JP2013078535A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice cooker that cooks rice with good thermal efficiency, and further improves the taste of the cooked rice.SOLUTION: The rice cooker 1 includes: an inner ring burner 3 disposed at a position for heating a part near the center of the bottom of the rice cooking pot 12 when the rice cooking pot 12 is set at a rice cooking position; and an outer ring burner 4 disposed at a position for heating the outer periphery of the bottom of the rice cooking pot 12, and burning toward the center of the bottom of the rice cooking pot 12.

Description

  The present invention relates to a rice cooker, and in particular, to a rice cooker that can cook rice with good thermal efficiency and good taste.

  Conventionally, many proposals have been made regarding rice cookers. Above all, with regard to a rice cooker for business that cooks a relatively large amount of cooked rice at once, how to cook cooked rice at a low energy cost with high heat efficiency has become a major issue. (竈) When a rice cooker is set at the rice cooking position in (竈), a surface combustion burner with high combustion efficiency is placed at the position where the bottom of the rice cooker is heated, and this is used as the heating source, so that rice with good thermal efficiency The rice cooking device which made it possible is disclosed.

  Further, in Patent Document 3, the amount of primary air supplied to the surface combustion burner is reduced, and secondary air is supplied from an air port provided near the surface of the burner plate, so that it is the same as the surface combustion burner. There has been disclosed a rice cooking apparatus that performs radiant combustion accompanied by a flame while using a porous burner plate, has high thermal efficiency, and enables uniform rice cooking.

  According to these conventional rice cookers, all have high combustion efficiency in the heating means and can be cooked with good thermal efficiency. However, if the thermal efficiency can be further improved, the energy saving and the emission of carbon dioxide are also possible. This is also preferable from the viewpoint of reducing the amount. In addition, unlike the rice cooker for home use, in the rice cooker for business use, thermal efficiency has been emphasized so far, and there is a tendency to postpone the taste of the cooked rice, but the rice cooker for business use. Of course, it is more preferable if cooked rice with good taste can be cooked.

JP 2001-224499 A JP 2005-69641 A JP 2006-145104 A

  The present invention was made in order to solve the above-mentioned problems required for commercial rice cookers, can cook rice more efficiently, and further enhances the taste of cooked rice. An object of the present invention is to provide a rice cooker that can be improved.

  As a result of intensive studies to solve the above problems, the present inventors have conventionally used a burner that has been disposed almost evenly at a position facing the bottom of the rice cooking pot set at the rice cooking position. Divided into an inner ring burner that heats the vicinity of the center of the bottom of the pot and an outer ring burner that heats the outer periphery of the bottom of the rice cooker, and the outer ring burner is arranged to burn toward the center of the bottom of the rice cooking pot As a result, it was found that the high-temperature combustion gas generated from the burner can be used more effectively for heating the rice cooker, and the present invention has been completed.

  That is, according to the present invention, when the rice cooker is set at the rice cooking position, the inner ring burner disposed at a position to heat the vicinity of the center of the bottom surface of the rice cooking pot and the outer peripheral portion of the bottom surface of the rice cooking pot are heated. And said problem is solved by providing the rice cooker provided with the outer-ring burner arrange | positioned in the position which burns toward the center part of the bottom face of the said rice cooking pot.

  According to the rice cooker of the present invention, as described above, the outer ring burner is disposed at a position that heats the outer peripheral portion of the bottom surface of the rice cooker and burns toward the center portion of the bottom surface of the rice cooker. The outer peripheral portion of the bottom surface of the rice cooker is heated by the radiant heat from the highest temperature portion, and the generated high-temperature combustion gas is ejected toward the center portion of the bottom surface of the rice cooker. The jetted high-temperature combustion gas first advances toward the bottom of the rice cooker while heating the bottom of the rice cooker, but it collides with and mixes with the combustion gas generated in the inner ring burner, and gradually decreases its speed. This time, along with the combustion gas generated in the inner ring burner, the bottom surface of the rice cooker is heated toward the outer periphery of the bottom surface of the rice cooker. The combustion gas of the outer ring burner and the combustion gas of the inner ring burner that have reached the bottom outer periphery of the rice cooker heat the side surface of the rice cooker, and the side wall of the rice cooker and the inner peripheral surface of the furnace (rice cake) that accommodates the rice cooker. As a result, the combustion gas passage formed between the upper part and the rice cooker is exhausted to the outside through the exhaust port.

  Thus, according to the rice cooker of the present invention, the combustion gas generated from the outer ring burner once collides with the combustion gas generated by the inner ring burner after traveling toward the bottom center of the rice cooker, and proceeds. Since the direction is reversed and it goes to the outer peripheral part of the bottom surface of the rice cooker, and then rises along the side surface of the rice cooker, it comes into contact with the bottom surface and side surface of the rice cooker over a wide range for a long time. For this reason, it becomes possible to transmit the combustion heat which it has to a rice cooker more effectively. In addition, the high-temperature combustion gas generated in the inner ring burner collides with the combustion gas of the outer ring burner ejected toward the bottom center of the rice cooker and mixes with it, so that the traveling speed decreases. It becomes possible to transmit the combustion heat which it has to the rice cooking pot more effectively. For this reason, according to the rice cooking device of the present invention, the combustion heat possessed by the combustion gas of the inner ring and outer ring burner can be more efficiently transmitted to the rice cooking pot, and the advantage that the thermal efficiency can be improved is obtained. It is done.

  In a preferred embodiment of the rice cooker of the present invention, it is desirable that a control device is provided for controlling the combustion of the inner ring burner and the outer ring burner independently of each other or in conjunction with each other. More preferably, the control device controls the combustion of the inner ring burner and the outer ring burner, and heats the bottom outer peripheral portion of the rice cooker more strongly than the vicinity of the center of the bottom surface so that the inner surface of the side wall is inside the rice cooker. Means for burning in a first combustion mode that causes convection to rise along, and heating the vicinity of the center of the bottom of the rice cooker more strongly than the outer periphery of the bottom, causing convection to rise in the center of the rice cooker Means for burning in the second combustion mode may be provided.

  When the control device in the rice cooker of the present invention includes the above-described means, the control device controls the combustion of the inner ring burner and the outer ring burner, and the heating of the rice cooker by one side of the rice cooker by the other side is controlled. By making it stronger or weaker than heating, it is possible to generate heat convection in the desired direction in the rice cooking pot during cooking, or to reverse the direction of heat convection at an appropriate timing, so Uniform heating rice cooking becomes possible, and the taste of cooked rice can be further improved.

  In addition, as an inner ring | wheel and outer ring | wheel burner used for the rice cooking apparatus of this invention, as long as a rice cooker can be heated with a radiant heat and combustion gas, you may use the burner of what kind of structure and structure, but it is high. From the viewpoint of obtaining thermal efficiency, for example, a surface combustion type burner or a blast burner is preferable, and among them, a surface combustion type burner using a porous member knitted in heat-resistant metal fibers in a knit shape is used. Is preferred.

  According to the rice cooking apparatus of the present invention, it is possible to cook rice with high thermal efficiency, so that it is possible to reduce the consumption of fuel gas such as city gas that is the fuel used, and also to reduce the amount of carbon dioxide generated. The advantage is obtained. In addition, by controlling the combustion of the inner ring burner and the outer ring burner, heat convection can be generated in the rice cooker at the appropriate timing or the direction can be reversed, making it possible to cook rice more uniformly. The advantage that the further improved taste of cooked cooked rice can be obtained.

It is a longitudinal cross-sectional view which shows an example of the rice cooking apparatus of this invention. It is a top view which shows an example of the rice cooking apparatus of this invention. It is a partial expanded sectional view which shows the combustion state of an inner ring | wheel burner and an outer ring | wheel burner. It is a longitudinal cross-sectional view which shows the whole combustion state by the rice cooker of this invention. It is a conceptual diagram which shows the outline of an example of the piping system of the rice cooker of this invention, and a control system. It is a figure which shows the state burned in 1st combustion mode. It is a figure which shows the state which burns in 2nd combustion mode. It is a figure which shows the state which uses an inner ring | wheel burner as adjustment fire.

  Hereinafter, although the rice cooker of this invention is demonstrated using drawing, this invention is not limited to the thing of illustration.

  Drawing 1 is a longitudinal section showing an example of a rice cooking device of the present invention. In FIG. 1, 1 shows the rice cooker of this invention, and the rice cooker 1 is arrange | positioned at the bottom part of the inner peripheral surface of the furnace 2 and the ring-shaped inner ring | wheel burner 3 arrange | positioned at the bottom face of the furnace 2. Also provided is a ring-shaped outer ring burner 4. Reference numeral 5 denotes a mixed gas chamber of the inner ring burner 3, and reference numeral 6 denotes a mixed gas chamber of the outer ring burner 4, which are connected to a mixed gas source (not shown) through a pipe 7. Reference numeral 8 denotes a temperature sensor, 9 denotes an outer cylinder of the temperature sensor 8, and 10 denotes a signal line. A temperature signal from the temperature sensor 8 is transmitted to a control device (not shown) via the signal line 10. 11 is a spacer installed on the upper surface of the furnace 2, and 12 is a rice cooker. For example, the rice cooking pot 12 is set at a rice cooking position indicated by a broken line in the figure by bringing the lower flange 12t into contact with the upper surface of the spacer 11.

  As shown in FIG. 1, the inner ring burner 3, when the rice cooker 12 is set at the rice cooking position, heats the vicinity 12 c of the center of the bottom of the rice cooker 12, that is, the vicinity of the center 12 c of the bottom of the rice cooker 12. It is arranged upward at a position opposite to. In FIG. 1, hatching is applied to a doughnut-shaped region excluding the central portion of the bottom surface of the rice cooker 12 with which the temperature sensor 8 contacts, as the vicinity 12 c of the center portion of the bottom surface of the rice cooker 12 heated by the inner ring burner 3. However, when the temperature sensor 8 does not exist at a position in contact with the center portion of the bottom surface of the rice cooker 12, the vicinity of the center portion 12c of the bottom surface does not need to be donut-shaped and continues to the center portion. It may be a circular region.

  On the other hand, when the rice cooker 12 is set at the rice cooking position, the outer ring burner 4 heats the outer peripheral portion 12w of the bottom surface of the rice cooker 12 shown by hatching in FIG. It is arranged sideways so that the generated combustion gas is directed to the center of the bottom surface of the rice cooker 12 at a position where it combusts toward the portion, that is, outside the side surface of the rice cooker 12.

  FIG. 2 is a plan view of the rice cooker 1 shown in FIG. However, the rice cooker 12 is omitted. As shown in FIG. 2, in the rice cooker 1 of this example, the inner ring burner 3 is a ring-shaped burner arranged upward on the bottom of the furnace 2, and the outer ring burner 4 is on the bottom of the inner peripheral surface of the furnace 2. It is a ring-shaped burner arranged sideways. However, the inner ring burner 3 and the outer ring burner 4 do not necessarily have to be in the form of a continuous ring, and the burners divided into two or more parts are arranged in a ring shape as a whole. It may be. Moreover, it does not necessarily need to be a perfect circular ring, and may be a polygonal shape in which a plurality of linear burners are arranged in a ring shape as a whole.

  Further, in the illustrated example, since the temperature sensor 8 is provided at a position in contact with the center of the bottom surface of the rice cooker 12, the inner ring burner 3 has a ring shape with a missing center portion, that is, a donut shape. When the temperature sensor 8 does not exist at a position in contact with the center of the bottom surface of 12, the inner ring burner 3 does not necessarily have a donut shape, and a burner plate or mixing is also provided at a position facing the bottom center of the rice cooker 12. It may be a circular or polygonal burner as a whole where the gas outlet is present.

  Moreover, as long as the inner ring burner 3 can heat the vicinity 12c near the center of the bottom surface of the rice cooker 12, the size thereof is not particularly limited. For example, the rice cooker 12 has a circular shape and a horizontal sectional shape. Is a circle, the outer diameter of the inner ring burner 3 is desirably 2/3 or less of the diameter of the circle, preferably 1/2 or less, and the inner ring burner 3 is set at the rice cooking position. It is desirable to be arranged concentrically with the rice cooker 12. Moreover, when the horizontal cross-sectional shape of the rice cooker 12 is polygons, such as a rectangle, the inner ring | wheel burner 3 is arrange | positioned concentrically with the rice cooker 12 when the center is set to the rice cooking position, It is desirable to set the size so that it does not exceed 2/3, preferably 1/2, of the distance from the center of the polygonal bottom surface to each side.

  A plurality of spacers 11 are arranged on the upper surface of the furnace 2 at equal intervals (eight in the illustrated example), and when the rice cooker 12 is set thereon, the lower surface of the bowl 12u. An exhaust port for combustion gas is formed between the upper surface of the furnace and the furnace.

FIG. 3 is a partially enlarged cross-sectional view showing the combustion state of the inner ring burner 3 and the outer ring burner 4. As shown in FIG. 3, the mixed gas G supplied from the mixed gas source (not shown) into the mixed gas chamber 5 of the inner ring burner 3 is ejected from the outlet 3p of the inner ring burner 3, and is ignited and burned by an appropriate ignition device. To do. Is F _A combustion flame of the inner ring burners 3, 13 is a combustion gas generated by combustion of the inner ring burner 3. When the inner ring burner 3 is a surface combustion type burner, the ejection port 3p is a burner plate formed of a porous material in which heat-resistant metal fibers are knitted or other porous material, If, in some cases combustion flame F _A is absent. As described above, the inner ring burner 3 is disposed at a position opposite to the central portion 12c of the bottom surface of the rice cooker 12 so that the central portion 12c of the bottom surface of the rice cooking pot 12 is burned by the inner ring burner 3. 3, or by the radiant heat and the combustion flame F _A , and further by the combustion gas 13.

On the other hand, the mixed gas G supplied from the mixed gas source (not shown) into the mixed gas chamber 6 of the outer ring burner 4 is ejected from the outlet 4p of the outer ring burner 4, and is ignited and burned by the combustion heat of the inner ring burner 3. . However, it goes without saying that an ignition device may be separately provided on the outer ring burner 4. F _B is the combustion flame of the outer ring burners 4, radiant heat R is radiated from the outer ring burner 4 by the combustion of the outer ring burner 4, 14 is a combustion gas generated by the combustion of the outer ring burner 4. When the outer ring burner 4 is a surface combustion type burner, the ejection port 4p is a burner plate formed of a porous material in which heat-resistant metal fibers are knitted or other porous materials, If, in some cases combustion flame F _B is absent. As described above, the outer ring burner 4 is disposed at a position where the outer peripheral portion 12w of the bottom surface of the rice cooker 12 is heated, so that the outer peripheral portion 12w of the bottom surface of the rice cooker 12 is emitted from the highest temperature portion of the outer ring burner 4. When heated by the heat R and the combustion flame F _B is present, it is also heated by the combustion flame F _B.

  Further, as described above, the outer ring burner 4 is disposed sideways so that the combustion gas 14 is directed toward the center of the bottom surface of the rice cooker 12, that is, the generated combustion gas 14 is directed toward the center of the bottom surface of the rice cooking pot 12. Therefore, the high-temperature combustion gas 14 ejected from the outer ring burner 4 first proceeds toward the center of the bottom surface of the rice cooker 12 while heating the bottom surface of the rice cooker 12 as indicated by arrows in FIG. . However, the inner ring burner 3 exists in the vicinity of the center of the bottom surface of the rice cooker 12, and the combustion gas 13 is ejected from the inner ring burner 3, so that the combustion gas 14 from the outer ring burner 4 passes from the inner ring burner 3 on the way. The combustion gas 13 of the rice cooker 12 is collided and mixed, gradually decreasing in speed, and eventually reversing its direction of travel, heating the bottom surface of the rice cooker 12 together with the combustion gas 13 of the inner ring burner 3, It goes to the outer peripheral part 12w of the bottom surface along the bottom surface. Combustion gas mixed with the combustion gas 13 and the combustion gas 14 reaching the outer peripheral portion 12w of the bottom surface passes through the combustion gas passage L formed between the side wall of the rice cooker 12 and the inner peripheral surface of the furnace 2, The side surface of the rice cooker 12 is heated.

  Thus, in the rice cooker 1 of the present invention, the combustion gas 14 generated by the outer ring burner 4 does not rise along the side surface of the rice cooker 12 as it is, but once cooks along the bottom surface of the rice cooker 12. After proceeding to the center of the bottom surface of the pot 12, the direction of travel is reversed, the process proceeds again along the bottom surface of the rice cooker 12, and finally rises along the side surface of the rice cooker 12. For this reason, the combustion gas 14 contacts for a long time over the wide range of the bottom face of the rice cooking pot 12, and can transmit the high temperature combustion heat which it has to the rice cooking pot 12 efficiently. Further, the combustion gas 13 generated by the inner ring burner 3 also collides with and mixes with the combustion gas 14 from the outer ring burner 4, so that the speed of the combustion gas 13 is slowed down. The combustion heat that is being transferred can be transmitted to the rice cooker 12 more efficiently.

  FIG. 4 is a longitudinal sectional view showing the entire combustion state by the rice cooker 1 of the present invention. In FIG. 4, 15 is a lid of the rice cooker 12, 16 is a combustion gas exhaust port formed between the upper part of the furnace 2 and the flange 12 t of the rice cooker 12, and 17 is accommodated in the rice cooker 12. Rice, water and other cooking ingredients.

  As shown in FIG. 4, the inner ring burner 3 and the outer ring burner 4 directly heat the bottom surface central portion 12 c and the bottom surface outer peripheral portion 12 w of the rice cooking pot 12, and cook rice by the high-temperature combustion gas 13 and the combustion gas 14 that are ejected. The bottom and side surfaces of the pot 12 are heated. The combustion gas 13 and the combustion gas 14 that have sufficiently supplied heat to the rice cooking pot 12 through the bottom surface and the side surface of the rice cooking pot 12 and absorbed the heat pass through the combustion gas passage L and rise along the side face of the rice cooking pot 12. The gas is discharged from the combustion gas exhaust port 16 formed in the upper portion of the furnace 2 to the outside.

Drawing 5 is a key map showing an outline of an example of a piping system and control system of rice cooking device 1 of the present invention. In FIG. 5, 18 is a control device, 19 is a fuel gas source, and 20 is a blower. 21 _A and 21 _B are mixers connected to the mixed gas chamber 5 and the mixed gas chamber 6, respectively, and 22 _A and 22 _B are installed between the fuel gas source 19 and the mixer 21 _A or 21 _B , respectively. The mass flow controllers 23 _A and 23 _B are pressure equalizing valves installed between the blower 20 and the mixer 21 _A or 21 _B , respectively, and 24 is an on-off valve.

As shown in FIG. 5, the fuel gas supplied from the fuel gas source 19 passes through the on-off valve 24 and then branches in two directions, passes through the mass flow controller 22 _A or 22 _B , and further passes through the on-off valves 24 and 24. It passes through and is supplied to the mixer 21 _A or 21 _B. On the other hand, the combustion air fed from the blower 20 also branches in two directions, passes through the pressure equalizing valves 23 _A and 23 _B , respectively, and then passes through the on-off valves 24 and 24, and then the mixer 21 _A or 21 _B. To be supplied. The fuel gas and air supplied to the mixer 21 _A or 21 _B are mixed there, supplied to the mixed gas chamber 5 or the mixed gas chamber 6, and combusted in the inner ring burner 3 or the outer ring burner 4.

On the other hand, the control device 18 is connected to the temperature sensor 8, the blower 20, the mass flow controllers 22 _A and 22 _B , and the plurality of on-off valves 24 through the signal line 10, and further, an ignition device and a flame detection device (not shown). The presence detector of the rice cooker 12 is also connected.

The rice cooking operation of the rice cooking device 1 of the present invention having the above piping system and control system is, for example, as follows. First, when the rice cooker 12 containing the necessary materials for rice, water and other rice cooking is set at a predetermined rice cooking position of the rice cooking device 1, a presence detection device (not shown) is activated, and the rice cooking pot 12 is in the rice cooking position. The control device 18 is informed that it has been set. The control device 18 opens the on-off valve 24 to which the fuel gas source 19 is connected, supplies fuel gas to the mixer 21 _A or 21 _B via the mass flow controllers 22 _A and 22 _B , and blower 20 the actuates, via a pressure equalizing valve ₂₃ a, 23 _B, and supplies the combustion air to the mixer 21 _a or 21 _B.

In a preferred example of the rice cooker 1 of the present invention, the inner ring burner 3 and the outer ring burner 4 are all primary air burners such as a surface combustion burner or a blast burner, and therefore pass through the mass flow controllers 22 _A and 22 _B. The pressure equalizing valves 23 _A and 23 _B are automatically adjusted in accordance with the flow rate of the fuel gas, and the total amount of air required for combustion is supplied to the mixer 21 _A or 21 _B by forced air supply from the blower 20. The Alternatively, an appropriate flow rate adjusting valve is provided in place of the pressure equalizing valves 23 _A and 23 _B , the flow rate of the fuel gas passing through the mass flow controllers 22 _A and 22 _B is controlled by the control device 18, and the mass flow controllers 22 _A and 22 are used. adjust the flow control valve in accordance with the flow rate of the fuel gas passing through the _B, and the amount of air corresponding to the supply amount of the fuel gas mixer 21 may be supplied to the _a or 21 _B.

The fuel gas and air are mixed with each other in the mixer 21 _A or 21 _B , and are supplied to the mixed gas chamber 5 of the inner ring burner 3 and the mixed gas chamber 6 of the outer ring burner 4 as a mixed gas. The control device 18 activates an ignition device (not shown) at an appropriate timing, ignites the mixed gas ejected from the outlets of the inner ring burner 3 and the outer ring burner 4, and starts cooking rice.

As described above, in the rice cooker 1 of this example, the mass flow controllers 22 _A , 22 _B , leveling are respectively connected to the piping system that supplies the mixed gas to the inner ring burner 3 and the piping system that supplies the mixed gas to the outer ring burner 4. By providing the pressure valves 23 _A and 23 _B , the mixers 21 _A and 21 _B , and the on-off valve 24, the control device 18 performs the combustion of the inner ring burner 3 and the combustion of the outer ring burner 4 independently of each other. It is possible to control. However, the combustion of the inner ring burner 3 and the combustion of the outer ring burner 4 do not always have to be independently and separately controlled. For example, instead of the two mass flow controllers 22 _A and 22 _B , one mass flow controller is arranged closer to the fuel gas source 19 than the branch point of the pipe 7 connected to the mixer 21 _A or 21 _B. The total amount of fuel gas supplied to the mixers 21 _A and 21 _B may be controlled by controlling the flow rate of the fuel gas passing through the mass flow controller by the control device 18. In the mixers 21 _A and 21 _B , the fuel gas that has passed through the one mass flow controller is divided at a ratio corresponding to the preset flow path resistance of the pipe 7 that leads to the mixer 21 _A or 21 _B. Will be supplied respectively.

  Cooking rice may be performed by adjusting the heating power of the inner ring burner 3 and the outer ring burner 4 according to a normal timetable, and based on a signal from the temperature sensor 8, information on the progress of cooking rice is obtained. Based on this information, the heating power of the inner ring burner 3 and the outer ring burner 4 may be adjusted, or these two may be used in combination. When the rice cooking is completed, the control device 18 closes the on-off valve 24 to stop the supply of the fuel gas from the fuel gas source 19, stop the blower 20, and stop the supply of combustion air.

  Furthermore, according to the rice cooking device 1 of the present invention, the control device 18 controls the combustion of the inner ring burner 3 and the combustion of the outer ring burner 4, and along the inner surface of the side wall in the rice cooking pot 12 at an appropriate stage of the rice cooking process. Or in a second combustion mode that causes convection to rise in the center of the rice cooker 12, or in both combustion modes. It can be repeated alternately.

  FIG. 6 shows a state in which combustion is performed in the first combustion mode, and FIG. 7 shows a state in which combustion is performed in the second combustion mode. By controlling the combustion of the inner ring burner 3 and the combustion of the outer ring burner 4 by the control device 18, for example, as shown in FIG. 6, the outer ring burner 4 is burned with a strong fire, and the inner ring burner 3 is burned with a low fire. The outer peripheral portion 12w of the bottom surface 12 is heated more strongly than the vicinity 12c of the center portion of the bottom surface, and rises along the inner surface of the side wall as indicated by the arrow in the rice cooker 12 and causes convection to descend near the center portion. It can be burned in the combustion mode. On the other hand, as shown in FIG. 7, the outer ring burner 4 is burned with a low heat and the inner ring burner 3 is burned with a high fire, whereby the vicinity of the bottom center portion 12c of the rice cooker 12 is heated more strongly than the bottom outer peripheral portion 12w. And it can be made to burn in the 2nd combustion mode which raises in the rice cooker 12 in the center as shown by the arrow in a figure, and raises the reverse convection which falls along the side wall inner surface.

  However, the combination of the strong fire and the low fire shown in FIGS. 6 and 7 is merely an example, and depending on the amount of heat generated by the combustion of the inner ring burner 3 and the outer ring burner 4, the first combustion mode or The combination of thermal power burned in the second combustion mode is different. For example, when the inner ring burner 3 is relatively small and the heat energy generated by combustion is relatively small, the outer peripheral portion of the bottom surface of the rice cooker 12 even when both the inner ring burner 3 and the outer ring burner 4 are set to high heat. 12w is heated more strongly than the bottom center vicinity 12c, rises along the side wall inner surface as shown in FIG. 6 in the rice cooker 12, and burns in the first combustion mode that causes convection to descend near the center. May be realized. In such a case, in order to cause convection in the second combustion mode as shown in FIG. 7 in the rice cooker 12, the inner ring burner 3 is set to a high fire and the outer ring burner 4 is set to a low fire, or It is necessary to put out the fire.

  On the contrary, when the inner ring burner 3 is relatively large and the heat energy generated by combustion is relatively large, the bottom center of the rice cooker 12 can be obtained even when both the inner ring burner 3 and the outer ring burner 4 are ignited. The portion vicinity 12c is heated more strongly than the bottom outer peripheral portion 12w, and combustion in the second combustion mode is caused in the rice cooker 12 to rise at the center as shown in FIG. 7 and cause convection to descend along the side wall inner surface. May be realized. In such a case, in order to cause convection in the first combustion mode as shown in FIG. 6 in the rice cooker 12, the outer ring burner 4 is set to a high fire and the inner ring burner 3 is set to a low fire, or It is necessary to put out the fire.

  In a preferred example, when both the inner ring burner 3 and the outer ring burner 4 are burned by a strong fire, the inner ring burner 3 and the outer ring burner 4 rise along the inner surface of the side wall as shown in FIG. It is preferable to realize combustion in the first combustion mode that causes convection. In order to realize combustion in the second combustion mode in which the convection that rises in the center portion as shown in FIG. 7 and descends along the inner surface of the side wall is caused in the rice cooker 12, the outer ring burner 4 is changed from high to low. You can do it. In this case, the direction of the convection generated in the rice cooker 12 can be alternately changed by switching the combustion of the outer ring burner 4 from a high flame to a low flame or vice versa.

The adjustment of the heating power of the inner ring burner 3 and the outer ring burner 4 as described above is performed by controlling the mass flow controllers 22 _A and 22 _B by the control device 18 to control the amount of fuel gas supplied to the inner ring burner 3 and the outer ring burner 4. This can be done by adjusting. As described above, such adjustment can be performed independently for each of the inner ring burner 3 and the outer ring burner 4. However, the inner ring burner 3 and the outer ring burner 4 in the first combustion mode and the second combustion mode can be adjusted. When the quantity ratio of the fuel gas supplied to each is known, the other is changed in conjunction with the change of either one of the mass flow controllers 22 _A or 22 _B , and the inner ring burner 3 or the outer ring burner 4 is controlled by the control device 18. One combustion control may be linked to the other combustion control.

  In any case, according to the rice cooking device 1 of the present invention as described above, the control device 18 controls the combustion of the inner ring burner 3 and the outer ring burner 4 and at the desired timing during the rice cooking process, It is possible to cause thermal convection in a desired direction. By generating heat convection in the rice cooker 12 or by alternately changing the direction thereof, the inside of the rice cooker 12 is agitated to enable more uniform cooked rice. According to this, it is possible to further improve the taste of cooked cooked rice.

  Furthermore, according to the rice cooking device 1 of the present invention, for example, as shown in FIG. 8, the outer ring burner 4 is put into a fire extinguishing state and the inner ring burner 3 is put into a low fire state, whereby the inner ring burner 3 is used as an adjustment fire at the end of rice cooking. It is also possible to use it. In FIG. 8, 25 is cooked rice.

  In addition, although the above demonstrated the case where the horizontal cross-sectional shape of the rice cooker 12 was circular, the rice cooker which the rice cooking device of this invention makes object is not restricted to a circular horizontal cross-sectional shape, even if it is square, It may be a rectangle, other polygons, an ellipse or an oval. When the horizontal cross-sectional shape of the rice cooker 12 is square or rectangular, the shape of the ring-shaped outer peripheral portion of the inner ring burner 3 can be square or rectangular according to the shape of the rice cooker 12. Moreover, the shape of the ring-shaped inner peripheral part of the outer ring burner 4 can also be made square or rectangular according to the shape of the rice cooker 12. Moreover, the case where the rice cooker of this invention is a rice cooker for business use is the most suitable, In the above, although the rice cooker for business was mainly demonstrated to the example, the rice cooker of this invention is a rice cooker for home use. Of course, it may be.

  As described above, the rice cooker according to the present invention can cook rice with high thermal efficiency, so it is energy saving and contributes to a reduction in the amount of carbon dioxide generated. Furthermore, the rice cooker of the present invention can control the combustion of the inner ring burner and the outer ring burner, and can cause upward or downward convection in the center of the rice cooker at a desired timing during rice cooking. Cooking can be performed, and the taste of cooked rice can be further improved. Thus, according to the rice cooking apparatus of the present invention, it is possible to further improve the taste of cooked rice with high thermal efficiency and the taste of cooked rice. It can be provided at low cost, and its industrial applicability is great.

DESCRIPTION OF SYMBOLS 1 Rice cooker 2 Furnace 3 Inner ring burner 4 Outer ring burner 5, 6 Mixed gas chamber 7 Piping 8 Temperature sensor 9 Outer cylinder 10 Signal line 11 Spacer 12 Rice cooker 13, 14 Combustion gas 15 Lid 16 Combustion gas exhaust port 17 Rice cooking material 18 Control 19 a fuel gas source 20 blower 21 _A, 21 _B mixer 22 _A, 22 _B mass flow controller 23 _A, 23 _B equalizing valve 24 open-close valve 25 rice F _{A, F B} flame G mixed gas L combustion gas passage R radiant heat

Claims (5)

When the rice cooker is set at the rice cooking position, the inner ring burner disposed at a position to heat the vicinity of the center of the bottom of the rice cooker, the bottom outer periphery of the rice cooker is heated, and the rice cooker A rice cooker comprising an outer ring burner disposed at a position where it burns toward the center of the bottom surface. Combustion gas exhaust port provided between the side wall of the rice cooker and the inner peripheral surface of the cooker when the rice cooker is set at the rice cooking position in the internal space. The rice cooker according to claim 1, wherein a combustion gas passage having a gas is formed.   The rice cooking apparatus of Claim 1 or 2 provided with the control apparatus which controls the combustion of the said inner ring | wheel burner and the said outer ring | wheel burner mutually independently or interlockingly. The control device controls the combustion of the inner ring burner and the outer ring burner, and heats the bottom outer peripheral portion of the rice cooker more strongly than the vicinity of the bottom center portion, and rises along the inner surface of the side wall in the rice cooker. Means for burning in a first combustion mode for causing convection, and second combustion for causing convection to rise in the rice cooker by heating the vicinity of the center of the bottom of the rice cooker more strongly than the outer periphery of the bottom The rice cooker of Claim 3 provided with the means to burn in a mode. The rice cooker according to any one of claims 1 to 4, wherein the inner ring burner and the outer ring burner are a surface combustion burner or a blast burner.

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