Part re-bricking using fused silica modules
Where the damage to the coke oven walls is already so severe that there are holes in the wall, brick-shaped modules made from fused silica grain are utilised. These are fixed in place by Ceramic Welding which is also used to fill any remaining gaps. The fused silica material will not display the thermal expansion seen with fired silica brick which is why there are no heat-up problems and why they are known in the coke-making industry as zero expansion bricks.

UDM Technology
These zero expansion characteristics combined with Ceramic Welding and a shape design replicating the original silica brick shapes of a coke oven heating flue, including the end flue, proved the principle for the Beroa NovoCOS UDM technology.

Sometimes the first flues of coke ovens are so severely damaged that Ceramic Welding repairs would technically not be possible, or would no longer be economical. Usually the decision is taken to have a re-bricking campaign. This utilises fired silica bricks matching the original design. After complete removal of the existing flues, the damaged flues are totally rebuilt and slowly heated up to avoid cracking due to expansion of the bricks.

Beroa NovoCOS UDM technology provides an interesting alternative. Based on the original design of the flues and the layers of bricks, a new modular brick design using a significantly lower total number of shapes is engineered by us. These bricks are manufactured in fused-silica. They are installed, using a minimal amount of very fine mortar not visible from the coke oven walls. The modules are designed so that all vertical and horizontal joints are closed by Ceramic Welding.

This Ceramic Welding operation is performed after the bricks have been heated up to working temperature usually within 12 to 20 hours. Once this is completed the oven can immediately go back into production.

UDM offers substantial savings in production losses due to the very fast turnaround from pushing the oven a last time to the next post-repair recharging with coal. In view of the world market prices for coke these savings bring significant benefits to the coke oven operator.