JPH0672743B2 - Combustion pause device in grain dryer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a grain dryer that dries grains with hot air from a burner.

(Prior art) This type of grain dryer stops the burning operation of the burner and performs rest drying as necessary during grain drying to eliminate moisture unevenness in the grain, thereby improving grain quality. Known are the ones intended. The rest drying time is uniform, for example, 3 hours or 6 hours.

(Problems to be solved by the invention) However, if the rest drying time is made uniform as described above, moisture unevenness is not sufficiently eliminated particularly when the mixing ratio of immature rice is large, and conventional rest drying is not possible. It turned out not to be appropriate.

Therefore, an object of the present invention is to sufficiently eliminate moisture unevenness irrespective of the mixing ratio of unripe rice and to improve grain quality.

(Means for Solving Problems) In order to achieve this object, the present invention has the following configuration.

That is, the present invention is a grain dryer having a moisture meter 20 for measuring the moisture content of grains dried with hot air from the burner 10, and based on the measured moisture value of the moisture meter 20, a variation detection for detecting variation in grain moisture content. Means C, a pause time setting means A for setting a pause time according to the detected variation, and a pause time when the moisture content measured by the moisture meter 20 reaches a predetermined value or after a predetermined time has elapsed from the start of drying. And a pause drying control means B for stopping the combustion of the burner 10 for the pause time set by the setting means A.

(Operation) Prior to the drying, the rest time setting means A sets the rest time.

When the drying is started, the variation detecting means C detects the variation of the grain moisture based on the measured moisture value of the moisture meter at a predetermined timing. The pause time setting means A sets the pause time according to the detected variation. Then, the pause drying control means B stops the combustion of the burner 10 for the set pause time, and reburns the burner 10 after the lapse of that time.

Therefore, when the mixing ratio of immature rice is high, the down time due to ventilation drying can be lengthened, and moisture unevenness can be sufficiently eliminated.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic sectional view of a grain dryer embodying the present invention. In the figure, reference numeral 1 denotes a storage chamber of a dryer, and two pairs of shed boards 2 are attached to the lower portion of the shed board so as to be inclined so that a space becomes narrower as it goes downward.
To form.

Two mesh plates 4 are connected in parallel to each lower side of the grain plate 2,
In the meantime, the drying chamber 5 is formed. Then, a hot air chamber 6 in which a burner 10 as a dry heat source is installed is formed between two inner mesh plates 4 provided near the center of the storage chamber 1, and two outer mesh plates 4 and 4 and left and right sides are formed. An exhaust chamber 8 is formed between the exhaust chamber 8 and the machine wall 7, and is connected to an exhaust fan 9 in the exhaust chamber 8.

Reference numeral 11 is a gutter-shaped grain collecting chamber, in which a lower helix 12 is installed on the bottom thereof, and the end of the lower helix 12 is connected to the lower inlet of the elevator 13. A rotary valve 14 is axially supported at the lower end outlet of the drying chamber 5, and the rotation of the rotary valve 14 causes the grains in the storage chamber 1 to flow out through the drying chamber 5 into the grain collecting chamber 11.

The upper outlet of the elevator 13 is connected to the upper helix 15 installed on the ceiling of the storage chamber 1, and the outlet of the upper helix 15 is connected to the upper chamber 15.
Peek into.

Reference numeral 20 denotes a one-grain type moisture meter for measuring the moisture content (moisture content) per grain of the grain being dried, which is installed, for example, in the grain mixing chamber 3. Reference numeral 21 is an outside air temperature sensor mounted on the machine wall for measuring the outside air temperature, and 22 is an outside air humidity sensor mounted on the machine wall 7 for measuring the outside air humidity.

23 is a grain temperature sensor installed in the grain shedding chamber 3 to measure the temperature of grains, 24 is an exhaust temperature sensor installed in the exhaust chamber 8, and 25 is a hot air temperature sensor installed in the hot air chamber 6. 26 is a burner
A fuel pump 10 supplies fuel to the burner 27, and a fuel valve 27 adjusts the fuel supplied to the burner 10.

FIG. 3 is a block diagram showing an example of the control system of the embodiment of the present invention.

In the figure, 30 is a CPU (central processing unit) in the form of a microprocessor, which controls each component by performing various calculations and judgments as will be described later by a predetermined procedure.

31 is, for example, an operation input provided with a dry button, a squeeze button, a discharge button, a stop button, a pause time setting switch for setting an initial value of the pause time, a stop moisture setting switch for setting moisture when the drying is stopped. Is a setting device,
It is connected to the CPU 30 via the input circuit 32. Also, a moisture meter 20
And each of the sensors 21 to 25 is connected to the CPU 30 via the A / D converter 33.

Reference numeral 34 denotes a display unit connected to the CPU 30 via the output circuit 35, and the display unit 34 performs various displays.

36 is a memory composed of a read-only memory (ROM) that stores control procedures for the CPU 30 to control each constituent element, and a random access memory (RAM) that temporarily stores various data such as measurement data. It is a device.

37 to 39 are output circuits connected to the CPU 30, respectively. The output circuit 37 includes a transport motor 40, a heater 41, and a moisture meter motor 42.
, The fan motor 43 is connected to the output circuit 38, and the fuel pump 26 and the fuel valve 27 are connected to the output circuit 39.
Connect.

Next, a first control example of the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG.

Now, when the dwell time is set by the dwell time setting switch and the drying button is turned on to start the drying, the target hot air temperature of the burner 10 is set according to the amount of grain stake and the outside air temperature (step S1), Ignite burner 10.

Next, the moisture content is measured by the moisture meter 20 and the initial moisture value is calculated from the measured data (step S2). Further, since the distribution of grain moisture in the initial stage of drying is as shown in, for example, FIG. 5, the variation (standard deviation) of grain moisture in the initial stage of drying is calculated based on each measurement data of the moisture meter 20 described above. (Step S3).

Based on the initial moisture value thus obtained and the variation in grain moisture at the initial stage of drying, the target hot air temperature of the burner 10 and the rest time that have been set are respectively corrected (step S4).

This correction is performed, for example, by obtaining a correction value from the table shown in FIG. 6 and based on the obtained correction value. Therefore,
As shown in FIG. 6, when the initial moisture value is as high as 25% and the variation in grain moisture in the initial stage of drying is large, the hot air temperature correction value is “−4 ° C.” and the rest time correction value is “ +4 hours "is selected, and the hot air temperature and the rest time that are currently set are corrected using the selected correction values. Therefore the burner
The rest time of 10 is set by changing the initial moisture value and the value according to the magnitude of variation in grain moisture in the initial drying period.

Then, while controlling the hot air temperature of the burner 10 so that the hot air temperature is corrected in this way, (step S5),
When the moisture value of the grain reaches a predetermined value such as 20% shown in FIG. 7 (step S6), the process shifts to rest drying (step S7).

The transition to the pause drying may be performed after a predetermined time has elapsed from the start of drying.

When the operation shifts to the idle drying, at least the burning operation of the burner 10 is stopped. Then, after the lapse of the corrected rest time, the rest drying is completed, and the burner 10 is ignited again to restart the drying. At this time, the hot air temperature of the burner 10 is returned to the initial set value and dried.

In addition, in FIG. 7, a solid line I, a broken line II, and an alternate long and short dash line III
In each of the drying curves shown in Fig. 6, the initial moisture value shown in Fig. 6 is "high".
And, the variation of initial moisture is "Large", "Medium", "Small"
In case of. According to the above control, when the initial moisture value is high and the variation in moisture is large, the hot air temperature is set lower than the set value for drying, and the rest time is set longer than the set value to stop the operation. Therefore, it is possible to improve the taste and prevent cracking of the body, and it is possible to suppress variations in water content at the end of drying.

Next, a second control example of the embodiment of the present invention will be described with reference to the flowchart of FIG.

When the dry button is pressed (step S11), the fan motor 43 of the exhaust fan 9 and the transfer motor 40 of the grain raising machine are driven (step S12) to start ventilation drying. Next, while reading the measured outside air temperature TA of the outside air temperature sensor 21,
(Step S13), outside air humidity HA measured by outside air humidity sensor 22
Is read (step S14).

When the outside air temperature TA is 25 ° C. or less (step S15) or the outside air humidity HA is 50% or more (step S16), the burner 10 is immediately ignited by hot air. Move to drying (step
S21).

On the other hand, the outside air temperature is 25 ° C or higher and the outside air humidity is 50%.
When it is less than or equal to%, the moisture value is calculated by the moisture meter 20 to calculate the moisture value (step S17). Then, the calculated moisture value M
If S is 22% or more, such as 22% (step S
18), a room temperature ventilation timer is set (step S19), ventilation is performed at room temperature without igniting the burner 10 until the set time T1 elapses (step S20), and then the burner 10 is ignited (step S21). ).

When the moisture value MS is 22% or less in step S18,
Immediately, the burner 10 is ignited to dry with hot air (step S21).

According to the above control, while the outside air temperature is high and the air is dry, and the grain moisture is high, the grain can be sufficiently dried by ventilation drying at the outside air temperature without using the burner. Energy saving can be achieved.

(Advantageous Effects of the Invention) According to the present invention, the variation in grain moisture is detected, and the pause time is set according to the variation to perform the pause drying. The unevenness of the grain can be sufficiently eliminated, and thus the grain quality can be improved.

[Brief description of drawings]

1 is a functional diagram of the present invention, FIG. 2 is a schematic sectional view of a grain dryer in which the present invention is implemented, FIG. 3 is a block diagram thereof, and FIG.
FIG. 6 is a flow chart showing a first control example of the embodiment of the present invention, FIG. 5 is a graph showing variations in grain moisture, FIG. 6 is a diagram showing a table for obtaining each correction value of hot air temperature and rest time, FIG. 7 is a graph showing a drying curve, and FIG. 8 is a flow chart showing a second control example of the embodiment of the present invention. 10 is a burner, 20 is a moisture meter, A is a pause time setting means, B is a pause drying control means, and C is a variation detecting means.

Claims (1)

[Claims] 1. A grain dryer having a moisture meter for measuring the moisture content of grains dried by hot air from a burner, and a variation detecting means for detecting variation in grain moisture content based on the measured moisture value of the moisture meter, A pause time setting means for setting a pause time according to the detected variation, and a pause time set by the pause time setting means when the moisture content measured by the moisture meter reaches a predetermined value or after a predetermined time has elapsed from the start of drying. A combustion pause device comprising: a pause drying control means for stopping combustion of the burner only.