JP3992262B2 - Gas burner and oven - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas burner used in an oven or the like, and an oven using a gas burner.
[0002]
[Prior art]
A rod burner used for a gas stove or the like is configured by providing an appropriate flame hole in a hollow rod such as a pipe. The shape of the flame hole is often circular, but is not necessarily circular. FIG. 4 shows an outline of the configuration of such a gas burner and attached equipment. In (a), air is mixed with fuel gas by the mixer 21 and supplied to the gas burner 22 as a premixed gas. (b) is a cross-sectional view of the gas burner 22, and (c) is a vertical cross-sectional view of the gas burner 22.
[0003]
The pipe 23 closed at both ends is formed with a plurality of flame holes 24 in one row of the circumference, and a premixed gas is supplied into the pipe 23 from a premixed gas pipe 25. And the premixed gas blown out from the flame hole 24 burns and becomes a flame. Since such a bar burner has a simple structure that can be configured simply by forming a hole in the bar, it is inexpensive and highly versatile, and is used in many gas appliances.
[0004]
However, because of its simple structure, the bar burner does not have a high flame holding capacity, and usually has an air ratio (the amount of air required for complete combustion is 1 and the ratio of the actual amount of air supplied to it). ) Is used at about 0.6, and when it is about 1.0, there is a problem that a lift (blown out flame) occurs and misfires occur. Therefore, it is necessary to supplement the insufficient combustion air with the secondary air. Therefore, the application range is usually limited to a gas appliance having a structure in which secondary air is naturally supplied.
[0005]
[Problems to be solved by the invention]
However, some large ovens and the like used for business use have difficulty in naturally supplying secondary air. In particular, in a bakery oven, the height is limited because a plurality of bakery ovens are often stacked vertically to form a multi-layer structure. Therefore, since a combustion method suitable for natural combustion in which air is introduced from the bottom and exhausted from the upper side cannot be taken, the exhaust is performed from the rear side.
[0006]
As described above, when the bar burner is used in a place where the secondary air is difficult to be supplied, the air supplied to the mixer is forced through the blower, and the air ratio is set to 1.0 or more and sent to the bar burner. As shown, a special flame holding structure 26 is provided near the flame holes, and the size and arrangement of the flame holes are devised to prevent fire transfer and lift. However, even in this case, incomplete combustion occurs when the air ratio is less than 1.0, and when the air ratio is high, lift occurs and it is easy to misfire.Therefore, the air ratio range in which stable combustion is possible is extremely high. There is a problem of being narrow.
[0007]
In an actual example, the range of the air ratio at which stable combustion is possible is about 1.02 to 1.18. On the other hand, the variation range of gas consumption allowed by design is about ± 10% of the displayed value, so when the allowable limit of gas consumption fluctuation occurs, the primary air ratio fluctuates and the There is a risk that it may be difficult to perform combustion. Moreover, it is desirable to eliminate a special flame holding structure especially in the case where the installation space is limited like a bakery oven.
[0008]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a gas burner and an oven capable of stable combustion over a wide range of air ratios.
[0009]
[Means for Solving the Problems]
A first means for solving the above problem is that a premixed gas pipe to which a premixed gas is supplied is surrounded by a casing to which secondary air is supplied, and a flame ejected from a flame hole of the premixed gas pipe has 2 A gas burner provided with a secondary air ejection hole in the housing so as to be enveloped by secondary air, a premixed gas pipe through which a premixed gas is formed, and a premixed gas pipe; Parallel to the secondary air pipe provided on the opposite side of the premixed gas pipe from the flame hole and provided with a hole for supplying secondary air necessary for combustion, except for the part where the flame is ejected, the outer box And the flame ejected from the flame hole is enveloped by the secondary air ejected from the secondary air pipe, and communicated with the premixed gas pipe and the secondary air pipe, respectively, to form two chamber-like spaces. Is provided on one side of the room-like space via a slit whose opening area can be changed. A gas supply nozzle is inserted from the opposite side of the premixed gas pipe in the room-like space connected to the premixed gas pipe to the premixed gas pipe side, and the premixed gas is installed. The chamber-like space communicating with the pipe is configured to be open to the atmosphere at a portion excluding a portion communicating with the premixed gas pipe and a portion where the blower is attached. Item 1).
[0010]
In this means, the combustion is performed such that the flame ejected from the flame hole of the premixed gas pipe is wrapped in the secondary air. Therefore, keep the air ratio of the premixed gas at an air ratio (about 0.6) that does not generate a conventional lift, and burn it so that the flame is wrapped with the secondary air blown out from the secondary air ejection holes of the housing. In this case, complete combustion is stably performed from the secondary air enclosing the flame. Therefore, neither lift nor incomplete combustion occurs over a wide air ratio range, and stable combustion can be performed even in a narrow space.
[0012]
In this means, the air is uniformly supplied into the outer box by the secondary air ejected from the secondary air pipe. The air flows around the premixed gas pipe along the premixed gas pipe, and blows out from the cutout portion of the outer box so as to wrap the flame blown out from the flame hole of the premixed gas pipe. At this time, if the air ratio of the premixed gas supplied to the premixed gas pipe is set to be approximately the same as the air ratio of the premixed gas supplied to the conventional premixed gas pipe, lift is unlikely to occur. The deficient air is then supplied when the flame is wrapped with air and complete combustion takes place. Therefore, neither lift nor incomplete combustion occurs, and stable combustion can be performed even in a narrow space.
[0013]
In this means, since the secondary air is ejected from the secondary air pipe provided in parallel with the premixed gas pipe, the secondary air flow rate in the length direction of the pipe as compared with the first means. The distribution is made uniform and uneven combustion in the length direction is eliminated.
[0015]
In this means, it is provided on one side surface of the first room-like space (space surrounded by a wall) communicating with the premixed gas pipe and the second room-like space communicating with the secondary air pipe. From one blower, air can be supplied through each slit. Further, the amount of air supplied to each room-like space can be adjusted by changing the opening area of each slit. Therefore, the air ratio of the premixed gas and the secondary air amount can be adjusted separately. In addition, in this means, “the fan is attached through the slit” means that the fan is attached so as to be in contact with the slit, and that the fan is attached across the space and piping from the slit. Is also included.
[0017]
In this means, if the slit is fully closed, air can be prevented from being sent to the room-like space. In addition, since the room-like space communicating with the premixed gas pipe can be opened to the atmosphere, if this room-like space is opened to the atmosphere and the slit is fully closed, the gas supply nozzle can provide air. Is sucked in and mixed with the gas and enters the premixed gas pipe, so that the flame ejected from the premixed gas pipe becomes a Bunsen combustion flame. And secondary air is further supplied to this Bunsen combustion flame, and the stable combustion is performed. Thus, in this means, the burner can be used as a blast (forced air supply) gas burner or a Bunsen burner.
[0020]
The second means for solving the problem is an oven ( Claim 2 ) using the gas burner of the first means .
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, examples of embodiments of the present invention and reference examples will be described with reference to the drawings. FIG. 1 is a diagram illustrating a first example of a reference example , and (a) is a schematic diagram of a gas burner and peripheral devices. (b) is a cross-sectional view of a gas burner which is an example of an embodiment of the present invention, and (c) is a horizontal cross-sectional view of the same gas burner. In FIG. 1, 1 is a blower, 2 is a mixer, 3 is a gas burner, 4 is an outer box, 5 is a secondary air pipe, 6 is a premixed gas pipe, 7 is a flame hole, 8 is a premixed gas pipe, white The arrows indicate secondary air flow, and the shaded arrows indicate flame.
[0025]
A premixed gas pipe 6 having a horizontally long structure is provided in the outer box 4, and a plurality of small flame holes 7 are provided in a row. The premixed gas adjusted to an air ratio of about 0.6 by the mixer is introduced into the premixed gas pipe 6 from the premixed pipe 8 and ignited by the ignition sequence. To do. Since the air ratio is about 0.6, there is no danger that lift will occur in this flame, but incomplete combustion will occur.
[0026]
Therefore, in this embodiment, the secondary air introduced into the outer casing 4 from the secondary air pipe 5 and detoured around the premixed gas pipe 6 becomes the flame hole 7 as shown in the figure. It is designed to wrap up the flame that erupts more. Therefore, the unburned portion in the flame that was in the incomplete combustion state becomes a complete combustion state by the secondary air. Therefore, both prevention of lift and complete combustion can be achieved over a wide range of air ratios (the air ratio of the sum of premixed air and secondary air). In addition, a flame holding structure is not particularly required.
[0027]
FIG. 2 is a diagram illustrating a second example of the reference example . 2, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 2, 9 is a secondary air chamber and 10 is a secondary air blowing hole. The connecting pipe to the burner is the same as that shown in FIG. (a) is a longitudinal cross-sectional view, (b) is an AA cross-sectional view.
[0028]
In the outer box 4, a horizontally long premixed gas pipe 6 and a secondary air pipe 9 are provided in parallel. If the side of the premixed gas pipe 6 where the flame hole 7 is provided is the front, the secondary air pipe 9 is provided behind the premixed gas pipe 6 and the secondary air is ejected from the back of the premixed gas pipe 6. It is supposed to be.
[0029]
The blown-out secondary air flows along the periphery of the premixed gas pipe 6 on the outside thereof, and flows so as to wrap the flame ejected from the flame hole 7 of the premixed gas pipe 6 from both sides. If the air ratio of the premixed gas supplied into the premixed gas pipe 6 is set to about 0.6, which is conventionally used, it is possible to prevent lift from occurring in the flame hole 7. Incomplete combustion occurs as it is, but since the flame that has exited the flame hole 7 is immediately enveloped with secondary air, sufficient air is supplied and complete combustion is performed.
[0030]
Therefore, this burner can achieve the same effect as the burner shown in FIG. 1, but since the secondary air pipe 9 is provided, it is more lateral than that shown in FIG. 1. The flow distribution of secondary air becomes uniform. Therefore, stable combustion can be performed over the entire lateral portion of the burner.
[0031]
FIG. 3 is a diagram showing an example of an embodiment of the present invention, and shows a burner having a structure in which a mixer is integrated with a burner and a blower is directly attached thereto. In FIG. 3, 11 is an air chamber, 12 is a burner section, 13 is a premixed gas pipe, 13a is a flame hole, 14 is a secondary air pipe, 14a is a secondary air blowing hole, 15 is a mixer chamber, 16 is a gas nozzle, Reference numeral 17 is a slit, 18 and 19 are partition plates, 20 is a secondary air introduction chamber, 21 and 22 are side walls, 23 is a lower side wall, and 24 is an air introduction port. (A) is a sectional view taken along the line BB in (b), (b) is a sectional view taken along the line AA in (a), and (c) is a plan view with the cover of the air chamber 11 in (a) removed. . Further, in the following description, “up, down, left, right, etc.” are all up, down, left, right, etc. in FIG.
[0032]
Air from the blower is introduced into the air chamber 11 through the air introduction port 24. Further, as will be described later, the blower can be directly connected by removing the cover of the air chamber 11 and bringing the blower outlet of the blower directly into contact with the slit 17. A slit 17 is provided below the air chamber 11, and the air chamber 11 communicates with the mixer chamber 15 and the air introduction chamber 20 through a gap between the slit 17 and the partition plate 18, respectively. By changing the size of the gap between the slit 17 and the partition plate 18, the air ratio in the premixed gas and the amount of secondary air can be changed separately.
[0033]
A gas nozzle 16 is inserted into the mixer chamber 15 from the side. The gas ejected from the gas nozzle 16 is mixed with the air introduced from the air chamber 11 into the mixer chamber 15 and enters the premixed gas pipe 13 that is in communication. The structure of the burner portion 12 is the same as that shown in FIG. 2, in which a premixed gas pipe 13 and a secondary air pipe 14 are provided, and from the flame hole 13 a of the premixed gas pipe 13. The blown-out flame burns in the secondary air blown out from the secondary air blowing hole 14a of the secondary air pipe 14 and burns, and is notched (not shown) 13a in front of 13a, that is, provided on the lower outer wall of (c).
[0034]
The air introduced from the air chamber 11 into the secondary air introduction chamber 20 is introduced into the communicating secondary air pipe 14. The mixer chamber 15 and the air introduction chamber 20 are partitioned by a partition plate 19.
[0035]
It is also possible to remove the cover of the air chamber 11 and directly connect the blower outlet to the slit 17 instead. That is, in (c), the portions corresponding to the mixer chamber 15 and the air introduction chamber 20 are fixed by covering the blower outlet from the upper side perpendicular to the paper surface. In this way, the burner, mixer, and blower can be integrated.
[0036]
Further, the side wall 21 or the burner side wall 22 or the lower side wall 23 opposite to the partition plate 19 of the mixer chamber 15 can be removed, and by removing this, the mixer chamber 15 is opened to the atmosphere, and instead the slit 17 It is also possible to eliminate the gap between the partition plate 18 and prevent air from the blower from entering the mixer chamber 15. In this way, the burner can be used as a Bunsen burner.
[0037]
In this manner, in the embodiment shown in FIG. 3, the air ratio of the premixed gas and the secondary air amount can be varied by the slit, and in some cases, the burner can be used as a Bunsen burner. .
[0038]
The three types of burners described above do not require a special flame holding structure and can perform stable combustion at a wide air-fuel ratio, so they are used in large-sized ovens, particularly bakery ovens where installation space is strict. Suitable for
[0039]
【Example】
A burner as shown in FIG. 3 was made as a prototype, and the range of the air ratio at which stable combustion was possible was investigated. As a result, when the air ratio of the premixed gas was about 0.6, it was confirmed that stable combustion was possible over a wide range (1.86) where the total air ratio was 1.39 to 3.25. In the case of a conventional bar burner, as described above, incomplete combustion may occur when the total air ratio is less than 1.02, and non-ignition due to lift may occur when the total air ratio exceeds 1.18. That is, the range of stable air ratio is 0.16. Therefore, in the present invention, it became clear that stable combustion can be performed in the air ratio range of 10 times or more than the conventional one.
[0040]
【The invention's effect】
As described above, in the invention according to claim 1 of the present invention, neither lift nor incomplete combustion occurs over a wide air ratio range, and stable combustion can be performed even in a narrow space.
[0041]
In addition , neither lift nor incomplete combustion occurs over a wide air ratio range, stable combustion can be performed even in a narrow space, and the secondary air flow rate distribution in the length direction of the tube is made uniform, Non-uniform combustion in the length direction is eliminated.
[0042]
Further , the air ratio of the premixed gas and the secondary air amount can be adjusted separately. Furthermore, the burner can be used as a blast gas burner or as a bunsen burner.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a first example of a reference example .
FIG. 2 is a diagram illustrating a second example of the embodiment of the reference example .
FIG. 3 is a diagram showing an example of an embodiment of the present invention.
FIG. 4 is a diagram showing an outline of the configuration of a gas burner and attached equipment.

Claims (2)

The casing is configured so that the premixed gas pipe to which the premixed gas is supplied is surrounded by a casing to which the secondary air is supplied, and the flame ejected from the flame hole of the premixed gas pipe is wrapped with the secondary air. A gas burner provided with secondary air ejection holes, a premixed gas pipe through which the premixed gas is formed and a premixed gas pipe in parallel with the premixed gas pipe. Covering the secondary air pipe provided with a hole for supplying secondary air required for combustion with the outer box except for the part where the flame is ejected, and the flame ejected from the flame hole, Two room-like spaces are provided in communication with the premixed gas pipe and the secondary air pipe, respectively, and are encased in secondary air ejected from the secondary air pipe, and one of the room-like spaces is provided. A blower is attached to the side surface through a slit whose opening area can be changed. From the opposite side of the premixed gas pipe in the room-shaped space communicating with the gas pipe, a gas supply nozzle is inserted toward the premixed gas pipe side, and the room-shaped space communicating with the premixed gas pipe is A gas burner characterized in that it can be opened to the atmosphere at a portion excluding a portion communicating with the premixed gas pipe and a portion to which the blower is attached . An oven comprising the gas burner according to claim 1 .

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