Electric roaster and roasting method using the same

Abstract

To provide an electric roaster 1 capable of suppressing contamination of a carbon heater 11 and extending the life.SOLUTION: The roasting device 1 includes a heater 11 for radiating heat rays for roasting the surface of the roasting object N, and a reflecting plate 13 for reflecting the heat rays radiated by the heater toward the object. A protection member 15 is arranged between the object N to be roasted and the heater 11. The protective member 15 transmits heat rays and shields an emission emitted from the object N.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a broiler for searing the surface of fish, meat, etc. In particular, it relates to an electric broiler that does not require special skill for searing and is excellent in safety and fire prevention. More specifically, it relates to an electric broiler equipped with a lamp heater such as a carbon heater, which has been improved to prevent heater contamination and extend its lifespan. It also relates to a searing cooking method using such a broiler. [Background technology]

[0002] "Searing" is a cooking method that has the following characteristics: (1) It is a baking method that heats only the surface of the food. (2) It is a baking method that browns the surface of food and removes moisture from the surface. (3) Food is often baked at high temperatures for short periods of time. (4) Broiling is also considered a part of grilling. "Baking" is a cooking method that has the following characteristics: (A) A baking method that heats the entire food item, even the inside. (B) Baking takes longer than broiling.

[0003] In recent years, the conveyor-belt sushi industry has seen a diversification of menu items. In particular, seared sushi is becoming increasingly popular among foreign tourists, who are increasing in number due to inbound demand. In addition to seared sushi, other popular seared dishes include seared pork as a topping for ramen and seared beef bowls. Examples of reasons for the increasing popularity of grilled dishes include: (1) Grilling can remove excess oil from fish or meat. (2) Grilling removes moisture, concentrating the umami components. (3) The added aroma enhances the flavor. For these reasons, broiling is becoming increasingly popular in a variety of food service and ready-made meal businesses, including conveyor belt sushi restaurants, supermarket delicatessens, and ramen shops.

[0004] The most common method of searing sushi is with a gas torch burner attached to a gas canister. The traditional method involves placing the toppings on a grill and searing them over the gas torch while checking the doneness. After searing, the toppings are removed with a fork or similar and placed on top of the rice. However, searing cooking requires skill from the chef, and in the restaurant and ready-meal industries that offer searing menus, there has long been a demand for the development of equipment that allows anyone to sear food easily, uniformly, and safely.

[0005] Patent Document 1 (JP 2018-89350, "Automatic Conveying and Grilling Device," Kura Corporation) discloses a device in which sushi ingredients are placed on sushi plates and grilled using an infrared heater while being transported on a conveyor. This document does not disclose any protective glass or other components to prevent oily smoke from adhering to the infrared heater. The inventors speculate that if the device described in Patent Document 1 is put into practical use, oily smoke will adhere to the quartz tube of the infrared heater, causing the tube to devitrify within a short period of time. This phenomenon would reduce the device's grilling capacity, necessitating heater replacement every few months.

[0006] Patent Document 2 (Patent 6050877, "Sushi Ingredients Grilling Device," Nichiwa Electric Co., Ltd.) discloses a grilling method that uses carbon heater heating and also blows hot air onto the sushi ingredients. This document does not disclose any protective glass or other components to prevent oily smoke from adhering to the carbon heater. The inventors speculate that if the device described in Patent Document 2 is put into practical use, the quartz tube of the infrared heater will become devitrified within a short period of time due to the adhesion of oily smoke to the quartz tube. This phenomenon will reduce the grilling capacity of the device, making it necessary to replace the heater every few months. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2018-89350 [Patent Document 2] Patent 6050877 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0008] The following are typical problems that currently exist in food grilling operations: (1) When using a gas torch burner for direct flame cooking, the degree of doneness varies depending on the skill of the chef, such as how the flame is applied to the ingredients and the cooking time. (2) For example, the standard time for searing sushi ingredients (tuna, salmon, sushi topped with mayonnaise, etc.) over an open flame is short, about 5 to 10 seconds. If it is seared for any longer, the inside of the ingredient will be heated, ruining the texture of the seared dish. Therefore, the chef must sear the entire surface of the ingredient evenly in a short time, while checking the condition of the surface of the ingredients, so that the cooking is concentrated only on the surface.

[0009] (3) The temperature of the flame (blue flame) generated from a torch burner is generally over 1,200°C, and if it is used incorrectly, there have been many accidents in which people have been burned by coming into contact with the flame or by touching the hot burner with their hands or body. (4) There have also been frequent incidents of fires caused by gas leaks from the connection (screw connection) between the torch burner and the cassette gas cylinder, and explosions caused by improper management of the cassette gas cylinder. (5) The reality is that there are no commercially available electric roasters that are durable enough for practical use. In particular, those that use infrared heaters (carbon heaters, etc.) have a serious drawback: the heater has an extremely short lifespan.

[0010] The present invention has been made to solve the above problems, and has as its object to provide an electric roaster having one or more of the following features: (A) It enables uniform and quick searing. (i) There is no transfer of the odor that is typical of gas. (c) Reduction of industrial accidents (d) Energy efficiency (E) Installation of safety devices (such as overheating prevention devices) (c) It will be possible to introduce it into gas-free facilities (underground shopping malls, leisure facilities, etc.). (K) The heater has a long lifespan. [Means for solving the problem]

[0011] In this "Means for Solving the Problem" and "Claims," ​​reference symbols for various parts in the attached drawings are shown in parentheses, but this is for reference only and is not intended to limit the scope of the rights to those in the attached drawings.

[0012] The electric roaster (1) of the present invention is characterized by comprising a heater (11) that radiates heat rays to roast the surface of an object (N) to be roasted, a reflector (13) that reflects the heat rays radiated by the heater toward the object, and a protective member (15) that is disposed between the object and the heater (11) and that transmits the heat rays and blocks radiation emitted from the object (N).The heat rays are light rays whose wavelength λ is mainly from the red end of visible light (λ=0.75 μm) toward the long wavelength region, up to about λ1 mm.

[0013] A suitable heater for a roaster is a carbon heater (one example is the "Mira Heater" (registered trademark, manufactured by Metro Electric Industries Co., Ltd.). This heater has a carbonaceous (including graphite) filament (11f) vacuum-sealed in a quartz glass tube (11b, protective tube, with high infrared transmittance). Heaters that emit mid-wavelength infrared rays (for example, 1.7 to 2.5 μm) are preferred, as they have the effect of concentrating heat on the surface of the food. Carbon heaters emit strong heat rays and have a fast heat radiation start-up time (for example, 2 to 3 seconds). However, if the quartz glass tube reaches high temperatures, for example, 800°C or higher, and alkali metals (such as sodium) adhere to the surface of the glass, the quartz glass tube will devitrify (become cloudy), reducing its infrared transmittance (reducing its heating capacity).When using sushi ingredients that contain a lot of salt (especially ingredients with mayonnaise), the salty oily smoke rising from the ingredients can come into contact with the outer surface of the glass tube, easily causing devitrification.

[0014] Therefore, in the present invention, a protective member (15, e.g., heat-resistant glass) is provided between the grilling object (N) and the heater (11) to allow heat rays to pass through and block the fumes emitted from the grilling object (N), preventing oily smoke and other particles from scattering onto the heater (11). Specifically, as will be described later with reference to Figures 3 and 4, a plate (15) of ultra-heat-resistant crystallized glass (e.g., Neoceram®) is installed as a protective member below the carbon heater. This prevents oily smoke generated by the grilled sushi ingredients from adhering to the carbon heater (11). As a result, the heater life can be extended, making it possible to provide an electric griller that can withstand long-term commercial use.

[0015] Furthermore, in this embodiment of the present invention, a cooling means (fan 31) for the protective member is also employed to prevent devitrification of the protective glass (15). Specifically, the heat resistance temperature of Neoceram is 800°C. At temperatures above this temperature, crystallization progresses, causing the glass to become cloudy (cloudy), reducing its infrared transmittance and resulting in a decrease in its roasting ability. Therefore, in the specific example described below, a cooling specification is established in which cooling air is blown by an axial fan to the protective glass to prevent the temperature from exceeding the heat resistance temperature. Specific examples of cooling methods for the protective glass (15), the reflector (13), the terminals of the carbon heater (11), etc. will be described later with reference to the drawings.

[0016] The electric roaster of the present invention preferably comprises one or more of the following: (1) A ventilation and cooling system that blows air onto the top surface of the protective glass (15) and maintains a positive pressure in the space between the reflector (13) and the protective glass (15) where the carbon heater (11) is located. (2) A ventilation and cooling system that blows air onto the underside of the protective glass (15) (the side facing the roasting chamber (10)). (3) Cooling mechanism for the end of the heater (11) (terminal, molybdenum foil (11z), etc.)

[0017] In the present invention, it is preferable that the heat radiation density of the heater (11) at the edges of the grilling chamber (10) where the object to be grilled (N) is placed is higher than the heat radiation density near the center of the grilling chamber (10). In the embodiment described below, the light-emitting length (length of the heating element) of the carbon heater filament is 260 mm, but to prevent heat from being concentrated near the center of the grilling chamber, the watt density in the left and right 50 mm sections is set to be approximately 5% higher. This allows for uniform grilling of sushi ingredients on both the left and right sides of the grilling chamber.

[0018] The reflector (13) directs heat rays emitted upward and toward the front and rear from the carbon heater (11) toward the object (N) below. In the embodiment described below, the inner and outer surfaces of this reflector (13) are cooled by air from the fan (31) and are shielded from oily smoke and the like from the object being roasted. Specific examples and detailed specifications of the reflector (13) will be described later with reference to the drawings. [Effects of the Invention]

[0019] According to the present invention, an electric roaster having one or more of the following features can be provided. (A) It enables uniform and quick searing. (i) The smell that is unique to gas does not transfer to food. (c) Reduction of industrial accidents (d) Energy efficiency (E) Installation of safety devices (such as overheating prevention devices) (c) It will be possible to introduce it into gas-free facilities (underground shopping malls, leisure facilities, etc.). (K) The heater has a long lifespan. [Brief explanation of the drawings]

[0020] [Figure 1]1 is a side cross-sectional view that schematically shows the structure of an electric roaster 1 according to an embodiment of the present invention. Note that hatching of thin plate portions has been omitted (the same applies to the other figures). [Figure 2] FIG. 2 is a front view schematically showing the structure of the electric roaster 1 of FIG. [Figure 3] 2 is a cross-sectional side view showing the arrangement of the carbon heater 11, the reflector 13, and the protective glass 15 of the electric grill 1 in FIG. 1, and the state of infrared radiation toward the sushi ingredients N. FIG. [Figure 4] 2 is a schematic cross-sectional side view illustrating the state of air blowing to a reflector 13 and a heater 11 in the electric roaster 1 of FIG. 1. FIG. [Figure 5] 2 is a schematic cross-sectional side view illustrating the state of airflow on the underside of a protective glass 15 in the electric roaster 1 of FIG. 1. FIG. [Figure 6] 2 is a schematic front cross-sectional view illustrating the air flow at the end of the carbon heater 11 in the electric roaster 1 of FIG. 1. FIG. [Figure 7] 2A and 2B are diagrams for explaining the air flow at the end of the carbon heater 11 in the electric roaster 1 of FIG. 1, where (A) is a schematic side cross-sectional view and (B) is a schematic plan cross-sectional view. [Figure 8] 1. FIG. 4 is a front view illustrating an example of changing the height of the roasting chamber 10 in the roaster 1 of FIG. [Figure 9] 1 is a schematic perspective view showing an example of a tray 19 for putting an object (sushi) into and taking it out of a grilling chamber 10. FIG. [Explanation of symbols]

[0021] N: Sushi topping (object to be grilled), S: Rice, W1, W2, W3, W4: Air flow (cooling air) 1; electric grill, 3; main body, 3b; inner chamber, 3g; grill 5: Electrical unit 5 (also serves as a stand for the main unit 3) 10; Roasting chamber, 10b; Opening, 10´; Heater installation space 11; heater, 11b; protective tube (quartz glass tube), 11f; filament, 11x; leaf spring part 11z; Molybdenum foil, 12; Insulator, 13; reflector, 13b; rear edge portion, 13f; curved rising portion, 13g; top flat portion, 13k; curved downward section, 13p; front piece, 13s; front rising section, 13x; ventilation hole 15; protective glass (protective material, heat-resistant glass), 15b; periphery, 15f; underside 17; protective glass tray, 17b; opening, 17p; gap, 17x; flow path, 17z: gap 19; Sushi tray, 19b; Handle, 19c; Long hole, 19x; Tray body 21; Roasting stand, 23; Roasting stand support, 25; Bottom plate 31; cooling means (axial flow fan), 32; vertical plate, 33; partition wall, 331; bracket, 331p; square hole 34; Ventilation duct, 35; Air baffle plate, 35b; Bottom surface, 35d; Front end, 35g; Top surface, 37; Exhaust pipe 39; forward bulkhead, 391; bracket 41; ceramic insulation board, 43; first air insulation layer, 43b; lower opening, 43x; upper opening 45; second air insulation layer, 45b; lower opening, 45x; upper opening, 46; duct, 81; Emergency stop button, 82-83; Cooking start button, 84-85; Timer embodiment of the invention

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The meanings of the directions shown in the diagram are as follows. "Front" is the front side as seen by a chef standing on the left side of the roaster 1 in Figure 1, and is the side where the opening 10b of the roasting chamber 10 is located. "Back" is the opposite direction of "front" and is the direction in which the object (sushi S) is placed into the roasting chamber 10 as seen by the chef. "Down" is the direction of the ground along the direction of Earth's gravity, and "up" is the opposite direction of down. "Left and right" are the "left and right directions" as seen by a chef standing on the front side of the roaster 1.

[0023] First, an outline of the structure of a broiler 1 according to an embodiment of the present invention will be described with reference to Figure 1. Broiler 1 comprises a main body 3 having a broiler chamber 10, a carbon heater 11, a fan 31, etc. inside, and an electrical component 5 (which also serves as a stand for main body 3) located below main body 3. The grilling chamber 10 is a relatively low space that extends from the front to the back of the lower part of the main body 3 (the specific height will be described later with reference to Figure 8). Objects to be grilled, such as sushi S, are placed in the grilling chamber 10. The back of the grilling chamber 10 is closed off by a partition wall 33. The front of the grilling chamber 10 is an opening 10b without a door or the like.

[0024] In the embodiment shown in Figure 2, the bottom of the grilling chamber 10 is composed of three parts, from top to bottom: a grilling stand 21, a grilling stand support 23, and an interior bottom plate 25. The grilling stand 21 is a 9mm thick SUS304 plate. This thickness is extremely thick for a kitchen appliance component (described below). The grilling stand support 23 is a stainless steel plate bent into a channel shape (20mm high). The interior bottom plate 25 is a 6mm thick flat stainless steel plate. None of the parts inside the roasting chamber are fixed with screws or other fasteners, but are simply stacked on top of each other, making them easy to remove and clean.

[0025] Next, we will explain the material of the grill. The broiling cooking method using this embodiment of the product employs a heater output and broiling chamber size suitable for broiling small dishes such as sushi toppings and roasted pork. The broiling time is expected to be approximately 8 to 20 seconds. This broiling time is adjusted using commercially available timers 84 and 85 (see Figure 2) located to the left of the cooking start buttons 82 and 83 on the front of the broiling unit 1. During peak cooking times, repeated broiling processes, i.e., continuous cooking, are performed. Therefore, it is important to select a material for the broiling stand that can withstand the instantaneous high-temperature heat generated by the carbon heater. Therefore, after considering not only durability but also cost-effectiveness, we determined that SUS304 (austenitic stainless steel) with a plate thickness of 9 mm was the appropriate material. When selecting the material for this grill, ferritic metals would glow red due to the instantaneous high-temperature heat, causing rust and raising concerns about the intrusion of foreign matter during cooking. Stainless steel with a plate thickness of 6 mm or less has a history of deformation and distortion during continuous cooking due to the instantaneous high-temperature heat. Therefore, taking into consideration rust prevention performance, durability, cost, and availability, it was determined that SUS304, with a plate thickness of 8 mm or more (more preferably 9 mm or more), was the preferred material. Furthermore, in installing the grill, consideration was given to preventing stains caused by the adhesion of grease and other substances released from ingredients during cooking. Therefore, the grill was designed to be placed simply on a grill support installed underneath the grill, making it easy to remove and clean.

[0026] Next, with reference to Figure 8, we will explain an example of changing the height of the grill chamber 10 in the griller 1 of Figure 1. Figure 8(A) shows the grilling table 21, grilling table support 23, and interior bottom plate 25 all present, and the height of the grill chamber 10 (the dimension from the top of the grilling table 21 to the bottom of the protective glass 15) is 45 mm. This dimension is the height (30 mm) of regular sushi (rice S and topping N), which is a standard menu item, plus the thickness of the tray 19 (1.5 mm) and the necessary gap (13.5 mm) above and below. Figure 8(B) shows the state where the grilling table 21 has been removed, leaving the grilling table support 23 and the interior bottom plate 25 in place, with the grilling chamber 10' having a height of 55 mm. Figure 8(C) shows the state where the grilling table 21 and grilling table support 23 have been removed, with the grilling chamber 10" having a height of 75 mm. In this way, for menus that are taller than standard menus, the grilling table and grilling table support can be easily removed, allowing grilling to be performed to suit the height of the individual menu.

[0027] Next, the protective glass 15 and its surrounding structure will be described with reference to FIG. 3. The roof of the grilling chamber 10 is covered with the protective glass 15, and above it are the carbon heater 11 and reflector 13. The periphery 15b of the protective glass 15 rests on a frame-shaped protective glass tray 17, and the central underside 15f of the protective glass 15 is exposed downward through an opening 17b in the tray 17. When cleaning the protective glass 15, the tray 17 is removed. In this embodiment, the protective glass 15 is made of a plate of ultra-heat-resistant crystallized glass (Neoceram (registered trademark) for example). This prevents oily smoke generated by the sushi ingredients being grilled from adhering to the carbon heater 11. As a result, the heater life can be extended. When grilling food that contains a lot of oil and fat, oily smoke is generated during the grilling process and can adhere to the surface of the protective glass 15. If oily smoke continues to adhere and accumulate, the glass surface will become cloudy, reducing the transmittance of mid-infrared rays and reducing the grilling ability, so measures to prevent oily smoke from adhering to the protective glass 15 will be described later with reference to Figures 4 and 5.

[0028] The preferred heater for a roasting grill is a carbon heater (one example is the "Mira Heater" registered trademark, manufactured by Metro Electric Industries Co., Ltd.). This heater consists of a carbonaceous (including graphite) filament vacuum-sealed in a quartz glass tube (protective tube with high infrared transmittance). Heaters that emit mid-wavelength infrared rays (for example, 1.7 to 2.5 μm) are preferred, as they have the effect of concentrating heat on the surface of the food. Carbon heaters emit strong heat rays and have a fast heat radiation start-up time (for example, 2 to 3 seconds).

[0029] In the grill 1 of this embodiment, three rod-shaped carbon heaters 11 are arranged on top of the grilling chamber 10 (through a protective glass 15) so as to extend in the left-right direction (see Figure 2). Each heater has an output of 2150 W, a diameter of 13 mm, and a light-emitting section length of 250 mm. The filament width is narrowed by 50 mm at each of the left and right ends of the 250 mm light-emitting section, and due to increased electrical resistance, the filament temperature is 1430°C, which is higher than the 1400°C in the center. This is to ensure that sushi ingredients N placed near the left and right walls of the grilling chamber 10 can be sufficiently grilled.

[0030] Next, we will explain the reflector 13. The reflector 13 is an aluminum plate (e.g., 2 mm thick) bent into a roof shape when viewed from the side cross section. The reflector 13 has a curved shape (parabolic mirror shape) on both sides, taking into account the light reflection angle, so that the mid-infrared rays emitted from the carbon heater 11 can be efficiently irradiated onto the sushi ingredients N placed below the heater. 3 (a view cut along a plane along the back-front / up-down direction), from back to front, there are rear edge portion 13b, curved rising portion 13f, flat ceiling portion 13g, curved falling portion 13k, front piece portion 13p, and front rising portion 13s. Rear edge portion 13b is flat and belt-shaped, extending left-right (perpendicular to the plane of FIG. 3), and rests on bracket 331 fixed to partition wall 33.

[0031] The curved rising portion 13f is concavely curved on the inside and rises from the rear edge portion 13b to above the carbon heaters 11 (viewed from the rear to the front). The flat top portion 13g is flat and covers the tops of the three heaters 11 arranged in parallel. The curved falling portion 13k is concavely curved on the inside and falls from the flat top portion 13g to above the protective glass 15 (viewed from the rear to the front). The front piece 13p rests on a bracket 391 fixed to the front partition wall 39. The front rising portion 13s rises up from the front edge of the front piece 13p in the right-front direction. This portion 13s guides the cooling air upward (see Figure 4).

[0032] For the reflector 13, aluminum was used, taking into consideration its high light energy reflection efficiency, versatility, cost, and durability against the instantaneous high temperature heat generated by the carbon heater. A mirror finish is considered preferable for the surface finish of the reflector 13, as it increases reflection efficiency, but it has been confirmed that the material color (silver anodized finish) also provides a sufficient scorching effect. Examples of aluminum materials include A1100 and A1050.

[0033] Next, measures for cooling the heater 11, protective glass 15, and reflector 13 and preventing oily smoke from blowing away will be described with reference to Figures 4 and 5. The roasting apparatus 1 of this embodiment is provided with a first ventilation / air-cooling system that blows air onto the upper surface of the reflector 13, a second ventilation / air-cooling system that blows air onto the upper surface of the protective glass 15 and maintains a positive pressure in the space where the carbon heater 11 is located between the reflector 13 and the protective glass 15, and a third ventilation / air-cooling system that blows air onto the underside of the protective glass 15 (the surface facing the roasting chamber 10). Note that cooling of the end of the heater 11 (terminals and molybdenum foil 11z) (a fourth ventilation / air-cooling system) will be described separately. Fig. 4 is a schematic side cross-sectional view illustrating the state of air blowing to the reflector 13 and heater 11 in the electric broiler 1 of this embodiment. Fig. 5 is a schematic side cross-sectional view illustrating the state of air blowing to the underside of the protective glass 15 in the electric broiler 1 of this embodiment.

[0034] In Figure 4, the grilling chamber 10 for grilling sushi ingredients N is shown at the bottom front, and above it, a carbon heater 11 and a reflector 13 are shown separated by a protective glass 15. Behind the reflector 13, a partition wall 33 that forms the rear wall of the grilling chamber 10 is shown as a wall-like structure that extends vertically. As shown in Figure 2, two axial fans 31 are arranged on the left and right sides of the upper rear part of the partition wall 33. The fans 31 are attached to a vertical plate 32 inside the main body 3, and blow air (indicated by a thick black arrow) from the rear side to the front side. When the fans 31 are operating, they draw air from the kitchen into the rear chamber 3b of the main body 3 through a grill (ventilation hole) 3g on the rear surface, and send the air toward the front through the ventilation duct 34.

[0035] Most of the air passing through the ventilation passage 34 (indicated by the thick black arrow) passes between the upper surface of the reflector 13 and the underside 35b of the air rectifier 35. The cooling air W1 from the axial fan 31 is blown directly against the back surface of the reflector 13 to cool it. To ensure that the cooling air hits the reflector 13 more efficiently, the air rectifier 35 is installed above the reflector 11 at an angle that narrows the exhaust direction, enhancing the cooling effect. The air rectifier 35 is a plate that extends downward from the top of the partition wall 33 toward the front. The air rectifier 35 extends left and right across almost the entire width of the roasting chamber 10, with the cross-sectional shape shown in Figure 4. The reflector 13 also extends left and right across almost the entire width of the roasting chamber 10, with the cross-sectional shape shown in Figure 4.

[0036] The reflector 13 is exposed to direct heat from the carbon heater 11 from a distance of 6 mm. Furthermore, because it is made of aluminum, which has a low melting point, it must be cooled to a temperature of approximately 340°C or less. The airflow W1 that passes over the reflector 13 toward the front side makes a U-turn above the front end 35d of the rectifier 35 and flows along the top surface 35g of the rectifier 35. The air is then exhausted from the exhaust pipe 37 into the kitchen above the rear side of the broiler 1 (the side farthest from the cook). This ensures an exhaust path that prevents workers in front of the appliance from being exposed to the cooling air. The exhaust temperature is approximately 80°C, which is acceptable for the ambient temperature of kitchen appliances.

[0037] Ventilation holes 13x (each with a diameter of, for example, 4.5 mm, are provided laterally) are formed in the lower, rearward portion of the reflector 13. A portion of the air passing through the ventilation passages 34 from the fan 31 enters the interior of the reflector 13 (the space between the reflector 13 and the upper surface of the protective glass 15) through the ventilation holes 13x. The air (airflow W2) flows along the upper surface of the protective glass 15, cooling it. The airflow W2 passes through the flow passages 17x on the upper surface of the protective glass tray 17 and is exhausted into the kitchen through the gap 17z (CL = 4 mm, extending laterally) on the front side. The air introduced through the holes 13x creates positive pressure between the lower surface of the reflector 13 and the upper surface of the protective glass 15 (the space where the carbon heater is located) because cooling air is constantly being blown in from the axial fan. This prevents oily smoke from the object being grilled during grilling from penetrating to a position where it would come into contact with the carbon heater 11.

[0038] Next, the air flow W3 below the protective glass 15 will be described. In Figure 5, the thick black arrow indicates airflow W3 flowing under the protective glass 15 (above the sushi ingredients N). This airflow W3 is a portion of the air that has passed through ventilation duct 34 from fan 31, passed through square hole 331p (e.g., 5 x 20 mm) in bracket 331 fixed to partition wall 33, passed through gap 17p in protective glass tray 17, and entered the upper part of roasting chamber 10.

[0039] The incoming air (air flow W3) flows under the protective glass 15, cooling it and removing oily smoke from the sushi ingredients N (forming a means for preventing oily smoke from adhering to the protective glass 15). Air flow W3 flows gently toward the front of the roasting chamber 10 and is exhausted into the kitchen through the front opening 10b of the roasting chamber 10. This prevents oily smoke from floating inside the roasting chamber, thereby improving the effectiveness of preventing oily smoke from adhering to the protective glass. The temperature of the exhaust air from the roasting chamber 10 is not much different from the temperature inside the kitchen. This is because heating by the carbon heater 11 has a significant effect of rapidly heating solid objects that receive infrared rays, but does not have much effect of heating the air inside the roasting chamber 10.

[0040] Next, a method for cooling the end of the carbon heater 11 will be described with reference to Figures 6 and 7. Figures 6 and 7 are schematic diagrams illustrating the airflow at the end of the carbon heater 11 in the electric roaster 1 of Figure 1. Figure 6 is a front cross-sectional view, Figure 7(A) is a side cross-sectional view, and Figure 7(B) is a plan cross-sectional view. Figures 6 and 7(B) show the carbon heater 11 extending in the left-right direction and the insulators 12 at its left and right end portions.

[0041] As mentioned above, the carbon heater 11 has a carbonaceous filament 11f sealed in a protective tube 11b made of quartz glass. The end of the heater 11 serves as a connection for supplying current to the filament 11f, and is connected to the insulator 12 via a wavy leaf spring 11x (made of molybdenum) and a molybdenum foil 11z. The heat resistance temperature of the molybdenum foil 11z is set to 250°C or less, as recommended by the manufacturer. Therefore, a three-layer insulation structure and cooling mechanism have been established to prevent the ends of the carbon lamp heater from reaching 250°C due to radiant heat and heat conduction from the roasting chamber 10 and the center of the heater 11 during roasting.

[0042] Specifically, as a first layer of the heat insulating structure, a layer of heat insulating material (ceramic heat insulating board 41) was provided so as to cover the left and right side surfaces (rear surfaces) of the roasting chamber interior 10 and the heater installation space 10'. The second layer of insulation is a first air insulation layer 43 provided on the outside (the backside of the left and right sides) of the insulation board 41. As shown in Figures 6 and 7(B), this first air insulation layer 43 extends vertically and in a front-to-back direction on the left and right sides of the roasting chamber interior 10 and the heater installation space 10'. As shown in Figure 6, this insulation layer 43 has an open bottom opening 43b and top opening 43x. By natural convection, room-temperature air flows in through the bottom opening 43b, flows upward from the bottom as cooling air (air flow W4-1), and then exits through the top opening 43x as air flow W4-1. This air flow W4-1 cools the end of the heater 11 and insulates against heat transfer to the left and right sides.

[0043] The third layer of insulation is a second air insulation layer 45 with a duct structure provided on the left and right side (back) surfaces of the first air insulation layer 43. As shown in FIG. 7(B), the second air insulation layer 45 includes a box-shaped, flat duct 46 that surrounds the corrugated leaf springs 11x (made of molybdenum) and molybdenum foil 11z at both ends of the three rows of carbon heaters 11, as well as the insulators 12. As shown in FIG. 6, the duct 46 and the second air insulation layer 45 have an open (or perforated) lower opening 45b and upper opening 45x. By natural convection, room-temperature air flows in through the lower opening 45b, flows upward from the bottom as cooling air (air flow W4-2), and then exits through the upper opening 45x. This air flow W4-2 cools the ends of the heaters 11 (such as the molybdenum foil 11z).

[0044] That is, in the second insulating air layer 45 of this embodiment, both ends of the carbon lamp heaters 11 that need to be cooled are structured to fit inside the duct 46, generating a strong draft inside the duct and enhancing the cooling effect. The ventilation path inside the duct has the smallest cross-sectional area possible to fit the ends of the three heaters 11, allowing the cooling air to flow intensively toward the heater ends, further enhancing the cooling effect. At least the second insulating air layer 45 has a duct structure that is narrower than the depth of the insulating material 41 layer and that can fit the molybdenum foil 11z at the ends of the heaters 11. As shown in Figure 7(A), the air that passes through the insulating air layers 43 and 45 is exhausted from the exhaust pipe 37 at the top of the broiler 1 into the kitchen above the back side of the broiler 1 (the side farthest from the cook). This ensures an exhaust path that prevents workers in front of the appliance from being exposed to heated cooling air.

[0045] Next, we will explain the dedicated tray 19 used to load and unload sushi S topped with toppings N into and from the grilling chamber 10, with reference to Figure 9. When grilling, we recommend placing the menu on a dedicated tray to prevent the cook from being burned by touching the high-temperature areas around the chamber. The dedicated tray 19 is made of stainless steel with a thickness of 1 mm to 1.5 mm, allowing its opening to be adjusted depending on the number of sushi toppings and the size of the items to be grilled. The method of placing the sushi toppings on the dedicated tray 19, inserting it into the grilling chamber 10, and grilling the sushi S while it is still on the tray 19 is a cooking method that significantly improves work efficiency compared to the traditional method of placing only the toppings on a grill, grilling them over a burner flame, and then removing the toppings from the grill and placing them on top of the rice.

[0046] Figure 9 is a perspective view of a wide tray 19 that can hold 10 pieces of sushi S. The tray 19 consists of a tray body 19z (flat portion 19k) that can hold 10 pieces of sushi S, and a handle 19b that protrudes from the front of the tray. The handle 19b of the dedicated tray 19 has four elongated holes 19c (6 mm wide x 90 mm long) to reduce the effects of heat conduction during grilling. These holes enhance heat dissipation and reduce heat conduction from the grilling chamber, thereby reducing the temperature rise of the handle and preventing burns. Reference numeral 19g denotes the slightly elevated portion between the handle 19b and the main body 19z, and reference numerals 19p and 19t denote raised edges around the flat portion 19k (to prevent the sushi from falling). If necessary, a medium-width tray for six pieces of sushi or a narrow tray for two pieces of sushi can also be used. For example, the width of the tray is 270 mm for 10 kan, 178 mm for 6 kan, and 86 mm for 2 kan.

[0047] Next, we will explain the cleanability of the broiler 1 of this embodiment. The components of the broiler 1, namely the protective glass 15, the broiler stand 21, the broiler stand holder 23, and the interior bottom plate 25, are not attached with screws or the like, and are designed to be easily removed and cleaned. This product generates instantaneous high-temperature heat for broiling, and it is expected that oil smoke and other substances will adhere, stick, and accumulate over long periods of use. Therefore, the design has been carefully considered to make the components easy to remove and clean.

[0048] Finally, the advantages of introducing the roaster 1 of this embodiment will be described. The advantages of introducing the roaster 1 can be listed as follows. (1) It enables uniform and short-time grilling. Grilling does not require skill, and anyone can grill the sushi evenly. In the case of grilled sushi, up to 10 pieces can be grilled at once. The grilling time is approximately 8 to 20 seconds (the grilling time is adjusted using timers 84 and 85 (see Figure 2)). This significantly improves work efficiency. (2) The gas-specific odor does not transfer to food. When grilling with a gas flame, the gas cartridge contains mercaptan, which gives off an odor so that gas leaks can be detected, and trace amounts of this odor adhere to the grilled object. This results in a gas smell in the texture. However, because this product uses electricity as the heat source, there is no transfer of the gas smell, allowing you to enjoy the original flavor of the ingredients.

[0049] (3) Reduction of industrial accidents, fires, and explosions Because no open flame is used, there is absolutely no risk of burns, ignition due to gas leaks, or explosions, which certainly reduces industrial accidents. When disposing of used gas cartridges, it is common to puncture the can to ensure that the gas inside the cartridge is empty before discarding, but explosions often occur during this gas release process. Therefore, since there is no need for gas cartridges, industrial accidents, fires, and explosions are also reduced. (4) Energy saving and reduced running costs High-temperature instantaneous heat generation with increased light energy reflection efficiency provides highly efficient searing. The searing time can be set using Timer 84 / 85 (see Figure 2), allowing for searing without energy loss. Eliminating the need for disposal costs for gas cartridges also reduces running costs.

[0050] (5) Installation of safety devices By installing an overheating prevention device (emergency stop button 81 (see Figure 2) and bimetal sensor), heating can be forcibly stopped in the unlikely event of an abnormal temperature rise. The bimetal sensor is attached to the vertical plate 32 between the two axial fans 31. (6) It can be installed in gas-free facilities (underground shopping malls, leisure facilities, etc.). (7) The heater has a long life.

Claims

1. a heater (11) that emits heat rays to heat the surface of the object (N); a reflector (13) that reflects the heat rays emitted by the heater toward an object; a protective member (15) disposed between the object (N) and the heater (11), through which the heat rays pass and which shields the emitted matter from the object (N); An electric grill (1) characterized by comprising:

2. The protective member (15) is heat-resistant glass, The electric roaster (1) according to claim 1, further comprising an air-blowing cooling system that blows air onto the upper surface of the glass and maintains a positive pressure in the space between the reflector (13) and the protective glass (15) in which the carbon heater (11) is located.

3. 3. The electric roaster (1) according to claim 1 or 2, further comprising an air blowing system for blowing air onto the underside of the protective member (15), i.e., the surface facing the roasting chamber (10).

4. As a cooling mechanism for the end of the heater (11), a layer of heat insulating material (41) provided so as to cover the side surfaces of the roasting chamber interior (10) and the heater installation space (10'); an air insulation layer (43, 45) provided outside the layer of insulation material; 3. An electric roaster (1) according to claim 1 or 2, characterized in that it comprises:

5. The electric roaster (1) according to claim 4, characterized in that the air insulation layer (45) has a duct structure narrower than the depth of the layer of insulation material (41) and into which the molybdenum foil (11z) at the end of the heater (11) is housed.

6. 3. The electric grill (1) according to claim 1 or 2, characterized in that the heat radiation density of the heater (11) at the end portions of the grilling chamber (10) where the object to be grilled (N) is placed is higher than the heat radiation density near the center of the grilling chamber (10).

7. 3. The electric roaster (1) according to claim 1 or 2, characterized in that the roasting table (21) on which the object to be roasted (N) is placed is a plate made of austenitic stainless steel and has a thickness of 8 mm or more.

8. The electric roaster (1) according to claim 1 or 2, characterized in that the protective member is a protective glass (15) placed on a frame-shaped protective glass tray (17), and the lower surface (15f) of the central part of the protective glass (15) is exposed downward from an opening (17b) of the tray (17), so that the protective glass (15) can be pulled out together with the tray (17).

9. A method for grilling an object (N) using the electric grill (1) according to claim 1 or 2, characterized in that the object (N) is grilled while being placed on a tray (19) that is taken in and out of the grilling chamber (10).

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