KR960005760B1 - Slurry burner - Google Patents

Abstract

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Description

Slurry burner

1 is a cross-sectional view of a slurry burner according to an embodiment of the present invention.

2 is a cross-sectional view showing the slurry burner in use.

3 is a cross-sectional view of a conventional slurry burner.

4 shows a boiler system using a burner according to the invention.

* Explanation of symbols for main parts of the drawings

1: burner plug 2: fuel supply passage

3: spray medium supply passage 4: burner plate

5: fuel distribution compartment 6: first mixed compartment

7: Burner tip 8: 2nd mixing compartment

9: nozzle

The present invention relates to a burner using a slurry as fuel as a mixture of coal and water (CWM).

As shown in FIG. 3, a conventional slurry burner includes a burner plug 1, a burner plate 4, a burner tip 7 and a tip nut 10, wherein the tip nut 10 includes a burner plug ( 1), it is fitted around burner plate 4 and burner tip 7 to fix the parts together (see, for example, published Japanese Utility Model Publication No. 87-204133). The burner plug 1 comprises a central fuel supply passage 2 and a plurality of spray medium supply passages 3 which are circumferentially spaced apart from the fuel supply passage 2. The burner plate 4 has a fuel distribution compartment 5 in communication with the fuel supply passage 2, a passage for distributing the fuel supplied from the fuel supply passage 2, and a fuel distribution compartment through the conduit 5a ( A plurality of first mixing compartments 6 are provided for mixing the fuel supplied from 5) and the spray medium supplied from the spray medium supply passage 3. The burner tip 7 is formed in the second mixing compartment 8 in communication with the first mixing compartment 6 and further mixing the fuel and spray medium, and one end of the burner tip spaced apart from the burner plate 4. A plurality of nozzles 9 are sprayed outward from the slurry burner.

Fuel such as high density coal-water slurry and spray medium such as compressed air are introduced into the burner plug 1. The fuel and spray medium are then flowed from the fuel supply passage 2 and the spray medium supply passage 3 into the burner plate 4 respectively. In the burner plate 4, fuel flows from the fuel distribution compartment 5 toward the first mixing compartment 6 and mixes with the spray medium. The mixture is then introduced into the burner tip 7. The mixture is mixed better than in the second mixing compartment 8. The mixture is then sprayed out of the slurry burner through the nozzle 9.

High density coal-water slurries are very abrasive. Thus, burner plate 4 and burner tip 7 are protected with a wear resistant material.

It is an object of the present invention that a mixture of fuel and spray medium supplied from a plurality of first mixing compartments is uniformly distributed in the second mixing compartment due to the collision and decelerates towards the inner side of the second mixing compartment (or burner tip). And a slurry burner capable of spraying the mixture homogeneously while minimizing abrasion of the inner side of the burner tip, the mixture being mixed better than in the second mixing compartment.

It is a further object of the present invention to provide a slurry burner which is subjected to shear forces while the fuel flows along the inner wall of the second mixing compartment to prevent the fuel from becoming relatively large droplets from the sprayed state.

According to the present invention, there is provided a burner plug including a fuel supply passage for supplying fuel slurry and a plurality of spray medium supply passages for supplying a spray medium, a fuel distribution compartment provided for dispensing fuel and a fuel supplied from the fuel distribution compartment. Further mixing the burner plate comprising a plurality of first mixing compartments provided for mixing with the spray medium supplied from the spray medium supply passage of the burner plug, and the mixture of fuel and spray medium supplied from the first mixing compartment of the burner plate A slurry burner is provided which comprises a second mixing compartment provided between the burner tip and the burner plate and a burner tip comprising a plurality of nozzles for spraying the mixture out of the slurry burner, wherein the first mixing compartment is provided. The axis with the respective axis flowing along the mixture Are inclined to cross each other in the second mixing compartment.

In the slurry burner of the present invention, the slurry fuel is first supplied from the fuel supply passage of the burner plug to the first mixing compartment through the fuel distribution compartment of the burner plate. The spray medium is also fed from the spray medium supply passage of the burner plug to the first mixing compartment of the burner plate and mixed with the fuel. The mixed mixture is then fed to a second mixing compartment at the burner tip. The mixture is further mixed in the second mixing compartment and then sprayed and combusted from the nozzle. When the mixture exits the first mixing compartment, the mixture is crossed in the second mixing compartment. This leads to collisions between the mixtures and thereby uniform dispersion. After the mixtures are thoroughly mixed in the second mixing compartment, they are sprayed out of the slurry burner.

The uniform dispersion in the second mixing compartment causes the mixtures to impinge on the inner side of the burner tip at a slower rate than when exiting the first mixing compartment. This reduces the wear of the burner tip.

Additionally, the sprayed fuel is homogeneous by being thoroughly mixed in the second mixing compartment.

The fuel is completely agitated by collision with each other as it enters the second mixing compartment from the first mixing compartment. The fuel is subjected to shear forces while flowing along the inner wall of the second mixing compartment. This creates a thin film of fuel to remove relatively large lumps in the fuel being sprayed.

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

1 shows one embodiment of the present invention. The same elements are denoted by the same reference numerals as in FIG.

In this embodiment, six first mixing compartments 6 are provided in the burner plate 4 spaced at equal intervals along the circumferential direction. The first mixing compartment 6 is inclined inwards towards the second mixing compartment 8 and intersects with each other at point C. The position of the point C is L as the distance between the point C and the end face of the burner tip 7, and L / L is 0.5 to 0.8 when L is the internal length of the burner tip 7. It is preferable to determine so as to be.

The burner tip 7 has eight nozzles 9 spaced at equal intervals along the circumferential direction.

In this embodiment, the burner plug 1 comprises a central tube or inner tube 1A and an outer tube 1B, which tubes are kept in a coaxial relationship with each other. The flange 1a extends radially outward from one end of the inner tube 1A and contacts the burner plate 4. The inner tube 1A forms a fuel supply passage 2 that receives a mixture of coal and water (CWH) through the conduit 12. The plurality of holes formed in the flange 1a of the inner tube 1A are the spray medium supply passages 3 through which the steam flows.

In the embodiment shown in FIG. 1, the portion of the first mixing compartment 6 corresponding to the upstream portion of the conduit 5a is smaller in diameter than the rest of the first mixing compartment 6. The structure of the remaining parts is the same as that of the parts shown in FIG. 3 except for the wear resistant material.

In the slurry burner having the above structure, the slurry fuel is supplied from the fuel supply passage 2 of the burner plug 1 to the first mixing compartment 6 through the fuel distribution compartment 5. The spray medium flows from the spray medium supply passage 3 into the first mixing compartment 6 of the burner plate 6 and mixes with the fuel. The fuel and spray medium are further mixed in the second mixing compartment 8. The fuel is then sprayed from the nozzle 9 and combusted. The mixture flows out of the first mixing compartment 6 and intersects with each other in the second mixing compartment 8. By this structure, the mixture is uniformly dispersed by the collision before it is sprayed from the nozzle 9.

By uniform dispersion in the second mixing compartment 8, the mixture impinges on the inner side of the burner tip 7 at a slower rate than when exiting the first mixing compartment 6. This serves to reduce wear of the burner tip 7.

Additionally, the sprayed fuel is homogeneous by being thoroughly mixed in the second mixing compartment.

As shown in FIG. 2, the fuel is agitated completely by the collision when it is introduced into the second mixing compartment 8 from the first mixing compartment 6. The fuel is subjected to shear forces while flowing along the inner wall of the second mixing compartment 8. This produces a thin fuel film to suppress the generation of relatively large fuel masses during spraying.

Burner tip 7 and burner plate 4 are prone to wear and are preferably made of ceramic (such as silicon nitride) to provide abrasion resistance.

In the present invention, after the combustion is completed, it is preferable to supply water, steam or air to the fuel supply passage 2 in the slurry burner to wash or remove the residue.

4 shows a fuel system of the boiler 21 equipped with the burner 20 described above.

The mixture of coal and water (CWM) is fed to the tank (32) via a pipe (31). The mixture is then fed from the tank 32 to the two single screw fuel injection pumps 35 and 36 via corresponding pairs of lines 33 and 34, respectively. Pumps 35 and 36 are connected to burner 20 through a pair of strainers 37 and 38. Thus, the mixture flows from the pumps 35 and 36 through the strainers 37 and 38 to the burner 220. The excess CWM is returned to tank 32 via lines 39 and 40. The heavy oil burner 41 is mounted to the boiler 21. Strainers 37 and 38 serve to separate the mass and the separated mass is pulverized in a sludge mixer 43. Thus, the mass is crushed and returned to the tank 32. An automatic combustion controller (ACC) 44 controls the amount of CWM supplied according to the boiler load.

Claims (7)

A burner plug comprising a fuel supply passage through which fuel in a slurry state passes and a spray medium supply passage through which a spray medium is supplied, a fuel distribution compartment for distributing fuel, and fuel and the burner supplied from the fuel distribution compartment A burner plate comprising a plurality of first mixing compartments for mixing the spray medium supplied from the spray medium supply passage of the plug, and a burner tip, the burner tip being formed between the burner tip and the burner plate to form the first mixing of the burner plate A burner tip comprising a second mixing compartment for mixing the mixture of fuel and spray medium supplied from the compartment and a plurality of nozzles for spraying the mixture out of the slurry burner, the first mixing compartment having a direction in which the mixture flows; Each having an extending axis, the axes mixing the second mixture The distance between the inner surface of the burner tip and the point where the axis line of the first mixing compartment intersects is equal to ℓ and the shaft between the end face of the burner plate and the inner surface of the burner tip is inclined to cross each other in the compartment. Slurry burner, characterized in that L / L is 0.5 to 0.8 when the direction distance is L. The fuel distribution compartment of claim 1, wherein the fuel distribution compartment is formed at the center of one side of the burner plate, and the plurality of first mixing compartments are formed at equal intervals along the circumferential direction around the fuel distribution compartment. And a fuel distribution compartment and the first mixing compartment communicate with each other through a conduit. The slurry burner of claim 1, wherein the burner plate comprises six or more first mixing compartments. The slurry burner of claim 1, wherein the burner tip includes eight or more nozzles. The slurry burner according to claim 1, wherein the nozzles are provided in the burner tip at equal intervals along the circumferential direction. 2. The slurry burner of claim 1, wherein the nozzles at the tip of the burner are larger in number than the first mixing compartment of the burner plate. The slurry burner of claim 1, wherein the slurry is a mixture of coal and water.