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Production of steel in oxygen converters.
Still two processes of melting of steel in converters were quite recently
applied: bessemerovskiya and tomasovskiya. Despite some distinctions in
designs of converters and processes, the essence of these ways of receiving steel
was the same and was that through liquid cast iron air there was an oxidation of
impurity was blown. Now these two ways (bessemerovskiya and tomasovskiya)
aren't applied, as are replaced in more progressive way - melting became in
oxygen converters.
Oxygen steel-making process consists in a purge of liquid cast iron in the
converter with the main line up by oxygen from above through water cooled
lance, lowered through a mouth. Now in oxygen converters make about 30 % of
all melted steel.
Application for blasting of pure oxygen allows to receive in oxygen converters
steel with the content of nitrogen no more, than in martin steel, and
approximately the same quality.
Oxygen steel-making process allows to apply high-capacity converters. Now
converters in capacity 300 t. already work.
When melting steel in the oxygen converter apply liquid cast iron, scrap
material, iron ore, a lime, fluorspar, rolling scale as initial materials.
Production of steel in martin furnaces.
Heat transfer to metal in these furnaces occurs generally emission (about 90 %
from all transferred heat) and only 5-10 % convection. The majority of high-
capacity furnaces now heat natural gas with a fuel oil additive.
These furnaces have regenerators which serve for heating of air and gas that
allows to increase torch temperature to 1800?С.
The capacity of martin furnaces reaches 900т. About 60 % of all steel are
melted in martin furnaces.
The working melting space of the furnace from above is limited to the arch,
from below - bottom, from the lateral parties - a lobby and back walls and from
end faces - "heads". Bottom has a form of an oblong bowl (bath) extending up.
Burden materials load on bottom through charging windows in a forward wall of
the furnace. In the lower part of a back wall there are openings for production of
slag and the ready steel, closed up by a fire-resistant stopper which at release
punch. In the heads symmetrical from both parties of the furnace, there are
channels through which gas and air arrive and burning products are removed. In
the lower part of a head incorporate to the regenerators intended for heating of
gas and air. During the moment when in the left head there is a fuel mixing to air
and receipt of products of burning in melting space, through the right head and
channels adjoining it from the furnace the products of the burning which have
been heated up to 1500-1600zs are removed. Flue gases after cleaning of firm
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