Most programs have been conducted along the NORMAL TRACK, with the CAVT performed during one outage and the controls installed during a later outage. Several sites have opted for the FAST TRACK approach, where controls are designed before the outage. The CAVT is done at the beginning of the outage with modifications made to the design if needed. Controls are then installed and a follow-up CAVT performed at the end of the outage to ensure adequacy of the controls. At one industrial site, controls were recommended without a supporting test because of an urgent need for erosion controls.
One utility recently requested a consultation to review the previously installed controls to upgrade to current standards, as improvements to the technology continue. Two sites have requested computer models as it was not possible to perform a standard CAVT. Simulations of the original backpass geometry were done to determine the cause of the erosion problem. Recommendations were made for correcting the problems, with simulations being run to determine their adequacy. This resulted in acceptable erosion control strategies for these units.
If you would like more details, or a utility to contact for reference purposes, see Contact Information for a number to call and make the request.RELEVANT EXPERIENCE
Utilities and industrial power plants across the United States, Canada and overseas have participated in various aspects of erosion control and plugging prevention. In the USA alone, 24 utilities, representing 31 units and all major boiler manufacturers, and 7 industrial sites have participated in some form of erosion/plugging control as previously described. Three units in India have also benefited recently.