JP2001090914A - Flame trap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frame trap in which an opening area per cell of each vent hole is reduced, and a total opening rate can be increased, and it is strong against impact and in which assembling work is facilitated. SOLUTION: A metal foil tape is joined with a tape surface comprising a metal foil like stainless steel in a corrugated manner, and is constructed of a spirally wound coil structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a frame trap.

[0002]

2. Description of the Related Art A pulse combustor for obtaining a combustion gas by sending a mixture of fuel gas and air to a combustion chamber and repeating pulsating explosive combustion in the combustion chamber is well known. For example, FIG. 6 shows an overall cross-sectional view of a pulse combustor, and FIG. 7 shows an enlarged cross-sectional view of a main part of the pulse combustor. A trap 34 is provided. The fuel gas introduced through the gas pipe 35 and the gas chamber 36 and the air introduced through the blower fan 37 and the air supply chamber 38 are mixed in the mixing chamber 33, and the air-fuel mixture is Through a number of vents (hereinafter referred to as “cells”) 39, 39.
The combustion gas generated by the explosive combustion in the combustion chamber 32 is discharged to a discharge port 40 provided in the combustion chamber 32.
Thus, it is sent out to a tail pipe (not shown). And
Due to the negative pressure of the combustion chamber 32 generated at that time, an air-fuel mixture of fuel gas and air is again introduced from the mixing chamber 33 into the combustion chamber 32 through the cells 39, 39... Explosive combustion is repeated by the return fire of.

[0003] As the frame trap 34 used in this pulse combustor, for example, a frame trap shown in FIG. 8 is generally known. That is, the frame trap 34 shown in FIG. 8 is formed of a heat-resistant porous plate made of a ceramic material.
41 are formed in large numbers.

[0004]

However, according to the frame trap of the porous plate made of a ceramic material shown in FIG. 8, the thickness of the ceramic wall between the cells 41, 41... In addition, the flame trap not only rectifies the air-fuel mixture flowing into the combustion chamber, but also prevents backfire (flashback) from the combustion chamber to the mixing chamber. It can be said that the smaller the opening area of each of the cells 41 is, the better the opening area is.

[0005] For this reason, the flame trap has a poor flashback prevention property during combustion, and the combustion property (CO / CO /
There was also a problem in terms of performance as a pulse combustor whose CO ratio was not good. Since the high-load combustion of the pulse combustor itself cannot be achieved due to this, there is also a problem that the size cannot be reduced. Furthermore, according to the frame trap made of the ceramic material, since the frame trap is weak in impact, it may be damaged by hitting parts or the like when assembling to the pulse combustor, and the fragments may block the ventilation holes. Therefore, there was also a problem in assembling to the pulse combustor.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to reduce the area of each ventilation hole per cell and to reduce the total number of holes. An object of the present invention is to provide a frame trap that can increase the rate and is resistant to impact and easy to assemble.

[0007]

In order to achieve this object, a frame trap according to the present invention comprises a tape made of a metal foil such as stainless steel and a tape made of the same metal foil joined in a wavy shape and wound in a spiral shape. The gist of the invention is that it is composed of a mainspring.

The frame trap of the present invention having the above-described structure is formed by winding a metal foil tape on a metal foil tape surface in the same manner as a metal foil tape and then winding the tape in a spiral shape. The opening area per cell of the vent formed by the corrugation can be reduced, and the total aperture ratio can be increased. Moreover, it is strong against impact, so it will not be damaged when assembled.
Therefore, the air holes are not blocked by the debris.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pulse combustor equipped with a frame trap according to an embodiment of the present invention will be described below in detail with reference to the drawings. First, since the pulse combustor of the present embodiment has many parts in common with the conventional one described above, FIG. 6 showing the entire cross section of the preceding pulse combustor and an enlarged cross section of the main part thereof are shown in FIG. This will be described in more detail with reference to FIG.

The pulse combustor 31 includes a gas chamber 3
6 and a mixing chamber 33 provided therein, and an air supply chamber 38 composed of a box formed in a closed state, a blower fan 37 for introducing air into the air supply chamber 38, and a communication with the mixing chamber 33. And the combustion chamber 32 fixed to the outer wall of the air supply chamber 38. The gas chamber 36 is formed by a closed container, and a gas pipe 35 is provided in communication with the outside of the air supply chamber 38.

On the other hand, in the gas chamber 36, as shown in FIG. 7, a nozzle cylinder 42 is attached and fixed to the tip of a protruding gas lead-out short cylinder 41, and the gas nozzle table 4
3 is provided, and the tip of the gas nozzle table 43 is connected to the mixing chamber 33. A vent hole 42a is formed at the tip of the nozzle cylinder 42, and a gas check valve 44 is provided to prevent the fuel gas passing through the vent hole 42a from flowing back. A gas distributor 45 having vent holes 45a formed on multiple sides is attached to the tip of the gas nozzle table 43 which is connected and located in the mixing chamber 33 so as to diffuse the fuel gas into the mixing chamber 33.

On the outer wall of the mixing chamber body 28 forming the mixing chamber 33, a ventilation hole 46 through which air introduced into the air supply chamber 38 flows is formed along the outer periphery of the gas nozzle table 43. In the mixing chamber 33, an air plate 47 is provided so as to face the outer wall in which the ventilation hole 46 is formed.
Is fitted. Also in this air plate 47, small-diameter ventilation holes 47a are formed at equal intervals on the same circumference, and an air check valve 48 is provided for the ventilation holes 47a.

On the other hand, the flame trap 1
The combustion chamber 32 communicated through the hole has a circular cavity. In the combustion chamber 32, an air-fuel mixture inlet 25 through which air-fuel mixture flows from a tangential direction of the circular cavity.
And a discharge port 40 for discharging the combustion gas in the direction perpendicular to the inflow surface of the air-fuel mixture. In addition, the mixed air inlet 25
In order to prevent the combustion flame from wrapping around, the tip is slightly exposed, and a plug 49 is provided below the tip.

Next, a frame trap which is a feature of the present invention will be described. Here, FIG. 1 is a perspective view of the frame trap, FIG. 2 is a plan view of the frame trap, and FIG. 3 is a perspective view showing a state in the process of manufacturing the frame trap. This frame trap 1
On one surface of a base tape 2 made of one long stainless steel foil, a corrugated tape 3 also made of one long stainless steel foil is joined in a regular wave form as shown in the figure, As a result, one frame trapping tape 4 having the corrugated surface A formed on one surface of the base tape 2 is formed.

The frame trapping tape 4 has a length of 0.05 mm and a width of 13 mm. Then, such a frame trapping tape 4 is wound in a spiral shape (spiral shape) with the wave surface A inside as shown in FIG. 3, and the wound tape material is brazed in a brazing furnace. Is performed, the frame trap 1 is formed. At this time, the frame trapping tape 4 has a wavefront A having a period of 2.2 mm and a height of 1.3 mm joined to the base tape 2, and the frame trap 1 has a large number of windings of the tape 4. , Its outer diameter is 90 mm. Further, as shown in FIG. 2, a number of ventilation holes (hereinafter, referred to as "cells") 5, 5...

The dimensions of the frame trap 1 according to the present embodiment are determined by the following experimental results in order to achieve high load pulse combustion. Here, FIG. 4 is a diagram showing the relationship between the total opening ratio of each ventilation hole (cell) of the frame trap and the input amount of fuel gas, and FIG. 5 shows the relationship between the opening area per frame trap cell. FIG. 4 is a diagram showing a relationship with a fuel gas input amount.

First, from FIG. 4, when the air-fuel mixture is supplied from the mixing chamber 33 into the combustion chamber 32 while increasing the opening ratio, as shown in FIG. While showing a constant value irrespective of the change, as shown in the graph (b), the input amount of the fuel gas rapidly increased around about 75%. Therefore, since it is necessary to supply a large amount of fuel gas in order to perform high load pulse combustion, it is understood that it is desirable to set the opening ratio of the frame trap to 75% or more.

Next, based on the above results, an experiment was conducted according to FIG. 5 with the aperture ratio of the frame trap set to 75% and 90%. According to this, when the aperture ratio is 75%, the area per cell of the frame trap is 2.8 mm.
Around the time, the input amount of fuel gas starts to decrease due to the flashback and the opening ratio is 90%,
It can be seen that the area per cell starts to decrease around 2.6 mm 2.

Therefore, based on this result, when the opening ratio of the frame trap is 75% or more, in order to supply a stable amount of fuel gas without being affected by flashback, the opening area of the frame trap must be reduced. It has been found that it is desirable to set the thickness to 2.25 mm ² or less. From the above results, when designing a flame trap for performing high-load pulse combustion, the opening area of the flame trap was set to 2.25 mm ^2.
It is desirable that the aperture ratio be 75% or less.

The pulse combustor according to the present embodiment having such a structure operates as follows. In the pulsating explosive combustion by the pulse combustor, first, the fuel gas is supplied to the gas chamber 36 through the gas pipe 35 and is equalized in the gas chamber 36. Then, the equalized fuel gas is supplied to the vent hole 42a of the nozzle cylinder 42 in the gas nozzle table 43.
Through the gas distributor 45, and flows out of the vent hole 45 a in multiple directions in the mixing chamber 33.

On the other hand, the combustion air supplied into the air supply chamber 38 by the blower fan 37 is pressure-equalized in the air supply chamber 38 and flows into the mixing chamber body 28 from the ventilation hole 46. The air that has flowed into the mixing chamber 28 is mixed with the mixing chamber 33 through an air plate 47 ventilation hole 47a.
Supplied within. In this way, the air and the fuel gas supplied into the mixing chamber 33 are mixed in the mixing chamber 33 to form an air-fuel mixture. After passing through the flame trap 1, the air-fuel mixture is supplied from the air-fuel mixture inlet 25 to the combustion chamber 32.

In the early stage of combustion, the air-fuel mixture explodes and burns under the forced supply of the air-fuel mixture to the combustion chamber 32 and the forced ignition by the plug 49. After a lapse of time, the rotation of the blower fan 37 is stopped. The cycle of air supply, explosion combustion, expansion, and exhaust based on self-inhalation due to the negative pressure and self-ignition due to exhaust heat, for example, is continuously spontaneously fired while repeating about 80 to 100 times per second, The combustion gas is discharged from the discharge port 40 of the combustion chamber 33 every cycle.

By the way, in the flame trap 1 of the present embodiment, when flowing from the mixing chamber 33 to the combustion chamber 32,
A large amount of air-fuel mixture equalized in the mixing chamber 33 is rectified by passing through the uniformly formed cells 5, 5,. On the other hand, in the flame trap 1 of the present embodiment, the combustion gas explosively combusted in the combustion chamber causes backfire to the mixing chamber, and the combustion gas causing the backfire has a small cross-sectional area of 2.25 mm ² or less. When passing through the cells 5, 5,... Of the area, the movement in the direction of the mixing chamber 33 is lost, and the supply amount of the air-fuel mixture to be supplied to the combustion chamber 32 is prevented from decreasing.

According to the frame trap 1 of the present embodiment having the above-described configuration, the cross-sectional area per cell is reduced, so that the flashback preventing property at the time of combustion is enhanced, and accordingly, the flammability (CO / CO) is reduced. Ratio) was improved and the performance as a pulse combustor was improved, so that high-load combustion of the pulse combustor itself was achieved. In addition, since the cross-sectional area per cell can be reduced and the aperture ratio can be increased, the frame trap 1 can be designed to be compact.
Accordingly, the pulse combustor itself can be made more compact. Furthermore, according to the frame trap made of stainless steel, since it is strong in impact resistance, it does not break even when hitting parts or the like when assembling to the pulse combustor. No more rubbing, eliminating the problem of assembling the pulse combustor.

The present invention is not limited to the above embodiment, and it goes without saying that various design changes and improvements can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, even if the opening shape of the tape joined in a sine wave shape is a triangular wave shape or a rectangular wave shape, it is included in the present invention.

[0026]

The frame trap of the present invention is formed by joining a tape made of a metal foil to a tape surface made of a metal foil such as stainless steel in a wavy shape and winding it in a spiral shape. While the hole area is reduced, the total aperture ratio can be increased. Moreover, since the material is made of a metal foil material instead of the conventional fragile ceramic material, it is strong in impact resistance, does not break when assembled, and does not block the ventilation holes with debris. . As a result, the assembling work is facilitated, and the productivity is also improved.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a frame trap of a pulse combustor according to one embodiment of the present invention.

FIG. 2 is a plan view of the frame trap shown in FIG.

FIG. 3 is a view for explaining a manufacturing process of the frame trap shown in FIG. 1;

FIG. 4 is a diagram for explaining the effect of the opening ratio of the frame trap on the combustion efficiency of pulse combustion, and shows the relationship between the opening ratio of the frame trap and the input amount of fuel gas.

FIG. 5 is a diagram illustrating the effect of the size of the opening area per cell of the vent hole of the frame trap on pulse combustion;
It shows the relationship between the opening area per cell of the vent hole of the frame trap and the input amount of combustion gas.

FIG. 6 is a cross-sectional view showing a schematic configuration of a conventionally known pulse combustor.

FIG. 7 is an enlarged sectional view showing a main part (frame trap portion) of the pulse combustor shown in FIG. 6;

8 is a perspective view showing a generally known configuration of a frame trap in the pulse combustor shown in FIGS. 6 and 7. FIG.

FIG. 9 is an enlarged view of the frame trap shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 frame trap 2 base tape 3 corrugated tape 4 frame trap tape 5 cell (vent) 31 pulse combustor 32 combustion chamber 33 mixing chamber 36 gas chamber 38 air supply chamber 40 outlet

Claims (1)

[Claims] 1. A tape made of a metal foil such as stainless steel is joined to a tape surface made of a metal foil like a wave, and
A frame trap comprising a mainspring wound in a mainspring shape.