and comparison operation.
The input information of the CPU 101 is the digital input circuit 59,
It is given through the input port 105, the A / D conversion circuit 61, and the input port 107. The information given to the CPU 101 via the digital input circuit 59 includes drying target temperature setting information, that is, hot air temperature setting information 63 and safety sensor information 6.
5, there is operation information 67. Hot air temperature setting 63, grain circulation type of the dry grain circulating (not shown) and the target temperature of hot air by setting the scale in accordance with the Chokomi amount in the dryer 1 (T _C) is Output from the target hot air temperature setting knob 69 that is automatically set. Safety sensor information 65
Is a drive system safety sensor group 71 for detecting the drive status of the dryer drive system such as an elevator motor, an upper spiral, a rotary valve and a lower spiral, and a dryer combustion system such as an ignition heater and a fuel supply pump (that is, an electromagnetic pump). It is output from the combustion system safety sensor group 73 that detects the driving condition. The operation information 67 is given from the operation switch 15 for starting / stopping the dryer motor, igniting, and the like. Other information given to the CPU 101 via the digital input circuit 59 is flame detection information 77 given from the frame rod 33 via the flame detection circuit 75 as shown in the figure.

The information given to the CPU 101 via the A / D conversion circuit 11 includes the actual hot air temperature (T _B ) information 81 in the dryer 1 output from the in-dryer actual temperature detection sensor, that is, the hot air temperature detection sensor 79, and the outside air. There is outside air temperature (T _A ) information 85 output from the temperature detection sensor 83.

A drive command signal for the dryer combustion system provided from the CPU 101 is supplied to the fuel supply pump 19, the fuel supply electromagnetic valve 21, via the output port 109 and the digital output circuit 111.
A drive circuit (not shown) for the vaporization cylinder motor 37, an ignition heater 35, and a digital display 115 are supplied to the drive circuit. C
The drive command signal of the dryer drive system given from the PU 101 is sent through the analog output circuit 113 to the fan motor 29.
Drive circuit (not shown).

The memory 103 has a control program and the like built therein and stores necessary data.

The CPU 101 has the functions described below. Target hot air temperature setting information based on the type and Chokomi amount of the dry grain output from the target hot air temperature setting knob 69 (T _C) 63
Is taken in through the digital input circuit 59 and the input port 105, and the information is stored in the memory 103. Actual hot air temperature (T _B ) output from hot air temperature detection sensor 79
The information 81 is fetched via the A / D conversion circuit 61 and the input port 107. The outside air temperature (T _A ) information 85 output from the outside air temperature detection sensor 83 is taken in through the A / D conversion circuit 61 and the input port 107. The differential temperature while calculation using the formula of T _C -T _B between the target hot air temperature setting (T _C) 63 captured by the actual hot air temperature (T _B) information 81 acquired at, difference temperature The temperature difference between the value and the outside air temperature (T _A ) information 81 acquired by the T _C is T
_C -T calculated using the formula of _A multiplied by the correction factor α which is preset in the calculation results. Difference temperature value calculated by (T
_C- T _B ) is compared with the value obtained by multiplying (T _C -T _A ) by α, and the process proceeds to the fuel control routine or the abnormal stop routine according to the comparison result.

The control operation of the above configuration will be described mainly with reference to the flowchart of FIG.

Prior to the start of the drying operation, the operator sets the target hot air temperature setting knob 69 on a predetermined scale according to the type and amount of the dried grains. The CPU 101 uses the setting knob 6
When it is recognized that 9 is set as described above (step 121), the target hot air temperature (TC) is set based on the set scale (step 123). CPU10
1 takes in the actual hot air temperature (T _B ) information 81 (step 125) and the outside air temperature (T _A ) information 85 (step 127), and shifts to step 129. The CPU 101 performs steps 123 to 12
Based on the data captured in 7 _(T C -T
The value of _B ) and the value of α (T _C −T _A ) are calculated, and the results of these calculations are compared (step 129).
Here, the value of α is a correction factor that can be recursively obtained from various experimental data or the like. When the CPU 101 recognizes that T _C -T _B > α (T _C -T _A ) in step 128, the dryer starts malfunctioning due to misfire as described above, and occurs in the control box, various safety sensors, etc. It judges that there is a continuous abnormal state such as a failure, and shifts to an abnormal stop routine. Step 1
28, when it is recognized that T _C -T _B ≤ α (T _C -T _A ), the CPU 101 indicates that the dryer is in a mere operation due to, for example, uneven temperature distribution in the dryer or blowing of outside air. Therefore, the combustion control routine is entered and it is determined that the engine is in a temporary abnormal state.

Although FIG. 4 is a block diagram according to the second embodiment of the present invention as described above, it is substantially the same in content as the configuration of FIG. The structural difference between this embodiment and the first embodiment is
In the first embodiment CPU101 said _{(T C} -
Those values of T _B) which has been compared with the values of α (T C _{-T A),} in the present _{embodiment, α × t ON (t ON} : fuel supply amount control pulse signal on-time duration) It is in comparison with the value. Therefore, also in FIG. 5, the operation from step 131 to step 135 is the same as the operation from step 121 to step 125 described in FIG. 3, and the operation contents of step 137 and step 129 are different. . Note _(T C -T _B) with a predetermined correction factor α
_ON time width t _ON of the fuel supply amount control pulse signal
The reason for comparing with the value multiplied by is that it means t _{ON, that} is, the heating value to the dryer.

The contents described above relate to the embodiments according to the present invention to the last, and it goes without saying that the present invention is not limited to the above contents.

[Effect] As described above, according to the present invention, the difference temperature value between the hot air temperature detected value and the outside air temperature detected value is compared with the preset reference value, and the ratio of the difference temperature value to the reference value is calculated. When it exceeds a predetermined rate, it is judged to be abnormal and the dryer combustion system and / or drive system is stopped. Therefore, it is determined whether the detected abnormal condition is such that the dryer must be stopped. It is possible to provide a grain dryer that can be manufactured and does not reduce the work efficiency.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a grain dryer according to the first and second embodiments of the present invention, FIG. 2 is a block diagram according to the first embodiment of the present invention, and FIG. 3 is of the configuration of FIG. A flow chart, FIG. 4 is a block diagram according to the second embodiment of the present invention, and FIG. 5 is a flow chart of the configuration of FIG. 10: Microcomputer 69: Target hot air temperature setting knob 79: Hot air temperature detection sensor 83: Outside air temperature detection sensor

Claims (3)

[Claims] 1. A drying target temperature setting means for setting a drying target temperature in accordance with the amount of grains to be dried loaded into the dryer, a means for detecting an outside air temperature, and an actual temperature for detecting a hot air temperature inside the dryer. The temperature difference between the hot air temperature detection value and the outside air temperature detection value is compared with a preset reference value, and the ratio of the differential temperature value to the reference value exceeds a predetermined rate. The grain dryer is characterized in that it is provided with arithmetic and control means for determining that there is an abnormality and stopping the dryer combustion system and / or drive system. 2. The grain dryer according to claim 1, wherein the reference value is a temperature difference value between a set temperature value given from the target temperature setting means and the detected outside air temperature value. . 3. A heating value which can be adjusted by varying an on-time time width of a fuel supply amount control pulse signal given to the combustion system by the arithmetic control means, as the reference value. The grain dryer according to the item.