JPH0654759U - Circulation pipe for vacuum degassing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a reflux pipe for a vacuum degassing equipment, which is intended to prevent early damage to constituent bricks by integrating bricks of multiple layers. In a recirculation pipe in a vacuum degassing facility, an inner winding brick 15 forming the recirculation pipe or a cylindrical body 18 in which an inner winding brick 15 and an inner winding brick 16 and an outer winding brick 17 are integrally formed, The cylindrical body 18 is characterized in that it is inserted and fixed in the outer shell iron shell 9.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a reflux pipe for vacuum degassing equipment.

[0002]

[Prior art]

 The vacuum degassing equipment, especially the RH type vacuum degassing equipment, has two dipping pipes 3, 4 for sucking and discharging at the lower part of the lower tank 2 of the degassing tank 1 as schematically shown in FIG. The immersion pipes 3 and 4 are immersed in the molten steel 6 in the ladle 5 to evacuate the tank, and a gas such as argon or nitrogen is blown from one of the immersion tubes to flow the molten steel into the tank. It is circulated for degassing, and the degassed molten steel is discharged from the other immersion pipe and returned to the ladle. Degassing is performed by continuing this.

The reflux tubes 7 and 8 used in such vacuum degassing equipment are provided at the bottom of the tank and are located between the tank and the dip tube, so that the dip tubes 3 and 4 can be easily replaced. It is not possible to replace it, so it is necessary to make it a structure that is not easily damaged, and proper material selection and lining construction will be performed.

The life of the lining of each part is generally the part where the flow velocity of molten steel is the maximum, and also due to the explosion of bubbles and the like, the opening part a in the lower tank 2 of the reflux pipe 7 is most easily damaged, and the degree of damage is The service life is determined by.

On the other hand, the construction of the return flow pipe is a work in a narrow and unscaffolding place in the outer shell iron shell 9 of the portion, so that it is difficult to perform the construction accurately. The inner-wall brick 10 is made of laterally-applied bricks whose circumferential direction is divided into a plurality of pieces as shown in the plan view in FIG. 7, or the inner-wall brick 10 and the middle-wall brick 11 are stacked in multiple stages to form one or two layers. This is a cylindrical metal structure, and this is a set metal product that clamps a brick group from above and below by tightening a presser member 12 and a receiver member 13 of means (FIG. 8) as described in Japanese Utility Model Laid-Open No. 3-99750 with bolts 14. The recirculation pipe is constructed by arranging the outer bricks and arranging the outer bricks, which are divided into a plurality of pieces in the circumferential direction, on the outer periphery thereof.

[0006]

[Problems to be solved by the device]

 However, at the bottom of the lower tank 2 of the above-mentioned RH type vacuum degassing equipment, when a dip tube is immersed in the molten steel in the ladle for vacuum degassing, the high temperature of the molten steel and the impact caused by the recirculation of the molten steel Wear caused by general turbulence, wear due to rapid heating and quenching due to repeated use, spalling, and wear due to promotion. In particular, as the molten steel circulates, the opening part a of the reflux pipe is pre-damaged from the inner peripheral surface to the upper surface as shown by the diagonal lines in Fig. 5, and becomes a morning glory cross section. Even if an outer wound brick is placed on the outer circumference of the upper part of the wound brick for the purpose of reinforcement, the outer wound brick is constructed in the outer shell iron shell 9 of this portion in a narrow and unscaffolded place as described above. However, there is a problem in that the joints are apt to loosen, and the molten steel is washed by the circulating fluid to accelerate the damage.

In particular, the outer shell iron shell 9 of the lower tank expands and contracts in accordance with repeated heating and cooling. Due to this expansion and contraction, the two reflux tubes 7 and 8 projecting vertically from the outer shell iron shell 9 at the bottom of the lower tank 2 are displaced in the direction of opening and closing in a “C” shape. In response to this, the outer bricks installed inside the outer shell will also move in conjunction with each other, and if the joints are loose, the movement will increase so much that the joints will be prone to breakage. It will be noticeable.

In view of this, the present invention reliably prevents early damage to the brick group including the outer wound brick from the above-mentioned problems in construction of the outer wound brick and phenomena in use. It is an object to provide a recirculation pipe for a vacuum degassing facility that enables it.

[0009]

[Means for Solving the Problems]

 As a means for solving the problems of the above-mentioned conventional techniques, the present invention provides an inner-flow brick, or an inner-wind brick, an inner-wind brick, and an outer-wind brick that constitute the free-flow tube in a free-flow tube in a vacuum degassing facility. It is characterized in that and are formed into an integrally configured cylindrical body, and this cylindrical body is inserted and fixed in the outer shell.

[0010]

[Action]

 Before the construction, the inner and outer wound bricks, or the inner and outer wound bricks and the inner and outer wound bricks are integrally set in the outer shell, so that the outer shell iron at the bottom of the lower layer is set. Even if the skin expands due to the radiant heat of molten steel in the ladle, the outer-wrapped brick is integrated with the inner-wrapped brick, or the inner-wrapped brick and the middle-wrapped brick, so that no joint breakage occurs. Brick wear and damage due to damage does not occur or increase.

[0011]

【Example】

 The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 shows a cross section of an example in which the present invention is used as a three-layer recirculation pipe, and FIG. 2 shows a plane of one recirculation pipe. The plurality of recirculation pipes are arranged in the circumferential direction. The inner winding brick 15 in which the bricks 15a divided into two are annularly arranged, the middle winding brick 16 in which a plurality of bricks 16a similarly divided in the circumferential direction are annularly arranged, and the plurality of bricks 16a in the circumferential direction are also divided. The brick 17a is divided into outer bricks 17a arranged in a ring shape, and these bricks 17a are formed as a single-body cylinder 18 before processing.

As a means for this integral structure, the bricks are assembled by assembling them with mortar interposed between the bricks, banding them on the outer periphery and drying them in a tightly fastened state, and integrally joining them to form the cylindrical body 18. I am trying.

The above-mentioned outer brick 17 is formed to be slightly longer than the vertical length of the brick 19 laid on the bottom of the outer shell iron shell 9 located on the outer periphery of the reflux pipe. The filling layer of the amorphous refractory material 20 to be filled between the lower part of 17 and the outer shell iron shell 9 is made as small as possible to improve the durability. The lower end of the outer brick 17 is formed as an inclined surface 21 so that the length of contact with the inner brick 16 is longer.

On the other hand, the outer winding brick 17 of the tubular body 18 has a brick shape so as to have an octagonal outer shape as shown in FIGS. In addition to this, other shapes such as an irregular quadrangle, a circle, and a petal shape partially shown in a portion B of FIG. 4 can be selected.

The tubular body 18 of the integral structure configured as described above holds the upper and lower sides of the tubular body 18 including the outer winding brick 17 and integrated with each other by the presser metal 12 and the metal receiver 13 as in the conventional case. Set with bolts 14 and hang it up and insert it into the specified place, and fill the irregular refractory up to the specified position between the outer shell 9 and the outer brick 17 and the required place. Fix by and.

In the illustrated embodiment, the case where the tubular body 18 constituting the reflux pipe has a three-layer structure has been described, but it may have two layers or four layers or more, and the inner bricks 15 may have a plurality of stages. The reflux pipe can be formed by stacking the stacks or stacking the middle-sized bricks 16 in multiple stages to form multiple layers.

[0018]

[Effect of device]

 As described above, according to the present invention, in the reflux pipe in the vacuum degassing equipment, the inner brick and the outer brick constituting the reflux pipe or the inner roll, the middle brick and the outer brick are integrally structured in advance. Since it was set as a cylindrical body of the object at a predetermined position in the outer shell, the brick was firmly integrated, and even if the outer shell of the bottom of the tank expanded by receiving radiant heat of molten steel The strength of the solidified bricks reduces the degree of deformation of individual bricks, and even if the bricks are washed by the circulating molten steel, the joint opening prevents the damage rate from accelerating and increasing due to the progress of joint melt loss, thus greatly improving durability. Can be improved.

Further, by making the length of the outer wound brick longer than that of the laid brick, even if a crack occurs in the inner wound brick or the middle wound brick, invasion of the metal is prevented, and the reflux pipe, and thus the lower portion. The service life of the entire tank can be greatly extended.

[Brief description of drawings]

FIG. 1 is a sectional view of an integrally structured tubular body for a reflux pipe according to the present invention.

FIG. 2 is a plan view of the cylindrical body of FIG.

FIG. 3 is a partial cross-sectional view of a state where the tubular body of FIG. 1 is installed in a lower tank.

FIG. 4 is a plan view taken along the line AA of FIG.

FIG. 5 is a cross-sectional view showing an outline of a vacuum degassing equipment to which the present invention is applied and a conventional defective portion.

FIG. 6 is a cross-sectional view showing a conventional reflux pipe structure.

FIG. 7 is a plan view of the same.

FIG. 8 is a cross-sectional view showing a conventional hanging means.

[Explanation of symbols]

 1 Degassing tank 2 Lower tank 3,4 Immersion pipe 7,8 Recirculation pipe 9 Outer shell iron shell 10,15 Inner winding brick 11,16 Middle winding brick 17 Outer winding brick 18 Cylindrical body 19 Floor brick 20 Irregular refractory material 21 Slope

Claims (2)

[Scope of utility model registration request] 1. A reflux pipe in a vacuum degassing facility,
The invention is characterized in that the inner-wall bricks forming the reflux pipe or the inner-wall bricks and the inner-wall bricks and the outer-wall bricks are integrally formed into a tubular body, and the tubular body is inserted and fixed in the outer shell iron shell. Circulation pipe for vacuum degassing equipment. 2. The recirculation pipe for a vacuum degassing facility according to claim 1, wherein the length of the outer brick is longer than that of the floor brick.