JPH03271690A - Control system for drying in grain drier - Google Patents

Abstract

PURPOSE:To obtain good dried grain by a method wherein a grain temperature is obtained from the moisture of grain, which is detected by a moisture sensor, or a coefficient, different depending on an elapsed time from the beginning of drying, to control the temperature of hot air. CONSTITUTION:During the drying operation of grain, the temperature of hot air generated from a burner 1 is detected by a hot air temperature sensor 3, the temperature of discharging air passed through a drying chamber 2 is detected by a discharging air temperature sensor 4, a coefficient, set and stored by the detected hot air temperature and the discharging air temperature as well as a grain moisture detected by a moisture sensor 5, is selected and the temperature of grain during drying is operated by the selected coefficient. The operated grain temperature is compared with a set grain temperature and the grain is dried while controlling the temperature of hot air, generated from the burner 1, so that the operated grain temperature is never increased to a temperature higher than the set grain temperature. On the other hand, a coefficient, set and stored by the elapsed time of drying from the beginning of the drying, is selected instead of the moisture of the grain, which is detected by the moisture sensor 5, and the temperature of grain during drying can be obtained by the selected coefficient and the temperatures of the hot air and discharging air.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a drying control method for a grain dryer.

Conventional technology Conventionally, the grains in the drying chamber were exposed to hot air at a predetermined temperature from a burner, which passed through the drying chamber. During this drying process, the hot air temperature is detected by a hot air temperature sensor, and the exhaust air that has passed through the drying chamber is detected by an exhaust air temperature sensor, and the detected hot air temperature and exhaust air temperature are The temperature of the grain during drying is calculated based on the set constant value coefficient, and the calculated grain temperature is compared with the set grain temperature, and the calculated grain temperature is equal to or higher than the set grain temperature. It was a drying control method that dried the grains while controlling the hot air temperature so that it did not rise.

Problems to be Solved by the Invention The grains in the drying chamber of a grain dryer are heated by hot air at a predetermined temperature that is generated from a burner, and this hot air passes through the drying chamber. The grains are dried by being exposed to this hot air, and when the moisture sensor detects the same grain moisture as the finishing target moisture, the dryer is automatically stopped and the drying of the grains is stopped.

During this drying work, the hot air temperature generated from the burner is detected by a hot air temperature sensor, and the exhaust air that has passed through the drying chamber is detected by an exhaust air temperature sensor, and the detected hot air temperature and exhaust air temperature are set. The grain temperature is calculated based on the constant value coefficient, and the calculated grain temperature is compared with the set grain temperature, and the grain temperature is set so that the calculated grain temperature does not rise above the set grain temperature. The grains are dried without controlling the temperature of the hot air generated from the burner, but the calculation formula for calculating the grain temperature differs depending on the grain moisture, and in the early stage of drying, drying of moisture (surface moisture evaporation) is the main process. Since grain temperature is used as latent heat of vaporization, the change in grain temperature due to hot air temperature is small.
On the other hand, when the dry finish is near, the amount of moisture dried decreases,
The hot air may be discharged as it is, so the accuracy of the exhaust air temperature is lower than when the moisture content is high. Therefore, the coefficients on the detected hot air temperature and exhaust air temperature are calculated based on the grain moisture etc. The purpose is to calculate accurate grain temperature by changing the temperature and accurately control the hot air temperature to obtain good dried grain.

Means for Solving the Problems This invention provides a drying chamber 2 in which grains are dried by passing hot air from a burner 1 while flowing down, a hot air temperature sensor 3 that detects the temperature of the hot air flowing into this drying chamber 2, and An exhaust air temperature sensor 4 is provided to detect the temperature of the exhaust air discharged from the drying room 2 to the outside of the machine, and a moisture sensor 5 is provided to detect grain moisture. The grain temperature during drying is calculated based on the exhaust air temperature detected by the temperature sensor 4 and the coefficient, and the grain is dried by controlling the hot air temperature so that the calculated grain temperature does not rise above a predetermined temperature. In the dryer, the drying control method is characterized in that the grain temperature is calculated by changing the value of the coefficient depending on the grain moisture detected by the moisture sensor 5 or the elapsed drying time.

Effect of the Invention The grains in the drying chamber 2 of the grain dryer are caused to flow down inside the drying chamber 2 by generating hot air at a predetermined temperature from the burner 1 and passing through the drying chamber 2. The grains inside are dried by being exposed to this hot air, and when the moisture sensor 5 detects the same grain moisture as the finishing target moisture, the dryer is automatically stopped and the drying of the grains is stopped.

During this grain drying work, the temperature of the hot air generated from the burner 1 is detected by the hot air temperature sensor 3, and the temperature of the exhaust air that has passed through the drying chamber 2 is detected by the exhaust air temperature sensor 4. The hot air temperature and exhaust air temperature, and the moisture sensor 5
The set and stored coefficient is selected based on the grain moisture detected by the controller, and the grain temperature of the grain during drying is calculated using the selected coefficient. The grain temperature is compared with the calculated grain temperature, and the grains are dried while controlling the temperature of the hot air generated from the burner 1 so that the calculated grain temperature does not rise above the set grain temperature.

In addition, instead of the grain moisture detected by the moisture sensor 5, a set and stored coefficient is selected based on the elapsed drying time from the start of drying, and the selected coefficient and the detected hot air temperature and exhaust air temperature are used. The grain temperature of the grains during drying is calculated, this calculated grain temperature and the set grain temperature are compared, and the temperature of the hot air generated from the burner 1 is controlled in the same manner as above based on the comparison result. The grains are then dried.

Effects of the Invention According to this invention, the coefficient used when calculating the grain temperature is not a constant value as in the conventional case, but varies depending on the grain moisture detected by the moisture sensor 5 or the elapsed time from the start of drying. By using the coefficient to calculate the grain temperature, an accurate grain temperature can be calculated, and the hot air temperature generated from burner 1 can be controlled to obtain good dried grains. .

Embodiment In addition, on the open side, the square wall 7 of the grain drying Ii6 has a long rectangular shape in the front and back direction, and the upper end of this mechanism 7 is equipped with a transfer gutter 8 and a ceiling plate 9 in which a transfer spiral is rotatably installed. established,
A storage chamber IO for storing grains is formed below this ceiling plate 9, and ventilation chambers 11 on both left and right outer sides are formed below this storage chamber 1o.
Each drying chamber 2 is provided between the air blowing chamber 12 in the center and communicated with this storage chamber 1°, and at the bottom of each drying chamber 2 there is a feed-out valve 13 that feeds out the grains and flows down. The structure is such that a grain collection gutter 14 is provided at the bottom of each drying chamber 2 and is connected to the grain collection gutter 14, which is rotatably equipped with a transfer spiral. A hot air temperature sensor 3 for detecting hot air temperature is provided, and the large side exhaust chamber 11
An exhaust air temperature sensor 4 is provided inside the exhaust air chamber 11 to detect the temperature of the exhaust air passing through the exhaust air chamber 11.

The front mechanism 7 is provided with a burner case 15 in which the burner 1 and the air volume sensor 46 are housed, and an operating device 116 for starting and stopping the burner 1 and the dryer 6 for each operation of drying and discharging. The burner 1 and the ventilation chamber 12 are configured to communicate with each other, and an exhaust duct chamber 17 is formed behind the rear mechanism 7, and an exhaust fan 18 and the exhaust duct chamber 17 are formed behind the rear mechanism 7. A variable-speed exhaust fan motor 19 for rotating the wind fan t8 at variable speeds is provided, and the exhaust fan 18 and each of the exhaust chambers 11 are communicated with each other via the exhaust channel chamber 17. A valve motor 21 is provided at the bottom of the mechanism 7 to rotate each delivery valve 13 via a deceleration mechanism 20.

A supply port for supplying grains into the storage chamber 10 is provided at the center in the longitudinal direction of the bottom plate of the transfer gutter 8, and a diffusion port for uniformly diffusing and returning grains into the storage chamber 10 is provided below the supply port. Board 2
This is a configuration with 2.

The grain raising machine 23 is provided in the front part of the front side mechanism 7.

A packet conveyor 24 belt is stretched inside, a discharging cylinder 25 is provided between the upper end and the starting end of the transfer gutter 8 for communication, and a belt is provided between the lower end and the terminal end of the grain collecting gutter 14. This is a configuration in which a supply gutter 26 is provided for communication.

A grain raising machine motor 27 is provided above the grain raising 1 m23, and this grain raising machine motor 27 drives the packet conveyor 24 belt,
The transfer spiral, the spreading plate 22, etc. in the transfer gutter 8 are rotationally driven, and the transfer spiral in the grain collection gutter 14 is rotationally driven via the packet conveyor 24 belt.

A moisture sensor 5 for detecting grain moisture is provided at the vertical center of the grain hoist 23, and this moisture sensor 5 is activated by transmitting an electrical measurement signal from the operating device 16. The moisture sensor 5 is configured so that each part of the moisture sensor 5 is rotationally driven by the rotation of the moisture motor 28, which receives grains that fall while being conveyed to the upper part of the packet conveyor 24, and simultaneously crushes the grains under pressure. It is configured to detect moisture in this crushed grain.

A fuel pump 29 having a fuel valve is provided on the outer side of the lower plate of the burner case 15, and by opening and closing the fuel valve,
The fuel pump 29 sucks fuel in the fuel tank 30 and supplies it to the burner 1, and a blower 31 and a blower motor 32 that rotate at variable speeds are provided on the outside of the upper plate.
The blower motor 32 rotates to drive the blower 31 to supply combustion air to the burner 1 in accordance with the amount of fuel to be supplied.

The operating device 16 is box-shaped, and the front cylinder plate of the box has a
A start switch 33 for starting the drying 1i6 and the burner 1, etc. for each operation of loading, drying, and discharging, a stop switch 34 for stopping the drying 1i6 and the burner 1, etc., a moisture setting switch 35 for setting the finishing target moisture of grains according to the operating position. , a grain type setting machine 36 for setting the temperature of the hot air generated from the burner 1 depending on the operating position, a loading amount setting machine 37, and a display window that alternately displays detected grain moisture, detected hot air temperature, remaining drying time, etc. 3
8 and a monitor display, etc., and internally includes an A-D converter 39 that converts various detected values from A to D.
An input circuit 40 to which the converted value converted by the D converter 39 is input, an input circuit 41 to which various input values are input manually, and various input values input from these input circuits 40 and 41 are subjected to arithmetic and logical operations and comparison operations. This CPU42 performs
Output circuit 4 that receives various commands from 2 and outputs them.
The structure includes a drying control device 44 and a timer 45 consisting of three components, etc., and each setting switch 35, 36, 37 is a rotary switch type, and a predetermined value and type are set depending on the operating position. be.

The drying control by the drying control device 44 is performed as follows, and the operating position of the moisture setting knob 35 is set to C.
When inputted to the PU 42, the grain finishing target moisture (MSI) is set by this input, and when the grain moisture (MS) detected by the moisture sensor 5 is inputted to the CPU 42, these detected grain moisture contents are set. (MS) and Finish Target Moisture (MS)
I), and if it is detected that they are the same, the drying control device 51 automatically controls the dryer 6 to stop drying the grains.

Combustion control by the drying control device 44 is performed as follows. When the operating position of each setting 3637 is input to the CPU 42, the temperature of the hot air generated from the burner 1 is set by this input. When the hot air temperature in the blowing chamber 12 is detected by the hot air temperature sensor 3 and input to the CPU 42, the detected hot air temperature and the set hot air temperature are compared, and if they are different, it is determined that the hot air temperature is the same as the set hot air temperature. The number of openings and closings of the fuel valve that supplies fuel to the burner 1 is controlled to increase or decrease so that the fuel temperature is maintained, and the amount of fuel sucked by the fuel pump 29 is controlled to increase or decrease and is supplied to the burner 1.

The grain temperature of the grains being dried by the drying control device 44 (
TG) control is performed as shown below, and grain temperature (TG) is calculated using the following formula set and stored in the CPU 42, where: Grain temperature (TG) = coefficient (K) x hot air temperature (TB) +
[(1-Coefficient (K) x Exhaust Air Temperature (TE)] This coefficient (K) changes depending on the grain moisture (MS) detected by the moisture sensor 5, as shown in Figure 2, and as shown in Figure 3. , the elapsed drying time from the start of drying detected by the timer 45 (T
), and as shown in FIG. 4, it is configured to change depending on the airflow rate (Q) detected by the airflow sensor 46, and this calculated grain temperature (TG) is set and stored in the CPU 42. Temperature (TGl) is compared, e.g. calculated grain temperature (
TG) is 42°C, and the set grain temperature (TGI) is 38°C.
If it is detected to be above ℃, the set grain temperature (TGI)
A configuration in which the number of opening and closing of the fuel valve that supplies fuel to the burner 1 is controlled to decrease, and the amount of fuel sucked by the fuel pump 29 is controlled to decrease and supplied to the burner 1 so that the temperature becomes 38° C. or less and detected grain moisture (MS) within the above.

The fuel amount is controlled by the detected drying time (T) or detected wind jl (Q), whichever is applicable.

Grain temperature (TG) is calculated when the grain moisture (MS) detected by the moisture sensor 5 is 28% and the hot air temperature (TB) detected by the hot air temperature sensor 3 is 50%, as shown in FIG.
℃, and the exhaust air temperature detected by the exhaust air temperature sensor 4 (
If TE) is 25°C, the grain temperature (TG) is calculated as 27t 75°C, and TG = [(K)0.11X (TB)50] + [1
-(K) 0. IIX (TE) 25] = 27.
In addition, the detected grain moisture (MS) is 14%, the detected hot air temperature (TB) is 50°C, and the detected exhaust air temperature (TE) is 75°C.
If the temperature is 8℃, the grain temperature (TG) is 31.3℃.
The configuration is calculated as TG=[(K)0.15x
(TB)50F + [l-(K)o, 15X (TE
)28] = 31.3℃ These calculated grain temperatures (TG) are 27.75℃, or 31
．． When the temperature is 3°C, it is below the set grain temperature (TGI) of 38°C, and the fuel supply amount is not controlled to decrease.

The grain temperature (TG) is calculated when the drying time (T) detected by the timer 45 is 7 hours and the hot air temperature (TB) detected by the hot air temperature sensor 3 is 50°C, as shown in FIG. Yes, the exhaust air temperature (TE
) is 25℃, the grain temperature (TG) is 27℃.
．． The configuration is calculated as 75°C, and TG = [(K)0.11x (TB)5o] + [1
-(K)0.11x (TE)25 = 27.7
5℃ Also, the detected drying time (T) is 18 hours, the detected hot air temperature (TB) is 50℃, and the detected exhaust air temperature (TE) is 2
If it is 8℃, the grain temperature (TG) is 31.96
It is a configuration calculated as °C, and TG = [(K)0.18
x (TB)50] +[1-(K) 0.18X (
TE) 28] = 31.96°C These calculated grain temperatures (TG) are 27.75°C, or 31
．． When the temperature is 96°C, it is below the set grain temperature (TGI) of 38°C, and the configuration is such that the amount of fuel supplied is not controlled to decrease.

Grain temperature (TG) is calculated based on the assumption that the air volume (Q) detected by the air volume sensor 46 is 0.9 m''/sec and the hot air temperature (TB) detected by the hot air temperature sensor 3 as shown in FIG.
) is 50°C, and the exhaust air temperature (TE) detected by the exhaust air temperature sensor 4 is 25°C, then the grain temperature (
TG) is calculated as 28.75℃, TG= [(K)0.15x (TB)50]
+[1-(K) 0.15x (TE) 25]
= 28.75℃ Also, detected wind 11. (Q) is 0.4 rn'/sec, the detected hot air temperature (TB) is 55°C, and the detected exhaust air temperature (TE) is 23°C.
) is the configuration calculated as 26.2℃, and TG=[(
K)0.10x (TB)55] +[1-(K) 0
．． 10x (TE) 23] = 26.2℃ These calculated grain temperatures (TG) are 28.75℃, or 26
．． When the temperature is 2°C, it is below the set grain temperature (TGI) of 38°C, and the structure is such that the amount of fuel supplied is not controlled to decrease.

Hereinafter, the operation of the above embodiment will be explained.

By operating each setting switch 35, 36, 37 of the operating device 16 to a predetermined position and operating the start switch 33 that starts drying, each part of the grain dryer 6, the burner l, the moisture sensor 5, etc. are started. Then, hot air at a set temperature is generated from the burner 1, and this hot air crosses the drying room 2 from the air blowing chamber 12, passes through the air exhaust chamber 11 and the air exhaust path room 17, and is sent to the air exhaust fan 18.
By suctioning and exhausting the air, the grains stored in the storage chamber 10 are exposed to the hot air and dried while flowing down from the storage chamber 10 into the drying chamber 2. The grain is fed out and supplied into the grain collection gutter 14, and this grain collection gutter 14
The grains are transferred from the grains through the supply gutter 26 into the grain hoisting machine 23 by the lower transfer spiral, transported to the upper part by the packet conveyor 24, passed through the dispensing cylinder 25, and supplied into the transfer gutter 8, where they are diffused. It is transferred and supplied onto the board 22 by the upper transfer spiral,
It is evenly diffused and returned into the storage chamber 10 by this diffusion plate 22, and is circulated and dried, so that the moisture sensor 5 can detect the moisture setting value 35.
When the moisture content of the grains is the same as the target moisture content set by operating the , the drying control device 44 of the operating device 16 automatically controls the drying 8!6 to stop the drying of the grains. .

During this drying work, the temperature of the hot air generated from the burner 1 (
TB) is detected by the hot air temperature sensor 3, and the exhaust air temperature (TE) of the exhaust air that has passed through the drying chamber 2 is detected by the exhaust air temperature sensor 4, and the detected hot air temperature (TB) and the exhaust air temperature (TE) and grain moisture detected by the moisture sensor 5 (MS
) is selected and the coefficient (K) set and stored is selected.
This selected person! a(K), the grain temperature (TG) of the grain during drying is calculated, and the calculated grain temperature (TG) and the stored grain temperature (TGI) are compared, The calculated grain temperature (TG) is the set grain temperature (T
The number of times the fuel valve opens and closes is controlled so that the temperature does not rise above GI), the amount of fuel sucked in by the fuel pump 29 is controlled and supplied to the burner 1, and the temperature of the hot air generated from the burner 1 is not controlled. The grains are dried.

In addition to the grain moisture (MS) described above, the elapsed drying time (T) from the start of drying detected by the timer 45 and the air volume sensor 4
The coefficient (K) set and stored is selected according to the air volume (Q) detected by the device 6, and the grain temperature (TG) is calculated in the same manner as above using this selected coefficient (K), and the hot air temperature ( Since TB) is not controlled, the grain is dried.

[Brief explanation of drawings]

The figures show one embodiment of the present invention; FIG. 1 is a block diagram, FIG. 2 is a relationship diagram between grain moisture and coefficient, FIG. 3 is a relationship diagram between elapsed drying time and coefficient, and FIG. Figure 4 is a relationship diagram between air volume and coefficient, Figure 5 is an overall side view of the grain dryer that can be partially cut away, Figure 6 is a sectional view taken along line A-A in Figure 5, and Figure 7 is the grain dryer. FIG. 8 is an enlarged partially cutaway front view of a portion of the grain dryer. Explanation of symbols 1 Burner 2 Drying chamber 3 Hot air temperature sensor 4 Exhaust air temperature sensor 5 Moisture sensor

Claims (1)

[Claims] A drying chamber 2 in which grains are dried by passing hot air from a burner 1 while flowing down, a hot air temperature sensor 3 that detects the temperature of the hot air vented to this drying chamber 2, and an exhaust gas that discharges air from this drying chamber 2 to the outside of the machine. An exhaust air temperature sensor 4 that detects wind temperature is provided, and a moisture sensor 5 that detects grain moisture is provided, and the hot air temperature detected by these hot air temperature sensors 3, the exhaust air temperature detected by the exhaust air temperature sensor 4, and In a grain dryer that calculates the grain temperature during drying using a coefficient and controls the hot air temperature to prevent the calculated grain temperature from rising above a predetermined temperature, the moisture sensor 5 detects the grain temperature. A drying control method characterized in that grain temperature is calculated by changing the value of the coefficient depending on grain moisture or elapsed drying time.