The sectional approach, introduced by Y. Tambour [6], is aimed at reducing the numerical costs when dealing with polydisperse sprays. Inked, by grouping the particles into sections of size, if is possible to write a system of equations involving mean quantities of each section. These mean quantities are the new unknowns of the problem, and the sectional approach proposes a method for deriving the equations. The relation between the Williams equation and the sectional approach mas made precise by, Greenberg et al. [3]. However, some choices in the derivation may appear arbitrary. The abl of this article is to show that, using kinetic schemes, one ran write precise schemes for evaporating sprays. The study emphasizes the meaning of the different parameters involved in the derivation of the scheme.