Some designers indicate (estimated values) such as:
coker naphtha (C5-350ºF) 10-15 ppmw
Ligth Coker GO (350-650ºF) 4-5 ppmw
Heavy Coker GO (650ºF-1050ºF 2-3 ppmw
Those values are for a 100000 cst antifoam
Remembers that depending on the type of antifoam, those distributions can change
60000 -100000 CSt is still pretty much the normal, but 600000 and even 1000000 are becoming more prevalent. the higher MW (molecular weight) tend to carry les silica over the fractionator. However, they may not break foam as well as lower MW (are more diluted)
There is a paper “Foam control methods in delayed coker” Lawrence Kremer (baker petrolite) & Timothy Hueston (Dow corning), where they explain very well the use of antifoam
I hope this help you, best regards
