In this paper, an improved analytical model incorporating
Bagnold effect is proposed as a modification to
the earlier approach by Kapur and Meloy (1999, 1998).
The model equations were reformulated to calculate the
mean flow depth, relative specific gravity of the particle
and particle size as a function of design and operating
parameters of the spiral. Sensitivity studies of the operating
parameters on the segregation behavior of particles across
the radial width of the trough during their motion along the
spiral have been carried out. It is believed that the model
reasonably mimics the segregation behavior of a particle
during its motion along the spiral with a reasonable degree
of realism. Themodel comprises three important aspects of
a spiral separator, namely, (i) modeling of spiral geometry,
(ii) fluid flow based on semi-empirical sediment transport
correlation and (iii) first principle based equilibrium force
balance on a particle moving down the spiral along the
helical path. These have been incorporated to formulate a
hybrid methodology using first principle based approach
coupled with semi-empirical correlations