JP3766514B2 - Structure of the combustion section of the premix burner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a premix burner having a disc-shaped or dish-shaped multi-flame plate in a combustion section.
[0002]
[Prior art]
FIG. 1 shows the structure of a conventional premixing burner of this type. A front end portion of a mixing chamber 3 having an air supply port 1 and a main fuel supply port 2 at the rear is constituted by a cylindrical body 4. A plate-shaped or dish-shaped multi-flame hole plate 5 is provided near the front end of the multi-flame plate, and a front portion of the multi-flame hole plate 5 is configured as a flame-holding cylinder 6, and fuel and air are premixed as much as possible. In a carbonated bath water heater of a type in which the flame is shortened and the shower water flow and high temperature exhaust are in direct contact, the flame does not come into contact with water droplets and cause incomplete combustion when installed in the concave portion of the side wall of the vertical boiler 11. It is what I did.
[0003]
[Problems to be solved by the invention]
In the above-described conventional configuration, the front side portion of the cylindrical body 4 with respect to the multi-flame hole plate 5 acts as a flame-holding cylinder 6 for adhering the root portion of the flame during combustion. 5 was welded to the inner peripheral surface slightly behind the tip of the cylindrical body 4. However, this multi-flame perforated plate 5 repeats expansion and contraction under severe conditions such as splashing of water flowing down the inner peripheral surface of the boiler 11 or being rapidly cooled by air mixed with sprayed water droplets when the burner is stopped, On the other hand, since the rear end flange portion 10 is fixed to the cylindrical body 4 and the flow straightening plate 9 for equalizing the flow rate is attached slightly behind the multi-flame hole plate 5, the rigidity is high. 5 is easily damaged by thermal stress. Therefore, when the burner is frequently inspected and the multi-flame plate 5 is replaced, it is necessary to remove the burner from the boiler and perform troublesome disassembly work. There was a drawback. Therefore, the present invention solves the above-mentioned problems and indirectly supports the multi-flame hole plate 5 while maintaining the confidentiality of the peripheral edge of the multi-flame hole plate 5, thereby providing the multi-flame hole plate 5 with a degree of thermal expansion. It is an object of the present invention to provide a premix burner of this type which is not easily damaged by heat even under such severe conditions.
[0004]
[Means for Solving the Problems]
In the present invention, as shown in FIGS. 1 to 3, a front end portion of a mixing chamber 3 having an air supply port 1 and a main fuel supply port 2 at the rear portion is constituted by a cylindrical body 4, and a disk is disposed near the front end of the cylindrical body 4. In a premixing burner having a plate-shaped or dish-shaped multi-flame hole plate 5 and having a front side of the multi-flame hole plate 5 as a flame-holding cylinder 6, the inner periphery of the flame-holding cylinder part 6 of the cylindrical body 4 The inner cylinder 7 is loosely fitted to the front end edges of the cylindrical body 4 and the inner cylinder 7, and the peripheral edge of the multi-flame hole plate 5 is welded to the rear end edge of the inner cylinder 7. The flame hole plate 5 is characterized in that the multi-flame hole plate 5 has a degree of freedom for thermal expansion by slightly lifting the peripheral edge of the flame hole plate 5 from the inner peripheral surface of the cylindrical body 4.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show an embodiment of a premixing burner according to the present invention, and a mixing chamber 3 having an air supply port 1 and a fuel supply port 2 at the rear is formed inside the burner body. The front end portion of the mixing chamber 3 is composed of a stainless steel cylinder 4, and a multi-flame hole plate 5 is provided near the front end of the cylinder 4, with a substantially disc shape and a peripheral edge portion squeezed into a dish shape. It has been. The front portion of the cylindrical body 4 with respect to the multi-flame hole plate 5 acts as a flame holding cylinder 6 for adhering the root portion of the flame during combustion. In the flame holding cylinder portion 6, the cylindrical body 4 A stainless steel inner cylinder 7 is loosely fitted on the inner periphery of the inner cylinder 7, and the front end edge of the inner cylinder 7 is fixed to the front end edge of the cylindrical body 4 by argon welding. The rear end edge of the inner cylinder 7 is made of stainless steel. The peripheral edge of the multi-flame hole plate 5 is fixed by argon welding. An L-shaped rectifying plate support fitting 8 is spot-welded to the inner peripheral surface of the cylindrical body 4 slightly behind the multi-flame plate 5, and the rectifying plate made of a metal mesh or a punching panel is connected to the rectifying plate support fitting 8. 9 is fixed with screws. FIG. 3 is a front view of the cylindrical body 4 viewed from the right side of FIG. 2 with the rectifying plate 9 removed.
[0006]
In FIG. 2, the cylindrical body 4 and the inner cylinder 7 are loosely fitted, and at first glance, the rear end edge of the inner cylinder 7 seems to have little freedom with respect to the cylindrical body 4. The thermal expansion of the multi-flame perforated plate 5 is not uniform in all directions, and is usually deformed in an elliptical shape. Therefore, most of the thermal expansion can be absorbed by the above structure.
[0007]
【The invention's effect】
According to the present invention, as described above, the inner tube 7 is interposed between the peripheral welded portion of the multi-flame hole plate 5 which is easily subjected to thermal stress and the inner peripheral surface of the cylindrical body 4 having high rigidity. By indirectly supporting the plate 5 and providing freedom of expansion and contraction while maintaining confidentiality, there is an advantage that breakage due to heat can be prevented, so that frequent maintenance is performed as in the past. There is an advantage that the running cost can be significantly reduced.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing an overall structure common to a conventional example and the present invention.
FIG. 2 is a cross-sectional view of a main part showing an embodiment of the present invention.
FIG. 3 is a front view of the main part of the above.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air supply port 2 Fuel supply port 3 Mixing chamber 4 Cylindrical body 5 Multi flame hole board 6 Flame holding cylinder 7 Inner cylinder 8 Current plate support metal fitting 9 Current plate 10 Flange part 11 Boiler

Claims (2)

The front end of the mixing chamber having an air supply port and a fuel supply port at the rear is formed of a cylindrical body, and is provided with a disk-shaped or dish-shaped multi-flame plate near the front end of the cylindrical body. In the premix burner in which the front side part is a flame holding cylinder, the inner cylinder is loosely fitted on the inner circumference of the flame holding cylinder part of the cylindrical body in the flame holding cylinder part, and the front end edges of the cylindrical body and the inner cylinder are The structure of the combustion part of the premix burner formed by welding the peripheral edge of the multi-flame hole plate to the rear end edge of the inner cylinder. 2. The structure of a combustion portion of a premix burner according to claim 1, wherein a rectifying plate made of a disk-shaped wire mesh or punching panel is provided slightly behind the multi-flame hole plate of the cylindrical body.

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