JPS59131813A - Burner device - Google Patents

Abstract

PURPOSE:To reduce NOX by dividing the flame of the Bunsen burner into a primary combustion flame and secondary combustion flame and further separating NOX generated in the primary combustion by an ABO3 catalyst provided on the inner wall of the primary combustion chamber. CONSTITUTION:The flame is divided into a primary combustion flame 6 and a secondary combustion flame 8, and stable flames are formed on the primary and secondary flame holes 5 and 7. Accordingly, the flame temperature is lowered, the NOX value is reduced to approximately 1/3. Further, an ABO3 complex oxide (perovskite structure) 10 (where A consists of La and Sr systems and B consists of Co, Fe and Mn systems) is carried as a catalyst on the inner wall of the primary combustion chamber 9, and in the reduced atmosphere NOX is separated into N2 and O2. Moreover, since primary combustion of less than theoretical air quantity is carried out within the primary combustion chamber 9, it may well be said that no oxygen exists therein. Further, since the primary combustion chamber 9 is in an atmosphere where a reduced gas such as CO or the like is dense, NOX generated in the primary combustion can be cracked.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to the field of oxygen combustion suitable for household combustion appliances.

Conventional configurations and their problems Many of the conventional home combustion appliances used Bunsen burners, which resulted in high NO values, and there was a demand for low NO values.

21. - Low No. burners are in practical use as atmospheric pressure full-order burners such as Schwank burners, but they have drawbacks such as high production costs, narrow combustion range (it is difficult to achieve TDR, and combustion is easily deteriorated by air currents). Because of this, its use was limited to things like stoves.

On the other hand, a burner device that divides the Bunsen burner into a primary combustion chamber and a secondary combustion chamber and lowers NOx has been proposed, as in Japanese Patent Application No. 74810/1981, and although it has been quite effective, There is a demand for lower NOx emissions.

OBJECTS OF THE INVENTION The present invention aims to further reduce NOx in the burner device disclosed in Japanese Patent Application No. 55-74810.

Structure of the Invention The present invention divides the combustion flame of a Bunsen burner into primary combustion and secondary combustion by providing a primary combustion chamber, and achieves low NOx by lowering the flame temperature. On the wall A is La, Sr, B is Co, Fe,
By supporting ABO3 composite oxide 3 pages (perovskite structure) consisting of Mn,
This is intended to further reduce NOx by decomposing and reducing NOx generated by primary combustion in the primary combustion chamber.

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a cross-sectional view thereof, and Fig. 3 shows the NoX characteristics depending on the primary air ratio of a conventional Bunsenbur and a Bunsenbar of two-stage combustion. Shows properties compared to values.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Gaseous fuel is ejected from a nozzle 1 and enters a mixing tube 3 of a burner 2, and the jet draws atmospheric air from the surroundings as primary air. At this time, the diameter of the mixing tube inlet 3 is adjusted using a damper or the like so that the amount of primary air is above the flammability limit and below the theoretical air amount. Gaseous fuel and air are mixed in a mixing tube 4 to become a flammable gas, and a primary combustion flame 6 is formed on a plurality of flame ports 5. The two-flame lower is formed by a single flame port, and surrounding air is supplied as secondary air to form a secondary combustion flame 8 on the two-flame lower. In this way, a container forming the primary combustion chamber 9 having two lower flames is provided so as to cover the first flame port 6, and the inner wall of the primary combustion chamber 9 is coated with A for La and Sr, and B for Go. ,F
e, an ABO3 composite oxide (perovskite structure) 10 consisting of Mn system is supported as a catalyst.

In the above configuration, the air-fuel mixture in the mixing tube is in an air-deficient state, and in this state flows into the first flame port 6 to form the primary combustion flame 6. The lack of air cannot be recovered because the first flame port 5 is covered by the primary combustion chamber 9, and the unburned gas is finally supplied with secondary air through the second flame lower.
Here, a secondary combustion flame 8 is formed. In this way, the flame is separated into the primary combustion flame 6 and the secondary combustion flame 8.
, 7, a stable flame is formed. Therefore, the flame is divided into primary combustion and secondary combustion with less than the stoichiometric amount of air, and the flame temperature is lowered compared to the conventional Bunsenburst, and the NOx value is reduced by about 1/3. Furthermore, an ABO3 composite oxide (perovskite 5 page structure) 1o consisting of La, Sr for A, and Co, Fe, and Mn system for B is supported on the inner wall of the primary combustion chamber 9 as a catalyst. It was confirmed that Product 10 can decompose NOx into N2 and O2 in a reducing atmosphere.

Since the primary combustion takes place in the primary combustion chamber 9 with less than the theoretical amount of air, it can be said that no oxygen exists at all, and
Since the atmosphere is rich in reducing gas such as co, it is possible to decompose NOx, which is mainly produced in the primary combustion.

Curves A, B, and C in Figure 3 show the NoX characteristics of a conventional Bunsen burner, a two-stage combustion in which the Bunsen burner's flame is divided, and a burner device of the present invention, respectively. It was shown that by installing ABO3 composite oxide on the wall of the primary combustion chamber of a burner designed to reduce NOx, it is possible to decompose NOx in a strong reducing atmosphere, reducing NOx by about 115 compared to conventional Bunsen burners. ing.

According to the burner device of this embodiment, the maximum temperature and average temperature of the flame are lower than the flame temperature of a conventional burner device, and NOx is generated due to a decrease in the o26 page concentration during primary combustion. By providing an ABO3 composite oxide that can suppress NOx in the primary combustion chamber and promote the decomposition of NOx into N2 and O2, it has become possible to further reduce NOx.

Furthermore, by providing the catalyst on the wall of the primary combustion chamber, the flame will not come into contact with the catalyst and deteriorate combustion.

In this embodiment, an example was described in which the primary combustion in the primary combustion chamber is performed using primary air, but it is also possible to introduce auxiliary air other than primary air into the primary combustion chamber and reduce the amount of primary air accordingly. , substantially the same effect can be obtained if the amount of air supplied to the primary combustion is the same.

Effects of the Invention As explained above, according to the burner device of the present invention, the flame of the Bunsen burner is divided into primary combustion and secondary combustion, and the ABo3 catalyst provided on the wall of the primary combustion chamber burns the primary combustion. Since it decomposes NOx generated during combustion, it has become possible to achieve low Nox emissions.

Page 7 Furthermore, by using a Bunsen burner to reduce NOx, it has become possible to provide a burner device that has a wide combustion stability range and is suitable for household combustion appliances.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a NoX characteristic diagram. 5...1 flame port, 7...2 coal washing port, 9
...Primary combustion chamber, 10...AB○3 composite oxide.

Claims (1)

[Claims] A primary combustion chamber covering a first flame port having a plurality of single flame ports is provided, a burner having two flame ports is formed in the primary combustion chamber, and A is La, Sr on the wall of the primary combustion chamber.
, B Iffo , Fe , Mn system ABO3
A burner device that supports a perovskite structure, which is a composite oxide, and performs primary combustion in the primary combustion chamber using primarily air above the flammability limit and below the theoretical air amount.