JPS58123010A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To equalize the jet pressure of premixed gas in a combustion cylinder, eliminate unevenness of red heat at a flame port, and obtain good combustion characteristics by providing a rectifying cylinder with large numbers of fine holes in the inside of the combustion cylinder with a flame port formed of metal netting by leaving a rectifying space. CONSTITUTION:A heater 2 is buried at the upper part of a carburetor chamber 1 and a throttle form of a mixing plate 3 is provided at the opened face. Also, an air blow fan 5 is provided through an air supply passage 4 to the side wall of the carburetor chamber 1, and a fuel small pipe 6 connected to a fuel tank 8 through a fuel pump 7 is provided on the intermediate shaft. Furthermore, a combustion cylinder 10 is provided through a cylindrical link 9 at the upper end of the carburetor chamber 1, and an outer cylinder 14 is provided on the periphery of the combustion cylinder 10 to form a combustion space 13. Then, in the inside of the combustion cylinder 10, a rectifying cylinder 16 having closed upper part and large number of small holes is provided. By this, the jet pressures of premixed gas on the upper and lower sides of the metal netting of the combustion cylinder 10 can be equalized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device that vaporizes liquid fuel and sends it together with primary air as a premixed gas to a flame port to perform surface combustion.

A conventional combustion device of this type is constructed as shown in FIG. That is, a heater 2 is embedded in the upper part of a bottomed vaporizing chamber 1, and a mixing plate 3 having a diaphragm shape is attached to the open surface. A blower fan 6 is provided on the side circumferential wall of the vaporization chamber 1 via a blower passage 4, and a fuel thin tube 6 whose tip forms a nozzle is placed on the central axis of the air passage 4 to face the vaporization chamber 1, and a fuel pump 7 It is connected to the fuel tank 8 via. A cylindrical ring 9 is joined to the upper end of the vaporization chamber, and a combustion cylinder 1o is provided with a wire mesh arranged around the cylinder.The upper end is integrally formed with a closing cap 11. The inside of the combustion tube forms a premixed gas chamber 12, and a combustion space 13 is provided around the combustion tube 10, and an outer tube 14 is arranged, the upper part is open, and the lower end is joined to the upper end of the vaporization chamber 1 and closed. ing.

In this case, the heater 2 of the vaporization chamber 1 is energized, and the vaporization chamber 1
After heating, the blower fan 4 installed through the blower passage 3
By driving the combustion air, combustion air is introduced into the vaporization chamber 1. Next, drive the fuel pump 6 to pump the fuel pump 7.
The fuel is drawn into the vaporization chamber 1 from the nozzle at the tip of the thin fuel tube 6, becomes vaporized gas on the high-temperature wall, passes through the constriction of the mixing plate 3 disposed at the top, and enters the premixing chamber 12. While being guided, it mixes with combustion air, and as a premixture, it is ejected outward from the periphery of the combustion tube 1o, which is covered with a wire mesh, and is fired by an igniter (not shown) in the combustion space 13 between the outer tube 14 and the combustion tube 10. It ignites and forms a combustion flame on the surface of the wire mesh.

In this method, in a certain combustion amount range, the air-fuel ratio balance is stable and the entire wire gauze becomes red-hot evenly, but if the temperature of combustion heat rises or the air-fuel ratio balance collapses even slightly, the entire wire gauze of the combustion tube, that is, the cylinder The temperature of the front and back surfaces of the body reaches almost the same temperature. Therefore, when the temperature is increased, the temperature of the premixture in the premixture chamber 12 rises and reaches the ignition point of the gas, causing spontaneous flashback or external interference. It had the disadvantage of causing backfire due to pressure changes caused by forced wind. There are also burners with multiple layers of wire mesh, but the adhesion deteriorates during the process of expansion and contraction due to combustion heat, causing thermal deformation, causing uneven red heat, creating localized high-temperature areas, increasing the combustion load, and causing nitrogen oxidation. This caused a large amount of material to be generated. In addition, when changing the combustion amount, as shown in Figure 2, the pressure balance becomes large at the top and bottom of the wire mesh flame port, causing a disordered distribution in which the ejection pressure increases at the top and decreases at the bottom. This has the drawback that the combustion amount can hardly be controlled because the combustion flames at the top and bottom become non-uniform, producing carbon dioxide, raw gas, and nitrogen oxides, which significantly deteriorates the exhaust gas characteristics. In addition, a heater is used to vaporize liquid fuel, but since the feedback of combustion heat accompanying combustion does not return sufficiently to the vaporization section, the heater is always energized, making it difficult to use high power. I was invited.

The present invention eliminates these conventional drawbacks by maintaining the combustion tube, which forms the flame nozzle, in a uniform red-hot state at all times, even over a wide range of combustion placement variations, thereby preventing backfire phenomena and nitrogen oxidation. The purpose is to prevent the generation of substances, obtain good combustion characteristics, and achieve power savings.

In order to achieve this object, the present invention provides a rectifying cylinder having a gap called a rectifying space and a large number of pores inside a combustion cylinder whose flame port is formed with a wire mesh, and the lower end surface of each is provided for heating. This is connected to the upper end of the vaporization chamber in which the heater is embedded.

With this configuration, the premixed gas that has entered the rectifying cylinder is jetted out into the rectifying space from the many pores in a uniform state in which vaporized gas and combustion air are sufficiently mixed, resulting in a pressure distribution between the upper and lower parts of the rectifying cylinder. At the same time, the temperature of the combustion tube, which has a wire gauze forming the flame opening, tends to rise as the temperature on the back surface increases, but the temperature of the rectifier tube increases. Since the jetting speed of the premixed gas from the pores is higher than before, it has the effect of cooling the back side in the rectifying space, and the radiant heat from the back side is propagated to the rectifying tube where it is absorbed and transferred to the vaporization chamber side. Because it is possible to maintain the vaporization temperature in the vaporization chamber by natural heating without using a heater, the temperature of the premixed gas does not reach the vaporization temperature or higher, and as a result, the premixed gas does not eject into the rectification space. Since the mixed gas is always maintained below the ignition point of the gas, it is possible to prevent flashback even if the air-fuel ratio is somewhat poor over a wide range of combustion amounts, and the time the heater is energized is also reduced, resulting in power savings. It is possible.

Hereinafter, one embodiment of the present invention will be described using the drawing of FIG. In FIG. 3, the same parts as in FIG. 1 are given the same numbers.

In the figure, a heating heater 2 is installed at the top of a bottomed vaporizing chamber 1.
is buried therein, and a mixing plate 3 having a diaphragm shape is attached to the open surface. A blower fan 5 is provided on the side circumferential wall of the vaporization chamber 1 via a blower passage 4, and a fuel thin tube 6 whose tip forms a nozzle is placed on the center axis of the blower passage 4 to face the vaporization chamber 1, and a fuel pump 7 It is connected to the fuel tank 8 via. A cylindrical ring 9 is joined to the upper end of the vaporization chamber, and a combustion cylinder 10 is provided with a heat-resistant wire mesh arranged around the periphery of the cylinder.The upper end is integrally constructed with a closing cap 11. A combustion space 13 is provided around the combustion tube 10, and an outer tube is made of a material with good heat absorption and dissipation, which has an increased surface area using heat-resistant glass with high heat transmittance, a cobalt oxide-based hollow-treated steel plate, or shot gelatin. 14 is arranged, the upper part is open, and the lower end is joined to the upper end of the vaporization chamber 1 and closed. Combustion tube 10
The inside of the rectifying space 1 has a gap of 911 or more than that of a wire mesh.
A rectifying cylinder 16 having a large number of pores and a closed top is joined to the upper end surface of the vaporizing chamber 1 to form a premixing chamber 12 therein. A gap is also provided between the upper closing surface of the straightening tube 16 and the closing cap 11 of the combustion tube 1o.

In this case, the heater 2 of the vaporization chamber 1 is energized, and the vaporization chamber 1
After heating, the blower fan 6 installed through the blower passage 4
By driving the combustion air, combustion air is introduced into the vaporization chamber 1. Next, the fuel pump 7 is driven to fill the fuel tank 8.
The fuel is drawn into the vaporization chamber 1 from the nozzle at the tip of the thin fuel tube 6, becomes vaporized gas on the high-temperature wall surface, passes through the restrictor 9 of the mixing plate 3 placed at the top, and enters the premixing chamber 12. While being guided, it mixes with the combustion air and is ejected as a premix from the numerous pores of the rectifying cylinder 16, and is further rectified in the rectifying space 15 and ejected outward from the periphery of the combustion cylinder 10, which has a wire mesh. Combustion space 1 between outer cylinder 14 and combustion cylinder 10
3, an igniter (not shown) ignites the flame, and a combustion flame is formed on the surface of the wire mesh.

In this way, the premixture is sufficiently mixed in the rectifying tube 16 which has a large number of pores and is ejected around the outside of the pores, and in the rectifying space 16, the ejected flow is sufficiently diffused in the combustion tube 10. The combustion tube 1o is used to form a combustion flame by ejecting it to the wire mesh.
The ejection pressure of the premixture between the top and bottom of the wire mesh becomes uniform, allowing combustion to occur in a stable and distributed state, thereby eliminating uneven red heat at the flame opening in the wire mesh section. In addition, the combustion heat at the wire mesh flame opening is transferred to the rectifier tube 1.
Due to the high ejection speed from the pores 6, the back surface is cooled by the cooling effect, and the rectifying tube 16 absorbs the radiant heat from the back surface, causing heat feedback to the lower vaporization chamber, which increases the temperature of the back surface of the wire mesh. can be prevented.

In addition, since the rectifying tube 16 absorbs heat from the wire gauze that is the flame opening of the combustion tube 1o and can provide heat feedback to the vaporization chamber 1, the vaporization chamber 1 can be maintained at a high temperature with the combustion heat itself. The energizing time can be shortened.

In addition, by providing the rectifying space 16 between the rectifying cylinder 16 and the wire gauze that is the flame opening of the combustion cylinder 1°, and making the gap 1 fi or more, the premixed gas ejected from the many pores of the rectifying cylinder 16 can be This is because the premixed gas can be diffused in the rectifying space 15 and ejected onto the entire surface of the wire gauze that is the flame outlet, thereby eliminating uneven red heat. , to maintain a high temperature atmosphere,
In the case of low calorific value, the load on the flame port decreases and the speed of ejection from the pores decreases, but the high temperature atmosphere in the rectification space 16 is maintained and no Go or raw gas is generated. When the calories are high, the flame load increases and the heat capacity increases, but the ejection speed increases and the temperature rise on the surface of the wire mesh can be suppressed, thereby preventing the occurrence of backfire.

Even with variations in the air-fuel ratio, rectification and diffusion are sufficiently performed in the rectification space 16, and a uniform premixture can be ejected, resulting in stable combustion without flashback. Also, 100
By providing a minute gap between the rectifying space 16 of 0 or more, the closing part on the upper part of the rectifying tube 16, and the closing cap 11 of the combustion tube 10, the combustion tube 10 and the rectifying tube 16 can thermally expand or extinguish due to combustion heat. However, although one end surface is in a bonded state, the upper part of the other end surface is not restricted by a free end, so expansion is not restricted, and the wire mesh and rectifier tube 16 are partially connected. This eliminates uneven red heat at the wire mesh flame port of the combustion tube 1o without coming into close contact with the flame. However, the outer cylinder 14 is made of heat-absorbing glass that increases the surface area by using heat-resistant glass with high heat transmittance, cobalt oxide-based hollow treatment material, or shot gelatin.
By using a material with good dissipation, the combustion heat from the combustion space 13 can be released to the outside of the outer cylinder 14, thereby preventing the temperature of the wire gauze of the combustion cylinder 1o from rising, and at the same time generating good infrared rays.

As described above, according to the liquid fuel combustion device of the present invention, the rectifying tube is provided with a rectifying space inside the combustion tube using a wire mesh, and one end is joined to the upper end surface of the vaporizing chamber, so that the flame opening can be By cooling the combustion heat in the wire mesh by increasing the ejection speed from the pores, and by absorbing the radiant heat from the back side and providing heat feedback into the vaporization chamber, the premixture temperature is always controlled below the gas ignition temperature. This prevents flashback over a wide combustion range. Furthermore, since the vaporization chamber can be maintained at a high temperature by thermal feedback, the power supply to the heater is shortened, resulting in power savings. In addition, the wire gauze, which is the flame opening, can be maintained in a uniform red-hot state, and there are no localized high-temperature areas, resulting in good exhaust gas characteristics with less nitrogen oxides.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic configuration of a conventional liquid fuel combustion device, FIG. 2 is a half sectional view of the main part of the same device, and FIG. 3 is a basic configuration of a liquid fuel combustion device according to an embodiment of the present invention. 9 is a cross-sectional view showing a ring-shaped cylinder, 1000010. Combustion cylinder, 11...Closing cap, 13...
, combustion space, 14... outer cylinder, 15...
Rectification space, 16... Rectification cylinder. Name of agent: Patent attorney Toshio Nakao and one other person
3 diagram

Claims (3)

[Claims] (1) A heat-resistant wire mesh is formed into a cylindrical shape to form an integrated combustion cylinder with a closing cap at the top and a ring-shaped cylinder at the bottom, and the lower end of the ring-shaped cylinder is opened to the upper end of the vaporization chamber. A cylindrical rectifier tube with many pores inside the combustion tube and closed at the top is joined to the upper open surface of the vaporization chamber, and a rectifier tube is connected to the gap between the combustion tube and the rectifier tube. A liquid fuel combustion apparatus comprising an outer cylinder having a combustion space around the outer periphery of the combustion cylinder, the upper part of which is open, and the lower end of which is closed by joining the upper end surface of the vaporization chamber. (2) The combustion tube formed of a wire mesh and the pores of the rectifying tube arranged inside form a rectifying space with a gap of 1s11 or more, and there is also a gap between the upper closing cap and the upper surface of the blocked rectifying tube. The liquid fuel combustion device according to claim 1, which has a minute gap. (3) The outer cylinder placed around the outer periphery of the combustion tube is made of heat-resistant glass material with high heat transmittance, cobalt oxide-based enamel-treated steel plate, and materials with good heat absorption and dissipation that increase the surface area by shot blasting. A liquid fuel combustion device according to claim 1.