JP5834286B2 - Rice washing equipment using microbubbles - Google Patents

Description

  The present invention relates to a rice cleaning apparatus using a microbubble generator.

Before cooking the polished rice, it is necessary to clean the attached matter such as dirt and rice bran attached to the rice. If the number of people is small, such as at home, it can be washed carefully by hand. However, when a large amount of rice is cooked at one time, such as in a lunch school or a bento plant, a large amount of rice is washed at one time, so the method of washing rice by hand only takes time and effort. In addition, the amount of water used is increased, the cleaning time is increased, and the work efficiency cannot be improved. In addition, the automatic cleaning method while agitation increases the equipment investment, resulting in a huge capital investment. Furthermore, the amount of water used is enormous, the amount of drainage increases, and the running cost increases. Recently, consumption of non-washed rice, which does not require washing before cooking rice, is increasing. This unwashed rice is made by washing a large amount of polished rice and then packing it in a bag. However, because it is a commercial product, it is necessary to clean and remove the dirt from the polished rice and rice bran, as well as scratches on the rice. It is necessary not to damage it. However, there is a problem that the quality of unwashed rice is deteriorated by the automatic washing method while stirring rice.

On the other hand, research using microbubbles and microbubbles to purify contaminated water in lakes is advancing. A microbubble is a bubble having a diameter of several tens of μm, and proposals have been made to use the microbubble for washing rice. For example, in Patent Document 1, pressurized air-dissolved water, in which air is dissolved in water by supplying pressurized air to water, is used as washed rice water, and this pressurized air-dissolved water is discharged from the bottom of the container. And a method of washing rice while generating fine bubbles from pressurized air-dissolved water has been proposed. Further, in Patent Document 2, air-mixed water in which air is dissolved in water in a substantially saturated state while mixing water and air is introduced into the bottom of the rice washing tank and reduced to a pressure corresponding to atmospheric pressure plus water pressure. There has been proposed a method for washing rice using microbubbles, which are generated ultrafine bubbles, and fine bubbles generated by jetting pressurized air into water through holes of 10 to 500 μm.

JP2000-189077 JP 2006-345723 A

Washing using pressure-dissolving microbubbles has a higher effect of removing deposits on the rice than simply washing water while stirring water, but it is insufficient as a method for washing rice. There is a problem that a plurality of washings are necessary, and that the adhering matter cannot be sufficiently removed even by a plurality of washings, and as a result, the amount of water used is not reduced so much. In addition, there is a problem that an air pressurizing pump is required and the equipment becomes large.

The present inventor has discovered that the reason why the washing ability of rice in the washing method using pressure-dissolving microbubbles is small is that the bubble potential of the generated microbubbles is small. When the deposits such as rice bran are strongly attached (mainly electrochemical adsorption) due to the low bubble potential, they cannot be removed. It will be enough. The present inventor has discovered that the washing ability of rice can be dramatically improved by using microbubbles having a large negative potential. For example, a large negative potential is obtained by using a self-feeding microbubble generator (gas-liquid shearing type microbubble generator) provided with a collision wall and / or a slit in the main body pipe instead of a pressure melting type. Since microbubbles can be generated, the washing ability of rice can be greatly improved by washing rice using this. Furthermore, a container having a curved surface such as a spherical surface is used. Rice and water are placed in this container, and water and rice flow are produced along the curved surface of the container by running water from a microbubble generator located at the bottom of the container.

Microbubbles generated by a self-priming microbubble generator (gas-liquid shearing microbubble generator) with a collision wall and / or slit in the main pipe have a large negative potential. Kimono can be removed effectively and efficiently. Further, by causing the flow of water and rice along the curved surface of the container, the generated microbubbles efficiently come into contact with the periphery of the rice grains, and the adhering matter attached to the rice is effectively adsorbed and removed. Moreover, the microbubble which adsorb | sucked the adhering matter floats from water with the flowing water and the flow of rice along this curved surface, and an adhering matter is removed. As a result, the rice washing time can be reduced, and the amount of water used and the amount of drainage can be reduced. Furthermore, large-scale equipment is not necessary, and capital investment can be reduced. Moreover, since the equipment can be made small, it can be applied to a small lunch box factory, a lunchroom, and an automatic rice washer for home use.

FIG. 1 is a diagram showing an embodiment of the rice washing apparatus of the present invention. FIG. 2 is a diagram showing the structure of the microbubble generator used in the present invention. FIG. 3 is a graph showing the cleaning effect of rice cleaned by various cleaning methods. FIG. 4 is a diagram illustrating a method for measuring the illuminance of cleaning water. FIG. 5 is a graph showing the bubble potential of the microbubbles generated by the microbubble generator. FIG. 6 shows the bubble size distribution of microbubbles. FIG. 7 is a graph comparing the cleaning effect of rice in different containers. FIG. 8 is a diagram showing the results of comparing sugar content, hardness, and stickiness when rice washed using microbubbles and rice washed by hand washing are cooked. FIG. 9 is a diagram showing the results of measuring the water absorption rate of rice washed with microbubbles and rice washed by hand washing.

The present invention is based on the discovery that the detergency of pressure-dissolving microbubbles in rice is weak because the bubble potential is small, and the ability to wash rice by using microbubbles having a large negative potential Based on the discovery that can dramatically improve.

FIG. 1 is a diagram showing an embodiment of the rice washing apparatus of the present invention. A microbubble generator 32 is disposed in a container 31 for washing rice by adding rice and water. The part where the microbubble 45 exits from the microbubble generator 32, that is, the opening 33 is arranged so as to come to the bottom of the container 31. Accordingly, the opening 33 of the microbubble generator 32 is arranged so as to be the bottom of the rice when the rice and water are washed. A water circulation tube (first water circulation tube) 34 for water circulation is connected to the upper portion of the container 31. The first water circulation tube 34 is connected to a circular pump (water circulation pump) 35. Water that has entered from the first water circulation tube 34 exits from the water circulation tube (second water circulation tube) 36 of the circular pump 35. The water flowing through the second water circulation tube 36 is connected to the microbubble generator 32. Further, the air supply pipe 47 is connected to the microbubble generator 32, and a gas such as air is supplied to the microbubble generator 32. The water discharged from the second water circulation tube 36 to the microbubble generator collides with a collision wall, which will be described later, while containing air, and / or generates microbubbles and / or microbubbles by slits provided in the main body pipe. Or flowing water containing microbubbles is released from the opening 33 into the container 31. (Such a microbubble generator belongs to a gas-liquid shearing type microbubble generator.) Thus, the rice washing apparatus of the present invention includes a container 31 for washing rice by adding rice and water, and a bottom portion of the container 31. A microbubble generator 32 disposed in the water, a water circulation pump 35 that sucks water in the container 31 and discharges the water into the container 31 through the microbubble generator 32, and a first that guides water from the container 31 to the water circulation pump 35. A circulation tube 34 and a second circulation tube 36 that guides water from the water circulation pump 35 to the microbubble generator 32 are provided.

When washing the rice, the lid 37 of the container 31 is opened, the rice is put into the lid 37, and water is put into the container from the water supply pipe 38. The rice 41 enters the bottom of the container 31, and the water 42 in the container is put so that all the rice 41 put in the container is fully immersed. The inlet of the first water circulation tube 34 is put into the water 42 in the container 31 so that the water 42 in the container can be sucked. The opening 33 of the microbubble generator 32 is arranged so as to come to the bottom of the rice 41 placed in the container at the bottom of the container. The container 31 is provided with a drain pipe (drain) 40, and dirt and deposits floating above the water 42 are discharged from the drain pipe (drain) 40 together with water. Further, the lifted scent etc. goes out to the air layer space 43 and is discharged from the air vent tube 39 to the outside. As described above, at the time of washing the rice, the rice in the container 31 is sufficiently immersed in the water 42, and the water 42 on the upper part of the rice is sucked into the circular pump 35 through the first water circulation tube 34, and the second water circulation tube 36. The microbubbles 45 and running water are discharged from the opening 33 of the microbubble generator, and the rice 41 in the container 31 is washed. After the washing of the rice 41 is completed, the rice 41 is taken out from the container 31 and the washed water and dirt are discharged from the drain 48.

The microbubble generator used in the present invention is not a pressurized microbubble generator using pressurized water or the like, but a gas-liquid shear type microbubble generator. That is, it is a microbubble generator that generates microbubbles by a shearing effect that causes water containing air to collide with a collision wall provided in the main pipe and suddenly changes the flow of water, and / or provided on the wall of the main pipe. A shear effect by bending the water flow in the main pipe abruptly in the slit direction using multiple slits and a shear effect by the velocity gradient when discharging the accelerated flow in a slit with a small cross-sectional area into a static fluid Is a microbubble generator that generates microbubbles using a combination of This type of microbubble generator invented by the present inventors can be used, and an example of the microbubble generator is shown in FIG. Details thereof are disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2005-334869) and Patent Document 4 (Japanese Patent Laid-Open No. 2009-189912).

As shown in FIG. 2, the microbubble generator 1 installed in the liquid includes a pump 4 that sucks water in the liquid, and a liquid supply that discharges water from the pump 4 into a main body pipe 11 disposed in the liquid. A pipe 5 is provided, the gas supply pipe 2 is communicated with the main body pipe 11, and the negative pressure generated in the main body pipe is utilized by the flow velocity of the liquid flowing in the main body pipe 11. (Ie, the gas is self-primed without having to be supplied using a pump or the like), and the gas and liquid are mixed in the main body pipe 11 and then placed on the downstream side in the main body pipe (impact wall) ) And collide with 18 (crush the gas mass using a shearing action) to generate microbubbles. The microbubbles are discharged into the water from the openings 12 to 17 formed in the main body pipe 11 disposed on the upstream side of the collision wall 18. (That is, the openings 12 to 17 are formed in the main body pipe 11 on the downstream side of the gas supply pipe 2, and the collision wall 18 is arranged further on the downstream side of the openings 12 to 17.) FIG. The second water circulation tube 36 and the circular pump (water circulation pump) 35 correspond to the liquid supply pipe 5 and the pump 4 shown in FIG. Further, the air supply pipe 47 in FIG. 1 corresponds to the gas supply pipe 2 in FIG. In FIG. 2, the openings 12 to 17 are slit-shaped. When the slit-shaped opening is used, the collision wall 18 is not necessarily required when the other end of the main body pipe 11 is closed. In either case of using a collision wall or a slit structure, microbubbles are generated by obtaining a shearing effect at the gas-liquid interface. In particular, in the slit structure, the shear effect is enhanced by generating a vortex at the slit and causing vortex breakdown at the slit exit.
In FIG. 2, the openings 12 to 17 are shown as slits, but as described in Patent Documents 3 and 4, other openings formed in the body pipe, a plurality of holes, and various shapes are formed. An opening may be used. Alternatively, a combination of these may be used. In addition, the gas supply pipe is not connected to the microbubble generator as shown in FIG. 2, but the gas can be mixed into the liquid upstream of the pump as described in Patent Document 3. But it ’s okay. That is, any of the microbubble generators described in Patent Document 3 and Patent Document 4 can be used in the present invention, and further, a microbubble generator that generates microbubbles having a large negative potential in other microbubble generators. Can be applied to the present invention.

The container 31 of the present invention has a curved surface where rice is contained. The curved surface is, for example, a spherical shape, an ellipsoidal surface shape, a hyperboloid shape, a paraboloid shape, a curved surface similar to these, or a combination thereof. Since the rice moves in the radial direction or the curvature direction of the curved surface by the water flow, the microbubbles can surround the circumference of each rice. For example, water and microbubbles flowing out from the opening 33 of the microbubble generator 32 shown in FIG. 1 flow in the substantially radial direction of the curved surface of the container through the bottom of the ball. Moreover, since the rice in the container also moves in the direction of running water, the microbubble 45 rises while contacting the whole rice in the container and one grain of rice while riding this flow. Since the microbubbles surrounding the rice have a large negative potential, the adhering substances such as rice bran are reliably adsorbed. The microbubbles adsorbing the adhering matter have a low negative potential, so they float while merging and the like, rise in the water 42 above the rice 41 and are discharged from the drain 40 to the outside. In addition, in FIG. 1, the direction in which the fluid in the tube through which water and air pass is shown by the arrow.

FIG. 3 shows an example of the rice washing method according to the present invention (the microbubble generator uses a tap having a slit in the opening, so-called slit type microbubble generator (type shown in FIG. 2)). Later, the washed rice 55 is put in a mesh-like net bag 52, and the mesh-like net bag 52 containing the rice 55 in clean water in the water tank 56 is immersed and stirred, and then the mesh containing the rice 55 is added. The net bag 52 is taken out from the water tank 56 and the illuminance of water in the water tank 56 is observed. The measuring method is shown in FIG. LED light is emitted from the LED light source 51 through the water 53 in the water tank, and the illuminance meter 54 measures the illuminance of the transmitted light. By this method, it is possible to evaluate the degree of deposits such as rice bran attached to the rice. The vertical axis in FIG. 3 indicates a dimensionless number based on clean water. That is, it shows the ratio I between the illuminance I ₀ (Lux) of clean water without rice and the illuminance Ix (Lux) of water after the rice after washing is stirred. I = Ix / I ₀ , where I is a dimensionless number. In order to grasp the rice washing effect of the method of the present invention, when using pressure-dissolving microbubbles, when using millibubbles (bubble size is millimeter size) used in goldfish tanks, only running water was used. Cases and cases where nothing is done are also shown.

The larger the value of I, the closer to clean water, the greater the cleaning effect of rice. As shown in FIG. 3, it can be seen that the cleaning effect A of the present invention is the highest. Compared to case E where nothing is done, there is a cleaning effect even if C is used when millibubbles are used or D is used when running water is used. Further, when pressure dissolution type microbubbles are used, B is more effective than C and D. In the case of the method of the present invention, the cleaning effect is further great. If only the magnitude of the value I of the comparative illuminance is viewed, assuming that E is 1 when nothing is done, C and D are about 2 and B is about 3.5. On the other hand, A is about 8, and the method of the present invention has a remarkable cleaning effect.

FIG. 5 is a graph showing the bubble potential of micro bubbles generated by a slit type micro bubble generator used in the method of the present invention. The bubble potential of the microbubble was evaluated by a zeta potential, and the zeta potential was measured by an electric peristaltic method. Further, the diameter of the microbubble was measured directly by a microscope and measured by a light transmission method. The vertical axis represents the bubble potential (zeta potential), and the horizontal axis represents the bubble size. For comparison, the bubble potential (zeta potential) of microbubbles generated by the pressure dissolution type microbubble generator used in FIG. 4 is also shown. The diamond mark is the slit type, and the square mark is the pressure dissolution type. Both bubble potentials are negative potentials, but the majority (90% or more) of the bubble potential of the pressure dissolution type microbubble is as small as −20 mV or less. In contrast, the bubble potential of the slit-type microbubbles used in the present invention is very large, with most (90% or more) being −20 mV to −80 mV. The gas-liquid shearing type microbubble of the present invention uses a shearing action caused by a violent collision of water containing air against the collision wall and / or a plurality of slits provided in the wall of the main body pipe. The gas mass is crushed and micro-pulverized using the shearing action by suddenly bending the water flow in the slit direction and the shearing action by the velocity gradient at the time of releasing the accelerated flow in the slit with a small cross-sectional area into the static fluid. It is considered to have a large negative potential when generating a bubble. Furthermore, since the slit type has a small pressure loss, a shearing effect can be obtained efficiently.

This large difference in bubble potential causes a difference in the cleaning power of rice. Deposits attached to rice such as rice bran are considered to be attached to rice with a positive charge. Therefore, since the microbubble of the present invention has a large negative bubble potential, when the microbubble approaches or comes into contact with the rice, the positively charged deposit attached to the rice is separated from the rice and the deposit is adsorbed to the bubble. To do. That is, microbubbles with a high potential effectively adsorb the adhering matter attached to the rice. Microbubbles with deposits move away from the rice and above the water (on their own buoyancy or flowing water). On the other hand, since the bubble potential of the pressurized microbubble is low, the rice deposits cannot float efficiently and float upward. That is, the slit-type microbubbles are distributed in a large negative potential band in which the bubble potential (zeta potential) is −20V or more. On the other hand, the bubble potential (zeta potential) of the conventional pressurized microbubble is distributed in a small negative potential band of −20V or less. Since microbubbles with high potential effectively adsorb deposits adhering to rice, slit-type microbubbles have a much higher rice washing effect than pressurized microbubbles.

As described above, the rice washing method of the present invention is a very effective method. Moreover, because the rice deposits are removed electrochemically, it is a cleaning method that is gentle to the rice without damaging the rice, as in the mechanical method (or physical method), and has a very effective cleaning effect. Is a great way.

FIG. 6 shows the bubble diameter (diameter) distribution of the microbubbles used in the present invention. As a comparison, the particle size distribution of the pressure dissolution type microbubble is also shown. The abscissa indicates the bubble diameter, and the ordinate indicates the bubble abundance ratio (PDF). The average particle diameter of the pressure-dissolving microbubbles indicated by the square marks is about 30 μm, which is considerably smaller than the average bubble diameter of the slit-type microbubbles indicated by the rhombus marks. Moreover, the dispersion of the diameters of the pressure-dissolving microbubbles is very small compared to the dispersion of the diameters of the slit-type microbubbles. Since the bubble size is small and the time spent floating in the water is long (thus, it is long around the rice), it is thought that microbubbles with a small bubble size are more likely to adsorb deposits attached to the rice. Conversely, if the size of the microbubbles is small, the ascending speed in water will be small, and even if the adhering matter is adsorbed from the rice, it will take a long time to float in the vicinity of the rice, so it will take time to rise. Is not expected to be removed. That is, in order to completely remove the deposits, the microbubbles in the rice existing in the lower part of the container must be transported to the upper water where no rice exists (42 in FIG. 1). Microbubbles cannot effectively carry the deposits on the rice into the water above. In contrast, the microbubbles having a diameter of about 10 μm to about 80 μm are widely distributed in the slit type microbubbles of the present invention, so that the small microbubbles of 40 μm or less adsorbing adhering substances attached to the rice are larger. It floats with the microbubbles and is carried into the water above the rice, effectively removing deposits. (There is also a flowing water effect due to the shape of the container described above.) The microbubbles by the rice washing method of the present invention not only have the above-mentioned large negative potential, but also have a broad diameter distribution as described above. The deposits attached to can be removed. (In order for bubbles to be adsorbed on the attached matter on the rice, microbubbles with a smaller bubble diameter that floats in the vicinity of the rice for a long time (the smaller the bubble diameter, the more likely to affect the viscosity and surface tension of water). It is thought that it is preferable, but it is considered that microbubbles having a large negative potential as in the present invention can more effectively adsorb deposits attached to rice.)

In the rice washing method of the present invention, after putting rice and water into a curved container, microbubbles are injected from the bottom of the container using a microbubble generator arranged at the bottom of the container. By attaching the microbubbles to the periphery of each rice grain, the adhered matter attached to the rice grains can be effectively adsorbed to the microbubbles. Flowing water flows out from the opening 33 and the tip 44 of the microbubble generator. By adjusting the direction of the opening 33 and the tip 44 so that the direction of the flow of the flowing water is approximately the radial direction or the direction of curvature of the container, the rice moves along the flowing water in the approximately radial direction of the container. While moving, it comes into contact with microbubbles in running water. In the case of the above-described slit type microbubble generator, since the tip end portion 44 is closed, the direction of the flowing water that exits from the slit of the opening may be adjusted to the substantially radial direction or the curvature direction of the container. Each rice grain uniformly contacts with microbubbles having a large negative potential, so that the microbubbles adsorb the attached matter on the rice grain, and the attached matter on the rice grain is pulled away. The curved surface is preferably a substantially spherical surface, but may be another curved surface, such as a substantially elliptical surface, a substantially parabolic surface, a substantially hyperboloid surface, or the like. Furthermore, by selecting the shape of the container and the flow of running water so that the rice does not stay in one place, the microbubbles and the rice can be uniformly contacted.

FIG. 7 shows a microbubble generator placed in the bottom of a bag containing rice and water, and after washing out the microbubbles and running water, the washed rice is put in an illuminance measurement bag and clean water is added and stirred. It is the graph (data shown by F) which looked at the illumination intensity of the water in the bag in dimensionless number. For comparison, data according to the present invention using a container having a spherical surface (data A as in FIG. 3) and data not washed with rice (data E in FIG. 3) are shown together. Although it is better than the data E without washing the rice, the washing effect is much smaller than that of the present invention using a container having a spherical surface. When compared with the dimensionless number, what is put in a bag has a cleaning effect of about ¼ that of the present invention. This indicates that the container for storing rice is also important, and the rice washing effect of the present invention having a spherical container is great. In addition to a substantially spherical surface, a substantially ellipsoidal surface, a substantially hyperboloid, and a substantially parabolic surface have the same effect. As described above, the rice washing ability of the rice washing method of the present invention is increased by the synergistic effect of the curved surface, running water and the microbubble effect. The data shown in FIGS. 3 to 7 are obtained using a slit-type microbubble generator, but the same cleaning effect is obtained for other microbubble generators described in Patent Documents 3 and 4. is there.

Furthermore, by installing a plurality of microbubble generators in the container, more microbubbles can be generated and brought into contact with rice, so that the washing ability of rice is further increased. In that case, it is important to align the direction of the flowing water from the plurality of microbubble generators with the substantially radial direction of the container, etc., so that the microbubbles are uniformly contacted with the rice without causing the rice to stay. Alternatively, a microbubble generator may be embedded in the container, and the container and the microbubble generator may be integrated. In this case, the opening of the microbubble generator must be open to the inside of the container, and preferably the opening of the microbubble is arranged so that the direction of running water is substantially the radial direction of the container. Need to be. By incorporating the microbubble generator into the container and not placing an extra obstacle in the container, the running water and the movement of the rice in the container can be made smoother, and the retention of rice can be further prevented. As a result, the contact between the microbubbles and the rice is more likely to occur and the washing ability of the rice can be further enhanced.

FIG. 8 shows sugar content and hardness when rice washed for 5 minutes using microbubbles and rice washed for 5 minutes by hand without using microbubbles are cooked using the rice-washing apparatus of the present invention. It is a figure which shows the result of having measured and compared stickiness.
The sugar content was measured using a sugar content meter (PAL-1, manufactured by ATAGO). That is, 20 cc of water was added to 10 g of cooked rice, stirred for 1 minute, the supernatant was taken, the supernatant was dropped onto the prism surface of the saccharimeter, and measurement was performed.
Moreover, hardness and stickiness were measured using a texturometer. That is, put 3 grains of cooked rice into a tex-chorometer cell, apply force from above, set the repulsive force measured when the rice is pressed to “hardness”, and the biting force measured when returning Was "stickiness".
As is clear from the results shown in FIG. 8, rice washed with microbubbles has improved sugar content and stickiness when cooked compared to rice washed by hand and unwashed rice. However, the hardness decreased. That is, it has been clarified that the taste of cooked rice is improved by washing the rice using microbubbles.
FIG. 9 shows the water absorption measured when the rice washed with microbubbles and the rice washed with hands were immersed in water. The horizontal axis represents time (minutes), and the vertical axis represents the water absorption obtained by dividing the weight of water absorbed by the washed rice by the weight of the rice.
As is clear from the results shown in FIG. 9, rice washed with microbubbles has a higher water absorption rate than rice washed by hand washing, which has an effect on improving the taste. Conceivable.

In summary, the present invention is to provide a rice washing apparatus having a large washing ability using microbubbles, and the conventional washing method using pressure dissolution type microbubbles is a rice bran because of the low bubble potential. Such deposits cannot be removed efficiently and effectively, and removal of deposits is insufficient even after multiple washings. On the other hand, the present invention is not a pressure-dissolving type, but uses a self-priming microbubble generator having a collision wall in the main pipe and / or a slit type microbubble generator. Since microbubbles having a negative potential can be generated, the washing ability of rice can be greatly improved. Furthermore, using a rice cleaning container having a curved surface such as a substantially spherical surface, the rice is put in this container, and gentle water flows along the curved surface of the container by flowing water from a microbubble generator disposed at the bottom of the container. Then, the microbubbles are brought into contact with each grain of rice, and the adhered matter of the rice is separated by adsorption, and floated and removed in water. In addition, since it is a gentle stream of water, it is unlikely that the rices will collide or rub against each other violently.

As described above, in the rice washing apparatus using microbubbles of the present invention, using a device that generates microbubbles having a large negative electric potential as a microbubble generator, washing rice having a curved surface such as a substantially spherical surface Use of a container for water, and by installing a microbubble generator at the bottom of the container and letting running water and microbubbles flow out of the bottom of the rice and water, it is possible to wash rice with very high efficiency and large washing capacity Become. The rice washing apparatus of the present invention has a very simple apparatus structure and can be easily downsized, so that the capital investment cost can be reduced. In addition, it is not necessary to replace cleaning water, and the amount of water used and the amount of drainage can be reduced. Furthermore, the energy to be used (equipment operating energy, etc.) is small and the environmental load is small, and the running cost is small. Furthermore, the rice actually washed using the present invention also improves the taste.

The present invention can be used as a rice cleaning apparatus.

DESCRIPTION OF SYMBOLS 1 ... Micro bubble generator, 2 ... Gas supply pipe, 3 ... Opening / closing cock,
4 ... pump, 5 ... liquid supply pipe, 6 ... flow rate adjusting valve,
10 ... micro bubble generating means, 11 ... main body pipe,
12, 13, 14, 15, 16, 17 ... opening (slit), 18 ... plate,
31 ... Container, 32 ... Microbubble generator, 33 ... Opening,
34 ... 1st water circulation tube, 35 ... Circular pump,
36 ... second water circulation tube, 37 ... lid, 38 ... water supply pipe,
39 ... Air vent tube, 40 ... Drain, 41 ... Rice, 42 ... Water,
43 ... air layer space, 44 ... tip, 45 ... microbubbles,

Claims (6)

A container for washing rice by adding rice and water, a gas-liquid shearing microbubble generator disposed at the bottom of the container, and sucking water in the container through the gas-liquid shearing microbubble generator A water circulation pump for discharging water into the container, a first water circulation tube for guiding water from the container to the pump, and a second water circulation tube for guiding water from the pump to the gas-liquid shearing microbubble generator A rice washing apparatus,
The container has a curved surface selected from a substantially spherical surface, a substantially elliptical surface, a substantially hyperboloid, or a substantially parabolic surface,
Furthermore, the gas-liquid shearing type microbubble generator generates microbubbles having a bubble potential with a large negative potential. The rice washing apparatus according to claim 1, wherein 90% or more of the microbubbles generated by the gas-liquid shearing type microbubble generator have a negative cell potential greater than -20 mV. The gas-liquid shearing microbubble generator includes a main body pipe disposed in a container, a gas supply pipe communicating with the main body pipe, an opening formed in the main body pipe on the downstream side of the gas supply pipe, and the The rice washing apparatus according to claim 1 or 2, further comprising a liquid supply pipe for discharging water into the main body pipe. The rice washing apparatus according to claim 3, wherein the opening includes a plurality of slits. The rice washing apparatus according to claim 3 or 4, wherein a collision wall is disposed further downstream than the opening. The opening is arranged so that the direction of flowing water from the microbubble generator opening of the gas-liquid shearing microbubble generator is substantially the radial direction or the curvature direction of the curved surface of the container. The rice washing apparatus according to any one of claims 1 to 5, wherein the rice washing apparatus is characterized.

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