JP7236048B2 - Method and apparatus for pre-drying seeds before hot water disinfection - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for pre-drying seeds before hot water disinfection, which is installed in a hot water disinfection facility for hot water disinfection of paddy rice seeds (seed rice).

Conventionally, in hot water disinfection of paddy rice seeds (hereinafter referred to as "seeds"), it is effective to reduce the water content to 7 to 10% before immersing the seeds in hot water in order to increase the high temperature resistance of the seeds. Based on the knowledge that there is such a problem, the present applicants have proposed a method of providing a drying treatment process prior to the hot water treatment process (see Patent Documents 1 and 2, for example).
By the way, in drying the seeds, it is conceivable to use a small circulating grain dryer for farmers to perform ventilation drying. Drying speed control is commonly employed in circulating grain dryers for drying edible rice. That is, in a high moisture region such as immediately after harvesting, the moisture content of the paddy is 30 to 23%. When the water content is 23 to 15% and it is in a low moisture region, the drying rate is changed, for example, to about 0.6 to 0.9 [% / hr] to slow down the drying rate and overheat. Control is performed so that cracked granules do not occur due to drying (see, for example, Patent Document 3).

However, in the case of the circulating grain dryer described in Patent Document 3, the time required to dry paddy with a moisture content of about 30%, such as immediately after harvest, to a moisture content of about 14% tends to be as long as 15 to 17 hours. be. For this reason, the number of times that the paddy circulates in the circulation type grain dryer inevitably increases, and when the paddy is circulated by the conveying part such as the screw conveyor and the bucket conveyor, the husked grains with the husks peeled off and part of the paddy. There is a high risk of producing damaged rice such as cracked grains that are missing.

In the subsequent hot water treatment step, immersing the cracked grains in hot water and disinfecting with hot water has little effect on the germination rate of the seeds, but on the other hand, immersing the dehulled grains and cracked grains in warm water and disinfecting with hot water. The germination ability of seeds is affected by the infiltration of hot water into the inside of the grain, and the germination rate of the seeds is remarkably reduced.

In other words, in the preceding drying step, the occurrence of cracked granules is not considered a problem, but the occurrence of mechanical dehulled granules and cracked granules must be avoided.

JP 2015-146775 A JP 2017-38535 A Japanese Patent Publication No. 8-33279

In view of the above-mentioned problems, the present invention has developed a method that avoids the occurrence of mechanical dehulled grains and cracked grains and reduces the moisture content of seeds to about 7 to 10% in as short a time as possible. The technical problem is to provide a method and an apparatus for drying in advance.

In order to solve the above-mentioned problems, the present invention provides a circulation system comprising a grain tank for storing grain in the upper part, a machine body having a ventilation drying part in the lower part, and a grain hoisting machine for circulating between the machine body and the grain tank. A method of drying seeds to a moisture content of 7 to 10% in advance before sterilizing seeds with hot water using a type grain dryer,
a hot air supply step of supplying hot air having a hot air temperature of 60° C. or more and less than 80° C. to the ventilation drying unit for a certain period of time during the drying of the seeds;
During the hot air supply step, the circulation amount is set so that the amount of seeds passing from the grain tank to the ventilation drying section is less than a predetermined amount and the residence time of the seeds in the ventilation drying section is longer than a predetermined amount. A circulation amount control step for controlling
A hot air temperature control step of detecting the grain temperature of the seed by a grain temperature detection unit provided in the grain tank, and reducing the temperature of the hot air supplied by the hot air supply step when the grain temperature reaches a certain temperature,
In the hot air supply step, hot air of 60° C. or more and less than 80° C. is supplied to the ventilation drying unit for 2 hours from 30 minutes to 2 hours from the start of drying,
In the hot air temperature control step, a technical measure is taken to control the temperature of the hot air to be lowered when the grain temperature of the seed detected by the grain temperature detection unit reaches 45°C or higher.

In the second aspect of the present invention, there is provided a seed comprising a grain tank in which grain is stored in an upper portion, a machine body having a ventilation drying section in a lower portion, and a grain raising machine for circulating between the machine body and the grain tank. A device that dries to a moisture content of 7 to 10% in advance before hot water disinfection while circulating
When pre-drying the seeds for hot water disinfection, hot air with a hot air temperature of 60 ° C. or more and less than 80 ° C. is supplied to the ventilation drying unit for 30 minutes to 2 hours from the start of drying during the drying of the seeds. In addition, the amount of seeds passing from the grain tank to the ventilation drying section is made smaller than a predetermined amount, the retention time of the seeds in the ventilation drying section is made longer than a predetermined amount, and further, the grain tank is provided with a It is preferable to provide control means for detecting the grain temperature of the seed by the grain temperature detection unit and lowering the temperature of the hot air when the grain temperature reaches 45° C. or higher.

According to the present invention, a circulating grain dryer comprising a grain tank in which grain is stored in the upper portion, a machine body having a ventilation drying section in the lower portion, and a grain hoisting machine that circulates between the machine body and the grain tank. A method of drying the seeds in advance to a moisture content of 7 to 10% before sterilizing the seeds with hot water, wherein hot air with a hot air temperature of 60 ° C. or more and less than 80 ° C. is applied for a certain period of time during the drying of the seeds. Between the step of supplying hot air to the unit and the step of supplying hot air, the amount of seeds passing from the grain tank to the ventilation drying unit is made smaller than a predetermined amount, and the residence time of the seeds in the ventilation drying unit A circulation amount control step of controlling the circulation amount so as to be longer than a predetermined amount, and a grain temperature detection unit provided in the grain tank detects the grain temperature of the seed, and when the grain temperature reaches a certain temperature, the hot air supply step. and a hot air temperature control step that lowers the temperature of the hot air supplied by
The hot air supply step supplies hot air of 60 ° C. or more and less than 80 ° C. to the ventilation drying unit for 2 hours from 30 minutes to 2 hours from the start of drying, while the hot air temperature control step includes the grain temperature detection unit. When the grain temperature of the seeds detected by the method reaches 45°C or higher, the hot air temperature is lowered.

As a result, the high-temperature hot-air drying in the hot-air supply step makes the drying rate in a high speed range (for example, a dry loss rate of 1.2 [%/hr]) for a certain period of time (for example, up to 2 hours) from the start of drying. Also, during the hot air supply step, the amount of circulation that makes the amount of seeds passing from the grain tank to the ventilation drying section less than a predetermined amount and that the retention time of the seeds in the ventilation drying section is longer than a predetermined amount. It has a control process. As a result, the number of times the seeds are circulated by conveying units such as screw conveyors and bucket conveyors is reduced due to the reduction in the amount of seeds circulated. In other words, the drying speed is shifted to a high speed region by high-temperature hot air drying and a decrease in the amount of circulation, the occurrence of mechanical dehulled grains and cracked grains is avoided, and the moisture content of the seeds is reduced to 7 to 10 in the shortest possible time. %.

Then, the grain temperature of the seeds is detected by the grain temperature detection unit, and when the grain temperature reaches a certain temperature or higher (for example, 45° C. or higher), control is performed to lower the hot air temperature so as not to adversely affect the quality. Even when the hot air temperature is lowered, the average drying rate of 0.9 [%/hr] can be maintained, contributing to short-time drying.

1 is a schematic front view of a circulating grain dryer; FIG. It is a schematic partial side view of a circulation type grain dryer. It is a control block diagram of a circulation type grain dryer. It is a front view of a control panel. It is a control flowchart. FIG. 6(a) is a time chart of hot air temperature and grain temperature, and FIG. 6(b) is a time chart of the number of rotations of a suction fan for exhaust air.

An embodiment of the present invention will be described. The present invention is based on the knowledge that it is effective to reduce the water content to 7 to 10% before immersing the seeds in hot water in order to increase the high temperature resistance in hot water disinfection of rice seeds. Applicants presuppose that a drying treatment process is provided prior to the hot water treatment process (see FIG. 1 of Patent Document 1). The pre-drying device uses a well-known circulating grain dryer equipped with a grain tank in the upper part for storing grain, a machine body with a ventilation drying part in the lower part, and a bucket elevator standing on the front side of the machine body. can do.

The overall configuration of the circulating grain dryer 1 will be described with reference to FIG. A circulating grain dryer 1 comprises an upper grain tank 2 and a lower ventilation drying section 3. A bucket elevator 4 is erected on the front side of the tank 2 as a grain lifting machine, and a suction fan 5 is mounted on the rear side. prepare.

A hot air chamber 6 is formed by perforated plates 6a, 6a extending from the front side to the back side of the ventilation drying section 3 at a substantially central position in the ventilation drying section 3. 7 is provided. One end (front side) of the hot air chamber 6 communicates with a hot air generator 14 (see FIG. 2) having a burner or the like, and the other end is closed so that the hot air does not blow through. Also, the upper ends of the pair of grain drying chambers 7 are connected to the bottom of the grain tank 2, the lower ends of the chambers are inclined inward and joined together, and an elongated delivery valve 8 is horizontally provided at the joining portion. .

The outer walls of the pair of grain drying chambers 7 are formed of perforated plates 7a, 7a, and the outer sides thereof are formed as exhaust chambers 9, respectively. One end side (rear side) of the exhaust chamber 9 is communicated with the suction fan 5, and the other end side (front side) is closed so as to prevent outside air from entering.

A funnel-shaped grain collecting plate 10 is provided on the bottom surface of the pair of exhaust chambers 9, and a lower screw conveyor 11 is horizontally provided at the center bottom thereof. is connected to the lower supply port (not shown) of the . A discharge port at the upper portion of the bucket elevator 4 is connected to an upper screw conveyor 12 horizontally arranged on the top plate of the grain tank 2 . A dispersing board 13 is vertically installed at the conveying terminal end of the upper screw conveyor 12 .

A main unit motor 15 is provided at the bottom of the front side of the ventilation drying section 3 . The main machine motor 15 and the lower screw conveyor 11 are interlocked by a pulley and a V-belt (not shown), and the main machine motor 15 and the lower shaft pulley (not shown) of the bucket elevator 4 are connected. are linked together. Further, an upper shaft pulley (not shown) of the bucket elevator 4 and a pulley (not shown) of the upper screw conveyor 12 are interlocked, and the upper screw conveyor 12 and the distribution disc 13 are connected by a bevel gear (not shown). ) are interlocked and connected.

A valve motor 16 for driving the delivery valve 8 is provided on the front side of the ventilation drying section 3 (see FIG. 2). The valve motor 16 and a sprocket (not shown) attached to the delivery valve shaft (not shown) are interlocked with each other by a chain or the like to rotate the delivery valve 8 intermittently, thereby opening the grain drying chamber 7 . Discharge the grain inside.

A top plate of the grain tank 2 may be provided with a dust discharge fan 17 for discharging dust in the grain tank 2. In this case, a dust discharge fan motor 18 is provided.

As shown in FIGS. 1 and 2, a hot air temperature sensor 19 for detecting the temperature of the hot air from the hot air generating section 14 equipped with the burner and the like is provided. , a grain temperature sensor 20 for detecting the temperature of the grain heated by the hot air generator 14 is provided. A control unit 21 (see FIG. 2) is provided on the upper part of the housing in which the hot air generating unit 14 is installed.

As shown in the control block diagram of FIG. 21 receives these detection signals as well as input signals from switches provided on an operation panel 23 shown in FIG. The controller 21 includes a hot air generator 14 having a burner or the like, a suction fan motor 24 that drives the suction fan 5, an inverter 25 that adjusts the rotation speed of the suction fan motor, and a valve motor 16 that drives the delivery valve 8. , an inverter 26 that adjusts the number of revolutions of the valve motor, and power output devices such as a motor that drives the bucket elevator 4 are connected, and these outputs are output in response to signals from signal input devices and input signals from switches Control the operation of equipment.

FIG. 4 is a front view of the operation panel 23 provided in the control section. The operation panel 23 has a power switch 27 for turning on/off the power, a charging amount switch 28 for setting the charging amount, a variety switch 29 for setting the variety, and a grain setting switch 30 for setting the type of grain to be dried. be provided.
The grain setting switch 30 has three options: a wheat mode for edible grains, a rice mode, and a pre-drying mode for sterilizing seeds with hot water. Thereby, it becomes possible to select a drying control pattern for each drying mode corresponding to each option.
Reference numeral 31 is a moisture/timer switch for setting whether automatic moisture meter operation using a moisture meter, timer operation, or nighttime automatic operation is set, and reference numeral 32 is hot air temperature, grain moisture, remaining operation time. 33 is a monitor switch for switching the display of the display unit 32, 34 is a hold-in switch to be pressed when performing a pre-load operation, and 35 is a fan operation. Reference numeral 36 is a drying switch to be pushed when performing a drying operation, Reference numeral 37 is a discharge switch to be pushed when performing a discharging operation, Reference numeral 38 is a stop to be pushed when stopping each operation. is a switch.

Operation control of the circulating grain dryer 1 having the above configuration will be described with reference to the flow chart of FIG.
First, grains are loaded into the grain tank 2 and the ventilation drying section 2 of the circulating grain dryer 1 (step S1). It is determined whether or not (step S2).
If the set position of the grain selection switch 30 is not the seed pre-drying mode (No in step S2), the edible grains are dried, and it is confirmed whether the grain selection switch 30 is in the wheat mode or the rice mode. (step S3). Then, if the operator sets the target moisture value and loading amount in step S4, for example, in the paddy mode, a drying speed control program (moisture content of paddy such as immediately after harvesting) that does not cause cracked grains due to overdrying. In the high moisture region of 30 to 23%, the drying rate is increased to, for example, about 1.0 to 1.4 [% / hr], and the paddy is dried and the moisture content is 23 to 15%. , the dryness rate is changed to, for example, about 0.6 to 0.9 [%/hr].) is called. Then, when the drying switch 36 is turned on (step S5), the hot air generator 14 is controlled so as to execute the control program.

After about 15 to 17 hours from the start of drying, it is determined whether or not the target moisture content has been reached (step S6), and if the target moisture content has been reached, the drying operation ends (step S7).

On the other hand, if the set position of the grain selection switch 30 is the seed pre-drying mode (Yes in step 2), a pre-drying drying operation for hot water disinfection of seeds is performed. Then, when the operator sets the target moisture value and the loading amount in step S8 and turns on the drying switch 36 (step S9 in FIG. 5), for example, a drying control program suitable for pre-drying seeds is called. The drying operation is carried out. This will be described with reference to FIG. Fig. 6 (a) is a time chart showing hot air temperature control and grain temperature of the hot air generating unit when the seed pre-drying mode is set, and Fig. 6 (b) is a time chart of the rotation speed of the exhaust suction fan Chart.

In the seed pre-drying mode, high-temperature hot air with a temperature of 60° C. or more and less than 80° C. is supplied for a certain period of time (for example, between 30 minutes and 2 hours) from the start of drying in order to hasten the temperature rise of the seeds (Fig. 5 step S10). A hot air temperature of 60° C. or higher is desirable. However, if the temperature exceeds 80°C, the seed quality may be adversely affected. The hot air is supplied from the hot air generator 14 (see FIG. 2), the hot air temperature is monitored by the hot air temperature sensor 19 (see FIG. 2), and the grain temperature is monitored by the grain temperature sensor 20 (see FIG. 2). . The hot air temperature is controlled to be maintained at 60° C. or more and less than 80° C. for a certain period of time (T11 area in FIG. 6(a)) from the start of drying. Also, for a certain period of time (region T1 in FIG. 6(b)) from the start of drying, the rotation speed of the exhaust suction fan 5 is controlled so as to be kept at a high rotation speed (for example, 1800 rpm). Furthermore, the amount of grain delivered by the delivery valve 8 is set to be less than a predetermined amount (wheat mode for edible grains, paddy mode), and the residence time of grains in the grain drying chamber 7 is set to a predetermined amount (wheat mode for edible grains, rice mode). The rotation speed of the valve motor 16 is controlled so as to be longer than the paddy mode).

As a result, due to the effect of high-temperature hot-air drying, the drying rate from the start of drying to 2 hours (region T1 in FIG. 6(a)) is, for example, 1.2 [%/hr], which is a high speed region. Then, when the grain temperature detected by the grain temperature sensor 20 reaches or exceeds a certain temperature (for example, 45° C. or higher) (step S11 in FIG. 5), control is performed to gradually lower the temperature of the hot air so as not to adversely affect the quality. (step S12 in FIG. 5, area T2 in FIG. 6A). Further, the rotation speed of the exhaust suction fan 5 is controlled so as to be kept at a low rotation speed (for example, 1350 rpm). At this time, the drying speed after four and a half hours have passed from the start of drying (regions T1 and T2 in FIG. 6A) is, for example, an average speed of 0.9 [%/hr]. After that, the hot air temperature is controlled to a constant value of 40°C (region T3 in Fig. 6(a)), and the grain temperature is also controlled to converge to 40°C.

The conventional drying control and the drying control of this embodiment will be compared with reference to FIG. In the conventional drying control, the hot air temperature is maintained at a constant temperature of 40° C. (reference N1 in FIG. 6A) from the start of drying. The increase in grain temperature (marked K1 in FIG. 6(a)) accompanying this is gradual, and reaches 40° C., which is the same as the temperature of the hot air, when about 4 hours have passed since the start of drying. On the other hand, the drying control of the present embodiment supplies hot air having a temperature of 60° C. or more and less than 80° C. (reference numeral N2 in FIG. 6A) for two hours from the start of drying. As a result, the grain temperature (marked K2 in FIG. 6(a)) rapidly rises to 45° C. or higher in two hours from the start of drying.

Comparing the drying speed, in the conventional drying control, the drying speed is 0.4 to 0.6 [% / hr], and the moisture content of the seeds of 14.5% of the starting material is about 7 to 10%. It took a long time of about 17.5 hours to dry to perfection. On the other hand, in the drying control of the present embodiment, the drying rate is 0.8 to 1.0 [%/hr], and the seeds of the starting material with a moisture content of 14.5% are dried to a moisture content of about 7 to 10%. 8 to 8.5 hours.

After about 8 to 8.5 hours from the start of drying, it is determined whether or not the target moisture content has been reached (step S13 in FIG. 5), and if the target moisture content has been reached, the drying operation ends (FIG. step S14).

As described above, in the embodiment of the present invention, in order to accelerate the temperature rise of the seeds, hot air with a hot air temperature of 60 ° C. or higher and 80 ° C. is supplied for a certain period of time from the start of drying, and the grain temperature is kept at a constant temperature. If it becomes above, if the hot air temperature is controlled to gradually lower, the drying speed can be realized, for example, at an average of 0.8 to 1.0 [% / hr], and the conventional drying time can be halved. It becomes possible.

Although several embodiments of the present invention have been described above, the above-described embodiments of the present invention are intended to facilitate understanding of the present invention, and do not limit the present invention. The present invention may be modified and improved without departing from its spirit, and the present invention includes equivalents thereof. In addition, within the range where at least part of the above problems can be solved or where at least part of the effect is achieved, the components described in the claims and the specification can be combined or omitted. .

INDUSTRIAL APPLICABILITY The present invention is useful for pre-drying in hot water disinfection equipment for hot water disinfection of paddy rice seeds (seeds).

1 Circulating grain dryer 2 Grain tank 3 Ventilation drying unit 4 Bucket elevator 5 Suction fan 6 Hot air chamber 6a Perforated plate 7 Grain drying chamber 7a Perforated plate 8 Delivery valve 9 Exhaust chamber 10 Grain collecting plate 11 Lower screw conveyor 12 Upper screw Conveyor 13 Distributor 14 Hot air generator 15 Main unit motor 16 Valve motor 17 Dust exhaust fan 18 Dust exhaust fan motor 19 Hot air temperature sensor 20 Grain temperature sensor 21 Control unit 22 Moisture meter 23 Operation panel 24 Suction fan motor 25 Inverter 26 Inverter 27 Power switch 28 Loading amount switch 29 Variety switch 30 Grain setting switch 31 Moisture/timer switch 32 Monitor display unit 33 Monitor switch 34 Loading switch 35 Air blower switch 36 Drying switch 37 Discharge switch 38 Stop switch

Claims (2)

A circulating grain dryer equipped with a grain tank that stores grain in the upper part, a machine body that has a ventilation drying part in the lower part, and a grain raising machine that circulates between this machine body and the grain tank, and seeds. A method of drying to a moisture content of 7 to 10% in advance before hot water disinfection,
a hot air supply step of supplying hot air having a hot air temperature of 60° C. or more and less than 80° C. to the ventilation drying unit for a certain period of time during the drying of the seeds;
During the hot air supply step, the circulation amount is set so that the amount of seeds passing from the grain tank to the ventilation drying section is less than a predetermined amount and the residence time of the seeds in the ventilation drying section is longer than a predetermined amount. A circulation amount control step for controlling
A hot air temperature control step of detecting the grain temperature of the seed by a grain temperature detection unit provided in the grain tank, and reducing the temperature of the hot air supplied by the hot air supply step when the grain temperature reaches a certain temperature,
In the hot air supply step, hot air of 60° C. or more and less than 80° C. is supplied to the ventilation drying unit for 30 minutes to 2 hours from the start of drying,
In the hot air temperature control step, when the grain temperature of the seeds detected by the grain temperature detection unit reaches 45 ° C. or higher, the hot air temperature is controlled to decrease. A method of pre-drying seeds before hot water disinfection. . A grain tank that stores grain in the upper part, a machine body that has a ventilation drying part in the lower part, and a grain hoisting machine that circulates between the machine body and the grain tank. A device that dries to a moisture content of 7 to 10%,
When pre-drying the seeds for hot water disinfection, hot air with a hot air temperature of 60 ° C. or more and less than 80 ° C. is supplied to the ventilation drying unit for 30 minutes to 2 hours from the start of drying during the drying of the seeds. In addition, the amount of seeds passing from the grain tank to the ventilation drying section is made smaller than a predetermined amount, the retention time of the seeds in the ventilation drying section is made longer than a predetermined amount, and further, the grain tank is provided with a and a control means for detecting the grain temperature of the seeds by means of the grain temperature detection part and reducing the temperature of the hot air when the grain temperature reaches 45°C or higher. Device.

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