SMALL ELECTRIC FURNACES FOR PRODUCING
THERMAL INSULATING MATERIALS AND FERROUS ALLOYS
I. M. Bershitskii,
A. A. Skochilov,
N. P. Belyakova,
V. M. Korovina,
R. R. Avedin,
and S. B. Mirskii
Translated from Novye Ogneupory, No. 4, pp. 27 – 29, March, 2007.
Original article submitted November 13, 2006.
The design principles and the technical and working characteristics are presented for a series of ovens of ca
pacity 250 – 500 kVA, which are intended for producing basalt wool and ferrous alloys.
The constantly increasing prices for energy have caused
a rise in the demand for efficient refractory and thermal-insu-
lation materials, in particular ones based on basalt wool.
They are much better than insulating materials made of min-
eral wool and glass fiber, which do not meet current specifi-
cations for ecology, hygroscopicity, and working life.
The VOSTIO Company has developed a single-stage
high-throughput method of making staple basalt fiber by the
use of arc furnaces. Lines have been designed and built for
producing basalt fiber materials.
The apparatus for making these fibers is a continuous-
acting flow line and includes an arc furnace, together with
built-in facilities for producing the liquid as a water-cooled
substance, a fiber-forming space consisting of a diffuser, ho
rizontal chamber for fiber deposition with grid conveyor, and
units for cutting and reeling the material.
The Eloterm Company has used the VOSTIO Company
technical specifications in a series of ovens of capacity
250 – 500 kVA intended for the production of ultrathin basalt
An advantage of a small electric furnace for melting ba
salt raw material by comparison with large ones is due to the
1) the scope for electrical supply from a line at 380 V or
from a gas generator, which does not require high-power fur
nace substations, or the use of expensive furnace trans
formers with oil cooling and corresponding high-voltage
2) much less consumption of cooling water;
3) scope for placing the equipment in small areas in
buildings with relatively small clearance from overhead
4) lack of need for expensive high-power fans and
dust-trapping equipment, which are characteristic of organi-
zations that operate high-power furnaces of this type;
5) short shutdowns associated with stopping the work of
the furnace for current or emergency repair; and
6) smaller numbers of service staff.
This means that small electric furnaces are particularly
effective in regions with relatively poor energy supplies, and
at organizations that use heat-insulating and refractory mate-
rials for their own purposes, and also at small organizations
providing for the needs of local users. Table 1 gives the basic
technical characteristics of this furnace series.
The melting vessel in each of the furnaces is an inter
nally lined steel framework made of welded rectangular pa
nels. In an RPO-0.25 single-phase two-electrode furnace, the
melting vessel is rectangular in cross section, while in the
three-phase furnaces RPO-0.25I3 and RPO-0.5, it is hexa
gonal. At the outer surfaces of the side panels there are
water-cooling channels formed by standard channeling
welded to the panels.
There is a difference from the RPO-0.25 and RPO-0.25I2
batch furnaces in that the melting vessel in the RPZ-0.5 has a
water-cooled lid with sand cover, three electrode holes and a
loading tube for injecting charge materials into the working
space. Tapping points are fitted to remove the basalt liquid in
all these ovens.
The melting vessels in the RPO-0.25 and RPO-0.25I2
furnaces have pneumatic mechanisms for tilting in order to
periodically pour off the residual liquid on the side opposite
to the working tap.
Refractories and Industrial Ceramics Vol. 48, No. 1, 2007
1083-4877/07/4801-0046 © 2007 Springer Science+Business Media, Inc.
Eloterm Production Company Ltd (Russia), VOSTIO Company
(Russia), and Emerol Ltd (Ireland).