JPH0144884Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical background of the invention] Figure 3 shows the schematic configuration of the entire pulse combustion device forming a radiant tube burner.
is a cylindrical outer cylinder with a bottom. The open end surface of this outer cylinder 1 is connected to the open end surface of an exhaust chamber constituent member 2 having a cylindrical shape with a bottom. Furthermore, an inner cylinder 3 is inserted into the outer cylinder 1 and the exhaust chamber constituent member 2, and is arranged concentrically with the outer cylinder 1. One open end of the inner cylinder 3 is extended near the closed end of the outer cylinder 1, and the other open end is connected to an external connecting pipe through an opening formed at the center of the closed end of the exhaust chamber component 2. It is connected to 4. Further, an air flapper valve mechanism 5 is connected to the other end of the connecting pipe 4. Also,
A tail pipe part 6 with a reduced diameter is formed on the closed end side of the outer cylinder 1 in the inner cylinder 3, and an exhaust passage 7 communicating with the tail pipe part 6 is formed between the outer cylinder 1 and the inner cylinder 3. is formed. Further, a support plate 10 having a spark plug 8 and a fuel injection part 9 projecting thereon is fitted in the middle part of the inner cylinder 3 where the pipe diameter is not narrowed, and the support plate 10 and the tail pipe part 6 are connected to each other. The interior of the inner cylinder 3 in between is used as a combustion chamber 11 for pulse combustion. Further, a fuel supply pipe 1 is provided in the fuel injection part 9 of the support plate 10.
2 and a fuel flapper valve mechanism 13 disposed outside the inner cylinder 3 are connected to each other. A plurality of air injection holes are formed around this fuel injection part 9. Further, an inner cylinder 4 and a fuel supply pipe 1 are provided between the support plate 10 and the air flapper valve mechanism 5.
An air supply passage 14 is formed between the combustion chamber 2 and the combustion chamber 2 for supplying air that has passed through the air flapper valve mechanism 5 to the combustion chamber 11 side. Further, the spark plug 8 is connected to an ignition device 16 outside the inner cylinder 3 via a lead wire 15.

On the other hand, the air flapper valve mechanism 5 includes a valve case 17 and a base plate 1 disposed inside the valve case 17, as shown in FIGS. 4 and 5.
8. Backer plate 19 and valve seat 2
It is formed by each component such as 0 and the like. Further, a spacer 21 is interposed between the base plate 18 and the backer plate 19, and the backer plate 1
9 are attached to the base plate 18 with a spacer 21 interposed therebetween so as to face each other at a distance. Further, a plurality of supply holes 22 are formed around the spacer 21 on the plate surface of the base plate 18, and a plurality of pressure propagation holes 23 are formed around the spacer 21 on the plate surface of the backer plate 19. There is. Further, the valve seat 20 is disposed between the base plate 18 and the backer plate 19, and the supply holes 22 of the base plate 18 are opened and closed by the valve seat 20 as the pressure inside the combustion chamber 11 fluctuates. It's becoming like that. Further, a combustion fan 24 is connected to the air flapper valve mechanism 5. In addition, the fuel flapper valve mechanism 13
The air flapper valve mechanism 5 has substantially the same structure as the air flapper valve mechanism 5 described above, and the supply hole in the base plate is opened and closed by a fuel valve seat (not shown) as the pressure within the combustion chamber 11 fluctuates. When the main body of the apparatus is started, the combustion air sent out by the combustion fan 24 is introduced into the combustion chamber 11 through the air flap valve mechanism 5, the air supply path 14, and the air jet hole of the support plate 10, and at the same time, the fuel flap valve The fuel gas introduced into the fuel supply pipe 12 through the mechanism 13 is injected in a direction substantially perpendicular to the direction of air flow in the air passage 25 around the fuel injection part 9 (in the radial direction of the inner cylinder 3), Air and fuel are mixed, and the mixture of air and fuel is ignited by a spark plug 8 to cause explosive combustion within a combustion chamber 11. Furthermore, since the pressure within the combustion chamber 11 rapidly increases due to this explosive combustion, the valve seat 20 of the air flapper valve mechanism 5 and the valve seat of the fuel flapper valve mechanism 13 are pressed against the base plate 18, and the supply hole of the base plate 18 is pressed. 22... to stop intake of air and fuel. moreover,
Both air and fuel flapper valve mechanisms 5, 13
When the combustion chamber 11 is closed, the combustion gas in the combustion chamber 11 expands toward the tail pipe section 6, and flows from the tail pipe section 6 to the exhaust passage 7, the exhaust chamber 26 formed between the exhaust chamber component 2 and the inner cylinder 3, and this It flows out at high speed through an exhaust pipe 27 connected to an exhaust chamber 26. Then, the pressure inside the combustion chamber 11 rapidly decreases to negative pressure due to the outflow of combustion gas, so that the valve seat 20 of the air flap valve mechanism 5 and the valve seat of the fuel flap valve mechanism 13 are separated from the base plate 18. Then, the supply holes 22 are opened, and air and fuel are sucked into the combustion chamber 11 again. in this case,
A portion of the high-temperature combustion gas on the side of the tail pipe 6 also flows back into the combustion chamber 11, so the mixture of air and fuel taken into the combustion chamber 11 is either the combustion gas flowing back into the combustion chamber 11, or the high-temperature combustion gas flowing back into the combustion chamber 11. When it comes into contact with the inner wall surface of the combustion chamber 11, it is ignited and explosive combustion occurs again.
Thereafter, similar operations are performed to repeat the explosion and combustion of the air-fuel mixture in the combustion chamber 11 in a pulsed manner, and the combustion fan 24 and spark plug 8 are no longer needed after starting.

[Problems with background technology]

Since each air ejection hole of the support plate 10 is parallel to the flow direction of the air flowing in the air passage 25 around the fuel ejection part 9, the air passes through the air flapper valve mechanism 5 during pulse combustion and is connected to the air supply path. 14
The speed of air ejected from the support plate 10 to the air passage 25 side through each air ejection hole was relatively high. Therefore, since the flow velocity of the air flowing around the fuel injection part 9 had become faster, the mixing time with the fuel gas ejected from the fuel injection part 9 was relatively short, and the degree of mixing between air and fuel was likely to deteriorate. There was a problem that the concentration of exhaust gas (particularly CO concentration) after pulse combustion increased.

In addition, as in Japanese Patent Application Laid-Open No. 58-104407, a swirling device formed by a plurality of blades is attached to the wall of the mixing chamber on the upstream side of the combustion chamber to swirl the air-fuel mixture flowing into the combustion chamber. A device that improves the degree of mixing with combustion gas has been proposed, but in this case, after mixing air and fuel gas, this mixture is swirled by a swirling device, so the mixing ratio is improved. In addition to the problem of high air flow resistance, the swirling device is heated by the flame during explosive combustion, which increases the combustion speed and causes flashback to the mixing chamber, which can lead to ignition and explosion within the mixing chamber. There were also problems that arose.

[Purpose of invention]

This device is a pulse combustion device that can improve the mixing degree of combustion air and fuel, reduce the CO concentration in exhaust gas, and eliminate the risk of increasing the flow resistance of the air-fuel mixture. The purpose is to provide the following.

[Summary of the idea]

The fuel injection device is characterized in that an air vortex forming member for swirling the air flowing in the air passage around the fuel injection portion is provided on the upstream side of the fuel injection portion.

[Example of idea]

FIGS. 1 and 2 show an embodiment of this invention. Note that FIG. 1 shows a schematic configuration of the vicinity of the fuel injection part 9 of the pulse combustion device shown in FIG. 3, and the same parts in FIGS. 1 and 2 as in FIGS. The same reference numerals are given and the explanation thereof will be omitted. That is, this invention is characterized in that an air vortex forming member 32 for swirling the air flowing in the air passage 25 around the fuel injection part 9 is provided on the upstream side of the fuel injection part 9. As shown in FIG. 2, this air vortex forming member 32 has a fuel passage 34 formed in the center of a thick disk-shaped main body 33. Further, a plurality of guide grooves 35 are formed along the circumferential direction on the peripheral edge of the main body 33. These guide grooves 35... penetrate between both plate surfaces 33a and 33b of the main body 33, and
It is formed in an inclined state with respect to the thickness direction of No. 3. By fitting the main body 33 into the inner cylinder 3, the guide holes 31 are formed between the inner surface of the inner cylinder 3 and each guide groove 35.
In addition, the fixed wing portions 36 formed by the partition walls between the guide holes 31 are formed to have the same width dimension from the upstream side to the downstream side with respect to the air flow direction, or have a shape that is formed with the same width dimension from the upstream side to the downstream side with respect to the air flow direction, or The guide hole 31 is formed in a shape that is tapered on the side.
The passage area is the same from the upstream side to the downstream side, or the passage area gradually decreases as it goes toward the combustion chamber 11 side. Furthermore, the total opening area of the opening ends of these guide holes 31 on the combustion chamber 11 side, that is, the area of the combustion air outlet, is such that when the combustion gas in the combustion chamber 11 flows backward toward the air flapper valve mechanism 5 side, the air It is formed to a size necessary to transmit enough pressure to operate the valve seat 20 of the flapper valve mechanism 5.

Therefore, in the case of the above structure, the air vortex forming member 32 is provided upstream of the fuel jetting part 9, and the fuel jetting part 9
Since a plurality of guide holes 31 for forming an air vortex are provided, which are inclined with respect to the flow direction of the air flowing in the air passage 25 around the The supplied combustion air flows through the air vortex forming member 3
When passing through each of the two guide holes 31 . . . , the direction of the flow of combustion air can be directed in the direction of inclination of each guide hole 31 . Therefore, the combustion air jetted from each guide hole 31 of the air vortex forming member 32 to the air passage 25 side around the fuel jetting part 9 can be swirled around the fuel jetting part 9,
Since the fuel gas ejected perpendicularly from the fuel injection part 9 can be mixed into this air vortex, the mixing time of the air flowing around the fuel injection part 9 and the fuel gas can be made longer than in the past. This makes it possible to improve the degree of mixing of air and fuel gas. Therefore, the combustion state of pulse combustion can be improved, and the concentration of exhaust gas (particularly CO concentration) after pulse combustion can be lowered compared to the conventional method. In addition, before mixing the air and fuel, a vortex is formed only in the air, and the fuel gas is drawn into this air vortex to mix the air and fuel gas, and a swirling device is installed in the mixture passage. Since there is no provision of a swirling device in the air-fuel mixture passage, there is no possibility that the flow resistance of the air-fuel mixture becomes high as in the case where a swirling device is provided in the air-fuel mixture passage. Furthermore, the fixed blade portions 36 of the air vortex forming member 32 have either a shape that is formed to have the same width dimension from upstream to downstream in the air flow direction, or a shape that is tapered on the upstream side compared to the downstream side. The passage area of each guide hole 31 is the same from the upstream side to the downstream side, or the passage area gradually becomes smaller as it goes toward the combustion chamber 11 side. 31...
It can smooth the air flow inside. In addition, the total opening area of the opening end on the combustion chamber 11 side of each guide hole 31 operates the valve seat 20 of the air flap valve mechanism 5 when the combustion gas in the combustion chamber 11 flows backward toward the air flap valve mechanism 5 side. Since the air-flutter valve mechanism 5 is formed to a size necessary to transmit the pressure of
The backflow of combustion gas to the side can be suppressed to the necessary minimum. Therefore, most of the combustion gas can be expanded toward the tail pipe portion 6 side, and the thermal energy of the combustion gas can be effectively utilized, so that thermal efficiency can be improved.

It should be noted that this invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of this invention.

[Effect of idea]

According to this invention, an air vortex forming member that swirls the air flowing in the air passage around the fuel injection part is provided on the upstream side of the fuel injection part, so that the degree of mixing of combustion air and fuel is improved. This improves the combustion conditions of pulse combustion and reduces CO in exhaust gas.
In addition to being able to lower the concentration, pulse combustion can also be stabilized without the risk of increasing the flow resistance of the air-fuel mixture.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of this invention. Figure 1 is a vertical cross-sectional view showing a schematic configuration near the fuel injection part in a pulse combustion device, and Figure 2 is a line taken along the line - in Figure 1. The sectional views and FIGS. 3 to 5 show conventional examples. FIG. 3 is a longitudinal sectional view showing the schematic structure of the entire radiant tube burner, and FIG. 4 is a longitudinal sectional view showing the schematic structure of the air flapper valve mechanism. , FIG. 5 is a partially cut away cross-sectional view of the air flapper valve mechanism. 9...Fuel injection part, 11...Combustion chamber, 25...
Air passage, 32... air vortex forming member.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A combustion chamber for pulse combustion, an air passage that communicates with the upstream side of this combustion chamber and supplies air to the combustion chamber, and a combustion chamber formed approximately in the center of this air passage. A fuel injection part that injects fuel in a direction substantially perpendicular to the direction of air flow, and an air vortex formed in an air passage in the upstream outer circumference of this fuel injection part to swirl the air flow sent to the fuel injection part side. A pulse combustion device characterized by comprising a forming member. (2) The air vortex forming member includes a plurality of guide holes for forming an air vortex formed at an angle with respect to the air flow direction of the air passage, and a fixed wing portion formed by a partition wall between each guide hole. A claim for utility model registration characterized in that the shape has the same width from the upstream side to the downstream side in the direction of air circulation, or the upstream side is tapered compared to the downstream side. Pulse combustion equipment as described in scope item (1).