METHODS AND LIMITS FOR IMPROVING THE ENERGY EFFICIENCY
OF MODULAR-POURING ELECTRIC FURNACES FOR FIRING
VERMICULITE. TRANSITIONING TO A NEW CONCEPT
A. I. Nizhegorodov
Translated from Novye Ogneupory, No. 12, pp. 13 – 18, December, 2016.
Original article submitted April 28, 2016.
Methods of making modular-pouring electric furnaces that are used to fire vermiculite more energy-efficient
and reliable are analyzed. Limits on improving these furnaces and the reasons for those limits are identified,
and the main principles behind the concept of a new generation of furnaces — electric furnaces with a vibrat
ing hearth platform — are elaborated.
Keywords: modular-pouring electric furnace, vermiculite concentrate, non-electrified “base” module, “la
tent” exergy of vermiculite, electric furnace with a vibrating hearth platform.
Foamed vermiculite is a raw material that is much in de-
mand for making refractories, materials resistant to fire and
heat, and thermal insulation [1 – 3]. However, producing
foamed vermiculite is an energy-intensive process. Nonethe-
less, the amount of energy consumed in this endeavor has
been reduced significantly with the advent of modular-pour-
ing electric furnaces [4 – 6].
The objectives of the project whose main aspects are the
subject of this article were to analyze ways of improving the
energy efficiency of these furnaces, determine the limits for
improving them, and formulate the main criteria for a new
energy-engineering approach to their design that will be free
of the aforementioned deficiencies and constraints.
The first modular-pouring electric furnaces for firing
vermiculite were built during the period 2003 – 2008 in
Irkutsk at the company “Kvalitet.” These furnaces were quite
large, as were the working refractories used for the surface of
the firing modules (with a length of 0.91 – 0.92 m and a
width of 0.92 – 0.126 m). As a result, accelerated movement
of the expanding vermiculite granules in the lower parts of
the modules sharply reduced the granules’ concentration.
This caused less of the heat from the surfaces of the electric
heaters to reach the granules and more of it to be dissipated
in the planar open firing space. The unit energy content of
the firing process in the second experimental furnace that
was used (shown in Fig. 1) averaged 250.1 mJ/m
ent fractions of vermiculite concentrate [4, 5].
The low energy efficiency of the furnaces necessitated
structural-design changes: a six-module furnace with short
modules having a length of 0.297 m was developed. This fur-
nace somewhat increased the concentration of the material
Refractories and Industrial Ceramics Vol. 57, No. 6, March, 2017
1083-4877/17/05706-0585 © 2017 Springer Science+Business Media New York
Irkutsk National Research Technical University (IRNITU), Ir
Fig. 1. Diagram of a three-module furnace (a) and a second proto
type furnace (b ) developed by the OOO “Kvalitet” (Irkutsk, 2005).