JPS61143613A - Radiant burner - Google Patents

Abstract

PURPOSE:To increase the heating efficiency of a radiant burner by contriving to uniformly heat an object to be heated from all the surface around the burner by its radiant heat, by coaxially fixing a cylindrical shape-holding body containing a cylindrical combustion part consisting of porous ceramic body on the inside of a cylindrical can casing body, by forming a circular flow passage in the gap between the shape-holding body and the can casing body, by sealing the can casing body by a lid, and by providing a feed opening to feed air-mixed fuel gas to the circular flow passage. CONSTITUTION:A mixed gas of air and fuel is fed into a circular flow passage 5 from a feed opening 7. As the passage 5 is sealed by a round lid 6, the mixed gas permeates through a cylindrical shape-holding body 2 and is uniformly burned on the whole surface of a combustion part 4 consisting of a cylindrical, porous and ceramic body, which uniformly radiates radiation heat toward the center part. A pipe can be heated uniformly, when a pipe such as a through-pipe for a fluid to be heated is pierced through the center of a cylindrical combustion part 4. The heating efficiency of a combustion part 4 is very large, because all radiation heat from it can be radiated to an object to be heated such as a through pipe for a fluid to be heated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cylindrical radiant burner suitable for radiant heating of an object to be heated with high thermal efficiency.

(Prior art) - Conventional radiant burners have a layered layer of porous material such as glass fiber or ceramic fiber attached to the surface of a shape-retaining member such as a wire mesh, and air and combustion gas are mixed from the back side of the shape-retaining member. Supplying air to advance combustion on the surface of the porous body,
A type of burner that generates a large amount of radiant heat is known, but the conventional radiant burner is disclosed in Japanese Patent Application Laid-Open No. 56-130524.
As shown in Japanese Patent Application No. 56-16018, it is rod-shaped, or as shown in Japanese Patent Application Laid-Open No. 16018-1983, it is flat plate-shaped, so when placed close to the side of the heated object, In this method, only the side of the object to be heated facing the radiant burner is strongly heated, whereas the back side of the object to be heated does not receive radiant heat, which has the disadvantage that the temperature distribution of the object to be heated is significantly uneven. This can cause cracks to occur due to thermal stress and shorten the service life.In addition, bar-shaped or flat-shaped radiant burners have low thermal efficiency because they have a large amount of radiant components that do not contribute to heating the heated object. When a plurality of radiant burners are disposed around the heated body in order to achieve this, there is a problem that not only the structure becomes complicated but also the volumetric combustion efficiency decreases.

(Problems to be Solved by the Invention) The present invention solves these conventional problems and uniformly heats a heated body, such as a heated fluid flow pipe, by radiation from the entire circumference, thereby eliminating uneven temperature distribution. This was completed with the aim of creating a radiant burner with a simple structure and high volumetric combustion efficiency, which prevents the various disadvantages associated with heating, eliminates radiant components that do not contribute to the heating of the heated object, and increases thermal efficiency.

(Means for Solving the Problems) The present invention concentrically fixes a cylindrical shape-retaining member in which a combustion part made of a ceramic porous body is formed on the inner circumferential surface of the cylindrical can body. At least one end surface of the annular flow path formed between the can body and the holding member is sealed with an annular lid, and
It is characterized in that a part of the can body is provided with a supply port for a mixture of air and fuel gas that communicates with the annular flow path.

(Examples) Next, the present invention will be explained in more detail with examples.
1+ is a cylindrical can body made of a heat-resistant metal or ceramic body, and (2) is a cylindrical shape-retaining member that is concentrically fixed inside the can body (1) with a support (3). (1) and shape-retaining member (2) are preferably cylindrical. Shape-retaining member (2) is a metal body with many openings, such as a wire mesh or punching metal, and its inner peripheral surface is A ceramic porous body such as a stack of ceramic fibers or a sintered body of ceramic particles is attached in a layered manner to a thickness of 5 to 25 mm.
Tsuru, packing density (1,05-0.35 g/cd, preferably 0.15-0.30 g/ctA (7)
It forms a combustion section (4). As the ceramic porous body, it is possible to use a material in which inorganic fine particles such as mullite, alumina, zirconia, silicon nitride, silicon carbide, etc. are press-molded together with a small amount of a binder, and the inorganic fine particles are fixed with the binder. S i that can withstand temperatures above 'C
Ox -A 1zOs system and AI! It is more preferable that 03 series ceramic fibers are attached to the inner circumferential surface of the shape retaining member (2) by vacuum forming, since the pressure loss and thermal conductivity are small and flashback is difficult to occur.In addition, the combustion part (4) is formed It is preferable to contain a catalytic combustion catalyst such as platinum or palladium that oxidizes and burns the fuel gas in the porous ceramic body.
At least one end surface of the annular flow path (5) formed between the annular channel (5) and the annular lid (6) is hermetically sealed, and
In the first embodiment shown in FIG. 1, a part of the can body (1) is provided with a supply port (7) for a mixture of air and fuel gas that communicates with the annular flow path (5). Only the upper end surface of the annular channel (5) is sealed by the annular lid (6), while the can body (
The lower end surface of 1) is the air-fuel mixture supply port (7),
As in the second embodiment shown in FIG. 2, both upper and lower end surfaces of the annular channel (5) are sealed with an annular lid (6), and
An air-fuel mixture supply port (7) may be provided in the central side of the can body (1). Note that (8) is an ignition device, and (9) is an opening on the inside of the shape-retaining member (2) at both end faces. The opening is heated, and a heated object such as a heated fluid flow pipe is passed through the opening.

(Function) The device configured in this way supplies a mixture of air and fuel gas to the can body (1) and the shape retaining member (2) from the supply port (7) provided in a part of the can body (1). An annular flow path formed between (
5), the mixture passes through the cylindrical shape-retaining member (2) because at least one end surface of the annular flow path (5) is sealed by the annular lid (6). The shape-retaining member (2) undergoes uniform surface combustion over the entire circumference on the surface of the combustion part (4) made of a cylindrical ceramic porous body formed on the inner peripheral surface.
Radiant heat is radiated uniformly toward the center of the radiant heat. Therefore, if a heated fluid flow tube or the like is passed through the center of the radiant heat, the temperature distribution in the circumferential direction will only vary within ±5°C.
Unlike the case where there was a variation of about 0°C, much more uniform heating becomes possible. In addition, all of the radiant heat is radiated to the heated body such as the heated fluid flow tube, so the thermal efficiency is extremely high.

(Effects of the Invention) As is clear from the above description of the embodiments, the present invention can uniformly heat a heated object from the entire circumference, has high thermal efficiency, has a simple structure, and has excellent volumetric combustion efficiency. ethylene cracking furnace, steam methane,
It is effective for pipe heating furnaces such as steam naphtha reforming furnaces, heavy oil heating furnaces, asphalt heating furnaces, etc. Furthermore, since the radiant burner of the present invention burns in a flameless state and there is no risk of backfire, it can be placed closer to the object to be heated than a normal burner, making the overall device more compact and energy saving. You can also do it. Therefore, the present invention greatly contributes to the development of industry as a solution to the conventional problems.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of the present invention;
FIG. 2 is a partially cutaway perspective view showing the second embodiment. (1): Can body, (2): Shape retaining member, (4): Combustion part, (
5): Annular channel, (6): Annular lid, (7): Supply port. Figure 1

Claims (1)

[Claims] 1. A cylindrical shape-retaining member (2) having a combustion part (4) made of a porous ceramic material formed on the inner circumferential surface thereof is placed concentrically inside a cylindrical can body (1). Fixing the can body (1) and the holding member (2)
At least one end surface of the annular flow path (5) formed between the can body (1) is sealed with an annular lid (6), and a part of the can body (1) is provided with air that communicates with the annular flow path (5). A radiant burner characterized by being provided with a supply port (7) for a mixture of gas and fuel gas. 2. The radiant burner according to claim 1, wherein the ceramic porous body is a stack of ceramic fibers. 3. Claims 1 or 2 in which the shape-retaining member is made of a metal body with a large number of openings, such as punching metal or wire mesh.
Radiant burner as described in section. 4. The radiant burner according to claim 1, 2 or 3, wherein the can body (1) and the shape retaining member (2) are cylindrical. 5. The inside of the shape-retaining member (2) is opened at both end faces,
5. The radiant burner according to claim 1, 2, 3, or 4, which can be penetrated by a heated fluid through-flow tube.