Development of Nusselt correlation for heat transfer studies in vertical transport duct using limestone and chalcopyrite for waste heat recovery

Process industries deal with high energy inputs and often generate high temperature exit gases, which can potentially be considered as secondary energy sources. If such waste heat is recovered, considerable savings in the net energy demand is possible. This report, based on this objective, details the outcome of an experimental study conducted in a vertical transport duct (riser) where solid particles, through a co-current contact with hot gas, recover the energy content of the gas. Data relevant to heat transfer patterns are collected as not much information is available in the literature on these aspects. Empirical correlation for heat transfer coefficient (Nusselt Number) is proposed as urn:x-wiley:19447442:media:ep13747:ep13747-math-0001. Fabricated experimental setup is a prototype of suspension preheater (riser – cyclone combination) used in a modern day cement industry but the correlation can be extended to diverse other industries, where waste heat recovery is possible.