Sweet potato roaster

Abstract

To provide a sweet potato roaster that can roast food (such as sweet potatoes) uniformly, regardless of its placement. [Solution] The sweet potato roaster 1 comprises a roasting chamber 5 for roasting sweet potatoes, a tray 75 placed inside the roasting chamber on which the sweet potatoes P to be roasted are placed, and a heating means 51 for raising the temperature inside the roasting chamber. Above the tray 75 in the roasting chamber 5 is a far-infrared radiating heater 51, and directly below it is a far-infrared diffusing plate 52 having numerous holes.

Description

Technical Field

[0001] The present invention relates to a sweet potato roaster suitable for placement on the fresh food floor of a supermarket or the like. In particular, the present invention relates to a sweet potato roaster capable of baking sweet and delicious baked sweet potatoes by improving the uniform baking ability and far-infrared heating ability.

Background Art

[0002] In supermarkets, near the fresh food floor or the entrance of discount stores, from autumn to winter and in the early spring, a business style of selling freshly baked sweet potatoes baked in the store has become popular. As the specifications of such stationary sweet potato roasters, those having a baking chamber with two to three stages and a warming chamber at the top are mainstream. After the baking of the sweet potatoes is completed, it is common to see the scene where the baked sweet potatoes are moved to a transparent box-shaped warming chamber that is easily noticeable to people, and face-to-face sales are conducted while appealing the freshness. Patent Document 1 discloses an electric sweet potato roaster (however, a tabletop type) invented by the inventors of the present application.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] According to the analysis and study by the inventors of the present application, the following problems (points to be improved) are considered to exist in the current general sweet potato roasters in the market. (1) Insufficient uniform baking ability; Currently, most sweet potato roasters on the market use a simple design where sweet potatoes are placed on a rack inside the roasting chamber, and heated by heaters located above and below. As a result, sweet potatoes placed near the heaters tend to be heated more easily, while those placed further away tend to be heated less evenly. In other words, they have poor uniform roasting capabilities, and sweet potato vendors tend to set the roasting time longer (for example, around 60-90 minutes) to compensate for undercooking. (2) Observation inside the firing chamber is inconvenient; The baking chamber is typically configured with two or three tiers in a vertical arrangement to allow for cooking according to the amount of sweet potatoes being baked. However, it generally lacks a window to check how many sweet potatoes are in each tier or how well they are baked during cooking.

[0005] (3) Opening and closing the firing chamber is time-consuming; During cooking, the surface of a sweet potato roaster becomes hot due to radiant heat and heat conduction from inside the roasting chamber. Therefore, most sweet potato roasters have double doors on the front that serve as air insulation to prevent burns from contact with the equipment. However, opening the large double doors on the front of the sweet potato roaster every time you put sweet potatoes in or take them out is a cumbersome task. (4) Insufficient durability of the heater; During the baking of sweet potatoes, the syrup produced by the saccharification of the starch in the sweet potatoes adheres to and hardens on the surface of the heater installed at the bottom of the baking chamber, causing localized overheating and resulting in frequent heater failures.

[0006] The present invention aims to provide a sweet potato roasting device that has one or more of the following advantages. (1) Uniform baking; the baked items (such as sweet potatoes) can be baked uniformly, regardless of their placement. (2) By enhancing the far-infrared heating of the baking chamber, heat penetration into the sweet potatoes is increased, the enzyme β-amylase contained in the sweet potatoes is activated, resulting in a finished product with a higher sugar content. (3) The installation of a viewing window allows the amount of potatoes and the baking status to be checked at all times. (4) By reducing radiation from the front of the sweet potato roaster body, sweet potatoes can be put in and taken out efficiently and easily without the need for burn prevention structures such as double doors on the front of the body. (5) Easy to clean; the syrup dripping from the potatoes and potato peel residue that accumulate at the bottom of the oven can be easily and with minimal effort to clean. [Means for solving the problem]

[0007] In this "Means for Solving the Problem" and "Claims," ​​the reference numerals for each part of the attached figures are indicated in parentheses, but this is for reference purposes only and is not intended to limit the scope of rights to those shown in the attached figures. Hereinafter in this specification, "potato" and "baked potato" will be used as representatives of the baked product, but the subject of the present invention is not limited to "potato," and "potato" comprehensively refers to baked products such as corn and potatoes.

[0008] The first sweet potato roaster (1) of the present invention comprises a roasting chamber (5) for roasting sweet potatoes, a tray (75) placed inside the roasting chamber for placing sweet potatoes (P) to be roasted, and a heating means for raising the temperature inside the roasting chamber, wherein the roaster (1) is provided with a far-infrared radiating heater (51) and a far-infrared diffusing plate (52) having numerous holes directly below it, above the tray (75) in the roasting chamber (5).

[0009] The far-infrared rays (heat rays) emitted by the far-infrared radiating heater (51) are diffused by the far-infrared diffusion plate (52) which has multiple holes, and are emitted towards the potatoes (P, baked product, tray) below. This prevents localized variations in the intensity of the far-infrared rays, enabling uniform far-infrared irradiation. Desired forms and examples of hole dimensions, number, arrangement, and aperture ratio will be described later with reference to the drawings. "Far-infrared radiation" is a commonly known technical term, referring specifically to infrared radiation, a type of light and electromagnetic wave, that lies in the wavelength range of 3 μm to 1000 μm. Many foods containing moisture, such as potatoes, have an absorption wavelength range between 2 μm and 20 μm, so far-infrared radiation has the property of effectively transferring and penetrating heat to these foods. "Heat rays" are also electromagnetic waves in almost the same wavelength range as "far-infrared radiation," and refer to wavelengths λ from the red end of visible light (λ=0.75 μm) towards the long-wavelength region, up to about λ≅1 mm. In this invention, "far-infrared radiation" also includes electromagnetic waves referred to as "heat rays." The far-infrared diffusion plate (52) can be installed directly below the far-infrared heater to prevent accidental contact and damage to the heater during cleaning of the interior of the oven.

[0010] In the first sweet potato roasting oven (1) of the present invention, it is preferable that a corner reflector (53) is installed at the front and / or rear of the upper part of the roasting chamber (5) to reflect the far-infrared rays emitted by the far-infrared radiating heater (51) downward. Far-infrared rays are reflected by the corner reflectors and irradiated to the front and / or back of the tray, supplementing the heating capacity of those areas. Because the front and back of the tray are structurally less irradiated by far-infrared rays and tend to have lower heating capacity, corner reflectors are installed at the front and back of the top of the baking chamber to improve the uniformity of far-infrared radiation to the tray (75). Examples of the shape and material of the corner reflectors (53) will be described later with reference to the diagram.

[0011] The second sweet potato roaster (1) of the present invention comprises a roasting chamber (5) for roasting sweet potatoes, a tray (75) placed inside the roasting chamber for placing sweet potatoes (P) to be roasted, and a heating means for raising the temperature inside the roasting chamber, wherein the surface of the tray (75) on which the sweet potatoes (P) are placed is coated with a black ceramic material, a number of vertical through holes (75h) are formed in a distributed manner on the tray (75), and the heating means (56) is positioned below the tray (75).

[0012] A black ceramic coating is a coating that exhibits a black color and contains a ceramic material that emits far-infrared rays. Examples include black ceramic coatings (coated and fired films) or black anodized aluminum. The emissivity of the coating is preferably 0.8 or higher. Specific examples of black ceramic coatings (coated and fired films) will be described later. Note that "black" here simply means "dark-colored." The desired form and embodiment of the "multiple vertical through holes (75h)" formed in the tray (75), including the hole dimensions, number, arrangement, and opening ratio, will be described later with reference to the drawings. A sheathed heater or the like can be used as the heating means (56). The hot air generated from the heating means (56), such as a sheathed heater, passes through the upper and lower through-holes (75h) of the tray and is transmitted to the sweet potatoes. At the same time, far-infrared rays are emitted from the black ceramic coating film on the upper surface (the surface on which the sweet potatoes P are placed) of the tray (75), which has been heated by the heater, and this has the effect of further enhancing the penetration of heat into the sweet potatoes.

[0013] In the sweet potato roaster (1) of the present invention, it is preferable that the heating means (56) below the object to be roasted (P) is a sheathed heater, and that a heater protective umbrella (57) covering the heater (56) is installed. The protective cover prevents the syrup and burnt residue that drip from the sweet potatoes during roasting from adhering to and sticking to the sheathed heater (56), thus preventing localized overheating and damage to the heater. By installing the heater protective cover directly above the heater, it also serves to prevent localized heating to the area directly above the sheathed heater (part of the underside of the tray (75)).

[0014] The sweet potato roaster (1) of the present invention may also preferably have both the characteristic configuration of the first sweet potato roaster (1) and the characteristic configuration of the second sweet potato roaster (1). In this case, the sweet potato receives far-infrared rays from above from the far-infrared heater (51) and far-infrared diffuser plate (52), and from below from the tray (75) which is coated with a black ceramic film. This allows the sweet potato to be baked moist and delicious while retaining its moisture. In other words, because far-infrared rays have high heat penetration into food, localized concentrated heating near the surface is less likely to occur, and the evaporation of moisture caused by concentrated heating is suppressed. Therefore, it is possible to bake sweet potatoes that are "juicy inside and crispy outside," or sweet potatoes that are particularly excellent in one or more of the characteristics of sweetness, aroma, stickiness, and texture.

[0015] The third sweet potato roaster (1) of the present invention comprises: a roasting chamber (5) for roasting sweet potatoes arranged in multiple vertical rows; a drawer (7) for each roasting chamber (5) that is retractable and retractable, and has a tray (75) for placing sweet potatoes (P) to be roasted, and a front door (71) thereon; and a heating means for raising the temperature inside each roasting chamber, wherein the door (71) is provided with a window (73) that allows the inside of the chamber to be seen through. A window (made of heat-resistant glass, etc.) is installed in the door (71) to check the baking progress and number of sweet potatoes. Even when the door is closed, the inside of the baking chamber is clearly visible, making it easy to check whether there are any sweet potatoes (items being baked), their number, and their degree of baking.

[0016] In the third sweet potato roasting device (1) of the present invention, it is preferable that an air insulation layer is provided in the front door (71) of the drawer (7), including the portion of the window (73). By incorporating an air insulation (air cooling) layer, including the window area, and reducing radiation from the front of the sweet potato roaster, safety measures such as preventing burns in areas that shoppers are likely to touch can be enhanced.

[0017] In the sweet potato roaster (1) of the present invention, it is preferable that the far-infrared diffusion plate (52), the tray (75) with a black ceramic coating, and / or the heater protective umbrella (57) can be removed from the door (71) opening. Each component is easy to clean outside the oven.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a sweet potato roasting device having one or more of the following features. (1) Effect of uniform baking It enables uniform baking of roasted sweet potatoes without being affected by the placement position of the sweet potatoes. (2) Baking effect using far-infrared rays · By baking using a far-infrared heater (51), a diffusion plate (52), and / or a far-infrared radiation tray (57), the heat permeability to the sweet potatoes is enhanced, the enzyme β-amylase contained in the sweet potatoes is activated, and it is possible to achieve a finished product of roasted sweet potatoes with increased sugar content. (3) Effect of the viewing window By installing the viewing window, the amount of sweet potatoes and the baking state can always be confirmed. (4) Effect of reducing radiation When an air heat insulation layer is provided on the front part of the drawer (7) to reduce radiation, it is possible to improve the efficiency of taking in and out the sweet potatoes without providing a burn prevention structure such as a Kannon door on the front part of the main body.

Brief Description of the Drawings

[0019] [Figure 1] It is a side view showing the overall configuration of the sweet potato roasting device 1 according to an embodiment of the present invention. [Figure 2] It is a front view of the sweet potato roasting device 1 in FIG. 1. [Figure 3] It is an enlarged side view schematically showing the configuration of the heating means for uniformly heating the roasted sweet potato P in the baking chamber 5 of the sweet potato roasting device 1 in FIG. 1, and the structure of the door 71 and the general arrangement of the heat insulating material. [Figure 4] It is a plan view of the infrared diffusion plate 52 of the sweet potato roasting device 1 in FIG. 1. [Figure 5] It is a perspective view of the tray 75 which is subjected to a black ceramic coating treatment and has a large number of holes 75h formed thereon in the sweet potato roasting device 1 in FIG. 1. [Figure 6] It is a perspective view of the heater protection umbrella 57 covering the sheath heater 56 of the sweet potato roasting device 1 in FIG. 1 as seen obliquely from above. [Figure 7]These are photographs showing the degree of browning on the surface of a slice of bread as a result of a test in which a slice of bread was baked using a sweet potato roaster according to one embodiment of the present invention and a sweet potato roaster according to a comparative example. (A) and (B) are from the embodiment, and (C) and (D) are from the comparative example. (A) and (C) are the top surface of the bread, and (B) and (D) are the bottom surface. [Figure 8] Figure 8(A) is a perspective view of the entire sweet potato roasting machine 1 shown in Figure 1. Figure 8(B) is a photograph showing the sweet potatoes P inside the roasting chamber 5, with a close-up view of the window 73 of the door 71. [Figure 9] Figure 1 is a schematic side cross-sectional view showing the cooling structure on the front side of the sweet potato roaster 1. [Figure 10] Figure 1 is a schematic side cross-sectional view showing the heat protector 70 and the cooling structure above the door 71 of the sweet potato roaster 1. [Figure 11] Figure 1 is a schematic front cross-sectional view showing the cooling structure of the left and right walls and ceiling of the sweet potato roasting machine 1. [Figure 12] Figure 1 is a schematic side cross-sectional view showing the cooling structure of the rear wall and ceiling of the sweet potato roasting machine 1, as well as the chimneys on the left and right side walls. [Figure 13] Figure 13(A) is a schematic side cross-sectional view with the drawer 7 pulled out, Figure 13(B) is a schematic side cross-sectional view with the tray 75 removed, and Figure 13(C) is a schematic side cross-sectional view with the protective cover 57 of the sheath heater 56 removed. [Figure 14] Figure 14 is a schematic side cross-sectional view showing the state after the drawer 7 has been pulled out and the infrared diffuser plate 52 has been removed. [Figure 15] Figure 15(A) is a schematic side cross-sectional view of the trash tray 59 with the front panel 46 removed, and Figure 15(B) is a schematic side cross-sectional view of the trash tray 59 with the trash tray 59 removed. [Explanation of Symbols]

[0020] 1; Sweet potato roaster, 2; Warming section, 24; Top surface, 25; Side wall, 27; Door, 29; Panel heater 3; Main body casing, 3v; Top plate, 3y; Outer skin, 34b; Outer skin, 34d; Outer hollow part, 34g; Outer middle plate 34j; external air passage, 34k; internal middle plate, 34p; internal air passage, 35b·35f; ceiling air passage, 38; Chimney, 38c; Outer channel, 38f; Middle channel, 38j; Center channel, 38jz; Top end 38 38p; middle flow path, 38s; outer flow path, 38z; top end 39; Control Panel 41; Outer ceiling air passage, 42; Inner ceiling air passage, 43; Outer left wall air passage 44; Air passage inside the left wall, 45; Air passage outside the right wall, 451; Air passage inside the right wall 46; Front panel for receiving debris, 46z; Burring holes 47; Dew tray, 48; Electrical components, 49; Caster 5; Baking chamber, 51; Far-infrared radiant heater (heating means, upper heater) 52; Far-infrared diffusion plate, 52b, 52c, 52d; Edge, 52j; Main body plate, 52m; Front diffusion section 52r; round hole, 52s; rib, 52t; central opening, 52w; back diffusion section, 52x; back opening 56; Sheathed heater (second heating means), 56b; protective tube 57; Heater protective cover, 57f; Upper flat strip section, 57g; Eaves strip section, 57y; Pipe 501-505; Insulation 7; drawer, 70; Heat protector, 70d; Outer shell, 70f: Gap, 70g; Air passage, 70h; Inner plate 70j;interior space, 70k;entrance, 70p;empty space 71; door, 71z; burring hole 73; window, 73b; front glass, 73f; front recess, 73g; external flow channel, 73h; middle panel window, 73k; internal flow channel, 73p; Oku glass, 73r; Oku recess, 75; Tray (far-infrared radiation tray), 75b; Edge, 75f; Main body plate, 75h; Upper and lower through holes, 75x; Knob hole, 76; Embodiment of the drawer frame invention

[0021] The embodiments of the present invention will be described below with reference to the attached diagrams. In each diagram, the "up" and "down" directions indicated by the arrows are in line with Earth's gravity. "Front" is the side in front of the baking chamber door 71 and the control panel 39 (see Figure 2) where people buying baked sweet potatoes (customers) or machine operators (supermarket staff, etc.) stand. "Back" is the direction farther away from the customer or operator standing in the front (towards the back of the baking chamber 5). "Left" and "right" are the left and right directions when viewing the sweet potato roaster 1 from front to back. The specific shapes of numbers, materials, and components described in the following description of embodiments are all examples only, and the present invention is not limited by such numerical values, etc.

[0022] First, the overall configuration of the sweet potato roaster 1 according to an embodiment of the present invention will be described with reference to Figure 1, which is a side view thereof, and Figure 2, which is a front view thereof. The sweet potato roaster 1 in this embodiment is a relatively large, floor-mounted roaster for supermarkets and mass retailers, having three roasting chambers 5A, B, and C arranged in upper and lower levels. Approximately 20 large sweet potatoes can be roasted in each roasting chamber 5. This sweet potato roasting machine 1 is broadly composed of the following components: the main casing 3, the roasting chamber 5, the warming unit 2, and the control panel 39 and electrical unit 48.

[0023] The main casing 3 is a rectangular box made of stainless steel plate (for example), with a vertical orientation, and inside it are three baking chambers 5 arranged in two tiers. Since heating control can be performed for each tier, it is possible to set the heating temperature and heating time according to the quantity and type of food being baked. Furthermore, by operating all tiers at full capacity during peak times and only one tier during idle times, depending on the sales situation of baked sweet potatoes, energy can be saved and running costs can be reduced. The top, bottom, left and right sides, and back of the firing chamber 5 are covered with insulation material 501-504 (made of ceramic wool board). Inside the firing chamber 5, a far-infrared heater 51 is installed at the top and a sheathed heater 56 is installed at the bottom, creating a space inside the firing chamber 5 that can be heated to approximately 200-300°C. Details of the heating mechanism of the firing chamber 5 will be described later. Each level of the baking chamber 5 is provided with a drawer 7 that can be pulled out towards the front. The drawer 7 has a tray 75 on which the sweet potatoes P to be baked are placed, and a door 71 on the front side of the tray 75. Details of the tray 75 and door 71 will be described later, referring to Figure 3.5 and other figures.

[0024] The warming unit 2 is mounted on top of the main casing 3 (above the baking chamber 5). The warming unit 2 is a box that keeps the baked sweet potatoes P in the baking chamber 5 warm while visible to customers. By storing the baked sweet potatoes in this warming unit 2, the ability to handle peak sales of baked sweet potatoes is enhanced. The side walls 25, top surface 24, and front door 27 (which can be opened and closed by hand) of the warming unit 2 are made of transparent plastic, allowing customers to clearly see the baked sweet potatoes inside and encouraging them to buy. The warming unit 2 is heated and kept warm to the desired temperature by a panel heater 29 located below it. The temperature of the warming unit 2 is set to maintain the baked sweet potatoes inside at around 70°C, within the β-amylase activity range, which also has the effect of increasing the sugar content of the baked sweet potatoes. The basic operation involves transferring the baked sweet potatoes to the warming unit 2 for warming and serving. However, since the heating control of the baking chamber 5 also has a warming function, it is possible to store any baked sweet potatoes that do not fit in the warming unit inside the baking chamber.

[0025] The electrical unit 48 and the control panel 39 located in front of it are positioned on the right side of the firing chamber 5. The operator uses this control panel 39 to adjust the temperature of the firing chamber 5 and other settings. The electrical unit 48 houses electrical components such as the heater power supply and control board. A condensation tray 47 is provided at the bottom front of the main casing 3 to catch condensation that forms on the door 71 and drips down. Casters 49 are attached to the bottom of the main casing 3, allowing the sweet potato roaster 1 to be moved.

[0026] The details of the heating means of the baking chamber 5 will be explained, mainly with reference to Figure 3. Figure 3 is an enlarged side view schematically showing the configuration of the heating means for uniform heating of the baked sweet potatoes P in the baking chamber 5 of the sweet potato roaster 1 shown in Figures 1 and 2, as well as the structure of the door 71 and the arrangement of the insulation material. In the upper part of the interior of the baking chamber 5, two rod-shaped far-infrared heaters 51F and 51R are arranged in parallel, one at the front and one at the back, extending in the direction perpendicular to the plane of the paper in Figure 3 (the left-right direction in Figure 2). As shown in Figure 2, the left and right ends of the heaters 51 penetrate the plate material (stainless steel plate, not shown) that makes up the left and right side walls of the baking chamber 5, and the side insulation material 504, and exit the chamber. The far-infrared heater 51 equipped in this example sweet potato roaster 1 consists of a carbon filament sealed inside a protective tube such as a quartz tube. One example is a carbon lamp heater manufactured by Metro Electric Industry Co., Ltd., with an output of 500W each, for a total output of 1kW for both. The filament is made of carbon.

[0027] The two upper heaters 51 are positioned such that, relative to the depth D of the firing chamber 5 (520 mm in one example), the rear upper heater 51R is approximately 20% (optimal range 18-25%) from the rear end, and the front upper heater 51F is approximately 10% (optimal range 8-15%) from the front end. This is because there is more temperature loss on the door side (front side) (due to air ingress when opening and closing the door and the presence of the window 73), so the front heater is positioned closer to the edge of the firing chamber 5 than the rear heater. The length from the rear upper heater 51R to the front upper heater 51F is approximately 70% (optimal range 60-75%) of the depth of the firing chamber 5.

[0028] The upper heater 51 has a flat carbon filament (with zigzag cuts) as a heating element. The normal of this flat plate (direction of heat radiation) is oriented towards the center of the front-rear rear of the firing chamber 5 (approximately 30 degrees to the vertically downward (suitable range 25-35°)). In other words, the heat radiation direction of the upper heater 51R on the rear side is directed towards the front, and the upper heater 51F on the front side is directed towards the rear. By selecting the positions of these two upper heaters 51, and through the combined effects of the far-infrared diffusion plate 52 and corner reflector 53 described below, uniform heating of the sweet potato P (the object to be baked) from above is achieved.

[0029] Below the upper heater 51, a far-infrared diffusion plate 52 is positioned to spread horizontally. Figure 4 is a plan view of the far-infrared diffusion plate 52 of the sweet potato roaster 1 shown in Figure 1. The infrared diffusion plate 52 has edges 52b, 52c, and 52d on all four sides, and a main body plate 52j inside them. The main body plate 52j has a front diffusion section 52m on the front side, a large central opening 52t on the back side, a rear diffusion section 52w on the back side, and a narrow rear opening 52x on the back side. The infrared diffusion plate 52 is a punched and bent product made from a SUS430 plate with a thickness of 1 mm (this is just an example; all the dimensions below are also just examples).

[0030] The edges 52b, 52c, and 52d are bent into a mountain shape to a height of approximately 15 mm, providing rigidity and strength. The front diffusion section 52m is a long plate with a width of approximately 110mm in the front-to-back direction and a length of approximately 440mm in the left-to-right direction, and has numerous circular holes 52r (8mm in diameter) drilled into it. The opening ratio of the circular holes 52r in the front diffusion section 52m is approximately 30%. A ratio of 25% to 40% is preferable. A rib 52s (for reinforcement) with a height of approximately 10mm is erected at the rear end of the front diffusion section 52m. Above the front diffusion section 52m, approximately in the front-to-back direction (20-30mm above in one example), the front upper heater 51F is positioned to extend in the left-to-right direction, as shown in Figure 2.

[0031] The central opening 52t is a void provided at the rear of the front diffusion section 52m, by cutting out a large section from the main body plate 52j. This central opening 52t is a large void with a width of approximately 260mm in the front-to-back direction and a length of approximately 410mm in the left-to-right direction. The role of this central opening 52t is to make the far-infrared effect of the entire upper heating element uniform. A rear diffusion section 52w is provided on the far side of the central opening 52t. The dimensions of the rear diffusion section 52w, the dimensions of the circular hole 52r, and the opening ratio are approximately the same as those of the front diffusion section 52m mentioned above. As shown in Figure 2, the rear upper heater 51R is positioned above the center of the rear-front direction of this rear diffusion section 52w (20-30 mm in one example) so as to extend in the left-right direction. At the rear of the rear diffusion section 52w, a rear opening 52x is formed as a slit-shaped cavity cut out of the main body plate 52j. This rear opening 52w has a width of approximately 30 mm in the direction from back to front. The role of this rear opening 52x is also to make the far-infrared effect of the entire upper heating element uniform.

[0032] The arrangement, dimensions, and aperture ratio of the perforated plate sections (front diffusion section 52m and rear diffusion section 52w) and openings 52t and 52x in the far-infrared diffusion plate 52 were determined through repeated experiments to ensure uniform irradiation without localized strength in the far-infrared radiation radiated (passing through) below the diffusion plate 52. The perforated plate sections 52m and 52w of the far-infrared diffusion plate 52 were manufactured using sheet metal and were provided only in the downward diagonal irradiation direction, i.e., within the irradiation range, from the front and rear far-infrared heaters 51. The far-infrared diffusion plate 52 is located directly below the far-infrared heater 51, which prevents accidental contact and damage to the heater 52 during cleaning of the interior of the oven.

[0033] Corner reflectors 53 are installed at the front and rear of the upper part of the firing chamber 5 to reflect the far-infrared rays emitted by the far-infrared radiating heater 51 downwards. The reflectors 53 are strip-shaped plates extending in the left-right direction, with a length equal to the left-right width of the firing chamber 5 (470 mm), a width of approximately 30 mm in the front-to-back direction, and an angle of approximately 30 degrees with respect to the horizontal. The corner reflectors 53 are made of silver anodized aluminum, which has high far-infrared reflection performance and is also economical. The reflectors 53 are installed on the front and back walls (made of stainless steel plates) of the ceiling of the firing chamber 5. Far-infrared rays emitted from the heater 51 are reflected by the corner reflector 53 and irradiated to the front and back of the top surface of the tray 75, supplementing the heating capacity of those areas. Structurally, the front and back of the tray tend to have poor heating capacity due to insufficient far-infrared irradiation. However, in the sweet potato roaster 1 of this embodiment, the uniformity of far-infrared radiation to the tray (75) is improved by installing the aforementioned corner reflector 53.

[0034] Next, the heating structure at the bottom of the baking chamber 5 will be described. In this embodiment of the sweet potato roaster 1, the lower heating means arranged below the interior space where the sweet potatoes P are baked includes a sheathed heater 56 and a far-infrared radiation tray 75 that spreads over the sheathed heater, which has a black ceramic coating on its upper surface and numerous hot air rising holes 75h dispersed therein. The sheathed heater 56, as the lower heat source, has an output of 650W (for example) and is arranged in a rectangular shape surrounding the center of the bottom of the chamber in a plan view (see the shape of the sheathed heater protective umbrella 57 in Figure 6). By making the heater rectangular in shape, the peripheral part of the baking chamber is sufficiently heated, while overheating of the center is prevented, and the heating of the bottom surface of the chamber is made more uniform.

[0035] Figure 5 is a perspective view of the far-infrared radiation tray 75 of the sweet potato roaster 1 in Figure 1, viewed from diagonally above. This tray 75 is a shallow, box-shaped tray that rests on the drawer frame 76 of the drawer 7. The base material of the tray 75 is 1.5 mm thick aluminum (this is just an example; all numbers and materials in this embodiment are just examples), which has high thermal conductivity and high thermal radiation, and the edges 75b of the main plate 75f are bent. The main plate 75f of the far-infrared radiation tray 75 (the bottom surface on which the sweet potatoes are placed) has numerous hot air passage holes 75h with a diameter of 8 mm (preferably in the range of 6 to 20 mm). These holes 75h allow hot air rising from the sheath heater 56 below the tray 75 to pass through. The ratio of the area of ​​the open hot air passage holes 75h to the total area of ​​the main plate 75f (opening ratio) is 18% (preferably in the range of 15 to 25%) in this example. Additionally, knob holes 75x are provided in the center of the front-rear direction of the left and right edges 75b, making it easier to lift the tray 75 upwards by placing your fingers on these knob holes 75x.

[0036] The black ceramic coating (film) is a film containing ceramic that emits far-infrared rays and appears black to the naked eye. As an example, in this embodiment, a film coated with "Paint No. 9353" manufactured by Okitsumo Co., Ltd. and fired was used. The specifications of the paint / film (example) are as follows. Paint components; as far-infrared radiators or black pigments, the paint contains 35% by weight of composite oxides, silica, and iron-manganese-cobalt composite oxides. The rest are resins and solvents. Baking conditions: 80°C x 10 minutes → 280°C x 20 minutes Base material: Aluminum Film thickness: 25 μm Emissivity: 0.83

[0037] In this embodiment, the hot air generated from the sheathed heater is transmitted to the sweet potatoes through the holes 75h in the tray 75. Furthermore, the upper surface of the tray 75 on which the sweet potatoes are placed is coated with a black ceramic coating that promotes far-infrared radiation when heated, thereby further enhancing the penetration of heat into the sweet potatoes. The quantitative and specific planar shape of the sheathed heater 56, as well as the arrangement of the hot air rise holes 75h of the far-infrared radiation tray 75, are determined by testing in order to make the temperature inside the firing chamber 5 as uniform as possible.

[0038] In the sweet potato roaster 1 of this embodiment, a heater protective umbrella 57 is provided above (directly above) the sheathed heater 56. Figure 6 is a perspective view of the heater protective umbrella 57 covering the sheathed heater 56 of the sweet potato roaster 1 in Figure 1, viewed from diagonally above. The protective umbrella 57 has the same square planar shape as the sheathed heater 56 (see Figures 1-3 for side and front views). The cross-sectional shape of the protective umbrella 57, as shown in the lower right of Figure 3, consists of an upper flat plate section 57f that covers the protective tube 56b of the round rod-shaped sheathed heater 56, and an eaves plate section 57g that extends diagonally downward from its lateral end. The protective umbrella 57 is placed on an indicator fitting (not shown) inside the oven so that it is at a height slightly above the heater. The material of the protective umbrella 57 is SUS430 (example), and its width is 25 mm (diameter of the sheathed heater 56 is 8 mm, both examples). The syrup and dew that drips from the potato P onto the protective cover 57 falls from the edge of the eaves board section 57g to the outside of the sheath heater protective tube 56b (down to the residue tray 59), and the syrup and dew do not come into contact with the sheath heater 56. This prevents damage to the sheath heater 56.

[0039] This heater protection umbrella 57 prevents syrup and burnt residue that drips from the sweet potatoes during baking from adhering to and sticking to the sheathed heater, thus preventing the heater from overheating and being damaged. Furthermore, by installing the heater protection umbrella directly above the heater, it also serves to prevent localized heating of the tray 75 directly above the sheathed heater.

[0040] In this embodiment, the sweet potato roaster 1 can roast sweet potatoes P evenly and moistly, retaining their moisture, thanks to the "uniform radiant heat and far-infrared effect" emitted from above by a far-infrared heater 51 + far-infrared diffusion plate 52 and from below by a far-infrared radiation tray 75.

[0041] The results of the experiment to confirm the effect of uniform firing will be explained with reference to Figure 7. Figure 7 shows photographs illustrating the degree of browning on the surface of sliced ​​bread, as a result of testing a test in which sliced ​​bread that browns easily was baked using a sweet potato roaster according to one embodiment of the present invention and a comparative example sweet potato roaster. (A) and (B) are from the embodiment, and (C) and (D) are from the comparative example. (A) and (C) are the top surface of the bread, and (B) and (D) are the bottom surface. A standard baking rack was used as the tray on which the sliced ​​bread in the comparative example was placed. The upper heating mechanism of the comparative example consisted only of a far-infrared heater 51, without a far-infrared diffusion plate 52. In Figure 7, the top of the diagram represents the back of the sweet potato roaster, and the bottom of the diagram represents the front of the sweet potato roaster.

[0042] Figure 7(A); The top view of the example shows that the bread is well-baked and very uniformly. On the other hand, in the comparative example (C); the top view shows that the bread on both the left and right sides is white and underbaked. This is thought to be the difference between having the far-infrared diffusion plate 52 or not. Figure 7(B); The toasting of the bread shown in the bottom view example is well done and very uniform. On the other hand, in the comparative example (D); the bottom view example, the bread is generally white and undercooked. However, the bread on the front left is overcooked and burnt due to the concentrated heat from the sheath heater. Thus, the results of the comparative baking experiment using "white bread," which browns easily, confirmed that the uniformity of baking performance was significantly improved when using the far-infrared radiation tray 75 and the far-infrared diffusion plate 52. Uniform baking leads to the ability to bake sweet potatoes with less uneven browning.

[0043] Furthermore, although optional, it has been found that the sweet potato roaster 1 of the present invention can adequately handle the roasting of items such as "roasted corn" and "potatoes," where uniform browning of the surface is required. Sweet potato roasters are typically used in supermarkets and other stores from autumn to spring, due to the distribution and storage period of sweet potatoes, and tend not to be used during the summer. Sweet potato roasters have a heating capacity of 250°C, and we have heard from stores that they would like to be able to cook a wide range of menu items other than roasted sweet potatoes throughout the year by improving the heating characteristics. The present invention opens up a business opportunity by expanding the range of menu items that can be roasted through uniform roasting.

[0044] Next, the structure of the door 71 will be described. The door 71 of the drawer 7 of the sweet potato roaster 1 in this embodiment is provided with a window 73 that allows the inside of the roasting chamber 5 to be seen through. As clearly shown in Figure 10, the window 73 portion of the door 71 has a multi-layer structure, and from the front side (outside) to the back side (inside), it is arranged as follows: front recess 73f ⇒ front glass 73b ⇒ outer flow path 73g ⇒ middle plate window 73h ⇒ inner flow path 73k ⇒ back recess 73r ⇒ back glass 73p. The front recess 73f is for fixing the front glass 73b. The front glass 73b and the back glass 73p are made of tempered glass. Between the two panes of glass, the outer channel 73g, the middle panel window 73h, the inner channel 73k, and the recessed area 73r form an air insulation (cooling) layer. In particular, an airflow rising from bottom to top is formed in the outer channel 73g and the inner channel 73k (described later), suppressing heat transfer from the firing chamber 5 towards the front of the door 71. The dimensions of the window 73 in this embodiment are 68 mm in width and 35 mm in height.

[0045] Furthermore, insulation material 504 is attached to the part of the door 71 of drawer 7 other than the window 73, just outside the firing chamber 5. Since it is not possible to install insulation material on the entire front of the drawer, the amount of heat radiating from the front increases, which tends to reduce the heating capacity near the front of the firing chamber. Therefore, as mentioned above, the front far-infrared heater 51F is positioned closer to the front, and a reflector plate 53 is installed on the upper front of the firing chamber 5 to strengthen the heating of the firing chamber part near the door 71.

[0046] Figure 8(A) is a perspective view of the entire sweet potato roaster 1 in Figure 1 with the door 71 closed. Figure 8(B) is a photograph showing the sweet potatoes P inside the roasting chamber 5, with a close-up of the window 73 of the door 71. The carbon lamp heater 51 in the sweet potato roaster 1 of this embodiment is a heater that also functions as a lamp, in which a carbonaceous heating element (filament tape, etc.) is sealed inside a transparent heat-resistant tube (quartz tube, etc.). This heater illuminates the inside of the chamber with red or orange visible light (red-hot color). This allows the presence or absence of sweet potatoes P inside the roasting chamber 5 and the roasting status to be checked through the window 73 of the door 71.

[0047] Next, the air insulation (cooling) structure in the sweet potato roaster 1 of this embodiment will be described. Figure 9 is a schematic side cross-sectional view showing the air insulation structure on the front side (front) of the sweet potato roaster 1 in Figure 1. As described above, each door 71 is provided with double air passages 73f and 73k. The air passages 73f and 73k of the doors 71 of the upper, middle, and lower roasting chambers 5A, 5B, and 5C are connected to each other vertically via the intermediate crumb tray front panel 46. The lowest part of the air passages 73f and 73k leads to the dew tray 47. The condensation tray 47 is designed to catch condensation water that drips from the door 71. When the door 71 is opened, it is cooled by the ambient temperature, causing its temperature to drop easily. When the door is closed, the moisture in the air inside the oven, which has become humid due to the evaporation of moisture from the sweet potatoes, is prone to condensation on the door surface. If this condensation drips down from the door, it can stain the floor of the shop where the sweet potato roaster is installed. With a sweet potato roaster equipped with a condensation tray 47, such staining does not occur, and the shop can be kept clean. The condensation collected in the condensation tray 47 can be removed from the sweet potato roaster and disposed of in a sink or similar.

[0048] On the front of each door 71, the front of the front panel 46 in front of the crumb tray, and the front of the front of the drip tray 47, there are burring holes (ventilation holes, see reference numerals 46z and 71z in Figure 8(A), elongated holes with dimensions of 6 mm x 50 mm, for example). In addition, gaps (width of 20 mm in one example) are formed between the door 71 and the front panel 46 in front of the crumb tray, and between the bottom door 71 and the drip tray 47. Through these burring holes and gaps, the air passages 73f and 73k are in communication with the air outside the sweet potato roaster 1 (inside the store). The air inside the air passages 73f and 73k, which are heated by the heat transferred from the roasting chamber 5, is at a higher temperature. As a result, negative pressure is created inside the passages, and an upward airflow (thick arrow) is generated inside the passages (chimney effect). This airflow keeps the front of the sweet potato roaster 1 (the surface of the door 71) at a temperature that is safe to touch (below 55°C in one example).

[0049] Electric sweet potato roasters are typically installed inside supermarkets, where customers can purchase freshly roasted sweet potatoes by taking them out of a warming cabinet themselves. To prevent customers from coming into contact with the roaster and getting burned, an air insulation tank is provided around the main body. However, in currently available sweet potato roasters, it is not possible to cover the entire front of the main body where sweet potatoes are loaded and unloaded with an air insulation layer. Therefore, a double door is provided to reduce radiation from the front of the main body, but this results in the cumbersome task of opening the double door each time sweet potatoes are loaded or unloaded. However, in the sweet potato roaster 1 of this embodiment, the multi-layer air insulation structure of the door 71 achieves safe low radiation from the front of the drawer without the need for a double door.

[0050] A heat protector 70 is provided at the top of the front of the sweet potato roaster 1, as clearly shown in Figure 10. The heat protector 70 is an inverted L-shaped box. A burring hole (an elongated hole of 6 mm x 50 mm in one example) is made in its outer shell 70d. The airflow rising from the airflow channels 73g·73k of the door 71 of the uppermost roasting chamber 5A exits through the gap 70f, or enters the airflow channel 70g on the back of the outer shell 70d, and then exits the machine through the burring hole. An inner plate 70h is provided inside the heat protector 70. The internal space 70j of the inner plate 70h has an inlet 70k at the bottom, but there are no outlets or openings such as holes at the back. The rear end 70k is shaped downwards, creating a cavity 70j·70p with no outlet in the rear direction. The airflow that enters this cavity 70j·70p is dispersed and discharged on both sides, thereby reducing the temperature of the heat protector 70 surface.

[0051] The airflow coming from the front of the lower drawer 7 flows into the heat protector 70 and is diffused and exhausted, thereby reducing radiation. This heat protector design prevents the diffusion of leaking hot air generated from the gap between the drawer 7 and the baking chamber 5, further reducing heat conduction to the heat protector 70. In this way, when removing baked sweet potatoes from the warming chamber 2, the heat protector 70, which extends in the left-right direction, is installed on the upper front of the main body, which is easily touched by hand, thereby reducing radiation and enhancing safety.

[0052] Figure 11 is a schematic side cross-sectional view showing the cooling structure of the rear wall and ceiling of the sweet potato roasting oven 1 in Figure 1, as well as the chimney sections of the left and right side walls. The rear of the three upper and lower roasting chambers 5A, 5B, and 5C is covered with a rear insulation material 502. The rear of the insulation material 502 is an internal air passage 34p. Beyond the internal air passage 34p is an external air passage 34j, separated by an internal middle plate 34k. Beyond the external air passage 34j is an external hollow section 34d, separated by an external middle plate 34g. Beyond the external hollow section 34d (outside) is a stainless steel plate outer shell 34b. Air flows through the internal air passage 34p and the external air passage 34j due to the chimney effect (thick arrows). Air from outside the machine (inside the store) enters these passages through the opening at the bottom.

[0053] Above the upper insulation material 501 of the top firing chamber 5A, there are two ceiling air passages 35b and 35f. Air flows into the lower ceiling air passage 35b from the inner air passage 34p in the back wall. Air flows into the upper ceiling air passage 35f from the outer air passage 34d in the back wall. Two air passages are also formed on the front side of the ceiling, and airflow W from the front air passage flows through each of them. The ceiling air passages are connected to the air passages of the chimney 38, which will be described later.

[0054] Figure 12 is a schematic front cross-sectional view showing the cooling structure of the left and right walls and ceiling of the sweet potato roaster 1 in Figure 1. Inside the left outer shell 3y of the main casing 3, a double air cooling channel is formed, consisting of a left wall outer air channel 43 and an inner left wall inner air channel 44, which spreads out and rises in the vertical and rear-front directions. Inside the inner channel 44 is the left wall insulation material 505 of the roasting chamber 5. Outside air is introduced into the left wall outer air channel 43 from the lower opening. Outside air is introduced into the left wall inner air channel 44 from the lower opening. Heat from the left wall insulation material 505 of the roasting chamber 5 is transferred to these channels 43 and 44, and an upward airflow is formed by the chimney effect.

[0055] The ceiling of the main casing 3 also has a double air cooling channel, consisting of an outer ceiling air channel 41 and an inner ceiling air channel 42 below it (inside), which extends to the left, right, and front and back. Inside the lower channel 42, separated by the outer wall 40 of the upper firing chamber, is the upper insulation material 501 of the firing chamber 5. Air from the outer left wall air channel 43 is introduced into the outer ceiling air channel 41 and discharged outside the machine through the outer channel 38s of the chimney 38. Air from the inner left wall air channel 44 is introduced into the inner ceiling air channel 42 and discharged outside the machine through the middle channel 38p of the chimney 38. In this way, the radiant heat generated from the firing chamber and the hot air accumulated below the top plate are efficiently guided to the chimney through an exhaust path inside the main unit and dissipated, thereby reducing radiation on the surface of the main unit and further enhancing safety.

[0056] On the right side of the right wall insulation 504 of the firing chamber 5, a double air cooling channel is formed, consisting of an inner right wall air channel 451 and an outer right wall air channel 45, which extends upward and downward in the front-back direction. Heat from the right wall insulation 504 of the firing chamber 5 is transferred to the inner right wall air channel 451, causing the air channel to become slightly negative pressure. Air from outside the casing 3 (store atmosphere) flows into this slightly negative pressure air channel through louvers and openings, creating an upward airflow (chimney effect). The outer right wall air channel 45 is connected to the inside of the firing chamber 5 by a pipe 45y.

[0057] The right wall outer air passage 45 rises straight up between the inside of the electrical unit 48 and the right side of the three-tiered baking chamber 5, at the front rear center of the sweet potato roaster 1, and merges with the central air passage 38j of the chimney 38. This right wall outer air passage 45 and the central air passage 38j of the chimney 38 have higher temperatures than the other air passages. Since air is not actively introduced into the baking chamber 5, the air flowing through the pipe 45y, passage 45, and passage 38j consists of steam from the sweet potatoes P being baked and air flowing in when the door 71 is opened and closed. However, since the temperature of the air in this passage is the highest, passage 38j is positioned at the very center of the chimney 38 to prevent it from being touched by human hands. Furthermore, the upper end 38jz of passage 38j is lower than the upper end 38z of the chimney 38, showing similar consideration.

[0058] In the right wall inner air passage 451, the air rises and merges with the central air passage 38p of the chimney 38. The air in this central air passage 38p of the chimney 38 is at a lower temperature than the central air passage 38j of the chimney mentioned above. The air that has passed from the left wall inner air passage 44 through the ceiling inner air passage 42 also merges with the central air passage 38p of the chimney 38. The outer air passage 38s of the chimney 38 receives air that has passed from the aforementioned left wall outer air passage 43 and the ceiling upper air passage 41. As a result, the temperature of the outermost air passage is the lowest in both the left wall of the casing 3 and the chimney 38, making it safe even if touched by human hands.

[0059] Next, although this will be partially repeated, I will explain chimney 38. The chimney 38 rises from the ceiling of the main casing 3 of the sweet potato roaster 1, in the center towards the front and back, and slightly to the right in the left-right direction. In this embodiment, the chimney 38 of the electric sweet potato roaster 1 does not emit smoke itself, but rather collects and exhausts the airflow heated by the heat emanating from the heated roasting chamber 5, as well as the steam released from the sweet potatoes P in the roasting chamber 5. Chimney 38 has a triple-layered structure, with outer passages 38c and 38s, middle passages 38f and 38p, and a central passage 38j. The cross-sectional shape of chimney 38 in plan view (rear-front x left-right direction) is a shape in which squares overlap the inner and outer sections.

[0060] Thus, to reduce the radiation temperature of the main unit's surface, this was achieved by establishing a specification in which three exhaust paths are formed inside the main unit and connected to a single chimney for exhaust. In other words, steam and other exhaust generated inside the oven 5 during the baking of sweet potatoes are exhausted through the right wall outer air passage 45, which is connected to each stage of the oven 5, and the central passage 38j ("first chimney") of the chimney 38. Radiant heat generated from around the oven 5 is exhausted through the middle passages 38f and 38p ("second chimney") via layers through which air flows (passages 34p, 44, 46, etc.) provided around the oven. Hot air generated below the top plate is exhausted through the "third chimney" (outer passages 38c and 38s) via layers through which air flows (passages 41 and 35f) provided below the top plate.

[0061] Next, we will explain how to remove and clean each component. Figure 13(A) is a schematic side cross-sectional view with drawer 7 pulled out. Figure 13(B) is a schematic side cross-sectional view with tray 75 removed. As shown in Figure 13(A), when the drawer 7 is pulled forward, most of the far-infrared radiation tray 75, which rests on the drawer frame 76, comes out of the oven chamber 5 (towards the front) from the front to the center. Then, by pinching the front of the tray 75 or by placing your fingers on the knob hole 75x (see Figure 5) in the center, the lightweight aluminum tray 75 can be easily removed diagonally upwards and towards the front, as shown in Figure 13(B). The tray 75 can then be cleaned outside the oven.

[0062] Figure 13(C) is a schematic side cross-sectional view of the sheathed heater 56 with the protective cover 57 removed. From the state in Figure 13(B) where the far-infrared radiation tray 75 is placed on top of the drawer frame 76, move the drawer 7 slightly back into the baking chamber 5. Now, by pinching the front side of the heater protective cover 57 and lifting it forward, the protective cover 57 can be removed diagonally upward and forward through the space inside the drawer frame 76, as shown in Figure 13(C). Then, the sweet potato syrup and peel scraps... Attached The protective umbrella 57 can be cleaned outside the storage compartment. When the heater protective umbrella 57 is placed inside the storage compartment, it simply rests on the heater support bracket inside the compartment.

[0063] Figure 14 is a schematic side cross-sectional view showing the state after the drawer 7 has been pulled out and the infrared diffuser plate 52 of the upper heater 51 has been removed. When the diffuser plate 52 is installed inside the oven 5, it is hung on a rail that protrudes from the inner wall of the oven. As shown in Figure 14, with the drawer 7 and far-infrared radiation tray 75 pulled out towards the front, the diffuser plate 52 can be removed by reaching inside the oven 5 and pulling it. The diffuser plate 52, which may have steam from the potatoes on it, can be cleaned outside the oven.

[0064] Figure 15(A) is a schematic side cross-sectional view of the crumb tray 59 with the front panel 46 removed, and Figure 15(B) is a schematic side cross-sectional view of the crumb tray 59 with the crumb tray 59 removed. A crumb tray 59 is installed at the bottom of the baking chamber 5 to collect the syrup and burnt crumbs that drip down when the sweet potatoes are baked. The crumb tray 59 is a shallow, box-shaped waste collection pan that extends across almost the entire bottom of each baking chamber 5. The crumb tray 59 is slidably placed on the lower insulation material 503, and is covered in front of it by a crumb tray front panel 46 (which is held in place by a hook) that has an internal air passage. As shown in Figure 15(A), by removing the crumb tray front panel 46 towards the front, the crumb tray 59 can be pulled out and cleaned.

[0065] The "advantages of introducing" the sweet potato roasting machine of this embodiment are summarized below. It should be noted that the present invention is not limited to those that achieve all of these advantages; even those that achieve only some of these advantages, as described in the claims and equivalents thereto, fall within the technical scope of the present invention. (1) Effect of uniform firing This technology enables uniform baking of sweet potatoes, regardless of their placement. Therefore, we have made it possible to offer options for grilling items such as grilled corn, which require uniform browning of the surface. (2) Firing effect using far-infrared rays By using a far-infrared heater, infrared diffuser, and far-infrared radiating tray for baking, heat penetration into the sweet potato is increased, activating the enzyme β-amylase contained in the sweet potato, resulting in a higher sugar content.

[0066] (3) Effect of the confirmation window The installation of inspection windows allows for constant monitoring of the quantity and baking status of sweet potatoes in each oven without having to open the doors. (4) Energy saving effect By utilizing energy efficiently and leveraging the characteristics of uniform heating, the sweet potato roaster achieved energy savings. Compared to the power consumption of other companies' products, it achieved energy savings of 15-20%. Furthermore, since sweet potato roasters are devices that continuously operate while heating during business hours, there is a high demand for energy efficiency. (5) Effects of reducing radiation By incorporating an air insulation layer on the front of the drawer to reduce radiation, the loading and unloading of potatoes was made more efficient without the need for burn prevention structures such as double doors on the front of the main unit. Furthermore, radiant heat generated from the baking chamber and hot air accumulated under the top plate are efficiently guided to the chimney through an exhaust path inside the main unit for heat dissipation, thereby reducing radiation on the surface of the main unit and enhancing safety.

Claims

1. A roasting chamber (5) for roasting sweet potatoes, A tray (75) for placing the sweet potatoes (P) to be baked is placed inside the baking chamber, A heating means for raising the temperature inside the firing chamber, A sweet potato roaster (1) equipped with, The sweet potato roaster (1) is characterized by having a far-infrared radiating heater (51) above the tray (75) in the roasting chamber (5), and a far-infrared diffusing plate (52) having numerous holes directly below it.

2. The sweet potato roaster (1) according to claim 1, characterized in that the far-infrared diffusing plate (52) has a diffusion section (52m・52w) having a number of holes (52r) directly below the far-infrared radiating heater (51), and an opening (52t・52x) formed in a part away from directly below the heater (51).

3. The sweet potato roaster (1) according to claim 1 or 2, characterized in that the aperture ratio of the numerous holes (52r) in the far-infrared diffusion plate (52) or the diffusion section (52m・52w) is 25% to 40%.

4. The sweet potato roaster (1) according to claim 1, characterized in that a corner reflector (53) is installed at the front and / or rear of the upper part of the roasting chamber (5) to reflect the far-infrared rays emitted by the far-infrared radiating heater (51) downward.

5. The surface of the tray (75) on which the potatoes (P) are placed is treated with a black ceramic coating. The sweet potato roaster (1) according to claim 1, characterized in that a number of vertical through holes (75h) are formed in a distributed manner in the tray (75).

6. A roasting chamber (5) for roasting sweet potatoes, A tray (75) for placing the sweet potatoes (P) to be baked is placed inside the baking chamber, A heating means for raising the temperature inside the firing chamber, A sweet potato roaster (1) equipped with, The surface of the tray (75) on which the potatoes (P) are placed is treated with a black ceramic coating. The tray (75) has numerous vertical through holes (75h) formed in a distributed manner. The sweet potato roaster (1) is characterized in that the heating means (56) is located below the tray (75).

7. The sweet potato roaster (1) according to claim 6 or 7, characterized in that the numerous upper and lower through holes (75h) have a diameter of 6 mm to 20 mm and the opening ratio of the area of ​​the holes is 15 to 25%.

8. The heating means (56) is a sheathed heater, The sweet potato roaster (1) according to claim 6, characterized in that a heater protective umbrella (57) is installed directly above the heater.

9. A baking chamber (5) for baking sweet potatoes arranged in multiple tiers vertically, Each baking chamber (5) is equipped with a drawer (7) that has a tray (75) for placing the sweet potatoes (P) to be baked, and a front door (71) for the tray (75), which is positioned to be pulled out and pushed in. A heating means for raising the temperature inside each firing chamber, A sweet potato roaster (1) equipped with, The sweet potato roasting oven (1) is characterized in that the door (71) is provided with a window (73) that allows the inside of the oven to be seen through.

10. The sweet potato roaster (1) according to claim 9, characterized in that an air insulation layer is provided in the front door (71) of the drawer (7), including the portion of the window (73).

11. The sweet potato roaster (1) according to claim 1, 6, or 8, characterized in that the far-infrared diffusion plate (52), the tray (75) coated with a black ceramic film, or the heater protective umbrella (57) can be removed to the outside through the opening of the pulled-out door (71).

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