JPS6363819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oven used for purposes such as baking bread.

Conventional electric ovens and indirectly heated ovens using kerosene or gas fuel have poor thermal efficiency. Furthermore, since the atmosphere within the heating chamber does not contain moisture, there is a risk that cracks may occur on the surface of the food to be cooked, such as bread, or the food to be cooked may become brittle. Therefore, water or steam is usually added to the heating chamber. In addition, in conventional direct heating type (direct type) ovens that use gas fuel, burnt marks are uniformly formed on the surface of the food, which limits the types of food to be cooked.

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide an oven which has excellent thermal efficiency, is capable of producing the desired browning, and which contains moisture in the atmosphere within the heating chamber.

In the present invention, a pair of annular tubes 5 and 6 are arranged on both sides of the upper part of the heating chamber 3, and each of the annular tubes 5 and 6 connects to one parallel tube 7 near the side of the heating chamber 3, and this The other parallel tube 8 is parallel to the one parallel tube 7 and is closer to the center than the one parallel tube 7, and one end of the one parallel tube 7 is provided with combustion gas in the one parallel tube 7. Injecting gas burners 9, 11
is attached, one end of the other parallel tube 8 is connected to the one end of the one parallel tube 7, and the other end of the other parallel tube 8 is connected to the other end of the one parallel tube 7. The other parallel tube 8 has a plurality of ejection holes 10 opened toward the center of the heating chamber 3 at intervals in the longitudinal direction, and the annular tubes 5 and 6 of the heating chamber 3 are connected to each other. A perforated plate 12 is arranged above the heating chamber 3 and the perforated plate 1
A pair of symmetrical convection ducts 20 and 21 are arranged on the bottom side of the heating chamber 3 and extend along the longitudinal direction of the annular tubes 5 and 6. Each convection duct 20, 21 has a triangular cross section perpendicular to the axis along the corner of the heating chamber 3, and an inclined wall portion 27 that slopes toward the center of the heating chamber 3 from the side wall of the heating chamber 3 toward the bottom plate 25. At the bottom of the convection ducts 20 and 21, a communication hole 23 is provided.
A gap 26 is formed between the lower portions of the convection ducts 20 and 21 and the bottom plate 25 of the heating chamber 3, and a gap 26 is formed between the inclined wall portion 27 and the heating chamber inner side than the inclined wall portion 27. The exhaust gas has a convection exhaust hole 30 that is continuous from the side wall of the heating chamber 3 to the bottom plate 25 and is formed along the longitudinal direction of the convection ducts 20 and 21 so that the space between the two sides increases as it approaches the bottom plate 25. A plate 28 is attached to exhaust the combustion gas from the air collection space 14 through a fan 16 provided outside the combustion chamber 3, and to exhaust the gas from this fan 16 through ducts 17, 18, 19. This oven is characterized in that it is introduced into the ends of convection ducts 20, 21 on the opposite side from the burners 9, 11.

1 is a sectional view of one embodiment of the present invention, FIG. 2 is a plan view, FIG. 3 is a right side view thereof, and FIG. 4 is a sectional view taken along the cutting plane line - in FIG. 3. Outer box 1
A casing 4 forming a heating chamber 3 via a heat insulating material 2 is provided inside. In the upper part of the heating chamber 3, annular tubes 5, 6 having the same structure according to the invention are provided. a parallel pipe 7 constituting the annular pipe 5;
8, their both ends communicate with each other, and these parallel tubes 7 and 8 are connected in the front-rear direction of the oven (the left-right direction in FIGS. 1 and 2, and the direction perpendicular to the paper plane in FIGS. 3 and 4). ). A high-speed gas burner 9 for ejecting combustion gas is attached to one parallel pipe 7 on the side of the heating chamber 3, and the combustion gas from this gas burner 9 is injected into the parallel pipe 7 in the axial direction. The side wall of the other parallel tube 8 is provided with a plurality of ejection holes 1 that open toward the center in the width direction of the heating chamber 3.
0 is provided. Another annular tube 6 is provided parallel to and symmetrically with this annular tube 5. Similarly, a high-speed gas burner 11 is connected to the annular pipe 6.
is installed. A perforated plate 12 is attached to the upper part of the heating chamber 3. An air gathering space 14 is formed between this perforated plate 12 and a ceiling plate 13 provided above it. The high-temperature combustion gas in this air collecting space 14 is exhausted from a passage 15 via a fan 16 provided at the top of the outer box 1. The gas from this fan 16 is transferred from the duct 17 to the branch ducts 18 and 1.
Guided by 9. The ducts 18 and 19 communicate with convection ducts 20 and 21, respectively, which are provided on the sides of the bottom of the heating chamber 3 and have a symmetrical structure in which a cross section perpendicular to the axis forms a triangular space. Duct 21
A communication hole 23 is formed in the lower part of the diaphragm, and the opening area of this communication hole 23 can be adjusted by a diaphragm plate 24. There is a space between the bottom of the duct 21 where the communication hole 23 is formed and the bottom plate 25 of the heating chamber 3.
A gap 26 is formed, and the gap 26 communicates with a space 29 between the exhaust plate 28 and the exhaust plate 28 disposed further inward of the heating chamber 3 than the inclined wall portion 27 of the duct 21. The exhaust plate 28 has a large number of convection exhaust holes 30. The duct 17 includes an exhaust damper 3
6 is provided.

When the gas burners 8 and 11 are operated to burn the gas fuel, the gas burners 9 and 11 are inserted into the annular pipes 5 and 6.
The combustion gas from the annular pipes 5 and 6 is circulated to heat the annular pipes 5 and 6. This radiant heat heats the object to be cooked in the heating chamber 3, such as bread. Since the combustion gas circulates within the annular pipes 5 and 6, it becomes possible to uniformly heat the inside of the annular pipes 5 and 6, and therefore the heating chamber 3. Further, a part of the combustion gas from the gas burner 9 is discharged from the jet hole 10 of the annular pipe 5, and the combustion gas from the gas burner 11 is also discharged from the annular pipe 5.
is exhausted into the heating chamber 3. Thereby, the food to be cooked in the heating chamber 3 is heated by convection heat transfer. Since this combustion gas contains moisture, the surface of the food to be cooked is prevented from cracking or becoming brittle. Moreover, since the food to be cooked is heated not only by radiation but also by convection, it is possible to reduce the thermal energy required by the gas burners 9 and 11. Moreover, since the annular tubes 5 and 6 extend over almost the entire length of the heating chamber 3, it is possible to eliminate unevenness in the temperature distribution within the heating chamber 3. Further, the combustion gas from the annular pipes 5 and 6 is sucked from the air gathering space 4 by the fan 16, passes through the convection ducts 20 and 21, and enters the heating chamber 3.
The food is forcibly heated by convection heat transfer, so it is possible to quickly heat the food.

As described above, according to the present invention, high-temperature combustion gas from the burner is introduced into the annular pipe provided in the heating chamber and refluxed, and a part of the combustion gas is injected and released from the annular pipe into the heating chamber. be made into Therefore, the surface of the food to be cooked is prevented from becoming too dry due to moisture contained in the combustion gas, and cracks on the surface of the food to be cooked can be prevented. Furthermore, since the food to be cooked is heated by radiation and convection, the amount of fuel consumed is small, promoting energy saving, and the heating rate is increased. Furthermore, since high-temperature combustion gas flows back inside the annular tube, it is possible to make the temperature distribution within the heating chamber uniform. Furthermore, the food to be cooked can be heated quickly at the same time as the burner is ignited, improving start-up performance.

In particular, according to the present invention, gas burners 9 and 11 are attached to one end of one of the parallel tubes 7 in each of the pair of annular tubes 5 and 6, and the combustion gas from the gas burners 9 and 11 is passed through the inside of the one parallel tube 7. radiant heating is performed, and then the ejection hole 10 is opened from inside the other parallel pipe 8.
Since the combustion gas is ejected through the convection heating, the food to be cooked can be heated efficiently.

The one parallel tube 7 is located closer to the side of the heating chamber 3 , the other parallel tube 8 is closer to the center than the one parallel tube 7 , and the ejection holes 10 are opened toward the center of the heating chamber 3 . are doing. Therefore, the combustion gas from the ejection hole 10 does not come into direct contact with the one-sided parallel tube 7, thereby preventing the temperature of the one-sided parallel tube 7 from decreasing, and radiant heat transfer can be carried out effectively.

Since the air collecting space 14 is formed above the annular pipes 5 and 6, the annular pipes 5 and 6 prevent the upper part of the heating chamber 3 from overheating.

Since the convection ducts 20 and 21 have a triangular cross-section perpendicular to the axis, the corner space in the heating chamber 3 can be used effectively, and a part of the food to be cooked may not adhere to the corners. It is easy to clean and hygienic.

Combustion gas is ejected from the communication hole 23 into the space 26 between the lower part of the convection ducts 20 and 21 and the bottom plate 25 of the heating chamber 3, and this combustion gas flows through the inclined wall portion 27.
and the exhaust plate 28, the combustion gas introduced from the ends of the convection ducts 20, 21 flows smoothly within the convection ducts 20, 21, and Combustion gas can be guided over the entire length. Therefore, the exhaust plate 28
Combustion gas can be discharged at a uniform flow rate from all the convection exhaust holes 30 formed in the combustion chamber.

Since the exhaust plate 28 is inclined so that the distance between the exhaust plate 28 and the inclined wall portion 27 increases as it approaches the bottom plate 25, this also ensures a uniform flow rate from the convection exhaust hole 30. Combustion gas can be discharged.

[Brief explanation of drawings]

Fig. 1 is an overall sectional view of an embodiment of the present invention, Fig. 2 is a plan view of the embodiment shown in Fig. 1, Fig. 3 is a right side view thereof, and Fig. 4 is a section line of Fig. 2. FIG. 5 is a cross-sectional view of the convection duct 21 at right angles to the axis. 1...Outer box, 3...Heating chamber, 4...Casing, 5,
6... Annular pipe, 9, 11... Burner, 10... Nozzle hole,
14...Air gathering space, 16...Fan, 17...Duct,
18, 19... Branch duct, 20, 21... Convection duct.

Claims (1)

[Scope of Claims] 1 A pair of annular tubes 5 and 6 are arranged on both sides of the upper part of the heating chamber 3, and each annular tube 5 and 6 is connected to one parallel tube 7 on the side of the heating chamber 3. and another parallel tube 8 which is parallel to this one parallel tube 7 and is closer to the center than said one parallel tube 7, and at one end of said one parallel tube 7, inside said one parallel tube 7. Gas burners 9 and 11 that emit combustion gas
is attached, one end of the other parallel tube 8 is connected to the one end of the one parallel tube 7, and the other end of the other parallel tube 8 is connected to the other end of the one parallel tube 7. The other parallel tube 8 has a plurality of ejection holes 10 opened toward the center of the heating chamber 3 at intervals in the longitudinal direction, and the annular tubes 5 and 6 of the heating chamber 3 are connected to each other. A perforated plate 12 is arranged above the heating chamber 3 and the perforated plate 1
A pair of symmetrical convection ducts 20 and 21 are arranged on the bottom side of the heating chamber 3 and extend along the longitudinal direction of the annular tubes 5 and 6. Each convection duct 20, 21 has a triangular cross section perpendicular to the axis along the corner of the heating chamber 3, and has an inclined wall portion 27 that slopes toward the center of the heating chamber 3 from the side wall of the heating chamber 3 toward the bottom plate 25. The lower part of the convection ducts 20 and 21 has a communication hole 23.
A gap 26 is formed between the lower part of the convection ducts 20 and 21 and the bottom plate 25 of the heating chamber 3, and a gap 26 is formed between the inclined wall portion 27 and the heating chamber. The exhaust gas has a convection exhaust hole 30 that is continuous from the side wall of the heating chamber 3 to the bottom plate 25 and is formed along the longitudinal direction of the convection ducts 20 and 21 so that the space between the two sides increases as it approaches the bottom plate 25. A plate 28 is attached to exhaust the combustion gas from the air collection space 14 through a fan 16 provided outside the combustion chamber 3, and to exhaust the gas from this fan 16 through ducts 17, 18, 19. An oven characterized in that it is introduced at the end of the convection ducts 20, 21 on the opposite side from the burners 9, 11.