JPH02298705A - liquid fuel combustion equipment - Google Patents

Abstract

PURPOSE:To allow the device to control the production of NOx and CO by providing a flame holding ring on the periphery of the side face of a burner head to perform the cooling of a primary burning flame and the guide of a secondary burning flame and setting a radiant body on the upper part of the burner head so as to cool the secondary burning flame. CONSTITUTION:A flame holding ring 7 is mounted at a specified interval from the periphery of a burner port cylinder 3 and a primary burning flame 9 is not fanned by a wind and the like as soon as the primary burning flame 9 is cooled. Furthermore, a secondary burning flame 10 is prevented from being widened. Therefore, the diameter of the secondary burning flame 10 is made constant in the case where an excess air ration changes and a quantity of flame of the primary burning flame varies. In addition, a radiant body 8 is mounted on a cap 6 to allow the device to radiate and release the heat of the secondary burning flame 10 so as to lower a flame temperature. By this constitution, the production of NOx and CO can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid fuel combustion device, and particularly to a technology for reducing the generation of NOx (nitrogen oxide).

[Prior Art] As a prior art for reducing NOx in a liquid fuel combustion device, there is one shown in FIG. 6. FIG. 6 shows, for example, the conventional N
This is a destroyed cross-sectional view showing the structure around the burner head of a liquid fuel combustion device aimed at reducing Ox. In the figure, (1) is the carburetor, (2) is the burner bed, and the burner head (
2) is the flame hole tube of (3).

It consists of a wire mesh (5) and a cap (6). Further, (4) shows the flame hole opened in the flame hole tube (3), (9) shows the secondary combustion flame, and (11) shows the radiator.

The device shown in Fig. 6 has a wire mesh (5) tightly wrapped around the outer periphery of a flame hole tube (3) having a large number of flame holes 4), and the upper part is closed with a cap (6). A burner head (2) is attached to the vaporizer (1), and a radiator <11) surrounds the outside of a wire mesh (5).

N generated when liquid fuel burns.

The main component of X is No (nitric oxide), and it is known that the combustion flame can be cooled in order to reduce this No. By installing a radiator (11) with excellent heat dissipation effect near the outer periphery of the wire mesh 5) where the combustion flame (9) is formed, -
The next combustion flame (9) is cooled to reduce NOx.

[Problems to be Solved by the Invention] In the conventional liquid fuel combustion device as described above, the radiator is mounted at a position where the primary combustion flame is formed, so the radiator is exposed to the high temperature primary combustion flame during combustion. Because the radiator is installed close to the burner head and facing the flame, various parts of the burner head may be overheated due to the radiant heat from the overheated radiator. Therefore, each part of the burner head and the radiator are likely to be deformed or damaged due to the heat, which may also cause backfire.

Furthermore, there were other problems such as a large amount of CO (carbon monoxide) being generated due to the rapid cooling of the combustion flame.

This invention was made to solve these problems, and it prevents excessive temperature rise of each part of the burner head and the radiator, prevents deformation and damage, and performs stable combustion without backfire. The object of the present invention is to obtain a liquid fuel combustion device that suppresses the generation of NOx and CO.

[Means for Solving the Problems] The liquid fuel combustion device according to the present invention includes a flame-holding ring provided on the outer periphery of the burner head in order to cool down the secondary combustion flame to some extent and guide and stabilize the secondary combustion flame. , and a radiator installed above the burner head to cool the secondary combustion flame.

[Function] In this invention, the primary combustion flame is cooled to some extent by the flame stabilizing ring provided on the outer periphery of the burner head, and then guided to form a stable secondary combustion flame in the upper part of the burner head. Since the secondary combustion flame is further cooled by the radiator, the flame can be cooled in two stages, and abnormal heating of the radiator can be avoided.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a exploded cross-sectional view showing the structure around the burner head of a liquid fuel combustion device that is an embodiment of the present invention. In the figure, the same reference numerals as in FIG. The ring (8) is a radiator in this embodiment, and is made of a heat-resistant metal material, ceramic material, etc., like the conventional radiator (11). Further, (10) indicates a secondary combustion flame.

As shown in FIG. 1, the liquid fuel combustion device according to the present invention has a burner head (2) consisting of a flame hole tube (3), a wire mesh (5), and two caps (6). A flame-holding ring (7) is attached to the outer periphery of the cap (6), and a radiator (8) is attached to the top of the cap (6).

Next, the operating principle of this invention will be explained.

This type of liquid fuel combustion device usually has a negative air ratio (μ) (
Since the fuel concentration in the fuel gas discharged to the outside from the flame hole (4) via the vaporizer (1) is set to μ=0.7 to 0.8, the combustion condition is that the fuel concentration is Therefore, the unburned part of the secondary combustion flame (9) and CO are absorbed by the surrounding air (
secondary air) to form a secondary combustion flame (10) that surrounds the burner head (2).

Also, as mentioned above, N generated by combustion.

The main component of It has been found by the inventors' measurement results that this occurs.

Therefore, NOx can also be effectively reduced by cooling the secondary combustion flame (10) again after cooling the primary combustion flame (<9) to some extent.

That is, the principle of operation of the present invention is that in the configuration shown in FIG.
- By cooling the secondary combustion flame (9) and reducing NOx generated in the secondary combustion flame (9) and immediately after it, and by inserting a radiator (8) into the secondary combustion flame (10), By lowering the temperature of the secondary combustion flame (10),
This is intended to reduce Ox.

Next, details of the configuration shown in FIG. 1 will be explained. As shown in the figure, the flame-holding ring 7) is installed at a predetermined distance from the outer periphery of the flame hole tube (3), and this flame-holding ring 7), together with gold y4 (5), is used for primary combustion as described above. flame(
9), while at the same time playing a role in cooling the -secondary combustion flame (
9) to prevent it from being fanned by wind etc.
In addition to ensuring the stability of the upper flame, the secondary combustion flame (1
0) has the role of preventing the spread. Therefore, by installing this flame holding ring (7), even if the air ratio changes or the flame amount of the secondary combustion flame 9) changes, the secondary combustion flame (10) will always be A flame with a constant diameter can be maintained.

Further, in this invention, the radiator 8) is the cap (6).
). This is to lower the temperature of the secondary combustion flame (10) as described above, and by being installed in the secondary combustion flame (10), the secondary combustion flame <10)
The secondary combustion flame (10) plays the role of lowering the combustion temperature of the secondary combustion flame (10) by radiating the heat to the outside.

The diameter of this radiator (8) is determined by the diameter of the secondary combustion flame (10
), which can significantly reduce NOx. In this case, the diameter of the secondary combustion flame (10) is always constant due to the flame-holding ring (7), so the radiator (8) is placed around the outer circumference of the secondary combustion flame (10). The temperature can be effectively lowered without being exposed to the gas, and a large amount of CO can be prevented from being generated, making it possible to maintain safe combustion at all times.

In addition, the radiator (8) has a burner head (
2), but is installed in the relatively low-temperature secondary combustion flame (10) well ahead of the primary combustion flame (9) at the top of the burner head (2). Therefore, excessive temperature rise of the radiator (8) itself is prevented,
The radiant heat from the radiator (8) is radiated throughout the combustion chamber space, making it possible to prevent excessive temperature increases in various parts of the burner head (2). Therefore, the radiator (8) and the burner head (2
) It is possible to eliminate deformation and damage of various parts due to heat and improve the durability of the device.

FIG. 2 is a diagram showing the measurement results comparing the conventional device and the device according to the present invention regarding the generation of NOx. When the radiator (11) is attached to the secondary combustion flame (9) as in the conventional device, the solid line indicates that the radiator (8) is attached to the secondary combustion flame (9) as in the embodiment of the present invention shown in FIG. 1
0) is shown.

As can be seen from the measurement results shown in Figure 2, this invention can significantly reduce NOx compared to the case where the radiator is not installed, as shown by the dotted line. It can be seen that there is a substantially improved effect compared to when the radiator (11) is attached to the secondary combustion flame (9).

FIG. 3 shows a comparison regarding the generation of CO. In the present invention, a significant reduction can be achieved compared to the case where the radiator (11) shown by the dashed line in the figure is attached to the secondary combustion flame (9). . The reason why CO generation becomes abnormally high when the radiator (11) is attached to the primary combustion flame (9) is because this structure rapidly cools down the temperature of the primary combustion flame (9). In this invention, the flame is cooled by the primary combustion flame.

Since the secondary combustion flame is used separately, the generation of CO is the same as when the radiator shown by the dotted line is not attached.

That is, in the present invention, as can be seen from FIGS. 2 and 3, by using the above-described structure, it is possible to reduce NOx by about 30% without deteriorating the CO characteristics.

Figure 4 is a diagram showing the measurement results plotting the temperature of the wire mesh (5) against the combustion amount, taking into account abnormal situations during use.
The measured values are shown at the primary air ratio μ=0.9, where the temperature of the wire mesh (5) is expected to be the highest.

As shown in the figure, the radiator (11) is connected to the next combustion flame (9).
When the radiator is attached to the radiator, the temperature rises significantly and the temperature of the wire mesh (5) reaches 1000°C or more, but in this invention shown by the solid line, the temperature is even lower than when the radiator is not attached, which is shown by the dotted line. The increase in temperature is slight and does not exceed the heat-resistant temperature of the wire mesh material used for -R, and there is no need to use a wire mesh made of a special heat-resistant material as in conventional devices.

Moreover, as a result of suppressing the temperature rise of the wire mesh (5), stable combustion without any fear of backfire can be realized.

FIG. 5 is a cross-sectional view showing the overall structure of a liquid fuel combustion device according to an embodiment of the present invention, in which the same reference numerals as in FIGS. 1 and 6 indicate the same or corresponding parts, and (21) is a heater. , (22
) is the aperture plate, (23) is the mixing plate, (24) is the nozzle, (
25) is a blower pipe, (26) is an air volume control valve, <27) is a blower, (28) is a needle, <29) is an orifice pipe,
(30) is a constant oil level device, (31) is a partition plate, (32) is a static pressure return pipe, 33〉 is an oil feed pipe, (34) is a sub tank,
(35) is the pump, <36) is the overflow pipe, (3
7) is a cartridge tank.

Next, the operation of this device will be explained. First, turn on the power switch (not shown) to energize the heater (21),
The vaporizer (1) is heated to the temperature required to vaporize liquid fuel (approximately 250℃
``C). When this preheating is completed, the blower (27) is driven to supply combustion air to the blow pipe (25), and at the same time, the oil level regulator (
30) Pressurize the internal fuel reservoir. Combustion air sent from the blast pipe (25) is ejected into the carburetor (1) through the nozzle (24).

Meanwhile, the electromagnetic pump (35) is driven and the sub tank (3
4) The liquid fuel in the tank passes through the oil pipe (33) to the oil level regulator (
30) sent within.

When the height of the fuel supplied to the fuel reservoir in the oil level regulator (30) exceeds the height of the partition plate (31), it returns to the oil supply pipe (<33) through the overflow pipe (36) and is burned by combustion. The consumed fuel is pumped up again by the electromagnetic pump (35), and the oil level regulator (3
0) is kept constant at all times.

This oil level regulator (30) is pressurized with wind pressure through the static pressure return pipe (32), so the oil level is pushed by this wind pressure, and the fuel passes through the orifice pipe (29) and enters the nozzle (2).
4) is fed to the centrally located needle (28).

The fuel supplied to this needle (28) is
4) The particles are atomized by the combustion air flow in the chamber, mixed with the combustion air, spread into a conical shape, collide with the inner wall of the vaporizer chamber 1>, and are heated and vaporized.

The vaporized fuel mixes with the surrounding combustion air and becomes a fuel gas whose mixed concentration is made uniform by the throttle plate (22) and the mixing plate (23).

The fuel gas, whose mixed concentration has been made uniform, is rectified in the space inside the flame hole pipe (3) and the cap (6), and then the fuel gas is rectified into a flame hole (4).

It is ejected through the wire mesh (5) and ignited by an ignition means (not shown) such as an electric discharge spark to form a primary combustion flame (9).

In the above embodiment, the shape of the radiator (8) is rake-like, but it is not limited to this, and various shapes such as a coil-like shape can be considered.

[Effects of the Invention] As explained above, in this invention, after the primary combustion flame is cooled to some extent by the flame stabilizing ring provided on the outer periphery of the burner head, a stable secondary combustion flame is formed in the upper part of the burner head, and the burner head Since the secondary combustion flame is further cooled by the radiator installed at the top, the flame can be cooled in two stages, and abnormal heating of the radiator can be avoided, reducing NOx In addition to effectively reducing CO2 emissions, it also prevents deformation and damage to the various parts of the burner head and the radiator caused by abnormal heating of the radiator, achieving stable combustion without the risk of backfire. There is an effect that it can be done.

[Brief explanation of the drawing]

゛ Fig. 1 is a fractured sectional view showing the structure around the burner spatula and dome which is an embodiment of this invention, Figs. 2 to 4 are diagrams showing measurement results, and Fig. 5 is an embodiment of this invention. A diagram showing the configuration of a certain liquid fuel combustion device, and FIG. 6 is a diagram for explaining a conventional device. (1) is a vaporizer, (2) is a burner head, (3) is a flame tube, (4) is a flame hole, (5) is a wire mesh, (6) is a cap,
(7) is a flame holding ring, 8) is a radiator, (9) is a secondary combustion flame, and (10) is a secondary combustion flame. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] A liquid fuel combustion device having a burner head having a flame hole tube having a flame hole on the side surface for ejecting fuel gas and forming a primary combustion flame, and a cap that closes the upper part of the flame hole tube. a flame-holding ring provided on the outer periphery of the side surface of the burner head to cool the primary combustion flame to some extent and guide and stabilize the secondary combustion flame formed at the upper part of the burner head; Equipped with a radiator installed at the top, the flame is cooled in two stages: the primary combustion flame and the secondary combustion flame, in order to suppress the generation of CO (carbon monoxide) and reduce the generation of NO_x (nitrogen oxide). A liquid fuel combustion device characterized by separate combustion.