JP2012031463A - Stirring desulfurization equipment and impeller for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide stirring desulfurization equipment in which an operator can perform impeller replacement work without approaching a hot impeller and impeller replacement time can be reduced.SOLUTION: An impeller shaft 8 is connected to the lower part of a main shaft 7 rotated by a driving source 5 for stirring. The main shaft 7 and the impeller shaft 8 are connected through a main shaft flange 7a and an impeller flange 8c. The impeller shaft 8 is divided into two in the vertical direction, and either one of a female screw 10 and a male screw 11 is formed at the bottom end of an upper divided impeller shaft 8a in which the impeller flange 8c is provided. The other of the female screw 10 and the male screw 11 which is threadedly connected to either one of the female screw 10 and the male screw 11 is formed at the top end of a lower divided impeller shaft 8b in which a rotor 4 is provided.

Description

  The present invention relates to a stirring type desulfurization apparatus and a desulfurization apparatus impeller in which an impeller (rotary blade) is immersed in hot metal in a ladle, and the impeller (rotary blade) is rotated to stir the hot metal and a desulfurizing agent to perform desulfurization.

  In the iron making process, it is well known that sulfur in molten steel is unevenly distributed on the surface and center with cooling, causing brittleness of the product steel material and adversely affecting the mechanical properties. In recent years, with the increasing demand for the quality of steel materials, the demand for low-sulfur steel and ultra-low-sulfur steel has increased, and improvement of desulfurization technology has been demanded. The desulfurization treatment is preferably performed on hot metal having a high sulfur activity from the viewpoint of reaction efficiency in the previous step, rather than secondary purification, which requires higher costs, and various methods have already been industrialized. Among them, an injection desulfurization method in which a desulfurizing agent is blown through a lance (pipe) immersed in hot metal, and a mechanical stirring method in which an impeller (rotary blade) is immersed in hot metal and the hot metal and the desulfurizing agent are mixed are widely used.

  The stirring-type desulfurization apparatus performs a desulfurization process by immersing an impeller attached to a lower end portion of a main shaft of a stirrer via a flange joint in hot metal in a ladle and rotating and stirring. In this stirring-type desulfurization apparatus, the impeller immersed in the hot metal usually has a surface covered with a refractory and is used repeatedly. When the number of times of use increases, the impeller is melted or missing, or hot metal or slag adheres. For this reason, the impeller must be replaced regularly.

  As described above, the impeller is connected to the main shaft via the flange joint. That is, an impeller flange is provided at the upper end of the impeller shaft, and a main shaft flange is provided at the lower end of the main shaft, and these flanges are joined to each other by a plurality of bolts and cotters. Conventional impeller replacement methods have been performed by an operator loosening a plurality of bolts and cotters of a flange joint, removing the impeller from the main shaft, and rejoining the new impeller to the main shaft via the flange joint.

  By the way, since the desulfurization process cannot be performed during the impeller replacement, the productivity is lowered. Even if an alternative injection desulfurization method is used, the cost is higher than that of the mechanical stirring method, and therefore, the impeller replacement operation needs to be completed in as short a time as possible.

  In order to shorten the impeller replacement work and facilitate the replacement work, Patent Document 1 provides a rod that penetrates the bolt hole of the flange instead of the bolt of the flange joint, and the rod is a retaining member such as a cotter. Is engaged, and the rod is moved up and down by a cylinder to connect the flange of the main shaft and the flange of the impeller.

  Patent Document 2 discloses an impeller replacement in which an overhang portion is provided at a lower portion of the upper end flange of the impeller shaft, the overhang portion is supported in an aerial manner by a support arm provided in the impeller replacement carriage, and the impeller is replaced under the aerial support. An apparatus is disclosed.

Japanese Utility Model Publication No. 5-37949 JP 2003-185358 A

  However, a plurality of bolts and cotters for joining the flange of the impeller and the flange of the main shaft are usually used in order to obtain sufficient joint strength. In the invention described in Patent Document 2, there is a problem that it takes time for the work because an operator needs to manually remove and attach a plurality of bolts when replacing the impeller. Furthermore, since the impeller is hot and the lime deposited on the equipment during the impeller replacement work is scattered, it is necessary to spend sufficient time before the impeller replacement work to cool the impeller and clean the equipment with air. is there.

  Even if a rod is used instead of the flange joint bolt as in the invention described in Patent Document 1, there is a problem that it takes time to operate the cylinder and to attach / detach the retaining member such as a cotter.

  The present invention solves the above-mentioned problems of conventional impeller replacement work, and allows the operator to perform impeller replacement work without approaching a high-temperature impeller, and also reduces the impeller replacement time. And it aims at providing the impeller for stirring-type desulfurization apparatuses.

  In order to solve the above-described problem, one aspect of the present invention is a stirring-type desulfurization device that rotates a rotating blade immersed in hot metal, the main shaft having a main shaft flange that extends in the vertical direction and has a main shaft flange, and the main shaft. And an impeller flange joined to the main shaft flange at the upper end and a rotating blade at the lower end, and the impeller flange and the rotating blade extend in the vertical direction. An impeller coupled by an impeller shaft, wherein the impeller shaft of the impeller is divided into two in the vertical direction, and one of a female screw and a male screw is formed at a lower end portion of the upper divided impeller shaft provided with the impeller flange The female screw and the male screw that are screwed into either the female screw or the male screw at the upper end of the lower split impeller shaft on which the rotor blades are provided Flip a stirring desulfurization apparatus other is formed.

  Another aspect of the present invention is an impeller for an agitating desulfurization device that is replaceably joined to a main shaft of an agitating desulfurization device that rotates a rotor blade immersed in hot metal, the impeller shaft extending vertically An impeller flange that is provided at an upper end of the impeller shaft and is joined to a main shaft flange of a main shaft that is rotationally driven by a stirring drive source; and a rotary blade that is provided at a lower end of the impeller shaft, and An impeller shaft is divided into two in the vertical direction, and either one of a female screw and a male screw is formed at the lower end of the upper divided impeller shaft on which the impeller flange is provided, and the lower divided impeller shaft on which the rotor blades are provided. The impeller for the agitation-type desulfurization apparatus, wherein the other of the female screw and the male screw that are screwed into either the female screw or the male screw is formed at the upper end.

  According to the present invention, the impeller shaft is divided into two in the vertical direction, and the two divided impeller shafts are joined by the female screw and the male screw. Therefore, the rotational drive of the stirring motor can be used when the impeller is disassembled and joined. Therefore, the operator can perform the impeller replacement work without approaching the high temperature impeller, and the impeller replacement time can be shortened. And since the impeller flange attached to a main shaft flange is provided in the upper end of an impeller shaft, the impeller shaft divided | segmented into the up-down direction can also be attached also to the existing stirring-type desulfurization apparatus. Even if the female screw and the male screw are firmly joined and the impeller shaft cannot be divided into two, the impeller shaft can be detached from the main shaft at the flange joint portion.

Sectional drawing of the desulfurization apparatus in one Embodiment of this invention Side view of a desulfurization apparatus impeller according to an embodiment of the present invention ((a) in the figure shows a state in which the impeller is joined to the main shaft, and (b) in the figure shows the lower divided impeller shaft from the upper divided impeller shaft). (Shows removed state) Side view of a desulfurization apparatus impeller of a comparative example ((a) in the figure shows a state in which the impeller is joined to the main shaft, (b) in the figure shows a state in which the impeller has been removed from the main shaft, and (c) in the figure is a diagram) The middle (b) CC line arrow view is shown)

  Hereinafter, based on an accompanying drawing, an impeller for a desulfurization device in one embodiment of the present invention is explained in detail. FIG. 1 shows an agitation desulfurization apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a ladle, 2 is hot metal, and 3 is a desulfurization agent introduced from a desulfurization agent supply device (not shown). The rotary blade 4 is immersed in the hot metal 2. The rotary blade 4 is rotationally driven around its axis at high speed by a stirring motor 5 as a stirring drive source. When the rotary blade 4 is rotated, a swirl portion is formed on the upper surface of the hot metal 2, and the hot metal 2 and the desulfurizing agent 3 are agitated.

  The stirring motor 5 is supported by the guide 6 of the moving mechanism. A moving mechanism (not shown) raises and lowers the guide 6 to which the stirring motor 5 is attached, and moves the guide 6 in the horizontal direction so that the rotary blade 4 can be taken in and out of the hot metal 2.

  A main shaft 7 extending in the vertical direction is connected to the stirring motor 5. An impeller shaft 8 is coaxially connected below the main shaft 7. The main shaft 7 and the impeller shaft 8 are solid tubes. A main shaft flange 7 a is provided at the lower end of the main shaft 7. An impeller flange 8c joined to the main shaft flange 7a is provided at the upper end of the impeller shaft 8. The main shaft 7 and the impeller shaft 8 are joined via a main shaft flange 7a and an impeller flange 8c which are flange joints. A rotary blade 4 is provided at the lower end of the impeller shaft 8. The rotation of the main shaft 7 of the stirring motor 5 is transmitted to the rotary blade 4 through the impeller shaft 8.

  Since the rotary blade 4 is immersed in the hot metal, a refractory material is provided on the surface. When the number of times of use increases, the refractory is melted or missing, or hot metal or slag adheres, and the stirring performance decreases. For this reason, periodic replacement is necessary. Usually, since the rotor blade 4 and the impeller shaft 8 have an integral structure, it is necessary to replace the rotor blade 4 at the same time as the impeller shaft 8.

  FIG. 2 shows a side view of the impeller for the desulfurization apparatus. 2A shows a state where the impeller shaft 8 is joined to the main shaft 7, and FIG. 2B shows a state where the lower divided impeller shaft 8b is removed from the upper divided impeller shaft 8a.

  The impeller shaft 8 of this embodiment is divided into two in the vertical direction and is coupled by a threaded portion. In other words, the impeller shaft 8 is divided into two in the vertical direction: an upper divided impeller shaft 8a and a lower divided impeller shaft 8b. A female screw 10 is formed at the lower end of the upper divided impeller shaft 8a where the impeller flange 8c is provided. A male screw 11 is formed at the upper end of the lower divided impeller shaft 8b where the rotor blade 4 is provided. The female screw 10 and the male screw 11 are screwed together.

  FIG. 3 shows a side view of a conventional impeller for a desulfurization apparatus as a comparative example. 3A shows a state in which the impeller shaft 28 is joined to the main shaft 27 of the stirring motor 25, FIG. 3B shows a state in which the impeller shaft 28 is removed from the main shaft 7, and FIG. FIG. 3B is a view taken along the line CC of FIG.

  In this comparative example, the main shaft 27 and the impeller shaft 28 are joined by a main shaft flange 27a and an impeller flange 28a. When replacing the impeller, the bolt 30 connecting the main shaft flange 27a and the impeller flange 28a is manually removed. A plurality of bolts 30 are provided radially on the flange joint (see FIG. 3C) in order to ensure the mounting strength, etc., and there are 12 bolts in the example of FIG. Since there are a plurality of bolts 30 and the removal of the bolts 30 is performed manually by an operator, it takes a very long time to replace the impeller.

  On the other hand, as shown in FIG. 2, in one embodiment of the present invention, the impeller is disassembled by disassembling the female screw 10 and the male screw 11 without disassembling the main shaft flange 7a and the impeller flange 8c. Exchange. At that time, the rotational driving force of the stirring motor 5 is used. That is, the rotation direction of the stirring motor 5 is rotated in the opposite direction to the rotation direction of the rotor blade 4 in the desulfurization process, for example, counterclockwise when viewed from above in FIG. Then, since the female screw 10 rotates in a loosening direction with respect to the female screw 11, the lower divided impeller shaft 8b can be easily detached from the upper divided impeller shaft 8a.

  Although not shown in FIG. 2, an impeller replacement carriage is used to assist the replacement of the impeller. The impeller exchange carriage has a storage container on which the impeller is loaded, and the storage container can be moved up and down. By placing the impeller on the storage container, stopping the rotation of the impeller by a detent provided in the impeller replacement carriage, rotating the stirring motor 5 to loosen the female screw 10 and the male screw 11, and gradually lowering the storage container, The removed impeller (lower divided impeller shaft 8b) is accommodated in the storage container.

  When a new impeller is attached, a new impeller (lower divided impeller shaft 8b) is placed on the storage container of the impeller replacement cart, and the new impeller is moved below the main shaft 7 by the impeller replacement cart. Then, after the impeller is stopped, the rotation direction of the stirring motor 5 is rotated clockwise as viewed from above in FIG. 2, for example, while gradually raising the storage container. Since the female screw 10 of the upper divided impeller shaft 8a rotates so as to be screwed into the male screw 11 of the new lower divided impeller shaft 8b, the lower divided impeller shaft 8b is joined to the upper divided impeller shaft 8a.

  As described above, the lower divided impeller shaft 8b can be easily detached and attached to the upper divided impeller shaft 8a by remote control without operating the existing stirring motor 5 by manual operation. it can. Further, since the impeller flange 8c is provided at the upper end of the upper split impeller shaft 8a, the split impeller shafts 8a and 8b that are divided in the vertical direction can be attached to the existing stirring desulfurization apparatus. Even if the joint between the female screw 10 and the male screw 11 is strong and the impeller shaft 8 cannot be divided into two even if the stirring motor 5 is rotated in the reverse direction, the impeller shaft 8 can be removed from the main shaft flange 7a. it can.

  When the rotation direction of the stirring motor 5 in the desulfurization process is clockwise when viewed from above in FIG. 2, the female screw 10 and the male screw 11 are prevented from loosening during the hot metal stirring of the rotary blade 4. 11 must be a right-hand thread. On the other hand, when the rotation direction of the agitation motor 5 in the desulfurization process is counterclockwise as viewed from above in FIG. 2, the female screw 10 and the male screw 11 need to be left-handed. In other words, the direction in which the female screw 10 of the upper divided impeller shaft 8a is rotated must always match the rotation direction of the rotor blade 4 in the desulfurization process.

  When the impeller is replaced, the slag attached to the impeller shaft 8 and the flanges 7a and 8c may fall. When a female screw is formed on the lower divided impeller shaft 8b, foreign matters such as fallen slag and lime deposits enter the female screw. Even if foreign matter enters the female screw of the used divided impeller shaft 8b, there is no particular problem. However, if foreign matter enters the female screw of the new divided impeller shaft 8b, sufficient joining with the upper divided impeller shaft 8a becomes impossible. In such a case, it is necessary to remove foreign matter such as slag that has entered the female screw by hand. As shown in FIG. 2B, this problem can be prevented if the screw formed on the divided impeller shaft on the lower side is a male screw 11. Even if it adheres to the surface of the male screw 11, the foreign screw can be easily removed because it is the male screw 11.

  Compared to the conventional example shown in the figure, the impeller replacement time was greatly reduced from 60 minutes to 20 minutes per time. When replacing the impeller, an injection desulfurization method was performed as a desulfurization backup. Since the injection desulfurization method is more expensive than the impeller desulfurization method, the desulfurization cost increases as the desulfurization backup is performed, that is, the time required for the impeller replacement increases. Since the impeller replacement time was significantly reduced to 1/3, the desulfurization cost could be greatly reduced.

3 ... Desulfurizing agent 4 ... Rotor 5 ... Stirring motor (stirring drive source)
7 ... Main shaft 7a ... Main shaft flange 8 ... Impeller shaft 8a ... Upper divided impeller shaft 8b ... Lower divided impeller shaft 8c ... Impeller flange

Claims (4)

A stirring type desulfurization device for rotating a rotary blade immersed in hot metal,
A spindle extending in the vertical direction and having a spindle flange at the lower end;
An agitation drive source for rotationally driving the main shaft about its axis;
An impeller flange joined to the main shaft flange at the upper end, a rotating blade at the lower end, and an impeller for connecting the impeller flange and the rotating blade with an impeller shaft extending in the vertical direction,
The impeller shaft of the impeller is divided into two in the vertical direction;
One of a female screw and a male screw is formed at the lower end of the upper divided impeller shaft on which the impeller flange is provided,
An agitation-type desulfurization apparatus in which the other of the female screw and the male screw that engages with either the female screw or the male screw is formed at an upper end portion of a lower divided impeller shaft on which the rotary blade is provided.   The stirring desulfurization apparatus according to claim 1, wherein a female screw is formed on the upper divided impeller shaft, and a male screw is formed on the lower divided impeller shaft.   When the upper divided impeller shaft is screwed into the lower divided impeller shaft, the direction in which the stirring drive source rotates the upper divided impeller shaft is such that the stirring drive source rotates the rotor blades in the desulfurization process. The stirring type desulfurization apparatus according to claim 1, wherein the stirring type desulfurization apparatus coincides with a direction in which the stirring desulfurization is performed. An impeller for a stirring desulfurization device that is replaceably joined to a main shaft of a stirring desulfurization device that rotates a rotating blade immersed in hot metal,
An impeller shaft extending vertically,
An impeller flange provided at an upper end of the impeller shaft and joined to a main shaft flange of the main shaft that is rotationally driven by a stirring drive source;
A rotary blade provided at the lower end of the impeller shaft,
The impeller shaft of the impeller is divided into two in the vertical direction;
One of a female screw and a male screw is formed at the lower end of the upper divided impeller shaft on which the impeller flange is provided,
An impeller for an agitation type desulfurization device, wherein the other of the female screw and the male screw that are engaged with either the female screw or the male screw is formed at an upper end portion of a lower divided impeller shaft on which the rotary blade is provided.

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