JPH10132279A - Roasting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roasting apparatus having a heating plate with excellent endurance using an inexpensive material. SOLUTION: In this roasting apparatus, a heating plate 2 is disposed above a gas burner 1 to roast a material to be heated by radiation heat from the heating plate 2. The heating plate 2 is provided on the surface of a metal base plate 15 with a protective cover ceramic layer whose thickness is 5-30μm and whose coefficient of linear expansion is nearly equal to that of the metal face plate 15. The metal base plate 15 is made of stainless steel or a heat resistant alloy. The protective cover layer 16 is made of one type of ceramic selected from a group consisting of stabilized zirconia, partially stabilized zirconia, alumina, magnesia-alumina composite, zirconia-alumina composite, zirconia-silica composite, magnesia, magnesia-silica composite, calcium fluoride-zirconia composite, felpathoid and feldspar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pottery device which heats a heating plate disposed above a gas burner by the gas burner, and burns a cooked object such as a yakitori by radiant heat radiated from the heating plate. It is about.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, a pottery apparatus having a heating plate 2 disposed above a main burner 1 is known.

In the above-mentioned pottery apparatus, the combustion air forcibly supplied to the main burner 1 through the primary air holes 10 by the combustion fan 7 is supplied to the combustion gas supplied from the gas pipe 3 and the combustion gas in the main burner 1. Mixed in. Then, as shown in FIG. 2, a mixture 12 of combustion air and combustion gas is ejected from a flame port 1 a to form a flame 13, and all primary combustion is performed, so that the mixture 12 is disposed above the main burner 1. The heated plate 2 is heated to a high temperature. The heating plate 2 generates radiant heat 14 by being heated by the flame 13 as described above, and the radiant heat 14 can bake a cooked object such as a grilled chicken disposed above the heating plate 2.

[0004] In the above-mentioned pottery apparatus, particularly in the case of a commercial appliance, the heating plate 2 is continuously heated to a high temperature for a long time. In addition, the oil, sauce, etc. of the food such as grilled chicken may be
When dropped, the heating plate 2 is corroded under the high temperature conditions. Therefore, the heating plate 2 is required to have not only heat resistance against high temperatures due to the entire primary combustion of the main burner 1 but also corrosion resistance against corrosion due to the oil, sauce and the like under the high temperature conditions.

As a material having both the heat resistance and the corrosion resistance, in the above-mentioned conventional pottery, a Ni-based super heat-resistant alloy called Haines alloy (for example, manufactured by Mitsubishi Materials Corporation,
(Product name: HA-214, containing about 80% of Ni) is used for the heating plate 2. However, the Haynes alloy is very expensive, and it is desired to use an inexpensive material instead.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a pottery device having a heating plate made of inexpensive material and having excellent durability.

[0007]

Means for Solving the Problems In order to achieve the above object, a pottery of the present invention has a heating plate disposed above a gas burner, and when the heating plate is heated by the gas burner,
In a pottery device for baking an object to be cooked by radiant heat radiated from the surface of the heating plate, the heating plate has a thickness on a surface of a metal substrate made of ceramics having a linear expansion coefficient close to a linear expansion coefficient of the metal substrate. Is provided with a protective coating layer in the range of 5 to 30 μm.

The metal substrate may be inexpensive as compared with the Haynes alloy, and may have sufficient heat resistance as the heating plate. There is a possibility that the food may be corroded by oil, sauce or the like. Therefore, in the pottery apparatus of the present invention, by providing a protective coating layer made of ceramic on the surface of the metal substrate, corrosion resistance to the oil, sagging, etc. can be imparted.

The protective coating layer is formed from ceramics having a linear expansion coefficient close to the linear expansion coefficient of the metal substrate, thereby preventing the protective coating layer from being separated from the metal substrate when heated as described above. be able to. Further, the thickness of the protective coating layer is in the range of 5 to 30 μm to impart corrosion resistance to the oil, sagging, etc. to the metal substrate, so that the metal substrate can be cooked such as grilled chicken when heated as described above. Radiant heat required for baking the product can be generated. If the thickness of the protective coating layer is less than 5 μm, the corrosion resistance to the oil, sagging and the like is not sufficient, and if it exceeds 30 μm, radiant heat required for baking the food such as yakitori may not be obtained.

In the pottery apparatus of the present invention, stainless steel or a heat-resistant alloy is preferably used as the metal substrate because it has sufficient heat resistance as a heating plate and is inexpensive. Examples of the stainless steel include martensitic, ferritic, austenitic, and duplex stainless steels. Examples of the heat-resistant alloy include Hastelloy (Ni-Mo aging resistant hydrochloric acid alloy), Inconel (Ni-Cr alloy), Incoloy,
Various alloys such as mnemonics can be mentioned.

The ceramic forming the protective coating layer needs to have corrosion resistance to the oil, sagging and the like. Further, in order to prevent separation from the metal substrate, the metal substrate has a linear expansion coefficient close to the linear expansion coefficient of the metal substrate. It is preferable that the value changes linearly by approximating the coefficient. Further, the ceramic is preferably chemically stable within the operating temperature range of the pottery in view of durability, and it is preferable that the raw material is rich in raw material cost.

[0012] In the pottery apparatus of the present invention, as the ceramics satisfying the above conditions, the metal substrate is made of stabilized zirconia, partially stabilized zirconia, alumina, magnesia-alumina composite, zirconia-alumina composite, zirconia-silica composite, magnesia. , A magnesia-silica composite, a calcium fluoride-zirconia composite, a feldspar, and a feldspar. Here, the stabilized zirconia refers to zirconium oxide which is completely cubic crystallized by adding an oxide such as magnesia, calcia, rare earth metal oxide or the like, and partially stabilized zirconia refers to the oxidized oxide. Zirconium oxide which is made cubic by adding a few percent of a substance.

The magnesia-alumina composite has a spinel type (MgAl ₂ O ₄ ) crystal structure, and the magnesia-silica composite has a clinoenstatite type (Mg ₂ Si ₂ O ₆ ) or a forslite type (Mg ₂ SiO ₄ ). Further, as the quasi-feldspar, nepheline, leucite,
Examples include calcite and the like, and examples of feldspar include albitite, anorthite and potassium feldspar.

Next, Table 1 shows the coefficient of linear expansion of the metal material and the ceramic.

[0015]

[Table 1]

In the pottery apparatus of the present invention, it is preferable to select a combination in which the expansion coefficient of the metal substrate and the expansion coefficient of the ceramics are close to each other. The combination with stabilized zirconia to which 8 mol% of yttria is added (stabilized zirconia A) is most suitable.

[0017]

Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a system configuration diagram showing the configuration of the pottery apparatus of the present embodiment, FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is an enlarged view of a main part of FIG. 2.

Next, the pottery apparatus of the present embodiment will be described with reference to FIGS.

As shown in FIG. 1, in the pottery apparatus of this embodiment, a heating plate 2 is provided above a main burner 1. The main burner 1 has a large number of flame ports 1a on its upper surface facing the heating plate 2, and a gas pipe 3 is connected to its base. In the middle of the gas pipe 3, a safety governor cock 4
The branch gas pipe 3a is branched downstream of the safety governor cock 4. A pilot burner 5 and a spark plug 6 are provided near the main burner 1.
The supporting gas pipe 3a is connected to the pilot burner 5.

The pottery apparatus shown in FIG. 1 is provided with a combustion fan 7, and combustion air taken in by the combustion fan 7 is sent from a fan casing 8 to an air supply box 9. The air supply box 9 is provided with a primary air hole 10 communicating with the inside of the main burner 1, and the combustion air is supplied from the primary air hole 10 into the main burner 1. In FIG. 1, reference numeral 11 denotes a thermocouple for detecting misfire of the main burner 1.

In the pottery apparatus shown in FIG. 1, during the ignition operation,
First, the combustion fan 7 operates to suck combustion air from the suction port 7a, and the combustion air that has passed through the fan casing 8 and the air supply box 9 is forcibly supplied into the main burner 1 from the primary air hole 10. Is done. At the same time, gas is supplied to the main burner 1 and the pilot burner 5 from the gas pipe 3 and the supporting gas pipe 3a.

Next, after spark is ignited to the ignition plug 6 and ignites the pilot burner 5, the combustion air forcibly supplied and the gas supplied from the gas pipe 3 are mixed in the main burner 1. Then, the gas is blown out from the flame opening 1 a and ignited from the pilot burner 5. At this time, the main burner 1
When a misfire occurs, the thermocouple 11 is cooled, a flame detection circuit (not shown) detects the misfire, the safety governor cock 4 is closed, and the outflow of raw gas is prevented.

When the main burner 1 is ignited, the branch gas pipe 3
a is closed, the safety governor cock 4 is proportionally controlled, and steady operation is started.

In the pottery apparatus of this embodiment having the above configuration, as shown in FIG. 2, the combustion air forcibly supplied into the main burner 1 and the gas supplied from the gas pipe 3 are mixed. The fuel-air mixture 12 is the flame 1 of the main burner 1.
a, a flame 13 is formed on the back side of the heating plate 2 having a semicircular cross section by the all-primary combustion. As a result, the heating plate 2 is heated to a high temperature to generate radiant heat 14, and the radiant heat 14 can bake a cooked object (not shown) such as a grilled chicken disposed above the heating plate 2.

When the object to be cooked is fired by the baking oven, oil, sauce and the like fall from the object to be heated onto the heating plate 2, and the heating plate 2 is corroded by the oil, sauce and the like under high temperature conditions. There is a fear. Therefore, in the pottery apparatus of this embodiment, as shown in FIG. 3, the heating plate 2 is provided on both surfaces of the metal substrate 15 with the protective coating layer 16 made of ceramics having a linear expansion coefficient close to the linear expansion coefficient of the metal substrate 15. 5-30
The thickness is set in the range of μm. The protective coating layer 16 may be provided only on the surface of the metal substrate 15 facing the object to be cooked.

In the present embodiment, when the protective coating layer 16 made of the ceramic is formed on the surface of the metal substrate 15, the surface of the metal substrate 15 is first roughened, degreased, washed, dried, and then prepared in advance. It is immersed in the slurry of the ceramic material for about 15 seconds. Next, the metal substrate 15
Is lifted from the slurry of the ceramic material, the slurry of the ceramic material attached to the surface of the metal substrate 15 is dried with cold air, and then baked at a temperature of 1100 to 1500 ° C. for 2 hours to form the protective coating layer 16. Is done.

The surface of the metal substrate 15 can be roughened, for example, by applying sandpaper of about # 240 along the longitudinal direction of the metal substrate 15.
Further, the metal substrate 15 whose surface is roughened as described above is used.
Can be degreased and cleaned by ultrasonic cleaning in acetone for about 3 minutes.
It can be dried by leaving it to stand for a minute.

The slurry of the ceramic material is prepared by wet-mixing the powder of the ceramic material with water and a dispersant in a ball mill for 16 hours.
It can be prepared by adding a predetermined amount of polyvinyl alcohol, further wet-mixing with a ball mill for 10 minutes, and leaving the mixture under a reduced pressure of about 10 ⁻³ torr for 15 minutes to remove bubbles. At this time, the thickness of the protective coating layer 16 to be formed can be controlled by adjusting the amount of water to be added.
In order to adjust the thickness to 30 μm, about 45 to 60% by weight of water is added to the powder of the ceramic material.

When the protective coating layer 16 is formed only on the surface of the metal substrate 15 facing the object to be cooked, the metal substrate 15 is immersed in the slurry of the ceramic material, pulled up, and then pulled up on the opposite surface. What is necessary is just to wipe off the slurry of the ceramic material adhered to the surface.

[0030]

EXAMPLE In this example, a high-temperature oxidation-resistant ferritic stainless steel (manufactured by Nissin Steel Co., Ltd., trade name: NCA-1) was used as a metal substrate 15, and # 240 sandpaper was applied along its longitudinal direction. Then, after the surface was roughened, it was degreased and cleaned by ultrasonic cleaning in acetone for 3 minutes. And after washing, it was left to dry at room temperature for 10 minutes.

Next, yttria having an average particle size of 0.5 μm
Stabilized zirconia (Tosoh Corporation, yttria: zirconia
= 8:92, molar ratio) 56% by weight of water with respect to the powder;
2% by weight of a dispersant and wet in a ball mill for 16 hours.
Formula mixed. Next, 10% -polyvinyl alcohol was used as a binder.
Rucohol to the yttria stabilized zirconia powder
20% by weight, and wet with a ball mill for 10 minutes
Mixed. Next, 10 ^-3Let stand for 15 minutes under reduced pressure of Thor
Removes air bubbles to remove the ceramic material
A rally was prepared.

Next, the metal substrate 15 having a roughened surface as described above is immersed in the slurry for 15 seconds, pulled up, dried with cold air, and baked at a temperature of 1150 ° C. for 2 hours. A protective coating layer 16 having a thickness of about 12 μm made of the above-mentioned yttria-stabilized zirconia was formed on both surfaces of No. 15 to obtain a heating plate 2.

The heating plate 2 is mounted on the apparatus shown in FIG.
As a result of the burning, the grilled chicken could be cooked under the conditions that the surface temperature of the heating plate 2 was 895 ° C. and the emissivity of the heating plate 2 was 88%. Also, at this time, even if oil, sauce, etc. from the yakitori fall onto the heating plate 2, no white smoke is generated, and traces of oil, sauce, etc. remain on the protective coating layer 16 of the heating plate 2, The heating plate 2 was not corroded by oil, sauce or the like.

The heating plate 2 of this embodiment can be used for a total of 3,700 hours (equivalent to one year and three months assuming that it is used for eight hours a day) under the above conditions, and has excellent durability. It is clear that there is.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a configuration example of a pottery device of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 2;

[Explanation of symbols]

1: gas burner, 2: heating plate, 14: radiant heat, 1
5: metal substrate, 16: protective coating layer.

Claims (3)

[Claims] A heating plate disposed above the gas burner, wherein when the heating plate is heated by the gas burner, the object to be cooked is baked by radiant heat radiated from the surface of the heating plate; A pottery, wherein the heating plate is provided with a protective coating layer made of ceramics having a linear expansion coefficient close to the linear expansion coefficient of the metal substrate and having a thickness in the range of 5 to 30 μm on the surface of the metal substrate. 2. The pottery apparatus according to claim 1, wherein said metal substrate is made of stainless steel or a heat-resistant alloy. 3. The protective coating layer is made of stabilized zirconia, partially stabilized zirconia, alumina, magnesia-alumina composite, zirconia-alumina composite, zirconia-silica composite, magnesia, magnesia-silica composite, calcium fluoride-zirconia composite. 3. The pottery device according to claim 1, wherein the pottery is made of one kind of ceramic selected from the group consisting of feldspar, feldspar, and feldspar.