CN113208415A

CN113208415A - Steam cooking device

Info

Publication number: CN113208415A
Application number: CN202010080806.1A
Authority: CN
Inventors: 张家齐; 洪兆宇
Original assignee: Team Young Technology Co Ltd
Current assignee: Team Young Technology Co Ltd
Priority date: 2020-02-05
Filing date: 2020-02-05
Publication date: 2021-08-06

Abstract

The invention provides a steam cooking device, comprising a pressure-accumulating steam boiler and a steam box. The pressure accumulation type steam boiler is used for heating liquid water and accumulating steam with the pressure of 1.1-5.0 atmospheres; the steam box is used for receiving steam from the pressure accumulation type steam boiler so as to cook food materials contained in the steam box. In addition, the electric heating conversion element in the pressure storage steam boiler ensures that the power consumption required by the food material containing chamber in the steam box is WH1 when the temperature is raised from room temperature to cooking temperature; the capacity of the food material containing chamber in the steaming box is V1, and the steam cooking device meets the condition that V1/WH1 is more than or equal to 160. Furthermore, the cooking temperature is between 101 ℃ and 150 ℃ and is lower than or equal to the temperature when the steam is output to the pressure accumulating type steam boiler.

Description

Steam cooking device

Technical Field

The present invention relates to a steam cooking device, and more particularly, to a steam cooking device for shortening cooking time of food materials.

Background

The reason is explored because the heating device in the cooking device is used for heating the food materials which are just opposite to the heating plate or the superheated gas nozzle are far higher in heat quantity to other parts during the heating period, so that the problems of local drying/coking and uneven heating of the food materials are caused, and the quality of the food materials cannot be effectively controlled.

In order to solve the problems, the power of the heating plate or the gas output of the superheated gas can be reduced selectively to slow down the temperature rise speed of the furnace chamber, so that the temperature of the furnace chamber is more uniform. However, in the case of fish meat, if the food material is placed in an environment with a low temperature rise rate for cooking, the meat quality of the food material is aged and hardened by the process of the fish meat becoming mature in the environment with a relatively low temperature and a long cooking time. Furthermore, considering the continuous variation of the ambient temperature in the oven cavity and the relationship of different degrees of influence of different food materials at different temperatures, the variation of the food materials during the period from the temperature rise of the oven cavity to the cooking temperature is difficult to grasp and control. In order to ensure that the food material is cooked thoroughly, consumers usually need a long cooking time, which causes the problem that the food material is too old and hard.

In order to solve the problem that the cooking quality of the food material is not ideal due to the fact that the heating degree of the food material cannot be accurately controlled due to the excessively long heating time, it is widely known to first "preheat" the oven cavity. The term "preheating" of the furnace chamber means that the furnace chamber is heated for a certain time before the food material is placed in the furnace chamber, and the furnace door is opened to place the food material after the temperature of the furnace chamber reaches the cooking temperature. Therefore, the food can be cooked from the environment close to the cooking temperature to minimize the influence of the food on the heating period of the oven cavity, but the step of the preheating procedure is relatively complicated and inconvenient for users, and even if the oven cavity is preheated to reduce the influence of the heating period, the existing cooking mode is mainly carried out by using a stuffy cooking mode of temperature diffusion, the actual cooking speed is slow, so the whole cooking time is still too long, the problem that the food is easy to be over-aged and over-hard is not solved, and the better food cooking effect cannot be obtained.

In summary, if the oven cavity is rapidly heated by a high power means, the problems of drying/coking of the surface of the food material or uneven heating of the food material are easily caused; if the furnace chamber is heated with lower power, the cooking effect of the food materials is difficult to control accurately due to longer cooking time, and the food materials are often too old and too hard; if the cavity is "preheated", the steps are complicated except for the long preheating waiting time, which is easy to cause confusion and inconvenience for users. At present, a cooking device which can overcome the above problems at the same time is not available.

For example, chinese patent No. CN202681613U discloses an energy-saving circulation type food steamer, which focuses on the circulation of water vapor and energy saving, and uses an air extractor as kinetic energy. The devices heat water to generate steam, and then contact the steam with the food materials by utilizing micro-pressure difference and heat convection, so that heat energy in the steam is transferred to the food materials.

However, in this type of apparatus, the gaseous water vapor in the vapor is easily transformed into liquid water molecules by collision or contact with a lower temperature environment during the transportation process, so the vapor includes a large amount of liquid water molecules after latent heat is released, and the vapor rich in liquid water molecules is likely to form a liquid water film on the surface of the food material when contacting the food material, and the liquid water film may interfere with the subsequent contact of the vapor with the surface of the food material, thereby reducing the heating efficiency of the food material, and the cooking speed cannot be increased, and at the same time, the heating degree of the food material cannot meet the expectation, and the cooking time is too long, so that the cooked food material is too old and too hard.

Another steam cooking device is a device with high-temperature steam cooking function, such as a water wave oven, and usually includes two functions of pure steaming and superheated steam baking. The known pure steaming function of the wave water boiler of each brand is that after steam is generated by a normal pressure (1 atmospheric pressure) steam boiler, the steam is directly conveyed to a normal pressure furnace chamber to cook food materials, and the situation of the wave water boiler is the same as that of the energy-saving circulating steamer, because the steam temperature is low, the surface of the food materials is easily coated by a liquid water film, and the cooking effect of the food materials cannot meet the expected problem. On the other hand, in the superheated Steam cooking function, after Steam is generated, Steam is further heated by means of a heating pipe, a heating plate, microwave heating or the like while being conveyed to or after entering the cavity, so that the Steam becomes superheated Steam (superheated Steam), thereby achieving the phenomena of heating the surface of the food material and evaporating and drying the surface moisture, and the cooking effect of the food material tends to a dry cooking effect rather than an unexpected moist, soft and tender cooking result, for example, U.S. Pat. No. US20070227364a1, "Steam cookie", which achieves the purpose of "cooking" by means of superheated Steam.

However, the steam is heated to a temperature above the saturated steam point by a device such as a wave oven to become superheated steam, the applied superheated steam temperature is usually above 200 ℃, and when contacting the surface of the food material, the steam can quickly evaporate the moisture on the surface of the food material, so that the skin is dried and even coked, which leads to the aforementioned problem of drying/coking of the food material.

Furthermore, some techniques use a high pressure steam oven to provide steam with multiple atmospheric pressure (e.g. 10 times) for cooking, however, the multiple atmospheric pressure is higher than the atmospheric pressure within 2 times of the normal pressure cooker for cooking, which is not only safe but also the cost is greatly increased due to the safety requirement, which is not favorable for product pricing.

Moreover, many cooking devices in the market facilitate cooking, the functions of cooking multiple dishes in a single time are called, the capacity of the oven chamber becomes a main reference basis for purchasing, and the capacity of the oven chamber is gradually increased due to the requirement of convenience for cooking multiple dishes simultaneously.

Therefore, in summary, in the prior art, a cooking device that can quickly cook and finish multiple colors of dishes in a short time without preheating, high temperature and special increase of the space of the food accommodating chamber, and can accurately control the heating degree and cooking effect of food materials is not available, so that the cooking result of the food materials can be accurately reproduced and controlled. The present invention has been made to solve the above problems.

Disclosure of Invention

In view of the foregoing problems, an embodiment of the present invention provides a steam cooking device, which can quickly cook a plurality of food colors in a short time without preheating, high temperature, or particularly increasing the space of a food container, and can precisely control the heating degree and cooking effect of food, so that the cooking result of food can be precisely reproduced and controlled.

Different from the design of the prior art that a high-power heating plate or high-temperature superheated gas is used for rapidly heating the food material containing chamber, the steam cooking device disclosed by the invention heats the food material by high-pressure latent heat-containing steam, but avoids the risk that the food material is dried/coked by the superheated steam or the heating plate, and has the advantages that the saturated steam temperature of the high-pressure steam is higher, the spraying speed is higher, when the high-pressure steam enters the food material containing chamber close to the normal pressure, the steam can rapidly fill and heat the furnace chamber of the steam box, and the heating speed of the food material containing chamber in the furnace chamber is maximized. In one embodiment of the present invention, the preheating process can be omitted, and the problems of drying and coking of the food material caused by high-temperature heating and poor cooking of the food material caused by slow heating or poor heating efficiency can be solved.

More specifically, in one embodiment of the present invention, the steam cooking device includes an accumulator steam boiler and a steam box. The pressure accumulating type steam boiler can be used for heating liquid water and accumulating saturated steam with the pressure of 1.1-5.0 atmosphere in the liquid water, the temperature of the steam in the pressure accumulating type steam boiler is not lower than the normal pressure saturated steam temperature, and the saturated steam temperature and the steam pressure in the pressure accumulating type steam boiler are mutually corresponding. In a preferred embodiment, the temperature of the steam accumulated in the pressure accumulating type steam boiler is between 110 ℃ and 130 ℃. In addition, the pressure accumulation type steam boiler comprises a heating kettle for storing liquid water and accumulating steam; and the electric heating conversion element is arranged in the heating kettle and is used for heating the liquid water and generating steam. The steam box is connected with the pressure accumulation type steam boiler and used for receiving steam from the pressure accumulation type steam boiler to cook food materials contained in the steam box, and the steam box comprises a food material containing chamber for containing the food materials and a steam spraying device. And the steam spraying device is connected with the food material accommodating chamber and the heating kettle and is used for inputting the steam from the heating kettle into the food material accommodating chamber. In addition, since the electric power consumption of the electrothermal conversion element is WH1 kW hours from the start of steam input to the food material containing chamber having a capacity of V1 liters and a room temperature until the food material containing chamber is heated to a cooking temperature by steam, the steam cooking device in one embodiment of the present invention can raise the temperature in the food material containing chamber having the food material from the room temperature by steam and maintain the cooking temperature at more than 100 ℃ when V1/WH1 is equal to or greater than 160, and the time required for warming the food material containing chamber can be effectively shortened. The cooking temperature is between 101 ℃ and 150 ℃ and is lower than or equal to the temperature when the steam is output from the heating kettle. In summary, by applying the high-pressure saturated steam, the large-capacity food material containing chamber can be effectively and quickly heated in a short time under the condition that the power consumption of the electric-heat conversion element is limited, so that the food material is quickly heated, the cooking time of the food material is effectively shortened, and the food material can achieve the expected wet, soft and tender taste.

In addition, the electrothermal conversion element adopted in one example of the invention can make the time required for raising the temperature in the food material accommodating chamber from the room temperature to the cooking temperature less than or equal to 5 minutes, and can also effectively reduce the cooking time of the food material.

In addition, in one example of the present invention, the difference between the temperature of the steam sprayed by the steam spraying device and the saturated steam temperature in the pressure accumulation type steam boiler is not more than 30 ℃; furthermore, the cooking temperature of the food material containing chamber is set between 101 ℃ and 110 ℃.

In addition, in one embodiment of the present invention, the movable element disposed in the steam box is used to reduce the space of the food material accommodating chamber, thereby shortening the time for filling the food material accommodating chamber with steam, and effectively shortening the time required for heating the food material accommodating chamber to the cooking temperature.

In one embodiment of the present invention, the apparatus includes a liquid level sensor disposed in the heating kettle, a water replenishing device connected to the heating kettle and the water source, and a control module connected to the liquid level sensor and the water source. The liquid level sensor is used for measuring the liquid level in the heating kettle and outputting a water level signal when the liquid level in the heating kettle is lower than a preset height; the water supplementing device is used for inputting liquid water from a water source into the heating kettle; the control module is used for controlling the on/off state of the water supplementing device according to the water level signal, and liquid water with a preset water supplementing amount is input into the heating kettle. Thereby preventing the liquid water in the pressure accumulating steam boiler from being burnt to dry and interrupting the air supply.

Based on the previous design, another object of one embodiment of the present invention is to design the water supplement amount by the rated power of the electrothermal conversion element, so as to effectively reduce the temperature reduction effect of liquid water and steam in the heating kettle during water supplement, so as to maintain stable steam supply and maintain the expected cooking effect, the water supplement amount of the steam cooking device of one embodiment of the present invention is designed to meet the condition that V2/W1 is less than or equal to 0.1, and the effect is better, wherein V2 refers to the preset water supplement amount, and the unit is liters, and W1 is the rated power of the electrothermal conversion element, and the unit is kilowatts.

Based on the same principle as the above, another object of the present invention is to increase the heating rate of liquid water to saturated vapor temperature and reduce the time required for heating liquid water by reducing the amount of liquid water stored in the heating kettle under the same rated power of the electrothermal conversion element. When the capacity of the heating kettle at the preset height is V4 liters, the rated power of the electric heating conversion element is W1 kilowatts, the capacity design of the steam cooking device at the preset height of the invention meets the condition that V4/W1 is less than or equal to 0.3, the time for heating the liquid water in the heating kettle to the saturated steam temperature is shorter under the condition, the time for generating steam is also shorter, and the time required by a steam gas storage program is reduced so as to shorten the time required by the whole cooking process.

Based on the same principle as described above, another object of one example of the present invention is to reduce the temperature drop of liquid water in a heating kettle due to a replenishing water and maintain the quality and continuity of steam output by controlling the ratio of a predetermined replenishing water amount (as described above, V2) added to the heating kettle and the maximum capacity (expressed as V3, in liters) of the heating kettle in a replenishing water program to satisfy the condition of V2/V3 ≦ 0.1.

In another example of the present invention, a design is provided in which the control module controls the starting time of the water replenishing device to be a fixed time or the amount of water replenished each time is a fixed amount, so that the control system can be effectively simplified and the cost can be reduced.

In another example of the present invention, the electrothermal converting element includes a resistor, the whole of the resistor is set below the predetermined height corresponding to the liquid level sensor, and the resistor can generate heat when current passes through it; because the water level can be supplemented when reaching the preset height, the liquid level can not be obviously lower than the preset height, and by means of the design, the whole heating part of the electric heating conversion element can be submerged under the liquid level, the heating efficiency is maximized, the time required by the steam gas storage procedure is shortened, and the time required by the whole cooking process is further shortened.

In one embodiment of the present invention, the steam cooking device may provide at least one or two preparation modes. More specifically, the steam cooking device may include a control module connected to the electric heat conversion element. The steam cooking device comprises at least one of a first preparation mode and a second preparation mode, and when in the first preparation mode, the control module controls the electric heating conversion element to heat and maintain the liquid water in the heating kettle at a preparation temperature which is lower than the saturated steam temperature in the heating kettle; in the second preparation mode, the control device controls the electric heat conversion element to heat the liquid water and enables the heating kettle to accumulate saturated vapor between 1.1 and 5.0 atmospheric pressure. The whole cooking time can be effectively shortened by preheating and maintaining the liquid water at high temperature or generating steam for standby before the liquid water is needed.

In summary, in one embodiment of the present invention, the steam cooking device utilizes the pressure accumulating steam boiler to provide high-pressure steam, so that the high-temperature steam can quickly fill the food material accommodating chamber, thereby greatly shortening the time required for heating the food material in the early stage, omitting the preheating process, and avoiding the problem of drying/coking of the food material caused by high-temperature heating. Meanwhile, in one embodiment of the present invention, saturated steam is supplied to the food material accommodating chamber by the pressure accumulation type steam boiler, and the food material is allowed to be heated by latent heat released rapidly, so that the cooking time of the food material is shortened maximally, and the food material can keep moist, soft and tender mouthfeel. Solves the problems that the whole cooking time is too long and the quality of the hard and astringent food materials is not good due to the slow heating.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below. However, it should be understood and appreciated that the specific details disclosed herein, and specific examples thereof, are set forth for purposes of illustration only and are not intended to limit the scope of the invention.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

FIG. 1 is a functional block diagram of a steam cooking device according to one embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating the relative positions of various components and the flow of water paths in a steam cooking device according to one embodiment of the present invention;

FIG. 3 illustrates a schematic cross-sectional view of an accumulator steam boiler in accordance with an embodiment of the present invention;

fig. 4 illustrates a cross-sectional view of a steam box according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

One of the important points of the present invention is to provide a steam cooking device, which utilizes an accumulator steam boiler to provide high-pressure steam, so as to quickly fill a food material accommodating chamber with high-temperature steam, thereby greatly shortening the time required for food material heating in the early stage, omitting a preheating process, and avoiding the problem of drying/coking of the food material due to high-temperature heating. Meanwhile, in one embodiment of the present invention, saturated steam is supplied to the food material accommodating chamber by the pressure accumulation type steam boiler, so that the food material is allowed to be heated by latent heat released rapidly, the cooking time of the food material is shortened maximally, and the food material can keep moist, soft and tender mouthfeel. Solves the problems that the whole cooking time is too long and the quality of the hard and astringent food materials is not good due to the slow heating.

In addition, compared with the design direction that the cooking chamber is larger and better in the market, in one example of the invention, the maximum capacity of the food material accommodating chamber is designed according to the power of the electric heating conversion element in the pressure storage type steam boiler and the time for reaching the cooking temperature, so that the temperature rising rate can be obviously improved, the negative influence on the food material in the temperature rising period of the food material accommodating chamber is reduced, and the cooking quality is further improved.

In summary, the steam cooking device provided in one example of the present invention has the advantages of fast cooking in a short time without preheating, high temperature, and particularly enlarging the space of the food material accommodating chamber, and precisely controlling the heating degree and cooking effect of the food material, so that the cooking result of the food material can be precisely reproduced and controlled.

The following description of the preferred embodiments of the present invention will be made with reference to the accompanying drawings. The components, dimensions and appearance of the steam cooking device in the drawings are merely illustrative of the features of the present invention and are not intended to limit the invention.

Referring to fig. 1 to 4, fig. 1 is a functional block diagram of a steam cooking device according to an embodiment of the present invention; FIG. 2 is a schematic diagram illustrating the relative positions of the components and the flow direction of the water paths of the steam cooking device according to one embodiment of the present invention; FIG. 3 illustrates a cross-sectional view of an embodiment of the present invention; fig. 4 illustrates a cross-sectional view of the steam box according to an embodiment of the present invention.

First, the steam cooking device 1 of the present invention generally refers to any device that consumes electric energy to generate steam S and uses the steam S to cook food material F. The steam cooking device 1 of the present invention can be used independently in an electric steaming oven, or can be combined with other heating means (such as microwave/electric heating conversion elements, heating plates, etc.) and then used in a multifunctional water wave oven, etc.

Before describing the operation of the present invention, the physical design of the steam cooking device 1 will be described. In this embodiment, the steam cooking device 1 is an electric steaming oven, and the food material chamber 22C does not need to have microwave heating or hot plate heating function. Please refer to fig. 1 and fig. 2 together. As can be seen, the steam cooking device 1 at least comprises a pressure accumulating steam boiler 10, a steam box 20, a water supply module 30, a control module 40, a casing 50 (casting), a door 60 and a water collecting tank 80. In which, the components such as power supply, etc. which are not the key points of the present invention are properly omitted, only the application should be compensated.

As can be seen from fig. 2, the water supply module 30 can be used to store and provide liquid water L to the accumulator steam boiler 10; the accumulator steam boiler 10 may be used to heat the liquid water L and generate steam S to be supplied to the steam box 20; the steam box 20 can be used to heat and cook the food material F using the steam S supplied from the accumulator steam boiler 10. The control module 40 can be used to control the water supply module 30, the accumulator-type steam boiler 10, and the electrical control components of the steam box 20 to complete the cooking process. And the housing 50 may be used to receive and fix the relative positions of the upper and lower components. The oven door 60 can be used to close the lateral opening 50A of the housing 50. The water collection sump 80 may be used to collect the vapor S discharged from the steam box 20 and store it in a liquid water state. The specific design of the steam cooking device 1 of the embodiment of the invention will be illustrated below.

Referring to fig. 2, it can be seen that the front of the housing 50 has a lateral opening 50A communicating with the central hollow portion thereof and one or more notches 53 for allowing components such as water pipes, electrical wires, etc. to pass through the interior of the housing 50. The front side surface of the housing 50 is provided with an interactive interface 51 for interaction with a user. The interactive interface 51 may include various known input-output devices (input-output devices). The door 60 is pivoted at an edge of a front side surface of the case 50 to rotate with respect to the case 50 to allow or prohibit communication between the inside of the steam box 20 and the outside.

Referring to fig. 2, the water supply module 30 includes a water source, a water replenishing device 32 and a water supply pipe PW. In this example, the water source is a water storage tank 31, and the water storage tank 31 generally refers to a container for containing liquid water L. The water storage tank 31 is provided with a water supply passage 31B communicating the inside and outside of the water storage tank 31. The water supply passage 31B is connected to the accumulator steam boiler 10 via a water supply pipe PW. A water replenishing device 32 is provided between the water supply pipe PW and the pressure accumulating type steam boiler 10 for supplying water in the water storage tank 31 to the pressure accumulating type steam boiler 10. On the other hand, a heat exchanger 312 may be disposed in the water storage tank 31, and the heat exchanger 312 is, for example, a hollow copper pipe in a three-dimensional spiral shape, and an inlet and an outlet thereof are respectively connected to the food material chamber 22C and the water collection tank 80 through a pipeline. The heat exchanger 312 and the pipeline thereof do not exchange with the water storage tank 31, on the contrary, the heat of the steam discharged from the food material chamber 22C can be effectively transferred to the liquid water in the water storage tank through the heat exchanger 312, and the temperature thereof is raised, thereby recovering the heat energy of the steam to a certain extent.

The water replenishing device 32 is a device for supplying liquid water L to the accumulator steam boiler 10, which is connected between a water source and the accumulator steam boiler 10. For example, the water replenishing device 32 may be a device for providing pressure to the liquid water L, such as a water pump, an electromagnetic pump, a dc motor, etc., but not limited thereto, the water replenishing device 32 may also be a component with flow control capability. For example, when the water source is a sufficient pressure device such as a tap water pipe, the water replenishing device 32 may be a device that can only use an electric valve or a device that can control a water meter and cannot provide a pressurizing function. In this embodiment, the water replenishing device 32 is an electromagnetic pump having only one-way water supply capability, and the electromagnetic pump used in this embodiment allows the liquid water L to enter and be pressurized to a pressure higher than the predetermined pressure accumulation pressure of the pressure accumulation type steam boiler 10 and then output, so that the liquid water L does not enter the heating kettle 12 due to the high pressure in the pressure accumulation type steam boiler 10.

Referring to FIG. 3, FIG. 3 shows a schematic view of a pressure accumulating steam boiler 10 in an embodiment of the present invention. The accumulator-type steam boiler 10 can internally generate and safely accumulate high-temperature steam S of several times atmospheric pressure or less. In this embodiment, the pressure accumulation type steam boiler 10 mainly includes a heating kettle 12, a liquid level sensor 13, a pressure release valve 14, a vacuum breaking valve 15, an electric heat conversion element 16, a physical parameter sensing module 17, an electronic steam valve 18, and other main components. In this embodiment, the outer walls of the above elements and the pipeline connecting the above elements can be selectively wrapped with a thermal insulation layer 70 to reduce the heat dissipation, and since the pressure accumulating steam boiler 10 in this embodiment does not provide 200-350 ℃ superheated steam S as in the prior art, a thermal insulation material with lower cost and melting point, such as polystyrene (melting point about 240 ℃), can be used as the main component of the thermal insulation layer, but the invention is not limited thereto.

The heating kettle 12 (also called as a steam chamber) has a containing space for storing liquid water L and steam S therein. The heating kettle 12 is required to be resistant to high pressure, which is greater than or equal to 1.1 times atmospheric pressure. While the maximum internal safety pressure that the heating still 12 can be loaded to is 10 times, 5 times, 4 times, 2 times or less atmospheric pressure, respectively, has good, excellent, better and better cost advantages. For example, the heating kettle 12 in this embodiment is a cylindrical closed steam boiler made of steel, the diameter of the circle is about 104 mm, the height is 150 mm, and the maximum working pressure is 5 times atmospheric pressure, but not limited to the above design. In addition, in application, the internal capacity of the heating kettle 12 of the present invention is not limited, and can be increased correspondingly with the increase of the power of the electrothermal conversion element 16, and vice versa. That is, the internal volume of the heating kettle 12 may be selectively designed to be 0.5 liter or less, 1 liter or less, 2 liter or less, 5 liter or less, 50 liter or less, 100 liter or less, 101 liter to 2000 liter, or the like, depending on the power of the electrothermal conversion element 16. For example, in this example, the electrothermal conversion element 16 is rated at about 1.5 kilowatts, while the heating vessel 12 of the accumulator steam boiler 10 has a capacity of about 1.155 liters.

As illustrated in fig. 3, in the present embodiment, the top surface of the heating kettle 12 is provided with a first port 12A, a second port 12B, a third port 12C, a fourth port 12D and a fifth port 12E. The first port 12A is a water inlet, connected to the water storage tank 31 by a water supply pipe PW, for receiving liquid water L; the second port 12B is an air outlet, and is connected to an electronic vapor valve 18 for outputting vapor S. The third interface 12C is used for fixedly arranging the liquid level sensor 13 and allowing the liquid level sensor to extend into the heating kettle 12 through the third interface 12C; the fourth interface 12D is used for fixing a pressure relief valve 14; the fifth port 12E is used for fixing a vacuum breaker 15. The bottom surface of the heating kettle 12 is provided with a plurality of sixth interfaces 12F for passing through electrodes of an electrothermal conversion element 16. The first port 12A, the second port 12B, the third port 12C, the fourth port 12D, the fifth port 12E and the sixth port 12F can be kept substantially watertight and airtight under the predetermined pressure accumulation environment of the heating kettle 12. For example, one example of each interface is a screw thread to match the film to achieve water and air tightness. The predetermined pressure accumulation means that the electrothermal conversion element 16 stops heating or reduces heating power after the pressure inside the heating kettle 12 reaches during the pressure accumulation period, so as to maintain the pressure inside the heating kettle 12 at a certain value, which is the predetermined pressure accumulation, and the corresponding saturated vapor temperature is called the predetermined pressure accumulation temperature. The effect is better when the temperature of the steam accumulated in the pressure accumulation type steam boiler is between 110 ℃ and 130 ℃. In this case, the predetermined pressure accumulation pressure is about 2 times atmospheric pressure, and the corresponding predetermined pressure accumulation temperature is about 120 ℃.

The liquid level sensor 13 (also referred to as a water level sensor, a water level meter or a liquid level meter) refers to an electronic device that can detect the height of the liquid level and output a corresponding signal. The liquid level sensor 13 can be in many forms, such as an electronic water level meter which detects the height of the water level by using a plurality of parallel exposed electrodes on a circuit board, or a liquid level electrode bar (also called an electrode liquid level meter, a steam boiler water level meter, an electrode probe) and the like. The liquid surface electrode rods can be of either a single-tube (monopolar) or multi-tube design (multipolar). The multi-tube liquid level electrode rod comprises a plurality of (for example, two, three, etc.) electrode rods with different lengths. The electrode rod mainly uses a conductive metal rod to measure the liquid level. When any point of the metal rod contacts the liquid surface, the electrode rod transmits a corresponding water level signal outwards to indicate that the metal rod is contacted with the liquid surface, and vice versa. In this case, the lowest sensing point 13A of the metal bar closest to the bottom of the heating kettle 12 is first in contact with the liquid surface. Therefore, the control module 40 can estimate the lower limit of the liquid level height according to the water level signal and the length of the corresponding electrode rod.

In this case, the liquid level sensor 13 is a single-pole liquid level electrode bar, which can detect whether the liquid level has reached its lowest sensing point. The level sensor 13 penetrates from the third port 12C of the top surface of the heating kettle 12 and extends toward the bottom surface of the heating kettle 12. The sensing point 13A at the lowermost end of the single-pole liquid level electrode rod is located at the end point of the electrode rod. In this example, the length of the level sensor 13 in the heating kettle 12 is slightly smaller than or equal to 114.5 mm, and after the installation, the distance between the sensing point 13A at the lowest end of the level sensor 13 and the bottom of the heating kettle 12 is about 35.5 mm. That is, when the liquid level is lower than and higher than 35.5 mm, the liquid level sensor 13 will output a corresponding water level signal indicating that the liquid level has not reached or has reached the minimum predetermined height H1, or simply the predetermined height or the water filling line. After being processed, the water level signal can be used as a warning for the over-low liquid level. While the length of the liquid level sensor 13 can be adjusted according to the desired liquid level, the invention is not limited to the above. In this example, the length or position of the level sensor 13 is a predetermined height H1 relative to the lower limit of the liquid level.

The pressure relief valve 14 (also called as a pressure relief safety valve) may be embedded at an interface of the heating kettle 12, so as to automatically allow the internal fluid (e.g. steam) to be output from the heating kettle 12 when the pressure in the heating kettle 12 is greater than the external air pressure by a preset value, so as to forcibly reduce the pressure in the heating kettle 12, thereby preventing the heating kettle 12 from being damaged due to an excessive internal pressure.

The electrothermal transducer 16 generally refers to each device, module or element that consumes electric energy and outputs thermal energy. For example, the electrothermal transducer 16 may be an electrothermal tube, an electrothermal sheet resistance heater, or the like. Taking the electrical heating tube as an example, the electrical heating tube can be an electrical heating tube with various shapes, such as a mosquito-repellent incense type electrical heating tube (or called a two-leg water barrel heating tube), a three-dimensional winding type electrical heating tube, or an electrical heating tube composed of a plurality of groups of electrical heating tubes which are arranged at the same plane height and are independent from each other, and the like, and all belong to feasible designs of the electrical heating conversion element 16. In this embodiment, the electrothermal converting element 16 is a flat, more specifically, a 110V, 15A mosquito coil type electrothermal tube with a power of about 1.5 kw, and occupies about 29 ml of volume in the heating kettle 12, and the mosquito coil type electrothermal tube has two electrodes and a heating portion mainly composed of a resistor. After the installation, the two electrodes are passed out of the heating kettle 12 through the two sixth ports 12F of the heating kettle 12, and the heating portion is disposed near the bottom of the heating kettle 12. The heat generating portion preferably has a space between the bottom of the heating kettle 12 and the heat generating portion, so that the liquid water L can enter and increase the space in contact with the liquid water L. Furthermore, when the electrothermal conversion element 16 is used, the heating portion is close to the liquid level of the heating kettle 12, but the whole body is submerged below the predetermined height of the liquid level or the liquid level sensor 13, so that the heating efficiency is better. In addition, as shown in the figure, the liquid level sensor 13 is preferably disposed close to the side wall of the heating kettle 12 so as to be vertically offset from the electrothermal conversion element 16, so as to reduce the possibility that bubbles adhere to the liquid level sensor 13 when the liquid water L boils, and thus the liquid level sensor 13 may misjudge the water level. If necessary, the liquid level sensor 13 may also be disposed right above the electrothermal conversion element 16, and the present invention does not limit this.

The vacuum breaker 15 (also called as a vacuum breaker or a vacuum breaker) may be fixed to the interface of the heating kettle 12, so as to automatically allow an external fluid (e.g. air) to enter the heating kettle 12 when the pressure in the heating kettle 12 is smaller than the external air pressure by a specific value, so as to forcibly raise the pressure in the heating kettle 12, thereby preventing the internal and external pressure difference inside the heating kettle 12 due to the cooling of the vapor S and the volume reduction, and preventing the heating kettle 12 from being damaged due to the pressure difference.

The physical parameter sensing module 17 refers to a sensor capable of sensing the temperature or air pressure of the environment where the sensor is located and outputting a signal correspondingly, such as an electronic thermometer or an electronic pressure gauge. In this embodiment, the physical parameter sensing module 17 includes an electronic manometer and an electronic thermometer, which are respectively disposed on the sidewall of the heating kettle 12 and electrically connected to the control module 40, and can be used for sensing the pressure and/or temperature of the vapor S or the liquid water L in the heating kettle 12 and outputting a corresponding physical parameter signal, such as a temperature signal and/or a pressure signal, to the control module 40. In addition, the physical parameter sensing module 17 is not limited to an independent component, and may be integrated into other components (such as the liquid level sensor 13, the pressure release valve 14, the vacuum breaking valve 15, the electronic vapor valve 18, and the like).

The electronic vapor valve 18 is a device, module or element that can be controlled by electronic signals to open or close and allow the vapor S to pass through. In this example, the electronic vapor valve 18 includes a motor and a ball valve, the motor drives the ball valve to rotate with a ball having a passageway in the center, the angle between the axis of the passageway in the center of the ball and the axis of the gas inlet passageway is referred to as the degree of opening. When the opening degree is maximum (90 degrees), the axis of the air inlet channel and the axis of the central channel of the ball body are approximately in a right angle and are not communicated, the ball valve is closed, and the steam S cannot circulate; conversely, when the opening degree is minimum (0 degree), the axis of the air inlet channel and the axis of the central channel of the ball body are substantially coaxial, and the ball valve is fully opened, so that steam can freely pass through. When needed, the opening degree can be freely adjusted in multiple stages according to needs. In this embodiment, the electronic steam valve 18 can be controlled by the electronic signal of the second control unit 44 in the control module 40 to adjust the opening degree thereof, so as to adjust the steam supply amount of the accumulator steam boiler 10 to the steam box 20. In this example, when the pressure and temperature of the pressure inside the heating kettle 12 is about 2 times atmospheric pressure and 120 ℃, and the opening degree of the electronic steam valve 18 is 60 degrees, 55 degrees, 50 degrees, 45 degrees, the cooking temperature of the steam box 20, also called steady-state temperature, of about 104, 107, 110, and 113 ℃ can be stably maintained. That is, the larger the opening (the smaller the opening), the higher the steady state temperature of the steam box 20, whereby the cooking temperature in the steam box 20 can be adjusted by adjusting the amount of air supplied to the electronic steam valve 18. The electronic vapor valve 18 is not limited to the multi-stage adjustment function with the upper ball opening valve, and the electronic vapor valve 18 with only full opening and full closing functions can be selected.

Referring to fig. 4, fig. 4 is a schematic diagram of a steam box 20 according to an embodiment of the present invention. The steam box 20 receives steam S from the accumulator steam boiler 10 to cook a food material F contained in the steam box 20. The steam box 20 mainly includes an inner box 22, a steam discharge device 24, and the like. In this embodiment, the outer wall of each of the above elements and the pipe connecting the above elements may be optionally wrapped with an insulation layer 70 to reduce the heat loss, and the design is not repeated as described above.

The inner case 22 is inserted from the lateral opening 50A of the outer case 50 and substantially fills the lateral opening 22A of the outer case 50. An accommodating space called as a cavity 22B is surrounded and defined inside the inner box 22, and the cavity 22B can be used for accommodating and cooking the food material F. The inner box 22 has a lateral opening 22A communicating with the accommodating space, and corresponds to the lateral opening 50A of the outer shell 50. When the oven door 60 is closed, the platform is smoothly attached to the inner side of the oven door 60, so that the oven cavity 22B is isolated from the external environment and the steam S is not easily leaked. In addition, the interior side walls of the inner box 22 may optionally be provided with a plurality of ribs 26 or corresponding members for carrying movable members 28 such as trays or partitions. The inner box 22 has a seventh port 22G and an eighth port 22H. The oven cavity 22B is connected to a gas pipe PS through a seventh port 22G, and the gas pipe PS is connected to the electronic steam valve 18 to input the steam S output from the electronic steam valve 18 into the inner box 22 through the seventh port 22G, i.e. the seventh port 22G is used as a gas inlet. And the seventh port 22G and the furnace chamber 22B inside the inner box 22 are connected via a steam blowing device 24. In addition, the furnace chamber 22B is connected to a water collection tank 80 through the eighth connection port 22H, and the steam S in the furnace chamber 22B can enter the exhaust pipe PE through the eighth connection port 22H and output out of the furnace chamber 22B, and can selectively release the heat energy to the liquid water L in the water tank through the heat exchanger 312 of the water storage tank 31 and then be guided to the water collection tank 80. The cavity 22B is defined as a food accommodating chamber 22C, which is a space inside the inner box 22 and is used for receiving steam S and cooking food material F.

A steam injection device 24, disposed between the seventh port 22G and the cavity 22B, for injecting steam S from the heating kettle 12 into the food material accommodating chamber 22C. The vapor injection device 24 may be a part of the inner wall of the inner box 22 having an opening, or may be a separate component disposed at the seventh port 22G, such as a perforated mesh or a nozzle. In this example, the vapor emitting device 24 is an opening in the inner box 22.

In this embodiment, the steam S can be freely discharged out of the furnace chamber 22B through the eighth port 22H and the exhaust pipe PE connected thereto, and the exhaust pipe PE does not need to be connected to the actuator. That is, a device such as a compressor or a fan is not connected. However, in another embodiment, an exhaust valve may be optionally disposed at the eighth port 22H. The exhaust valve is an electrically controlled fluid valve which can receive an electronic signal to switch the on and off states of the exhaust valve so as to allow and prohibit fluid to circulate through the exhaust valve. In another embodiment, the exhaust valve may be selectively provided with a driving device, such as a fan or a compressor, for actively exhausting the steam in the cavity 22B out of the cavity 22B and delivering the steam to a water collecting tank 80. In this embodiment, the exhaust pipe PE and the eighth connection port 22H are located on the upper surface of the inner box 22, and may be located on the bottom of the inner box 22 if necessary, which is not limited in the present invention.

Referring again to fig. 2, it can be seen that in this example, the water collection sump 80 is adapted to receive the vapor S from the exhaust pipe PE, which is cooled by the water storage tank 31. Optionally, a gap is left between the water collection tank 80 and the outer shell 50 for discharging the steam S, and the steam S can be cooled in the water collection tank 80 into liquid water L and stored therein as waste water to be discharged. The user may periodically withdraw the sump 80 from the housing 50, clean the waste water and insert it back.

Referring to fig. 1, the control module 40 refers to a device for controlling any of the aforementioned components. The control module 40 may include a plurality of control units, such as a first control unit 42 and a second control unit 44, each of which may be independent elements, such as operating independently in separate loops and not connected to each other. On the contrary, each control unit may be different components on a single circuit board or integrated into the same component, and the invention is not limited thereto. Furthermore, each control unit may be a digital or analog element or module, such as a central processing unit, an MCU, a single chip, or a PCL, which is capable of receiving a signal and outputting a corresponding signal after processing. The structure of the control unit is conventional, and therefore, will not be described in detail. In this embodiment, the first control unit 42, also called an automatic water replenishing unit, is electrically connected to the liquid level sensor 13 and the water replenishing device 32, and is configured to control the water replenishing device 32 to replenish the liquid water L to the heating kettle 12 according to the water level signal of the liquid level sensor 13. The second control unit 44, also called an air supply unit, is electrically connected to at least the interactive interface 51, the electrothermal conversion element 16, the physical parameter sensing module 17, and the electronic vapor valve 18, and is configured to control the electrothermal conversion element 16 to heat the liquid water and control the electronic vapor valve 18 to output the vapor according to the signal of the physical parameter sensing module 17.

The operation of the steam cooking device 1 will be described below. The steam cooking device 1 comprises a water injection mode, a standby mode, a gas storage mode, a cooking mode and a shutdown mode in sequence according to the using process.

The water filling mode is exemplified below. For example, when the steam cooking device 1 is powered on, the device can enter a water filling mode and execute a water filling procedure according to a user instruction or automatically. During the water filling process, the first control unit 42 determines whether the water level has reached a predetermined height H1 (also called a water filling line) according to the water level signal of the liquid level sensor 13, if so, it is not activated, otherwise, a water filling process is executed. In the water filling procedure, the first control unit 42 activates the water replenishing device 32 to fill the heating kettle 12 with the liquid water L from the water source through the first interface 12A located on the top surface of the heating kettle 12 until the liquid level reaches the predetermined height H1, and then further fills the predetermined amount of liquid water to raise the liquid level from the minimum predetermined height H1 to the maximum water replenishing height H2 (also called full water line). In this example, the predetermined water replenishing amount is a fixed amount, and for this reason, the activation time period of the water replenishing device 32 is fixed.

In this embodiment, the water source is the water storage tank 31, but the invention is not limited to the water storage tank 31, and the water source may be a tap water supply pipe if necessary, and the invention is not limited thereto. In addition, in this example, a water pump with an idle flow rate of about 500 ml/min is selected as the water replenishing device 32. However, the actual injection flow rate was about 439 ml per minute after considering various pressure losses. The idle flow rate of the water replenishing device 32 may be 100, 300, 500 and 1000 ml/min or more, which respectively provide good, preferred and better water replenishing efficiency. Further, the time required for filling the water from the empty water level to the minimum predetermined height H1 of the water level may be 100 seconds, 60 seconds, 40 seconds and 20 seconds or less, which are good, preferable and better water replenishing efficiency, respectively. In the example, about 269 ml of water is filled from the empty water level to the lowest preset height H1 of the water level, and about 37 seconds is consumed; the water is replenished from the lowest preset water level H1 to the highest water replenishing height H2 for 44 milliliters, which takes about 6 seconds. The entire water injection procedure was filled with about 313 ml of water.

On the other hand, when the power of the electrothermal conversion element 16 is fixed, the less liquid water is heated in the heating kettle 12, the faster the water temperature increases. In response to the steam S demand of the steam box 20 and the power limitation of the household electric line, the present embodiment controls the water amount in the heating kettle 12 to be a very small volume to increase the temperature rise rate of the liquid water L in the heating kettle 12. For example, when the amount of water below the predetermined height H1 of the liquid level sensor 13 in the heating kettle 12 is 30%, 25%, 20%, 10% or less of the total internal volume of the heating kettle 12, the efficiency of raising the temperature of the liquid water in the heating kettle 12 is high, preferable, better, and better, with a reduction in the time required for steam generation and the preparation time before cooking. In this example, the amount of water below the predetermined height H1 of the level sensor 13 is about 0.269 liter; the total volume of the heating kettle 12 is 1.155 liters; the former is about 23.3% of the latter.

Furthermore, by controlling the ratio (V4/W1) of the amount of liquid water in the kettle 12 at the predetermined height H1 (V4) to the rated power (W1) of the electrothermal conversion element 16 to be less than or equal to 0.4L/kW, 0.3L/kW, 0.2L/kW, and 0.1L/kW, the temperature increase efficiency of the liquid water in the steam cooking device 1 is good, preferable, better, and better. In this example, the amount of water below the predetermined height H1 of level sensor 13 is about 0.269 liter, the rated power of electrothermal conversion element 16 is 1.5 kilowatts, and the ratio of the amount of liquid water V4 at the predetermined height H1 in heated kettle 12 to the rated power (W1) of electrothermal conversion element 16 is about 0.18 liters/kilowatts.

On the other hand, the electrothermal conversion element 16 of the present example is flat due to the low water amount. Due to its flat structure, it can be entirely submerged below the liquid level, and the heating efficiency can be correspondingly improved. If necessary, the electrothermal conversion element 16 may be replaced by a three-dimensional spiral heating tube or other elements, and the liquid amount may be increased and the heating time may be affected. In addition, the power of the electrothermal conversion element 16 can also be adjusted according to the power supply capability, for example, when the input voltage is 220V, the electrothermal conversion element 16 with power of 2 kw or higher can be used, as an example.

In one example, after the user powers on the steam cooking device 1, the steam cooking device 1 can selectively enter a standby mode (also referred to as a first standby mode) or an air accumulation mode (also referred to as a second standby mode) according to default parameters while the water filling procedure is running.

The standby mode will be explained below. When entering the standby mode, the second control unit 44 controls the electrothermal conversion element 16 to heat the liquid water L in the heating kettle 12 at its maximum rated power, and after determining that the preparation temperature is, for example, between 60 ℃ and 99 ℃ according to the data obtained by the physical parameter measurement module 70, the electrothermal conversion element 16 is controlled to be turned on and off at a proper time to maintain the liquid water L at the preparation temperature. The preparation temperature is preferably lower than the saturated vapor temperature in the heating kettle 12, so that the liquid water L in the heating kettle 12 is kept substantially in a liquid state. In order to reduce the energy required to maintain the liquid water L at a predetermined temperature, the outer walls of the components of the pressure accumulating steam boiler 10 of this embodiment are wrapped with a thermal insulation layer 70 to reduce the dissipation of heat energy, and thus the energy consumption is maintained within about 2 watts (0.002 kw) per hour.

The gas accumulation mode (also referred to as a second preparation mode) is explained below. In the air accumulation mode, the second control unit 44 controls the electrothermal conversion element 16 to heat the liquid water L in the heating kettle 12 at full power, so that the liquid water L quickly reaches the predetermined pressure accumulation temperature from a temperature lower than the predetermined pressure accumulation temperature (for example, 20 ℃ of room temperature or the preparation temperature in the first preparation mode), and generates the steam S corresponding to the predetermined pressure accumulation temperature. The predetermined pressure accumulation is preferably between 1.1 and 5.0 atmospheres, corresponding to a saturated vapor temperature of between 103 ℃ and 152 ℃. Meanwhile, the on/off of the electrothermal conversion element 16 is controlled to maintain the vapor S at a predetermined pressure or a predetermined pressure-accumulating temperature. In this case, the predetermined pressure accumulation temperature corresponds to about 2 times atmospheric pressure, that is, the temperature of the vapor in the heating kettle 12 is about 120 ℃ as the saturated vapor temperature when the pressure accumulation is completed. After the pressure accumulation is completed, the interactive interface 51 may be provided with a light or other signal to notify the user that the pressure accumulation is completed. In order to reduce the heat energy loss, the outer walls of the components of the pressure accumulating steam boiler 10 of this embodiment are wrapped with a heat insulating layer 70 to reduce the heat energy dissipation.

The cooking mode will be explained below. When the cooking mode starts, the second control unit 44 controls the electronic steam valve 18 to open the channel, and allows the saturated steam S with 2 times atmospheric pressure and 120 ℃ to enter the gas pipe, enter the steam box 20 through the seventh port 22G, and enter the food material accommodating chamber 22C in the oven cavity 22B through the steam blowing device 24 to cook the food material F.

The shutdown mode will be explained below. The steam cooking device 1 can be switched into a power-off mode according to the instruction input by the user in the steam cooking device 1. In the shutdown mode, the liquid water heat-retaining function in the heating kettle 12 is stopped.

The following describes an application scenario of the steam cooking device 1 of this example. In this embodiment, when the steam cooking device 1 is powered on, the system will first execute the water filling procedure and confirm that the heating kettle 12 has liquid water, i.e. omit the standby mode and automatically enter the gas storage mode to start to produce and store steam. After the user puts the food material F into the cavity 22B and closes the door 60, the interactive interface 51 is operated to select the cooking procedure of the steam cooking device 1, and the steam cooking device 1 enters the cooking mode and outputs steam S to the cavity 22B according to the cooking procedures to cook the food material F. After the cooking process is finished, the user can open the oven door 60 and take out the food material F, thereby completing the whole cooking process. The system will re-enter either the standby mode or the gas accumulation mode according to the default procedure. In addition, after the user powers on the steam cooking device 1, the steam cooking device 1 may enter the standby mode first, and then enter the gas storage mode when the user inputs an instruction through the interactive interface 51 or opens the door 60.

In this example, the preparation temperature in the standby mode is 80 ℃, and when the electrothermal conversion element 16 with the rated power of 1.5 kilowatts in this example is used in combination with the volume of liquid water, the temperature of the liquid water L is increased from the room temperature of 20 ℃ to 80 ℃ for only 1.5 minutes. If the gas storage mode is directly selected, the temperature is increased from the room temperature of 20 ℃ to 120 ℃, and the time for 2 times of atmospheric pressure is only 2.5 minutes. In this embodiment, when entering the steaming mode, the heating kettle 12 can provide steam to the steam box 20 in real time because the device has already finished storing gas in advance due to the gas storage mode, so that the preparation time can be saved by about 2.5 minutes. In addition, if the design of the first standby mode and the second pressure accumulation mode is changed, the liquid water L is preheated to 80 ℃, and the liquid water L can be heated to the predetermined pressure accumulation temperature only in about 1 minute, so that the time required for producing the steam S can be reduced to a certain extent.

Furthermore, in addition to the high pressure saturated steam S, the present invention reduces the size of the oven cavity 22B in order to further reduce the time required to raise the steam box 20 from ambient temperature (e.g., 20℃.) to cooking temperature, relative to the design of the oven cavity 22B corresponding to 30 liters or more of the currently available 1.5 kilowatt electrothermal conversion elements 16. In this example, a cavity 22B having a capacity of only about 14 liters is used. Thereby reducing the required heat by more than half relative to the 30 liter cavity 22B.

In order to further reduce the capacity of the food material compartment 22C while retaining the flexibility of application, the present invention utilizes a movable element 28 disposed in the steam box 20 to divide the cavity 22B into a main steam-injection region and a non-injection region, thereby further reducing the time required to heat the food material compartment 22C to the cooking temperature. The main spraying area is referred to as a food material chamber 22C. In this embodiment, the movable element 28 can be disposed on the highest rib 26, the next highest rib 26 or the lowest rib 26 by the ribs 26 in the steam box 20, and the capacities of the corresponding food material accommodating chambers 22C are about 5 liters, 9 liters (including 5 liters) and 14 liters (including 9 liters), respectively. For example, when the power of the electrothermal conversion element 16 is 1.5 kw, 5 liters, 9 liters and 14 liters of the food material accommodating chambers 22C are filled with steam and the temperature is raised to a stable cooking temperature within about 1, 2 and 3 minutes from the start of the gas injection. And if the food material compartment 22C is 20 liters, the time required is about 5 minutes. The cooking temperature is, for example, 101 to 150 ℃, preferably 101 to 130 ℃, more preferably 101 to 110 ℃, and even more preferably 103 to 106 ℃, and in this embodiment, the cooking temperature is about 104 ℃. In another example, when the power of the electrothermal conversion element 16 is 2 kilowatts, the food material chambers 22C of 6 liters, 14 liters and 20 liters can be filled with steam and raised to a stable cooking temperature within about 0.75, 2 and 3 minutes. In this example, the movable element 28 may be a tray, a hollow block of material, a valve disposed at various portions of the furnace chamber 22B, or any other element, module or device that may partition, occupy, or otherwise reduce the area of the furnace chamber 22B in which the steam S primarily circulates. In this case, the movable element 28 is a tray, whose four sides are respectively in contact with the ribs on the three side walls of the cavity 22B and are very close to the oven door, so that the food receiving chamber 22C and the other parts of the cavity 22B can be effectively separated by reducing the gap. It should be noted that the movable element 28 only needs to limit the steam S to a relatively small area to achieve the effect of increasing the temperature rise speed, and the movable element 28 can, but need not, hermetically separate the food material chamber 22C from other parts of the cavity 22B, that is, the food material chamber 22C and other parts of the cavity 22B can be separated, but need not, by a small portion being in communication and being a gap. The separation is good, preferred, better and better when the horizontal area of the gap is equal to or less than 15%, 10%, 5% or 0% of the horizontal area of the movable element 28.

In addition, by applying the high-pressure saturated steam, even when the electric power consumption of the electrothermal conversion element 16 is limited, the large-capacity food material containing chamber 22C can be heated effectively in a short time. For example, according to the design of this embodiment, the amount of electricity consumed by the electrothermal conversion element 16 is WH1 kwh from the time when the food material chamber 22C is filled with steam S and heated to the cooking temperature, since steam S is initially supplied to the food material chamber 22C having a capacity of V1 liters and a room temperature. And when V1/WH1 is greater than or equal to 100, 160, 200 and 300, there are good, preferred and better heating efficiencies, respectively. In this example, the above-mentioned example that V1 is 5 liters, the heating time is 1 minute, and the rated power of the electrothermal conversion element is 1.5 kilowatts, the electricity consumption during the heating period is about 0.025 kilowatt-hour, and V1/WH1 is about 200. Accordingly, by limiting the capacity of the food material accommodating chamber 22C, the time required for temperature rise can be further reduced, and the problem that the quality of food materials is difficult to control due to an excessively long temperature rise time can be greatly alleviated. Meanwhile, the high-pressure steam can effectively prevent the food material from being coked, effectively shorten the cooking time of the food material and keep the taste of the food material.

In addition, during the steaming mode, in order to continuously inject the steam S, the accumulator steam boiler 10 continuously converts the liquid water L into the steam S, and when the liquid water L in the heating kettle 12 falls below the lowest sensing point 13A at the lowest end of the liquid level sensor 13, it is determined that the liquid level is lower than the water level minimum predetermined height H1 (also referred to as a water injection line). At this time, the liquid level sensor 13 may output a corresponding water level signal to the first control unit 42 in the control module 40, and the first control unit 42 performs a water replenishing procedure according to the water level signal. The water replenishing process injects a certain amount of water into the heating kettle, so as to raise the minimum predetermined water level H1 in the heating kettle to the maximum water replenishing height H2 (also called full water level). That is, in this example, the predetermined water replenishing amount is a fixed amount, and for this reason, the activation time period of the water replenishing device 32 is fixed.

It is to be understood that the addition of low temperature liquid water L will lower the temperature of the liquid water L in the heating still 12. If too much liquid water L is added, the temperature of the liquid water L in the heating kettle 12 is greatly reduced, and the generation of steam S is interrupted, which affects the gas supply quality. Referring to fig. 3, when the predetermined water supplement amount V2 (in liters) divided by the rated power W1 (in kilowatts) of the electrothermal conversion element 16 is less than or equal to a specific value, the power of the electrothermal conversion element 16 is sufficient to heat the cooled liquid water L back to the saturated steam temperature in a short time, so that the water supplement does not have an excessive influence on the steam generation. That is, when the predetermined water replenishment amount V2 (in liters) divided by the rated power W1 (in kilowatts) of the electrothermal conversion element 16 is less than or equal to 0.01, 0.03, 0.05 and 0.1, it has good, excellent, preferable and better effects, respectively. And the effect is good, better and better when the liquid water is cooled to 2 ℃, 1 ℃, 0.5 ℃ and 0.2 ℃ or below on average per second during each water replenishing period. To illustrate this example, each time the replenishment procedure is performed, 0.044 liters of liquid water L will be replenished within 5.9 seconds, which is about 0.029 in terms of a V2/W1 ratio, while the liquid water in the heating kettle 12 is cooled down only by 2.6 ℃ and the average temperature is cooled down by 0.44 ℃ per second. Incidentally, the flow rate of the amount of supplementary water per second is preferably not lower than the average consumption amount during the cooking mode, but not limited thereto. In the cooking mode of this example, the average steam consumption S of 500 seconds is 240 ml, and the average consumption per minute is about 28.8 ml.

Referring to fig. 3, when the predetermined amount of make-up water V2 (in liters) is equal to or less than a specific ratio of the maximum capacity V3 (in liters) of the heating kettle 12, the make-up water may be supplied to a certain extent without causing an excessive influence on the steam generation. For example, it is good, preferred and better when the steam cooking device 1 meets the conditions of V2/V3 being less than or equal to 0.1, 0.07, 0.04 and 0.02. To illustrate by this example, each time the water replenishing program is executed, the predetermined amount of water replenishment V2 is 0.044 liters, and the maximum capacity V3 of the heating kettle 12 is 1.155 liters, which is a ratio of about 0.038.

Referring to fig. 3, when the ratio between the predetermined amount of water supply V2 (in liters) and the volume V4 (in liters) at the predetermined height H1 is controlled to be less than or equal to a predetermined value, the water supply may not have an excessive influence on the generation of steam. For example, it is good, preferred and better when the steam cooking device 1 meets the conditions of V2/V4 being less than or equal to 0.3, 0.25, 0.2 and 0.15. In this example, the predetermined water replenishment amount V2 is 0.044 liters and the volume V4 below the predetermined height H1 of the liquid level sensor 13 is about 0.269 liters per one water replenishment procedure, which is about 0.164.

Incidentally, in this example, the height H3 of the vent at the top of the heating still 12 is 150 mm relative to the bottom of the heating still 12. The distances between the minimum preset height H1 and the maximum refill height H2 and the bottom of the heating kettle 12 are about 41.3 mm and 35.5 mm respectively, and the minimum preset height H1 is the same as the height of the minimum sensing point 13A of the liquid level sensor 13.

In addition, in order to solve the problem that wet steam is easy to form a liquid water film on the surface of the food material F, the design of providing high-pressure steam can reduce the liquefaction of latent heat accidentally released by the steam in the conveying process, effectively maintain the high dryness state of the steam S before reaching the surface of the food material F, reduce the formation chance of the liquid water film and effectively transfer the latent heat of the steam to the food material. Therefore, the food materials can be cooked in a short time, and the fresh and tender mouthfeel of the food materials is kept.

In practical applications, when the rated power of the electrothermal conversion element 16 is 1.5 kilowatts, the steam cooking device 1 of the present invention can complete a cooking process for a tail of 450 g of fish within six minutes from the beginning of steam ejection from the material chamber 22C, so as to make the fish meat well-cooked and maintain its moist, soft and tender taste. On the contrary, the present invention has a beneficial technical effect compared with the conventional steam cooking device, which requires fifteen to twenty minutes or more to cook fish. In addition, although the food material container 22C is designed to be smaller than the conventional large oven cavity, the steam cooking device 1 of the present invention can perform multiple dishes in the same or shorter time because the cooking time is significantly shorter.

In addition, unlike the conventional mechanism in which the steam S is output from the heating kettle 12 and then heated to 200 ℃ or higher to be superheated steam to heat the food, in one example of the present invention, the temperature of the steam S discharged by the steam discharge device 24 is lower than the temperature of the saturated steam in the pressure accumulation type steam boiler 10.

On the other hand, by increasing the height difference between the liquid level of the liquid water L in the heating kettle 12 and the gas outlet of the heating kettle 12, the vapor S can be prevented from accidentally carrying the molecules of the liquid water L away from the heating kettle 12 when the liquid water L boils, and the dryness of the vapor can be further increased. More specifically, when the liquid water L is heated to boil, the bubbles will be accelerated to break toward the liquid surface, and push the liquid water L away from the liquid surface. The liquid particles on the sprayed liquid surface are carried away from the cavity 22B along with the steam S, and latent heat is released before the steam S contacts food on the way, thereby reducing dryness of the steam S. In one embodiment of the present invention, the gas outlet is disposed at a higher position or at the top of the heating kettle 12, and the liquid level of the liquid water L is controlled below a specific ratio of the total height difference between the gas outlet and the bottom of the heating kettle 12, or the gas outlet and the bottom are maintained at a height difference not less than the minimum height difference, so as to increase the possibility that the liquid molecules are re-flowed back to the liquid level under the action of gravity, thereby reducing the chance that the liquid particles are accidentally carried away.

Referring to fig. 3, it can be seen that when the water level of the liquid level sensor 13 in the heating kettle 12 is lower than the minimum predetermined height H1 (also called water filling line), the control module 40 controls the water replenishing device 32 to replenish water to the heating kettle 12 and raise the liquid level to the maximum water replenishing height H2 (also called full water line). The water level minimum predetermined height H1 is close to the water level maximum refill height H2, and the water level minimum predetermined height H1 is the same as the height of the minimum sensing point 13A of the liquid level sensor 13. Therefore, in view of the principle, when the distance between the lowest sensing point 13A of the level sensor 13 and the bottom of the heating kettle 12 is less than or equal to a specific ratio of the total height difference H3 between the gas outlet of the heating kettle 12 and the bottom of the heating kettle 12, the vapor S can be effectively prevented from being carried away by boiling.

More specifically, the effect of improving the dryness of the vapor S is good, preferred and better when the ratio H1/H3 is less than or equal to 0.3, 0.25, 0.2 and 0.1 and is non-zero (e.g., greater than 0.001), respectively. In this example, the distance between the lowest sensing point 13A and the bottom of the heating kettle 12, i.e., the lowest predetermined height H1 of the water level, is about 35.5 mm; the distance between the highest water replenishing height H2 of the water level and the bottom of the heating kettle 12 is about 41.3 mm; the total height difference H3 between the gas outlet at the top and the bottom of the heating kettle 12 is 150 mm; therefore, the H1/H3 ratio is about 0.237.

In addition, when the distance between the lowest sensing point 13A of the liquid level sensor 13 and the air outlet of the heating kettle 12 is greater than or equal to 60 mm, 80 mm, 100 mm and 120 mm, the effect of improving the dryness of the vapor S is good, better and better, respectively. In this example, the distance is about 114.5 mm.

Moreover, a water blocking module is selectively arranged between the liquid level in the heating kettle 12 and the air outlet of the heating kettle 12, so that the liquid water L splashed due to boiling can be effectively blocked, and the aim of improving the dryness of the steam S is fulfilled; in addition. The water blocking module may be a porous Mesh plate, a barrier Mesh (Mesh), a multi-gap partition, a step-shaped baffle, or any element disposed between the predetermined height H1 and the outlet of the heating kettle 12 for blocking or allowing the liquid water L to adhere thereto. Referring to fig. 3, the water blocking module may be disposed at a position P of the water blocking module in the figure, except that the water blocking module is not disposed in the embodiment.

In summary, the steam cooking device in one embodiment of the present invention can effectively solve the problem that the food drying and cooking speed cannot be increased in the prior art by applying high-pressure steam. Meanwhile, the cooking device disclosed by the invention has the advantages that a plurality of dish colors can be quickly cooked in a short time without preheating, high temperature or special increase of the space of the food material accommodating chamber, the heating degree and the cooking effect of the food material can be accurately controlled, and the cooking result of the food material can be accurately reproduced and controlled.

Finally, it is emphasized that the components disclosed in the above embodiments are merely examples and should not be taken as limitations on the scope of the invention, and other equivalents and modifications of the components may be covered by the claims.

Claims

1. A steam cooking device, comprising:

a pressure accumulating steam boiler for heating liquid water and accumulating steam at a pressure of 1.1 to 5.0 atmospheres, the temperature of the steam in the pressure accumulating steam boiler being not lower than a saturated steam temperature corresponding to the pressure of the steam in the pressure accumulating steam boiler, the pressure accumulating steam boiler comprising:

a heating kettle for storing the liquid water and accumulating the vapor; and

the electric heating conversion element is arranged in the heating kettle and is used for heating the liquid water and generating the steam; and

a steam box connected to the pressure accumulating type steam boiler, the steam box for receiving the steam from the pressure accumulating type steam boiler to cook food materials contained in the steam box, the steam box comprising:

a food material containing chamber for containing the food material; and

the steam spraying device is connected with the food material accommodating chamber and the heating kettle and is used for inputting the steam from the heating kettle into the food material accommodating chamber;

the capacity of the food material accommodating chamber is V1 liters, the electric heating conversion element enables the electric consumption quantity required by the temperature in the food material accommodating chamber to be increased from the room temperature to the cooking temperature to be WH1 kilowatt hours, the steam cooking device meets the condition that V1/WH1 are more than or equal to 160 so as to increase the temperature in the food material accommodating chamber with the food materials from the room temperature and maintain the temperature at the cooking temperature, the cooking temperature is between 101 ℃ and 150 ℃, and the cooking temperature is lower than or equal to the temperature when the steam is output to the heating kettle.

2. The steam cooking device of claim 1, wherein the time required for the electrothermal conversion element to raise the temperature in the food material compartment from the room temperature to the cooking temperature is less than or equal to 5 minutes.

3. The steam cooking device of claim 1, wherein the difference between the temperature of the steam sprayed by the steam spraying device and the saturated steam temperature in the accumulator steam boiler is no greater than 30 ℃.

4. The steam cooking device of claim 3, wherein the cooking temperature is between 101 ℃ and 110 ℃.

5. The steam cooking device of claim 1, further comprising a movable element disposed in the steam box for reducing the time required to heat the food material compartment to the cooking temperature.

6. The steam cooking device of claim 1, further comprising:

the liquid level sensor is arranged in the heating kettle and used for measuring the liquid level height in the heating kettle and outputting a water level signal when the liquid level height in the heating kettle is lower than a preset height;

the water supplementing device is connected with the heating kettle and a water source and is used for inputting liquid water of the water source into the heating kettle; and

and the control module is electrically connected with the liquid level sensor and the water supplementing device, and is used for controlling the switch of the water supplementing device according to the water level signal so as to input the liquid water with the preset water supplementing amount into the heating kettle.

7. The steam cooking device of claim 6, wherein the predetermined amount of water added is V2 liters, the electrothermal transducer element is rated at W1 kilowatts, and the steam cooking device meets the condition of V2/W1 ≦ 0.1.

8. The steam cooking device of claim 6, wherein the vessel has a volume of V4 liters at the predetermined height, the electrothermal conversion element is rated at W1 kW, and the steam cooking device meets the condition of V4/W1 ≦ 0.3.

9. The steam cooking device of claim 6, wherein the predetermined amount of water added is V2 liters and the maximum capacity of the kettle is V3 liters; the steam cooking device meets the condition that V2/V3 is less than or equal to 0.1.

10. The steam cooking device of any one of claims 6 to 9, wherein the control module controls the water replenishing device to be activated for a fixed length of time or the predetermined amount of water replenishment to be a fixed amount.

11. A steam cooking device as claimed in any of the claims 6-9, characterized in that the electrothermal conversion element comprises an electric resistor, the whole of which is arranged below the predetermined height.

12. The steam cooking device of claim 1, further comprising:

the control module is electrically connected with the electric heating conversion element;

wherein the steam cooking device comprises at least one of a first preparation mode and a second preparation mode, and in the first preparation mode, the control module controls the electric-heat conversion element to heat and maintain the liquid water in the heating kettle at a preparation temperature which is lower than the saturated steam temperature in the heating kettle; in the second preparation mode, the control device controls the electrothermal conversion element to heat the liquid water and enables saturated vapor between 1.1 and 5.0 atmospheric pressure to be accumulated in the heating kettle.