Effects of header design on thermal characteristics of multi-nozzle steam spraying

Abstract

The distribution header of small-scale steam systems, commonly employed in household items like steam cleaners, is pivotal for dictating the spray characteristics of the steam generated. For uniform spray performance across multiple outlets, it's imperative to discern the design factors influencing this outcome. We numerically assessed the flow characteristics of steam in a spraying system with three nozzle outlets and scrutinized the impact of header design parameters on uniformity. Through a multiphase numerical model, numerical simulations were conducted. Our analysis revealed that decreasing the diameter of the three outlets promoted a more even mass flow rate of the sprayed steam from each outlet, having a minimal effect on temperature consistency. In contrast, enlarging the tapering angle of the header improved temperature uniformity up to 62.5 % but negatively influenced the uniformity of the steam spray amount when outlet diameters were consistent. Notably, when the combined area of the outlets was increased, there was a decline of up to 85 % in the uniformity of the discharged steam mass among the outlets with an increased tapering. This research offers insights that are anticipated to inform future studies and advancements in steam spraying system optimization, enhancing performance and efficiency for applications such as steam cleaning and sterilization processes.