JPH0555770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heating cooker, and more particularly to a gas oven using a fluid fuel such as city gas, LP gas, natural gas, or petroleum as a heating source.

[Conventional technology]

A gas oven is an appliance that cooks food in a high-temperature chamber.It heats food evenly from the surrounding area, so it bakes quickly, and it heats the surface of the food in a high-temperature atmosphere before passing the heat inside, so it retains nutrients, It is said that it can be cooked without losing its flavor or shape.

To explain a typical gas oven that has been used in the past, the interior of the oven is covered with an insulating material such as asbestos, and the cooking section and heating section are connected vertically via a hot plate with a vertically communicating gap. Separate. Inside the cooking area, there is a grill and shelves for placing food to be heated, and on one side of the outer wall of the cooking area, there is a door fitted with heat-resistant glass to allow you to take in and take out food and observe the progress of cooking. establish.

The heating section is provided with a secondary air intake at the bottom and a gas burner inside. The above-mentioned secondary air is essential for gas combustion, and for guiding the secondary air, an exhaust hole using natural convection is provided in the rear wall near the ceiling of the cooking section.

[Problem that the invention seeks to solve]

Gas ovens heat food using convection of combustion gas rising from gaps around the heating plate and radiant heat from the inner wall of the cooking section. The most important thing is to heat it.

However, the temperature inside the cooking area near the heating plate, which is directly heated by the gas burner, becomes extremely high, but because there is an exhaust hole near the ceiling, the temperature drops rapidly at the top of the cooking area, causing the inside of the cooking area to become even. A high temperature atmosphere cannot be obtained. Furthermore, a portion of the high-temperature air is discharged to the outside through the exhaust hole, and not all of it can be used for cooking, which is extremely disadvantageous in terms of energy usage.

[Means for solving problems]

The present invention provides a gas oven formed in the shape of a housing with a cooking section and a heating section located above and below through a heating plate having a large number of through holes. The cooking section is semi-sealed without exhaust holes in the top wall and side walls, and the heating section includes a gas burner and a heat insulating material surrounding the gas burner. By disposing the cylinder, a space is formed in the heat insulating cylinder between the gas burner and the hot plate in which convection circulation of combustion gas occurs, and the gas burner is disposed on the side wall of the heating section. To provide a gas oven characterized by being provided with a secondary air intake hole and an exhaust device.

[Effect]

A small amount of air drawn into the heating part through the secondary air intake hole by the suction of the exhaust device completely burns out the gas coming out of the gas burner arranged in the heating part. The resulting high-temperature combustion gas flows upward and collides with a hot plate having a large number of through holes, first heating the hot plate and making it red-hot, thereby emitting a large amount of radiation. In addition to it,
A part of the combustion gas passes through the through holes of the hot plate and flows into the space inside the cooking part, directly increasing the temperature of the gas inside the cooking part, so that in the space inside the cooking part, high temperature hot air flows upward from the hot plate. The direction will increase.
However, in the gas oven of the present invention, the top wall and side wall of the cooking section are not provided with exhaust holes, so the temperature in the upper space of the cooking section does not drop due to the exhaust air, and the food in the upper space is also prevented. It becomes high temperature. By applying heat to the food and the walls of the cooking area, the temperature drops and the hot air increases in density and falls downward, but this creates a gentle convection of hot air in the space inside the cooking area. The inner wall surface of the heated cooking section, etc., emits radiation. As a result, the food, walls, etc. within the cooking section are heated substantially uniformly, and the temperature of each part within the cooking section rises evenly.

Inside the heat insulating cylinder installed in the heating section and in the space between the gas burner and the hot plate, high-temperature combustion gas rises from the gas burner, and heat is applied to the hot plate to lower the temperature and increase density. As the combustion gas that has been released descends, convective circulation of the combustion gas occurs, but
Furthermore, the same volume of combustion gas that has passed through the through holes of the hot plate and flowed from the heating section into the cooking section, the combustion gas, etc. whose temperature has decreased and the density has increased in the cooking section,
It flows out from the cooking section to the heating section through the through holes in the periphery and center of the hot plate, and joins the convection of combustion gas in the internal space of the heat insulating cylinder. As a result, combustion gas does not immediately flow out from the heating section to the exhaust system.
Since the combustion gas stays in the space between the gas burner and the hot plate inside the heat insulating cylinder for a relatively long period of time, the heat held by the combustion gas is completely given to the inside of the hot plate or the cooking part during that time, or Heat will be stored in the heat insulating cylinder etc. The heat stored in the heat insulating cylinder etc. not only stabilizes the combustion state, but is also emitted in the form of radiation or carried by the gas it comes into contact with, and is ultimately used to heat the food in the cooking section. .

Of the combustion gas circulating in the internal space of the heat insulating cylinder by forming convection, only the part whose temperature has decreased and density has increased by applying heat to the hot plate etc. flows to the lower part of the gas burner. It will descend and be exhausted to the outside little by little by the exhaust system. Therefore, the temperature of the exhaust gas passing through the exhaust device is sufficiently low, and its flow rate is also small.

In addition, since heat is supplied to the space inside the semi-sealed cooking section, after the temperature inside the cooking section rises to a high temperature, it is possible to maintain the inside of the cooking section at a uniform high temperature by replenishing a small amount of heat. This results in less water evaporation from the food, and the food is heated in a state where heat is trapped in the cooking area.

Furthermore, due to this effect, not only the amount of fuel gas consumed by the gas burner is reduced, but also the amount of secondary air or the amount of exhaust gas is small, so the amount of gas burner or exhaust gas is reduced. A small device will suffice, and the heat resistance of the exhaust device will not be so required.

[Example] Hereinafter, a gas oven of the present invention will be described with reference to an example. The gas oven is formed in the shape of a substantially rectangular hexahedral housing, and has a heating plate 1 disposed horizontally in the middle part.
A cooking section 2 and a heating section 3 are divided above and below through the.

The hot plate 1 is made of a thermally conductive material such as a copper plate or a stainless steel plate, has a large number of through holes 4, and is coated over almost the entire surface with a far-infrared ray generating treatment such as ceramic coating.

The cooking section 2 is equipped with an openable/closable door 6 having a see-through plate 5 made of heat-resistant glass or the like on the front surface of the housing, making it convenient to take in and take out food and observe the progress of cooking. A shelf board and a grill 7 are arranged inside the cooking section 2, and at least both sides and the back surface are covered with a heat insulating material 8.

The above configuration is similar to that of a conventional gas oven, but unlike the conventional gas oven, the cooking section 2 is not provided with an exhaust hole. Therefore, when the door 6 is closed, the cooking section 2 is almost in a sealed state. Further, the inner wall of the cooking section 2 is subjected to far-infrared ray generation treatment in the same manner as the hot plate 1.

Inside the heating section 3, a heat insulating tube 10 made of a heat insulating material is provided, surrounding a normal gas burner 9 provided at the bottom. In the case of this embodiment, the heat insulating tube 10 has an upper end connected to the lower surface of the hot plate 1, and a lower end with a slight gap from the bottom surface of the gas oven. Further, a secondary air intake hole 11 is provided on one side of the heating section 3, and an exhaust device 12 consisting of a blower or the like is provided corresponding thereto. This exhaust device 12 serves to assist the combustion of gas by taking in additional air necessary for combustion of the gas from outside the oven through the intake hole 11.

In the embodiment shown in FIG. 1, a hollow cylindrical flame shielding tube (or heat storage tube) 13 is attached above the gas burner 9 inside the heat insulating tube 10 by support legs 14 shaped like trivets. It is supported so that a ventilation gap 15 is formed between it and the gas burner 9. The flame shield tube 13 in this example is preferably made of a heat-resistant material such as ceramic,
A large number of small holes may be provided on the entire surface, as is often done in ceramic plates for infrared heaters.

The present invention utilizes far infrared rays to
The far infrared rays emitted from the inner wall surface of the cooking section are uniformly and concentratedly irradiated in the form of electromagnetic waves onto the object to be heated by the reflective optical system, and are not irradiated to surrounding areas that do not require heat, so there is little energy loss. Furthermore, if the metal parts of the hot plate 1 and the inner wall of the cooking section are coated with ceramic, not only can the high temperature state be maintained for a long time, but also the heat resistance of the metal parts can be improved.

In operation, when gas is combusted by the gas burner 9 and the exhaust device 12 is turned on at the same time, secondary air necessary for combustion is sucked through the intake hole 11 and the gas is completely combusted. The high-temperature combustion gas flows upward and collides with the hot plate 1 having a large number of through holes 4, and first heats the hot plate 1 to make it red hot, thereby emitting a large amount of radiation including far infrared rays. In addition, a part of the combustion gas passes through the through holes 4 of the hot plate 1 and flows into the space inside the cooking section 2, directly increasing the temperature of the gas inside the cooking section 2. In the space, high-temperature hot air rises upward from the hot plate 1. However, since no exhaust holes are provided on the top wall and side walls of the cooking section 2, the hot air whose temperature drops and density increases by applying heat to the food and the wall of the cooking section 2 flows downward. As a result, a gentle convection of hot air occurs in the space within the cooking section. the result,
The food and walls inside the cooking section 2 are heated almost uniformly, and since the inner walls of the cooking section 2 emit far-infrared rays, the temperature of the food and each part inside the cooking section 2 is even. Rise.

In the internal space of the heat insulating cylinder 10 disposed in the heating section 3, high-temperature combustion gas rises from the gas burner 9, while combustion gas whose temperature decreases by applying heat to the hot plate 1 and whose density increases falls. This causes convection of the combustion gas, but the temperature also drops within the cooking section 2 by the same volume as the combustion gas that has passed through the through hole 4 of the hot plate 1 and flowed into the cooking section. The combustion gas, etc. whose density has increased through the through-holes 4 in the periphery and center of the hot plate 1 flows out to the heating section 3, joins the convection of the combustion gas in the heat insulating cylinder 10, and causes its downward flow. ride and descend.

In the embodiment shown in FIG.
Inside the gas burner 9, a hollow cylindrical flame shielding tube (or heat storage tube) 13 is supported by support legs 14 so as to create a ventilation gap 15 between the gas burner 9 and the gas burner 9. Gas is flameproof cylinder 1
3 along the inner wall surface of the flame shielding tube 13.
As a result, convection flows downward along the outer wall surface of the flame shield tube 13, and the flame shield tube 13 receives heat from the combustion gas swirling around its cross section, becomes red-hot, stores heat, and emits far-infrared rays, etc. It becomes like this.

In this way, in the gas oven of the embodiment, the combustion gas does not immediately flow out from the heating section 3 to the exhaust device 12, and stays inside the heat insulating cylinder 10 for a relatively long time, so that the combustion gas retained during that time is The heat is completely applied to the hot plate and the inside of the cooking section 2, or is stored in the heat insulating cylinder 10 and the flame shield cylinder 13. The heat stored in the heat insulating tube 10, flame shield tube 13, etc. not only stabilizes combustion, but also acts as radiation.
Alternatively, it is carried by the gas it comes into contact with and is ultimately used to heat the food in the cooking section 2. Only the part of the combustion gas whose temperature has decreased and density has increased by giving heat to other gases is used as a gas burner 9.
Since the exhaust gas descends to the lower part of the exhaust gas and is gradually discharged to the outside by the exhaust device 12, the temperature of the exhaust gas passing through the exhaust device 12 is sufficiently low, and its flow rate is also small.

In addition, since heat is supplied to the space inside the cooking section 2 which is semi-sealed in this way, after the temperature inside the cooking section 2 rises to a high temperature, the inside of the cooking section 2 is evenly distributed by replenishing a small amount of heat. Can be maintained at a high temperature,
There is little evaporation of moisture in the food, and the food can be heated in a state where heat is trapped in the cooking section 2. Furthermore,
Due to this effect, not only the amount of fuel gas consumed by the gas burner 9 is small, but also the amount of secondary air or the amount of exhaust gas is small, so the gas burner 9 and the exhaust gas are A small device will suffice, and the heat resistance of the exhaust device 12 will not be so required.

As mentioned above, if a ceramic coating is applied to the entire surface of the hot plate 1, the metal part of the inner wall of the cooking section 2, etc., the far-infrared radiation effect will be increased.

〔Effect of the invention〕

In the gas oven of the present invention, no exhaust hole is provided in the top wall or side wall of the cooking section, and the cooking section is semi-sealed except for the through hole of the heating plate, so that the temperature inside the cooking section is uniform everywhere. This allows food to be heated evenly.

In addition, since heat is supplied to the space inside the semi-sealed cooking section, after the temperature inside the cooking section rises to a high temperature, a small amount of heat is supplied to maintain the inside of the cooking section at a uniform high temperature. There is less evaporation of moisture in the food, and the food can be heated evenly with heat trapped inside the cooking section.

Furthermore, apart from some of the combustion gas going in and out of the cooking section, hot air remains inside the cooking section, and combustion gas also remains inside the heating section due to convection within the insulated cylinder, and only the portion where the temperature has dropped is exhausted. Since only a small amount of gas is emitted by the device, a small gas burner, exhaust device, etc. is sufficient, and the amount of fuel gas consumed by the gas burner is also small, making it extremely economical. Another advantage is that since the temperature of the exhaust gas is low, the exhaust system does not require much heat resistance. In the gas oven of the present invention, part of the combustion gas passes through the through holes in the hot plate and enters the cooking section, directly heating the inside, so the thermal efficiency is higher than that of an indirect heating type gas oven. Leads to consumption reduction.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a gas oven according to the present invention, and FIG. 2 is an enlarged sectional view of a hot plate. 1...Hot plate, 2...Cooking section, 3...Heating section, 4
...Through hole, 9...Gas burner, 10...Insulating tube, 11...Secondary air intake hole, 12...Exhaust device.

Claims (1)

[Claims] 1 A gas oven formed in the shape of a housing with a cooking section and a heating section located above and below through a heating plate having a large number of through holes, the cooking section having exhaust holes in its top wall and side wall. The gas burner and the hot plate are formed in a semi-sealed shape without any heat dissipation, and a gas burner and a heat insulating tube made of a heat insulating material surrounding the gas burner are disposed inside the heating section. A space for convection circulation of combustion gas is formed inside the heat insulating cylinder between the heating section, and a secondary air intake hole for the gas burner and an exhaust device are provided on the side wall of the heating section. A gas oven featuring