Blast Furnace Gas Dust Collector

A blast furnace gas dust collector is a core integrated purification system dedicated to treating high-temperature,high-pressure,dust-laden blast furnace exhaust gas in iron and steel metallurgical production.It removes iron oxide dust,fine particulate impurities,and harmful solid particles from raw blast furnace gas,realizes high-purity gas purification,guarantees safe operation of downstream power generation and pipeline equipment,recovers valuable iron powder resources,and meets strict industrial emission environmental protection standards.

Working Background&Gas Characteristics

Raw blast furnace gas exhausted from blast furnace ironmaking carries massive suspended solid dust,with complex working conditions distinct from ordinary industrial flue gas:

High initial dust concentration:10–30 g/m³of iron oxide dust,fine particle proportion is large

Medium-high temperature:normal exhaust temperature at furnace top ranges 150–250℃

High pressure:top gas pressure reaches 0.15–0.25 MPa,with continuous stable gas output

Flammable&explosive properties:BFG contains CO,hydrogen and combustible components,requiring strict sealing,anti-explosion and safety control throughout the dust removal system

Corrosive medium:contains trace acidic gases,requiring corrosion-resistant material matching

Main System Types&Working Principles

At present,industrial mainstream processes are divided into dry dedusting and wet dedusting two technical routes,with multi-stage combined purification as the standard configuration.

1.Wet Dust Collection System(Traditional Process)

Adopts multi-stage water washing and scrubbing purification.

Process flow:Raw BFG→Gravity dust catcher→Cyclone pre-dedusting→Venturi scrubber→Dehydration demister→Clean gas delivery

Principle:Uses water spray,impact and mass transfer to wash and capture dust particles in gas;dust is carried away by sewage,and clean gas is output after dehydration.

Features:Mature technology,stable operation,low initial investment;large water consumption,serious sewage discharge,low gas calorific value after humidity increase,high subsequent energy consumption,and low recovered dust utilization value.

2.Dry Baghouse Dust Collection System(Current Mainstream Advanced Technology)

Most widely promoted modern BFG purification solution,also named pulse-jet dry bag filter system for blast furnace gas.

Process flow:Raw blast furnace gas→Gravity coarse dust removal→Cyclone pre-separation→Multi-chamber pulse baghouse filter→Purified high-quality gas→Downstream TRT power generation&pipeline supply

Principle:High-temperature resistant filter bags intercept fine dust in high-pressure gas;a thin initial dust layer formed on bag surface undertakes main fine filtration.Compressed air pulse back-blowing automatically cleans accumulated dust regularly to maintain stable filtration resistance.Collected iron-rich dust is recycled to sintering process for iron resource reuse.

Special filter material selection:Adopts PTFE,high-temperature resistant glass fiber composite filter bags,resistant to high temperature,pressure,corrosion and CO atmosphere,adapting to harsh BFG working conditions.

3.Dry Electrostatic Precipitator(ESP)

Uses high-voltage electric field ionization to charge dust particles,which are adsorbed on polar plates and removed by mechanical rapping ash cleaning.Suitable for large-capacity large-scale blast furnace projects,with ultra-low emission performance.

Core System Components

Preliminary Pre-dedusting Unit

Gravity dust catcher and multi-stage cyclone separator,primarily remove large coarse iron oxide particles above 10μm,greatly reducing dust load of subsequent main filter equipment,alleviating filter material abrasion and blockage risk.

Main Dust Removal Host

Multi-compartment split structure baghouse body,high-temperature pressure-bearing shell,special filter bag assembly,cage framework,high-pressure pulse cleaning valve group,compressed air supply station.

Ash Handling System

Ash hopper,screw conveyor,air slide conveying device,ash storage bin,realizing sealed collection,transportation and recycling of recovered iron powder dust.

Pressure&Safety Control System

Top pressure stabilizing device,anti-explosion relief valve,temperature monitoring,CO concentration interlock protection,static grounding system,automatic differential pressure monitoring and interlock control,preventing gas leakage,combustion and explosion accidents.

Induced Draft&Gas Conveying Pipeline

High-pressure resistant induced draft fan,heat-insulating anti-corrosion gas pipelines,ensuring stable negative pressure suction and closed transmission of whole-process gas.

Technical Performance Advantages

Ultra-high purification efficiency:Overall dust removal efficiency exceeds 90%,outlet dust concentration stably controlled below 5 mg/m³,achieving ultra-low emission standard.

Energy&resource saving:No massive water consumption and sewage discharge compared with wet process;purified dry BFG maintains high calorific value,efficiently matching TRT top pressure power generation to recycle gas energy;recovered high-quality iron oxide dust is fully recycled to smelting production,reducing raw material consumption.

Stable pressure resistance:Adapts to continuous high-pressure fluctuation of blast furnace top gas,with stable system operation and small resistance fluctuation.

Excellent safety performance:Fully enclosed negative pressure operation,complete anti-explosion,anti-leakage and gas monitoring interlock,eliminating CO leakage safety hazards.

Low long-term operation cost:Less auxiliary consumption,convenient maintenance,long service life of filter media,prominent comprehensive economic benefit.

Typical Process Flow

Raw Blast Furnace Gas→Gravity Coarse Dust Removal→Cyclone Pre-separation→Main Dry Baghouse Filtration Purification→Pulse Ash Cleaning&Dust Recycling→Purified Clean Gas(to TRT Power Generation/Industrial Gas Supply)

Industrial Application Scope

Exclusively applied to blast furnace ironmaking workshops in large and medium iron and steel enterprises,supporting whole-process purification of blast furnace coal gas,matching with gas power generation,industrial heating,pipeline gas supply systems,and being a core environmental protection and energy-saving essential equipment for modern iron and steel metallurgical industry.