JPH068475Y2 - Drying control device in grain dryer - Google Patents

Description

[Detailed Description of the Invention] Industrial field of application The present invention relates to a grain dryer for drying grains by hot air, in order to automatically stop the dryer when a preset dry finish moisture value is detected. The device of
In particular, the present invention relates to a drying control device for drying a grain in a uniform and high quality state by obtaining the magnitude of variation in water content of the grain at the start of drying and during drying.

2. Description of the Related Art Conventionally, in a grain dryer that measures the moisture content of a grain during drying at an appropriate time interval and automatically stops the dryer when a preset dry finish moisture value is detected. The drying control device is, for example, Japanese Patent Publication No. 58-23549.
It is already known as described in Japanese Patent Publication No.

Problems to be Solved by the Invention By the way, according to the grain dryer having the above-described drying control device, the moisture content of the grain is measured many times from the start to the end of the drying. Since the average moisture value is calculated for each measurement and the drying control is performed, if the moisture content of the grain to be dried is large, the variation in the moisture value of the dry grain is eliminated until the end of drying. However, it has been a problem that the quality of the dried grain is deteriorated because a large amount of insufficiently dried or overdried grains are mixed in the dried finished grain.

In view of such problems of the conventional ones, the present invention performs appropriate control according to the average moisture value of grains at the start of drying and during drying and the magnitude of variation in moisture at that time, and the grains to be dried are controlled. Even if there are large variations in water content,
It is an object of the present invention to provide a drying control device in a grain dryer that can obtain uniform and high quality dried grains.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention has a constitution in which a grain dryer for drying grains by hot air blows a sample from the grains put in the dryer at appropriate time intervals. This is a device for extracting the grain, measuring the moisture content of the grain, and stopping the dryer when a preset dry finish moisture value is detected.Measured average moisture value measured at the start of drying and during drying. , And the standard deviation, variation coefficient, and average value of the moisture value of each grain extracted at the time of measurement, or the value obtained by adding the range of variation to the average value, or the magnitude of the variation detected by the circuit that combines and calculates them appropriately. A control circuit for comparison is provided, and this control circuit is provided with a control function of restricting the hot air temperature and the moisture measurement time interval in the direction of reducing the comparison value of the variations. The present invention provides a drying control device for a grain dryer, which is characterized by being formed.

Action To dry the grain in the grain dryer, the average moisture value of the dry finish is set in advance. Then, the moisture content of the grain is measured at the start of drying and at appropriate intervals during the drying process, and when the average moisture content of the dry finish is detected, the dryer is automatically stopped and the grain drying is completed.

During the measurement of each of the moisture content, the magnitude of the variation in the average moisture value and the measured moisture value is detected, and is compared with the magnitude of the variation in the reference average moisture value and the measured moisture value, which are preset for each measurement time, Since the hot air temperature and the time interval for measuring the water content are controlled so as to reduce the variation in the measured water content with the progress of drying, the water content of the dry-finished grain becomes uniform throughout.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

The grain dryer according to the present invention circulates grains to dry them by hot air.

FIG. 1 shows a circuit configuration of a main part of a drying control device in the grain dryer. 1 is a moisture measuring circuit, 2
Is a control circuit, 3 is a reference moisture value setting circuit, 4 is a moisture measurement time setting circuit, 5 is a combustion amount control circuit, and 6 is a dryer stop circuit. The water content of the grain is measured, and the reference water content value setting circuit 3 presets the reference average water content value and the magnitude of variation in each measurement. The control circuit 2 receives the measured moisture signal from the measurement circuit 1 and the reference moisture signal from the reference moisture value setting circuit 3. Then, the two are compared, and the moisture measurement time setting circuit 4, so that the variation in the measured moisture value is successively reduced along with the progress of drying according to the variation in the measured average moisture value and the measured moisture value, The combustion amount control circuit 5 is controlled to send a stop signal to the dryer stop circuit to stop the dryer when the measured average moisture value and the variation thereof reach the set finish value. Has been done.

At each measurement, about 100 grains are extracted as sample grains,
The measured average moisture value and the amount of variation in the measured moisture value are detected from the moisture of each grain, but the amount of variation is not limited to the standard deviation, but also the coefficient of variation (standard deviation / average value) and the average value. Numerical values, etc., including the range of variation,
Numerical values obtained by appropriately combining them are used. As a mode of control during drying, when the variation is large, the hot air temperature is increased and the measurement time interval is lengthened, and as the variation decreases, the hot air temperature is sequentially decreased and the measurement time interval is shortened.

The operation mode of the above apparatus is shown in a flowchart of FIG.

FIG. 3 illustrates the result of drying the grain according to the above-mentioned embodiment. That is, compared to the large variation in water content of the grain at the start of drying, it gradually becomes smaller as the drying progresses, and even if the grain has a large variation in water content at the start of drying, at the time of the dry finish , Water content is 15
It is clear that it is uniformly dried to the extent of%.

Effect of the Invention According to the present invention, the range of variation is added to the measured average moisture value measured at the start of drying and during drying, and the standard deviation, variation coefficient, and average value of the moisture value of each grain extracted at the time of measurement. The average moisture value of the grain at the start of drying and during drying and the amount of variation in moisture at that time are compared by comparing each of these values with the amount of variation detected by the circuit that calculates them in combination. According to the present invention, appropriate control can be performed, and even if the water content of the grain to be dried has a large variation, a uniform and high-quality dried grain can be obtained.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a block diagram showing the configuration of the main part of a drying control device in a grain dryer, FIG. 2 is a flow chart showing its operation mode, and FIG. 3 is a grain drying process. It is explanatory drawing which shows a mode. 1 ... Moisture measurement circuit, 2 ... Control circuit, 3 ... Standard moisture value setting circuit, 4 ... Moisture measurement time setting circuit, 5 ... Combustion amount control circuit, 6 ... Dryer stop circuit

Claims (1)

[Scope of utility model registration request] 1. In a grain dryer for drying grains by hot air, sample grains are extracted from the grains stretched in the dryer at appropriate time intervals, and the moisture content of the sample grains is measured. A device for stopping the dryer when a value is detected, the measured average moisture value measured at the start of drying and during drying, and the standard deviation and coefficient of variation of the moisture value of each grain extracted at the time of measurement. , And a control circuit that compares the average value with the range of variation, or the magnitude of the variation detected by the circuit that appropriately combines them and calculates the comparison value of the variation in this control circuit. A drying control device for a grain dryer, which is configured to have a control function of restricting a hot air temperature and a moisture measurement time interval in a direction of decreasing.