JPS62242719A - Atomization method and apparatus for slurry-like fuel - Google Patents

Abstract

PURPOSE:To make a stable ignition, improve an efficiency of combustion and reduce a fuel cost by a method wherein coal, water and slurry (CWS) are injected in liquid film form to increase a contact area with atomized gas to make fine particles of these substances, the liquid film are expanded at a target tapered part and the fine particles are promoted for their generation with injection from an annular slit. CONSTITUTION:A target axis 5 is concentrically inserted into a steam guide 10, has a plurality of communication holes 12 on its circumference. Its front part is made as a column form so as to form an annular slit 13 with an extremity end inner peripheral surface of the steam guide 10. At its extremity end is removably attached the target 7 and its rear end part is communicated with a first passage 1 acting as a communication passage for CWS. CWS is guided from a fuel communication passage to the annular slit 13 and is injected as an annular liquid film. Atomization gas is struck against the annular liquid film as the annular gas flow so as to make fine particles of fuel under a peeling off and separation from the liquid film, thereafter the liquid film is expanded along the tapered target 7 to increase a contact area with the atomization gas to promote a making of fine particles and then a stable continuous combustion can be performed.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a spraying method and apparatus for atomizing and burning a slurry-like fuel such as coal, water, and slurry (hereinafter referred to as CWS). be.

Conventional CWS is pressurized and supplied to the burner of a boiler by a pump or the like, and like 1-alpha fuel, it can be atomized with steam or air as an atomization gas and then combusted.

However, since CWS is manufactured by containing multiple types of pulverized coal, using water as a solvent, and adding additives,
It has characteristics that should be taken into consideration when developing an atomizer, such as high viscosity, easy clogging in the nozzle, and difficulty in atomizing the pulverized coal particles due to the influence of the J force on the surface of the water.

CWS's 7 tomizer is still under development, but it can be broadly divided into two types: an external mixing type and an internal mixing type. It is generally said that the internal mixing type has a better atomization state than the external mixing type.

Therefore, typical examples of the internal mixing type will be explained with reference to FIGS. 5 and 6.

In the figure, 31 is a slurry fuel passage, 32 is an atomizing gas passage, 33 is a fuel outlet, 34 is a flow path, 35 is a mixing chamber, 36 is an injection nozzle, and 37 is an atomizer. The slurry-like fuel pumped from D31 is ejected from the fuel outlet 33 in a columnar shape and passes through the atomizing gas passage 32.
It joins with the atomizing gas from the mixing chamber 35? The mixture is atomized and ejected from the injection fJ4 nozzle 36, and combusted within the combustion chamber. In this internal mixed type,
Although the structure is complex, it cannot be said that sufficient atomization has been achieved yet. Further, the measures against wear are not sufficient due to the complicated structure.

For this reason, 1) the atomization state of the CWS is poor, ignition is unstable, and the combustion efficiency is low; 2) the atomization gas used to improve the atomization characteristics has a large amount of efface 1m; 3) the mixing room 4) There are many parts that wear out, resulting in low reliability.

Problems to be Solved by the Invention The present invention solves the above-mentioned problems in CWS atomization, namely, the fact that the atomization state of CWS is poor and the combustion efficiency is low, which increases the fuel cost. The cost of atomizing increases because multiple atomizing gases are required, and the structure of the atomizer becomes complicated, making it more likely to become clogged with atomized coal particles. The aim is to solve these problems, thereby enabling stable continuous operation of CWS combustion, increasing the combustion efficiency of CWS, and promoting the commercial spread of CWS in small and medium-sized boilers. .

Means for Solving the Problems The present invention is based on the fact that promoting exfoliation and splitting is effective in obtaining good atomization of CWS.
In order to increase the contact area between the CWS and the atomizing gas,
The above-mentioned problem is solved by a liquid 15I atomization method in which the outlet port is an annular port, CWS is supplied in the form of a liquid film, and atomizing gas is applied to the CWS.

Therefore, the atomizer body is removably connected to the tip of the supply conductor, which has a first passage that is a conduction path for the CWS and a second passage that is a conduction path for atomizing gas outside the supply conductor. , a plurality of communication holes communicating with the first passage, a target axis forming an inner circumferential surface of an annular slit through which slurry fuel is ejected in an annular liquid film shape, and an outer circumferential surface of the annular slit; a Methi-11 guide having an annular jet port that communicates with the second passage and supplies the atomizing gas as an annular air flow; and a cutting circle Etlu that is attached to the target axis and expands the surface area of the slurry fuel liquid. It consists of a target and a steam cap having a trumpet-shaped opening facing the inner surface of the target and forming an annular slit.

The working CWS is guided from the fuel conduit to the annular slit and ejected as an annular liquid film, and the atomizing gas is collided with the annular liquid film as an annular air stream to atomize the fuel by rJ1 separation from the liquid film, After that, by spreading the liquid film along the tapered target, the contact area with the atomizing gas is increased, further promoting atomization, and further atomization is promoted from the annular slit fuel injection port. It will be sprayed.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 4.

FIG. 4 shows a CWS supply system applied to the CWSO spraying method and device according to the present invention.
Tank A, CWS pressure feeding device B such as a pump, strainer C, flow meter, and atomizer E that sprays CWS.
etc.

1 and 2 show an atomizer according to an embodiment of the present invention.

This atomizer body consists of a target axis 5 to which a target 7 is removably attached, and a steam guide 1.
0 and a steam cap 9.

The target axis 5 is inserted concentrically into the steam guide 10 and has a plurality of communication holes 12 on the circumference,
The front part has a cylindrical shape to form a ring slit (13) with the inner circumferential surface of the tip of the Mechi-11 guide 10, and a target 7 is detachably attached to the tip.
The rear end portion communicates with the first jffi'tB1 which is a conduction path of the CWS.

The steam guide 10 is press-fixed by the steam cap 9 and the target axis 5, has a plurality of steam communication holes 16 on the circumference, and has a steam passage 1 of the burner outer tube 3.
7, it communicates with the second passage 2 which is a vapor conduction passage for the atomizing gas at the rear.

The outer peripheral surface of the tip of the steam guide 10 and the inner peripheral surface of the tip of the steam gap 9 are both tapered surfaces.
6 to form an annular steam outlet 15, and a hole is provided to form an annular slit 13 in cooperation with the cylindrical portion of the target axis 5.

The steam cap 9 has a trumpet-shaped opening surface 9a on the inner periphery of the tip and a tapered surface 9b of about 45° on the outer periphery of the tip.
1 and a steam guide 10.

The target 7 has a conical shape and is arranged concentrically inside the steam cap 9, and is fixed to the center of the tip surface of the target axis 5 with a target holding bolt 7b.

The tapered inner surface 7a of the target 7 faces the closed surface 9a of the methi-11 cap 9, forming an annular slit fuel injection port 8.

The inner peripheral surface 9c of the tip of the steam cap 9 forms an annular slit with the outer surface of the cylindrical tip of the target axis 5, and a short flow path 1 is formed between the contact between the fuel and steam and the end of the target.
4 is formed.

A target clearance adjustment ring 6 for adjusting a target clearance h related to the fuel injection port 8 is press-fixed by a steam guide 10 and a target 7 xis 5.

Note that the #i oblique angle of the annular steam outlet 15 formed by the steam cap 9 and the steam guide IO is 30″~
60" is appropriate, and the clearance between the trumpet 1j mouth surface 9a of the steam cap forming the fuel injection port 8 and the target inner surface 7a is in order to prevent coal particulates from clogging 111 and to perform appropriate atomization. 1.0~2.0m
A range of m is appropriate. Further, since the target 7 is subject to severe wear due to coal particles, it is preferably made of new ceramics, and is preferably screwed to the target axis 5 to facilitate replacement.

In the embodiment shown in FIG. 3, the plurality of communication holes 12 formed in the target axis 5 are slightly different from the first embodiment, and the other configuration is that Since it is substantially the same as the first embodiment, the explanation is omitted and only the reference numerals are given.

The CWS in the CWS tank A is sent by a CWS pressure feeding device B such as a pump to an atomizer E that sprays the CWS via a strainer C and a flow meter, where it is atomized and sprayed into a furnace F for combustion.

The CWS that has passed through the flow meter is the first nth in the fuel introduction pipe 4.
"tBl, it passes through the communication hole 12 and is ejected from the annular slit 13 as an annular liquid film. On the other hand, the atomizing gas passes through the second passage!!!2, the steam passage 17, and the It becomes an annular air flow from the steam outlet 15 and collides with the liquid film of the CWS at path 1=path!4, and the CWS is atomized by peeling and splitting from the liquid film surface, and then the liquid film is transferred to the tapered target. It spreads along the inner surface 7a to increase the contact area with the atomizing gas, further promoting atomization, and further atomizing the fuel from the annular slit fuel injection port 8 indicated by the target clearance h. It is sprayed into the furnace 1?

Although the description has been made using steam as the atomizing gas, air or the like may also be used as the gas.

Effects of the Invention According to the present invention, peeling and splitting, which is effective in atomizing CWS, is atomized by ejecting CWS in the form of a liquid film and increasing the contact area with the atomizing gas. By expanding the liquid film and promoting atomization by jetting from the annular slit, the atomization is sufficiently performed. Therefore, the amount of atomizing gas supplied is smaller than in conventional liquid column atomization methods and devices, and sufficient atomization stabilizes ignition, provides high combustion efficiency, and reduces fuel costs.

In addition, CWS does not have an internal mixing chamber like conventional ones;
The flow path from when the atomizing gas comes into contact with the atomizing gas until it is injected is short and the structure is simple, so there is no possibility of clogging.

Furthermore, since the target is simply attached to the target axis, it can be easily replaced when it wears out.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an atomizer according to the present invention, Fig. 2 is a front view thereof, Fig. 3 is a sectional view of a 7 atomizer according to another embodiment of the present invention, and Fig. 4 is a supply system diagram of the cws. 5 is a sectional view of a conventional 7 atomizer, and FIG. 6 is a sectional view of another conventional atomizer.

Claims (7)

[Claims] (1) Slurry fuel is guided from the fuel conduit to an annular slit and ejected as an annular liquid film, and atomizing gas is made to collide with this annular liquid film as an annular air stream to atomize the fuel by peeling and splitting from the liquid film. After that, by spreading the liquid film along the tapered target, the contact area with the atomizing gas is increased and further atomization is promoted. A method of spraying slurry fuel, characterized by spraying while accelerating the spraying. (2) The atomizer main body is removably connected to the tip of a supply conductor that has a first passage that is a passage for slurry fuel and a second passage that is a passage for atomizing gas outside the supply conductor,
a target axis in which the atomizer body forms a plurality of communication holes communicating with the first passage and an inner circumferential surface of an annular slit that ejects the slurry fuel in an annular liquid film shape;
a steam guide that forms the outer circumferential surface of the annular slit and has an annular jet port that communicates with the second passage and supplies atomizing gas as an annular air stream; A slurry fuel spraying device comprising a cone-shaped target that expands the surface area of a liquid film, and a steam cap that has a trumpet-shaped opening that faces the inner surface of the target and forms an annular slit. (3) The collision angle of the atomizing gas with respect to the annular slit through which the slurry fuel is jetted in the form of an annular liquid film is set at 300 to 6
3. The slurry fuel spraying device according to claim 2, wherein the angle is 0°. (4) The slurry fuel spraying device according to claim 2, wherein the clearance between the trumpet-shaped opening surface of the steam cap and the inner surface of the target is 1.0 to 2.0 mm. (5) The slurry fuel spraying device according to claim 2, wherein the target is made of new ceramics. (6) The slurry fuel spraying device according to claim 2, wherein the target can be attached to and detached from the target axis with a screw. (7) The slurry fuel spraying device according to claim 2, characterized in that a target clearance adjustment ring is provided between the target axis and the steam guide.