JP7272387B2 - gas distributor - Google Patents

Description

The present invention is a gas distribution device installed in a bottom-blown converter or a top-bottom blown converter, capable of evenly distributing a gas or a solid-gas two-phase fluid to a plurality of tuyeres installed at the bottom of the converter. Regarding.

In a steelmaking plant of an ironworks, a converter 2 as shown in FIG. 1, for example, is installed in order to adjust the composition of molten steel. In general, the converter is designed to satisfy the following performance requirements: good agitation of the molten iron M by the bottom-blown gas F of the converter, small vibration of the furnace body, less sloshing, and no spitting. A plurality of tuyeres 3 are provided at the bottom. A bottom-blown gas distribution device for the converter is installed below the bottom of the converter 2 in order to distribute the bottom-blown gas to the tuyeres 3 in the limited space of the bottom.

In the refining in the converter 2 equipped with such a bottom-blown gas distribution device, in order to decarburize and improve metallurgical properties, a gas such as pure oxygen, an inert gas, or a mixture of both is used. Alternatively, a solid-gas two-phase fluid (hereinafter also referred to as bottom-blown gas) is blown from a plurality of tuyeres 3 through the distributor 1 . The solids blown from the plurality of tuyeres 3 together with the gas are powders such as quicklime that act as a flux.

When the bottom-blown gas is blown from a plurality of tuyeres 3, if the distribution of powder or gas is uneven among the tuyeres 3, the expected blowing performance cannot be obtained, and the bottom-blown gas of the converter is not obtained. At the tuyere 3 where the flow rate of F is large, the amount of spark reaction and the amount of powder wear increase, and the wear of the tuyere 3 progresses quickly. If the wear of the tuyeres 3 due to powder progresses quickly, not only the tuyeres 3 but also the entire bottom of the converter must be repaired. Therefore, when a solid-gas two-phase fluid is blown from a plurality of tuyeres 3 on the bottom of the converter, it is desired that not only the gas distribution but also the powder distribution be equal among the tuyeres 3 .

2 and 3 show the structure of the converter bottom-blown gas distributor 1 installed below the bottom of the converter 2. FIG. As shown in FIGS. 2 and 3 , in the distributor 1 , the bottom-blown gas is introduced into the plurality of tuyeres 3 from the introduction pipe 5 connected to the outer cylinder 4 . Arrows in FIGS. 2 and 3 indicate the flow (inflow) of bottom-blown gas supplied from a supply device (not shown) through the introduction pipe 5, and R from the introduction pipe 5 through the opening 41 of the outer cylinder. A swirling flow caused by an inflow I flowing into the swirling chamber 8 inside the outer cylinder 4 is shown.

The swirl chamber 8 in which the swirl flow R is generated includes an outer cylinder 4 with a lid and an outer cylinder opening 41 formed thereon, and an inner cylinder 6 . there is An introduction pipe 5 is connected to the outer cylinder 4 . Reference numeral 7 indicates a compartment partitioned for each tuyere 3 . Each compartment 7 is connected to a communication pipe (not shown) for pneumatically transporting the bottom-blown gas distributed by the distributor 1 to the tuyeres 3 .

In the converter bottom-blown gas distribution apparatus 1 having such a structure, when the bottom-blown gas is supplied to the introduction pipe 5, as shown in FIG. A swirling flow R that rises while swirling in the swirling chamber 8 is generated by I. The swirl flow R generated in the swirl chamber 8 then flows into the inner cylinder 6 while swirling the upper end of the inner cylinder 6, descends while swirling inside the inner cylinder 6, and then flows into the plurality of compartments 7. Then, it is jetted from the tuyere 3 into the converter 2 as a converter bottom-blown gas F through a connecting pipe connected to the compartment 7 .

Therefore, when the bottom-blown gas is blown from a plurality of tuyeres 3, if the distribution of the bottom-blown gas for each chamber 7 of the converter bottom-blown gas distribution device 1 is large, the converter refining and the converter 2 This will cause problems with bottom life. In addition, it is required to operate without allowing solids to remain in the swirl chamber 8 .

For example, in Patent Document 1, as a distribution device capable of evenly dividing a solid-gas two-phase fluid, an orifice made of a material that is sufficiently durable against powder abrasion is provided in the middle of a distribution device or a pipe downstream of the distribution device. , a powder feeder mounted at each tuyere is disclosed. Further, Patent Literatures 2 and 3 disclose a distributing device for airflow-transporting granular materials having an axially symmetrical shape as a distributing device capable of evenly distributing a solid-gas two-phase fluid. Furthermore, in Patent Document 4, as a distribution device capable of evenly dividing a solid-gas two-phase fluid, by reducing the interference between the swirl flow generated in the swirl chamber and the inflow flow from the introduction pipe, A converter bottom-blown gas distribution apparatus is disclosed for evenly distributing a solid-gas two-phase fluid into a plurality of compartments.

Japanese Patent Application Laid-Open No. 2001-304773 JP-A-58-69620 JP-A-58-216829 JP-A-2009-68033

Patent Document 1 shows a structure in which an orifice is attached to each tuyere. The structure of the dispensing device itself is not shown.
In addition, the pneumatic transport/distribution devices described in Patent Documents 2 and 3 are suitable devices for pneumatically transporting pulverized coal and coke powder to the tuyeres of blast furnaces, as described in FIGS. However, it is difficult to apply it to a distribution system for bottom-blown converter gas. Also, the powder that is blown into the converter together with the air flow contains foreign matter that is mixed in during the powder manufacturing process, especially foreign matter that is unavoidably mixed in a pulverizing mill or the like. In general, foreign substances are removed by installing magnets or sieves in the conveying path. However, even if these measures are taken, it is still impossible to completely remove the foreign matter.

Furthermore, in the distributor disclosed in Patent Document 4, centrifugal separation causes powder with a large specific gravity and a coarse particle size to concentrate and stagnate, which may hinder uniform distribution of the solid-gas two-phase flow. Furthermore, Patent Document 4 does not consider measures for preventing powder retention. In actual operation, the residual powder is periodically discharged, which reduces the operating rate of the converter, which hinders productivity.
The present invention has been made in view of the above-described problems of the prior art, and is installed in a bottom-blown converter or a top-bottom blown converter to feed a gas or a solid-gas two-phase fluid to a plurality of tuyeres at the bottom of the converter. It is an object of the present invention to provide a gas distribution device capable of evenly distributing and not causing powder to stagnate.

According to one aspect of the present invention, a gas distribution device in which an outer cylinder and an inner cylinder are arranged in the upper part and a plurality of compartments partitioned for each tuyere of a converter are arranged in the lower part, The inner cylinder has an upper end that opens into the outer cylinder and a lower end that is connected to the plurality of compartments. The outer cylinder has a bottom plate at the lower end and an outer cylinder opening to which an introduction pipe for supplying gas is connected. is provided on the side wall, and the connection height a, which is the distance in the height direction between the lower end of the opening of the outer cylinder and the bottom plate, is 1 of the height b of the swirl chamber inside the outer cylinder in which the gas swirls. A gas dispensing device is provided that is less than or equal to /10.

According to one aspect of the present invention, a gas distribution device in which an outer cylinder and an inner cylinder are arranged in the upper part and a plurality of compartments partitioned for each tuyere of a converter are arranged in the lower part, The inner cylinder has an upper end that opens into the outer cylinder and a lower end that is connected to the plurality of compartments. The outer cylinder has a bottom plate at the lower end and an outer cylinder opening to which an introduction pipe for supplying gas is connected. is provided on the side wall and a baffle is provided on the underside of said swirl chamber.

According to one aspect of the present invention, a gas distribution device in which an outer cylinder and an inner cylinder are arranged in the upper part and a plurality of compartments partitioned for each tuyere of a converter are arranged in the lower part, The inner cylinder has an upper end that opens into the outer cylinder and a lower end that is connected to the plurality of compartments. The outer cylinder has a bottom plate at the lower end and an outer cylinder opening to which an introduction pipe for supplying gas is connected. is provided on the side wall, and the connection height a, which is the distance in the height direction between the lower end of the opening of the outer cylinder and the bottom plate, is 1 of the height b of the swirl chamber inside the outer cylinder in which the gas swirls. /10 or less, and a baffle plate is provided on the underside of the swirl chamber.

According to one aspect of the present invention, it is installed in a bottom-blown converter or a top-bottom blown converter, and is capable of evenly dividing a gas or a solid-gas two-phase fluid into a plurality of tuyeres at the bottom of the converter, and A gas dispensing system is provided that does not cause body retention.

It is a schematic diagram showing the structure of a bottom-blown converter. 1 is a perspective view of a gas distribution device; FIG. 1 is a schematic diagram showing a gas distribution device; FIG. 1 is a cross-sectional view showing a gas distribution device according to a first embodiment of the present invention; FIG. It is a graph which shows the relationship between ventilation time and residual powder. It is a graph which shows the relationship between connection height a/height b of a swirling chamber, and a residual rate of powder. FIG. 4 is a cross-sectional view showing a gas distribution device according to second and third embodiments of the present invention; It is a schematic diagram which shows the shape of a baffle plate, (A) shows a rectangular baffle plate, (B) shows a flap-shaped baffle plate, and (C) shows a cylindrical baffle plate. It is a schematic diagram which shows the installation position of a baffle plate. It is a graph which shows the relationship between the height H of a baffle plate/height b of a swirl chamber, and a residual ratio of powder. 4 is a graph showing the relationship between the width W of the baffle plate/the width w of the swirl chamber and the residual rate of powder.

The following detailed description describes embodiments of the invention with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals, and overlapping descriptions are omitted. Each drawing is schematic and may differ from the actual one. In addition, the embodiments shown below are examples of apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is based on the material, structure, arrangement, etc. of component parts. It is not specific to the following. Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims.

In order to solve the above-described problems, the inventors conducted experiments by changing the dimensions of each part of the dispensing device 1 itself. In the experiment, a distribution device 1 was used in which the inner diameter of the inner cylinder, the height of the inner cylinder, the diameter of the outer cylinder, the height of the outer cylinder, and the cross-sectional dimensions of the introduction part were fixed, and the connection height a of the introduction part was changed. The dispensing device 1 is similar to that shown in FIGS. That is, the distribution device 1 is provided in the converter 2 shown in FIG. The bottom-blown gas is pure oxygen, an inert gas, or a mixture of both. Further, the distribution device 1 may be a device that supplies a solid-gas two-phase fluid containing powder in the bottom-blown gas to a plurality of tuyeres 3 . The distribution device 1 comprises an outer cylinder 4, an introduction tube 5, an inner cylinder 6, and a plurality of compartments 7, as shown in FIGS. The outer cylinder 4 has a cylindrical shape, and an outer cylinder opening 41 to which the introduction pipe 5 is connected is formed on the peripheral surface. Further, the outer cylinder 4 is provided with a lid 42 so as to cover the opening at the upper end, and is provided with a bottom plate 43 at the lower end to cover the opening surface excluding the inner cylinder 6, which will be described later. In addition, in this embodiment, the vertical direction is the vertical direction. The space inside the outer cylinder 4 excluding the inner cylinder 6 (the space inside the outer cylinder 4 outside the inner cylinder 6 ) is also called a swirl chamber 8 . The introduction pipe 5 is connected to the outer cylinder opening 41 and supplies the swirl chamber 8 with bottom-blown gas supplied from a supply device (not shown). The inner cylinder 6 is a cylindrical member, and is provided inside the outer cylinder 4 so that the axis of the cylinder is the same as that of the outer cylinder 4 . A lower end of the inner cylinder 6 is connected to a plurality of compartments 7 . In such a distribution device 1, the portion where the bottom-blown gas is introduced into the swirl chamber 8 and the portion where the outer cylinder opening 41 is formed is called an introduction portion. The cross-sectional dimension of the part is called the cross-sectional dimension of the introduction part. The connection height a of the introduction portion is the distance from the upper surface of the bottom plate 43 to the lower end of the outer cylinder opening 41, as shown in FIG.

In this experiment, oxygen gas and lime powder mixed with iron powder having a mass fraction of 1% were supplied from the introduction pipe 5 . The oxygen gas supply rate was 500 Nm ³ /min, and the lime powder supply rate was 500 kg/min. After a predetermined time of ventilation, the supply of oxygen gas and lime was stopped, the distributor 1 was opened, and the volume of the remaining powder and the mass concentration of iron in the remaining powder were measured. In this experiment, the lime powder and the iron powder were sieved to a size of 200 μm or less. Furthermore, since the blowing of the converter 2 is performed for about 10 to 20 minutes, the maximum experimental time was set to 20 minutes. Furthermore, as a result of a separate study of the flow rate deviation and uniform distribution of solid and gas, it was confirmed that the residual rate should be 5% or less, preferably 1% or less, and the concentration rate should be 50 times or less.

FIG. 5 shows the measurement results of the residual ratio of powder for each aeration time when using the distribution device 1 in which the ratio a/b, which is the ratio of the connection height a to the height b of the swirl chamber 8, is 0.26. . The height b of the swirling chamber 8 is the height of the outer cylinder 4 from the upper surface of the bottom plate 43 (the height from the upper end of the cylindrical portion of the outer cylinder 4), as shown in FIG. Further, the residual ratio of powder is the percentage of the value obtained by dividing the volume of the powder staying in the distribution device 1 by the internal volume of the outer cylinder 4 .
As shown in FIG. 5, it was confirmed that the residual rate of powder increased as the passing amount of powder increased, but the residual rate did not increase beyond a certain threshold value.

FIG. 6 shows the residual ratio of powder to a/b when the connection height a and the height b of the swirl chamber 8 are changed. In addition, in the experiment shown in FIG. 6, experiment time was made into 20 minutes. It can be confirmed that the residual ratio decreases as a/b becomes smaller. It was confirmed that the powder residual rate was 5% or less. Also, when the distribution device 1 was made of acrylic and the behavior of the powder inside was observed, it was found that the powder tended to stay below the swirl flow generated in the swirl chamber 8 . From this, it was found that by reducing a/b to 0.1 or less, it is possible to prevent the powder from stagnation below the swirling flow. Then, it was suggested that by installing a baffle plate in the swirl chamber 8 sandwiched between the outer cylinder 4 and the inner cylinder 6, the powder can be discharged more effectively.

Furthermore, based on the above knowledge, the inventors of the present invention used the distribution device 1 in which the baffle plate 9 is installed on the bottom plate 43 in the swirl chamber 8 as shown in FIG. investigated the impact of The distribution device 1 shown in FIG. 7 is the same as that explained in FIG. 4 except for the presence or absence of the baffle plate 9 . In this investigation, the experimental time was 20 minutes, and the shape of the baffle plate 9 was a rectangle as shown in FIG. 8(A). In addition, in the shape of the baffle plate 9 shown in FIG. 8, the length in the vertical direction of the cross-sectional shape perpendicular to the swirling direction of the bottom-blown gas swirling in the swirl chamber 8 is defined as the height H, and the length in the horizontal direction is defined as H. is the width W. The swirl direction is parallel to the horizontal direction with respect to the flow direction of the bottom-blown gas. Moreover, the square shape of the baffle plate 9 means that the cross-sectional shape perpendicular to the turning direction is square. Furthermore, in this investigation, the width of the whirling chamber 8 was set to w, and the width W of the baffle plate 9 was set to 0.3w. The width w of the swirl chamber 8 is the horizontal distance from the outer peripheral surface of the inner cylinder 6 to the inner peripheral surface of the outer cylinder 4, as shown in FIG. (outer diameter)/2". Further, in this investigation, as the baffle plate 9, a steel plate having a thickness of 20 mm was cut into a rectangular shape having a width W and a height H specified later. 9 shows a schematic plan view showing the installation position of the baffle plate 9 (the position of the black circle on the bottom plate 43) in the distribution device 1. As shown in FIG. In this survey, the installation position of the baffle plate 9 was the position shown in FIG. 9(A).

In this investigation, first, the residual ratio of powder was investigated under a plurality of conditions in which the width W of the baffle plate 9 was fixed at 0.3w and the height H of the baffle plate 9 was changed. FIG. 10 shows the relationship between the ratio (H/b) of the height H of the baffle plate 9 to the height b of the swirling chamber 8 when the height H of the baffle plate 9 is changed, and the residual ratio of powder. show. As shown in FIG. 10, it was confirmed that the residual ratio of the powder is as low as less than 5% when H/b is 0.25 or more and 0.8 or less.

Next, the residual ratio of powder was investigated under a plurality of conditions in which the height H of the baffle plate 9 was set to 0.3a and the width W of the baffle plate 9 was changed. FIG. 11 shows the relationship between the ratio (W/w) of the width W of the baffle plate 9 to the width w of the swirl chamber 8 when the width W of the baffle plate 9 is changed, and the residual ratio of powder. As shown in FIG. 11, it was confirmed that when W/w is 0.1 or more, the powder residual rate is as low as 5% or less.
From these results, by installing the baffle plate 9 on the bottom plate 43 of the swirl chamber 8 and setting the height H of the baffle plate 9 to 0.25b or more and 0.8b or less, the retention of powder in the swirl chamber 8 can be reduced. It has been found that by setting the width W of the baffle plate 9 to 0.1 w or more, the retention of the powder in the swirl chamber 8 is further suppressed.

Furthermore, the present inventors conducted a similar experiment without changing the cross-sectional area of the baffle plate 9 and changed the shape of the baffle plate 9 to the flap shape shown in FIG. 9(B). It was confirmed that the residual powder rate was reduced by about 20 to 40% as compared with the rectangular baffle plate 9 shown in FIG. The flap shape is a shape in which the height H gradually increases toward the downstream side in the turning direction. More than 70° or less is preferable. Note that the flap shape may have a gentle upper surface slope when viewed from the width direction of the baffle plate 9, and may be a linear slope or a curved slope.

<First embodiment>
(Gas distributor)
The gas distribution device 1 according to the first embodiment of the present invention is based on the findings of the above experiments and investigations, and as shown in FIG. and a plurality of compartments 7. The converter 2 in which the distributor 1 is installed is a bottom-blown converter or a top-bottom-blown converter.

The outer cylinder 4, the introduction pipe 5, the inner cylinder 6 and the plurality of compartments 7 are the same as those described in the above experiments and investigations. That is, the distribution device 1 has a swirl chamber 8 inside the outer cylinder 4 and a plurality of compartments 7 divided by the tuyeres 3 under the swirl chamber 8 . Further, the upper end of the inner cylinder 6 is open to the inside of the outer cylinder 4 , and the lower end of the inner cylinder 6 is connected to a plurality of compartments 7 . Furthermore, the ratio a/b of the height b of the whirling chamber 8 to the connection height a of the introduction portion of the outer cylinder 4 is 1/10 or less.

In the distributor 1 configured as described above, the bottom-blown gas flows into the swirl chamber 8 from the introduction pipe 5 through the outer cylinder opening 41 , and a swirl flow R is generated in the swirl chamber 8 . At this time, by setting a/b within the above range, fluid retention in the lower side of the swirling chamber 8 (in the vicinity of the bottom plate 43, preferably the region including the range from the bottom plate 43 to the connection height a) can be prevented. can be reduced. Therefore, when a solid-gas two-phase fluid containing powder is used, retention of powder is reduced, and uniform distribution of solid and gas to the plurality of compartments 7 can be maintained for a long period of time.

<Second embodiment>
(Gas distributor)
The gas distribution device 1 according to the second embodiment of the present invention is based on the findings of the above experiments and investigations, and as shown in FIG. , a plurality of compartments 7 and baffle plates 9 . The converter 2 in which the distributor 1 is installed is a bottom-blown converter or a top-bottom-blown converter.
The outer cylinder 4, the introduction pipe 5, the inner cylinder 6 and the plurality of compartments 7 are the same as those described in the above experiments and investigations. That is, the distribution device 1 has a swirl chamber 8 inside the outer cylinder 4 and a plurality of compartments 7 divided by the tuyeres 3 under the swirl chamber 8 . Further, the upper end of the inner cylinder 6 is open to the inside of the outer cylinder 4 , and the lower end of the inner cylinder 6 is connected to a plurality of compartments 7 .

The baffle plate 9 is provided on the lower side of the swirl chamber 8 and is preferably installed on the upper surface of the bottom plate 43 . The baffle plate 9 has a cross-sectional shape perpendicular to the swirling direction of the swirling bottom-blown gas (that is, a cross-sectional shape perpendicular to the circumferential direction of the cylindrical swirl chamber 8) having a height H of 0.25 b or more. The width W is preferably 0.8 or less, and the width W is preferably 0.1w or more. Although the shape of the baffle plate 9 is not particularly limited, it is preferable that the maximum length of the height H and the width W meet the above conditions. Therefore, the baffle plate 9 may have a rectangular shape as shown in FIG. 8(A) or a flap shape as shown in FIG. 8(B). In the case of the flap shape, the inclination of the linear upper surface with respect to the bottom plate 94 when viewed in the width direction is preferably 30° or more and 70° or less. Also, the baffle plate 9 may have a columnar shape as shown in FIG. 8(C). Further, the installation position of the baffle plate 9 is set at any position (for example, all positions in FIGS. 8(A) to 9(E)) in the swirling chamber 8 in plan view as shown in FIG. 9(A) to 9(D).

In the distributor 1 configured as described above, the bottom-blown gas flows into the swirl chamber 8 from the introduction pipe 5 through the outer cylinder opening 41 , and a swirl flow R is generated in the swirl chamber 8 . At this time, by providing the baffle plate 9, it is possible to reduce the retention of the fluid under the swirl chamber 8. FIG. Therefore, when a solid-gas two-phase fluid containing powder is used, retention of powder is reduced, and uniform distribution of solid and gas to the plurality of compartments 7 can be maintained for a long period of time.

<Third Embodiment>
(Gas distributor)
The gas distribution device 1 according to the second embodiment of the present invention is based on the findings of the above experiments and investigations, and as shown in FIG. , a plurality of compartments 7 and baffle plates 9 . The converter 2 in which the distributor 1 is installed is a bottom-blown converter or a top-bottom-blown converter.
The outer cylinder 4, the introduction pipe 5, the inner cylinder 6 and the plurality of compartments 7 are the same as those described in the above experiments and investigations. That is, the distribution device 1 has a swirl chamber 8 inside the outer cylinder 4 and a plurality of compartments 7 divided by the tuyeres 3 under the swirl chamber 8 . Further, the upper end of the inner cylinder 6 is open to the inside of the outer cylinder 4 , and the lower end of the inner cylinder 6 is connected to a plurality of compartments 7 . Furthermore, the ratio a/b of the height b of the whirling chamber 8 to the connection height a of the introduction portion of the outer cylinder 4 is 1/10 or less.
The baffle plate 9 is the same as in the second embodiment.

In the distributor 1 configured as described above, the bottom-blown gas flows into the swirl chamber 8 from the introduction pipe 5 through the outer cylinder opening 41 , and a swirl flow R is generated in the swirl chamber 8 . At this time, by setting a/b within the above range and providing the baffle plate 9, it is possible to further reduce the retention of the fluid in the lower side of the swirl chamber 8. FIG. Therefore, when a solid-gas two-phase fluid containing powder is used, retention of powder is reduced, and uniform distribution of solid and gas to the plurality of compartments 7 can be maintained for a long period of time.

<Modification>
Although the invention has been described with reference to particular embodiments, it is not intended that the invention be limited by these descriptions. Along with the disclosed embodiments, other embodiments of the invention, including various modifications, will be apparent to persons skilled in the relevant art(s) upon reference to the description of the invention. Therefore, the embodiments of the invention set forth in the claims should be construed to cover the embodiments that include these variations described herein singly or in combination.

For example, in the above embodiment, the baffle plate 9 is provided on the upper surface of the bottom plate 43 as a preferred aspect, but the present invention is not limited to this example. The baffle plate 9 may be provided on the lower side of the swirl chamber 8, and may be provided on the inner peripheral surface of the outer cylinder 4, for example.
Further, in the second and third embodiments, one baffle plate 9 is provided, but the present invention is not limited to such an example. A plurality of baffle plates 9 may be provided, preferably one to three.

<Effects of Embodiment>
(1) In a gas distribution device 1 according to one aspect of the present invention, an outer cylinder 4 and an inner cylinder 6 are arranged in the upper part, and a plurality of compartments 7 partitioned for each tuyere 3 of the converter 2 are arranged in the lower part. The gas distribution device 1 is arranged, wherein the inner cylinder 6 is opened into the outer cylinder 4 at the upper end and connected to the plurality of compartments 7 at the lower end, and the outer cylinder 4 has a bottom plate 43 at the lower end. An outer cylinder opening 41 to which the introduction pipe 5 for supplying gas is connected is provided in the side wall, and the connection height a, which is the distance in the height direction between the lower end of the outer cylinder opening 41 and the bottom plate 43, is It is 1/10 or less of the height b of the swirl chamber 8 in which the gas inside the cylinder 4 swirls.

According to the configuration (1) above, by making the connection height a sufficiently small relative to the height b of the swirl chamber 8 , it is possible to suppress gas from stagnation below the swirl chamber 8 . Therefore, when the gas contains powder, the powder can be prevented from staying, and the uniform distribution of solid and gas to the plurality of compartments 7 can be maintained for a long period of time. Further, the distribution device 1 can be operated for a long period of time without reducing the production volume of the converter 2 .

(2) In the gas distribution device 1 according to one aspect of the present invention, the outer cylinder 4 and the inner cylinder 6 are arranged in the upper part, and a plurality of compartments 7 partitioned for each tuyere 3 of the converter 2 are arranged in the lower part. The gas distribution device 1 is arranged, wherein the inner cylinder 6 is opened into the outer cylinder 4 at the upper end and connected to the plurality of compartments 7 at the lower end, and the outer cylinder 4 has a bottom plate 43 at the lower end. An outer cylinder opening 41 to which an introduction pipe 5 for supplying gas is connected is provided on the side wall, and a baffle plate 9 is provided below the swirl chamber 8 .

According to the configuration (2) above, by providing the baffle plate 9 on the lower side of the swirl chamber 8 , gas retention in the lower side of the swirl chamber 8 can be suppressed. Therefore, when the gas contains powder, the powder can be prevented from staying, and the uniform distribution of solid and gas to the plurality of compartments 7 can be maintained for a long period of time. Further, the distribution device 1 can be operated for a long period of time without reducing the production volume of the converter 2 .

(3) In the gas distribution device 1 according to one aspect of the present invention, the outer cylinder 4 and the inner cylinder 6 are arranged in the upper part, and a plurality of compartments 7 partitioned for each tuyere 3 of the converter 2 are arranged in the lower part. The gas distribution device 1 is arranged, wherein the inner cylinder 6 is opened into the outer cylinder 4 at the upper end and connected to the plurality of compartments 7 at the lower end, and the outer cylinder 4 has a bottom plate 43 at the lower end. An outer cylinder opening 41 to which the introduction pipe 5 for supplying gas is connected is provided in the side wall, and the connection height a, which is the distance in the height direction between the lower end of the outer cylinder opening 41 and the bottom plate 43, is The height b of the swirl chamber 8 in which the gas inside the cylinder 4 swirls is 1/10 or less, and a baffle plate 9 is installed below the swirl chamber 8 .

According to the configuration (3) above, the connection height a is made sufficiently small with respect to the height b of the swirl chamber 8, and the baffle plate 9 is provided on the lower side of the swirl chamber 8. stagnation of gas on the side can be further suppressed. Therefore, when the gas contains powder, the powder can be prevented from staying, and the uniform distribution of solid and gas to the plurality of compartments 7 can be maintained for a long period of time. Further, the distribution device 1 can be operated for a long period of time without reducing the production volume of the converter 2 .

(4) In the configuration of (2) or (3) above, the baffle plate 9 has a cross-sectional height H of 0.25 b or more and less than 0.8 b that is perpendicular to the gas flow direction of the swirling chamber 8. and the width W of the cross-sectional shape is 0.1w or more.
(5) In any one of the configurations (2) to (4) above, the baffle plate 9 is installed on the bottom plate 43. (6) In any one of the configurations (2) to (6) above, the baffle The plate 9 has a flap shape in which the height H of the cross-sectional shape perpendicular to the swirl direction gradually increases toward the downstream side in the swirl direction in which the gas in the swirl chamber 8 swirls.
According to the configurations (4) to (6) above, it is possible to further reduce the stagnation of gas and powder.

Next, Example 1 conducted by the present inventors will be described. In Example 1, the distribution device 1 according to the first embodiment is used to flow a solid-gas two-phase fluid, which is a bottom-blown gas containing powder, to the tuyeres 3, and the powder discharge amount for each tuyere 3 is was measured. The distribution device 1 used had an inner diameter of the outer cylinder 4 of 900 mm, a total height of the distribution device 1 of 750 mm, and a height of the inner cylinder 6 of 450 mm. Further, in the distribution device 1, the cross-sectional shape of the introduction pipe 5 to the outer cylinder 4 is a square of 250 mm or 300 mm, and the connection height a is an arbitrary distance from 0 to 80 mm. Furthermore, in the embodiment, a baffle plate 9 is installed in the swirl chamber. The baffle plate 9 has a rectangular shape, a flap shape, or a cylindrical shape as shown in FIGS. 8A and 8B, and is installed at the installation position shown in FIGS. bottom. Further, 500 Nm ³ /min of oxygen gas and 500 kg/min of CaO-1% Fe powder were flowed through the introduction pipe 5 . Then, the gas flow rate and powder discharge amount for each tuyere 3 were measured for 20 minutes.

In addition, as a comparative example, investigations were also conducted under the same conditions as in the embodiment, but with different connection heights a, shapes of the baffle plates 9, and installation positions of the baffle plates 9. FIG.
Table 1 shows the conditions in the examples and the comparative examples, and the flow rate deviation, powder deviation, residual ratio of powder in the distribution device 1, and concentration ratio of Fe powder in CaO powder, which are measurement results. The flow rate deviation is the deviation of the gas flow rate measured at each tuyere 3 , and the powder deviation is the deviation of the discharge amount of powder measured at each tuyere 3 .

As is clear from Comparative Examples 1-1 to 1-4, by carrying out the present invention, the retention of powder in the distribution device 1 can be reduced to 5% or less, and the concentration rate of Fe powder, which is a combustible substance, can be reduced to 5% or less. It has been confirmed that it is possible to increase it by 50 times or less.

Next, Example 2 performed by the present inventors will be described. In Example 2, the distribution device 1 according to the second embodiment is used to flow a solid-gas two-phase fluid, which is a bottom-blown gas containing powder, to the tuyeres 3, and the powder discharge amount for each tuyere 3 is was measured. The distribution device 1 used had an inner diameter of the outer cylinder 4 of 900 mm, a total height of the distribution device 1 of 750 mm, and a height of the inner cylinder 6 of 450 mm. In the distribution device 1, the cross-sectional shape of the introduction pipe 5 to the outer cylinder 4 was a square of 300 mm square, and the connection height a was 0 mm. Furthermore, in Example 2, a baffle plate 9 is installed in the swirl chamber. The baffle plate 9 has a rectangular shape, a flap shape, or a cylindrical shape as shown in FIGS. 8A and 8B, and is installed at the installation position shown in FIGS. bottom. Further, 500 Nm ³ /min of oxygen gas and 500 kg/min of CaO-1% Fe powder were flowed through the introduction pipe 5 . Then, the gas flow rate and powder discharge amount for each tuyere 3 were measured for 20 minutes.

In addition, as a comparative example, investigations were also conducted under the same conditions as in the embodiment, but with different shapes and installation positions of the baffle plate 9 .
Table 2 shows the conditions in the examples and comparative examples, and the flow rate deviation, powder deviation, powder residual rate in the distribution device 1, and concentration rate of Fe powder in CaO powder, which are measurement results. The flow rate deviation is the deviation of the gas flow rate measured at each tuyere 3 , and the powder deviation is the deviation of the discharge amount of powder measured at each tuyere 3 . Further, the walls A and E, which are the installation positions of the baffle plate 9 in Comparative Examples 2-3 and 2-6, are the inner wall surfaces of the outer cylinder 4 at the positions shown in FIGS. 9A and 9E. It shows that the baffle plate 9 is attached. Regarding the installation height of the baffle plate 9, the baffle plate 9 was installed on the wall A and the wall E so that the upper end of the baffle plate 9 was H from the bottom plate 43. As shown in FIG.

As is clear from Comparative Examples 1-1 and 2-2 to 2-6, by carrying out the present invention, the retention of powder in the distribution device 1 can be reduced to 5% or less, and Fe powder, which is a combustible substance, can be reduced to 5% or less. It was confirmed that it is possible to make the concentration rate of 50 times or less.

Next, Example 3 performed by the present inventors will be described. In Example 3, the solid-gas two-phase fluid, which is a bottom-blowing gas containing powder, was flowed through the tuyeres 3 using the distribution device 1, and the amount of powder discharged from each tuyere 3 was measured. The distribution device 1 used had an inner diameter of the outer cylinder 4 of 900 mm, a total height of the distribution device 1 of 750 mm, and a height of the inner cylinder 6 of 450 mm. Further, in the distribution device 1, the cross-sectional shape of the introduction pipe 5 to the outer cylinder 4 is a square of 250 mm or 300 mm, and the connection height a is an arbitrary distance from 0 to 80 mm. Furthermore, in the embodiment, a baffle plate 9 is installed in the swirl chamber. The baffle plate 9 has a rectangular shape, a flap shape, or a cylindrical shape as shown in FIGS. 8A and 8B, and is installed at the installation position shown in FIGS. bottom. Further, 500 Nm ³ /min of oxygen gas and 500 kg/min of CaO-1% Fe powder were flowed through the introduction pipe 5 . Then, the gas flow rate and powder discharge amount for each tuyere 3 were measured for 20 minutes.

Further, as a comparative example, under the same conditions as in the embodiment, investigations were also conducted under conditions in which the connection height a, the shape of the baffle plate 9, or the installation position of the baffle plate 9 were different.
Table 1 shows the conditions in the examples and the comparative examples, and the flow rate deviation, powder deviation, residual ratio of powder in the distribution device 1, and concentration ratio of Fe powder in CaO powder, which are measurement results. In addition, in the installation positions of the baffle plates in Table 1, bottoms A to E are positions corresponding to FIGS. 9A to 9E, respectively. Further, the flow rate deviation is the deviation of the gas flow rate measured at each tuyere 3, and the powder deviation is the deviation of the discharge amount of powder measured at each tuyere 3.

As is clear from Comparative Examples 2-2 to 2-6 and 1-1 to 1-4, by using the distribution device 1 according to the above embodiment, the retention rate of powder in the distribution device 1 is 1% or less. As a result, it was confirmed that the concentration ratio of Fe powder, which is a combustible substance, can be reduced to 50 times or less.

REFERENCE SIGNS LIST 1 distributor 2 converter 3 tuyere 4 outer cylinder 41 outer cylinder opening 42 lid 43 bottom plate 44 swirling chamber 5 introduction pipe 6 inner cylinder 7 compartment M molten iron F converter bottom blown gas

Claims (4)

A gas distribution device in which an outer cylinder and an inner cylinder are arranged in the upper part and a plurality of compartments partitioned for each tuyere of a converter are arranged in the lower part,
The inner cylinder has an upper end opened into the outer cylinder and a lower end connected to a plurality of compartments,
The outer cylinder has a bottom plate at the lower end, and an outer cylinder opening to which an introduction pipe for supplying gas is connected is provided on the side wall,
A baffle plate is installed on the lower side of the swirl chamber in which the gas swirls inside the outer cylinder and has a height b ,
The baffle plate has a cross-sectional height H of 0.25 b or more and less than 0.8 b perpendicular to the swirling direction of the gas swirling in the swirling chamber, and a cross-sectional width W of 0.25b or more and less than 0.8b. A gas distribution device that is 1 w or more . A gas distribution device in which an outer cylinder and an inner cylinder are arranged in the upper part and a plurality of compartments partitioned for each tuyere of a converter are arranged in the lower part,
The inner cylinder has an upper end opened into the outer cylinder and a lower end connected to a plurality of compartments,
The outer cylinder has a bottom plate at the lower end, and an outer cylinder opening to which an introduction pipe for supplying gas is connected is provided on the side wall,
A connection height a, which is the distance in the height direction between the lower end of the opening of the outer cylinder and the bottom plate, is 1/10 or less of the height b of the swirl chamber in which the gas swirls inside the outer cylinder,
A baffle plate is installed on the lower side of the swirl chamber ,
The baffle plate has a cross-sectional height H of 0.25 b or more and less than 0.8 b perpendicular to the swirling direction of the gas swirling in the swirling chamber, and a cross-sectional width W of 0.25b or more and less than 0.8b. A gas distribution device that is 1 w or more . 3. The gas distribution device according to claim 1 or 2 , wherein the baffle plate is installed on the bottom plate. According to any one of claims 1 to 3 , the baffle plate has a flap shape in which a height H of a cross-sectional shape perpendicular to the swirling direction gradually increases toward the downstream side in the swirling direction in which the gas swirls in the swirling chamber. A gas dispensing device according to any one of the preceding claims.

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