JP3300727B2 - Burner chip for slurry fuel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a COM (Coal Oil Mixtu)
re: Coal / oil slurry or CWM (Coal Water M)
ixture: coal / water slurry), etc., relates to improvement of burner chips in a slurry-fired boiler, and more particularly to improvement of durability.

[0002]

FIG. 9 is a longitudinal sectional view showing an example of a conventional burner chip for CWM, FIG. 10 is an enlarged view of a portion X in FIG.
1 is a vertical sectional view and a front view showing a ceramic sleeve (5) shown in FIG.

[0003] In these figures, (1) is a burner chip. (2) is a large-diameter fuel spray hole, (3) is a small-diameter spray medium introduction hole whose downstream end communicates coaxially with the upstream end of the fuel spray hole (2), and a step is formed in the communicating portion. is there. (4)
Numeral denotes a fuel introduction hole inclined at the side of the fuel spray hole (2) and having a downstream end opened.

[0004] The inner surface of the entire length of the large diameter fuel spray hole (2) is:
Divided ceramic sleeve (5), (6) fitted
Is formed. Slurry fuels such as COM and CWM have extremely high abrasion properties. Therefore, in a burner chip (1) using a normal alloy steel as a base material, a passage downstream of a junction between the fuel and a spray medium (such as steam) is used. A ceramic sleeve made of tungsten carbide (WC) or the like having excellent wear resistance is used for the inner surface. The upstream ceramic sleeve (5) has a notch (5a) at the base (upstream end).
Is provided, and a stopper pin (11) is inserted to prevent rotation. Further, the ceramic sleeve (6) on the downstream side is fixed in the axial direction by a snap ring (12) fitted into a groove provided on the outer periphery.

[0005]

The above-mentioned conventional burner chip for slurry fuel has the following problems to be solved.

[0006] 1) At the stepped portion which moves from the small diameter spray medium introduction hole (3) to the large diameter fuel spray hole (2), the base material of the burner tip (1) and the stopper pin (11) are connected to each other as shown in FIG.
Partial wear or erosion as shown in (a) (13)
Occurs.

2) Abrasion and erosion (13) as shown in FIG. 12 (b) occur on the burner chip base material (1) around the fuel introduction hole (4), and the slurry fuel is mixed with the ceramic sleeve (5). The fuel may penetrate into the gap with the material (1), or the fuel introduction hole (4) and the spray medium introduction hole (3) may be connected.

3) Uneven wear occurs as shown in FIG. 13A on the ceramic sleeve made of tungsten carbide.
The circle drawn by the dotted line in FIG. 13 is the inner surface before wear.

[0009]

The present inventor proposes the following slurry fuel burner in order to solve the above-mentioned conventional problems.

1) A large-diameter fuel spray hole, a small-diameter spray-medium introduction hole whose downstream end communicates coaxially with the upstream end of the fuel spray hole, and a downstream end inclined to the side of the fuel spray hole. In a burner chip for a slurry fuel having a fuel introduction hole that opens, an inner surface of the entire length of the fuel spray hole and an inner surface of a downstream portion of the spray medium introduction hole each have a separate ceramic sleeve fitted into the burner chip. Ceramic sleeve formed on the inner surface of the downstream portion of the spray medium introduction hole
A burner chip for a slurry fuel, characterized in that the fuel spray hole is prevented from rotating by a stopper pin together with a ceramic sleeve forming the entire inner surface of the fuel spray hole.

2) In addition to the above requirements, the entire length of the inner surface of the fuel introduction hole is different from that of the ceramic at the downstream side and the upstream side.
2. The burner chip for slurry fuel according to claim 1, wherein the sleeve is formed by fitting the lock sleeve into the burner chip.

3) A burner chip for a slurry fuel, wherein the material of the ceramic sleeve is dense silicon carbide in addition to the requirements of the above 1) or 2).

[0013]

1) In the above solution 1), the inner surface of the fuel spray hole of the large diameter and the inner surface of the downstream portion of the small diameter spray medium introduction hole are fitted with ceramic sleeves separate from each other into the burner chip. The ceramic sleeve, which is formed and forms the inner surface of the downstream portion of the spray medium introduction hole, is prevented from rotating by the stopper pin together with the ceramic sleeve forming the entire inner surface of the fuel spray hole. At the step that moves from the hole to the large diameter fuel spray hole, a vortex occurs in the spray medium mixed with the slurry fuel, and even if a part of the fuel is caught in the upstream small diameter portion, that is, the spray medium introduction hole, No abrasion or the like occurs at the step. Also,
Ceramic sleeve forming the inner surface of the downstream portion of the small diameter spray medium introduction hole is a separate structure and the ceramic sleeve forming the inner surface of the entire length of the fuel spray holes of the upper SL larger diameter,
If damage occurs, it is only necessary to replace it, which is economical.

2) Further, in the above solution 2),
The inner surface of the entire length of the fuel introduction hole is also separate from the downstream and upstream sides
Formed by inserting a ceramic sleeve into the burner chip
As a result , the slurry fuel does not directly contact the base material of the burner chip, and the base material does not wear. What
Note that a ceramic tree that forms the inner surface of the fuel introduction hole
If the switch is damaged, replace only the damaged
To save expensive ceramic sleeves.
Can be planned.

3) In addition, in the above solution 3), the material of the ceramic sleeve is dense silicon carbide (SiC) which is more excellent in abrasion resistance than conventional tungsten carbide (WC). Wear is reduced and the sleeve has a longer life.

Therefore, the durability of the burner chip for slurry fuel such as COM and CWM is improved.

[0017]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.
2 is an enlarged view of a part II in FIG. 1, FIG. 3 is a vertical sectional view and a front view showing a ceramic sleeve (7) in FIG.
FIG. 4 is a vertical sectional view and a front view showing the ceramic sleeve (8) in FIG. 2 taken out.

In this embodiment, the inner surface of the downstream portion of the small diameter spray medium introduction hole (3) is also formed by a ceramic sleeve (8), and the ceramic sleeve (8) has an axial groove on the outer peripheral side. (8a) is provided. A conventional notch is also provided at the upstream end of the upstream one (7) of the ceramic sleeves (6) and (7) forming the inner surface of the large-diameter fuel spray hole (2) (see FIG. Instead of 5a)), an axial groove (7a) is provided on the outer peripheral side as in the case of the ceramic sleeve (8). The stopper pins (11) are inserted into the grooves (7a) and (8a) to stop the rotation of the ceramic sleeves (7) and (8). In this embodiment, dense silicon carbide (SiC) is used as the material of the ceramic sleeves (6), (7), and (8). Other configurations are the same as those of the conventional one.

In such a burner chip, a spray medium such as steam is supplied at a high pressure from the spray medium introduction hole (3), and a slurry fuel such as CWM is supplied from the fuel introduction hole (4). Then, the slurry fuel joins and mixes with the spray medium, and is sprayed into the furnace or the like from the outlet of the fuel spray hole (2) in a mist state and burned.

In this embodiment, in the fuel spray hole (2) slightly downstream of the step between the small diameter spray medium introduction hole (3) and the large diameter fuel spray hole (2), the fuel introduction hole (4) is formed. When the slurry fuel from the nozzle and the spray medium from the spray medium introduction hole (3) merge and a vortex is generated near the step and the fuel is caught in the spray medium introduction hole (3), the spray medium introduction hole Since the inner surface of (3) is also made of a ceramic material, its abrasion resistance is equivalent to that of the inner surface of the fuel spray hole (2), and is not worn or eroded as in the prior art.

In this embodiment, the grooves (7a), (8a)
Is present only on the outer peripheral side of the ceramic sleeves (7) and (8) and is not related to the inner peripheral side.
The slurry fuel does not come into contact with the head or the like of the stopper pin (11) as described above, so that the stopper pin (11) is not worn or eroded.

Further, in this embodiment, since the dense silicon carbide (SiC) is used as the material of the ceramic sleeves (6), (7) and (8), the wear resistance is higher than that of the conventional tungsten carbide (WC). Is significantly improved. While the conventional ceramic sleeve was unevenly worn as shown in FIG. 13A, the ceramic sleeve of this embodiment using silicon carbide has the same inner surface as shown in FIG. It has been found that the uneven wear is eliminated and the entire circumference is worn evenly, and the amount of wear is reduced to about 1/2 of the conventional value, as shown in FIG.

FIG. 5 is a longitudinal sectional view showing a second embodiment of the present invention, FIG. 6 is an enlarged view of a portion VI in FIG. 5, and FIG. 7 is a longitudinal sectional view showing a ceramic sleeve (9) shown in FIG. FIG. 8 is a longitudinal sectional view and a front view showing the ceramic sleeve (10) in FIG. 6 taken out.

In this embodiment, the inner surface of the fuel introduction hole (4) is also formed by the ceramic sleeves (9) and (10). That is, the downstream sleeve (10) having the shape shown in FIG. 8 and the upstream sleeve (9) having the shape shown in FIG. 7 are fitted into the large-diameter hole formed in the burner chip (1). The provision of a groove (9a) on the outer periphery of the upstream sleeve (9) and the fixing in the axial direction by the snap ring (12) is similar to the conventional ceramic sleeve (6). The ceramic sleeves (6), (7), (8), (9), (1)
0) also uses silicon carbide (SiC) as a material.

In this embodiment, the inner surface of the fuel introduction hole (4) is also made of a ceramic sleeve (9) using dense silicon carbide,
Since the slurry is formed in (10), even if the slurry fuel passes through the fuel introduction hole (4), the fuel does not come into contact with the base material as in the conventional case, and the contacting portion is made of only the ceramic material. Therefore, its wear resistance is equivalent to that of the fuel spray holes (2) and the spray medium introduction holes (3), and is not worn or eroded as in the prior art.

[0026]

According to the present invention, since the entire length of the fuel injection hole, the downstream portion of the spray medium supply hole, and the inner surface of the fuel introduction hole are also formed by the ceramic sleeve, the slurry fuel having high abrasion property is used for the burner chip. There is no contact with the base material, and no wear or erosion occurs on the base material. Since the ceramic has abrasion resistance, the ceramic sleeve itself is not subject to wear or erosion. If silicon carbide is used as the material of the ceramic sleeve, the effect is further enhanced. In this way, the life of the burner tip is significantly extended.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion II in FIG.

FIG. 3 is a vertical sectional view and a front view showing a ceramic sleeve (7) in FIG. 2 taken out.

FIG. 4 is a vertical sectional view and a front view showing a ceramic sleeve (8) in FIG. 2 taken out.

FIG. 5 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 6 is an enlarged view of a portion VI in FIG. 5;

FIG. 7 is a vertical sectional view and a front view showing a ceramic sleeve (9) in FIG. 6 taken out.

FIG. 8 is a vertical sectional view and a front view showing the ceramic sleeve (10) in FIG. 6 taken out.

FIG. 9 is a longitudinal sectional view showing an example of a conventional slurry fuel burner chip.

FIG. 10 is an enlarged view of a portion X in FIG. 9;

FIG. 11 is a vertical sectional view and a front view showing a ceramic sleeve (5) in FIG. 10 taken out.

FIG. 12 is a view illustrating the state of wear and erosion of a conventional burner tip for slurry fuel.

FIG. 13 is a view showing the state of wear of the inner surface of the ceramic sleeve by comparing the present invention with the conventional one.

FIG. 14 is a diagram showing the wear amount of a ceramic sleeve in comparison with the present invention and the conventional one.

[Explanation of symbols]

 (1) Burner tip (2) Fuel spray hole (3) Spray medium introduction hole (4) Fuel introduction hole (5) Ceramic sleeve (5a) Notch (6), (7) Ceramic sleeve (7a) Axial groove ( 8) Ceramic sleeve (8a) Axial groove (9) Ceramic sleeve (9a) Circumferential groove (10) Ceramic sleeve (11) Stopper pin (12) Snap ring (13) Wear or erosion

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23D 21/00 F23D 11/38

Claims (3)

(57) [Claims] 1. A large-diameter fuel spray hole, a small-diameter spray medium introduction hole having a downstream end coaxially communicating with an upstream end of the fuel spray hole, and a downstream end inclined to a side portion of the fuel spray hole. In a burner chip for a slurry fuel having a fuel introduction hole that opens, an inner surface of the entire length of the fuel spray hole and an inner surface of a downstream portion of the spray medium introduction hole each have a separate ceramic sleeve fitted into the burner chip. Ceramic sleeve formed on the inner surface of the downstream portion of the spray medium introduction hole
A burner chip for a slurry fuel, characterized in that the fuel spray hole is prevented from rotating by a stopper pin together with a ceramic sleeve forming the entire inner surface of the fuel spray hole. 2. The slurry fuel according to claim 1, wherein the entire length of the inner surface of the fuel introduction hole is formed by fitting separate ceramic sleeves to the burner chip on the downstream side and the upstream side. Burner tip. 3. The burner chip for a slurry fuel according to claim 1, wherein the material of the ceramic sleeve is dense silicon carbide.