JP2012147902A - Rice cooker which cooks uniformly with nonuniform heating, strong in central part of pot bottom and weak in peripheral part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable uniform cooking of rice by conducting heat to rice grains in a pot by convection, to enable flavor of cooked rice fine to be finished by restraining excessive lowering of pressure, and to enable prevention of stain of the periphery by preventing boiling over.SOLUTION: On the basis of this principle, strong heat is concentrated for heating on the central part of the pot bottom by a heater 2 for cooking, while the peripheral part is heated by a heater 3 with weak heat for keeping warmth by steaming. By heating with different heats, the rice grains in the pot are stirred up by the convection generated by an ascending current with buoyant force of foam formed in the central part and a descending current in the outer peripheral part, and thereby uniform heat is conducted for cooking to the whole area of the pot. A pressure regulating valve 8 constantly maintains a certain fixed pressure equal to or higher than atmospheric pressure and puts out only steam, not putting out the foam.

Description

  The present invention relates to a rice cooker for cooking. The present invention relates to a rice cooker that promotes the generation of convection in the kettle and allows the thermal power to be uniformly transmitted to the kettle by convection. As a trick to cook well with rice cakes, start with a little bit of chopsticks in the middle, burn it all the way, don't take the lid even if you cry the babies. It is said.

Although rice cooking technology has been improved, the cooking condition of rice still seems to be less than that of rice-cooked rice, but many places were changed at once when rice-cooked rice was replaced with electric rice cookers Because of this, it became difficult to understand where the key was the key to controlling the flavor of rice cooked rice. First, the heating power was changed from firewood to electricity, and the heating method was changed to heating the entire bottom of the pot. Second, the shape of the pot bottom changed from a mortar-shaped pot bottom to a flat pot-bottomed inner pot. Third, it is conceivable that the pressure adjustment has changed from a thick and heavy wooden lid to a pressure adjustment valve.

It is thought that the heating method has changed because the first heating power is changed from firewood to electricity, and the flame of the firewood has a conical shape, the high temperature part is at the tip of the flame and the center of the mortar-shaped pot bottom It is thought that it hit the part. It is probable that the outer peripheral part of the bottom of the feather pot was away from the flame of the spear, and the flame hit diagonally and the heating power was weakened. That is, it is considered that the central portion of the bottom of the pot was heated with a strong heating power, the outer peripheral portion of the bottom of the pot was heated with a weak heating power, and the central portion and the outer peripheral portion of the bottom of the pot were heated unevenly with different heating powers. In order to generate convection in the kettle, it is necessary to create an upward flow and a downward flow, but due to the strong thermal power at the center of the bottom of the kettle and the buoyancy of foam that foams, It is thought that a strong upward flow with enough force to push up was generated and the strong thermal power penetrated to the upper part.On the other hand, there were few bubbles generated by weaker thermal power at the outer periphery of the pot and the temperature was lowered, so a downward flow was generated, Rice grains with a specific gravity greater than water fall by gravity and gather at the center of the mortar-shaped pot bottom. The rice grains in the pot are stirred by the convective flow that is heated again by the strong heat of the center and circulates. It is thought that uniform firepower was transmitted to the whole rice grain. In addition, it is important to adjust the fire, and no matter how much you boil it with rice cake, it seems that the rice is not good even if you cook it with a big flame. In addition, it is said that rice cooked in a large kettle is more delicious than rice cooked in a small kettle because convection is less likely to occur in a small kettle.

However, it became an electric rice cooker, and the shape of the bottom of the kettle changed to a flat-bottomed pan, and the heating became heating of the entire bottom of the kettle. If the entire bottom of the kettle is heated with a strong heating power, the boiling will become too intense and the heating power will have to be slightly weakened, and there will be fewer bubbles generated compared to the unit area due to the weak heating power distributed over the entire bottom of the kettle. Although upward force is generated in the entire bottom of the kettle but there is no room for downward flow, convection is incomplete, there is no force to push up rice grains with a specific gravity greater than water, and the rice grains in the kettle are just up and down on the spot The position of the rice grain is almost unchanged. Due to the temperature sensor at the center of the bottom of the pot, the upward flow at the center is further obstructed and weakened. Convection does not occur unless both upward and downward flows occur. The rice grains in the kettle are not turned upside down, and thermal power is transmitted to the rice grains at the bottom of the kettle near the heat source, but in the center of the kettle, sufficient heating power is required only by being indirectly heated through the thick rice layer below. It becomes uncooked and becomes uncooked and loses flavor. Heating the entire bottom of the kettle eliminates room for downflow, and convection does not occur with upflow alone. Heating the entire bottom of the kettle results in incomplete convection, so that the rice grains in the lower part and the rice grains in the upper part are not turned upside down, and the cooking power is not evenly transmitted, resulting in uneven cooking and the flavor of the rice is impaired.

When the shape of the second pot bottom is a mortar-shaped mortar, the high temperature part of the flame of the conical bowl hits the central part of the pot bottom, and the peripheral part of the pot bottom is away from the flame and receives a relatively weak heating power. Therefore, a strong upward flow is generated in the central portion of the hook, and the temperature in the peripheral portion of the hook is lower than that of the periphery and a downward flow is generated. Rice grains with a greater specific gravity than water fall down due to gravity and gather in the central part of the mortar-shaped pot bottom and are heated by the strong heating power in the central part to become an upward flow again. It can be said that the mortar-shaped pot bottom has a reasonable shape in consideration of convection. On the other hand, when the bottom of the pot has a flat pan-bottom shape and the bottom of the pot is heated, only upward flow is generated on the entire surface of the pot, and convection does not occur unless downward flow occurs. Furthermore, the temperature sensor in the center part weakens the upflow of the convection remarkably and creates a drop in the upflow in the center part. The reason why the capacity of the kettle is reduced is that it is difficult to control the pressure and it is difficult for convection to occur.

Thirdly, the pressure adjustment has changed from a thick and heavy wooden lid to a pressure regulating valve. The thick and heavy wooden lid hardly lifts even with steam pressure, and the steam oozes through a narrow gap that is slightly formed. I went out in the same way. Since the steam that exited was always resisted, the pressure above the atmospheric pressure was always maintained. The teahouse's sip mouth looks like it bends and knees. It became an electric rice cooker, and pressure adjustment was performed with a pressure regulating valve, but the pressure regulating valve is composed of a valve seat and a sphere, and when pressure against the weight of the sphere is applied, the valve path is opened to exceed the maximum pressure There is no function to always maintain a fixed pressure above atmospheric pressure. The sphere has inertial force and the open valve passage does not return immediately even if the pressure drops, but sits after the pressure has dropped sufficiently. Since the sphere is suddenly separated from the valve seat and the pressure is suddenly reduced, bumping occurs and the temperature is lowered to 100 ° C. It is more difficult to adjust the pressure due to the smaller size of the rice cooker, and it is said that “Do not take the lid even if you cry the baby” in the tradition of rice cooking techniques, but the lid is constantly being opened and closed.

The shape of the bottom of the feather pot used for rice cooking is a mortar shape, and no temperature sensor is provided in the center of the bottom of the pot. A firewood is used for the thermal power, and the flame is conical, and the tip of the strongest flame hits the center of the bottom of the pot and heats it. For this reason, the central portion of the bottom of the kettle is heated strongly, but the thermal power is weak in the peripheral portion of the bottom of the kettle, and the entire area of the bottom of the kettle is not heated uniformly. Strongly heated at the center of the bottom of the kettle causes a strong upward flow in the middle of the kettle that lifts the rice particles that are heavier than water by the buoyancy and thermal power of the foam that foams. In this part, a downward flow is generated to become weaker thermal power away from the flame of the firewood, and the thermal power is uniformly transmitted to the rice grains in the kettle by the cyclic convection caused by the combination of both the upward flow and the downward flow.

Conventional rice cookers are equipped with a temperature sensor in the center of the bottom of the pot for ease of installation, hindering the upward flow at the center of the bottom of the pot, and many heating the entire bottom of the pot uniformly. Therefore, the thermal power is distributed over the entire bottom of the kettle and becomes weaker per unit area, foaming bubbles are less if seen per unit area, and there is no room for downward flow, so there is no room for downward flow, so upward flow to the rice grains There is no strong upward flow to generate, and the rice grains simply vibrate up and down on the spot, and the thermal power is not sufficiently transmitted to the rice grains in the center of the pot.

In order to cause convection in the pot of the rice cooker, it is necessary to cause circulatory convection due to upward and downward flow. The buoyancy is added and a strong upward flow is generated, and the rice grains are put on the upward flow. In addition, the thermal power is weakened in the periphery of the pot, and a downward flow is generated, and the rice grains are put on the downward flow together with the gravity. At the bottom of the pot, it gathers at the center of the mortar-shaped pot bottom due to gravity and is circulated as an upward flow again under the strong heat of the center.

In addition, there is a way to escape the steam that has been greatly changed with rice cooker and rice cooker. It is doubtful whether a thick wooden lid is used in rice-cooked rice, but it is replaced with a pressure regulating valve in a rice cooker, but it functions as a thick wooden lid.

  Considering that rice-cooking rice cooking is a rice-cooking technology that has been completed through trial and error and experience by many ancestors, the structure and principle of rice cookers are brought closer to rice-cooking rice cooking.

It is considered that the rice can be cooked evenly because of the convection that heat is transmitted to the rice grains in the kettle.

It is necessary to change the heating method because it is not possible to heat both the upflow and the downflow by heating the entire bottom of the kettle.

The pressure regulating valve is a pressure regulating valve having a function of constantly maintaining a certain pressure higher than the atmospheric pressure.

Preventing blow-over, blow-over occurs when bubbles are broken by the pressure regulating valve and go out together with steam, but only steam is emitted without producing bubbles.

  In order to easily cause convection in the water in the kettle containing rice grains, a kettle with a mortar bottom is considered reasonable.

In order to generate an upflow at the center of the pot and a downflow at the outer periphery, the heating power should be concentrated and heated at the center of the pot bottom. A strong upward flow is generated in the center due to the high temperature and the buoyancy of the generated bubbles, and the outer periphery has a lower temperature than the surroundings, resulting in a downward flow. .

The temperature sensor is installed on the outer periphery of the bottom of the kettle that does not interfere with the central heating.

The pressure regulating valve always maintains a certain pressure above the atmospheric pressure even while discharging steam. In order to prevent overflowing from the pressure regulating valve, do not let the foam come out. Inside the kettle, the steam is wrapped in the foam, but break the foam to expel the steam from the foam and remove only the steam from the pressure regulating valve. Make it out.

In the rice cooker, the central part of the bottom of the kettle is heated centrally to generate a strong upward flow due to the high temperature of the central part and the buoyancy of the foamed foam, and the force to lift the grains of rice grains with a higher specific gravity than water. On the other hand, the outer peripheral part of the kettle has a lower temperature than the surroundings, so a downward flow is generated, and the thermal power is distributed to the rice grains in the kettle by agitation by the cyclic convection that occurs in the upward and downward flows. I can do it.

By making the pressure regulating valve a pressure regulating valve that has a function of constantly maintaining a certain pressure above atmospheric pressure, it is possible to prevent the pressure from dropping too much and improve the flavor of cooking.

By preventing the overflow and discharging only water vapor, it is possible to prevent the surroundings from becoming dirty.

The shape of the inner pot of the rice cooker is a mortar-shaped inner pot considering the convection. Heating is done by concentrating the central part of the bottom of the kettle with about 2/3 of the diameter of the kettle. Heating is performed continuously by adjusting the output so that the convection state is not interrupted. With thermal power control, foaming stops with ON / OFF control, and continuous convection does not occur. Try to foam evenly in the center of the inner pot as much as possible. The outer periphery of the bottom of the pot is left as a room for downflow. The temperature sensor is installed on the outer periphery of the bottom of the pot. The pressure regulating valve can always maintain a certain pressure above atmospheric pressure to prevent overflow.

  An embodiment of the present invention will be described with reference to FIG. In FIG. 1, the inner pot 1 of the rice cooker has a mortar shape in consideration of convection. A rice cooking heater 2 is provided for heating the central part of the pot bottom over almost two thirds of the pot diameter. A steaming and warming heater is provided on the outer peripheral portion and side surface of the bottom of the pot. Further, a pressure regulating valve 8 is provided on the lid. The temperature detector 4 is provided on the outer periphery of the bottom of the hook.

In the inner pot 1, washed rice and a quantity of water are put and heated by a rice cooking heater 2. Rice grains have a greater specific gravity than water, so they settle on the bottom of the kettle, but the temperature rises with heating and eventually begins to boil. Bubbles are generated by boiling in the center of the bottom of the kettle, and a strong upward flow 5 accompanied by the buoyancy of the bubbles is generated, and the rice grains are pushed up. On the other hand, since the thermal power is weaker than the surroundings at the outer peripheral portion of the hook, a downward flow 6 is generated, and a convection 7 that circulates in the hook is generated by the upward flow 5 generated at the central portion of the hook and the downward flow 6 generated at the outer peripheral portion. Due to the convection 7, the strong thermal power of the rice grains in the kettle spreads and allows for uniform cooking. Steaming heater 3 is descending 6
It may be weakened so as not to hinder the generation of rice or during cooking rice heating. When the water evaporates and decreases, and the convection is not performed, the rice cooking heater 2 weakens the heating power and steams together with the heat retaining heater 3. The temperature detector 4 is used to detect cooking and keep warm.

  FIG. 2 shows the pressure regulating valve 8 that prevents overflow. The valve plate 10 is seated on the valve seat 11. It is attached to the valve plate 10 via a spring 13 that supports the weight 12. It is assumed that the weight 12 generates a pressure corresponding to the thick wooden lid of the rice cooker. The valve plate 10 and the spring 13 excluding the weight 12 are made of light and small inertial force. The water vapor is discharged outside by pushing the valve plate 10 open, but the diameter of the pressure regulating valve 8 is made as large as possible so that a necessary amount can be discharged through a narrow gap as much as possible.

The discharged water vapor is discharged by pushing the valve plate 10 open, and a weight 12 always acts on the valve plate 10 via a spring 13. Since the gap to be pushed open is narrow, if the pressure drops, it is immediately closed by the force of the spring 13 and the pressure drop more than necessary is suppressed. The valve plate 10 is not pushed open more than necessary, and is immediately closed when the pressure falls below a certain pressure that is equal to or higher than the atmospheric pressure, and the pressure drop is suppressed.

A bubble breaker 9 is provided at the outlet to the pressure regulating valve 8 in the kettle to break the water vapor bubbles wrapped in the bubbles, and the water vapor is discharged from the bubbles and only the water vapor discharged is discharged from the pressure regulating valve 8. . In FIG. 2, a rotating blade or a rotating body 15 is rotated by a motor 14 and bubbles are broken by a physical force. The mesh or porous diaphragm is vibrated by an electromagnet or a piezoelectric element and passes therethrough. The foam may be destroyed by physical force. (The figure is omitted)

In the present invention, the central portion of the bottom of the rice cooker is heated intensively to generate an upward flow 5 in the central portion of the pot, and a convection 7 circulated in the pot along with a downward flow 6 generated in the outer peripheral portion of the pot. It spreads the thermal power evenly over the rice grains in the kettle, and can be applied to ordinary and IH heater rice cookers and gas rice cookers.

Vertical section of the rice cooker of the present invention Longitudinal cross section of pressure regulating valve and foam breaker (cross section and part of rice cooker lid)

In FIG. 1 1 Inner pot 2 Heater for cooking rice 3 Heating heater for steaming 4 Temperature detector 5 Upflow 6 Downflow 7 Convection 8 Pressure regulating valve 9 Foam breaker

In FIG. 2, 10 pressure regulating valve 11 valve seat 12 weight 13 spring 14 motor 15 rotating body

Claims (2)

  In order to cause convection in the pot of the rice cooker, it is necessary to generate both upward flow and downward flow. The central part of the bottom of the kettle is roughly concentrated in the range of about two thirds of the diameter of the kettle and heated with a strong heating power to generate a strong upward flow with the buoyancy of foam foaming in the central part of the kettle. Because the thermal power is weaker than the surroundings, the section generates a downward flow, and the convection that circulates in the pot due to the upward flow and the downward flow causes the rice grains having a specific gravity greater than that of water to stir to distribute the thermal power uniformly in the pot. In the rice cooker that cooks rice, the temperature sensor is installed at the outer periphery of the bottom of the kettle, and when the water is low and convection stops, the heating power is weakened and steamed together with the steaming warming heater provided at the outer periphery of the kettle to keep the temperature warm Concentrated at the center of the bottom of the pot and heated strongly, The rice grains are stirred by the convection circulated by the upflow in the center of the pot and the downflow of the outer periphery by heating the pot weakly and heating the bottom of the pot non-uniformly. A featured rice cooker. Steam in the rice cooker is wrapped in bubbles that are generated, and the foam is broken by the pressure regulating valve and discharged together with the steam, but the motor is connected to the outlet to the pressure regulating valve in the kettle. A pressure regulating valve that prevents blow-over by destroying bubbles that pass by physical force with a rotating body by an electromagnet or a vibrating body by an electromagnet, or a piezoelectric body, releasing water vapor from the foam, and discharging only water vapor from the pressure regulating valve.

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