JP2019116980A - Grain dryer - Google Patents

Abstract

To effectively carry out grain drying while controlling detection of abnormal air volume.SOLUTION: A grain dryer comprising a controller controlling the rotation speed of an air discharge member according to the volume of grain detected by a grain-volume detection member, restricts its air-volume detection member to detect air volume when the rotation speed is below a prescribed threshold, to prevent improperly stopping a drying operation thereof caused by detection of abnormal air volume by the air-volume detection member during a normal operation, and thereby can effectively carry out grain drying while controlling abnormal air volume detection.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a grain dryer for drying grain.

In the grain dryer which dries the grain after harvest, the technique of the following patent documents 1-3 is known.
Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-163603) describes a technology for controlling the number of rotations of an exhaust fan according to the decrease in grain moisture value, the ambient air humidity, and the amount of grain in a grain dryer. It is done.

According to Patent Document 2 (Japanese Patent Application Laid-Open No. 7-71876), the air flow sensor (29) detects the suction air flow of the grain drier and detects the air flow deficiency when the suction air flow is less than or equal to a predetermined value. A technique is disclosed for preventing the detection of an air volume shortage abnormality at the time of activation of the fan (12).
Patent Document 3 (Japanese Patent No. 5391560) describes a technique for burning the burner (5) with a small amount of combustion when the grain loading amount is small in the grain drier.

JP, 2011-163603, A Japanese Patent Application Laid-Open No. 7-71876 Patent No. 5391560

In the grain drier described in Patent Documents 1 and 3, the number of rotations of the exhaust fan and the amount of combustion of the burner are controlled in accordance with the amount of graining. Here, if the amount of insertion is small, the combustion amount of the burner is reduced and the rotational speed of the exhaust fan remains unchanged, the balance between the temperature and the air volume (wind speed) is bad, and there is a concern that the grain is easily broken. There is. Therefore, in order to dry the grain well, it is desirable to reduce the rotational speed of the exhaust fan when reducing the amount of combustion.
However, when the air flow rate is reduced by reducing the rotational speed of the exhaust fan, an air flow rate sensor such as that described in Patent Document 2 may detect an abnormality.

  An object of the present invention is to dry grains well while suppressing the detection of air volume abnormalities.

The object of the present invention is solved by the following solution.
The invention according to claim 1 comprises a drying chamber (5) for storing grains, an exhaust member (13a) for exhausting air in the drying chamber (5), and grains in the drying chamber (5). The grain amount detecting member (12) for detecting the amount of air, the air amount detecting member (88) for detecting the air amount of air sucked into the drying chamber (5), and the grain amount detecting member (12) A control unit (50) for controlling the number of revolutions of the air discharge member (13a) based on the amount of grain, wherein the air volume detection member (88) when the number of revolutions does not reach a predetermined threshold value And a control unit (50) for regulating the detection of the grain dryer (1).

  The invention according to claim 2 comprises a drying chamber (5) in which grains are stored, an exhaust member (13a) for exhausting air in the drying chamber (5), and suction into the drying chamber (5). And a normal mode for driving the air discharge member (13a) at a predetermined rotational speed or higher, and a predetermined air discharge member (13a). A control unit (50) for controlling the air discharge member (13a) in any one of a low rotation mode driven at a rotational speed or lower, wherein the air volume detection member (the low rotation mode is set) 88) A grain drier (1) characterized by comprising: the control section (50) for regulating the detection of (88).

  The control unit according to claim 3 controls the exhaust member (13a) in the low rotation mode when the amount of grains in the drying chamber (5) does not reach a predetermined amount. A grain drier (1) according to claim 2, characterized in that it comprises 50).

  The invention according to claim 4 is characterized in that, when the air volume detection member (88) detects an air volume abnormality in a state where the detection of the air volume detection member (88) is not restricted, the air volume abnormality is eliminated. The grain drier (1) according to any one of claims 1 to 3, further comprising the control unit (50) for increasing the rotational speed of the air discharge member (13a).

  The invention according to claim 5 relates to the presence / absence detection member (17) for detecting the presence or absence of the grain in the grain dryer (1) and the operation for drying the grain in the absence of the grain, when the operation described above is started. The grain drier according to any one of claims 1 to 4, further comprising: the control section (50) for rotating the number of revolutions of the exhaust member (13a) at a predetermined low number of revolutions. 1).

  The invention according to claim 6 comprises a presence / absence detection member (17) for detecting the presence or absence of grains in the grain drier (1), and the drying chamber (5) without grains after completion of the operation of drying the grains. And the control unit (50) for rotating the number of revolutions of the exhaust member (13a) at a predetermined high number of revolutions when performing the ventilation operation for ventilating the air without raising the temperature of A grain drier (1) according to any of the preceding claims, characterized in that

  According to the first aspect of the present invention, when controlling the number of rotations of the exhaust air member (13a) based on the amount of grain detected by the grain amount detection member (12), the number of rotations is a predetermined threshold value. If the air volume detection member (88) is not detected, the air volume detection member detects an air volume abnormality during normal operation, and the operation of the grain dryer (1) is prevented from stopping. Ru. Therefore, good grain drying can be performed while suppressing the detection of air volume abnormalities.

  According to the second aspect of the invention, when the air discharge member (13a) operates in the low rotation mode, the air amount detection member detects an air amount abnormality during normal operation by restricting the detection of the air amount detection member (88). And the grain dryer (1) is prevented from being shut down. Therefore, good grain drying can be performed while suppressing the detection of air volume abnormalities.

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, the exhaust member in the low rotation mode when the amount of grain in the drying chamber (5) does not reach a predetermined amount. By operating (13a), the drying operation can be favorably performed even in a situation where the amount of bending is small.

  According to the invention of claim 4, in addition to the effect of the invention according to any one of claims 1 to 3, the air volume detection member (88) in a state where the detection of the air volume detection member (88) is not restricted. If the air flow rate abnormality is detected, the rotation speed of the exhaust member (13a) is increased until the air flow rate abnormality is eliminated, so that it can be expected to be eliminated even if the air flow path is clogged. It can be done well.

  According to the invention of claim 5, in addition to the effect of the invention according to any one of claims 1 to 4, when starting the operation of drying the grain without the grain, the exhaust member (13a By rotating the number of revolutions of the above at a predetermined low number of revolutions, the flow rate at the time of trial operation can be suppressed, and the flame for drying can be stabilized.

  According to the invention of claim 6, in addition to the effect of the invention according to any one of claims 1 to 5, after the operation of drying the grain is completed, the temperature in the drying chamber (5) is raised without grains. When performing the ventilation operation to ventilate, the cleaning operation can be favorably performed by rotating the number of rotations of the exhaust member (13a) at a predetermined high number of rotations.

FIG. 1 is a perspective view of a grain dryer according to the present embodiment of the present invention. FIG. 2 is a view seen from the direction of arrow II of FIG. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 and shows the internal structure inside the dryer. FIG. 4 is an explanatory view of a state in which the dust collector is connected to the grain dryer in the drying equipment of the present embodiment. FIG. 5 is an explanatory view of the flow of exhaust air. FIG. 6 is an explanatory view of an operation panel of the grain dryer of the present embodiment. FIG. 7 is a block diagram showing a control mechanism of the grain dryer of the present embodiment. FIG. 8 is an explanatory diagram of a flowchart of exhaust air return control processing of the present embodiment. FIG. 9 is an explanatory diagram of a flowchart of the regulation control process of the air volume abnormality of the present embodiment.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a grain dryer according to the present embodiment of the present invention.
FIG. 2 is a view seen from the direction of arrow II of FIG.
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 and shows the internal structure inside the dryer.
In FIGS. 1 to 3, the grain drier 1 according to the present embodiment of the present invention has the storage room 2, the exhaust air room 3, the hot air room 4 and the grain collecting room 6 arranged in order from the upper side There is. And, the elevator 16 is disposed outside the wall surface of the grain dryer 1. The exhaust air chamber 3 and the hot air chamber 4 may be collectively referred to as a drying chamber 5.

A grain flow passage 9 is formed between the exhaust air chamber 3 and the hot air chamber 4, and a funnel-like grain is dropped from the upper side to the lower side, while the grain flow path 9 is dropped The kernels are dried by hot air.
Therefore, the grain in the storage chamber 2 is dried in the grain flow path 9 between the exhaust air chamber 3 and the hot air chamber 4 in the process of falling downward from the ceiling portion 10. At this time, due to the diffusion vanes (not shown) provided on the ceiling portion 10 in the storage chamber 2, the grains are spread and spread over the entire horizontal cross section in the storage chamber 2 and easily fall dry.

  The dried grains are collected at the lower end of the grain flow channel 9 and collected in the grain collecting chamber 6 via the rotary valve 38 provided at the lower end of the grain flow channel 9. The lower conveyer 39 provided at the lower part of the tray pulls out to the elevator 16 outside the grain dryer 1 and is conveyed to the ceiling 10 side of the grain dryer 1. The grain conveyed to the ceiling 10 is conveyed rearward by the upper spiral 23 disposed inside the upper spiral weir 22 provided on the ceiling 10 and dropped from the top of the storage chamber 2 and supplied.

In FIG. 1, an automatic moisture meter 17 as an example of a detection member for the presence or absence of grain is disposed at an appropriate position of the elevator 16. Furthermore, as an example of a heat source for supplying hot air to the hot air chamber 4 next to the elevator 16, for example, a combustion burner 19 or the like is provided, and a controller (control unit, control device for performing drive control of the grain dryer 1 above the heat source ) 50 is provided.
At the upper end of the elevator 16, a discharge unit 20 for discharging the dried grain to the outside is connected. A switching valve (not shown) is installed at the upper end portion of the discharge unit 20, and it is possible to switch to which of the discharge unit 20 side and the upper helical weir 22 side grain is to be sent.
In FIG. 3, the indented sensor 12 is disposed at an appropriate position in the storage chamber 2 and can appropriately detect the intruded grain amount.

FIG. 4 is an explanatory view of a state in which the dust collector is connected to the grain dryer in the drying equipment of the present embodiment.
FIG. 5 is an explanatory view of the flow of exhaust air.
In FIG. 2, FIG. 4 and FIG. 5, the exhaust part 13 is supported at the rear of the grain dryer 1. In the inside of the exhaust part 13, the exhaust fan 13a as an example of the exhaust member is arrange | positioned. The exhaust fan 13a is configured to operate by a motor (not shown), and discharges the air of the exhaust chamber 3 to the outside of the grain dryer 1.

  An exhaust duct 14 is connected to the rear of the exhaust fan 13a. An exhaust air return duct 15 as an example of an exhaust air return passage is connected to an upper portion of the exhaust air duct 14. The exhaust air return duct 15 has an upstream portion 15 a extending upward, and a downstream portion 15 b connecting the upper portion of the upstream portion 15 a and the exhaust air chamber 3. In the exhaust air duct 14, an exhaust air guide plate 60 as an example of a guide member is disposed below the upstream portion 15 a. The exhaust air guide plate 60 is formed with a plurality of through holes (not shown). Therefore, a part of the exhaust air is guided by the exhaust air guide plate 60 toward the exhaust air return duct 15, and the remaining part passes through the through hole and is sent to the downstream side of the exhaust air duct 14.

  At an upstream portion 15 a of the exhaust air return duct 15, an exhaust air adjustment valve 61 as an example of an exhaust air adjustment member is disposed. The exhaust air adjustment valve 61 is formed rotatably by a motor (not shown). Therefore, as shown in FIG. 4, the exhaust air control valve 61 closes the upstream portion 15a, and as shown in FIG. 5, the exhaust air control valve 61 enlarges the flow passage area of the upstream portion 15a. It is possible. The exhaust air control valve 61 may be configured to rotate in a predetermined stage (for example, five stages) to adjust the flow passage area, but the flow passage area is continuously (steplessly) It is also possible to make it an adjustable configuration.

In the present embodiment, at the downstream portion 15b of the exhaust air return duct 15, a return pressure sensor 62, which is an example of an air volume detection member, is installed. The return pressure sensor 62 measures the pressure (back pressure) of the air returned to the exhaust air return duct 15 to measure the amount of air returned.
In addition, it is not limited when measuring air pressure, It is also possible to measure the volume of air returned by measuring wind speed and wind pressure.

In FIG. 4, a dust collection apparatus 71 can be connected to the exhaust air duct 14. In addition, the dust collection apparatus 71 is an optional item attached according to a user's request, and may not be connected. Therefore, when the dust collection device 71 is not connected, the exhaust air duct 14 is directly connected to the outside, and the exhaust air from the exhaust air chamber 3 is directly discharged to the outside air.
The dust collector 71 of the present embodiment has a housing 72. A dust collection chamber 73 is formed in the upper part of the housing 72, and an exhaust air duct 14 is connected to the dust collection chamber 73. Below the dust collection chamber 73, a tank 74 as an example of a liquid storage unit is disposed. In the tank 74, a liquid for dust collection is stored. In the tank 74, a pump 76 for delivering a liquid is disposed. The liquid delivered by the pump 76 is sprayed to the collision plate 78 by the nozzle 77 in the dust collection chamber 73, and the liquid for dust collection diffuses in the form of a mist. Therefore, the chaff and dust contained in the exhaust air sent to the dust collection chamber 73 are absorbed by the misty liquid and removed from the exhaust air. Exhaust air from which dust and the like have been removed passes through a filter 79 installed at an exhaust port 73a formed in the upper part of the dust collection chamber 73 and is discharged to the outside.

In the present embodiment, a so-called wet dust collector is used as the dust collector 71, but the present invention is not limited to this. It is also possible to use a so-called dry dust collector, which removes dust and the like with the filter 79 without using a liquid for dust collection.
In the present embodiment, the configuration in which the dust collector 71 is connected to the grain dryer 1 is referred to as a drying facility S.

  In FIG. 4, the combustion burner 19 has a burner case 81 as an example of a housing. On the side surface of the burner case 81, a plurality of intake ports 81a for taking in air to the inside of the drying chamber 5 are formed. Inside the burner case 81, a burner main body 82 is installed. In the burner body 82, the fuel sent from the fuel pump 83 is ignited by the igniter 84 as an example of the ignition member, and air is fed from the burner blowing fan 86. The heat generated by the burner body 82 heats the drying chamber 5 by the far infrared radiator 87.

  Further, inside the burner case 81, a suction anemometer 88, which measures the wind speed of the air sucked from the suction port 81a, is installed as an example of an air volume detection member. In the present embodiment, the configuration for measuring the amount of sucked air by the wind speed is exemplified, but the present invention is not limited to this, and the configuration may also be such that the measurement is performed by the wind pressure.

FIG. 6 is an explanatory view of an operation panel of the grain dryer of the present embodiment.
In FIG. 6, in the operation panel 32 of the grain dryer 1 of the present embodiment, the grain loading button 33a, the ventilation button 33b, the drying button 33c, the discharge button 33d, and the stop button 33e are arranged in parallel. Each driving operation can be performed by ~ 33e. The hot air temperature, the moisture, and the remaining time can be displayed on the liquid crystal screen 34, and the dryer can be stopped by the emergency stop button 35.
Also, on the left side of the operation panel, it was measured with a heat recycling lamp 41a that displays the amount of recovered waste heat, a moisture dispersion lamp 41b that displays the dispersion of grain moisture based on the moisture measured with a moisture meter, and a moisture meter An immature rice lamp 41c is provided to display the immature rice mixing amount based on the water content.

  On the right side of the operation panel 32, a button 45a for transitioning to a mode for setting the drying pause time, a button 45b for transitioning to a mode for setting a timer, a button 45c for transitioning to a mode for setting the amount of indentation, a moisture amount There are provided a button 45d for shifting to a mode in which setting is performed, and an increase button 45e and a decrease button 45f for performing increase and decrease in each mode. The set values by the buttons 45 a to 45 f are displayed on the liquid crystal screen 34.

  In addition, on the right side of the operation panel 32, a grain setting button 46a for setting the kind of grain, a grain setting display lamp 46b for displaying the kind of grain being set, and a drying setting button 46c for setting the drying speed , And a drying setting display lamp 46d for displaying the drying speed during setting.

FIG. 7 is a block diagram showing a control mechanism of the grain dryer of the present embodiment.
In addition, in the functional block diagram of FIG. 7, illustration is abbreviate | omitted about the structure which is not relevant to description of this invention.
In FIG. 7, the control device 50 of the present embodiment has an input / output interface I / O that performs input / output of signals with the outside, and the like. Further, the control device 50 stores a program 47 for performing necessary processing, a ROM in which information and the like are stored, a read only memory, and a RAM 47 for temporarily storing necessary data: a memory 47 including random access memory. Have. Further, the control device 50 has a central processing unit (CPU) that performs processing according to the program stored in the memory 47. Therefore, the control device 50 of the present embodiment is configured by a small information processing device, so-called microcomputer. Therefore, the control device 50 can realize various functions by executing the program stored in the ROM or the like.

In the control device 50 of the present embodiment, detection signals of the automatic moisture meter 17, the insertion sensor 12, the return pressure sensor 62, and the suction anemometer 88, and various buttons 33 a to 33 e, 35, 45 a to 45 f, Input signals from 46a and 46c are input.
Further, the control device 50 is a control member such as the exhaust air fan 13a, the elevator 16, the combustion burner 19, the upper spiral 23, the stirring blade, the rotary valve 38, the lower spiral 39, the exhaust air control valve 61, the dust collector 71 and the like. Outputs a control signal.

  The control device 50 according to the present embodiment includes the elevator 16, the combustion burner 19, and the upper helix according to the inputs of the loading button 33a, the ventilation button 33b, the drying button 33c, the discharge button 33d, the stop button 33e, and the emergency stop button 35. 23, driving or stopping driving the diffusion blade, the exhaust air fan 13a, the rotary valve 38, the lower spiral 39 and the like to perform the penetration operation, the ventilation operation, the drying operation, the discharge operation, the operation stop, and the emergency stop.

Note that, in the squeezing operation, the grain is circulated by the spirals 23, 39 and the like and the grain is squeezed into the drying chamber 5 without operating the combustion burner 19 and the exhaust fan 13a.
In the ventilation operation, the exhaust fan 13a is operated without operating the combustion burner 19, and the respective spirals 23, 39, etc. are operated.
In the drying operation, the combustion burners 19 and the exhaust fan 13a are operated, and the respective spirals 23, 39 are operated to dry the grain.
In the discharge operation, the respective lathes 23, 39 are operated to discharge the grain from the discharge unit 20.

In addition, the control apparatus 50 of this embodiment is comprised so that a trial run (testing mode) may be selected, when the loading button 33a and the drying button 33c are simultaneously pressed as an example. The trial operation mode is basically performed to confirm whether the grain drier 1 normally operates in the absence of grain, as in the case where the combustion burner 19 or the like is replaced for maintenance. It is a mode.
In the grain dryer 1 of the present embodiment, when the drying button 33 c is input in a state where the test operation mode is selected, the controller 50 operates the combustion burner 19 with the set combustion amount if there is no grain. While performing the above operation, the drying test operation is performed to operate the exhaust fan 13 and the respective spirals 23, 39 and the like. Then, when the stop button 33 e is input, the drying trial operation is ended. The presence or absence of grains can be determined based on the detection result of the automatic moisture meter 17.

Further, the control device 50 of the present embodiment controls the exhaust air control valve 61 to use the drying chamber 5 of the grain dryer 1 as compared to the case where the dust collection device 71 is not used when the dust collection device 71 is used. Reduce the amount of exhaust air returned to the In the present embodiment, when the dust collection device 71 is connected, the exhaust air flow control valve 61 is controlled in a direction in which the one-stage flow passage area decreases as an example, as compared to the case where the dust collection device 71 is not connected. By doing this, the amount of exhaust air returned is reduced.
In addition, it is not limited to the structure which controls the opening degree of the exhaust air adjustment valve 61 as a method of reducing the amount of exhaust air returned. For example, instead of the exhaust air control valve 61, an additional fan may be installed to control the rotational speed of the additional fan to control the amount of exhaust air returned.

Further, in the present embodiment, as an example, when the dust collecting apparatus 71 is connected, it is possible to register that the dust collecting apparatus 71 is connected (dust collection mode) by an input from the operation panel 32 by the service engineer. It is configured. In addition to this, it is also possible to provide a sensor or connector for detecting that the dust collecting device 71 is connected, a switch, or to provide a button, a switch or the like for inputting when the dust collecting device 71 is mounted.
Furthermore, in the configuration in which the dust collector is provided on the upper spiral weir 22, it is desirable to reduce the sensitivity of the detection sensor of the dust collector in a situation where the dust collector 71 is attached and back pressure is applied.

Furthermore, even when the detection result of the return pressure sensor 62 reaches a predetermined threshold value (first threshold value), the control device 50 of the present embodiment controls the exhaust air control valve 61 to be returned to the grain dryer 1 Reduce the air flow.
In the dust collection mode, or when the detection result of the return pressure sensor 62 reaches the first threshold, the air volume is reduced, but the invention is not limited thereto. For example, the air volume may be reduced only in one of the cases, or the air volume may be reduced only when both are satisfied.

  Moreover, although the structure which provides the return pressure sensor 62 in the downstream part of the exhaust air return duct 15 was illustrated in this embodiment, it is not limited to this. The dust collection apparatus 71 can be installed at any position where it can measure the air pressure (back pressure) that increases when the dust collection apparatus 71 is mounted. For example, it can be provided in the exhaust air duct 14 or the drying chamber 5.

  Further, the control device 50 of the present embodiment controls the amount of combustion of the combustion burner 19 and the number of rotations of the exhaust fan 13a according to the amount of grain loading, based on the detection result of the loading sensor 12. In this embodiment, the amount of combustion and the number of rotations are controlled to increase as the amount of compression increases. For example, in the case where the amount of compression is determined in five steps as an example, the amount of combustion and the exhaust fan 13a can also be adjusted in five steps. In addition, it is also possible to constitute so that a combustion amount etc. may be adjusted by six steps or more, four steps or less, or continuously (stepless). The amount of combustion of the combustion burner 19 can be adjusted by adjusting the amount of fuel supplied from the fuel pump 83 or adjusting the amount of air blown from the burner blower fan 86.

  In the present embodiment, when the amount of grains in the drying chamber 5 does not reach a predetermined amount, the exhaust fan 13a is controlled at the lowest rotation speed (low rotation mode). Note that the amount determined in advance is, for example, when the amount of grain (the amount of entanglement) does not reach the upper end of the wall 8 that divides the exhaust air chamber 3 and the hot air chamber 4, that is, the upper end of the dividing wall 8 It is set when it comes out above the top of the grain. Therefore, at the upper end of the dividing wall 8 formed of a mesh-like member, in a situation where hot air is blown out directly from the mesh into the drying chamber 5 without touching the grain, the exhaust fan 13a is controlled at the minimum rotation speed. Ru.

  And the control apparatus 50 of this embodiment increases the rotation speed of the exhaust fan 13a compared with the case where the dust collecting device 71 is not used, when using the dust collecting device 71. FIG. As an example, when the dust collecting device 71 is connected, the number of rotations is controlled to be one step higher than when the dust collecting device 71 is not connected (the number of rotations is corrected to be one step higher). , Increase the rotational speed and increase the exhaust air volume.

In addition, the control device 50 of the present embodiment controls the rotational speed of the exhaust fan 13a to be increased also when the detection result of the return pressure sensor 62 reaches a predetermined threshold (first threshold).
Furthermore, the control device 50 of the present embodiment regulates the detection of the suction anemometer 88 when the rotational speed of the exhaust fan 13a does not reach a predetermined threshold value (second threshold value). In the present embodiment, when the number of revolutions of the exhaust fan 13a is equal to or less than the second threshold, even if the suction anemometer 88 detects an air volume abnormality, it is not treated as an air volume abnormality, and the detection result is ignored (discarded). . The detection of the air volume abnormality by the suction anemometer 88 can be regulated by any method such as stopping the power supply to the suction anemometer 88 without being limited to the case where the detection result is ignored.

The second threshold may be set, for example, to the slowest rotational speed of the first speed at the rotational speed of the exhaust fan 13a adjusted in five stages, but is not limited to this. Depending on the number of steps of the rotational speed, it is also possible to set it as 2nd speed or 3rd speed, and when the rotational speed is changed steplessly, it is also possible to set it as a numerical value predetermined by experiment etc.
In the present embodiment, for example, in the number of rotations of the exhaust fan 13a adjusted in five steps, the lowest speed 1 speed is set to the low rotation mode, and the 2nd to 5th speeds are set to the normal mode, and the amount of stretching is small. In the case where the low rotation mode (first speed) is set according to the type of grain and the user's input from the operation panel 32 as well as the case, the detection of the suction anemometer 88 is restricted. It is also possible.

Further, in the control device 50 according to the present embodiment, the detection of the suction anemometer 88 is not restricted, that is, the rotation speed of the exhaust fan 13a exceeds the second threshold (or the normal mode is set). In the situation where the suction anemometer 88 detects an air volume abnormality, the rotational speed of the exhaust fan 13a is increased until the air volume abnormality is resolved. In the present embodiment, as an example, the motor is rotated at the maximum number of rotations (five speeds). Further, the present invention is not limited to the configuration in which the exhaust fan 13a is rotated at high speed until the air volume abnormality is resolved, and the drying operation or the like may be performed when the air volume abnormality is not resolved even after a predetermined time has elapsed after starting high speed rotation. It is also possible to adopt a configuration in which the ventilation operation or the like ends in error.
Furthermore, in the control device 50 of the present embodiment, when starting the operation of drying the grain without grain (in the case of the above-mentioned test run mode), the number of rotations of the exhaust fan 13a is set to a predetermined low. Rotate at rotation speed. In this embodiment, in the test operation mode, as one example, the exhaust fan 13a is controlled to rotate in the low rotation mode (first speed).

  In the present embodiment, after the end of the drying operation, a ventilation operation (cleaning operation mode) is performed in which the drying chamber 5 is ventilated without raising the temperature in a state without grains. At this time, in the cleaning operation mode, the rotational speed of the exhaust fan 13a is rotated at a predetermined high rotational speed. In the present embodiment, in the cleaning operation mode, the exhaust fan 13a is controlled to rotate at five speeds of five stages, as an example.

(Description of the flowchart of the present embodiment)
Next, the flow of control in the grain dryer 1 of the present embodiment will be described using a flowchart, a so-called flowchart.

(Description of the flowchart of the exhaust air return control process)
FIG. 8 is an explanatory diagram of a flowchart of exhaust air return control processing of the present embodiment.
The process of each step ST of the flowchart of FIG. 8 is performed according to a program stored in the control device 50. Also, this process is performed in parallel with various other processes of the grain dryer 1.
The flowchart shown in FIG. 8 is started by turning on the power of the grain dryer 1.

In ST1 of FIG. 8, it is determined whether or not an input to start the drying operation has been made. That is, in the operation panel 32, it is determined whether or not the drying button 33c has been pressed. If the determination is yes (Y), the process proceeds to ST2, and if the determination is no (N), ST1 is repeated.
In ST2, it is determined whether or not the dust collection mode is set, that is, whether or not the dust collection device 71 is connected. If the determination is yes (Y), the process goes to ST3, and if the determination is no (N), the process goes to ST4.
In ST3, the following processes (1) and (2) are executed, and the process goes to ST6.
(1) The exhaust air control valve 61 is controlled so that the exhaust air returned to the grain dryer 1 is reduced.
(2) The exhaust fan 13a is controlled to rotate at one step high rotational speed.

In ST4, it is determined whether or not the pressure of the return pressure sensor 62 is equal to or greater than a first threshold. If the determination is yes (Y), the process goes to ST3; if the determination is no (N), the process goes to ST5.
In ST5, the following processes (1) and (2) are executed, and the process goes to ST6.
(1) The exhaust air control valve 61 is controlled so that the exhaust air returned to the grain dryer 1 has a normal amount of exhaust air.
(2) The exhaust fan 13a is controlled to rotate at the normal rotational speed (without correcting the rotational speed).
In ST6, it is determined whether the drying operation has ended. If the determination is yes (Y), the process returns to ST1, and if the determination is no (N), the process returns to ST4.

(Description of the flowchart of the regulation control process of the air volume abnormality)
FIG. 9 is an explanatory diagram of a flow chart of regulation control processing of air volume abnormality of the present embodiment.
The process of each step ST of the flowchart of FIG. 9 is performed according to a program stored in the control device 50. Also, this process is performed in parallel with various other processes of the grain dryer 1.
The flowchart shown in FIG. 9 is started by turning on the power of the grain dryer 1.

In ST11 of FIG. 9, it is determined whether or not an input to start the drying operation has been made. If the determination is yes (Y), the process proceeds to ST12, and if the determination is no (N), ST11 is repeated.
In ST12, it is determined whether or not the test operation mode is selected, that is, whether or not an input for performing the drying operation with no grain is input. If the determination is yes (Y), the process goes to ST13; if the determination is no (N), the process goes to ST15.
In ST13, the rotational speed of the exhaust fan 13a is set to a low rotational speed (first speed) for test operation. Then, the process proceeds to ST14.
In ST14, it is determined whether the drying operation (test operation mode) is finished. If the determination is yes (Y), the process proceeds to ST24, and if the determination is no (N), ST14 is repeated.

In ST15, it is determined whether or not the amount of indentation is less than or equal to the set value, that is, whether the amount of indentation is less than the amount of exposure of the upper end of the partitioned wall 8. If the determination is yes (Y), the process goes to ST16; if the determination is no (N), the process goes to ST17.
In ST16, the exhaust fan 13a is set to the low rotation mode (first speed) and controlled. Then, the process proceeds to ST19.
In ST17, the exhaust fan 13a is controlled at a rotational speed corresponding to the amount of tension. Then, the process proceeds to ST18.
In ST18, it is determined whether the rotational speed of the exhaust fan 13a is equal to or less than a second threshold. If the determination is yes (Y), the process goes to ST19; if the determination is no (N), the process goes to ST25.

In ST19, detection of the suction anemometer 88 is restricted. Then, the process proceeds to ST20.
In ST20, it is determined whether or not the drying operation has ended. If the determination is yes (Y), the process proceeds to ST21, and if the determination is no (N), ST20 is repeated.
In ST21, after the drying operation is finished, it is determined whether or not the grain is discharged and the ventilation operation (cleaning operation) is started. If the determination is yes (Y), the process proceeds to ST22, and if the determination is no (N), ST21 is repeated.
In ST22, the number of rotations of the exhaust fan 13a is set and controlled to a high number of rotations (five speeds) for cleaning. Then, the process proceeds to ST23.
In ST23, it is determined whether or not the ventilation operation has ended. If the determination is yes (Y), the process proceeds to ST24, and if the determination is no (N), ST23 is repeated.
In ST24, the exhaust fan 13a is stopped. Then, the process returns to ST11.

In ST25, it is determined whether or not an air volume abnormality (not reaching the predetermined air volume) is detected in the suction anemometer 88. If the determination is yes (Y), the process goes to ST26; if the determination is no (N), the process goes to ST28.
At ST26, the rotational speed of the exhaust fan 13a is increased. Then, the process proceeds to ST27.
In ST27, it is determined whether or not the air volume abnormality has been eliminated. If the determination is yes (Y), the process returns to ST15, and if the determination is no (N), ST27 is repeated.
In ST28, it is determined whether the drying operation has ended. If the determination is yes (Y), the process goes to ST21; if the determination is no (N), the process returns to ST15.

  In the drying facility S provided with the grain dryer 1 having the above-described configuration, part of the exhaust air is returned through the exhaust air return duct 15 during the drying operation, thereby returning the heat contained in the exhaust air to the drying chamber 5 The thermal efficiency is improved by Here, when the dust collector 71 is connected to the grain dryer 1, the resistance of the exhaust becomes higher (the exhaust gas is less likely to be discharged) as compared with the case where the dust collector 71 is not connected. Therefore, when the position of the exhaust air control valve 61 is not changed, the exhaust air does not easily flow to the dust collection device 71 side, and the amount of the exhaust air returned to the drying chamber 5 through the exhaust air return duct 15 increases. If the amount of exhaust air returned is larger than expected, the heat, moisture, dust and the like contained in the returned exhaust air may be increased more than necessary. Therefore, by returning more heat than expected, there is a possibility that problems such as condensation due to moisture, adhesion of dust, etc. may occur.

On the other hand, in the present embodiment, when the dust collector 71 is connected to the grain dryer 1, the exhaust air control valve 61 is controlled so that the amount of exhaust air returned through the exhaust air return duct 15 is reduced. Ru. Therefore, it is suppressed that the amount of returned exhaust air becomes more than necessary, and it is possible to reduce problems due to excessive return of heat, moisture, and dust.
Further, in the present embodiment, when the pressure detected by the return pressure sensor 62 reaches the first threshold value, it is determined that the amount of air returned is large, and the exhaust air adjustment valve 61 is controlled to return the exhaust air. The amount of Therefore, it is suppressed that the quantity of the returned exhaust air becomes more than necessary, and the malfunction by heat, moisture, and dust being returned excess can be reduced.

  In addition, when the dust collection device 71 is connected, when the exhaust air returned only by the exhaust air control valve 61 can not be controlled, etc., the amount of heat returned is reduced by reducing the amount of combustion of the combustion burner 19. It is also possible to control so that the total amount of heat falls within a predetermined range.

Furthermore, in the present embodiment, when the dust collector 71 is connected to the grain dryer 1, the rotational speed of the exhaust fan 13a is increased to increase the amount of air conveyed to the exhaust duct 14 side. There is. Therefore, the amount of exhaust air sent to the dust collector 71 side is increased, and a large amount of dust is sent to the dust collector 71 side, and the inside of the grain drier 1 is not increased as compared to the case where the exhaust fan 13a is not accelerated. The amount of dust is reduced rapidly. As a result, the amount of dust contained in the flowing air is reduced early, and the inflow of dust and moisture more than necessary to the drying chamber 5 through the exhaust air return duct 15 is suppressed.
Further, in the present embodiment, even when the pressure detected by the return pressure sensor 62 reaches the first threshold value, the rotational speed of the exhaust fan 13a is increased, and the amount of dust is rapidly reduced. Therefore, the inflow of dust and moisture more than necessary to the drying chamber 5 through the exhaust air return duct 15 can be suppressed.

  Furthermore, in the grain drier 1 of the present embodiment, the amount of combustion and the amount of exhaust air are balanced by controlling the amount of combustion of the combustion burner 19 and the amount of exhaust air of the exhaust fan 13a according to the amount of filling. It is suppressed that the drying capacity of the dryer 1 becomes excessive or undersized. Here, when the exhaust air volume decreases, the suction anemometer 88 can not detect the air volume, and detects an air volume abnormality. The suction anemometer 88 is originally clogged up with the dividing wall 8 or an abnormality such as clogging of the exhaust air duct 14 or the dust collecting device 71 with dust or the like, a failure occurs, and the air volume does not flow. It is a safety device for detecting abnormalities and stopping the grain dryer 1 in an emergency. In addition, when the drying facility S is newly installed or after disassembly and maintenance, etc., the exhaust duct 14 is bent, or when a part of the exhaust duct 14 uses a bellows, the bellows is twisted. Even if the air is difficult to flow due to bending or bending, it can be detected by the suction anemometer 88.

  However, when the amount of entanglement is small and the exhaust fan 13a rotates at a low speed, the grain dryer 1 is determined to be abnormal although the grain dryer 1 is operating normally, and the grain dryer 1 is stopped. And, there is a problem that the drying operation of grain is delayed. On the other hand, in the present embodiment, when the exhaust fan 13a rotates at low speed, the detection of the suction anemometer 88 is restricted. Therefore, even if the suction anemometer 88 detects an air volume abnormality despite the fact that the drying operation is being performed normally, the grain dryer 1 is prevented from stopping. Therefore, at the time of low speed rotation of the exhaust fan 13a, good grain drying can be performed while suppressing the detection of air volume abnormality.

Further, even when the low rotation mode (first speed) is set by the user's input from the operation panel 32 or the like, the grain dryer can be restrained while suppressing the air volume abnormality detection by regulating the detection of the suction anemometer 88. One can operate without stopping and good grain drying can be performed.
Furthermore, in the present embodiment, the exhaust fan 13a is rotated at low speed (first speed) when the amount of insertion is small. Therefore, in a situation where hot air is directly blown out to the drying chamber 5 without touching the grain from the mesh partition wall 8, the exhaust fan 13a is controlled at the minimum rotational speed. Therefore, a part of the dividing wall 8 excessively blows the wind and grain flies, and the flow of the wind is too uneven to suppress unevenness of grain drying, so that drying is performed even in a situation where the amount of drawing is small. It can drive well.

  Further, in the present embodiment, in a situation where the detection of the suction anemometer 88 is not restricted, when the suction anemometer 88 detects an air volume abnormality, the rotational speed of the exhaust fan 13a is increased. Therefore, when the air volume decreases due to clogging of dust and the like, the rotational speed of the exhaust fan 13a is increased to increase the exhaust air volume, thereby blowing off the clogged dust and the like and eliminating the air volume abnormality. Can be

Furthermore, in the present embodiment, the rotational speed of the exhaust fan 13a is reduced at the time of test operation. Since the trial operation is conducted without grains, the grains do not resist the flow of the wind and the wind is likely to come off. Therefore, for the combustion burner 19, the wind is likely to be too strong, and the flame becomes difficult to stabilize. Therefore, in the present embodiment, by lowering the rotational speed of the exhaust fan 13a, it is possible to improve the stability of the combustion at the time of the trial operation.
Further, in the present embodiment, the rotational speed of the exhaust fan 13a is increased during the ventilation operation (cleaning operation) after grain discharge. In the ventilation operation, since the combustion burner 19 is not burned, there is no problem even if the air volume becomes excessive, and chaff, dust and the like attached to the drying chamber 5 and the inner surface of the exhaust air duct 14 and the dividing wall 8 by high speed exhaust air. Is more likely to be blown away. In addition, condensation and the like can be easily eliminated. Thus, the drying chamber 5 and the like can be cleaned efficiently.

  In addition, in this embodiment, although the structure for registering that the dust collector 71 was connected was provided, it is not limited to this. For example, when there is no grain (at the start of filling or at the end of discharging), the exhaust air flow control valve 61 is fully opened, and when the detection value of the return pressure sensor 62 at that time is a predetermined value or more, the back pressure is It is also possible to determine that the dust collection device 71 is connected based on the judgment that it is applied. Then, the exhaust air control valve 61 is fully opened, and based on the detection value of the return pressure sensor 62 at that time, the opening degree of the exhaust air control valve 61 is adjusted such that the amount of exhaust air returned is a predetermined return amount. It is also possible to issue a correction.

  In addition, it is determined that the exhaust air duct 14 and the filter 79 of the dust collection device 71 are clogged when the exhaust air flow control valve 61 is fully opened and the detected value of the return pressure sensor 62 at that time is equal to or more than a predetermined value. It is also possible to set up an alarm. Further, for example, the detected value of the return pressure sensor 62 is compared at the start of the expansion and the end of the discharge, and the exhaust duct 14 or the like is clogged (or clogged) when the difference between the detected values is equal to or more than the predetermined value. It is also possible to have a configuration in which an alarm is issued by determining that the Furthermore, when the difference between the previous detection value and the value detected by the pressure sensor 62 is large or the threshold value is exceeded by comparing the detection value of the pressure sensor 62 at predetermined time intervals during operation without being limited to the start and end of ejection. Can be configured to issue an alarm. It is also possible not to issue an alarm immediately, but to warn when the difference from the previous detection value reaches a certain level, and to issue an alarm when the difference increases. At this time, in a situation where attention is to be paid, dust is about to be clogged up, and there is a danger of fire if maintaining a high temperature, so it is desirable to reduce the amount of combustion of the combustion burner 19.

  Furthermore, instead of fully opening the exhaust air control valve 61, the detection value of the return pressure sensor 62 in a state where the dust collection device 71 is not connected is used for each opening degree of the exhaust air control valve 61. If it is measured in advance and the detection value of the return pressure sensor 62 with no grain is higher than the value corresponding to the opening degree of the exhaust air control valve 61, it is determined that the dust collection device 71 is connected It is also possible to send an alarm or to send an alarm.

Further, in the grain dryer 1 of the present embodiment, when the drying chamber 5 becomes high temperature, the temperature of the combustion burner 19 is lowered to lower the temperature, and the exhaust air control valve 61 is fully closed. It is desirable not to return exhaust air (hot air) to the drying chamber 5.
When it is detected that the air volume is reduced due to the dust or the like being clogged, it is difficult for cold outside air to enter the drying chamber 5 and the temperature of the drying chamber 5 is likely to rise. Therefore, since it is not desirable to return the exhaust air in this state, it is desirable to make the exhaust air control valve 61 fully closed.
When the drying operation is continued with the drying chamber 5 at a high temperature or with a reduced air volume, the operation is continued at a high temperature or in a clogged (or clogged) state, so the exhaust air control valve until the end of the operation It is desirable to keep 61 closed.

  In addition, when the drying facility S of the present embodiment is newly installed or the layout is changed, the exhaust air duct 14 may be curved or bent halfway due to the layout, and the exhaust air is less likely to flow. is there. On the other hand, trial operation (in the absence of a weir) is performed to calculate the air quantity when there is a weir from the measurement air quantity of the suction anemometer 88, and it is determined whether the layout is appropriate from the ratio to the standard air quantity predetermined. It is also possible. That is, it can be seen that the flow of exhaust air is hardly impeded if it is close to the standard air volume, and the exhaust air becomes difficult to flow when it is separated from the standard air volume. For example, when the ratio to the standard air volume is 100% to 80%, it can be displayed as OK, 79% to 70% as caution, and 69% or less as NG. By displaying in this manner, the user or the service engineer can confirm whether the exhaust layout is appropriate or not, and it is possible to reduce the occurrence of trouble after the drying facility S actually starts operating.

  In addition, in the drying facility S of the present embodiment, when a predetermined period (for example, 3 months) has passed since the previous drying operation, it is identified as the first operation in the season, and the return immediately before the end of the drying operation The measured values of the pressure sensor 62 and the suction anemometer 88 are stored. Thereafter, every time the drying operation is performed, the measured value immediately before the end is stored and compared with the reference measured value. Then, when the air volume decreases by a predetermined value (for example, 30%) or more, it is desirable to determine that dust such as dust has accumulated in the exhaust duct 14 etc. and display a message prompting confirmation and cleaning on the operation panel 32 . The comparison with the reference measurement value may be the latest measurement value, or an average of multiple times (for example, three times) may be used.

  Moreover, in the grain drier 1 of this embodiment, although the drying operation, the ventilation operation, etc. were illustrated as a mode of operation, it is not limited to this. It is also possible to have a configuration having modes other than those illustrated. For example, in the drying of "buckwheat" as an example of grain, it takes time to reap, so it takes time to put it in the first step. During this time, it is desirable to ventilate in order to prevent the deterioration of the quality, but it is desirable not to increase the number of circulations because the skin is easily broken. Therefore, when the setting of the type of grain is "side", when the ventilation button 33b is pressed with the amount of pulling "0" (the amount of pulling does not reach the upper end of the dividing wall 8), until the next harvest In order to prevent steaming, it is also possible to drive only the exhaust fan 13a without circulating the grain and to have a mode in which only a wind is sent to the side. By mounting and executing this mode, it is possible to wind the whole grain because the amount of filling is smaller than the upper end of the mesh-like partitioning wall 8, and the deterioration of the embedded grain can be suppressed. Can.

  Furthermore, when the grain type is “side” and the amount of indentation is “1” (the amount of indentation is small but more than the upper end of the dividing wall 8), when the ventilation button 33b is pressed, the rotary valve 38 or It is desirable to control the rotation period and the number of rotations so that the number of rotations of the spirals 22 and 39 is reduced compared to the time of drying when the amount of tension is "2" or more. That is, since the whole grain can not be exposed to wind unless the grain is circulated as in the case of "0", the rotary valve 38 or the like is driven to circulate when the amount is "1". However, it is desirable to drive the rotary valve 38 or the like at a low speed and at a low frequency so as not to increase the number of circulations as described above. By carrying out such an operation mode, it is possible to apply wind to the whole grain, and to reduce surface breakage and to suppress deterioration of grain quality.

In addition, when controlling a rotation period, it is possible not to operate continuously but to control to circulate once every 30 minutes, for example.
In addition, when the grain is circulated at a low frequency, it is desirable to stop the rotation of the diffusion blade in order to make the diffusion blade of the ceiling portion 10 less likely to be broken. In addition to this, for example, an opening that falls toward the storage chamber 2 is formed while being sent toward the diffusion blade by the upper spiral 23, and the opening is usually closed by a shutter and sent to the diffusion blade. At the same time, when the grain is infrequently circulated, the shutter is opened, and the grain is dropped and flowed into the storage chamber 2 in front of the diffusion blade, whereby breakage of the grain due to the diffusion blade can be suppressed.

Also, even when the amount of “0” or “1” is not input from the operation panel 32, if the detection result of the insertion sensor 12 corresponds to “0” or “1”, the automatic operation is performed automatically. It is also possible to execute each operation mode.
In addition, for example, in the case of the type of grain being beer barley, barley, it is likely to be clogged in the hole of the wall 8 partitioned by the mixed straw. Therefore, if the type of grain is "beer's oats" or "barley", it is desirable that the cleaning operation be automatically performed after the drying operation. Furthermore, in the cleaning operation, it is preferable to make it easy to drop the hook caught in the hole by repeatedly turning on and off the exhaust fan 13a at predetermined time intervals (for example, about 10 seconds).

  Moreover, although the grain drier 1 of this embodiment illustrated the structure which can confirm clogging of a wind volume, the exhaust air duct 14, etc. at the time of test operation, it is not limited to this. For example, at the time of test operation, the operation panel 32 displays that there is no wrinkle based on the detection result of the automatic moisture meter 17 or opens the cleaning lid 91 below the combustion burner 19 to check the flame of the burner main body 82 It is also possible to In particular, when the cleaning lid 91 is opened, air is released from the opening where the cleaning lid 91 is installed. Therefore, it is expected that a part of the wind which has escaped to the drying chamber 5 will come out also from the part of the cleaning lid 91, and the stability of the flame of the combustion burner 19 will be improved.

  Furthermore, in the grain drier 1 of the present embodiment, during the cleaning operation, the rotation speed of the exhaust fan 13a is illustrated to be high, but it is not limited thereto. For example, in the configuration in which the dust collector is provided to the upper spiral weir 22, when performing the cleaning mode, the dust discharger is operated by providing a time for operating only the exhaust fan 13a and a period for operating only the dust collector. The duct inside the duster can also be cleaned.

  Furthermore, in the grain dryer 1 of the present embodiment, the return pressure sensor 62 and the suction anemometer 88 exemplify the configuration for measuring the pressure and the wind speed, but for example, a lever whose inclination angle changes according to the wind pressure It is also possible to use a wind pressure switch having a detection unit with which the lever contacts when the value of. When a wind pressure switch is used instead of the suction anemometer 88, the air volume becomes abnormal when the detection unit is below the detectable range, and the exhaust air fan 13a is detected until the wind pressure switch detects that the amount of stretching is more than a certain amount. The speed of rotation of the

1 grain dryer,
5 drying rooms,
12 grain amount detection members,
13a Exhaust member,
17 Presence detection member,
50 controls,
88 Air flow detection member.

Claims (6)

A drying room (5) in which the grains are stored,
An exhaust member (13a) for exhausting the air in the drying chamber (5);
A grain amount detection member (12) for detecting the amount of grain in the drying chamber (5);
An air volume detection member (88) for detecting an air volume of air drawn into the drying chamber (5);
A control unit (50) for controlling the number of revolutions of the air discharge member (13a) based on the amount of grains detected by the grain amount detection member (12), wherein the number of revolutions reaches a predetermined threshold value If not, the control unit (50) for restricting the detection of the air volume detection member (88);
A grain dryer (1) characterized in that it comprises. A drying room (5) in which the grains are stored,
An exhaust member (13a) for exhausting the air in the drying chamber (5);
An air volume detection member (88) for detecting an air volume of air drawn into the drying chamber (5);
The normal mode in which the exhaust air member (13a) is driven at a predetermined rotational speed or more, and the low rotation mode in which the exhaust air member (13a) is driven at a predetermined rotational speed or less A control unit (50) for controlling the air discharge member (13a), wherein the control unit (50) restricts the detection of the air volume detection member (88) when the low rotation mode is set;
A grain dryer (1) characterized in that it comprises. The control unit (50) for controlling the exhaust member (13a) in the low rotation mode when the amount of grain in the drying chamber (5) does not reach a predetermined amount,
Grain dryer (1) according to claim 2, characterized in that it comprises. When the air volume detection member (88) detects an air volume abnormality in a state where the detection of the air volume detection member (88) is not restricted, the number of rotations of the exhaust air member (13a) until the air volume abnormality is resolved The control unit (50) to increase
The grain drier (1) according to any one of the preceding claims, characterized in that it comprises A presence / absence detection member (17) for detecting presence / absence of grain in the grain dryer (1);
The controller (50) for rotating the number of revolutions of the exhaust member (13a) at a predetermined low number of revolutions when starting the operation of drying the grains without grains;
The grain drier (1) according to any of the preceding claims, characterized in that it comprises A presence / absence detection member (17) for detecting presence / absence of grain in the grain dryer (1);
In the case of performing a ventilation operation in which the drying chamber (5) is ventilated without raising the temperature in a grain-free state after the operation of drying the grain, the number of rotations of the exhaust member (13a) is determined in advance. The control unit (50) to rotate at a high speed of rotation;
Grain drier (1) according to any of the preceding claims, characterized in that it comprises

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