JPH01200185A - Drying control device for circulating grain dryer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a method for transporting grains discharged from a drying section that dries grains supplied from a grain storage section during a conveyance path that returns the grains to the grain storage section. A moisture detection means for detecting moisture in the grain is provided, and based on detection information of the moisture detection means,
Control combustion of a burner that heats the drying air while a blower device that supplies drying air to the drying section blows air at a set air volume so that the drying speed of the grains is maintained at a set speed. The present invention relates to a drying control device for a circulating grain dryer provided with drying control means.

[Conventional technology]

This type of circulating grain dryer described above is configured to dry the grain by applying hot air while circulating the grain within the dryer.

In order to dry the grain while preventing quality defects such as shell cracking, a burner that heats the drying air is installed to detect moisture in the grain and maintain the drying speed at the set speed. The combustion is controlled.

However, in the past, in order to reduce the heat energy discharged outside the machine, in other words, to use heat energy efficiently for grain drying, the amount of air blown by the blower was adjusted from the start of drying to the grain drying process. A constant small air volume was set until the end of drying when the moisture level reached the set finish moisture level.

[Problem to be solved by the invention]

By the way, when hot air drying is performed with a small air volume, the gradient of the hot air temperature in the drying section is as shown by the solid line in Figure 7.
Compared to the temperature on the popular side heated by the burner, the temperature on the exhaust side is much lower and steeper. This is the result of heat energy being used efficiently by the grain.

Therefore, the grains passing through the exhaust side of the drying section dry more slowly than the grains passing through the exhaust side, which may result in uneven drying. Such drying unevenness can be reduced to some extent due to the fact that as the grain is circulated between the drying section and the grain storage section, the grain that previously passed through the exhaust side may pass through the popular side next time. However, there are some things that cannot be reduced sufficiently.

The present invention has been made in view of the above circumstances, and its purpose is to suppress the occurrence of uneven drying in the final stage of drying while making it possible to utilize thermal energy effectively.

[Means to solve the problem]

The characteristic configuration of the drying control device for a circulating grain dryer according to the present invention is as follows.

That is, as the moisture detected by the moisture detection means approaches the set finish moisture content within a set value, the drying control means increases the air flow rate of the air blower to a value larger than the set air flow rate. The point is that it is configured to increase.

[For production]

In other words, until the moisture content measured by the moisture detection means approaches the set finishing moisture content, the airflow rate of the blower is maintained at the set airflow rate to efficiently utilize the amount of heat generated by the burner. During drying, at the end of the drying period when the detected moisture approaches the set value for the finished moisture, the air flow rate is increased to reduce the temperature difference between the hot air side and the exhaust side in the drying section. This is to suppress the occurrence of uneven drying.

〔Effect of the invention〕

Therefore, it is possible to suppress the occurrence of uneven drying in the final stage of drying while minimizing wasteful discharge of thermal energy in the early and middle stages of drying, so thermal energy can be used efficiently for drying. However, it has now been possible to dry the grain so that the moisture in the entire grain becomes the finishing moisture.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in FIGS. 3 to 5, a grain storage section (1) having a rectangular plan view is formed in the upper part of the fuselage, and below the grain storage section (1), the grain storage section (1) is formed. Two drying passages (2) that allow the grain stored in the drying passages (2) to flow down under their own weight, and ventilation holes (3) in the wall forming each of the drying passages (2).
A drying section (5) is provided which includes a hot air introducing cylinder (4) through which hot air for drying is introduced into the drying passageway (2).

At the lower end of each of the drying passages (2), a cylindrical rotary valve (6) having a recessed groove for accommodating grains in the axial direction on the outer periphery is provided, and the rotary valve (6) allows the A lower screw conveyor (7) cross-feeds the grain taken out in a set amount at a set time from the drying passageway (2) and collects it on the side of the machine; a packet conveyor (8) that lifts the grains toward the upper side of the grain storage section (1); and a packet conveyor (8) that transports the grains to a central location above the grain storage section (1). an upper screw conveyor (9) that transports the grains laterally, and a spreading rotating body (10) that spreads and drops the grains transported by the upper screw conveyor (9) toward the inner peripheral wall of the grain storage section (1). )
and a conveying section (1) for returning the grains discharged from the drying section (5) to the grain storage section (1).
1) is formed.

As shown in FIGS. 4 and 6, the hot air introduction cylinder (4)
A burner (12) is installed inside the aircraft to heat the outside air introduced from below outside the aircraft.
) The burner (12
) A suction fan (13) that sucks and discharges the heated drying air from one end side of the drying section (5) toward the other end side.
is provided. In other words, this suction fan (13)
This corresponds to a blower device that blows drying hot air to the drying section (5).

In addition, in FIGS. 3 to 5, (14) is a fuel tank, (15) is a suction motor that rotationally drives the suction fan (13), and (16) is the packet conveyor (8).
and a conveyance motor that drives the upper screw conveyor (9), (17) a lower screw motor that drives the lower screw conveyor (7), (18) a pulp motor that drives the rotary valve (6), (19
) is a dust removal fan provided on the conveyance starting end side of the upper screw conveyor (9), (20) is its drive motor, and (21) is provided on the lower side of the packet conveyor (8). The grain to be dried is fed into the machine from this hopper (21).

Further, (S,) is a moisture meter as a moisture detection means that takes in a part of the grains transported by the packet conveyor (8) and measures its moisture, and (S2) is a moisture meter that is a moisture meter that measures the moisture content of the grains transported by the packet conveyor (8).
), a hot air temperature sensor (S3) detects the outside temperature of the burner (12), and (S4) a grain temperature sensor that detects the temperature of the grain. a sensor, the moisture meter (S,) configured to detect the temperature of grain taken into the moisture meter (S,);
S1).

Next, a control configuration for controlling the operation of the dryer configured as described above will be explained.

As shown in Figure 1, there is a grain type setting device (22) for setting and inputting the type of grain to be dried, a filling amount setting device (23) for setting and inputting the amount of grain to be dried, and a finishing device for the grain to be dried. A finishing moisture setting device (24) for setting and inputting the moisture content and a drying speed setting device (25) for setting and inputting the target drying speed per unit time are provided, and the setting information by the setting devices and the detection of the various sensors are provided. A fuel pump (2) adjusts the amount of fuel supplied to the burner (12) based on the information.
6), and also controls the suction fan motor (15).
), the conveyance motor (16), the lower screw motor (17), the pulp motor (18), and
A control device (27) using a microcomputer is provided to control the operation of each of the drive motors (20) of the dust removal fan (19).

Basically, the control device (27) controls the moisture content of the grain stored in the grain storage section (1) until the moisture content of the grain reaches the finishing moisture set and inputted by the finishing moisture setting device (24).
While blowing drying air heated by burning the burner (12) to the drying section (5) at a set air volume using the suction fan (13), the grains are transferred to the grain storage section (1).
and a drying section (5).

Then, based on various setting information and detection information of the various sensors, so as to maintain the drying speed at the set speed,
The combustion of the burner (12) and the suction fan (1
3) will be controlled.

However, the drying speed is determined based on the detection information of the moisture meter (S), and the drying speed is adjusted to the set speed based on the drying speed and the detection information of the grain temperature sensor (S4). In addition, the hot air temperature is automatically corrected so that the grain temperature is maintained below a temperature that does not cause quality defects.

In addition, in order to suppress the occurrence of uneven drying, the moisture meter (S
The moisture value detected by 1) is determined by the finishing moisture setting device (24).
At the end of the drying period when the finished moisture content approaches the set value (1%), the amount of drying air blown by the suction fan (13) is increased to a level higher than that during the previous drying period. The temperature of the hot air is increased and the temperature of the hot air is decreased.

In addition, by changing the rotation speed of the suction fan motor (15), the amount of drying air blown to the drying section (5) is changed and adjusted, and the burner ( 12) By adjusting the fuel supply amount to change the heating power, the temperature detected by the hot air temperature sensor (St) is controlled to be the set or corrected hot air temperature.

In other words, a drying control means (100) is configured that uses the control device (27) to control the combustion of the burner (12) and the operation of the suction fan (13) as a blowing device. .

Next, the operation of the control device (27) will be explained based on the flowchart shown in FIG.

First, before starting the operation of the dryer, the grain type setting device (22), the filling amount setting device (23), the finishing moisture setting device (24), and the drying speed setting device (25) are set.
By manually operating each of these, the grain type, charging amount, finished moisture content, and target drying speed are set and input as operating conditions.

Then, the grains are stored in the grain storage section (1) and the drying section (5).
) is set based on the amount of filling. Note that the circulation speed is set by adjusting the ON time per unit time during which the valve motor (18) operates in accordance with the amount of filling, and is
The relationship with time is set and stored in advance so that the circulation speed increases as the amount of filling increases.

Next, at every set time (10 minutes), the inlet air temperature sensor (S3) detects the popular temperature as the outside temperature, and sets the target hot air temperature. However, the hot air temperature corresponding to the inlet air temperature is preset and stored in correspondence with the grain type.

Further, the moisture value of the grain is detected by the moisture meter (S1) E at every set time, and the grain temperature is detected by the grain temperature sensor (S4) at every set time (10 minutes).

Then, the drying speed is determined from the difference between the two moisture values before and after measured every set time (1 hour), and the target value of the hot air temperature is corrected so that the drying speed becomes the set drying speed. . However, if the grain temperature detected by the grain temperature sensor (S4) is higher than a preset value, the hot air temperature may be corrected to lower it to prevent quality deterioration due to overheating. become.

The relationship between the drying rate and the hot air temperature and the relationship between the grain temperature and the hot air temperature are each set and stored in advance.

After setting or correcting the hot air temperature, the burner (12
) and controlling the operation of each of the motors,
Drying control will now begin.

However, after the end of drying when the moisture value detected by the moisture meter (S1) approaches within 1% of the finished moisture, in order to prevent overdrying, the outside temperature and grain temperature should be detected. In order to shorten the detection time interval so that the detection is performed every short set time (10 minutes), which is the same as the time interval, and to reduce uneven drying as described above, the rotation speed of the suction fan motor (15) is adjusted. The set value is increased from the set rotation speed set at the start of operation to increase the air flow rate to a large air volume, and the hot air temperature is adjusted so that the detected moisture value is within 1% of the finished moisture content. The set temperature is maintained at a lower value than the value before the approach.

On the other hand, the detected moisture value is 1 relative to the finished moisture.
%, the suction fan motor (1
5) The hot air temperature sensor (S2) operates at a set rotation speed corresponding to the small air volume set at the start of operation, and the hot air temperature sensor (S2) Based on the detected information, the fuel pump (26) is controlled to control combustion in the burner (12).

However, each motor other than the suction fan motor (15) rotates at a constant rate and its rotational speed is not changed.

After starting drying, every set time (1 hour or 10 minutes)
Then, it is determined whether or not the moisture value of the grain detected by the moisture meter (S1) is less than or equal to the finished moisture value set and inputted by the finished moisture setting device (24), and the detected moisture value is determined. If the moisture content is below the finishing moisture level, it is determined whether or not this condition has been detected two or more times in a row, and if the condition has been detected two or more times in a row, the fuel pump (26) is stopped and the burner is turned off. This will stop the combustion of (12).

However, after stopping combustion, until the set time has elapsed,
The operation of each motor other than the burner (12) is continued and the grain is circulated until the temperature of the drying section (5) decreases, and then each motor is stopped and the operation is stopped. Become.

In addition, if the detected moisture value is not below the finishing moisture level, and if the number of detections below the finishing moisture level does not occur two or more times in a row, the outside temperature and the grain temperature should be adjusted every set time (10 minutes) and , While detecting the moisture value of the grain at every set time (1 hour or 10 minutes), the process of controlling the rotation speed of the dust removal motor (20) and the temperature of the hot air are performed based on the detected information. Each process will be repeated.

Therefore, the process of controlling the combustion of the burner (12) and the motors of each part based on various setting information and detection information of various sensors corresponds to the drying control means (100).

[Another example]

In the above embodiment, the case is illustrated in which the blower device that blows drying air to the drying section (5) is configured as a suction fan (13) that sucks and discharges the drying air discharged from the drying section (5). However, hot air generated by the burner (12) may be blown, or outside air may be forced to be blown to the burner (12). Moreover, the burner (12)
The temperature and drying speed of the hot air may be controlled by controlling both the combustion of the air and the amount of air blown by the suction fan (13), and the specific configuration of the drying control means (100) and
The specific configuration of each part such as the blower device and the burner (12) can be changed in various ways.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the drying control device for a circulating grain dryer according to the present invention, in which Fig. 1 is a block diagram of the control configuration, Fig. 2 is a flowchart of control operation, and Fig. 3 is a longitudinal sectional front view of the dryer. , Fig. 4 is a longitudinal sectional side view of the same, Fig. 5 is a schematic front view of the same,
FIG. 6 is a cross-sectional plan view of the drying section, and FIG. 7 is an explanatory diagram of temperature distribution in the drying section.

Claims (1)

[Claims] Moisture detection means for detecting moisture in the grain during a conveyance path for returning grain discharged from a drying section (5) that dries the grain supplied from the grain storage section (1) to the grain storage section (1). (S_1) is provided, and its moisture detection means (S_1) is provided.
Based on the detection information of _1), a blower device (13) that supplies drying air to the drying section (5) is blown at a set air volume so that the drying speed of the grains is maintained at the set speed. and a burner (12) for heating the drying air.
), the drying control device for a circulating grain dryer is provided with a drying control means (100) for controlling the combustion of the moisture detecting means (S_1).
) is configured to increase the air volume of the air blower (13) to a larger air volume than the set air volume as the moisture detected by the moisture content approaches the set finish moisture level within a set value. Drying control device for circulating grain dryer.