System and method for fluidized reduction of iron ore powder

Patent metadata

Field	Value
Publication number	US-10202662-B2
Application number	US-201415109399-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Dec 31, 2013
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A system and method for fluidized reduction of iron ore powder. Use of oxidation increases the iron ore reduction rate. Use of high-gas-velocity processing accelerates iron ore reduction speed and greatly improves the gas-treatment capabilities of a unit-cross-sectional fluidized bed. Use of parallel-connections involving reduced coal gas lessens the volume of gas passing through a single-stage fluidized bed. The invention achieves the highly-effective reduction of iron ore powder in a fluidized bed under near-atmospheric pressure.

First claim

What is claimed is:

1. A system for fluidized mineral powder reduction, comprising: an iron ore powder bin, a screw feeder, an oxidizing fluidized bed, a primary feeder, a primary circulating fluidized bed, a secondary feeder, a secondary circulating fluidized bed, a tertiary feeder, a tertiary circulating fluidized bed, a discharger, a product bin, a burning chamber, a primary coal gas preheater, a secondary coal gas preheater, a tertiary coal gas preheater, a cyclone dust collector, a bag dust collector, an induced draft fan, and a chimney;
wherein the oxidizing fluidized bed comprises an oxidizing fluidized bed body, a first cyclone separator, a second cyclone separator, and a feeder;
the primary circulating fluidized bed comprises a primary riser, a third cyclone separator, a fourth cyclone separator and a primary circulating dipleg;
the secondary circulating fluidized bed comprises a secondary riser, a fifth cyclone separator, a sixth cyclone separator and a secondary circulating dipleg;
the tertiary circulating fluidized bed comprises a tertiary riser, a seventh cyclone separator, an eighth cyclone separator and a tertiary circulating dipleg;
a gas outlet of the first cyclone separator is connected to an inlet of the second cyclone separator by a pipeline, a feed outlet of the iron ore powder bin is connected to a feed inlet of the screw feeder, and a feed outlet of the screw feeder is connected to the pipeline connecting the gas outlet of the first cyclone separator and the inlet of the second cyclone separator;
an inlet of the first cyclone separator is connected to a feed outlet of the second cyclone separator, a feed outlet of the cyclone dust collector, a feed outlet of the bag dust collector and a gas outlet of the oxidizing fluidized bed body through respective pipelines, a feed outlet of the first cyclone separator is connected to a feed inlet of the feeder;
a gas inlet of the feeder is connected to an air main pipe, and a feed outlet of the feeder is connected to a feed inlet of the oxidizing fluidized bed body through a pipeline;
a gas outlet of the second cyclone separator is connected to an inlet of the cyclone dust collector, a gas outlet of the cyclone dust collector is connected to a gas inlet of the bag dust collector, a gas outlet of the bag dust collector is connected to an inlet of the induced draft fan through a pipeline, and a gas outlet of the induced draft fan is connected to the chimney;
a gas inlet of the oxidizing fluidized bed body is connected to a gas outlet of the burning chamber through a pipeline, and a feed outlet of the oxidizing fluidized bed body is connected to a feed inlet of the primary feeder through a pipeline;
a gas inlet of the primary feeder is connected to a coal gas main pipe, and a feed outlet of the primary feeder is connected to a feed inlet of the primary riser through a pipeline;
a gas outlet of the primary riser is connected to an inlet of the third cyclone separator, a gas inlet of the primary riser is connected to a coal gas outlet of the primary coal gas preheater through a pipeline, and a circulating return port of the primary riser is connected to a return port of the primary circulating dipleg;
a gas outlet of the third cyclone separator is connected to an inlet of the fourth cyclone separator, and a discharge port of the third cyclone separator is connected to the primary circulating dipleg;
a discharge port of the primary circulating dipleg is connected to a lower feed inlet of the secondary riser, and a gas inlet of the primary circulating dipleg is connected to the coal gas main pipe;
a gas outlet of the fourth cyclone separator is connected to an inlet of the reduction exhaust gas treatment system, and a discharge port of the fourth cyclone separator is connected to a feed inlet of the secondary feeder through a pipeline;
a gas inlet of the secondary feeder is connected to the coal gas main pipe, and a feed outlet of the secondary feeder is connected to an upper feed inlet of the secondary riser through a pipeline;
a gas outlet of the secondary riser is connected to an inlet of the fifth cyclone separator, a gas inlet of the secondary riser is connected to a coal gas outlet of the secondary coal gas preheater through a pipeline, and a circulating return port of the secondary riser is connected to a return port of the secondary circulating dipleg;
a gas outlet of the fifth cyclone separator is connected to an inlet of the sixth cyclone separator, and a discharge port of the fifth cyclone separator is connected to the secondary circulating dipleg;
a discharge port of the secondary circulating dipleg is connected to a lower feed inlet of the tertiary riser, and a gas inlet of the secondary circulating dipleg is connected to the coal gas main pipe;
a gas outlet of the sixth cyclone separator is connected to an inlet of a reduction exhaust gas treatment system, and a discharge port of the sixth cyclone separator is connected to a feed inlet of the tertiary feeder through a pipeline;
a gas inlet of the tertiary feeder is connected to the coal gas main pipe, and a feed outlet of the tertiary feeder is connected to an upper feed inlet of the tertiary riser through a pipeline;
a gas outlet of the tertiary riser is connected to an inlet of the seventh cyclone separator, a gas inlet of the tertiary riser is connected to a coal gas outlet of the tertiary coal gas preheater through a pipeline, and a circulating return port of the tertiary riser is connected to a return port of the tertiary circulating dipleg;
a gas outlet of the seventh cyclone separator is connected to an inlet of the eighth cyclone separator, and a discharge port of the seventh cyclone separator is connected to the tertiary circulating dipleg;
a discharge port of the tertiary circulating dipleg is connected to the product bin through a pipeline, and a gas inlet of the tertiary circulating dipleg is connected to the coal gas main pipe;
a gas outlet of the eighth cyclone separator is connected to the inlet of the reduction exhaust gas treatment system, and a discharge port of the eighth cyclone separator is connected to a feed inlet of the discharger through a pipeline;
a gas inlet of the discharger is connected to the coal gas main pipe, and a feed outlet of the discharger is connected to the product bin through a pipeline;
a nozzle of the burning chamber is connected to the coal gas main pipe and air main pipe, and is capable of heating the air by burning a coal gas such that the heated air is connected to the gas inlet at the bottom of the oxidizing fluidized bed body through a pipeline;
a nozzle of any one of the primary coal gas preheater, the secondary coal gas preheater and the tertiary coal gas preheater is connected to the air main pipe and the coal gas main pipe through one or more pipelines arranged such that a high temperature flue gas is generated by burning the coal gas for preheating a reducing coal gas, a flue gas outlet of any one of the coal gas preheaters is connected to a flue gas main pipe arranged such that discharged flue gas enters into a flue gas treatment system via the flue gas main pipe for heat recovery, a coal gas inlet of any one of the coal gas preheaters is connected to the coal gas main pipe, and the coal gas outlet of any one of the coal gas preheaters is connected to the gas inlets at the bottom of the primary riser, the secondary riser and the tertiary riser, respectively.

2. The system for fluidized iron ore powder reduction according to claim 1 , wherein a bubbling fluidized bed is used as the oxidizing fluidized bed.

3. A method of reduction of fluidized iron ore powder in a system according to claim 1 , the method comprising: causing a powder and gas to enter into and pass through the system simultaneously in the following way: the iron ore powder enters into the bubbling fluid

Assignees

• Inst Of Process Engineering Chinese Academy Of Science
• Beijing Zhongkaihongde Tech Co Ltd
• Inst Process Eng Cas

Inventors

• Zhu Qingshan
• Fan Chuanlin
• Li Hongzhong
• Xie Zhaohui
• Mu Wenheng
• Wang Cunhu
• Jiao Xingang

Classifications

• F27B15/10

  Arrangements of air or gas supply devices · CPC title

• C21B13/0033 Primary

  In fluidised bed furnaces or apparatus containing a dispersion of the material · CPC title

• F27B15/12

  Arrangements of dust collectors · CPC title

• F27B15/003

  Cyclones or chain of cyclones · CPC title

• Y02P10/136

  Cross-Sectional Technologies · mapped topic