KR100584752B1 - A apparatus for capturing the evaporated volatile fume segregation in twin roll strip caster - Google Patents

Abstract

The present invention relates to an apparatus for collecting volatile vapor gas in a twin roll sheet casting machine.

The present invention, while passing through the filter portion 10 and the ceramic fiber 12 is filled with the ceramic fiber 12 in the inner space (P1) through which the volatile vapor gas generated in the molten steel pool 5 is passed. The deposition unit 20, in which the deposition metal plate 22 is filled in the internal space P2 so as to adsorb and remove the contaminants of the filtered vapor gas, is mounted on the lower surface of the meniscus chamber 9 in a vertically stacked structure. Including the inhaler 30 for forcibly suctioning the vapor gas to pass through the filter unit 10, the deposition unit 20 from the shield space (M) above the molten pool (5) in the deposition unit 20 In a sheet casting machine that injects molten steel between two casting rolls and rapidly solidifies it through contact with the rolls, the sheet casting machine effectively captures and removes harmful vapor gases of volatile elements in the molten steel component to remove the non-oxidizing atmosphere in the meniscus shield. To prevent contamination of the gas, roll table Delays while suppressing the occurrence mill scale manufacture a defect-free cast in, and may extend sikilsu the exchange period of the casting rolls.

 Sheet casting machine, volatile vapor gas, filter part, adsorption part, ceramic fiber, metal plate for evaporation

Description

A device for capturing volatile vapor gas of a twin roll sheet caster {A APPARATUS FOR CAPTURING THE EVAPORATED VOLATILE FUME SEGREGATION IN TWIN ROLL STRIP CASTER}

1 is a schematic view showing a typical twin roll sheet casting machine,

Figure 2 (a) is a schematic diagram showing the shape of the initial surface-treated dimple of the casting roll

(B) is a schematic diagram which shows the shape of the dimple after casting,

Figure 2 (c) is the surface shape of the initial surface-treated casting roll

Figure 2 (d) is the surface shape of the casting roll after a certain time casting

Figure 3 (a) is a composition table showing the shape of the black skin layer and black skin powder and the average components thereof taken from the surface of the casting roll after casting for a certain time

Figure 3 (b) is the shape of the black layer (black layer) formed on the upper surface of the casting roll dimple

Figure 3 (c) is the shape of the black powder (black powder) filled in the casting roll surface dimple bottom (bottom)

4 is a state diagram showing the installation of the volatile vapor gas collecting device of the twin-roll sheet caster according to the present invention,

Figure 5 is a detailed view showing a volatile vapor gas collecting device of the twin-roll sheet caster according to the present invention,

Figure 6 (a) (b) is a deposit shape on the surface of the ceramic fiber accommodated in the filter unit before and after casting in a thin plate casting machine employing a volatile vapor gas collecting device according to the present invention

7 is a composition chart of the deposits and the composition of the deposit particles condensed on the deposition metal plate after casting in a thin plate casting machine employing a volatile vapor gas collecting device according to the present invention.

Explanation of symbols on the main parts of the drawings

1,1a ... casting roll 2 ..... edge dam

4 ..... Immersion nozzle 5 ..... molten steel pool

6 ..... Cast 9 ..... Maniscus Shield

10 .... Filter section 11 .... Wire mesh

12 .... Ceramic Fiber 20 .... Deposition

21 .... metal case 22 .... metal plate for deposition

30 .... inhaler 31 .... inlet

33 .... gas suction line 42,43 ... cooling water supply and discharge line

45 .... Chilled water pipe 100 .... Sheet casting machine

The present invention relates to a device for capturing volatile vapor gas in a twin roll sheet casting machine, and more particularly, injecting molten steel between two casting rolls to rapidly solidify through contact with a roll to produce a thin sheet casting machine. By collecting and removing harmful vapors of volatile elements effectively, it prevents contamination of non-oxidizing atmosphere gas in the meniscus shield, produces defect-free casts by inhibiting black skin generation on roll surface, and exchanges casting rolls. The present invention relates to a volatile vapor gas collecting device of a twin roll sheet casting machine capable of extending the period.

As shown in FIG. 1, a typical double roll type sheet casting machine 100 includes two casting rolls 1 and 1a attached to the molten steel of the tundish 3 and an edge dam attached to both sides thereof. (2) The molten steel is supplied to form the molten steel pool 5 therebetween, and the casting rolls 1 and 1a are rotated in opposite directions to heat the heat into the roll through contact between the roll and the molten steel. The molten steel is rapidly solidified by flux to manufacture the cast steel 6.

In manufacturing the slab 6 as the sheet caster 100, an atmospheric gas existing between the roll and the solidification shell, that is, the hot water surface of the molten steel pool 5, the meniscus shield 9, the gas knife 8 and The role of the non-oxidizing atmosphere gas which is supplied to the vernier shield space M (hereinafter referred to as shield space) surrounded by the edge dam 2 on the side to prevent oxidation of molten steel is very important.

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The gas layer present at the casting roll (1) (1a) and the solidification shell interface is not only the gas film thickness or gas film profile, but also the reactivity with molten steel, that is, whether it is inert, oxidizing, reducing and dissolving. Therefore, the action and effect of the gas is very different.

In general, in the case of thin cast stainless steel (stainless steel) it is known that the use of nitrogen gas as the non-oxidizing atmosphere gas supplied to the shield space (M).

Here, the nitrogen gas not only prevents reoxidation of the molten steel as an inert gas, but also nitrogen is easily absorbed into the molten steel to reduce the surface tension of the molten steel, thereby reducing the wettability of the molten steel. To improve.

In particular, in the casting roll surface where dimples are imprinted by texturing technology such as photo etching or shot blasting, nitrogen gas is induced during solidification by inducing uniform solidification. It effectively prevents the occurrence of cracks on the surface of the cast steel by effectively dispersing and releasing stress.

Accordingly, in the sheet casting process, a technique for controlling the composition, amount, and flow of the atmosphere gas in the lower space of the meniscus shield 9 is a key technique for producing a flawless cast.

It is of utmost importance that the atmosphere in the meniscus shield 9 is extremely strong so as not to be contaminated by inflow of harmful gases or pollutants such as oxygen from the outside during casting.

In other words, metals such as Mn, Al, Ca, Zn, Cu, Si, etc., which have low melting point and low vapor pressure and are more easily volatilized than other elements, are added to the molten steel. It is easily evaporated in the molten steel pool and becomes the main culprit of pollution of atmospheric gases in the meniscus shield 9. The volatile vapor gas not only contaminates the internal atmosphere of the meniscus shield 9 but also reacts with oxygen in the meniscus shield 9 to form an oxide to form another contaminant or a low melting compound to roll. It acts as a large heat-resisting resistor at the solidification shell interface, causing microcracks on the surface of the cast steel.

In addition, as shown in Fig. 2 (a) (b) (c) (d), the dimple (D) initially attached to the casting roll (1) (1a) surface to promote the black skin layer and black skin powder Because of the distortion of the shape in a short time, the use cycle of the casting roll (1) (1a) caused a problem of sharply dropping.

Accordingly, in the related art, the cleanliness in the meniscus shield 9 was maintained only by controlling the supply amount or the discharge amount of the atmospheric gas supplied to the shield space M under the manikus shield 9, but Mn, Al, Volatilization and deposition of elements such as Ca, Zn, Cu, Si, and the like are very serious, and thus there is a limit to maintaining the cleanliness of the atmosphere gas in this manner.

Particularly, in Mn-added steels such as STS304 steel or high manganese steel, volatilization and deposition of Mn causes a very serious problem, so that the surface of the meniscus shield 9 and the molten steel pool 5 is heated. In order to prevent contamination of the surface of the casting roll while ensuring the cleanliness of the atmosphere gas in the shield space M therebetween, more aggressive countermeasures are required.

In FIG. 1, reference numeral 7 denotes a brush roll for removing and removing foreign substances attached to the outer circumferential surface of the roll.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, the purpose of which is to collect and remove the volatile vapor gas generated in the hot water surface of the molten pool, the lower space of the meniscus shield, high-purity atmosphere gas Is maintained in the shield space and at the same time to prevent contamination of the casting roll surface by volatile vapor gas or oxides thereof, and to prevent distortion of the shape of the initial surface-treated dimples as well as to manufacture flawless casts It is an object of the present invention to provide a volatile vapor gas collecting device of a twin roll sheet casting machine that can extend the use cycle of a roll.

As a technical configuration for achieving the above object, the present invention

A pair of casting rolls that rotate in opposite directions, an edge dam installed to form molten steel pools on both sides thereof, and a meniscus for supplying an inert atmosphere gas to the upper surface of the molten steel pool to block contact between outside air and molten steel. In the twin-roll type sheet casting machine having a shield and a gas knife installed in the width direction of the casting roll to cast the slab,

A filter part in which ceramic fibers are filled in an inner space through which volatile vapor gas generated from the molten steel pool passes, and a metal plate for deposition to adsorb and remove contaminants of the filtered vapor gas while passing through the ceramic fiber Filled deposition portion is mounted on the lower surface of the manikus shield in a vertical stacking structure,

By providing a volatile vapor gas collecting device of a twin-roll sheet caster, characterized in that the vapor deposition unit comprises an inhaler for forcibly sucking the vapor gas to pass through the filter unit, the deposition unit from the shield space of the molten pool upper portion.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

4 is an installation state diagram showing a volatile vapor gas collecting device of a twin roll thin casting machine according to the present invention, Figure 5 is a detailed view showing a volatile vapor gas collecting device of a twin roll thin casting machine according to the present invention.

As shown in Figs. 4 and 5, the apparatus 90 of the present invention contaminates the atmospheric gas by harmful vapor gas generated in the molten steel filled with molten steel during sheet casting, and the surface of the roll is damaged to shorten the service life. The device 90 is composed of a filter unit 10, a deposition unit 20, an inhaler 30, and the like, by trapping and removing harmful vapor gas installed in a shield space so as to prevent them from being prevented.

That is, the filter unit 10 is filled with the ceramic fiber 12 in the internal space (P1) through which the volatile vapor gas generated in the molten steel pool 5 is passed, the casting roll (1) (1a) Is a receiving member having a long side parallel to a longitudinal direction of the edge dam 2 and a short side parallel to the edge dam 2, and the filter unit 10 has a volatile vapor without the ceramic fiber 12 having a fine size of several μm without flowing out. The gas is composed of a ceramic enveloping wire mesh 11 having a hole having an outer surface that is natural enough to pass therethrough.

In addition, the deposition unit 20 passes through the ceramic fiber 12 of the filter unit 10, and the deposition metal plate 22 is disposed in the internal space P2 to absorb and remove contaminants contained in the filtered vapor gas. Only the lower surface of the filling portion, which is in contact with the filter portion 10, is an accommodating member having long and cross-sections opened downward, such that the deposition portion 20 has a large specific surface area for the deposition metal plate 22 to flow out. It is composed of a metal case 21 is attached to the lower opening in the intermediate plate 23, which is bored to the extent that the ceramic fiber 12 is not introduced therein.

Here, the metal case 21 is detachably assembled as a plurality of screw members on the lower surface of the manikus shield (9), the metal of the wire mesh 11 and the deposition unit 20 of the filter unit 10 The case 21 has a vertically stacked structure.

On the other hand, the inhaler 30 generates a suction force so that the vapor gas effectively passes through the filter unit 10 and the deposition unit 20 from the shield space (M) on the molten pool (5), such an inhaler ( 30 has a suction port 31 detachably assembled as a bolt member 34 to coincide with the suction hole 32 formed in the upper surface of the metal case 21 of the deposition unit 20, the suction port ( 31 is in communication with the gas suction line 33 having a control valve 33a to adjust the suction amount.

In addition, in the metal case 21 of the deposition unit 20 in which the deposition metal plate 22 is accommodated, a cooling water supply valve 44a is provided to maintain a low temperature within a range that does not cause scull formation of the hot water surface. The cooling water supply line 42 is mounted at one end, and the cooling water pipe 45 having the cooling water discharge line 43 having the cooling water discharge valve 44b is mounted at the other end in a plurality of rows.

In the case of casting the slab 6 in the sheet casting machine 100 by employing the apparatus 90 having the above-described configuration, the molten steel pool 5 formed between the casting roll 1, 1a and the edge dam 2 The steam gas is volatilized and evaporated at the hot water surface. When suction power is transmitted to the suction port 31 through the gas suction line 33 by the driving of a suction fan, not shown, the molten steel pool 5 and the manikus shield 9 Volatile vapor gas in the shield space (M) between the first pass through the ceramic fiber 12 accommodated in the wire mesh 11 of the filter unit 10, the pollutant is collected.

At this time, in order to maximize the collection function in the ceramic fiber 12, the specific surface area of the ceramic fiber 12 is configured to the maximum, the diameter of the ceramic fiber 12 is advantageously fine to a few μm.

Subsequently, the vapor gas passing through the filter unit 10 filled with the ceramic fiber 12 passes through the deposition metal plate 22 accommodated in the metal case 21 of the deposition unit 20. At this time, as in the ceramic fiber 12, in order to maximize the deposition (condensation) of the volatile vapor gas, the specific surface area of the metal plate 22 should be large.

In addition, since the lower the temperature of the metal plate 22 while the volatile vapor gas passes through the deposition metal plate 22 of the deposition unit, the deposition efficiency is better, the cooling water supply line 42 and the cooling water discharge line 43 The valves 44a and 44b are opened to operate, and the opening degree is adjusted to control the coolant flow through the coolant pipe 45.

Here, the filter unit 10 having the ceramic fiber 12 is provided at the bottom and the deposition unit 20 containing the deposition metal plate 22 is installed at the top to separate the deposition unit 20 from the molten steel pool 5. The reason why it is arranged so as to suppress the generation of the skull on the surface of the molten steel pool 5 is cooled by the evaporation unit 20 in which the cooling water pipe 45 is disposed, the metal surface for deposition This is to prevent the deposit of the volatile vapor gas deposited at (22) from reflowing into the hot water surface.

In addition, the ceramic fiber 12 is made of a material having a high heat resistance that does not melt or burn at high temperatures, and should be very thin so that the specific surface area can be maximized, and the metal wire mesh 21 for accommodating them in the inner space is also heat resistant. On the other hand, the ceramic fiber 12 of the inner space should be very dense so as not to fall on the hot water surface of the molten pool 5.

In addition, the deposition metal plate 22 of the deposition unit 20 is also composed of a material having a large heat resistance, the larger the specific surface area is advantageous to maximize the deposition efficiency.

In addition, the inhaler 30 is evenly disposed over the entire width of the upper surface of the deposition unit 20 to evenly inhale the volatile vapor gas generated in the shield space M.

Figure 6 (a) (b) shows the change of deposits on the surface of the ceramic fiber accommodated in the filter section before and after casting in a thin plate casting machine employing a volatile vapor gas collecting device according to the present invention, Figure 7 is a present invention The shape and composition of the deposits condensed on the deposition metal plate after casting in a sheet casting machine employing a volatile vapor gas collecting device according to the present invention.

Here, the ceramic fiber 12 is mainly composed of Al-O and Si-O oxides and has a diameter of about 5 to 10 μm. As shown in FIG. 6 (b), it can be seen that Mn, Si, Al, Ca, Zn, Cu-O fine oxides, which are vapor vapor deposits of volatile elements, adhere to the surface of the ceramic fiber 12. According to the component analysis, the most deposit was Mn-O oxide when casting STS304 steel.

As shown in FIG. 7, the deposit particles attached to the deposition metal plate 22 of the deposition unit 30 exhibit ultrafine powders of about 0.1 to 0.2 μm and aggregates of these ultrafine powders, and these particles are Mn-O. It can be seen that the oxide is the main component and a small amount of oxides of some other elements are mixed.

According to the results shown in FIGS. 6 and 7, it was confirmed that the main component of the volatile vapor gas was Mn element when casting STS304 steel, and the composition of the deposit was Mn-O oxide. This result is based on the surface of the casting roll (1) (1a), that is, the base (P) and the dimple (D) of the surface of the casting roll (1) (1a) when sheet-casting the STS304 steel with the dimple surface-treated casting roll shown in FIGS. The black powder and the black skin layer respectively formed on the upper portion (L) of the well matched the analysis results.

Therefore, in the case where the cast steel is cast by applying the volatile vapor gas collecting device 90 of the present invention, the atmosphere gas in the shield space M under the meniscus shield 9 is formed in an atmosphere of high purity non-oxidizing gas. It is easy to manufacture a defect-free cast, to prevent contamination of the surface of the casting roll (1) (1a), and to be able to manufacture a defect-free cast for a long time through the maintenance of the initial dimple shape .

According to the present invention as described above, the filter unit, the vapor deposition unit and the suction unit in which the vapor gas of Mn, Si, Al, Ca, Zn, Cu, which are volatile elements generated in the molten steel pool, are mounted on the shield space in a vertical stacking structure. By collecting it as a catalyst, since it is possible to prevent contamination of nitrogen atmosphere, which is an atmospheric gas, in the shield space under the meniscus shield, it is possible to produce a flawless cast steel, and cast rolls by harmful contaminants such as volatile vapor gas deposits and oxides. It can not only prevent and suppress the surface contamination, but also maintain the proper dimple condition of the initial surface treatment for a long time to extend the service life of the casting roll, while being subject to high Mn steel, where volatile Mn vapor gas is a serious problem. The effect of increasing the steel grade can be obtained.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to clarify that knowledge is easy to know.

Claims (5)

A pair of casting rolls (1) 1a rotating in opposite directions to each other, an edge dam 2 provided to form molten steel pools 5 on both sides thereof, and an inert atmosphere on the upper surface of the molten steel pools 5. Twin roll sheet casting machine for casting cast steel with a meniscus shield 9 for supplying gas to block contact between outside air and molten steel and a gas knife 8 installed in the width direction of the casting rolls 1 and 1a. To Filter portion 10 in which the ceramic fiber 12 is filled in the internal space P1 through which the volatile vapor gas generated from the molten steel pool 5 passes, and the vapor filtered while passing through the ceramic fiber 12. The deposition unit 20, in which the deposition metal plate 22 is filled in the internal space P2 so as to adsorb and remove the contaminants of the gas, is mounted on the lower surface of the manikus chamber 9 in a vertically stacked structure. It includes an inhaler 30 for forcibly sucking the vapor gas to pass through the filter unit 10, the deposition unit 20 from the shield space (M) above the molten pool (5) in the deposition unit 20 A volatile vapor gas collecting device of a twin roll sheet casting machine, characterized in that. The method of claim 1, The filter unit 10 has a ceramic fiber 12 having a fine size of several micrometers, the ceramic wrap wire 12 for the ceramic wrapper 11 is formed in the entire outer surface of the hole volatile vapor gas is naturally passed through without flowing out to the outside Volatile vapor gas collecting device of a twin-roll sheet caster, characterized in that consisting of. The method of claim 1, The deposition unit 20 has a lower surface of the intermediate plate 23, which is perforated to the extent that the ceramic fiber 12 is not introduced into the metal plate 22 having a large specific surface area without leaking to the outside. Volatile vapor gas collecting device of a twin-roll sheet caster, characterized in that consisting of a metal case 21 mounted. The method of claim 1, The inhaler 30 has a suction port 31 detachably assembled as a bolt member 34 to coincide with the suction hole 32 formed in the upper surface of the metal case 21 of the deposition unit 20, The suction port 31 is connected to the gas suction line 33 having a control valve (33a) so as to adjust the suction amount of the volatile vapor gas collecting device of the twin roll type sheet caster. The method of claim 4, wherein In the metal case 21, a cooling water supply line 42 having a cooling water supply valve 44a is mounted at one end, and a cooling water discharge line 43 having a cooling water discharge valve 44b is mounted at the other end thereof. A volatile vapor gas collecting device of a twin roll sheet casting machine, characterized in that 45) are arranged in a plurality of rows.

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