In contrast to fossil fuel power stations, pellet power stations are CO2 neutral, and are becoming increasingly important. If dry wood is used, the energy required to make the wooden pellets is only about 2.7 % of their total energy value. Wood pellets are in most cases manufactured close to the source in forested areas. First, wood scrap or logs are chopped. The chopped material is pressed, under high pressure, in a pelleting press through a steel grille containing holes to create the desired pellet diameter. As it emerges from the grille, the strand is cut by a scraping knife to form pellets in the desired length. In this application, the pressure required to make the pellets is generated by a three-stage steam turbine. For reasons of cost, the first two stages of the steam turbine are sealed by labyrinth seals. For the third stage, the additional length of shaft would become too large to use a labyrinth. The seal needed here had to be compact and short. It had to provide facilities for removing steam and leaking condensate, and had to withstand both high pressures and high temperatures while requiring minimal servicing.

Solution from EagleBurgmann Espey:

To meet the needs of the operator, Espey chose the compact, short Espey WKA400 chamber seal with steam and condensate leakage removal facilities and 8 seal rings for a temperature of up to 500 °C (932 °F), a pressure of 23 bar (333.59 PSI), and rotation speeds of up to 8200 rpm. The segmentation of the seal rings means that they are easier to change if repair is needed. The seal solution has a long service life, is maintenance-free, and is designed for dry running.

Contact our experts

for more information

Show locations
Newsletter

Excellence in Practice

With our free e-mail newsletter „Excellence in Practice“, you will receive first-hand information about current products, services, references and worthwhile industry insights.