JPH0461249B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides efficient radiation heat transfer.
The present invention relates to an improvement in a radiant burner including a surface combustion type burner body and a porous body facing the combustion surface of the burner body.

Conventionally, in order to form a porous plate-like body in the above-mentioned radiant burner, only one wire mesh was provided, or
Glass rods were lined up in parallel rows.

However, due to the weak directivity of radiation, both methods are still insufficient in terms of radiation heat transfer efficiency for spot heating, such as heating at a specific location in a large area, or for cooking fish or meat. There was a strong desire for a burner with even better radiation heat transfer efficiency.

An object of the present invention is to provide a burner with extremely strong radiation directionality that can fully satisfy this need.

The characteristic configuration of the radiant burner according to the present invention is that a porous plate-like body is provided with a plurality of holes having a constant cross-sectional area in a predetermined radial direction, which is the burner front-back direction, in parallel in a direction perpendicular to the burner front-back direction. The porous body is formed of 20 to 400 meshes with a thickness of 5 mm or more, and its functions and effects are as follows.
That is, in this structure, the radiant heat that travels in a straight line through the plurality of straight columnar holes in the porous plate is selectively radiated from the porous plate, and the heat rays that deviate from the straight direction are radiated from the hole wall surface. suppressed,
Heat is collected in the straight direction, and as a result it contributes to heating the front side of the burner.

Experiments conducted by the inventors regarding numerical limiting elements will be explained below.

In other words, we conducted an experiment to confirm how the thickness and aperture of the porous plate affect the directivity of radiation, and found that when the thickness of the porous plate is less than 5 mm, the radiant heat is widely dispersed. However, if the thickness of the porous plate exceeds 5 mm, spot heating can be performed at a sufficiently high thermal efficiency. It turned out that it can be done. In addition, when the number of porous plates is less than 20 meshes, the radiant heat is dispersed over a wide area, making general spot heating unsuitable, and when the number of porous plates exceeds 400 meshes, the flow resistance against combustion exhaust gas becomes low. If it becomes too large, it will cause poor combustion even with a blast burner, but it has been found that if the porous plate has a mesh size of 20 to 400, this will not occur and spot heating can be performed with sufficiently high thermal efficiency. .

In addition, when we investigated how the radiant energy intensity distribution differs between the burner of the present invention and the conventional burner through experiments, we found that
We obtained the results shown in the figure. In other words, in the case of the burner B of the present invention shown in the experiment, a large amount of energy is concentrated and radiated in a narrow range in front of the burner B, whereas in the case of the conventional burner B shown by the dashed line, a large amount of energy is emitted in a wide range in front of the burner B. It is clear that the energy is distributed and radiated over a range.

As a result, various types of spot heating can be performed with extremely high radiation heat transfer efficiency.
It is now possible to provide a radiant burner that is superior in terms of economy and energy saving.

Next, an example will be shown with reference to FIGS. 1 and 2.

A porous ceramic plate 1 forming a combustion surface 1a is attached to a dish-shaped case 2 so as to cover it, and a fuel gas supply pipe 3 and a combustion air supply pipe 4 are installed.
is connected to the case 2 to constitute a burner body A for ejecting premixed fuel gas and fuel air from the plate 1 and performing surface combustion on the combustion surface 1a.

A porous ceramic sintered body 5 formed in a rectangular lattice shape is arranged facing the combustion surface 1a and preferably at an interval of about 5 to 10 mm, and a plate pair 1 is arranged.
A cover 6 is provided between the porous ceramic sintered body 5 and the porous ceramic sintered body 5 to prevent stable combustion on the combustion surface 1a from being impaired by the porous ceramic sintered body 5.

Further, the porous ceramic sintered body 5 is made with a thickness d.
The thickness d is formed so that it is 5 mm or more, preferably 20 mm or less, and more preferably 10 to 15 mm, so that the thickness d can be prevented from becoming too small and the radiation directivity will deteriorate. This is designed to prevent the pressure drop from becoming too large, resulting in an increase in costs, and from an unnecessary increase in pressure loss with respect to the combustion exhaust gas.

Furthermore, the porous ceramic sintered body 5 is formed so that the opening state is 20 to 400 meshes, preferably 80 to 120 meshes, and further,
In the case of a Bunsen burner, it is formed to have a mesh size of 100 mesh or less to prevent the hole diameter r from becoming too large and deteriorating the radiation directivity. It is designed to prevent it from becoming unnecessarily large. Note that the above-mentioned "mesh" represents the number of cells per square inch.

In short, by appropriately setting the thickness and opening state of the porous ceramic sintered body 5, spot heating can be performed with sufficiently high radiation heat efficiency, and even with a blast type burner, it is possible to perform spot heating. It is configured to cause combustion.

Next, another example will be described.

When forming the porous ceramic sintered body 5 as a porous plate-like body, various changes can be made in size, shape, etc. For example, as shown in FIG. 3, it may be formed into a honeycomb shape.

The specific configuration of the burner body A, the type of fuel gas,
Others can be changed as appropriate.

The radiant burner can be used for, for example, spot heating in homes or other places, various types of cooking appliances, industrial spot heating or drying, and any other applications.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention;
FIG. 2 is a view taken along the - line in FIG. 1. FIG. 3 is a front view showing another embodiment of the present invention. Fourth
The figure is a graph showing experimental results. 1a... Burning surface, 5... Porous plate-like body, A...
Burner body.

Claims (1)

[Scope of Claims] 1. A radiant burner comprising a surface combustion type burner body A and a porous plate-like body 5 facing a combustion surface 1a of the burner body A, wherein the porous plate-like body 5 is arranged in a predetermined manner. a porous ceramic sintered body in which a plurality of holes having a constant cross-sectional area in the front-rear direction of the burner, which is the radial direction of the burner, are arranged in parallel in a direction perpendicular to the front-rear direction of the burner; 5 is a radiant burner formed into 20 to 400 meshes with a thickness d of 5 mm or more. 2. The radiant burner according to claim 1, wherein the porous plate-like body 5 is formed to have a thickness of 20 mm or less. 3. The radiant burner according to claim 1 or 2, wherein the porous plate-like body 5 is arranged at an interval of 5 to 10 mm from the combustion surface 1a.