JPS6358092A - Dispersing plate nozzle for fluidized bed furnace - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dispersion plate nozzle for a fluidized bed furnace, and more specifically, to a dispersion plate nozzle that spouts fluidizing gas to fluidize particles in a high-temperature furnace. be.

[Conventional technology] Conventionally, for example, cement raw material powder is granulated and fired,
As a firing furnace for firing cement clinker, there is a fluidized bed furnace (for example, see Utility Model Publication No. 40-15109).This fluidized bed furnace injects fluidizing gas from below to burn inside the furnace in a combustion state. A fluidized bed is formed by causing a bed of particles to move in a manner similar to a boiling state.

by the way,! I1. In a fluidized bed furnace, in order to eject the fluidizing gas G into the furnace, a dispersion plate nozzle 50 shown in FIG. ing. Conventionally, the above-mentioned dispersion plate nozzle 50
By forming the head 52 from a heat-resistant metal, it is possible to prevent the head 52 from burning out when exposed to high temperature conditions for a long period of time.

[Problems to be solved by the invention] However, like the cement clinker kiln, 1300
In a fluidized bed furnace where the temperature is very high, from about 1400°C to 1400°C, the above-mentioned burnout cannot be sufficiently prevented. Therefore, it is conceivable to make the dispersion plate nozzle 50 made of ceramic. However, in a fluidized bed furnace, there is a large temperature difference between the upper and lower parts of the furnace bottom plate 51, that is, there is a large temperature difference between the fluidized bed and the wind box, so there is a large temperature difference between the upper and lower parts of the dispersion plate nozzle 50. Since a temperature gradient occurs, there is a risk that the ceramic dispersion plate nozzle 50, which has low mechanical strength, may be damaged due to thermal stress. Further, since ceramic has poor workability, for example, it is difficult to process the male screw 53, so it is not easy to attach it to the furnace bottom plate 51.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a dispersion plate nozzle for a fluidized bed furnace that is free from burnout and damage and can be easily attached to a furnace bottom plate.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, first, the base fixed to the furnace bottom plate is formed of metal. On the other hand, a nozzle portion including an ejection hole facing into the fluidized bed is made of ceramic. The base portion and the nozzle portion are connected.

[Function] According to the present invention, the nozzle part, which faces the fluidized bed and becomes hot, is made of ceramic with excellent heat resistance, so there is no risk of burnout. The base where the temperature gradient occurs is made of metal with high mechanical strength, so there is no risk of damage due to thermal stress.
Furthermore, since the metal base with good workability is fixed to the furnace bottom plate, the base can be easily attached to the furnace bottom plate. on the other hand,
The nozzle portion is connected to the base.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

In Figure 1, ■ is a fluidized bed furnace, 2 is a fluidized bed, 3 is a wind box, 4 is a distribution plate, 5 is a furnace bottom plate, 6 is a castable, 7 is a distribution plate nozzle, 8 is a fuel supply path, 9 is a fluidized bed chemical gas supply line,
10 is a raw material powder supply path. The fluidizing gas G at 800'C to 1000°C supplied from the fluidizing gas supply path 9 was injected into the furnace through the wind box 3 and the dispersion plate nozzle 7, and was supplied from the fuel supply path 8. reacts with fuel,
It becomes 1350℃ to 1400℃. On the other hand, the cement raw material powder supplied from the raw material powder supply path 10 forms a fluidized bed 2 by the fluidizing gas G, and cement clinker is fired.

- The distribution plate 4 mainly consists of a furnace bottom plate 5 fixed to the fluidized bed furnace l, a castable 6 made of refractory material attached to the furnace bottom plate 5, and a distribution plate nozzle for spouting the fluidizing gas G. It consists of 7.

1: In FIG. 2 showing the first embodiment of the distribution plate nozzle 7, the distribution plate nozzle 7 includes a base 11 made of a heat-resistant metal, a lock nut 12, a union nut (connecting member) 13, and a ceramic plate nozzle 7. It consists of a nozzle i14 and a buffer member 15 made of ceramic fiber, for example. The plate nozzle 7 has a through hole 6a of the castable 6.
゛L through, ノ, (external thread ll screwed on the bottom of part 11
a is screwed onto the hearth bottom plate 5, and is prevented from turning by a lock nut 12, and is removably fixed to the hearth bottom plate 5.

The bipedal base 11 is entirely pipe-shaped, has a gas passage through which the fluidizing gas G flows, and has a male screw llc screwed onto the outer periphery of a flange 11b provided at the top of the base ti. The opening at the lower end faces the wind box 3, while the -L end is disposed within the castable 6. Therefore, (a large temperature gradient occurs in the portion 11 along the axial direction.

The nozzle portion 14 has a cap-like shape as a whole, has a gas passage 17 through which the fluidizing gas G flows, and has a large number of ejection holes 1.
The pipe portion 14b provided with the pipe 4a and the pipe portion 14
a ceiling portion 14c that closes the upper end of the nozzle portion 14;
It consists of a flange 14d provided at the lower part of the flange. The ejection holes 14a face the inside of the fluidized bed 2, and the upper ejection holes 14a
a is provided in contact with the lower surface 14g of the ceiling portion 14c.

The above-mentioned union oak) 13 has its engaging portion 13a engaged with the flange portion 14d of the nozzle portion 14 via the above-mentioned buffer member 15, while its female screw 13b has the male screw llc of the base portion 11.
The base 11 and the nozzle part 14 are connected by screwing into the nozzle part 14, and both gas passages 16 and 17 are communicated with each other. Between the union nut 13 and the nozzle part 14, and
Flange portion 14d of nozzle portion 14,! - Flange 11b of base 11
An MWi member 15 is interposed between the two. In addition,
” - The union nut 13 is the upper surface 6b of the castable 6.
It is located below.

In the structure mentioned above, the nozzle fl14 facing into the fluidized bed 2, which is at a high temperature of about t300'c to 1400°C, is made of ceramic with excellent heat resistance, so that the nozzle part 14 is Burnout can be prevented.

Moreover, it is fixed to the furnace bottom plate 5.

The base 1 faces the wind box 3, so there is a large temperature gradient.
1 is made of a metal with high mechanical strength, so there is no risk of damage due to thermal stress.

Therefore, long-term continuous operation of the wave bed furnace (Fig. 1) becomes possible.

In addition, since the base nil fixed to the furnace bottom plate 5 is made of metal, the workability for the above-mentioned fixing, or in this example, the workability of the male thread lla, is good, so the attachment of the base 11 to the furnace bottom plate 5 is easy. It's easy. On the other hand, since the nozzle part 14 is connected to the base part 11 by a connecting member consisting of a union nut 13, for example, the ceramic acid nozzle 11 has poor workability.
Since there is no need to perform thread processing etc. on the nozzle part 14.
Good manufacturability. As described above, since the installation and manufacturing are easy, the manufacturability of the dispersion plate 4 (FIG. 1) is less likely to deteriorate compared to the case where a conventional metal dispersion plate nozzle is used.

Furthermore, while ceramics are generally more expensive than metals, in this invention, the nozzle part 14 is made of ceramic acid and the base part 11 is made of metal, that is, the entire dispersion plate nozzle 7 is not made of ceramic acid. It is possible to suppress an increase in the cost of the plate nozzle 7 and, in turn, the dispersion plate 4 (FIG. 1).

Incidentally, the hearth bottom plate 5 and the castable 6 attached to the hearth bottom plate 5 are slightly misaligned in the direction of arrow A. For this reason, generally, the inner diameter of the through hole 6a of the castable 6 is formed to be slightly larger than the outer diameter of the dispersion plate nozzle 7, so there is a gap between the dispersion plate nozzle 7 and the castable nozzle 6. ■IS will arise. Then, the fluid medium gets caught in the gap S located IXth below the ejection hole 14a where the fluidized bed 2 is not formed, and presses the single dispersion plate nozzle 7.

Here, in this embodiment, since the base 11 that is long inserted into the castable 6 is made of metal with high mechanical strength, there is little risk that the dispersion plate nozzle 7 will be damaged by the above-mentioned pressure.

Further, in this embodiment, since the buffer member 15 is interposed between the ceramic acid nozzle i14 and the metal base 11 and the connecting member 13, the elasticity of the buffer member 15 allows the metal and ceramic to A large difference in coefficient of thermal expansion can be absorbed, and the tightening force when assembling the dispersion plate nozzle 7 can be prevented from increasing locally. Therefore, there is no risk that the fragile ceramic acid nozzle portion 14 will be damaged.

By the way, the fluidizing gas G introduced into the wind box 3 often contains a large amount of minute dust because exhaust gas from a fluidized bed cooler (not shown) is used, for example.

Taking FIG. 5 as an example, the fluidizing gas G containing a large amount of minute dust passes through the inside of the dispersion plate nozzle 50 and passes through the ceiling part 5.
It collides with the lower surface 52g of 2c. For this reason, the dust easily adheres to and grows on the lower surface 52g of the ceiling portion 52c, and the gradually grown dust blocks the ejection hole 52a and impairs the function of the dispersion plate nozzle 50.

Here, in this embodiment, the jet hole 1 in contact with the ceiling part 14c
4a, the fluidizing gas G flows through the nozzle part 14.
The water flows inside from bottom to top, then along the lower surface 14g of the ceiling portion 14c, and is ejected from the ejection hole 14a. Therefore, the fluidizing gas G along the lower surface 14g of the ceiling portion 14c
This flow can prevent dust from adhering to the lower surface 14g of the ceiling portion 14c, so there is no risk of clogging of the ejection holes 14a due to adhesion and growth of dust.

In the second embodiment shown in FIG.
The upper surface 14e of the union nut 13 and the lower surface 13c of the engagement portion 13a of the union nut 13 are each formed in a tapered shape that extends downward toward the outer circumferential side. Note that the other configurations are the same as those of the first embodiment, and the same or corresponding parts are given the same reference numerals, and a detailed explanation thereof will be omitted.

According to this embodiment, when tightening the union oak 13,
The upper surface 14e of the nozzle portion 14 is connected to the union nut 13.
Since the nozzle part 14 is guided by the lower surface 13c of the union nut 13, the nozzle part 14 is horizontally centered with respect to the union nut 13. Therefore, since the nozzle part 14 is centered with respect to the part 11, both gas passages 16, 17 are automatically centered during said tightening.

Furthermore, since the upper surface 14e of the flange 14d of the nozzle portion 14 is tapered downward toward the outer periphery, it is possible to reduce stress concentration occurring in the portion 14f between the flange 14d and the pipe portion 14b. Therefore, nozzle parts 14 and 2! There is no risk that the flange portion 14d will be damaged when engaged with the i portion 11.

FIG. 4 shows a third embodiment of the invention.

In FIG. 4, the base portion 11 and the nozzle portion 14 are fitted and connected to each other by a spigot joint. That is, the lower fi 14h of the pipe portion 14b of the nozzle portion 14 (7) is fitted into the spigot portion lid provided at the upper portion of the base portion 11. The spigot part lid is made of a metal having a thermal expansion coefficient similar to that of the ceramic forming the nozzle part 14, such as a Fe-Ni alloy.
1d is welded and joined to the pipe portion 11f of the base 11 at the lower end surface 11e.

The method of connecting the nozzle part 14 and the nozzle part 11 is as follows:
An insert material (not shown) that does not melt at the operating temperature of the furnace but melts at a lower temperature than the metal constituting the base 11,
A method is used in which the ingot 7% 11d and the lower part 14h of the nozzle part 14 are interposed, brazed, and shrink-fitted.

In addition, as a pre-process of this brazing, the nozzle portion 14
A metal layer may be formed on the outer circumferential surface of the lower portion 14h by scattering powder of an intermetallic additive such as nickel on the outer circumferential surface and heating the powder. In other words, the direct metallization method may be used.The other configurations are the same as those in the first or second embodiment, and the same or equivalent parts are given the same reference numerals and detailed explanation thereof will be omitted. .

According to this embodiment, the nozzle portion 14 has a
Since the flange portion 14d shown in the figure is unnecessary, the nozzle portion 14 of FIG. 4 made of ceramic can be made smaller. Furthermore, since no connecting member is required, the entire distribution plate nozzle 7 can be made smaller and lighter.

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent burnout and damage to the dispersion plate nozzle, so that long-term continuous operation of the fluidized bed furnace can be achieved. In addition, since the dispersion plate λ゛ nozzle can be easily attached to the furnace bottom plate, there is little risk that the manufacturability of the dispersion plate will deteriorate.Furthermore, since the base is made of metal, the cost increase of the dispersion plate can be suppressed. .

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a fluidized bed furnace to which the present invention is applied, FIG. 2 is a partially sectional side view showing the first embodiment of the present invention, and FIG. FIG. 4 is a vertical cross-sectional view of the main part showing the embodiment, FIG. 4 is a vertical cross-sectional view of the main part showing the third embodiment, and FIG. 5 is a partially sectional side view showing the conventional example. l... Fluidized bed furnace, 2... Fluidized bed, 3... Wind box, 4
... Dispersion plate, 5 ... Furnace bottom plate, 7 ... Dispersion plate nozzle, 11 ... Base, lie ... Male thread, 13 ... Connection member (union oak)), 14 ... Nozzle Part, 14
a...Blowout hole, 14b...Pipe part, 14c...
Ceiling part, 14d... Flange part, 14g... Lower surface of ceiling part, 15... Buffer member, G... Fluidization gas. Figure 1 1-Jirokushi 9b layer large> 4. Q乍C(IZ and 22 fluidized bed 5:χ?A汲3:Reject 1b 7 pieces/min 1z not!
Nozzle 1 Figure 3 Figure 4

Claims (7)

[Claims] (1) Supported by the furnace bottom plate forming the distribution plate of the fluidized bed furnace,
A dispersion plate nozzle for ejecting fluidizing gas, wherein a base portion fixed to the furnace bottom plate is formed of metal, and a nozzle portion provided with an ejection hole facing into the fluidized bed is formed of ceramic;
A dispersion plate nozzle for a fluidized bed furnace in which the base portion and the nozzle portion are connected. (2) The dispersion plate nozzle for a fluidized bed furnace according to claim 1, wherein the base is removably fixed to the furnace bottom plate. (3) A dispersion plate nozzle for a fluidized bed furnace according to claim 1 or 2, wherein the base portion and the nozzle portion are connected by a connecting member. (4) The dispersion plate nozzle for a fluidized bed furnace according to claim 1 or 2, wherein the base portion and the nozzle portion are fitted and joined to each other. (5) The dispersion plate nozzle for a fluidized bed furnace according to claim 3, wherein a buffer member is interposed between the nozzle portion, the base portion, and the connecting member. (6) A patent claim in which a flange is provided at the lower part of the nozzle part, a male thread is provided at the upper part of the base, and the connecting member engages with the flange and a union nut is screwed onto the male thread. A dispersion plate nozzle for a fluidized bed furnace according to item 3 or 5. (7) Claims 1 to 6, wherein the jetting holes are provided in the pipe portion of the nozzle portion, and at least one of the jetting holes is provided in contact with the lower surface of the ceiling portion of the nozzle portion. A dispersion plate nozzle for a fluidized bed furnace according to any one of the above.