JP6563034B2 - Bottom blow plug with improved workability - Google Patents

Description

  The present invention relates to a gas injection plug for molten metal. Specifically, the present invention relates to a bottom blowing plug incorporated in a bottom wall of a converter or the like for blowing gas into a molten metal such as a converter.

  Conventionally, in a converter, gas is blown from a bottom blowing plug embedded in the bottom of the converter for promoting refining or stirring molten steel.

  The schematic structure of the bottom of the converter is as shown in the vertical end view of FIG. 10 is an iron skin at the bottom of the furnace, and 20 is a tuyere for gas blowing. A permanent brick 9 is stretched on the iron skin 10 at the bottom of the furnace, and a work brick 5 is laminated on the permanent brick 9. As shown in FIG. 4, the work brick 5 is composed of a lower brick 5b and an upper brick 5a, and a long brick having two upper and lower layers. There are cases where it is even more tensioned. In the figure, 6 is a long integrated brick forming a tuyere, 7 is a furnace body, and 8 is a steel exit (see, for example, Patent Document 1).

JP-A-5-70819

  Since the refractory bricks of converters are exposed to high temperature molten metal and corrode, they need to be rebuilt regularly. When the refractory brick of the converter is re-stretched, the brick is stretched coaxially around the predetermined position when the brick is in the vertical and horizontal directions from a predetermined position of the iron skin.

  The bottom blowing plug is also installed at a position close to the position where the gas supply pipe of the bottom blowing plug provided on the iron shell is passed in the order in which the refractory bricks are stretched.

  There may be an inconvenience that the gas supply pipe of the bottom blowing plug does not enter the hole for the gas supply pipe of the iron skin due to an error that occurs when attaching the refractory brick. In particular, when installing multiple plugs in the case of an interpolated bottom blow plug, since the hole in the tuyere's iron skin is small (see Fig. 4), the gas supply pipe of the bottom blow plug is placed in the hole in the iron skin. Inconvenience that does not enter. In such a case, work to change the position of the bottom blowing plug is performed by changing the refractory brick or by cutting a part of the refractory brick. However, such work requires a great amount of time and causes inconveniences such as lengthening the repair time of the converter.

  This invention is made | formed in view of said problem, and makes it a subject to provide the bottom blow plug which can be easily integrated in furnace bottoms, such as a converter.

  The present invention made to solve the problem includes an iron shell having a tuyere at the furnace bottom, a furnace refractory provided inside the iron shell, and a bottom blowing plug for blowing gas into the molten metal in the furnace. The bottom blow plug is provided in the furnace bottom refractory, and has a plug main body for injecting gas, and a gas supply pipe for supplying gas to the plug main body. A part or all of the gas supply pipe is a bending free pipe, and the bending free pipe is inserted into the tuyere with one end connected to the plug body.

  Since part or all of the gas supply pipe is a bending-free pipe, the gas supply pipe can be easily inserted into the hole in the iron skin through which the gas supply pipe is inserted. As a result, the bottom blowing plug can be easily incorporated into the furnace bottom.

  In the bottom blow plug, the bent free pipe may be a flexible hose and / or a bellows. The bent free pipe must have heat resistance, pressure resistance and airtightness.

  The plug body may have a fan-shaped cross-sectional shape. Accordingly, it becomes easy to incorporate the bottom blowing plug so as to surround the core around the core.

  The plug body may include a plurality of through holes. Thereby, the hole into which the gas is blown is not blocked by the molten metal.

  Since part or all of the gas supply pipe is a bending-free pipe, the gas supply pipe can be easily inserted into the hole in the iron shell of the converter through which the gas supply pipe is inserted.

It is a longitudinal cross-sectional view of the bottom blow plug which concerns on embodiment of this invention. It is a cross-sectional view of a bottom blow plug according to an embodiment of the present invention. It is a partial end elevation view showing a deformation mode of a bending free pipe. It is a longitudinal cross-sectional view which shows schematic structure of a converter bottom part.

  Hereinafter, an embodiment of a bottom blowing plug provided in a bottom refractory such as a converter according to the present invention will be specifically described with reference to FIGS.

  As shown in FIG. 1, the bottom blow plug of the embodiment is composed of a plug body 1 having a plurality of through holes 11 and a bent free pipe 2 attached to the lower portion of the plug body 1.

The plug main body 1 has a trapezoidal shape in which the upper side is small and the lower side is large and has a flat upper surface 13, a lower surface 12, and an outer peripheral surface 14 facing the molten metal of the converter. As shown in FIG. 2, the outer peripheral surface 14 of the plug body 1 is composed of two flat surfaces 14a and curved surfaces 14b and 14c. The curved surface 14b is a circular arc with a radius R ₀ centered on the converter core O, and the curved surface 14c is a circular arc with a radius R ₁ (> R ₀ ) centered on O.

  A base 3 forming a gas chamber 31 is attached to the lower surface 12 of the plug body 1. A gas chamber 31 in which a lower portion of the through hole 11 is opened is provided at the lower portion of the plug body 1, and the bending free pipe 2 communicates with the gas chamber 31.

  The refractory material of the plug body 1 is preferably a highly durable magnesia-carbon material.

  As shown in FIG. 2, the through hole 11 has a circular cross-sectional shape and extends along the axis of the plug body 1. Each through hole 11 opens at the upper surface 13 of the plug body 1 and also opens at the bottom surface 12, whereby gas can be blown into the molten metal. In the plug body 1 of the present embodiment, 90 through holes 11 are arranged at regular intervals on 6 concentric regular hexagons.

  The gas chamber 31 is formed by closing the lower part of the cylindrical base 3 with a disk 4. An attachment port 41 arranged coaxially with the plug body 1 is fixed at the center of the disk 4. Reference numeral 5 denotes a metal disk that contacts the lower surface 12 of the plug body 1.

  One end of the bending free pipe 2 is connected to the attachment port 41. The metal bending free pipe 2 includes a thin-walled pipe 21 and a member 22 that spirally wraps around the outer periphery of the pipe 21, and is excellent in heat resistance, pressure resistance, and airtightness. The spirally wound member 22 acts to maintain a circular cross section even when the thin pipe 21 is bent.

  The bending free pipe 2 may be a flexible hose 2A shown in FIG. The flexible hose 2A is formed by coating the outer periphery of a stainless steel core tube 2A1 with a stainless steel overblade 2A2. 2A3 is a stainless steel end connection. The core tube 2A1 is a kind of bellows, and the overblade 2A2 is a knitted stainless steel wire.

  The flexible hose 2A is superior to the bending free pipe 2 in bending property, heat resistance, pressure resistance, and airtightness.

  The bend free pipe 2 may be a bellows.

  In the bottom blow plug of this embodiment, all of the gas pipes 2 communicating with the gas chamber 31 are bent free pipes, but some may be bent free pipes.

  In the blow plug of the embodiment, the gas supply pipe that supplies gas to the through hole 11 of the plug body 1 includes the bending-free pipe 2, so that the gas is supplied to the hole in the iron shell of the converter that passes through the gas supply pipe. The tube can be easily inserted.

Further, blowing plug embodiment, the radius R ₁ of the outer peripheral surface 14 of the plug main body 1 around the curved surface 14b and O is an arc of a circle with a radius R ₀ centered on furnace core O of the converter _(> R ₀ ) and the curved surface 14c that is a circular arc of the circle, it is easy to incorporate the bottom blowing plug so as to surround the core around the core.

1 ···· Plug body 2 ··· Bend free tube 2A ··· Flexible hose

Claims (2)

A converter having an iron skin provided with tuyere at the furnace bottom , a furnace refractory provided inside the iron skin, and a bottom blow plug for blowing gas into the molten metal in the furnace,
The bottom blow plug is
Rutotomoni provided in the furnace bottom refractory, having a top surface facing the molten metal, a lower surface facing away from said upper surface, and a through hole for ejecting the gas opens into each of the top and the bottom surface A columnar plug body;
A gas supply pipe that is inserted into the tuyere and attached to a lower portion of the plug body , and supplies gas to the through hole ;
Have
Part or all of the gas supply pipe is a bent free pipe,
The converter is characterized in that the bent free pipe extends to the outside through the tuyere with one end connected to the plug body. The converter according to claim 1, wherein the bending-free pipe is a flexible hose or a bellows.

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