KR20060070019A - Pig-iron producing melt furnace utilizing powder and lump raw materal - Google Patents

Abstract

The present invention is a melting furnace for reducing the iron ore while the coke is burned by injecting a mixture of iron ore and subsidiary materials with coke and then blowing hot air from the bottom, the upper part of the molten pig iron melted in the lower portion of the melting furnace and the melting furnace A plurality of supports are installed in the horizontal direction at the bottom of the raw material inlet, respectively, and the upper portion of the melting furnace is provided with a cyclone for supplying powder from the molten material back to the melting furnace. The pig iron production smelting furnace which makes a point is made. In addition, the present invention allows the bulk gas to be stacked on the upper portion of the support located in the lower part of the furnace to heat the iron ore while the gas at the bottom easily moves to the gap between the bulk refractory, and the Pigment using powder and bulk mixed fuel, characterized in that the hot reducing gas is directly in contact with the center of the melting furnace to maintain the breathability, the powder is raised to the upper side of the melting furnace to the wall of the melting furnace through a cyclone. The production melting furnace operation method is the point.

Smelting furnace

Description

Pig-iron producing melting furnace using powder and bulk mixed fuel and method for operating melting furnace using same {Pig-iron producing melt furnace utilizing powder and lump raw materal}             

1 is a schematic view of a melting furnace for pig iron production according to the present invention.

The present invention relates to a pig iron production melting furnace using powder and bulk mixed fuel and a melting furnace operating method using the same, and in particular, pig iron using powder and bulk mixed fuel that maximizes the efficiency of the melting furnace by increasing the breathability by stacking the bulk refractory. It relates to a production furnace and a melting furnace operating method using the same.

In general, the conventional method for producing pig iron from iron ore is to inject coke into a furnace with a mixture of iron ore and a subsidiary material which is easy to separate by melting impurities in the iron ore and blows coke by blowing high temperature air from the bottom of the furnace. The iron ore is reduced by using heat and the reducing power of carbon monoxide generated by burning coke, and the method of melting pig iron and slag and discharging it to the bottom of the furnace. Another purpose of using coke in this method is to maintain sufficient voids in the furnace to facilitate the flow of gas and to increase the utilization of heat.

However, in this method, the air hits the coke layer and burns the coke, passes through the coke layer, and has sufficient reducing power, and then moves to the upper part of the furnace to reduce iron ore. At this time, air is injected through the radially vents around the furnace, and after combustion, there is a limit to passing through the coke layer, so that more gas flows toward the wall than the center of the furnace, and the hot gas flows toward the wall. It gives a lot of heat to the wall, which leads to huge heat loss. Currently, raw materials charged to the upper part are separated by particle size to arrange small particles on the wall side and large particles on the center side to induce gas flow toward the center, but there is a limit in this method, so heat loss is inevitable. Excessive coke and other fuels should be used to make up for the losses.

Another problem with these furnaces is that a large amount of high pressure gas moves upwards and is discharged, so when the powder is mixed in the raw material, it cannot be loaded out of the furnace and charged, thus making the powder raw material in the sintering machine. It must be committed. In this case, a heat source is required for the sintering machine, and thus generation of combustion gas and consumption of energy are inevitable.

Therefore, additional equipment is also needed to prevent pollution of the combustion gases. In addition, it is inevitable to use excessive coke in the furnace to ensure breathability and heat source. Because coke is obtained by distilling coal, additional fuel is needed to supply heat required for distillation, and It can cause environmental pollution in the process of refining.

The present invention uses the melting furnace of the structure that can be injected without making the raw material to make the raw material mixed with the powder without pretreatment and to minimize the heat flow through the furnace wall to minimize the gas flow to the wall do.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is a melting furnace for reducing the iron ore while the coke is burned by injecting a mixture of iron ore and subsidiary materials with coke and then blowing hot air from the bottom, the upper part of the molten pig iron melted in the lower portion of the melting furnace and the melting furnace A plurality of supports are installed in the horizontal direction at the bottom of the raw material inlet, respectively, and the upper portion of the melting furnace is characterized in that the cyclone is installed so that the powder coming from the molten material can be supplied back to the melting furnace. In addition, the present invention is to allow the mass of the refractory to be stacked on the upper portion of the support located in the bottom of the melting furnace to heat the iron ore while the gas in the lower easily moved to the gap between the bulk refractory, and between the bulky refractory and the molten pig iron It is characterized in that the hot reducing gas is directly contacted to the center of the melting furnace to maintain the air permeability, and the powder which has risen to the upper part of the melting furnace is supplied to the wall of the melting furnace through a cyclone. EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

As shown in Fig. 1, the melting furnace has a structure in which a support is placed at the bottom to support a solid charge. In addition, the charge is mixed with a refractory mass that can withstand high heat in addition to the existing iron ore raw materials and auxiliary materials. By doing so, the porosity in the furnace can be maintained without coke, so that breathability can be maintained. The charge may also be mixed with waste plastics, coal and the like as fuel. Depending on how much solid fuel is mixed, the amount of fuel blown into the bottom and the amount of air or oxygen will vary.

The melting furnace structure according to the present invention has a structure for maintaining the space between the molten pig iron and the solids for maintaining breathability by using a support, unlike the existing furnace that the coke is suspended in the upper portion of the molten pig iron Gas passes straight through the center of the furnace. By doing so, it is possible to minimize the amount of gas flowing to the wall and thus reduce the amount of heat lost to the wall group, so that the temperature of the furnace can be maintained and the melting temperature of pig iron can be maintained even if the temperature of the furnace is lower than that of the conventional furnace. It becomes possible.

In addition, the fuel used in the lower portion may be a gas fuel or a liquid fuel, powder fuel, and the like, by injecting air or oxygen therein to incomplete combustion to generate a gas having a reducing power and sufficient heat. The amount of fuel and air or oxygen injected is adjusted in consideration of the proper gas flow, gas reducing power, calorific value, and the like.

In the upper part of the melting furnace, raw materials including fuel and fuel are introduced. The raw material input stage is separated by using the bottom of the melting furnace and the support, and the gas used for heating and reducing the melting furnace passes through the support so as to be reused in the raw material input stage to penetrate the raw material and fuel layers.

In this way, the remaining heat brought from the lower part is transmitted to the raw material, thereby improving the thermal efficiency. The gas which has risen through the feed stage contains light powder, which passes through a cyclone located at the top of the furnace to separate the powder, and the separated powder is connected to the furnace wall to connect the bottom of the cyclone to the furnace wall. do.

Since the powder injected into the wall of the furnace is poor in gas permeability, the gas coming from the bottom passes mainly to the center of the furnace, thereby minimizing heat loss. The support of the raw material input stage maintains a certain gap so that the bulk raw materials and fuel can pass down the support.

A nozzle for injecting air, oxygen, fuel, etc. is placed under the support of the raw material input stage to replenish the calorie reducing power of the gas and to promote preheating and reduction when the gas contacts the raw material. The amount introduced here is optimized to a sufficient amount of reducing power and calorific value in the raw material input stage and the cyclone.

Since the present invention can be operated regardless of the particle size of raw materials and fuel in the furnace, it is not necessary to use sintered ore and coke, and the contact efficiency of the powder and gas is higher than the contact efficiency of the bulk material and the gas so that the efficiency of the furnace Can be significantly improved compared to existing furnaces. In addition, the cost of producing coke and sintered ore can be reduced and the resulting pollution treatment costs can be reduced.

Claims (2)

In the melting furnace of reducing the iron ore while the coke is combusted by injecting a mixture of iron ore and secondary raw materials with coke and then blowing hot air from the bottom, Cyclone to install a plurality of supports in the horizontal direction in the upper part of the molten iron melted in the lower part of the melting furnace and the lower end of the raw material inlet of the melting furnace, the powder from the molten material can be supplied to the melting furnace again in the upper part of the melting furnace Pig iron production melting furnace using powder and bulk mixed fuel, characterized in that the installation. The bulky refractory is stacked on the upper part of the support in the lower part of the melting furnace of claim 1, so that the gas in the lower part is easily moved to the upper part by the gap between the bulky refractory and heats the iron ore, and into the space between the bulky refractory and the molten pig iron. The high temperature reducing gas is in direct contact with the center of the furnace to maintain breathability, and the powder that has risen to the top of the furnace is supplied to the wall of the furnace through a cyclone, so that the raw material can be introduced without making a bulk. Process for melting pig iron production using bulk mixed fuel.

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