JPH037805A - Burner - Google Patents

Abstract

PURPOSE:To make it possible to conduct the detection of the level of combustion in a combustion flame and its control by providing a mixer and a burner head installed on the mixer, used for burning a mixture gas, and made of a ceramic material which has conductivity of electricity and an electrode for monitoring combustion which is provided above the burner head. CONSTITUTION:A burner is provided with a mixer 10 to make a mixture gas C by mixing a vaporized fuel B that is heated and vaporized in a vaporizer 40 and primary air A and a burner head 20 that is provided on the mixer 10 and burns the mixture gas C and is made of ceramics, and an electrode 30 for monitoring combustion that is provided above the burner head 20. The burner head 20 has conductivity of electricity. Since the burner head 20 has conductivity it can be connected to an electric circuit E through a felt 70 made of a metal fiber. When a combustion flame is formed, an ion current flows between the electrode 30 for monitoring combustion and the burner head 20. The ion current corresponds to the level of combustion of the combustion flame. The ion current is detected by the microcomputer M in the electric circuit E that is connected to the burner head 20, and the level of combustion of the combustion flame is controlled based on the result of the detection.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a combustion device used in a petroleum forced vaporization combustion type combustor.

<Prior Art> A conventional combustion device of this type will be described with reference to FIG. 16.

This type of combustion device heats and vaporizes liquid fuel using a vaporizer n.
A vaporizer 4o designated as B and primary air A from this vaporizer 4o.
At the same time, a mixer 10 that supplies vaporized fuel B, stabilizes the mixed gas C in which secondary air A and vaporized fuel B are uniformly mixed, and prevents flashback due to excessive combustion speed. It has a pack net 16 and a burner head 20 made of a wire mesh that is installed on the upper surface of the pack net 16 and burns the mixed gas C. A combustion flame monitoring electrode 30 is installed above the burner head 20. If a predetermined voltage is applied between the combustion flame monitoring electrode 30 and the burner head 20 as a counter electrode, an ionic current corresponding to the flame level of the combustion flame will flow between the combustion flame monitoring electrode 30 and the burner head 20 as a counter electrode. It flows between the head 20 and the head 20.

By detecting this ionic current with electric circuit E,
It detects and controls flame levels.

However, the conventional combustion apparatus described above has the following problems.

That is, the primary air A introduced together with the vaporized fuel B from the suction port 11 of the mixer IO may contain dust such as thread-like waste and cotton-like waste. In such a case, the dust enters the mixer 10 and gradually becomes entangled with the pack net 16. If this state continues, the mesh of the pack net 16 becomes blocked, the supply of primary air to the burner head 20 becomes insufficient, and abnormal combustion accompanied by red flame occurs. Furthermore, since the burner head 20 is made of wire mesh, the distance between the flame holes inevitably becomes too small, causing the combustion flames to come into contact with each other and increasing the flame length, so the burner head 20 must be made larger. There was a need.

Furthermore, the burner head 20 made of wire mesh not only has a high flame hole opening ratio per unit area and a small overall combustion area, but also has a low heat radiation efficiency because it is made of metal, so the temperature of the combustion surface increases. There is a problem in that too much carbon dioxide is too much and promotes the generation of NOx.

Therefore, in order to solve the above problem, a plurality of flame holes 21
Burner head 2 is equipped with a ceramic plate.
Combustion devices for use as zero have been proposed.

Such a combustion device has the advantage of being able to be constructed in a small size because it does not cause abnormal combustion or increasing the flame length of the combustion flame, and also reduces the generation of NO.

<Problems to be Solved by the Invention> However, since the ceramic burner head has insulating properties, it cannot be used as a counter electrode to the combustion flame monitoring electrode. , it is necessary to install a counter auxiliary electrode made of wire mesh below the burner head, but even if this counter auxiliary electrode is installed, there is a ceramic burner head between the combustion flame monitoring electrode and the combustion flame The ability to detect the combustion level is not sufficient compared to conventional ones.

That is, when a ceramic plate is used as the burner head, a counter auxiliary electrode is required to detect the flame level, and the burner head is present between the combustion flame monitoring electrode and the counter auxiliary electrode.・It becomes difficult to sufficiently detect the flame level of combustion flame.

The present invention was devised in view of the above circumstances, and is a combustion device that takes advantage of the advantages of a ceramic burner head and is capable of detecting and controlling the combustion level of a combustion flame in conjunction with conventional combustion devices. is intended to provide.

<Means for Solving the Problems> The combustion device according to claim 1 includes: a mixer for mixing vaporized fuel heated and vaporized in a vaporizer with primary air to produce a mixed gas; and a mixer installed on the mixer. A combustion device comprising a burner head made of ceramic for burning the mixed gas, and a combustion flame monitoring electrode disposed above the burner head, the burner head being made of ceramic having conductivity.

The combustion device according to claim 2 includes a mixer that mixes vaporized fuel heated and vaporized in a vaporizer with primary air to produce a mixed gas, and a ceramic that is provided on the mixer and burns the mixed gas. This combustion device has a burner head consisting of a burner head, and a combustion flame monitoring electrode disposed above the burner head, and a conductive oxide film is attached to the surface of the burner head.

The combustion device according to claim 3 includes a mixer that mixes the vaporized fuel heated and vaporized by the vaporizer and primary air to produce a mixed gas, and a ceramic that is provided on the mixer and burns the mixed gas. and a combustion flame monitoring electrode disposed above the burner head, the burner head having negative electrical characteristics and thermal shock resistance, and the burner head having negative electrical characteristics and thermal shock resistance. A counter auxiliary electrode is provided on the underside of the burner head.

Effect> In the combustion apparatus according to the first and second embodiments, the flame level of the combustion flame is detected by the ionic current flowing between the combustion flame monitoring electrode and the burner head. That is, since the ionic current flowing between the two corresponds to the flame level of the combustion flame, the flame level of the combustion flame can be detected by detecting this ionic current. This ionic current is input into an electric circuit, and a microcomputer in the electric circuit detects and controls the flame level of the combustion flame from the ionic current.

In the combustion apparatus according to the third embodiment, the flame level of the combustion flame is detected by an ionic current flowing between the combustion flame monitoring electrode and the opposing auxiliary electrode via the burner head.

This ion current is input to the electric circuit as in the first and second embodiments to detect and control the flame level of the combustion flame.

<Example> Hereinafter, an example according to the present invention will be described with reference to the drawings.

1 to 8 are drawings relating to a first embodiment, in which FIG. 1 is a sectional view of a combustion device according to the first embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. Figure 1 is an enlarged view of part a of Figure 1, Figure 4 is a circuit diagram showing an example of an electric circuit that detects and controls the flame level of the combustion flame in this combustion apparatus, and Figure 5 is a manufacturing process for the burner head of this combustion apparatus. A process diagram showing
Fig. 6 is a graph showing the combustion flame detection state in the first embodiment, Fig. 7 is a graph showing the relationship between oxygen concentration and flame level during weak combustion, and Fig. 8 is a graph showing the relationship between oxygen concentration and flame level during strong twist firing. A graph showing the relationship with the flame level, Figure 9 is the second
FIG. 10 is an explanatory diagram showing the essential parts of the combustion device according to the embodiment; FIG. is the third
A cross-sectional view of the combustion device according to the embodiment, FIG. 12 is a graph showing the negative electrical characteristics of the ceramic used in the burner head in the third embodiment, and FIG. 13 shows the difference in combustion flame detection depending on the ceramic material. FIG. 14 is a graph showing the relationship between oxygen concentration and flame level during weak combustion, and FIG. 15 is a graph showing the relationship between oxygen concentration and flame level during strong twist firing. In addition, between the conventional one and the road
Components and the like will be described with the same reference numerals.

The combustion apparatus according to the first embodiment of the present invention includes a mixer 10 that mixes vaporized fuel B heated and vaporized in a vaporizer 40 and primary air A to produce a mixed gas C; The burner head 20 is provided with a burner head 20 made of ceramic for combusting the mixed gas C, and a combustion flame monitoring electrode 30 disposed above the burner head 20. have.

As the ceramic material having conductivity constituting the burner head 20, the ceramic conductive material (
For example, TiC, TiN%TiBz, CrzCz,
Although there are some that contain SiC-based ceramics (Mo5xz, etc.), SiC-based ceramics are suitable as the material for the burner head 20. In particular, a SiCSi3N4 ceramic material made of SiC and metallic silicon and sintered in an N2 atmosphere has both heat resistance and thermal shock resistance as shown in Table 2 on page 17 of the specification. It is the most suitable because it is also inexpensive. A manufacturing process diagram of the burner head 20 made of the ceramic material shown in FIG. 5 is shown.

Such a burner head 20 is attached to a burner receiver 50 installed above the mixer 10, as shown in FIGS. 1 and 3. Specifically, a conductive metal fiber felt 70 is interposed between the burner receiver 50 and the burner head 20, and the burner head 20 is fixed to the burner receiver 50 with a presser metal fitting 60. Note that 15 in the drawing indicates a current plate that makes the mixed gas C static pressure.

Since the burner head 20 is electrically conductive as described above, it can be connected to an electric circuit via the metal fiber felt 70. By forming the combustion flame, an ion current corresponding to the combustion level of the combustion flame flows between the combustion flame monitoring electrode 30 and the burner head 20. This ionic current is transferred to an electric circuit E connected to the burner head 20.
The combustion level of the combustion flame is controlled based on the detection result.

Next, a combustion device according to a second embodiment will be explained with reference to FIG. 9.

The combustion device according to the second embodiment includes a mixer 10 that mixes vaporized fuel B heated and vaporized in a vaporizer 40 and primary air A to produce a mixed gas C, and is provided on the mixer 10, This combustion device has a burner head 20 made of ceramic for burning the mixed gas C, and a combustion flame monitoring electrode disposed above the burner head 20, and the burner head 20 has a surface coated with conductive oxide. A material coating 22 is attached.

To form the conductive oxide film 22 on the surface of the burner head 20, there are methods such as a printing method, a spraying method, a dipping method, and a brush coating method. For example, to form the conductive oxide film 22 by spraying or dipping, a liquid in which fine particles of tin oxide and antimony oxide are dispersed in water, such as Ceramase G (trade name) manufactured by Taki Chemical Co., Ltd., is applied to the burner head. After spraying the surface of the burner head 20 or immersing the burner head 20 in the liquid, the burner head 20 is heated at 800 to 1000 degrees.
This is done by firing at C. Further, the conductive oxide film 22 is formed by printing a ruthenium oxide-antimony oxide paste, such as the R-GX series (trade name) manufactured by Sumitomo Metal Mining Co., Ltd., by screen printing on the surface of the burner head 20. After drying, 850″
This is done by firing at C.

The burner head 20 with the conductive oxide film 22 formed on its surface in this way has electrical conductivity, and is attached to the burner receiver 50 in the same manner as the burner head 20 according to the first embodiment. That is, the burner head 20 is attached and fixed to the burner receiver 50 by means of the holding metal fitting 60 with the conductive metal fiber felt 70 interposed therebetween. The burner head 20 is connected to an electric circuit via a metal fiber felt 70 and a burner receiver 50.

In addition, although the burner head 20 was explained as a plate-shaped thing in the 1st and 2nd Example mentioned above, this invention is not limited to this. For example, it is also possible to use a burner head 20 as shown in FIG. 10, that is, an inverted container shape with a large number of flame holes 21 formed on the side surface.

Next, a combustion device according to a third embodiment will be explained.

The combustion device according to the third embodiment includes a mixer 10 that mixes vaporized fuel B heated and vaporized by a vaporizer 40 and primary air A to produce a mixed gas C, and is provided on the mixer 10, This combustion device includes a burner head 20 made of ceramic for burning the mixed gas C, and a combustion flame monitoring electrode 30 disposed above the burner head 20, wherein the burner head 20 has an electrically negative characteristic. The burner head 20 has thermal shock resistance, and a counter auxiliary electrode 80 is provided on the lower side of the burner head 20.

The combustion device according to this embodiment differs greatly from the combustion devices of the first and second embodiments described above in that it requires a counter auxiliary electrode 80, which was not necessary in the first and second embodiments. That is, in the combustion apparatuses according to the first and second embodiments, the burner head 20 serves as the counter electrode, and the combustion flame monitoring electrode 30 serves as the counter electrode.
In the combustion apparatus according to the present embodiment, an opposing auxiliary electrode 80 is provided below the burner head 20.
It requires.

The burner head 20 of the combustion device according to this embodiment is made of a dense lithium-based ceramic having electrically negative characteristics and having the characteristics shown in Table 1 on page 17 of the specification. Therefore, this burner head 20 has a high resistance value before combustion starts, and when combustion starts and heats up, the resistance value decreases (see FIG. 12). That is, the ionic current reaches the combustion flame monitoring electrode 30 only after combustion has started.
This causes the current to flow between the opposite auxiliary electrode 80 and the opposite auxiliary electrode 80.

The counter auxiliary electrode 80 is most preferably installed on the current plate 15 so as to be in contact with the back surface of the burner head 20 as shown in FIG. It may be part of

Next, the operation of the combustion devices according to the three embodiments described above will be explained.

In the combustion apparatuses according to the first and second embodiments, the flame level of the combustion flame is determined between the combustion flame monitoring electrode 30 and the burner head 20.
It is detected by the ionic current flowing between the That is, since the ionic current flowing between the two corresponds to the flame level of the combustion flame, the flame level of the combustion flame can be detected by detecting this ionic current. This ion current is input to an electric circuit, and a microcomputer M in an electric circuit E shown in FIG. 4 detects and controls the flame level of the combustion flame from the ion current. In FIG. 4, R1-R4 represent resistors, and FL represents the flame level of the combustion flame.

Further, according to the combustion devices according to the first and second embodiments, the sixth
As shown in the figure, between the burner head and the path formed of wire mesh.
Combustion flame can be detected at the level of .

In the combustion apparatus according to the third embodiment, the flame level of the combustion flame is detected by the ionic current flowing between the combustion flame monitoring electrode 30 and the opposing auxiliary electrode 80. This ionic current flows between the combustion flame monitoring electrode 30, the burner head 20, and the opposing auxiliary electrode 80, and is manually input to the electric circuit, and the combustion level of the combustion flame is detected by the microcomputer M based on this ionic current. , controlled.

Furthermore, in the three embodiments described above, changes in the combustion level of the combustion flame in accordance with changes in oxygen concentration as shown in FIGS. 7, 8, 14, and 15 are detected. By doing so, it is also possible to provide a function to stop combustion in the event of oxygen deficiency.

Table 1 <Effects of the Invention> As described above, the combustion device according to the present invention maintains the advantages of the ceramic burner head, and can detect the combustion level of the combustion flame in the path, etc. compared to the conventional one. can be controlled.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a combustion device according to a first embodiment of the present invention;
Figure 2 is a plan view, Figure 3 is an enlarged view of part a in Figure 1,
Fig. 4 is a circuit diagram showing an example of an electric circuit for detecting and controlling the flame level of the combustion flame in this combustion device, Fig. 5 is a process diagram showing the manufacturing process of the burner head of this combustion device, and Fig. 6 is A graph showing the detection state of combustion flame in the first embodiment, FIG. 7 is a graph showing the relationship between oxygen concentration and flame level during weak combustion, and FIG. 8 is a graph showing the relationship between oxygen concentration and flame level during strong twist firing. A graph showing the relationship, FIG. 9 is an explanatory diagram showing the main parts of the combustion device according to the second embodiment, and FIG. 11 is a sectional view of the second table of the combustion device according to the third embodiment, and FIG. 12 is a sectional view showing the negative electrical characteristics of the ceramic used in the burner head in the third embodiment. Figure 13 is a graph showing the difference in combustion flame detection by ceramic materials, Figure 14 is a graph showing the relationship between oxygen concentration and flame level during weak combustion, and Figure 15 is a graph showing the oxygen concentration during strong combustion. FIG. 16 is a graph showing the relationship between the flame level and the flame level, and is a cross-sectional view of a conventional combustion device. 10...mixer, 20...burner head, 22...
- Conductive oxide film (second embodiment), 30... electrode for monitoring combustion flame, 40... vaporizer, 80... counter auxiliary electrode (third embodiment), A...-next Air, B... vaporized fuel, C... mixed gas.

Claims (1)

[Claims] (1) A mixer that mixes the vaporized fuel heated and vaporized in the vaporizer and primary air to produce a mixed gas, and a ceramic that is installed above the mixer and burns the mixed gas. What is claimed is: 1. A combustion device comprising: a burner head consisting of a burner head; and a combustion flame monitoring electrode disposed above the burner head, wherein the burner head is made of an electrically conductive ceramic. (2) a mixer that mixes the vaporized fuel heated and vaporized in the vaporizer and primary air to form a mixed gas; a burner head made of ceramic that is installed on the mixer and burns the mixed gas; A combustion device having a combustion flame monitoring electrode disposed above the burner head, wherein a conductive oxide film is attached to a surface of the burner head. (3) a mixer that mixes the vaporized fuel heated and vaporized by the vaporizer and primary air to form a mixed gas; a burner head made of ceramic that is installed on the mixer and burns the mixed gas; In this combustion device having a combustion flame monitoring electrode disposed above the burner head, the burner head has negative electrical characteristics and thermal shock resistance, and the burner head has opposite electrodes on the lower side. A combustion device characterized in that it is provided with an auxiliary electrode.