JPH0438230Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a control device for a grain dryer, and in particular reduces the moisture difference between grains by stopping the drying operation in the middle of the drying operation, thereby improving the accuracy of the stop moisture value. The present invention relates to a control device for a grain dryer that improves the quality of grain drying, prevents deterioration of grain due to stuffiness, etc. when the drying operation is suspended, and ensures safety during the suspension operation.

[Prior Art] In a grain dryer, the input grain is tempered in a storage section to balance the moisture within the grain.
After drying with hot air in the drying section, the grain is collected in the grain collecting section.
The grain is lifted up by a lifting machine, dispersed in the storage section, and tempered again, repeating the cycle until it reaches a predetermined stop moisture value. In this kind of
There is one disclosed in Japanese Unexamined Patent Publication No. 147975/1983. This device includes a stop means for determining whether the measured moisture content is a predetermined value larger than the stop moisture content and stopping the hot air generator when the measured moisture content reaches the predetermined value; a determining means for determining whether or not a measured moisture content has reached the stop moisture content when a predetermined drying pause time has elapsed after the generator is stopped by the stopping means; and a restart means for restarting the hot air generator when it is determined that the measured moisture content has not reached the stop moisture content.

[Problem that the invention aims to solve] However, since the moisture content of grains when they are put into the dryer is not constant and varies,
If the grains were continuously dried in this state, the moisture difference between grains would be eliminated even at the end of drying, and the accuracy of the stop moisture value would not be good. In this case, it is known that increasing the time for tempering the grains during the drying process can reduce the moisture difference due to moisture transfer between the grains. Since it is in an atmosphere of high temperature and high humidity, there is a risk of quality deterioration due to stuffiness, etc. In addition, in the case of automatic operation that incorporates a drying pause operation as disclosed in the above-mentioned Japanese Patent Application Laid-open No. 59-147975, even when the drying operation is suspended, the dryer does not know when it will restart, making it difficult for the operator to Safety considerations were desired. In addition, in this method, the drying operation was not carried out thoroughly, sometimes with drying pauses, and sometimes not, so that the drying did not take full advantage of the tempering effect.

[Purpose of the invention] Therefore, this invention solves these problems and
By stopping the drying operation in the middle, it is possible to promote tempering, reduce the moisture difference between grains, improve the accuracy of the stop moisture value, and prevent grain deterioration due to stuffiness during the drying period. The object of the present invention is to realize a control device for a grain dryer that can ensure safety when restarting.

[Means for Solving the Problems] In order to achieve this object, this invention includes a circulation mechanism for circulating the loaded grains, a hot air generation mechanism for generating hot air to dry the grains with hot air,
In the device comprising a moisture meter that detects the moisture value of the grain and a plurality of ventilation mechanisms including an exhaust fan that constitutes the hot air generation mechanism, the moisture value detected by the moisture meter during drying operation is set to When a predetermined value 2 to 3% higher than the stop moisture value is reached, the circulation mechanism and the hot air generation mechanism are controlled to stop for a predetermined time, and at least one of the ventilation mechanisms is controlled to be driven, and after a predetermined time elapses, the circulation is stopped. The present invention is characterized in that a control circuit is provided for canceling the stop control of the mechanism and the hot air generating mechanism and controlling the drive until a set stop moisture value is reached.

[Operation] Since this device takes the above-mentioned measures, when the grain moisture value measured during the drying operation reaches a predetermined value that is 2 to 3% higher than the set stop moisture value, Tempering is performed by stopping the circulation mechanism and hot air generation mechanism, and the moisture difference is reduced by moisture transfer between grains. At this time, at least one of the ventilation mechanisms is driven to discharge the moisture inside the dryer to the outside of the dryer. After a predetermined period of time has elapsed, the circulation mechanism and the hot air generation mechanism are driven again to dry the product until the set stop moisture value is reached.

[Example] Next, an example of this invention will be described in detail based on the drawings. In FIG. 1, a grain dryer 2 has a storage section 4, a drying section 6, and a grain collecting section 8. The grain lifted by the grain lifting machine 10 is conveyed by an upper conveyor 12 and dropped into the storage section 4 in equal portions. The grain is
After drying in the drying section 6, it is collected in the collecting section 8 by the feeding valve 15, transferred to the lower part of the grain lifting machine 10 by the lower conveyor 14 and lifted up again, and then returned to the storage section 4 by the upper conveyor 12. The grain is dried by repeating this cycle. In order to perform this circulation, a grain lifting machine 10, an upper and lower conveyor 12,
A conveyor motor 16 that drives the feed valve 14 and a circulation motor 18 that drives the feed valve 15 are provided to form a circulation mechanism. Further, a dust ejector motor 20 is installed on the upper part of the grain lifting machine 10 to operate a dust ejector that separates impurities from grains and discharges them to the outside of the machine.

The drying section 6 is provided with a hot air generation mechanism to dry the grains with hot air. That is, a combustion machine 22 that generates high-temperature air is provided on the front side of the drying section 6, and an exhaust fan 26 that sucks and discharges high-temperature air with an exhaust fan motor 24 is provided on the back side. The grain is dried by passing hot air through it. A control panel 28 is provided on the front side of the combustion machine 22. Further, on the front side of the dryer 2, a moisture meter 30 is provided to detect the moisture value of the grain loaded inside the dryer 2.

FIG. 2 shows the control panel 28, which includes a monitor display 32 that displays the operating status of each part of the dryer 2, a numerical display 34, an operation switch 36, and a stop switch 3.
8. A stop moisture value setting switch 40 and a grain amount setting switch 42 are provided.

FIG. 3 is a block diagram of the control circuit. In the figure, 44 is an outside air humidity sensor, 46 is an outside air temperature sensor, 48 is a hot air temperature sensor, 30 is a moisture meter,
40 is a stop moisture value setting switch, 42 is a grain amount setting switch, 36 is an operation switch, and 38 is a stop switch. Further, 50 is various safety switches.

52 is a clock transmission circuit, 54 is an A/D conversion circuit, 58 is an encoder, and 58 is a control microcomputer mainly composed of a CPU (central processing unit).

The monitor display 32 displays the operating status of the dryer. The numerical display 34 alternately digitally displays the moisture value detected by the moisture meter 30 and the hot air temperature.

60 is a burner drive circuit, and 62 is a motor drive circuit, which drive their respective loads in accordance with data output from the microcomputer 58. The burner drive circuit 60 includes an ignition heater 64, an ignition valve 66,
The pump 68 and the burner fan motor 70 are driven and controlled. The motor drive circuit 62 also includes a conveyor motor 16, a circulation motor 18, a dust remover motor 20,
The exhaust fan motor 24 and further the moisture meter motor 72 are driven and controlled.

FIG. 4 is a flowchart showing the operation of the control device.

First, when the operation switch 36 is turned on, the drying starts at 100, and the various motors 16 to 20, 24,
72 starts. Next, the burner drive circuit 60 operates to drive the ignition heater 64 to the burner fan motor 70 to ignite the combustor 22 (101).

Next, the grain moisture value M obtained by the moisture meter 30 and the stop moisture value Ms set by the stop moisture value setting switch 40 are determined.
If the stop moisture value Ms has been reached, the burner extinguisher 128 causes the burner drive circuit 60 to start the burner 2.
Take a series of actions to digest 2 and stop the motor 129
Then, the various motors are stopped by the motor drive circuit 62, and the drying is completed 130.

If the grain moisture value M has not reached the stop moisture value Ms, signals from various sensors and set values are input 103. That is, outside air humidity HD, outside air temperature Ta,
The hot air temperature Tb, grain moisture value M, stop moisture value Ms, and grain amount C are each input using a sensor, a moisture meter, a switch, etc.

Next, it is determined 104 whether a suspension flag indicating the completion of suspension operation, which will be described later, is set. If the stop operation has been completed, the grain is circulated and dried with hot air until the stop moisture value Ms is reached. That is,
If YES, the microcomputer 58 calculates 108 the set temperature Tc based on the numerical value input in step 103 above. When the calculation is completed, the sampling timer Ts is set 109, and the fuel supply pump 68 is controlled 110 so that the temperature reaches the set temperature Tc. Next, the burner fan motor 70 is controlled.
111, conveyor motor 16, exhaust fan motor 24,
Controls circulation motor 18 and dust remover motor 20 in sequence
112-115.

In addition, it is determined 116 whether the various safety switches 50 are operating, and if they are operating, the monitor display 3
Display 118 to that effect in 2 and execute the error handling routine.
Process with 119.

If the safety switch 50 is not operating,
It is determined 117 whether the sampling timer Ts has timed out. If NO, jump to pump control 110 and execute the routines 110 to 117.
If YES, the process jumps to judgment 102 as to whether the grain moisture value M has reached the stop moisture value Ms.

Determining whether the suspension flag is set
If 104 is NO and no idle operation is being performed, then
Grain moisture value M is 2~ than the set stop moisture value Ms.
Determine whether the moisture value is 3% higher than 18%105. If YES, the set temperature Tc is calculated 108 as in the previous period, and the grain is dried with hot air while being circulated. If NO, it is determined 106 whether the grain moisture value M is being measured for the first time. If YES, calculate the set temperature Tc as described above and select NO.
In this case, it is determined 107 whether the operation switch 36 has been turned on twice. In the case of NO, the set temperature Tc is calculated 108 as described above, and in the case of YES, the pause operation routine of steps 120 to 127 is executed. That is, until the grain moisture value M becomes 18% or less during the hot air drying operation, the grain is circulated and dried using hot air as described above, and when it becomes 18% or less, the halt operation described later is executed. do.

The details of the pause operation will be explained. Operation switch 36
If it is YES in judgment 107 whether it was ON twice,
That is, if the operator wishes to pause the drying operation, first the pump 68 is stopped and the combustor 22 is extinguished. Next, the burner fan motor 70 is stopped 121, and the conveyor motor 16, exhaust fan motor 24,
The circulation motor 18 is sequentially stopped 122-124. Then, in order to prevent the grain from deteriorating in quality due to stuffiness caused by the high temperature and high humidity atmosphere during the drying operation, only the dust extractor motor 20 is driven 125 to dehumidify the inside of the dryer.

During this idle operation, moisture transfer between grains reduces the moisture difference between grains. For example, pause operation is 5
When five hours have elapsed (126), a pause flag provided in the memory of the microcomputer 58 is set (127), and the process jumps to judgment (102) as to whether the grain moisture value M has reached the stop moisture value Ms.

Therefore, after the stop operation is completed, as mentioned above, if the stop moisture value Ms has been reached, the routines 128 to 130 are executed, and if it has not been reached, the routines 103, 104, 108 are executed.
Repeat the routine ~117 until the stop moisture value Ms is reached.

In this way, this invention has a predetermined moisture value of 18%, which is 2 to 3% higher than the stop moisture value set during drying operation.
When it reaches, it enters a rest operation, and only the dust extractor motor 20 is driven for a predetermined period of time to prevent moisture etc. while reducing the moisture difference between grains by tempering, until reaching the stop moisture value Ms after a predetermined period of time. Since the drying operation is performed again, when the stop moisture value Ms is reached, the moisture difference between the grains has also become smaller. For this reason,
Improves stop moisture value accuracy. Further, even during the idle operation, the dust remover motor 20 is driven to prevent quality deterioration due to stuffiness, etc., and the operating sound of the motor notifies the operator that the dust removal machine is in the idle operation, thereby ensuring safety.

Furthermore, in this example, the time to enter the suspension operation is when the moisture value of the grain reaches 18%, but the reason for this is that if the moisture value approaches the stop moisture value as drying progresses, the tempering operation will start. It is clear that this method is disadvantageous because it is less effective and takes more time to transfer moisture between grains, and on the other hand, if the moisture value is too high, there is a greater risk of stuffiness. Also, the moisture value does not need to be exactly 18%; the commonly used stopping moisture value is 15-16%.
%, it is possible to set the moisture value as a predetermined value about 2 to 3% higher than the predetermined value to enter the idle operation, and even in that case, the same effect can be obtained.

[Effects of the invention] With the above-mentioned configuration, this invention stops circulation/hot air drying for a predetermined time when the moisture value reaches a predetermined value 2 to 3% higher than the stop moisture value during drying operation. It is possible to improve the accuracy of the stop moisture value by reducing the moisture difference through moisture transfer between grains. By continuously discharging moisture to the outside of the dryer, it is possible to prevent deterioration of the grain due to stuffiness, etc. Also, by driving the ventilation mechanism, it is possible to notify workers and others that the dryer is in operation, This not only ensures safety but also prevents erroneous operations such as accidentally turning off the power switch.

[Brief explanation of drawings]

The figures show an embodiment of this invention; Fig. 1 is a side view of the dryer, Fig. 2 is an enlarged front view of the control panel, and Fig. 3 is an enlarged front view of the control panel.
FIG. 4 is a block diagram of the control circuit diagram, and FIG. 4 is a flowchart of the operation. In the figure, 2 is a dryer, 10 is a grain fryer, 12
is an upper conveyor, 14 is a lower conveyor, 16 is a conveyor motor, 18 is a circulation motor, 20 is a dust remover motor, 22 is a combustion machine, 24 is an exhaust fan motor, 26 is an exhaust fan, 30 is a moisture meter, 58 is a microcomputer.

Claims (1)

[Scope of utility model registration request] A circulation mechanism for circulating loaded grains, a hot air generation mechanism for generating hot air to dry the grains, a moisture meter for detecting the moisture value of the grains, and an exhaust fan constituting the hot air generation mechanism. In the case where the moisture value detected by the moisture meter during the drying operation reaches a predetermined value that is 20% or less and 2 to 3% higher than the set stop moisture value. At times, the circulation mechanism and the hot air generation mechanism are controlled to stop for a predetermined period of time, and at least one of the ventilation mechanisms is controlled to be driven, and after a predetermined period of time, the stop control of the circulation mechanism and the hot air generation mechanism is released. A control device for a grain dryer, comprising a control circuit that controls the drive until a set stop moisture value is reached.