JPS62224249A - Humidification of rice - Google Patents

Abstract

PURPOSE:To enable uniform moistening of rice grains in a desired rice-polishing stage with a simple apparatus and to prevent the generation of grain breakage and cracking, by using a U-shaped through furnished with a number of specific stirring blade sets, feeding the through with rice grains together with water mist product by using air as a carrier and mixing the rice in the through. CONSTITUTION:A rotary shaft 2 rotatable by power transmitted from a pulley 10 is placed in a U-shaped trough 1. A number of stirring blade sets each composed of four rectangular flat blades are radially attached to the rotary shaft 2 in a manner staggered by 45 deg. from each other. The tip end of the blade 31 is separated from the semicircular bottom of the U-shaped trough 1 keeping a specific gap therebetween to enable the free rotation of the blade. Rice grains are continuously supplied at a specific flow rate from the grain-feeding pipe 8 into the U-shaped trough 1. Separately, water is atomized to water droplets of <=10mu diameter by an atomizer 4 by ultrasonic oscillation, etc., and suspended in the form of mist in an air stream sucked with a blower 5 through a grain-discharge pipe 9 and a filter 6. The mist is supplied together with the above rice to the U-shaped trough 1 and the stirring blade 3 is rotated so as to make the rice grain contact with the water droplet in high frequency. The surface of each rice grain can be uniformly moistened by this process and the moistened grains are discharged through the grain-discharge pipe 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for humidifying milled rice that can be continuously processed for brown rice tempering in the pre-processing process of milling, humidification during the milling process, and tempering of polished rice after the milling process. .

Conventional technology In order to prevent the rice from cracking due to humidification, the conventional method of humidifying rice is the so-called Danish silo method, in which highly humid air is passed between the grains of ready-to-eat rice, and due to the difference in water vapor pressure between the air and the rice grains, Japanese Patent Laid-Open No. 56-26164 discloses a method of making rice grains absorb moisture, and a tank in which rice is allowed to flow down at a low speed and humidified by passing between the rice grains, or a tank in which this method is developed. There are inventions such as Japanese Patent Publication No. 57-44502 in which a grain frying device is attached to a grain hoist to form a circulation path through which rice flows, and a predetermined amount of water is directly sprayed on the circulating rice to humidify it. In this method, a predetermined amount of rice is stored in a tank, and the rice is circulated and flowed, and the rice in the tank or in the grain path is humidified.The humidification process is performed in batches for each tank capacity. However, since it cannot be processed continuously, it cannot be attached to a rice milling device that continuously mills rice as a continuous process.

Means to Solve the Problem The weight of one water droplet when water is atomized is proportional to the cube of the diameter, and the number of water droplets of the same weight is inversely proportional to the sixth power of the diameter.

The average weight of one grain of rice is approximately 20'+9, and the diameter, weight, and number of water droplets of 0.2rNi water when humidifying at one rate per grain of rice are shown in Table 1 below. .1
When it is 1, it is about 380,000 pieces, and when it is 5μ, it is about 3 million pieces (this is a huge number).

(Table 1) Mist water droplet diameter, weight, and number of 1% humidified water droplets per rice grain Weight of 1,000 rice grains 20P (this space is used to store continuously fed rice and humidified grains) The rice is atomized into water droplets and continuously supplied by flowing air as a carrier, causing frequent contact between rice grains and water droplets and rice grains to evenly moisten the surface of each rice grain and continuously humidify the rice. The gist is to continuously supply rice at a predetermined flow rate into the U-shaped trough 1 and atomized air in which a predetermined flowing water mainly atomized into water droplets with a diameter of 10p or less is suspended, Rotate the rectangular wings!112
By rotating stirring blades 3 installed radially in the U-shaped trough I, the difference in passing speed in the U-shaped trough I due to the difference in the flow rate of the rice and mist air, and the difference between the air as a fluid and the rice grains as a granule. Due to differences in the state and direction of motion due to gender differences, the rice and mist air move in parallel in the U-shaped trough 1 and undergo long-distance rotational motion, resulting in rice grains, fine water droplets, and a huge number of water droplets. The rice grains come into contact with each other frequently, and are stirred to evenly deposit fine water droplets on the surface of each grain of rice. The rice can be continuously moisturized by uniformly moistening the surface of the rice to prevent cracks from forming on the side of the humidifying body.

Effect When humidifying 1 grain of rice, the atomized water droplet diameter is 10
Assuming an average of 5 μ below μ, the number of water droplets reaches approximately 3 million as shown in Table 1.

Rice and atomized air that are continuously supplied into the U-shaped trough 1 move in a cocurrent flow through the U-shaped trough 1 due to the rotation of a large number of stirring blades 3, but the air flows faster than the rice. The flow rate is large, and the time and speed of passing through the U-shaped trough 1 are large, and the atomized air is rotated and agitated, passing through the rice grains that scatter and fall repeatedly. and proceed.

Air rotates in the trough 1 as a perfect fluid, but
The rotation radius of the rice on a large number of stirring blades 3 differs depending on their position, and the rice on the stirring blades 3 rotating at the same rotation speed also has a difference in circumferential speed depending on the rotation radius, and some of the rice is stirred due to the acceleration of gravity. When the blades 3 become horizontal and the centrifugal force cannot be blocked by the inner surface of the bottom of the U-shaped trough 1, each grain of rice is scattered diagonally upward a distance corresponding to its circumferential velocity, and an acceleration smaller than the acceleration of gravity moves ( When the stirring blade 3 rotates and the angle of the blade becomes larger than the angle of repose of the rice, the rice rotating at a circumferential speed slides down the blade surface and scatters on the bottom of the U-shaped tray 1.

As mentioned above, the rice and the mist-like air that flow together in the U-shaped tray 1 due to the 30 revolutions of the stirring blade rotate while moving in the same direction, and the rice flows in the U-shaped tray 1 under scattered rain at a low packing density. However, when humidifying at 1%, a large number of fine and huge water droplets are suspended in the intergranular area, which undergoes repeated long-distance and high-frequency convection, shearing, and diffusion mixing. As air passes through, the water droplets come into contact with the rice grains and adhere to the surface.

Due to the mixing and stirring movement of rice convection, shear, and diffusion, rice grains 1
The water droplets that adhere uniformly to the surface of each grain are not only given and received by each other due to frequent contact with each other, which not only averages out the amount of humidification of the flowing rice, but also makes the surface of each rice grain more even. become moist.

Example Embodiments of the invention will be described with reference to the drawings.

A rotating shaft 2 that rotates by transmitting power from a pulley 10 is provided in the U-shaped trough 1, and the rotating shaft 1 has many sets of stirring blades 3 each consisting of four rectangular flat blades. : They are attached radially in the radial direction so as to cross each other alternately, and the tips 24 are provided so as to rotate while maintaining a predetermined gap with the semicircular bottom of the U-shaped trough 1.

A predetermined flow rate of rice is continuously supplied into the U-shaped trough 1 through a grain feeding pipe 8, and is discharged through a grain discharging pipe 9.

The atomizer 4 atomizes a predetermined flow rate of water into fine particles with a droplet size of mainly 10 μm or less and mainly 7 μm or less using ultrasonic waves. The supplied air is suspended in a mist-like airflow as a carrier, and is caused to flow into the U-shaped trough 1 together with the rice from the grain feeding pipe 8 as a mist-like airflow. The air as a carrier is chained inside the humidifying device, and the atomized water is not released outside the device, and the entire amount is absorbed into the rice and humidified at +7 Hz.

A large number of stirring blades 3 rotate at a predetermined number of revolutions in the U-shaped trough 1, and the angular velocity does not change, but the radius of rotation and circumferential speed change depending on the position on the surface of the stirring blades 3, and the acceleration increases in proportion to the radius of rotation. Become.

The acceleration of gravity is 9.8 m/ depending on the position on the three surfaces of the stirring blades.
Some of the particles fall through the S2 gap, but when the stirring blade becomes horizontal and the centrifugal force is no longer blocked by the inner surface of the bottom of U-shaped trough 1, they are scattered diagonally upward due to inertia with a flight distance corresponding to the difference in circumferential speed, and on the other hand, due to the acceleration of gravity For rice that is rotating at a circumferential speed with a smaller acceleration acting on it, the inclination of the stirring blade 3 is wider than the angle of repose of the rice (if this happens, it will slide down the surface of the stirring blade 3 and be scattered at the bottom of the U-shaped trough 1,
A synergistic effect is produced by adding the mixing movement mainly based on convection and shear caused by the 30 rotations of a large number of sets of stirring blades, and the diffusion mixing movement due to the difference in circumferential speed on the three surfaces of the flat stirring blades.

On the other hand, in the atomized airflow using air as a carrier, the radial flat plate blades of the stirring blades 3 act in the same way as the radial blades of a centrifugal blower due to their rotation, giving rotational motion and centrifugal force to the atmospheric flow, and
Water droplets in the airflow within the shaped trough 1 move forward while rotating due to the centrifugal force so that the outer periphery becomes highly concentrated.

There tends to be a large difference in the flow rate of air and rice supplied inside the U-shaped trough 9.
, the rice with a low packing density is stirred by the rotation of many stirring blades 3, and is scattered while rotating inside the gU-shaped human rough 1, and is attacked in detail by manipulating the long-distance, large-frequency convection, shear, and diffusion mixing motion that decreases pN. In addition, a mist-like air current in which a huge number of water droplets are suspended passes between the grains of rice rotating at the same speed, and the water droplets adhere uniformly to the surface of the rice grains, and at the same time, the rice grains come into contact with each other and exchange the attached water. Then, spread it out evenly.

The movement of the rice mixed and humidified in the U-shaped trough 1 and the A-shaped airflow is confirmed by transparent observation using a testing machine in which the lid of the U-shaped trough 1 is a transparent plate.

An experimental example of mixing conditions in which almost all of the water droplets adhered to the rice grains in the U-shaped trough 1 and no fog was visible at the terminal was as follows.

U-shaped trough bottom radius 0.15m U-shaped trough length 1.5m Number of stirring blades (15X
4) 60 sheets rotation speed (100RPM)
1.67r, p, s trough polished rice flow rate (approximately 1.2
5/11) Approximately 21 kg/min trough polished rice density
Approximately 0.1 trough white rice passing time
Approximately 50 seconds Carrier air current approximately 1.0
m'/min Air passage time in the trough: Approximately 8 seconds Maximum movement distance (approximately assuming that the trough rotates with a radius of 0.15 m at the bottom) 2yr, D, 15xi, 67r, p, 5x30 seconds + 15
m () rough length) = 4s7m Maximum movement distance of air 2π, 0.15xt67r, p, sx8 seconds + 1.5m (
) Rough length) = 14.1 m To understand the degree of mixing, estimate based on the maximum movement distance °r. When humidifying 1 inch with the average diameter of water droplets in the mist air stream being 5 μ, the mixing of each grain of rice is The conditions were that a huge number of water droplets (5 million grains per 7ζ grain of rice) flowed 14 meters while rotating approximately 13 times in the U-shaped tray 1, and the rice flowed 49 meters while rotating 50 times for 50 seconds. During this time, the mixture is stirred 3000 times by 60 stirring blades 3, and is also affected by the turbulence of the air current and buoyancy, resulting in convection, shearing, and diffusion mixing movements.

Atomization can be carried out as long as the water droplets are suspended in the air and the air can flow as a gear at a diameter of 100 μm or less, but nozzle spraying can also be carried out with a water droplet diameter of 10 μm or less, which is technically possible. Then you will get good results.

Effectiveness: No need for tank size, bond setting A'a, brown rice tempering in the pre-processing process of rice milling, humidification and polishing in the middle of the milling machine, white rice for milled rice, etc. It can be installed in series in all rice production processes, and its small volume allows for significant savings in installation space and installation costs.

As a result of evenly moistening the surface of each grain of rice, when polished rice is moistened with MJ, rice grains open during soaking in the cooking Ail, which can occur depending on the quality of the rice. It has the effect of reducing rice cracking that causes cracks.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of an apparatus showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line A-A' inside the U-shaped trough 1.

Claims (1)

[Claims] (1) Continuously supply rice at a predetermined flow rate to the U-shaped trough (1) and air at a predetermined flow rate in the form of mist in which a predetermined flow rate of water that has been atomized into water droplets with a diameter of 10μ or less is suspended. ) The rice and mist air move through the trough (1) at different speeds by rotating a large number of stirring blades (3), each of which has rectangular blades installed in a rotating shaft (2) radially in the radial direction. It rotates over a long distance while proceeding as a parallel current, and mixes and stirs the rice grains with a large number of minute water droplets that frequently come into contact with each other, evenly moistening the surface of each rice grain. A rice humidification method characterized by: