KR20080101271A - An electric rice-cooker using heat pipe - Google Patents

Abstract

A rice cooker using a heat pipe is provided to improve the durability of the rice cooker for removing damage of the deformation of a structure in the inner pressure increase. The rice cooker includes an inner container(10) and an outer container(11) using the heat pipe principle. A plurality of grooves(14) which is arranged within a constant interval according to the circumference direction of the inner container for the quick collection of the condensate water and is extended to the lower part of the vertical direction in the outside surface of a wall of the inner container. A plurality of corn shaped pines is formed in the lower surface of the inner container for rapidly dropping the condensate water to the outer container floor.

Description

An electric rice-cooker using heat pipe}

1 is a perspective view showing a cooker using the heat pipe principle according to an embodiment of the present invention

Figure 2 is a side cross-sectional view showing a cooker using the heat pipe principle according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram for showing a chimp effect for preliminarily excluding droplets formed on the inner bottom surface of the inner cylinder shown in FIG.

Figure 4 is a plan sectional view showing a rice cooker using the heat pipe principle according to an embodiment of the present invention

Figure 5 is a bottom view showing an example of the reinforcing material installed between the inner cylinder and the outer cylinder in the cooker using the heat pipe principle according to the embodiment of the present invention

Figure 6 is a bottom view showing another example of the reinforcing material installed between the inner cylinder and the outer cylinder in the cooker using the heat pipe principle according to the embodiment of the present invention

Figure 7 is a bottom view showing another example of the reinforcing material installed between the inner cylinder and the outer cylinder in the cooker using the heat pipe principle according to an embodiment of the present invention

<Description of the symbols for the main parts of the drawings>

10: inner cylinder 11: outer cylinder

12: space portion 13: reinforcement

14 groove 15 chimp

16 metal screen 17 bead

18: cooker body 19: cooker lid

20: heater

The present invention relates to a rice cooker to cook using the temperature uniformity of the heat pipe, and more particularly, the process of circulating after the condensation of the working fluid is made quickly to maximize the heat transfer efficiency to shorten the time to cook rice The present invention relates to a rice cooker using a heat pipe principle capable of improving durability of a rice cooker, such as eliminating the risk of deformation or breakage of a structure when an internal pressure rises.

In general, maintaining a constant temperature on the wall and bottom of the cooker is very important for cooking.

By maintaining the temperature of the wall surface and the bottom surface in this way, food can be heated evenly to improve its taste, and thermal efficiency can be improved.

For example, it is based on this principle to cook rice in a cauldron, or to cook steamed rice in a pot with a wire-like structure.

It is for this reason that when making stainless cookers with low thermal conductivity coefficients, a multi-layered structure bonded with aluminum with good thermal conductivity in between is produced.

However, aluminum having excellent thermal conductivity does not have an infinitely large thermal conductivity, and thus it is not possible to make an ideal cookware.

In other words, the ideal cooking utensil cannot be realized only by the thermal conduction phenomenon.

Overcoming this limitation, it has been proposed in a way that can theoretically cook at full isothermal, heat pipe cooker, or thermosyphon cooker.

The heat pipe cooker is an application of the heat pipe technology developed to maintain the surface temperature of the satellite uniformly. The heat pipe cooker is made of a double hermetic container in the internal structure of a cooking utensil such as a frying pan, a pot and a rice cooker.

The working liquid in this confined space is evaporated and condensed at a constant temperature to maintain a constant temperature in any part of the cooker, which is as effective as making a cookware from an ideal material with an infinite thermal conductivity. do.

That is, even if somewhat uneven or locally heated by a flame or heating wire from outside the cooker, since all parts are cooked evenly while maintaining the inside surface of the cooker at a uniform temperature, the cooking effect is good.

Moreover, the internal structure of the cooker contains only a small amount of working fluid, so the overall heat capacity is very small, making the temperature control of the cooker very fast and the risk of overheating extremely low.

The advantage of this instrument is that the temperature at all locations in the confined space is constant as the saturation temperature of the working liquid.

In other words, a certain temperature is maintained at all positions, even if one portion is more cooling than the other or the heating is not uniform.

In addition, since the saturation temperature of the sealed liquid and vapor mixture can be continuously changed, for example, when the steam is used as the working fluid, the temperature of the inner cylinder is not only changed to 100 degrees Celsius, but even lower or much higher temperature. The content inside can be heated while maintaining a uniform temperature.

It is a recent trend that many cooking utensils using the principle of such a heat pipe, for example, a rice cooker, are provided.

In general, an electric rice cooker receives heat from the floor according to the heating of a heater installed on the floor, and rice and water are heated, and water is boiled down to make rice.

In this process, the existing electric rice cooker is only heat transfer from the bottom, so it takes a long time to boil the water initially, and once the water boils, heat is transferred only by the heat conduction through the rice from the bottom. In order to fully cook the inside of the rice must be raised the temperature of the bottom of the cooker excessively, due to this there is a problem that the rice burns on the bottom and sticks.

In order to solve this problem, some rice cookers using the principle of heat pipes have been proposed.

For example, there is a rice cooker equipped with a heat pipe inside the inner cylinder (Japanese Laid-Open Patent Publication No. 6-24627), and a rice cooker using a grooved heat pipe (Korean Registered Utility Model 20-0175946).

In the former case, there is a disadvantage in that the heat pipe is inserted into the inside of the rice, so that the rice is buried in the heat pipe, and only the bottom is heated and the side is not heated.

In the latter case, the grooved heat pipe is used, but the grooves are distributed only at the bottom, so the circulation of the condensate is accelerated only by the capillary phenomenon at the bottom. It takes a long time. Therefore, the liquid film is dried at the bottom surface, the heat is transmitted only by the heat conduction by the heater from the bottom, the problem that the rice is burned and pressed on the floor continues to occur.

In addition, these conventional techniques have a problem that the structural deformation occurs due to the pressure rise due to the temperature rise in the closed space of the inner cylinder and the outer cylinder, thereby lowering the reliability of the product.

Therefore, the present invention has been devised in view of the above, the process of circulating after the condensation of the working fluid is made quickly, maximizing the heat transfer efficiency to reduce the time to cook the rice as well as improve the taste of the rice The purpose is to provide a rice cooker using the heat pipe principle.

In addition, another object of the present invention is to provide a rice cooker using the heat pipe principle that can improve the durability of the cooker, such as to eliminate the risk from deformation or breakage of the structure when the internal pressure rises.

Rice cooker using the heat pipe principle according to an embodiment of the present invention for achieving the above object in the cooker using the heat pipe principle including the inner cylinder and the outer cylinder, the inner wall of the inner cylinder for the rapid recovery of condensate It is characterized in that a plurality of grooves are arranged at regular intervals along the circumferential direction and extend to the bottom in the vertical direction.

In addition, the outer bottom surface of the inner cylinder is characterized in that a plurality of cone-shaped chimpanes for quickly dropping the condensate water to the outer cylinder bottom.

In addition, the space between the inner cylinder and the outer cylinder filled with the working fluid is characterized in that a plurality of strip-shaped reinforcement in the bottom portion is installed in a structure that is fusion-fixed to the inner surface and the outer surface of the inner cylinder by spot welding.

In addition, the space between the inner cylinder and the outer cylinder filled with the working fluid is characterized in that a plurality of strip-shaped reinforcement in the side portion is installed in a structure that is fused and fixed to the inner surface and the outer surface of the inner cylinder by spot welding.

Preferably, the plurality of reinforcing members are characterized in that arranged in the form of radially extending straight from the center in the case of the portion installed on the bottom surface.

More preferably, the plurality of reinforcement is characterized in that arranged in the form extending in a radial spiral form from the center to the outer portion in the case of being installed on the bottom surface.

Here, the radial straight or spiral shape of the reinforcing material is characterized in that it consists of a straight or spiral shape with a bend.

In addition, the space portion formed by the inner cylinder and the outer cylinder is characterized in that a plurality of metal screens are provided in the form disposed between the reinforcing material.

In the present invention, not only the bottom surface but also the wall surface is heated to a temperature substantially equal to the bottom surface by evaporative condensation of the heat pipe working liquid, thereby reducing the time for cooking and preventing the rice from burning.

For this purpose, the evaporated liquid is condensed on the wall surface, and the condensed water is rapidly returned to the heating part by the capillary phenomenon of the groove formed on the wall surface.

In addition, the path for moving the liquid returned to the evaporation part of the heat pipe to the heating part of the bottom plate is caused by cone-shaped chimps and beads by spot welding, thereby preventing the liquid from evaporating part from drying out.

In addition, the heat pipe is filled with a working liquid in a sealed space, and the working liquid transfers heat while repeating evaporation and condensation between the heating part and the cooling part, so that the temperature of the heating part and the cooling part is uniform. The cooker of the present invention applies the temperature uniformity of such a heat pipe.

For example, using a cooker as a double structure, a working liquid is placed between an inner cylinder and an outer cylinder, and the working liquid is heated from the bottom heat to evaporate, and then condensed on the inner wall of the cylinder to raise the temperature, and then returns.

In addition, the deformation of the inner cylinder and the outer cylinder may occur as the internal pressure of the space enclosed by the heat input from the bottom increases. In the present invention, the spot reinforcement is welded between the inner cylinder wall and the outer cylinder wall to prevent such deformation. At this time, the beads generated in the spot welding process is a path connecting the liquid film returned from the evaporator to the heating part of the bottom.

Hereinafter, a cooker using a heat pipe principle according to an embodiment of the present invention with reference to the accompanying drawings in detail as follows.

1 is a perspective view showing a cooker using the heat pipe principle according to an embodiment of the present invention, Figure 2 is a side cross-sectional view showing a cooker using the heat pipe principle according to an embodiment of the present invention, Figure 3 4 is an explanatory diagram for showing a chimp effect for preliminarily excluding droplets formed on the inner bottom surface of the inner cylinder, and FIG. 4 is a plan sectional view illustrating a cooker using a heat pipe principle according to an embodiment of the present invention.

As shown in Figures 1 to 4, the rice cooker of the present invention is a rice cooker body 18, which is provided with power from the outside, like a normal electric rice cooker, a rice cooker lid 19 for closing the rice cooker body 18, The heater 20, which is a heating means, consists of a structure including an inner barrel 10, an outer cylinder 11, and the like, which are substantially cooked portions.

In addition, the inner cylinder 10 and the outer cylinder 11 is made of a metal material such as aluminum, copper, stainless steel with a thin thickness, and is combined in the form of forming a space 12 sealed between each other, wherein The space portion 12 is filled with a working fluid for transferring heat while repeating evaporation and condensation.

In particular, the space portion 12 between the inner cylinder 10 and the outer cylinder 11 is provided with a plurality of band-shaped reinforcement 13 which is fusion-fixed to the inner surface and the outer cylinder inner surface by spot welding, the reinforcement at this time 13 is installed not only on the bottom but also on the wall.

The installation form of the reinforcing material 13 may be a form continuously connected to the wall surface from the bottom surface as in the embodiment provided by the present invention.

Alternatively, it may be a broken form that is installed separately on the bottom surface and the wall surface, for example, one arranged on the bottom surface and one wall surface along the circumferential direction.

Here, the cross-section of the reinforcing material 13 may be a variety of forms, such as square, triangle, at least two or more may be installed, preferably about eight is most suitable.

Such a reinforcement 13 may be in the form of being installed on the wall surface is vertically extended at the same time along the circumferential direction is arranged at a predetermined interval, particularly as shown in Figure 5 to 6 The part may be arranged in a radial shape extending outward from the center of the bottom of the barrel.

At this time, the radial shape of each reinforcing material 13 may be a straight shape, preferably in the form of a spiral in terms of increasing the strength by ensuring a wide contact area of the passage, particularly in the straight or spiral shape By zooming in, a larger contact area can be obtained.

As such, the reinforcing material 13 that couples the inner cylinder 10 and the outer cylinder 11 serves to uniformly distribute condensate to prevent local rupture and also to increase the pressure of the inner cylinder 10 and the outer cylinder 11. It can play a role of preventing deformation.

In other words, if the condensed working fluid is not evenly formed on the inner wall of the cylinder, even if there is a wick at the bottom, it will not be spread evenly, which will result in a locally ruptured portion, thereby failing to achieve maximum heat transfer.

Therefore, in the present invention, by placing a plurality of reinforcing members at regular intervals along the circumference on the wall side and radially on the bottom side, evenly distributed condensate can be prevented to prevent local bursting, It can prevent deformation due to pressure rise.

In addition, a plurality of grooves 14 having a small groove shape are formed on the outer wall surface of the inner cylinder 10 while being disposed at regular intervals along the circumferential direction and extending in the vertical direction.

At this time, the groove 14 is for rapid recovery of condensate, and when the evaporated vapor of the working liquid is condensed in the inner cylinder 10, which is relatively lower than the outer cylinder 11, the groove 14 quickly returns to the heating unit by using a capillary phenomenon. To help them become

In addition, a plurality of cone-shaped chimney pin 15 is formed on the outer bottom surface of the inner cylinder 10, so that the condensate can quickly fall to the outer cylinder bottom by riding the needle pin (15).

For example, the condensate moved down the wall of the inner cylinder 10 is suspended in the cone-shaped needle pin 15 formed on the bottom of the inner cylinder, and even a small amount of the working fluid can quickly fall to the outer cylinder bottom. Will be.

This is because the smaller the contact diameter (contact area) between the medallion working fluid droplet (droplet) and the solid surface on the hydrophilic surface, the faster the equilibrium is broken and falls quickly as shown in Equation 1 below.

mg = πD _Sl σ _sl

Where mg is the mass of the droplet, D _Sl is the contact diameter of the droplet and the solid surface, and σ _sl is the surface tension. In addition, Figure 3 (a) shows that the droplets are generated when there is no chimp pin on the bottom surface of the conventional inner barrel, Figure 3b shows the droplets on the needle pin when the chimp is formed to characterize the present invention It shows what is produced.

In addition, a plurality of metal screens 16 are disposed on the bottom side of the space portion 12 formed by the inner cylinder 10 and the outer cylinder 11 so as to be disposed between the reinforcing members, and at this time, the metal screen ( 16 serves to evenly disperse the condensate dropped to the bottom of the outer cylinder (11).

For example, a metal screen is bonded to the bottom surface of the outer cylinder between the reinforcement, and when the metal screen is condensed and the working fluid is recovered, the metal screen is spread evenly on the bottom of the heating surface, where the bottom of the heating surface is locally heated. There will be no.

Thus, looking at the function of the rice cooker according to an embodiment of the present invention configured as described above are as follows.

Put rice and water in the inner bowl of the rice cooker properly and select cooking, and the rice starts to cook by heating the heater.

As the heater is heated, the working liquid in the space part 12 formed in a vacuum between the inner cylinder 10 and the outer cylinder 11 is uniformly transferred heat to the entire cylinder such as the bottom surface as well as the wall surface while repeating evaporation and condensation. The heat efficiency can be maintained, and the rice can be cooked quickly.

At this time, the condensate on the outer wall of the inner cylinder is quickly returned to the bottom through the groove 14, the reinforcement 13, the chimney 15, and the like, and evenly through the bottom reinforcement 13, the metal screen 16, and the like. Since the bottom of the heating surface is uniformly heated while being dispersed, it is possible to maintain a balanced heating state of the entire container, and therefore, even if the temperature is lower than that of a conventional electric rice cooker, for example, 15-20 minutes (a conventional rice cooker The rice can be cooked evenly to the inside without sticking to the bottom.

As described above, the present invention implements a new type of rice cooker capable of cooking rice by heating the entire tub of the rice cooker uniformly, thereby shortening the cooking time and reducing the amount of electricity consumed accordingly. In addition, there is an effect that can prevent the rice sticking to the floor.

In addition, since the process of circulating after the condensation of the working fluid is performed quickly, there is an advantage of maximizing the heat transfer efficiency, and the durability of the rice cooker, such as the risk of deformation or breakage of the structure when the internal pressure rises, can be eliminated. There is an advantage that can be improved.

Claims (10)

In the rice cooker using the heat pipe principle including the inner cylinder 10 and the outer cylinder 11, Heat pipe, characterized in that the outer wall surface of the inner cylinder 10 is formed with a plurality of grooves 14 which are arranged at regular intervals along the inner cylinder circumferential direction to extend to the bottom in the vertical direction for rapid recovery of condensate Rice cooker using the principle. The rice cooker using the heat pipe principle of claim 1, wherein a plurality of cone-shaped chimney pins (15) are formed on the outer bottom surface of the inner cylinder (10) to quickly drop the condensed water to the outer cylinder bottom. The space portion 12 between the inner cylinder 10 and the outer cylinder 11 filled with the working fluid is fused and fixed to the inner surface of the inner cylinder and the outer surface of the outer cylinder by spot welding in the bottom portion. Rice cooker using the heat pipe principle, characterized in that a plurality of structures are installed. The inner space 10 between the inner cylinder 10 and the outer cylinder 11 filled with the working fluid is provided with a band-shaped reinforcing member 13 on the side surface of the inner cylinder outer surface and the outer cylinder inner surface by spot welding. Rice cooker using the heat pipe principle, characterized in that the plural fixed structure is installed on the heat pipe. The space 12 between the inner cylinder 10 and the outer cylinder 11 in which the working fluid is filled is provided with a band-shaped reinforcing member 13 extending from the bottom portion to the side portion by spot welding. Rice cooker using the heat pipe principle, characterized in that a plurality of the structure is installed to be fused and fixed to the inner surface of the outer cylinder. The rice cooker using the heat pipe principle according to claim 3, wherein the plurality of reinforcing members (13) are arranged in a form of radially extending straight from the center to the outside in the case of the portion installed on the bottom surface. The rice cooker using the heat pipe principle according to claim 3, wherein the plurality of reinforcing members (13) are arranged in a radial spiral form extending from the center to the outside in the case of the portion installed on the bottom surface. 8. The cooker using the heat pipe principle according to any one of claims 3, 6 and 7, wherein the radial straight or spiral shape of the reinforcing member (13) has a curved straight or spiral shape. The method according to claim 8, wherein the reinforcing material (2) is a field pot using the heat pipe principle, characterized in that formed at least two. 10. The heat pipe principle according to claim 9, wherein the space portion 12 formed by the inner cylinder 10 and the outer cylinder 11 is provided with a plurality of metal screens 16 arranged in between the reinforcement members. Rice cooker using.

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