JP2003021459A - Method and equipment for drying raw unhulled rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dry raw unhulled rice up to a prescribed moisture value in a short time without deteriorating the quality thereof. SOLUTION: A process wherein the raw unhulled rice is exposed to warm air, while being irradiated with a microwave, and a process wherein the raw unhulled rice is cooled after completion of the above process, are conducted one time respectively or repeated until the rice reaches the prescribed moisture value. These processes are executed with the rice held in a rotary drum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a drying method and a drying apparatus for drying cut rice to a predetermined moisture value suitable for storage, and particularly to the quality of raw rice. The present invention relates to a drying method and a drying device capable of drying in a short period of time without dropping.

[0002]

2. Description of the Related Art Generally, cut rice grain is brought into a country elevator for storage, threshed at a rice center, and shipped as brown rice. In this process, the raw rice brought into the country elevator must be dried to a predetermined moisture value suitable for storage. In addition, in order to check the quality of raw paddy brought in to the cant elevators from each farmer, a sample of raw paddy is taken, dried, and then a voluntary inspection device is used to calculate the percentage of polished brown rice and the percentage of scrap rice. Conventionally, when drying the unhulled rice for these purposes, in order to dry the unhulled rice in a state as close to natural drying as possible, wind the unhulled rice with a temperature of about 45 ° C. or less to reduce the water content of the unhulled rice to about 15% or less. The method of drying until it is adopted is adopted.

[0003]

[Problems to be Solved] However, a method of drying raw rice by blowing air at about 45 ° C. or lower has a drawback that the drying time becomes long. For example, a large amount of raw rice containing about 24% water is dried at 0.6% per hour in order to apply warm air of about 45 ° C. to dry the rice to a moisture value of 15% or less. It takes about 15 hours to treat the paddy, and the same time is required to dry the sample. Such a long drying time causes the following problems. In other words, the quality of the raw rice brought into the country elevator will deteriorate unless it is dried within 24 hours. Therefore, when a large amount of raw rice is brought in, a large-scale device with a large processing capacity is used for day and night. Processing work has to be done. Moreover, when examining the quality of raw paddy, a large amount of raw paddy brought in from each farmer must be put into a dry state and evaluated promptly, so that a long drying time makes rapid evaluation impossible.

As a method of drying the raw rice in a short time, a method of applying a high temperature wind exceeding about 45 ° C. can be considered. However, when I tried to dry the raw rice with high temperature wind, only the surface of the brown rice part inside the rice husk was dried and the inside became undried state, so the strain was generated in the brown rice part, and the strain caused the "crack cracking". "
It was found that cracks called "rice cracking" occurred and brown rice became defective rice or scrap rice. Therefore, in order to heat and dry the brown rice part from the inside, we tried to irradiate microwave on the raw rice, but the inside of the brown rice part was dried, but the water that came out near the surface was blocked by the rice husks. It was found that the drying efficiency of the whole raw rice is poor because it is difficult to get outside.
It was also found that even with this method, the moisture inside the brown rice portion and in the vicinity of the surface became unbalanced, causing a cracking phenomenon.
Therefore, it is conceivable to use the above two methods together. A drying method in which internal heating by microwaves and external heating by warm air are simply used together has already been used for drying other grains, for example, coffee beans. However, even if the drying method is directly applied to the drying of raw paddy, the cracking phenomenon of brown rice often occurs, and the raw paddy cannot be dried in a short time without degrading the quality. The reason is that in the drying of raw rice, delicate treatment is required to remove moisture as uniformly as possible from the inside of the brown rice portion to the vicinity of the surface, and simply heating the inside and outside of the raw rice with different heating means. It is considered that this is because the above processing cannot be achieved.

Therefore, regarding the drying of raw paddy, it is possible to realize a drying method capable of drying to a predetermined moisture value in a short time without deteriorating the quality of the raw paddy, and a drying apparatus suitable for carrying out the method. Was desired.

[0006]

[Means for Solving the Problems] As a result of various experiments for solving the above problems, as a result of using the following means, raw rice can be obtained in a predetermined moisture value in a short time without causing a cracking phenomenon of brown rice. It turned out that it can be dried up to.

That is, first, as a basic drying method, raw rice is prepared by irradiating the raw rice with microwaves while irradiating microwaves with the hot air and cooling the raw rice after the completion of the step. A method of performing each once or repeatedly is used until a predetermined moisture value is reached. A particularly important point in this method is to carry out a step of cooling the raw rice with cold air of, for example, about 10 ° C. after the step of applying the hot air while irradiating the raw rice with microwaves. When the rice inside is heated by microwaves, the moisture in the brown rice part gradually comes out near the surface, so more intense self-heating occurs near the surface of the brown rice part, and heat from the outside is added to this, The brown rice portion becomes excessively heated just before and immediately after the end of heating, which causes cracking of the brown rice. Cooling the raw rice after heating lowers the temperature of the excessively heated surface of the brown rice portion, and has an important function of preventing excessive removal of water.

Secondly, as a method suitable for carrying out the above-mentioned basic drying method, the raw rice is stored in a drum which is rotated around a rotary shaft provided in a horizontal direction, and the drum is A method of applying warm air while irradiating microwaves to the raw paddy while rotating and cooling the raw paddy after a predetermined time elapses to dry the raw paddy to a predetermined moisture value is used.

An important point in this method is that the unhulled rice is housed in a rotating drum, and hot air is applied while irradiating the unhulled rice with microwaves while rotating the drum. As a result, microwaves and warm air can be evenly applied to the raw rice, so that a large amount of raw rice can be uniformly dried.

Thirdly, as a device suitable for carrying out the above-mentioned method, a drying device main body provided with a microwave source, and a drying device main body which rotates about a horizontal rotation axis inside the drying device main body. A rotary drum for storing raw rice made of a microwave transmitting material installed in the rotary drum, and an air blower capable of sending air for heating or cooling from the outside to the inside of the rotary drum during rotation of the rotary drum; A detection device for detecting the temperature and weight of raw rice stored in a rotary drum, and control for adjusting the output of the microwave generation source and the output of the blower device based on detection data of the detection device or a preset program And a device for drying raw rice with a device.

An important point in this device is that the output of the microwave generator and the output of the blower are adjusted according to the temperature and weight of the raw rice stored in the rotary drum. With this, regardless of the water content of the raw rice to be dried, the amount of dry treatment, etc.,
Raw rice can be accurately dried to a specified water content.

Fourthly, as a rotary drum suitable for the drying device, a drum main body made of microwave permeable material for accommodating raw rice and a hollow rotary shaft inserted and fixed in the center of the drum main body are used. The drum main body has a raw rice input / discharge port in a part thereof and a shelf portion extending along the rotation axis in a part of an inner wall, and the rotation shaft is fixed to the drum. A rotary drum for a raw rice drying apparatus is used, which has a blower opening for sending the air blown through the rotary shaft into the drum main body at a portion located inside the main body.

An important point in this construction is that the inner wall of the drum body is provided with a shelf portion extending along the rotation axis and that the portion of the rotation axis located inside the drum body is fed through the rotation axis. That is, a blower opening is provided to blow the wind into the drum body. With this configuration, the microwave and the wind can be evenly applied to the raw paddy that falls from the shelf due to the rotation of the drum.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view schematically showing a main part of an apparatus for carrying out the method for drying raw rice according to the present invention. In the figure, 1 is a drying apparatus main body, 2 is a microwave generation source installed inside the drying apparatus main body 1, and 3 is a rotary drum also installed inside the drying apparatus main body 1. The rotary drum 3 is composed of a drum body 4 made of a microwave transparent material for storing raw rice and a hollow rotary shaft 5 inserted and fixed in the drum body 4. One end of the rotary shaft 5 is closed, and the other end is connected to a blower (not shown). Also, the rotating shaft 5
In the portion of the drum body 4 located inside the drum body 4, there are provided blower openings 6a, 6b, ... Reference numeral 7 denotes raw rice stored in the drum body 4.

The basic process for drying raw rice with such a drying apparatus will be described below. First, while rotating the rotary drum 3, the microwave generation source 2 irradiates the raw rice 7 in the drum body 4 with microwaves. Simultaneously with the microwave irradiation, a step of sending warm air of about 30 to 35 ° C. into the drum body 4 through the rotary shaft 5 and applying it to the raw rice 7 is carried out. When the raw rice is heated from the inside and outside in this way, the moisture that has come out from the inside to the surface due to the self-heating of the brown rice portion is dried by the warm air that hits the rice husk, so that the raw rice is dried in an extremely short time.
In this way, when the moisture value of the raw rice decreases and reaches a predetermined value, the step of applying warm air while irradiating microwaves is stopped, and cold air of about 5 to 10 ° C. is drummed through the rotating shaft 5 this time. A step of cooling the raw rice 7 by sending it into the main body 4 is carried out. The step of cooling the raw rice is extremely important when the heating with microwaves and the heating with warm air are used together as described above. That is, when the inside of the raw rice is heated by microwaves, the moisture in the brown rice part gradually comes out near the surface, so that more intense self-heating occurs near the surface of the brown rice part, and when heat from warm air is added to this. The brown rice portion becomes excessively heated immediately before and immediately after the end of heating, which causes cracking of the brown rice. The cooling process of the raw rice has an important function of preventing the cracking of the barrel due to such a cause. Incidentally, the step of applying warm air while irradiating the microwave and the step of cooling the raw paddy, according to the initial moisture value of the raw paddy and a predetermined target moisture value for drying, each once or Repeat appropriate times.

[0016] In these steps, if the raw rice is heated under uniform conditions regardless of the amount of dry treatment, the initial moisture content, and the change in moisture content accompanying the drying treatment, an appropriate drying treatment can be performed. There is a risk of disappearing. FIG. 2 is a block diagram showing a drying device having a function of adjusting the intensity of microwaves and the temperature of wind corresponding to the above case. In the figure, 1 is a drying apparatus main body, 2 is a microwave source, and 3 is a rotary drum for storing raw rice. Reference numeral 8 is a blower for blowing air into the drum body 4 through the hollow rotary shaft 5 while the rotary drum 3 is rotating, 9 is a detector for detecting the temperature of the raw rice in the rotary drum, 1
0 is a detection device for detecting the weight of raw paddy in the rotary drum, 11 and 12 are microwave generators based on the detection data of the detection devices 9 and 10, or based on a preset program. It is a control device that adjusts the output of the source 2 and the output of the blower 8. According to the apparatus having such a configuration, if the temperature inside the rotary drum becomes too high despite the small amount of raw rice being dried, the control device 11 controls the detection data by the detection device 9. The blast temperature will be lowered. Further, as the water content in the raw rice decreases with the progress of the drying treatment of the raw rice, the weight of the whole raw rice becomes lighter. Therefore, the detection device 10 operates and the output of the microwave generation source 2 is limited by the control device 12. Will be done.

Further, what is important when the raw rice is dried by such an apparatus is that the microwave and the wind are uniformly applied to the whole raw rice. Therefore, in the present invention, the rotating drum is used as described above, but the rotating drum having the structure shown in FIG. 3 is suitable. In the figure, 3 is a rotary drum, 4 is a drum body for storing raw paddy made of a microwave transmitting material, and 5 is a hollow rotary shaft which is inserted and fixed in the drum body 4. In the portion of the rotary shaft 5 located inside the drum body 4, blower ports 6a, 6b, ... There is. Further, a part of the drum body 4 is provided with an opening / closing port 13 for opening and closing raw rice, and a part of an inner wall of the drum body 4 has a shelf portion 14 extending along the rotation axis 5. Is provided. The shelf portion 14 plays an important role in uniformly applying microwaves and wind to the raw paddy inside when the rotary drum 3 is rotated. Fig. 4- (a)
4 to FIG. 4- (f) are for explaining the operation of the shelf portion 14 when the drum body 4 is rotated.
4 (c), when the drum body 4 is rotated in the direction of the arrow, the position of the shelf 14 changes as shown in the figure, and when it comes to the position of FIG. Part of the rice begins to fall, and after passing through the state of FIG. 4- (e), all the rough rice falls as shown in FIG. In these processes, the shelves 14
Since the microwave and the wind hit the raw rice while the raw rice falls from the rice paddy, this structure makes it possible to uniformly apply the microwave and the wind to the raw rice. FIG. 5 shows another embodiment of the rotary drum suitable for carrying out the present invention. In the figure, the reference numerals indicating the respective components correspond to those of the embodiment shown in FIG. The feature of this embodiment is that the cylindrical portion forming the drum body 4 is formed in a spiral shape instead of a perfect cylindrical shape, so that the raw rice input / discharge port 13 and the shelf portion 14 are integrated with the drum body 4. Is formed. In this structure, when the paddy rice is put into the drum body 4, the drum body 4 is fixed at the position shown in FIG. 6 at the time of putting and the drum body 4 is rotated in the direction of the arrow A so that the shelf portion 1
4 has the same function as in the embodiment of FIG. Then, when the raw rice is discharged, the drum body 4 may be rotated in the direction of the arrow B as in the case of discharging the rice. According to this structure, it is not necessary to provide an opening / closing opening / closing opening as shown in FIG. 3, and there is an advantage that the shelf portion 14 does not need to be attached separately.

7- (a) to 7- (d) show the drum body 4
This is for explaining the action of the shelf 14 when the drum is rotated. When the drum body 4 is rotated in the direction of the arrow, the position of the shelf 14 changes as shown in FIG. ) Position, a part of the raw paddy begins to fall from the shelf portion 14, and FIG.
In the state of (d), all the raw paddy drops. In these processes, the microwave and wind hit the raw paddy while the raw paddy falls from the shelf portion 14, so that the microwave and the wind can be uniformly applied to the raw paddy according to this structure. FIG. 8 shows an apparatus for drying a sample of raw rice using the rotary drum of the apparatus shown in FIG. 1 having the structure shown in FIG.
It is a graph which shows the relationship between the drying time, the weight of raw paddy, and the moisture content in the case of performing a drying experiment of 00 g.

The experimental apparatus and experimental specifications are as follows. Microwave output: Water content of raw rice (W) = up to 21.1 to 17.3%:
600W 17.4 to 16.1%: 500W Hot air temperature: 35 ° C Cold air temperature: 10 ° C Heating / Cold air time: (W) = 21.1 to 17.3%: Heating 30 seconds,
Cold air 15 seconds 17.4 to 16.1%: Heating 15 seconds, cold air 3 seconds

As a result of this experiment, as shown in FIG. 8, the initial moisture value of raw paddy was 21.1% and the moisture content of dry paddy was 16.1% (brown rice 1
It took only 14 minutes to dry to (5.6%). Moreover, no cracking of the brown rice portion occurred at all.

[0021]

As is apparent from the above description, according to the method and apparatus for drying raw rice according to the present invention, a predetermined moisture value can be obtained in a very short time without deteriorating the quality of cut raw rice. Can be dried up to. Therefore, the sample drying for quality evaluation of raw rice and the drying of a large amount of raw rice brought into the country elevator are promptly performed.
Can be implemented accurately. Moreover, since the drying device according to the present invention has a relatively simple structure, it can be easily implemented from a small device for testing to a large device for production. Furthermore, according to the present invention, raw rice can be stably dried to a specified moisture value regardless of the water content of the raw rice to be dried, the amount of dry treatment, and the like.

[Brief description of drawings]

FIG. 1 is a view showing a main configuration of an apparatus for carrying out a method for drying raw rice according to the present invention.

FIG. 2 is a block diagram showing the overall configuration of a raw rice drying apparatus according to the present invention.

FIG. 3 is a perspective view showing an embodiment of a drying rotary drum used in the raw rice drying apparatus according to the present invention.

FIG. 4 is a diagram showing a situation of raw paddy inside the rotary pad for drying in the raw paddy drying apparatus according to the present invention.

FIG. 5 is a perspective view showing another embodiment of the rotary drum for drying used in the raw rice drying apparatus according to the present invention.

[Fig. 6] Fig. 6 is a diagram for explaining a state in which raw rice is put in and discharged in the rotary drum for drying used in the apparatus for drying raw rice according to the present invention.

FIG. 7 is a diagram showing a situation of raw paddy inside the rotating rotary drum for drying in the raw paddy drying apparatus according to the present invention.

FIG. 8 is a graph showing the relationship between the drying time and the weight and water content of raw paddy when a raw paddy sample was dried using the method and apparatus according to the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiki Ijima             471-4 Ikari, Kawaguchi City, Saitama Prefecture F term (reference) 3L113 AA06 AB03 AB07 AC01 AC13                       AC45 AC48 AC52 AC54 AC58                       AC63 AC67 BA03 CA02 CA03                       CA04 CB08 CB24 DA10 DA24

Claims (4)

[Claims] 1. A step of applying hot air while irradiating microwave to the raw rice and a step of cooling the raw rice after completion of the step, once each until the raw rice reaches a predetermined moisture value. Alternatively, a method for drying raw rice is characterized in that it is repeatedly performed. 2. The raw rice is stored in a drum which rotates about a rotary shaft provided in a horizontal direction, and while the drum is rotated, hot air is applied while irradiating the raw rice with microwaves for a predetermined time. cooling the Namamomi after elapse, raw rice drying wherein the to drying raw rice to a predetermined moisture content. 3. A drying apparatus main body having a microwave generation source, and a microwave transmitting material installed inside the drying apparatus main body so as to rotate about a horizontal rotation axis. A rotating drum, an air blower capable of sending air for heating or cooling from the outside to the inside of the rotating drum during rotation of the rotating drum, and detecting temperature and weight of raw rice stored in the rotating drum And a control device that adjusts the output of the microwave generation source and the output of the blower based on the detection data of the detection device. 4. A drum body for storing raw rice, which is made of a microwave transmitting material, and a cylindrical rotating shaft which is inserted and fixed in the central portion of the drum body. And a shelf portion extending along the rotary shaft on a part of the inner wall, and the rotary shaft is provided at a portion located inside the drum body fixed to the rotary shaft. A rotary drum for a drying unit of raw rice, which has a blower opening for blowing the air blown through the drum body into the drum body.