JPS6220254B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a sealing device that can more completely seal between the furnace mouth and the skirt of a converter exhaust gas treatment device.

[Background of the invention]

First, the outline of the converter exhaust gas treatment apparatus will be explained using FIG. 1. In the figure, pure oxygen is blown into hot metal in a converter 1 from an oxygen injection lance 11 for refining (hereinafter referred to as blowing). During this blowing process, a large amount of CO gas is generated.

This CO gas is drawn into the hood 3 by the induced blower 7, cooled by the cooler 4, removed by dust collectors 5 and 6, and recovered as valuable gas in the gas holder 9. . In addition, unexpired exhaust gas with a low CO concentration in the initial stage of blowing is released from the chimney 8 by switching the damper 10.

In the above series of processes, the skirt 2 is
It is important in fulfilling the following functions.

In other words, in converter operation, hot metal produced in a blast furnace is
A receiving process in which the converter is tilted to receive the pig iron, a refining process in which the space between the converter mouth and the hood is sealed with a skirt for blowing, and a steel extraction process in which the molten steel in the converter is taken out after refining. It is carried out in three steps.

The skirt 2 in the converter exhaust gas treatment equipment seals between the converter mouth and the hood during the refining process.
This is designed to prevent outside air from entering in order to prevent CO gas from leaking to the outside and to suppress combustion.When tilting the so-called converter in the pig iron receiving and tapping processes, the skirt must be raised upwards. The skirt 2 is moved to enable tilting of the converter, and at the time of refining, the skirt 2 is lowered to seal the space between the converter mouth and the hood 3.

Also, recently, the intrusion of outside air is restricted as much as possible,
In order to obtain high-purity CO gas, there is a trend to operate with the pressure inside the equipment higher than atmospheric pressure, and in addition to the above-mentioned requirement for a skirt, a more complete seal has become required.

The seal between the conventional converter mouth and skirt is
Shown in Figure 2. In the figure, 1 is a converter, and 2 is a skirt. The lower end of the skirt 2 is formed to match the shape of the converter mouth, and is sealed by surface contact. In addition, 17 in the figure is a water seal part, and when the skirt 2 is moved up and down by the skirt cylinder 19 suspended on the floor 20, the seal cylinder 1
The lower end of the skirt 8 is immersed in the water filling the seal portion 17, thereby creating a water seal between the skirt 2 and the hood 3.

In this conventional sealing device, the slag that adheres to the furnace mouth of the converter 1 is not uniform and adheres irregularly with considerable unevenness, and the lower end of the skirt 2 has a low mechanical strength. was low, and it was not possible to crimp with very strong force.

As a result, a large gap was created between the furnace mouth and the skirt 2, and a complete seal could not be achieved.

For this purpose, in the past, the pressure inside the hood was set equal to or slightly lower than atmospheric pressure during operation, so some outside air was sucked in through the gap between the furnace mouth and the skirt, resulting in highly pure air. CO gas could not be obtained.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and aims to provide a sealing device that satisfies higher sealing performance and can sufficiently withstand high temperatures.

[Summary of the invention]

That is, in the present invention, instead of avoiding sealing at the part where slag is attached or sealing with an elastic body as in the past, sealing is performed by actively crushing slag. In the invention, a first seal ring made of heat-resistant cast iron and water-cooled with a circular cross section is provided at the bottom of the skirt, and the slag that adheres to the furnace mouth is destroyed by the combined effect of thermal shock and crushing due to pressing force. At the same time, a first seal is formed between the furnace mouth and the skirt, and a second chain-shaped seal is provided outside the first seal ring so as to surround the first ring, thereby preventing gas leaking from the first seal ring. It is characterized by being sealed.

In the second invention, the lower end of the skirt is widened into a conical shape to match the shape of the furnace opening, so that the skirt can be lowered as much as possible, and a plurality of chains are hung around the outer periphery of the lower end of the skirt. With the lower end of the chain rope hanging down longer than the lower end of the skirt, leaving a gap between the furnace opening and the skirt, run multiple chains of chain rope along the outer periphery of the furnace opening. It is characterized by a seal between it and the skirt.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail below. In FIG. 3, 12 is a furnace opening, 2 is a skirt, and 3 is a hood. At the bottom of skirt 2,
A first sealing ring 17 is provided, which is attached to an annular frame 19 that holds the skirt 2. The first seal ring 17 has a circular cross section and is made of heat-resistant cast iron, and has a hollow part 17' formed in its center, and has a water-cooled structure in which cooling water flows through the hollow part.
18 is located outside the first seal ring 17,
This is a chain-shaped second seal provided so as to surround the first seal ring 17. Reference numeral 20 denotes a bracket provided on the annular frame 19, and a skirt cylinder 2 connected to this bracket 20.
1, skirt 2, first seal ring 17
and the second seal 18 are both moved up and down.

Note that 22 is a seal jacket, and 23 is a seal cylinder.The lower end of the seal cylinder 23 is immersed in water filling the seal jacket 22, and the space between the skirt 2 and the hood 3 is sealed with water so that the skirt 2 can be raised and lowered. ing.

The operation of this embodiment configured as above will be explained below.

In the pig iron receiving, refining and tapping processes of converter operation,
The skirt 2, the first seal ring 17, and the second seal 18 are all moved up and down by a skirt cylinder 21.

At the time of sealing during refining, the first seal ring 17 is first pressed against the furnace mouth 12 by the skirt cylinder 21 and crimped. During this crimping, the high-temperature slag adhering to the furnace mouth 12 is rapidly cooled by the cooling of the first seal ring 17, destroyed by thermal shock caused by this rapid cooling, and further crushed by strong force. Ru. Due to the mutual effect of this thermal shock and crushing, the furnace mouth 12 and the first seal ring 17 are brought into a substantially close contact state.

In addition, in the above-mentioned crimping, since the first seal ring 17 is formed with a circular cross section, the slag adhered in an uneven manner and the first seal ring 17 come into point contact, and a large pressing force is applied to the slag. It acts as a structure and makes crushing easier.

At the same time as the first seal ring 17 is crimped, the chain-shaped second seal 18 comes into contact with the furnace mouth 12 according to the thermal deformation of the furnace mouth 12 or the distortion caused by manufacturing errors, and a kind of chain-like seal 18 is brought into contact with the It is formed around the seal ring 17 to seal gas leaking from the first seal ring 17.

Next, a second embodiment will be described in detail. Fourth
In the figure, 3 is a hood and 2 is a skirt.
The lower end 24 of this skirt 2 is connected to the outer periphery 2 of the furnace opening 12.
It is formed into a conical shape along the shape of 7. 18
is a chain support member 2 provided at the bottom of the support ring 19 supporting the skirt 2.
A chain tie 18 is formed to extend vertically from the skirt 5 and to wrap around the outer periphery of the lower end 24 of the skirt 2. Reference numeral 21 denotes a skirt cylinder, which is connected to a bracket 20 provided on the support ring 19, and is connected to a bracket 20 provided on the support ring 19.
and raise and lower the chain noren 18. 26 is a seal cylinder provided inside the chain tie 18 to protect the lower end 24 of the skirt 2 and to supplement the sealing performance of the chain tie 18.

Note that 22 is a seal jacket and 23 is a seal cylinder.

The operation of this embodiment configured as above will be explained below. In the pig iron receiving, refining, and tapping processes of converter operation, the chain link also moves up and down together with the skirt 2. During the sealing of the refining process, the skirt 2 is lowered by the skirt cylinder 21. In the state of being lowered to the furnace opening 12, the lower end of the chain rope 18 first stretches along the outer circumference 27 of the furnace mouth, and overlaps the weight of the chain and the weight of the plurality of chain ropes 18. blockade. On the other hand, the lower end 24 of the skirt 2 stops descending at a position where it contacts the highest peak of the slag deposited on the outer periphery 27 of the furnace mouth.

In this state, the chain slag 18 overlaps with the shape of the outer periphery of the furnace mouth 27 or along the unevenness of the slag, completely sealing off the space between it and the outer periphery of the furnace mouth 27. Further, the hanging portion of the chain 18 has a plurality of strips, and the chains are mixed together to become dense and sealed.

〔Effect of the invention〕

As detailed above, according to the sealing device of the present invention, the first sealing ring is provided at the lower part of the skirt,
Furthermore, a chain-shaped second seal is provided outside of the first seal ring so as to surround the first seal ring to achieve double sealing, and the first seal ring is further water-cooled to prevent the mutual effects of thermal shock and crushing. By using the slag to break the slag and sealing it together, the chain-shaped second seal was allowed to hang down in accordance with the deformation of the furnace mouth, making it possible to create a complete seal between the furnace mouth and the skirt.

Furthermore, since the first seal ring and the second seal were formed of heat-resistant cast iron and chains, they had sufficient heat resistance and a long-life sealing device. Since the lower end of the skirt is widened into a conical shape and a plurality of chains are hung around the outer circumference of the skirt, the skirt can be lowered close to the furnace mouth and the chains can be made to run along the outer periphery of the furnace mouth. Also, since the chain rope was made to hang long below the bottom edge of the skirt, it was possible to overlap the chain rope in multiple layers around the outer periphery of the furnace mouth, creating a complete seal.

In this way, we were able to completely seal the chain slag according to the deformation of the furnace mouth and the unevenness of the slag.
This method has excellent effects such as no outside air entering during refining, making it possible to obtain highly pure CO gas.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the entire converter exhaust gas. FIG. 2 shows a conventional example, and is a vertical sectional view showing an enlarged seal portion between the skirt and the furnace mouth. Third
FIG. 4 and FIG. 4 each show an embodiment of the present invention, and are longitudinal cross-sectional views showing only essential parts in an enlarged manner. 2... Skirt, 12... Furnace, 17... 1st
Seal ring, 18... chain seal (second seal), 24... lower end of skirt, 27... outer periphery of furnace mouth.

Claims (1)

[Claims] 1. A first seal ring having a circular cross section and made of heat-resistant cast iron and water-cooled and provided at the bottom of the skirt to seal between the skirt and the furnace mouth; and a first seal ring located outside the first seal ring. and a chain-shaped second seal vertically arranged to surround the first seal ring,
The first seal ring crushes the slag and seals it, and the chain-shaped second seal seals the slag.
A sealing device between a furnace mouth and a skirt of a converter exhaust gas treatment device, characterized by further sealing gas leaking from a seal ring. 2 Consists of a skirt whose lower end is spread out into a conical shape to match the outer circumference of the furnace mouth, and a plurality of chain ties hanging down from the outer periphery of the lower end of this conically spread skirt. A converter exhaust gas treatment device characterized by having a plurality of chains that hang down longer than the lower end, with a gap between the outer periphery of the furnace mouth and the lower end of the skirt, and run along the outer periphery of the furnace mouth. A sealing device between the furnace mouth and the skirt.