Employing the H-type finned heat exchangers with the circular tube for energy-saving purposes of the spray dryers

Abstract

In this paper, two heat exchangers along with 50% recirculation of exhaust air are used to recover the exhaust heat from the spray dryers and use them to preheat the atomizing and drying air. The H-type finned heat exchangers with circular holes are used here. All of the results are extracted by two different approaches, including standard k-ε and SST k-ω models. First, the influence of different parameters on the performance of the first and second heat exchangers is evaluated. It is shown that the Nusselt number increases by increasing the Reynolds number. While the friction factor of both heat exchangers decreases. Then, the influence of adding heat exchangers on the energy consumption of the factory and spray dryer is estimated. It is shown that the suggested system can be effectively used to 23.52% decrease the energy consumption of the spray dryer.