Discussion: "An Assessment of Deposition in PFBC Power Plant Turbines" (Wenglarz, R. A., 1981, ASME J. Eng. Power, 103, pp. 552–557)
Journal of Engineering for Power
RAW) assessment of ash deposition in a turbine downstream of a pressurized fluidized bed (coal) combustor (PFBC)  provides a timely summary of the neglected area of mass transfer in the gas turbine (GT) industry. While further details of RAW's procedures will be of interest, we focus attention here on: (a) recent advances in our understanding of particle mass transport; (b) parts of RAW's assessment which warrant re-examination in the light of (a); and (c) areas in need of further research.
... further research. Our common goal is to increase the accuracy and generality of predictions. Attention is directed here at both inertial [2-4] and thermophoretic  particle deposition, and the relevant dimensionless groups. Details are available in the references cited below. For reasons discussed below RAW's procedures may systematically overestimate deposition rates for particles above 0.5 p.m dia (as in Region B, Fig. 1 ) and underestimate deposition rates for particles well below 0.1 ^m dia (Region A, Fig. 1 ). These would not be compensating effects, however, since more than 50 percent of the depositable particle mass is above 0.5 /an dia, and less than 3 percent of the depositable particle mass is less than 0.1 fim dia. Thus, RAW's mass arrival rate estimates may be too high-indeed, we wonder whether this accounts for most (if not all) of the 4.3 percent (apparent) "adherence fraction"?