JPS6126716A - Skirt for treating apparatus of waste converter gas - Google Patents

Abstract

PURPOSE:To provide the titled skirt capable of preventing burnout, prolonging the service life, and improving the availability factor by providing a water- cooled wall in succession to the water-cooled wall at the lower end of the skirt in the horizontal direction at the outer periphery, and lowering sufficiently the temp. of the flame blown out from the port of a converter. CONSTITUTION:In a skirt 9 consisting of water-cooled pipes for sealing the furnace port 12 of a converter and a hood 10 of a waste converter gas treating apparatus, a water cooled-wall 20 of heat-transfer pipes is provided in the horizontal direction at the outer periphery in succession to the lower end part 14 of the skirt 9 which is extended conically along the inclined part of the furnace port 13. Consequently, the flame blown out from the clearance between said lower end part 14 and the furnace port 12 is sufficiently cooled, and the temp. is lowered. The burnout and falling-off of an amorphous refractory 15 such as castable, provided in succession to the water-cooled wall 20, is also prevented. Accordingly, the generation of deformation and cracks due to heat in lifting mechanisms of the skirt 9 such as a cylinder 16 and a bracket 22, a parting cylinder 17, a sealing mechanism such as a seal jacket 19, etc. is prevented, and the converter can be operated for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a skirt for a converter exhaust gas treatment device that prevents burnout and has a longer life.

[Prior art and its problems]

The outline of the converter exhaust gas treatment device will be explained with reference to FIG.

When pure oxygen is blown into the hot metal introduced into the converter 1 through the oxygen injection lance 11 for refining (hereinafter referred to as blowing), a large amount of CO gas is generated at high temperatures. This CO gas is
After being drawn into the hood 10 by the induced blower 5 and cooled by the cooler 2, the dust is removed by the dust removers 3 and 4, and collected into the gas holder 6. Gas with a low CO concentration at the beginning and end of blowing is combusted at the top by a switching damper 8, passes through a chimney 7, and is then dissipated.

On the other hand, the converter operation is performed as follows.

First, hot metal produced in a blast furnace is charged into the converter 1 (hereinafter simply referred to as charging). In this case, the material is charged, and the tube 9 is lowered to close and blow. Next, the molten steel that has been completely blown is taken out of the converter 1 (hereinafter referred to as tapping). In this tapping process, the converter 1 is also tilted.

Since the converter 1 is thus tilted during charging and tapping, the skirt 9 is lifted upward so that the converter 1 can be tilted.

The skirt 9 is lowered during the blowing because the CO gas generated during the blowing has the risk of causing monoxide poisoning if it leaks to the outside, or because it will rapidly burn if outside air is sucked into the device. Therefore, it is necessary to close the space between the furnace opening of the converter 1 and the door 10. In this way, the skirt 9 has the function of raising and lowering to enable charging and tapping. During training, C
This is an important part that plays a role in preventing the leakage of O gas to the outside and the suction of outside air.

For example, if the lifting and lowering functions are impaired, the converter operation will be forced to stop.

By the way, the conventional skirt 9 shown in FIG. 6 is formed of a water pipe and has a water-cooled wall structure that is cooled by water flowing through the water pipe. The lower end 14 of the skirt 90 has a conical shape widened along the inclined surface 13 of the furnace mouth 12. This is done between the lower end 14 of the skirt 90 and the sloped surface 13 of the furnace mouth, but in reality, slag adheres to the furnace mouth 12 and the sloped surface 13, and the lower end 14 and the furnace mouth 12 are closed. There is a gap equal to the amount of slag deposited. Therefore, by the induced blower 5 (see Q in Figure 2),
The pressure inside the door #1 is controlled to be close to atmospheric pressure to prevent leakage of CO gas or suction of outside air from this gap.

On the other hand, the seal between the door 10 and the skirt 9 is achieved by immersing the partition tube 17 in the seal jacket 18.
The skirt 9 is sealed with water so that it can be raised and lowered. 16 is a cylinder for raising and lowering the skirt 9. Reference numeral 15 denotes a heat insulating plate made of fireproof material to protect the cylinder 16 from heat.

In the conventional skirt configured as described above, the flame 19 emitted from the gap between the furnace mouth 12 and the lower end 14 of the skirt during blowing can burn out the refractory material cast on the heat shield plate 15. If the refractory material falls off and the exposed heat shield plate 15 is burned out, the cylinder 16 for raising and lowering the skirt 9 will be deformed by the heat and will no longer move.

In this way, if the skirt 9 cannot be raised or lowered,
There was a problem in that the converter operation became impossible] and the converter operation had to be stopped.

In addition, if the heat shield plate is burnt out during blowing and the cylinder does not move, the repair work must be left until the temperature in the work environment is sufficiently low before work can be done, and tapping may not be possible. This has a negative effect on the properties of the steel and makes it extremely difficult to take out the molten steel that has reached a low temperature, so it is necessary to periodically repair the heat shield), and the converter operation was suspended during this period. Therefore, there was a problem in that the operating rate of the converter was significantly reduced.

Further, as shown in FIG. 7, a gear rally 21 for maintenance and inspection is provided in the enclosure of the skirt 9. This gallery 2
1 is provided below the skirt 9, as shown in FIG. 8, and uses a heat shield plate 15 to lower the atmospheric temperature of the working environment.

However, if the heat shield plate 15 burns out and falls off, it will not be directly heated by the flame 19 ejected from between the skirt lower end 14 and the furnace opening 12, which is dangerous, but it should be done in a particularly dangerous work environment. There was a problem in that it deteriorated rapidly.

Furthermore, as shown in FIG. 6, a skirt structure 23 is provided around the skirt 90, which maintains the strength of the skirt 9 and also serves as a fulcrum for the bracket 22 of the skirt lifting cylinder 16. If the heat insulating plate 15 is burnt out and the skirt structure 23 is heated by the flame 19, the shape of the skirt 9 will not be maintained and it will become unusable.

In this way, the heat shield 15 is exposed to the flame 19, causing a small amount of fireproofing material to fall off.
If the heat shield plate 15 burns out, a number of problems will occur.

In addition, as shown in Fig. Since the heat load is different between the inner and outer circumferential sides, there is a large difference in the surface temperature of the heat shield plate 25 between the inner circumferential side and the outer circumferential side;
As a result, the difference in thermal expansion becomes large, and cracks occur especially in welded parts in integral parts. Therefore, water-cooled jacket)
Since the cooling water of 24.24' leaks, the operation of the converter must be stopped for repairs, which reduces the operating rate of the converter.

Moreover, there is a large temperature difference between the outer surface of the heat insulating plate 25 that receives the flame and the inner surface that does not receive the flame, and the outer surface of the heat insulating plate 25 tends to undergo large thermal expansion, but the inner surface of the heat insulating plate 25 thermally expands only slightly. Thermal expansion of the outer surface cannot be absorbed, and thermal stress concentrates on a part of the welded joint between the inner and outer surfaces, resulting in cracks. Therefore, as above, water-cooled jacket)
Since the cooling water of 24.24' leaked, the operation of the converter had to be stopped and repaired, which caused a problem that the operating rate of the transfer furnace decreased.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a skirt for a converter exhaust gas treatment device that prevents burnout, extends the life of the converter, and improves the operating rate of the converter. It is something.

[Structure of the invention]

In the present invention, the heat insulating plate is constituted by a water-cooled wall using one heat exchanger tube without providing a refractory material as in the past. It is characterized by having a wall.

〔Example〕

One embodiment of the present invention will be described with reference to FIG. 1, where 9 is a skirt and 10 is a hood. The lower end portion 14 of this skirt 9 is widened into a conical shape along the sloped portion 13 of the converter mouth, and is further provided with a water-cooled wall 20 of a heat exchanger tube in the outer peripheral horizontal direction continuously from the lower end portion 14. This water-cooled wall 20 is located at a portion where the flame jetting out from the gap between the furnace mouth 12 and the lower end 14 of the skirt 90 comes into contact.

15 is a refractory material, 16 is a cylinder for raising and lowering the skirt 9, 17 is a partition tube, and 19 is a seal jacket.

Also, as shown in FIGS. 2 and 3, the skirt 9 has an area DI
A C gear rally 21 is provided, and a water cooling wall 20 of the heat transfer tube is provided below the gear 2 21. In addition, as shown in FIG. 4, the water cooling wall 20 of the heat exchanger tube is further extended, and the bracket 2
It is also possible to cover 2.

[Effect]

In this embodiment configured as described above, the converter furnace opening 12
If flame erupts from between and the lower end 14 of the skirt,
It is cooled by touching the water-cooled wall 20, and its temperature decreases. In this state where the flame temperature has decreased, the refractory material 15 can sufficiently withstand the temperature and will not burn out. In particular, the outer periphery of the skirt 9 includes piping for circulating cooling water within the skirt 9 and the water cooling wall of the lower end portion 14 of the skirt, and the skirt structure 23. Since the cylinder 16 and brackets 22 for raising and lowering the skirt 9 are attached with complicated shapes, it is necessary to use monolithic refractories 15 such as casters to protect them from heat. Covering is the best option.

For these reasons, the water-cooled wall 20 of the heat exchanger tube is not provided within the range necessary to lower the temperature of the flame to a temperature that the refractory 15 can sufficiently withstand thermally.

Also, if the outer circumference of the skirt 9 has a simple shape,
As shown in FIG. 8, it goes without saying that the refractory 15 may not be used and only the water-cooled wall 20 of the heat exchanger tube may be used for heat insulation.

〔Effect of the invention〕

The skirt of the converter exhaust gas treatment apparatus according to the present invention as described in detail above has a water-cooled wall in the outer circumferential direction of the skirt, which is continuous with the conical water-cooled wall at the lower end of the skirt. By sufficiently lowering the temperature of the flame ejected through the gap between the skirt and the skirt, the refractory could be thermally protected, the refractory would not fall off due to burnout, and the life of the skirt could be extended.

Therefore, there is no need to stop converter operation for repairs.
It has great effects such as being able to operate for long periods of time, greatly improving the operating rate of the converter, and improving the working environment above gear 2 to ensure worker safety. play.

Fig. 1 is a longitudinal sectional view of a skirt portion showing an embodiment of the present invention, Fig. 2 is a plan view of Fig. 1'S, and Fig. 3 is a partially enlarged view showing the lower end of the skirt shown in Fig. 1. Fig. 4 is a longitudinal sectional view showing another embodiment in which the portion of the heat shield plate is a water-cooled wall; Fig. 5 is a schematic view showing the entire converter exhaust gas treatment device; The figure is a longitudinal sectional view showing an example of a conventional skirt part, Fig. 7 is a plan view of Fig. 6, Fig. 8 is a partially enlarged longitudinal sectional view showing the relationship between the furnace opening and the skirt, and Fig. 9 is a conventional It is a longitudinal cross-sectional view which shows another example of a skirt part.

9... Skirt 12... Furnace mouth 13... Furnace mouth slope 14... Lower end of skirt 15...
・Refractory 20...Water cooling wall

Claims (1)

[Claims] 1. A skirt for a converter exhaust gas treatment device, characterized in that a water-cooled wall is provided continuously at the lower end of the skirt in the horizontal direction of the outer periphery.