REFRATHERM® Eco: High-end insulation for the tunnel kiln car Biogenic silica (SiO2) is produced through the burning of biomass, the ashes of which mostly contain SiO2. REFRATHERM® Eco is thus based on a naturally renewable resource. Production The term biogenic silica shows the origin of the product. In modern biomass power plants, subject to quality controls, these raw materials are used as an energy source because they burn CO2 neutrally.
That is, when burned, no more CO2 is released than the plant had previously absorbed from the atmosphere. An aspect which is becoming increasingly important for the raw materials of the future. Characteristics Biogenic silica is chemically very pure and consists of 94-96% SiO2. The main phases after a special burning process are amorphous silica, tridymite and cristobalite.
Thermal conductivity in W/m·K
Innovation
0.6 0.5 0.4 0.3 0.2 0.1 0
250
REFRATHERM® Eco
600 800 Temperature °C
1000
BUROLIT® 230
BUROLIT® G
Comparison of insulation effect This causes the high melting point of approx. 1650 °C. In production, the volatiles burn but the microporous structure of the SiO2 is maintained. This structure results in both the extremely low thermal conductivity as well as the low bulk weight. REFRATHERM® Eco based on microporous silica shows a unique combination of well-defined characteristics such as high insulation, good flow properties, set grain structure. This allows for very low installation heights and thus more usable firing capacity for the brick manufacturer. The installation time of the insulating layer in the tunnel kiln car can be reduced by about 50% depending on the flow properties set.
Tunnel kiln car with REFRATHERM® Eco insulation
Typical characteristics • Sintering point: 1550 °C • Melting point: 1650 °C • High microporosity and thus excellent insulation • Perfectly optimised flow properties • Low density • Extreme low thermal conductivity
BURCOLIGHT® – Energy saving by weight reduction Kiln car systems equipped with BURCOLIGHT® bricks achieve energy saving by means of weight reduction. The less mass needs to be heated up, the more energy is saved. When used for kiln cars, BURCOLIGHT® brick types with a bulk density of ~1.3 to 1.5 kg/dm3 achieve energy savings up to 30% compared with BURCOTOP® brick types (depending on kiln car type and tunnel kiln temperature). Thanks to these outstanding properties, the total energy savings of the kiln are between 8 and 12%. BURCOLIGHT® features low mass, excellent thermal shock resistance and low thermal conductivity.
Refratechnik Ceramcis GmbH Barkhausener Str. 55 - 49328 Melle - Germany - Phone +49 5427 81 0 - ceramics@refra.com - www.refra.com