JPS5993817A - Method for sealing throat of converter - Google Patents

Abstract

PURPOSE:To seal tightly the throat of a converter under high pressure without discharging a sealing liq. during the tilting of the converter by sealing the gap between the throat and a liftable hood hanging over the throat with a magnetic fluid. CONSTITUTION:A magnetic fluid 8 is charged into an annular groove 3 fixed on the peripheral iron shell 1 of an upper part of the body of a converter. An exciting means 9 is installed around the groove 3 so that the fluid 8 is present in the groove 3 independently of the direction of gravity. The bottom of a liftable hood 6 is immersed in the fluid 8 in the groove 3 to carry out tight sealing. Thus, the throat of the converter can be sealed tightly under high pressure without requiring a large depth of the fluid 8 and discharging the fluid 8 during the tilting of the converter. Accordingly, exhaust gas from the converter is effectively utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a converter mouth sealing method, and in particular, by sealing a recovery system for converter exhaust gas, gas generated in the converter and which should be recovered while unburned is removed. The purpose is to increase the Co purity of the exhaust gas, and the use of an induction fan (IDF), which was conventionally required in the exhaust gas recovery system, can be made unnecessary.

By the way, the above-mentioned exhaust gas has the highest Co concentration among the steel by-product gases, is an excellent heat source, and has a high possibility of being used as a chemical raw material.

In order to increase the value of this type of use, it is necessary to remove the contaminant gases contained in the recovered gas, especially the air that is drawn in through the gap between the converter mouth and the movable hood, and to prevent such entrainment. It is desirable to at least reduce or eliminate the incorporation of curtain-like high-pressure jet gases such as N, Co, N, water vapor, etc. for gas sealing of the gaps.

For this purpose, instead of sealing the gap between the converter mouth and the movable hood with gas, it has been proposed to seal the gap with liquid using a so-called U-trap method to completely seal the gap.

That is, as schematically shown in FIG. 1, a groove 8 filled with water 2 is provided on the outer circumference of the upper part of the converter 1, while a groove 8 filled with water 2 is provided around the lower end of the fixed hood 4. 5, and by immersing the cuttings fixed to the movable hood 6 and the top layer sealing plate 7° 7' in these water at the lowered position of the movable hood 6, the furnace mouth is water-sealed. However, in this case, it is necessary to compensate for the evaporation loss of water, and it has also been proposed that low melting point metals can be used to avoid the trouble of loss and replenishment.

Even with such a liquid seal, instead of the conventional gas seal,
It is possible to prevent the escape of unburned gas or suction of air in the gap between the converter mouth and the movable hood, and the exhaust gas pressure in the gap can be adjusted according to the amount of gas generated in the converter. When the pressure is high, the amount of gas sucked into the recovery system is increased, and when the exhaust gas pressure is low, the amount of gas sucked into the recovery system is controlled to be controlled. Even without IDF, stable gas recovery is possible, and equipment costs can be reduced by omitting IDF and IDF
Although it is possible to consider the cost advantage of reducing the power cost required for driving, in a practical sense, it has the following obvious drawbacks in terms of operation, making it difficult to put it into practical use.

That is, the converter is tilted every time hot metal is charged, tapped steel, and slag is discharged, and therefore, the liquid 2 in the groove 3 provided in the shell 1 at the upper outer periphery of the converter is rotated when the converter is tilted. Therefore, when the converter is erected and blowing starts, there is a mess in this groove 3 that requires replenishment each time, and the liquid sealing liquid flows into the converter during tapping. It is not suitable for practical use because there is a risk that it will flow onto the molten steel in the receiving ladle directly below the converter during tilting and cause a steam explosion, and that low melting point metals will be mixed into the molten steel. In addition, the liquid sealing pressure depends exclusively on the depth of the groove 3, and is several hundred mrn aq, which is the sealing pressure necessary for smooth gas recovery without IDF.
In order to enable the high-pressure sealing of the converter, the amount of replenishment liquid required each time the converter is heated also becomes quite large, and the cost can no longer be ignored if low melting point metals are used. (naru)

The difficulties of the conventional liquid sealing method as described above are completely eliminated by the present invention described below.

That is, this invention provides a liquid seal between the furnace mouth of the converter body and the movable hood which is the tip of the exhaust gas recovery system.
As shown in Fig. 2, a magnetic fluid 8 is used as the liquid sealing liquid, and a permanent magnet or an electromagnet is installed along the outer periphery of the groove 8 on the iron skin 1 on the outer periphery of the upper part of the converter body that accommodates the magnetic fluid. By arranging it as the excitation means 9 and holding the magnetic fluid in the magnetic field formed thereby, the fluid is allowed to exist in the groove a regardless of the direction of the gravity applied to the magnetic fluid, and the movable hood is placed in this liquid. Seal plate 7 fixed to 6
Soak.

The magnetic fluid 8 can be easily prepared by adsorbing a surfactant on ferromagnetic fine powder and dispersing it in a solvent such as water, aliphatic hydrocarbon, aromatic hydrocarbon, or the like.

The magnetic fluid 8 is preferably energized by excitation means 9 as shown in FIG. 3 in a magnetic field such that M is the magnetization of the magnetic fluid and H is the strength of the magnetic field.

The magnetic fluid is held within the magnetic pole by the magnetic force exerted by the magnetic force, which resists the pressure difference ΔP=pl-po between the inside and outside of the liquid sealing part.

Therefore, by selecting a magnetic fluid with large magnetization or simply by strengthening the magnetic field, it is possible to achieve high-pressure sealing that enables gas recovery without IDF, and it is possible to achieve a high-pressure seal that enables gas recovery without the need for an IDF. Not only does it have extremely superior features compared to conventional liquid sealing technology, but it also has
There is no need to worry about liquid leakage during converter tilting, which was an essential drawback of the conventional technology, because the magnetic fluid is held in a magnetic field against gravity, which eliminates safety issues and operational complications. This is particularly useful in practice.

Further, by taking advantage of the feature that the magnetic fluid can be held arbitrarily regardless of the direction of gravity, a groove 3' can be moved and provided in the movable 7-door 6 as shown in FIG. That is, in the arrangement shown in FIG. 2, when the converter is tilted and hot metal is charged, tapped, or slag is discharged, hot metal, Contrary to concerns that flying objects such as molten steel and molten slag may adhere and cause blockage of the opening, magnetic fluid 8
A groove 3' containing a magnet 9 is fixed to the lower end of the movable hood 6, and a seal fixed to the outer periphery l of the converter body is placed in a groove 8' which opens downward as the movable hood 6 descends. If you create a structure that seals by accepting plate work 0,
There is no chance that the magnetic fluid 8 storage area will be damaged by flying debris, and the removal of the debris from the seal plate 10, which tends to attract flying debris during tilting of the converter, is carried out in the magnetic fluid housing area shown in FIG. In other words, it is much easier to remove deposits from inside the groove 3, so it is extremely practical in implementing sealing of the converter mouth using magnetic fluid.

Although shown in common in FIGS. 2 and 4, the magnetic fluid 8
In order to more accurately seal the opening of the converter furnace, a refractory dust-proof/heat-insulating plate 11 is provided adjacent to the inside of the accommodating section for the magnetic fluid 8, and grooves 3, 3 for accommodating the magnetic fluid 8 are provided. It is desirable to install a protective structure 12 which can be water-cooled so as to surround '' together with the excitation means 9.

Of course, the above-mentioned magnetic fluid may also be applied to the liquid seal between the fixed hood 4 and the upper part of the movable hood 6, but from the viewpoint of necessity, a liquid seal similar to that shown in FIG. That's enough.

As described above, according to the present invention, the gap between the movable hood that covers the converter mouth and the furnace mouth can be airtightly and accurately sealed, so that the converter exhaust gas can be efficiently removed. It can be used in a wide range of applications and can also contribute to the simplification of operating equipment.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the main parts showing a conventional sealing method in which the space between the outer wall of the converter and the movable hood is sealed using water filled in a groove on the outer wall of the converter, and a low melting point alloy. A sectional view of a main part showing an embodiment of the method of the present invention in which fluid is filled in a groove on the outer wall of a converter and held by a magnetic field, FIG. 8 is a characteristic diagram of liquid seal behavior, and FIG. 4 is a modified example. FIG. Special 'F Applicant Kawasaki Steel Co., Ltd. Page 1 Continued 0 Author Sadayuki Saito 1 Kawasaki-cho, Chiba City Kawasaki Steel Co., Ltd. Chiba Works

Claims (1)

[Scope of Claims] A method for sealing the furnace mouth of a J converter, characterized in that the circumference of an elevating and movable hood that covers the furnace mouth of the L converter is hermetically sealed with a liquid seal using magnetic fluid. The magnetic fluid is contained in a liquid reservoir consisting of an annular groove fixed at the hip on the steel shell around the furnace mouth of the converter. The method described in l which governs. & The method according to 2, wherein the magnetic fluid is excited at least during tilting of the converter in the raised shelter position of the movable hood. Table 1. A ferrofluid is kept under constant excitation in a downwardly opening annular groove in the cuttings of the movable hood, and is placed under the upper infiltration of an annular sealing plate fixed on the shell around the converter mouth. The method described in l, which controls the internal and external liquid seals.