JPH06235508A - Surface burning burner - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a surface combustion burner using a metal fiber mat having a large surface area as a combustion surface with a simple structure. A surface combustion burner having a metal fiber mat 11 forming a combustion surface, a mixed gas chamber formed on the back side of the metal fiber mat, and a casing 83 surrounding the mixed gas chamber. A heat-resistant porous metal plate 12 is integrally fixed to the back surface of 11 with bolts and nuts 20. [Effect] With a simple structure, deformation of the metal fiber mat due to heat can be suppressed, and a surface combustion burner having a large-area combustion surface can be easily obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a surface combustion burner,
In particular, the present invention relates to a surface combustion burner that minimizes the occurrence of distortion due to heat in the metal fiber mat that is the combustion surface.

[0002]

2. Description of the Related Art Conventionally, there is provided a porous member having pores which are communicated with each other on the front and back sides and which is sufficient for the combustion gas mixture to diffuse therein. Surface burning burners are known which are designed to pass through the cylinder to reach its front surface and are ignited and burned in the vicinity of the front surface. This type of surface combustion burner heats a porous member to make it red heat, and a part of the energy is released as radiant heat, and the thermal conductivity of a porous member such as ceramic is usually small and the combustion temperature of the surface is reduced. Since the backside temperature does not rise so much even if it is considerably raised, it is possible to prevent the occurrence of flashback, and it is used as a burner with high thermal efficiency and in a wide range of fields, not limited to household combustion equipment.

An example of the basic structure of the surface combustion burner will be described with reference to FIG. 8. In the surface combustion burner 80 shown in FIG. 8, a square or circular planar porous member 81 is heat resistant packing. It is attached to the front side of a tubular casing 83 via 82. A spacer 84 is arranged inside the casing 83.
The porous member 81 is integrally fixed to the casing 83 by the back plate 85 via. A cylindrical pipe 86 is attached to the center of the back plate 85, and the cylindrical pipe 86 is connected to a combustion gas supply source via an appropriate pipe (not shown).

Combustion gas A from a gas source (not shown) is press-fitted from a cylindrical tube 86. The injected combustion gas A passes from the back surface of the porous member 81 through the continuous pores to reach the front surface, and is ignited and burned at the front surface. Due to the combustion, the front surface of the planar porous member 81 becomes red and radiant heat is emitted. In such a surface combustion burner, the porous member 8
Reference numeral 1 is a sintered body of long fibers made of porous ceramics or alloys such as iron, chromium, silicon, aluminum and yttrium, and a so-called metal fiber mat having a heat resistance of 1200 ° C. or higher is used. However, since such materials are deformed by heat, the size of the porous member that can be used in a single surface combustion burner has conventionally been limited to some extent, and combustion equipment that requires a combustion area above a certain area. In the case of producing the above, as shown in FIG. 9, a casing 90 capable of accommodating a required number of unit burners 80 is prepared, and the required number of unit burners 80, 80 are collectively gathered in the casing 90. Was traditionally normal. In that case,
As is apparent from FIG. 9, the side wall portion and the flange portion 91a of the casing existing in the peripheral portion of each burner unit,
As shown in b), many parts that do not directly affect combustion exist on the surface of the burner, resulting in a decrease in combustion efficiency.

The Applicant has conducted diligent research to solve the above inconvenience, and has developed a structure for supporting a porous member having a large surface area in a more stable state in a casing without reducing the effective combustion area. Previously proposed a surface combustion burner having a different structure (Japanese Patent Application No. 3-341335).
issue).

[0006]

The above-mentioned proposal is shown in FIG.
As shown in FIG. 3, a plurality of columnar bodies 88, 88 are erected from the bottom inside the casing 83, and the porous member 81 is fixed to the casing 83 in addition to the peripheral portion of the casing 83, and also at the tip of the columnar body 88. Even if a porous member having a surface area of about 600 mm × 800 mm, which was conventionally limited to about 500 mm × 500 mm, is created, the effective combustion area is not reduced and warp due to heat is generated. It has become possible to create a surface combustion burner that can sufficiently prevent large deformation. However, on the other hand, the additional processing of fixing the columnar body to the casing was required.

Applicants have continued to study the use of larger area porous members. There, of course, it is necessary to increase the number of columnar members that stand upright in the casing as the surface area of the porous member increases, and the process of standing up the columnar member becomes more complicated and the porous member to the casing It became difficult to assemble. In particular, when a metal fiber mat made of a sintered body of long fibers made of an alloy such as iron, chromium, silicon, aluminum, and yttrium as described above is used as the material of the porous member, the columnar bodies are formed with the same density. Although the porous member has a surface area of about 600 mm × 800 mm even if it is provided, it does not cause a large warp-like deformation when its combustion surface reaches a temperature of about 500 ° C. or higher. We perceived wrinkles on the surface and small warps between the columns.

FIG. 1 shows the state thereof. In the figure, 1 is a metal fiber mat constituting a combustion surface, 83 is a casing for supporting it, 3 is a tip of a columnar member standing on the casing, and metal. It is a locking part with the fiber mat. In actual combustion, many wrinkles as shown by S in the figure were generated and small warps were generated. In particular, this wrinkle appeared in a raised state on the surface, and when the cross section was analyzed, the porosity was higher than other parts. Then, the permeability of the combustion gas in the wrinkle portion becomes larger than that in the other portions, and a local high temperature portion, that is, a hot spot occurs, resulting in local damage to the metal fiber mat and shortening the life of the mat, and also preferable in appearance. It became nothing.

Although it has been possible to prevent the generation of wrinkles and small warps by increasing the standing density of the columnar members as the area of the porous member increases, as described above, the columnar members are erected at a high density in the casing. The installation was extremely difficult to manufacture and structurally complicated, and the casing itself was difficult to design. The present invention aims to eliminate the above-mentioned disadvantages that occur when a large-area metal fiber mat is used as a porous member, and more specifically, a metal fiber mat as a porous member is effective. It is an object of the present invention to provide a surface combustion burner which has a larger combustion surface and can be supported on the casing easily and stably without reducing the combustion area and has a simple structure.

[0010]

In order to solve the above-mentioned problems and to achieve the object, the present invention provides a metal fiber mat constituting a combustion surface, and a mixed gas formed on the back surface side of the metal fiber mat. In a surface combustion burner having a chamber and a casing enclosing the mixed gas chamber, a metal fiber mat posture holding structural member is integrally fixed to the back surface of the metal fiber mat to prevent deformation of the metal fiber mat. Disclosed is a surface combustion burner characterized by the above.

As the structure for maintaining the posture, the temperature of the back surface of the metal fiber mat during combustion (usually about 200 to 300 ° C.)
Any structure can be used as long as it has heat resistance to withstand heat and mechanical strength to some extent, and does not obstruct the flow of combustion gas for more than a specified amount, but it is a heat-resistant porous material that is fixed substantially all over the back surface of the metal fiber mat. It is a preferable embodiment that it is a high quality metal plate. It is a particularly preferred embodiment that the heat-resistant porous metal plate is a heat-resistant Ni-Cr alloy or Cr alloy having a porosity of about 75% to 95%.

The metal fiber mat and the heat-resistant porous metal plate are fixed by using a plurality of appropriate fixing means such as heat-resistant bolts and nuts or heat-resistant rivets. When fixed by separable means such as bolts and nuts, when the burning surface of the metal fiber mat is deteriorated or damaged by the combustion action or by external requirements, the metal fiber mat and the heat resistant porous metal plate are Since it can be temporarily separated and the metal fiber mat can be fixed again on the heat-resistant porous metal plate by reversing the front and back sides, both sides of the metal fiber mat can be effectively used as combustion surfaces and their life is extended. be able to.

As another aspect of the structure for holding the posture, it is effective to integrally fix a plurality of metal strips on the back surface of the metal fiber mat at appropriate intervals. As the material of the metal strip, the back surface temperature of the metal fiber mat is 200 to 300 ° C.
There is no particular limitation as long as it is a material having heat resistance to some extent, but SUS310 can be given as an example. Although the shape is arbitrary, it is necessary to use an L-shaped cross-section rather than a flat one and fix the narrow portion to the back surface of the metal fiber mat.
This is a preferred embodiment because the required mechanical strength can be obtained without reducing the effective combustion area more than necessary.

The metal fiber mat and the metal strip can be fixed to each other by using an appropriate fixing means such as heat-resistant bolts and nuts or heat-resistant rivets, but the surface of the metal fiber mat is fixed at the position where the metal strip is located. Crushing and fixing the two parts by applying welding means such as spot welding to the part surely fixes the metal strip to the back surface of the metal fiber mat in a state where the ineffective burning area is minimized. This is a very preferable embodiment because it can prevent the deformation of the metal fiber mat.

A plurality of metal strips are fixed in the longitudinal direction and / or the transverse direction, preferably at regular intervals. In addition to this, the metal fiber mat may be fixed along the outer periphery of four circumferences. The porous member composed of the metal fiber mat and the posture-maintaining structural member integrated as described above is fixed to the casing by a conventionally known appropriate fixing means. In addition, in the present invention, the other configuration of the surface combustion burner excluding the structure of the metal fiber mat and the structural member for maintaining the posture of the metal fiber mat integrally fixed to the back surface thereof is the same as that of the conventionally known surface combustion burner. The structure can be used as is.

[0016]

[Operation] In the surface combustion burner according to the present invention, a state in which the flow of the combustion gas is not blocked more than a predetermined amount on the back side of the metal fiber mat constituting the combustion surface, that is, the pressure loss of the combustion gas does not cause actual damage to the combustion. Then, prepare the one in which the posture maintaining structural member is integrally fixed, and fix it to the casing. As a result, the deformation of the metal fiber mat during combustion can be substantially suppressed without unnecessarily complicating the structure of the casing (that is, minimizing the number of pillars or erection at all). It will be possible. Therefore, even when the combustion surface has a large area, wrinkles and small warpage due to thermal deformation of the metal fiber mat can be prevented, and a surface combustion burner using a large area metal fiber mat as the porous member. Can be obtained. Further, the metal fiber mat can stably function as a combustion surface for a long period of time.

[0017]

EXAMPLES The present invention will now be described in more detail based on the description of examples. In the surface-combustion burner according to the present invention, except for the structure of the metal fiber mat that functions as a combustion surface and the posture-maintaining structural member that is integrally fixed to the back surface of the mat, the other structure is, for example, the conventional structure described with reference to FIG. It is the same as the known one, and it can be used as it is by only changing the design corresponding to the increase of the area of the metal fiber mat. Therefore, in the following, the configuration of the metal fiber mat and the posture-maintaining structural member integrally fixed to the back surface thereof will be mainly described, and other configurations will be touched as necessary.

FIG. 2 is a view of the combustion surface in one embodiment of the surface combustion burner according to the present invention as seen from above, and FIG. 3 is a schematic cross-sectional view thereof. For convenience of description, the casing 83, the spacer 84, and the like are of the same type as those described in FIG. 3, but are not limited thereto.
In this embodiment, the metal fiber mat 11 constituting the combustion surface is conventionally known, and includes iron, chromium, silicon,
It is composed of a sintered body of long fibers made of an alloy such as aluminum or yttrium. 60 for the metal fiber mat 11
The size is 0 mm x 800 mm, and the back surface is Ni-C.
A heat-resistant porous metal plate 12 (trade name "Celmet" manufactured by Sumitomo Electric Industries, Ltd.) made of r as a material and having a porosity of 95% is integrally fixed by bolts and nuts 20 as a structural member for maintaining a posture of a metal fiber mat. In this way, the so-called porous member 10A in the surface combustion burner is constituted by the metal fiber mat 11 and the heat-resistant porous metal plate 12 which are integrally fixed.

FIG. 4 is an enlarged view showing a state in which the metal fiber mat 11 and the heat-resistant porous metal plate 12 are integrally fixed by bolts and nuts 20, and the metal fiber mat 11 and the heat resistant porous metal plate 12 are integrally fixed to each other. A hole penetrating the heat-resistant porous metal plate 12 is opened in advance, a bolt 21 having a flat head is inserted into the hole, a washer 22 is fitted, and then a nut 23 is tightened to fix.

There are no particular restrictions on the portion or number of the metal fiber mat 11 and the heat-resistant porous metal plate 12 integrally fixed to each other, but they should be spaced at equal intervals depending on the surface area of the metal fiber mat. Set up. In this embodiment, as shown in FIG. 2, the vertical direction is largely divided into 3 minutes, and the horizontal direction is largely divided into 4 minutes, and they are fixed by bolts and nuts 20 at 50 mm intervals, and the divided center is further fixed. There is.

The porous member 10A thus constructed is fixed to the casing 83 by a conventional means. In this embodiment, the plurality of bolts 31, 31 are erected on the flange portion 89 of the casing 83, and the porous member 10 is provided.
After forming an opening at a corresponding position on the periphery of A and inserting the opening of the porous member 10A into the bolt 31, a nut 32 is formed.
Fixed by.

Then, the back surface material 85 and the like are fixed to the casing 83 to form the surface combustion burner. In this embodiment, the metal fiber mat 11 and the heat-resistant porous metal plate 12 are fixed by bolts and nuts at a plurality of points, so that the casing 83 can be erected without arranging the columnar body. As in the case where the tip and the metal mat are fixed, it is possible to suppress deformation of the metal mat 11 due to heat. Therefore, even when a metal fiber mat with a large area is used, it is possible to obtain a combustion surface without wrinkles or deformation due to thermal expansion, and since the columnar body is not installed upright, the structure of the casing becomes complicated. Instead, the conventional casing can be used as it is by simply changing the surface property as needed. Further, since the fixing of the metal fiber mat 11 and the heat-resistant porous metal plate 12 and the assembling of the formed porous member to the casing can be performed as separate operations, the burner assembling process becomes easy.

Further, the metal fiber mat 11 and the heat-resistant porous metal plate 12 are released by releasing the engagement between the bolt and the nut.
Since they can be easily separated from each other, they can be easily replaced when either of them is damaged. Also, the two are temporarily separated and the front and back of the metal fiber mat 11 are reversed and the heat-resistant porous metal plate is once again replaced. By fixing the metal fiber mat 12 on both sides, both surfaces of the metal fiber mat 11 can be effectively used as combustion surfaces and the life thereof can be lengthened.

It is not always necessary to fix the metal fiber mat and the heat-resistant porous metal plate with bolts and nuts, and heat-resistant rivets or the like may be used. In that case, the effect of the exchangeability of the members or the reversal use of the metal fiber mat is sacrificed, but the manufacturing process of the porous member can be simplified. In addition, as the heat-resistant porous metal plate, the porosity of Ni-Cr is 95% in the above embodiment.
The heat-resistant porous metal plate (trade name "Celmet" manufactured by Sumitomo Electric Industries, Ltd.) was used, but this is just an example, and a Ni alloy heat-resistant porous metal plate marketed under the same trade name may be used. Further, as described above, the combustion gas permeation porosity (preferably the same as the porosity of the metal fiber mat has heat resistance against the lower surface temperature of the metal fiber mat at the time of combustion and does not hinder combustion). It will be appreciated that any porosity of the order of magnitude or higher, with a porosity of about 75% to 95%) can be used.

FIG. 5 is a schematic drawing of a cross section of another embodiment of the surface combustion burner according to the present invention. In this embodiment, a metal piece 40 having an L-shaped cross section is used as a structural member for maintaining the attitude of the metal fiber mat, and the metal piece 40 is fixed to the back surface of the metal fiber mat 11 at regular intervals in the vertical and horizontal directions. ing. FIG. 6 shows a state in which the metal pieces 40, 40 having the L-shaped cross section are assembled in a cross shape, and the short piece portions 41, 41 forming the upper flat surface of the metal fiber mat 11 as shown in FIG. It is fixed to the back surface by spot welding. At this time, at least the metal fiber mat portion used for spot welding is crushed into a recess 42 as shown in FIG. Assembling of the porous member 10B into the casing 83 may be performed in the same manner as in the conventional case or the same as the case of the first embodiment.

Also in this embodiment, the metal fiber mat 11 is used.
Can be fixed to the metal-like piece 40 in many places, the displacement due to thermal expansion can be suppressed, and the metal-like piece 4 can be suppressed.
Since 0 has an L-shaped cross section, even if it has a considerably large area, it is securely held without sagging. Further, compared with the case of assembling a large number of burners each having a large positive area as in the conventional example shown in FIG. 9, the ineffective combustion area can be greatly reduced.

In this embodiment, as the metal fiber mat posture maintaining structural member, metal pieces 40 having an L-shaped cross section arranged in a cross shape at appropriate intervals were used, but the metal pieces have an L-shaped cross section. Not limited to a rectangular shape, rectangular cross section,
It may have a circular or oval cross section or the like, and may be appropriately selected and used in combination. Further, it is not always necessary to arrange them in a cross shape, and they may be arranged in the vertical or horizontal direction. They are appropriately selected according to the physical properties or size of the metal fiber mat.

As described above, the joining of the metal fiber mat and the metallic piece is not limited to spot welding. The above description is of the preferred embodiments of the present invention and there are many other variations. For example, in the embodiment, the case where the metal fiber mat is held only by the structural member for holding the attitude of the metal fiber mat without providing the columnar body for supporting the porous member in the casing has been described. Depending on the size or combustion conditions, an arbitrary number of columnar bodies may be provided upright in the casing so that the porous member can be fixed at the tip of the columnar body as well. Alternatively, the heat-resistant porous metal plate and the metallic piece may have a three-layer structure.

Further, according to the present invention, it is of course possible to obtain a surface combustion burner having a combustion surface having a large surface area, but it is clear that the present invention is equally applicable to a conventional surface combustion burner having a small area. Is.

[0030]

According to the present invention, a surface combustion burner having a combustion surface of a metal fiber mat having a large surface area can be obtained with a simple structure without unnecessarily complicating the casing with the above structure. Further, in a preferred embodiment, the life of the metal fiber mat can be extended.

[Brief description of drawings]

FIG. 1 is a view showing an example in which wrinkles occur on a combustion surface of a surface combustion burner.

FIG. 2 is a front view of an embodiment of the surface combustion burner according to the present invention.

FIG. 3 is a sectional view of an embodiment of the surface combustion burner according to the present invention.

FIG. 4 is an enlarged sectional view showing a fixed portion.

FIG. 5 is a cross-sectional view of another embodiment of the surface combustion burner according to the present invention.

FIG. 6 is a perspective view showing an assembled state of the metal strip.

FIG. 7 is an enlarged cross-sectional view showing a fixed state of the metal fiber mat and the metal strip.

FIG. 8 is a sectional view of a conventional example of a surface combustion burner.

FIG. 9 is a sectional view of another conventional example of the surface combustion burner.

FIG. 10 shows a casing of an improved surface combustion burner.

[Explanation of symbols]

10A ... Porous member, 11 ... Metal fiber mat, 12 ... Heat-resistant porous metal plate, 20 ... Bolt nut, 83 ... Casing

Claims (5)

[Claims] 1. A surface combustion burner comprising a metal fiber mat forming a combustion surface, a mixed gas chamber formed on the back surface side of the metal fiber mat, and a casing surrounding the mixed gas chamber, wherein the metal fiber A surface combustion burner characterized in that a structure member for maintaining a posture of a metal fiber mat is integrally fixed to the back surface of the mat. 2. A surface combustion burner comprising a metal fiber mat forming a combustion surface, a mixed gas chamber formed on the back surface side of the metal fiber mat, and a casing surrounding the mixed gas chamber, wherein the metal fiber A surface-combustion burner characterized in that a heat-resistant porous metal plate is integrally fixed to substantially the entire back surface of the mat by an appropriate fixing means, whereby deformation of the metal fiber mat is suppressed. 3. The surface combustion burner according to claim 2, wherein the heat-resistant porous metal plate is a heat-resistant Ni—Cr alloy or Ni alloy having a porosity of about 75% to 95%. 4. A surface combustion burner having a metal fiber mat forming a combustion surface, a mixed gas chamber formed on the back surface side of the metal fiber mat, and a casing surrounding the mixed gas chamber, wherein the metal fiber A surface-combustion burner characterized in that a plurality of metal strips are integrally fixed to the back surface of the mat by appropriate fixing means to prevent deformation of the metal fiber mat. 5. The surface combustion according to claim 4, wherein the metal fiber mat is crushed from the surface side at a portion where the metal strip is located and partially welded at that portion. Burner.