Furnace bottom structure capable of realizing reduction of deep bed for rotary hearth furnace

Abstract

The invention provides a furnace bottom structure for a rotary hearth furnace. The furnace bottom structure comprises a heat preserving layer, a heating layer and an anti-slag-corrosion heat transfer layer in sequence from bottom to top, wherein the heat preserving layer and the heating layer are fixed; the anti-slag-corrosion heat transfer layer can rotate relative to the heat preserving layer and the heating layer; resistance wires are buried in the heating layer; the inside of the rotary hearth furnace is partitioned into a plurality of regions; the quantity of the resistance wires in the heating layer correspondsing to each region is set in advance; a layer of second steel plate is fixed on the upper part of the heating layer; a layer of first steel plate is fixed on the lower part of the anti-slag-corrosion heat transfer layer; a certain gap is kept between the first steel plate and the second steel plate, so that radiation heat transfer can be realized, and friction is prevented. By adopting the furnace bottom structure for the rotary hearth furnace provided by the invention, effective heat transfer and rapid reduction of a deep bed in a reduction process can be realized.

Description

technical field [0001] The invention relates to a bottom structure of a rotary hearth furnace, in particular to a bottom structure of a rotary hearth furnace for realizing rapid reduction of thick material layer pellets. Background technique [0002] At present, rotary hearth furnaces are generally used to process various composite ores, low-grade complex refractory ores, and metallurgical iron-containing solid wastes. During the reduction process, it is difficult to avoid the reflow of the furnace charge, which will generate liquid metallurgical slag and molten iron, and eventually cause the charge to be in the furnace. Bottom bonding, erosion of furnace bottom materials, and shortening the life of the rotary hearth furnace. In addition, the heating of carbon-containing pellets in the rotary hearth furnace and the heat required for the reaction mainly depend on the radiation heat transfer of the furnace wall and furnace gas. Therefore, it is required that the pellets in the...

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Problems solved by technology

But it is not difficult to see that the material spreading process of this invention is complicated, and the different particle sizes will greatly increase the equipment investment in the front-end process (ball making and drying) of the rotary hearth furnace. The pellets can just be laid on one layer, so it will be difficult to improve the overall metallization rate of the thick material layer during the reduction process

[0008] At present, there are the following problems in realizing the reduction of the thick material layer of the rotary hearth furnace and improving the heat transfer efficiency of the rotary hearth furnace: (1) For the reduction of the thick material layer of the rotary hearth furnace, the main method at present is to change the composition and particle size of the raw material, especially to control The particle size of each layer of raw materials is difficult to achieve in actual continuous production; (2) the rotary hearth furnace mainly relies on the radiation heat transfer of the furnace wall and furnace gas to increase the temperature of the carbon-containing pellets. Good reduction and high metallization rate are obtained, the height of the material layer is limited, and it is difficult to realize the reduction of the thick material layer in the rotary hearth furnace; The bottom of the rotary hearth furnace or the phenomenon of eroding the bottom of the furnace is not conducive to the continuous operation of the rotary hearth furnace, and also seriously affects the life of the rotary hearth furnace

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