Superheated steam generator and cooking device

Abstract

To improve the amount of superheated steam generated per unit time.SOLUTION: A superheated steam generation device comprises: a mist generation part for generating mist from liquid; a flow passage part comprising an upward flow passage extending from the side of an inflow port into which the mist generated by the mist generation part flows, toward the side of an outflow port located at a position higher than the inflow port; an air flow generation part for generating an upward air flow going from the inflow port toward the outflow port, in the upward flow passage; and a superheated steam generation heater arranged in the upward flow passage, and for generating superheated steam by heating the mist flowing into the upward flow passage.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a superheated steam generator and a cooking device. [Background technology]

[0002] Conventionally, there has been known a superheated steam generator that generates superheated steam (also called superheated water vapor) by heating mist generated from water (see, for example, Patent Document 1). With such a configuration, it is possible to generate superheated steam with less energy than a configuration in which superheated steam is generated by, for example, boiling water and heating the generated water vapor. Specifically, in this superheated steam generator, mist generated by a mist generator provided in a water tank moves to a superheating section through an upper opening of the water tank, and is heated by a heater provided in this superheating section to generate superheated steam. For example, oxidation of the ingredients can be suppressed by supplying superheated steam into a heating chamber in which ingredients are placed and subjecting the ingredients to a low-oxygen treatment. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-205705 A Summary of the Invention [Problem to be solved by the invention]

[0004] Mist is a liquid of fine particles and is heavier than air. Therefore, the amount of mist moving from the upper opening of the water tank to the superheating section is relatively small compared to the amount of mist generated by the mist generator, and as a result, there is a risk that a sufficient amount of superheated steam cannot be generated in the superheating section. If a sufficient amount of superheated steam cannot be generated, for example, problems such as the inability to suppress oxidation of ingredients due to an insufficient supply of superheated steam to the heating chamber will occur.

[0005] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The technology disclosed in this specification can be realized, for example, in the following forms.

[0007] (1) The superheated steam generator disclosed in this specification comprises a mist generating unit that generates mist from a liquid, a flow path unit having an ascending flow path extending from an inlet side into which the mist generated by the mist generating unit flows toward an outlet side located at a higher position than the inlet, an air current generating unit that generates an ascending air current from the inlet to the outlet within the ascending flow path, and a superheated steam generating heater that is disposed within the ascending flow path and heats the mist flowing into the ascending flow path to generate superheated steam.

[0008] In this superheated steam generator, the mist generated by the mist generating section rises in the updraft caused by the updraft in the ascending flow passage, and is heated by the heater for generating superheated steam to become superheated steam. That is, the mist and the superheated steam generated from the mist (which may contain saturated water vapor depending on conditions such as the amount of mist generated, the heat generation temperature, and the flow speed of the updraft) rise against gravity in the ascending flow passage due to the updraft, and move toward the outlet while maintaining a relatively high concentration (density). As a result, in this superheated steam generator, the amount of superheated steam generated per unit time can be improved compared to a configuration in which the mist moving in a flow passage extending horizontally is heated.

[0009] (2) The above superheated steam generator may further include a container having an internal space to which the mist generated by the mist generating unit is supplied, the flow path unit is disposed in the internal space and includes an inner tube whose lower side is open to the internal space and whose upper side is open to the outside of the container, at least a part of the superheated steam generating heater is disposed in the inner tube, the airflow generating unit is disposed in the internal space and includes an outer tube surrounding the inner tube, both upper and lower sides of the outer tube are open to the internal space, and the ascending airflow is generated in the inner tube by a pressure difference caused by a temperature difference between the inside and outside of the inner tube due to heating by the superheated steam generating heater. In this superheated steam generator, an ascending airflow is generated in the inner tube by a pressure difference caused by a temperature difference between the inside and outside of the inner tube due to heating by the superheated steam generating heater. This makes it possible to increase the amount of superheated steam generated per unit time while suppressing energy loss caused by the temperature drop in the inner tube due to air, etc., compared to a configuration in which air or the like is directly supplied into the ascending flow path to generate an ascending air current.

[0010] (3) In the above superheated steam generator, at least a part of the heater for generating superheated steam may be a rod-shaped body extending in the axial direction of the inner tube, and a metal body may be disposed between the heater for generating superheated steam and the inner wall of the inner tube. According to this superheated steam generator, in the inner tube (in the ascending flow passage), the ascending air current collides with the heated metal body and flows further upward. Therefore, the mist and saturated water vapor (wet steam, dry steam) contained in this ascending air current are efficiently heated by the heated metal body, and the amount of superheated steam generated per unit time can be further improved.

[0011] (4) In the above-mentioned superheated steam generator, at least the heater for generating superheated steam may be configured to have a rod shape extending from the lower side of the inner tube toward the inside of the inner tube. According to this superheated steam generator, a large amount of mist present below the inner tube can be heated to generate superheated steam and the superheated steam can be efficiently drawn into the inner tube, compared to a configuration in which the heater for generating superheated steam is not located below the inner tube.

[0012] (5) The above superheated steam generator may further include a secondary heating section disposed outside the accommodating section, the secondary heating section being formed with a transmission passage communicating with the inner tube and a discharge port opening from the transmission passage to the outside, and the superheated steam generating heater may include a primary heater disposed within the inner tube, and a secondary heater disposed in the transmission passage and having a lower heat generation temperature than the primary heater. This superheated steam generator can increase the amount of superheated steam generated per unit time while reducing the temperature on the discharge side of the superheated steam, compared to a configuration in which the superheated steam generating heater is a single heater.

[0013] (6) In the above-mentioned superheated steam generator, the mist generating unit may include a tank for storing liquid, an ultrasonic vibrator disposed in the liquid of the tank, and an air injection unit for injecting air into the tank and capable of changing the volume of the air. According to this superheated steam generator, the amount of superheated steam generated per unit time can be adjusted by changing the volume of air flowing from the air injection unit into the tank.

[0014] (7) The above-mentioned cooking device may be a cooking device that heat-treats ingredients, and may include the superheated steam generator according to any one of claims 1 to 6, a cooking section having a heating chamber to which superheated steam generated by the superheated steam generator is supplied, and a cooking heater that heats ingredients placed in the heating chamber. According to this cooking device, a large amount of superheated steam can be supplied from the superheated steam generator into the heating chamber, and ingredients can be heat-treated in an atmosphere with a high concentration of superheated steam.

[0015] (8) In the above cooking device, the superheated steam generator may be configured to output superheated steam toward an opposing wall including at least one of a ceiling wall and a side wall that configure the heating chamber, and the opposing wall may be configured to have a curved shape that allows the superheated steam to flow back into the heating chamber. With this cooking device, it is possible to heat the food in an atmosphere with a high concentration of superheated steam while preventing the pressure of the superheated steam from being applied to the food.

[0016] (9) In the above-mentioned cooking device, the cooking section may be configured such that the heating chamber is open to the outside through an inlet and an outlet, and the cooking device may further be configured to include a transport section that transports food from the inlet to the outlet. According to this cooking device, even in a configuration having a so-called tunnel-type heating chamber, the food can be heat-treated in an atmosphere with a high concentration of superheated steam. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a cooking device 10 according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing a cross-sectional configuration of the cooking device 10 taken along the line II-II in FIG. [Diagram 3] FIG. 1 is a perspective view showing a schematic configuration of a superheated steam generator 100. [Figure 4] FIG. 1 is a perspective view showing a schematic top view of a superheated steam generator 100; [Diagram 5] FIG. 4 is an explanatory diagram showing a cross-sectional configuration of the superheated steam generator 100 at the position VV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A. Embodiment: A-1. Basic configuration of the cooking device 10: FIG. 1 is a perspective view showing the configuration of a cooking device 10 in an embodiment, and FIG. 2 is an explanatory diagram showing the cross-sectional configuration of the cooking device 10 at the position II-II in FIG. 1. FIG. 2 shows an enlarged view of the X1 portion of the cooking device 10. Each drawing shows mutually orthogonal XYZ axes for specifying a direction. In this specification, for convenience, the Z axis direction is the vertical direction of the cooking device 10, the Y axis direction is the conveying direction of the conveying unit 40 described later, and the X axis direction is the conveying width direction. The same applies to FIG. 3 and subsequent figures.

[0019] The heating cooking device 10 is a device for supplying superheated steam G3 into a heating chamber S1, which has an inlet 36 and an outlet 37, to create a high-concentration superheated steam atmosphere in which the volume fraction of superheated steam G3 is high inside the heating chamber S1, while subjecting a large amount of food ingredients which are transported successively into the heating chamber S1 to a heating process.

[0020] As shown in FIGS. 1 and 2, the cooking device 10 includes a stand 20, a cooking section 30, a conveying section 40, a control section 22, and a superheated steam generator 100.

[0021] The stand 20 includes a frame body 24, a plurality of legs 25, and a shelf board 26. The frame body 24 is a rectangular frame body extending in a predetermined horizontal direction (transport direction Y in FIG. 1). Each leg 25 extends downward from each corner of the frame body 24. The shelf board 26 is a rectangular plate-like body parallel to the horizontal direction, and is fixed to the plurality of legs 25 at a position below the frame body 24. The control unit 22 is disposed in an installation space formed between the frame body 24 and the shelf board 26.

[0022] The cooking section 30 includes a cooking chamber cover 32. The cooking chamber cover 32 is disposed on the stand 20. A heating chamber S1 is formed inside the cooking chamber cover 32. The heating chamber S1 is a tunnel-type furnace that is open on both the front and rear sides in the conveying direction Y.

[0023] Specifically, the cooking chamber cover 32 has a ceiling wall 33, an entrance side wall 34, and an exit side wall 35. The ceiling wall 33 is a rectangular plate-like body that is parallel to the horizontal direction and extends in the conveying direction Y, and is disposed above the frame body 24 of the stand 20. The entrance side wall 34 is disposed between the stand 20 and the ceiling wall 33 on the entrance side in the conveying direction (the Y-axis positive direction side in FIG. 1). An entrance 36 is formed in the entrance side wall 34 (see FIG. 2). The exit side wall 35 is disposed between the stand 20 and the ceiling wall 33 on the exit side in the conveying direction (the Y-axis negative direction side in FIG. 1). An exit 37 is formed in the exit side wall 35. As a result, in the cooking section 30, the heating chamber S1 is open to the outside via each of the entrance 36 and the exit 37.

[0024] The conveying unit 40 is a conveyor device that is provided so as to penetrate the heating chamber S1 and sequentially conveys a plurality of ingredients (not shown) from the entrance 36 to the exit 37. The conveying unit 40 includes a driving unit 44, a driven unit 46, and a belt 48 (see FIG. 1). The driving unit 44 is disposed on the exit 37 side and has a driving roller and a motor. The driven unit 46 is disposed on the entrance 36 side and has a driven roller. The belt 48 is an endless mesh belt made of, for example, a metal (stainless steel, etc.) mesh material, and is stretched between the driving roller and the driven roller. When the conveying unit 40 is started, a plurality of ingredients arranged on the belt 48 are conveyed into the heating chamber S1 through the entrance 36, move through the heating chamber S1 at a predetermined speed, and are conveyed to the outside through the exit 37.

[0025] The heating chamber S1 is divided into a plurality of zones (for example, four zones) aligned in the conveying direction Y, and an upper heater 164 and a lower heater 166 are provided in each zone. The upper heater 164 is disposed above the belt 48 (conveyor section 40), and the lower heater 166 is disposed below the belt 48. In this embodiment, the temperature of the upper heater 164 and the lower heater 166 provided in each zone can be individually controlled. In addition, a superheated steam generator 100 is provided in each zone. The upper heater 164 and the lower heater 166 are examples of cooking heaters in the claims.

[0026] A-2. Configuration of the superheated steam generator 100: Fig. 3 is a perspective view that shows a schematic configuration of the superheated steam generator 100, and Fig. 4 is a perspective view that shows a schematic configuration of the top surface of the superheated steam generator 100. Fig. 4 shows an enlarged view of the X2 portion of the superheated steam generator 100. Fig. 5 is an explanatory view that shows a cross-sectional configuration of the superheated steam generator 100 at the position VV in Fig. 3.

[0027] As shown in FIGS. 3 to 5, the superheated steam generator 100 includes a mist generating section 110, a mist heating section 120, and a secondary heating section .

[0028] The mist generating unit 110 is a device for generating a mist G1 from a liquid W (e.g., water). The mist G1 is a mist of liquid (droplets), and can be, for example, fine particles of liquid with a diameter of 10 μm or less suspended in the air. The mist generating unit 110 includes a tank 112, an ultrasonic vibrator 114, and a volumetric fan 116. The tank 112 has a storage chamber S2 formed therein, and the liquid W is stored in the storage chamber S2 (see FIGS. 3 and 5). The ultrasonic vibrator 114 is disposed in the liquid W contained in the tank 112, and the mist G1 is generated from the liquid W by vibrating the ultrasonic vibrator 114 (see FIG. 5). In this embodiment, as shown in Figures 3 and 4, the tank 112 (storage chamber S2) is a box-shaped body that is long in a specific direction (the transport direction Y in Figure 1) when viewed from the top to bottom, and two ultrasonic transducers 114 are arranged within the tank 112 so as to be aligned in the transport direction Y.

[0029] A mist outlet 113 is formed at the top of the tank 112, and the mist G1 generated in the tank 112 is discharged to the outside of the tank 112 through the mist outlet 113. The space above the liquid W in the tank 112 has a relatively small volume that is filled with the generated mist G1. The air volume fan 116 is provided, for example, on the side wall of the tank 112, and injects air F1 (outside air) into the space above the liquid W in the tank 112 (see FIG. 5). The air volume fan 116 is, for example, a sirocco fan. The rotation speed (air volume) of the air volume fan 116 can be controlled by the above-mentioned control unit 22, and the amount of air F1 injected into the tank 112 per unit time (hereinafter referred to as "air volume") is changed by changing the rotation speed of the fan. The greater the air volume, the greater the amount of mist G1 discharged from the tank 112 to the mist heating unit 120 per unit time.

[0030] The mist heating unit 120 includes a mist retention section 121, a double pipe 150, and a mist heating heater 160. The mist retention section 121 has a retention chamber S3 formed therein. The mist retention section 121 is formed of, for example, a heat insulating material. A mist supply port 122 is formed on the bottom surface of the retention chamber S3, and the mist supply port 122 is connected to the mist outlet 113 of the tank 112 via the connecting pipe 140. Therefore, the mist G1 generated by the mist generating unit 110 is supplied to the retention chamber S3 and retains (convects) in the retention chamber S3. In this embodiment, as shown in FIG. 4, the mist retention section 121 (retention chamber S3) is a box body that is narrower in width in the conveying direction Y than the tank 112 when viewed in the vertical direction Z, and is long in the conveying width direction X, and is arranged so as to be located in the center with respect to the two ultrasonic transducers 114. With this configuration, approximately equal amounts of mist G1 generated by each of the two ultrasonic transducers 114 are collected through the connecting pipe 140 and supplied to the retention chamber S3. The mist retention section 121 is an example of a storage section in the claims, and the retention chamber S3 is an example of an internal space in the claims.

[0031] The double pipe 150 is disposed so as to extend in the vertical direction Z in the retention chamber S3. When viewed in the vertical direction Z, the double pipe 150 is disposed at a position different from the mist supply port 122 (see Figs. 3 and 4). The double pipe 150 has a double pipe structure including an outer pipe 152 and an inner pipe 154. The outer pipe 152 is a tubular body extending linearly in the vertical direction. The outer pipe 152 has a cylindrical shape, but may have a square tube shape or the like. The upper end of the outer pipe 152 opens into the retention chamber S3 at a position lower than the ceiling wall of the retention chamber S3 (see Figs. 3 and 5). A mist inlet 156 is formed on the outer peripheral surface of the lower end of the outer pipe 152. The mist inlet 156 is formed on the mist supply port 122 side of the outer peripheral surface of the lower end of the outer pipe 152. The outer peripheral surface of the lower end of the outer tube 152, on the opposite side to the mist supply port 122, extends to the bottom surface of the retention chamber S3 and is not open. Therefore, the mist G1 supplied to the mist outlet 113 efficiently flows into the double tube 150 through the mist inlet 156.

[0032] The inner pipe 154 is a tubular body that extends linearly in the vertical direction. The shape of the inner pipe 154 is cylindrical, but may be a square tube. The inner pipe 154 is disposed coaxially with the outer pipe 152 on the inner periphery side of the outer pipe 152. A sub-flow passage R2 that communicates from the lower end side to the upper end side of the outer pipe 152 is formed between the outer pipe 152 and the inner pipe 154. The upper end of the inner pipe 154 penetrates the ceiling wall of the retention chamber S3 and protrudes to the outside of the mist retention section 121. The gap between the outer periphery of the inner pipe 154 and the ceiling surface of the retention chamber S3 is sealed. The lower end of the inner pipe 154 is located above the mist inlet 156 of the outer pipe 152. The inner pipe 154 is an example of a flow path portion in the claims, the lower end opening of the inner pipe 154 is an example of an inlet in the claims, and the upper end opening of the inner pipe 154 is an example of an outlet in the claims. The outer pipe 152 and the inner pipe 154 are formed of, for example, a metal (stainless steel, etc.).

[0033] The mist heating heater 160 is disposed in a space on the inner periphery side of the inner tube 154 (hereinafter referred to as "upward flow passage S4"). The mist heating heater 160 is a rod-shaped heating element extending in the vertical direction Z (axial direction of the inner tube 154), and the outer diameter of the mist heating heater 160 is smaller than the inner diameter of the inner tube 154. Therefore, a main flow passage R1 that communicates from the lower end side to the upper end side of the outer tube 152 is formed between the inner wall of the inner tube 154 and the mist heating heater 160. The mist heating heater 160 extends from the lower side of the inner tube 154 toward the inside of the inner tube 154. Specifically, the mist heating heater 160 extends to a position exposed from the mist inlet 156. Furthermore, the mist heating heater 160 extends to the bottom surface of the retention chamber S3. The position of the upper end of the mist heating heater 160 is lower than the position of the upper end of the outer tube 152. The outer tube 152 and the mist heating heater 160 are an example of an airflow generating section in the claims, and the mist heating heater 160 is an example of a primary heater in the claims.

[0034] A metal body is disposed between the inner wall of the inner tube 154 and the outer circumferential surface of the mist heating heater 160. The length of the metal body in the vertical direction Z is shorter than the length of the mist heating heater 160 in the vertical direction Z. The metal body is, for example, a mass of metal formed of a metal having high thermal conductivity. Specifically, the metal body is a plurality of metal balls 170. The plurality of metal balls 170 are arranged around the periphery of the mist heating heater 160 while being spaced apart in the circumferential direction. Each metal ball 170 is supported by a support member (not shown) while exposing a spherical surface in the main flow path R1. It is preferable that at least the surface of each metal ball 170 on the inlet side of the inner tube 154 is exposed. The shape of the metal ball 170 is not limited to a spherical shape, but may be, for example, a cylindrical shape, or may have a spherical or curved surface.

[0035] The secondary heating section 130 is disposed outside the mist retention section 121. The secondary heating section 130 includes a heat transfer section 312 and a secondary heater 162. The heat transfer section 312 extends in the conveyance width direction X as a whole, and is cylindrical with a transmission flow path S5 formed therein. The base end side of the heat transfer section 312 is connected to the upper end of the inner pipe 154 via a connecting pipe 142, and the tip side of the heat transfer section 312 is disposed in the heating chamber S1 of the cooking section 30 (see FIG. 2). The tip side of the heat transfer section 312 is bent toward the ceiling wall 38 that forms the heating chamber S1, and the tip surface of the heat transfer section 312 has a discharge port 133 that opens from the transmission flow path S5 to the heating chamber S1 and opens toward the ceiling wall 38.

[0036] The secondary heater 162 is disposed in the transmission flow path S5 of the heat transfer section 312. The secondary heater 162 is a rod-shaped heating element extending in the transport width direction X, and the outer diameter of the secondary heater 162 is smaller than the inner diameter of the heat transfer section 312. Therefore, a flow path is formed between the inner wall of the heat transfer section 312 and the secondary heater 162, which communicates from the base end side to the tip end side of the secondary heater 162. The mist heating heater 160 and the secondary heater 162 are an example of a heater for generating heated steam in the claims.

[0037] The superheated steam generator 100 is provided with three fixing members 101, and the mist generation section 110 and the mist heating section 120 are fixed to the stand 20 and the cooking section 30 via the fixing members 101 outside the heating chamber S1 (on one side in the transport width direction X).

[0038] 2, the shape of the ceiling wall 38 toward which the outlet 133 of the heat transfer section 312 faces is a curved shape that allows the superheated steam G3 to return to the heating chamber S1. Specifically, the ceiling wall 38 is provided with a heat equalizing plate 39 having an arc-shaped surface that opens downward when viewed in the horizontal direction (e.g., the conveying direction Y). The surface of the heat equalizing plate 39 is mirror-finished.

[0039] A-3. Operation of the cooking device 10: When the cooking device 10 is started, the control unit 22 controls each part of the cooking device 10. For example, the superheated steam generator 100 generates superheated steam G3 in the heating chamber S1 of the cooking unit 30. Specifically, as shown in FIG. 5, mist G1 is generated from the liquid W stored in the tank 112 by the vibration of the ultrasonic vibrator 114. The temperature of the liquid W and the mist G1 is, for example, 30°C or higher and 40°C or lower. The control unit 22 can adjust the amount of mist G1 generated per unit time by changing the vibration frequency of the ultrasonic vibrator 114. The generated mist G1 fills the space above the liquid W in the storage chamber S2 of the tank 112 and moves into the retention chamber S3 of the mist heating unit 120 through the connecting pipe 140.

[0040] Air F1 injected into the storage chamber S2 by the air volume fan 116 provided in the tank 112 generates an air current that flows into the retention chamber S3 through the connecting pipe 140 while convecting in the storage chamber S2. The mist G1 generated in the storage chamber S2 efficiently flows into the retention chamber S3 by the air current of the air F1. Here, the flow path cross section (XY cross-sectional area) in the connecting pipe 140 is narrower than both the XY cross-sectional area of ​​the storage chamber S2 and the XY cross-sectional area of ​​the retention chamber S3. In this way, the connecting pipe 140 that narrows the flow path area is provided between the storage chamber S2 and the retention chamber S3, thereby suppressing the later-described semi-superheated steam G2 heated in the retention chamber S3 from flowing back into the storage chamber S2. This makes it possible to suppress, for example, the ultrasonic transducer 114 from breaking down due to the temperature rise of the liquid W in the tank 112 caused by the backflowing semi-superheated steam G2.

[0041] The mist G1 that has flowed into the retention chamber S3 convects (retains) within the retention chamber S3. The mist G1 convecting within the retention chamber S3 is drawn into the main flow path R1 by an ascending air current F2 generated within the inner pipe 154 of the double pipe 150 and heated by the mist heating heater 160 to generate semi-superheated steam G2. The semi-superheated steam G2 has a lower volumetric ratio of superheated steam than the superheated steam G3 described below, and also contains a large amount of saturated steam (wet steam, dry steam) and mist G1. The heat generation temperature of the mist heating heater 160 is, for example, 450°C or higher and 550°C or lower, and the temperature of the semi-superheated steam G2 is, for example, 100°C or higher and 200°C or lower.

[0042] Specifically, when the mist heating heater 160 is heated, an ascending air current F2 is generated in the ascending flow path S4 of the inner tube 154 due to a pressure difference resulting from a temperature difference between the main flow path R1 around the mist heating heater 160 and the space above the main flow path R1 (the mist heating heater 160).

[0043] Furthermore, the inner pipe 154 is surrounded by the outer pipe 152 to form a sub-passage R2, which further strengthens the momentum of the ascending air current F2. The reason for this is unclear, but the following is thought to be the case. That is, a temperature difference occurs between the main passage R1 on the inner periphery side of the inner pipe 154 and the sub-passage R2 on the outer periphery side, and this temperature difference causes a pressure difference. It is thought that the momentum of the ascending air current F2 is strengthened by the Venturi effect occurring in the main passage R1, which has a relatively high pressure.

[0044] When an ascending air current F2 is generated in the inner pipe 154 of the double pipe 150, the mist G1 that is retained in the retention chamber S3, particularly near the bottom surface where the density of the mist G1 is high, is drawn into the main flow path R1 from the mist inlet 156. The drawn-in mist G1 is heated by the mist heating heater 160 to generate semi-superheated steam G2. The semi-superheated steam G2 rises against gravity due to the ascending air current F2, and moves toward the secondary heating section 130 while maintaining a relatively high concentration (density: volume ratio of semi-superheated steam G2 per unit volume).

[0045] The semi-superheated steam G2 that has moved to the secondary heating section 130 side is heated by the secondary heater 162 while moving through the transmission flow path S5, generating superheated steam G3. The superheated steam G3 has a higher volumetric ratio of superheated steam than the semi-superheated steam G2, and contains almost no saturated steam (wet steam, dry steam) or mist G1. The heat generation temperature of the secondary heater 162 is lower than the heat generation temperature of the mist heating heater 160, for example, not lower than 350°C and not higher than 450°C, and the temperature of the superheated steam G3 is not lower than 330°C and not higher than 370°C. By keeping the heat generation temperature of the secondary heater 162 as low as possible, it is possible to prevent the secondary heater 162 from burning the ingredients in the heating chamber S1.

[0046] The generated superheated steam G3 is discharged from the discharge port 133 of the heat transfer section 312 toward the ceiling wall 38, circulated by the heat equalizing plate 39, and uniformly filled in the retention chamber S3. Here, as described above, the heating chamber S1 is a tunnel-type furnace that opens to the outside through the inlet 36 and the outlet 37, and the superheated steam G3 supplied into the heating chamber S1 flows out to the outside. However, since the superheated steam generator 100 generates a large amount of superheated steam G3 per unit time, the heating chamber S1 can be maintained in a high-concentration superheated steam atmosphere with a high volumetric ratio of superheated steam. In addition, since the superheated steam G3 is not directly sprayed toward the food, it is possible to suppress the pressure of the superheated steam G3 from being directly applied to the food.

[0047] The conveyor 40 is started, the food ingredients are sequentially placed on the belt 48, and the upper heater 164 and the lower heater 166 are turned on. Then, the food ingredients are sequentially conveyed to the heating chamber S1 in a high-concentration superheated steam atmosphere, and are heated and grilled by the upper heater 164 and the lower heater 166. In a high-concentration superheated steam atmosphere, a large amount of superheated steam G3 adheres to the surface of the food ingredients and easily penetrates into the inside of the food ingredients. Therefore, the surface and the inside of the food ingredients are heated in a low-oxygen state, and as a result, the food ingredients can be grilled evenly from the surface to the inside while suppressing oxidation of the food ingredients.

[0048] As described above, the control unit 22 is configured to be able to execute temperature control and on / off control of the heaters 160, 162, 164, 166, air volume control of the air volume fan 116, and vibration frequency control of the ultrasonic vibrator 114. For this reason, for example, by controlling to change at least one of the temperature control of the heaters 160, 162, the air volume control of the air volume fan 116, and the vibration frequency control of the ultrasonic vibrator 114, it is possible to adjust the amount of mist G1 generated per unit time, the ratio of superheated steam in the semi-superheated steam G2 and the superheated steam G3, and the like. This allows the amount of mist G1 generated in the heating chamber S1 to be adjusted to a desired amount. Furthermore, the control unit 22 is able to execute temperature control and on / off control of the heaters 160, 162, 164, 166, air volume control of the air volume fan 116, and vibration frequency control of the ultrasonic vibrator 114 individually for each zone. For this reason, it is possible to switch the heating temperature, on / off, and amount of superheated steam of each heater for each zone.

[0049] A-4. Advantages of this embodiment: As described above, in the superheated steam generator 100 of this embodiment, the mist G1 generated by the mist generating unit 110 rises in the ascending passage S4 by the ascending air current F2 generated in the ascending passage S4, and is heated by the mist heating heater 160 to become semi-superheated steam G2. That is, the semi-superheated steam G2 rises in the ascending passage S4 against gravity by the ascending air current F2, and moves toward the outlet while maintaining a relatively high concentration (density). As a result, in this embodiment, the amount of superheated steam G3 (semi-superheated steam G2) generated per unit time can be improved compared to a configuration in which mist moving in a passage extending in the horizontal direction is heated.

[0050] In this embodiment, an ascending air current F2 is generated in the inner tube 154 due to a pressure difference resulting from a temperature difference between the inside and outside of the inner tube 154 caused by heating by the mist heating heater 160. As a result, compared to a configuration in which an ascending air current is generated by directly supplying air or the like into the ascending flow path, it is possible to improve the amount of superheated steam G3 (semi-superheated steam G2) generated per unit time while suppressing energy loss caused by a temperature drop in the inner tube 154 due to air or the like.

[0051] The mist heating heater 160 is a rod-shaped body extending in the axial direction of the inner tube 154, and metal balls 170 are disposed between the mist heating heater 160 and the inner wall of the inner tube 154. In the inner tube 154 (in the ascending flow path S4), the ascending air current F2 flows further upward while colliding with the heated metal balls 170. Therefore, the semi-superheated steam G2 contained in this ascending air current F2 is efficiently heated by the heated metal balls 170, and the amount of superheated steam G3 (semi-superheated steam G2) generated per unit time can be further improved by providing the metal balls 170. In addition, by providing the metal balls 170, the length of the mist heating heater 160 in the vertical direction Z can be shortened, and the mist G1 can be effectively heated to generate semi-superheated steam G2.

[0052] The mist heating heater 160 is rod-shaped and extends from the lower side of the inner tube 154 toward the inside of the inner tube 154. As a result, compared to a configuration in which the mist heating heater 160 is not positioned below the inner tube 154, a large amount of mist G1 present below the inner tube 154 can be heated to generate semi-superheated steam G2 and can be drawn into the inner tube 154 more efficiently.

[0053] As the heater for generating superheated steam, a mist heating heater 160 and a secondary heating heater 162 having a lower heating temperature than the mist heating heater 160 are provided, and superheated steam G3 is generated from the mist G1 by multi-stage heating. As a result, compared to a configuration in which the heater for generating superheated steam is a single heater, it is possible to reduce the temperature on the release side of the superheated steam G3 while improving the amount of superheated steam G3 generated per unit time.

[0054] By changing the volume of air F1 blown per unit time from the air volume fan 116 into the tank 112, the amount of superheated steam G3 generated per unit time can be adjusted.

[0055] B. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0056] The configurations of the cooking device 10 and the superheated steam generator 100 in the above embodiment are merely examples, and can be modified in various ways. For example, in the above embodiment, the inner pipe 154 (upward flow passage S4) extending in the vertical direction Z is illustrated as the flow passage portion (upward flow passage), but the inner pipe extending in an oblique direction inclined with respect to the vertical direction Z may be used. The flow passage portion (upward flow passage) is not limited to being linear, and may be curved. The flow passage portion may have a portion extending in the horizontal direction on at least one of both sides of the upward flow passage. In short, the flow passage portion may be configured to have an upward flow passage extending from the inlet side where the mist flows in toward the outlet side located at a higher position than the inlet.

[0057] In the above embodiment, the heating chamber is exemplified as a tunnel-type heating chamber S1 that opens to the outside via the entrance 36 and the exit 37, but the heating chamber may be configured without at least one of the entrance 36 and the exit 37. In addition, the heating chamber may be configured to have a plurality of openings, three or more.

[0058] In the above embodiment, the heating chamber S1 of the cooking device 10 is divided into a plurality of zones, and each zone is provided with a superheated steam generator 100 and heaters 164, 166, but the heating chamber S1 may not be divided into a plurality of zones, and may be provided with one superheated steam generator 100 and one heater 164, 166. In addition, in the above embodiment, the upper heater 164 and the lower heater 166 are exemplified as cooking heaters, but the heating chamber S1 may be provided with only one of the upper heater 164 and the lower heater 166.

[0059] In the above embodiment, the storage chamber S2 of the tank 112 and the retention chamber S3 of the mist retention section 121 are connected via the connecting pipe 140 having a relatively small cross section of the flow path, but the storage chamber S2 and the retention chamber S3 may be integrated without the connecting pipe 140. Also, in the above embodiment, the tank 112 is located below the mist retention section 121, but this is not limiting, and for example, the tank 112 may be located to the side of the mist retention section 121.

[0060] In the above embodiment, a sirocco fan is exemplified as the air injection unit, but other air volume fans such as a propeller fan may be used. Also, a configuration in which an air tank that ejects air and has an adjustment valve capable of adjusting the amount of air ejected is connected to the tank 112 may be used. Also, the mist generation unit 110 may be configured without including the air volume fan 116. Also, the mist generation unit 110 may be configured to include one or three or more ultrasonic vibrators 114.

[0061] In the above embodiment, the double pipe 150 is disposed at a position different from the mist supply port 122 when viewed in the vertical direction Z (see FIG. 4). This allows the mist G1 to be sufficiently retained while suppressing the momentum of the air F1 flowing from the mist generating unit 110 in the retention chamber S3 of the mist heating unit 120, thereby drawing in a large amount of mist G1 into the double pipe 150. However, in the above embodiment, the double pipe 150 may be configured to be disposed at the same position as the mist supply port 122 when viewed in the vertical direction Z.

[0062] In the above embodiment, the outer tube 152 may not be provided. Even in such a configuration, an ascending air current can be generated in the inner tube 154 by the temperature difference between the inside and outside of the inner tube 154 caused by heat generated by the mist heating heater 160 or by the air F1 from the air volume fan 116. In this case, the air volume fan 116 is an example of an air current generating section in the claims. The air current generating section may be configured to generate an ascending air current in the inner tube 154 by, for example, partially narrowing the flow passage cross section of the inner tube 154.

[0063] In the above embodiment, one or more discharge ports may be formed in a side wall of the heat transfer section 312 of the secondary heating section 130. Alternatively, the discharge port 133 of the heat transfer section 312 may open toward a side wall constituting the heating chamber S1, and the heat equalizing plate 39 may be formed on that side wall. Alternatively, the discharge port 133 of the heat transfer section 312 may be directed toward the food material (conveyance section 40).

[0064] In the above embodiment, two heaters (mist heating heater 160 and secondary heating heater 162) are provided as the heater for generating superheated steam, and superheated steam G3 is generated from mist G1 by heating in two stages using these two heaters. However, this is not limited to the above, and superheated steam G3 may be generated from mist G1 by heating in multiple stages using multiple heaters (three or more). Also, for example, the heater for generating superheated steam may be a single heater, and superheated steam G3 may be generated from mist G1 by heating this single heater. For example, the above embodiment may be configured without the secondary heating unit 130, and superheated steam G3 may be generated from mist G1 by heat generated by mist heating heater 160.

[0065] The materials of the components in the above embodiment are merely examples and can be modified in various ways.

[0066] In the above embodiment, for example, chlorine is stored in tank 112, and under the control of control unit 22, mist generating unit 110 is operated with each heater 160, 162, 164, 166 turned off, thereby supplying chlorine mist to heating chamber S1 to perform sterilization treatment. [Explanation of symbols]

[0067] 10: Cooking device 20: Stand 22: Control unit 24: Frame 25: Legs 26: Shelf 30: Cooking unit 32: Cooking chamber cover 33, 38: Ceiling wall 34: Inlet side wall 35: Outlet side wall 36: Inlet 37: Outlet 39: Heat equalizing plate 40: Transport unit 44: Drive unit 46: Driven unit 48: Belt 100: Superheated steam generator 101: Fixing member 110: Mist generating unit 112: Tank 113: Mist outlet 114: Ultrasonic vibrator 116: Air flow fan 120: Mist heating unit 121: Mist retention unit 122: Mist supply port 130: Secondary heating unit 133: Discharge port 140, 142: Connecting pipe 150: Double pipe 152: Outer pipe 154: Inner pipe 156: Mist inlet 160: Mist heating heater 162: Secondary heater 164: Upper heater 166: Lower heater 170: Metal ball 312: Heat transfer section F1: Air F2: Upward air current G1: Mist G2: Semi-superheated steam G3: Superheated steam R1: Main flow path R2: Sub-flow path S1: Heating chamber S2: Storage chamber S3: Retention chamber S4: Upward flow path S5: Transmission flow path W: Liquid

Claims

1. A mist generating unit that generates mist from liquid; a flow path portion having an upward flow path extending from an inlet side into which the mist generated by the mist generating portion flows toward an outlet side located at a position higher than the inlet; an air current generating unit that generates an ascending air current from the inlet toward the outlet in the ascending flow passage; A heater disposed in the upward flow passage and configured to heat the mist flowing into the upward flow passage; A control unit; Equipped with The control unit is an on control for turning on the heater to heat the mist flowing into the upward flow passage and generate superheated steam; an off control in which the heater is turned off to allow only the mist to flow out from the outlet without heating the mist flowing into the upward flow passage; temperature control for adjusting a ratio of superheated steam and mist contained in the ascending air current flowing out from the outlet by changing a heating temperature of the heater; The control system is configured to selectively execute at least two of the following controls: Superheated steam generator.

2. A superheated steam generating apparatus as described in claim 1, The mist generating unit includes a tank that contains a liquid, an ultrasonic vibrator that is disposed in the liquid of the tank, and an air injector that injects air into the tank and can change the volume of the air. Superheated steam generator.

3. A cooking device for subjecting food to a heat treatment, The superheated steam generator according to claim 1 or 2, A cooking section having a heating chamber to which the superheated steam generated by the superheated steam generating device is supplied; A cooking heater that heats food placed in the heating chamber; Equipped with Heating cooking device.

4. A heating and cooking device as described in claim 3, The superheated steam generator is configured to output superheated steam toward an opposing wall including at least one of a ceiling wall and a side wall that configure the heating chamber, The shape of the facing wall is a curved shape that allows the superheated steam to return to the heating chamber. Heating cooking device.

5. A cooking device according to claim 3 or claim 4, The cooking section is configured such that the heating chamber is open to the outside through an inlet and an outlet, The cooking device further includes a conveying unit that conveys food from the inlet to the outlet. Heating cooking device.

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