JPH0861609A - Marine liquid fuel burner - Google Patents

Abstract

PURPOSE: To eliminate the formation of local high-temperature section by a method wherein combustion system with thick and thin fuel concentration combustion, employing an atomizer having a plurality of oil injection holes having two kinds of large and small sizes, is combined with multi-stage combustion, in which combustion air is supplied in three stages. CONSTITUTION: Fuel oil and steam for spraying arrive at an oil atomizer 2 at the tip end of an oil sprayer 1 through the inside of the same and is injected obliquely forward from a plurality of large and small injection holes. In this case, there are two kinds of large and small sizes in the size of the injection holes and, therefore, differences are generated in the flow rate of the fuel whereby the area of flame, in which air is excessive, and another area of flame, in which fuel is excessive, are formed while being mixed by air, coming through a housing tube 3, and swirler 5 while being mixed with primary combustion air 21 supplied while being wirled. Accordingly, the peak producing area of NOx can be avoided and the temperature of the flame can be restrained so as to be low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine liquid fuel burner,
In particular, the present invention relates to a burner that suppresses the generation of nitrogen oxides, but it can also be applied to burners for general industrial boilers and the like.

[0002]

2. Description of the Related Art FIG. 3 is a vertical sectional side view showing an example of a conventional typical liquid fuel burner for a marine boiler. In the figure (0
1) is an oil atomizer, (02) is an oil atomizer provided at the tip of this oil atomizer (01) and having oil injection holes of the same diameter, (03) is a housing tube, (05) is a housing tube (03) A swirler provided in the vicinity of the outer surface oil atomizer (02) at the tip portion, and (06) is a burner throat provided around the housing tube (03).

[0003]

In the conventional burner, the fuel oil and the air are uniformly mixed, so that the burnout time is short and the flame temperature is high. Therefore, the generation rate of nitrogen oxides (hereinafter referred to as NO _x ) was extremely high.

[0004]

In order to solve the above-mentioned conventional problems, the inventor of the present invention has a plurality of oil injection holes of different sizes.
It is attached to the oil sprayer equipped with atomizers of various types, a cylindrical housing tube that surrounds the above oil sprayer at intervals and has multiple air intake holes, and the outer surface of the end of the housing tube. Swirler,
A cylindrical burner throat which surrounds the housing tube and the swirler with a space therebetween to form a secondary combustion air passage therein, and a variable air damper and damper opening adjusting means formed on the outer periphery of the burner throat. A liquid fuel burner for a marine vessel is proposed, which is provided with a tertiary combustion air passage having a.

[0005]

The present invention has the above-mentioned structure, and since the plurality of oil injection holes provided in the atomizer have two sizes, large and small,
The fuel ejected from the atomizer has large and small flow rates, and is mixed with the air coming through the air intake hole opened in the housing tube and the air supplied while being swirled by the swirler, while the excess air is mixed. Form a flame zone and a flame zone with excess fuel. Therefore, the NO _x peak generation region can be avoided, and the flame temperature can be kept low.

Further, the unburned portion deviating from the flame region of excess fuel is mixed with the secondary combustion air passing through the clearance between the swirler and the burner throat and the tertiary combustion air supplied from the outside of the burner throat, A stable excess-air flame region is formed downstream of the main flame.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical sectional side view showing an embodiment of the present invention. 2 is a detailed view showing the oil atomizer in FIG. 1, FIG. 2 (a) is a vertical side view, and FIG. 2 (b) is a front view.

Reference numeral (1) in the drawing denotes an oil sprayer, and a plurality of large-diameter jet holes (for jetting fuel oil obliquely forward due to the pressure of steam or the like are provided at the tip of the oil sprayer (1) ( 9A)
And an oil atomizer (2) having a small diameter ejection hole (9B). Moreover, a housing tube (3) having an air intake hole (4) on the outer periphery of the oil sprayer (1).
A swirler (5) for supplying and swirling the primary combustion air (21) is provided near the oil atomizer (2) on the outer surface of the tip end thereof. The housing tube (3) and the swirler (5) are covered with a cylindrical burner throat (6) to form a passage for the secondary combustion air (22), and the tertiary combustion air (23) is provided on the outer periphery thereof.
An air passage for supplying air is provided, and a variable air damper (7) is provided in the air passage.

In such a structure, the fuel oil and the spraying vapor pass through the inside of the oil sprayer (1) to reach the oil atomizer (2) at the tip end, and a plurality of large and small ejection holes (9A),
(9B) spouts diagonally forward. At this time, since the injection holes (9A) and (9B) have two sizes, large and small, a difference in fuel flow rate occurs, and the swirler (5) is swirled by the air and swirler (5) passing through the housing tube (3). While mixing with the supplied primary combustion air (21), an excess air flame region and an excess fuel flame region are formed. Therefore, the peak generation region of NO _x can be avoided, and the flame temperature can be kept low.

On the other hand, the swirler (5) and the burner throat
Secondary combustion air (22) passing through the clearance (6)
And tertiary combustion supplied from outside the burner throat (6)
The burnt air (23) has not deviated from the excess fuel flame region.
While mixing with the fuel, a stable excess of air is provided downstream of the main flame.
Form a flame zone. At this time, the state of the flame and the rear flue
NO provided in_xTotal and O₂Measured by a meter
NO in exhaust gas_x, O ₂Depending on the concentration and variable air
Operate the damper (7) with the damper opening adjustment handle (8),
The supply amount of the tertiary combustion air (23) is adjusted.

As described above, the large and small types of ejection holes (9
Due to the combination of the rich / lean combustion by the oil atomizer (2) having (A) and (9B) and the multi-stage combustion by the supply of combustion air in three stages, a local high temperature part is not formed in the flame and NO _x is generated. Can be suppressed.

[0012]

EFFECTS OF THE INVENTION In the present invention, dark and light combustion using an atomizer having a plurality of oil injection holes of different sizes,
By combining with multi-stage combustion in which combustion air is supplied over three stages, a local high temperature part is not formed,
Generation of NO _x can be suppressed in the entire combustion region. Further, since the fuel and the air are mixed very efficiently, there are advantages that combustion can be performed even in a low O ₂ concentration and the amount of oil spraying vapor is small. In addition, since the multi-stage combustion structure is incorporated in the burner body, it can be carried out without significantly changing the boiler body.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is a detailed view showing the oil atomizer in FIG. 1, FIG. 2 (a) is a vertical side view, and FIG. 2 (b) is a front view.

FIG. 3 is a vertical side view showing an example of a conventional marine liquid fuel burner.

[Explanation of symbols]

 (01), (1) Oil atomizer (01), (2) Oil atomizer (03), (3) Housing tube (4) Air intake hole (05), (5) Swirler (06), (6) Burner throat (7) Variable air damper (8) Damper opening adjustment handle (9A), (9B) Oil injection port (10) Oil flow path (11) Steam flow path (21) Primary combustion air (22) Secondary combustion air (23) Tertiary combustion air

Claims (1)

[Claims] 1. An oil sprayer equipped with an atomizer having a plurality of oil injection holes of two sizes, large and small, and a cylindrical shape in which the oil sprayer is surrounded at intervals and a plurality of air intake holes are formed. A housing tube, a swirler attached to the outer surface of the front end of the housing tube, and a cylindrical burner throat that surrounds the housing tube and the swirler with a gap and forms a secondary combustion air passage therein. A liquid fuel burner for marine use, comprising a variable combustion air damper and a tertiary combustion air passage having a damper opening adjusting means formed on the outer periphery of the burner throat.