JPH0318085B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a porous ventilation plate mainly composed of two heat-resistant metal meshes, and more particularly to a porous ventilation plate suitable for a plate-shaped nozzle of a gas burner. Conventionally, plate-shaped nozzles for gas burners have been made by bonding and fixing heat-resistant particles with a bond to form a porous ventilation plate, but these have the drawbacks of low mechanical strength, high ventilation resistance, and heavy weight, making them difficult to use industrially. It has few uses.

The inventor invented an original porous ventilation plate that compensated for these drawbacks, and has been conducting research since 1975 and has applied for a patent (Patent application published in 1982-
85530).

However, no matter how much we tested the gas burner using the perforated ventilation plate of the invention by changing the wire diameter of the plain-woven wire mesh and the rolling ratio, we were unable to produce a burner that achieved complete combustion near the stoichiometric air ratio; 1.13～
I was only able to make a burner that burns completely at 2. As a result of extensive research, the inventor devised and put into practical use a burner nozzle with ideal combustion characteristics. In other words, when examining the opening area of the ventilation holes by looking at a porous ventilation plate made by overlapping two metal meshes and compression-molding them from various angles, the opening area of one regular part was compared to the other parts. It was discovered that the area is about three times the size of the previous one. Therefore, we created a perforated plate by sealing only the maximum opening area hole part by welding and fixing two overlapping upper and lower meshes together, and used it as a gas burner nozzle. We succeeded in manufacturing a burner nozzle with combustion characteristics.

That is, (a) Maximum thermal combustion amount: 1Kw/cm ² (b) Complete combustion with excess air ratio = 1.02.

(c) Combustion is completed at about 5 mm directly below the burner nozzle (previously it was 10 to 15 mm).

(d) The combustion gas temperature rose to 1870℃.

Significant effects such as these were observed. As a result, it is possible to heat the object closer to the object than before, and the combustion gas temperature is also higher, improving the heat transfer coefficient.
%. Due to the structure of the burner of the present invention, the distribution of ventilation holes is almost uniform, but the direction of the ventilation holes is random, and the structure generates large turbulent flow, so mixing at the nozzle is good, and the flames are not entangled with each other. Therefore, it has a great feature of high combustion efficiency and no blowout. On the other hand, the biggest problem, backfire, can be almost completely prevented in atmospheric heating because only the largest opening area is sealed, and the turndown ratio is 1:15, which greatly exceeds the performance of conventional burners. Ta.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Two identical plain-woven stainless steel wire meshes with a wire diameter of 2.6 mmφ and a 3 mm square opening are placed one on top of the other so that the intersection of the metal wires on the lower mesh faces the mesh on the upper mesh.
Roll to mm thickness. Next, as shown in FIG. 1, only the hole with the largest opening area formed by the lower mesh wire 1a and the upper mesh wires 1b and 1c is fixed with the welded portion 2, and at the same time, the air permeability of the mesh is sealed. By stacking the mesh in this way and welding the mesh in a regular distribution,
By fixing the two nets together and increasing the ventilation resistance, the flame can be evenly distributed over a flat surface for combustion, and the mechanical strength can be maintained. A porous ventilation plate that can be formed into a shape can be provided.

The gas burner using the porous ventilation plate according to the present invention has many uses, mainly for atmospheric heating such as preheating and postheating of welding, stress relief annealing of spherical tanks, rapid preheating of forging dies, brazing, etc. The invention is industrially useful. The porous ventilation plate of the present invention is not limited to use only as a burner nozzle, but can be applied to various uses. It goes without saying that the mesh wire diameter and rolling ratio are not limited to this example, and can be modified in many ways without departing from the spirit of the invention.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1a and 1b are a plan view and a front view, respectively, showing two plain-woven wire meshes stacked one on top of the other and only the holes with the largest opening area aligned and welded, and FIG. 2 is a front view. FIG. 3 is a longitudinal cross-sectional view of the burner. 1a...lower mesh line, 1b...upper mesh line, 1c...
...Top mesh line, 2...Welding part, 3...Burner,
4... Porous ventilation plate, 5... Mixture distribution pipe.

Claims (1)

[Claims] 1 Two sheets of plain-woven wire mesh are overlapped and compression molded so that the intersecting parts of the metal wires of one mesh appear in the mesh of the other mesh, and the meshes are welded in a regular distribution, and the welded parts are A porous ventilation board characterized by sealing only the maximum opening area hole portion and having two meshes fixed together.