Evaluation of Steam Washers in Power-Plant Boilers

A research program was undertaken to study the feasibility of employing steam washers to control silica deposition in high-pressure turbines. Under certain laboratory conditions, steam washing was found to be effective; however, its useful application appears to be limited to a very small number of power stations. Space limitations in modern boiler drums make it difficult to install the bulky equipment without interfering with flow and distribution through the drum. A washer installation can actually be the cause of mechanical carry-over. The use of high-quality make-up water and the prevention of raw-water contamination provide a more economical and trouble-free solution to the silica problem. A steam washer has little practical value in plants where good external control of silica is practiced.