JP3836049B2 - Gas burner device with premixed pilot burner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a gas burner device equipped with a premixed pilot burner equipped in a hot water boiler, a steam boiler, etc., and by improving the stability of the ignition fire of the pilot burner and simplifying the structure, The present invention relates to a gas burner apparatus equipped with a premixed pilot burner capable of reducing manufacturing costs, improving ignition performance, and stabilizing.
[0002]
[Prior art]
In a gas burner apparatus having a calorific value of about 300,000 kcal / h or more, an ignition method using a pilot burner is usually employed, and as a pilot burner for this purpose, a stable pilot flame can be obtained relatively easily. Mixed pilot burners are generally widely used.
[0003]
FIGS. 6 and 7 show an example of the original mixed pilot burner. The fuel gas F and the air A are mixed in a predetermined ratio in the pilot burner body 30 in advance, and the mixed gas Q is mixed. It is jetted into the pilot head 33 through the pilot short pipe 31 and the sleeve-fire formation body 32, and the mixed gas Q is ignited and burned by the spark generated at the tip of the ignition rod 34 to generate a so-called pilot flame ( Utility model registration No. 2583041).
6 and 7, 35 is a fixing insulator, 36 is a pilot gas nozzle, 37 is an air regulating valve, 38 is an ignition rod fixture, 39 is a viewing window, 40 is a back plate, and A ₀ is main combustion air. Current.
[0004]
This conventional seed mixing type pilot burner has the following features: (1) a so-called premixed flame holding function is obtained by the flame holding portion 33a at the tip of the pilot head 33; Even if the air-fuel ratio λ of the mixed gas Q is slightly changed due to the fact that a stable fire is formed, and (3) the air A and the fuel gas F are premixed relatively uniformly, etc. It can hold a stable pilot flame and has excellent practical utility.
[0005]
However, there are still many problems to be solved in the original mixed pilot burner. Among them, (1) the supply amounts of both the premixing air A and the fuel gas F are highly accurate. It is necessary to adjust each, and not only a considerable skill is required for the operation, but also a lot of work is required for the adjustment. (2) If the air-fuel ratio λ of the premixed gas Q is not within a predetermined range, It is difficult to ignite and (3) a large number of parts are required for assembling the pilot burner, which makes it difficult to reduce the manufacturing cost.
[0006]
On the other hand, a so-called premixed pilot burner has been developed as an alternative to the former mixed pilot burner.
The premixed pilot burner injects a fuel gas for forming a pilot flame from a short tube with a nozzle to the pilot combustion section, and mixes a part of the main combustion air flow with the injected fuel gas to ignite the fuel. The mixed gas is ignited and burned by a spark from the tip of the rod.
[0007]
However, the premixed pilot burner is easily influenced by the main combustion air flow, and particularly when the flow rate of the main combustion air flow fluctuates rapidly, the fuel gas and the air are not sufficiently mixed. As a result, there is a basic weakness that a stable pilot flame cannot be formed and maintained.
[0008]
[Problems to be solved by the invention]
The present invention has the above-mentioned problems in the conventional premixed pilot burner and the premixed pilot burner, that is, in the former, it takes time to adjust the supply amount of fuel gas and air for premixing. It is difficult to reduce the manufacturing cost, and in the latter case, the stability of the pilot flame is impaired due to fluctuations in the main combustion air flow, and as a result, it is difficult to form and maintain a stable pilot flame. The structure is simple, the manufacturing cost can be greatly reduced, and a stable pilot flame can be formed and maintained without being affected by fluctuations in the main combustion air flow. A gas burner device provided with the premixed pilot burner is provided.
[0009]
[Means for Solving the Problems]
The invention of claim 1 is a cylindrical draft tube 1 to which combustion air is supplied from one side, and a fuel gas F which is disposed in the draft tube 1 and is supplied from one side to the outer wall surface of the tip. A double cylinder-shaped manifold 3 that radiates radially from the gas nozzle hole 3d provided between the draft tube 1 and the manifold 3 and located behind the gas nozzle hole 3d. An air ring plate 5 provided with a combustion air intake hole 5a communicating with one air passage 8a, and a front end face and a gap G provided on the front surface of the double cylindrical manifold 3 and fixed; A cover plate 6 having an air intake hole 6a communicating with the inner second air passage 8b, and a fuel supply pipe 12 are disposed in the first air passage 8a. Air A protective shroud 9 surrounding at least three sides of a premixed pilot burner P inserted through the ring plate 5 and projecting forward, a short pipe 12 with a pilot nozzle projecting forward from the air ring plate 5, and the pilot The gap sealing plate 10 that closes the gap G in the vicinity of the short tube with nozzle 12 is a basic configuration of the invention.
[0010]
The invention according to claim 2 is the invention according to claim 1, wherein the protruding length of the protective enclosure plate from the air ring plate 5 is made larger than the protruding length of the short tube 13 with a pilot nozzle.
[0011]
The invention of claim 3 is the invention of claim 1, wherein the draft tube 1 and the manifold 3 are respectively formed into a cylindrical shape and a double cylindrical shape, and both are arranged concentrically. .
[0012]
The invention of claim 4 is the invention of claim 1, wherein the length of the inner pipe 3a forming the manifold 3 is made longer than the length of the outer pipe 3b, and the front end surface of the outer pipe 3b and the inner surface of the cover plate 6 are arranged. The gap G ₀ is made larger than the gap G between the front end surface of the inner pipe 3 a and the inner surface of the lid plate 7.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a gas burner apparatus provided with a premixed pilot burner according to the present invention will be described based on the drawings.
FIG. 1 is a partial longitudinal sectional view of a main part of the gas burner device, FIG. 2 is a view as seen from FIG. 1, and FIG. 3 is an enlarged view of a portion A in FIG.
[0014]
The gas burner apparatus B according to the present invention is formed of a main gas burner M and a premixed pilot burner P, and the premixed pilot burner P is inserted and supported between a draft tube 1 and a manifold 3 constituting the main gas burner M. Has been.
[0015]
The main gas burner M includes a double cylindrical draft tube 1 whose rear end face is sealed, an air supply pipe 2 for introducing air A from the rear end portion of the draft tube 1 to the inside thereof, and a front portion of the draft tube 1. A manifold 3 for introducing the fuel gas F inserted inward, a fuel gas supply pipe 4 inserted inward from the rear end face of the draft tube 1 and supplying the fuel gas F into the manifold 3, and a tip of the manifold 3 A flange-shaped air ring plate 5 having an air intake hole 5 a disposed between the manifold 3 and the draft tube 1, located inside the gas nozzle hole 3 d provided in the outer wall surface; Are formed of a cover plate 6 having an air intake hole 6a disposed opposite to the support plate 7, a support body 7 of the cover plate 6, and the like.
[0016]
That is, the draft tube 1 is made of SGP (200A) having a thickness of 5.8 mm, an outer diameter of 216.3 mm, and a length of about 350 mm, and its rear end face is closed by an end plate (not shown). A flange-like back plate 1 a is welded to the outer peripheral surface of the draft tube 1.
[0017]
The air supply pipe 2 is disposed on the rear end face side of the draft tube 1, and is located between the manifold 3 inside the draft tube 1 and the draft tube 1 (first air passage 8 a) and inside the manifold 3. Combustion air A is supplied to each of the second air passages 8b.
The air supply pipe 2 is provided with an air supply amount / air supply pressure adjusting device, a shutoff valve, and the like, but the description thereof is omitted here.
[0018]
The manifold 3 is formed into a double cylinder by arranging and supporting the inner pipe 3a and the outer pipe 3b concentrically, and fuel gas for main combustion is provided between the inner and outer pipes 3a and 3b. F is supplied.
The rear end portion of the manifold 3 is sealed with a rear end plate 3c, and the front end portion is sealed with a front end plate 3e. Further, a plurality of gas nozzle holes 3d (4.2 mmφ × 22) are formed in the wall surface of the outer tube 3b forming the manifold 3, and the fuel gas F is ejected radially from the gas nozzle holes 3d. Is done.
[0019]
As shown in FIG. 3, the front end of the manifold 3 is formed so that the inner pipe 3a is about 1 mm longer than the outer pipe 3b.
Further, a lid plate 6 described later is disposed in front of the inner pipe 3a with a gap G of about 1 mm. As a result, a gap G _{0 of} about 2 mm is formed between the outer pipe 3b and the cover plate 6, and travels through the second air passage 8b inside the manifold 3 through the gaps G and G _0. A part of the air A which has come is ejected radially into the mixed gas of the fuel F and the air A, and the mixing of the fuel F and the air A is further promoted.
[0020]
The fuel gas supply pipe 4 passes through the rear end plate of the draft tube 1 and is inserted and fixed inward thereof, and communicates with the rear part of the manifold 3. The fuel gas supply pipe 4 is provided with a gas amount adjusting device, a gas pressure adjusting device, a shut-off valve, etc., but the description thereof is omitted here.
[0021]
The air ring plate 5 is positioned inside the gas nozzle hole 3d provided on the outer wall at the tip of the manifold 3, and is provided vertically in the first air passage 8a between the draft tube 1 and the manifold 3. It is formed from a 3 mm thick steel plate.
The air ring plate 5 is provided with 11 combustion air intake holes 5a having a diameter of about 23 mm, through which the combustion air A is supplied to the combustion section through the air intake holes 5a. the gas nozzles 3d fuel gas F ejected radially are mixed from, the more the gap G, the air flow a, which is ejected in vertical form through G ₀ is mixed into the mixing gas.
[0022]
Further, as will be described later, pilot burner air intake holes 5b (6 in total) having a diameter of about 3 mmφ are formed in the vicinity of the portion of the air ring plate 5 through which the premixed pilot burner P described later passes. In addition, a protective enclosure plate 9 and a gap sealing plate 10 for the pilot combustion section associated therewith are fixed.
[0023]
The cover plate 6 has a thickness 3 mm, a disc having a diameter of 110 mm, the central portion thereof, the nozzle hole 6a for ejecting air flow A ₂ from the second air passage 8b to the burner combustion section (diameter about 6mm 8) are perforated.
Further, the cover plate 6 is supported and fixed by the cover plate support 7 so that the inner surface of the outer peripheral portion forms a gap G between the end surface of the inner tube 3a of the manifold as described above.
[0024]
The lid plate support 7 is inserted and supported in the inner space (that is, the second air passage 8b) of the inner tube 3a of the manifold 3, and the air intake holes 6a having a diameter of 6 mmφ × 6 are formed in this. The provided cover plate 6 is disposed and supported so as to face the front end surface of the manifold 3.
Incidentally, most of the supply air A through the second air passage 8b is supplied to the burner combustion unit through the air inlet holes 6a, and some of the air A is the gap G, into the mixed gas through the G ₀ It is ejected radially.
[0025]
The premixed pilot burner P is disposed in the first air passage 8a between the draft tube 1 and the manifold 3, and as shown in FIGS. 1, 2, 4, and 5, the fuel for the pilot burner is used. A supply 12 and a short tube 13 with a pilot nozzle fixed to the tip thereof, an ignition rod 14, a frame rod 15, an earth rod 16 and the like are constituted.
[0026]
That is, the short pipe 13 with pilot nozzle is disposed and fixed in a state where the air ring plate 5 is inserted and the front portion protrudes from the front side of the air ring plate 5 by about 5 to 6 mm. The fuel gas F is ejected radially from the holes 12a.
[0027]
In addition, six pilot burner air intake holes 5b having a diameter of 3 mmφ are formed in the vicinity of the portion of the air ring plate 5 through which the short pipe 13 with a pilot nozzle is inserted, and these air intake holes A part of the air A in the air passage 8a is ejected as pilot combustion air from 5b, so that a mixed atmosphere of fuel F and air A is formed in the front space portion (pilot combustion portion) 17 of the air ring plate 5. The
[0028]
The ignition rod 14, the frame rod 15 and the earth rod 16 have the same functions as those of the former original mixed pilot burner, and the ignition rod 14 has a mixture of fuel gas F and air A. It ignites and burns it.
The frame rod 15 is a flame detection type safety device that detects a flame. Specifically, the current flowing through the flame is detected by using the rectifying action of the flame, and when an ignition failure or abnormality occurs in the pilot flame, this is detected and the safety device is operated.
Further, the earth rod 16 stabilizes the flame detection by the frame rod 15, and stabilizes the detection current by increasing the ground contact area.
[0029]
In the gas burner apparatus B according to the present invention, the protective shroud plate 9 having a height of about 15 mm is air-ringed in the vicinity of the portion where the short tube 13 with pilot nozzle of the premixed pilot burner P penetrates the air ring plate 5. By projecting from the front surface of the plate 5, it is enclosed from three sides.
That is, the protective shroud 9 divides the pilot combustion part 17 in the vicinity of the pilot nozzle short pipe 13 from the air flow A flowing in through the air intake hole 5a. Mixing of the pilot combustion air flow A flowing in from the inlet hole 5b and the pilot combustion fuel gas F ejected from the pilot nozzle hole 12a is performed stably without being affected by the burner combustion air flow A. .
[0030]
Further, the gaps G and G ₀ for ejecting the air flow A ₁ formed between the manifold 3 in the vicinity of the pilot combustion part 17 and the cover plate 6 are closed by the gap sealing plate 10.
As a result, the air flow A ejected through the gaps G and G ₀ is prevented from flowing directly into the pilot combustion section 17, thereby the pilot combustion fuel gas F and the pilot combustion fuel in the pilot combustion section 17 are prevented. Mixing with the air A is performed more stably.
[0031]
In addition, since the operation | movement itself of the said gas burner apparatus B is the same as the operation | movement of the conventional gas burner apparatus, the description is abbreviate | omitted here.
Also, the outer diameter and length of the draft tube 1 in the embodiment shown in the figure, the outer diameter and length of the inner tube 3a and the outer tube 3b forming the manifold 3, and the air of the short tube 13 with a pilot nozzle. projecting distance from the ring plate 5, the gap G, the size of G _0, the number and the height of the protective shroud 9, the range of the pilot combustion section 17 which surrounds the protective shroud 9, each of the air inlet holes 5a, 5b, The inner diameter and the like such as 6a are appropriately selected according to the capacity of the gas burner device B.
Furthermore, in the embodiment shown in the figure, the draft tube 1 and the manifold 3 are formed in a cylindrical shape, but it is needless to say that the shape may be other than a cylindrical shape, for example, a rectangular tube shape.
[0032]
【The invention's effect】
In the present invention, the periphery of the short pipe 13 with pilot nozzle of the premixed pilot burner P protruding forward from the air ring plate 5 is a protective enclosure slightly longer than the protruding length of the short pipe 13 with pilot nozzle. In addition to being surrounded by the plate 9, the manifold 3, the lid plate 6, and the gaps G and G ₀ in the vicinity of the pilot nozzle short tube 13 are sealed by the gap sealing plate 10.
As a result, the mixing of the pilot combustion fuel gas F and the pilot combustion air A in the pilot combustion portion 17 of the premixed pilot burner P can be stably performed without being influenced by the main combustion air flow A. Therefore, a more stable pilot flame can be formed.
[0033]
Further, since the adjustment work required for the operation of the pilot burner P is mainly only the adjustment of the supply amount of the pilot combustion fuel gas F, the labor required for the adjustment is greatly increased as compared with the former original mixed pilot burner. In addition, the ignition failure and the pilot flame are extremely less likely to become unstable.
[0034]
Further, the number of parts forming the pilot burner P is significantly reduced as compared with the case of the original mixed pilot burner, and as a result, the manufacturing cost of the gas burner device B can be reduced.
As described above, the present invention has excellent practical utility.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view in which a part of a gas burner device including a premixed pilot burner according to an embodiment of the present invention is omitted.
FIG. 2 is an easy view in which a part of FIG. 1 is omitted.
FIG. 3 is an enlarged view of a portion A in FIG.
FIG. 4 is a partially enlarged longitudinal sectional view showing a main part of a premixed pilot burner.
FIG. 5 is a view as seen from FIG.
FIG. 6 is a longitudinal sectional view of a conventional former mixed pilot burner.
7 is a view as seen from the easy view of FIG. 6;
[Explanation of symbols]
B is a gas burner device, M is a main gas burner, P is a premixed pilot burner, F is fuel gas, A is air, G · G ₀ is a gap, 1 is a draft tube, 1a is a back plate, 2 is an air supply pipe, 3 is a manifold, 3a is an inner pipe, 3b is an outer pipe, 3c is a rear end plate, 3d is a gas nozzle hole, 3e is a front end plate, 4 is a fuel gas supply pipe, 5 is an air ring plate, and 5a is an air intake for combustion. Inlet 5b is an air inlet for pilot burner, 6a is an air inlet, 7 is a cover plate support, 8a is a first air passage, 8b is a second air passage, 9 is a protective shroud, and 10 is a gap. A sealing plate, 12 is a fuel supply pipe for a pilot burner, 12a is a pilot nozzle hole, 13 is a short pipe with a pilot nozzle, 14 is an ignition rod, 15 is a frame rod, 16 is a ground rod, and 17 is a pilot combustion section.

Claims (4)

A cylindrical draft tube to which combustion air is supplied from one side, and a fuel gas which is disposed in the draft tube and which is supplied from one side, is radially ejected from a gas nozzle hole provided on the outer wall surface of the tip. A double cylindrical manifold and an air ring that is located behind the gas nozzle hole and is disposed between the draft tube and the manifold and has a combustion air intake hole that communicates with the first air passage outside the manifold. A plate, a lid plate fixed to the front surface of the double cylindrical manifold with a front end face and a gap, and having an air intake hole communicating with the second air passage inside the manifold at the center, the first plate A fuel supply pipe is installed in the air passage, and the tip of the short pipe with pilot nozzle is inserted through the air ring plate and protrudes forward. A premixed pilot comprising a protective shroud that surrounds at least three sides of a short pipe with a pilot nozzle protruding forward, and a gap sealing plate that closes a gap in the vicinity of the short pipe with a pilot nozzle Gas burner device with a burner. 2. A gas burner apparatus equipped with a premixed pilot burner according to claim 1, wherein the protruding length of the protective enclosure plate from the air ring plate is larger than the protruding length of the short pipe with pilot nozzle. 2. A gas burner apparatus having a premixed pilot burner according to claim 1, wherein the draft tube and the manifold are respectively formed in a cylindrical shape and a double cylindrical shape, and both are arranged concentrically. The length of the inner pipe forming the manifold is made larger than the length of the outer pipe, and the gap between the front end surface of the outer pipe and the inner side surface of the lid plate is larger than the gap between the front end surface of the inner pipe and the inner side surface of the lid plate. A gas burner apparatus comprising the premixed pilot burner according to claim 1, which is configured as described above.

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