JPH0443699Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] This invention is a combination of a pre-mixing type gas burner and a pre-mixing type gas burner, and is a gas burner that is particularly capable of stable combustion from low combustion to medium to high combustion. [Prior art] In a conventional gas burner, the gas ejected from the gas outlet hole in the peripheral wall of the gas pipe is pilot-combusted near the flame-holding plate, and when the amount of gas is increased, the gas is combusted in front of the gas burner. No. 63-131915 is a pre-mixing type gas burner, which is equipped with a flame-holding nozzle and a fuel gas pipe inside the tube, and an outer cylinder surrounding the inner cylinder with the flame-holding nozzle, which absorbs some of the combustion air. It was developed in 1982 as a device that blows out secondary air.
There is a premix burner number 198329. [Problem to be solved by the invention] According to the former pre-mixing type gas burner, the air and gas are mixed and burned after being ejected from the primary air hole and the gas outlet hole, so the amount of air and gas ejected is small. At the flame level, especially in the case of high calorific value gas such as LPG gas, the volume ratio of gas to air is, for example, 1:29, resulting in poor mixing of air and gas, resulting in combustion with a bright flame. The carbon in the process of decomposing the gas remains, producing black smoke and causing soot to adhere to the flame holder. There was also the problem that there was a large possibility that it would easily blow out if the air/gas ratio changed slightly. In addition, in the former mixed burner like the latter, the maximum combustion amount is determined by the area of the burner's main flame hole, and if the gas amount is increased to achieve high combustion and the combustion amount exceeds the specified value, the flame will not settle on the burner and will lift. , because the flame tends to blow out, the range of stable combustion is narrow, and combustion tends to become unstable, which causes combustion oscillations.
There were problems such as loud combustion noise. This idea combines a pre-mixing type flame holder such as a Stectite type flame holder on the inside of the primary air pipe and a pre-mixing type cup type flame holder on the outside. By providing gas ejection holes in the direction, flame holding ability is extremely good, and by mixing air and fuel gas well, stable combustion from pilot flame to high combustion is achieved, resulting in quiet, high-load combustion with little vibration. The purpose of the present invention is to provide a gas burner that can achieve the following. [Means for Solving the Problems] In order to achieve the above object, the gas burner of this invention includes a primary air pipe 4 concentrically within a secondary air pipe 1, and a main flame port 3a inside the primary air pipe 4. A stectite-type flame stabilizer 3 having a flame port 3b for a side flame is provided, and a fuel gas pipe 6 whose tip is closed at the center thereof and a plurality of gas jet ports 5 are provided on the circumferential surface is provided, and the primary air pipe A cup-shaped flame stabilizer 2 having through holes 2a and 2b is provided on the outside of the flame stabilizer 4 to enhance flame holding ability and provide stable combustion from low combustion to high combustion. Main flame port 3 at the center of the Stectite type flame holder 3
A fuel gas pipe 6 is provided protruding through a to facilitate mixing of gas and air to aid combustion. [Operation] According to the above structure, when the burner is ignited, a small amount of fuel gas (approximately 10,000 Kcal/h), a small amount of primary air, and a constant flow of secondary air flow; The mixture is premixed in the tube, and the flame is completely stabilized by the Stectite flame holder at the tip, which burns the pilot flame as a blue flame. In this case, the air-to-gas ratio is stable when the gas is slightly larger than the theoretical air amount, and it is combusted by partially contacting the secondary air flowing into the outer cup-shaped flame holder. Next, when the amount of combustion increases, the amount of primary air increases in proportion to the amount of fuel gas, but at maximum combustion, the ratio of gas to air increases, and the fuel gas is diluted with air. gas (dilute gas), and in this state, the inner stectite type flame holder lifts the flame and cannot hold the flame.
The flame is held in place by an external pre-mixed cup-type flame holder, and the flame is mixed with secondary air to continue high combustion. Furthermore, by protruding the fuel gas pipe to the main flame port 3a, the input of the pilot flame at the main flame port can be reduced, and at the time of maximum combustion, gas and air can be mixed to assist combustion. [Example] An example will be described with reference to the drawings. In the figure, 1 is a secondary air pipe, 4 is a primary air pipe equipped with a pre-mixed cup type flame holder 2 on the outside of the tip, and a pre-mixed type flame holder 3 such as a Stectite type on the inside; Reference numeral 6 denotes a fuel gas pipe with a narrow diameter portion closed and a plurality of gas jet ports 5 provided in a direction perpendicular to the axis on the upstream side of the Stectite-type flame stabilizer 3, and inside the secondary air pipe 1. A primary air pipe 4 is provided in the primary air pipe 4, and a fuel gas pipe 6 is provided concentrically within the primary air pipe 4. The cup-shaped flame holder 2 has an outer diameter slightly smaller than the inner diameter of the secondary air pipe 1, and has holes 2a and 2b for secondary air _a2 in its peripheral wall, so that the flame holder 2 allows the secondary air to flow through the flame holder 2. It is mixed with fuel gas and combusted. Moreover, the Stectite type flame holder 3 is provided with the outer periphery inscribed in the primary air pipe 4,
A main flame port 3a is provided in the center, side flame ports 3b are radially bored near the outer periphery, and a small diameter portion of the tip of the fuel gas pipe 6 is inserted through the center of the main flame port 3a. Primary air flowing axially through the primary air pipe 4
Fuel gas g is injected perpendicularly to a ₁ from the gas injection port 5 of the fuel gas pipe 6, premixed and diluted. Hold the flame with type flame holder 2. That is, when the burner is ignited, a small amount of fuel gas, a small amount of primary air, and a constant flow of secondary air flow through the burner, and as shown by the chain line in FIG. When the main flame is completely held flame-stabilized by the side flame opening 3b and the amount of combustion increases, the amount of primary air will increase in proportion to the amount of fuel gas, but at maximum combustion, the amount of primary air will increase. As the ratio of air increases and becomes a dilute gas, it becomes impossible to hold the flame with a Stectite flame holder, so a cup-type flame holder is used to stabilize the flame, as shown by the chain line in Figure 2. Mix and burn. [Effects of the invention] According to this invention, a cup-type flame holder is provided on the outside of the primary air pipe, a Stectite-type flame holder is provided on the inside, and the fuel gas outlet is provided in a direction perpendicular to the direction in which the primary air flows. This enables sufficient dilution with premixing, and even when the amount of gas is small, the main flame and side flame can be reliably held in the main flame and side flame opening of the Stectite type flame holder, and the gas amount is small. When the flame is increased, the flame lifts, but the flame can be reliably held by the cup-shaped flame holder on the outside, so the combustion is very stable from low to high combustion, so there is no vibration.
The combustion noise can also be made quieter. In addition, since the fuel gas is sufficiently diluted with the primary air before it is combusted, it may cause black smoke or soot in the flame stabilizer.

[Table] This table shows that conventional burners cannot achieve good combustion from low combustion to high combustion, but in this application, good combustion can be achieved from low combustion to high combustion by combining the original mixture flame holder and the premix flame holder. can. In addition, by making the fuel gas pipe protrude to the tip of the Stectite flame holder and making the main flame port ring-shaped, the area of the main flame port is reduced, reducing the impact of the pilot flame, and the gas is centered during combustion. This makes it easier to mix with air without concentrating on it, which helps combustion.

[Brief explanation of the drawing]

Figures 1 and 2 are longitudinal sectional views showing the gas burner of this invention, showing how it burns at low combustion, and
The figure shows how the fuel burns during high combustion. 1...Secondary air pipe, 2...Cup type flame holder, 3
...Flame stabilizer such as Stectite type, 4...Primary air pipe, 5...Gas outlet, 6...Fuel gas pipe.

Claims (1)

[Claims for Utility Model Registration] (1) A system that has a primary air pipe 4 concentrically arranged within a secondary air pipe 1, and has a main flame port 3a and a side flame port 3b inside the primary air pipe 4. Tektite type flame holder 3
A fuel gas pipe 6 is provided in the center thereof, the tip of which is closed, and a plurality of gas jet ports 5 are provided on the circumferential surface of the fuel gas pipe 6.
A gas burner characterized in that a cup-shaped flame stabilizer 2 having a shape of 2b is provided. (2) The gas burner according to claim 1, wherein a fuel gas pipe 6 is provided protruding through the main flame port 3a at the center of the Stectite flame holder 3.