## Transport behaviour of solids

# Transport behaviour of solids (4)

According to the study by Macke deposit free states can be reached by a steady flow, when the following conditions at the critical velocity v_{c} are met:

Equation 5: (wastewater)

Equation 6: (combined and rain water)

The corresponding wall shear stress is determined using the equation:

Equation 7:

with

ρ = density of the wastewater [kg/m

^{3}]
g = gravitational acceleration [m/s

^{2}]
r

_{hy}= hydraulic radius (A/l_{U}) [m]
I

_{R}= friction factor [-]