JPH0584404B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a combustion method in which the flame front propagates by continuously repeating the cycles of air supply and exhaust, ignition, combustion, and extinguishing within a tubular combustion chamber. Regarding combustion equipment.

[Prior Art] A conventional propagation combustion device of this type is shown, for example, in FIGS. 9 to 16 as an ignition heat source P' disposed adjacent to a tip ignition site B' of a tubular combustion chamber 1'. In this case, one heater 2' is inserted and installed in the center of the cross section of the tubular combustion chamber 1' (see Figures 9 to 12), and a pair of igniter rods (electrodes) 4' are inserted into the tubular combustion chamber 1'. The one inserted in the center of the cross section of 1' and placed oppositely with a slight gap (No. 13)
(see Figures 15 and 14), or a series of heaters 3' bent into an inverted U shape and inserted almost to the center of the cross section of the tubular combustion chamber 1' (see Figures 15 and 1).
(See Figure 6).

[Problems to be Solved by the Invention] In propagating combustion, it is preferable for the flame front to propagate uniformly to each part of the inner circumferential wall of the tubular combustion chamber in terms of combustion efficiency.
In all of the above-mentioned conventional techniques, since local ignition occurs, the shape of the flame collapses and the flame is significantly distorted (see flame a' in Figure 9), making it impossible for the flame to spread uniformly to each part of the inner circumferential wall of the tubular combustion chamber. It was hot. The current situation is to deal with this problem by uniformly mixing the fuel gas and combustion air or by making the flow velocity distribution of the flame flow uniform.

This invention has been made in view of the problems of the prior art,
The air-fuel mixture at the tip ignition position of the tubular combustion chamber can be ignited over the entire surface to form an even flame that does not lose its shape (see flame a in Figure 1), resulting in uniform flame propagation. The purpose is to provide a propagation combustion device that improves combustion efficiency.

[Means for Solving the Problems] In order to achieve the above object, the propagation combustion device according to the present invention continuously repeats the cycle of supplying and exhausting air, ignition, combustion, and extinguishing in the tubular combustion chamber to reduce the flame front. In the propagation combustion apparatus of the combustion type in which the air-fuel mixture is propagated, the invention of claim 1 is characterized in that the ignition heat source is configured by distributing heaters, etc. almost uniformly over the cross section of the tubular combustion chamber, so that the entire surface of the air-fuel mixture is heated. This made it possible to ignite.

Further, in the invention of claim 2, the ignition heat source is constituted by arranging several heaters arranged at approximately equal intervals with respect to the cross section of the tubular combustion chamber, and in the invention of claim 3, the ignition heat source is constituted by a series of heaters arranged at approximately equal intervals with respect to the cross section of the tubular combustion chamber. In the fourth aspect of the present invention, the ignition heat source is arranged such that the ignition heat source is connected to a pair of heaters approximately at the center of the cross section of the tubular combustion chamber. They are arranged to intersect at right angles.

[Function] The propagation combustion device of the present invention configured as described above allows the air-fuel mixture to reach the tip ignition position of the tubular combustion chamber at the time of ignition during the continuous repetition of air supply and exhaust, ignition, combustion, and extinguishing. When the combustion chamber reaches its tip, it is ignited by an ignition heat source, but in the invention as claimed in claim 1, the ignition heat source includes heaters and the like distributed almost uniformly over the cross section of the tubular combustion chamber. Since the ignition heat source ignites the tip of the air-fuel mixture at the same time over the entire surface, the shape of the flame during combustion is averaged and the flame surface is shaped like a tubular combustion chamber. Propagates uniformly to the inner peripheral wall. In addition, in the invention described in claims 2, 3, and 4, since the heaters are arranged evenly over the entire surface of the cross section of the tubular combustion chamber at equal intervals, it is possible to reliably ignite the air-fuel mixture over the entire surface. It is something.

[Embodiments] Examples of the propagation combustion apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the entire propagation combustion device of the present invention.
A constricted part 5 is provided at the proximal extinguishing position A to rapidly change the velocity of the flame flow during extinguishing to create a barrier and ensure extinguishment, and one end is opened on the upstream side of the constricted part 5. A gas supply nozzle 7 is provided in the mixing chamber 6 through its opening, and a primary air intake port 8 is provided around the gas supply nozzle 7 so that the fuel gas and the combustion air are connected to each other. The mixture is mixed in a mixing chamber 6. Further, an ignition heat source P such as a ceramic heater is provided on the downstream side of the straight-tubular combustion chamber 1, that is, at the tip ignition position B, and an exhaust pipe 9 is provided on the downstream side of the ignition heat source P.
are connected in series to form a propagation combustion device. In addition,
In the above embodiment, the combustion chamber 1 is shaped like a straight tube, but
Of course, it is also possible to use a continuous tubular combustion chamber with a bend or the like in the middle.

Therefore, the invention as set forth in claim 1 constitutes the ignition heat source P by distributing ceramic heaters and the like almost uniformly over the cross section of the straight tube-shaped combustion chamber 1, and as a specific means thereof, In the present invention, as illustrated in FIGS. 1 and 2, there is provided an ignition heat source P in which several heaters (for example, three ceramic heaters) 2 are arranged at equal intervals l with respect to the cross section of a straight tube-shaped combustion chamber 1. None, the invention according to claim 3 is
As illustrated in FIG. 4 and FIG. 4, a series of heaters (for example, nichrome wire) 3 are bent in a spiral shape, and each bent piece 3a is arranged at the same interval l with respect to the cross section of the straight tube-shaped combustion chamber 1. In addition to the heat source P for
As illustrated in FIGS. 5 and 6, a series of heaters (for example, nichrome wire) 3 are continuously bent in parallel so that the distance l between each bent piece 3a is the same with respect to the cross section of the straight tube-shaped combustion chamber 1. Furthermore, the invention according to claim 4 provides a pair of heaters (for example, ceramic heaters) 4 arranged in the ignition heat source P, as illustrated in FIGS. 7 and 8. They intersect at right angles (cruciform shape) at the center and are arranged close together to form the ignition heat source P, which is uniformly distributed. In the embodiments of the invention described in claims 2 and 3 above, the interval l between each heater is optimally about 5 to 10 mm when the inner diameter of the straight combustion chamber 1 is 32 to 35 φ. However, if the spacing l between the heaters becomes too narrow, it will become a flame folder and the flame will not propagate smoothly.

Propagation combustion equipment consists of air supply and exhaust, ignition, combustion,
The extinguishing cycle is repeated continuously, and each part of the straight-tubular combustion chamber 1 is heated evenly by the flame surface propagating inside the straight-tubular combustion chamber 1 for each cycle, so that the surface temperature of each part is equal. Because of its uniform heating and extremely high thermal efficiency, it is extremely useful when used as a heating source for, for example, road heating, greenhouse cultivation, hydrological cultivation, etc., and its combustion mechanism is based on the gas supply nozzle 7. The fuel gas from the primary air intake port 8 and the combustion air from the primary air intake port 8 are mixed in the mixing chamber 6, and when the mixture is fed from the mixing chamber 6 through the constriction 5 into the straight tubular combustion chamber 1, mixing occurs. Air flows from the upstream side to the downstream side in the straight tube-shaped combustion chamber 1, and when the tip of the mixture reaches the tip ignition position B, it is ignited by the ignition heat source P, and the mixture starts burning from the tip side. The flame flow flows from the downstream side to the upstream side in the straight tube-shaped combustion chamber 1, performs flame propagation combustion, and evenly heats each part of the straight tube-shaped combustion chamber 1. When reaching part 5, a barrier is created in the narrowed part 5 to give a sudden change to the flow velocity of the flame flow to ensure extinguishment.
A flame propagation combustion operation is continuously performed in which the air supply operation moves to the next cycle and pushes the combustion exhaust gas in the combustion chamber 1 of the previous cycle downstream and releases it from the exhaust pipe 9 to the outside of the chamber. It is something to give back.
In the above series of flame propagation combustion operations, when the air-fuel mixture reaches the tip ignition position B of the straight tube-shaped combustion chamber 1, the tip is ignited by the ignition heat source P at the time of ignition. In this case, the ignition heat source P has a structure in which heaters and the like are distributed almost uniformly over the cross section of the straight tube-shaped combustion chamber 1, so that the ignition of the tip of the air-fuel mixture by the ignition heat source P is as simple as that. Since the combustion is carried out simultaneously over the entire surface without unevenness, the shape of the flame during combustion becomes bamboo shoot-like and is averaged (see flame a in Fig. 1), and the flame surface is uniformly distributed on the inner circumferential wall of the straight-tubular combustion chamber 1. propagate. Further, in the invention according to claim 2, several heaters 2 are arranged at equal intervals, and in the invention according to claim 3, a series of heaters 3 are bent and the intervals between the respective bent pieces 3a are arranged the same, Furthermore, in the invention set forth in claim 4, the pair of heaters 4 are arranged in a cross-section, and the heaters are evenly distributed over the entire surface of the cross section of the straight tube-shaped combustion chamber 1. It is possible to reliably ignite the whole surface.

[Effects of the Invention] Since the present invention is configured as described above, it has the following effects. Claim 1: A combustion type propagation combustion device in which a cycle of supplying and exhausting air, ignition, combustion, and extinguishing is continuously repeated in a tubular combustion chamber so that the flame front propagates.
In the described invention, since the ignition heat source is constructed by distributing heaters and the like almost uniformly over the cross section of the tubular combustion chamber, the mixture can be ignited uniformly and simultaneously over the entire surface during ignition. The shape of the flame during combustion becomes even, and the flame surface spreads uniformly to the inner peripheral wall of the tubular combustion chamber, and the high-temperature zone of the flame flow moves evenly in contact with each part of the peripheral wall, which equalizes heat conduction and improves temperature distribution. . Therefore, combustion efficiency is significantly improved.

Further, in the invention as claimed in claim 2, the ignition heat source is configured by arranging several heaters at approximately equal intervals with respect to the cross section of the tubular combustion chamber, and in the invention as claimed in claim 3, the ignition heat source is configured as a series of heaters. In the fourth aspect of the present invention, the ignition heat source is arranged such that the ignition heat source is arranged at the center of the cross section of the tubular combustion chamber. Since they are arranged close to each other so as to intersect at almost right angles, ignition of the entire air-fuel mixture can be ensured. Therefore, a flame with an even shape and no deformation can be formed, and raw gas and leakage are eliminated, improving ignitability.

[Brief explanation of the drawing]

1 to 8 show an embodiment of the invention according to claim 1 of the propagation combustion apparatus according to the present invention, and FIG.
The figure is an overall cutaway front view showing an embodiment of the invention as claimed in claim 2, FIG. 2 is a cutaway side view, and FIGS. 3 to 6 are main parts showing an embodiment of the invention as claimed in claim 3. 7 and 8 are cutaway front views and cutaway side views of only essential parts showing an embodiment of the invention according to claim 4, and FIGS. 9 to 16 are cutaway front views and cutaway side views. FIG. 2 is a cutaway front view and a cutaway side view showing a conventional example. 1...Tubular combustion chamber, P...Ignition heat source, 2,
3, 4...Heater.

Claims (1)

[Scope of Claims] 1. In a propagation combustion device using a combustion method in which the flame front propagates by continuously repeating the cycle of supplying and exhausting air, ignition, combustion, and extinguishing in a tubular combustion chamber 1, the heat source P for ignition is A propagation combustion apparatus characterized in that heaters and the like are arranged almost uniformly distributed over the cross section of the tubular combustion chamber 1. 2. The propagation combustion apparatus according to claim 1, wherein the ignition heat source P includes several heaters 2 arranged at approximately equal intervals with respect to the cross section of the tubular combustion chamber. 3. The propagation combustion apparatus according to claim 1, wherein the ignition heat source P is formed by bending a series of heaters 3 and arranging the bent pieces at substantially the same intervals with respect to the cross section of the tubular combustion chamber. 4. The propagation combustion apparatus according to claim 1, wherein the ignition heat source P includes a pair of heaters 4 arranged close to each other and intersecting each other at a substantially right angle at the center of the cross section of the tubular combustion chamber.