JPS58124110A - Combustion device - Google Patents

Abstract

PURPOSE:To enable a stable flame formation independent from changes of combustion rate by a method wherein a combustion cylinder is divided in the vertical direction by a ring-shaped disc, with the diameter of the lower cylinder smaller than that of the upper cylinder. CONSTITUTION:Above a vaporization chamber wherein liquid fuel is vaporized, an outer cylinder 2 is provided, and within the outer cylinder 2, a bottomed combustion cylinder 3 is provided. The combustion cylinder 3 has a side peripheral surface of metallic net or punched member and the ring-shaped disc 5 which divides the combustion cylinder 3 into two parts in the vertical direction. The ring-shaped disc 5 has a flame port 4 in the center. In this instance, the lower cylinder 3' is designed to have a smaller diameter than the upper cylinder 3. By this, the stable flame can be formed independent from the changes of the combustion rate. Further, the rising of flame temperature can be prevented, the combustion can be stabilized, the combustion gas can be maintained to be clean, and the generation of NOX can be effectively reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an indoor heating appliance for home use,
The present invention aims to provide a combustion device that cleans combustion gas, expands the stable combustion range, and is fully capable of varying the amount of combustion.

Conventional combustion devices for indoor heating appliances that are open indoors have the disadvantage that the flame temperature becomes extremely high due to high-load combustion, and large amounts of nitrogen oxides (hereinafter referred to as NOx) are generated in the combustion gas. Ta. Therefore, a premix burner that performs surface combustion is used in combustion equipment for heating appliances that are used for long periods of time to achieve low NO.
I was trying to make it x.

Page 2 However, premix burners that perform surface combustion form a stable and uniform flame at a certain combustion rate, but when the combustion rate is varied, the air-fuel ratio range is narrow, so the flame becomes less uniform. However, the amount of NOx contained in the combustion gas tended to increase.

A premix burner of a conventional combustion device will be explained based on FIG.

In FIG. 2, reference numeral 2 denotes an outer cylinder having a fan-shaped primary air port 31 at the bottom and an opening at the top, and a gas nozzle 32 is provided opposite the primary air port 31 provided in the outer cylinder 2. 3 is a bottomed cylinder-shaped combustion cylinder provided inside the outer cylinder 2;
The side wall of this combustion tube 3 is provided with numerous small holes.

33 is a mixing chamber formed by the bottom of the combustion tube 3 and the outer tube 2;
12 is a premixed gas passage formed between the outer cylinder 2 and the side wall of the combustion cylinder 3.

In such a configuration, the fuel gas ejected from the gas nozzle 32 is supplied into the mixing chamber 33 from the primary air port 31 of the outer cylinder 2, and combustion air is also drawn into the fuel gas and pre-filled in the mixing chamber 33. The mixture becomes a three-base gas and is ejected to the combustion section in the combustion tube 3 through the premixed gas passage 12. The premixed gas ejected into the combustion tube 3 is ignited by an igniter (not shown) to form a flame. This flame is in a constant combustion state, and since the combustion tube 3 is provided with countless small holes, the area of the flame hole can be very large, so the load on the flame hole is small and surface combustion occurs. Therefore, the flame temperature decreases and the air-fuel ratio collapses, making it impossible to obtain a uniform flame, causing incomplete combustion locally, causing gas to be discharged beforehand, and soot adhering to the combustion tube 3, resulting in the composition of the combustion gas. becomes significantly worse.

Furthermore, if the flame that is formed becomes non-uniform, high-temperature areas will occur locally, leading to an increase in NOx.

Furthermore, when the combustion amount is varied, the air-fuel ratio balance is disrupted, resulting in a pressure difference such that the ejection pressure of the premixed gas is high in the high temperature part of the upper part of the combustion tube 3 and lower in the lower part, as shown in FIG. Therefore, there are disadvantages in that the flame becomes non-uniform, Cσ is generated, and gas is emitted beforehand.

The present invention consists of an outer cylinder and a bottomed cylindrical combustion cylinder provided in the outer cylinder and having countless small holes around the outer cylinder, and the combustion cylinder is divided into upper and lower parts by a ring-shaped disk, In addition, by configuring the diameter of the lower combustion tube to be smaller than the diameter of the upper combustion tube, the above-mentioned conventional drawbacks are solved.

An embodiment of the present invention will be described below with reference to FIG.

Note that the same members as in the conventional combustion device will be described with the same reference numerals.

In FIG. 1, reference numeral 1 denotes a vaporization chamber for vaporizing liquid fuel, and an outer cylinder 2 is provided above the vaporization chamber 1. As shown in FIG. 3 is outer cylinder 2
It is a cylindrical combustion tube with a bottom, and the sides are lined with wire mesh or d
Composed of a punching member, this combustion tube 3 is divided into upper and lower parts by a ring-shaped disk 6 having a flame port 4 in the center, and the diameter of the lower combustion tube 3' is the same as that of the upper combustion tube 3. It is configured to be smaller than the diameter of. Reference numeral 6 denotes a combustion air blowing passage provided five pages through the side wall of the vaporization chamber 1;
A blower fan 7 is attached to the. A fuel pipe 8 has a nozzle at one end facing into the vaporization chamber 1 from the air passage 6, and the other end is connected to a fuel tank 10 via a fuel pump 9. 11 is a heater embedded in the side wall of the vaporization chamber 1.

In the combustion device configured in this way, the fuel gas generated in the vaporization chamber 1 is mixed with combustion air and the premixture is passed through the passage 1.
2 and divided by a ring-shaped disc 5 -1 =
It is ejected into the combustion tubes 3, 3' to be buried and starts combustion.

When changing the combustion amount, if the combustion amount is large, the amount of combustion air and the amount of fuel gas should be
, 3' surface increases, and a flame is formed on the combustion tube 3° 3' surface where the load on the flame hole is small, thereby preventing a rise in flame temperature.

Furthermore, combustion heat is also smoothly discharged, so combustion tubes 3, 3
Since there is no heat retention inside the unit and the high temperature condition is alleviated, low N
It enables oxygen conversion.

Page 6 Also, when the combustion amount is small, the ejection speed of the premixture is slow, so it is mainly burned in the lower combustion pipe, but since the premixture is also supplied to the upper combustion pipe 3, some of the premixture is It also burns in the upper combustion tube 3. However, the ratio of the amount of combustion to the area of the flame hole becomes larger than when the amount of combustion is large. That is, since the flame hole load is reduced, the flame temperature on the surface □ of the combustion tube 3' is reduced, and NOx can be reduced.

In addition, since the diameter of the lower combustion tube is smaller than the diameter of the upper combustion tube 3, the combustion heat in the lower combustion tube 3' is exhausted from the center of the upper combustion tube 3. Radiation and conduction heat to the flame hole portion of the upper combustion tube 3 is alleviated. Therefore, the temperature of the flame on the surface of the combustion tube 3 is stabilized, and a uniform combustion flame without backfire combustion can be obtained.

Furthermore, by arbitrarily setting the diameter of the ring-shaped disc 5, a desired combustion amount variable range can be obtained.

Also, by dividing the combustion tube 3 into upper and lower sections, only one of the combustion tubes 3. Since flame stability is achieved on the surface of the strut, there is no misfire or lift flame, the generation of CO and soot is prevented, and clean combustion gas components are obtained.

As described above, according to the combustion device of the present invention, the bottomed cylindrical combustion tube having numerous small holes around the periphery is divided into upper and lower parts by a ring-shaped disk, and the diameter of the lower combustion tube is adjusted upward. By making the diameter smaller than the diameter of the combustion tube, a stable flame is formed even when the combustion amount is varied, and a rise in flame temperature is prevented, resulting in stable combustion, cleaner combustion gas, and lower N
This has the effect of achieving oxygen conversion.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a combustion device showing an embodiment of the present invention, Fig. 2 is a cross-sectional view of a combustion device showing a conventional example, and Fig. 3 shows the injection pressure of the premixture in the combustion tube of the combustion device. It is a characteristic diagram. 2... Outer cylinder, 3, 3'... Combustion cylinder, 5
・・・・・・Disk. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] It consists of an outer cylinder and a cylindrical combustion cylinder with a bottom that is provided inside the outer cylinder and has numerous small holes around the periphery, and the combustion cylinder is divided into an upper part and a lower part by a ring-shaped disc. A combustion device in which the diameter of the lower combustion tube is smaller than the diameter of the upper combustion tube.