CN108652439A - Insulating pot - Google Patents

Abstract

The invention discloses a kind of insulating pots, including bottom of the pot wall (1) and heating film (4), heating film is arranged in the bottom surface of bottom of the pot wall, and the area of heating film is not less than 3/5 with the area ratio of bottom of the pot wall, and heating film is not more than 30W/cm for the power density of bottom of the pot wall², and the insulating pot is also not more than the low thermal conductivity plate of material (10) of 60W/m.k containing thermal coefficient, which is set between bottom of the pot wall and heating film.In the insulating pot of the present invention, by the way that heating film is arranged in the bottom surface of bottom of the pot wall, increase the thermocontact area for being set to heating element and bottom of the pot wall on the bottom surface of bottom of the pot wall, advantageously reduce the degree of superheat of bottom of the pot wall, to reduce the frequency of bubble departure bottom of the pot wall, the frequency that steam bubble ruptures in water is reduced, significant noise reduction is reached.

Description

electric kettle

technical field

The invention belongs to the field of household appliances, and in particular relates to an electric kettle.

Background technique

The bottom wall of the conventional electric kettle mostly adopts a horizontal kettle bottom wall, and the electric heating plate is installed on the bottom surface of the horizontal kettle bottom wall, directly heats the horizontal kettle bottom wall, and then heats the liquid in the electric kettle. Wherein, the heat source of the electric heating plate comes from the electric heating tube, and the bottom wall of the horizontal pot is heated intensively through the electric heating tube to heat the liquid in the pot.

When the electric kettle is working, the electric heating tube conducts heat to the bottom wall of the kettle in the form of contact heat conduction. The bubbles are small and the frequency of detachment is high. The small bubbles detached from the bottom wall of the pot will transfer their own heat to the surrounding liquid during the rising process, making the small bubbles more likely to burst due to heat loss and generate loud noise.

Contents of the invention

In view of the above-mentioned shortcomings or defects in the prior art, the present invention provides an electric kettle, which can effectively reduce the frequency of bubbles detaching from the bottom wall of the kettle, thereby reducing the frequency of bubbles breaking in water and achieving the effect of noise reduction.

To achieve the above object, the present invention provides an electric kettle, which includes a bottom wall of the kettle and a heating film, the heating film is arranged on the bottom surface of the bottom wall of the kettle, and the area of the heating film is the same as that of the bottom of the kettle. The area ratio of the walls is not less than 3/5, and the power density of the heating film to the bottom wall of the pot is not greater than 30W/cm ² .

Preferably, the ratio of the area of the heating film to the area of the bottom wall of the pot is not less than 7/10 and not more than 9/10, and the power density of the heating film to the bottom wall of the pot is not greater than 25W/cm ² .

Preferably, the heating film is arranged concentrically on the bottom surface of the bottom wall of the kettle, or the heating film is arranged symmetrically with respect to the center of the bottom surface of the bottom wall of the kettle.

Preferably, the bottom wall of the kettle is a circular bottom wall, and the heating film is arranged on the bottom surface of the bottom wall of the kettle in a disc shape, a square shape or a ring shape.

Preferably, the disc-shaped, square-shaped or ring-shaped heating film is further formed with linear, circular or circular cuts.

Preferably, the heating film is an electrothermal film or a thick film, and the electrothermal film or thick film is covered with an insulating layer. Preferably, the insulating layer is a ceramic layer or a glass-ceramic layer.

Preferably, the electric kettle further includes a low thermal conductivity material plate with a thermal conductivity not greater than 60W/m.k, and the low thermal conductivity material plate is located between the bottom wall of the kettle and the heating film.

Preferably, the vertical projection area of the heating film toward the bottom wall of the pot is located within the vertical projection area of the low thermal conductivity material plate toward the bottom wall of the pot, preferably, the outer peripheral edge of the low thermal conductivity material plate The radial width beyond the outer peripheral edge of the heating film is not greater than 10mm.

Preferably, the thickness of the low thermal conductivity material plate is not less than 0.5 mm and not greater than 5 mm, preferably not less than 0.5 mm and not greater than 1 mm.

Preferably, the low thermal conductivity material plate is 45# steel plate, 304 stainless steel plate, 430 stainless steel plate or high manganese steel plate.

Through the above technical scheme, in the electric kettle of the present invention, by setting a heating film on the bottom surface of the bottom wall of the kettle, and the ratio of the area of the heating film to the area of the bottom wall of the kettle is not less than 3/5 and not greater than 1, the The thermal contact area between the heating element arranged on the bottom surface of the pot bottom wall and the bottom wall of the pot is improved, which is beneficial to reduce the superheat degree of the bottom wall of the pot, thereby reducing the frequency of bubbles leaving the bottom wall of the pot and reducing the frequency of bubbles breaking in water , to achieve a significant noise reduction effect.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is the front view of electric kettle of the present invention;

Fig. 2 is the overall sectional view of electric kettle of the present invention;

Fig. 3 is an enlarged view of part A in Fig. 2;

Fig. 4 is the bottom view when the electric heating tube is installed on the bottom surface of the kettle bottom wall in the prior art;

Fig. 5 is the heating area of the electric heating tube on the bottom wall of the kettle in the prior art and the improved heating area of the present invention;

Fig. 6 is a schematic diagram of bubbles on the top surface of the bottom wall of the pot when the electric heating tube is installed on the bottom wall of the pot in the prior art;

Fig. 7 is a schematic diagram of bubbles on the top surface of the bottom wall of the pot when the heating film is installed on the bottom wall of the pot in the present invention;

Fig. 8 is a bottom view when the heating film is arranged on the bottom wall of the pot according to the first preferred embodiment of the present invention;

Fig. 9 is a bottom view when the heating film is arranged on the bottom wall of the pot according to the second preferred embodiment of the present invention;

Fig. 10 is a bottom view when the heating film is arranged on the bottom wall of the pot according to the third preferred embodiment of the present invention;

11A to 11F are bottom views of the heating film with different linear cutouts of the present invention when it is arranged on the bottom wall of the pot;

12A to 12C are bottom views of the heating film with different annular cutouts of the present invention when it is arranged on the bottom wall of the pot;

13A to 13C are bottom views of the heating film with different round cuts of the present invention when it is arranged on the bottom wall of the pot;

Fig. 14 is a sectional view of the bottom wall of the pot having a low thermal conductivity material plate of the present invention;

FIG. 15 is an enlarged view of part B in FIG. 14 .

Explanation of reference signs:

1 Jug bottom wall 6 Handle

2 Kettle body 7 Steam pipe

3 Lid 8 Electric heating tube

4 heating film 9 insulating layer

5 Housing 10 Plate of low thermal conductivity material

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

In the present invention, unless stated to the contrary, the used orientation words such as "up, down, top, bottom" generally refer to the directions shown in the drawings or refer to the vertical, perpendicular or gravitational directions The terms used to describe the mutual positional relationship of the various components mentioned above.

The present invention will be described in detail below with reference to the accompanying drawings and examples.

Referring to Fig. 1 to Fig. 3, the present invention provides an electric kettle, which comprises a kettle bottom wall 1, a kettle body 2 and a kettle cover 3 constituting the kettle body, and a heating device for heating the liquid in the kettle is installed on the bottom of the kettle bottom wall 1 Membrane 4, the outside of the pot body is provided with a shell 5, the shell 5 is connected with a handle 6, a steam pipe 7 is arranged in the pot body, in the handle 6 or between the pot body and the shell 5, and the bottom of the pot body is provided with a thermostat , the steam pipe 7 guides the steam in the kettle body to the thermostat, and when the thermostat detects that the steam temperature reaches a preset value, the bimetal sheet is deformed to disconnect the power supply of the heating film 4, or a temperature is set on the kettle body. Sensor, when the temperature sensor detects that the temperature in the pot reaches the preset value, the power supply of the heating film 4 is disconnected by the micro-processing chip.

In the electric kettle of the prior art, with reference to Fig. 4, the electric heating tube 8 for heating the liquid in the kettle is arranged on the bottom surface of the bottom wall 1 of the kettle. The heat of self conducts to the bottom surface of the pot bottom wall 1, and the thermal contact area is annular and has a small area, that is, the current heating area shown in the left part of Fig. The higher the heat flux, the greater the superheat in this thermal contact area. Specifically, the greater the degree of superheat in the thermal contact area between the bottom wall 1 of the pot and the electric heating tube 8, the greater the evaporation power generated by the gas generated after the liquid vaporizes replenishing into the bubbles, and the gas gives the bubbles a vertical upward direction. The lifting force is also greater, and then the small bubbles will break away from the bottom wall 1 of the pot without waiting for the small bubble to grow up. In this way, when the liquid in the pot is heated by the electric heating tube 8 arranged on the bottom surface of the bottom wall 1 of the pot, The bubbles generated on 1 are difficult to grow up and the frequency of leaving the bottom wall 1 of the pot is also high, so that the bubbles that leave the bottom wall 1 of the pot and enter the water are small and dense, see Figure 6, and the small bubbles are rising During the process, it is also easier to break in water due to heat loss, resulting in loud noise.

In view of this, in order to reduce the superheat of the top surface of the bottom wall 1 of the kettle, thereby reducing the frequency of the bubbles leaving the bottom wall 1 of the kettle, and achieving the effect of noise reduction, referring to Fig. 2 and Fig. 8, in the electric kettle of the present invention, The heating film 4 is arranged on the bottom surface of the bottom wall 1 of the pot, and the ratio of the area of the heating film 4 to the area of the bottom wall 1 of the pot is not less than 3/5, and the power density of the heating film 4 to the bottom wall 1 of the pot is not more than 30W/cm ² . Such setting increases the thermal contact area between the heating element arranged on the bottom surface of the kettle bottom wall 1 and the kettle bottom wall 1, that is, the improved heating area of the present invention shown in the right part of FIG. The power density of the heating element to the bottom wall 1 of the pot is beneficial to reduce the superheat of the top surface of the bottom wall 1 of the pot, so that the vaporization power generated by the gas generated by the liquid vaporization entering the bubble is also reduced, and the gas is correspondingly The vertical upward lifting force given to the bubbles is also reduced, so that the bubbles can grow into larger bubbles on the bottom wall 1 of the pot and then break away from the bottom wall 1 of the pot. See Figure 7. In this way, it can effectively reduce the The frequency at which the bubbles break away from the bottom wall 1 of the kettle reduces the frequency of the bubbles breaking in the water, thereby reducing the noise value when the electric kettle is in operation and achieving a significant noise reduction effect.

Furthermore, the ratio of the area of the heating film to the area of the bottom wall 1 of the pot is not less than 7/10 and not more than 9/10, and the power density of the heating film 4 to the bottom wall 1 of the pot is not greater than 25W/cm ² . It can be understood that the power density of the heating film 4 to the bottom wall 1 of the kettle is inversely proportional to the coverage area of the heating film 4 on the bottom surface of the bottom wall 1 of the kettle, that is, the larger the area of the heating film 4 arranged on the bottom surface of the bottom wall 1 of the kettle, The smaller the power density of the heating film 4 for the bottom wall 1 of the pot is, the smaller the degree of superheat of the top surface of the bottom wall 1 of the pot is, which is more conducive to noise reduction.

Wherein, in order to make the heating film more evenly pass through the bottom wall 1 of the kettle to heat the liquid in the kettle, the heating film 4 should be concentrically arranged on the bottom surface of the bottom wall 1 of the kettle, or the heating film 4 should be concentrically arranged on the bottom surface of the bottom wall 1 of the kettle. Symmetrical arrangement. Specifically, the heating film disposed on the bottom surface of the circular kettle bottom wall 1 can be in various appropriate shapes, such as a disk shape, a square shape or a ring shape (see FIGS. 8 to 10 ). Of course, the heating film attached to the bottom surface of the bottom wall 1 of the pot can also be designed to have a notch shape, such as a linear incision is also formed in a disc-shaped, square-shaped or annular electric heating film (see Fig. 11A to Fig. 11F ), annular notches (see FIGS. 12A to 12C ) or back-shaped notches (see FIGS. 13A to 13C ), which will not be repeated here.

Specifically, the heating film 4 arranged below the bottom wall 1 of the kettle can be an electrothermal film (ie, an infrared heating film 4 ) or a thick film attached to the bottom surface of the bottom wall 1 of the kettle, or can be a heating film arranged under the bottom wall 1 of the kettle. The coil plate or the PTC heating sheet can certainly also be other heating elements with a larger thermal contact area with the kettle bottom wall 1 . Among them, in order to prevent the charged electrothermal film or thick film from contacting other parts in the kettle, the electricity in the electrothermal film or thick film is guided to the shell 5 of the electric kettle, causing electric shock or electric shock to the user. Refer to Figure 2 And Fig. 3, cover insulating layer 9 outside electrothermal film or thick film. Similarly, the outside of the PTC heating sheet is also covered with an insulating layer 9 . Among them, the insulating material covering the electric heating film, thick film or PTC heating sheet can be selected from high temperature resistant and insulating materials such as ceramics and glass ceramics.

In addition, in order to make the bottom wall 1 of the pot more evenly heated and further reduce the superheat degree of the top surface of the bottom wall 1 of the pot, referring to Fig. 14 and Fig. 15 , between the bottom wall 1 of the pot and the heating film 4, there is a thermal conductivity not greater than 60W. The low thermal conductivity material plate 10 of /m.k is set in such a way that the heat of the heating film is first conducted upwards to the bottom wall 1 of the pot through the low thermal conductivity material plate 10, and then conducted upwards to the liquid in the pot through the bottom wall 1 of the pot. The thermal contact area The increase of the thickness of the kettle bottom wall 1 slows down the heat conduction along the thickness direction of the kettle bottom wall 1, and at the same time increases the lateral heating area of the kettle bottom wall 1, which is beneficial to the horizontal heating of the kettle bottom wall 1, so that the top surface of the kettle bottom wall 1 Reduced overheating contributes to noise reduction. Of course, the low thermal conductivity material plate 10 can be made of various suitable materials, such as 45# steel plate, 304 stainless steel plate, 430 stainless steel plate or high manganese steel plate, and its thermal conductivity should not be greater than 60W/m.k.

Wherein, the vertical projection area of the heating film 4 toward the bottom wall 1 of the kettle is located in the vertical projection area of the low thermal conductivity material plate 10 towards the bottom wall 1 of the kettle, that is, the outer peripheral edge of the low thermal conductivity material plate 10 should be aligned with or beyond the edge of the heating film 4 outer perimeter. Further, the radial width of the outer peripheral edge of the low thermal conductivity material plate 10 beyond the outer peripheral edge of the heating film 4 is not greater than 10 mm. Specifically, the smaller the radial width value of the outer peripheral edge of the low thermal conductivity material plate 10 exceeding the outer peripheral edge of the heating film 4, the larger the area of the heating film 4 arranged on the bottom wall 1 of the kettle, and the larger the area of the heating film 4 of the bottom wall 1 of the kettle. The less superheat the top surface is, the better it is for noise reduction.

Specifically, the thickness of the low thermal conductivity material plate 10 should be not less than 0.5mm and not more than 5mm. Further, the thickness of the low thermal conductivity material plate 10 should be no less than 0.5 mm and no more than 1 mm, but it is not limited thereto. It can be understood that the thicker the low thermal conductivity material plate 10 is, the smaller the heat flux density of the bottom wall 1 of the pot is, and accordingly the superheat degree of the top surface of the bottom wall 1 of the pot is also smaller, which is more conducive to noise reduction, but the production cost But it also increased.

The present invention is described in detail below with three preferred embodiments.

In the first preferred embodiment shown in Figure 8, a disc-shaped electrothermal film is provided on the bottom surface of the bottom wall 1 of the electric kettle, and the area of the electrothermal film is equal to the area of the bottom wall 1 of the kettle. The ratio is 4/5, and the electrothermal film is also covered with a ceramic layer (that is, the insulating layer 9). Of course, a low thermal conductivity material plate 10 (such as a high manganese steel plate) can also be set between the kettle bottom wall 1 and the electrothermal film, so as to slow down the heat conduction along the thickness direction of the kettle bottom wall 1 and make the top surface of the kettle bottom wall 1 Reduced superheat.

In the second preferred embodiment as shown in Figure 9, a box-shaped electrothermal film is provided on the bottom surface of the bottom wall 1 of the electric kettle, and the ratio of the area of the electrothermal film to the area of the bottom wall 1 of the kettle is is 3/5, and the electrothermal film is covered with a glass-ceramic layer (that is, the insulating layer 9). Of course, a low thermal conductivity material plate 10 (such as a high manganese steel plate) can also be set between the kettle bottom wall 1 and the electrothermal film, so as to slow down the heat conduction along the thickness direction of the kettle bottom wall 1 and make the top surface of the kettle bottom wall 1 Reduced superheat.

In the third preferred embodiment shown in Figure 10, an annular thick film is arranged on the bottom surface of the bottom wall 1 of the electric kettle, and the ratio of the area of the electrothermal film to the area of the bottom wall 1 of the electric kettle is 7/10, the electrothermal film is also covered with a ceramic layer (that is, the insulating layer 9). Of course, a low thermal conductivity material plate 10 (such as a high manganese steel plate) can also be set between the kettle bottom wall 1 and the electrothermal film, so as to slow down the heat conduction along the thickness direction of the kettle bottom wall 1 and make the top surface of the kettle bottom wall 1 Reduced superheat.

In the process of heating the liquid in the kettle, the electric kettles of the above three embodiments are provided with a larger electric heating film or thick film on the bottom surface of the bottom wall 1 of the kettle (that is, the ratio of the area of the bottom wall 1 to the kettle bottom wall 1 is between The heating film 4) between 3/5 and 1 increases the thermal contact area between the heating element arranged on the bottom surface of the kettle bottom wall 1 and the kettle bottom wall 1, which is beneficial to reduce the degree of superheat of the kettle bottom wall 1, thereby The frequency at which the bubbles leave the bottom wall 1 of the pot is reduced to achieve a significant noise reduction effect.

Specific embodiment 1: adopt the electric kettle structure shown in Fig. 8, promptly be provided with the electrothermal film that is disc shape on the bottom surface of the pot bottom wall 1 of electric kettle, and also be covered with ceramic layer outside this electrothermal film (namely insulating layer 9). Among them, the heating power of the electric heating film is 1800W, and the water volume in the pot is 1.7L.

Test steps:

1) The water volume of the highest water level in the pot;

2) The temperature sensor is placed in the middle of the water level in the center of the kettle;

3) Press the "Start" button to start timing measurement;

4) When the water temperature in the pot rises to 80°C, stop the timing measurement;

5) Eliminate the noise value with sound power value ≤ 45dB, carry out A-weighting on the test noise value, and take the average sound power as the judgment value.

Under different ratios of the area of the electric heating film to the area of the bottom wall 1 of the kettle, the power density data of the electric heating film on the bottom wall 1 of the kettle and the noise data of the electric kettle during operation are shown in Table 1 below.

Table 1: Power density and noise data table under different area ratios

Comparative Example 1: The structure of the electric kettle shown in FIG. 4 is adopted, and the electric heating tube 8 is coiled and installed on the bottom surface of the bottom wall 1 of the kettle. In addition, other experimental parameters are consistent with those in Example 1.

Test results: the maximum sound power value of the electric kettle is 68.1dB, the average sound power value is 64.8dB, and the power density of the electric heating tube 8 to the bottom wall 1 of the kettle is 91.7W/cm ² .

Comparing Example 1 and Comparative Example 1, it can be seen that, compared with setting the electric heating tube 8 on the bottom surface of the bottom wall 1 of the pot, an electric heating film with a ratio of not less than 3/5 of the area of the bottom wall 1 of the pot is arranged on the bottom surface of the bottom wall 1 of the pot The electric kettle, the power density of the electric heating film to the bottom wall 1 of the kettle is far less than 91.7W/cm ² , and its maximum sound power value is also significantly less than 68.1dB, and the average sound power value is also less than 64.8dB, and the noise reduction effect is obvious . Wherein, when the ratio of the area of the electric heating film to the area of the bottom wall 1 of the kettle is 3/5, the power density of the electric heating film to the bottom wall 1 of the kettle is less than 30W/cm ² , and the noise value emitted by the electric kettle during operation is at a lower level than that of the user. Acceptable range (that is, the average sound power value is less than 60dB, and the maximum sound power value is less than 62dB). In addition, the larger the ratio of the area of the electric heating film to the area of the bottom wall 1 of the kettle, the smaller the corresponding power density of the electric heating film to the bottom wall 1 of the kettle, and the noise value emitted by the electric kettle during operation is also reduced accordingly. It is also more conducive to noise reduction; but the larger the ratio of the area, the larger the area of the electric heating film required for the same area of the kettle bottom wall 1, and the corresponding electric heating required for the production of the electric kettle The cost of the film is also higher, therefore, in order to balance the influence of the area of the electric heating film to the area of the bottom wall 1 of the electric kettle on the noise and the production cost of the electric kettle, the area of the electric heating film and the bottom wall of the kettle 1 The area ratio of is preferably not less than 7/10 and not more than 9/10.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (10)

1. a kind of insulating pot, which is characterized in that the insulating pot includes bottom of the pot wall (1) and heating film (4), the heating film (4) It is arranged in the bottom surface of the bottom of the pot wall (1), the area of the heating film (4) and the area ratio of the bottom of the pot wall (1) are not less than 3/5, the heating film (4) is not more than 30W/cm for the power density of the bottom of the pot wall (1)²。

2. insulating pot according to claim 1, which is characterized in that the area of the heating film (4) and the bottom of the pot wall (1) Area ratio not less than 7/10 and be not more than 9/10, the heating film (4) is little for the power density of the bottom of the pot wall (1) In 25W/cm²。

3. insulating pot according to claim 1, which is characterized in that the heating film (4) is concentrically disposed in the bottom of the pot wall (1) bottom surface, alternatively, the heating film (4) is arranged symmetrically relative to the bottom center of the bottom of the pot wall (1).

4. insulating pot according to claim 3, which is characterized in that the bottom of the pot wall (1) is circular bottom wall, the heating film (4) in disk form, square frame-shaped is circular layout in the bottom surface of the bottom of the pot wall (1).

5. insulating pot according to claim 4, which is characterized in that the heating film (4) of disc, square frame-shaped or annular In be also formed with linear, annular or back-shaped notch.

6. insulating pot according to claim 1, which is characterized in that the heating film (4) is Electric radiant Heating Film or thick film, the electric heating It is covered with insulating layer (9) outside film or thick film.

7. insulating pot according to claim 1, which is characterized in that the insulating pot also contains thermal coefficient and is not more than 60W/ The low thermal conductivity plate of material (10) of m.k, the low thermal conductivity plate of material (10) are located at the bottom of the pot wall (1) and the heating film (4) between.

8. insulating pot according to claim 7, which is characterized in that the heating film (4) is hung down towards the bottom of the pot wall (1) Straight view field is located at the low thermal conductivity plate of material (10) towards in the upright projection region of the bottom of the pot wall (1).

9. insulating pot according to claim 7, which is characterized in that the thickness of the low thermal conductivity plate of material (10) is not small In 0.5mm and it is not more than 5mm.

10. insulating pot according to claim 7, which is characterized in that the low thermal conductivity plate of material (10) is 45# steel Plate, 304 stainless steel plates, 430 stainless steel plates or high manganese steel sheet.