JP2008130406A - Sheathed heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheathed heater capable of restraining temperature rise of fat or the like adhered to an opposite side of a heated object, and hardly absorbing fat or the like. <P>SOLUTION: The sheathed heater 11, provided with a heating wire 12, and a metal tube 14 covering an outside face of the heating wire 12 through an insulator 13, heats the heated object 120 by having it opposed to one side of the metal tube 14 in a radial direction, and is also provided with a hollow heat insulating pipe 16 with a part coupled to an opposite side of the heated object 120 of the metal tube 14, extended along the metal tube 14, with both ends closed, and with a gap formed between the metal tube 14 and the heat insulating tube 16. The heat insulating pipe 16 has a small contact area with the metal tube 14, and has little heat transferred to it, resulting in high heat insulating effect. Heat received by an object 144 from the sheathed heater 11 on the opposite side of the heated object 120 is small, so that temperature rise of fat or the like 121 adhered to the opposite side of the heated object 120 can be suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheathed heater.

  Some cooking devices that cook food by heating food such as fish and meat use a sheathed heater as a heat source. In this type of heating cooker, for example, a sheathed heater is disposed below a net for placing food, and a saucer (grill pan) for receiving fat or moisture dripping from the food when the food is heated below that Is provided.

  However, according to this type of heating cooker, since the sheathed heater radiates heat from its entire circumference, not only the food above it but also the fat accumulated on the saucer below it is heated, and the saucer There is a disadvantage that smoke may be generated from the container, or the dirt may stick to the tray.

  Therefore, it is known that a part of the outer surface of the sheathed heater is covered with a heat insulating member to suppress the radiation of heat in unnecessary directions (see, for example, Patent Documents 1 and 2). By adopting such a sheathed heater in the above-mentioned cooking device, it is possible to obtain sufficient heating for ingredients, and to prevent the saucer from being heated, and to reduce the generation of smoke and dirt on the saucer. Can do.

However, the heat insulating member that covers a part of the conventional sheathed heater is formed by spraying, painting, or dipping a material having high heat resistance and heat resistance such as porous refractory and heat resistant inorganic fiber on the outer surface of the metal tube. Alternatively, it is formed by bonding and pressing with an inorganic binder or a metal plate. For this reason, when the fat etc. which fall from a foodstuff adhere to a sheathed heater, there exists a problem that the fat etc. and odor may be adsorbed by a heat insulation member.
JP 59-171488 A JP 59-167986 A

  The present invention provides a sheathed heater that eliminates such inconvenience and suppresses the temperature rise of fat or the like adhering to the opposite side of the object to be heated, thereby preventing unnecessary smoke generation or dirt sticking. For the purpose.

  In order to achieve such an object, the sheathed heater of the present invention includes a heating wire and a metal tube that covers an outer surface of the heating wire through an insulator, and an object to be heated is opposed to one side of the metal tube. In the sheathed heater for heating, a hollow heat-insulating tube is provided which is connected to the opposite side of the metal tube opposite to the object to be heated and extends along the metal tube and is closed at both ends. A gap is formed between the metal tube and the heat insulating tube.

  The sheathed heater according to the present invention has a small contact area between the metal tube and the heat insulation tube because a part of the heat insulation tube is connected to the metal tube. Since gaps are formed between them, it is difficult for heat to be conducted from the metal tube to the heat insulating tube. On the other hand, the heat radiated from the metal tube is blocked by the heat insulating tube on the side opposite to the object to be heated. The said heat insulation pipe | tube is hollow, Comprising: Since the both ends are obstruct | occluded, the heat insulation effect is high. And the heat radiated | emitted from the said heat insulation pipe | tube is very small by the heat insulation effect of this heat insulation pipe | tube itself. Therefore, according to the sheathed heater of the present invention, the heat received from the sheathed heater on the opposite side of the sheathed heater from the sheathed heater is small. An increase in temperature can be suppressed, and unnecessary smoke generation and contamination can be prevented. And since the sheathed heater of this invention does not need to provide a heat insulating member in an external surface like the conventional sheathed heater, fats and odors are not adsorbed.

  In the sheathed heater of the present invention, it is desirable that a heat insulating member is provided in the gap. Since the heat radiated from the metal tube is blocked by the heat insulating member, the heat received from the sheathed heater on the opposite side of the sheathed heater from the sheathed heater is further reduced. Suppresses the temperature rise of fat or the like adhering to the opposite side, and can prevent unnecessary smoke generation or dirt sticking. The heat insulating member is provided in a gap between the metal tube and the heat insulating tube, and its exposed area is small. Therefore, unlike a conventional sheathed heater covered with a heat insulating member, oil or the like And odor is difficult to be absorbed.

  Moreover, in the sheathed heater of the present invention, it is preferable that the metal tube and the heat insulating tube are connected to each other via a protruding portion that protrudes from both or one of the outer surfaces facing each other. The protrusion is formed so as to protrude from both or one of the metal tube and the heat insulating tube so as not to be exposed on the outer surface of the sheathed heater. Is difficult to adhere. In addition, when the said heat insulation member is provided in the said space | gap, it is provided avoiding the said projection part.

  Moreover, the inside of the said heat insulation pipe | tube may be vacuum and does not need to be vacuum. However, when not in a vacuum, it is considered that the heat insulating tube is damaged when the internal air is heated and expanded by the heat conducted from the metal tube. Therefore, in the sheathed heater of the present invention, it is desirable that the heat insulating pipe has a vent hole that communicates the inside and the outside on the outer wall portion. Since a part of the warmed air inside the heat insulating pipe is discharged to the outside of the heat insulating pipe through the vent, it is possible to prevent the heat insulating pipe from being damaged.

  Furthermore, in the sheathed heater according to the present invention, it is preferable that the metal tube and the heat insulating tube are both formed of a triangular tube, and one side faces each other. Thereby, for example, it becomes suitable for a heating cooker that arranges an object to be heated above the sheathed heater and cooks it.

  That is, since the heat insulating pipe faces the side opposite to the object to be heated of the metal tube, and the object to be heated is disposed above the sheathed heater, the metal pipe and the heat insulating pipe are opposed to each other. All the side surfaces other than the side surfaces are inclined obliquely downward with respect to the heated object. Therefore, even if grease or the like from the object to be heated falls on the metal tube, it is caused to flow downward further by guiding the side surfaces of the metal tube and the heat insulating tube inclined obliquely downward, thereby smoothly removing the drop. Therefore, it is possible to prevent fat or the like from the object to be heated from adhering to the outer surface of the metal tube or the heat insulating tube.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory view showing a configuration example of a heating cooker provided with the seed heater of the present embodiment, FIG. 1 (a) is a front sectional view of the heating cooker, and FIG. 1 (b) is a seed of the present embodiment. FIG. 1C is a plan view of the heater, and FIG. 1C is an enlarged front sectional view showing a cross section of the end portion of the sheathed heater of the present embodiment. FIG. 1A shows an enlarged cross section of a portion surrounded by a circle A.

  A heating cooker 141 shown in FIG. 1A is provided in a grill main body 142 with a sheathed heater 11 according to the present embodiment and a sheathing net for placing a food material to be heated 120 provided above the sheathed heater 11. 143 and a grill pan 144 that is provided below the sheathed heater 11 and receives the grease 121 etc. from the heated object 120 that has been heated by heating, and a grill lid 145 is provided on the top.

  The sheathed heater 11 of the present embodiment is opposite to the heating wire 12, the metal tube 14 that covers the outer surface of the heating wire 12 via the insulator 13, and the heated object 120 of the metal tube 14, And a heat insulating pipe 16 partially connected through a connecting portion 15 by welding. The metal tube 14 and the heat insulating tube 16 are both formed of a triangular tube, and one side surface 19a of the metal tube 14 and one side surface 20a of the heat insulating tube 16 face each other. A gap is formed between one side surface 19 a of the metal tube 14 and one side surface 20 a of the heat insulating tube 16, and a heat insulating member 17 is provided in the space.

  The heating wire 12 is a spiral nichrome wire. Both ends of the heating wire 12 extend to the outside of the grill main body 142 and are connected to a power source (not shown). In addition, the spiral description is abbreviate | omitted in the figure.

  The insulator 13 is made of a material having excellent electrical insulation at high temperatures and high thermal conductivity. In this embodiment, a sintered body of magnesia powder is used.

  The metal tube 14 is a Ni—Cr—Fe alloy, for example, a circular tube made of Inconel 600 (registered trademark). By being made of Inconel 600, the corrosion resistance at high temperatures is high. As shown in FIG. 1B, the metal tube 14 is disposed in the grill main body 142 in a state of being bent in the middle of the longitudinal direction. The metal tube 14 has the ridge line 18 facing the side surface 19a facing the object to be heated 120, that is, upward. The side surfaces 19b and 19c other than the side surface 19a of the metal tube 14 are inclined obliquely downward. Moreover, both ends of the metal tube 14 are closed by a heat-resistant glass shielding member 21 as shown in FIG.

  The heat insulating tube 16 is a tube made of a Ni—Cr—Fe alloy, for example, Incoloy 800 (registered trademark), has a length and a cross-sectional area similar to those of the metal tube 14, and extends along the metal tube 14. Yes. Both ends of the heat insulating tube 16 are closed by a heat-resistant glass shielding member 22. The heat insulation pipe 16 is hollow and has a high heat insulation effect because both ends are closed.

  The side surfaces 20b and 20c other than the side surface 20a of the heat insulation pipe 16 are inclined obliquely downward. Furthermore, the side surface 20b is provided with a vent 23 that allows the inside and outside of the heat insulating pipe 16 to communicate with each other. The vent 23 is formed with a small diameter so that the air inside the heat insulation pipe 16 is less likely to convect with the air outside the heat insulation pipe 16 in order to maintain a high heat insulation effect of the heat insulation pipe 16.

  The heat insulating member 17 is a rectangular plate made of foam metal, and has a cross-sectional area similar to that of the side surface 19 a of the metal tube 14 and the side surface 20 a of the heat insulating tube 16. The heat insulating member 17 is provided in a space between the side surface 19a of the metal tube 14 and the side surface 20a of the heat insulating tube 16, and is locked by the plurality of connecting portions 15 so as not to drop out of the space.

  Next, the operation of the sheathed heater 11 of this embodiment will be described. When the power supply connected to both ends of the heating wire 12 is turned on, a current flows through the heating wire 12 and the heating wire 12 generates heat. The heat generated by the heating wire 12 is conducted to the metal tube 14 through the insulator 13. The heat conducted to the metal tube 14 is radiated from the outer surface of the metal tube 14 and is conducted to the heat insulating tube 16 through the connecting portion 15.

  The heat radiated from the external surface of the metal tube 14 on the heated object 120 side raises the temperature of the heated object 120. In addition, as the temperature of the object to be heated 120 rises, fat or the like 121 comes out of the object to be heated 120. The fat 121 adheres to the upper surface of the grill pan 144, the inner wall surface of the grill main body 142, and the like by dropping, scattering, or the like. At this time, the oil 121 or the like 121 that has fallen and scattered on the metal tube 14 flows further downward by the guides of the side surfaces 19b, 19c, 20b, and 20c inclined obliquely downward, and is smoothly dropped and removed. Further, the heat radiated from the outer surface (side surface 19a) of the metal tube 14 opposite to the object to be heated 120 is blocked by the air, the heat insulating member 17, and the heat insulating tube 16 existing in the gap.

  On the other hand, since the heat insulating pipe 16 is partially connected to the metal pipe 14 by the connecting portion 15, the contact area between the metal pipe 14 and the heat insulating pipe 16 is small, and between the metal pipe 14 and the heat insulating pipe 16. Since the gap and the heat insulating member 17 are provided in the heat pipe, heat is not easily conducted from the metal pipe 14 to the heat insulating pipe 16. Therefore, the heat conducted to the heat insulating tube 16 and radiated from the outer surface of the heat insulating tube 16 becomes extremely small due to the heat insulating effect of the heat insulating tube 16 itself. As a result, the grill pan 144 facing the opposite side of the sheathed heater 11 from the object to be heated 120 receives a small amount of heat from the sheathed heater 11. Smoke generation and adhesion of dirt to the grill pan 144 can be suppressed.

  Moreover, in the sheathed heater 11, the heat insulating member 17 is provided in the space between the metal tube 14 and the heat insulating tube 16, and since the exposed area is small, a conventional sheath in which a part is covered with the heat insulating member. Unlike heaters, fats and odors generated from an object to be heated are not easily adsorbed.

  The heat insulation pipe 16 is expanded by being heated by the heat conducted from the metal pipe 14 to the heat insulation pipe 16, but a part of the air is discharged to the outside of the heat insulation pipe 16 through the vent 23. The insulation tube 16 can be prevented from being damaged.

  In addition, in the sheathed heater 11, the grease 121 or the like 121 that has fallen and scattered from the heated object 120 is eliminated by the guidance of the outer surfaces 19b, 19c, 20b, and 20c inclined obliquely downward. The extracted grease 121 is difficult to adhere to the external surface.

  In the sheathed heater 11 of this embodiment, the heat insulating member 17 is provided in the space between the metal tube 14 and the heat insulating tube 16, but the heat insulating member 17 may not be provided and only the space may be provided. Although the heat insulating effect is reduced as compared with the case where the heat insulating member 17 is provided, the heat radiated from the outer surface of the metal tube 14 to the side opposite to the object to be heated 120 is caused by air existing in the gap and the heat insulating tube 16 Since radiation is blocked, the heat received from the sheathed heater 11 by the grill pan 144 can be reduced.

  Further, in the sheathed heater 11, the metal tube 14 and the heat insulating tube 16 are triangular tubes, but a circular tube or other shapes may be used, and the shapes may be different. Moreover, although the both ends of the metal pipe 14 and the heat insulation pipe | tube 16 are obstruct | occluded by the shielding members 21 and 22, you may make it obstruct | occlude by crimping | bonding each both ends.

  Moreover, although the metal tube 14 is a circular tube, other shapes may be used. Although the metal tube 14 is arranged in a bent state in the middle of the longitudinal direction, the metal tube 14 may be arranged in parallel using a plurality of linear metal tubes 14. Further, the outer surface of the metal tube 14 may be subjected to a water-repellent coating treatment such as silicone or fluorine. By doing in this way, adhesion of the fat 121 etc. to the sheathed heater 11 can be suppressed, smoke generation from the fat etc. 121 can be prevented, and the corrosion resistance of the sheathed heater 11 can be improved.

  Moreover, although the heat insulation pipe | tube 16 was made from the metal foam, you may make it use a ceramic fiber, a ceramic bulk, etc. instead. In addition, although the heat insulating pipe 16 has the same cross-sectional area as that of the metal pipe 14, it may have a different cross-sectional area. In addition, although the heat insulating pipe 16 is partly connected to the metal pipe 14 via the connecting portion 15 formed by welding, although not shown, the metal pipe 14 and the heat insulating pipe 16 have outer surfaces facing each other. You may make it connect both by providing the projection part which protrudes from both or any one, and welding the top part of a projection part. Furthermore, although the vent hole 23 is provided on the side surface 20b of the heat insulating tube 16, it may be provided on the side surfaces 20a and 20c, or may be provided on the shielding member 22. Further, the inside of the heat insulating tube 16 may be evacuated and the vent 27 may not be provided.

Explanatory drawing which shows one structural example of a heating cooker provided with the sheathed heater of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Sheath heater, 12 ... Heating wire, 13 ... Insulator, 14 ... Metal pipe, 16 ... Heat insulation pipe, 17 ... Heat insulation member, 19a ... One side surface facing the heat insulation pipe of a metal pipe, 20a ... Metal pipe of a heat insulation pipe One side surface opposite to 23, 23 ... vent, 120 ... heated object.

Claims (5)

In a sheathed heater comprising a heating wire and a metal tube that covers an outer surface of the heating wire with an insulator interposed therebetween, and heating an object to be heated against one side of the metal tube,
A part of the metal tube is connected to the opposite side of the object to be heated, the hollow portion is connected to the metal tube, extends along the metal tube, and is closed at both ends.
A sheathed heater, wherein a gap is formed between the metal tube and the heat insulating tube. The sheathed heater according to claim 1,
A sheathed heater, wherein a heat insulating member is provided in the gap. In the sheathed heater according to claim 1 or 2,
The said metal pipe and the said heat insulation pipe | tube are connected via the projection part which protrudes from the external surface which mutually faces, or any one, The sheathed heater characterized by the above-mentioned. In the sheathed heater according to any one of claims 1 to 3,
The said heat insulation pipe | tube has a ventilation hole which connects an inside and the exterior in an outer wall part, The sheathed heater characterized by the above-mentioned. In the sheathed heater according to any one of claims 1 to 4,
The metal tube and the heat insulating tube are both formed of a triangular tube, and one side faces each other.

Images