JPS6252219B2 - - Google Patents

Description

[Detailed description of the invention] The present invention uses a wire mesh made of a heat-resistant metal such as stainless steel on a ceramic surface containing at least one of Al ₂ O ₃ or SiO ₂ as a main component as a heat source for heating food. To provide an efficient infrared gas grill that powerfully radiates infrared rays by heating a heating element with a gas burner.

Generally, when a heated object is heated by infrared rays, the influence of the spectral characteristics of the heated object in the infrared region is extremely large. As a result of researching the spectral characteristics of raw fish meat (mackerel) and the changes in spectral characteristics caused by heating, the following findings were discovered. Figure 1 shows the reflection spectrum and transmission spectrum of raw fish (mackerel). The measurement was performed using a spectrophotometer capable of measuring up to an infrared region of 15 μm. As can be seen from Figure 1, fish meat reflects or transmits a large amount of light or infrared rays with a wavelength of 0.4 μm to 2.5 μm, and is difficult to absorb. On the other hand, infrared rays with wavelengths longer than 2.5 μm hardly reflect or pass through, and are sufficiently absorbed by fish meat and converted into thermal energy, which is thought to be used effectively for heating fish meat. When this fish meat is further heated, the proteins in the fish meat undergo thermal denaturation, and the water content gradually decreases.
Infrared spectral characteristics also change. Figure 2 shows the change in spectral transmittance of fish meat (horse mackerel) due to heating.
It is observed that the transmittance gradually decreases in the near-infrared region of 0.9 μm to 1.5 μm from a to b, c, d, and e as it is heated. Also the third
The figure shows the change in spectral reflectance of fish meat (horse mackerel) due to heating. As it heats up, from a to b,
It is observed that the reflectance gradually increases in the near-infrared region of 0.9 μm to 1.5 μm.

Therefore, when cooking fish meat, it is important to provide the fish meat with radiant energy at a wavelength that corresponds to these spectra and the spectral changes that occur with heating. It becomes possible to prevent loss and serve delicious fish meat that is properly grilled to the table.

In other words, when heating fish meat, infrared rays with long wavelengths of 2.5 μm or more, which have a high absorption rate of fish meat, are effective, but when the fish meat is still raw or almost raw at the early stage of heating,
Near-infrared rays in the range of 0.9 μm to 1.5 μm have a relatively low reflectance in fish meat, so they penetrate well into the fish meat from the surface. Furthermore, near-infrared rays in this wavelength range have a relatively high transmittance through fish meat, and can penetrate well into thick fish meat. This makes it extremely effective for heating fish meat from the inside. That is, near infrared rays of 0.9 μm to 1.5 μm double the heating effect of infrared rays of 2.5 μm or more, which have a high absorption rate for fish meat, in the early stage of heating.
As it is heated, the internal temperature of the fish meat rises, and as the protein begins to denature due to heat, the surface of the fish meat changes as mentioned above.
The reflectance for near-infrared rays of 0.9 μm to 1.5 μm increases and the transmittance decreases, making it difficult for radiant energy to penetrate inside. On the other hand, infrared rays with wavelengths longer than 2.5 μm are still well absorbed by fish meat even if the protein in the fish meat is thermally denatured, so the temperature increases near the surface of the fish meat, causing further thermal denaturation of the protein. It was thus found that the movement of moisture within the fish meat was suppressed and excessive evaporation of moisture from the surface of the fish meat was prevented.

Not only fish (mackerel), but also 200g of flour and 200g of water.
Similar results were obtained for cake seeds kneaded with . This is thought to be common not only to fish and cake seeds, but also to a wide variety of heated foods that contain large amounts of water.

In conventional household gas grills, two methods are generally used: a gas burner heats a metal plate to a high temperature and then radiates infrared rays to heat the food, and a bunk burner radiates infrared rays to heat the food. Widely used. However, even when the wavelength distribution of infrared rays emitted from these materials is measured, the main wavelength is 2 to 3 μm. Figure 4 (A) shows the wavelength distribution in an infrared grill using a stainless wire mesh as a radiator, and (B) shows a wavelength distribution in an infrared grill using a Shubank burner as a radiator. 2.5μ, which is thought to be well absorbed by heated objects containing a large amount of moisture.
There is less infrared rays with wavelengths longer than m, and there is also less near infrared rays with a wavelength of 0.9 to 1.5 μm, which is effective at the initial stage of heating, resulting in poor heating efficiency.

The present invention provides a new infrared gas grill that can efficiently heat an object according to the spectral characteristics of the object using gas, which is currently the most commonly used heat source for cooking.

The details of the present invention will be explained below along with examples.

First, we searched for a radiator that emits more infrared rays with a wavelength of 2.5 μm or more, which is thought to be well absorbed by heated objects containing a lot of moisture.
It is generally known that ceramics emit longer wavelength infrared rays than metals, but TiO ₂
Of ceramics such as ZrO ₂ , BN, etc., especially Al ₂ O ₃ ,
It has been found that ceramic elements containing at least one of SiO ₂ as a main component are excellent as radiators.

At 500℃, the total radiant energy of surface oxidized stainless steel is only 78%, whereas Al ₂ O ₃
It was also found that ceramic elements containing at least one of SiO ₂ as a main component contain 92 to 94% of the radiant energy with a wavelength of 2.5 μm or more in the total radiant energy.

Second, the object to be heated passes through well at the initial stage of heating.
Graphite, tungsten, aluminum, iron, silver, stainless steel, etc. are known as materials that emit a large amount of near-infrared rays of 0.9 μm to 1.5 μm that can be heated from the inside. Among these, heat-resistant metals such as stainless steel are particularly superior.

Moreover, the composition of the radiator is Al ₂ O ₃ or SiO ₂
The greatest effect can be achieved by providing a wire mesh made of a heat-resistant metal such as stainless steel on a ceramic surface containing at least one of these as a main component.

When the radiator of the present invention is heated with a gas burner,
First, the temperature of a heat-resistant wire mesh made of stainless steel or other material with a small heat capacity rises quickly, and from there the temperature increases by 0.9 to 1.5 μm.
A powerful near-infrared ray is emitted. Next, ceramics containing at least one of Al ₂ O ₃ and SiO ₂ as main components, which have a large heat capacity, are heated over time.
It begins to strongly emit infrared rays with wavelengths longer than 2.5 μm. Therefore, infrared rays having a wavelength that exactly corresponds to the spectral characteristics and changes in the spectral characteristics of the food to be heated are emitted, thereby ideally and efficiently heating the food.

In addition, since metal is less durable than ceramic, the structure of the present invention makes it possible to easily replace only the wire mesh, significantly extending the lifespan of the entire infrared grill. It is also possible.

Furthermore, since the wire mesh made of heat-resistant metal is used, there is almost no fear that the infrared rays emitted from the ceramic will be blocked by the wire mesh. Near-infrared rays emitted from the wire mesh are reflected by the ceramic and effectively used for heating.

An example of the configuration will be explained using figures. FIG. 5 is an exploded perspective view of a radiator in an infrared gas grill according to an embodiment of the present invention, in which a pipe-shaped ceramic 1 containing at least one of Al ₂ O ₃ or SiO ₂ as a main component is made of a heat-resistant material such as stainless steel. It is inserted into a metal holder 2 and mechanically fixed with a stopper 3. Further, a wire mesh 4 made of a heat-resistant metal such as stainless steel is placed over the surface and mechanically fixed to the holder 2 to form a radiator 5 .

FIG. 6 shows, in cross section, an example of an applied configuration of the present invention.
FIG. 7 is a side sectional view.

The gas is guided through a pipe 6 and burnt at the flame port 8 of the burner 7.The burned high-temperature gas heats the radiator 5 on the upper part.The radiation from the ceramic 1 and wire mesh 4 incorporated in the radiator 5 is transferred to the receiver 9 on the lower surface. to the wire mesh 10 built in. In addition, the saucer is surrounded by a guide 11 and a stopper 12 at the back to prevent heat from radiating to the outside.The front surface is connected to the saucer 9 with a glass door 13 and a handle 14 installed thereon, allowing it to be taken in and out of the refrigerator. .

The combustion gas that heated the radiator is transferred to the upper cover 14.
The air exits through an exhaust port 15 provided at the top of the exterior case 16 and exits through an exhaust port 17 opened at the top of the exterior case 16 . The outer case is provided with a slight gap from the installation surface by legs 18 to prevent the temperature of the floor from rising. Note that the air necessary for combustion flows in through an air port 19 provided on the lower surface of the outer case 16.

Example Pipe-shaped ceramic (Al ₂ O ₃ 88%, SiO ₂ 10%)
A radiator as shown in Figure 5 was constructed using a wire mesh made of SUS430.

This is done in the grill of a commercially available gas table stove with a grill, which conventionally heats with a Bunsen burner using a metal SU430 wire mesh as a radiator. I placed it in the configuration.

150 g of a commercially available cake premix and 100 c.c. of water were mixed, poured into a stainless steel plate placed on a wire mesh, and heated. With the conventional product, the surface was burnt in 4 minutes and 20 seconds, and it took 6 minutes and 20 seconds for the bottom of the cake to be completely cooked, whereas with the infrared grill of the present invention, it took 2 minutes and 50 seconds.
It started burning in seconds, and in 4 minutes the bottom of the cake was completely cooked.

In addition, with the infrared gas grill of the present invention, fish (mackerel) can be cooked.
When I grilled it, the fish was beautifully browned in 13 minutes. On the other hand, with conventional products, even after 15 minutes, the fire did not get through enough and only cooked food with a lot of moisture.

As is clear from the above examples, the infrared gas grill of the present invention has a ceramic element containing at least one of Al ₂ O ₃ and SiO ₂ as a main component.
It can emit a large amount of far infrared rays of μm or more,
In addition, a large amount of near-infrared rays of 0.9 μm to 1.5 μm can be emitted from the wire mesh made of heat-resistant metal such as stainless steel. It can efficiently heat objects containing a large amount of moisture, contributing to energy savings in heating equipment, and also prevents excessive loss of moisture from the surface when cooking food, improving cooking effectiveness. It also has the great feature of being able to increase

[Brief explanation of the drawing]

Figure 1 is a diagram showing the reflection spectrum A and transmission spectrum R of fish (horse mackerel), Figure 2 is a diagram showing changes in the transmission spectrum of fish (horse mackerel) due to heating, and Figure 3 is a diagram showing the change in the transmission spectrum of fish (mackerel). Figure 4 shows the radiation wavelength distribution of a conventional infrared grill, a grille using a stainless steel wire mesh as a radiator, and a grille using a Schwank burner as a radiator. , FIG. 5 is a partially exploded perspective view showing an example of the structure of the radiator of the present invention, FIG. 6 is a diagram of an example of the applied configuration of the infrared gas grill of the present invention, and FIG. 7 is an example of the applied structure of the infrared gas grill of the present invention. FIG. 3 is a side cross-sectional view of a configuration example. 1... Ceramic pipe (Al ₂ O ₃ or SiO ₂
at least one of the main components), 2... holder,
3... Stopper, 4... Wire mesh (stainless steel), 5... Infrared radiator, 7... Burner, 9
... saucer, 10 ... wire mesh, 11 ... guide, 12
...Saucer stopper, 15...Top cover, 16
...Top cover exhaust port, 17...Exterior case, 1
8... Exterior case exhaust port, 19... Leg, 20...
Air vent, 6...pipe, 8...flame port, 13...glass door, 14...handle.

Claims (1)

[Claims] 1 Equipped with a radiator in which a wire mesh made of a heat-resistant metal such as stainless steel is provided on a ceramic surface containing at least one of Al ₂ O ₃ or SiO ₂ as a main component, and a gas burner for heating the radiator. Infrared gas grill.