Multiport Diffuser Mixing Zones in Rivers

Mixing zones downstream from multiport diffusers discharging hot water in rivers are considered. The area enclosed in the isotherm defining the boundary of a single-port mixing zone is determined as a function of downstream distance from port, velocity ratio, and critical dilution ratio. The same variables are used to predict the discharge passing through the mixing zone isotherm. A procedure is presented wherein the semi-empirical single-port mixing zone relationships are used to predict the portion of river’s discharge that is included in the mixing zone of a multiport diffuser. This procedure can be extended to estimate the river discharge below which environmental mixing zone limitations will be violated for specific multiport diffuser installations.