JPH0789023B2 - Grain dryer stop moisture correction device - Google Patents

Description

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

(Prior Art) This type of grain dryer measures moisture of grain with a moisture meter during drying, and automatically dries when the measured moisture value matches a preset stop moisture value. It is known that it was stopped.

(Problems to be solved by the invention) However, even if the water content of the grain is equal to the water content value at the end immediately after the completion of drying, the water content value may be lower than the water content value at the time of stoppage due to environmental conditions such as outside air humidity and the mixing ratio of unripe rice. Moisture may return above that. Therefore, for example, the moisture value at the end of drying is 15
Even if it was%, there was a problem that it returned to 16% and calmed down after a predetermined time.

Therefore, an object of the present invention is to provide a device capable of finishing a grain to a desired moisture value regardless of environmental conditions and rice mixed with immature rice, thereby improving accuracy of finishing moisture. It is in.

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

That is, in the present invention, the moisture content of the grain dried by the hot air from the burner 10 is measured by the moisture meter 20, and when the measured moisture value matches the stopped moisture value set by the stopped moisture value setting means A, In a grain dryer having a drying end control means B for stopping the burning of the burner 10 and ending the drying, the burning of the burner 10 is stopped at a predetermined timing during the drying to perform pause drying, and after a predetermined time elapses, the burner is dried. A pause drying control means C for reburning 10 and each moisture content value measured by the moisture meter 20 at the start and end of the pause drying by the pause drying control means C, and the return of moisture content is detected from the both measured moisture content values. A stopped water content correction device comprising return detection means D and stopped water value correction means E for correcting the stopped water value set by the stopped water value setting means A in response to the return.

(Operation) First, prior to drying, the operator sets the stop moisture value with the stop moisture value setting means A.

Then, the burner 10 is ignited to start drying, and at a predetermined timing after a lapse of a predetermined time from the start, the pause drying control means C stops combustion of the burner 10 to perform pause drying, and after a lapse of a predetermined time. Reburn burner 10.

At the start and end of this pause drying, the return detection means D
Reads each measured moisture value of the moisture meter 20 and detects the return of moisture from both measured moisture values.

In response to the detected return, the stopped moisture value correction means E
The stop moisture value set by the stop moisture value setting means A is corrected.

Then, the drying is performed until the measured moisture value of the moisture meter 20 matches this corrected value, and when the measured moisture value matches, the combustion of the burner 10 is stopped and the drying is completed.

Therefore, it is possible to settle down to the stopped moisture value by utilizing the return of moisture after the completion of drying.

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 moisture meter for measuring the moisture content (moisture content) of the grain being dried, which is installed, for example, in the shed 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.

Reference numeral 31 is an operation input setting device in which, for example, a drying button, a squeeze button, a discharge button, a stop button, a stop moisture setting switch for setting moisture when stopping drying is arranged, and is connected to the CPU 30 via the input circuit 32. . Further, the moisture meter 20 and each of the sensors 21 to 25 are 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, an operation example of the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG.

First, prior to drying, the operator sets the stop moisture setting switch stop moisture value ML.

Then, when the dry button is turned on to start drying,
The target hot air temperature of the burner 10 and the like are set according to the amount of grain infiltration and the outside air temperature, and the burner 10 is ignited (step S1). Next, the burner 10 is adjusted to reach the target hot air temperature.
The hot air temperature is controlled (step S2), and the moisture content of the grain is measured by the moisture meter 20 (step S3).

Next, it is determined whether or not the measured moisture value MS is higher than the stopped moisture value ML (step S4), and if it is higher, the above-mentioned processing is repeated until the reservation or the rest time is reached (step S2 to S5).

Then, when the reservation or the rest time comes (step S5),
As shown in FIG. 5, at the pause start time t1, the measured moisture value MS1 of the moisture meter 20 is stored (step S7), the burner 10 operation is stopped, and the burner 10 is suspended (step S8). During this suspension period, at least the operation of the burner 10 is stopped and ventilation drying is performed by the exhaust fan 9, but the burner 10 and the exhaust fan 9 may be stopped simultaneously.

When such a pause is completed and re-drying is started (step S9), the burner 10 is turned on again and its hot air temperature control is performed (steps S10, S11). Further, as shown in FIG. 5, the moisture meter 20 measures the moisture at time t2 immediately after the end of the rest (step S12) to obtain the measured moisture value MS2.

Then, the measured moisture value MS2 thus obtained, and the step S
Based on the measured moisture value MS1 stored in 7, the stop moisture value ML is corrected by the following procedure to obtain the corrected stop moisture value MLS (step S13).

First, the return Δx of grain moisture during the rest period is calculated by the following equation.

Next, the magnitude of the obtained grain moisture return Δx is compared with predetermined constants x and y, and the corrected stop moisture value MLS is calculated according to the comparison result to correct the stop moisture value ML. . Table 1 shows an example of the relationship between the magnitude of the return Δx of grain moisture and the corresponding corrected stop moisture value MLS.

It should be noted that x1 and x2 in Table 1 are constants determined in advance and are assumed to have a relationship of 0 <x1 <x2.

Therefore, according to Table 1, the return of grain moisture Δx is x ≦ Δ
When x, the corrected stop moisture value MLS is MLS = ML−x1.

Then, while controlling the hot air temperature of the burner 10 (step S14), the measured moisture value MS of the moisture meter 20 is corrected to the stopped moisture value MLS.
When it reaches (step 15), the burner 10 is stopped and the drying is completed. As shown in FIG. 5, the drying end time t3
The grain moisture value at is the corrected stop moisture value MLS,
After a lapse of a predetermined time from the completion of the drying, the moisture returns to settle down to the desired moisture value, the stopped moisture value ML.

In the embodiment of the present invention, the corrected stop moisture value MLS is obtained according to the return Δx of grain moisture at the time of rest, but the outside air humidity may be extremely different between the time of rest and the end of drying, In this case, the above-mentioned control is not preferable, so it is necessary to consider the change in the outside air humidity.

Therefore, when the outside air humidity at the end of drying is significantly higher than the outside air humidity at the time of rest, the drying should be continued, while the outside air humidity at the end of drying is significantly reduced compared to the outside air humidity at the time of rest. When it is, it is configured to suppress the drying.

(Effect of the invention) As described above, in the present invention, the return of grain moisture during the rest period is obtained, and the stop moisture value is corrected according to this return, so that the measured moisture value reaches this corrected value. Drying can be performed, and after the drying is completed, the return of moisture can be used to settle down to the stopped moisture value. Therefore, in the present invention, the grain can be finished to a desired moisture value regardless of the environmental conditions and the mixing ratio of unripe rice, and thus the precision of finishing moisture 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. 5 is a flow chart showing an operation example of the embodiment of the present invention,
The figure is a graph showing an example of a drying curve. 10 is a burner, 20 is a moisture meter, A is a stopped moisture value setting means, B
Is a drying end control means, C is a pause drying control means, D is a return detection means, and E is a stopped moisture value correction means.

Claims (1)

[Claims] 1. The burner is burned when the moisture content of grains dried by hot air from the burner is measured by a moisture meter and the measured moisture value matches the stopped moisture value set by the stopped moisture value setting means. In a grain dryer having a drying end control means for stopping and ending the drying, in the drying drying control, the combustion of the burner is stopped at a predetermined timing during the drying to perform the idle drying, and the burner is reburned after a predetermined time elapses. Means, a return detection means for reading each measured moisture value of the moisture meter at the start and end of the pause drying by the pause drying control means, and detecting return of moisture from both measured moisture values, and the return detection means according to the return. A stopped moisture correction device provided with a stopped moisture value correcting means for correcting the stopped moisture value set by the stopped moisture value setting means.