JP2002000012A - Method of disinfecting and drying seeds - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of disinfecting and drying plant seeds in which seeds can be dried in high heat efficiency for a shot time, as the plant pathogenic microbes sticking to the seeds are disinfected safely to human bodies without adverse effect on the germination and the like. SOLUTION: The drying chamber is kept at a reduced pressure by controlling the aspiration from the outside and the exhaustion toward the outside, the seeds are fed thereto batchwise or continuously and the seeds are radiated with far-infrared rays from far-infrared heaters, while the air heated with the far-infrared rays is forcedly circulated in the drying chamber whereby the seeds are brought into contact with the circulated air flow and disinfected and dried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for sterilizing and drying seeds. More specifically, the present invention relates to a method for simultaneously sterilizing and drying seeds by far infrared rays.

[0002]

2. Description of the Related Art Seeds are dried and stored until sowing. For this reason, various dryers such as a conduction heat transfer dryer, a rotary drum dryer, a vacuum dryer, and a fluidized bed dryer have been conventionally used. In particular, in recent years, attention has been paid to coated seeds having improved germination ability or artificial seeds (coated with somatic embryos) with improved germination ability in order to promote labor-saving and efficiency in agriculture. Also, the above-mentioned conventional dryer is used. In general, seeds lose germination when exposed to high temperatures at high humidity, so that they are relatively cool (3
At present, it is dried in air at 0 to 40 ° C. for several hours to over ten hours.

[0003] In addition, various microorganisms and viruses are attached to seeds, and among them, many pathogenic bacteria (phytopathogenic bacteria) which are not desirable for germination or plant growth are also contained. In the present specification, for the sake of convenience, the "phytopathogenic fungi" include molds (filamentous fungi) and viruses. Therefore,
Virus inactivation is also included in the expression "kill". As viral diseases caused by viruses, TMV
(Tobacco mosaic virus or tomato mosaic virus), and bacterial diseases caused by bacteria include soft rot (potato), bacterial wilt (eggplant), spot bacterial disease (cucumber), wilt disease (tomato), Vine disease (cucumber), pickling disease (eggplant) and the like. In particular,
Young seedlings immediately after germination have low resistance to various diseases and are susceptible to various growth inhibitions (ie, disease and rot). This is caused by various fungi (phytopathogenic fungi) in the soil, but is often caused by phytopathogenic fungi attached to the seeds. By sterilizing the seeds, it is possible to prevent such growth inhibition, plant growth,
In turn, it will help increase crop sales. For this reason, seeds have been conventionally sterilized and disinfected by immersing the seeds in a chemical solution of a bactericide (agrochemical), spraying the chemical solution on the seeds, or spraying the seeds with a chemical. However, in the sterilization by each of the above methods, it was difficult to completely remove the fungicide even if the treated seed was washed with water. For example, seed rice is typically subjected to seed disinfection by diluting a Spoltak stana SE agent 200-fold before seedling and immersing it for 24 hours. Therefore, attempts have been reported to use strongly acidic water (for example, JP-A-9-224422) or ozone water (for example, JP-A-5-221808) as a disinfectant. Treatment with highly acidic water or ozone water, which is relatively low in toxicity or detoxified, also immerses the seed in the chemical solution, so that the seed may absorb water during the treatment operation and germinate. Furthermore, a sterilization method using an electron beam has been proposed (for example, Japanese Patent Application Laid-Open No. H11-32514). This sterilization method has the advantage that the above problem can be avoided and the seed can penetrate through the seed to the inside of the seed coat, but an expensive and complicated electron beam generator is required. Therefore, the electron beam sterilization method cannot be performed in a general farm or a JA-related facility, and cannot be a general-purpose sterilization method.

[0004]

In the conventional drying method using the above-mentioned dryer, it has not been easy to dry the seeds quickly without damaging the seeds or adversely affecting the germination activity thereof. . For this reason, there has been a demand for a drying method that further reduces damage to seeds and has high drying efficiency (such as a reduction in drying time).

[0005] When a fungicide is used for sterilizing seeds,
Various problems such as chemical damage to the crop itself, adverse effects on humans and animals, drug resistance and residue problems can occur. For this reason, there has been a public interest in minimizing the use of fungicides. At least, it has been desired that a bactericide which is usually harmful to the human body does not adhere to seeds after the bactericidal treatment.

Therefore, one of the objects of the present invention is to provide a method for drying seeds with reduced damage to the seeds and high drying efficiency.

Another object of the present invention is to rapidly, reliably and safely kill phytopathogenic bacteria attached to seeds,
An object of the present invention is to provide a method for disinfecting seeds that does not adversely affect germination and growth of the seeds. The term "safe" as used herein includes the fact that there is no danger of residual chemicals in the seed.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, focused on the drying effect of far-infrared rays and the bactericidal effect, the seeds using far-infrared rays were used. A sterilization / drying method was established, and it was confirmed that the above two objects could be simultaneously achieved, thereby completing the present invention.

That is, the method for sterilizing and drying seeds according to the present invention is characterized in that the seeds are dried under far infrared rays.

Further, the present invention supplies seeds to a drying chamber, which is provided with a far-infrared heater, and is controlled to supply air from the outside and exhaust to the outside, and is kept in a reduced pressure state. While irradiating infrared rays, on the other hand, a method for sterilizing and drying seeds, comprising forcibly generating a circulating air flow in a drying chamber heated by the far-infrared heater and bringing the seeds into contact with the circulating air flow. provide.

[0011] In the method for sterilizing and drying seeds, the circulating air flow may be such that an internal circulating air flow for circulating air in the drying chamber and air in the drying chamber are once led out.
It is characterized by comprising an external circulating airflow that circulates air by introducing air again into the drying chamber.

Further, in the above method for sterilizing and drying seeds, the internal circulating air flow is further heated by a far-infrared heater and circulated.

[0013] In the above method for disinfecting and drying seeds, the seeds are supplied to the drying chamber by storing the seeds in the drying chamber. Further, in the method for sterilizing and drying seeds, the supply of seeds to a drying chamber is continuously performed.

In the above method for sterilizing and drying seeds, the far-infrared ray heater is preferably made of a ceramic material containing titanium oxide.

Further, in the above method for sterilizing and drying seeds, preferably, the reduced pressure state is a water column of 50 mm to 20 mm.
The range is 0 mm.

Further, in the above method for sterilizing and drying seeds, the temperature in the drying chamber is preferably 5 ° C. to 45 ° C.
Range.

By configuring the method for disinfecting and drying seeds in this way, the drying chamber is uniformly heated by the far-infrared heater, the drying chamber is maintained at a reduced pressure, and the circulating air flow is forced into the drying chamber. Since the seeds are brought into contact with the circulating air flow, moisture can be evaporated from the surface as well as from the inside of the seeds in a short time.

Further, according to the above configuration, irradiation of far-infrared rays directly sterilizes seeds, and far-infrared rays from a far-infrared heater sterilizes circulating air, and the seeds are dried in sterilized air. Efficient and safe sterilization of seeds becomes possible.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION As used herein, “seed”
It generally means plant seeds, and the kind to which the present invention can be applied is not particularly limited. Cereals include seeds such as rice, wheat, barley, and corn; vegetables include seeds such as Chinese cabbage, ginseng, lettuce, spinach, radish, and onion; and flowers include seeds such as betunia and bekoniya. The “seed” also includes the aforementioned coated seed and artificial seed. However, since the method of drying rice seed, which is a kind of cereal, that is, the method of drying rice is the subject of Japanese Patent Application No. 11-172997, which is the invention of the present inventors, it is preferable to remove rice from “seed”. exclude.

As used herein, “plant disease” refers to bacteria,
It means a plant disease caused by a fungus or a virus, and the scope to which the present invention can be applied is not limited to a specific pathogen. Representative examples include, in addition to the above-mentioned plant diseases, idiot disease, blast disease, sesame leaf blight, and bacterial blight disease of paddy.

Hereinafter, the present invention will be described in detail according to preferred embodiments.

The method for sterilizing and drying seeds according to the present invention is characterized in that the seeds are dried under far infrared rays. As used herein, "under far-infrared rays" means under irradiation with far-infrared rays or under the influence of far-infrared rays, and the latter includes indirect thermal effects. The term “far infrared” refers to infrared rays in a long wavelength region, which is the same as far infrared used in a normal sense, but the wavelength distribution varies depending on the ceramic member of the far infrared heater used.

Furthermore, the method for sterilizing and drying seeds according to the present invention comprises supplying the seeds to a drying chamber equipped with a far-infrared heater, in which the supply of air from the outside and the exhaust to the outside are controlled and maintained in a reduced pressure state, While irradiating far-infrared rays to the seeds by the far-infrared heater, a circulating air flow is generated in the drying chamber heated by the far-infrared heater, and the seeds are brought into contact with the circulating air flow.

The method for disinfecting and drying the seeds (hereinafter also referred to as the disinfecting and drying method of the present invention) is preferably a method disclosed in
This is carried out by a drying apparatus disclosed in JP-A-89844.
Therefore, using the drying device or an equivalent device,
Performing the sterilization / drying method of the present invention constitutes the first embodiment of the present invention.

Hereinafter, the structure of the drying apparatus used in the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a main part of the drying device. FIG. 2 is a plan sectional view of the drying device. The drying device 10 has a length of 3 m and a width of 2.4.
m, and includes one or more (preferably four) drying units composed of a large box having a heat insulating structure with a height of about 2.6 m. These drying units are connected to form a drying chamber 11.
Becomes As shown in FIG. 2, an operator can enter and exit the drying chamber 11 through an entrance 13. After the seeds are carried in, the entrance 13 is closed and the drying chamber 11 is sealed. You. In the drying chamber 11, seeds are spread in layers on trays 12 stacked in advance in multiple stages.
The loading and unloading of the tray 12 is carried out through the
4 is performed. Thus, seeds are stored in the drying chamber 11. The drying chamber 11 shown in FIG.
Consists of two drying units.

A far infrared heater unit 20 is provided above the drying chamber 11. A far-infrared heater 21 is provided inside the far-infrared heater unit 20. The far-infrared heater unit 20 emits far-infrared rays, irradiates the seeds on the tray 12 with far-infrared rays, and heats the air circulating in the drying chamber 11. In the particular embodiment shown, the far infrared heater unit 20
Is installed on the ceiling surface of the drying room 11, but may be installed on a floor surface or a wall surface of the drying room other than or instead of the ceiling surface. The wavelength of far infrared rays emitted from the far infrared heater 21 can be appropriately selected for sterilization and drying of a specific seed. For example, when the seed is rice (paddy), the optimal wavelength is 4 to 13 μm, preferably 7 to 9 μm. By using such a far-infrared heater 21, it is possible to release moisture not only from the surface of the seed but also from the inside with a small amount of input energy due to high far-infrared radiation efficiency.

The far-infrared heater 21 is made of a base material (for example, 2
A ceramic sprayed layer (about 20 to 30 microns thick) is formed on the surface of an aluminum plate or a stainless steel plate having a thickness of mm. The substrate may be generally in the form of a flat plate, but a perforated plate such as a punching plate may be used, and the holes may be used as passages for heated air.

The ceramic does not need to be one kind of raw material, but may be a composition in which various raw materials are mixed. Raw materials that can be used are not particularly limited, but as ceramics that radiate much far infrared rays, for example, zirconia, magnetite, alumina, zircon, iron, chromium, titania,
A composite oxide such as manganese can be used. The ceramic spray layer is applied using a plasma spray gun employed in the prior art. In particular, in the present invention from the point of the bactericidal effect,
Preferably, the ceramic contains titanium oxide (titania).

The far infrared heater unit 20 is usually
Operated by a 0V power supply, a temperature sensor 23 installed in the drying chamber 11 monitors the temperature of the drying chamber, and the controller 40 adjusts the intensity of far-infrared radiation within a set value based on the temperature.

The far infrared heater unit 20 is provided with a fan 22a at one end thereof.
Is for circulating the air in the drying chamber 11 and the fan 2
Indoor air is introduced into the far-infrared heater unit 20 from a suction port opened at the lower part of the 2a. The air introduced into the far-infrared heater unit 20 flows in the direction indicated by the arrow in FIG. 1, is heated and sterilized by the far-infrared heater 21, and is discharged from the outlet located at the other end of the far-infrared heater unit 20. Then, it is returned to the drying chamber, whereby an air circulation path is formed in the room.
The far-infrared heater 21 heats the air in the entire drying chamber 11 and further heats the air passing through the far-infrared heater unit 20. The air circulating along this path is called an internal circulating air flow, and circulates inside the drying chamber 11 while uniformly sterilizing and drying it. Thus, it allows the seed to be dried under sterile conditions.

On the other hand, the side wall chambers 31a and 31a of the drying chamber 11
1b includes a number of intake ports (jet ports) 51 and exhaust ports 5;
2 are formed respectively. The air in the drying chamber 11 is
The air is exhausted from the exhaust port 52, passes through the side wall chamber 31b, and passes through the drying chamber 1
The air is pressurized by a fan 32 via a pipe 30 disposed above 1 and, if desired, passes through an air conditioner (not shown) attached to the fan 32. The air conditioner has a function of removing moisture while cooling the air. Therefore, the air that has passed through the air conditioner has a predetermined temperature and humidity (preferably, 1).
(About 1 to 15%). The air pressurized by the fan 32 enters the side wall chamber 31 a via the pipe 33, and is supplied from the air inlet 51 into the drying chamber 11. In this way, another indoor air circulation path is formed. The air circulating along this path is referred to as an external circulating air flow, which contacts the seeds on the tray 12 and flows in the drying chamber 11 horizontally, that is, laterally, while sterilizing and drying, and crosses the room. The air blown out from the air inlet 51 is substantially the same above and below the tray 12, enabling the seeds to be dried uniformly. That is, the internal circulating airflow mainly has a function of adjusting the temperature of the airflow circulating in the drying chamber 11,
Further, the external circulating air flow mainly has a function of drying the seeds. In the latter case, the inside of the drying chamber 11 per hour,
Preferably, the air stream is circulated 600 to 2000 times or more.

Desirably, the external circulating air, which is cooled and the humidity is controlled, and the heated internal circulating air are mixed in the drying chamber 11, and the temperature in the room is optimized for sterilization and drying of seeds. The temperature is adjusted (for example, 5 ° C. to 45 ° C.), more preferably, in the range of 15 ° C. to 35 ° C.

As shown in FIGS. 1 and 2, an air supply pipe 16 and an exhaust pipe 17 are separately connected to the drying chamber 11, and each pipe is connected to an air supply port 16a. An exhaust port 17a is provided toward the inside of the drying chamber 11. Further, the fan 18 and the air filter 18a and the fan 19
The air filters 19a are disposed on the pipes 16 and 17, respectively. The outside air is introduced into the drying chamber through the air filter 18a, the fan 18, and the pipe 16, and the air in the drying chamber 11 is exhausted outside through the pipe 17, the fan 19, and the air filter 19a. In this way, outside air is supplied from the pipe 16 to the air supply port 16a.
Through the drying chamber 11. The humidified air humidified by the drying of the seed is exhausted to the outside through the pipe 17 from the exhaust port 17a. By providing a cooling / dehumidifying device in the outside air introduction system (preferably immediately after the fan 18 or in the middle of the pipe 16), regardless of changes in the temperature or humidity of outside air, the air introduced into the drying chamber 11 can be cooled. Temperature and humidity can be fine-tuned.

Both the amount of air supply and the amount of exhaust air into the drying chamber 11 are determined by controlling the amount of air blown by the fans 18 and 19.
It can be set as appropriate by controlling with. Therefore, the amount of exhaust can be greatly increased as compared with the amount of air supply, and the inside of the drying chamber can be reduced in pressure. For example, if the intake capacity is 240
0m ³ / H, exhaust capacity up to 1500m ³ / H to 5 min
The range may be 00m ³ / H. Note that both the intake means (fan) and the exhaust means are operated by a 100V power supply. By reducing the pressure in the drying chamber 11, the drying of the seeds becomes more efficient. The preferred decompression conditions employed in the present invention are in the range of 50 to 200 mm with a water column,
Depending on the type of seed, a reduced pressure outside this range may be used in some cases. Decompression below a water column of less than 50 mm is not sufficient to promote evaporation of moisture from the inside of the seed, and therefore requires a lot of processing time for drying. In addition, 200
Although a reduced pressure of not less than mm is possible, the drying chamber 11 must have a structure that can withstand such reduced pressure, which is disadvantageous in terms of apparatus cost. From such considerations, a preferable reduced pressure is in the above range, that is, 50 to 200 mm.

In the drying chamber 11, the seeds are dispersed and placed on the tray 12 in a layer as thin as possible. By layering the seeds, the circulating air stream can flow through the tray 12 (for example, a mesh-like tray) while being in contact with the seeds, and the seeds can be irradiated with far-infrared rays. The structure of the carriage 14 including the tray 12 is not particularly limited, and a person skilled in the art can design or use a commercially available product as it is in consideration of the above. The cart 14 is preferably provided with a caster so that it can be easily carried in and out.

The second embodiment of the present invention is an improvement of the drying device 10 of the first embodiment of the present invention.
Particularly suitable for sterilizing and drying a large amount of seeds. In this apparatus 100, a conveyor 60 is provided as a supply unit for continuously supplying seeds. FIG. 3 is an exploded view of a main part of the continuous drying apparatus 100. Drying device 100
Most of the structure is substantially the same as that described above, and thus the description thereof is omitted. The details of this device are disclosed in Japanese Patent Application No. 11-172997, the disclosure of which is incorporated herein as a part of the disclosure of the present specification.

In the drying apparatus 100 shown in FIG.
A hopper 61 is provided at one end of a conveyor 60 installed therein, and seeds are supplied from the hopper 61 to the conveyor 60 via a rotary valve 62. The rotary valve 62 plays a role of supplying a predetermined amount of seeds while the drying chamber 111 remains in a reduced pressure state. Further, a doctor blade 63 is provided downstream of the conveyor 60, and the supplied seeds are thinned to a predetermined thickness on the conveyor 60. The seeds on the conveyor 60 are conveyed in the direction of the arrow, while contacting the heated circulating air circulating in the drying chamber 111, and receiving the far-infrared radiation from the far-infrared heater 221 in the far-infrared heater unit 200. And sterilized and dried. After treatment, the seeds
It is transferred from one end of the conveyor 60 to the outside of the drying chamber 111. Note that the temperature in the drying chamber 111 is adjusted to a preferable temperature range by appropriately mixing the internal circulating air and the external circulating air, just as in the case of the above-described drying apparatus. Also,
Conveyor 60 is preferably formed from a porous material to maximize contact between the circulating air flow and the seeds.

After the seed sterilization / drying step is completed in the drying apparatus described above, the operation of the far-infrared ray heater is stopped, the fan is desirably driven continuously, and the ventilation is performed only for natural ventilation (that is, without heating) for a certain period of time. Cure the seeds.
The time required for sterilization and drying can vary depending on the water content of the specific seed used and the treatment amount of the seed, but is usually about several hours to 24 hours.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to only the following examples.

[0040]

Example 1 Drying of Rice Paddy Rice was dried using the actual drying device shown in FIG. The outline of the apparatus is as follows. A far-infrared heater (width: 90 cm, length: 150 cm, length: 150 cm, drying room (width: 2.3 m, depth: 4.0 m, height to ceiling: 2.5 m))
Height: 30m, heater capacity is 3KWx3, air volume is 2
400 m ³ / min, power supply: 220 volts). The drying conditions were generally as follows.

Outside air temperature: 23 to 30 ° C. Outside air humidity: 19 to 55% Indoor temperature: 34 to 37 ° C. Indoor humidity: 19 to 36% Indoor pressure: 58 to 61 (−mmAq) Circulating air volume: 58.5 to 66 m ³ / Min Circulating wind speed: 3.9 to 4.4 m / sec Exhaust air volume: 5.13 to 5.29 m ³ / min Exhaust air speed: 0.95 to 0.98 m / sec Power consumption: 6.3 KW / hr Akita "Akitakomachi" produced from paddy rice (water content about 23
%), And the temperature in the drying chamber is set to about 3 as described above.
As a result of performing a drying test while maintaining the temperature at around 5 ° C., primary drying was achieved in an extremely short time. Some of the test results are shown in Tables 1 and 2.

[0042]

[Table 1]

[0043]

[Table 2] In the test of Table 2, stirring was used in combination. In each of the tests in Tables 1 and 2, a moisture content of 17% was obtained by drying for about 3 hours.
Of paddy was obtained. Furthermore, comparing the test results in Tables 1 and 2, it can be seen that the drying time is shorter in Table 1 where the wind speed above the paddy is faster. By the way, according to the prior art method of burning kerosene and drying the paddy (e.g. using a country elevator machine), it takes about 24 hours to reach a comparable moisture content. (Taste test) The rice grain obtained in the tests of Tables 1 and 2 was further dried for about 3 hours to a water content of about 15% (about 35 ° C.), and then subjected to a taste test as a rice meal. Compared with the sample of cooked rice obtained by the conventional drying method, as a result of an expert tasting test (tasting), it was confirmed that the sample by the sterilization and drying method of the present invention was excellent in taste and aroma. Was. In addition, it was evaluated that "it is comparable to sun drying". (Body cracking test) Under the above drying conditions, various samples of "Akitakomachi" were dried, and the body cracking phenomenon of rice was inspected.
The inspection was carried out by the Oita Village Country Elevator Public Corporation in Minami-Akita-gun, Akita Prefecture, and the inspection method was visually followed according to the standards of the public corporation. Table 3 shows the test results.

[0044]

[Table 3] Primary drying (1 hour) and secondary drying (3 hours) were performed on the inspection product numbers 1 to 6. On the other hand, inspection part numbers 7-11
, Only primary drying (1 hour) was performed. Since the paddy dried according to the drying method of the prior art usually shows a cut rate of about 10%, the cut rate of the paddy dried by the sterilization / drying method of the present invention is extremely low.

Further, the relationship between the grain temperature at the time of drying the paddy and the cracking rate was examined. Primary drying (1 hour) was performed on the same specimen as the test part number 7 at various grain temperatures under substantially the above conditions.
Inspection was also carried out by the Oita Village Country Elevator Public Corporation in Minami-Akita-gun, Akita Prefecture. Table 4 shows the test results.

[0046]

[Table 4] In the table, the pre-drying split ratio indicates the split ratio when the same sample to which the drying method of the present invention was not applied was used as a control. The post-drying cracking rate indicates the cracking rate of the sample treated by the drying method of the present invention. The differential split ratio is a difference between the split ratio before drying and the split ratio after drying, and represents an increase in the split ratio by the treatment according to the drying method of the present invention. From the results in Table 4, it is understood that when the drying method of the present invention is applied at a grain temperature of less than 40 ° C, an increase in body cracks is suppressed.

Example 2 Germination test Germination of paddy The dried paddy obtained in Example 1 was subjected to a germination test according to a conventional method. The rice germinated by the sterilization and drying method of the present invention showed a germination rate of almost 100%, whereas the germination rate of the rice hull dried according to the conventional drying method was about 7%.
5%. In addition, there was a significant difference in germination.

2. Germination of vegetable seeds In this example, a germination test was performed using black mappe seeds, which are raw seeds of sprouts, as vegetable seeds. That is, the sample seed 1 was placed on a petri dish with wet cotton wool.
0 g was evenly placed, covered, and cultured at 30 ° C. to observe the state of seed germination every day. The number of germinated seeds was counted to determine the germination rate. When comparing seeds treated by the sterilization / drying method of the present invention with untreated seeds, the germination rate was improved in the former, and the average number of germination days required for germination was significantly reduced.

Example 3 Sterilization Test In this example, a sterilization test was performed using the black mappe seeds used in Example 2-2. The viable cell count was measured by the following method. That is, 2.5 g of sample seeds is 0.9%
A suspension obtained by homogenizing in 25 ml of an aqueous sodium chloride solution (physiological saline) using a homogenizer.
2 ml was spread on a normal agar medium and cultured at 30 ° C. for 48 hours, and the number of viable cells was determined from the number of colonies formed on the medium. If the viable cell count was 100 / g or less, it was determined that the bacteria had been almost completely sterilized. The viable cell count of untreated seeds is 10 ³ to 1
0 was ^four / g. According to the sterilization and drying method of the present invention,
The seeds treated at a dry room temperature of 40 ° C. for about 24 hours had a viable cell count of 100 / g or less.

[0050]

As described above, the method of sterilization and drying of the present invention utilizes the heating effect and the sterilization effect of far-infrared rays to treat the seed, so that the drying and sterilization of the seed can be achieved simultaneously.

Further, in the sterilization / drying method of the present invention, the drying chamber, which is kept under reduced pressure, is uniformly heated by a far-infrared heater, and a forced circulating air flow is generated in the chamber to dry the seeds. Therefore, drying can be efficiently achieved in a short time.

Further, in the sterilization / drying method of the present invention, the external circulating air flow of the circulating air flow flows in the drying chamber in a substantially horizontal direction, and the seeds can be dried quickly and uniformly.

Seeds treated by the sterilization / drying method of the present invention have no deterioration in germination ability, have a germination activity, and can withstand long-term storage.

Further, in the sterilization / drying method of the present invention, the circulating air stream is heated and sterilized with far-infrared rays, and then dried while contacting the seeds and irradiating the seeds with far-infrared rays. So the seeds are dried under sterile conditions,
In addition, since it can be sterilized directly by far infrared rays, the sterilizing effect is synergistic and excellent.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of a drying apparatus according to the present invention.

FIG. 2 is a plan sectional view of the drying device of FIG. 1;

FIG. 3 is an exploded perspective view showing a main part of the continuous drying apparatus according to the present invention.

[Explanation of symbols]

 10, 100: Drying device 11, 111: Drying chamber 12: Tray 16, 17: Piping 18, 19, 22a, 32: Fan 18a, 19a: Air filter 20, 200 ... far-infrared heater unit 21, 221 ... far-infrared heater 31a, 31b ... side wall chamber 40 ... control device 51 ... intake port 52 ... exhaust port 60 ... conveyor

Continued on the front page F-term (reference) 2B051 AA01 AB01 BA09 BB03 BB05 BB06 BB09 3L113 AA01 AB01 AC10 AC23 AC51 AC64 BA01 DA04

Claims (9)

[Claims] 1. A method for sterilizing and drying seeds, comprising drying the seeds under far infrared rays. The seeds are housed in a drying chamber provided with a far-infrared heater, which is controlled to supply air from the outside and exhaust to the outside, and is kept in a reduced pressure state. The far-infrared heater irradiates the seeds with far-infrared rays. The sterilization and drying of seed according to claim 1, wherein a circulating air flow is forcibly generated in the drying chamber heated by the far-infrared heater, and the seed is brought into contact with the circulating air flow. Method. 3. The circulating air flow includes an internal circulating air flow that circulates air in the drying chamber, and an external circulating air flow that once derives air in the drying chamber to the outside and introduces air into the drying chamber again to circulate. 3. The method for sterilizing and drying seeds according to claim 2, comprising a stream. 4. The method for sterilizing and drying seeds according to claim 3, wherein the internal circulating airflow is further heated and circulated by a far-infrared heater. 5. The method for sterilizing and drying seeds according to claim 2, wherein the seeds are supplied to the drying chamber by storing the seeds in the drying chamber. . 6. The method for sterilizing and drying seeds according to claim 2, wherein the supply of the seeds to the drying chamber is continuously performed. 7. The heater according to claim 2, wherein the far-infrared heater is made of a ceramic material containing titanium oxide.
7. The method for sterilizing and drying seeds according to any one of items 6 to 6. 8. The depressurized state is 50 mm to 200 m water column.
The method for sterilizing and drying seeds according to any one of claims 2 to 6, wherein the range is m. 9. The temperature in the drying chamber is 5 ° C. to 45 ° C.
The method for disinfecting and drying seeds according to any one of claims 2 to 6, characterized in that: