Cylindrical burner

Abstract

 A cylindrical burner includes a heat chamber 1 constituted by combining plural strip-shaped combustion plates 7, a coupling member 2 that extends in an axial direction inside the heat chamber, a pair of holding plates 3 and 4 fixed to both ends of the coupling member. The respective holding plates are set in abutment against respective end faces of the heat chamber via end face packings 6 overlapping the respective end faces to sandwich the heat chamber with both the holding plates from both sides in the axial direction. The respective combustion plates are tightened inwardly in a radial direction to prevent gas from leaking from gaps among the combustion plates. Outer peripheral packing sections 6a overlapping outer surfaces at ends of the combustion plates 7 are projected to outer peripheries of the end face packings 6. The outer peripheral packing sections 6a are sandwiched between cylindrical flange sections 3a and 4a, which bend inwardly in the axial direction formed on the outer peripheries of the holding plates 3 and 4, and the outer surfaces at the ends of the combustion plates 7 while being compressed by a predetermined interference such that the combustion plates 7 are tightened inwardly in the radial direction. In addition, ring members 9, which bind the combustion plates 7, are mounted in an outer periphery at an end of the heat chamber 1.

Description

[0001] The present invention relates to a cylindrical burner including a heat chamber constituted by combining plural strip-shaped combustion plates, which have a plurality of burner ports, in a cylindrical shape.

[0002] Conventionally, in this type of the cylindrical burner, the heat chamber is assembled by using a frame having plural window frames in a peripheral direction, fitting combustion plates in the respective window frames from the outside, screwing protection frames abutting against outer surfaces in peripheral parts of the respective combustion plates to the frame, and fixing the respective combustion plates to the frame (e.g., see Japanese Utility Model Publication No. 44-2634).

[0003] In this cylindrical burner, the frame of a complicated structure having the plural window frames and the protection frames for the respective combustion plates are required. Thus, there is an inconvenience in that the number of components increases, time and labor are required to assemble the cylindrical burner, and cost increases.

[0004] Thus, in Japanese Patent Laid-Open Publication No. 2004-324910, the applicant proposed a cylindrical burner including: a heat chamber constituted by combining plural strip-shaped combustion plates, which have a plurality of burner ports, in a cylindrical shape; a coupling member that extends in an axial direction inside the heat chamber; and a pair of holding plates fixed at both ends of the coupling member, wherein the respective holding plates are set in abutment against respective end faces of the heat chamber via end face packings overlapping the respective end faces to sandwich the heat chamber with both the holding plates from both sides in the axial direction. According to this cylindrical burner, the frame with a complicated structure and the protection frames are made unnecessary, assembling is easy, and cost can be reduced.

[0005] However, when the heat chamber is simply sandwiched from the axial direction, it is likely that the respective combustion plates shift to the outside in a radial direction, gaps are formed among the respective combustion plates, and gas leaks from the gaps. Thus, in the cylindrical burner of the prior application described above, cylindrical flanges section bending inwardly in the axial direction are formed in outer peripheries of the respective holding plates and outer surfaces at ends of the heat chamber are covered by the flange sections such that it is possible to prevent the combustion plates from shifting to the outside in the radial direction.

[0006] Here, in order to hold the combustion plates without causing loosening in the radial direction, it is necessary to externally fit the flange sections of the holding plates firmly in the outer surfaces at the ends of the heat chamber. However, the outer surfaces at the ends of the combustion plates may be scraped by the flange sections when the holding plates are assembled with the heat chamber. This makes it difficult to assemble the holding plates. In particular, in order to improve a sealing property among the respective combustion plates, when plural combustion plates are combined in a cylindrical shape to form the heat chamber in a state in which side packings along side edges of the respective combustion plates are provided among the respective combustion plates, it is necessary to tighten the respective combustion plates inwardly in the radial direction such that the side packings are compressed by a predetermined interference. For this purpose, it is necessary to set an inner diameter of the flange sections smaller than an outer diameter of the heat chamber in a free state. This makes it extremely difficult to assemble the holding plates with the heat chamber.

[0007] In view of the problems described above, embodiments of the invention seek to make it possible to tighten the respective combustion plates inwardly in the radial direction and make it easier to assemble the holding plates in order to provide a cylindrical burner having improved assemblability in which gas does not leak from gaps among the combustion plates.

[0008] Preferably, a cylindrical burner includes a heat chamber constituted by combining plural strip-shaped combustion plates, which have a plurality of burner ports, in a cylindrical shape a coupling member that extends in an axial direction inside the heat chamber and a pair of holding plates fixed to both ends of the coupling member, the heat chamber being sandwiched from both sides in the axial direction by both the holding plates by setting the respective holding plates in abutment against end faces of the heat chamber via end face packings overlapping the respective end faces, wherein outer peripheral packing sections overlapping outer surfaces at the ends of the respective combustion plates are extended to outer peripheries of the respective end face packings and cylindrical flange sections bent inwardly in the axial direction are formed on outer peripheries of the respective holding plates such that the outer peripheral packing sections are compressed by a predetermined interference and sandwiched between the inner surfaces of the flange sections and the outer surfaces of the respective combustion plates thereof.

[0009] According to the structure described above, an inner diameter of the flange sections can preferably be set larger than an outer diameter of the ends of the heat chamber by a thickness of the outer peripheral packing sections in a compressed state. Thus, the outer surfaces at the ends of the combustion plates are never scraped by the flange sections when the holding plates are assembled with the heat chamber. In addition, as the flange sections come closer inwardly in the axial direction from the end face sides of the heat chamber, the outer peripheral packing sections are naturally sandwiched between inner surfaces of the flange sections and the outer surfaces at the ends of the combustion plates from base end sides thereof while being compressed. In other words, the flange sections are externally fit in the outer surfaces at the ends of the heat chamber smoothly while sandwiching the outer peripheral packing sections between the outer surfaces at the ends of the combustion plates and the flange sections when the flange sections are pressed inwardly in the axial direction. Therefore, it is easy to assemble the holding plates with the heat chamber.

[0010] In a state in which the holding plates are assembled with the ends of the heat chamber, the respective combustion plates are tightened inwardly in the radial direction by a compression reaction of the outer peripheral packing sections and the respective combustion plates are held firmly without loosening in the radial direction. Therefore, it is possible to surely prevent the inconvenience in that the combustion plates shift to the outside in the radial direction, gaps are formed among the combustion plates, and gas leaks from the gaps. In addition, when the heat chamber is constituted by combining the plural combustion plates in a cylindrical shape in a state in which side packings along side edges of the respective combustion plates are interposed among the respective combustion plates, even if the inner diameter of the flange sections are set larger than the outer diameter of the ends of the heat chamber in a free state, it is possible to compress the side packings by tightening the respective combustion plates strongly inwardly in the radial direction by a compression reaction of the outer peripheral packing section. Therefore, in this case, it is also possible to make it easy to assemble the holding plates and secure a sealing property by the side packings among the combustion plates.

[0011] Incidentally, in general, the end face packings and the side packings are formed by a ceramic packing molded by impregnating a binder in a ceramic fiber. Although the ceramic packing has a heat resistance, the binder gradually decomposes thermally and disappears as time elapses and thickness of the ceramic packing decreases (becomes thin). When the outer peripheral packing sections become thin, a tightening force of the combustion plates decreases. As a result, it is likely that the combustion plates shift to the outside in the radial direction, gaps are formed among the combustion plates, and gas leaks. Moreover, when deterioration of the packings advances, the outer peripheral packing sections may separate from the end face packings and come off to fall from gaps between the flange sections of the holding plates and the outer surfaces at the ends of the combustion plates. It is likely that the outer peripheral packing sections, which have fallen from the gaps, touch flames to cause combustion failure.

[0012] Therefore, it is desirable that ring members, which bind the plural combustion plates in a cylindrical shape, are mounted in parts adjacent to the outer peripheral packing sections on the outer surface of the heat chamber inwardly in the axial direction, and the gaps, which are formed between the outer surfaces at the ends of the respective combustion plates and the inner surfaces of the flange sections of the respective holding plates, are closed by the ring members.

[0013] Consequently, even if the external packing sections become thin and the tightening force of the combustion plates decreases, since the plural combustion plates constituting the heat chamber are bound in a cylindrical shape by the ring members, the combustion plates never shift to the outside in the axial direction to form gaps among the combustion plates and gas is prevented from leaking from gaps between the combustion plates. In addition, even if the outer peripheral packing sections separate from the end face packings, the outer peripheral packing sections are prevented from coming off to fall from the gaps between the outer surfaces at the ends of the combustion plates and the inner surfaces of the flange sections of the holding plates by the ring members closing the gaps. Therefore, the outer peripheral packing sections are also prevented from touching flames to cause combustion failure. In this way, since the inconvenience due to deterioration of the packings is eliminated, limitation on a life of the packings due to deterioration is eased and durability of the packings is improved.

[0014] Here, in order to prevent the outer peripheral packing sections from coming off to fall, it is necessary to prevent the ring members from shifting inwardly in the axial direction from the position for closing the gaps between the outer surfaces at the ends of the combustion plates and the inner surfaces of the flange sections of the holding plates. In this case, it is conceivable to push the ring members into the inner sides of the flange sections of the holding plates and, then, caulk edges of the flange sections inwardly in the radial direction partially, and prevent shift of the ring members with the caulked portions. However, time and labor are required.

[0015] Thus, it is desirable to form sunken sections sunken inwardly in the radial direction on the outer surfaces of the respective combustion plates thereof, set an inner diameter of the flange sections of the respective holding plates such that the outer peripheral packing sections are compressed by a predetermined interference and sandwiched between the inner surfaces of the flange sections and the sunken sections, and mount the ring members to engage with the sunken sections. Consequently, steps at inner ends in the axial direction of the sunken sections work as stoppers to prevent the ring members from shifting. Therefore, post processing for preventing the ring members from shifting is made unnecessary, which is advantageous in realizing a reduction in cost.

[0016] Incidentally, when the side packings are provided among the respective combustion plates, first, it is necessary to tighten the respective combustion plates strongly inwardly in the radial direction to compress the side packings to adapt the side packings to the combustion plates. Here, if such a strong tightening force is obtained only with the ring members, the combustion plates do not have to be tightened by the flange sections of the holding plates via the outer peripheral packing sections. However, when the combustion plates are tightened by the ring members, since an area of contact of the ring members with the combustion plates is small, a local stress is applied to the combustion plates. Therefore, it is difficult to obtain a strong tightening force only with the ring members because of strength of the combustion plates. On the other hand, when the combustion plates are tightened by the flange sections of the holding plates via the outer peripheral packing sections, it is possible to secure a large area of contact of the outer peripheral packing sections with the combustion plates. Thus, it is possible to naturally tighten the combustion plates strongly. Once the side packings are adapted to the combustion plates by the compression of the side packings due to the tightening, even if the tightening force decreases because of deterioration of the outer peripheral packing sections, the sealing property among the respective combustion plates is secured as long as the combustion plates are bound in a cylindrical shape by the ring members.

[0017] However, when the side packings become thin and gaps are formed between the side packings and the combustion plates, gas leaks- In this case, if the ring members are formed by elastic rings that elastically tighten the plural combustion plates inwardly in the radial direction, the combustion plates are pushed inwardly in the radial direction by an elastic force of the elastic rings as the side packings becomes thinner, and a diameter of the heat chamber is reduced. Therefore, gaps are never formed between the side packings and the combustion plates and gas is prevented from leaking.

[0018] For a better understanding of the present invention and to show how it may be carried into effect, reference shall now be made, by way of example, to the accompanying drawings, in which:

FIG. 1 is a plan view of a cylindrical burner according to a first embodiment of the invention;

FIG. 2 is a sectional view cut along line II-II in Fig. 1;

FIG. 3(a) is a sectional view cut along line III-III in FIG. 2;

FIG. 3 (b) is an enlarged sectional view of a part encircled by an alternate long and short dash line b in FIG. 3(a);

FIG. 4 is a perspective view of a heat chamber of the burner in FIG. 1: and

FIG. 5 is a perspective view of a disassembled state of a main part of a cylindrical burner according to a second embodiment of the invention.

[0019] A cylindrical burner of the embodiment shown in FIG. 1 includes a heat chamber 1 of a cylindrical shape, a coupling member 2 (see FIGS. 2 and 3) that extends in an axial direction inside the heat chamber 1, a pair of holding plates 3 and 4 fixed to both ends of the coupling member 2 to sandwich the heat chamber 1 from both sides in the axial direction and an attaching plate 5 fixed to an outer surface of the holding plate 3 on one end side. The cylindrical burner is attached in a body of a machine such as a water heater or a heater at the attaching plate 5. As shown in FIG. 3 (a), the respective holding plates 3 and 4 are set in abutment against respective end faces of the heat chamber 1 via respective end face packings 6 overlapping the respective end faces.

[0020] The heat chamber 1 is constituted by combining plural (e.g., six) strip- shaped combustion plates 7 made of ceramics, which have a plurality of burner ports 7a, in a cylindrical shape. Side packings 8 along side edges of the combustion plates 7 are provided among the respective combustion plates 7, 7. Note that the burner ports 7a are not formed in parts closer to ends of the combustion plates 7. However, dummy burner ports 7b of a blank hole shape are formed in the parts closer to the ends of the combustion plates 7 due to a reason relating to formation such as uniformalization of a shrinking percentage at the time of formation of the combustion plates 7.

[0021] Referring to FIG. 3(a), a gas inlet 5a is opened in a central part of the attaching plate 5. The attaching plate 5 is fixed to an outer surface of the holding plate 3 on one end side, which is formed in an annular shape, by spot welding or the like such that the gas inlet 5a faces an inner peripheral space of the holding plate 3. The coupling member 2 is formed in a square cylindrical shape. The coupling member 2 is fixed to an inner surface in a peripheral edge of the gas inlet 5a of the attaching plate 5 at one end by spot welding or the like. Therefore, the holding plate 3 on one end side is fixed to one end of the coupling member 2 via the attaching plate 5. A plurality of through holes 2a are formed in a peripheral surface of the coupling member 2. A mixed gas of a fuel gas flowing in from the gas inlet 5a and a primary air is supplied into the heat chamber 1 via these through holes 2a and blows out from burner ports 7a of the respective combustion plates 7 to burn. Here, the coupling member 2 functions as a distributing pipe for distributing the mixed gas into the heat chamber 1 uniformly.

[0022] A cap 2b is fastened to the other end of the coupling member 2. A projected portion 2c, which is fit into an inner periphery of the holding plate 4 on the other end side formed in an annular shape, is formed in this cap 2b. In assembling the burner, first, the coupling member 2 is inserted into the heat chamber 1 and the holding plate 3 on one end side is set in abutment against one end face of the heat chamber 1 via the end face packing 6. Next, the holding plate 4 on the other end side is set in abutment against the other end face of the heat chamber 1 via the end face packing 6. In this case, the projected portion 2c is inserted into the inner periphery of the holding plate 4. Finally, the projected portion 2c is crushed inwardly in the axial direction. Consequently, the holding plate 4 is caulked and fixed to the coupling member 2 in a state in which the holding plate 4 is pressed inwardly in the axial direction. Thus, the heat chamber 1 is sandwiched firmly between both the holding plates 3 and 4.

[0023] Cylindrical flange sections 3a and 4a bending inwardly in the axial direction are formed in outer peripheries of the respective holding plates 3 and 4. Sunken sections 7c sunken inwardly in a radial direction are formed in outer surfaces at the ends of the respective combustion plates 7. As shown in FIG. 4, plural outer peripheral packing sections 6a overlapping the sunken sections 7c of the respective combustion plates 7 are projected to outer peripheries of the end face packings 6 at an interval in a peripheral direction. Moreover, ring members 9, which consist of a C-shaped elastic ring cut out at one place in a periphery , are mounted on the outer surfaces at the ends on one end side and the other end side of the heat chamber 1 so as to engage with the sunken sections 7c of the combustion plates 7. The plural combustion plates 7 are bound by the ring members 9 in a cylindrical shape. Note that, although the ring members 9 are formed of a spring material circular in section in this embodiment, the ring members 9 may be formed of a spring material square in section.

[0024] When the respective holding plates 3 and 4 are set in abutment against the respective end faces of the heat chamber 1 via the respective end face packings 6, the respective outer peripheral packing sections 6a are bent inwardly in the axial direction from base end sides by the flange sections 3a and 4a. As clearly shown in FIG. 3(b), the respective outer peripheral packing sections 6a are sandwiched between the sunken sections 7c of the respective combustion plates 7 and the inner surfaces of the flange sections 3a and 4a. Here, an inner diameter of the flange sections 3a and 4a are set such that the outer peripheral packing sections 6a are sandwiched between the inner surfaces of the flange sections 3a and 4a and the sunken sections 7c while being compressed by a predetermined interference. Therefore, the combustion plates 7 are tightened inwardly in the radial direction by a compression reaction of the outer peripheral flange sections 6a. Side packings 8 among the respective combustion plates 7, 7 are compressed by this tightening force. Consequently, the side packings 8 are adapted to the combustion plates 7 and a sealing property among the respective combustion plates 7, 7 is secured.

[0025] Incidentally, in order to tighten the combustion plates 7 inwardly in the radial direction with the flange sections 3a and 4a without providing the outer peripheral packing sections 6a, it is necessary to set an inner diameter of the flange sections 3a and 4a smaller than an outer diameter of the end of the heat chamber 1 in a free state (a state before compression of the side packings 8). Thus, the outer surfaces at the ends of the combustion plates 7 may be scraped by the flange sections 3a and 4a when the holding plates 3 and 4 are assembled with the heat chamber 1. This makes it very difficult to assemble the holding plates 3 and 4. On the other hand, in this embodiment, it is possible to set the inner diameter of the flange sections 3a and 4a larger than the outer diameter of the end of the heat chamber 1 in a free state by a thickness of the outer peripheral packing section 6a in a compressed state. Therefore, the outer surfaces at the ends of the combustion plates 7 are never scraped by the flange sections 3a and 4a at the time when the holding plates 3 and 4 are assembled with the heat chamber 1. This makes it easy to assemble the holding plates 3 and 4 with the heat chamber 1. Moreover, in this embodiment, taper sections 3b and 4b, a diameter of which expands inwardly in the axial direction, are formed at inner ends in the axial direction of the flange sections 3a and 4a. Therefore, the edges of the flange sections 3a and 4a are prevented from cutting in the outer peripheral packing sections 6a when the holding plates 3 and 4 are assembled. This makes it easier to assemble the holding plates 3 and 4 with the heat chamber 1.

[0026] A length in the axial direction of the sunken sections 7c of the combustion plates 7 are set shorter than a length in the axial direction of the flange sections 3a and 4a. Even if the ring members 9 are pushed by the flange sections 3a and 4a to shift inwardly in the axial direction when the respective holding plates 3 and 4 are assembled, the ring members 9 are prevented to shift further by steps at inner ends in the axial direction of the sunken sections 7c of the combustion plates 7. Thus, the ring members 9 never slips out from the inner sides of the flange sections 3a and 4a. Therefore, the ring sections 9 are held surely in parts adjacent to the outer peripheral packing sections 6a of the outer surface of the heat chamber 1 inwardly in the axial direction. The gaps between the sunken sections 7c of the combustion plates 7 and the inner surfaces of the flange sections 3a and 4a are closed by the ring members 9.

[0027] Here, the end face packings 6 and the side packings 8 are formed by a ceramic packing molded by impregnating a binder in a ceramic fiber. Thus, the binder gradually decomposes thermally and disappears as time elapses and thickness of the ceramic packing decreases (becomes thin). When the outer peripheral packing sections 6a become thin, a tightening force of the combustion plates 7 decreases. However, since the combustion plates 7 are bound by the ring members 9 in a cylindrical shape, the combustion plates 7 are prevented from shifting to the outside in the radial direction to cause gas to leak from the gaps among the combustion plates 7, 7. When the side packings 8 become thin, the respective combustion plates 7 are pushed inwardly in the radial direction by an elastic force of the ring members 9, which are constituted by elastic rings, to reduce the gaps among the combustion plates 7, 7 by an amount equivalent to the reduced thickness of the side packings 8. In addition, a diameter of the heat chamber 1 is also reduced by the amount equivalent to the reduced thickness of the side packings 8. Therefore, even if the side packings 8 become thin, a sealing property among the combustion plates 7, 7 is secured and gas is prevented from leaking surely.

[0028] In addition, even if deterioration of the outer peripheral packing sections 6a advances and the outer peripheral packing sections 6a separate from the end face packings 6, since the gaps between the sunken sections 7c of the combustion plates 7 and the inner surfaces of the flange sections 3a and 4a are closed by the ring members 9, the outer peripheral packing sections 6a never come off to fall from the gaps. Therefore, the outer peripheral packing sections 6a are surely prevented from coming off to fall and touching flames to cause combustion failure. Note that the gaps between the sunken sections 7c of the combustion plates 7 and the inner surfaces of the flange sections 3a and 4a by the ring members 9 are closed sufficiently if the outer peripheral packing sections 6a are prevented from coming off. The gaps do not have to be closed completely. The ring members 9 may be exposed partially from the inner sides of the flange sections 3a and 4a as long as gaps at the inner ends in the axial direction of the flange sections 3a and 4a, which are opening ends of the gaps between the sunken sections 7c of the combustion plates 7 and the inner surfaces of the flange sections 3a and 4a, are closed to a degree enough for preventing the outer peripheral packing sections 6a from coming off. However, in order to control deterioration of the ringmembers 9 by heat, as in this embodiment, it is desirable to hold the ring members 9 on the inner sides of the flange sections 3a and 4a completely.

[0029] In the explanation of the embodiment, the side packings 8 are provided among the respective combustion plates 7, 7. However, it is also possible to set the side ends of the combustion plates 7 in direct contact with the side ends of the adjacent combustion plates 7 to remove the side packings 8. In this case, it is unnecessary to reduce a diameter of the heat chamber 1 according to a reduction in thickness of the side packings 8. Therefore, the ring members 9 only have to simply bind the plural combustion plats 7 in a cylindrical shape. FIG. 5 shows such an embodiment. In this embodiment, the ring member 9 is formed by a band having a matching section 9a for spot welding in one place in a periphery. This band (rig member) 9 is mounted on the outer sides of the respective ends of the heat chamber 1 so as to engage with the sunken sections 7c of the respective ends of the combustion plates 7 as in the embodiment described above to bind the plural combustion plates 7.

[0030] A cutout 4c of a slit shape corresponding to the matching section 9a of the band 9 is formed in the flange section 4a of the holding plate 4. When the holding plate 4 is mounted at the end of the heat chamber 1 so as to sandwich the end face packing 6, the matching section 9a is inserted in the cutout 4c. In this embodiment, the gaps between the sunken sections 7c of the combustion plates 7 and the inner surface of the flange section 4a are also closed by the band 9 to prevent the outer peripheral packing sections 6a from coming off to fall from the gaps. Here, in FIG. 5, the holding plate 3 on one end side is not shown. However, a cutout corresponding to a matching section of a band mounted on an outer surface at an end on one end side of the heat chamber 1 is also formed in the flange section 3a of the holding plate 3. Note that the matching section 9a of the band 9 may be fixed by spot welding before or after a step of mounting the band 9 on the outer surface at the end of the heat chamber 1.

[0031] In addition, in the burner in which the side packings 8 are provided among the respective combustion plates 7, 7, when gas leakage due to reduction in thickness of the side packings 8 does not cause such a significant problem, the band described above may be used as the ring member 9- In the embodiment, the plural outer peripheral packing sections 6a corresponding to the plural combustion plates 7 are projected to the outer peripheries of the end face packings 6. However, it is also possible to project cylindrical outer peripheral packing sections, which bend in the axial direction, to the outer peripheries of the end face packings 6.

Claims

1. A cylindrical burner comprising:

a heat chamber constituted by combining plural strip-shaped combustion plates, which have a plurality of burner ports, in a cylindrical shape;

a coupling member that extends in an axial direction inside the heat chamber: and

a pair of holding plates fixed to both ends of the coupling member,

   the heat chamber being sandwiched from both sides in the axial direction by both the holding plates by setting the respective holding plates in abutment against end faces of the heat chamber via end face packings overlapping the respective end faces, characterized in that
   outer peripheral packing sections overlapping outer surfaces at the ends of the respective combustion plates are extended to outer peripheries of the respective end face packings and cylindrical flange sections bent inwardly in the axial direction are formed on outer peripheries of the respective holding plates such that the outer peripheral packing sections are compressed by a predetermined interference and sandwiched between the inner surfaces of the flange sections and the outer surfaces of the respective combustion plates thereof.

2. The cylindrical burner according to claim 1.
characterized in that ring members, which bind the plural combustion plates in a cylindrical shape, are mounted in parts adjacent to the outer peripheral packing sections on the outer surface of the heat chamber inwardly in the axial direction, and the gaps, which are formed between the outer surfaces at the ends of the respective combustion plates and the inner surfaces of the flange sections of the respective holding plates, are closed by the ring members.

3. The cylindrical burner according to claim 2,
characterized in that sunken sections sunken inwardly in the radial direction are formed on the outer surfaces of the respective combustion plates thereof, an inner diameter of the flange sections of the respective holding plates is set such that the outer peripheral packing sections are compressed by a predetermined interference and sandwiched between the inner surfaces of the flange sections and the Sunkens and the ring members are mounted to engage with the sunken sections.

4. The cylindrical burner according to claim 2 or 3,
characterized in that, the heat chamber is constituted by combining the plural combustion plates in a cylindrical shape in a state in which side packings along side edges of the respective combustion plates are provided among the combustion plates, the ring members are constituted by elastic rings that elastically tighten the plural combustion plates inwardly in the radial direction.

Drawing