CN113046508B - High-efficiency reduction shaft furnace for oxidized pellets and reduction process - Google Patents
High-efficiency reduction shaft furnace for oxidized pellets and reduction process Download PDFInfo
- Publication number
- CN113046508B CN113046508B CN202110355644.2A CN202110355644A CN113046508B CN 113046508 B CN113046508 B CN 113046508B CN 202110355644 A CN202110355644 A CN 202110355644A CN 113046508 B CN113046508 B CN 113046508B
- Authority
- CN
- China
- Prior art keywords
- reduction
- chamber
- gas
- communicated
- combustion chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/02—Making spongy iron or liquid steel, by direct processes in shaft furnaces
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0073—Selection or treatment of the reducing gases
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Iron (AREA)
Abstract
The invention relates to an efficient reduction shaft furnace and a reduction process for oxidized pellets. A blanking throat is arranged at the position where the top of the reduction chamber and the heating section are communicated with each other, and a coal injection pipe is arranged at the top of the reduction chamber; the top of the reduction chamber is provided with a vent hole communicated with the outer heat storage chamber and the inner heat storage chamber. The top of the heating section is communicated with a gas purification and cooling circulation system, and an output pipe of the gas purification and cooling circulation system is communicated with the lower part of the cooling section to form gas circulation. The invention greatly improves the efficiency of the reduction reaction of the oxidized pellet and the reduction taste, shortens the cooling time, improves the discharging efficiency and increases the yield.
Description
Technical Field
The invention relates to an iron-making technology, in particular to a high-efficiency reduction shaft furnace for oxidized pellets and a reduction process.
Background
The traditional coking, sintering and blast furnace iron making have the problems of complex process, large investment, serious energy waste, long process, serious pollution and the like, so that the iron making development of the blast furnace is greatly limited. In order to overcome the disadvantages of blast furnace ironmaking, various non-blast furnace ironmaking processes have been developed, including direct reduction and smelting reduction. The smelting reduction iron-making process has more than 3O, and especially makes great progress in double-base reducing furnace iron-making process, and has the powerful foundation and sufficient conditions for producing double-base deoxidized pellets of coal and gas. The double-base reduction furnace is divided into a preheating section, a reduction section and a cooling section from top to bottom, high-temperature gas in a combustion chamber is subjected to reduction reaction with oxidized pellets at 850-1050 ℃ in the reduction section through a heating furnace wall of a regenerative chamber, and the generated sponge iron is cooled to below 200 ℃ through the cooling section and discharged by a discharging machine and a rotary cooling system. However, the reaction furnace often has some defects in the production process, such as overlong reduction section time, low efficiency, small influence range of furnace wall heat conduction, poor reduction grade, difficult meeting of steelmaking requirements of product quality, reduction of the pellets into sponge iron with the tail temperature higher than 200 ℃ through the cooling section, difficulty in belt transportation, only slowing of discharging speed and prolonging of cooling time, and great influence on yield.
Disclosure of Invention
The invention aims to provide an efficient reduction shaft furnace and a reduction process for oxidized pellets, and aims to solve the problems of low reduction efficiency, poor reduction taste and slow discharging speed of the conventional double-base reduction furnace.
The invention is realized by the following steps: an oxidized pellet high-efficiency reduction shaft furnace comprises a heating section, a reduction section and a cooling section, wherein the reduction section comprises an annular reduction chamber, an outer heat storage chamber is arranged on the outer side of the reduction chamber, an inner heat storage chamber is arranged on the inner side of the reduction chamber, the outer heat storage chamber and the inner heat storage chamber are mutually communicated through a plurality of layers of heat conduction communicating pipes, a plurality of heat conduction communicating pipes are distributed along the circumference of each layer, and the heat conduction communicating pipes penetrate through the reduction chamber; and a blanking throat is arranged at the position where the top of the reduction chamber and the heating section are communicated with each other, and the blanking throat thins the furnace burden so that the furnace burden can be rapidly heated before high-temperature coal powder enters the reduction chamber. A coal injection pipe for injecting coal powder below the blanking throat is arranged at the top of the reduction chamber; the top of the reduction chamber is provided with a vent hole communicated with the outer regenerative chamber and the inner regenerative chamber;
the top of the heating section is communicated with a gas purification and cooling circulation system which is used for collecting gas in the shaft furnace and carrying out dust removal and cooling treatment; an output pipe of the coal gas purification and cooling circulation system is communicated with the lower part of the cooling section to form a coal gas circulation passage, and the output pipe is indirectly communicated with the inner heat storage chamber and the outer heat storage chamber through the combustion chamber.
The adjacent upper and lower layers of heat-conducting communicating pipes are arranged in a staggered manner.
The coal injection pipes are arranged in two circles, the outer circle at the top of the reduction chamber is a peripheral coal injection pipe, and the inner circle at the top of the reduction chamber is a central coal injection pipe.
The bottom of the outer regenerative chamber is communicated with an outer combustion chamber, the bottom of the inner regenerative chamber is provided with an inner combustion chamber communicated with the outer combustion chamber, and the outer combustion chamber and the inner combustion chamber are respectively communicated with an output pipe of the coal gas purification cooling circulation system.
The coal gas purification and cooling circulation system comprises a collecting pipe communicated with the top of the heating section, the collecting pipe is sequentially connected with a cyclone washing tower, a washing and dewatering tower, a draught fan, a coal gas pressurizer and an output pipe through pipelines, and the output pipe is communicated with the bottom of the cooling section.
The output pipe is communicated with the outer combustion chamber and the inner combustion chamber through gas transmission branch pipes, and the gas transmission branch pipes are connected with combustion-supporting fans through combustion-supporting air pipelines.
The high-efficiency reduction process for the oxidized pellets is characterized by comprising the following steps of:
a. establishing gas circulation, collecting gas containing carbon monoxide in the shaft furnace from a heating section of the shaft furnace, purifying and cooling the collected gas, inputting the purified and cooled gas into a cooling section of the shaft furnace for the second time, and collecting low-temperature gas which absorbs heat in the cooling section and then reaches the heating section through a reduction section;
b. adding furnace burden containing oxidized pellets and a reducing agent into a heating section from the furnace top, and preheating the furnace burden by the heating section;
c. furnace burden passes through the blanking throat, the furnace burden enters the reduction chamber under the necking action of the blanking throat, and high-temperature hot air generated by the combustion chamber is fully mixed with the furnace burden at the top of the reduction chamber, so that the furnace burden is fully and quickly heated;
d. spraying pulverized coal to the top of the reduction chamber, mixing the pulverized coal with high-temperature hot air generated by the combustion chamber, and reacting the pulverized coal with carbon dioxide in the high-temperature hot air to form a reducing gas with the main component of carbon monoxide, so that the gas environment in the reduction chamber is improved;
e. high-temperature hot air generated by the inner combustion chamber and the outer combustion chamber heats the wall of the reduction chamber through the inner heat storage chamber and the outer heat storage chamber, and the high-temperature hot air flows in the heat conduction ventilation pipe to transfer heat into the reduction chamber through the heat conduction ventilation pipe;
f. furnace burden falls in the reduction chamber and passes through a plurality of layers of heat conduction ventilation pipes, the furnace burden is heated and stirred by the heat conduction ventilation pipes, and the reduction reaction of the oxidized pellets is completed in the falling process to obtain sponge iron;
g. the sponge iron obtained by reduction enters a cooling section, the temperature of the sponge iron is reduced through the heat absorption effect of low-temperature coal gas, and the sponge iron is output from the bottom of the cooling section after the temperature of the sponge iron is reduced to a proper discharging temperature; the low-temperature coal gas absorbs heat and then rises into the reduction chamber.
The gas participating in the gas circulation is also used for the combustion of the inner combustion chamber and the outer combustion chamber to generate high-temperature hot air with the main component of carbon dioxide.
The inner combustion chamber and the outer combustion chamber are controlled to lead the temperature inside the inner combustion chamber and the outer combustion chamber to be inconsistent, thereby forming pressure difference to lead high-temperature hot air to flow in the heat conduction ventilation pipe.
The invention adds a blanking throat at the joint of the heating section of the shaft furnace and the reduction chamber to ensure that the furnace charge has thinner thickness when entering the reduction chamber, and simultaneously, a vent hole is arranged between the top of the regenerative chamber and the top of the reduction chamber to ensure that high-temperature hot air starts to be mixed with the furnace charge at the blanking throat and wraps the furnace charge to fully heat the oxidized pellets. Pulverized coal is sprayed to the top of the reduction chamber, the sprayed pulverized coal is mixed with high-temperature hot air, and the pulverized coal and carbon monoxide react to generate reducing gas with carbon monoxide as a main component, so that the gas environment in the reduction chamber is improved, the concentration of carbon monoxide in the gas is increased, and the reduction reaction of the oxidized pellets in the reduction chamber is facilitated.
The inner side and the outer side of the annular reduction section are respectively provided with an inner heat storage chamber and an outer heat storage chamber, and the wall body of the reduction section is heated simultaneously in the inner direction and the outer direction, so that the temperature in the reduction section is increased. The furnace burden close to the wall body can only obtain higher temperature due to low heat transfer efficiency of the wall body, and the furnace burden at the middle position of the inner wall body and the outer wall body of the reduction chamber can not obtain better temperature, so that the reduction reaction at the middle position is not ideal. Therefore, a plurality of layers of heat conduction communicating pipes are arranged in the reduction chamber from top to bottom, and the heat conduction communicating pipes of two adjacent layers are arranged in a staggered manner. Like this, can pass through multilayer heat conduction communicating pipe when the in-process of charge from reduction chamber to whereabouts, heat conduction communicating pipe is because there is hot-blast circulation, so has higher temperature to heat the charge that passes through, simultaneously because the heat conduction communicating pipe staggered arrangement of upper and lower floor, the charge rolls the whereabouts at the whereabouts in-process, thereby is heated by abundant stirring. Thereby improving the efficiency of the reduction reaction and the reduction taste.
Introducing low-temperature coal gas (or other gases) into the bottom of the cooling section, absorbing heat of the sponge iron entering the cooling section by the low-temperature coal gas (gases), reducing the temperature of the sponge iron to a proper discharging temperature below 200 ℃, and raising the coal gas absorbing the heat into the reduction chamber to provide carbon monoxide for the reduction chamber. The coal gas is continuously circulated in the shaft furnace and the coal gas purification and cooling circulation system, and the coal gas is fully utilized.
The invention greatly improves the efficiency of the reduction reaction of the oxidized pellet and the reduction taste, shortens the cooling time, improves the discharging efficiency and increases the yield.
Drawings
FIG. 1 is a schematic view of a shaft furnace according to the invention.
Fig. 2 is a schematic structural view of the whole of the present invention.
In the figure: 1. a heating section; 2. a reduction section; 3. a cooling section; 4. a blanking throat; 5. a reduction chamber; 6. an outer regenerator; 7. an internal heat storage chamber; 8. a heat conducting communicating pipe; 9. a central coal injection pipe; 10. a peripheral coal injection pipe; 11. a vent hole; 12. an outer combustion chamber; 13. an inner combustion chamber; 14. a gas purification cooling circulation system; 15. a toothed roller unloader; 16. vibrating the unloader; 17. a rotary cooler; 14-1, collecting pipes; 14-2, a cyclone washing tower; 14-3, washing a dehydration tower; 14-4, a draught fan; 14-5, a gas pressurizer; 14-6, an output pipe; 14-7, a combustion-supporting fan; 14-8, a combustion-supporting air pipeline; 14-9, a closed cooling tower; 14-10 parts of an ammonia water tank; 14-11 parts of a tar ammonia water tank.
Detailed Description
As shown in fig. 1 and 2, the high-efficiency reduction shaft furnace for oxidized pellets of the present invention comprises a heating section 1, a reduction section 2 and a cooling section 3. Wherein, the reduction section 2 comprises an annular reduction chamber 5, the top of the reduction chamber 5 is communicated with the bottom of the heating section 1, and the bottom of the reduction chamber 5 is communicated with the top of the cooling section 3. An outer regenerator 6 is arranged on the outer side of the reduction chamber 5, an inner regenerator 7 is arranged on the inner side of the reduction chamber 5, the heights of the outer regenerator 6 and the inner regenerator 7 are consistent with that of the reduction chamber 5, and the reduction chamber 5 and the outer regenerator 6 and the reduction chamber 5 and the inner regenerator 7 are separated by a furnace wall.
The outer heat storage chamber 6 and the inner heat storage chamber 7 are communicated with each other through a plurality of layers of heat conducting communicating pipes 8, each layer comprises a plurality of heat conducting communicating pipes 8 distributed circumferentially, and the heat conducting communicating pipes 8 transversely penetrate through the reduction chamber 5. Besides the wall body can conduct heat to transfer the heat of the regenerator to the reduction chamber 5, the heat can also be transferred into the reduction chamber 5 through the heat-conducting communicating pipe 8.
The upper and lower adjacent layers of heat conducting communicating pipes 8 are arranged in a staggered manner, furnace burden falling from the upper heat conducting communicating pipe 8 just falls on the heat conducting communicating pipe 8 on the lower layer, and the furnace burden can roll continuously in the process of reaching the bottom from the top of the reduction section 2 to play a role in stirring.
The blanking throat 4 which reduces the horizontal thickness of the blanking is arranged at the position where the top of the reduction chamber 5 and the heating section 1 are communicated with each other, the communicated part of the reduction chamber 5 and the heating section 1 is an annular channel, and the annular width is reduced after the blanking throat 4 is arranged, so that the blanking thickness is reduced when furnace burden passes through, and the blanking is completely heated by high-temperature gas more easily.
In order to heat the blanking at the blanking throat 4, the top of the reduction chamber 5 is provided with a vent hole 11 communicated with the outer regenerative chamber 6 and the inner regenerative chamber 7, the vent hole 11 leads hot air from the outer regenerative chamber 6 to the outer side of the blanking and leads hot air from the inner regenerative chamber 7 to the inner side of the blanking, thereby rapidly heating the blanking.
The top of the reduction chamber 5 is provided with a coal injection pipe for injecting coal powder below the blanking throat 4, the number of the coal injection pipes is two, the coal injection pipe is arranged on the outer ring of the top of the reduction chamber 5 and is a peripheral coal injection pipe 10, and the coal injection pipe is arranged on the inner ring of the top of the reduction chamber 5 and is a central coal injection pipe 9. The pulverized coal sprayed by the peripheral coal injection pipe 10 is mixed with the hot air introduced by the vent holes 11 at the outer side, and the pulverized coal sprayed by the inner coal injection pipe is mixed with the hot air introduced by the vent holes 11 at the inner side. Since the hot blast from the regenerator mainly contains carbon dioxide, the pulverized coal reacts with the carbon dioxide to produce carbon monoxide for the reduction reaction of the oxidized pellets.
The top of the heating section 1 is communicated with a collecting pipe 14-1 of a gas purification cooling circulation system 14, the collecting pipe 14-1 collects gas in the shaft furnace, then the collected gas is subjected to dust removal and cooling treatment through the gas purification cooling circulation system 14, and the qualified gas is communicated with the lower part of the cooling section 3 through an output pipe 14-6, so that the circulation of the gas is formed.
The bottom of the outer heat storage chamber 6 is communicated with an outer combustion chamber 12, the bottom of the inner heat storage chamber 7 is provided with an inner combustion chamber 13 communicated with the outer combustion chamber, the inner combustion chamber 13 and the outer combustion chamber 12 are respectively provided with a burner, the outer combustion chamber 12 and the inner combustion chamber 13 are respectively communicated with an output pipe 14-6 of a gas purification and cooling circulation system 14, and gas for combustion is provided by the output pipe 14-6. The heat generated by the gas combustion and the flue gas containing carbon dioxide are conveyed into the reduction section 2 through the inner heat storage chamber 7 and the outer heat storage chamber 6.
The coal gas purification and cooling circulation system 14 comprises a collecting pipe 14-1 communicated with the top of the heating section 1, the collecting pipe 14-1 is sequentially connected with a cyclone washing tower 14-2, a washing and dehydrating tower 14-3, an induced draft fan 14-4, a coal gas pressurizer 14-5 and an output pipe 14-6 through pipelines, and the output pipe 14-6 is communicated with the bottom of the cooling section 3. The output pipe 14-6 is communicated with the outer combustion chamber 12 and the inner combustion chamber 13 through a gas transmission branch pipe, the gas transmission branch pipe is connected with a combustion-supporting fan 14-7 through a combustion-supporting air pipeline 14-8, and the combustion-supporting fan 14-7 inputs oxygen-containing air or oxygen into the system, so that coal gas can be combusted in the combustion chamber to generate carbon dioxide.
Most of the gas is directly output to the washing and dehydrating tower 14-3 through the cyclone washing tower 14-2, and a part of the gas output from the cyclone washing tower 14-2 passes through the tar ammonia water tank 14-11, the ammonia water tank 14-10 and the closed cooling tower 14-9 in sequence and then returns to the cyclone washing tower 14-2 to form a washing and cooling cycle. A part of the gas after washing and cooling is directly conveyed to the middle part of the washing and dehydrating tower 14-3, and the front part and the rear part of the washing and dehydrating tower 14-3 are respectively communicated with a pipeline between the cyclone washing tower 14-2 and the tar ammonia water tank 14-11 through pipelines.
The collecting pipe 14-1 is provided with an explosion valve and an ignition and dispersion port, and the ignition and dispersion port is also arranged between the induced draft fan 14-4 and the gas pressurizer 14-5, so that the gas is safely dispersed to maintain the stability of the pressure of the whole system.
Instead of using coal gas as the cooling medium, nitrogen gas, a mixed gas of nitrogen gas and coal gas, or the like may be used.
The pulverized coal is sprayed into the reduction chamber 5, the pulverized coal reacts with carbon dioxide to generate carbon monoxide, the formed carbon monoxide is used as a reduction gas, but most of the carbon monoxide cannot be consumed by the reduction reaction, the gas containing the carbon monoxide is collected, the collected gas contains a large amount of carbon monoxide, so the gas can be used as gas, the gas is purified and cooled by the gas purification and cooling circulation system 14, the treated gas is introduced into the shaft furnace again to be used as a cooling heat absorption medium, and meanwhile, one part of the treated gas is used as fuel of the combustion chamber.
The sponge iron passing through the cooling section 3 is absorbed by the low-temperature coal gas with the temperature being input, and the temperature of the sponge iron in the cooling section 3 is reduced to be below 200 ℃, and the temperature lower than 200 ℃ is a relatively proper discharging temperature. A tooth roller unloader 15 is arranged at the bottom of the cooling section 3, a vibration unloader 16 is arranged below the tooth roller unloader 15, the outlet of the vibration unloader 16 is communicated with a rotary cooler 17, and finally, the rotary cooler 17 conveys the sponge iron onto a belt conveyor.
The high-efficiency reduction process for the oxidized pellets comprises the following steps:
a. establishing gas circulation, collecting gas containing carbon monoxide in the shaft furnace from a heating section 1 of the shaft furnace, purifying and cooling the collected gas, inputting the purified and cooled gas into a cooling section 3 of the shaft furnace for the second time, and enabling low-temperature gas to reach the heating section 1 through a reduction section 2 after the cooling section 3 absorbs heat and then to be collected again.
b. Charging materials containing oxidized pellets and reducing agents are added into the heating section 1 from the furnace top, and the charging materials are preheated by the heating section 1.
c. Furnace burden passes through the blanking throat 4 and enters the reduction chamber 5 under the necking action of the blanking throat 4, and high-temperature hot air generated by the combustion chamber and the furnace burden are fully mixed at the top of the reduction chamber 5, so that the furnace burden is fully heated.
d. Coal dust is sprayed into the top of the reduction chamber 5, the coal dust is mixed with high-temperature hot air generated by the combustion chamber, and the coal dust and carbon dioxide in the high-temperature hot air react to form a reduction gas with the main component of carbon monoxide, so that the gas environment in the reduction chamber 5 is improved.
e. The high-temperature hot air generated by the inner combustion chamber 13 and the outer combustion chamber 12 heats the wall of the reduction chamber 5 through the inner regenerative chamber 7 and the outer regenerative chamber 6, and the high-temperature hot air flows in the heat-conducting ventilation pipe 8 to transfer heat into the reduction chamber 5 through the heat-conducting ventilation pipe 8.
f. Furnace burden falls in the reduction chamber 5 and passes through the multilayer heat conduction ventilation pipe, the furnace burden is heated and stirred by the heat conduction ventilation pipe, and the reduction reaction of the oxidized pellets is completed in the falling process to obtain sponge iron.
g. The sponge iron obtained by reduction enters a cooling section 3, the temperature of the sponge iron is reduced through the heat absorption effect of low-temperature coal gas, and the sponge iron is output from the bottom of the cooling section 3 after the temperature of the sponge iron is reduced to a proper discharging temperature; the low-temperature coal gas absorbs heat and then rises into the reduction chamber 5.
The coal powder reacts with carbon dioxide in the high-temperature hot air in the reduction chamber 5 to form carbon monoxide, the coal gas containing the carbon monoxide is collected and then returns to the shaft furnace through the coal gas purification and cooling circulation system 14, part of the coal gas returning to the shaft furnace is used for burning the inner combustion chamber 13 and the outer combustion chamber 12 except for cooling sponge iron to generate high-temperature hot air with the main component of the carbon dioxide, and the carbon dioxide in the high-temperature hot air reacts with the coal powder in the reduction chamber 5 to generate carbon monoxide, so that the circulation of the carbon monoxide and the carbon dioxide is formed.
In order to rapidly transfer the heat of the inner regenerative chamber 7 and the heat of the outer regenerative chamber 6 into the reduction chamber 5, the inner combustion chamber 13 and the outer combustion chamber 12 are controlled to make the internal temperatures of the two different, so that pressure difference is formed to make high-temperature hot air flow in the heat-conducting ventilation pipe 8, and the heat is conveniently transferred into the reduction chamber 5 through the heat-conducting ventilation pipe 8.
According to the invention, a feeding throat is added at the joint of the heating section 1 of the shaft furnace and the reduction chamber 5, so that the furnace burden has a thinner thickness when entering the reduction chamber 5, and meanwhile, a vent hole 11 is formed between the top of the regenerative chamber and the top of the reduction chamber 5, so that high-temperature hot air is mixed with the furnace burden at the feeding throat 4, and the furnace burden is wrapped to fully heat the oxidized pellets. The oxidized pellets are fully heated before entering the reduction chamber 5 for reduction reaction, which is beneficial to the next reduction reaction.
Pulverized coal is sprayed to the top of the reduction chamber 5, the sprayed pulverized coal is mixed with high-temperature hot air, and the pulverized coal and carbon monoxide react to generate reducing gas with carbon monoxide as a main component, so that the gas environment in the reduction chamber 5 is improved, the concentration of carbon monoxide in the gas is increased, and the reduction reaction of the oxidized pellets in the reduction chamber 5 is facilitated. The generated carbon monoxide is mainly positioned below the blanking throat 4 and can directly contact with high-temperature furnace burden falling from the blanking throat 4, thereby promoting the generation of reduction reaction.
The inner side and the outer side of the annular reduction section 2 are respectively provided with an inner heat storage chamber 7 and an outer heat storage chamber 6, and the wall of the reduction section 2 is heated simultaneously in the inner direction and the outer direction, so that the temperature in the reduction section 2 is increased. The heat transfer efficiency of the wall is low, and only the furnace burden close to the wall can obtain higher temperature, but the furnace burden at the middle position of the inner wall and the outer wall of the reduction chamber 5 can not obtain better temperature, so that the reduction reaction at the middle position is not ideal. Therefore, a plurality of layers of heat-conducting communicating pipes 8 are arranged in the reduction chamber 5 from top to bottom, and the heat-conducting communicating pipes 8 of two adjacent layers are arranged in a staggered manner. Therefore, when the furnace burden falls from the reduction chamber 5, the furnace burden passes through the plurality of layers of heat conducting communicating pipes 8, the heat conducting communicating pipes 8 have higher temperature due to hot air circulation, and the furnace burden is heated, and meanwhile, due to the staggered arrangement of the heat conducting communicating pipes 8 of the upper layer and the lower layer, the furnace burden rolls and falls in the falling process, and is heated by full stirring. Thereby improving the efficiency of the reduction reaction and reducing the taste.
The coal gas purification and cooling circulation system 14 not only realizes the recycling of the coal gas, but also directly utilizes the coal gas as a cooling medium, absorbs heat to cool the sponge iron, simultaneously enables the coal gas entering the reduction chamber 5 to have certain temperature, and the coal gas which has absorbed certain heat is easier to be heated to the required temperature in the reduction chamber 5, thereby improving the reduction efficiency.
The invention greatly improves the efficiency of the reduction reaction of the oxidized pellet and the reduction taste, shortens the cooling time, improves the discharging efficiency and increases the yield.
Claims (8)
1. An efficient reduction shaft furnace for oxidized pellets comprises a heating section, a reduction section and a cooling section, and is characterized in that the reduction section comprises an annular reduction chamber, an outer heat storage chamber is arranged on the outer side of the reduction chamber, an inner heat storage chamber is arranged on the inner side of the reduction chamber, the outer heat storage chamber and the inner heat storage chamber are mutually communicated through a plurality of layers of heat conduction communicating pipes, a plurality of heat conduction communicating pipes are circumferentially distributed on each layer, the heat conduction communicating pipes penetrate through the reduction chamber, and the adjacent upper and lower layers of heat conduction communicating pipes are mutually staggered and arranged in a quincunx shape; a blanking throat is arranged at the position where the top of the reduction chamber and the heating section are communicated with each other, and a coal injection pipe for injecting coal powder below the blanking throat is arranged at the top of the reduction chamber; the top of the reduction chamber is provided with a vent hole which is communicated with the outer heat storage chamber and the inner heat storage chamber;
the top of the heating section is communicated with a gas purification and cooling circulation system which is used for collecting gas in the shaft furnace and carrying out dust removal and cooling treatment; an output pipe of the coal gas purification and cooling circulation system is communicated with the lower part of the cooling section to form a coal gas circulation passage, and the output pipe is indirectly communicated with the inner heat storage chamber and the outer heat storage chamber through the combustion chamber.
2. The shaft furnace for efficiently reducing the oxidized pellets according to claim 1, wherein the number of the coal injection pipes is two, the outer ring of the top of the reduction chamber is a peripheral coal injection pipe, and the inner ring of the top of the reduction chamber is a central coal injection pipe.
3. The shaft furnace for efficiently reducing the oxidized pellets according to claim 1, wherein an outer combustion chamber is communicated with the bottom of the outer regenerative chamber, an inner combustion chamber communicated with the outer combustion chamber is arranged at the bottom of the inner regenerative chamber, and the outer combustion chamber and the inner combustion chamber are respectively communicated with an output pipe of the gas purification and cooling circulation system.
4. The shaft furnace for efficiently reducing the oxidized pellets according to claim 1, wherein the gas purification and cooling circulation system comprises a collecting pipe communicated with the top of the heating section, the collecting pipe is sequentially connected with a cyclone washing tower, a washing and dewatering tower, an induced draft fan, a gas pressurizer and an output pipe through pipelines, and the output pipe is communicated with the bottom of the cooling section.
5. The shaft furnace for efficiently reducing oxidized pellets according to claim 3, wherein the output pipe is communicated with the outer combustion chamber and the inner combustion chamber through a gas transmission branch pipe, and the gas transmission branch pipe is connected with a combustion fan through a combustion air pipeline.
6. A high-efficiency reduction process of oxidized pellets based on the high-efficiency reduction shaft furnace of oxidized pellets as claimed in any one of claims 1 to 5, characterized by comprising the following steps:
a. establishing gas circulation, collecting gas containing carbon monoxide in the shaft furnace from a heating section of the shaft furnace, purifying and cooling the collected gas, inputting the purified and cooled gas into a cooling section of the shaft furnace for the second time, and collecting low-temperature gas which absorbs heat in the cooling section and then reaches the heating section through a reduction section;
b. adding furnace burden containing oxidized pellets and a reducing agent into a heating section from the top of the furnace, and preheating the furnace burden by the heating section;
c. furnace burden passes through the blanking throat, the furnace burden enters the reduction chamber under the necking action of the blanking throat, and high-temperature hot air generated by the combustion chamber is fully mixed with the furnace burden at the top of the reduction chamber, so that the furnace burden is fully heated;
d. spraying pulverized coal to the top of the reduction chamber, mixing the pulverized coal with high-temperature hot air generated by the combustion chamber, and carrying out mixed reaction on the pulverized coal and the high-temperature hot air to form a reducing gas with the main component of carbon monoxide, so that the gas environment in the reduction chamber is improved;
e. high-temperature hot air generated by the inner combustion chamber and the outer combustion chamber heats the wall of the reduction chamber through the inner heat storage chamber and the outer heat storage chamber, and the high-temperature hot air flows in the heat conduction ventilation pipe to transfer heat into the reduction chamber through the heat conduction ventilation pipe;
f. furnace burden falls in the reduction chamber and passes through the multiple layers of heat conduction ventilation pipes, the furnace burden is heated and stirred by the heat conduction ventilation pipes, and the oxidized pellets complete reduction reaction in the falling process to obtain sponge iron;
g. the sponge iron obtained by reduction enters a cooling section, the temperature of the sponge iron is reduced through the heat absorption effect of low-temperature coal gas, and the sponge iron is output from the bottom of the cooling section after the temperature of the sponge iron is reduced to a proper discharging temperature; the low-temperature coal gas absorbs heat and then rises to enter the reduction chamber.
7. The process for efficiently reducing oxidized pellets according to claim 6, wherein the gas participating in the gas circulation is also used for combustion in the inner combustion chamber and the outer combustion chamber to generate high-temperature hot air mainly containing carbon dioxide.
8. The process for efficiently reducing oxidized pellets according to claim 6, wherein the inner combustion chamber and the outer combustion chamber are controlled to have different internal temperatures, so that a pressure difference is formed to allow high-temperature hot air to flow in the heat-conducting ventilation pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110355644.2A CN113046508B (en) | 2021-04-01 | 2021-04-01 | High-efficiency reduction shaft furnace for oxidized pellets and reduction process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110355644.2A CN113046508B (en) | 2021-04-01 | 2021-04-01 | High-efficiency reduction shaft furnace for oxidized pellets and reduction process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113046508A CN113046508A (en) | 2021-06-29 |
| CN113046508B true CN113046508B (en) | 2022-09-27 |
Family
ID=76517293
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110355644.2A Active CN113046508B (en) | 2021-04-01 | 2021-04-01 | High-efficiency reduction shaft furnace for oxidized pellets and reduction process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113046508B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1030775C (en) * | 1992-12-23 | 1996-01-24 | 东北工学院 | Process and apparatus for reducing spongy iron in coal-base shaft furnace |
| KR100276324B1 (en) * | 1996-12-20 | 2000-12-15 | 이구택 | Melt reduction apparatus and method for manufacturing molten pig iron using the same |
| CN101935732B (en) * | 2010-08-11 | 2014-06-11 | 中冶赛迪上海工程技术有限公司 | Charging method of reducing coal gas for gas-based reduction shaft furnace |
| CN209685837U (en) * | 2018-09-20 | 2019-11-26 | 中晋冶金科技有限公司 | A kind of gas-based shaft kiln producing cold direct reduced iron |
| CN111424130B (en) * | 2020-06-01 | 2023-07-21 | 唐山中科乾海环保科技有限公司 | Improved heat accumulating type coal-based reduction device and reduction method |
-
2021
- 2021-04-01 CN CN202110355644.2A patent/CN113046508B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113046508A (en) | 2021-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106834573B (en) | A kind of full oxygen blast furnace method | |
| CN104152165B (en) | The metallurgical reducing process of coal gas circulation coal wholegrain radial sector pyrolysis coupling and system | |
| CN108753368A (en) | A kind of circulation fluidized bed coal gasifying system and method | |
| CN106554826A (en) | Circulation fluidized bed coal gasifying method and device with fine ash melting | |
| WO2022262792A1 (en) | Pre-reduced pellet preparation apparatus and method based on grate-rotary kiln | |
| CN102796568B (en) | Device and technology for producing blau-gas and carbon monoxide | |
| CN216712149U (en) | Pellet reduction system based on melting furnace top gas circulation | |
| CN101481752B (en) | Self-sealing nitrogen circulating cooling method and apparatus | |
| CN105084361B (en) | A kind of gas heating multistage calcium carbide reactor and its technique | |
| CN113046508B (en) | High-efficiency reduction shaft furnace for oxidized pellets and reduction process | |
| SU1138036A3 (en) | Method of operation of blast furnace and system for producing molten iron and reducing gas | |
| CN107299176A (en) | A kind of system and method for shaft furnace production DRI | |
| CN207130292U (en) | A kind of system of shaft furnace production DRI | |
| CN115820954A (en) | Blast furnace blowing CO 2 Biomass charcoal tempering co-production carbon emission reduction system and application process | |
| CN101307372A (en) | Device for manufacturing and reducing crust pellet and production process | |
| CN113881842B (en) | System and method for integrally producing metallized pellets by pellet roasting and reduction | |
| CN109652099A (en) | A kind of high temperature carbonization assembly of reduction furnace | |
| CN101665851A (en) | Three-step metal reducing method | |
| CN205023864U (en) | Coal gas heat supply multistage carbide reactor | |
| CN107419048A (en) | It is a kind of to use nuclear reaction system to produce the system and method for sponge iron technique heat supply | |
| CN202849353U (en) | Device for producing blau gas and carbon monoxide | |
| CN107058663A (en) | A kind of system and method for producing DRI | |
| CN208362269U (en) | Bottom ash treatment device for fluidized-bed gasification furnace | |
| CN207193202U (en) | The system that a kind of high temperature pyrolysis gas recycle | |
| CN205838931U (en) | A kind of preparation system of gas-based shaft kiln reducing gases |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |