Ironmaking system and ironmaking process of two-section downdraft bed

Abstract

An ironmaking system and process of a two-section downdraft bed, including: a vertical melting furnace, where a basic combustor/gasifier is at the top, first and second inlets evenly along a side wall of the melting furnace below the basic combustor/gasifier, and the first inlet connected to coke powder/pulverized coal, air, and water vapor sources; a slag pool, at a bottom of the melting furnace; a vertical pre-reduction furnace, the top portion connected to the outlet of the melting furnace, third and fourth inlets on an upper portion of the pre-reduction furnace and connected respectively to a temperature-adjusting and tempering medium source and an iron mineral powder source, an outlet at a bottom of the pre-reduction furnace; and a separator, an inlet of the separator connected to the outlet of the pre-reduction furnace, and an outlet at a bottom of the separator connected to the second inlet through a pipeline.

What is claimed is: 
     
         1 . An ironmaking system of a two-section downdraft bed, the system comprising:
 a melting furnace section, vertically downward disposed, wherein a basic combustor/gasifier is disposed at a top portion thereof, a first inlet and a second inlet are provided below the basic combustor/gasifier, both the first inlet and the second inlet are evenly provided along a side wall of the melting furnace section, and form a tangent circle in the melting furnace section, the second inlet is located below the first inlet, and the first inlet is connected to a coke powder/pulverized coal source, an air source, and a water vapor source;   a slag pool, disposed at a bottom portion of the melting furnace section, and equipped with a slag discharging device and a tapping device, wherein an outlet end is downstream of the slag pool;   a pre-reduction furnace section, vertically downward disposed, wherein a top portion thereof is connected to the outlet end of the melting furnace section, a third inlet and a fourth inlet are provided on an upper portion of the pre-reduction furnace section, an outlet is disposed at a bottom portion of the pre-reduction furnace section, the third inlet is connected to a temperature-adjusting and tempering medium source, and the fourth inlet is connected to an iron mineral powder source; and   a first separator, wherein an inlet of the first separator is connected to the outlet of the pre-reduction furnace section, and an outlet at a bottom portion of the first separator is connected to the second inlet through a conveying pipeline.   
     
     
         2 . The ironmaking system of a two-section downdraft bed according to  claim 1 , wherein a funnel structure is disposed at the bottom portion of the melting furnace section, and the slag pool is disposed at an outlet end of the funnel structure. 
     
     
         3 . The ironmaking system of a two-section downdraft bed according to  claim 1 , wherein the first inlet comprises 2 to 8 inlets, circumferentially arranged along the melting furnace section; or the second inlet comprises 2 to 8 inlets, circumferentially arranged along the melting furnace section. 
     
     
         4 . The ironmaking system of a two-section downdraft bed according to  claim 1 , wherein the pre-reduction furnace section is connected to the melting furnace section through an arc-shaped pipeline. 
     
     
         5 . The ironmaking system of a two-section downdraft bed according to  claim 1 , further comprising a second separator, wherein an inlet of the second separator is connected to a gas outlet of the first separator through a pipeline, a fifth inlet is provided on the pipeline, and the fifth inlet is connected to a cold iron mineral powder source; and
 further, a solid outlet of the second separator is connected to the fourth inlet through a conveying pipeline, and a gas outlet is connected to a first heat exchanger through a pipeline.   
     
     
         6 . The ironmaking system of a two-section downdraft bed according to  claim 1 , further comprising a pulverized coal coking furnace section and a third separator, wherein the pulverized coal coking furnace section is vertically disposed, a bottom portion of the pulverized coal coking furnace section is connected to the gas outlet of the first separator, a sixth inlet is provided at a lower end of the pulverized coal coking furnace section, the sixth inlet is connected to a pulverized coal source, and a top portion of the pulverized coal coking furnace section is connected to an inlet of the third separator;
 further, a solid outlet end of the third separator is connected to the first inlet; and   further, a gas outlet end of the third separator is connected to a second heat exchanger through a pipeline.   
     
     
         7 . An ironmaking process of a two-section downdraft bed, comprising the following steps:
 entering, by coke powder/pulverized coal carried by air and water vapor, a melting furnace section from a side wall of the melting furnace section, to form a swirling flow in the melting furnace section;   jetting, by a basic combustor/gasifier at a top portion of the melting furnace section, a flame inward to ignite or gasify a fluid, to generate reducing gas;   jetting pre-reduced iron mineral powder into the melting furnace section, to fully mix the pre-reduced iron mineral powder with a coke powder/pulverized coal gas flow;   under the action of high-temperature reduction, reducing an iron oxide in iron mineral powder into an iron element, and melting the iron element into molten iron at a high temperature; and   flowing, by a high-temperature reducing gas after the reaction, from the melting furnace section to a pre-reduction furnace section, and pre-reducing iron mineral powder jetted into the pre-reduction furnace section; and conveying the pre-reduced iron mineral powder to the melting furnace section.   
     
     
         8 . The ironmaking process of a two-section downdraft bed according to  claim 7 , further comprising a step of pre-heating cold iron mineral powder by using a high-temperature gas flow flowing out from the pre-reduction furnace section; or
 further comprising a step of coking pulverized coal by using a high-temperature gas flow flowing out from the pre-reduction furnace section.   
     
     
         9 . The ironmaking process of a two-section downdraft bed according to  claim 7 , wherein a temperature of a reaction in the melting furnace section ranges from 1300° C. to 1700° C.; or
 a temperature of the pre-reduction furnace section ranges from 700° C. to 1100° C. 
 
     
     
         10 . The ironmaking process of a two-section downdraft bed according to  claim 7 , wherein a circulating coal gas or a mixture of pulverized coal and a circulating coal gas is added into the pre-reduction furnace section as a cooling and temperature-adjusting medium.