JPH0222704B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention is a rice bran-type rice milling device that is used to finish milled rice with a glossy surface by adding water during milling of rice to moisten the bran layer on the surface of the rice grains and milling the rice. Regarding. [Conventional technology] The technology of adding water during rice milling to make it easier to remove bran and improve the surface finish has existed for a long time, and in recent years, various improved technologies have been proposed, such as the following: . For example, Special Publick No. 39-25314
The publication discloses a technique in which 0.5 to 4% water is added to rice, stirred, tempered for 5 to 20 minutes, and then milled. In addition, the special public
No. 10161 and Japanese Patent Publication No. 35-1771 disclose a technique for ejecting humidified air or water from holes in the wall of a whitening roll in a whitening room. Furthermore, in Japanese Patent Publication No. 39-25312, the first
A technique is shown in which water is added at the entrance of a conveyor that sends rice from a stage rice mill to a second stage rice mill. Also, Tokko Akira
In Publication No. 55-25900 and Publication No. 54-27345,
Techniques for adding water from the rice inlet or the outer wall of the milling room are shown. [Problems to be Solved by the Invention] However, none of the conventional water milling methods can be said to be practically sufficient, and it is not possible to obtain polished rice with a high gloss and a good surface finish. There are various possible reasons for this, but most of them are due to insufficient consideration of the milling theory regarding water-milled rice. In particular, no consideration is given to the selection of the timing of adding water to the rice grains or the milling effect associated with water addition, and the current situation is that water is simply added in the milling room or grain feeder. However, when water is added at the grain feeding port, the inner wall of the grain feeding port gets wet with moisture, which impedes the passage of rice, and in some cases makes it impossible for the rice to pass through. The surface gloss of the rice is insufficient. Furthermore, when water is added in the whitening room, the rice grains and water are not sufficiently kneaded and the surface gloss is insufficient. As described above, in all conventional methods, it was not possible to obtain the sufficient effect of water-milled rice, and it was not possible to finish polished rice with a high surface gloss as expected. In view of these points, the present invention has thoroughly researched the theory of rice polishing with water and provides a rice bran polishing device that can add water most effectively and thereby obtain polished rice with an extremely glossy finish. It's in the middle of the day. [Means for solving the problem] A grain feeding tube with a non-perforated wall surface, a grain feeding spiral rotated inside the grain feeding tube, a polishing tube with a perforated wall surface connected to the grain feeding tube, It consists of a jet friction type whitening roll that is rotated inside the whitening cylinder and a water adding device.
The grain feeding spiral and the milling roll are integrally connected and rotated at a high speed of 1000 to 1400 RPM, and a grain feeding opening is formed on the wall of the grain feeding chamber, and The water supply port of the water adding device is opened on the wall of the grain feeding tube between the mouth and the milling tube.
The purpose is to cause the supplied water to adhere to the inner peripheral wall surface of the grain feeding cylinder together with bran powder, so that a layer of clay bran is formed on the inner peripheral wall surface. [Function] In the wet rice bran milling apparatus of the present invention, water is added from the wall surface of the grain feeding chamber. Further, water is simply water at room temperature that is continuously injected from a water supply port having a needle-shaped hole provided on the wall of the grain feeding chamber. The appropriate amount of water to be supplied is about 0.2 to 1.5 wt% based on the amount of rice, and it is best to adjust the amount as appropriate depending on the type of rice, moisture content, precision of the first stage pounding, etc. Furthermore, since the grain feeding spiral rotates at high speed inside the grain feeding chamber, the rice grains in the grain feeding chamber are moving while rolling at high speed and under low pressure. Due to the movement of the rice grains in the grain feeding chamber, almost none of the water injected from the grain feeding chamber wall directly attaches to the rice grains, and most of the water adheres to the inner peripheral wall of the grain feeding chamber. This means that the wall surface of the grain feeding room has the highest water distribution rate in the room. Further, the rice polishing device of the present invention is for finishing purposes, and a separate rice polishing device is always provided at the front stage. Therefore,
The rice grains sent into the grain feeding chamber of the rice milling device are semi-milled rice that has already been milled to a certain extent. The appropriate degree of halfway milling is to pound the rice for 5 to 9 minutes. The rice grains sent to the grain feeding room in this way are half-milled and still have a considerable amount of bran remaining, so the water adhering to the inner peripheral wall absorbs the bran from this half-milled rice. This is kneaded by the high-speed rolling of rice grains to form a highly viscous clay-like or slimy bran (hereinafter referred to as clay bran). This clay bran forms and adheres to the inner circumferential wall of the grain feeding chamber in a layered manner, and is successively adhered to the surface of rolling rice grains and carried away. Moreover, the clay bran attached to the rice grains is uniformly dispersed on the surface of each rice grain while the rice grains are rolling. In this state, the grain is sent from the grain delivery room to the milling room. The rice grains with such high-moisture clay bran are further milled using a milling roll in the milling room. This whitening roll is of the blast friction type, and whitening ridges are attached to the surface of the roll, and a blast of air is constantly blown from the roll surface. In this way, the rice grains are polished by friction in the polishing room, and during this process, the moisture in the clay bran penetrates into the bran layer on the surface of the rice grains. Since the rate of penetration is through the clay bran, it is slower than when water is applied directly. Furthermore, since the clay bran on the surface of the rice grains is sticky, it is difficult to separate from the surface of the rice grains, and there is no rapid progress in removing the rice bran in the milling room. Therefore, in the polishing room, each rice grain is subjected to the polishing and bran removing action, as the rice bran newly generated from the surface of the rice grain is absorbed into the clay bran, and the polishing progresses slowly.
As this clay bran grows, it gradually becomes detached from the surface of the rice grain in the form of small lumps.
This separated bran is expelled to the outside through holes in the wall of the whitening chamber. In this way, the rice grains are slowly removed in the whitening chamber, and the rice grains are gradually sent toward the whitening chamber outlet, and the bran on the surface of the rice grains is completely removed before reaching the outlet. In addition, in the whitening room, air is blown out from the holes of the whitening roll, and this blast contributes to the removal of the bran and the surface finish of the rice grains. As described above, since the removal of bran from rice grains in the milling room progresses slowly, the surface of the rice grains after the removal of bran has a very good finish, resulting in extremely glossy polished rice. [Example] An example of the rice bran polishing apparatus of the present invention will be described with reference to the drawings. 1 is the grain feeding port, from which rice is supplied. However, this rice is not brown rice, but semi-polished rice that has been milled to a certain extent. Therefore, usually
A separate rice milling device is connected to the front stage, and the rice milled and milled at the front stage is continuously supplied to the grain feeding port 1. Rice grains supplied from the grain feeding port 1 enter into the grain feeding chamber 2. The outer wall of the grain feeding room 2 is a grain feeding tube 3 with no holes.
It is formed by. The shape of the grain feeding cylinder 3 is the second
It can be either a hexagonal cylinder as shown in the figure or a cylinder as shown in Fig. 3. Inside the grain feeding chamber 2, a grain feeding spiral 4 is rotated at high speed (1000 to 1400 RPM). The grain feeding spiral 4 is fixed to a hollow shaft 5,
As the shaft 5 is rotated by a drive device (not shown), it rotates integrally. The rice grains are located in the gap between the grain feeder spiral 4 and the grain feeder tube 3, and are stirred and rolled as the grain feeder spiral 4 rotates, and are also subjected to a pressure feeding action to be sequentially transferred toward the milling room. It will be done.
Reference numeral 6 denotes a water supply device, the water supply port of which is opened in the inner wall of the grain feeding cylinder 3, through which room temperature water is injected. The suitable diameter of the water supply port is 0.3 to 1 mm.
Simply inject water continuously. The appropriate amount of water to be supplied is about 0.2 to 1.5 wt% based on the amount of rice, and this amount can be adjusted freely. A milling room 7 is formed continuous with the grain feeding room 2. Reference numeral 8 denotes a milling cylinder, which is integrally continuous with the grain feeding cylinder 3, has a hexagonal cross-sectional shape, and has a large number of holes in its wall. Reference numeral 9 denotes a polished roll, which has polished ridges on its outer wall, is hollow in cross section, and has blowholes formed in its wall surface. The polishing roll 9 is fixed to the shaft 5 and rotates together with the shaft 5. Air is blown into the inner surface of the shaft 5 from a blower 10, and this air is blown out from holes in the wall of the shaft 5 and further out from the wall of the whitening roll. The rice grains entering the milling chamber 7 are subjected to milling and bran removal by the rotation of the milling rolls 9, and are sequentially sent to the grain discharging port 11. A pressure plate 12 is attached to the grain threshing port 11 so that the milling pressure inside the milling chamber 7 can be adjusted. A comparison of milling tests between the present invention and a conventional grain feeder or milling room in which a water adding device is attached is shown below. Test conditions: Rice used in the test: Nipponbare Pre-milling accuracy: 65% Rice feeding flow rate: 2.8t/hour Water addition rate: 0.7wt% Rice temperature before milling: 16℃ Milling horsepower: 20 HP The same rice milling equipment was used during the test. was used, and only the location of water addition was different.

〔Effect of the invention〕

In the rice bran milling device of the present invention, water is supplied from the wall surface of the grain feeding tube, and since the grain feeding spiral rotates at high speed, the supplied moisture is mainly applied to the inner peripheral wall surface of the grain feeding tube along with the bran powder. As a result, a layer of clay bran is formed on the inner peripheral wall surface. This clay bran then adheres to the surface of the rice grains, and the rice grains receive moisture from the clay bran. Therefore, unlike the case where water is directly attached to the rice grains, water permeates into the rice grains slowly, and the addition of water does not cause any adverse effects such as cracking, thereby preventing deterioration in taste. In addition, the clay bran attached to the rice grains has strong stickiness, so
Even in the milling room, there is no rapid progress in removing the bran, and as a result of slow milling, the surface finish of the rice grains is very good, and polished rice with a rich surface gloss can be obtained. Furthermore, since the water supply port is simply formed on the wall of the grain feeding cylinder, the structure is simple and a separate stirring device is not required.

[Brief explanation of drawings]

The drawings show an embodiment of the rice bran polishing device of the present invention,
Figure 1 is a vertical side view, Figure 2 is a sectional view of the grain feeding section,
FIG. 3 is a cross-sectional view of one using a cylindrical grain feeder. 1... Grain feeder, 2... Grain feeder, 3... Grain feeder,
4...Grain feeding spiral, 5...Shaft, 6...Water supply device, 7
...Refining room, 8... Refining tube, 9... Refining roll,
10...Blower device, 11...Grain removal port.

Claims (1)

[Claims] 1 A grain feeding tube with a non-perforated wall surface, a grain feeding spiral that rotates inside the grain feeding tube, a milling tube with a perforated wall surface connected to the grain feeding tube, and a jet that rotates inside the milling tube. It consists of a wind friction type whitening roll and a water adding device, and the grain feeding spiral and the whitening roll are integrally connected and are rotated at a high speed of 1000 to 1400 RPM. A grain feeding port is formed, and the water supply port of the water adding device is opened on the wall surface of the grain feeding tube between the grain feeding port and the milling tube, and the supplied moisture is mainly distributed around the inner periphery of the grain feeding tube. A wet rice bran type rice polishing device characterized in that clay bran is deposited on a wall surface together with rice bran so that a layer of clay bran is formed on the inner peripheral wall surface.