Things can get hot in rotary kilns – very hot, in fact. For example, when it comes to manufacturing cement, the mercury often rises above 1,000 degrees Celsius. Despite these “volcanic” conditions, sealing systems from EagleBurgmann, a Freudenberg Group company, make lasting contributions to environmental protection, energy efficiency and process safety.
“If you want to picture what a rotary kiln looks like, imagine a large horizontal tube that slowly rotates,” says Bernd Hoeflein, Senior Sales Director for Packings and Gaskets at EagleBurgmann. The kilns’ diameters range from half a meter to more than eight meters. “Our job is to seal the two ends of the tube,” he explains. This mostly involves the reliable separation of scorching hot process gases from the cool outside air. On the one hand, the toxic gases generated by processes at work in the kiln’s core cannot be allowed to escape into the atmosphere, polluting the environment. On the other, no outside air can be allowed to penetrate the system; this would disrupt the process and require additional primary energy to heat the cold outside air that was inadvertently introduced.