WO2020027582A1 - Molten iron processing apparatus and molten iron processing method - Google Patents

Abstract

A molten iron processing apparatus according to an embodiment of the present invention comprises: a vessel having an internal space that can accommodate molten iron; a stirrer having a rotatable impeller that is inserted into the vessel so as to be immersed in and stir molten iron; and a flow generator which can be at least partially immersed in the molten iron in the vessel and can introduce and discharge molten iron by means of changes in internal pressure. Thus, according to a molten iron refining apparatus and a molten iron method according to an embodiment of the present invention, the downward flow of molten iron is forcibly increased by the flow generator, thus increasing the downward flow throughout the molten iron and at the molten iron surface compared to the prior art. Accordingly, the infiltration of refining agents, injected onto the molten iron surface, into the molten iron, or the mixing of the molten iron and the refining agents is promoted and increased. Furthermore, due to the powerful downward flow, the refining agents infiltrated or incorporated into the molten iron are unable to easily rise to the molten iron surface, thus increasing the residence time of the refining agents in the molten iron.

Description

Molten iron processing apparatus and molten iron processing method

The present invention relates to a molten iron processing apparatus and a molten iron processing method, and more particularly, to a molten iron processing apparatus and a molten iron processing method that can improve the refining efficiency.

The molten iron produced through the blast furnace process is refined to control the content of some of the molten iron in order to finally obtain the molten steel and the product of the desired component. And, in the case of general steel except free cutting steel etc., a low concentration of sulfur (S) is required.

Sulfur in the molten iron is a component that is mainly removed by a reduction reaction, and it is difficult to remove it to a low concentration in an converter that performs oxidation refining. Therefore, in the molten iron phase, it is common to react with a desulfurization agent containing CaO as a main component and desulfurization treatment.

Recently, a method for desulfurization using a KAR apparatus (KR; Kanvara reactor), which is a mechanical stirring type molten iron desulfurization facility, has been widely used.

A common KAR apparatus (KR; Kanvara reactor) is a ladle containing a molten iron for refining, an agitator having an impeller rotatable and rotatable into the ladle to mechanically stir the molten iron, and positioned outside the ladle to inject the refining agent into the molten iron in the ladle. A refiner injector.

Hereinafter, a desulfurization method using the above-mentioned KAL apparatus (KR; Kanvara reactor) will be described.

First, the impeller is immersed by the molten iron in the ladle and rotated, and a desulfurizing agent is added to the molten iron surface. As the impeller rotates, the molten iron in the ladle is stirred and a vortex is formed, and downward flow occurs in the molten iron surface. Thus, the desulfurization agent introduced into the molten iron surface of the molten metal stays on the molten iron surface of the molten metal, and then moves in the direction in which the vortex is formed in the molten steel surface to penetrate or reel into the molten iron. The desulfurization agent penetrated or wound into the molten iron reacts with sulfur (S) in the molten iron, and desulfurization is performed to remove sulfur (S) in the molten iron.

On the other hand, in order to contribute to the desulfurization reaction of the desulfurization agent injected into the molten iron molten metal desulfurization agent injected into the molten iron molten metal must be penetrated into the molten iron and mixed with the molten iron.

By the way, at the time of desulfurization using the current KAL apparatus, among the desulfurization agents introduced into the molten iron surface, the rate of penetration and reaction of the molten iron is very low, around 10%. This causes a problem of increasing the desulfurization time and the amount of desulfurization agent used.

The present invention provides a molten iron processing apparatus and a molten metal processing method capable of promoting the introduction of a refining agent into the molten iron.

The present invention provides a molten iron processing apparatus and a molten iron processing method which can further provide downflow in addition to the downflow caused by the operation of the impeller.

The present invention provides a molten iron treatment apparatus and a molten iron treatment method capable of increasing the residence time of the refinery flowing into the molten iron.

(Prior art document)

Korea Patent Registration KR1709134

The molten iron processing apparatus according to the embodiment of the present invention comprises a container having an internal space that can accommodate the molten iron; A stirrer inserted into the vessel, the stirrer being rotatable into the molten iron and having a rotatable impeller; And a flow generator capable of immersing at least a portion of the molten iron in the vessel and allowing inflow and exhaust of the molten iron by a change in internal pressure.

The flow generator includes a lance having an internal space and immersable in the molten iron; And a pressure adjusting unit connected to communicate with the inner space of the lance, and depressurizing and pressurizing the inside of the lance, wherein the pressure adjusting unit depressurizes the inside of the lance to introduce a molten iron into the lance. Pressurized to discharge the molten iron inside the lance.

In the molten iron in the vessel, the downflow due to the vortex caused by the rotational operation of the impeller and the downflow due to the vortex generated by the force discharged into the vessel the molten iron introduced into the lance is generated.

The immersion depth of the lance is lower than the immersion depth of the impeller.

The pressure control unit may include: a connection line having one end connected to the lance so as to communicate with an internal space of the lance; A pump connected to the other end of the connection line; A first valve installed on an extension path of the connection line to control communication with the pump; And a second valve positioned between the lance and the first valve on an extension path of the connection line and controlling gas inflow into the lance.

The pressure regulator may include a vacuum control chamber positioned between the first valve and the second valve on an extension path of the connection line and having an internal space; And a third valve positioned between the vacuum regulating chamber and the second valve on an extension path of the connection line.

A refiner injector for injecting a refining agent into the molten iron in the vessel, wherein the refining agent injected into the molten iron molten water, the downward flow due to the vortex caused by the rotation of the impeller and the force of the molten iron introduced into the lance is discharged into the vessel It flows into the molten iron by the downward flow due to the vortex generated by

The refining agent includes a desulfurization agent.

The molten iron treatment method according to an embodiment of the present invention comprises the steps of immersing the impeller with the molten iron in the container, and rotating the impeller; And immersing the lance with the molten iron in the vessel, and varying the pressure in the lance to allow the inflow and discharge of the molten iron into the lance alternately, thereby forming a flow of molten iron.

The molten iron in the vessel generates downward flow caused by the vortex due to the rotation of the impeller and downward flow due to the vortex generated by the force of the molten iron introduced into the lance is discharged into the vessel.

The generating of the downflow using the lance may include: depressurizing the inside of the lance to introduce molten iron into the lance; And pressing the inside of the lance to discharge the molten iron inside the lance.

Inflowing the molten iron into the lance, the height of the molten iron in the lance is higher than the height of the molten iron in the vessel, and in the discharge of the molten iron in the lance, the height of the molten iron in the lance is the molten iron in the vessel Adjust the height to be equal to or lower than.

The height of the molten iron in the lance is higher than the height of the molten iron in the vessel, wherein the pressure in the lance is adjusted to a vacuum pressure, the height of the molten iron in the lance is equal to or lower than the height of the molten iron in the vessel In the adjustment, the pressure in the lance is adjusted above atmospheric pressure.

The rate at which the molten iron flows into the lance is controlled to be slower than the rate at which the molten iron in the lance is discharged.

The depressurization speed inside the lance is controlled to be slower than the pressurization speed inside the lance.

Injecting a refining agent into the molten iron; And introducing the refining agent into the molten iron.

The flow of the refining agent into the molten iron may include a main inflow process in which the refining agent is introduced into the molten iron by a downward flow generated by the vortex caused by the rotation of the impeller; And a secondary inflow process in which the refining agent is introduced into the molten iron by the downflow generated by the vortex due to the force of the molten iron in the lance is discharged into the vessel.

The refining agent includes a desulfurization agent.

According to the molten iron refining apparatus and the molten iron method according to an embodiment of the present invention, as the flow generator forcibly generates downward flow of the molten iron, downflow in the entire molten iron and molten iron surface increases more than in the prior art. As a result, the penetration of the refiner into the molten iron and the mixing of the molten iron with the refiner are promoted and increased. In addition, due to the strong downflow, the refining agent penetrated or wound into the molten iron does not easily rise to the molten iron surface, thereby increasing the time for the refining agent to stay inside the molten iron.

As described above, the penetration of the refining agent into the molten iron becomes easy, and as the time for which the refining agent stays in the molten iron is increased, the refining efficiency is improved. In addition, this can reduce the consumption of refining agent, and can shorten the refining time to improve productivity.

1 is a view for explaining a molten iron processing apparatus according to an embodiment of the present invention.

Figure 2 is a conceptual diagram for explaining the flow of molten iron by the operation of the flow generator according to an embodiment of the present invention

FIG. 3 conceptually illustrates the main parts of a first experimental device for comparing the penetration of smelters with and without using a flow generator according to an embodiment of the invention.

4 conceptually illustrates the main parts of a second experimental apparatus for comparing the refining efficiency with and without using the flow generator according to the embodiment of the present invention.

5 is a graph showing the sulfur concentration in the molten iron according to the desulfurization time of the third and fourth experimental examples

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. In the drawings, like reference numerals refer to like elements.

The present invention relates to a molten iron processing apparatus and a molten iron processing method, and more particularly, to a molten iron processing apparatus and a molten iron processing method that can improve the refining efficiency.

The present invention relates to a molten iron processing apparatus and a molten iron processing method which can promote the penetration or inflow of the refining agent into the molten iron and can increase the residence time of the refining agent penetrated or introduced into the molten iron. In addition, the present invention relates to a molten iron processing apparatus and a molten iron processing method that can further provide a downflow in addition to the downflow by the operation of the stirrer.

1 is a view for explaining a molten iron processing apparatus according to an embodiment of the present invention. 2 is a conceptual diagram for explaining the flow of the molten iron by the operation of the flow generator according to an embodiment of the present invention.

Referring to Figure 1, the molten iron processing apparatus according to an embodiment of the present invention can be immersed and rotated inside the container 100 to mechanically stir the vessel 100, the molten iron (M) is accommodated molten iron (M) for refining Stirrer 200 having an impeller 210, a refiner injector 300 positioned outside the vessel 100 to inject the refiner R into the molten iron M in the vessel 100, and a molten iron in the vessel 100 ( M) is immersable and includes a flow generator 400 having a lance 410 having an internal space that can pass through the molten iron (M).

Hereinafter, in describing the molten iron treatment apparatus and the molten iron treatment method according to an embodiment of the present invention, a desulfurization treatment apparatus and a desulfurization method for adjusting the components of sulfur (S) in the molten iron (M) will be described by way of example.

In addition, the molten iron treatment apparatus or the desulfurization apparatus according to the embodiment may be a Kanvara reactor (KR) which is a means for refining molten iron or molten steel in the steelmaking field of the technical field.

Of course, the molten iron processing apparatus is not limited to a KAR apparatus (KR; Kanvara reactor), and has an impeller, and can be applied to various apparatuses in which downflow generation of molten iron is required.

The container 100 is a means for forming a space therein to allow the molten iron M to be stored or accommodated, and may be, for example, a ladle used to take or take the molten iron M in various operation steps. The container 100 may include a refractory wall provided inside the shell and the shell because it stores the hot molten iron M.

Of course, the container 100 is not limited to the ladle, it is possible to accommodate the molten iron, and the container of various means capable of installing the stirrer 200 and the lance 410 is possible.

The stirrer 200 is immersed in the molten iron (M) received in the vessel 100, a means for stirring the molten iron (M) by the rotational motion, it may be formed in a similar or the same form as the general stirrer of the KAL apparatus. That is, the stirrer 200 is composed of a plurality of blades, the impeller 210 to be immersed in the molten iron (M) to stir the molten iron (M), extending in the vertical direction, the shaft 220 connected to the upper portion of the impeller 210 ), A drive unit 230 that provides rotational power to the shaft 220.

Here, the impeller 210 composed of a plurality of blades may be formed larger than the width of the lower end portion. That is, it may be inclined so that the width becomes narrower from the upper end to the lower end. The shape of the impeller 210 should just be able to fully stir the molten iron M received by the container 100, and the structure and shape are not specifically limited.

According to the rotation of the impeller 210 of the stirrer 200, the molten iron M is agitated to generate a vortex, and the vortex flows downwardly in the molten iron and the molten iron M surface, that is, the hot water surface. Downflow occurs.

The impeller 210 of the stirrer 200 is immersed in the molten iron (M) in the vessel 100 for stirring of the molten iron (M), it is immersed so that the impeller 210 is located in the center of the width direction of the vessel 100 desirable.

The refining agent injector 300 is a chute 320 for refining the refining agent R stored in the refining agent R for refining the molten iron M, and the refining agent R provided from the refining agent storage 310 into the container 100. ).

The chute 320 extends in the direction of the container 100 from the refining agent storage part 310, and may be inclined downward so as to be closer to the center of the width direction of the container 100 toward the lower side.

According to the chute 320, the refining agent R can be introduced into a position adjacent to the impeller 210, that is, a position adjacent to the center in the width direction of the container 100.

Refining agent (R) is a material for controlling the content of a specific component in the molten iron (M), for example, may be a desulfurization agent for removing the sulfur (S) in the molten iron (M). And the desulfurization agent may be a raw material containing CaO as a main component. More specifically, the desulfurization agent contains CaO as a main component, and includes a solvent, and the solvent may include at least one of fluorite and aluminum (Al-ash).

Hereinafter, in describing the refining agent R in the molten iron M in the container 100, the desulfurizing agent is described as the refining agent R by way of example.

For refining, that is, desulfurization of the molten iron (M), the impeller 210 is immersed and rotated by molten iron in the container 100, and a desulfurizing agent is introduced into the molten iron (M) water surface through the chute 320. When the impeller 210 rotates, the molten iron M in the vessel 100 is stirred and a vortex is formed, and downward flow occurs in the molten iron M and the molten iron M surface. At this time, the desulfurization agent introduced into the molten iron (M) melt surface stays in the molten iron (M) molten surface, and moves in the direction in which the vortex (vortex) is formed in the molten iron (M) is penetrated or introduced or introduced into the molten iron (M). The desulfurization agent introduced into the molten iron (M) reacts with sulfur (S) in the molten iron (M), and this is carried out desulfurization to remove the sulfur (S) in the molten iron (M).

On the other hand, in order to contribute to the desulfurization reaction of the desulfurization agent injected into the molten iron (M) water surface, the desulfurization agent injected into the molten iron (M) water surface must be mixed with the molten iron (M).

And, the desulfurization agent introduced into the molten iron (M) hot water flows into the molten iron by the downward flow of the molten iron, the downward flow is mainly formed by the vortex caused by the rotation of the impeller (210). Thus, when the downflow of the molten iron is increased, the inflow of the desulfurizing agent is promoted. However, the rotation of the impeller 210 has a limit in increasing downflow.

Accordingly, the molten iron processing apparatus according to the embodiment of the present invention includes a flow generator 400 for generating additional downflow in addition to the downflow caused by the rotation of the impeller.

The flow generator 400 according to the embodiment is a means for forcing a downward flow of the molten iron M. In other words, the flow generator 400 is a means for generating the downflow of the molten iron separately or in addition to the downflow of the molten iron by the rotation of the impeller 210. The flow generator 400 is lance 410, which can be immersed in the molten iron (M) in the vessel 100, the inner space capable of passing the molten iron (M), inflow of the molten iron into the lance 410 and the lance The molten iron in 410 is connected to communicate with the inner space of the lance 410 to be discharged into the container 100, and includes a pressure regulator 420 to adjust the pressure in the lance 410.

The lance 410 has an empty space extending in the vertical direction therein, the lower end is in the form of a tube (tube) opened to allow the inlet and outlet of the molten iron (M), it is made of a refractory.

As described above, the lance 410 is immersed in the molten iron in the vessel 100, it is installed to be spaced apart from the side wall and the stirrer 200 in the vessel 100. In addition, the lance 410 may be immersed in a direction symmetrical with the refining agent R, that is, the position into which the desulfurization agent is introduced, or may be positioned to be adjacent to the position into which the desulfurization agent is introduced.

Also, the immersion depth D ₂ of the lance 410 may be lower, deeper, or the same as the immersion depth D ₁ of the impeller 210. However, it is more preferable that the immersion depth D ₂ of the lance 410 is set lower than the immersion depth D ₁ of the impeller 210 (D ₁ > D ₂ ), which may generate a downward flow more strongly. Because it can.

Immersion depth means the distance from the bottom surface in the container 100. And, the deeper the immersion depth, the closer to the bottom surface in the container 100, the larger the distance from the hot water surface. On the contrary, the lower the immersion depth, the farther it is from the bottom surface of the container 100 and the closer to the hot water surface.

Pressure control unit 420 is connected to one end of the connection line (L) connected to the lance 410, the pump 421 connected to the other end of the connection line (L), the connection line (L) in communication with the internal space of the lance 410 Is installed on an extension path of the first valve V ₁ , which controls communication with the pump 421, between the lance 410 and the first valve V ₁ on the extension path of the connection line L; , A second valve V _{2 for} controlling gas to flow into the lance 410, and a pressure gauge 422 positioned between the lance 410 and the second valve V ₂ on an extension path of the connection line L. It includes.

The pump 421 and the first and second valves V ₁ and V ₂ may be means for finely adjusting the connection line L and the lance 410.

Hereinafter, the pressure change in the lance 410 due to the operation of the pressure adjusting unit 420 as described above, and the molten iron inflow and discharge into the lance 410 will be described.

First, the second valve V ₂ is closed, and the first valve V ₁ is opened and the pump 421 is operated while the lance 410 is immersed in the molten iron M in the container 100. The inside of the line L and the lance 410 is decompressed. The molten iron flows into the lance 410 by the pressure difference due to the reduced pressure, and it is preferable to reduce the molten iron so that the molten iron in the lance 410 is higher than the molten iron in the container 100. To this end, the inside of the lance 410 may be pressurized with a vacuum pressure. This can be adjusted by controlling the operation of the pump 421 and the first valve V ₁ .

Thereafter, when the first valve V ₁ is closed and the second valve V ₂ is opened, gas, for example, air, is introduced into the lance 410. When the inside of the lance 410 is pressurized by the gas inflow, the molten iron inside the lance 410 is discharged to the outside, that is, the container 100.

The pressure reduction and pressurization as described above are alternately repeated to repeat the flow of molten iron into and out of the lance 410.

The pressure adjusting unit 420 is not limited to the above-described example, and may further include a vacuum adjusting chamber C and a third valve V ₃ . That is, the pressure regulator 420 is positioned between the first valve V ₁ and the second valve V ₂ on the extension path of the connection line L, and connects the vacuum control chamber C having an internal space and the connection. It may further include a third valve (V ₃ ) located between the vacuum regulating chamber (C) and the second valve (V ₂ ) on the extension path of the line (L).

When the vacuum control chamber (C) is installed, the pressure in the lance can be adjusted more precisely or finely. In addition, it is easier to adjust the pressure in the lance 410 that is immersed in the small volume container 100.

Hereinafter, the pressure change in the lance 410 and the molten iron flow into the lance 410 by the operation of the pressure regulator 420 further including the vacuum control chamber C and the third valve V ₃ as described above. Explain the discharge.

First, in a state where the second valve V ₂ and the third valve V ₃ are closed, only the first valve V ₁ is opened to operate the pump 421. At this time, since the size of the vacuum control chamber C is very small, the vacuum control chamber C is decompressed instantly. When the first valve V ₁ is closed and the third valve V ₃ is opened, the inside of the lance 410 is depressurized, and thus molten iron flows into the lance 410. At this time, it is preferable to reduce the pressure so that the molten iron height in the lance 410 is higher than the molten iron height in the container 100. To this end, the inside of the lance 410 may be pressurized with a vacuum pressure.

Thereafter, the third valve V ₃ is closed and the second valve V ₂ is opened to pressurize the inside of the lance 410. As a result, the molten iron inside the lance 410 is discharged to the outside, that is, the container 100.

Then, the pressure and pressure as described above are alternately repeated to repeat the flow of molten iron into and out of the lance 410.

As in the above-described embodiments, when the inside of the lance 410 is pressed, the molten iron M in the lance 410 is discharged to the outside, and the height of the molten iron in the lance 410 according to the pressure will be described below.

When the inside of the lance 410 is pressurized, the molten iron M is discharged. When the inside of the lance 410 is at atmospheric pressure (or normal pressure), as shown in FIG. 2B, the molten iron M in the lance 410 is removed. The height may be equal to the height of the molten iron in the vessel 100.

When the pressure inside the lance 410 is further pressurized to exceed the atmospheric pressure, the molten iron in the lance 410 is further discharged, and the height of the molten iron in the lance 410 is increased in the container 100 as shown in FIG. It may be lower than the water level, and then all the molten iron in the lance 410 is discharged.

In the above, the molten iron inside the lance is discharged, the pressure inside the lance is pressurized to the atmospheric pressure so that the molten iron (M) height in the lance 410 is the same as the molten iron (M) height in the vessel 100, the inside of the lance The pressure of the pressure exceeds the atmospheric pressure of the molten iron (M) in the lance 410 was described by dividing the step to further press the lower than the height of the molten iron (M) in the container (100).

However, when the molten iron inside the lance 410 is discharged, it may be adjusted at a time from a vacuum pressure to a pressure exceeding the atmospheric pressure.

According to the above-described operation of the pressure adjusting unit, the molten iron M introduced into the lance 410 is discharged to the outside. In this case, the molten iron M is discharged from the container 100 by the force discharged, more specifically, the lance ( A vortex is generated around 410. The vortices generate downward flows flowing downward in the molten iron M and on the molten iron M surface, that is, the water surface.

That is, in addition to the vortices caused by the rotation of the impeller 210 in the container 100, vortices are further formed by the force from which the molten iron M in the lance 410 is discharged to the outside. Thus, in addition to the downward flow due to the rotation of the impeller 210, the downward flow due to the force from which the molten iron in the lance 410 is discharged to the outside is further formed.

In addition, the greater the force that the molten iron M in the lance 410 is discharged or discharged to the outside, the strength of the vortex increases, the force of the molten iron M can be controlled by the discharge rate. And, the discharge rate of the molten iron (M) can be adjusted according to the pressure rate. Accordingly, the discharge rate, that is, the pressurization rate is adjusted within the range in which the molten iron M discharged from the lance 410 is not scattered by the molten iron M or the molten iron M.

Here, the decompression rate may mean a depressurization amount per hour, and the pressurization rate may mean a pressurization amount of pressure per hour.

In addition, the inflow rate of the molten iron M into the lance 410 is preferably slower or smaller than the discharge rate of the molten iron M. In other words, it is desirable to make the decompression rate in the lance 410 smaller than the pressurization speed.

This is because the molten iron M is introduced into the lance 410 again after the molten iron M of the lance 410 is discharged, so that the inflow rate of the molten iron M is greater than that of the molten iron M. This is because the vortex due to the discharge of the molten iron (M) disappears in the previous stage or the strength of the vortex is reduced. This is a factor to reduce the strength of the downflow by the lance 410.

Therefore, in the embodiment, the inflow rate of the molten iron M into the lance 410 is made smaller than the discharge rate of the molten iron M, thereby suppressing the reduction of the strength of the vortex and the downflow caused by the lance 410.

As described above, according to the molten iron processing apparatus according to the embodiment of the present invention, the strength of the downward flow of the molten iron M in the container 100 is larger than in the related art. In other words, the downward flow of the molten iron M in the container 100 of the molten iron processing apparatus according to the embodiment is stronger than in the prior art.

This increase in strength or size of the downflow increases the infiltration of the molten iron into the molten iron M, or the mixing between the molten iron M and the refiner R. That is, the operation of introducing the refinery of the hot water into the molten iron is due to the main inflow due to the downflow generated by the rotation of the impeller 210 and the inflow due to the downflow generated by the molten metal discharge from the lance 410. Is made by.

In addition, due to the strong downflow, the refining agent R penetrated or introduced into the molten iron M does not easily rise to the molten iron surface, thereby increasing the time for the refining agent R to stay inside the molten iron. As described above, as the refining agent R is easily penetrated into the molten iron M, and the residence time in the molten iron M increases, the reaction rate and reaction time between the molten iron M and the refining agent R are increased. Increased, there is an effect that the refining efficiency is improved. In addition, this can reduce the consumption of refining agent and can improve the productivity by shortening the refining time.

3 is a view conceptually showing the main parts of the first experimental device for comparing the penetration of the refiner when using the flow generator according to the embodiment of the present invention, and otherwise.

The first experimental apparatus is a male model experimental apparatus, which has an internal space, and has a beaker 10a having an upper side opened, which can be immersed into the beaker 10a, and includes a rotatable impeller 21a and a beaker. A pressure regulating member (10a) capable of being immersed inward and connected to an upper end of the tube 41a having an inner space and the tube 41a protruding upward from the beaker 10a to adjust the pressure inside the tube 41a ( 42a), a support 50 is disposed outside the beaker 10a to support the tube 41a.

The beaker 10a has an inner diameter of 130 mm.

The stirrer 20a is composed of a plurality of blades, the impeller 21a for immersing the water in the container to agitate the water, extending in the vertical direction, the shaft 22a, the shaft 22a connected to the upper portion of the impeller 21a And a motor 23a for providing rotational power.

The pressure regulating member 42a has an inner space, and a rubber bulb 42-1 and a rubber bulb 42-1, which can be deformed so that the inner space is contracted or restored by a force applied from the outside or the inside. It may include a valve 42-2 connected to the) to control the air flow into the rubber bulb 42-1 according to the operation.

For the experiment, water W is charged into the beaker 10a, and the impeller 21a and the tube 41a are immersed in the water W in the beaker 10a. At this time, the tube 41a is spaced apart from the side walls of the impeller 21a and the beaker 10a. At this time, the separation distance between the impeller 21a and the tube 41a was 40 mm, and the separation distance between the tube 41a and the side wall in the beaker 10a was 4 mm.

Here, each of the beaker 10a, the stirrer 20a, and the tube 41a of the male model experiment apparatus corresponds to the vessel 100, the stirrer 200, and the lance 410 of the molten iron refining apparatus according to the embodiment of the present invention. It is a constitution.

When the impeller 210 and the tube 41a are immersed in the beaker 10a in which the water W is accommodated, the impeller 210 is rotated for 1 minute by operating the motor 23a. While the impeller 21a is rotating, the test material A which is lighter than water is injected into the water W surface in the beaker 10a. Here, the test material (A) is lighter than the water (W), as described above, is in the form of a tube of 0.5 cm in diameter, 1 cm in length. The test material A is a configuration corresponding to the refining agent R injected into the vessel 100 of the molten iron refining apparatus.

In the first experimental example, while rotating the impeller 21a for 1 minute, the operation of depressurizing and pressurizing the inside of the tube 41a was repeated to further form an additional downflow in addition to the downflow caused by the operation of the impeller 21a. In the second experimental example, only the impeller 21a was rotated, and the inside of the tube 41a was not reduced or pressurized.

The test method of the first experimental example will be described in more detail. First, while the rubber bulb 42-1 is pressed by hand, the lower end of the tube 41a is immersed in water W, and then the rubber bulb 42 is immersed. When 1-1 is released, the rubber bulb 42-1 returns to its original state and water flows into the tube 41a. Subsequently, when the valve 42-2 of the rubber bulb 42-1 is opened, the inside of the tube 41a is pressurized while air flows into the rubber bulb 42-1 and the tube 41a. As a result, the water W inside the tube 41a is discharged to the beaker 10a, and a downward flow of the water W is formed in the beaker 10a.

Thus, in the pressure reduction and pressurization of the inside of the tube 41a, it repeated alternately in 10 second period. The change in pressure in the rubber bulb 42-1 and the tube 41a of the first experimental apparatus described above is similar to the operation of the pressure regulator 420 and the lance 410 of the flow generator 400 according to the embodiment.

In addition, in the first experimental example, the test was performed by dividing the tubes 41a into first to third cases having different immersion depths. Here, the immersion depth of the tube 41a according to the first case is 30 mm, the immersion depth of the tube 41a according to the second case is 55 mm, and the immersion depth of the tube 41a according to the third case is 80 mm.

In order to compare the penetration of the test material A according to the first test example and the second test example, the test material A introduced to the surface of the water W of the beaker 10a starts to penetrate or flow into the water. The impeller rotation speed (hereinafter referred to as penetration start rotation speed) was measured.

In Table 1, the downflow cycle means a cycle in which pressure and pressure in the tube are alternately performed.

division Impeller Immersion Depth (D ₁ ) Tube Immersion Depth (D ₂ ) Downflow Cycle Penetration Initiation Speed (rpm) Experimental Example 1 First case 55 mm 30 mm 10 sec 130 2nd case 55 mm 55 mm 150 3rd case 55 mm 80 mm 160 Experimental Example 2 55 mm - - 175

Referring to Table 1, the penetration start rotation speed (rpm) of the first experimental example is lower than that of the second experimental example. In addition, in the first to third cases of the first experimental example, the penetration start rotation speed (rpm) is lower than that of the second experimental example. That is, irrespective of the immersion depth of the tube 41a, when further downflow is formed using the tube 41a, the penetration start rotation speed (rpm) is lower than in the case where it is not (the second experimental example). In other words, in the first experimental example, the test material A can be introduced or wound even at a lower rpm (rpm) of the impeller 21a than in the second experimental example. This is because, in the case of the first experimental example, the downward flow due to the reduced pressure and the pressure inside the tube 41a is further formed. That is, in the first experimental example, in addition to the downward flow due to the rotation of the impeller 21a, the downward flow due to the pressure reduction and the pressurization inside the tube 41a is additionally formed, so that the water in the beaker 10a is downward compared to the second experimental example. This is because the size or strength of the stream is large.

4 conceptually illustrates the main part of the second experimental apparatus for comparing the refining efficiency with and without using the flow generator according to the embodiment of the present invention. 5 is a graph showing sulfur concentration in molten iron according to desulfurization time of the third and fourth experimental examples.

The second experimental apparatus has an internal space, an agitator 20b that can be immersed into an atmospheric induction furnace 10b capable of dissolving raw materials charged therein, an internal induction furnace 10b, and a rotatable impeller 21b. And a flow generator 40 which can be immersed into the atmospheric induction furnace 10b and has a lance 41b having an internal space.

Here, the stirrer 20b and the flow generator 40 of the second experimental apparatus have the same configuration and shape as the stirrer 200 and the flow generator 400 of the molten iron processing apparatus according to the above-described embodiment. However, since the size of the atmospheric induction furnace 10b of the second experimental apparatus is smaller than that of the container 100 according to the embodiment, the stirrer 20b and the flow generator 40 of the second experimental apparatus are the atmospheric induction furnace ( The size is applied or modified to conform to 10b). The lance 41b of the flow generator 40 of the second experimental apparatus has an inner diameter of 10 mm and an outer diameter of 50 mm.

On the other hand, when the pump 42-3 of the second experimental apparatus is operated, the connection line L and the inside of the lance 41b become vacuum, the molten iron M is introduced into the lance 41b, and the lance 41b. The height of the molten iron which flows into the lance 41b changes with the vacuum pressure in it. Therefore, a pressure regulator for precisely adjusting the pressure in the lance 41b is required, but for the convenience of the experiment, the vacuum control chamber C is installed on the extension path of the connection line L, so that excessive vacuum is not formed. It was not.

That is, the pressure adjusting part 42b of the second experimental apparatus has one end connected to the connection line L connected to the lance 41b and the pump 42 connected to the other end of the connection line L so as to communicate with the internal space of the lance 41b. -3), the first valve (V ₁ ), which is installed on the extension path of the connection line (L), controls the communication with the pump 42-3, and the lance 41b on the extension path of the connection line (L). Located between the first valve (V ₁ ), and includes a second valve (V ₂ ) for introducing gas back into the lance (41b).

In addition, on the extension path of the connection line (L) is located between the first valve (V ₁ ) and the second valve (V ₂ ) on the extension path of the connection line (L), the vacuum control chamber (C) having an internal space And a third valve V positioned between the second valve V ₂ and the vacuum control chamber C on the extension path of the connection line L to control communication between the vacuum control chamber C and the lance 410. ₃ ).

Accordingly, the pump 42-3 and the lance 41b are not directly connected in the pressure regulating unit 42b of the second experimental apparatus, but are indirectly connected through the vacuum adjusting chamber C. At this time, the degree of vacuum in the lance 41b is determined by the size and the vacuum pressure in the vacuum adjusting chamber C, and the molten iron height in the lance 41b is adjusted accordingly.

The third and fourth experimental examples will be described below.

For the experiment, 150 kg of electrolytic iron was added and dissolved in the atmosphere induction furnace 10b, and a charcoal agent and sulfur were added thereto. Hereinafter, a state in which a carbonization agent and sulfur are added to the dissolved electrolytic iron is called molten iron.

For the experiments, in both the third and fourth experimental examples, the impeller 21b was immersed in the molten iron in the atmospheric induction furnace while the internal temperature of the atmospheric induction furnace 10b was maintained at 1350 ° C. to rotate at 500 rpm. Then, a refining agent, ie, a desulfurization agent, in which condensed lime, an aluminum material (Al-ash) and fluorspar were mixed into a molten iron M surface, was charged at 7.3 kg / t.

In addition, in the third experimental example, the downflow was further formed by using the flow generator 40 in addition to the impeller 210, wherein the penetration depth of the lance 41b is 100 mm below the molten iron surface. On the other hand, the fourth experimental example did not use the flow generator 40 according to the embodiment.

In the third experimental example, the operation of the flow generator 40 of the second experimental apparatus will be described in more detail as follows.

First, the second opening is closed the valve (V ₂₎ and the third valve (V _3), only the first valve (V _1), and operating the pump (42-3). At this time, since the size of the vacuum control chamber C is very small, a vacuum is formed in the vacuum control chamber C in an instant. Then, when the first valve V ₁ is closed and the third valve V ₃ is opened, a vacuum is formed inside the lance 41b and molten iron flows into the inside. Thereafter, when the third valve V ₃ is closed and the second valve V ₂ is opened, the molten iron inside the lance 41b flows to the outside while the inside of the lance 41b becomes atmospheric pressure. This process was repeated in a 30-second cycle, which causes a downward flow of the molten iron inside the atmospheric induction furnace 10b, which is not caused by the rotation of the impeller 21b, but is reduced by the depressurization and pressurization of the lance 41b. Ryu.

In order to compare the refining efficiency, that is, the desulfurization effect according to the third and fourth experimental examples, a molten iron sample was taken during the experiment, and the sulfur (S) concentration in the molten iron was analyzed over time to compare the desulfurization rate.

In general, the desulfurization rate per unit time is represented by Equation 1 below.

[Equation 1]

Here, K _t is the apparent rate constant and [% S] _e is the sulfur concentration at equilibrium. Since [% S] _e is a very low value, it may be regarded as 0 (zero). If [% S] _{e is set} to 0 (zero) and the Equation 1 is integrated and summarized, Equation 2 below is obtained.

[Formula 2]

Where t is time and [% S] ₀ is the initial sulfur concentration.

5 shows the desulfurization behavior according to time (min), referring to FIG. 5, it can be seen that the desulfurization rate is larger in the third experimental example than in the fourth experimental example. In other words, the sulfur (S) concentration in the molten iron in the same time is low. In the third experimental example, in addition to the downward flow caused by the rotation of the impeller 21b, the downward flow due to the depressurization and pressurization inside the lance 41b is additionally formed, and thus, the molten iron in the air induction furnace 10b compared with the fourth experimental example. This is because the intensity of the downflow of the total and molten iron surface is large.

In addition, in the third experimental example, due to the limitations of the second experimental apparatus, only the reduced pressure to pressurize to the vacuum and the double pressure to restore to atmospheric pressure from the vacuum state and the pressurization were not further performed, but the downflow according to the embodiment of the present invention. If pressure is further applied, such as the operation of the generator 400, it can be inferred that the magnitude or intensity of the downflow in the molten iron is increased, so that the desulfurization rate can be further improved.

As described above, according to the molten iron refining apparatus and the molten iron method according to the embodiment of the present invention, as the flow generator 400 forcibly generates the downward flow of the molten iron, the molten iron is lowered from the entire molten iron and from the molten iron surface. Ryu increases. Thus, penetration of the refining agent R into the molten iron M and the mixing of the molten iron M and the refining agent R are promoted and increased.

In addition, due to the strong downflow, the refining agent R penetrated or introduced into the molten iron M does not easily rise to the molten iron surface, thereby increasing the time for the refining agent R to stay inside the molten iron.

As described above, the penetration of the refining agent R into the molten iron M becomes easy, and as the time for which the refining agent R stays in the molten iron M is increased, the refining efficiency is improved. In addition, this can reduce the consumption of the refining agent (R), and can shorten the refining time to improve productivity.

 According to the molten iron refining apparatus and the molten iron method according to an embodiment of the present invention, as the flow generator forcibly generates downward flow of the molten iron, downflow in the entire molten iron and molten iron surface increases more than in the prior art. As a result, the penetration of the refiner into the molten iron and the mixing of the molten iron with the refiner are promoted and increased. In addition, due to the strong downflow, the refining agent penetrated or introduced into the molten iron does not easily rise to the molten iron surface, thereby increasing the time for the refining agent to stay inside the molten iron.

Claims (17)

A container having an inner space capable of receiving molten iron; A stirrer inserted into the vessel, the stirrer being rotatable into the molten iron and having a rotatable impeller; A flow generator at least partially immersed into the molten iron in the vessel and capable of introducing and discharging the molten iron by a change in internal pressure; A molten iron processing apparatus comprising a. The method according to claim 1, The flow generator, A lance having an inner space and immersed in the molten iron; And Is connected to communicate with the inner space of the lance, and includes a pressure regulator for reducing and pressurizing the inside of the lance, And the pressure adjusting unit depressurizes the inside of the lance, introduces molten iron into the lance, pressurizes the inside of the lance, and discharges the molten iron inside the lance. The method according to claim 2, The molten iron in the vessel, the molten iron processing apparatus is generated in the downflow due to the vortex generated by the force discharged into the vessel and the downflow due to the vortex caused by the rotation operation of the impeller. The method according to claim 2. The immersion depth of the lance is lower than the immersion depth of the impeller. The method according to claim 3, The pressure control unit, A connection line having one end connected to the lance so as to communicate with an internal space of the lance; A pump connected to the other end of the connection line; A first valve installed on an extension path of the connection line to control communication with the pump; A second valve positioned between the lance and the first valve on an extension path of the connection line, the second valve controlling gas inflow into the lance; A molten iron processing apparatus comprising a. The method according to claim 5, The pressure control unit, A vacuum regulating chamber positioned between the first valve and the second valve on an extension path of the connection line and having an internal space; And A third valve positioned between the vacuum regulating chamber and the second valve on an extension path of the connection line; A molten iron processing apparatus comprising a. The method according to any one of claims 1 to 6, Refining agent injecting the refining agent to the molten iron in the container, The refining agent injected into the molten iron surface of the molten metal is introduced into the molten iron by the downflow due to the vortex due to the rotation operation of the impeller and the downward flow due to the vortex generated by the force discharged into the vessel. Molten iron processing unit. The method according to claim 7, The refining agent is a molten iron processing apparatus comprising a desulfurization agent. Immersing the impeller with a molten iron in the container and rotating the impeller; Immersing the lance with the molten iron in the vessel and varying the pressure inside the lance to alternately repeat the introduction and discharge of the molten iron into the lance, thereby forming a flow of molten iron; Chartering treatment method comprising a. The method according to claim 9, The molten iron processing method of the molten iron in the vessel, the downflow generated by the vortex due to the rotation of the impeller and the downflow due to the vortex generated by the force of the molten iron introduced into the lance is discharged into the vessel. The method according to claim 10, The process of generating the downflow using the lance, Depressurizing the inside of the lance to introduce molten iron into the lance; And Pressurizing the inside of the lance to discharge the molten iron inside the lance; Chartering treatment method comprising a. The method according to claim 11, In flowing molten iron into the lance, the height of the molten iron in the lance is higher than the height of the molten iron in the vessel, The molten iron processing method of adjusting the height of the molten iron in the lance is equal to or lower than the height of the molten iron in the vessel in discharging the molten iron inside the lance. The method according to claim 12, In such that the height of the molten iron in the lance is higher than the height of the molten iron in the vessel, the pressure in the lance is adjusted to a vacuum pressure, The molten iron processing method of adjusting the pressure in the lance above the atmospheric pressure in the adjustment so that the height of the molten iron in the lance is equal to or lower than the height of the molten iron in the vessel. The method according to claim 11, The molten iron processing method of controlling the rate of the molten iron flow into the lance is slower than the rate of the molten iron in the lance is discharged. The method according to claim 14, The molten iron treatment method of controlling the decompression rate inside the lance is slower than the pressurization rate inside the lance. The method according to any one of claims 9 to 15, Injecting a refining agent into the molten iron; And Introducing the refining agent into the molten iron; Including, The process of introducing the refining agent into the molten iron, A main inflow process in which the refining agent is introduced into the molten iron by the downflow generated by the vortex due to the rotation of the impeller; A secondary inflow process in which the refining agent is introduced into the molten iron by the downflow generated by the vortex due to the force of the molten iron in the lance being discharged into the vessel; Chartering treatment method comprising a. The method according to claim 16, The refining agent is a molten iron treatment method comprising a desulfurization agent.

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