JPS6138771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a gas combustor for all secondary air combustion, which uses LPG gas with good performance such as uniform red heat transfer after ignition and CO/CO ₂ from ignition to stable combustion. It provides a combustor.

Gases have different combustion characteristics depending on the type of gas. In particular, with LPG, it is necessary to burn pure propane gas and pure butane gas, which has a heavy specific gravity and has a slow combustion speed compared to general city gas, and requires a large amount of combustion air per capacity. There is a problem in that it is very difficult to ignite the mixed gas and smoothly ignite the outer periphery of the outer flame tube, which will be described later. Moreover, since it is a new combustor, there is no one for LPG on the market. To explain the conventional example for city gas,
As shown in FIG. 1, an inner flame tube 1 and an outer flame tube 2 are fitted into a burner 3, and a heat-resistant glass 4 is placed on a heat shield tube 6 having a glass stopper 5. Inner flame tube 1 Outer flame tube 2
There is a lid 7, and a glass lid 8 is placed on the heat-resistant glass 4. Shitauke 9 under burner 3
The center rod 10 is passed through the center of the glass lid 8, the upper lid 7, and the cover 9, and the inner flame tube 1, the outer flame tube 2, the heat-resistant glass 4, the heat shield tube 6, etc. are kept concentrically. At the bottom, a spring 11, a washer 12, and a pin 13 are used to pull the center rod 10 downward, thereby elastically fixing the above-mentioned parts. 14 is a nozzle. In the above configuration, when comparing the lowermost positions of the inner flame cylinder combustion hole 15 and the outer flame cylinder combustion hole 16, the inner flame cylinder combustion hole 15 is at the same level or slightly lower. Further, the outer periphery of the outer flame cylinder 2 is made to have the same size and diameter.
The upper porosity of the outer flame tube combustion hole 16 is made large and the lower porosity is small. As described above, in the case of a gas lighter than air such as city gas, the gas ejected from the burner 3 immediately rises together with the premixing air from the lower air holes 17 and 18 of the inner flame tube 1 and the outer flame tube 2. The flame from the ignition burner (not shown) ignites in the outer flame tube combustion hole 16, and the area between the inner flame tube combustion hole 15 and the outer flame tube combustion hole 16, the outer flame tube combustion hole 16 part, and the outer periphery is ignited. to perform combustion. In the case of city gas, less air is needed for combustion compared to LPG, and combustion occurs well in the lower part of the outer flame tube combustion hole 16, so as mentioned above, the degree of opening of the outer flame tube combustion hole 16 is lower and slightly higher. The larger one was better. However, when LPG is burned, the gas specific gravity is heavier than air, so the rate of rise from burner 3 is slow. Furthermore, since air mixing from the premixing holes 17 and 18 is not sufficient, the premixed gas is not easily ignited by the flame from the ignition burner. Also, sometimes raw gas flows out of the pores 17, 18, mixes with the outside air, and even ignites the gas. Even if the premixed gas is ignited, there are cases where flame does not come out outside the combustion hole 16 of the outer flame tube. Sometimes even if it appears outside the combustion hole 16 of the outer flame tube,
1 to 1 for fire transfer from the upper part with large pores to the lower part.
It may take up to 2 minutes. Also, the outer flame tube 2 at the time of red heat
The difference in temperature between city gas and LPG is also different, with the highest temperature being at the bottom for the former and at the top for the latter, which requires improvement.

The present invention solves the above problems. Examples of the present invention will be described below. In FIG. 2, the inner flame tube 19 and the outer flame tube 20 are fitted into the burner 21, and the heat-resistant glass 22 is placed on a heat shield tube 24 having a glass stopper 23. Numeral 25 is a glass lid, 26 is a lid, and 27 is a cover. Each part is assembled concentrically with a center rod 28, and the center rod 28 is fixed with a spring 29, a washer 30, and a pin 31. 32 indicates a nozzle;
The lowest stage of the inner flame cylinder combustion vent 33 is located at a higher position than the lowest stage of the outer flame cylinder combustion vent 34. As shown in FIG. 3, the lowermost stage of the outer flame tube combustion vent 34 is opened above the convex band portion 35 of the outer flame tube 20. The upper and lower outer flame cylinder combustion holes 34 have a vertical pitch of B dimension.
The middle part is made so that B<A in dimension A, so the open area ratio is B part>A part. With the above configuration, even in LPG, the raw gas ejected from the burner 21 mixes with air from the lower premixing holes 36 and 37 of the inner flame tube 19 and the outer flame tube 20,
It ascends between the inner flame tube 19 and the outer flame tube 20, but the combustion holes 34 of the convex band 35 of the outer flame tube 20 are facing upward and are below the lowest stage of the inner flame tube combustion holes 33. Therefore, the premixed raw gas does not flow out from the inner flame cylinder combustion hole 33 to the inside of the inner flame cylinder, and since the degree of aperture of the convex band part 35 is large, the turbulent flow generated in the convex band part 35 easily It overflows to the heat-resistant glass 2 side, ignites from the flame of an ignition burner (not shown), and instantly spreads to the entire circumference of the convex band portion 35 of the outer flame cylinder 20.
Therefore, there is no explosion and ignition when the premixed raw gas is ignited inside the inner flame tube, making it safe. Next, the convex band portion 3
The outer flame cylinder 20 becomes red hot from the bottom to the top due to the flame near 5. When the top is red hot and the bottom is difficult to spread, as in the conventional case, unburned gas comes out from the bottom and the appliance cannot be used.
A large amount of CO is generated, and a large amount of ketones, which are permeation products of LPG combustion, are also emitted and the odor can be severe. However, in this embodiment, the convex band portion 35 is provided, and the porosity of the outer flame cylinder combustion hole 34 is increased.
The premixed gas is made to easily overflow near the convex band 35, and the amount of premixed gas overflowing from the outer flame tube combustion hole 34 is increased before other outer flame tube combustion holes 34 and inner flame tube combustion holes 33. This increases the amount of diffused combustion. Since LPG has a slow combustion speed, the red-hot part is located higher than that of ordinary city gas, which has a fast combustion speed. Therefore, the porosity of the pitch A part of the outer flame cylinder combustion hole 34 is reduced, increasing the red-hot area and emitting radiation. It improves efficiency and increases the heat transfer area.
It works to improve heat transfer between the four parts and reduce unevenness, and it also works to increase the area of the part that reaches the highest temperature to disperse the red-hot temperature and eliminate unevenness. Since there is insufficient premixed gas for diffusive combustion in the upper part of the outer flame tube 20, the aperture ratio is increased to raise the red-hot temperature.

As described above, when the present invention is used in a combustor for all secondary combustion, especially in a stove that is open to the public, it can ignite the flame of LPG, provide stable combustion with less CO/CO ₂ , and reduce unevenness in red heat, resulting in good radiation efficiency. You can get a combustor.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional combustor, FIG. 2 is a sectional view of a combustor according to an embodiment of the present invention, and FIG. 3 is a perspective view of an outer flame tube in the combustor. 19...Inner flame tube, 20...Outer flame tube, 22...Heat-resistant glass, 24...Heat shield tube, 33...Inner flame tube combustion hole, 34...Outer flame tube combustion hole, 35...Convex Obi.

Claims (1)

[Claims] 1. An inner flame tube in which a combustion hole is formed in the upper part and a premixing hole is formed in the lower part with a space between the combustion hole and the combustion hole in the lower part. The outer flame includes an outer flame tube in which a premixing air hole is formed with a gap from the combustion hole, and a cylinder arranged around the outer periphery of the outer flame tube and made of a heat-resistant, heat-transmitting material and a heat shield tube. The lowest hole of the combustion pores of the tube is located below the lowest hole of the combustion hole of the inner flame tube and forms a convex band so as to face upward, and the porosity of the combustion hole of the outer flame tube is increased. A combustor in which the upper and lower outer flame tubes are large and the middle portion is small, and the upper portions of the inner and outer flame tubes are closed.