JPH06281340A - Abnormal burning detection device in circulation grain drier - Google Patents

Abstract

PURPOSE:To provide a circulation type grain drier which is prevented from being erroneously operated even when fresh air temperature around the drier is rapidly changed and which accurately determines abnormal temperature to inform a hot air temperature trouble. CONSTITUTION:There are communicated to a CPU 37 through an input circuit 36 a hot air temperature setting switch 33, a fresh air temperature sensor 34 for detecting temperature around a drier, and a hot air temperature sensor 35 for detecting hot air temperature, and the CPU 37 is communicated through an output circuit 38 to a fuel pump 39, a fuel nozzle 40, a suction air exhaust fan 32, and an alarm buzzer 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormal combustion detection device for a circulating grain dryer, which notifies an abnormal hot air temperature when the temperature of the hot air becomes abnormally high or extremely low.

[0002]

2. Description of the Related Art In a circulation type grain dryer having a storage section, a drying section, a grain lifting machine, etc., the combustion amount of fuel oil is increased or decreased so that the hot air temperature is close to a set value. Is being controlled. However, when an abnormality occurs on the combustion device side, the hot air temperature becomes abnormally high, and conversely becomes abnormally low. When such an abnormal situation occurs,
In addition to the grain being damaged, there are problems that the combustion device is thermally damaged, and conversely, fuel oil comes out to the hot air chamber of the grain dryer to give the grain an oily odor.

Therefore, conventionally, the hot air temperature is constantly monitored, and the occurrence of an abnormal temperature is detected by detecting that the measured temperature exceeds the allowable range with respect to the set value and opens. However, if an allowable range is set for the set temperature and an abnormality occurs when the allowable range is exceeded, there is a problem that the abnormality determination cannot be accurately performed depending on how the allowable range is taken. Therefore, JP-A-62-162883
In the circulation type grain dryer disclosed in the publication,
Hot air temperature current value measured by hot air temperature detection means,
The hot air temperature previously stored is compared with the previous value, and a hot air temperature abnormality signal is output to notify the hot air temperature abnormality.

[0004]

However, in the conventional circulation type grain dryer as described above, the shutter of the barn is suddenly opened during the operation at night, and the ambient temperature around the circulation type grain dryer is temporarily changed. When the temperature of the hot air is drastically reduced, the hot air temperature is also temporarily and sharply decreased (see FIG. 5).
At this time, the hot air temperature present value T _A measured by the hot air temperature detecting means changes from the hot air temperature previous value T _B before the hot air temperature drastically decreases to a predetermined value α or more. Therefore, the circulation type grain dryer determines that the hot air temperature is abnormal and stops the operation even though the combustion is normally performed.

The present invention solves the above-mentioned drawbacks of the circulation type grain dryer and provides an abnormal combustion detection device in the circulation type grain dryer capable of accurately discriminating the abnormal temperature and notifying the abnormal hot air temperature. The purpose is to provide.

[0006]

To achieve this object, the present invention has the following constitution.

In a circulation type grain dryer in which a grain circulation process is formed by a storage section for storing the material to be dried, a drying section provided below the storage section, and a grain lifting machine connecting the drying section and the storage section. A hot air temperature detector that measures the hot air temperature of the drying unit,
An outside air temperature detector that measures the outside air temperature around the dryer, and the rising temperature of the hot air is calculated from the detection values of the hot air temperature detector and the outside air temperature detector. A means for solving the above problem is provided by providing a control device that compares the previous value and outputs a hot air temperature abnormality signal when the temperature difference between the two exceeds a predetermined range.

Then, the control device calculates the rising temperature of the hot air at regular time intervals, compares this rising temperature rising value with the previously stored rising temperature rising value, and determines the difference between the two values within a predetermined range. When it exceeds 5 times in succession, a hot air temperature abnormality signal is output.

[0009]

When the grain stored in the storage portion of the grain dryer flows down through the drying chamber provided in the drying unit, the drying air blown by the heat generating device passes through the drying chamber to be dried. In this grain dryer, the detected value from the hot air temperature detector and the detected value from the outside air temperature detector are input to the control device almost at the same time, and the control device calculates the temperature rise of the hot air at regular time intervals. Then, the control device compares the current temperature increase value with the previously stored temperature increase previous value, and when the temperature difference between the two exceeds a predetermined range, a hot air temperature abnormality signal is output. The hot air temperature abnormal signal is output to the display unit, the alarm buzzer, the fuel pump, and the fuel nozzle to notify the abnormal temperature and stop the heat generation device.

[0010]

EXAMPLE FIG. 1 is a partial front sectional view of a circulating grain dryer. 1 is a circulation type grain dryer, which is provided with a storage section 2 for storing the material to be dried, and a drying section 3 below the storage section 2,
A grain lifting machine 4 that connects the drying unit 3 and the storage unit 2 is erected on one side thereof to form a grain circulation process. The drying unit 2 is provided with a drying chamber 5, a hot air chamber 6 and an air exhaust chamber 7, which are partitioned by a porous wall plate, and the upper portion of each drying chamber 5 communicates with the storage unit 2 and each drying chamber 5
The lower part of is connected to the grain flow down route 8. The drying unit 2 is further provided with a hot air temperature sensor 35 for measuring the hot air temperature blown out from the hot air chamber 6 and an outside air temperature sensor 34 for measuring the outside air temperature around the circulation type grain dryer. The grain flow-down path 8 is connected to a grain collecting trough 10 via a discharge valve 9, and a lower carrier 11 is provided at the bottom of the grain collecting trough 10. The lower carrier 11 is connected to the storage unit 2 via the grain elevator 4, the upper carrier 12, and the scattering plate 13. Fried machine 4
A moisture measuring device 15 is further provided on one side through a supply cylinder 14, and the grain is supplied from a guide plate 18 that collects the returned grain from the bucket 17 between the belts 16 and 16 of the grain lifting machine 4. . The moisture measuring device 15 communicates with the bottom of the fried machine 4 via the discharge gutter 19 and the return gutter 20.

FIG. 2 is a cross-sectional view of the circulating grain dryer. An air supply port 22 is opened at a boundary surface of the front wall 21 with each end of the hot air chambers 6, and an air exhaust port 24 is opened at a boundary surface of the rear wall 23 with each air exhaust chamber 7. The front wall 21 is provided with an air supply box 25, the rear wall 23 is provided with a fan box 26, the opening 27 of the air supply box 25 is provided with a burner box 29 having a built-in burner 28, and the opening 30 of the fan box 26 is provided. A suction / exhaust fan 32 having a suction fan 31 mounted therein is arranged in each of the above.

FIG. 3 is a block diagram of the controller 44.
Temperature setting switch 33 for setting the hot air temperature to the target temperature
And an outside air temperature sensor 34 for detecting the temperature around the dryer,
The input circuit 36 includes a hot air temperature sensor 35 for detecting the hot air temperature.
To the CPU 37 via. Then, the CPU 37 communicates with the fuel pump 39 for feeding the fuel to the burner through the output circuit 38, the fuel nozzle 40, the suction / exhaust fan 32 for sucking dry air, and the alarm buzzer 41 for notifying the abnormal hot air temperature. . Further, the CPU 37 communicates with a storage device 42 including a ROM storing a program and a writable RAM, and a display 43 for displaying the hot air temperature detected by the hot air temperature sensor 35.

Next, the operation of the above configuration will be described.
Grain (for example, paddy) supplied to a hopper (not shown)
The grain is lifted by the grain elevator 4, passed through the upper transporter 12, and scattered from the scattering plate 13 to the storage unit 2 and accumulated evenly. When the burner 28 and the suction / exhaust fan 32 are operated to operate the discharge valve 9, the grain in the storage section 2 flows down in the drying chamber 5. The dry air blown by the burner 28 and the suction / exhaust fan 32 flows into the hot air chamber 6 through the opening 27, the air supply box 25, and the air supply port 22, and moves laterally from the hot air chamber 6 to the air exhaust chamber 7. Grains flowing down in the drying chamber 5 are dried by the drying air flowing to the. The dry air, which has become high humidity by drying the grains, flows from the air exhaust chamber 7 to the air exhaust port 24, the fan box 26, and the opening 30.
The suction fan 31 of the suction / exhaust device 32 is rotated to be discharged outside the machine.

The grain dried by the dry air flows down through the grain flow path 8 and is intermittently discharged by the outflow valve 9.
The discharged grain flows down through the grain collecting trough 10 and the lower carrier 1
1 is sent to the fried machine 4 and is again fed to the storage section 2,
It is circulated and dried until the water content measuring device 15 detects a predetermined water content.

Grains to be pumped by the grain lifting machine 4 are spilled from the bucket 17 between the belts 16 and 16 due to discharge during transportation. The spilled grain is collected by the guide plate 18, flows down from the guide plate 18 through the supply cylinder 14 and is supplied to the moisture measuring device 15, where the moisture of the grain is measured. The grain whose moisture has been measured is discharged from the moisture measuring device 15, flows down the discharge gutter 19, and is supplied from the return gutter 20 to the lower part of the grain elevator 4.

Next, the operation of the abnormal combustion detection device will be described with reference to the flowchart of FIG. 4 and the block diagram of FIG. In step 101, the CPU 37 reads the target hot air temperature T from the temperature setting switch 33 and stores it in the storage device 42. In step 102, the contents of the low temperature abnormality counter CT and the high temperature abnormality counter CK are all initialized, and step 1
At 11, the 12-second timer is started. Subsequently, in step 103, the first hot air temperature N is measured, and step 1
At 04, the outside air temperature G around the first circulation type grain dryer is measured. In step 105, the first hot air temperature N and the first outdoor air temperature G are compared with each other to calculate the previous value (N−G) _B of rising temperature of hot air, which is stored in the storage device 42.

In step 106, the previous value of hot air temperature rise previously stored in step 105 (NG)
_B is compared with the hot air temperature rise value (NG) _A calculated from the hot air temperature N measured after the second time and the outside air temperature G.

This comparison becomes the following equation.

[0019]

[Equation 1] In this comparison, in step 107, if the temperature difference Δ between the previous temperature increase value and the current temperature increase value is 1 ° C. or more, the low temperature abnormality counter CT counts up by 1 and reaches step 108. The abnormality counter CT is reset and the process proceeds to step 109. In step 108,
If the low temperature abnormality counter CT is 5 counts or more, a low temperature abnormality signal is output, and if the low temperature abnormality counter CT is less than 5 counts, the process proceeds to step 109. In step 107 and step 108, the low temperature abnormality signal output under the condition that the difference Δ of the temperature rise is 1 ° C. or more and the low temperature abnormality counter CT is 5 counts or more causes the display unit 43 to display the low temperature abnormality, and outputs the alarm buzzer. 41 is sounded to stop the operation of the fuel pump 39 and the fuel nozzle 40. In addition, the suction and exhaust device 3
For No. 2, the work is continued due to the blowing operation.

In step 109, a high temperature abnormality signal is output in the same process as in step 107. As for the high temperature abnormality signal, when the temperature difference Δ is less than -2 ° C, the high temperature abnormality counter CK is 5
It is output under the condition that it is equal to or greater than the count. Then, the low temperature abnormality is displayed on the display unit 43 and the alarm buzzer 41 is sounded,
The operation of the fuel pump 39 and the fuel nozzle 40 is stopped. The suction / exhaust fan 32 continues to operate due to the blowing operation. When the output condition of the high temperature abnormality signal is not satisfied, the process goes to step 110.

In step 110, the timer counter is activated and it is determined whether 12 seconds have elapsed. That is, 1
The low temperature or high temperature abnormality detection time for each time is set to 12 seconds, which is the same as the combustion level timing. Here, in consideration of the low temperature abnormality counter CK and the high temperature abnormality counter CT, when a low temperature or high temperature abnormality is detected five times consecutively every 12 seconds, an abnormality signal is output. When 12 seconds have passed in step 110, the process returns to step 111.

FIG. 6 shows a dynamic characteristic diagram in which the present invention is implemented. An allowable temperature range ± α is set so that there is no erroneous determination with respect to the target temperature T, and the hot air temperature N changes with time within this range. The outside air temperature G around the dryer is almost constant over time. However, when the shutter of the barn is opened, the outside air temperature G starts to decrease rapidly, and the hot air temperature N also decreases accordingly, and finally exceeds the allowable temperature range ± α. However, in the present invention, the upper temperature increase current value (NG)
_A , the previous temperature rise value before the outside temperature decreased (NG) _B
Since abnormal temperature is detected by comparing with, the operation of the circulating grain dryer is not stopped during normal combustion. However, in the case of the conventional example, as shown in FIG. 5, the abnormal temperature is detected by comparing the current value N _A of the hot air temperature N with the previous value N _B , so that the allowable temperature range is maintained even during normal combustion. If it exceeds ± α, the operation of the circulating grain dryer will be stopped.

In the embodiment of the present invention, although the abnormal combustion is detected by comparing the current value of the hot air temperature increase with the value before the temperature increase, it is not applied to the sequential temperature increase drying shown in FIG. .
Sequential temperature rising drying is a drying method in which the higher the moisture content of the grain is, the lower the hot air temperature is, and the lower the moisture content is, the higher the hot air temperature is gradually raised to maintain the quality of the grain. Therefore, the hot air temperature is increased stepwise during the period from the moisture content of the grain to 25% to 18%, and it is determined that the normal combustion is performed, so that the hot air temperature abnormality signal is not output.

[0024]

According to the circulating grain dryer of the present invention, a hot air temperature detector for measuring the hot air temperature in the drying section, an outside air temperature detector for measuring the outside air temperature around the circulating grain dryer, and The rising temperature of the hot air is calculated from the detected values of the hot air temperature detector and the outside air temperature detector, and this upper temperature rise current value is compared with the previously stored upper temperature rise previous value, and the temperature difference between them is within a predetermined range. When the temperature exceeds the limit, a control device that outputs a hot air temperature abnormality signal is provided, so even if there is a situation where the outside air temperature around the dryer suddenly changes, the abnormal temperature can be accurately determined without malfunctioning. It became possible to notify the abnormal hot air temperature. Further, the control device calculates the rising temperature of the hot air at regular time intervals, compares the current value of the upper temperature increase with the previously stored value of the previous temperature increase, and the difference between the two values continues within a predetermined range. When the temperature exceeds 5 times, a hot air temperature abnormality signal is output, which enables more accurate determination of the abnormal temperature.

[Brief description of drawings]

FIG. 1 is a partial front sectional view of a circulation type grain dryer.

FIG. 2 is a cross-sectional view of a circulating grain dryer.

FIG. 3 is a block diagram of an abnormal combustion detection device embodying the present invention.

FIG. 4 is a flowchart of an abnormal combustion detection device embodying the present invention.

FIG. 5 is a dynamic characteristic diagram of a conventional example.

FIG. 6 is a dynamic characteristic diagram in which the present invention is implemented.

FIG. 7 is an equilibrium moisture curve of the sequential temperature rising drying method according to the present invention.

[Explanation of symbols]

 1 Circulating Grain Dryer 2 Storage Section 3 Drying Section 4 Lifting Machine 5 Drying Room 6 Hot Air Chamber 7 Exhaust Chamber 8 Grain Downflow Path 9 Discharge Valve 10 Grain Gutter 11 Lower Conveyor 12 Upper Conveyor 13 Scattering Plate 14 Supply Cylinder 15 Moisture measuring device 16 Belt 17 Bucket 18 Guide plate 19 Exhaust gutter 20 Return gutter 21 Front wall 22 Air inlet 23 Back wall 24 Air outlet 25 Air supply box 26 Fan box 27 Opening 28 Burner 29 Burner box 30 Opening 31 Suction Fan 32 Suction / exhaust fan 33 Temperature setting switch 34 Outside air temperature sensor 35 Hot air temperature sensor 36 Input circuit 37 CPU 38 Output circuit 39 Fuel pump 40 Fuel nozzle 41 Alarm buzzer 42 Storage device 43 Display unit 44 Control device

Claims (2)

[Claims] 1. A circulation-type grain drying device in which a grain circulation process is formed by a storage unit for storing a material to be dried, a drying unit provided below the storage unit, and a grain elevator connecting the drying unit and the storage unit. In the machine, a hot air temperature detector that measures the hot air temperature of the drying unit, and an outside air temperature detector that measures the outside air temperature around the dryer,
The rising temperature of the hot air is calculated from the detection values of the hot air temperature detector and the outside air temperature detector at regular time intervals, and this upper temperature increase current value and the previously stored upper temperature increase previous value are compared to determine the temperature difference between the two. And a control device for outputting a hot air temperature abnormality signal when the temperature exceeds a predetermined range. 2. The control device calculates the rising temperature of the hot air at regular time intervals, compares the current rising temperature value with a previously stored rising temperature previous value, and determines the difference between the two values within a predetermined range. The abnormal combustion detection device in the circulating grain dryer according to claim 1, wherein a hot air temperature abnormality signal is output when the number of times exceeds 5 times in succession.