Design Characteristics of Single Hub Paddle Wheel Aerator

Aeration experiments, based on dimensional analysis, were conducted in brick masonry tanks of dimensions $2.9\times 2.9\times 1.6{\mathrm{m}}^3$ and $5.9\times 2.9\times 1.6{\mathrm{m}}^3$ to study the design characteristics of a single hub paddle wheel aerator. A generalized equation has been developed to estimate the optimum volume of water to be aerated at a given paddle wheel diameter $\left(d\right)$ and speed $\left(N\right)$ . A simulation equation with $E$ [nondimensional number characterizing standard aeration efficiency (SAE)] and $P^{*}$ (nondimensional number characterizing power input per unit volume) provided a correlation better than that with $E$ and $\mathsf{F}$ (Froude number) and $E$ and $\mathsf{R}$ (Reynolds number) only. A simplified generalized equation correlating $E$ and $P^{*}$ was developed which can be used to predict aeration efficiency for $P^{*}⩽6.56$ . Similarly, a simulation equation with $N_e$ [(power number)(nondimensional number charcterizing power consumption)] and $P^{*}$ provided a correlation better than that with $N_e$ and $\mathsf{F}$ and $N_e$ and $\mathsf{R}$ only. The optimum dynamic condition at which maximum SAE is produced has also been presented. All the above results are valid subject to $1.47⩽P^{*}⩽15.54$ .