Gravity-induced flocculation system

In this paper we propose a simple procedure whereby one can estimate the overall stability of a given colloidal system undergoing simultaneous creaming and flocculation. Since case (iii) has not been solved yet, we will focus our attention only on case (ii). As an example, we use this procedure to compare the net rates of particle loss due to creaming and gravity-induced flocculation when electrostatic repulsion is negligible. 

For a polydisperse system of particles undergoing both creaming and gravity-induced flocculation, the time evolution of the particle size distribution, and hence the time rate of change of the total particle concentration, can only be determined from the solution of the governing population balance equations (10,11). For the special case of two different sized particles, this system of balance equations reduces to ... 

He have presented a simple procedure whereby one can estimate the stability of a colloidal system undergoing simultaneous creaming and gravity-induced flocculation. This procedure is by no means restricted to only this case. One can easily take into account other particle loss mechanisms, such as shear-induced flocculation or Brownian flocculation. What is required in these cases are the appropriate particle/particle collision kernels, which can be computed by solving the governing convective-diffusion equation. 

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