JPH08226760A - Cereal drying device - Google Patents

Abstract

PURPOSE: To reduce the temperature of hot blast for drying and to perform rapid drying without widely increasing a cereals temperature by executing drying of cereals in such a way that the feed of air to a drying chamber where cereals are stored and dried and exhaust of gas from the drying chamber are adjusted, the interior of the drying chamber is kept in a pressure reduction state in a specified range from an atmospheric pressure. CONSTITUTION: A drying device is provided in a drying chamber A with a drying part, a conveyance part, and a burner 3 serving as a drying heat source, and a feed output port part 4, a blower, and a suction fan 6 are arranged. The output of a suction fan 6 to discharge air in the drying chamber A is increased to a value higher than the output of the blower to input air for drying in the drying chamber A. The interior of the drying chamber A under drying operation is maintained in a pressure reduction state wherein a pressure in the drying chamber is reduced from an atmospheric pressure by approximate 5-20 g/cm<2> (50-200mm water column). Thereby, since a moisture content is more apt to vaporize from cereals compared with an atmospheric pressure state, drying is executed in such a state that a hot blast temperature is kept at 40 deg.C or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grain drying apparatus.

[0002]

2. Description of the Related Art Grains such as rice are used for long-term storage.
It is necessary to dry the water to about 15% or less, and various drying means have been proposed. Specifically, hot air drying means, vacuum drying means, and reduced pressure drying means are known. The hot air drying means blows hot air to the grain to dry it, the vacuum drying means places the drying chamber in a vacuum state to promote evaporation of water at a low temperature, and the reduced pressure drying means is Japanese Patent Publication No. 60- As disclosed in Japanese Patent No. 12544, the indoor air is forcibly discharged from a closed drying chamber to reduce the pressure to dry the air.

[0003]

Each of the above-mentioned conventional drying means has advantages and disadvantages. That is, in hot air drying, the temperature of the grain to be dried rises too much, causing thermal denaturation of the grain itself, leading to deterioration of the grain quality. Further, the vacuum drying and the conventional reduced-pressure drying must have a closed drying chamber, which requires a large investment in equipment, and the degree of drying depends on the degree of vacuum. Therefore, the present invention proposes an efficient drying device at a grain temperature that does not cause heat denaturation.

[0004]

A grain drying apparatus according to the present invention is provided with a suitable drying heat source, and comprises a drying chamber for storing and drying grains and a suction fan for exhausting air from the drying chamber. In the grain drying device, the hot air from the drying heat source is set to 40 ° C or less, and an air inlet control mechanism or blower to the drying chamber is provided, and the amount of air introduced into the drying chamber is controlled or the suction fan output. Is larger than the blower output, and the inside of the drying chamber is 5 to 20 g / c above atmospheric pressure.
It is characterized in that a reduced pressure state of about m ² (50 to 200 mm water column) is maintained.

[0005]

The grain in the drying chamber is dried by the hot air from the heating source installed in the drying chamber, and the air containing the moisture from the grain is discharged outside the drying chamber by the suction fan. Therefore, the grain in the drying chamber is dried by operating the drying device for a predetermined time. In particular, since the amount of air introduced into the drying chamber is controlled by the air inlet control mechanism, or the depressurized state is maintained in the drying chamber due to the output difference between the blower and the suction fan, the moisture content is higher than that in the normal atmospheric pressure state. Because evaporation is accelerated,
The temperature of the hot air for drying in the drying chamber can be lower than that of normal hot air drying, and the drying can be realized while suppressing the increase in grain temperature.

[0006]

EXAMPLES Next, examples of the present invention will be described. FIG.
2 shows a first embodiment of the present invention. The drying device of this embodiment has a drying unit 1, a transport unit 2,
A burner 3 as a heat source for drying is provided, and a supply / exit port 4 is provided.
A blower 5 and a suction fan 6 are attached. The drying unit 1 sprays a grain (paddy state) B in a drying chamber 11, a guide unit 12 that collects the grain B scattered in the drying chamber A at a predetermined location, and measures the moisture content of the grain. Sensor (not shown), and the transport unit 2 includes a guide unit 12
Lower transverse conveyor 21 provided below the vertical conveyor 22, a vertical conveyor 22 provided at an end of the lower transverse conveyor 21, and an upper transverse conveyor provided between the end of the vertical conveyor 22 and the spraying mechanism 11. It consists of 23.

The burner 3 is a device for generating hot air for drying grains, and the supply / exit port 4 is an opening / closing door (not shown).
And is provided at the end of the lower horizontal conveyor 21. The blower 5 supplies drying air (atmospheric temperature) into the drying chamber A. The suction fan 6 discharges the moist air in the drying chamber A to the outside.
A device having an output larger than that of the blower 5 is adopted.

Thus, in order to dry the grain B with the above apparatus,
The grain B is supplied from the supply / discharge port 3 into the drying chamber A to operate each unit for a predetermined time.
2. It is conveyed to the spraying mechanism 11 by the upper horizontal conveyor 23 and is sprayed by the spraying mechanism 11. During this spraying, the water is evaporated by contact with the hot air a, guided by the guide plate 12 onto the lower horizontal conveyer 21, and further conveyed by the vertical conveyer 22 for circulation. The air b containing the air is discharged to the outside of the drying chamber A by the suction fan 6, the grain B is gradually dried, and the drying is performed until the grain is reduced to a predetermined moisture content by the sensor, and the predetermined drying is performed. When is finished, the dried grain is taken out from the supply / discharge port 3.

In particular, the present invention makes the output of the suction fan 6 for discharging the air in the drying chamber A larger than the output of the blower 5 for introducing the drying air into the drying chamber A so that the drying chamber in the drying operation is in operation. The inside of A is 5 to 20 g / cm ² (50 to 20 g) from atmospheric pressure.
It is designed to maintain a reduced pressure state of about 0 mm water column). For this reason, since water is more likely to evaporate from the grain than in the atmospheric pressure state, sufficient drying can be performed even when the hot air temperature is 40 ° C. or lower and the grain temperature is 30 ° C. or lower. Therefore, the grain can be dried with the same drying time as the normal hot air drying or a drying time shorter than that, without causing thermal denaturation that deteriorates the quality of the grain.

FIG. 3 shows a second embodiment of the present invention, in which an electric heater 7 is adopted in place of the burner 3 and an air inlet control mechanism 8 is adopted in place of the blower 5. Therefore, by adjusting the amount of air introduced into the drying chamber A in accordance with the output of the suction fan 6, the atmospheric pressure in the drying chamber A can be maintained at a predetermined depressurized state and the drying operation can be performed.

The present invention reduces the pressure in the drying chamber by adjusting the introduction of air into the drying chamber and the exhaust from the drying chamber.
The present invention realizes efficient drying in a temperature range where thermal denaturation of grains does not occur, and the specific configurations of the drying unit 1 and the transporting unit 2 are not limited to those in the above-described embodiment and may be arbitrarily set. As long as the burner 3, the blower 5, the suction fan 6, the heater 7, and the air inlet control mechanism 8 can implement the present invention, their specific structures can be arbitrarily determined.

[0012]

As described above, according to the present invention, the air supply to the drying chamber for storing and drying the grains and the exhaust air from the drying chamber are adjusted so that the inside of the drying chamber is 50 to 200 g / cm ² from the atmospheric pressure.
Grain drying is performed while maintaining a reduced pressure level.
The hot air temperature for drying was lowered, and the rapid drying could be realized without significantly increasing the grain temperature.

[Brief description of drawings]

FIG. 1 is a perspective view of a drying device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the same.

FIG. 3 is a block diagram of the second embodiment of the present invention.

[Explanation of symbols]

 A Drying room 1 Drying section 2 Conveying section 3 Burner 4 Supply / exit section 5 Blower 6 Suction fan 7 Heater 8 Air introduction control mechanism

Claims (1)

[Claims] 1. A grain drying device comprising an appropriate drying heat source, a drying chamber for storing and drying grains, and a suction fan for exhausting air from the drying chamber. Keep the temperature below 40 ° C., and install an air inlet control mechanism or blower into the drying chamber and control the amount of air introduced into the drying chamber or make the suction fan output larger than the blower output to keep the drying chamber from atmospheric pressure. 5-20
A grain drying device, characterized in that a reduced pressure state of about g / cm ² (50 to 200 mm water column) is maintained.