JPH0776672B2 - Dispersion plate nozzle for fluidized bed furnace - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dispersion plate nozzle for a fluidized bed furnace, and more particularly to a dispersion plate nozzle for ejecting a fluidizing gas that fluidizes particles in a high temperature furnace. is there.

[Prior Art] Conventionally, for example, by granulating and firing cement raw material powder,
There is a fluidized bed furnace as a baking furnace for baking a cement clinker (see, for example, Japanese Utility Model Publication No. 40-15109). This fluidized bed furnace forms a fluidized bed by injecting a fluidizing gas from below and causing a particle layer in the furnace in a burning state to move like a boiling state.

By the way, in a fluidized bed furnace, in order to jet the fluidizing gas G into the furnace, for example, a dispersion plate nozzle 50 shown in FIG.
Is screwed to and supported by a furnace bottom plate 51 forming a dispersion plate of the fluidized bed furnace. Conventionally, the dispersion plate nozzle 50 is formed of a heat-resistant metal to prevent the top portion 52, which is exposed to a high temperature state, from being burnt out for a long period of time.

[Problems to be Solved by the Invention] However, in a fluidized bed furnace that has an extremely high temperature of about 1300 ° C. to 1400 ° C. like a cement clinker firing furnace,
The above burning cannot be sufficiently prevented. Therefore, the dispersion plate nozzle 50
It is conceivable to make the product ceramic. However, in the fluidized bed furnace, since the temperature difference between the upper side and the lower side of the furnace bottom plate 51 is large, that is, the temperature difference between the inside of the fluidized bed and the inside of the wind box is large, so that the upper part and the lower part of the dispersion plate nozzle 50 are large. Due to the temperature gradient, the ceramic dispersion plate nozzle 50 having low mechanical strength may be damaged by thermal stress. Also,
Since the ceramic has poor workability, for example, it is difficult to process the male screw 53, so that it is not easy to attach it to the furnace bottom plate 51.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a dispersion plate nozzle for a fluidized bed furnace that is not likely to be burnt or damaged and can be easily attached to the furnace bottom plate.

[Means for Solving the Problems] In order to achieve the above object, the present invention is a dispersion plate nozzle that is supported by a furnace bottom plate forming a dispersion plate of a fluidized bed furnace and ejects a fluidizing gas, This dispersion plate nozzle is made of a heat-resistant metal and has a pipe-shaped base portion having a flange portion at the upper end, which has a male screw threaded on the outer periphery, and a jet hole formed at the outer periphery by closing the top portion and facing the flange portion. A ceramic pipe-shaped nozzle portion having a collar portion at the lower end portion, and an internal thread having an engaging portion for engaging with the collar portion of the nozzle portion at the upper end portion and screwed to the male screw of the pipe-shaped base portion. It is characterized by comprising a tubular connecting member provided on the inner surface of the lower end portion, and a heat resistant cushioning member interposed between the connecting member and the nozzle portion and between the flange portions of the nozzle portion and the pipe-shaped base portion.

[Action]

According to the above configuration, the dispersion plate nozzle includes a pipe-shaped base portion made of a heat-resistant metal, and a ceramic nozzle portion, and since the nozzle portion facing the high temperature fluidized bed is made of ceramic excellent in heat resistance, It is possible to prevent the nozzle part from being damaged, and since the pipe-shaped base part is made of metal with high mechanical strength, there is no risk of damage due to heat treatment, and moreover, it can be engaged with the flange part of the nozzle part. Since the nozzle portion is connected to the pipe-shaped base portion by screwing the connecting member to the pipe-shaped base portion, not only the connecting work of these two is easy, but also the base portion is made of metal. , Its workability is good.

Further, since the buffer member is interposed between the connecting member and the nozzle portion and between the flange portions of the nozzle portion and the pipe-shaped base portion, due to the elasticity of the buffer member, the thermal expansion difference between the metal and the ceramic and the connecting member It is possible to locally absorb an excessive tightening force due to screwing and effectively prevent the ceramic nozzle portion from being damaged.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a fluidized bed furnace, 2 is a fluidized bed, 3 is a wind box, 4 is a dispersion plate, 5 is a furnace bottom plate, 6 is a castable plate, 7 is a dispersion plate nozzle, 8 is a fuel supply passage, and 9 is a fluidized plate. A vaporized gas supply passage, 10 is a raw material powder supply passage. The 800 ° C. to 1000 ° C. fluidized gas G supplied from the fluidized gas supply passage 9 is ejected into the furnace through the wind box 3 and the dispersion plate nozzle 7 and reacts with the fuel supplied from the fuel supply passage 8. And then 1350 ° C
It reaches 1400 ℃. On the other hand, the cement raw material powder supplied from the raw material powder supply passage 10 is converted into the fluidized bed 2 by the fluidizing gas G.
And the cement clinker is fired.

The dispersion plate 4 mainly includes a furnace bottom plate 5 fixed in the fluidized bed 1, a castable 6 made of a refractory material attached to the furnace bottom plate 5, and a dispersion plate nozzle 7 for ejecting a fluidizing gas G. It consists of

In FIG. 2 showing the first embodiment of the dispersion plate nozzle 7, the dispersion plate nozzle 7 is a base 1 made of a heat resistant metal.
1, lock nut 12 and union nut (connecting member) 1
3, a nozzle portion 14 made of ceramic, and a cushioning member 15 made of ceramic fiber, for example. The dispersion plate nozzle 7 penetrates the through hole 6a of the castable 6, and the male screw 11a screwed to the lower part of the base 11 is screwed to the furnace bottom plate 5 and is locked by the lock nut 12 to prevent the furnace bottom plate from rotating. 5 is detachably fixed.

The base 11 has a pipe shape as a whole, and has a fluidizing gas G inside.
Has a gas passage 16 through which a male thread 11c is screwed on the outer periphery of a collar portion 11b provided at the upper portion of the base portion 11. The opening at the lower end faces the wind box 3, while the upper end thereof is the castable 6
It is arranged inside. Therefore, a large temperature gradient is generated in the base 11 along the axial direction.

The nozzle portion 14 has a cap shape as a whole, has a gas passage 17 through which the fluidizing gas G flows, and has a pipe portion 14b provided with a large number of ejection holes 14a and an upper end of the pipe portion 14b. It comprises a top portion 14c and a collar portion 14d provided below the nozzle 14.

The union nut 13 has its engaging portion 13a engaged with the collar portion 14d of the nozzle portion 14 via the buffer member 15, while
The female screw 13b is screwed onto the male screw 11c of the base portion 11 to connect the base portion 11 and the nozzle portion 14, and both gas passages 16, 1
7 are in communication. This union nut 13 and nozzle part 1
A cushioning member 15 is interposed between the flange portion 14d of the nozzle portion 14 and the flange portion 11b of the base portion 11. The union nut 13 is arranged below the upper surface 6b of the castable 6.

In the above structure, according to the present invention, since the nozzle portion 14 facing the high temperature fluidized bed 2 of about 1300 ° C. to 1400 ° C. is formed of ceramic having excellent heat resistance,
It can prevent the 14 from burning out. Further, since the base 11 fixed to the furnace bottom plate 5 and facing the wind box 3 and having a large temperature gradient is made of metal having high mechanical strength, there is no risk of damage due to thermal stress. Therefore,
It enables long-term continuous operation of the fluidized bed furnace (Fig. 1).

Further, since the base portion 11 fixed to the furnace bottom plate 5 is made of metal, the workability for fixing is good and the workability of the male screw 11a is good, so that the base portion 11 can be easily attached to the furnace bottom plate 5. on the other hand,
Since the nozzle portion 14 is connected to the base portion 11 by a connecting member made of, for example, a union nut 13, it is not necessary to perform screw processing or the like on the ceramic nozzle portion 14 having poor workability, so that the manufacturability of the nozzle portion 14 is improved. good. As described above, since the mounting and manufacturing are easy, the manufacturability of the dispersion plate 4 (FIG. 1) is less likely to be deteriorated as compared with the case where the conventional metal dispersion plate nozzle is used.

Further, while ceramics are generally more expensive than metals, the present invention is characterized in that the nozzle portion 14 is made of ceramic and the base portion 11 is made of ceramic.
Since it is made of metal, that is, the entire dispersion plate nozzle 7 is not made of ceramic, the dispersion plate nozzle 7 and thus the dispersion plate 4
The cost up shown in FIG. 1 can be suppressed.

By the way, the furnace bottom plate 5 and the castable 6 attached to the furnace bottom plate 5 are slightly decentered in the arrow A direction. Therefore, in general, the inner diameter of the through hole 6a of the castable 6 is
Since the diameter of the dispersion plate nozzle 7 is slightly larger than the outer diameter of the dispersion plate nozzle 7, a gap S is formed between the dispersion plate nozzle 7 and the castable 6. And the ejection holes that do not form the fluidized bed 2
The fluid medium is caught in the gap S located below 14a and presses the dispersion plate nozzle 7. Here, in this embodiment, the base portion 11 that is long inserted in the castable 6 is used.
However, since it is made of metal having high mechanical strength, there is little risk that the dispersion plate nozzle 7 will be damaged by the pressure.

Further, since the cushioning member 15 is interposed between the ceramic nozzle portion 14 and the metal base 11 and the connecting member 13, the elasticity of the cushioning member 15 causes a large coefficient of thermal expansion between the metal and the ceramic. Can be absorbed, and the tightening force at the time of assembling the dispersion plate nozzle 7 can be prevented from locally increasing. Therefore, the fragile ceramic nozzle 14
There is no risk of damage.

In the second embodiment shown in FIG. 3, the collar portion 14d of the nozzle portion 14 is
The upper surface 14e and the lower surface 13c of the engaging portion 13a of the union nut 13 are each tapered downward toward the outer peripheral side. The other configurations are the first
This embodiment is similar to the embodiment described above, and the same reference numerals are given to the same or corresponding portions, and the detailed description thereof will be omitted.

According to this embodiment, when the union nut 13 is tightened, the upper surface 14e of the nozzle portion 14 is guided to the lower surface 13c of the union nut 13 described below, so that the nozzle portion 14 is horizontally oriented with respect to the union nut 13. Centered. Therefore, since the nozzle portion 14 is centered with respect to the base portion 11, both gas passages are
16 and 17 are automatically centered during the above tightening.

Further, since the upper surface 14e of the collar portion 14d of the nozzle portion 14 is formed in a taper shape that is downwardly directed toward the outer circumference, the collar portion 14d
Since the stress concentration generated at the corner 14f between the pipe portion 14b and the pipe portion 14b can be reduced, the collar portion 14d when the nozzle portion 14 and the base portion 11 are engaged with each other.
There is no risk of damage.

〔The invention's effect〕

As described above, according to the present invention, since the nozzle portion is made of ceramic, its burnout can be prevented, and since the base portion is made of metal, there is no risk of damage due to thermal stress, and the nozzle portion and Since the base is connected by screwing the connecting member, the connecting work and the workability of the metal base are good.

In addition, since the cushioning member is interposed between the connecting member and the nozzle portion and between the flange portions of the nozzle portion and the base portion, due to the elasticity of the cushioning member, a difference in thermal expansion between metal and ceramic or a screwing of the connecting member is caused. It is possible to locally absorb an excessive tightening force and effectively prevent the ceramic nozzle portion from being damaged.

[Brief description 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 side view showing a partial cutaway of the main part, and FIG. FIG. 4 is a side view showing a part of a conventional fluidized bed furnace with a part thereof cut away. 1 ... Fluidized bed furnace, 4 ... Dispersion plate, 5 ... Furnace bottom plate, 7 ...
Dispersion plate nozzle, 11 …… Pipe-shaped base, 11c …… Male thread, 1
1b, 14d ... Collar portion, 13 ... Cylindrical connecting member, 13a ... Engaging portion, 13b ... Female screw, 14 ... Cap-shaped nozzle portion, 14a ...
… Spout hole, 14c… Top, 15… Cushioning member, G… Fluidizing gas.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-721 (JP, A) Actual development 62-198493 (JP, U)

Claims (1)

[Claims] 1. A dispersion plate nozzle, which is supported by a furnace bottom plate forming a dispersion plate of a fluidized bed furnace and ejects a fluidizing gas, wherein the dispersion plate nozzle is formed of a heat-resistant metal and has an external thread on its outer periphery. A pipe-shaped base portion having a screwed collar portion at its upper end portion, and a ceramic pipe-shaped nozzle portion having a collar portion at the lower end portion which has a spout hole formed in the outer periphery by closing the top portion and which faces the collar portion. A tubular connecting member having an engaging portion at an upper end portion for engaging with a flange portion of the nozzle portion, and an internal thread screwed to a male screw of the pipe-shaped base portion at an inner surface of the lower end portion; A dispersion plate nozzle for a fluidized bed furnace, comprising: a heat-resistant cushioning member interposed between the nozzle portions and between the nozzle portion and each flange portion of the pipe-shaped base portion.