RU2370545C1 - Iron notch of blast furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: iron notch consists of frame connected to case of hearth arranged in wind boxes, of cover out of refractory material adjoining walls of frame and forming cover seat for tip of gun, and of notch channel made in form of metal cylinder tube of 80-100 mm internal diametre having common lengthwise axis with cavity of drilled hole in brickwork. The frame contains an external ring welded to the case the walls of which are included into protective sheath out of fire-proof concrete with welded anchors.

EFFECT: increased operation life of notch for tapping hot melt of iron.

2 dwg

Description

The invention relates to metallurgy, and in particular to the equipment of the hearth of a blast furnace.

Known cast-iron notch of a blast furnace, the frame of which is cylindrical, and the walls of the frame with a flange are enclosed in a high-alumina packing on an anhydrous binder. The thickness of this packing inside the frame, replacing the brick cancer, is 0.2 ÷ 0.5 of the width of the channel of the frame. The case with the case for the gun sock is made of a case mass in the form of a truncated cone (1).

The disadvantages of the design of the famous cast-iron notches are:

- short-term case service;

- a significant amount of manual labor in the manufacture of the case;

- the drying of the case is accompanied by the release of a volatile binder and the products of combustion of the gas of the burner.

The closest in technical essence and the achieved effect to the claimed device is a cast iron notch of a blast furnace containing a horn frame connected to a casing, placed in refrigerators, a case made of refractory material with a case for the gun toe and a channel made in the form of a drilled hole in carbon blocks hearth walls (2). This design of cast iron taphole is taken as a prototype.

The reasons that impede the achievement of the technical result indicated below when using a known tap hole include the fact that the outer ring of the frame is not protected by wear-resistant refractory concrete. The problem associated with the operation of such a notch is that as a result of thermal expansion and compression of the various components of the refractory material under the sharp heat of molten iron, the concrete surface cracks, in particular, in the area located under the outer ring of the frame. Strengthening the outer ring of the frame by attaching the external reinforcing stiffening ribs has the disadvantage that the frame begins to bend locally and protrude outward. Attempts made in this case to force cooling (air or water) lead to the destruction and decrease in the resistance of the cast iron notch of the blast furnace.

The problem to which the invention is directed, is to increase the service life of a notch for the production of hot molten iron.

The problem is achieved due to the fact that the proposed cast iron notch of the blast furnace, containing a frame connected to the casing of the furnace, placed in the refrigerators, a case made of refractory material adjacent to the walls of the frame, forming a case for the gun’s toe, and a channel made by a metal cylindrical pipe with an internal diameter of 80-100 mm, having a common longitudinal axis with a cavity of a drilled hole in the masonry, the frame contains an outer ring welded to the casing, the walls of which are enclosed tnuyu lining of refractory concrete provided with a metal sheath with welded anchoring.

An essential distinguishing feature is that the metal shell and the protective casing around the outer ring of the frame are connected to each other by anchor means. As a result of the connection, a aligned heat flow is generated both in the longitudinal and transverse sections of the notch. According to the invention, the metal shell with anchor means can not be cooled externally, on the contrary, due to the protective sheathing (insulation) to maintain it at high temperature due to the effect of radiation from molten iron. The technical result of the invention is the reduction of thermal stress in the cavity of the case, in the channel of the notch.

The invention is illustrated by drawings, where figure 1 presents a cast-iron cage, figure 2 is a section aa.

The lining of the tap hole becomes denser, the resistance increases, the gas emissions of the furnace gas from the blast furnace are reduced.

The cast iron notch contains a frame 1, which reinforces the casing of the furnace 2, protects the refrigerators 3. The outer ring of the frame 4 is enclosed in a casing 5 made of refractory concrete, protected by a metal sheath 6 with reinforced material 7. Anchors (steel needles) are used as reinforced material, which are welded to a metal shell and embedded in a refractory sheathing. Similar refractory concrete protects the frame walls inside the furnace. Refractory concrete filling the cavity of the frame forms a case of cast iron notch 8 with a case 9. Through the longitudinal axis of the notch frame and refractory masonry of the furnace passes a channel of cast iron notch 10, made of a metal cylindrical pipe with an inner diameter of 80-100 mm, filled when closing the production of cast iron mass. The design of the cast iron notch provides reliable protection for the summer coolers 3. To close the cast iron notch, use a cannon with a toe 11 tightly pressed to the case 8.

Cast iron taphole blast furnace works as follows. The frame of the cast iron notch 1 with the outer ring 4 provides structural rigidity and compensates for the weakening of the casing at the hole in the casing of the furnace. The design of the channel of the frame 1 must be combined with the inclination of the longitudinal axis of the frame at an angle of 18 ° to the horizontal plane to prevent the flow of cast iron of channel 10 of the cast iron notch from the air coolers 3. The outer ring of the frame is filled with refractory concrete to a metal shell 6 with welded anchors 7. For hardening protective sheath made of refractory concrete is connected to the metal shell with anchor means. The metal pipe installed in the frame of the tap hole forms a channel of the tap hole 10 in the case 8. The cavity of the metal pipe and the cavity of the drilled hole in the brickwork have a common longitudinal axis.

High-alumina pouring concrete (type CERALIT CAST KU 71014), subjected to heat treatment after manufacturing and hardening for 12 hours, has increased heat resistance, high resistance to corrosion against liquid cast iron. Concrete pouring, located under the frame of 1 notch and around the perimeter of the metal shell 6 with reinforcing reinforcing material 7 - welded anchors, prevents cracking in the case. When closing the tap hole with a gun, an anhydrous tap mass fills the tap channel 10. The releases of pig-iron are made according to the schedule.

Case made of bulk concrete provides many months of service. Its re-manufacturing is carried out during the overhaul of the third category. Concrete drying is provided by heat accumulated in the furnace.

Increasing the service life of the case, reducing emissions into the atmosphere improve working conditions.

Information sources

1. USSR Copyright Certificate No. 1523571 A1, C21B 7/12, 1989

2. Patent of the Russian Federation No. 31578 U1, C21B 7/12, 2003.

Claims (1)

A cast-iron notch of a blast furnace, containing a frame connected to the casing of the furnace, placed in refrigerators, a case made of refractory material, adjacent to the walls of the frame, forming a case for the gun’s nose, and a notch channel made in the form of a metal cylindrical pipe with an inner diameter of 80-100 mm having a common longitudinal axis with a cavity of a drilled hole in masonry, characterized in that the frame contains an outer ring welded to the casing, the walls of which are enclosed in a protective casing of refractory concrete, equipped metal sheath with welded anchors.

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