The influence of sedimentation particles’ distribution in depth on the working length of gravity clarifier basins
The authors calculated the settlement probability of suspended particles inflowing to the clarifier. The limit distributions of dangerous sedimentation particles are considered: in a parabola and uniform for all the groups of particles, as well as distribution in trapezia having upper and lower bases with gradual increase of the length of the upper base from zero to the length of the lower base. It was stated that the sedimentation pattern of the particles in depth of the flow at the inlet of the settling basin greatly influences the required length of the basins. It was established that at the 80 % probability of dangerous particles’ sedimentation and at the flow velocity of 0.5 m/s the fluctuations range of the relative basin length S/H is 5 ea, for 94 % probability - 8.5 ea, and the fluctuations range is increasing with the increase of the probability. It is recommended to organize the experimental study of the distribution of suspended particles’ concentration at the inlet of operating clarifier basins and to take a uniform or close to the uniform distribution before obtaining this experimental data.