Large Particle Ash Screen

Large Particle Ash (LPA), also known as popcorn ash, is formed in the boiler. The high velocities of the flue gas carry the LPA into the SCR reactor, where the rock-like particles can become lodged in the catalyst layers, causing erosion damage and decreased NOx removal performance.


In use since 1996, the patented LPA screens reliably stop those rocks in their tracks, using a unique pleated and hinged design. The pleats and use of hardened materials give the screen a high inherent strength, and minimize both erosion and pressure drop by reducing the force of ash particles as they impact the screen. CORMETECH's screens are typically installed at the boiler's economizer outlet, allowing them to use the economizer hopper for continual LPA removal.


To keep the screen itself clear of any LPA, the fully automated hinged design periodically raps the entire piece of equipment, shaking loose lodged LPA (typically 1-3 times per day). As a result, your SCR equipment lasts longer and removes NOx more efficiently. CORMETECH also incorporates CFD modeling into LPA screen design. This results in an integrated solution that takes into account overall conditions throughout the reactor. For more information about CORMETECH's CFD modeling service