JPS6262111A - Surface shape of combustion improver composed of ceramic particles - Google Patents

Abstract

PURPOSE:To obtain stable surface burning at high burning load by placing an adequate number of recessed parts having specified size at the surface in the surface burning side of a burning stabilizer for a surface burning burner composed of a ceramic particle layer. CONSTITUTION:Irregular polygonal ceramic particles are formed into a flat plate-shaped combustion improver 2 with inorganic binders such as alumina-sol or water-glass. At the burning side surface of the burning stabilizer an adequate number of concave parts having such specified shape as rectangular parallelogram, cylinder or divergent trapezium are installed. Surface burning of the combustion improver yields small pressure loss in the recessed parts and large pressure loss in the projected parts. Therefore, when input quantity of mixed gas is increased, stable and fine flame is formed and exhibits function of pilot burners at those projected parts and at the projected parts lifting of flame is prevented though flow velocity of mixed gas is increased at the recessed parts, and gas mixing function peculiar to a ceramic particle layer and effect caused by uniformity characteristic in gas flow have combined to obtain stable high load burning.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a surface shape of a combustion aid in a surface combustion burner intended to improve surface combustion load.

[Technical background of the invention and its problems] This type of surface combustion burner generally uses a combustion aid made of ceramic particles hardened with a special binder.

For example, FIG. 3 shows a surface combustion burner in which a flat combustion auxiliary body is vertically supported by a holding part, and FIG. 4 shows a surface combustion burner in which a cylindrical combustion auxiliary body is supported at its lower end by a holding part. The outer surfaces of these auxiliary combustion bodies are all formed into a planar shape. Therefore, when the input of fuel gas becomes extremely large, the average flow velocity of the gas becomes larger than the combustion velocity, and a flame lift phenomenon occurs on the surface of the combustion aid, making it impossible to obtain stable combustion. For this reason, there was a limit to the increase in surface combustion load.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a combustion aid that can provide stable surface combustion under high combustion loads.

[Summary of the Invention] In order to achieve the above object, the present invention provides a combustion aid for a surface combustion burner made of a layer of ceramic particles, in which an appropriate number of recesses of required dimensions are provided on the surface on the surface combustion side. Features.

[Embodiments of the Invention] The present invention will be explained below based on embodiments shown in the drawings.
Ru. FIG. 1 is an explanatory diagram of one embodiment of the present invention.

(1) is a layer of irregular polygonal ceramic particles constituting the combustion aid (2), which is formed into a flat plate-like combustion aid using an inorganic binder such as alumina sol or water glass. A suitable number of four parts (3) each having a desired shape, such as a rectangular parallelepiped, a cylindrical shape, or a trapezoid whose upper end is widened, are provided on the combustion side surface of the auxiliary combustion body. (4) in the drawing is a casing member (5) which will be described later.
This is a chamber formed on the back surface of the combustion auxiliary body. This chamber is formed to cover the entire back surface of the combustion auxiliary body so that the supplied mixed gas can be evenly pressured against the back surface of the combustion auxiliary body and can supply the mixed gas. (5) is a casing member, and the casing member is provided to surround the combustion aid (2) with a part opened, so that the surface of the combustion aid facing the opening side is a surface combustion A chamber for distributing the mixed gas is formed on the back side of the auxiliary combustion body opposite to the combustion surface. (6) is a mixed gas supply pipe provided in the casing member and communicated with the chamber. A mixing element (7) is provided in the air supply pipe and includes a mixing valve or the like for mixing fuel gas and air at a predetermined ratio.

Next, surface combustion according to j3 of the present invention will be explained.

Fuel gas and air are supplied to the mixing element. The mixing element mixes combustion gas and air at a predetermined ratio and supplies the mixed gas to the chamber. This gas mixture is evenly distributed in the chamber and enters the combustion aid. In this combustion auxiliary ceramic particle layer, the mixed fuel gas becomes a more homogeneous mixed fuel gas due to the function of the gap flow paths between the variously changing ceramic particles, and a uniform gas flow is formed to cool the ceramic particles. However, it reaches the surface of the combustion aid, and is ignited by an ignition means (not shown) provided close to the combustion surface, resulting in surface combustion.

At this time, the combustion auxiliary body combustion surface is provided with a recessed portion of a required size d5, and the pressure loss is small in the concave portion of the combustion auxiliary body, and the pressure loss is large in the convex portion. Therefore, in the concave portions, there is a large flow of mixed gas, forming a large main flame, and in the convex portions, the flow is small, forming a stable pilot flame with excellent flame-holding effect. Therefore, by increasing the input amount of the mixed gas, a small stable flame is always maintained in the convex part and has the performance of a pilot burner, and even if the flow rate of the mixed gas increases in the concave part, the pilot Due to the burner function, the main flame in the recess does not lift, and together with the mixing effect of the fuel gas and air by the particle layer described above, stable high-load combustion can be performed as a whole. Note that in the ceramic particle layer,
By making the average particle diameter of the surface combustion side particle layer A smaller than the average particle diameter of the particle layer B on the opposite side, especially by reducing the average particle diameter of the convex portion, the input amount of the mixed gas can be reduced. Even if the height of the convex part is increased, the pressure loss of the convex part is increased without increasing the height of the convex part, the mixed gas flow rate is maintained at an optimum level, and a pilot flame with a good flame holding effect is formed on the surface of the convex part. Ru.

Therefore, by selecting the average particle diameter of the particle layer relative to the input amount of the mixed gas, stable surface combustion can be performed without increasing the pressure loss of the entire auxiliary body. FIG. 2 is an explanatory diagram of an embodiment of a pond,
(2) is a combustion auxiliary body formed of ceramic particles in the shape of a capped cylinder, and has an appropriate number of four parts (3) of a desired shape and size on its combustion surface, and (8) is a combustion auxiliary body that supports the combustion auxiliary body and This is a support body that communicates between the intake pipe (6) and the inside of the auxiliary combustion body.

The other configurations, functions, and effects are the same as those shown in FIG. 1, so their explanations will be omitted.

[Effects of the Invention] As described above, the present invention has a configuration in which an appropriate number of recesses are provided on the surface of the combustion aid made of ceramic particles, so even if the input amount of mixed gas is increased, the convex parts have a stable and good effect. A flame hold is formed, and this part functions as a pilot burner, preventing the flame from lifting despite the increase in the mixed gas flow rate in the recess, and the ceramic particle layer's unique gas mixing action and gas flow uniformity properties. In combination with the effects of the present invention, it is possible to provide an extremely stable combustion aid for surface combustion of unprecedented high-load combustion.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of the present invention, FIG. 2 is an explanatory diagram of another embodiment of the present invention, and FIGS. 3 and 4 are explanatory diagrams of conventional embodiments. (1) is a ceramic particle layer (2) is a combustion aid (3) is a recess (4) is a chamber (5) is a casing member (6) is an air supply pipe (7) is a mixing element Patent applicant Representative of Miura Industries Co., Ltd. Miura
Ho Fig. 1 (a) rr Fig. 2 ↑ ir Fig. 4 v ↑ Mixed gas

Claims (3)

[Claims] (1) A combustion aid (2) of a surface combustion burner consisting of a ceramic particle layer (1), characterized in that a suitable number of recesses (3) of required dimensions are provided on the surface on the surface combustion side. The surface shape of the combustion aid consisting of. (2) In the ceramic particle layer, the average particle size of the particle layer A on the surface combustion side is smaller than the average particle size of the particle layer B on the side opposite thereto. Surface shape of combustion aid made of ceramic particles. (3) Claim 2, characterized in that the point at which the average particle diameter of the ceramic particles changes is located on the bottom surface T of the recess.
Surface shape of a combustion aid made of ceramic particles as described in Section 2.