JPH09196562A - Dryer control device for grain dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect abnormal combustion without failure by outputting a pump driving signal to a pump on the basis of a pump control signal of a drying control means and comparing the pump control signal with the pump driving signal to decide whether any abnormality exists in a combustor. SOLUTION: A drying control section 31 outputs a motor starting signal to a motor driving circuit 33 to start driving a group of motors 37. After the group of the motors 37 have been started driving, the drying control section 31 outputs a burner control signal S1 to a burner control circuit 32a of a combustion control section 32 and a control signal S2 for turning on and off a pump (P) to a pump driving circuit 32h. The pump driving circuit 32h changes pulse width of the pump control signal S2 to convert the pump control signal S2 into a pump drive signal S3, which is then outputted to the pump (P). The drying control section 31 reads the pump drive signal S3 and compares the pump drive signal S3 with the pump control signal S2. By this comparison a decision is made whether any abnormality exists in a combustor to detect abnormal combustion without failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying controller for a grain dryer, which circulates the grain while hot air is blown onto the grain by a combustor to dry the grain.

[0002]

2. Description of the Related Art Conventionally, a circulation type grain dryer has a storage section formed in an upper part of a substantially box-shaped machine body, a drying section is formed below the storage section, and a grain collecting section is further formed below the storage section. The grain collected in the grain collecting section is conveyed to the upper part of the storage section by a lifting machine or the like to circulate the grain, and hot air generated by the combustor and the blower is applied to the grain passing through the drying section during this circulation. The grain is dried by bathing.

In order to improve safety, the grain dryer is generally equipped with a drying controller for detecting abnormal combustion of the combustor during drying and stopping the combustor. This drying control device has a temperature sensor such as a thermistor for detecting the temperature in the drying section and a control device for setting a preset temperature, and the temperature difference between the temperature detected by the temperature sensor and the preset temperature is a predetermined value. When the value exceeds the limit, the control device determines that there is an abnormality and stops the operation of the homp that supplies fuel to the combustor.

[0004]

However, in the drying control device that determines abnormal combustion based on the difference between the temperature detected by the temperature sensor and the set temperature, the drying control device takes into consideration the responsiveness of the combustor, for example, the initial stage. After the dry combustion time has elapsed, the presence or absence of abnormality in the combustor is determined about 5 to 10 minutes later. Therefore, after the operator starts the operation of the grain dryer and leaves the dryer, abnormal combustion is detected. Then, the grain dryer may stop, and in such a case, there is a problem that the abnormality of the combustor cannot be detected reliably and promptly.

Further, in the determination based on the temperature difference from the set temperature, abnormal combustion when the fuel supplied from the pump is too much in the dry state in which the set temperature is raised, a pump drive circuit for controlling the pump during the drying, etc. However, there is a problem in that it is difficult to reliably detect abnormal combustion such as when an abnormality occurs.

The present invention has been made in view of the above circumstances, and an object thereof is to reliably detect abnormal combustion by determining, for example, whether or not there is an abnormality in the combustor based on a pump drive signal. It is to provide a drying control device for a grain dryer.

[0007]

In order to achieve the above object, the drying control device for a grain dryer according to claim 1 exposes the grain circulating in the storage section, the drying section and the grain collecting section to the hot air from the combustor. In a circulation type grain dryer that dries by drying, a drying control unit that outputs a pump control signal that controls a pump of a combustor, and a combustion control unit that outputs a pump drive signal to the pump based on the pump control signal of the drying control unit And a comparison means for comparing the pump control signal and the pump drive signal.

According to the drying control device of this grain dryer,
The combustion control unit outputs a pump drive signal to the pump to operate the pump based on the pump control signal from the drying control unit, and supplies a predetermined amount of fuel to the combustor for combustion. The pump drive signal output from the combustion control means is input to the comparison means and compared with the pump control signal output from the drying control means, and the comparison means determines whether or not there is an abnormality in the combustor based on the comparison result. To detect. Therefore, the presence or absence of abnormal combustion of the combustor is detected according to the operating state of the pump that most affects the combustion of the combustor, that is, the fuel supply state.

Further, in the drying control device for a grain dryer according to a second aspect of the present invention, the comparing means determines that the pump drive signal is abnormal when the pump drive signal is out of a predetermined range with respect to the pump control signal, and the comparing means determines that the drying control means. It is characterized by outputting an abnormal signal and stopping the output of the pump control signal. According to this drying control device, the abnormal combustion can be detected more accurately by appropriately setting the range in which the comparison means determines the abnormal combustion, and the combustor is reliably stopped when the abnormal combustion occurs.

Further, the drying control device for a grain dryer according to claim 3 is characterized in that the drying control means stops the drying operation when an abnormality signal is inputted from the comparison means. According to this drying control device, when it is determined that the comparison means is abnormal, by the drying control means, for example, a combustor,
All operations of the blower, grain elevator, etc. are stopped to stop the drying operation, and the secondary damage due to abnormal combustion is reliably prevented.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show an embodiment of a grain dryer using a drying control device according to the present invention, FIG. 1 is a side view thereof, FIG. 2 is a sectional view taken along line AA of FIG.
FIG. 3 is an enlarged front view of the control panel.

1 and 2, the grain dryer 1 is
A substantially box-shaped machine body 2 including a storage unit 3, a drying unit 4, and a grain collecting unit 5.
Grains lifted by a grain lifting machine 6 that is erected outside the machine body 2 are transported by the upper transport mechanism 7 and stored in the storage unit 3.
It is evenly dropped inside. Grains in this storage part 3 are dried part 4
After being boiled with hot air in the above, it is collected in the lower part of the grain collecting section 5 by the feeding valve 8, is transferred to the grain elevator 6 by the lower transport mechanism 9 and is lifted up to the storage section 3 again, and is dried. To be done.

In order to perform this circulation, the machine 2 has a grain elevator 6
A transport motor 10 that drives the upper transport mechanism 7 and the lower transport mechanism 9, and a circulation motor 1 that drives the delivery valve 8.
1 is provided, and a dust remover motor 12 that discharges contaminants in the grain is provided above the grain fried machine 6.

Further, the drying section 4 is provided with a burner 13 as a combustor for generating hot air on the front side thereof, and
On the back side, the burner 13 is rotated by the rotation of the blower motor 15.
A blower 14 that sucks hot air from the machine and discharges the hot air to the outside of the machine body 2 is provided. A moisture meter 16 for measuring the moisture value of grain is provided on the front surface of the fried machine 6.

A control panel 18 shown in FIG. 3 is provided on the front surface of the burner 13. The control panel 18 has a monitor display section 19 for displaying the operating state of each section of the grain dryer 1, a moisture value and a drying time. And the like, a number display 20 for displaying a dry operation, an operation switch 21 for starting a dry operation, a stake switch 22 for rotating the circulation motor 11 to stick grains into the machine body 2, a stop switch 23 for stopping the operation, and a stop moisture value. A stop moisture setting switch 24 for setting, a grain amount setting switch 25 for setting the amount of grains stored in the machine body 2, a grain type setting switch 26 for setting the type of grain, and the like are provided.

The switches and the like of the control panel 18 are connected as shown in FIG. 4 to form a drying control device 30.
Hereinafter, the drying control device 30 will be described. The drying control device 30 is composed of a microcomputer mainly composed of a CPU, a ROM, a RAM, etc., and is a drying control unit 31 as a drying control unit and a comparison unit, and a combustion control unit connected to the drying control unit 31. Combustion control unit 32
And a motor drive circuit 33 and the like. Further, a switch group 34 including the various setting switches of the control panel 18, a surrounding temperature sensor 35, a temperature sensor 36 provided in the drying unit 4, and the like are connected to the drying control unit 31.

The combustion control section 32 includes a burner control circuit 32a for outputting various signals for controlling a combustion fan, a diffusion motor, an igniter, a frame rod and the like provided in the burner 13, and a pump P provided in the burner 13. It has a pump drive circuit 32b that outputs a pump drive signal S3 for driving the.

The burner 13 is connected to the burner control circuit 32a and the pump P is connected to the pump drive circuit 32b. The pump drive circuit 32b outputs its output signal (pump drive signal S3) to the drying controller 31. It is configured to be fed back. In addition, the motor drive circuit 33
A motor group 37 including the transport motor 10, the circulation motor 11, the dust collector motor 12, and the like is connected to the.

Next, the operation of the drying control device 30 will be described with reference to FIG.
A description will be given based on the flowchart of FIG. It should be noted that this flowchart is executed according to a program stored in the ROM of the drying control unit 31. First, the operator turns on the swelling switch 22 of the control panel 18, squeezes the grain into the machine body 2, sets the amount of the grain with the grain amount setting switch 25, and the grain type setting switch 26.
Set the type of grain (eg paddy) with. Further, the stop moisture setting switch 24 is used to set a moisture value for stopping the drying, and then the operation switch 21 is turned on.

When the operation switch 21 is turned on, the operation is started (S100), and the drying controller 31 outputs a motor start signal to the motor drive circuit 33 (S101) to start each motor. When each motor starts, the drying control unit 3
1 outputs a burner control signal S1 (see FIG. 4) to the burner control circuit 32a of the combustion control unit 32 (S102), and serves as a reference signal for turning on / off the pump P to the pump drive circuit 32b. A pump control signal S2 having a pulse width T (see FIG. 4) is output (S103).

The pump drive circuit 32b receives the pump control signal S
When 2 is input, for example, the pulse width T of the signal S2 is changed and converted into a pump drive signal S3 having a pulse width t capable of suppressing the variation in the flow rate of the pump P and output. This pump drive signal S3 is input to the pump P, the pump P is driven, fuel is supplied to the burner 13 and the burner 13 is turned on (combustion starts), and the drying control unit 31
Feedback is input to.

When the pump drive signal S3 is input, the drying controller 31 reads this signal S3 (S104).
Then, it is compared with the pump control signal S2 (S105). This comparison is made based on whether or not the read pump drive signal S3 is within a predetermined range with respect to the pump control signal S2, that is, the following equation. T-α ≦ t ≦ T where T: pulse width of pump control signal t: pulse width of pump drive signal α: predetermined value

If "NO" in this step 105, that is, if the pump drive signal S3 is the pump control signal S
If the burner 13 is out of the predetermined range with respect to 2, it is determined that the combustion of the burner 13 is abnormal, and the output of the pump control signal S2 and the burner control signal S1 from the drying control unit 31 is stopped (S1).
06). As a result, the pump drive signal S3 output from the pump drive circuit 32b to the pump P is stopped, the fuel supply to the burner 13 is cut off, and the output of various signals from the burner control circuit 32a is also appropriately stopped. Then, the burner 13 is turned off (combustion is stopped).

Therefore, when the burner 13 is burning, the burner 13 is immediately turned off if the pump drive signal S3 is abnormal under any circumstances. When the burner 13 is turned off, the drying controller 31 outputs a motor stop signal to the motor drive circuit 33 (S107) to stop the rotation of each motor, whereby the grain dryer 1 is completely stopped and the operation ends. (S10
9) Do.

On the other hand, if "YES" in step 105, that is, the pump drive signal S3 is the pump control signal S2.
On the other hand, when it is within the predetermined range, it is determined that the combustion of the burner 13 is normal, and the drying operation is continued. And
It is judged whether or not the drying is completed (S108). For example, when the stop switch 23 is turned on or the moisture value measured by the moisture meter 16 reaches the stopped moisture value, step 108 becomes "YES" and the operation is performed. Ends (S109). In addition,
If “NO” in the step 108, the step 104,
105 is repeated, and the pump drive signal S3 is checked every moment.

Thus, the drying control device 3 of the above embodiment
According to 0, the pump drive signal S3 of the pump P that supplies the fuel to the burner 13 is compared with the pump control signal S2 that is the reference signal for turning the pump P on and off, and the pump drive signal S3 is set in advance. Since abnormal combustion is detected when it is out of the range, abnormal combustion of the burner 13 can be reliably detected while the operator is near the grain dryer 1 immediately after the burner 13 is turned on, for example. As a result, after the operator leaves the grain dryer 1, the burner 13 does not stop for a long time due to abnormal combustion.

Further, since abnormal combustion of the burner 13 is detected based on the pump drive signal S3 that actually drives the pump P, for example, when the combustion air of the burner 13 is normal and the flow rate of the pump P is higher than the specified value. Even in this case, it is possible to reliably detect the large flow rate from the pump drive signal S3.
As a result, it becomes possible to detect abnormal combustion in the burner 13 without overlooking when the set temperature is set high. If the flow rate of the pump P is less than the prescribed value, misfire is likely to occur, and therefore it can be detected by a conventional misfire sensor (frame rod or the like).

Further, if an abnormality occurs in the combustion control section 32 during the drying operation, some abnormality also occurs in the pump drive signal S3, so that the abnormal combustion that is actually occurring is reliably detected from this signal S3. It is also possible to predict the occurrence of abnormal combustion from the abnormality of the pump drive signal S3. In particular, by appropriately setting the value of the range (predetermined value α) serving as a criterion for abnormality determination, the detection accuracy can be further enhanced. From these facts, the drying control apparatus having high detection accuracy and high safety 30 can be obtained, and safe unmanned operation of the grain dryer 1 becomes possible.

In the above embodiment, the pump drive signal S3 is directly supplied from the pump drive circuit 32b to the drying control unit 3
1 was fed back, but for example, as shown in FIG.
The pump drive signal S3 may be fed back to the drying control unit 31 via the burner control circuit 32a.
That is, the pump drive signal S from the pump drive circuit 32b.
3 is input to the burner control circuit 32a, and a signal S4 corresponding to the pump drive signal S3 is input to the drying control unit 31 from the burner control circuit 32a. And this signal S4
The abnormal combustion of the burner 13 is detected by comparing the pump control signal S1 with the pump control signal S1 in the drying control unit 31, for example. Even with such a configuration, it is clear that the same operational effects as those of the above embodiment can be obtained.

Further, in the above embodiment, the comparing means for comparing the pump control signal S2 and the pump drive signal S3 is provided in the drying control section 31, but the present invention is not limited to this, and for example, the comparison is made. The means may be provided in the combustion control unit 32, or may be separately provided in addition to the drying control unit 31 and the combustion control unit 32. Further, in the above embodiment, the case where the abnormal combustion of the burner 13 is detected by the comparison result of the comparison means has been described, but the pulse width or the like of the pump control signal S2 can be controlled based on the comparison result, for example. .

Furthermore, the block diagram in the above embodiment is an example, and for example, the drying control section 31 and the combustion control section 32 may be integrally formed on one substrate.
It is needless to say that the configuration of the grain dryer 1 and the configuration and arrangement of various switches of the control panel 18 in the above embodiment are also examples, and various modifications can be made without departing from the scope of the present invention.

[0032]

As described above in detail, according to the drying control device for a grain dryer of the present invention, by comparing the pump drive signal for actually driving the pump with the pump control signal, for example, the abnormality of the combustor is detected. Therefore, it is possible to reliably detect abnormal combustion without being affected by the set temperature or the like.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a grain dryer using a drying control device according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged front view showing an example of the control panel.

FIG. 4 is a block diagram showing an example of the drying control device.

FIG. 5 is a flowchart for explaining the operation thereof.

FIG. 6 is a block diagram showing another embodiment of the drying control device according to the present invention.

[Explanation of symbols]

 1 ・ ・ Grain dryer 3 ・ ・ Reservoir 4 ・ ・ ・ ・ Dryer 5 ・ ・ ・ ・ Grain collector 13 ・ ・ ・ Burner 14 ・ ・ ・ ・-Blower 18 ... Control panel 21 ... Operation switch 30 ... Drying control device 31 ... Drying control unit 32 ... Combustion control unit 32a ... Burner control circuit 32b ... Pump drive circuit P ... Pump S2 ... Pump control signal S3 ... Pump drive signal

Claims (3)

[Claims] 1. A circulation type grain dryer which dries hot air of a combustor on a grain circulating in a storage section, a drying section and a grain collecting section to output a pump control signal for controlling a pump of the combustor. A drying control means; a combustion control means for outputting a pump drive signal to the pump based on a pump control signal of the drying control means; and a comparison means for comparing the pump control signal with the pump drive signal. A drying control device for a grain dryer. 2. The comparing means determines that the pump control signal is abnormal when the pump drive signal is out of a predetermined range with respect to the pump control signal, and outputs an abnormality signal to the drying control means to output the pump control signal. 2. The drying control device for a grain dryer according to claim 1, wherein the drying control device is stopped. 3. The drying control device for a grain dryer according to claim 2, wherein the drying control means stops the drying operation when an abnormality signal is input from the comparison means.