A METHOD FOR REPAIRING TUNNEL FURNACE CARS
I. V. Tropinova
and A. M. Tropinov
Translated from Novye Ogneupory, No. 5, pp. 15 – 19, May, 2007.
Original article submitted March 20, 2007.
The NPF Alineka company has developed refractory construction concretes BRSB20I11 based on water glass
and concretes BRAB50I13 and BRAB50I15 with the traditional content of aluminate cement, which have a
high class of thermal resistance (T
80) and the maximum application temperature of 1100 – 1500°C, as
well as heat-insulating lightweight plates of size 300 ´ 200 ´ 80 mm and density 400 kg/m
, with a maximum
application temperature of 1150°C. These materials can be used as lining of tunnel furnace cars for firing wall
ceramics, as well as porcelain and faience products. The experience in repairing a furnace car is described.
Taking into account the low level of power resources in
Ukraine (not more than 10% ), a priority in Ukrainian eco-
nomics is the implementation of power-saving technologies
. A tunnel furnace car in the wall ceramic production in
Ukraine is typically lined with small-size chamotte refrac-
tory ShA-5 fastened by refractory mortar. The refractory
ShA-5 is placed along the car perimeter, and on the outer
side it is fastened by a metal angle or band (Fig. 1). The mid-
dle of the car is usually filled with broken brick, which pre-
vents getting a smooth surface in the bottom layer of the
fired product. This lining of the car is inexpensive and easy
to make but has a number of disadvantages, which increase
power consumption in ceramics production. First, such lin
ing has numerous joints, which decreases its total service life
and, combined with cyclic heating (up to 1000°C) and cool
ing (20°C), leads to its destruction due to the deformation of
metal that squeezes the mortar from the brickwork; collisions
between the cars accelerate the destruction process. As a
consequence, after 5 – 10 thermal cycles the lining and the
metal structure of the car require routine repair using
power-consuming materials: refractories, marl, and metal.
Second, the use of chamotte materials causes large clear
ances between the car lining and the furnace lining – at least
100 mm (Fig. 2); consequently, heat losses in firing grow.
Furthermore, such materials are not suitable for making lat
eral heat locks between the cars, which also increases the
heat losses and accelerates the deformation of the metal
structure of the car. Third, the absence of a heat-insulating
layer covering the middle of the car also increases heat
losses, which is corroborated by the high temperature in the
hearth channel (as a rule, > 120°C) ; furthermore, the car hub
bearings frequently wear and their repair raises the total cost
of ceramic production. Thus, design solutions for lining
should provide for a minimal number of joints between the
elements and prevent ceramic crumbs from penetrating into
the lining joints.
The use of a chamotte refractory as a lining material that
withstands 8 – 10 thermal cycles does not ensure a long ser-
vice life. The lining experiences one thermal cycle per
24 – 48 h: heating to 1000°C, exposure at this temperature
(4 – 8 h), and cooling to the ambient temperature. Conse-
quently, the heat resistance of lining material is one of the
critical factors in the energy and economic efficiency of pro
duction technology. Furthermore, the lining material should
have high grade strength and residual strength, and should be
used without predrying and withstand high temperatures
without perceptible destruction. Another essential factor is
the applicability of lining materials for producing complex-
geometry lining, simplicity and technological suitability, and
Refractories and Industrial Ceramics Vol. 48, No. 2, 2007
1083-4877/07/4802-00083 © 2007 Springer Science+Business Media, Inc.
NPF Alineka company, Ukraine.
Fig. 1. Metal structure of a furnace car after 30 thermal cycles re
quiring capital repair.