INERT GAS BLOWING UNITS FOR USE IN STEEL LADLES:
AN EXPERTISE FROM THE DINUR JOINT-STOCK Co.
A. G. Donich,
R. A. Donich,
A. M. Gorokhovskii,
and L. A. Karpets
Translated from Novye Ogneupory, No. 5, pp.3–5,May,2004.
Development, fabrication, testing, and service under industrial conditions of blowing tuyeres and blowing
units commercially available from the DINUR Joint-Stock Co. are described. The high performance charac
teristics of the newly-developed facilities, not inferior to those of the world’s best analogs, are emphasized.
At present, therequirements placed by international stan
dards on the quality characteristics of commercial metals
have become increasingly more stringent. To meet this chal-
lenge, metallurgists have developed advanced and innovative
technologies for steel treatment such as the extra-furnace
processing and continuous metal casing. The extra-furnace
steel processing is effected in a steel ladle using an argon-ox-
ygen treatment or vacuum degassing techniques; this method
makes it possible to remove oxygen and hydrogen from mol-
ten metal, to minimize the amount of nonmetallic inclusions,
to control the molten metal temperature, and to provide a
uniform distribution of alloying additives.
Currently, two types of blowing tuyeres are used depend
ing on technological requirements:
– porous-outlet tuyeres — for production of high-purity
stainless steels. Shortcomings of tuyeres of this type: they are
unsuitable for injecting powdery reagents and have rather
short service life;
– tuyeres with directional channeled porosity (slit
tuyeres); these are made of a hard material and have a special
outlet geometry for gas passage. These tuyeres exhibit high
wear resistance, long service life, and good blowing effi
ciency; they are also used as a means of controlling (averag
ing out) the temperature and homogenizing the composition
of the molten bulk.
Choice of the type of tuyere is determined by the require
ments of technology. The tuyere (more specifically, the mate
rial it is made of) must be resistant to high temperature and
high temperature gradient, chemical corrosion, mechanical
and dynamic loads, and to oxygen attack during repair or
cleaning period. At present, steel manufacturers give prefe
rence to the latter type owing to its versatility, higher reliabi
lity, and longer service life.
In recent years, tuyere units for inert gas blowing of mol
ten metal in a steel ladle were developed at the Dinur JSC.
Currently, blowing tuyeres (Fig. 1) and assembled blowing
units (Fig. 2) are available from the Dinur JSC. The blowing
unit consists of a blowing tuyere 1 embedded in a block 2 us-
ing a chromium aluminophosphate mortar.
The main components of the blowing tuyere (Fig. 1) are:
ceramic 1 with gas inlet channels 0.15 – 0.2 mm in diameter;
wear rate indicator 2; sleeve 3 of high-temperature stainless
steel with a wall thickness of 0.8 mm; a metal adapter lid
8 mm thick; remover 4 for interchangeable tuyeres; metal
gas inlet tube 5, and load-lifting loop 6.
Refractories and Industrial Ceramics Vol. 45, No. 4, 2004
1083-4877/04/4504-0232 © 2004 Springer Science+Business Media, Inc.
DINUR Joint-Stock Co., Pervouralsk, Sverdlovsk Region, Russia.
Fig. 1. Bottom-blowing tuyere
(for notations, see text).