JPH02165044A - Dry control system for grain particle drying machine - Google Patents

Abstract

PURPOSE:To judge the weight and ripening of feed grain particles as well by computing weight per particle from a volume of a grain particle and water detected as calculated by a crushing passage time and a crushing pressure when grain particles being dried are crushed by squeezing with a pair of detection rolls provided on a water sensor to control a drying machine. CONSTITUTION:A water sensor 25 is provided at the vertical center of a grain lifter 20 to detect water and a shape of a grain particle and a pair of detection rolls 26 is provided therein 25. Grain particles being dried in circulation are supplied to the detection rolls 26 one at a time to be crushed by squeezing while a water value is detected from an electric resistance value thereof to check time when the grain particles pass through detection rolls 26. At this point a crushing pressure is detected with a distortion sensor 28 mounted on a shaft 27 of the detection rolls 26. Thus, a weight per particle is computed from water and a volume of a grain particle based on a passage time, crushing pressure and grain particle water to a control a drying machine thereby enabling judgement of weights of feed grain particles and a ripening thereof as well.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a drying control method for a grain dryer.

Conventional technology In the past, the grains to be dried were put into a grain dryer, the grains were visually observed through the viewing window of the dryer to determine the amount of grains, and the hot air temperature, etc. This is a drying control method in which the grains are dried by being exposed to hot air, and the moisture sensor installed in this dryer detects only the moisture content of the grains to control the drying.

Problem to be Solved by the Invention Grain is loaded into a grain dryer, and the amount of loaded grain is visually detected through a viewing window provided on the wall of the dryer. The hot air temperature is set according to the grain content,
The grains that are repeatedly circulated in the dryer are exposed to the set hot air and dried.

Also, during this drying, grain moisture is detected by a moisture sensor, and if this moisture sensor detects the same grain moisture as the finishing target moisture, the dryer is automatically stopped and drying of the grains is stopped.

At the time of drying, the weight of a single grain or the total weight of the whole grain can be detected without using a scale to measure the weight of the grain. The method for detecting the weight of loaded grains can be made inexpensive, and the amount of water removed from grains and the amount of dust removed can be reduced!
! This is intended to control the amount of suction and discharge of dust by detecting the amount of dust and controlling the dust removal device that sucks and discharges the dust.

Means for Solving the Problems Regarding the Invention of Claim 1 This invention is directed to crushing drying grains between a pair of detection rolls provided in a moisture sensor.During this crushing, grains are crushed between the detection rolls. The weight per grain is calculated from the time it takes for the grain to pass while being crushed, the volume of the grain calculated from the crushing pressure, and the density of the grain itself, calculated from the moisture content of the grain detected during drying. A drying control system for a grain dryer is configured as follows.

Effects of the Invention The loaded grains loaded into the grain dryer are exposed to hot air and dried while being repeatedly circulated through the dryer.

Some of the grains during this circulation drying are supplied one by one between a pair of detection rolls of the moisture sensor, and the supplied grains are sequentially crushed under pressure between the detection rolls. At the same time, the water content of the crushed grains is detected, and the passing time during which the grains pass while being crushed between the detection rolls during this crushing and the crushing pressure during this crushing are detected. The volume of the grain is calculated from the time and the detected crushing pressure, the density of the grain itself is calculated from the detected moisture, and the weight per grain is calculated from this volume and the density of the grain itself. Detected.

Effects of the Invention According to the present invention, the weight per grain can be easily calculated from the grain density calculated from the grain moisture detected by the moisture sensor and the grain volume. It is possible to accurately detect the weight of grains, and it is also easy to judge the grain content, making it easy to predict the yield.

Means for Solving the Problems Regarding the Invention of Claim 2 This invention provides a volume of packed grains calculated based on the wind pressure in a storage chamber for storing grains and the wind pressure on the hot air blowing side of a drying chamber for hot air drying. and the grain density calculated from the moisture content, volume, and weight of the grains detected by crushing the grains between a pair of detection rolls, and calculating the weight of the loaded grains in the storage chamber. The structure of the drying control system of the grain dryer is as follows.

Effect of the Invention The grains loaded into the storage chamber of the grain dryer are exposed to hot air and dried while being repeatedly circulated downward from the storage chamber into the drying chamber.

The setting of the hot air temperature at the start of drying is such that some of the circulating grains are supplied one by one between a pair of detection rolls of the moisture sensor; At the same time, the moisture content of the crushed grains is detected as they are successively crushed under pressure, and the passage time during which the grains pass between the detection rolls while being crushed, as well as the crushing pressure during this crushing. is detected, the shape of the grain is calculated from this detected passage time and this crushing pressure, and from this calculated shape, the grain volume per grain and the grain density in the temporary storage chamber are calculated based on this volume. be done.

In addition, the density of the grain itself is calculated based on the detected moisture,
The average weight per grain is calculated from the grain volume and the density of the grain itself.

The grain density in the temporary storage chamber obtained from this grain volume is grain -
It is corrected by the average weight per grain and, for example, a set and memorized coefficient, and is calculated as the average grain/density of the grains loaded into the storage chamber.

Also, at the same time as the wind pressure in the storage chamber is detected, the wind pressure on the hot air blowing side of the drying chamber is detected, and the volume of the loaded grain is calculated based on each of these detected wind pressures, and this calculated volume and the obtained result from the above are calculated. For example, the hot air temperature is set based on the loaded grain weight obtained by this calculation, and the set hot air temperature is calculated based on the calculated average grain density. The temperature dries the grain.

Effects of the Invention According to the present invention, the weight of the loaded grain is automatically calculated based on the average grain density and volume of the loaded grain.
When discharging dried grains from the machine and packing them into bags, it is convenient to be able to predict the number of bags in advance.Also, by setting the hot air temperature according to the weight, the hot air temperature will change as the weight decreases due to moisture. is controlled, and therefore stable drying of grains can be obtained.

Means for Solving the Problems Regarding the Invention of Claim 3 This invention provides a virtual loaded grain weight calculated by crushing drying grains between a pair of detection rolls for detecting moisture, and a storage chamber. , the volume of the loaded grain calculated based on the wind pressure on the hot air blowing side of the drying window, and the total loaded grain weight calculated based on the grain density of this loaded grain. A drying control system for a grain dryer is configured to calculate the amount of water removed from grains and the amount of dust removed.

Effect of the Invention The grains loaded into the storage chamber of the grain dryer are exposed to hot air and dried while being repeatedly circulated downward from the storage chamber into the drying chamber.

Some of the grains undergoing this circulation drying are supplied one by one between a pair of detection rolls of the moisture sensor at predetermined time intervals, and the supplied grains are successively sandwiched between the detection rolls. At the same time as the crushed grains are crushed, the moisture content of the crushed grains is detected.
Also, at the time of this moisture detection, the grain density and the weight per grain are calculated from the grain volume, and the virtual piling weight during drying is calculated from the calculated single grain weight and the number of grains during drying. is calculated,
The amount of water removed is calculated based on the amount of change between this time and the previous time in the virtual loaded grain weight obtained by this calculation.

Also, at the same time as the wind pressure in the storage chamber is detected, the wind pressure on the hot air blowing side of the drying chamber is detected, and the volume of the loaded grain is calculated based on each of these detected wind pressures, and this calculated volume and the obtained result from the above are calculated. The total pitched grain weight is calculated based on the grain density obtained above, and the total dust amount is calculated from this total pitched grain weight and the virtual pitched grain weight obtained above. The amount of dust removed is calculated from the obtained amount of water removed, and the amount of water removed from the grains being dried and the amount of dust removed from the grains being dried are calculated.
For example, the amount of dust to be suctioned and discharged is controlled by controlling a dust removal device that sucks and discharges dust based on the amount of dust to be removed.

Effects of the Invention According to the present invention, by automatically detecting both the amount of water removed from grains and the amount of dust removed during drying, dust mixed into grains during drying can be reliably removed. This makes the post-hulling work easier.

Example In the case of rotation, (1) is a grain dryer, and the machine wall (2) of this dryer (1) has a rectangular shape that is long in the front and back direction, and consists of one front and rear wall plate and a left and right wall plate. The front wall board is equipped with a burner case (5) containing an operating device (3) for starting and stopping the dryer (1) and a burner (4), and the rear wall board is equipped with an air exhaust system. 42 (6) and motor (
7).

A grain collection gutter (8) is provided in the center of the lower part of the inside of the machine wall (2) in the front-rear direction and is equipped with a transfer spiral, and above the grain collection gutter (8) there is a drying chamber ( 9) are arranged in parallel and communicated with each other, and a feed valve (10) is installed in the lower part of the drying chamber (9) to feed and flow down the grains by rotation. forms a hot air chamber (11), this hot air chamber (11) and the burner (4) are configured to communicate with each other, and the hot air chamber (11) is connected to the machine wall (2).
The structure includes a hot air temperature sensor (12) that detects the hot air temperature inside the air, and a wind pressure sensor (13) that detects the wind pressure.
A ventilation chamber (14) is formed outside each of the drying chambers (9), and each of the ventilation chambers (14) and the ventilation fan (6) are configured to communicate with each other, and the motor (7) The transfer spiral, each delivery valve (lO), the exhaust fan (6), etc. are rotationally driven.

A storage chamber (15) is formed above each drying chamber (9) and is communicated with the machine wall (2) forming this storage chamber (15).
is equipped with a wind pressure sensor (16) that detects the wind pressure inside this storage chamber (15), and a ceiling plate (
17) and a transfer gutter (18) equipped with a transfer spiral;
In the central part of this transfer gutter (1 day), the transferred grain is stored in this storage chamber (1 day).
15) Provide a supply port for supplying into the storage chamber (15), provide a diffusion 1 (19) below this supply port, and use this diffusion plate (18) to uniformly diffuse and return grains into the storage chamber (15). The configuration is
Above the starting end of the transfer gutter (18) is a dust removal device (47) and a variable speed motor (47) for driving the dust removal device (47) in variable speed rotation.
46) is provided, and the dust mixed in the grains is sucked up and discharged to the outside of the machine by the rotation of this dust removal device (47).

The grain raising machine (20) is installed in front of the front wall plate, and inside the packet conveyor (21) belt is stretched between the upper and lower pulleys, and between the upper end and the starting end of the transfer gutter (18). A dispensing pipe (22) is provided and communicated with the lower end and the grain collection gutter (8).
A supply gutter (23) is provided to communicate with the terminal end, and a motor (24) is installed above the grain hoist 41 (20).
), and this motor (24) drives the packet conveyor (
21) It is configured to rotationally drive the belt, the transfer spiral in the transfer gutter (18), the diffusion plate (18), etc.

A moisture sensor (25) for detecting the moisture content and shape of grains is provided in the vertical center of the grain raising machine (20), and a pair of detection rolls (26) are provided within the moisture sensor (25).
The grains supplied between the detection rolls (26) are crushed one by one under pressure, and at the same time, the moisture value is detected based on the electrical resistance value detected during the crushing of the grains. In addition, during this crushing, the passage time during which the grains pass between the detection rolls (28) is detected, and during this crushing, each of the detection rolls (2B) mounted on a shaft is detected. The strain in the detection roll shaft (27) is detected by a strain sensor (2B) based on an electrical resistance value, and the crushing pressure is detected based on this detected resistance value, and the detected passage time, crushing pressure, and grains are The shape of the grain is detected by moisture, and the moisture sensor (25) is equipped with a motor (28), and each part of the moisture sensor (25) is rotationally driven by the motor (29). It is.

A fuel pump (30) having a fuel valve is provided on the outer side of the lower plate of the burner case (5), and when the fuel valve is opened or closed, the fuel pump (30) sucks the fuel in the fuel tank (31) to supply the burner. (4), and a configuration in which a blower (32) for blowing combustion air commensurate with the amount of fuel to be supplied and a motor (33) for rotationally driving this blower (32) are installed on the outside of the upper plate. It is.

The operating device (3) is box-shaped, and the surface plate of the box has a start switch (34) that is operated to start the drying IN (1), drying and discharge operations separately, and a stop switch (34) that is operated to stop the drying IN (1). A switch (35), a grain type setting switch (38) in which a part of the reference temperature of the hot air generated from the bar (4) is set depending on the operating position, and a moisture setting switch (38) in which the finishing target moisture is set depending on the operating position. Komori (37), detected moisture detected by the moisture sensor (25), detected hot air temperature detected by the hot air temperature sensor (12), detected loaded grain weight, detected water removed amount, detected dust removed amount, and The structure is equipped with a display window (38) and a monitor display for displaying the remaining drying time, etc., and a drying amount'S device (38) and a hot air control device (40) are installed inside. Setting Komi (3)
13) and (37) are of the rotary switch type, and are configured to set a predetermined numerical value depending on the operating position.

The drying control device! (39) represents each of the wind pressure sensors (13
), (ie) A-, in which the detected values detected by the moisture sensor (25) and the strain sensor (28) are A-D converted.
A D converter (41), an input circuit (42) into which the converted value converted by the A-D converter (41) is input, the respective switches (34) and (35), and the moisture setting knob (37). ), an input circuit (43) into which operations are input; a CPU (44) which performs arithmetic and logical operations, comparison operations, etc. on various input values input from these input circuits (42) and (43);
The configuration includes an output circuit (45) that receives various commands from the CPU (44) and outputs them.

The hot air control device (40) includes the hot air temperature sensor (1
2) an A-to-D converter into which the detected value is A-to-D converted; an input circuit into which the converted value to be converted by the A-D converter is input; and operation of the grain type setting knob (38). an input circuit into which is input, and the CPU which performs arithmetic and logical operations, comparison operations, etc. on various input values input from these input circuits.
(44) This configuration includes an output circuit that receives and outputs various commands from the CPU (44).

The drying control and the grain amount control by the drying control device (39) mean that the moisture sensor (25) controls the moisture content of the grains to be the same as the finishing target moisture set by operating the moisture setting knob (37). When detected, the drying control device (38) automatically controls and automatically stops the dryer (1), and the weight of each grain loaded into the dryer (1) is The drying control device (3S) is configured to detect the total grain weight, the number of grains, the amount of water removed from the grains during drying, and the amount of dust removed.

The moisture sensor (25) detects the weight per grain.
The structure is such that the shape of the grain is detected by the detected moisture detected by the sensor, the detected crushing pressure, and the detected passing time. The time taken for a grain to pass between the detection rolls (28) while being crushed is detected, and the length of the grain is set according to the detected passing time, and the setting is stored in the CPU (44). .

For example, if the detection passing time is 2.0 seconds, the length of the grain is detected to be 4.0 mm from the set memory value, and the detection in the width direction of the grain is for each moisture value. As shown in Fig. 2, the width of the grain is set and stored in the CPU (44) according to each crushing pressure, and the detected pressure is
V, and when the detected moisture value is 20%, the width of the grain is detected as 1.8 cm from the set memory value, and the volume of the grain ( VA) is detected by setting the grain volume (VA) according to grain length and width as shown in Fig. 3 and storing it in u CPU (44). The detection length of is 4.0■,
When the detection width is 1.8■, the grain body m is determined from the set memory value.
(VA) is detected to be 0.045 mm'.

The density of the grain itself (1110) is set as shown in FIG. 4 according to the detected grain moisture and grain type, and the CPU
(44), and if the type of grain is paddy and the grain moisture is 20%, the density (xO) of the grain itself is 1.2 g/mts from the set stored value. The detected grain-grain volume (VA) and the density of the grain itself (MO) are substituted into the following formula set and stored in the CPU (44) to determine the grain size. - This is a configuration in which the weight per grain (WA) is calculated, where: Grain - Weight per grain (WA) = Volume of one grain (VA
) X Density of the grain itself (NO) For example, detected grain -
If the grain body Mi (VA) is 0.045 mm'' and the density (MO) of the grain itself is 1.2 g/m♂, when this is substituted into the above formula and calculated, the grain - grain Weight per unit (WA) = 0.045 x 1.2 = 0.0
54g.

The whole weight (WB) of the loaded grain is detected by the CPU (44), as shown in FIG. If the grain detection length is 4.0 mm and the detection width is 1.81 mm, then the grain volume (V
A) is 0.045 mm', and this grain body a (VA
) Separately, a provisional grain density (MA) is set as shown in Fig. 5 and stored in the CPU (44), and if the grain-to-grain volume (VA) is, for example, 0.045 mm', If so, the tentative grain density (MA) is [100Kg/♂] from the set memory value.
The temporary grain density (MA) detected by the following formula set and stored in the CPU (44) is configured to be detected as being present.
and the grains detected above - the weight per grain (WA) and a fixed value correction coefficient (M) 1. Density (MB)
is calculated, and the grain density of the entire grain (MB) = tentative grain density (MA)
X - weight per grain (WA) , the whole grain weight (WB) is detected based on this grain density (MB) and the body a (VB) of the whole grain that has been tensioned.

The volume (VB) of the entire packed grain is detected by the wind pressure (Pin) in the hot air chamber (11) detected by the wind pressure sensor (13) and the storage volume detected by the wind pressure sensor (1G). The wind pressure (P roof) in the chamber (15) is
The configuration is such that the wind pressure ratio (SA) is calculated by substituting it into the following formula whose settings are stored in the PU (44).
= Wind pressure (P roof) / Wind pressure (Pin) For example, if the detected wind pressure (Pin) is 20.5 mmAq and the detected wind pressure (ProoD is 9.0+smAq), the wind pressure ratio (SA) = 9.0 /20. 5 = 0.44, and the body a (VB) of the entire grain is set for each wind pressure ratio (SA) as shown in Figure 6, and the CPU
(44), and the detected wind pressure ratio (SA)
is 0.44, the volume of the entire grain (
VE) is a configuration detected as 4+a'.

Detection of the weight of the whole grain (IIB) is carried out according to the above C.
The grain density (MB) of the entire grain detected above and the body m (V
B) is calculated by substituting: Weight of the whole grain (WB) = Density of the whole grain (MB)
Volume of whole grain (VB) For example, density of whole grain (MB) is 820Kg/I11
', and the volume of the whole grain (VB) is 411111, the weight of the whole grain (WB) = 820 x 4
= 2480Kg, and the total weight (WS) of the grains stuffed into the storage chamber (15) is detected as 2480Kg.

The weight of moisture (Y) and the weight of dust (Z) of grains are detected by comparing the weight per grain (WA) detected at the start of drying and the weight (WA) of grains as drying progresses. Grain detected in - Amount of change in weight per grain (wC) and number of grains (N)
The grain-per-grain weight (WA) detected at the start of drying and the total grain weight (B) are stored in the CPU (44) as shown below. The structure is such that the number of grains (N) is calculated by substituting it into the formula,
Number of grains (N) = Total weight of grains (WB) / Weight per grain (WA) For example, if the grain - weight per grain (WA) is 0.054 g, the total weight of grains If the weight (WB) is 2480 kg, the number of grains (N) is calculated as 45,925,925 grains, and the grain-weight per grain (WC) 5 hours after the start of drying is 0. .048g, the change in total grain weight (WB) is 45,825,
Calculated as 925 grains x 0.048g = 2204Kg,
Total weight at the start of drying Fl (WB) 2480Kg
,! :, the weight changed from the overall weight (WB) 2204Kg after 5 hours is calculated as 276Kg, and this 278K
This is a configuration in which g is detected to be the amount of water removed from the grain ft (Y).

To detect the dust removal weight (Z), for example, if the wind pressure ratio (SA) calculated 5 hours after the start of drying is 0.55, the volume of the whole packed grain (VB) is calculated from Fig. 6 above. 3.4♂ was detected, and at the same time, the grain density (MB) of the whole grain was tentatively detected grain density (MA), detection - weight per grain (WA)
) and correction coefficient (M), and the grain density (NB) obtained by this calculation is calculated to be 622Kg/mJ, these grain density (MB) 822Kg/mJ and volume (
VB) 3.4♂, the change in overall weight (WB) is calculated as 622Kg/m'X 3.4m'= 2115Kg, and the overall weight (WB) at the start of drying is 2480
The total weight changed from Kg and the total weight after 5 hours, f12115Kg, is calculated as 365Kg, and this 3ft5Kg is the dust removal weight (Z), water removal weight (Y), and the weight of crushed grains crushed for moisture detection. If the number of grains crushed during 5 hours is 2,500 grains, then these 2,500 grains and grains - weight per grain (-G) 0.
048g, the crushed grain weight is calculated to be 120g, and the breakdown of the changed weight of 365Kg is the amount of water removed, 51 (Y) is 276Kg, and the weight of dust removed (Z) is 88.880Kg.
The crushed grain weight is calculated as 120g, and the amount of water removed and the amount of dust removed, etc. are detected.The detected dust removal weight (Z) is calculated per hour, and at this time, the If the dust removal weight of is outside the predetermined weight range, the drying control device (38) controls the rotation of the variable speed motor (4B) to variable speed rotation, and the rotation of the dust removal device 1 (4?) is controlled to variable speed rotation. The structure is such that the weight of dust sucked and discharged by this dust removal device (47) is controlled to be within a predetermined range.

The hot air control by the hot air control device (40) is performed based on the detected hot air temperature detected by the hot air temperature sensor (12), the operation position of the grain type setting arc (36), and the detected grain type setting arc (36). The overall weight (WB) of the fuel pump is compared with the set hot air temperature set by 30), the amount of fuel sucked in and supplied to the burner (4) is controlled.

Hereinafter, the operation of the above embodiment will be explained.

Operate each setting knob (38), (37) of the operating device (3) to a predetermined position, and press the start switch (34) to start the drying work.
), the grain dryer (1) and the moisture sensor (25) are started, and the moisture sensor (25) detects the moisture content, volume, and weight per grain of the grain, and the grain dryer (1) and moisture sensor (25) are started. The grain density (Me) of the entire grain is detected, while each wind pressure sensor (13), (1B) detects the hot air chamber (11) and storage chamber (1).
5) The wind pressure is detected and the wind pressure ratio (SA) is calculated,
By this wind pressure ratio (SA), the volume of the entire loaded grain (VB)
is calculated, and these grain density (MB) and field ffl (V
B), the weight (WB) of the entire loaded grain is calculated, and the hot air temperature is set based on this weight (WB) of the entire loaded grain and the operation position of the grain type setting knob (36). ,
This set hot air temperature is generated from the burner (4), and this hot air is passed from the hot air chamber (11) across the drying chamber (9), passes through the exhaust chamber (14), and is sucked and exhausted by the exhaust fan (6). As a result, the grains accommodated in the drying chamber (1) are exposed to this hot air while flowing down from the storage chamber (15) into the drying chamber (9) and are dried. ) and flow down to the lower part and supplied into the grain collection gutter (8), and from this grain collection gutter (8) via the supply gutter (23), it is transferred to the grain raising * (20) by the lower transfer spiral. Packet conveyor (2
1) and is conveyed to the upper part through the dispensing tube (22) and into the transfer gutter (1).
8), and is transferred and supplied to the diffusion plate (19) by a transfer spiral in this transfer gutter (18), and is supplied onto the diffusion plate (19).
The moisture senna (25) is evenly diffused and reduced into the storage chamber (15), circulated and dried, and the moisture senna (25) is spread to the moisture setting (37).
When the dryer (1) is automatically stopped under automatic control by the drying control device (39) of the operating device (3) when the same grain moisture as the finishing target moisture is detected by operating the dryer (1).

During this drying work, the water removed weight (Y) of grain water and the dust removed weight (Z) are detected, and if the removed dust weight (Z) is outside the predetermined weight range, the dust removal device (47) The variable speed motor (46) that rotationally drives the M (
Since the amount of dust to be sucked and discharged in step 47) is not controlled within a predetermined weight range, the grains are dried.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a block diagram, Fig. 2 shows grain width differences depending on crushing pressure and grain moisture, and Fig. 3 shows grain widths and grain lengths. Grain volume diagram, Figure 4 is a diagram of the relationship between grain moisture and the density of the grain itself, Figure 5 is a diagram of the relationship between grain-grain volume and grain density, and Figure 6 is a diagram of the relationship between grain-to-grain volume and grain density. Figure 7 is an overall side view of the dryer that can be partially cut away, Figure 8 is a sectional view taken along line A-A in Figure 7,
Fig. 9 is a partially cutaway front view of a part of the dryer, and Fig. 10 is an enlarged side sectional view of a part of the moisture sensor.
1) is a grain dryer, (13) and (16) are wind pressure sensors,
(25) is a moisture sensor, (26) is a detection roll, (47
) indicates a dust removal device.

Claims (1)

[Scope of Claims] 1. Grain being dried is crushed between a pair of detection rolls provided in a moisture sensor, and the passing time during which the grain passes between the detection rolls while being crushed during this crushing; A grain dryer characterized in that the weight per grain is calculated from the volume of grain calculated by crushing pressure and the density of the grain itself calculated by grain moisture detected during drying. Drying control method. 2. The volume of the loaded grains is calculated based on the wind pressure in the storage chamber where the grains are stored and the wind pressure on the hot air blowing side of the hot air drying chamber, and the grains are compressed and crushed between a pair of detection rolls. A drying control method for a grain dryer, characterized in that the weight of loaded grains in the storage chamber is calculated from the grain density calculated from the detected grain moisture, volume, and weight. 3 Calculated based on the virtual loaded grain weight calculated by compressing and crushing the drying grain between a pair of detection rolls that detect moisture, the wind pressure in the storage chamber, and the wind pressure on the hot air blowing side of the drying room. The amount of water removed from the grain and the amount of dust removed are calculated based on the volume of the loaded grain and the total weight of loaded grain calculated based on the grain density of the loaded grain. Drying control method for grain dryers.