JPS63238388A - Exhaust fan controller for 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 (Industrial Application Field) The present invention relates to a grain dryer that dries grain with hot air while circulating the inside of the machine, and in particular, the present invention relates to a grain dryer that dries grain with hot air while circulating the inside of the machine. Concerning fan control.

(Prior art) In this type of dryer, during drying, the hot air generated by the burner is suctioned by an exhaust fan, and is exhausted from the ventilation chamber to the outside through the drying chamber. Grain is dried in a drying room using hot air supplied to the drying chamber.

When the grain is discharged from the machine after drying, the exhaust fan is rotated at the same speed as during drying to air-dry the grain.

(Problems to be Solved by the Invention) Incidentally, there has often been a problem that the moisture value of grain discharged from the dryer deviates by about 0.5% from the moisture value at the end of drying. As a result of searching for the cause of this problem, it was found that the cause was that when the grain was being discharged, the exhaust fan was rotated uniformly in the same manner as during drying to allow ventilation and drying.

Therefore, the present invention changes the amount of ventilation by the exhaust fan depending on various conditions during the operation of discharging grains,
The purpose is to prevent deviations in the grain moisture value in the finished product, as well as to avoid deterioration in quality such as moisture absorption of grain sideways.

(Means for Solving the Problems) In order to achieve the above object, the present invention exhausts hot air from a heat source to the outside by an exhaust fan 9 via a drying chamber,
The grains are dried in a drying room using the hot air obtained at this time, and the moisture content of the grains is measured using a moisture meter 20, and when the measured value reaches a predetermined finished moisture value, the drying is completed.
In a grain dryer having a discharge instruction means A for instructing to discharge the grain outside the machine after completion of drying, a grain temperature sensor 23 for detecting the temperature of the grain, and an outside air condition detection sensor B for detecting the condition of the outside air. , When the discharge instruction means A is operated, the moisture meter 2
0, operate the grain temperature sensor 23 and the outside air condition detection sensor B to obtain each detected value, and perform a predetermined calculation based on each detected value and the finished moisture value;
The airflow rate setting means C sets the amount of ventilation by the exhaust fan 9 based on the calculation result, and the exhaust fan control means C controls the exhaust fan 9 so that the amount of ventilation is achieved.

(Operation) In FIG. 1, when the discharge instruction means A is now instructed,
As the grain in the grain dryer begins to be discharged to the outside, the moisture meter 20, the grain temperature sensor 23, and the outside air condition detection sensors B such as the outside temperature sensor and the outside air humidity sensor start operating.

The ventilation amount setting means C performs a predetermined calculation based on each detection value obtained from the moisture meter 20 or the like and a preset finished moisture value, and sets the ventilation amount by the exhaust fan 9 based on the calculation result. In other words, depending on the outside air condition or the drying condition of the grain, if ventilation causes the drying to progress or return, the amount of ventilation by the exhaust fan should be set to a weak level, or ventilation should not be performed.

The exhaust fan control means controls the exhaust fan 9 so that the ventilation amount thus set is achieved.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic sectional view of a grain dryer embodying the present invention. In the figure, reference numeral 1 denotes the storage chamber of the dryer, and two pairs of floating grain plates 2 are attached to the lower part of the dryer at an angle so that the interval becomes narrower toward the bottom.
form.

Two mesh plates 4 are connected in parallel to each lower side of the floating grain plate 2,
A drying chamber 5 is formed between them. Then, a hot air chamber 6 in which a burner 10 as a drying heat source is installed is formed between two inner mesh plates 4 provided near the center of the storage chamber l, and a hot air chamber 6 in which a burner 10, which is a drying heat source, is installed is formed between the two outer mesh plates 4. An exhaust chamber 8 is formed between the machine wall 7 and the
It is connected to the exhaust fan 9 of the exhaust chamber 8.

Reference numeral 11 denotes a grain collection room formed in the shape of a gutter, and a lower helix 12 is installed at the bottom of the grain collection room, the end of which is connected to the lower entrance of the elevator 13. Reference numeral 14 denotes a rotary valve pivotally supported at the lower end outlet of the drying chamber 5, and its rotation causes the grains in the storage chamber 1 to flow out through the drying chamber 5 into the grain collection chamber 11.

The upper outlet of the lift 4!113 is connected to an upper helix 15 installed on the ceiling of the storage chamber 1, and the outlet of this upper helix 15 looks into the storage chamber l.

A moisture meter 20 measures the moisture content (moisture) per grain of grain during drying, and is installed, for example, in the grain chamber 3. 2
Reference numeral 1 denotes an outside air temperature sensor attached to the aircraft wall 7 to measure the outside air temperature, and 22 an outside air humidity sensor attached to the aircraft wall 7 to measure the outside air humidity.

23 is a grain temperature sensor installed in the grain flow chamber 3 to measure the temperature of the grain; 24 is an exhaust temperature sensor installed in the exhaust chamber 8;
5 is a hot air temperature sensor installed in the hot air chamber 6. Also 26
27 is a fuel pump that supplies fuel to the burner 10;
is a fuel valve that adjusts the fuel supplied to the burner IO.

FIG. 3 is a block diagram showing an example of a control system according to an embodiment of the present invention.

In the figure, 30 is a microprocessor type CPU (
It is a central processing unit (central processing unit) that controls each component according to predetermined procedures as described below.

31 is, for example, a drying button, a tensioning button, and an ejection button 31
A is an operation input setting device equipped with a stop button, a finishing moisture setting switch for setting the moisture when stopping drying, etc., and is connected to the CPU 30 via an input circuit 32. Further, the moisture meter 20 and each of the sensors 21 to 25 are connected to the CPU 30 via the A/D converter 33.

34 is a display section connected to the CPU 30 via an output circuit 35, and this display section 34 performs various displays.

36 is a memory consisting of a read-only memory (ROM) that stores control procedures for the CPU 30 to control each component, and a random access memory (RAM) that temporarily stores various data such as measurement data. It is a device.

37 to 39 are output circuits connected to the CPU 30, respectively, and the output circuit 37 includes a transport motor 40. Heater 41, moisture meter motor 4
2 are connected to each other, an exhaust fan motor 43 that drives the exhaust fan 9 is connected to the output circuit 38, and an output circuit 39
A fuel pump 26 and a fuel valve 27 are connected to.

Next, an example of the operation of the embodiment configured as described above will be described.

Now, when drying is nearing completion and the average moisture value of the grain measured by the moisture meter 20 reaches the finishing moisture value preset with the finishing moisture setting switch located in the operation input setting device 31, the burner 1° is turned off. Combustion is stopped and drying is completed.

Thereafter, when the grain discharge starts by operating the discharge button 31A, the moisture meter 20. The outside air temperature sensor 21, the outside air humidity sensor 22, and the grain temperature sensor 23 are each driven, and the CPU 30 reads each measurement data.

Next, a temperature difference ΔT between the grain temperature measured by the grain temperature sensor 23 and the outside air temperature measured by the outside air temperature sensor 21 is determined. Further, from each measurement value measured by the moisture meter 20, the ratio per unit number of immature rice whose value is abnormally high, that is, the immature rice contamination rate M is calculated. Furthermore, the equilibrium moisture content of the outside air is determined from the outside air temperature measured by the outside air temperature sensor 21 and the outside air humidity measured by the outside air humidity sensor 22 using a predetermined calculation formula or table processing, and the equilibrium moisture content of the outside air and the above-mentioned The moisture content difference ΔW is calculated from the finished moisture value. Here, the equilibrium moisture content of outside air refers to the moisture content when grains neither dry nor absorb moisture in the atmosphere under certain conditions.

Next, the optimum rotational speed of the exhaust fan 9 is set as follows according to the temperature difference ΔT, moisture content difference ΔW, and immature rice contamination rate M calculated as described above.

In other words, for example, if the stop moisture value is 15.0%, the grain temperature is 35°C, the outside temperature is 20°C, and the outside humidity is 5.
When it is 0%, the equilibrium moisture content of the outside air is determined to be 11.1%. Therefore, when the equilibrium moisture content of the outside air is much lower than the stop moisture value and the moisture content difference ΔW is large, if the exhaust fan 9 is rotated to air dry the grain while it is being discharged, the dry outside air will be It acts on grains and causes them to dry out, resulting in overdrying. Therefore, the rotation speed N of the exhaust fan 9 is set to zero (N=
0), or the rotational speed N is set to a low value (N=N1) that is sufficient to suppress the dust being discharged.

Further, when only the outside air humidity is 90% and all other values are the same as above, the equilibrium moisture content of the outside air is determined to be 17.8%. Therefore, when the equilibrium moisture content of the outside air greatly exceeds the stop moisture value and the moisture content difference ΔW is large,
When the exhaust fan 9 is rotated to ventilate and dry the grains while the grains are being discharged, moist outside air acts on the grains and the grains are returned to dryness. Therefore, the rotation speed N of the exhaust fan 9 is set to fi (N=0), or the rotation speed N is set to a low value (N=N1) that can suppress the dust being discharged.

On the other hand, when only the outside air humidity is 80% and all other values are the same as above, the equilibrium moisture content of the outside air is determined to be 15.3%. Therefore, when there is no difference between the equilibrium moisture content of the outside air and the stop moisture value and the moisture content difference ΔW is extremely small, it is preferable to cool the residual heat by ventilation drying while the grain is being discharged. The value hardly changes. Therefore, either set the rotation speed N of the exhaust fan 9 to the same value as during drying operation, or set the rotation speed N to a relatively high value (N
= N2).

By the way, even in cases where the moisture content difference ΔW is small and the exhaust fan is rotated at high speed to perform ventilation drying, the temperature difference ΔT between the grain temperature and the outside air temperature may be large. In such a case, if the exhaust fan 9 is rotated for ventilation drying, the drying progresses and becomes over-dry. Therefore, at this time, the correction value ΔX is determined according to the magnitude of the temperature difference ΔT.
is determined, and a new corrected rotation speed N is set by subtracting the correction value ΔX from the rotation speed N=N2 once set as described above.

Furthermore, when the temperature difference ΔT and the moisture content difference ΔW are extremely small and the value of the immature rice contamination rate M is large, the tendency of water return can be suppressed by rotating the exhaust fan 9 to perform ventilation drying.

Therefore, under such conditions, the rotation speed N of the exhaust fan 9 is set to the same value as during drying operation, or the rotation speed N is set to a relatively high value (N=N2).

In addition, when the value of the immature rice contamination rate M is large and the equilibrium moisture content of the outside air is significantly higher than the stop moisture value, and the moisture content difference ΔW is large, the effect of ventilation drying as described above will not be obtained. I can't.

Therefore, at this time, the correction value ΔX is determined according to the magnitude of the water content difference ΔW, and the new rotation speed N is calculated by subtracting the correction amount ΔX from the rotation speed N=N2 that has been set as described above. Set.

The rotation speed of the exhaust fan motor 43 is controlled by the CPU 30 so that the rotation speed is thus set, so that the exhaust fan 9 rotates at the set rotation speed while grain is being discharged. After the discharge of the fI material is completed, the operation of the exhaust fan motor 43 is stopped and the exhaust fan 9 is stopped.

(Effects of the Invention) As described above, the present invention changes the amount of ventilation by the exhaust fan depending on the outside air condition and the dryness of the grain during the grain discharge operation, so that the grain moisture content during the grain discharge operation is reduced. If the value advances, it can suppress the return and maintain the finished moisture value,
Moreover, there is an effect that deterioration in quality such as shell cracking can be avoided.

[Brief explanation of the drawing]

FIG. 1 is a functional diagram of the present invention, FIG. 2 is a schematic diagram of a grain dryer to which the present invention is applied, and FIG. 3 is a block diagram thereof. 9 is an exhaust fan, 2o is a moisture meter, 23 is a grain temperature sensor, A
B is an outside air condition detection sensor, C is an airflow setting means, and D is an exhaust fan control means. Patent applicant: Iseki Agricultural Machinery Co., Ltd. Representative: Tobe Maki (and 2 others) Figure 1 Figure 2 Figure 2/Zb

Claims (1)

[Claims] Hot air from a heat source is passed through a drying chamber and exhausted to the outside by an exhaust fan, and the hot air obtained at this time dries the grains in the drying chamber, and the moisture content of the grains is measured with a moisture meter. Detecting the temperature of grain in a grain dryer having a discharge instruction means for instructing to end drying when the measured value reaches a predetermined finished moisture value and to discharge the grain outside the machine after completion of drying. When the grain temperature sensor, the outside air condition detection sensor that detects the condition of the outside air, and the discharge instruction means are operated, the moisture meter, the grain temperature sensor, and the outside air condition detection sensor are operated to detect each detected value. ventilation amount setting means that performs a predetermined calculation based on each of the detected values and the finished moisture value, and sets the ventilation amount by the exhaust fan based on the calculation result;
An exhaust fan control device for a grain dryer, comprising an exhaust fan control means for controlling an exhaust fan so that the ventilation amount is achieved.