KR101059958B1 - Electric hot plate - Google Patents

Abstract

Disclosed is a hotplate. The hot plate includes a heat generating layer due to electrical resistance in the substrate, and the heat generating layer has a structure in which a plurality of conductive nanoparticles formed of an oxide semiconductor material or silica are physically necked.

Cooking, Hot Plates, Heating Layers, Heating Equipment

Description

Electric hot plate {Electric hot plate}

Disclosed is a hot plate usable in various fields such as cooking, and in particular, a lightweight thin hot plate using a plate heater.

Conventional heating apparatuses, for example, cooking heaters include a hot plate method in which a coil-type heating wire is embedded in a heater made of a casting, and a highlight method in which a so-called highlight heater (heating element) is provided below the ceramic upper plate. Existing highlight-type heating device has a structure in which the ceramic top plate is indirectly heated by convection and radiation, so that the thermal efficiency is low, and the temperature rise rate is low, so that the time to reach the target temperature, for example, the boiling temperature, is long. In addition, the top plate and the heating element not only maintain a constant gap, but also increase the overall height due to securing a constant space between the bottom portion. According to this, the height of the upper plate on which the cooking vessel is placed increases, and thus, the instability of the container in cooking increases.

According to exemplary embodiments, a hotplate having a high heat utilization efficiency is provided.

Further, according to exemplary embodiments, a hot plate capable of light weight and thinning is provided.

In addition, there is provided a hot plate that can be designed to be portable with low power consumption.

According to one embodiment,

A heat resistant plate on which the heating object is placed;

An electrical heating layer formed on one surface of the heat resistant sheet material, in which a plurality of conductive nanoparticles are physically necked;

A power supply unit supplying electricity to the heating layer; And

Provided is a hot plate having a housing for supporting the heat resistant plate.

According to one embodiment, the nanoparticles are formed of an oxide semiconductor material or silica. The oxide semiconductor is a material in which at least one of ZnO, InO, SnO, and MgO is doped with at least one of Al, Ga, In, Sb, C, and Sn.

According to another embodiment, the power supply unit includes an internal battery.

According to another embodiment, the heat resistant plate is transparent.

According to another embodiment, the electrical heating layer may be formed on the inner surface of the heat-resistant plate.

According to another embodiment, the electrical heating layer may be formed on the outer surface of the heat-resistant plate on which the cooking vessel is placed.

According to another embodiment, the electrical heating layer may be formed only at the center portion away from the edge of the heat resistant plate.

Hereinafter, a hot plate according to embodiments will be described with reference to the accompanying drawings.

1 and 2 are perspective views showing the appearance of the hot plate 10 according to the present embodiment in different directions, and FIG. 3 is a cross-sectional view of the hot plate 10.

1 to 3, the hot plate 10 includes a planar heating element 11 and a housing 12 or a frame supporting the planar heating element 11. In the upper part of the housing 12, the planar heating element 11 in which a heating element, for example, a cooking vessel is placed, is provided. The planar heating element 11 has two electrodes 11d and 11d for supplying power to the heat-resistant plate 11a, a thin film-shaped electrical heating layer 11c and a heating layer 11c formed on one surface thereof. It includes. The heat resistant plate 11a may be made of a transparent, translucent, or opaque material, and according to another embodiment, a transparent ceramic material, and, according to a specific embodiment, silicon oxide (SiO ₂ ), calcium oxide (CaO), and aluminum as an oxide-based material. Oxide (Al ₂ O ₃ ); The heat resistant plate 11a may be marked with a heat resistant fire resistant mark 11b indicating a position where the container is placed.

Meanwhile, the electrically heating layer 11c has a physical structure in which a plurality of conductive nanoparticles are physically necked. That is, the electrical heating layer 11c is formed on the one surface, that is, the upper surface or the bottom surface of the heat resistant plate 11a, and has a texture where the conductive nanoparticles are physically necked (ie connected). The path has a structure formed by necking. The nanoparticles of the conductive heating layer 11c may have a loose texture structure in which a plurality of conductive nanoparticles made of silica or an oxide semiconductor are physically necked. This may be due to the heat treatment conditions in the manufacturing process described below may have a dense structure (Close-Packed Texture), according to another embodiment may have a complete film state. The heat generating layer 11c may be formed in a single stack, but may include two or more multiple layers 111c, 112c, and 113c as shown in FIG. 4 or including a homogeneous material layer or a dissimilar material layer. have. The heat generating layer 11c of the single layer or multilayer structure may be protected by the protective layer 11d or the like, which may be formed of a carbon thin film, Si nanoparticles, oxide nanoparticles, or the like. The electrode 11d connected to the heating layer 11c is exaggeratedly represented symbolically. In practice, the electrode 11d may have a very large thickness compared to the heat generating layer 11c and may be implemented in various forms of structures for electrical connection from the outside.

Hereinafter, the formation of the heat generating layer 11c of the heat resistant plate 11a, that is, the manufacturing process of the plate-like heat generating element 11 will be briefly described.

After the heat resistant plate 11a made of heat resistant glass or ceramic is prepared, it is cleaned. The cleaning may use a known solvent or agent that does not damage the plate.

Apart from the cleaning, a nanoparticle dispersion is prepared (prepared). As a solvent, a mixed liquid of methanol and calcium hydroxide, a mixed liquid of methanol and calcium hydroxide, a single benzene substance, and water are used. As a nanoparticle, at least one of ZnO, SnO, MgO, and InO is used as a doped oxide semiconductor. At least one of one and silica may be used. At least one of In, Sb, Al, Ga, C, and Sn is used as the dopant. In preparing the dispersion, the above-mentioned oxide semiconductor nanoparticle is added as a precursor while the solvent is heated to 50 to 200 ° C.

The nanoparticle dispersion is coated on the cleaned plate. As the coating method, various methods as described above may be used, and the coating area is at least one area defined in the whole or the plate.

Heat treatment of the nanoparticle dispersion-coated plate to form a heat generating layer by the nanoparticles on one side, that is, the top or bottom of the plate. At this time, the heat treatment is accompanied by evaporation (drying) of the solvent in which the nanoparticles are dispersed. In some cases the evaporation of the solvent may be carried out separately, but in general it may proceed simultaneously with the heat treatment. However, during the heat treatment, drying proceeds first, followed by sintering of the remaining nanoparticles, thereby obtaining an exothermic layer in which the nanoparticles are physically necked. The above-described coating and heat treatment processes may be performed one or more times, thus obtaining a heat generating layer having a multilayer structure.

The electrodes (electric terminals) described above are formed on both sides of the heat generating layer. The electrode may be formed of a metal, a conductive epoxy, a conductive paste, a solder, a conductive film, or the like. The metal electrode may be formed by a deposition method, the conductive epoxy or conductive paste electrode may be formed by known screen printing, the solder may be formed by a soldering method, and the conductive film may be formed by a laminating method.

The wiring is connected by the method as described above. The wiring may be formed by wire bonding, soldering, or the like with respect to the electrode.

Finally, a protective layer is formed on the heat generating layer. The protective layer is formed using a dielectric oxide, perylene nanoparticles, a polymer film, etc., the nanoparticles, dielectric oxide or perylene protective layer is formed by a deposition method, the nanoparticle protective layer is spray coating, spin coating or dipping method Or the like. In addition, the process of forming the protective layer may be performed once, according to another embodiment may be performed a plurality of times.

The heating plate obtained through the process as described above has a very high thermal efficiency and a fast heating rate, light and simple compared to the conventional highlight type heating device.

5 is a graph showing repeated measurements of the temperature increase rate under 220V for 10 times for one sample of the 80W heating plate according to the present embodiment. This is to examine the reproducibility according to the repetitive operation, and it can be seen that it has similar electrical characteristics in 10 tests.

Figure 6a is a graph showing the temperature distribution for each part of the heating plate material showing the results as shown in Figure 5, Figure 6b is a graph showing the temperature distribution in the cross section A-A of 6a.

6A and 6B, low temperatures are distributed in the left and right portions of the heating plate, and this portion is an electrode layer forming portion for the heating layer, in which no heat is generated. In Fig. 6a, a large temperature gradient appears in the upper and lower portions, which may be due to heat loss to the surroundings due to convection. As shown in FIGS. 6A and 6B, it can be seen that a very even temperature distribution is shown as a whole except for a portion where the electrode is formed and a part of the upper and lower edges.

 7A and 7B show simulation results of the heat generation characteristics of the hot plate and the conventional highlight type hot plate according to the present embodiment, respectively. In each of the figures of FIGS. 7A and 7B the top image shows the planar heat distribution of the hot plate, and the bottom image shows the heat distribution in the transverse direction of the hot plate. Under simulated conditions, the ambient temperature is usually 20 degrees, and this embodiment is a direct heating in which a heating layer of 80 W is formed entirely on the ceramic top plate, and a conventional hot plate has a highlight of 80 W at 1.5 cm intervals below the same size ceramic top plate. It is a simulation result under the conditions of indirect heating which located the heat generating body.

7A and 7B, the hot plate according to the present embodiment is capable of generating heat (heating) of the entire surface, and is widely distributed in a high temperature center of heat, and the conventional hot plate has a high temperature heat with partial heat generation (heating). It can be seen that the center is narrowly distributed.

8a and 8b are photographs showing the actual heating state of the hot plate and the conventional indirect heating type hot plate according to the present embodiment.

As shown in FIG. 8A, the hot plate according to the present embodiment generates heat evenly over the entire surface, whereas as shown in FIG. 8B, the conventional hot plate generates local heat corresponding to the shape of the lower heating element. Able to know. By the way, the hot plate according to the present embodiment shown in Figure 8a is 220V 80W, the conventional hot plate shown in Figure 8b is 220V 1800W. Through this, it can be seen that the hot plate according to the present embodiment can generate heat better than the conventional hot plate with high power consumption while having lower power consumption than the conventional hot plate.

9A and 9B are graphs showing a time-temperature change of the hot plate shown in FIGS. 8A and 8B, respectively. 8A and 8B, the 80W hot plate and the 1800W conventional hot plate all show similar time-temperature change characteristics reaching 300 degrees in 60 seconds. That is, it can be seen that the hot plate according to the present embodiment has similar thermal characteristics while having lower power consumption than the conventional hot plate.

As described above, the hot plate according to the present embodiment may be applied as a general heating device, for example, a cooking hot plate, with a very low power consumption compared to the conventional hot plate. As such, low power consumption, for example, 80 W, is extremely low compared to a conventional cooking heater, and can be driven by a battery or the like. In other words, the recent rechargeable battery has been rapidly improving the performance, it is easy to implement the 80VA. Therefore, the hot plate according to another embodiment may have a battery in its housing. Of course, since the battery is built in the heating element, a means for protecting the battery from the heat source will be required. These measures are not difficult in light of the current level of technology.

10 symbolically illustrates a hot plate 10a incorporating a battery.

Referring to FIG. 10, the hot plate 10a includes a planar heating element 11 and a housing 12 or a frame supporting the planar heating element 11 as described above. In the upper part of the housing 12, the planar heating element 11 in which a heating element, for example, a cooking vessel is placed, is provided. On the other hand, the housing 12 has an internal power supply 13, such as a battery for supplying power to the planar heating element 11 and the internal circuit portion 14 is built. The internal circuit unit 14 may be provided in the hot plate 10 of the above-described embodiment shown in FIG. 1, and in the hot plate 10a of the present embodiment, the internal power source 13 is a disposable battery or a rechargeable battery. The internal circuit unit 14 may further include a charging circuit for the rechargeable battery when the internal power source 13 applies the rechargeable battery.

The hot plate of the above-described embodiments may have a so-called built-in configuration according to the recent trend of installation of kitchen equipment, and the hot plate may also have a plurality of heating layers to perform various cooking at the same time. Controlled power may be applied.

To date, exemplary embodiments have been described and illustrated in the accompanying drawings in order to facilitate understanding of the present invention. However, it should be understood that such embodiments are merely illustrative of the invention and do not limit it. And it is to be understood that the invention is not limited to the details shown and described. This is because various other modifications may occur to those skilled in the art.

1 is a perspective view showing a graphic implementation of a hot plate according to the present embodiment.

2 is a perspective view showing the appearance of the hot plate according to the present embodiment in different directions.

3 is a cross-sectional view of the hot plate shown in FIGS. 1 and 2.

4 illustrates a heating layer of a multilayer structure in a hot plate according to another embodiment.

FIG. 5 is a graph illustrating repeated measurements of a temperature increase rate under 220V for 10 times for a sample of an 80W heating plate according to one embodiment.

FIG. 6A is a graph showing temperature distribution for each part of the heating plate having the same result as in FIG. 5.

6b is a graph showing the temperature distribution in the cross section along line A-A in FIG. 6a.

7A and 7B show simulation results of the heat generation characteristics of the hot plate and the conventional highlight type hot plate according to the present embodiment, respectively.

8a and 8b are photographs showing the actual heating state of the hot plate and the conventional indirect heating type hot plate according to the present embodiment.

9A and 9B are graphs showing a time-temperature change of the hot plate shown in FIGS. 8A and 8B, respectively.

10 is a cross-sectional view symbolically showing a cross-sectional structure of a hot plate according to another embodiment.

Claims (9)

A heat resistant plate on which the heating object is placed; An electrical heating layer formed on one surface of the heat resistant plate and having a loose texture in which conductive nanoparticles formed of an oxide semiconductor material or silica are physically necked; A power supply unit supplying electricity to the heating layer; And And a housing for supporting the heat resistant plate. delete The method of claim 1, The oxide semiconductor is a hot plate, characterized in that the doped with at least one of Al, Ga, In, Sb, C, Sn at least one of the material of ZnO, SnO, MgO. The method according to claim 1 or 3, The power supply unit has a built-in battery, characterized in that the hot plate. The method of claim 4, wherein The built-in battery includes a rechargeable battery, and the power supply unit further comprises a charging circuit. The method of claim 4, wherein The electrical heating layer is hot plate, characterized in that formed on any one of the inner surface and the outer surface of the heat-resistant plate. The method according to claim 1 or 3, The electrical heating layer is hot plate, characterized in that formed on any one of the inner surface and the outer surface of the heat-resistant plate. The method according to claim 1 or 3, The heating plate is provided with a plurality of heating layers, each heating layer is a hot plate, characterized in that the power is independently applied. The method of claim 4, wherein The heating plate is provided with a plurality of heating layers, each heating layer is a hot plate, characterized in that the power is independently applied.

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