Rice pre-treatment method and rice pre-treatment system

Abstract

To provide a pretreatment method of cooked rice and a pretreatment system of cooked rice which reduce rice bran attached to an immersion tank, and thereby can cleanly use the immersion tank.SOLUTION: A pretreatment system 10 of cooked rice includes an immersion tank 61 for storing a predetermined amount of immersion water W4, and immersing washed rice grains which are washed and polished rice grains in the immersion water and making them immersed rice grains, and a flowing pipe 46 which extends in an approximately vertical direction and falls and flows the washed rice grains into the immersion water, wherein the opening of the flowing pipe is positioned below the water surface of the immersion water and a water surface of the immersion water is formed in the flowing pipe, and the washed rice grains having been made to fall and flow in the flowing pipe are dropped on the water surface of the immersion water formed inside the flowing pipe.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention particularly relates to a pre-treatment method for rice cooking and a pre-treatment system for rice cooking when a relatively large amount of rice is required, such as in school lunches, hospital meals, and large-scale food industries.

Background Art

[0002] When washing rice and cooking rice in a relatively large amount, a pre-treatment system for rice cooking is often used in which polished rice grains are washed to obtain washed rice grains, and the washed rice grains are stored in a soaking tank filled with soaking water and soaked in the soaking water to obtain soaked rice grains that have absorbed the soaking water.

[0003] Patent Document 1 describes a rice washing device in which polished rice grains are flowed together with rice washing water through a rice washing means provided in a pipe to obtain washed rice grains, and the mixed fluid of the rice washing water and the washed rice grains is supplied to an inclined plate composed of a mesh net, so that the washed rice grains are separated from the mixed fluid, and the separated washed rice grains are allowed to fall and flow into a soaking tank filled with soaking water to soak the washed rice grains in the soaking water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the rice washing device described in Patent Document 1, the washed rice grains separated from the mixed fluid are attached with the rice washing water mixed with rice bran peeled from the polished rice grains by the rice washing means, and the washed rice grains with the attached rice washing water mixed with rice bran flow down into the soaking water stored in the soaking tank.

[0006] When a large quantity of pre-washed rice grains are sent to the soaking tank, the pre-washed rice grains, still coated with the water containing rice bran, fall and flow into the soaking tank, generating a large amount of rice bran foam on the surface of the soaking water stored in the tank. The soaking tank is designed to discharge the soaking water along with the rice bran foam floating on the surface by overflowing it, but only the rice bran foam near the overflow pipe is discharged, and the design does not actively discharge the rice bran foam floating on the surface of the soaking water. As a result, the generated rice bran foam spreads on the water surface, adheres to the walls of the soaking tank, and dries, making it difficult to use the equipment cleanly.

[0007] The present invention aims to solve the aforementioned conventional problems and to provide a rice pre-treatment method and a rice pre-treatment system that allow the immersion tank to be used cleanly by reducing the amount of rice bran adhering to the immersion tank. [Means for solving the problem]

[0008] The rice pre-treatment method of the present invention is: Polished rice grains are washed to become pre-washed rice grains. The process includes a soaking step in which the pre-washed rice grains are dropped and flowed into a soaking tank containing soaking water, and the pre-washed rice grains are soaked in the soaking water to become soaked rice grains. In the aforementioned immersion step, The opening of the flow pipe, which extends in a substantially vertical direction, is positioned below the water level of the immersion water to form the water level of the immersion water within the flow pipe. The washed rice grains, which have been allowed to fall and flow through the flow pipe, are brought to the surface of the soaking water formed inside the flow pipe. It is characterized by the following:

[0009] Furthermore, the rice pre-treatment method of the present invention is Polished rice grains are washed to become pre-washed rice grains. The process includes a soaking step in which the pre-washed rice grains are dropped and flowed into a soaking tank containing soaking water, and the pre-washed rice grains are soaked in the soaking water to become soaked rice grains. In the aforementioned immersion step, Within the partitioned area, which is a region where the surface of the soaking water is partitioned by the inner wall of the soaking tank and a plate-shaped partitioning member, the washed rice grains that have been dropped and flowed are brought to the surface of the soaking water. It is characterized by the following:

[0010] The rice pre-processing system of the present invention is A soaking tank stores a predetermined amount of soaking water, and soaks pre-washed rice grains, which are polished rice grains that have been washed, in the soaking water to make soaked rice grains, A flow pipe extending in a substantially vertical direction, which causes the washed rice grains to fall and flow into the soaking water, Equipped with, The opening of the flow pipe is positioned below the water level of the immersion water to form the water level of the immersion water inside the flow pipe. The washed rice grains, which have been allowed to fall and flow through the flow pipe, are brought to the surface of the soaking water formed inside the flow pipe. It is characterized by the following:

[0011] The rice pre-processing system of the present invention is A soaking tank stores a predetermined amount of soaking water, and soaks pre-washed rice grains, which are polished rice grains that have been washed, in the soaking water to make soaked rice grains, A plate-shaped partitioning member that partitions the rice bran foam floating on the surface of the immersion water, Equipped with, A partitioned area is formed on the surface of the immersion water, which is a region partitioned by the inside of the wall surface of the immersion tank and the partitioning member. The washed rice grains, which have been allowed to fall and flow, are brought to the surface of the soaking water within the designated area. It is characterized by the following: [Effects of the Invention]

[0012] According to the rice pretreatment method and rice pretreatment system of the present invention, the amount of rice bran adhering to the immersion tank can be reduced, thereby allowing the immersion tank to be used in a clean manner. [Brief explanation of the drawing]

[0013] [Figure 1] Block diagram showing the overall configuration of the rice cooking pretreatment system according to an embodiment of the present invention. [Figure 2] Block diagram showing the configuration of the rice washing section of the rice cooking pretreatment system. [Figure 3] Front cross-sectional view (hatching omitted) showing the configuration of the main members of the separation section of the rice cooking pretreatment system. [Figure 4] External view showing the configuration of the separator of the rice cooking pretreatment system, where (a) is a top view, (b) is a front view, and (c) is a front end view (hatching omitted) along line A-A of (a). [Figure 5] Top cross-sectional view (hatching omitted) showing the configuration of the main members of the immersion section of the rice cooking pretreatment system and showing the state where immersion water is stored up to the full water level in the immersion tank. [Figure 6] Top cross-sectional view (hatching and immersed rice grains omitted) showing the flow state of the immersion water when the immersion water is stored up to the full water level in the immersion tank of the rice cooking pretreatment system and a predetermined amount of immersed rice grains are stored. [Figure 7] Cross-sectional view (hatching omitted) along line B-B of FIG. 5. [Figure 8] Cross-sectional view (hatching omitted) along line D-D of FIG. 6 (the immersed rice grains are represented only by the ridge lines). [Figure 9] Cross-sectional view (hatching omitted) along line B-B of FIG. 5, showing the state where the guide plate is pulled upward by pulling the chain upward. [Figure 10] Perspective view showing the configuration of the fixed partition member and the movable partition member of the immersion section of the rice cooking pretreatment system, where (a) shows the state of only the fixed partition member and (b) shows the state where the movable partition member is attached to the fixed partition member. [Figure 11] Cross-sectional view (hatching omitted) along line C-C of FIG. 5, showing the state where the pre-washed rice grains are falling and flowing in the immersion tank but the movable partition member is still closed. [Figure 12] Cross-sectional view (hatching omitted) along line E-E of FIG. 6, showing the state where a predetermined amount of pre-washed rice grains are stored and the movable partition member is opened by a predetermined angle. [Figure 13] Figure 6 is a cross-sectional view (hatching omitted) along the EE line, showing the state in which soaked rice grains stored in the soaking tank flow through the piping to the rice distribution section. [Figure 14] A block diagram showing the configuration of the main components of the rice distribution and water supply sections of the pre-processing system for rice cooking described above. [Figure 15] A block diagram showing the configuration of the main components of the purification section of the rice cooking pre-treatment system described above. [Figure 16] A step diagram showing the operation of the rice pre-processing system described above. [Modes for carrying out the invention]

[0014] The first invention is, Polished rice grains are washed to become pre-washed rice grains. The process includes a soaking step in which the pre-washed rice grains are dropped and flowed into a soaking tank containing soaking water, and the pre-washed rice grains are soaked in the soaking water to become soaked rice grains. In the aforementioned immersion step, The opening of the flow pipe, which extends in a substantially vertical direction, is positioned below the water level of the immersion water to form the water level of the immersion water within the flow pipe. The washed rice grains, which have been allowed to fall and flow through the flow pipe, are brought to the surface of the soaking water formed inside the flow pipe. This is a pre-treatment method for rice cooking characterized by the following features.

[0015] This configuration limits the water surface into which the washed rice grains land to the water inside the pipe, compared to a configuration where the opening of the flow pipe is positioned above the water surface. This reduces the amount of rice bran foam generated when the washed rice grains land in the water. Furthermore, it prevents rice bran from adhering to the walls of the soaking tank, allowing the tank to be used in a clean environment.

[0016] The second invention is, in the first invention, In the immersion step, Within a partitioned area, which is a region where the surface of the immersion water is divided by the inner wall of the immersion tank and a plate-shaped partition member, pre-washed rice grains that have been flowed down through a flow pipe are brought to the surface of the immersion water formed inside the flow pipe. This is a pre-treatment method for rice cooking characterized by the following features.

[0017] This allows the rice bran foam generated when pre-washed rice grains come into contact with the soaking water to be kept within the designated area.

[0018] The third invention is, Polished rice grains are washed to become pre-washed rice grains. The process includes a soaking step in which the pre-washed rice grains are dropped and flowed into a soaking tank containing soaking water, and the pre-washed rice grains are soaked in the soaking water to become soaked rice grains. In the aforementioned immersion step, Within the partitioned area, which is a region where the surface of the soaking water is partitioned by the inner wall of the soaking tank and a plate-shaped partitioning member, the washed rice grains that have been dropped and flowed are brought to the surface of the soaking water. This is a pre-treatment method for rice cooking characterized by the following features.

[0019] This allows the rice bran foam generated when pre-washed rice grains come into contact with the soaking water to be kept within the designated area. Furthermore, it prevents rice bran from adhering to the walls of the soaking tank, allowing the tank to be used in a clean environment.

[0020] The fourth invention is, in the third invention, In the immersion step, The opening of the flow pipe, which extends in a substantially vertical direction, is positioned below the water level of the immersion water to form the water level of the immersion water within the flow pipe. Within the designated area, the washed rice grains that have been allowed to fall and flow through the flow pipe are brought to the surface of the soaking water formed inside the flow pipe. This is a pre-treatment method for rice cooking characterized by the following features.

[0021] This allows the water surface into which the pre-washed rice grains land to be limited to the water surface inside the flow pipe, compared to when the opening of the flow pipe is positioned above the water surface, thereby reducing the amount of rice bran foam generated when the pre-washed rice grains land in the soaking water.

[0022] The fifth invention is based on any one of the first to fourth inventions, By repeatedly changing the direction of flow of pre-washed rice grains that have been washed from polished rice grains, the kinetic energy of the pre-washed rice grains as they flow is reduced. The pre-washed rice grains, whose kinetic energy has been reduced, are then placed in the soaking water. This is a pre-treatment method for rice cooking characterized by the following features. This reduces the impact on the washed rice grains when they hit the surface of the soaking water, compared to when the kinetic energy is not reduced, and also reduces the amount of rice bran foam generated on the surface of the soaking water stored in the soaking tank.

[0023] The sixth invention is, A soaking tank stores a predetermined amount of soaking water, and soaks pre-washed rice grains, which are polished rice grains that have been washed, in the soaking water to make soaked rice grains, A flow pipe extending in a substantially vertical direction, which causes the washed rice grains to fall and flow into the soaking water, Equipped with, The opening of the flow pipe is positioned below the water level of the immersion water to form the water level of the immersion water inside the flow pipe. The washed rice grains, which have been allowed to fall and flow through the flow pipe, are brought to the surface of the soaking water formed inside the flow pipe. This is a rice pre-processing system characterized by the following features:

[0024] This configuration limits the water surface into which the washed rice grains land to the water inside the pipe, compared to a configuration where the opening of the flow pipe is positioned above the water surface. This reduces the amount of rice bran foam generated when the washed rice grains land in the water. Furthermore, it prevents rice bran from adhering to the walls of the soaking tank, allowing the tank to be used in a clean environment.

[0025] The seventh invention is, in the sixth invention, It further includes a plate-shaped partitioning member that divides the rice bran foam floating on the surface of the soaking water, A partitioned area is formed on the surface of the immersion water, which is a region partitioned by the inside of the wall of the immersion tank and the partitioning member. Within the aforementioned compartment, the washed rice grains that have been flowed through the fluid pipe are brought to the surface of the soaking water formed inside the fluid pipe. This is a rice pre-processing system characterized by the following features:

[0026] This allows the rice bran foam generated when pre-washed rice grains come into contact with the soaking water to be kept within the designated area.

[0027] The eighth invention is, A soaking tank stores a predetermined amount of soaking water, and soaks pre-washed rice grains, which are polished rice grains that have been washed, in the soaking water to make soaked rice grains, A plate-shaped partitioning member that partitions the rice bran foam floating on the surface of the immersion water, Equipped with, A partitioned area is formed on the surface of the immersion water, which is a region partitioned by the inside of the wall surface of the immersion tank and the partitioning member. The washed rice grains, which have been allowed to fall and flow, are brought to the surface of the soaking water within the designated area. This is a rice pre-processing system characterized by the following features:

[0028] This allows the rice bran foam generated when pre-washed rice grains come into contact with the soaking water to be kept within the designated area. Furthermore, it prevents rice bran from adhering to the walls of the soaking tank, allowing the tank to be used in a clean environment.

[0029] The ninth invention is, in the eighth invention, It further includes a flow pipe that extends in a nearly vertical direction and causes the washed rice grains to fall and flow into the soaking water, The opening of the flow pipe is positioned below the water level of the immersion water to form the water level of the immersion water inside the flow pipe. Within the designated area, the pre-washed rice grains, which have been flowing through the fluid pipe, are brought to the surface of the immersion water formed inside the fluid pipe. This is a rice pre-processing system characterized by the following features:

[0030] This allows the water surface into which the pre-washed rice grains land to be limited to the water surface inside the flow pipe, compared to when the opening of the flow pipe is positioned above the water surface, thereby reducing the amount of rice bran foam generated when the pre-washed rice grains land in the soaking water.

[0031] The tenth invention is based on any one of the seventh to ninth inventions, The configuration is such that when the mass of the edged rice grains located on the ridges of the edged rice grains stored in the edging tank is applied to the partition member, at least a portion of the partition member rotates toward the outside of the edging tank. This is a rice pre-processing system characterized by the following features: This allows more rice grains to be stored in the soaking tank, even if the lower end of the partition member is in contact with the ridge line of the soaked rice grains stored in the soaking tank.

[0032] (Embodiment 1) (Overview of the rice pre-processing system) The following describes a rice pre-treatment method and a rice pre-treatment system 10, which are embodiments of one embodiment of the present invention.

[0033] First, the basic configuration of the rice cooking pre-treatment system 10 of the present invention will be explained. As shown in Figure 1, the rice cooking pre-processing system 10 is broadly composed of the following components. (1) The rice washing unit 20 mixes air, water W2 for supplying rice, and polished rice grains (rice grains) R1 to form a mixed fluid, and then flows this mixed fluid within the rice washing means 32 to wash the polished rice grains R1 and supply the rice. (2) Separation unit 40 separates the mixed fluid that has been mixed, washed, and delivered in the rice washing unit 20 into the delivered water W3 containing air and the pre-washed rice grains (rice grains) R2. (3) The pre-washed rice grains R2 separated by the separation unit 40 are stored in the soaking tank 61 while being soaked in the soaking water W4 stored in the soaking tank 61, and the soaking unit 60 overflows the soaking water W4 stored in the soaking tank 61. (4) The rice distribution unit 90 distributes a predetermined amount of the soaked rice grains (rice grains) R3 that have been soaked in the soaking unit 60 to the rice cooker pot 97. (5) Water supply unit 100 that supplies cooking water W6 at a predetermined temperature to the rice cooker pot 97 into which soaked rice grains R3 have been supplied. (6) The purification unit 120 purifies the air-containing rice supply water W5, which is mixed with soaking water, so that it can be used again in the rice washing unit 20 to wash polished rice grains R1. (7) Control unit 140 which is electrically connected to the equipment of each part and performs centralized control.

[0034] Furthermore, rice grains that have been milled from brown rice are referred to as "polished rice grains (rice grains) R1", polished rice grains R1 that have been washed in the washing section 20 with air-containing rice supply water W3 are referred to as "pre-washed rice grains (rice grains) R2", and pre-washed rice grains R2 that have been soaked in soaking water W4 in the soaking section 60 are referred to as "soaked rice grains (rice grains) R3".

[0035] Furthermore, the water supplied to the rice that is stored in the purification unit 120 and flows to the ejector 26 of the rice washing unit 20 is called "supplied rice water W2," the water supplied to the rice that is mixed with air in the rice washing unit 20 and used for supplying and washing polished rice grains R1 is called "supplied rice water containing air W3," the water stored in the immersion tank 61 is called "immersion water W4," and the water supplied to the rice cooker 97 is called "cooking water W6." In addition, while the clean water W1 refers to tap water for example, pure water or soft water, or other water different from tap water, may be used.

[0036] The term "piping" may refer to metal pipes such as stainless steel, or resin pipes such as polyvinyl chloride. However, considering the ease of cleaning the inside of the pipes, it is preferable to use resin pipes, which are easier to attach and detach than metal pipes.

[0037] The term "valve" may refer to an electromagnetic valve or electric valve controllable by a control panel 141 located in the control unit 140. Manual adjustments or electrical control may be unnecessary in certain locations where they are not required; in such cases, a manual valve may be used. However, to prevent operator errors when operating the rice pre-processing system 10, it is preferable to use an electromagnetic valve or electric valve that can be controlled by a program on the control panel 141, as well as one that can be controlled independently.

[0038] Note that in Figures 2, 14, and 15, there are areas indicated by dashed lines. These areas are not included in the rice washing section 20, rice distribution section 90, water supply section 100, and purification section 120 shown in Figures 2, 14, and 15, respectively.

[0039] (1)Rice washing department Next, the configuration of the rice washing unit 20 will be explained.

[0040] The rice washing section 20 shown in Figure 2 washes the polished rice grains R1 by flowing a mixed fluid M1 of air-containing water and polished rice grains, which is created by mixing air, clean water W1 and polished rice grains R1 using an ejector 26, within the rice washing means 32, and then sending the rice to the separation section 40 for the next process.

[0041] The rice washing section 20 is An introduction guide 21 guides the supplied polished rice grains R1 and prevents them from scattering to the outside, A hopper-shaped receiving cylinder 22 receives the polished rice grains R1 that are guided and fall by the introduction guide 21, Multiple clean water nozzles 25 are used to spray clean water W1 supplied through the piping 23 into the inside of the wall of the receiving cylinder 22 by opening the valve 24, causing the polished rice grains R1 to flow down along the inside of the wall of the receiving cylinder 22. A pump 29 draws in the rice-supplied water W2 stored in the second purification tank 128 of the purification unit 120 (described later) via a filter 134, discharges it, and discharges it through the piping 28 to the ejector 26 to cause it to flow. A valve 30 adjusts the flow rate of the rice water W2 discharged from the pump 29 and flowing to the ejector 26, The ejector 26 draws in air from the receiving cylinder 22 and polished rice grains R1 that are flowing down the inside of the wall of the receiving cylinder 22 together with clean water W1 through the suction port 27, mixes the air, clean water W1 and polished rice grains R1 with the rice supply water W2 that is discharged and flowing through the piping 28 by the pump 29, and discharges the mixture fluid M1 of the rice supply water containing air and polished rice grains. A rice supply pipe (piping) 31 sends the mixed fluid M1 of rice supply water containing air and polished rice grains, which is discharged from the ejector 26 and flows, to the separation unit 40 which performs the next process. A rice washing means 32 is incorporated into the middle of the rice supply pipe 31 and washes the polished rice grains R1 by flowing a mixed fluid M1 of rice supply water containing air and polished rice grains inside the pipe. It is equipped with.

[0042] The cylindrical introduction guide 21 is connected to a hopper-shaped receiving cylinder 22, which has a roughly triangular shape with its apex at the bottom when viewed in front. Because the introduction guide 21 is cylindrical with openings at the top and bottom, polished rice grains R1 can be supplied to the receiving cylinder 22 without scattering by supplying them from the top of the introduction guide 21.

[0043] Multiple clean water nozzles 25 are attached to the inside of the slanted wall surface of the receiving cylinder 22, which is connected from the lower opening (not indicated) of the installation guide 21. These multiple clean water nozzles 25 are connected through piping 23 to, for example, a water tap that supplies tap water.

[0044] A valve 24 is attached to the piping 23 so that, when opened, it can supply clean water W1, such as tap water. When the valve 24 is opened, clean water W1 is sprayed downward from multiple clean water nozzles 25 along the inside of the slanted wall surface of the receiving cylinder 22.

[0045] In a front cross-sectional view, the opening (not indicated by a reference numeral) at the apex of the receiving cylinder 22, which faces downwards, is connected to the suction port 27 of the ejector 26. Furthermore, a pipe 28 is connected to the upstream side of the ejector 26, which draws in the rice-transport water W2 stored in the second purification tank 128 of the purification unit 120 (described later) via a filter 134 and is then pumped in by a pump 29 and discharged to the ejector 26.

[0046] A valve 30 is attached to the discharge side of the pump 29 in the piping 28, and by adjusting the opening of the valve 30, the flow rate per unit time of the rice supply water W2 discharged by the pump 29 and flowing to the ejector 26 is adjusted. A rice supply pipe 31 is connected to the downstream side of the ejector 26 to flow a mixed fluid M1 of rice supply water containing air and polished rice grains, which will be described later, mixed by the ejector 26.

[0047] A rice delivery pipe 31 connected to the ejector 26 is equipped with a rice washing means 32 in the middle of which a mixed fluid M1 of rice delivery water containing air and polished rice grains is flowed internally to wash the polished rice grains R1. The rice washing means 32 is a component that can statically agitate the fluid flowing inside, such as a static mixer.

[0048] The rice delivery pipe 31, which incorporates a rice washing mechanism 32, is connected to the separation section 40 that performs the next process. A mixed fluid M2 of rice delivery water containing air and pre-washed rice grains flows through the rice delivery pipe 31 downstream of the rice washing mechanism 32.

[0049] (2) Separation part Next, the configuration of the separation unit 40 will be described.

[0050] The separation unit 40 shown in Figure 3 separates the mixed fluid M2 of air-containing water and pre-washed rice grains flowing from the rice washing unit 20 into air-containing water W3 and pre-washed rice grains R2 using a separator 43, and then allows the pre-washed rice grains R2 to flow down into the immersion unit 60 for the next step.

[0051] The separation unit 40 is A circular plate-shaped lid 41, which is attached to the first water receiving section 44 so as to extend radially around the opening 31a of the rice supply pipe 31 through which a mixed fluid M2 of air-containing rice supply water and pre-washed rice grains flows from the rice washing section 20, is provided. A diffuser 42, which is attached to the lid 41 so as to be located below the opening 31a of the rice supply pipe 31, is a downward-spreading cone-shaped diffuser 42 that causes the mixed fluid M2 of air-containing rice supply water and pre-washed rice grains, which flows in a substantially horizontal direction from the opening 31a of the rice supply pipe 31 in a substantially vertical direction, A cylindrical separator 43 separates the mixed fluid M2 of air-containing rice water and pre-washed rice grains, which has been flowed in a nearly horizontal direction by the diffuser 42, into air-containing rice water W3 and pre-washed rice grains R2. The lid 41 is placed on top to create a near-sealed enclosure, and the first water receiving section 44 receives and flows the air-containing rice water W3 separated by the separator 43 on the inside of the wall, A first return pipe (pipe) 45 causes the air-containing rice water W3 flowing inside the wall surface of the first water receiving section 44 to fall and flow, The system includes a flow pipe 46 that allows the pre-washed rice grains R2 separated by the separator 43 to flow into the immersion section 60 for the next step.

[0052] The first water receiving section 44 is covered with a lid 41 that can be detachably closed on the upper surface of the first water receiving section 44. Furthermore, by attaching connecting members (not shown) that can be easily attached and detached with simple operations to, for example, the lid 41 connected from the rice washing section 20 and the lid 41, the rice supply pipe 31 connected from the rice washing section 20 and the lid 41 are made detachable.

[0053] On the underside of the lid 41, a wall-shaped guide section 41a is attached, which is a plate-shaped member formed in a circular shape when viewed from below, surrounding the opening 31a of the rice supply pipe 31, so as to be located inside the separator 43. The guide section 41a extends substantially vertically from the underside of the lid 41. When the lid 41 is attached to the first water receiving section 44, the lower end of the guide section 41a is configured to be spaced apart from both the wall surface 43a of the separator 43 and the inclined section 42a and horizontal section 42b of the diffuser 42.

[0054] Furthermore, the opening 45a of the first return pipe 45 is connected to the lower part of the side surface of the first water receiving section 44. The first return pipe 45 continues to the overflow section 76 of the immersion section 60, which will be described later.

[0055] Furthermore, below the opening 31a of the rice supply pipe 31 of the rice washing section 20 connected to the lid 41, there is a conical diffuser 42 fixed to the lower surface of the lid 41 via, for example, a rod-shaped stay (not shown). The conical diffuser 42 has its apex facing upward and, in a front cross-sectional view, has an inclined portion 42a that is inclined with respect to the horizontal direction and a horizontal portion 42b that extends substantially horizontally from the lower part of the inclined portion 42a. The horizontal portion 42b is formed around the edge of the conical diffuser 42. The diffuser 42 is provided in the upper half of the cylindrical separator 43, which is open at the top and bottom.

[0056] More specifically, the first diffusion in the diffusion step S40, described later, changes the direction of flow to approximately horizontal, and the mixed fluid M2 of the rice-transmitting water containing air with reduced kinetic energy and the washed rice grains is positioned at a height that reaches the inside of the drainage section 43c on the wall surface 43a of the separator 43. This allows the first separation step S51, described later, to be carried out effectively.

[0057] Furthermore, a gap is provided between the outer end of the horizontal section 42b of the diffuser 42 in the diametrical direction and the wall surface 43a, so that the washed rice grains R2 can flow during the first separation step S51 and induction step S52, which will be described later.

[0058] As shown in Figures 4(a) and 4(b), the separator 43 is a cylindrical member made of, for example, stainless steel, with a roughly conical shape with its apex pointing downwards and openings at the top and bottom. The wall surface 43a, which is inclined at a predetermined angle with respect to the horizontal, for example, approximately 45 degrees, is divided into three sections from top to bottom: the upper flow section (flow section) 43b, the drain section 43c, and the lower flow section (flow section) 43d.

[0059] In the wall surface 43a of the separator 43, the drainage section 43c is provided with a plurality of substantially straight holes 43e, for example, that are inclined at a predetermined angle with respect to the horizontal direction. The upper flow section 43b and the lower flow section 43d are not provided with holes 43e.

[0060] The multiple holes 43e provided in the drainage section 43c are configured to be too small for pre-washed rice grains R2 to pass through. However, they are configured to allow broken pre-washed rice grains R2, or crushed rice grains R4, to pass through. The size of the crushed rice grains R4 that the holes 43e should be able to pass through is determined by considering the type of rice, the effect the crushed rice grains R4 have on cooking, etc. Note that in Figure 4(a), the holes 43e are omitted for clarity.

[0061] The multiple holes 43e provided in the drainage section 43c are formed in an elongated shape, with both ends of the elongated holes being semicircular. This prevents pre-washed rice grains R2 and crushed rice grains R4 from getting stuck in the holes 43e, thereby suppressing a decrease in separation efficiency due to clogging of the holes 43e, and also facilitates cleaning of the separator 43 during the cleaning of the separator 43 performed in the final step S120 described later.

[0062] The shape of the multiple holes 43e in the wall surface 43a of the separator 43 and the predetermined angles with respect to the horizontal direction are not limited to those exemplified in this embodiment. For example, the multiple holes 43e in the wall surface 43a may be formed at multiple different angles with respect to the horizontal direction and combined.

[0063] Furthermore, as shown in Figure 4(c), the upper end of the wall surface 43a of the separator 43 has a plate-shaped top surface portion 43g that extends inward in a substantially horizontal direction. The separator 43 is placed on the flow pipe 46 inside the first water receiving section 44, and the lid 41 is placed over the top of the first water receiving section 44, thereby forming a substantially continuous surface with the wall surface 43a, the top surface portion 43g, the lower surface of the lid 41, and the guide portion 41a attached to the lower surface of the lid 41.

[0064] As shown in Figures 3 and 4(b), the lower part of the separator 43 has a fitting portion 43f that can be detachably installed by fitting it onto the upper end face of the flow pipe 46 that leads to the immersion tank 61 of the immersion section 60 where the next step is carried out. This allows the installation to be completed simply by fitting the fitting portion 43f of the separator 43 onto the flow pipe 46, reducing the effort required to install the separator 43 in the correct position within the first water receiving section 44.

[0065] Furthermore, since the diffuser 42 provided in the separation unit 40 is fixed to the underside of the lid 41 via, for example, a rod-shaped stay, the diffuser 42 can be removed from the first water receiving unit 44 by removing the lid 41 from the first water receiving unit 44. Also, since the separator 43 is detachably installed on the flow pipe 46, it can be easily removed from the first water receiving unit 44.

[0066] (3) Immersion section Next, the configuration of the immersion section 60 will be described.

[0067] The immersion section 60 shown in Figures 5 and 7 stores the pre-washed rice grains R2 separated by the separation section 40 while immersing them in the immersion water W4 stored in the immersion tank 61, and then flows the immersed rice grains R3 stored in the immersion tank 61 to the rice distribution section 90 for the next process. In addition, the immersion water W4 stored in the immersion tank 61, along with the rice bran foam floating on the surface of the immersion water W4, flows to the overflow section 76 to cause an overflow.

[0068] As shown in Figures 1, 7, and 11, the immersion section 60 is The pre-washed rice grains R2 that have fallen and flowed through the flow pipe 46 of the separation unit 40 are immersed in the stored soaking water W4 to absorb water, and the soaking tank 61 stores them. A lid 62 is placed over the opening of the immersion tank 61 to prevent foreign matter from entering the immersion tank 61 from above, A conical hat-shaped guide plate 64 guides the flow of soaked rice grains R3 in the soaking water W4 stored in the soaking tank 61, By opening the valve 67, a water supply nozzle 68 sprays clean water W1 into the immersion tank 61 through the water supply pipe (piping) 66, A water level detection means 69 detects the water level of the immersion water W4 stored in the immersion tank 61 and sends an electrical signal to the control panel 141, A storage amount detection means 70, which is a paddle-type sensor, detects when a predetermined amount of soaked rice grains R3 has been stored in the soaking tank 61 and sends an electrical signal to the control panel 141, The two substantially parallel frames 71 are provided horizontally and are detachably secured at both ends to four protrusions (not shown) on the edge of the immersion tank 61, A gate-shaped plate-like fixed partition member (partition member) 72 is attached to each of the two roughly parallel frames 71 and partitions the rice bran foam floating on the surface of the immersion water W4 stored in the immersion tank 61, A plate-shaped movable partition member (partition member) 73 is rotatably attached by hinges 74 fixed to each fixed partition member 72, The opening 45a of the first return pipe 45 is connected from above, and the overflow section 76 is a waterway that allows the immersion water W4 stored in the immersion tank 61 to overflow and flow when the water level exceeds a predetermined level. The opening 77a is connected below the overflow section 76, and the second return pipe (pipe) 77 causes the air-containing rice water W3 that flows down the first return pipe 45 and the immersion water W4 that is stored in the immersion tank 61 and flows down the overflow section 76 by overflow, to flow down. A pipe 78 connects from a flow opening 61a located at the bottom of the immersion tank 61 to the rice distribution section 90 where the next process is carried out, A rice distribution valve (valve) 79, which closes to store soaked rice grains R3 in the soaking tank 61, and opens for a predetermined time to allow the soaking water W4 and the soaked rice grains R3 stored in the soaking tank 61 to flow down to the rice distribution section 90 through the piping 78, It is equipped with.

[0069] As shown in Figure 7, below the opening 46a of the fluid pipe 46 of the separation section 40, there is an immersion tank 61 which is a cylindrical tank with an open top and a conical shape with its lower part pointing downwards. The immersion tank 61 has a fluid opening 61a at its lower part, and a rice distribution valve 79 is attached to the piping 78 connected to the fluid opening 61a.

[0070] By closing the rice distribution valve 79, the soaking water W4 stored in the soaking tank 61 and the flowing pre-washed rice grains R2 are stored in the soaking tank 61 and kept in a soaked state as soaked rice grains R3. By opening the rice distribution valve 79, the soaking water W4 and soaked rice grains R3 stored in the soaking tank 61 are allowed to flow down into the separate rice distribution container 92 of the rice distribution section 90, which will be described later and is located below the soaking tank 61.

[0071] As shown in Figure 7, the water level when the immersion water W4 is filled to the full capacity of the immersion tank 61 is referred to as H3.

[0072] Furthermore, a lid 62 that can be detachably closed over the opening (not indicated by a reference numeral) at the top of the immersion tank 61 is placed over the immersion tank 61. The lid 62 is fitted with multiple handles 62a to facilitate removal, and a notch is provided in the approximate center to allow clearance for the flow pipe 46. It is preferable that the lid 62 be divided, for example, into two sections when viewed from above, in order to facilitate removal.

[0073] As shown in Figures 5 and 7, one end of several plate-shaped support members 63 for placement on the bottom of the immersion tank 61 is fixed to the lower surface of the guide plate 64 by welding or the like, and the other end of the support members 63 is placed on the bottom of the immersion tank 61. In this embodiment, as shown in Figure 5, eight support members 63 are fixed to the guide plate 64 in a top view.

[0074] By placing the other end of the support member 63, which is fixed to the lower surface of the guide plate 64, on the bottom of the immersion tank 61, a predetermined gap is formed between the conical outer edge of the guide plate 64 and the inner surface of the immersion tank 61, allowing the immersed rice grains R3 to flow through the predetermined gap. The predetermined gap is set to, for example, 50 to 60 mm. One end of a chain 65, for example made of stainless steel, is connected to the top of the guide plate 64. The other end of the chain 65 is connected to the upper edge of the immersion tank 61, and by pulling up the chain 65, the guide plate 64 and the support member 63 can be lifted from the bottom of the immersion tank 61.

[0075] As shown in Figure 8, the soaked rice grains R3 stored in the soaking tank 61 in a mountain-like shape are stored such that their ridges 80 have an angle of repose θ1 with respect to the horizontal, for example, approximately 35 degrees. The hypotenuse of the conical guide plate 64 has an angle θ2 with respect to the horizontal, for example, approximately 30 degrees. Angle θ2 is formed to be smaller than the angle of repose θ1.

[0076] The angle of repose of the soaked rice grains R3, which are stored in a mound shape in the soaking water W4, will change depending on the type of rice used, but will be approximately 35 degrees. If it changes significantly, the angle of repose corresponding to that change should be used as θ1. It is also preferable to change the angle θ2 of the hypotenuse of the guide plate 64 relative to the horizontal to match the angle of repose θ1.

[0077] As shown in Figure 9, the guide plate 64, with a support member 63 fixed to its underside, which is placed on the bottom of the immersion tank 61, can be lifted up from the bottom of the immersion tank 61 by pulling the chain 65 upward. Alternatively, by slowly lowering the guide plate 64, with the support member 63 fixed to its underside, into the immersion tank 61 while pulling the chain 65 upward, the other end of the support member 63 can be placed on the bottom of the immersion tank 61, and the guide plate 64 can be repositioned at the bottom of the immersion tank 61.

[0078] As shown in Figures 1 and 7, the immersion section 60 is provided with a water supply pipe 66 that connects to, for example, a water tap. A water supply nozzle 68 is provided at the end of the water supply pipe 66, which is located inside the immersion tank 61. By opening the valve 67, clean water W1 is injected and supplied to the immersion tank 61, and stored as immersion water W4.

[0079] Furthermore, as shown in Figure 11, the immersion tank 61 is provided with a water level detection means 69, such as a float-type level sensor. The water level detection means 69 detects when the water level of the immersion water W4 stored in the immersion tank 61 is below a predetermined water level H3, which is the water level when the immersion tank 61 is full.

[0080] When it is detected that the water level of the immersion water W4 stored in the immersion tank 61 is below the water level H3, an electrical signal is sent to the control panel 141 (described later), and from the control panel 141, an electrical signal is sent to the valve 67 to open the valve 67. Then, clean water W1 is injected into the immersion tank 61 from the water supply nozzle 68 through the water supply pipe 66 until the water level of the immersion water W4 stored in the immersion tank 61 reaches H3.

[0081] As shown in Figures 7 and 8, the water supply nozzle 68 is positioned higher than the water level H3 of the soaking water W4 stored in the soaking tank 61 to its maximum capacity. It is also positioned higher than a predetermined water level in the soaking water W4 when a predetermined amount of pre-washed rice grains R2 falls into the soaking water W4 stored in the soaking tank 61 to its maximum capacity H3. This prevents the soaking water W4 stored in the soaking tank 61 from flowing back into the water supply pipe 66 through the water supply nozzle 68.

[0082] Furthermore, there are two water supply nozzles 68 positioned opposite the overflow section 76, with the direction of the spray of clean water W1 directed toward the overflow section 76. One nozzle is configured to spray clean water W1 at a predetermined angle downward from the horizontal, for example, at an angle of 20 degrees downward from the horizontal, while the other nozzle is configured to spray clean water W1 in a nearly horizontal direction (see Figure 5).

[0083] As shown in Figure 8, a paddle-type sensor, the storage volume detection means 70, is attached to the wall of the immersion tank 61. The storage volume detection means 70 rotates within the immersion water W4 stored in the immersion tank 61, with the paddle portion (not indicated) at its tip rotating about the longitudinal axis of an axis that is positioned approximately horizontally.

[0084] When a predetermined amount of soaked rice grains R3 is stored in the soaking water W4 in the soaking tank 61, the paddle portion touches the ridge 80 of the soaked rice grains R3, and the storage amount detection means 70 detects the resistance of the rotation of the paddle portion. When resistance is detected, the storage amount detection means 70 sends an electrical signal to the control panel 141 (described later), and the control panel 141 displays that the amount of soaked rice grains R3 stored in the soaking tank 61 has reached a predetermined amount. It then warns to stop supplying polished rice grains R1 to the introduction guide 21 of the rice washing section 20.

[0085] As shown in Figures 5 and 7, the ends of two parallel frames 71 extending horizontally are detachably secured to four protrusions (not shown) on the upper edge of the immersion tank 61. The four protrusions on the upper edge of the immersion tank 61 are plate-shaped members shorter than the frames 71, with a flat top surface to which the ends of the frames 71 are detachably secured. This allows the support members 63 and guide plates 64 to be lifted from the bottom of the immersion tank 61 and cleaned by removing the frames 71 from the four protrusions on the edge of the immersion tank 61 and then pulling the chain 65 upward.

[0086] As shown in Figures 10(a) and 11, the lower ends on both sides of the inner opening 72d of the gate-shaped fixed partition member 72 are provided with notches 72c that are chamfered in a direction inclined with respect to the horizontal. Furthermore, by bending the upper end of the fixed partition member 72, a bent portion 72a that is approximately horizontal and a folded portion 72b that is approximately vertical are formed by further folding back the end of the bent portion 72a. The fixed partition member 72 is then secured to four protrusions provided on the edge of the immersion tank 61, and the bent portion 72a and folded portion 72b of the fixed partition member 72 are placed on and secured to each of the two horizontally positioned frames 71.

[0087] Furthermore, as shown in Figure 10(b), a movable compartment member 73 is rotatably attached to a hinge 74 that is attached to a fixed compartment member 72 formed in a gate shape. Also, as shown in Figure 11, the hinge 74 is configured to be located below the water level H3 of the immersion water W4 stored in the immersion tank 61.

[0088] Furthermore, a hinge 74 is attached to the fixed compartment member 72 so that the movable compartment member 73 can rotate toward the outside of the immersion tank 61. Alternatively, the movable compartment member 73 may be configured to rotate only toward the outside of the immersion tank 61.

[0089] Alternatively, holes may be drilled in the bent portion 72a of the fixed compartment member 72 and the frame 71, and the bent portion 72a of the fixed compartment member 72 and the frame 71 may be fixed together with bolts and nuts. In that case, if the bolts and nuts fixing the bent portion 72a of the fixed compartment member 72 and the frame 71 were to loosen and come off, they might fall into the immersion tank 61 and get mixed into the immersed rice grains R3. For this reason, it is preferable not to fix the bent portion 72a of the fixed compartment member 72 and the frame 71 together with bolts and nuts.

[0090] As shown in Figures 5, 7, and 11, two fixed partition members 72 and a movable partition member 73, each attached to one of the two frames 71, are installed to partition the inside of the wall surface of the immersion tank 61. When immersion water W4 is filled into the immersion tank 61 to a water level H3, the water surface at water level H3 is partitioned between the two fixed partition members 72 and the inside of the wall surface of the immersion tank 61. The water surface in this partitioned area is called the partitioned area 75. The partitioned area 75 is the area indicated by hatching in Figures 5 and 6.

[0091] As shown in Figure 6, an overflow section 76, which is roughly triangular in shape when viewed from above, is provided at the top of the wall surface of the immersion tank 61, communicating with the wall surface of the immersion tank 61. The overflow section 76 is located opposite the water supply nozzle 68, and is positioned in the direction of the spray of clean water W1 ejected from the water supply nozzle 68.

[0092] As shown in Figure 7, the opening 45a of the first return pipe 45 is positioned so as to face downwards at the top of the overflow section 76, which is connected to the upper part of the wall of the immersion tank 61. The opening 77a of the second return pipe 77 is connected to the lower part of the overflow section 76.

[0093] The overflow section 76 directs the immersion water W4 and the like that overflowing from the compartmentalized area 75, which is partitioned by the fixed compartmentalized member 72 and the inside of the wall surface of the immersion tank 61, to the second return pipe 77.

[0094] The overflow section 76 has a wall portion 76a that rises vertically at the boundary with the immersion tank 61. When the immersion tank 61 is filled with immersion water W4, the water level H3 will be such that the immersion water W4 reaches approximately the upper end of the wall portion 76a.

[0095] By pre-determining the height of the upper end of the wall portion 76a, the water level at which the immersion water W4 stored in the immersion tank 61 overflows into the overflow portion 76 can be predetermined. In addition, by providing the wall portion 76a, it is possible to prevent the immersion water W4 that has flowed into the overflow portion 76 from flowing back into the immersion tank 61.

[0096] The second return pipe 77, whose upper end is connected to the overflow section 76, is connected to the first purification tank 121 of the purification section 120, which will be described later.

[0097] As shown in Figure 11, when the immersion tank 61 is filled with immersion water W4 to a water level H3, the opening 46a of the flow pipe 46 is located within the compartment 75 at a distance H4, for example, approximately 10 to 20 millimeters below the water level H3. In other words, when the water level of the immersion water W4 is at water level H3, the opening 46a of the flow pipe 46 is located in the immersion water W4 within the compartment 75. Furthermore, the lower ends of the fixed compartment member 72 and the movable compartment member 73 are located at a distance H5, for example, 120 to 130 millimeters below the water level H3 of the immersion water W4 stored in the immersion tank 61.

[0098] Furthermore, even if the soaking tank 61 is filled with a predetermined amount of soaked rice grains R3, if the configuration ensures that the edges 80 of the soaked rice grains R3 do not come into contact with the lower end of the fixed partition member 72, then the movable partition member 73 does not need to be attached to the fixed partition member 72. In that case, the fixed partition member 72 shown in Figure 10 can be made substantially rectangular instead of gate-shaped, making it easier to manufacture the partition members 72 and 73.

[0099] The shape of the movable partition member 73, which is rotatably attached to the fixed partition member 72, is merely an example. For example, it is also possible to attach one or more movable partition members to the opening 72d of the fixed partition member 72 so that it opens in a single-leaf or double-leaf configuration.

[0100] In this embodiment, the partition member is configured by attaching the movable partition member 73 to the fixed partition member 72, but the partition member may also be composed of only the movable partition member 73. In that case, for example, the upper end of the movable partition member 73 is provided with a bent portion and a folded portion similar to those of the fixed partition member 72, and it is placed on and locked to each of the two frames 71. The movable partition member 73 is then configured to move relative to the frame 71. Furthermore, a different movable partition member may be attached to the lower part of the movable partition member 73.

[0101] (4) Rice distribution department Next, the configuration of the rice distribution unit 90 will be explained.

[0102] The rice distribution unit 90 shown in Figure 14 causes the soaked rice grains R3 and soaking water W4, which have been soaked in the soaking unit 60, to fall and flow into the separation and distribution container 92, separating the soaking water W4 from the soaked rice grains R3 and distributing a predetermined amount of soaked rice grains R3 to the rice cooker 97.

[0103] The rice distribution department 90 is, A separation and distribution container 92 stores a predetermined amount of soaking water W4 and soaking rice grains R3 that flow through the piping 78 of the soaking tank 61, and separates the soaking water W4 from the soaking rice grains R3 through a plurality of holes 92a (not shown) provided on the cylindrical wall surface, A rice distribution amount regulator 91, which is used in combination with the separate rice distribution container 92, adjusts the amount of soaked rice grains R3 that are dropped and flowed into the separate rice distribution container 92 through the piping 78 of the soaking tank 61 and stored in the container, A second water receiving section 93 receives the immersion water W4 separated by the rice separation container 92 on the inside of the wall surface, A drain pipe (piping) 94 is connected to the lower part of the second water receiving section 93 and drains the immersion water W4 received by the second water receiving section 93, A plate-shaped shutter 95 closes the lower part of the rice separation container 92 to store soaked rice grains R3 in the rice separation container 92, and is driven by a movable drive means 96 such as an air cylinder to open the shutter for a predetermined time, thereby supplying a predetermined amount of soaked rice grains R3 stored in the rice separation container 92 to the rice cooker 97 located below for distribution. It is equipped with.

[0104] The lower end of the piping 78 of the immersion section 60 is positioned inside the rice separation container 92. Near the lower end of the piping 78, a rice distribution amount adjuster 91 is attached so as to close the upper opening of the cylindrical rice separation container 92, which has openings at the top and bottom, and so as to be movable in the vertical direction. By moving the rice distribution amount adjuster 91 in the vertical direction, the volume inside the rice separation container 92 is changed, thereby changing the amount of immersed rice grains R3 that flow down from the immersion tank 61 through the piping 78.

[0105] The cylindrical rice separation container 92 has multiple holes 92a (not shown) in its walls, which are sized so that the soaked rice grains R3 cannot pass through. By opening the rice distribution valve 79, the soaked water W4 from the soaked rice grains M3 and the soaking water flowing down the piping 78 of the soaking section 60 are separated by flowing through the multiple holes 92a to the outside of the walls of the rice separation container 92. The separated soaked water W4 is received by a second water receiving section 93 that is positioned to surround the rice separation container 92.

[0106] A drain pipe 94 is connected to the lower part of the second water receiving section 93, and the immersion water W4 received in the second water receiving section 93 is drained through the drain pipe 94.

[0107] After closing the rice distribution valve 79, the shutter 95 attached to the bottom of the separated rice distribution container 92 is driven by the drive means 96, thereby dropping and supplying a predetermined amount of soaked rice grains R3 to the rice cooker 97 placed on a conveyor 98 located below the shutter 95. Furthermore, a predetermined amount of cooking water W6 is supplied to the rice cooker 97 by a water supply unit 100, which will be described later. The conveyor 98 on which the rice cooker 97 is placed is followed by a lid-covering device (not shown) that covers the rice cooker 97 with a lid (not shown), and further followed by a rice cooking device (not shown) that heats the lidded rice cooker 97 at a high temperature.

[0108] (5) Water supply section Next, the configuration of the water supply unit 100 will be described.

[0109] The water supply unit 100 shown in Figure 14 supplies a predetermined amount of cooking water W6 at a predetermined temperature to the rice cooker 97 into which a predetermined amount of soaked rice grains R3 has been supplied.

[0110] The water supply unit 100 is A tank 104 for storing the rice cooking water W6, which is clean water W1, The water level of the cooking water W6 stored in the tank 104 is controlled by the float valve 103, and a water supply pipe (piping) 101 supplies clean water W1 to the tank 104 until the cooking water W6 stored in the tank 104 reaches a predetermined level, for example, when the tank 104 contains 50 to 60 liters. A valve 102 is provided in the water supply pipe 101 and, when opened manually, supplies clean water W1 to the tank 104 through the water supply pipe 101. A heater 105 raises the cooking water W6 stored in tank 104 to a predetermined temperature and maintains it at that predetermined temperature using a temperature sensor (not shown), By opening the valve 107 for a predetermined time, a predetermined amount of cooking water W6, heated to a predetermined temperature by the heater 105, is supplied to the rice cooker pot 97 located below the shutter 95 of the rice distribution section 90 via a pipe 106. It is equipped with.

[0111] Alternatively, the valve 102 may be configured as a solenoid valve or an electric valve, electrically connected to the control unit 140, and the valve 102 may be opened and closed by the control unit 140.

[0112] (6) Purification section Next, the configuration of the purification unit 120 will be explained.

[0113] The purification unit 120 shown in Figure 15 removes rice bran foam and crushed rice grains R4 from the air-containing rice supply water W5 mixed with soaking water, and purifies it so that it can be used again in the rice washing unit 20 to wash polished rice grains R1.

[0114] As shown in Figures 1 and 15, the purification unit 120 is The second return pipe 77 of the immersion section 60 is connected to the side wall, and the first purification tank 121 stores the air-containing rice supply water W5, which is a mixture of the immersion water flowing down the second return pipe 77, as rice supply water W2. When the water supplied with rice W2 stored in the first purification tank 121 exceeds a predetermined water level, the drain hopper 122 overflows the water supplied with rice W2, and drains the rice bran foam floating on the surface of the water supplied with the water supplied with rice W2 through the drain pipe (piping) 122a. A third return pipe (pipe) 125 adjusts the flow rate using a valve 126 and causes the rice water W2 stored in the first purification tank 121 to flow to the second purification tank 128, A plate-shaped flow restricting member 127 is installed in the first purification tank 121 and prevents the flow of air-containing rice supply water W5, which is a mixture of immersion water and flows through the second return pipe 77, from flowing directly from the first purification tank 121 to the third return pipe 125 and then directly to the second purification tank 128. A second purification tank 128 stores the rice water W2 that has been flowed from the first purification tank 121 through the third return pipe 125, A float valve 129 is used to detect the water level of the rice-transported water W2 stored in the second purification tank 128, and a water supply pipe 130 is used to supply clean water W1 to the second purification tank 128 when the water level falls below a predetermined level. A valve 131 is provided in the water supply pipe 130 and, when opened manually, supplies clean water W1 to the second purification tank 128 through the water supply pipe 130. An overflow water drain pipe 132 is inserted into a drain port 128a located at the bottom of the second purification tank 128, and when the rice-supplied water W2 stored in the second purification tank 128 exceeds a predetermined water level, it overflows from the upper opening and is drained as overflow water. By opening the valve 124, the water supplied with rice W2 stored in the first purification tank 121, the rice bran foam stored in the first purification tank 121, and the crushed rice grains R4 stored in the first purification tank 121 are discharged from the drain pipe (piping) 123 located at the bottom of the first purification tank 121. By removing the overflow water drain pipe 132 from the drain port 128a, a drain pipe 133 is installed at the bottom of the second purification tank 128 to discharge the rice water W2 and rice bran foam stored in the second purification tank 128, It is equipped with.

[0115] As shown in Figure 15, the second return pipe 77 is connected to the side of the first purification tank 121. The first purification tank 121 is a rectangular tank in top view with an open top, and its lower part is shaped like a square pyramid with its apex pointing downwards. A drain pipe 123 with a valve 124 is connected to the apex of the downward-pointing square pyramid at the bottom of the first purification tank 121. By opening the valve 124, the drain pipe 123 discharges the rice water W2 etc. stored in the first purification tank 121.

[0116] Inside the first purification tank 121 is a hopper that is open at the top and has a rectangular shape when viewed from above. Below this is a drain hopper 122 which has a square pyramidal shape with its apex pointing downwards. The lower apex of the drain hopper 122 is connected to a drain pipe 122a. When the water W2 supplied to the rice stored in the first purification tank 121 exceeds the water level H6 when it is stored up to the edge of the upper opening of the drain hopper 122, it overflows from the drain hopper 122 and is drained through the drain pipe 122a.

[0117] One end of the third return pipe 125, which has a valve 126, is connected to the side of the first septic tank 121 opposite to the side to which the second return pipe 77 is connected. The other end of the third return pipe 125 is connected to the side of the second septic tank 128.

[0118] Furthermore, within the first purification tank 121, between the point where the second return pipe 77 is connected and the point where one end of the third return pipe 125 is connected, a plate-shaped flow restricting member 127 is provided near the wall surface of the first purification tank 121 at the point where one end of the third return pipe 125 is connected.

[0119] The plate-shaped flow restricting member 127 is installed so as to be approximately perpendicular to the flow direction of the air-containing rice supply water W5 mixed with immersion water flowing from the second return pipe 77 to the first purification tank 121, preventing the air-containing rice supply water W5, which is mixed with immersion water flowing from the second return pipe 77 to the first purification tank 121, from flowing directly to the third return pipe 125.

[0120] The second purification tank 128, to which the other end of the third return pipe 125 is connected on its side, is equipped with a float valve 129 that detects the water level of the rice-transporting water W2 stored in the second purification tank 128, and a water supply pipe 130 that supplies clean water W1 to the second purification tank 128 when the water level falls below a predetermined level H7. The water supply pipe 130 is equipped with a valve 131, and by opening the valve 131, clean water W1 is supplied, making it possible to store rice-transporting water W2 in the second purification tank 128.

[0121] Furthermore, the second purification tank 128 is roughly cubic in shape and has a drain port 128a at its bottom. An overflow drain pipe 132 is inserted into the drain port 128a to allow the rice-supplied water W2 stored in the second purification tank 128 to flow out when the water level exceeds a predetermined water level H7.

[0122] When the water supplied to the rice, W2, stored in the second purification tank 128 exceeds the water level H7 (which is reached when the tank is filled to the edge of the upper opening of the overflow drain pipe 132), it overflows and is drained through the overflow drain pipe 132 to the drain pipe 133. The overflow drain pipe 132 is constructed such that the edge of its upper opening is approximately equal to or slightly higher than the water level H7.

[0123] From the side of the second purification tank 128, a pipe 28 is connected via a mesh filter 134 to the pump 29 of the rice washing section 20.

[0124] The water level H3 when the immersion tank 61 shown in Figure 7 is filled with immersion water W4 is configured to be higher than the water level H6 of the first purification tank 121 shown in Figure 15.

[0125] As a result, when the water level of the immersion water W4 stored in the immersion tank 61 exceeds the water level H3, the immersion water W4 overflows over the upper end of the wall 76a of the overflow section 76, and can be allowed to flow down to the first purification tank 121 through the second return pipe 77 by gravity, without the need for a pump or the like.

[0126] (7) Control Unit Next, the configuration of the control unit 140 will be described.

[0127] The control unit 140 shown in Figure 1 is electrically connected to the equipment in each section and performs centralized control.

[0128] The control unit 140 includes a control panel 141 that electrically connects to and controls each component and equipment, as described below. - The pump 29 of the rice washing unit 20 is electrically connected to control its operation and stopping. By driving the pump 29, the rice water W2 stored in the second purification tank 128 is discharged to the ejector 26. By stopping the pump 29, the discharge of rice water W2 to the ejector 26 is stopped. • The valve 24 of the rice washing section 20 is electrically connected to control its opening and closing. Opening the valve causes clean water W1 to be sprayed from the clean water nozzle 25 attached to the inside of the wall of the receiving cylinder 22. Closing the valve stops the spraying of clean water W1 from the clean water nozzle 25. The valve 67 of the immersion section 60 is electrically connected and receives an electrical signal from the water level detection means 69 to control opening and closing. Opening the valve allows fresh water W1 to be sprayed into the immersion tank 61 from the water supply nozzle 68. Closing the valve stops the spraying of fresh water W1 from the water supply nozzle 68. The immersion section 60 is electrically connected to the storage volume detection means 70 and receives an electrical signal from the storage volume detection means 70. The system electrically connects to the rice distribution valve 79 of the immersion section 60 and controls its opening and closing. Opening the valve allows the immersion water and immersed rice grains M3 stored in the immersion tank 61 to flow through the piping 78 to the separate rice distribution container 92. Closing the valve stops the flow of the immersion water and immersed rice grains M3. - It is electrically connected to the drive means 96 that drives the shutter 95 of the rice distribution section 90, and controls the opening and closing of the lower opening of the separated rice distribution container 92. By electrically connecting to the valve 107 of the water supply unit 100 and opening and closing it, a predetermined amount of cooking water W6 is supplied to the rice cooker pot 97. The heater 105 of the water supply unit 100 and a temperature sensor (not shown) installed in the tank 104 are electrically connected to adjust the cooking water W6 to a predetermined temperature.

[0129] (Operation of the rice cooking pre-processing system) The operation of the rice pre-processing system 10 of this embodiment will be described below.

[0130] The operation of the rice pre-processing system 10 in one embodiment of the present invention is broadly composed of the following, as shown in Figure 16. (1) Preparation step S10: Preparation to carry out each of the steps from (1) onward. (2) Supply step S20: Supply the pre-prepared polished rice grains R1 to the rice washing section 20. (3) In the rice washing step S30, air, the rice supply water W2, and the polished rice grains R1 supplied in the supply step S20 are mixed to form a mixed fluid M1 of air-containing rice supply water and polished rice grains, and the polished rice grains R1 are washed by flowing this mixed fluid M1 of air-containing rice supply water and polished rice grains within the rice washing means 32. (4) Diffusion step S40: The mixed fluid M2 of the air-containing water used to deliver the rice after the rice washing step S30 and the washed rice grains is diffused in a substantially horizontal direction by the diffuser 42 within the separator 43. (5) The mixed fluid M2 of the air-containing rice water and pre-washed rice grains diffused in the diffusion step S40 is brought to the wall surface 43a of the separator 43, and the first separation step (separation step) S51 separates the air-containing rice water W3 and the pre-washed rice grains R2 by the drain section 43c of the separator 43. (6) Of the mixed fluid M2 of the rice-delivery water containing air and pre-washed rice grains that has been diffused in the diffusion step S40, the mixed fluid M2 of the rice-delivery water containing air and pre-washed rice grains that has flowed upward along the wall surface 43a is guided downward by the guide unit 41a in the guide step S52 to the draining unit 43c. (7) The washed rice grains R2 remaining inside the separator 43 after separation in the first separation step S51 are mixed with the mixed fluid M2 of air-containing rice water and washed rice grains that has been guided to the drainage section 43c by the induction step S52, and the mixed fluid M2 of air-containing rice water and washed rice grains is separated into air-containing rice water W3 and washed rice grains R2 by the drainage section 43c of the separator 43 in the second separation step (separation step) S60. (8) Flow step S70, which causes the pre-washed rice grains R2 separated in the first separation step S51 and the second separation step S60 to fall and flow downward, and the pre-washed rice grains R2 separated on the inside of the wall surface 43a to flow downward with the air-containing rice water W3 that could not be separated from the mixed fluid M2 of air-containing rice water and pre-washed rice grains in the first separation step S51 and the second separation step S60. (9) In the immersion step S80, the washed rice grains R2 separated in the separation steps S51 and S60 are immersed in the immersion water W4 stored in the immersion tank 61, and the rice bran foam floating on the surface of the immersion water W4 is made to flow out along with the immersion water W4 stored in the immersion tank 61. (10) In the soaking step S80, the soaked rice grains R3 are supplied in a predetermined amount to the rice cooker pot 97 in the rice distribution section 90 in the rice distribution step S90. (11) Water supply step S100: A predetermined amount of cooking water W6 is supplied from the water supply unit 100 to the rice cooker 97 to which the soaked rice grains R3 were supplied in the rice distribution step S90. (12) The air-containing rice water W3 separated in the first separation step S51 and the second separation step S60, and the immersion water W4 that overflowed in the immersion step S80 are mixed to form air-containing rice water W5 mixed with immersion water, and the mixture is purified in the purification unit 120 in the purification step S110. (13) A predetermined amount of polished rice grains R1 to be washed is placed in the rice cooker pot 97 as soaked rice grains R3, and after a predetermined amount of cooking water W6 is added, the completion step S120 is performed to prepare for the next preparation step S10.

[0131] (1) Preparation Steps In the rice cooking pre-processing system 10 of this embodiment, a preparation step S10 is first performed to prepare for each of the subsequent steps.

[0132] First, the power to the control panel 141 of the control unit 140 shown in Figure 1 is turned on.

[0133] Next, the valve 67 of the water supply pipe 66 of the immersion section 60 is opened, and clean water W1 is injected from the water supply nozzle 68 through the water supply pipe 66 to be stored in the immersion tank 61 as immersion water W4. When the immersion water W4 stored in the immersion tank 61 reaches a water level H3 (see Figure 7), the water level detection means 69 detects the water level H3 of the immersion water W4 stored in the immersion tank 61 and sends an electrical signal to the control panel 141. The control panel 141 then receives the electrical signal and closes the valve 67 of the water supply pipe 66.

[0134] The valve 102 of the water supply unit 100 is opened, and fresh water W1 is supplied to the tank 104 through the water supply pipe 101 and stored as cooking water W6. When the cooking water W6 stored in the tank 104 reaches a predetermined level, the float valve 103 is activated, and the supply of fresh water W1 from the water supply pipe 101 is stopped. Then, the control panel 141 activates the heater 105 to raise the temperature of the cooking water W6 stored up to the predetermined level to a predetermined temperature and maintain it at that predetermined temperature.

[0135] The valve 131 of the purification unit 120 is opened, and clean water W1 is supplied to the second purification tank 128 through the water supply pipe 130 and stored as rice supply water W2. When the stored rice supply water W2 reaches a predetermined water level H7 (see Figure 15), the float valve 129 is activated, and the supply of clean water W1 from the water supply pipe 130 is stopped. At this time, the predetermined water level H7 is approximately equal to or slightly lower than the edge of the upper opening of the overflow water drain pipe 132.

[0136] Furthermore, the supplied rice water W2 flows from the second purification tank 128 through the third return pipe 125 to the first purification tank 121, where it is stored up to the same water level as H7. The flow rate of the supplied rice water W2 flowing between the second purification tank 128 and the first purification tank 121 through the third return pipe 125 is regulated by the valve 126.

[0137] The pump 29 of the rice washing section 20 is activated, and the water W2 supplied to the rice, which has been stored in the second purification tank 128, is discharged and flows into the ejector 26 of the rice washing section 20. Furthermore, the valve 24 of the rice washing section 20 is opened, and the injection of clean water W1 from the clean water nozzle 25 into the inside of the wall surface of the receiving cylinder 22 is started.

[0138] The rice water W2 is mixed with the air in the receiving cylinder 22 and the clean water W1 sprayed from the clean water nozzle 25 by the ejector 26 and passes through to become rice water W3 containing air. The rice water W3 containing air then flows almost vertically down through the rice supply pipe 31 and the rice washing means 32 to the diffuser 42 of the separation unit 40. The water level in the second purification tank 128 decreases, but the float valve 129 supplies clean water W1 to maintain the water level H7.

[0139] The air-containing rice-supplied water W3 that reaches the upper surface of the diffuser 42 changes its flow direction to a nearly horizontal direction due to the inclined section 42a and the horizontal section 42b, and then flows through the multiple holes 43e provided in the wall surface 43a of the separator 43 to the first water receiving section 44. Then it flows inside the first water receiving section 44 and flows to the first return pipe 45.

[0140] The air-containing rice water W3 that flows into the first return pipe 45 flows down into the overflow section 76 of the immersion section 60, and then flows down into the second return pipe 77. The air-containing rice water W3 that flows down into the second return pipe 77 flows into the first purification tank 121 of the purification section 120 and is stored there.

[0141] Then, the air-containing rice water W3 flows into and is stored in the first purification tank 121 until it reaches a predetermined water level H6 (see Figure 15). At this time, the second return pipe 77 is also filled to the same water level as the predetermined water level H6.

[0142] Furthermore, at this time, the balance between the flow rate overflowing from the drain hopper 122 of the first septic tank 121 and the flow rate overflowing from the overflow water drain pipe 132 of the second septic tank 128 is adjusted by the valve 126 of the third return pipe 125.

[0143] Finally, the position of the rice distribution amount adjuster 91 is adjusted so that a predetermined amount of soaked rice grains R3 is stored in the separate rice distribution container 92 of the rice distribution unit 90, and the preparation step S10 is completed.

[0144] (2) Supply step After the preparation step S10 is completed, the supply step S20 is performed to supply the pre-prepared polished rice grains R1 to the rice washing section 20.

[0145] As shown in Figure 2, the operator supplies the polished rice grains R1, which have been prepared in advance, to the introduction guide 21 of the rice washing section 20. It is preferable that the polished rice grains R1 supplied to the introduction guide 21 are supplied in a state that has been pre-adjusted for the pre-cooking processing system 10. For example, the configuration of the pre-cooking processing system 10 may change depending on the degree of polishing (polishing level) of the polished rice grains R1.

[0146] In addition, in supply step S20, an operator supplies polished rice grains R1 to the introduction guide 21. However, it is also possible to configure the system to automatically supply polished rice grains R1 to the introduction guide 21 by installing a rice silo (not shown) for storing the polished rice grains R1, a weighing device (not shown) for dispensing a predetermined amount of polished rice grains R1 from the rice silo, and a rice lifting machine (not shown) for transporting the polished rice grains R1 dispensed from the weighing device.

[0147] In that case, the weighing device and the rice lifting machine will continue to supply polished rice grains R1 by the weighing device and the rice lifting machine until a predetermined amount of polished rice grains R1, as set in advance by the control panel 141, is supplied to the introduction guide 21, or until the storage amount detection means 70 installed in the immersion tank 61 detects a predetermined amount of immersed rice grains R3 stored in the immersion tank 61.

[0148] (3) Rice washing step After starting the supply step S20, air, the rice supply water W2, and the polished rice grains R1 supplied in the supply step S20 are mixed to form a mixed fluid M1 of air-containing rice supply water and polished rice grains. The rice washing step S30 is then performed to wash the polished rice grains R1 by flowing this mixed fluid M1 of air-containing rice supply water and polished rice grains within the rice washing means 32.

[0149] As shown in Figure 2, the water W2 supplied to the rice, stored in the second purification tank 128, is drawn into the pump 29 via the filter 134 and discharged, flowing into the ejector 26. Meanwhile, the polished rice grains R1 supplied in the supply step S20 are guided by the introduction guide 21, pass through the receiving cylinder 22, and are sucked into the suction port 27 along with the air inside the receiving cylinder 22. At that time, the polished rice grains R1 adhering to the inside of the wall surface of the receiving cylinder 22 flow together with the clean water W1 sprayed from the clean water nozzle 25 attached to the inside of the wall surface of the receiving cylinder 22, and are sucked into the suction port 27.

[0150] In this way, the polished rice grains R1 and clean water W1 that are drawn into the suction port 27 are drawn into the suction port 27 together with the air in the receiving cylinder 22, and are mixed with the flowing rice water W2 discharged from the pump 29 in the ejector 26 to become a mixed fluid M1 of air-containing rice water and polished rice grains.

[0151] The mixed fluid M1 of air-containing rice water and polished rice grains, which is mixed in the ejector 26 and flowed into the rice delivery pipe 31, flows through a rice washing means 32, such as a static mixer, which is incorporated into the middle of the rice delivery pipe 31. This washes the polished rice grains R1 into pre-washed rice grains R2. Then, the mixed fluid M2 of air-containing rice water and pre-washed rice grains flows through the rice delivery pipe 31 toward the separation unit 40.

[0152] When polished rice grains R1 are washed by passing them through the rice washing means 32, some of the polished rice grains R1 break due to the impact of contact with the rice washing means 32, other polished rice grains R1, and the inside of the wall of the rice delivery pipe 31, becoming crushed rice grains R4. These crushed rice grains R4 flow through the rice delivery pipe 31 together with the mixed fluid M2 of the rice delivery water containing air and the already washed rice grains, and then flow to the separation section 40.

[0153] (4) Diffusion step After the rice washing step S30 is completed, a diffusion step S40 is performed in which the mixed fluid M2 of the rice water containing air after the rice washing step S30 and the already washed rice grains is diffused in a substantially horizontal direction by the diffuser 42 within the separator 43.

[0154] As shown in Figure 3, the mixed fluid M2 of air-containing rice water and pre-washed rice grains flows through the rice supply pipe 31 to the separation section 40, and then flows downward in a nearly vertical direction from the opening 31a of the rice supply pipe 31 attached to the lid 41, retaining its kinetic energy as it reaches the inclined section 42a of the diffuser 42.

[0155] When the mixed fluid M2 of air-containing rice water and pre-washed rice grains reaches the inclined section 42a of the diffuser 42, the direction of flow is changed to follow the inclined section 42a, spreading 360 degrees in a top view along the conical shape.

[0156] At this time, the mixed fluid M2 of the air-containing water being supplied and the pre-washed rice grains reaches the inclined section 42a of the diffuser 42, and the direction of flow is changed, causing the kinetic energy of the mixed fluid M2 of the air-containing water being supplied and the pre-washed rice grains to decrease.

[0157] Then, the mixed fluid M2 of the air-containing water and pre-washed rice grains flowing through the inclined section 42a of the diffuser 42 reaches the horizontal section 42b of the diffuser 42. When the mixed fluid M2 of the air-containing water and pre-washed rice grains reaches the horizontal section 42b, the direction of flow is changed to approximately horizontal.

[0158] At this time, the mixed fluid M2 of air-containing water and pre-washed rice grains reaches the horizontal section 42b, and the direction of flow is changed, further reducing the kinetic energy of the mixed fluid M2 of air-containing water and pre-washed rice grains.

[0159] Thus, in the diffusion step S40, the diffuser 42 can change the direction of flow of the mixed fluid M2 of air-containing rice water and pre-washed rice grains that has flowed in a substantially vertical direction from the opening 31a of the rice supply pipe 31, while reducing its kinetic energy.

[0160] Then, as the direction of flow is changed to a nearly horizontal direction, the mixed fluid M2 of the rice-transmitting water containing air and pre-washed rice grains, whose kinetic energy has decreased, flows away from the outer end in the diametrical direction of the horizontal section 42b of the diffuser 42 and flows through the space inside the separator 43, reaching the inside of the drainage section 43c on the wall surface 43a of the separator 43.

[0161] In this embodiment, the action of diffusing the mixed fluid M2 of the air-containing rice water and pre-washed rice grains onto the wall surface 43a of the separator 43 by the diffuser 42 in the diffusion step S40 is referred to as the "first diffusion".

[0162] The shape of the diffuser 42 is merely an example, and other shapes are acceptable as long as they can change the flow direction of the mixed fluid M2 of air-containing rice water and pre-washed rice grains, which flows in a substantially vertical direction from the opening 31a of the rice supply pipe 31, to a substantially horizontal direction. For example, the inclined part 42a and the horizontal part 42b of the diffuser 42 may be made into a continuous curved surface.

[0163] (5) First separation step Following the diffusion step S40, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains diffused in the diffusion step S40 is brought to the wall surface 43a of the separator 43, and the first separation step S51 is performed in which the air-containing rice water W3 and pre-washed rice grains R2 are separated by the drain section 43c of the separator 43.

[0164] As shown in Figure 3, the first diffusion in diffusion step S40 changes the direction of flow to approximately horizontal, and the mixed fluid M2 of the supplied rice water and pre-washed rice grains, which contains air with reduced kinetic energy, reaches the inside of the drainage section 43c on the wall surface 43a of the separator 43.

[0165] Since the drainage section 43c of the wall surface 43a of the separator 43 that reaches it is provided with multiple holes 43e, the mixed fluid M2 of the supplied rice water containing air and the washed rice grains that reaches the inside of the drainage section 43c of the wall surface 43a of the separator 43 undergoes a "first separation" in which the washed rice grains R2 and the supplied rice water containing air are separated by the multiple holes 43e.

[0166] Of the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that reaches the inside of the drainage section 43c on the wall surface 43a of the separator 43, the air-containing rice water W3 flows through multiple holes 43e and out to the outside of the separator 43. The pre-washed rice grains R2, however, cannot pass through the holes 43e and remain inside the separator 43.

[0167] In this way, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains, which flows in a nearly horizontal direction due to the "first diffusion" in diffusion step S40, undergoes a first separation when it reaches the inside of the diffuser 42 in the first separation step S51, and the mixed fluid M2 of the air-containing rice water and pre-washed rice grains is separated into the air-containing rice water W3 and pre-washed rice grains R2.

[0168] At this time, the air contained in the air-containing rice water W3 is released into the atmosphere as it flows down from the opening 31a of the rice supply pipe 31 to the diffuser 42, causing the air to dissipate and separate from the air-containing rice water W3. Subsequently, as it reaches the diffuser 42, the direction of flow changes as it expands 360 degrees in a top view along the conical shape, passes through multiple holes 43e of the separator 43, and continues to dissipate from the air-containing rice water W3 until it flows to the first water receiving section 44.

[0169] In this way, the kinetic energy of the mixed fluid M2 of air-containing rice water and pre-washed rice grains is reduced twice by the diffusion step S40 until it reaches the wall surface 43a of the separator 43. This mitigates the impact when the mixed fluid M2 of air-containing rice water and pre-washed rice grains reaches the wall surface 43a of the separator 43, thereby suppressing the breaking of the pre-washed rice grains R2 into crushed rice grains R4.

[0170] Furthermore, when the mixed fluid M2 of the air-containing rice water and pre-washed rice grains reaches the inclined section 42a or horizontal section 42b of the diffuser 42 or the wall surface 43a of the separator 43, the air contained in the air-containing rice water W3 acts as a buffer, preventing the pre-washed rice grains R2 from cracking and becoming crushed rice grains R4 due to the impact of contact.

[0171] Furthermore, the flow direction of the mixed fluid M2 of air-containing rice water and pre-washed rice grains is changed by the diffuser 42 from a nearly vertical direction when it flows down from the opening 31a of the rice supply pipe 31, to a flow direction that changes when it reaches the inclined section 42a of the diffuser 42, and then to a nearly horizontal direction when it reaches the horizontal section 42b. The angle of change in the flow direction each time is modified is obtuse.

[0172] This reduces the impact on the pre-washed rice grains R2 each time the mixed fluid M2 of air-containing rice water and pre-washed rice grains changes direction, thereby preventing the pre-washed rice grains R2 from breaking and becoming crushed rice grains R4 due to the impact when they reach the diffuser 42 and separator 43.

[0173] Furthermore, the surface of the conical diffuser 42 has no holes or other defects, allowing the mixed fluid M2 of air-containing rice water and pre-washed rice grains to flow smoothly, and suppressing the generation of crushed rice grains R4 when the direction of flow is changed in the diffuser 42.

[0174] Furthermore, the mixed fluid M2 of air-containing rice water and pre-washed rice grains that has been flowing down is spread 360 degrees in a nearly horizontal direction by the diffuser 42, so that it reaches a wider surface on the inside of the drain section 43c. In other words, the amount of mixed fluid M2 of air-containing rice water and pre-washed rice grains that reaches the unit area of ​​the drain section 43c can be reduced as much as possible. As a result, the mixed fluid M2 of air-containing rice water and pre-washed rice grains can be effectively separated into air-containing rice water W3 and pre-washed rice grains R2.

[0175] Then, the rice supply water W3 containing air, which has passed through the holes 43e provided in the wall surface 43a of the separator 43 and separated to the outside of the separator 43, flows to the first water receiving section 44 and then to the first return pipe 45.

[0176] The pre-washed rice grains R2 that are separated to the inside of the separator 43 without passing through the holes 43e provided in the wall surface 43a of the separator 43 flow downwards along the inside of the wall surface 43a of the separator 43 and flow into the flow pipe 46.

[0177] At this time, the rice supply water W3 containing air that cannot be completely separated and flows along the inside of the drainage section 43c of the wall surface 43a of the separator 43 along with the washed rice grains R2 flows along the wall surface 43a in small quantities and flows downward toward the flow pipe 46 along with the washed rice grains R2.

[0178] Furthermore, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that reached the wall surface 43a due to the first diffusion in diffusion step S40 diffuses upward and downward along the wall surface 43a. This diffusion upward and downward along the wall surface 43a is referred to as the "second diffusion." In the first separation step S51, this "second diffusion" and the separation of the air-containing rice water W3 and pre-washed rice grains R2 are carried out in parallel.

[0179] (6) Induction step Next, we will explain the guidance step S52, in which the mixed fluid M2 of the air-containing water and pre-washed rice grains diffused in the diffusion step S40 reaches the wall surface 43a, and the mixed fluid M2 of the air-containing water and pre-washed rice grains that has flowed upward along the wall surface 43a is guided downward by the guidance section 41a to lead it to the drainage section 43c.

[0180] As shown in Figure 16, this induction step S52 is performed in parallel with the first separation step S51 after the diffusion step S40.

[0181] As shown in Figure 3, the diffusion step S40 changes the direction of flow to approximately horizontal, and the mixed fluid M2 of the supplied rice water and pre-washed rice grains, which contains air with reduced kinetic energy, reaches the inside of the drainage section 43c on the wall surface 43a of the separator 43.

[0182] At this time, in the mixed fluid M2 of the air-containing rice water and the washed rice grains, in addition to the air-containing rice water W3 that flows outwards from the separator 43 through the holes 43e as a result of the first separation step S51, there is also a portion that comes into contact with the inside of the wall surface 43a, excluding the holes 43e, and flows upward along the wall surface 43a of the separator 43.

[0183] The wall surface 43a of the separator 43, the top surface 43g, the bottom surface of the lid 41, and the guide section 41a attached to the bottom surface of the lid 41 are configured to form a substantially continuous surface. Therefore, the mixed fluid M2 of the rice supply water containing air and pre-washed rice grains, which flows upward along the wall surface 43a of the separator 43, flows from the wall surface 43a of the separator 43 along the top surface 43g and the bottom surface of the lid 41, and reaches the guide section 41a.

[0184] At this time, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains, which flows upward along the wall surface 43a of the separator 43, flows through the upper flow section 43b of the wall surface 43a of the separator 43, where there are no holes 43e. In the upper flow section 43b, the air-containing rice water W3 is not separated, so the pre-washed rice grains R2 are easily flowed by the air-containing rice water W3. This suppresses the retention of pre-washed rice grains R2 in the upper flow section 43b, while allowing the fluid to flow from the wall surface 43a of the separator 43 along the top surface 43g and the underside of the lid 41, reaching the guide section 41a.

[0185] Then, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains is guided downward along the guide section 41a which extends in a substantially vertical direction, changing the direction of flow, and is passed between the outer end in the diametrical direction of the horizontal section 42b of the diffuser 42 and the wall surface 43a, and can be guided to the drain section 43c of the separator 43.

[0186] Furthermore, this prevents the mixed fluid M2 of the air-containing rice water and pre-washed rice grains, which flows upward along the wall surface 43a of the separator 43, from flowing beyond the upper end of the wall surface 43a, that is, beyond the top surface 43g, and flowing out of the separator 43.

[0187] Furthermore, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains, which reaches the inside of the wall surface 43a excluding the hole 43e in the first separation step S51 and flows upward along the wall surface 43a of the separator 43, may flow downward along the inside of the upper flow section 43b of the wall surface 43a without reaching the guide section 41a. This also allows the mixed fluid M2 of the air-containing rice water and pre-washed rice grains to be guided to the drain section 43c of the separator 43.

[0188] At this time, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains flows through the upper flow section 43b, which does not have holes 43e. In the upper flow section 43b, the air-containing rice water W3 is not separated, so it is possible to suppress the remaining pre-washed rice grains R2 in the upper flow section 43b and allow them to flow downward along the inside of the upper flow section 43b.

[0189] Even if pre-washed rice grains R2 remain on the inner surface of the upper flow section 43b, the inner surface of the top surface section 43g, or the surface of the guide section 41a, the mixed fluid M2 of the air-containing rice supply water and pre-washed rice grains flowing in this guide step S52 will guide them to the drain section 43c, allowing them to flow downwards so that as few pre-washed rice grains R2 as possible remain inside the separator 43.

[0190] Furthermore, even if the wall surface 43a of the separator 43 is not provided with an upper flow section 43b, it is still acceptable if the mixed fluid M2 of the air-containing rice water and pre-washed rice grains can be guided to the drain section 43c of the separator 43 in the induction step S52 so that as little of the fluid remains as possible. In other words, the separator 43 may have a shape that includes multiple holes 43e extending to the upper end of the wall surface 43a.

[0191] (7) Second separation step Next, we will describe the second separation step S60, in which the pre-washed rice grains R2 remaining inside the separator 43 after separation in the first separation step S51 are mixed with the mixed fluid M2 of air-containing rice water and pre-washed rice grains that has been guided to the drainage section 43c in the induction step S52, and this mixed fluid M2 of air-containing rice water and pre-washed rice grains is separated into air-containing rice water W3 and pre-washed rice grains R2 by the drainage section 43c of the separator 43.

[0192] As shown in Figure 16, this second separation step S60 is performed after the first separation step S51 and induction step S52, which are performed in parallel.

[0193] In the first separation step S51, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that reached the inside of the drainage section 43c of the wall surface 43a of the separator 43 by the diffusion step S40 diffuses upward and downward along the wall surface 43a by the "second diffusion". Of this, some of the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that diffuses downward remains inside the drainage section 43c, and the remaining pre-washed rice grains R2 are left behind.

[0194] Furthermore, in the first separation step S51, the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that reached the inside of the drainage section 43c on the wall surface 43a of the separator 43 shown in Figure 3 by the diffusion step S40 was separated into the inside and outside of the separator 43 by multiple holes 43e. Because the pre-washed rice grains R2 separated from the air-containing rice water W3 have a weak flow force, some of the pre-washed rice grains R2 that remain inside the separator 43 remain inside the drainage section 43c.

[0195] In addition, in the induction step S52, the mixed fluid M2 of the rice-supplying water containing air and pre-washed rice grains, which flows upward with weak momentum, does not reach the induction section 41a but flows downward along the inside of the upper flow section 43b on the wall surface 43a toward the drain section 43c. However, because the downward flow is also weak, it may remain inside the drain section 43c, leaving behind pre-washed rice grains R2.

[0196] The remaining pre-washed rice grains R2 that stay inside the drainage section 43c are then mixed with the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that was guided to the drainage section 43c by the induction step S52.

[0197] The mixed fluid M2 of the air-containing rice delivery water and pre-washed rice grains flows downward inside the drainage section 43c, and is separated into the air-containing rice delivery water W3 and pre-washed rice grains R2 by the multiple holes 43e. In this way, the pre-washed rice grains R2 that remain inside the drainage section 43c during the first separation step S51 can be separated into the air-containing rice delivery water W3 and pre-washed rice grains R2 by flowing downward along the drainage section 43c with the mixed fluid M2 of air-containing rice delivery water and pre-washed rice grains that was guided to the drainage section 43c in the induction step S52.

[0198] This effectively separates the mixed fluid M2 of the air-containing rice water and pre-washed rice grains that has flowed almost vertically into the separator 43 into the air-containing rice water W3 and pre-washed rice grains R2 by the first separation step S51 and the second separation step S60, while also reducing the amount of pre-washed rice grains R2 remaining inside the drain section 43c of the separator 43 as much as possible.

[0199] In particular, since the holes 43e in the wall surface 43a of the present invention are elongated holes inclined with respect to the horizontal direction, the downward flow of pre-washed rice grains R2 is easily obstructed inside the drainage section 43c, and the pre-washed rice grains R2 tend to remain inside the wall surface 43a. The pre-washed rice grains R2 that tend to remain in the drainage section 43c are effectively separated into the air-containing rice supply water W3 and the pre-washed rice grains R2 by the second separation step S60, and the amount of pre-washed rice grains R2 remaining inside the separator 43 can be reduced as much as possible.

[0200] The air-containing rice water W3, separated to the outside of the separator 43 through the multiple holes 43e, flows to the first water receiving section 44 and then to the first return pipe 45. The pre-washed rice grains R2, separated to the inside of the separator 43 through the multiple holes 43e, flow downward and reach the lower flow section 43d of the separator 43.

[0201] The shape of the separator 43 is not limited to that exemplified in this embodiment. For example, the separator 43 may be a flat plate-shaped member, in which case the same effect can be achieved by providing a drainage section 43c and a downward flow section 43d on the flat plate-shaped wall surface 43a as shown in Figure 3.

[0202] (8) Flow step Next, we will describe the flow step S70, in which the pre-washed rice grains R2 separated in the first separation step S51 and the second separation step S60 are allowed to fall and flow downward, and the pre-washed rice grains R2 separated on the inside of the wall surface 43a are flowed downward by the air-containing rice water W3 that could not be separated from the mixed fluid M2 of air-containing rice water and pre-washed rice grains in the first separation step S51 and the second separation step S60.

[0203] The pre-washed rice grains R2 separated to the inside of the wall surface 43a of the separator 43 by the first separation step S51 and the second separation step S60 flow downward inside the drainage section 43c and reach the lower flow section 43d of the wall surface 43a.

[0204] Since the lower flow section 43d does not have holes 43e, the air-containing rice water W3 that could not be completely separated from the mixed fluid M2 of air-containing rice water and pre-washed rice grains in the first separation step S51 and the second separation step S60 can smoothly cause the pre-washed rice grains R2 to flow downward toward the flow pipe 46.

[0205] Furthermore, the force of the mixed fluid M2 of air-containing rice water and pre-washed rice grains, whose flow direction has been changed downward by the guide section 41a in the induction step S52, allows the pre-washed rice grains R2 to flow smoothly downward towards the flow pipe 46.

[0206] Furthermore, even if pre-washed rice grains R2 remain on the inner surface of the lower flow section 43d, as already described in the flow step S70, the air-containing rice supply water W3, etc., flowing downwards can smoothly move the pre-washed rice grains R2 remaining in the lower flow section 43d downwards towards the flow pipe 46.

[0207] Furthermore, before the completion of the first separation step S51 and the second separation step S60, the following crushed rice grains R4 may mix with the mixed fluid M2 of the air-containing rice supply water and the washed rice grains. (1) The broken rice grains R4 that were originally broken were supplied in supply step S20. (2) Crushed rice grains R4 generated by the impact when supplied to the introduction guide 21 in the supply step S20 (3) In the rice washing step S30, when the rice is flowed through the rice supply pipe 31 and the rice washing means 32, crushed rice grains R4 (4) In the diffusion step S40, when the mixed fluid M2 of the air-containing water and the washed rice grains reaches the diffuser 42, crushed rice grains R4 are generated. (5) In the first separation step S51, when the mixed fluid M2 of the air-containing rice water and the washed rice grains reaches the wall surface 43a of the separator 43, crushed rice grains R4 are generated. (6) In the induction step S52, the flow direction is changed downward by the induction section 41a and the crushed rice grains R4 are generated when they are guided to the drain section 43c.

[0208] Most of the crushed rice grains R4 from (1) to (6) pass through the multiple holes 43e of the separator 43 when the mixed fluid M2 of air-containing rice water and pre-washed rice grains reaches the wall surface 43a of the separator 43, and flow into the first return pipe 45 together with the air-containing rice water W3. The crushed rice grains R4 that do not pass through the multiple holes 43e of the separator 43 flow into the fluid pipe 46 together with the pre-washed rice grains R2 and the air-containing rice water W3.

[0209] Furthermore, since the multiple holes 43e in the wall surface 43a of the separator 43 are elongated holes inclined with respect to the horizontal, the rice supply water W3 containing air, which flows along the inside of the wall surface 43a of the separator 43 together with the washed rice grains R2, flows in a swirling motion inside the wall surface 43a of the separator 43.

[0210] Furthermore, compared to flowing linearly downwards along the inside of the wall surface 43a of the separator 43, the mixed fluid M2 of air-containing rice water and pre-washed rice grains can flow along the inside of the wall surface 43a, which has multiple holes 43e, for a longer period of time. This allows for more effective separation of the mixed fluid M2 of air-containing rice water and pre-washed rice grains into air-containing rice water W3 and pre-washed rice grains R2.

[0211] As a result, in the separation steps S51 and S60, without requiring power from a drive mechanism or the like, the cracking of the pre-washed rice grains R2 can be suppressed, and almost the entire amount of pre-washed rice grains R2 washed in the rice washing step S30 can be sent to the immersion section 60 for the next step.

[0212] Furthermore, assuming that there may be some pre-washed rice grains R2 remaining on the upper surface of the diffuser 42 and inside the wall surface 43a of the separator 43 after the flow step S70 and before moving to the immersion step S80, after the flow step S70, the supply of polished rice grains R1 to the introduction guide 21 of the rice washing section 20 shown in Figure 1 may be temporarily stopped, and only the rice supply water W3 containing air may be allowed to flow from the rice supply pipe 31 to the diffuser 42 and separator 43. This ensures that the pre-washed rice grains R2 that have flowed out of the rice washing section 20 are allowed to flow into the immersion section 60.

[0213] In this embodiment, the direction of flow of the mixed fluid M2 of air-containing rice water and pre-washed rice grains, which flows in a substantially vertical direction from the opening 31a of the rice supply pipe 31, is changed multiple times (twice), reducing the kinetic energy each time, and allowing it to reach the inside of the wall surface 43a of the separator 43. However, by changing the shape of the diffuser 42, the number of times the direction of flow of the mixed fluid M2 of air-containing rice water and pre-washed rice grains is changed may be three or more.

[0214] For example, the surface of the inclined portion 42a of the diffuser 42 may be embossed or otherwise made uneven to reduce the kinetic energy of the mixed fluid M2 of air-containing rice water and pre-washed rice grains flowing through the inclined portion 42a. Alternatively, a member for changing the flow direction of the mixed fluid M2 of air-containing rice water and pre-washed rice grains, such as a flow direction changing member made of sheet metal, may be provided below the conical diffuser 42 to change the flow direction and reduce the kinetic energy.

[0215] This allows the kinetic energy of the mixed fluid M2 of air-containing rice water and pre-washed rice grains to be more effectively reduced and reach the wall surface 43a of the separator 43, thereby suppressing the generation of crushed rice grains R4.

[0216] (9) Immersion step After the separation steps S51 and S60 are completed, the washed rice grains R2 separated in the separation steps S51 and S60 are immersed in the immersion water W4 stored in the immersion tank 61, and the immersion step S80 is performed to cause the rice bran foam floating on the surface of the immersion water W4 to flow out along with the immersion water W4 stored in the immersion tank 61, resulting in an overflow.

[0217] As shown in Figure 11, the pre-washed rice grains R2, separated from the mixed fluid M2 of the air-containing rice water and pre-washed rice grains by the separation steps S51 and S60, flow through the flow pipe 46 from the opening 46a into the immersion tank 61. Furthermore, although not shown in Figure 11, the air-containing rice water W3 that was not separated to the first water receiving section 44 also flows through the flow pipe 46 from the opening 46a into the immersion tank 61.

[0218] The washed rice grains R2 and the air-containing rice supply water W3 fall and flow onto the surface of the soaking water W4 stored in the soaking tank 61, and the washed rice grains R2 are stored in the soaking water W4 as soaked rice grains R3. Then, when the soaking water W4 is filled to the full water level H3 in the soaking tank 61, the water level rises above H3 by the volume of the fallen washed rice grains R2 and the air-containing rice supply water W3.

[0219] Then, the immersion water W4 stored in the immersion tank 61 flows over the upper end of the wall portion 76a of the overflow portion 76 and flows into the overflow portion 76. The immersion water W4 that overflows into the overflow portion 76 flows into the opening 77a of the second return pipe 77 and flows downwards within the second return pipe 77.

[0220] The soaked rice grains R3 fall into the soaking water W4, which is filled to a water level H3 in the soaking tank 61, and sink in the soaking water W4. The soaked rice grains R3 flow in the direction indicated by the arrows in Figure 11 and reach the guide plate 64. The soaked rice grains R3 that reach the guide plate 64 flow in the direction indicated by the arrows, that is, from the upper surface of the slope of the guide plate 64, through the gap between the conical outer edge of the guide plate 64 and the wall of the soaking tank 61, along the inside of the wall of the soaking tank 61, and flow from the flow opening 61a into the pipe 78. Since the rice distribution valve 79 provided in the pipe 78 is closed, the soaked rice grains R3 are stored in the soaking tank 61.

[0221] As shown in Figure 12, when the soaked rice grains R3 are stored in the soaking tank 61 and accumulate in a mountain-like shape formed at the angle of repose θ1, the soaked rice grains R3 stored in the soaking tank 61 eventually come into contact with the lower end of the movable compartment member 73. The soaked rice grains R3 stored outside the area enclosed by the fixed compartment member 72 and the closed movable compartment member 73 form a ridge line 80a.

[0222] As the pre-washed rice grains R2 continue to fall and flow into the immersion tank 61, the immersed rice grains R3 are stored in the area enclosed by the fixed compartment member 72 and the movable compartment member 73, forming a ridge line 80b. This ridge line 80b is located above the line extending toward the flow pipe 46 from the side of the ridge line 80a of the aforementioned immersed rice grains R3 that is in contact with the lower end of the movable compartment member 73.

[0223] Then, the soaked rice grains R3 stored in the area surrounded by the fixed compartment member 72 and the movable compartment member 73 are stored until a mass is applied to the movable compartment member 73 that causes it to open outwards from the soaking tank 61.

[0224] Until the movable partition member 73 is subjected to a mass sufficient to open to the outside of the immersion tank 61, the immersed paddy grains R3 stored inside the range surrounded by the fixed partition member 72 and the movable partition member 73 flow through the gap between the notch portion 72c of the fixed partition member 72 and the movable partition member 73 in the outer direction of the partition area 75. Then, as the washed paddy grains R2 continue to fall and flow into the immersion tank 61, the movable partition member 73 gradually opens in the outer direction of the immersion tank 61.

[0225] When the movable partition member 73 opens in the outer direction, the notch portion 72c provided in the fixed partition member 72 allows the immersed paddy grains R3 to gradually flow from the range surrounded by the fixed partition member 72 and the movable partition member 73 to the outside thereof. Thereby, while stabilizing the mountain of the immersed paddy grains R3 stored at the angle of repose θ1 outside the partition area 75, the immersed paddy grains R3 within the partition area 75 can be made to flow to the outside of the partition area 75.

[0226] Furthermore, as the immersed paddy grains R3 flow through the gap between the notch portion 72c of the fixed partition member 72 and the movable partition member 73 in the outer direction of the partition area 75, the mountain of the immersed paddy grains R3 stored so as to form the ridge line 80b can be gently collapsed, and the immersed paddy grains R3 stored so as to form the ridge line 80b can be guided to flow in the outer direction of the partition area 75. And by this guidance, the opening of the movable partition member 73 in the outer direction can be promoted.

[0227] When a predetermined amount of the immersed paddy grains R3 is stored in the immersion tank 61, each movable partition member 73 rotates by a predetermined angle θ3, for example, approximately 10 degrees, in the outer direction of the immersion tank 61 with the axis of the hinge 74 as the rotation axis. As a result, the immersed paddy grains R3 stored in the range surrounded by the fixed partition member 72 and the movable partition member 73 flow to the outside of the range surrounded by the fixed partition member 72 and the movable partition member 73, and are stored in a mountain shape so as to form a ridge line 80 inside the immersion tank 61, that is, between the range surrounded by the fixed partition member 72 and the movable partition member 73 and the outside of that range.

[0228] Then, by gradually allowing the soaked rice grains R3 to flow outwards from the area surrounded by the fixed compartment member 72 and the movable compartment member 73, and by opening the movable compartment member 73 to the outside of the soaking tank 61, the soaked rice grains R3 can be stored stably, and more soaked rice grains R3 can be stored in the soaking tank 61.

[0229] Furthermore, as shown in Figure 11, the hinge 74 is configured to be located below the water level H3 of the immersion water W4 stored in the immersion tank 61. This allows the rice bran foam floating on the surface of the immersion water W4, which will be described later, to remain within the compartment area 75 even if the movable compartment member 73 rotates outward by a predetermined angle θ3.

[0230] Furthermore, when the ridge line 80 of the piled-up soaked rice grains R3 reaches the storage amount detection means 70, the storage amount detection means 70 detects that the amount of soaked rice grains R3 stored in the soaking tank 61 is a predetermined amount. Then, an electrical signal is sent from the storage amount detection means 70 to the control panel 141, and a lamp or the like attached to the control panel 141 informs the operator that a predetermined amount of soaked rice grains R3 has been stored in the soaking tank 61.

[0231] The operator supplying polished rice grains R1 to the introduction guide section 21 sees a lamp or other indicator on the control panel 141 that signals that a predetermined amount of soaked rice grains R3 has been stored in the soaking tank 61, and stops supplying the polished rice grains R1. In other words, the supply step S20 stops when the amount of soaked rice grains R3 stored in the soaking tank 61 reaches a predetermined amount.

[0232] The soaked rice grains R3 stored in the soaking tank 61 are soaked in the soaking water W4 stored in the soaking tank 61 for a predetermined time, for example, 30 to 90 minutes.

[0233] Furthermore, the operator may voluntarily stop supplying polished rice grains R1 before the amount of soaked rice grains R3 stored in the soaking tank 61 reaches a predetermined amount. In this case, the predetermined amount of soaked rice grains R3 will not be stored in the soaking tank 61, but the supply amount of polished rice grains R1 may be controlled according to a predetermined amount of cooked rice. In addition, when the rice distribution step S90 described later is started and the soaked rice grains R3 stored in the soaking tank 61 flow to the rice distribution unit 90, and the amount of soaked rice grains R3 stored in the soaking tank 61 decreases, the supply step S20 may be performed again.

[0234] Furthermore, if the supply step S20 is configured to automatically supply polished rice grains R1 to the introduction guide 21 shown in Figure 1 by combining a rice silo, a weighing scale, and a rice lifting machine, the storage amount detection means 70 may be used to stop the operation of the weighing scale and the rice lifting machine and stop the supply of polished rice grains R1 when it detects that the amount of soaked rice grains R3 stored in the soaking tank 61 is a predetermined amount.

[0235] Next, we will explain in detail what happens when pre-washed rice grains R2 are dropped and flowed into the soaking water W4, which is filled to a water level H3 in the soaking tank 61, and the pre-washed rice grains R2 hit the soaking water W4.

[0236] As shown in Figure 1, when polished rice grains R1 are washed by the washing means 32 in the rice washing section 20, the rice bran attached to the polished rice grains R1 separates from the polished rice grains R1 and mixes with the air-containing rice supply water W3. The washed rice grains R2, having finished washing by the washing means 32, then flow to the separation section 40 as a mixed fluid M2 of the air-containing rice supply water and the washed rice grains. The air-containing rice supply water W3 contains the rice bran that was attached to the polished rice grains R1. The surface of the washed rice grains R2 separated in the separation section 40 is then covered with this air-containing rice supply water W3 mixed with rice bran.

[0237] Pre-washed rice grains R2, to which air-containing rice bran-infused water W3 has adhered, land on the surface of the soaking water W4 stored in the soaking tank 61 up to a water level H3, entraining air as it falls. At this time, the rice bran contained in the air-infused rice water W3 that was attached to the surface of the pre-washed rice grains R2 mixes with the air and soaking water W4, forming rice bran foam. The rice bran foam spreads over the surface of the soaking water W4 stored in the soaking tank 61, sinks to a predetermined depth from the water level H3, and then floats back up to the surface.

[0238] As shown in Figure 11, the lower ends of the fixed compartment member 72 and the movable compartment member 73 are positioned vertically downward at a distance H5 from the water level H3 when the immersion tank 61 is full. In addition, both ends of the fixed compartment member 72 are configured to be substantially in contact with the inside of the wall surface of the immersion tank 61.

[0239] Therefore, even if pre-washed rice grains R2 land on the surface of the soaking water W4 stored in the soaking tank 61, and rice bran foam generated by the rice bran attached to the pre-washed rice grains R2 spreads over the surface of the soaking water W4 stored in the soaking tank 61, the fixed partition member 72, which extends vertically upward from the surface of the soaking water W4 stored in the soaking tank 61, can keep the rice bran foam within the partitioned area 75, preventing the rice bran foam from flowing outside the partitioned area 75.

[0240] Furthermore, even if the rice bran foam sinks to a predetermined depth from the surface of the immersion water W4 at water level H3 and then floats back up to the surface, the lower ends of the fixed compartment member 72 and the movable compartment member 73 are positioned below the depth from the water surface to which the rice bran foam sinks. In other words, the fixed compartment member 72 and the movable compartment member 73, which extend vertically downward to a distance H5 from the surface of the immersion water W4 stored in the immersion tank 61, can prevent the rice bran foam from flowing outside the compartment area 75 by passing below the fixed compartment member 72 and the movable compartment member 73.

[0241] Then, within the partitioned area 75, which is separated by the fixed partition member 72 and the inside of the wall of the immersion tank 61, the rice bran foam rises to the surface and spreads out above the water. As a result, the rice bran foam generated when the washed rice grains R2 come into contact with the immersion water W4 stored in the immersion tank 61 can be kept within the partitioned area 75, and the immersion tank 61 can be used cleanly without contaminating the outside of the partitioned area 75 as much as possible.

[0242] Furthermore, when pre-washed rice grains R2 fall into the immersion water W4 stored in the immersion tank 61 up to a water level H3, and are stored as immersion rice grains R3, the water level rises above H3 by the volume of the fallen pre-washed rice grains R2. Then, the immersion water W4 stored in the immersion tank 61 flows over the upper end of the wall 76a of the overflow section 76, along with the rice bran foam floating in the compartment 75, and overflows into the overflow section 76. The immersion water W4 and rice bran foam that overflow into the overflow section 76 flow into the opening 77a of the second return pipe 77 and flow down through the second return pipe 77.

[0243] As a result, without the need to use equipment such as a pump to provide power, the rice bran foam floating in the compartment 75 of the immersion water W4 stored in the immersion tank 61 can be overflowed together with the immersion water W4 to the overflow section 76 and flowed into the second return pipe 77, thereby discharging the rice bran as rice bran foam from the immersion water W4 stored in the immersion tank 61 and purifying the immersion water W4.

[0244] Furthermore, the kinetic energy of the pre-washed rice grains R2 as they fall and flow onto the surface of the soaking water W4 is reduced not only by the diffusion step S40 described above, but also by the change in the direction of flow in the first separation step S51, the induction step S52, and the second separation step S60. As a result, the impact when the pre-washed rice grains R2 hit the surface of the soaking water W4 is smaller compared to the case where the kinetic energy of the pre-washed rice grains R2 as they fall and flow is not reduced by the diffuser 42.

[0245] This can suppress the cracking of the pre-washed rice grains R2 when they come into contact with the water surface of the immersion water W4 stored in the immersion tank 61. Further, after the pre-washed rice grains R2 come into contact with the water surface of the immersion water W4 stored up to the full water level H3 in the immersion tank 61, the depth to which the rice bran foam sinks into the immersion water W4 is made shallow, and the fixed partition member 72 and the movable partition member 73 can surely partition the rice bran foam floating on the water surface of the immersion water W4 stored in the immersion tank 61 into the partition area 75.

[0246] Also, the distance H5 between the positions of the lower ends of the fixed partition member 72 and the movable partition member 73 and the water level H3 of the immersion water W4 can be made small, and thereby, the fixed partition member 72 and the movable partition member 73 can be miniaturized.

[0247] Furthermore, by reducing the kinetic energy when the pre-washed rice grains R2 come into contact with the immersion water W4 stored in the immersion tank 61, the amount of air entrained when the pre-washed rice grains R2 come into contact with the water surface of the immersion water W4 while entraining air is reduced, and the rice bran foam generated by the mixing of air and rice bran on the water surface of the immersion water W4 stored in the immersion tank 61 can be reduced.

[0248] In addition, the opening 46a of the flow pipe 46 when the pre-washed rice grains R2 come into contact with the immersion water W4 stored in the immersion tank 61 is located below the water level H3 of the immersion water W4 stored up to the full water level in the immersion tank 61 by a distance H4. And also, on the inside of the flow pipe 46, a water surface of the immersion water W4 at the same water level as the water level H3 is formed.

[0249] Thereby, the pre-washed rice grains R2 entrain air only at the water surface of the immersion water W4 in the flow pipe 46, and compared with the case where the opening 46a of the flow pipe 46 is located above the water surface H3, the rice bran foam generated when the pre-washed rice grains R2 come into contact with the immersion water W4 can be reduced.

[0250] The rice bran foam generated by the mixing of air and rice bran comes into contact with the fixed compartment member 72, the movable compartment member 73, and the inside of the walls of the immersion tank 61, causing the rice bran to adhere to the surfaces of the walls and these members. If the rice bran foam adheres to areas that have little contact with the clean water W1 sprayed from the water supply nozzle 68 or the immersion water W4 stored in the immersion tank 61, it tends to dry out over time, becoming rice bran that is difficult to wash away by spraying clean water W1.

[0251] Furthermore, if mold or other contaminants develop on the rice bran adhering to the fixed compartment member 72, the movable compartment member 73, or the inside of the walls of the immersion tank 61, it may peel off and mix with the immersed rice grains R3, and be supplied to the rice cooker 97 by the rice distribution step S90 described later, potentially contaminating the cooked rice as foreign matter.

[0252] This risk can be suppressed by reducing the generation of rice bran foam when the pre-washed rice grains R2 hit the surface of the soaking water W4.

[0253] Furthermore, the opening 46a of the flow pipe 46 may be located above the water level H3 of the soaking water W4 stored in the soaking tank 61 until it is full. In that case, when the washed rice grains R2 falling and flowing through the flow pipe 46 hit the surface of the soaking water W4, a large amount of rice bran foam can be generated on the surface of the soaking water W4 stored in the soaking tank 61.

[0254] Then, when the water level of the immersion water W4 stored in the immersion tank 61 rises above the upper end of the wall 76a of the overflow section 76, the large amount of rice bran foam floating on the surface of the immersion water W4 stored in the immersion tank 61 is more effectively moved along with the immersion water W4, causing it to overflow over the wall 76a into the overflow section 76.

[0255] As described above, the effect produced varies depending on the height position of the opening 46a of the flow pipe 46, but the height position of the opening 46a of the flow pipe 46 should be set appropriately depending on the type of polished rice grains R1 to be washed. Alternatively, a member that can be moved vertically may be provided at the opening 46a of the flow pipe 46, so that the position of the opening 46a of the flow pipe 46 can be varied according to the type of polished rice grains R1 to be washed.

[0256] Next, we will describe in detail the state of the compartmentalized area 75 of the soaking water W4 stored in the soaking tank 61 when the pre-washed rice grains R2 are stored in the soaking tank 61.

[0257] As shown in Figure 8, when the pre-washed rice grains R2 and the supplied rice water W3 containing air begin to flow into the immersion water W4 stored in the immersion tank 61 up to the water level H3, the water level of the immersion water W4 rises above the water level H3 by the volume of the pre-washed rice grains R2 and the supplied rice water W3 containing air that have flowed into the immersion tank 61. As a result, the water level of the immersion water W4 becomes above the upper end of the wall 76a of the overflow section 76, and the immersion water W4 stored in the immersion tank 61 overflows the wall 76a into the overflow section 76.

[0258] As a result, when pre-washed rice grains R2 and air-containing rice water W3 are dropped and flowed into the soaking water W4 stored in the soaking tank 61, the rice bran attached to the pre-washed rice grains R2 floats in the compartment 75 as rice bran foam and can be discharged by overflowing into the overflow section 76 along with the soaking water W4. This allows the soaking tank 61 to be used as cleanly as possible. In addition, it is possible to suppress the decrease in the cleanliness of the soaking water W4 stored in the soaking tank 61.

[0259] Then, as the flow of pre-washed rice grains R2 into the soaking water W4 stored in the soaking tank 61 continues, the amount of soaked rice grains R3 stored in the soaking tank 61 reaches a predetermined amount. When the amount of soaked rice grains R3 stored in the soaking tank 61 reaches a predetermined amount, the operator stops supplying polished rice grains R1 to the introduction guide 21 of the rice washing unit 20, and eventually the flow of pre-washed rice grains R2 falling into the soaking tank 61 also stops.

[0260] When the amount of soaked rice grains R3 stored in the soaking tank 61 reaches a predetermined amount, the storage amount detection means 70 comes into contact with the ridge 80 of the pile of soaked rice grains R3 stored in the soaking tank 61. The storage amount detection means 70 then detects that a predetermined amount of soaked rice grains R3 has been stored in the soaking tank 61 and sends an electrical signal to the control panel 141. Upon receiving this electrical signal, the control panel 141 opens the valve 67 of the water supply pipe 66 and sprays clean water W1 from the water supply nozzle 68 for a predetermined time, for example, 10 seconds.

[0261] As shown in Figure 6, even if the falling flow of the washed rice grains R2 stops, by spraying clean water W1 from the water supply nozzle 68 for a predetermined time, the rice bran foam floating in the compartment 75 continues to flow together with the immersion water W4 and overflows to the overflow section 76 for discharge, thereby reducing the amount of rice bran foam floating in the compartment 75 and allowing the immersion tank 61 to be used cleanly. Furthermore, the mixing of clean water W1 with the immersion water W4 suppresses a decrease in the cleanliness of the immersion water W4 stored in the immersion tank 61.

[0262] Furthermore, there are two water supply nozzles 68, both facing in approximately the same direction. One is configured to spray clean water W1 downwards from the horizontal at a predetermined angle, for example, 20 degrees, while the other is configured to spray clean water W1 in a nearly horizontal direction.

[0263] Furthermore, by injecting clean water W1 from one water supply nozzle 68, the flow of rice bran foam floating in the compartment 75 towards the overflow section 76 can be promoted. Additionally, by injecting clean water W1 from the other water supply nozzle 68, the flow of rice bran foam floating in the compartment 75 closer to the overflow section 76 than where the clean water W1 injected from one water supply nozzle 68 lands can be promoted towards the overflow section 76.

[0264] Then, the immersion water W4 that overflows beyond the wall section 76a into the overflow section 76 flows into the second return pipe 77 along with the rice bran foam.

[0265] The angle at which the water supply nozzles 68 spray the clean water W1 may be different from the angle exemplified. For example, one nozzle may be configured to spray the clean water W1 at a predetermined angle downward from the horizontal, for example, 60 degrees downward from the horizontal, and the other nozzle may be configured to spray the clean water W1 at a predetermined angle downward from the horizontal, for example, 30 degrees downward from the horizontal. Alternatively, for example, the angle at which one water supply nozzle 68 sprays the clean water W1 may be the same as the angle at which the other water supply nozzle 68 sprays the clean water W1.

[0266] Furthermore, the number of water supply nozzles 68 may be increased or decreased. For example, one water supply nozzle 68 may be provided that sprays clean water W1 over a width equal to or greater than the width sprayed by two water supply nozzles 68. Alternatively, three or more water supply nozzles 68 may be provided.

[0267] Furthermore, although the water supply nozzle 68 is positioned opposite the overflow section 76, it may be positioned in a different location. For example, it may be positioned above the frame 71 or above the overflow section 76. It may be positioned and oriented in any direction as long as the flow of rice bran foam floating in the compartment 75 towards the overflow section 76 can be promoted by injecting clean water W1 from the water supply nozzle 68.

[0268] (10) Rice distribution step After the soaking step S80 is completed, the rice distribution step S90 is performed in which a predetermined amount of the soaked rice grains R3 from the soaking step S80 is supplied to the rice cooker pot 97 by the rice distribution unit 90.

[0269] The soaked rice grains R3, which have been immersed in the soaking tank 61 of the soaking section 60 shown in Figure 1 for a predetermined time and have absorbed water, are then allowed to flow through the pipe 78 into the separate rice distribution container 92 by opening the rice distribution valve 79 provided in the piping 78 of the soaking section 60 for a predetermined time, for example, 3 seconds.

[0270] As shown in Figures 13 and 14, the soaked rice grains R3 stored in the soaking tank 61 are guided by the slanted edge of the upper surface of a guide plate 64 installed below the soaking tank 61, and flow through the gap formed between the outer edge of the guide plate 64 and the wall surface of the soaking tank 61 to the flow opening 61a. In this way, the mass of the soaked rice grains R3 stored in the soaking tank 61 can be supported by the upper surface of the guide plate 64.

[0271] Furthermore, by preventing the mass of soaked rice grains R3 stored above the guide plate 64 from acting on the soaked rice grains R3 flowing into the flow opening 61a, the soaked rice grains R3 stored in the soaking tank 61 can be smoothly flowed into the flow opening 61a. In addition, of the soaked rice grains R3 stored in the soaking tank 61, the soaked rice grains R3 that have fallen and flowed from the separation section 40 and been soaked first can be flowed to the rice distribution section 90 first, thereby suppressing variations in the soaking time of the soaked rice grains R3 supplied to the rice cooker 97 in the rice distribution section 90.

[0272] Furthermore, the angle θ2 of the hypotenuse of the guide plate 64 with respect to the horizontal is set to be smaller than the angle of repose θ1. Therefore, while the soaked rice grains R3 stored in the soaking tank 61 are flowing down from the flow opening 61a through the piping 78 to the separated rice container 92, the ridge line 80 of the soaked rice grains R3 stored in the soaking tank 61 maintains the angle of repose θ1. This stabilizes the flow of the soaked rice grains R3 stored in the soaking tank 61 to the piping 78 and prevents clogging of the soaked rice grains R3 at the flow opening 61a.

[0273] When the rice distribution valve 79 is opened, the soaked rice grains R3 stored in the soaking tank 61 are sent to the separate rice distribution container 92 through the piping 78. Along with the soaked rice grains R3, the soaking water W4 also flows to the separate rice distribution container 92 through the piping 78. When the water level of the soaking water W4 stored in the soaking tank 61 falls below the water level H3, it is detected by the water level detection means 69, which sends an electrical signal to the control panel 141.

[0274] The control panel 141, upon receiving the electrical signal, sends an electrical signal to the valve 67, which opens the valve 67 and injects clean water W1 from the water supply nozzle 68 into the immersion tank 61 through the water supply pipe 66 of the immersion section 60 until the immersion water W4 stored in the immersion tank 61 reaches a full water level H3.

[0275] When the immersion water W4 stored in the immersion tank 61 reaches a full water level H3, the water level detection means 69 detects the water level of the immersion water W4 and closes the valve 67. At this time, taking into account the effect of water level fluctuations due to waves on the surface of the immersion water W4 stored in the immersion tank 61, the control unit 140 controls the system so that when the water level detection means 69 detects that the immersion water W4 is at a full water level H3 for a predetermined time, for example, 3 to 10 seconds, it determines that the water level of the immersion water W4 is at water level H3.

[0276] In other words, each time the rice distribution valve 79 is opened and the soaking water W4 stored in the soaking tank 61 and the soaked rice grains R3 stored in the soaking tank 61 are sent to the separate rice distribution container 92, the water level of the soaking water W4 stored in the soaking tank 61 decreases.

[0277] Whenever the water level of the immersion water W4 stored in the immersion tank 61 drops, the water level detection means 69 detects the water level of the immersion water W4 stored in the immersion tank 61, opens the valve 67, and sprays clean water W1 from the water supply nozzle 68 through the water supply pipe 66 into the immersion tank 61 until the immersion water W4 stored in the immersion tank 61 reaches a full water level H3.

[0278] Furthermore, when the control unit 140 detects that the immersion water W4 stored in the immersion tank 61 is at water level H3 for a predetermined period of time, the predetermined time until the control unit 140 determines that the immersion water W4 is at water level H3 may be longer than the time exemplified. By extending the predetermined time, clean water W1 will be sprayed from the water supply nozzle 68 into the immersion tank 61 for a longer period of time.

[0279] This raises the water level of the immersion water W4 stored in the immersion tank 61, allowing the immersion water W4 to overflow into the overflow section 76 beyond the upper end of the wall 76a of the overflow section 76. This allows the rice bran foam floating in the compartment 75 to flow along with the immersion water W4 and overflow into the overflow section 76. This reduces the amount of rice bran foam floating in the compartment 75, and the mixing of clean water W1 with the immersion water W4 suppresses a decrease in the cleanliness of the immersion water W4 stored in the immersion tank 61.

[0280] Then, as the rice distribution step S90 continues and the soaking water W4 and soaked rice grains R3 stored in the soaking tank 61 flow down through the piping 78 to the separated rice distribution container 92, the ridge line 80 that was in contact with the movable compartment member 73 of the soaked rice grains R3 stored in the soaking tank 61 moves downward. As the ridge line 80 moves downward, the lower end of the movable compartment member 73 that was in contact with the ridge line 80 also moves downward, and the movable compartment member 73, which was open at an angle θ3, rotates around the axis of the hinge 74 and closes.

[0281] As shown in Figure 14, by opening the rice distribution valve 79 for a predetermined time, the soaking water and soaking rice grains M3 flow from the flow opening 61a of the soaking tank 61 through the piping 78 to the separate rice distribution container 92.

[0282] Of the soaking water and soaking rice grains M3 that fall into the separate rice container 92, the soaking water W4 flows through multiple holes 92a (not shown) made in the wall surface of the separate rice container 92 to the second water receiving section 93. The soaking water W4 that flows into the second water receiving section 93 is drained through the drain pipe 94.

[0283] Of the soaking water and soaked rice grains M3 that fall into the separate rice distribution container 92, the soaked rice grains R3 are stored in the separate rice distribution container 92 in a predetermined amount determined by adjusting the rice distribution amount regulator 91 in the preparation step S10. Then, a predetermined time for opening the rice distribution valve 79 has elapsed, and the rice distribution valve 79 is closed.

[0284] After the rice distribution valve 79 is closed, the drive means 96 drives the shutter 95 to open the opening at the bottom of the separate rice distribution container 92, and a predetermined amount of soaked rice grains R3 stored in the separate rice distribution container 92 is supplied to the rice cooker 97.

[0285] Furthermore, by repeating the rice distribution step S90, when the soaking water W4 and soaked rice grains R3 stored in the soaking tank 61 shown in Figure 13 are allowed to flow down into the rice distribution section 90, the water level of the soaking water W4 stored in the soaking tank 61 fluctuates.

[0286] Due to these fluctuations, the lower ends of the fixed compartment member 72 and the movable compartment member 73 are positioned below the lowest water level of the immersion water W4. Furthermore, both horizontal ends of the fixed compartment member 72 are configured to be substantially in contact with the inside of the wall surface of the immersion tank 61. In addition, the hinge 74 attached to the fixed compartment member 72 is also positioned below the lowest water level of the immersion water W4 stored in the immersion tank 61.

[0287] As a result, by causing the soaking water W4 and soaked rice grains R3 stored in the soaking tank 61 to flow down into the rice distribution section 90, even if the water level of the soaking water W4 stored in the soaking tank 61 fluctuates, the rice bran foam floating within the compartment 75 of the soaking water W4 stored in the soaking tank 61 can be kept within the compartment 75.

[0288] The temporarily lowered water level in the immersion tank 61 is detected by the water level detection means 69, and the control panel 141 opens the valve 67, and clean water W1 is injected into the immersion tank 61 from the water supply nozzle 68 through the water supply pipe 66 until the immersion water W4 stored in the immersion tank 61 reaches the full water level H3.

[0289] This increases the amount of soaking water W4 stored in the soaking tank 61 while keeping the amount of rice bran floating in the soaking water W4 the same, thereby reducing the proportion of rice bran in the soaking water W4 used to soak the rice grains R3. As a result, the rice grains R3 can be soaked in cleaner soaking water W4, which helps to suppress the bran-like odor of the cooked rice when the rice is heated in the rice cooker pot 97, which contains the soaked rice grains R3 and cooking water W6 and has a lid (described later).

[0290] Furthermore, the soaking water W4 separated from the soaked rice grains R3 and flowing from the second water receiving section 93 may not be drained through the drain pipe 94, but instead flow into the first purification tank 121 of the purification section 120, which will be described later. This makes it possible to further reduce the amount of water used for washing the rice.

[0291] Furthermore, when the rice distribution valve 79 is opened for a predetermined time, allowing the soaking water and soaked rice grains M3 to flow from the soaking tank 61 through the piping 78 to the separate rice distribution container 92, and clean water W1 is sprayed from the water supply nozzle 68 for a predetermined time, the amount of clean water W1 sprayed from the water supply nozzle 68 may be greater than the amount of soaking water and soaked rice grains M3 that flows from the soaking tank 61 to the separate rice distribution container 92 in one rice distribution step S90. This ensures that the rice bran foam, along with the soaking water W4, is reliably overflowed into the overflow section 76.

[0292] Furthermore, the timing of spraying clean water W1 from the water supply nozzle 68 for a predetermined period of time may be different. For example, the valve 67 may be opened for a predetermined period of time before opening the rice distribution valve 79, and clean water W1 may be sprayed into the immersion tank 61 from the water supply nozzle 68 for a predetermined period of time.

[0293] (11) Water supply step After the rice distribution step S90 is completed, a water supply step S100 is performed in which a predetermined amount of cooking water W6 is supplied from the water supply unit 100 to the rice cooker 97 that was supplied with soaked rice grains R3 in the rice distribution step S90.

[0294] As shown in Figure 14, the rice cooking water W6, heated to a predetermined temperature by the heater 105, is supplied in a predetermined amount to the rice cooking pot 97 to which the soaked rice grains R3 have been supplied in the rice distribution step S90, through the piping 106 by opening the valve 107.

[0295] After the rice distribution step S90 and water supply step S100 are completed, the rice cooker 97 containing a predetermined amount of soaked rice grains R3 and a predetermined amount of cooking water W6 is transported by conveyor 98 to a lid-covering device (not shown). The lid-covering device places the lid on the rice cooker 97, which is then transported by conveyor 98 to a continuous rice cooking device (not shown).

[0296] In this embodiment, the water supply step S100 is performed after the rice distribution step S90, but the rice distribution step S90 may be performed after the water supply step S100 has started. Alternatively, the rice distribution step S90 and the water supply step S100 may be performed simultaneously. This shortens the time required from the start of the rice distribution step S90 to the end of the water supply step S100 for one rice cooker 97, allowing the preparation for cooking the same amount of delicious rice to be completed in a shorter time.

[0297] (12) Purification Step The air-containing rice water W3 separated in separation steps S51 and S60 and the immersion water W4 that overflowed in immersion step S80 are mixed to form air-containing rice water W5 mixed with the immersion water, and the purification step S110 is performed in the purification unit 120.

[0298] As shown in Figure 15, the air-containing rice water W3 separated in the separation steps S51 and S60 and the immersion water W4 overflowed in the immersion step S80 flow down and mix through the second return pipe 77, and the air-containing rice water W5 mixed with the immersion water flows down to the first purification tank 121 of the purification unit 120.

[0299] The air-containing rice supply water W5, which is mixed with the immersion water and flows down the second return pipe 77, hits the surface of the rice supply water W2, which is stored in the second return pipe 77 up to water level H6, while entraining the air inside the second return pipe 77. As a result, some of the rice bran contained in the air-containing rice supply water W5, which is mixed with the immersion water, turns into rice bran foam.

[0300] Then, the rice supply water W5, which is mixed with immersion water and contains air, flows down from the second return pipe 77 to the first purification tank 121 and mixes with the rice supply water W2 stored in the first purification tank 121.

[0301] The rice water W2 stored in the first purification tank 121 contains, as described above, rice bran foam generated when it flows down the second return pipe 77 and hits the surface of the rice water W2 while entraining air, and rice bran foam that flows together with the immersion water W4 stored in the immersion tank 61 and overflows to the overflow section 76. When the air-containing rice water W5 mixed with the immersion water mixes with the rice water W2 stored in the first purification tank 121, the rice bran foam floats on the surface of the rice water W2 stored in the first purification tank 121.

[0302] Then, air-containing rice water W5, which is a mixture of soaking water and rice water W2, is added to the rice water W2 stored in the first purification tank 121. The water level of the rice water W2, which had been stored in the first purification tank 121 up to the full water level H6, rises, and the rice water W2, along with the rice bran foam floating on the surface of the rice water W2, is discharged through the drain pipe 122a by the drain hopper 122.

[0303] Furthermore, when the air-containing rice water W5 mixed with soaking water is allowed to flow down from the second return pipe 77 to the first purification tank 121, the flow of the air-containing rice water W5 mixed with soaking water flows in a straight line within the first purification tank 121 and collides with the flow restricting member 127. This prevents the flow of the air-containing rice water W5 mixed with soaking water from flowing directly to the second purification tank 128 through the third return pipe 125.

[0304] Then, the rice bran foam is retained in the first purification tank 121, and the rice bran foam is allowed to overflow into the first purification tank 121 along with the supplied rice water W2 that exceeds a predetermined water level, thereby effectively discharging it into the drain hopper 122.

[0305] Furthermore, if a large amount of rice bran foam is generated and remains in the first purification tank 121, the rice bran foam will flow into the drain hopper 122, so the rice bran foam can be discharged into the drain hopper 122 without overflowing the supplied rice water W2 into the drain hopper 122.

[0306] Furthermore, by storing the air-containing rice supply water W5, which is a mixture of the immersion water that has flowed down from the second return pipe 77 to the first purification tank 121, in the first purification tank 121, the air component of the air-containing rice supply water W5 mixed with the immersion water, and the air component that was drawn in when the air-containing rice supply water W5 flowed down the second return pipe 77 and hit the surface of the rice supply water W2, rise up as bubbles in the rice supply water W2 and can be released into the atmosphere from the surface of the rice supply water W2 stored in the first purification tank 121.

[0307] Furthermore, the flow of air-containing rice supply water W5, which is a mixture of immersion water that has fallen from the second return pipe 77 to the first purification tank 121, collides with the flow restricting member 127. As a result, the air component in the rice supply water W2 in the first purification tank 121 becomes bubbles and floats up in the rice supply water W2, allowing it to be released into the atmosphere from the surface of the rice supply water W2 stored in the first purification tank 121.

[0308] As a result, some of the air components in the rice water W2 supplied from the first purification tank 121 form bubbles, causing the remaining rice bran components in the rice water W2 to float to the surface and be discharged together with the rice water W2 from the drainage hopper 122.

[0309] Furthermore, the air-containing rice water W5, which is a mixture of the immersion water that flows from the second return pipe 77 to the first purification tank 121, contains crushed rice grains R4. These crushed rice grains R4 settle and are stored at the bottom of the first purification tank 121.

[0310] The water level H6 in the first purification tank 121 is adjusted by valve 126 so that it is higher than the water level H7 in the second purification tank 128.

[0311] Therefore, due to the difference in water level H6 between the first purification tank 121 and the second purification tank 128, the rice water W2 stored in the first purification tank 121 flows to the second purification tank 128 through the third return pipe 125.

[0312] The rice water W2 that flows into the second purification tank 128 is drawn back into the pump 29, which is still running, through the filter 134 and the piping 28, and then discharged back into the pump 29. The rice water W2 discharged from the pump 29 flows again into the ejector 26 and then flows through the rice supply pipe 31 to the separation section 40.

[0313] Furthermore, during the operation of the rice pre-processing system 10, depending on the timing, only the air-containing rice water W3 separated in the separation steps S51 and S60, or only the immersion water W4 that overflowed in the immersion step S80, may flow down through the second return pipe 77 and flow down into the first purification tank 121 of the purification unit 120. In this case as well, the purification step S110 described above can be performed in the same manner.

[0314] Furthermore, while the second purification tank 128 can drain the rice water W2 that exceeds the water level H7 through the overflow drain pipe 132, it is preferable to adjust the flow rate of the valve 126 to drain more rice water W2 from the first purification tank 121, which can effectively discharge the rice bran foam into the drain hopper 122, and to discharge the rice bran foam along with the rice water W2 being drained.

[0315] (13) End step A predetermined amount of polished rice grains R1 is placed in the rice cooker pot 97 as soaked rice grains R3, and after supplying a predetermined amount of cooking water W6, the final step S120 is performed to prepare for the next preparation step S10.

[0316] First, after completing the supply of a predetermined amount of polished rice grains R1, the supply of polished rice grains R1 to the introduction guide 21 shown in Figure 1 is stopped, and the supply step S20 is completed.

[0317] Next, after stopping the supply of polished rice grains R1, the pump 29 of the rice washing section 20 is operated for a predetermined time, for example, 1 minute, and then stopped, and the valve 24 is closed. This ensures that the supplied polished rice grains R1 are reliably flowed into the separation section 40, and that the rice bran, crushed rice grains R4, etc., attached to the rice washing section 20 and the separation section 40 are allowed to fall and flow into the first purification tank 121 of the purification section 120.

[0318] Then, the rice distribution valve 79 is opened, and a portion of the soaked rice grains R3 stored in the soaking tank 61, enough for several minutes of cooking in the rice cooker 97, is transferred to the separate rice distribution container 92 and supplied to the rice cooker 97. This completes the soaking step S80 and the rice distribution step S90.

[0319] After the immersion step S80 and the rice distribution step S90 are completed, the valve 102 of the water supply unit 100 is closed, and then the power to the control panel 141 is turned off. Then, the valve 131 of the purification unit 120 is closed.

[0320] Then, the valve 124 installed in the drain pipe 123 of the first purification tank 121 is opened, and the rice water W2 stored in the first purification tank 121, the crushed rice grains R4 that have settled at the bottom and are stored, and the rice bran foam floating on the surface of the rice water W2 are discharged. At the same time, the overflow water drain pipe 132 of the second purification tank 128 is removed, and the rice water W2 stored in the second purification tank 128 is drained from the drain pipe 133 through the drain port 128a.

[0321] Furthermore, the rice supply water W2 stored in the first purification tank 121 and the second purification tank 128 is discharged, and the rice distribution valve 79 is opened manually. When the rice distribution valve 79 is opened, the soaking water W4 stored in the soaking tank 61 and the remaining soaked rice grains R3 flow through the piping 78 into the separated rice distribution container 92.

[0322] The soaking water W4 flows from the second water receiving section 93 to the drain pipe 94 and is drained. The soaked rice grains R3 that remain in the soaking tank 61 and flow down into the separate rice distribution container 92 along with the soaking water W4 can be discharged by manually operating the shutter 95 and opening the opening at the bottom of the separate rice distribution container 92, and can then be collected by receiving them in a sieve or the like.

[0323] Next, using a hose connected to a water tap (not shown), clean water is sprayed into the rice washing section 20, separation section 40, immersion section 60, rice distribution section 90, and purification section 120 to clean them.

[0324] If the receiving cylinder 22 and rice washing means 32 of the rice washing section 20, the diffuser 42 and separator 43 of the separation section 40, the fixed compartment member 72 and movable compartment member 73 of the immersion section 60, the immersion tank 61, etc. are contaminated with rice bran or the like, they are cleaned by spraying water on each component.

[0325] In this process, the lid 41 of the separation unit 40 can be removed from the rice supply pipe 31 and the first water receiving unit 44. Also, the separator 43, with its fitting part 43f fitted into the flow pipe 46, can be removed from the first water receiving unit 44. These methods allow for easy cleaning of the lid 41, the diffuser 42 integrated with the lid 41, and the separator 43.

[0326] In addition, the fixed compartment member 72 and the movable compartment member 73 of the immersion section 60 are lifted and removed from the locked frame 71, and then the frame 71 is removed from the four protrusions provided on the edge of the immersion tank 61. Then, by pulling the chain 65 upward and lifting the guide plate 64, to which the support member 63 is fixed on the lower surface, out of the immersion tank 61, the fixed compartment member 72 and the movable compartment member 73, the support member 63 and the guide plate 64 can also be cleaned.

[0327] Furthermore, by removing the drain hopper 122 of the purification unit 120 from the first purification tank 121 and the overflow water drain pipe 132 from the second purification tank 128, the drain hopper 122 and the overflow water drain pipe 132 can be cleaned.

[0328] After cleaning these components, the reverse procedure of removal can be followed to install each component in a clean state.

[0329] After cleaning and installing each component, the rice distribution valve 79 of the immersion section 60 and the valve 124 of the drain pipe 123 of the first purification tank 121 are closed, and the overflow water drain pipe 132 of the second purification tank 128 is inserted into the drain port 128a in preparation for the next preparation step S10.

[0330] Thus, in this embodiment of the rice pre-treatment system 10, the entire rice pre-treatment system 10 can be easily cleaned by operating several valves and the pump 29, removing the components of each part, and then spraying clean water using a hose connected to a water tap.

[0331] Furthermore, when cleaning the separator 43 by spraying it with clean water, the separator 43 may be cleaned inside the first water receiving section 44. Doing so eliminates the need to remove the separator 43 from the first water receiving section 44 for cleaning, and also prevents the separator 43 from being dropped and damaged.

[0332] Depending on the condition of the polished rice grains R1, the first return pipe 45 may be connected directly to the drainage system instead of to the second return pipe 77, in accordance with the predetermined condition of the polished rice grains R1 supplied to the rice washing section 20. In this case, the immersion water W4 and rice bran foam flowing over the upper end of the wall 76a of the overflow section 76 of the immersion tank 61 will flow down through the second return pipe 77 and into the first purification tank 121.

[0333] (Regarding the rice washing cycle) As described above, the rice pre-processing system 10 of this embodiment performs the supply step S20, rice washing step S30, diffusion step S40, first separation step S51, induction step S52, second separation step S60, fluidization step S70, soaking step S80, rice distribution step S90, water supply step S100, and purification step S110, allowing for the continuous supply of soaked rice grains R3 and cooking water W6 to the rice cooker 97. By repeating each of these continuously supplying steps, a rice washing cycle can be formed that allows for the supply of a large amount of polished rice grains R1 as soaked rice grains R3 to the rice cooker 97.

[0334] It is preferable that the polished rice grains R1 supplied in a single rice washing cycle are supplied to the rice cooker pot 97 as soaked rice grains R3 in the rice distribution step S90 within the same rice washing cycle.

[0335] Furthermore, the rice washing section 20 is not limited to using the static mixer described in this embodiment; other rice washing devices can also be used.

[0336] For example, another rice washing device can be a circulating type rice washing device in which the water supplied to the rice washing tank is pumped into a fluidized pipe, returned to the rice washing tank, and washed while being circulated, and the washed rice is sent to the separation section 40 via a rice supply pipe 31 along with the supplied water.

[0337] Alternatively, a screw-type rice washing device can be used in which rice and water are washed while flowing along a rotating screw in the rice washing tank, and the washed rice is sent to the separation section 40 via a rice supply pipe 31 along with the water. In these cases, the fluid flowing from the rice supply pipe 31 to the separation section 40 may be a mixture of air-free water and pre-washed rice grains.

[0338] As described above, the rice pre-treatment method and rice pre-treatment system of this embodiment effectively discharge the rice bran foam floating on the surface of the soaking water along with the soaking water, thereby reducing the amount of rice bran foam floating on the surface of the soaking tank and allowing the soaking tank to be used cleanly.

[0339] Furthermore, the soaking water used to soak the pre-washed rice grains stored in the soaking tank can be kept clean. Then, the soaked rice grains, along with clean cooking water, are supplied to the rice cooker, the lid is closed, and the rice is heated. The resulting cooked rice is free of any bran odor and tastes delicious.

[0340] In addition, in the separation section, the pre-washed rice grains, which have become difficult to flow after being separated from the mixed fluid of air-containing rice water and pre-washed rice grains, are smoothly flowed downward by the rice water that was not completely separated, or by the rice water that flows to the draining section via the induction step, thereby reducing the amount of pre-washed rice grains remaining on the inside of the separator wall as much as possible. By reducing the amount of pre-washed rice grains remaining on the inside of the separator wall as much as possible, the amount of pre-washed rice grains processed per unit time by the separator can be increased.

[0341] In this embodiment, polished rice grains R1 are supplied to the introduction guide 21 of the rice washing unit 20 shown in Figure 2. However, pre-washed rice grains may also be supplied to the introduction guide 21. In that case, since pre-washed rice does not need to be washed, it is preferable that the rice washing unit 20 of the pre-cooking processing system 10 does not have a rice washing means 32.

[0342] Furthermore, this invention is not limited to polished rice grains, but can also be applied to the pretreatment of unpolished rice such as brown rice and other grains.

[0343] It should be noted that the present invention is not limited to the configurations and shapes exemplified above, and various modifications are possible. Furthermore, it is certainly possible to modify the configuration, such as by omitting parts, without departing from the spirit of the present invention. [Explanation of symbols]

[0344] W1 Shimizu W2 Rice water W3 Air-infused rice water W4 Immersion water W5 Rice water mixed with soaking water and containing air W6 Rice Cooking Water M1 A mixed fluid of water containing air and polished rice grains. M2 A mixed fluid of water containing air and pre-washed rice grains. M3 Soaking water and soaked rice grains R1 Polished rice grains (rice grains) R2 Washed rice grains (rice grains) R3 Soaked rice grains (rice grains) R4 Crushed rice grains (rice grains) 10. Rice Pre-processing System 20 Rice washing department 21. Introduction Guide 22 Receiver 23 Piping 24 valves 25 Clean water nozzle 26 Ejectors 27 Suction port 28 Piping 29 pumps 30 valves 31 Rice pipe (piping) 31a aperture 32 Rice washing means 40 Separation part 41 Lid 41a Guidance part 42 Diffuser 42a Slope 42b Horizontal part 43 Separator 43a Wall surface 43b Upper flow section (flow section) 43c Drainage section 43d Lower flow section (flow section) 43e hole 43f Insertion part 43g top section 44. First water receiving section 45. First return piping (piping) 45a opening 46 Flow pipe 46a aperture 60 Immersion section 61 Immersion Tank 61a Flow opening 62 Lid 62a Handle 63 Support Member 64 Information board 65 chain 66 Water supply pipe (piping) 67 valves 68 Water supply nozzle 69 Water level detection means 70 Storage volume detection means 71 frames 72 Fixed partition members (partition members) 72a Bend part 72b Folded section 72c Notch 72d Opening 73. Movable partition member (partition member) 74 Hinge 75 plots 76 Overflow section 76a Wall section 77. Second return piping (piping) 77a aperture 78 Piping 79. Rice distribution valve (valve) 80 Ridge 80a Ridge 80b Ridge 90 Rice distribution department 91 Rice distribution amount adjuster 92 Separated rice distribution container 92a hole 93 Second water receiving section 94 Drain pipe (piping) 95 Shutter 96 Driving means 97 Rice Cooker Pot 98 Conveyor 100 Water supply section 101 Water supply pipe (piping) 102 Valves 103 Float valve 104 tanks 105 Heater 106 Piping 107 Valves 120 Purification section 121 First purification tank 122 Drainage hopper 122a Drain pipe (piping) 123 Drain pipe (piping) 124 valves 125 Third return piping (piping) 126 valves 127 Flow regulating member 128 Second purification tank 128a Drain 129 Float valve 130 Water supply pipe 131 Valve 132 Overflow water drain pipe 133 Drain pipe 134 filters 140 Control Unit 141 Control Panel S10 Preparation Steps S20 Supply Step S30 Rice Washing Step S40 Diffusion step S51 First separation step (separation step) S52 Induction Step S60 Second separation step (separation step) S70 Flow Step S80 Immersion Step S90 Rice Distribution Step S100 Water Supply Step S110 Purification Step S120 End step

Claims

1. Polished rice grains are washed to become pre-washed rice grains. The process includes a soaking step in which the pre-washed rice grains are dropped and flowed into a soaking tank containing soaking water, and the pre-washed rice grains are soaked in the soaking water to become soaked rice grains. In the aforementioned immersion step, The opening of the flow pipe, which extends in a substantially vertical direction, is positioned below the water level of the immersion water to form the water level of the immersion water within the flow pipe. The washed rice grains, which have been allowed to fall and flow through the flow pipe, are brought to the surface of the soaking water formed inside the flow pipe. A method for pre-treating rice before cooking, characterized by the following features.

2. In the immersion step, Within a partitioned area, which is a region where the surface of the immersion water is divided by the inner wall of the immersion tank and a plate-shaped partition member, pre-washed rice grains that have been flowed down through a flow pipe are brought to the surface of the immersion water formed inside the flow pipe. The pre-treatment method for rice cooking according to feature 1.

3. Polished rice grains are washed to become pre-washed rice grains. The process includes a soaking step in which the pre-washed rice grains are dropped and flowed into a soaking tank containing soaking water, and the pre-washed rice grains are soaked in the soaking water to become soaked rice grains. In the aforementioned immersion step, Within the partitioned area, which is a region where the surface of the soaking water is partitioned by the inner wall of the soaking tank and a plate-shaped partitioning member, the washed rice grains that have been dropped and flowed are brought to the surface of the soaking water. A method for pre-treating rice before cooking, characterized by the following features.

4. In the immersion step, The opening of the flow pipe, which extends in a substantially vertical direction, is positioned below the water level of the immersion water to form the water level of the immersion water within the flow pipe. Within the designated area, the washed rice grains that have been allowed to fall and flow through the flow pipe are brought to the surface of the soaking water formed inside the flow pipe. The pre-treatment method for cooking rice according to feature 3.

5. By repeatedly changing the direction of flow of pre-washed rice grains that have been washed from polished rice grains, the kinetic energy of the pre-washed rice grains as they flow is reduced. The pre-washed rice grains, whose kinetic energy has been reduced, are then placed in the soaking water. A method for pre-treating rice before cooking, according to any one of the features 1 to 4.

6. A soaking tank stores a predetermined amount of soaking water, and soaks pre-washed rice grains, which are polished rice grains that have been washed, in the soaking water to make soaked rice grains, A flow pipe extending in a substantially vertical direction, which causes the washed rice grains to fall and flow into the soaking water, Equipped with, The opening of the flow pipe is positioned below the water level of the immersion water to form the water level of the immersion water inside the flow pipe. The washed rice grains, which have been allowed to fall and flow through the flow pipe, are brought to the surface of the soaking water formed inside the flow pipe. A rice pre-processing system characterized by the following features.

7. It further includes a plate-shaped partitioning member that divides the rice bran foam floating on the surface of the soaking water, A partitioned area is formed on the surface of the immersion water, which is a region partitioned by the inside of the wall of the immersion tank and the partitioning member. Within the aforementioned compartment, the washed rice grains that have been flowed through the fluid pipe are brought to the surface of the soaking water formed inside the fluid pipe. The rice pre-treatment system according to claim 6.

8. A soaking tank stores a predetermined amount of soaking water, and soaks pre-washed rice grains, which are polished rice grains that have been washed, in the soaking water to make soaked rice grains, A plate-shaped partitioning member that partitions the rice bran foam floating on the surface of the immersion water, Equipped with, A partitioned area is formed on the surface of the immersion water, which is a region partitioned by the inside of the wall surface of the immersion tank and the partitioning member. The washed rice grains, which have been allowed to fall and flow, are brought to the surface of the soaking water within the designated area. A rice pre-processing system characterized by the following features.

9. It further includes a flow pipe that extends in a nearly vertical direction and causes the washed rice grains to fall and flow into the soaking water, The opening of the flow pipe is positioned below the water level of the immersion water to form the water level of the immersion water inside the flow pipe. Within the designated area, the pre-washed rice grains, which have been flowing through the fluid pipe, are brought to the surface of the immersion water formed inside the fluid pipe. The rice pre-treatment system according to feature 8.

10. The configuration is such that when the mass of the edged rice grains located on the ridges of the edged rice grains stored in the edging tank is applied to the partition member, at least a portion of the partition member rotates toward the outside of the edging tank. A rice pre-treatment system according to any one of claims 7 to 9.

Images