JPH0712877Y2 - Fluidized bed furnace dispersion plate cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention is for cleaning dust by adhering and growing on the lower surface of a dispersion plate forming a fluidized bed of a fluidized bed furnace used in a smelting reduction ironmaking process or the like. Regarding the device.

2. Description of the Related Art In a smelting reduction ironmaking process, dust floating in a gas adheres to a dispersion plate of a fluidized bed furnace that performs the reduction, and the adhered dust adheres and grows, hindering stable operation.

A typical prior art is shown in FIG. A dispersion plate 3 is attached to a furnace body 1 of a fluidized bed furnace by a flange 2. A gas containing dust is pressure-fed from an inlet 5 of a wind box 4 provided below the dispersion plate 3, and the granular material charged into the furnace forms a fluidized bed 6 above the dispersion plate 3.

FIG. 5 is an enlarged cross-sectional view of a part of the dispersion plate 3. The dispersion plate 3 is made of a refractory material and has a large number of nozzle holes 8. The nozzle hole 8 is, for example, 10 to 50 mmφ.
The gas pressure-fed from the wind box 4 contains, for example, iron oxide-based and slag-based dust, and these dusts are in a semi-molten state when the temperature of the gas is high, as indicated by reference numeral 9. And is attached to the lower surface of the dispersion plate 3. Since the gas flow velocity in the nozzle hole 8 is extremely high, dust hardly adheres to the inner wall surface of the nozzle hole 8, but the gas flow velocity in the vicinity of the inlet portion of the nozzle hole 8, that is, the lower surface of the dispersion plate 3 is The flow velocity of the gas in the nozzle hole 8 is several tenths, and therefore the dust 9 adheres and adheres and grows as described above. When such dust 9 adheres, the smooth flow of gas to the nozzle hole 8 is hindered. Therefore, the flow rate passing through each nozzle hole 8 becomes non-uniform, and a stable and good fluidized state cannot be obtained. Further, when the flow velocity in the nozzle hole 8 becomes extremely small due to the adhesion of the dust 9, not only the above-mentioned problem occurs but also the powder particles in the fluidized bed 6 fall into the wind box 4 from the nozzle hole 8. To do.

In order to solve this problem, it is conceivable to remove the dispersion plate 3 from the furnace body 1 and clean it. Since the dispersion plate 3 has a large diameter of 1 to several meters and is a refractory material, it has a large weight and therefore is extremely difficult to handle.
Since the dispersion plate 3 is sandwiched by the flanges 2 and installed in the furnace body 1, removing the dispersion plate 3 is a very troublesome work.

As another prior art, the manhole cover 10 provided on the wind box 4 is opened, and the worker enters the wind box 4 to clean the lower surface of the dispersion plate 3. In such a prior art, the inside of the wind box 4 is at a high temperature during the operation of the fluidized bed furnace, and therefore, it is not cooled until a few days after the operation is stopped, and the wind box 4 is not operated until then. Workers cannot enter inside. When an operator enters the air box 4 for cleaning, the air in the air box 4 becomes extremely bad due to dust or the like. Moreover, after the worker has entered the wind box 4 for cleaning, the furnace body 1
Since the temperature of the dispersion plate 3 is lowered to about room temperature, it is impossible to restart the operation immediately, and it takes about 1 to 2 days for preheating. Therefore, the operating rate of the equipment is extremely poor.

Still another prior art is disclosed in Japanese Utility Model Laid-Open No. 62-76896. In this prior art, a plurality of dispersion plates are selectively inserted into and removed from the furnace body in the horizontal direction, and the dispersion plates extracted from the furnace body are cleaned.

In such a prior art, since the dispersion plate is heavy as described above, it is difficult to insert and remove such a dispersion plate from the furnace body.

Another prior art is disclosed in Japanese Utility Model Publication No. 62-76897. In this prior art, a water-cooling cleaning rod is inserted into the nozzle hole of the dispersion plate from below and is driven up and down to clean the dispersion plate.

In such a prior art, it is difficult to individually insert the cleaning rod into a large number of nozzle holes of the dispersion plate, and it can be applied only to a dispersion plate having a small number of nozzle holes.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to provide a cleaning device for a fluidized bed furnace dispersion plate, which can easily clean the dispersion plate.

Means for Solving the Problems The present invention is to provide a powder under a dispersion plate of a fluidized bed furnace that forms a fluidized bed above the dispersion plate by gas from a wind box provided below the dispersion plate. A cleaning device for a fluidized bed furnace dispersion plate, characterized in that an injection means for injecting a mixture of a body and a gas is provided so as to be able to swirl or swing so that the powder collides with the lower surface of the dispersion plate.

Operation According to the present invention, the jetting means is provided below the dispersion plate so as to be capable of turning or swinging, and the mixture of the powder and the gas is jetted from the jetting means. As a result, the powder collides with the wall of the dispersion plate. Therefore, the dust adhering to the wall of the dispersion plate is removed from the dispersion plate, and the dispersion plate can be cleaned.

Since the jetting means can swivel or swing, the powder can be made to collide over the entire lower surface of the dispersion plate.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention. In a fluidized bed furnace 12 for performing preliminary reduction in a smelting reduction ironmaking process, a furnace body 13 is provided with a dispersion plate 14 made of a refractory material. High-temperature gas is pressure-fed from an inlet 16 to a wind box 15 provided below the dispersion plate 14. This gas rises through the nozzle holes 17 that penetrate the dispersion plate 14 in the vertical direction, and a fluidized bed 18 is formed above the dispersion plate 14. Iron ore or the like is inserted into the fluidized bed 18 through the insertion port 19. A gas containing CO, H _{2, and the} like as main components is pumped into the gas inlet 16 at about 1100 ° C. as described above. The fluid medium forming the fluidized bed 18 is iron oxide (such as Fe ₂ O ₃ , Fe ₃ O ₄ and FeO), and the temperature inside the bed is about 800 ° C.

In order to prevent dust contained in the gas pumped to the wind box 15 from adhering to the lower surface of the dispersion plate 14 in a semi-molten state and sticking and growing to the extent possible, the cleaning device 20 according to the present invention uses a furnace body. 13
Is provided at the bottom of the. The bottom surface 21 of the wind box 15 is inclined and continues to the discharge port 22. An injection unit 23 is provided near the discharge port 22 so as to be swingable around a horizontal axis. Injection means 23
At the same time, a high pressure gas is pumped from the pipe line 24,
The powder is supplied from the pipe 25. The pipe lines 24, 25 are connected to the injection means 23 via the pipe line 26, and thus the mixture of the powder and the gas is injected from the injection device 23 as indicated by the reference numeral 27. The gas from line 24 is an inert gas such as nitrogen. The powder is, for example, iron ore as a raw material fluidized in the fluidized bed 18. Such iron ore has a high hardness, and when it collides with the lower surface of the dispersion plate 14, it gives a large impact force to the dust adhering to the lower surface to pulverize and remove the dust from the dispersion plate 14. can do.

The powder sprayed from the spraying means 23 collides with the lower surface of the dispersion plate 14, and then is collected in the discharge port 22 via the bottom surface 21 of the wind box 15. The powder from this discharge port 22 is discharged from
It is led to the sieving means 30 via 29, and here only the powder having a predetermined particle size is led to the pipe line 25.

FIG. 2 is a perspective view of the injection means 23. This injection means 23
Is an injection member 32 having an injection port 31, a shaft 33 to which the base end portion of the injection member 32 is fixed, a bearing 34 that supports the shaft 33 so as to be angularly displaceable around a horizontal axis, and the shaft 33 is angularly supported. And a drive source 35 for displacement driving.

FIG. 3 is a sectional view showing a part of the injection member 32 and the shaft 33. The injection port 31 is expanded in a trapezoidal shape toward the dispersion plate 14, and an inverted frustoconical guide piece 36 for expanding and injecting a mixture of powder and gas is fixed to the injection member 32. Injection member
A passage for guiding a mixture of powder and gas is provided in the shaft 32 and the shaft 33.
37 is formed. The passage 37 is connected to the pipe line 26 via the rotary pipe joint 38.
Connected to.

By swinging the jetting member 32 by the drive source 35 in this manner, the mixture can be jetted over the entire lower surface of the dispersion plate 14 to collide the powder. Even during the operation of the fluidized bed 18, the dust adhered to the lower surface of the dispersion plate 14 can be removed and cleaned. Since the gas from the pipe line 26 is the inert gas as described above, it does not hinder the operation of the fluidized bed. The spraying means 23 is water-cooled, and the powder used is heat resistant, so that the cleaning operation can be performed even in a high temperature environment.

As shown in FIG. 1, the wind box 15 is provided with a shield plate 40 made of a refractory material, and the double-action cylinder 41 is used to insert the shield plate 40 into and remove it from the wind box 15. By inserting the shielding plate 40 into the wind box 15 as indicated by the reference numeral 42, the jetting means 23 can be protected from high temperature radiant heat when cleaning is not performed. The shield plate 40 can be housed in a case 43 attached to the furnace body 13.

Cleaning of the lower surface of the dispersion plate 14 can be performed even during the fluidized bed operation as described above, but may be performed while the operation of the fluidized bed is stopped. The high pressure gas may be, for example, air.

As another embodiment of the present invention, instead of using the shield plate 40, when cleaning is not performed during operation of the fluidized bed,
The jetting means 23 may be retracted into a recess formed in the wall of the wind box 15 so that the jetting means 23 is not directly exposed to the high temperature gas.

In the above-mentioned embodiment, the injection means 23 is provided so as to be swingable around the horizontal axis, but as another embodiment of the present invention,
This injection means 23 can be swung using a spherical bearing, etc.
That is, it may be configured to be swivelable, or the jetting means 23 may be driven in another mode so as to cause the powder to collide with the entire surface of the dispersion plate 14.

As described above, according to the present invention, it is possible to easily remove and clean the dust adhered to the lower surface of the dispersion plate and fixedly growing without moving the dispersion plate forming the fluidized bed. As a result, the operating rate of the fluidized bed furnace can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is an injection means.
23 is a perspective view, FIG. 3 is a sectional view showing a part of the injection member 32 and the shaft 33, FIG. 4 is a sectional view of the prior art, and FIG. 5 is an enlarged sectional view of a part of the dispersion plate 3 in the prior art. Is. 12 ... Fluidized bed furnace, 13 ... Furnace body, 14 ... Dispersion plate, 15 ... Wind box, 18 ... Fluidized bed, 20 ... Cleaning device, 23 ... Injection means,
30 …… Sieving means, 40 …… Shielding plate

Claims (1)

[Scope of utility model registration request] 1. Mixing powder and gas below a dispersion plate of a fluidized bed furnace that forms a fluidized bed above the dispersion plate by means of gas from a wind box provided below the dispersion plate. A cleaning device for a fluidized bed furnace dispersion plate, characterized in that a spraying means for spraying a body is provided so as to be capable of swirling or swinging, and the powder is made to collide with the lower surface of the dispersion plate.