DOMESTIC EXPERIENCE OF PRODUCING BLOW UNITS
FOR NON-FURNACE STEEL TREATMENT
S. I. Kazakov,
A. M. Chuklai,
O. I. Frolov,
and V. Ya. Gushchin
Translated from Novye Ogneupory,No.12,pp.3–6,December, 2006.
Original article submitted April 12, 2006.
The Terg-K Research-and-production company has developed blow units with ring contours and vertical slot
channels, as well as a method for fastening the blow unit in a pocket block. Testing of the prototype blow units
at the Magnitogorsk Metallurgical Works (MMW) have made it possible to estimate the specifics of the wear
of domestic blow units compared to imported units and the reliability of the proposed blow lance designs.
The testing has proved the possibility of steady operation of domestic slot-shaped blow units during 50 and
more blowdown campaigns
The study of the advanced practice of blow units used for
blowing down molted metal in ladles at domestic metallur-
gical works has shown that blow units with non-directed
open porosity are not common in practice, as increased po-
rosity is responsible for intense wear of the blow units (its re-
sistance is 10 – 20 heats) and infiltration of steel. The gene-
ral trend is changing over to blow units with oriented open
porosity, which have a longer service life. Due to the unsatis-
factory resistance of the domestic blow units, most metallur-
gical works currently use imported units whose resistance
reaches 50 heats .
Most lances with directed open porosity constitute chan
nel-shaped or slot-shaped blow units made of low-cement
mixtures using tabular alumina, which is not produced in
Russia. Gas conduits are shaped as point-like cylindrical
holes of diameters 0.2 – 0.5 mm or as narrow slots of size
0.1 – 0.4 mm and up to 20 mm wide arranged radially along
a circumference, as well as thin slots of size up to 0.4 mm
aranged perpendicular to the circumference. The blow unit
channels may be formed by melting an organic or mineral
material or by extruding metal strips (bands) from a concrete
mixture after its solidification.
As published sources do not contain data on the advan
tages of a particular geometry of directed gas-conducting
channels in blow units, manufacturers in selecting a blow
unit design are guided by the following criteria: simplicity of
manufacture, minimizing thermomechanical stresses in the
unit during its operation; ensuring the element performance
under a relatively high gas flow rate; preventing the penetra-
tion of metal into the gas channels, which may affect the per-
meability of the plug or totally block it; ensuring steady per-
formance for the whose service period.
To make blow units consistent with the contemporary re-
quirements, it is necessary to solve several problems related
to refining the blow unit design. The most promising direc-
tions include the development of blow units with plugs
which have directed (oriented) open porosity, which ensures
technologically justified permeability for the inert gas, and
designing a pocket block integrated in a single structural ele
ment with the blow unit .
The Terg-K Research-and-Production company since
2000 has been working on blow lances with a pocket block
and on refractory materials for making slot blow units.
Taking into account the experience of domestic and foreign
analogs, the company has developed rational blow units with
one or two circular contours of slot channels in the lance and
the blow units with slot channels .
The blow unit with a circular contour of slot channels in
cludes a truncated inner solid cone, on which outer truncated
hollow cones are placed, which comprises the working part
of the lance. At the base, the working part of the blow unit is
coupled with a porous safety insert. The blow unit is faced
with metal casing and a metal flange with a gas-conducting
tube is welded to the base. The channels in the lance are
formed due to the embossed inner surface of the outer hollow
cones conjugated to each other and to the truncated solid
cone (Fig. 1). However, in assembling the working part of
Refractories and Industrial Ceramics Vol. 47, No. 6, 2006
1083-4877/06/4706-0337 © 2006 Springer Science+Business Media, Inc.
* Report of the Faich-Radex company at the seminar at the Metallurg
prom, Moscow, on February 25 – 26, 1997.
Magnitogorsk Metallurgical Works, Terg-K Research-and-Pro
duction Company, Russia.