JPS5829167Y2 - A-kurobutatsurikouzou - Google Patents

Description

[Detailed description of the invention] The present invention is an invention regarding a small ceiling suspension structure for an arc furnace lid.

In recent years, arc furnaces have become larger, and the types of furnaces they manufacture have become more high-grade, so operations such as ladle refining and continuous casting have led to higher tap temperatures.

The refractories used are also highly refractory, and the basicity of the furnace lid has increased to cope with this problem.

The refractory composition of basic furnace lids consists of basic bricks for the outer periphery, high alumina bricks for the small ceiling, and high alumina monolithic refractories, and basic bricks are also being used for the small ceiling.

A dome-shaped ceiling structure in which the outer ring has a suspended structure of basic firebrick is described in Japanese Patent Publication No. 44-27124, but the small ceiling part does not have a suspended structure. The instability during operation has not yet been resolved.

Mechanically, the small ceiling part has electrode holes, and the cooling cylinder is subject to local weight, making it unstable during use.

In addition, it is structurally difficult to insert the appropriate amount of expansion absorbing material to absorb the coefficient of thermal expansion of the refractory, which causes deformation and spalling during use, causing the small ceiling to fall during the latter half of use. Sometimes I do.

The present invention focuses on this point, and by suspending the refractories used in small ceilings with a hanging structure, it is possible to insert an appropriate amount of thermal expansion absorbing material in the refractories, so there is no deformation due to thermal expansion. It also suppresses mechanical spalling and can withstand local loads.

In addition, the safe use limit for refractories is generally a residual dimension of 5Q mm.
The above seems to be the case, but hanging a refractory can extend the life of the furnace lid compared to conventional ones.

Therefore, the hanging structure of the present invention is a significant invention in terms of effective use of refractories and extension of their lifespan.

Next, we will look at an example of a suspension structure for the small ceiling of the arc furnace lid for steelmaking. Drawings based on the combination of will be explained.

In Fig. 1, 1 is an outer basic brick, 2 is a dust collection hole ring basic brick, 3 is an unshaped refractory, 4 is a small ceiling basic brick, 5 is a small ceiling electrode hole ring basic brick, 6 is a monolithic refractory.

A furnace lid is constructed from a combination of the bricks and monolithic refractories.

Next, the small ceiling suspension structure includes a ring metal fitting 7 that is concentric with the small ceiling refractory, and a plurality of frames 8 fixed to and inscribed therein, extending to the center and assembled at a gathering point 9 to form a hanging structure as necessary. This is a structure in which an arcuate or linear auxiliary support hardware 10, which serves both as a body reinforcement and a suspension support, is provided across the ring hardware 7 and approximately the center of the frame 8.

The small ceiling hanging structure is fixed to the small ceiling hanging structure supporting frame 11 fixed to the hearth peripheral ring 13 with bolts or bolts.

Construction of the refractory will begin with the outer perimeter bricks, and will be completed with the stamping of the monolithic refractory around the electrode holes in the small ceiling.

The method for suspending the small ceiling refractory is to first fix the small ceiling suspension structure supporting frame 11 to the furnace cover peripheral ring 13, and then attach the small ceiling suspension structure to the center support so that it is connected to the opening 12. The ring 7 of the small ceiling hanging structure on which the body is placed and the opening 12 of the center support of the small ceiling hanging structure supporting frame 11 are connected and fixed with bolts or bolts.

Construction is completed by suspending and connecting the hanging tools 14 provided on each refractory to this small ceiling suspension structure using hanging hardware.

By suspending and connecting the small ceiling refractory to the small ceiling suspension structure, the present invention makes it possible to insert an appropriate absorbent material that absorbs the coefficient of thermal expansion of the refractory. It is always stable even when exposed to vibrations and tilting, suppressing deformation and spalling of refractories.
This is a very effective method because refractories can be used safely until the end.

Examples of the results of using the small ceiling suspension structure according to the present invention in an actual furnace are shown below.

(1) Conditions of use Furnace Capacity: 80 tons Arc wave tone Type 2 stainless steel tapping temperature: 1650℃ Number of times of tapping: 4 to 5 times/day (2) Bricks around the furnace cover structure: Basic brick dust collection holes : Basic bricks and monolithic refractories Small ceiling part: Basic bricks and monolithic refractories (3) Usage results When the small ceiling suspension structure according to the present invention is applied with the above-mentioned furnace lid support structure, The average lifespan of the furnace lid was as follows when only the peripheral part had a hanging structure and the small ceiling part had the conventional structure.

Invented structure・152 times Conventional structure 129 times In other words, it was confirmed that the lifespan was extended by about 18%.

The effects of this invention are listed below.

(1) Spalling can be suppressed because an expansion absorbing material (for example, cardboard) that absorbs the coefficient of thermal expansion of the refractory can be appropriately inserted.

(2) Deformation of the small ceiling due to drying shrinkage or thermal expansion of the refractory is prevented.

(3) Different types of refractories with different coefficients of thermal expansion and contraction can be used together with confidence.

(4) The life of the furnace cover can be extended.

(5) The small ceiling suspension structure can be made of any combination of refractories, such as bricks, monolithic refractories, or a combination of bricks and monolithic refractories.

[Brief explanation of drawings]

FIG. 1 is a plan view showing details of the steel-making arc furnace lid constructed according to the present invention and its structure. FIG. 2 is a vertical sectional view taken along the line AA' in FIG. In the figure, 4 is a brick equipped with a hanging tool, 7 is a ring hardware, 8 is a plurality of frames, 9 is a gathering point of the frames, 10 is auxiliary support hardware,
Reference numeral 11 indicates a small ceiling structure support frame, reference numeral 12 indicates a center support of 11, and reference numeral 13 indicates a ring metal fitting around the furnace lid.

Claims (1)

[Scope of utility model registration request] In the arc furnace lid, the refractory of the small ceiling part is suspended on a suspension structure consisting of a ring fitting 7 concentric with the small ceiling part, a plurality of frames 8 inscribed in the ring fitting 7, and auxiliary support fittings 10. An arc furnace lid suspension structure, characterized in that the suspension structure is joined to a frame 11 for supporting a small ceiling suspension structure.