Blast boiler is a affiliated assemblage of shaft-type. The charging of accountability is conducted from above, through the archetypal charging unit, which is the gas damper of the bang furnace. It is bargain affluent adamant ore (at present time assets of affluent adamant ore are preserved alone in Australia and Brazil), sinter or pellets in the bang furnace. Sometimes diminutive pellets are acclimated instead of awkward ore.
Blast boiler consists of bristles effective elements: top annular allotment is top throat, that is all-important for the charging and administration of accountability in furnace; the accomplished splayed cone-shaped allotment is shaft, area the heating action of abstracts and the abbreviation of adamant from oxides pass; the widest annular allotment is belly, in which the action of abatement and melting of the bargain adamant passes; cone-shaped cone-shaped allotment is bosh, area a abbreviation gas – carbon monoxide is generated, the annular allotment is hearth, that is acclimated to accrue aqueous articles of bang boiler adjustment – casting adamant and slag.
And the top aspect is tuyere zone, area is the bang of accumulated bang into the furnace, and the lower aspect is blast-furnace bottom. There are tuyeres on the top of address – holes for bartering of acrimonious to aerial temperature blast. Bang is aeroembolism air, accomplished with oxygen and hydrocarbon fuel. At the akin of the tuyeres temperature rises to about 2000 ° C. As the ambit advancement the temperature drops, and it alcove 270 ° C in the top throat. Thus, altered temperatures are set at altered heights in the furnace, because of that altered actinic processes of alteration of ore into metal proceed. pic] Bang boiler in Sestao, Spain. Coke burns off and generates carbon dioxide and ample bulk of calefaction at the top allotment of hearth, area oxygen accumulation is big enough. [pic][pic][pic][pic][pic] Carbon dioxide, abrogation accomplished oxygen zone, reacts with the coke and generates carbon monoxide is the capital bang boiler adjustment abbreviation agent. [pic][pic][pic] Rising upward, carbon monoxide reacts with adamant oxides, demography oxygen and abbreviation to beneath breakable oxide: [pic][pic][pic][pic][pic][pic]
Resulting from the reaction, the aqueous metal drips the hot atramentous down, acceptable saturated with carbon, and after-effects in alloy, that contains 2. 14 - 6. 67% of carbon. This admixture is alleged casting iron. Except carbon, it includes a baby allotment of silicon and manganese. In the cardinal of deciles of a percent sulfur and phosphorus, adverse impurities, are included in the casting adamant composition. Except casting iron, in the address charcoal is generated and accumulated, in which all adverse algae gather. Earlier charcoal was broke through a charcoal notch.
Now both adamant and charcoal are broke through the adamant cleft at the aforementioned time, so the acquaintance of casting adamant and charcoal increases while bond and the allotment of sulfur casting adamant transits in slag. Separation of casting adamant and charcoal passes already above the bang boiler - in a runner, with the advice of the bowl aboideau of skimmer adjustment because of altered melting aqueous densities. Separated from the slag, casting adamant gain into hot metal ladles, or into mixer ladles. Charcoal is caked into charcoal pots through charcoal runners. Blast-furnace foundation
Modern boiler calm with all constructions and metal structures, lining (brickwork) and accountability banal and melting articles can accept a accumulation of added than 30 thousand tons. This accumulation should be analogously transferred to the ground. The lower allotment of the foundation (sole) is fabricated in the anatomy of a massive accurate slab with array of 4 m. Columns angular on the sole, boiler metal structures (shell). The high allotment of the foundation (pie) is a caked butt of adverse compression, on which is the boiler hearth. Blast-furnace hearth
Blast-furnace address is the lower allotment of bang furnace, it is annular central and cone-shaped (sometimes cylindrical) due to the alien form. Address has casting adamant and charcoal aperture assemblies (iron and charcoal notches) and assemblies (tuyeres) for alarming broiled up (at cowper stove) to 1100-1400 ° C, oxygen accomplished to 23-25?? % air. Address bang boiler is the best capital allotment of its construction. It collects up to 1,000 bags and added aqueous admixture articles – casting adamant and slag. The accountability column, with the accumulation of 9-12 tons, presses the basal of the furnace.
The burden of address gases is 0. 4-0. 5 MPa, and their temperature alcove 1700-2100 ° C in the coke agitation sources. Coke, aqueous casting adamant and charcoal address gases move and are adequate continuously aural the hearth. In actuality it is a powerful, continuously affective reactor. In this regard, austere requirements for strength, binding and blaze attrition are accepted to these constructions. The capital constructional elements of the address are shell, coolers, adamant and charcoal notch, tuyere assemblies. Adamant cleft Adamant cleft is a ellipsoidal channel, 250-300 mm ample and 450-500 mm tall.
The approach is fabricated in address brickwork at the acme of 600-1700 mm from the apparent of the blast-furnace bottom. Charcoal cleft channels are fabricated at the acme of 2000-3600 mm. The adamant cleft is bankrupt by adverse mixture. The adamant cleft is opened via conduct out the aperture of 50-60 mm bore with conduct machine. After borer of casting adamant and charcoal (the borer of casting adamant and charcoal is agitated out through adamant notches on ample avant-garde bang furnaces), holes are blocked with the advice of an electron-beam gun.
The electro-beam gun tip gets in and adverse admixture of the cleft is supplied beneath pressure. The bang boiler snag cleft is adequate by water-cooled elements, which are alleged charcoal admiration and compressed-air operated lever-type construction, controlled distantly. Ample aggregate bang furnaces (3200-5500 m ? ) are able with four adamant notches, alive by terms, and one charcoal notch. The borer of casting adamant and charcoal from the bang boiler includes the following: 1. aperture of the adamant cleft (if all-important in the charcoal notch); 2. aintenance, anon affiliated with arising of casting adamant and slag; 3. closing of the adamant cleft (if charcoal was broke through the charcoal notch, again closing of charcoal too); 4. notches and runners repair. [pic] 1. Hot bang 2. Melting area (bosh and hearth) 3. Reduction area of adamant oxide (belly) 4. Reduction area of adamant oxide (shaft) 5. Pre-heating area (top throat) 6. Feed of ore, limestone and coke 7. Exhaust gases 8. Cavalcade of ore, coke and limestone 9. Removal of charcoal 10. Borer of aqueous pig adamant 11. Collection of decay gases
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