JP3711748B2 - Dust removal equipment for converter exhaust gas treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for removing dust deposited on a skirt seal portion in a converter exhaust gas treatment facility.
[0002]
[Prior art]
The converter exhaust gas treatment facility is provided with a skirt capable of moving up and down between the converter furnace opening and the hood in order to allow the converter to tilt. Also, the CO gas generated from the converter may explode due to the reaction with air depending on the mixing ratio, which is very dangerous and the outside air is not allowed to enter, and it is necessary to completely seal it with the skirt. A seal portion is provided.
[0003]
In general, this skirt seal portion is provided with a U-shaped groove around the skirt, filled with water in this annular groove, and the lower end of the partition tube provided in the hood can be moved up and down so as to be immersed in water. Sealed.
Since the gas generated from the converter contains a large amount of dust containing fine iron powder, the dust blown up by the exhaust gas during blowing is an annular groove that is the water seal part of this skirt seal part. Or when the skirt is moved up and down, the dust adhering to the partition tube etc. is washed away by the seal water and enters the annular groove, and the dust gradually accumulates at the bottom of the annular groove, and eventually the partition tube As the lower end comes into contact with the accumulated dust, the vertical movement of the skirt becomes impossible, and the dust trouble that the converter operation must be stopped occurs.
[0004]
In order to solve this dust trouble, Japanese Patent Application Laid-Open No. 59-229409 discloses that the exchanged water is ejected from the exchange water jet nozzle provided at the bottom of the outer wall of the annular groove to the inner wall at a substantially right angle, and the settled dust flows. And a method of discharging the exchanged water in the tangential direction of the annular wall and generating a rotating flow in the annular groove to improve the flow characteristics of the settled dust in the annular groove. . In any of these methods, the seal water in the annular groove is caused to flow by the exchange water ejected from the exchange water ejection nozzle, and the dust having a small specific gravity is discharged to the outside by the exchange water overflowing the annular groove. Is discharged from the lower replacement water discharge pipe.
[0005]
[Problems to be solved by the invention]
However, in the method disclosed in Japanese Patent Laid-Open No. 59-229409, the method of jetting from the replacement water jet nozzle to the inner wall at a substantially right angle has a low function of conveying dust settled in the annular groove, Not only does the water need to be changed, but dust gradually accumulates at the bottom of the annular groove, which also causes dust trouble that makes the skirt unable to move up and down. For this reason, the operation | work which removes dust regularly from the inside of an annular groove is needed, and there existed a problem that the operation rate of a converter fell.
[0006]
On the other hand, even in the method of improving the conveying characteristics of the settled dust in the annular groove by jetting exchange water in the tangential direction of the annular groove to generate a rotating flow in the annular groove, the fluidity of the dust is still poor. Dust from the replacement water discharge pipe could not be discharged sufficiently, and the problem that dust gradually accumulates at the bottom of the annular groove and causes dust trouble remained.
[0007]
In particular, in converters with large specific gravity and particle size that generate a large amount of dust that tends to settle in the seal water, the ability to discharge dust from the annular groove is not sufficient in any of the above methods. It was necessary to stop the operation and remove the accumulated dust from the annular groove, which was a main factor for reducing the operating rate of the converter.
Examination and examination of the dust accumulation mechanism of the annular groove disclosed in the above-mentioned JP-A-59-229409 revealed that when the replacement water was ejected from the replacement water ejection nozzle almost at right angles to the inner wall, the replacement water ejection nozzle It was found that a stagnation point was generated because local circulation and recirculation occurred near the outlet, and that dust accumulated at this stagnation point started as a starting point. On the other hand, in the case of generating such a rotating flow also in the method of improving the conveying characteristics of the settled dust in the annular groove by jetting exchange water in the tangential direction of the annular groove to generate a rotating flow in the annular groove It was found that the flow velocity distribution in the width direction of the annular groove was generated, and dust was likely to accumulate especially when the flow velocity near the inner wall decreased.
[0008]
The present invention is based on the above knowledge, eliminates the conventional problems, and can greatly reduce the load of the settled dust removal work on the annular groove, the dust removal device for the skirt seal portion in the converter exhaust gas treatment facility The purpose is to provide.
[0009]
[Means for Solving the Problems]
In the present invention, a hood in which the lower end of the flue is opened to the converter furnace port, a skirt attached to the hood so as to be movable up and down and provided with an annular groove on the outer periphery, and a partition tube provided on the outer periphery of the hood A dust removing device for a converter skirt seal portion in a converter exhaust gas treatment facility in which a lower end portion of the partition tube is immersed in a seal water in the annular groove and sealed, wherein the annular groove is formed on the outer wall. It has one or more replacement water jet nozzles having a jet port near the bottom and a plurality of replacement water discharge pipes having a discharge port for discharging seal water, and at least a part of the bottom of the annular groove has a water depth in the outer circumferential direction. The above-mentioned problem is solved by inclining to deepen.
[0010]
In particular, the inclination angle is more than the angle of repose of dust in still water (the maximum angle where the slope where dust is deposited is stable without collapsing. It is regarded as a cone and is expressed by the angle between the horizontal plane and the generatrix). It is further preferable from the viewpoint of fluidity of the deposited dust.
In addition to the above, by providing a plurality of the exchange water jet nozzles in the tangential direction of the inner wall of the annular groove, the conveying characteristics of the settled dust are further improved.
[0011]
Furthermore, the present inventors have found that it is preferable that the flow rate of the sealing water is 1 m / sec or more at any of the bottoms of the annular groove so that dust does not remain.
Also, at the bottom of the annular groove, the discharge port or within 100 mm from the discharge port is the end point, and the desired position from the end point to at least another adjacent discharge port is at least 200 mm away from the start point. It has been found that it is suitable for discharging dust that each bottom slope having a downward slope toward the end point direction is formed in the circumferential direction.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a configuration of a converter skirt seal portion to which the present invention is applied. In FIG. 1, a hood 2 that guides exhaust gas to a flue 1 is provided at the top of the furnace port 11 of the converter 10. A partition tube 3 is fixedly attached to the outer periphery of the hood 2 so as to face downward. On the other hand, the annular groove 8 formed by the inner wall 4, the outer wall 5 and the bottom plate 7 is configured such that the inner wall 4 is higher than the outer wall 5, and a drainage groove is provided around the upper edge of the outer wall 5. There are six. The annular groove 8 is fixed around the skirt 12 via an upper annular connecting member 9 provided in the lower part, and moves up and down together with the skirt 12. The inside of the annular groove 8 is filled with sealing water 13 and can be sealed with water by immersing the partition tube 3, and a complete seal is realized when the skirt 12 is lowered and the furnace port 11 of the converter 10 is covered. are doing.
[0013]
FIG. 2 shows a configuration of the dust removing device of the present invention in the converter skirt seal portion shown in FIG. In the present invention, one or more replacement water ejection nozzles 14 are installed in the vicinity of the bottom of the annular groove outer wall 5 and nozzle openings are provided so that the nozzle tip does not protrude into the annular groove. Similarly, one or more replacement water discharge pipes 15 are installed near the bottom of the annular groove outer wall 5. Further, an inclined portion 16 that is inclined so that the water depth increases in the outer peripheral direction is provided at least at a part of the bottom of the annular groove. The inclined portion 16 is configured as an inclined surface having a vertex on the wall surface of the inner wall 4 and a lower point on the upper surface portion of the bottom plate 7, but the lower point may be in contact with the outer wall 5. As described above, the inclination angle is preferably equal to or greater than the repose angle of dust in still water.
[0014]
FIG. 3 shows an example of the arrangement of the replacement water ejection nozzles in the annular groove. In FIG. 3, the nozzles are arranged in the direction of the inner wall tangent. Here, it is preferable that a plurality of replacement water ejection nozzles be disposed along the outer wall of the annular groove. Further, as shown in the figure, each vertex of a regular polygon circumscribing the inner wall (this vertex is the annular groove). The annular groove is designed to be on the outer wall surface.) By arranging the outlet of the replacement water ejection nozzle in the outer wall, the replacement water is ejected from each ejection port until the next collision with the outer wall of the annular groove. The reachable distance can be maximized, and the number of ejection nozzles can be minimized.
[0015]
Furthermore, it is preferable to provide a bottom slope 20 as shown in FIG. 5 at the bottom of the annular groove in order to discharge dust more smoothly. Here, the bottom slope 20 is inclined downward toward the discharge port of the exchange water discharge pipe 15. However, in FIG. 5, the illustration of the inclined portion 16 is omitted for easy illustration.
As shown in FIG. 5, by providing the bottom slope 20, dust can be more smoothly guided to the replacement water discharge pipe 15 without disturbing the flow of the seal water flow 13a. Therefore, dust is easily discharged and does not stay at the bottom. The end point 21 of the bottom slope 20 is a discharge port of the exchange water discharge pipe 15 or a position within 100 mm from the discharge port. By doing so, dust can be easily discharged from the discharge port, and the discharge port itself can be prevented from becoming a starting point of dust retention. The starting point 22 of the bottom slope 20 is preferably 200 mm or more, more preferably 300 mm or more from the end point, and preferably has a certain slope distance or more. However, the starting point 22 is not extended to a position beyond other adjacent outlets.
[0016]
Here, the supply water to the replacement water ejection nozzle and the piping routes for discharging the water discharged from the drain groove 6 and the replacement water discharge pipe 15 are both omitted in this description and the drawings.
[0017]
【Example】
An embodiment of the present invention having the above configuration will be described.
In this embodiment, the annular groove 8 has a diameter of 4.3 m, a groove width of 12 cm, the depth of the seal water in the annular groove 8 is 1.2 m, and the flow rate of the seal replacement water is about 40 t / hour. In addition, eight replacement water jet nozzles are installed at equal intervals in the circumferential direction with the tangential direction of the inner wall of the annular groove, and two replacement water discharge pipes are installed facing each other. Here, in the annular groove having a diameter of 4 to 6 m and a depth of about 1 m including the above example, the flow rate of the sealing water is uniformly 1 m at the bottom of the annular groove by uniformly installing eight of the replacement water jet nozzles. A flow rate of at least / s can be achieved. However, the properties of the dust are particle size ≦ 6 mm and specific gravity ≦ 6.5. In the annular groove with the above specifications, it is optimal to place two replacement water discharge pipes at a position of 180 degrees. In other words, if the number of pipes is increased unnecessarily and the diameter of the discharge pipe is reduced, dust is easily clogged in the discharge pipe at that portion, which becomes the starting point of dust accumulation.
[0018]
Using a converter 10 with a processing capacity of 160 tons, the dust accumulation after 100 deburring of stainless steel with an average blowing time of 70 minutes was changed, and the inclination angle of the inclined part 16 of the annular groove was changed. We investigated and compared the cases.
In this comparison, the inclined portion is set to 90% width of the groove bottom portion, and the angle of inclination is changed for each investigation.
[0019]
As a result, when the flat bottom was used as in the conventional example without giving an angle, the maximum dust accumulation was 750 mm.
When the angle was 15 degrees, the maximum was 500 mm. When the angle was 35 degrees, no dust accumulation was observed when the angle was 100 mm and the angle was 45 degrees.
Here, when the angle is 45 degrees, the dust accumulation does not occur because, as described above, the flow rate of the sealing water is uniformly 1 m / s or more at the bottom of the annular groove. FIG. 4 is a graph in which the horizontal axis represents the flow rate of the sealing water and the vertical axis represents the residual dust accumulation height. From this graph, it can be seen that dust accumulation does not occur if the flow rate of the seal water is 1 m / s or more. And if the flow rate of the sealing water is less than 1 m / s, dust accumulation is not eliminated and remains. That is, in order not to generate dust accumulation, it is preferable that the flow rate of the sealing water is 1 m / s or more.
[0020]
Here, it has been confirmed by experiments that the angle of repose of stainless steel decarburized blown dust in still water is 40 degrees as a measured value.
As described above, dust accumulation can be greatly improved by providing the inclined portion at the bottom of the annular groove. The effect is particularly remarkable when the inclination angle is set to be greater than or equal to the angle of repose, but even when the angle of repose is equal to or less than the angle of repose, a sufficient effect is recognized, and the dust removal cycle can be greatly extended. .
[0021]
At that time, the flow rate of the sealing water is preferably 1 m / s or more uniformly at the bottom of the annular groove. Moreover, it confirmed that the effect further increased by providing a bottom slope at the bottom of the annular groove.
[0022]
【The invention's effect】
As described above, according to the present invention, the dust accumulated inside the annular groove flows to the outside where the flow velocity is fast due to the inclined portion of the groove bottom, and the effect is further enhanced by the bottom slope, and the dust is discharged more effectively. The load of dust removal work is greatly reduced. In addition, the inclined portion or the like also increases the overall flow velocity near the bottom of the annular groove, so that the effect of increasing the dust conveyance capability can be obtained. For this reason, the flow rate of the exchange water can be reduced, and the operating rate of the converter is greatly improved due to the drastic reduction of dust troubles, thereby achieving a remarkable industrial effect.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a converter skirt seal portion to which the present invention is applied.
FIG. 2A is a plan view of an annular groove to which the present invention is applied, and FIG.
FIG. 3 is a plan view of an annular groove showing an example of the arrangement of replacement water ejection nozzles according to the present invention.
FIG. 4 is a graph showing the relationship between the flow rate of sealing water and the residual dust accumulation height.
FIG. 5 is a partial cross-sectional view showing a bottom slope of an annular groove bottom.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flue 2 Hood 3 Partition cylinder 4 Inner side wall 5 Outer side wall 6 Drainage groove 7 Bottom plate 8 Annular groove 9 Upper annular connection member
10 Converter
11 Furnace
12 Skirt
13 Seal water
13a Seal water flow
14 Replacement water jet nozzle
15 Exchange water discharge pipe
16 Inclined part
20 Bottom slope
21 End point (of bottom slope)
22 Start point (of bottom slope)

Claims (5)

A hood provided at the lower end of the flue and opening to the converter furnace port; a skirt attached to the hood so as to be movable up and down; and provided with an annular groove on the outer periphery; A dust removing device for a converter skirt seal portion in a converter exhaust gas treatment facility in which a lower end portion of a partition tube is immersed in a seal water in the annular groove and water-sealed. One or more replacement water jet nozzles having outlets and a plurality of replacement water discharge pipes having discharge ports for discharging seal water, so that at least a part of the bottom of the annular groove has a deep water depth in the outer circumferential direction. An apparatus for removing dust from a converter skirt seal, which is inclined. The dust removal device for a converter skirt seal part according to claim 1, wherein the inclination of the bottom of the annular groove is an angle equal to or greater than the angle of repose of dust. 3. The dust removal device for a converter skirt seal according to claim 1, wherein a plurality of the replacement water jet nozzles are provided facing a tangential direction of the inner wall of the annular groove. 4. The dust removal device for a converter skirt seal part according to any one of claims 1 to 3, wherein the water flow of the seal water is set to a flow velocity of 1 m / sec or more at any bottom part of the annular groove. At the bottom of the annular groove, the end point is within 100 mm from the discharge port or the discharge port, and the desired position from the end point to at least another adjacent discharge port is at least 200 mm away from the end point. 5. The dust removing device for a converter skirt seal portion according to claim 1, wherein bottom slopes having a downward slope toward the direction are respectively formed in a circumferential direction.

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