JP3000271B1 - Gas oven, method for firing object to be fired, method for controlling gas combustion apparatus, and method for preventing backflow of combustion gas - Google Patents

Abstract

An object of the present invention is to provide a gas oven in which a space for storing heat of a combustion gas is widely formed in an upper part of a firing chamber in order to prevent an erosion of an object to be fired. A fixed type gas oven is provided with a baking chamber for accommodating a baking material such as dough.
An upper fire burner 3 a is disposed above the firing chamber 11, and a lower fire gas burner 3 is disposed below the firing chamber 11.
b is provided. On the back side of the firing chamber 11, the combustion gas of the gaseous fuel burned by the upper fire burner 3a is supplied.
A plurality of upper discharge ports 4a for discharging to the outside of the fuel cell 1 are provided, and the upper discharge ports 4a are provided at positions lower than the flame port of the upper fire burner 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas oven for baking objects such as confectionery and bread. More specifically, the present invention relates to a gas oven capable of preventing spatter burning of a material to be fired, and a gas burner used for preventing combustion gas in a firing chamber from flowing back into a gas burner when combustion of the gas burner is interrupted. Things.

[0002]

2. Description of the Related Art Referring to FIG. For example, in a gas oven for baking confectionery, bread, and the like, a gas burner 3a for an upper fire (abbreviated as an upper fire burner in this specification) is provided above an inner side of a baking chamber 11 in which an object 2 is housed. Some are provided.

Usually, the firing chamber 11 of the gas oven is provided with an upper discharge port 50 for discharging the combustion gas of the gaseous fuel burned by the upper fire burner 3a to the outside of the firing chamber 11. The upper discharge port 50 is generally provided at a position higher than the upper fire burner 3a in order to smoothly discharge the combustion gas and increase the combustion efficiency of the upper fire burner 3a.

[0004]

However, the above-described conventional device has the following problems. That is, in the conventional gas oven, the combustion gas is supplied to the upper exhaust port 50.
, A heat reservoir 60 (shown by a dotted line in FIG. 7) was difficult to be formed at the upper part of the firing chamber. For this reason, it is difficult to sufficiently obtain radiant heat due to the combustion gas accumulated in the heat reservoir 60, and unevenness is caused in baking depending on a difference in the position of the object 2 to be fired.

The inventor of the present invention provided the upper discharge port 50 at a position lower than the upper fire burner 3a to prevent the material 2 from being burnt, thereby forming a large space for the heat reservoir above the upper fire burner 3a. Tried to do. Thus, it has been found that spatter burning of the object 2 can be prevented.

However, if a large heat reservoir is formed in the upper part of the firing chamber 11, the gas pressure around the upper fire burner 3a during combustion becomes higher than that of the conventional one, and the upper fire burner 3
It was found that when the combustion of a was interrupted, the combustion gas in the firing chamber 11 flowed back into the upper fire burner 3a.

That is, when the backflow of the combustion gas as described above occurs, the oil smoke and the steam in the firing chamber 11 generate the upper fire burner 3.
a, and dew is formed in the burner cylinder. Then, it has been found that, if powder such as flour or dust floating in the baking chamber adheres to the dew condensation, a problem arises in that the flame opening and the burner cylinder are clogged.

In particular, in the case of a gas oven provided with a steam generator used for baking French bread or the like,
A large amount of wet gas penetrated into the upper fire burner, and the above-mentioned adverse effects were likely to occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas oven in which a large space for a heat reservoir of combustion gas is formed at an upper portion in a firing chamber in order to prevent porcine burning of an object to be fired. Another object of the present invention is to prevent the combustion gas in the firing chamber from flowing back into the gas burner when the combustion of the gas burner is interrupted.

[0010]

Means of the present invention taken to achieve the above object are as follows. According to the first invention, in a gas oven having an upper fire burner in a firing chamber, the gas oven has an outlet for discharging combustion gas, and the upper air burner has primary air together with gas fuel.
And a blower for feeding the fuel gas. The discharge port is provided at a position where the combustion gas is stored in an upper portion of the firing chamber and the object to be fired can be fired by using the radiant heat of the combustion gas.
When the gas oven is used,
This applies regardless of whether gas fuel is burning or when combustion is interrupted.
Always operates below the motor's rating, inside the gas burner
At a pressure that prevents the combustion gas in the combustion chamber from flowing back.
A gas oven, characterized in that the gas oven is provided with a gas oven.

According to a second aspect of the present invention, there is provided a gas oven having an upper fire burner in a firing chamber , wherein the gas oven has an outlet for discharging combustion gas and the upper fire burner.
Blower that feeds primary air with gas fuel
When the has, the outlet, Ri Oh provided at a position lower than the burner port of the upper fire burner, the blower motor
When using a gas oven, when burning gas fuel or
Is always below the motor rating, regardless of when combustion is interrupted.
Operating time, the combustion gas in the combustion chamber of the gas burner over the reverse
A gas oven characterized in that the pressure is maintained such that it does not flow .

In the third invention, the gas burner includes:
In the gas combustion apparatus of a gas oven to feed the primary air blow ring with gas fuel, in use of a gas oven, whether at the time of or combustion interrupting combustion of fuel gas, constantly blower motor below the rated of the motor A method for controlling a gas combustion device in a gas oven, characterized by operating the gas burner to maintain the inside of the gas burner at a pressure such that the combustion gas in the combustion chamber does not flow backward.

[0013] In the fourth invention, when the combustion interruption of gas fuel, characterized by operating the blower motor at a lower voltage than during the combustion, gas combustion apparatus in a gas oven according to the third aspect of the present invention Is a control method.

According to a fifth aspect of the present invention, there is provided a method for controlling a gas combustion apparatus in a gas oven according to a third aspect, wherein a blower motor is operated at a constant voltage lower than a rated voltage. .

According to the sixth aspect of the present invention, an upper fire burner is provided in the firing chamber, and the discharge port for discharging the combustion gas stores the combustion gas in the upper part of the firing chamber and uses the radiant heat of the combustion gas to cover the combustion gas. In what is provided at a position where the fired product can be fired,
Regardless of whether the gas fuel is burning or the combustion is interrupted, the blower for sending air into the upper fire burner is always operated to maintain the pressure inside the gas burner so that the combustion gas in the combustion chamber does not flow backward. This is a method for preventing backflow of combustion gas.

(Operation) An outlet for discharging the combustion gas is provided at a position where the combustion gas is stored in the upper portion of the firing chamber and the object to be fired can be fired by using the radiant heat of the combustion gas, or the flame of the upper fire burner. In the gas oven provided at a position where the outlet is lower than the mouth, due to the radiant heat of the combustion gas accumulated at the top of the combustion chamber,
Since a sufficient amount of heat for uniformly firing the fired product is ensured in the entire firing chamber, it is possible to prevent spotted burning of the material to be fired.

When the gas oven is used, the motor of the blower is always operated below the rating of the motor, regardless of whether the gas fuel is burning or the combustion is interrupted, so that the combustion gas in the combustion chamber does not flow backward in the gas burner. In the case where the pressure is maintained, even if the upper fire burner is in the atmosphere of the combustion gas as described above, the combustion gas does not flow back into the upper fire burner. Therefore,
Occurrence of dew condensation in the burner cylinder due to oil smoke and water vapor in the firing chamber entering the upper fire burner, and eyes due to the adhesion of flour and other powder and dust floating in the firing chamber to the burner cylinder. Clogging can be prevented.

When the combustion of the gas burner is interrupted, the motor of the blower is operated at a voltage lower than that at the time of combustion of the gas burner, so that the motor is always operated at the same voltage as that at the time of combustion of the gas burner. The calorific value of the motor can be kept low. Therefore, it is possible to prevent oil from leaking out or oil out of the bearing portion due to the high temperature state of the motor, and it is possible to keep the life of the blower long.

By operating the blower motor at a constant voltage lower than the rated voltage, the rotation of the motor is controlled differently from the above case where the magnitude of the voltage is changed between when the gas burner is burning and when the combustion is interrupted. There is no need to provide any equipment for performing this. Therefore, the manufacturing cost of the gas oven can be kept low, and there is no need for maintenance or the like due to failure of the control device or the like.

[0020]

Embodiments of the present invention will be described in more detail with reference to the drawings. 1 is a schematic cross-sectional view showing the internal structure of a gas oven according to a first embodiment of the present invention, as viewed from the front, FIG. 2 is a schematic cross-sectional view corresponding to II in FIG. 1, and FIG. It is a partial sectional view showing a gas combustion device of an oven.

Reference numeral 1 denotes a fixed-type gas oven having a baking chamber 11 for accommodating a baking material 2 such as bread dough (see FIGS. 1 and 2). An upper fire burner 3a is provided above the firing chamber 11, and a gas burner 3b for lower fire (hereinafter abbreviated as a lower fire burner) is provided below the firing chamber 11. . In addition, the code | symbol 1 shown on the left side of FIG.
Reference numeral 2 denotes a work door, and reference numeral 13 denotes an access port for taking in and out the object 2 to be fired.

The back side of the firing chamber 11 (right side in FIG. 2)
Is provided with a plurality of upper discharge ports 4a for discharging the combustion gas of the gaseous fuel burned by the upper fire burner 3a to the outside of the firing chamber 11, and the upper discharge port 4a is connected to the upper fire burner 3a.
It is provided at a position lower than the flame outlet of a. In the present embodiment, the upper outlet 4a is formed from a plurality of small holes, but is not limited to this.

An exhaust damper 41a for properly adjusting the amount of combustion gas discharged is attached to each of the upper outlets 4a (see FIG. 2, not shown in FIG. 1). Normally, when the gas oven 1 is used, the upper exhaust port 4a is opened to a required size by the exhaust damper 41a.
For example, in a gas oven having a steam generator, when it is desired to fill the inside of the firing chamber 11 with steam, it is completely closed. When it is desired to quickly cool the inside of the firing chamber 11 after using the gas oven 1, the upper exhaust port 4a is completely opened by the exhaust damper 41a.

With the above configuration, the upper fire burner 3
The combustion gas of the gas fuel burned in the upper discharge port 4
A space (shown by a dotted line in FIGS. 1 and 2) of a large heat reservoir 14 is formed in the upper part of the baking chamber 11 without being immediately discharged from a. Due to the radiant heat of the combustion gas accumulated in the heat reservoir 14, a sufficient amount of heat for uniformly firing the object to be fired 2 is ensured in the entire firing chamber 11, thereby preventing the object to be fired 2 from being scorched.

A plurality of lower discharge ports 4b for discharging the combustion gas of the gaseous fuel burned by the lower fire burner 3b to the outside of the gas oven 1 are provided below the discharge port 4a. . The lower discharge port 4b is connected to the lower burner 3b.
In order to smoothly discharge the combustion gas generated from the gas oven 1, it is provided at a position higher than the flame port of the lower fire burner 3b. Therefore, the lower fire burner 3b
Even if the combustion is stopped, the gas pressure around the lower fire burner 3b does not become higher than the gas pressure inside the lower fire burner 3b, and the backflow phenomenon of the combustion gas does not occur.

Further, a partition plate 5 is provided above the lower fire burner 3b, and a tray 21 on which the material to be fired 2 is placed is placed on the partition plate 5.

A description will be given of piping devices for supplying gas fuel to the burners 3a and 3b (see FIG. 1). The combustion gas is distributed and supplied to each burner 3a, 3b through a gas line 6 having branch pipes 6a, 6b. Further, a shutoff valve 7 for shutting off gas fuel when the gas oven 1 is not used is provided upstream of the gas line 6.
Electromagnetic valves 81, 81 for controlling gas supply to the burners 3a, 3b and pressure regulators 8 are provided at required positions of the burners 3a, 3b.
2 are provided.

A gas combustion device for feeding gas fuel and primary air to each burner 3a, 3b will be described. A pipe is connected from the branch pipe 6a of the gas line 6 to the upper fire burner 3a via a gas mixer 9a (see FIG. 3). The gas mixer 9a is a T-shaped pipe joint, and a gas nozzle 61a piped from a branch pipe 6a to one side of an opposed mounting portion.
However, the upper flame burner 3a
Are attached to the base side.

A blower 10a for supplying primary air into the upper fire burner 3a is attached to another attachment portion of the gas mixer 9a which is bent at a right angle via an air supply pipe 20a. An orifice 2 for blowing out the air supplied from the blower 10a at a high speed is provided in the air supply pipe 20a.
01a is attached. The orifice 2
The size of the diameter of 01a can be adjusted appropriately.

The blower 10a has a fan unit 101a for sending out air and a blower motor 102a for rotating a fan in the fan unit 101a. The blower motor 102a has a rated voltage of 100
V-spec ones are used.

The tip of the gas nozzle 61a is located at a position intersecting with the air feeding direction in the gas mixer 9a (indicated by a two-dot chain line in FIG. 3), and the air supplied from the blower 10a is supplied to the tip of the gas nozzle 61a. It is arranged to directly hit the part. Thereby, the gas fuel supplied from the gas nozzle 61a is efficiently mixed with the air supplied from the blower 10a.

Further, the blower motor 102a is connected to the blower motor 102a when the combustion of the upper fire burner 3a is interrupted.
A control device 30 for suppressing the voltage applied to a is low (see FIG. 1, not shown in FIG. 3).

The branch pipe 6b of the gas line 6 is connected to the lower fire burner 3b via a gas mixer 9b having the same structure as that of the upper fire burner 3a. The gas mixer 9b is also provided with the upper fire burner 3
A blower 10b (including a fan unit 101b and a blower motor 102b), an air supply pipe 20b, and an orifice 201b each having the same structure as that provided in FIG.

In the present embodiment, the blower motors 102a and 102b have a rated voltage of 100 V, but are not limited thereto, and are required for combustion of the burners 3a and 3b. Standards are selected as appropriate according to the amount of air.

(Operation) FIG. 4 is a graph showing a change in voltage applied to the blower motor for the upper fire burner per firing time. The operation of the present embodiment will be described with reference to FIGS. Each of the gas mixers 9a, 9a, via the respective branch pipes 6a, 6b of the gas line 6,
The gas fuel introduced into the gas mixers 9a, 9b
In b, the air is mixed with the air supplied from the blowers 10a and 10b. The gas fuel mixed with the air is supplied to each of the gas burners 3a and 3b and used for combustion.

Here, the blower 10 for the upper fire burner 3a is used.
The operation of a will be described. Gas fuel is supplied to the upper fire burner 3a from the branch pipe 6a only when the upper fire burner 3a is burning. However, the blower motor 102a for the upper fire burner 3a always operates regardless of the time of combustion of gas fuel or the time of interruption of combustion, and always supplies air into the upper fire burner 3a. Thus, the gas pressure in the upper fire burner 3a is always kept higher than the gas pressure in the firing chamber 11.

Therefore, when the combustion of the upper fire burner 3a is interrupted, the combustion gas does not flow back into the upper fire burner 3a. Therefore, oil smoke and water vapor in the firing chamber 11 do not enter the upper fire burner 3a, and no dew condensation occurs in the burner cylinder. Accordingly, flour such as flour or dust floating in the baking chamber 11 does not adhere to the inside of the burner cylinder, and there is no problem such as clogging.

Further, when the combustion of the upper fire burner 3a is interrupted, a voltage 70V lower than the rated voltage 100V at the time of combustion of the upper fire burner 3a is controlled by the control device 30.
To operate the blower 10a (see FIG. 4). Therefore, the amount of heat generated by the blower motor 102a can be suppressed lower than when the blower 10a is constantly operated at the rated voltage of 100V. Accordingly, it is possible to prevent oil leakage or oil outflow of the bearing portion due to the high temperature state of the blower motor 102a, and it is possible to keep the life of the blower 10a long.

When the combustion of the lower fire burner 3b is interrupted, the backflow phenomenon of the combustion gas does not occur as described above, so that the blower 10b for the lower fire burner 3b is operated only during combustion.

FIG. 5 is a schematic sectional view showing the internal structure of a gas oven according to a second embodiment of the present invention, as viewed from the front. The same or equivalent parts as those in the first embodiment are denoted by the same reference numerals. The description of the parts described in the first embodiment will be omitted, and differences will be mainly described.

Blower motor 40 attached to blower 40a for upper fire burner 3a of gas oven 1A
2a is the blower motor 10 shown in the first embodiment.
A rated voltage of 125 V higher than the rated voltage 100 V of 2a is used. The blower motor 4
The control device 30 as shown in the first embodiment is not attached to 02a.

Similarly, a blower motor 402b having the same rated voltage of 125 V as the blower motor 402a is attached to the blower 40b for the lower burner 3a.

(Operation) FIG. 6 is a graph showing the change per hour of the voltage applied to the blower motor for the upper fire burner. The operation of the present embodiment will be described with reference to FIG. The description of the same functions as those of the first embodiment will be omitted.

Blower motor 40 for upper fire burner 3a
2a is constantly operated at a voltage of 100 V which is equal to or lower than the rated voltage of 125 V, regardless of whether gas combustion is performed or the combustion is interrupted. Therefore, at a rated voltage of 125 V, the blower 40
a, the blower motor 4
02a can be kept low, and the blower 40a
Life can be kept long.

The upper fire burner 3a is set so that appropriate combustion is performed with the amount of air supplied from the blower motor 402a rotating at a voltage of 100V.

Further, since the blower 40a is always operated at a constant voltage without changing the voltage between when the upper fire burner 3a is burning and when the combustion is interrupted, it is possible to increase or decrease the voltage as shown in the first embodiment. No control device 30 for controlling is required. Therefore, the manufacturing cost of the gas oven 1A can be reduced, and there is no need for maintenance or the like due to a failure of the control device 30.

Further, a blower 40b for the lower fire burner 3b
Also, the voltage of 100 V which is equal to or lower than the rated voltage of 125 V is constantly applied irrespective of when the gas fuel is burned or when the combustion is stopped. Thus, there is no need for a control device or the like for controlling the voltage of the blower 40b.

The terms and expressions used in the present specification are for explanation only, are not restrictive, and do not exclude terms and expressions equivalent to the above-mentioned terms and expressions. Further, the present invention is not limited to the illustrated embodiment, and various modifications are possible within the scope of the technical idea.

[0049]

The present invention has the above configuration and has the following effects. (A) The discharge port for discharging the combustion gas is located at a position where the combustion gas is stored in the upper part of the firing chamber and the object to be fired can be fired by using the radiant heat of the combustion gas, or is discharged from the flame outlet of the upper fire burner. In the gas oven in which the outlet is provided at a lower position, the radiant heat of the combustion gas accumulated in the upper portion of the combustion chamber secures a sufficient amount of heat for uniformly firing the fired product throughout the firing chamber. It is possible to prevent spotted burning of the material to be fired.

(B) When the gas oven is used, the motor of the blower is constantly operated below the rated value of the motor, regardless of whether the gas fuel is burning or the combustion is interrupted, and the combustion gas in the combustion chamber flows backward in the gas burner. If the pressure is maintained such that the combustion gas does not flow, the combustion gas does not flow back into the combustion burner even when the combustion burner is in the atmosphere of the combustion gas as described above. Therefore, dew condensation occurs in the burner cylinder due to oil smoke and water vapor in the firing chamber entering the upper fire burner, and powder and dust, such as flour, floating in the firing chamber adhere to the burner cylinder. Clogging and the like can be prevented.

(C) When the combustion of the gas burner is interrupted,
By operating the blower motor at a lower voltage than when the gas burner is burning, the amount of heat generated by the motor can be reduced compared to when the motor is always operated at the same voltage as when the gas burner is burning. it can. Therefore, it is possible to prevent oil from leaking out or oil out of the bearing portion due to the high temperature state of the motor, and it is possible to keep the life of the blower long.

(D) By operating the blower motor at a constant voltage lower than the rated voltage, the magnitude of the voltage is changed between when the gas burner is burned and when the combustion is interrupted. There is no need to provide devices for controlling rotation. Therefore, the manufacturing cost of the gas oven can be kept low, and there is no need for maintenance or the like due to failure of the control device or the like.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the internal structure of a gas oven according to a first embodiment of the present invention as viewed from the front.

FIG. 2 is a schematic cross-sectional view corresponding to a portion II in FIG.

FIG. 3 is a partial sectional view showing a gas combustion device of a gas oven.

FIG. 4 is a graph showing a change in a voltage applied to a blower motor for an upper fire burner per firing time.

FIG. 5 is a schematic sectional view showing the internal structure of a gas oven according to a second embodiment of the present invention as viewed from the front.

FIG. 6 is a graph showing a change per hour of a voltage applied to a blower motor for an upper fire burner.

FIG. 7 is a schematic sectional view showing the internal structure of a conventional gas oven viewed from a side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1A Gas oven 11 Firing chamber 12 Working door 13 Doorway 14 Heat reservoir 2 Heating object 21 Tray 3a Upper fire burner 3b Lower fire burner 4a Upper outlet 41a Exhaust damper 4b Lower outlet 5 Partition plate 6 Gas line 6a 6b Branch pipe 61a Gas nozzle 7 Shut-off valve 81 Solenoid valve 82 Pressure regulator 9a, 9b Gas mixer 10a, 10b Blower 101a, 101b Fan unit 102a, 102b Blower motor 20a, 20b Air supply pipe 201a, 201b Orifice 30 Control device 40a, 40b Blowers 402a, 402b Blower motor 50 Upper outlet 60 Heat reservoir

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F24C 3/04 A21B 1/26 F24C 3/12 F24C 15/20 F23N 1/02 F23N 5/20

Claims (6)

(57) [Claims] 1. A gas oven having an upper fire burner in a firing chamber, wherein the gas oven has an outlet for discharging combustion gas ,
Send primary air together with gaseous fuel to the upper fire burner
A blower it has a said outlet, Ri Oh provided at a position capable of firing the baked product using a radiation heat reservoir the combustion gas of the combustion gases at the top of the baking chamber, the blower When using a gas oven,
Regardless of the time of gas fuel combustion or combustion interruption,
The gas burner operates at all times below the
Keep the pressure so that the combustion gas in the firing chamber does not flow back
A gas oven, characterized by being prepared . 2. A gas oven having an upper fire burner in a firing chamber , wherein the gas oven has an outlet for discharging combustion gas ,
Send primary air together with gaseous fuel to the upper fire burner
A blower you have a said outlet, Ri Oh provided at a position lower than the burner port of the upper fire burner, the motor of the blower is, in use of a gas oven,
Regardless of the time of gas fuel combustion or combustion interruption,
The gas burner operates at all times below the
Keep the pressure so that the combustion gas in the firing chamber does not flow back
A gas oven, characterized by being prepared . To 3. A gas burner, in a gas combustion apparatus of a gas oven to feed the primary air blow follower <br/> together with the gas fuel, when using the gas oven, though at the time or combustion interrupting combustion of fuel gas A method for controlling a gas combustion device in a gas oven, characterized in that the blower motor is always operated at a rating of the motor or lower to maintain a pressure in the gas burner so that the combustion gas in the combustion chamber does not flow backward. . 4. The method for controlling a gas combustion device in a gas oven according to claim 3 , wherein when the combustion of the gas fuel is interrupted, the motor of the blower is operated at a lower voltage than during the combustion. 5. The method for controlling a gas combustion device in a gas oven according to claim 3 , wherein the motor of the blower is operated at a constant voltage lower than the rated voltage. 6. An upper fire burner is provided in the firing chamber, and an outlet for discharging combustion gas is located at a position where the combustion gas is stored in an upper portion of the firing chamber and the object to be fired can be fired by using radiant heat of the combustion gas. The blower for sending air into the upper fire burner is always operated irrespective of combustion of gas fuel or interruption of combustion, so that the combustion gas in the combustion chamber does not flow backward in the gas burner. A method for preventing backflow of combustion gas, characterized by maintaining the pressure state.