JPS6071806A - Multipipe type slurry burner - Google Patents

Abstract

PURPOSE:To contrive simultaneously an improvement in burning characteristics, smooth switchover of fuel from oil to slurry and reduction of NOX in exhaust gas, by providing a flow path and a blow-off opening making slurry fuel (slurry) and liquid fuel (other fuel) other than the slurry blow off without mixing them on a main body of an atomizer. CONSTITUTION:As fuel of two kinds are sprayed separately from a nozzle by providing separately flow paths for slurry 1 in an internal cylinder 4 and the other fule 3 in an external cylinder within a tripipe burner nozzle 12 in the inside of an air flow 14, supply, suspension and adjustment of a flow can be done separately, an exclusive use burner of oil for starting becomes unnecessary and complicated switchover operation through a plurality of burners becomes unnecessary also. As a sprayed particle of a slurry 8 and a sprayed particle 10 of the other fuel are mixed independently with the air flow 14 for combustion due to a matter that a blow-off opening 7A of the slurry 8 and a blow-off opening 9 of the other fuel 3 are so constituted that their blow-off axes do not cross each other, combustion characteristics are improved. In addition to the above, a reduction of nitrogen oxide becomes possible by varying a flow rate of air to the slurry and the other fuel by providing a partition 13 corresponding to the blow-off openings 7A, 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-tube slurry burner device, and particularly to a slurry burner device suitable for improving the combustibility of water slurry and reducing nitrogen oxides.

For fuels that are fluid substances consisting of liquid and solid and can be directly combusted, such as highly concentrated coal-water slurry, atomization of the slurry during combustion and mixing with air are very important.

Conventionally, in order to combust such slurry fuels, a method similar to that used for oil fuels, namely, atomization with the aid of a steam or air atomization medium, has generally been used. ing. In particular, in the case of coal-water slurry, strong atomization, mixing with air, raising the combustion atmosphere temperature, etc. are necessary in order to improve the time delay until the fuel reaches the ignition temperature due to the latent heat of water. To solve this difficult combustion problem, especially when starting up a boiler, the temperature inside the furnace and the combustion air are low, so in order to achieve stable combustion, easily flammable fuels such as oil and gas are used. It is often used to start up. In this case, if the main fuel is slurry and the startup fuel is oil fuel, dedicated burners are required for each, and it is uneconomical to install these in the furnace.
In addition, switching using the same burner causes inconveniences and disadvantages such as intermittent supply of fuel during switching, complicated nozzle replacement or valve opening/closing/purging operations, and increased time required for switching.

An object of the present invention is to provide a multi-pipe slurry burner device that eliminates the drawbacks of the above-mentioned prior art and can simultaneously achieve improved combustibility, smooth fuel switching from oil to slurry, and reduction of NO0 in exhaust gas. It is about providing.

The present invention provides a multi-tube slurry burner device having an atomizer that collides and mixes slurry fuel supplied from a plurality of channels formed in the multi-tube with a spray medium, and then sprays the spray medium from a jet port. The present invention is characterized in that the atomizer main body is provided with a flow path and an ejection port for ejecting the liquid fuel without mixing the fuel with the slurry.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a side sectional view of a multiple tube burner device showing one embodiment of the present invention. In the figure, an inner cylinder 4,
A middle cylinder 5 and an outer cylinder 6 are provided, and the inner cylinder 4 contains a slurry fuel (hereinafter referred to as slurry) 1, the middle cylinder 5 contains a spray medium (such as steam) 2, and the outer cylinder 6 contains the above-mentioned fuel. Fluid fuel other than slurry (hereinafter referred to as single fluid fuel or other fuel)
Three channels are formed. In this case, if there is a risk of paper locking due to vapor generation when the slurry is adjacent to the heating medium, a heat insulating section 15 made of a heat insulating material or air is provided between the slurry and the medium to prevent vapor generation. can do.

The slurry and the fluid fuel are collided and atomized by the spray medium 2 at the tip of the nozzle, and are sprayed into the furnace from the slurry spout lower and the fluid fuel spout 9. In the figure, there is one injection hole 7 for slurry in the center, and one injection hole 7 for fluid fuel (
For example, a large number of injection holes 9 (for example, oil) are arranged in an annular shape around the injection hole 9.

According to this embodiment, these two fuels are sprayed separately from the nozzle through separate flow paths, so they are not mixed during the process and can be supplied, stopped, and adjusted in flow rate separately. For example, if slurry is used as the main fuel,
If fluid fuel is used as starting oil, only the oil in the outer cylinder is used when starting the boiler, and when the temperature conditions inside the furnace are correct, slurry can be continuously introduced without stopping the oil. Next, the oil and slurry are burned in a coaxial burner, and when the oil is no longer needed, only the oil can be stopped without stopping the slurry supply. Therefore, there is no need for a burner dedicated to starting oil as in the past, and there is no need for complicated switching operations that would be required when using a plurality of burners.

Next, FIG. 2 is a sectional view of a similar burner nozzle showing another embodiment of the present invention, and FIG. 3 is a front view thereof. The difference from the device shown in FIG. 1 is that the method of supplying the slurry 1 and the fluid fuel 30 through the passages is the same, but the injection lower part of the slurry 8 and the injection port 9 of the other fluid fuel 3 are arranged alternately in large numbers. The structure is such that the nozzle has a wide width relative to the center axis of the nozzle, and the respective injection axes do not intersect.

In the figure, 8 and 9 indicate slurry spray particles and other fuel spray particles, and it can be seen in FIG. 3 that they are injected in non-intersecting spray directions.

According to this embodiment, when two fuels are combusted simultaneously,
When mixed with the combustion air flow 14 that is introduced into the furnace from around the nozzle along the nozzle axis, the slurry spray particles 8 and the other fluid fuel spray particles 10 are mixed with air independently, so that the slurry is difficult to burn. The combustion is also carried out sufficiently and good combustion is achieved. In addition, in the figure, 11 is a mixing chamber. Further, corresponding to the jet fuel and 9, a partition 13 is preferably provided to separate the air and to change the flow rate ratio of air to the slurry and air to other fluid fuels, thereby achieving an air ratio appropriate for the combustion of each fuel. settings can be made.

Further, when the other fluid fuel is, for example, light oil or alcohol with good combustibility, by setting the air ratio to this fuel to be less than or equal to the stoichiometric air ratio, the denitrification effect of slurry combustion is also possible due to the generation of intermediate products.

That is, this change in air ratio enables two-stage combustion by division in the annular direction or partial denitrification combustion, making it possible to reduce nitrogen oxides.

Furthermore, FIG. 4 is a front view of a nozzle showing another embodiment of the present invention. The difference is that the axes intersect.

In this way, the spray particles 10 of the other fluid fuel collide with the spray particles 8 of the slurry, which further promotes atomization of the slurry and improves the ignitability and combustion efficiency of the slurry. Further, even when the other fluid fuel is at rest, only the spray medium 2 collides with the slurry spray particles 8, so that the same effect can be obtained. Furthermore, in this nozzle, highly concentrated fuel spray particles are distributed along the injection axis, while fresh combustion air 14 is supplied to the dead zone between the injection ports, so there is a zone of fuel concentration in the annular direction. is formed and combustion becomes slow,
Effective in reducing fluorine oxides.

Although the above embodiment is a case of a spraying method using a spraying medium, a pressure spraying method may be used for both or either of the fuels, and the positional relationship between the slurry and other fluid fuels is as follows.
Either side may be on the outside, and the type of other fluid may be liquid, gas, or slurry. Further, the number of flow passages in the nozzle is not limited either, as long as passages for at least two types of fuel are arranged in the coaxial nozzle.

As described above, according to the present invention, by injecting the slurry and other fluid fuel from the coaxial nozzle and correlating the positions of the injection holes,
(1) Switching between two types of fuel can be performed smoothly.
(2) There is no need to replace the burner nozzle, (3) Slurry atomization is promoted and combustibility is improved, (4) Low NO□ is achieved by fuel concentration, (5) Furthermore, air flow is improved. By using radial partitions and air ratio control, it is possible to perform the denitrification effect between the two types of fuel, and as another side effect, it is possible to burn the two types of fuel without changing the number of burners (coaxial Excellent effects can be achieved, such as improved economic efficiency (improved economy) and immediate backup of auxiliary fuel.

[Brief explanation of the drawing]

FIG. 1 is a side view of a burner nozzle showing one embodiment of the present invention, FIG. 2 is a side view of a burner nozzle showing another embodiment of the present invention, and FIG. 3 is a front view of FIG. 2. FIG. 4 is a front view of a burner nozzle showing still another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Slurry, 2... Spraying medium, 3... Single fluid fuel, 4... Inner cylinder, 5... Middle cylinder, 6... Outer cylinder, 7
...Slurry spout, 8...Slurry spray particles, 9...
Single fluid fuel jet nozzle, 10... Single fluid fuel spray droplet,
DESCRIPTION OF SYMBOLS 11... Mixing chamber, 12... Nozzle, 13... Air partition plate, 14... Air flow, 15... Heat insulation part. Agent Patent Attorney Takenaga Kawakita Figure 1

Claims (1)

[Scope of Claims] (1) In a multi-tube slurry burner device having an atomizer that mixes the slurry fuel supplied from a plurality of channels formed in the multi-tube with a spray medium by collision, and then sprays the mixture from a jet port, A multi-tube slurry burner device, characterized in that the atomizer main body is provided with a flow path and an ejection port for ejecting liquid fuel other than the slurry without mixing it with the slurry. (2. The multi-pipe slurry burner device according to claim (1), characterized in that a heat insulating section is provided between each supply channel of the slurry fuel and the atomizing medium. (3) Claim (1) ), the injection ports for each fuel are arranged so that the injection axis of the slurry fuel and the injection axis of the other liquid fuel do not intersect with the injection direction, and each fuel is sprayed independently. (4) Permissible claim (3), wherein a partition is provided so as to divide the combustion air around the nozzle into each fuel according to the spray direction of each fuel. A multi-tube slurry burner device featuring: