Heat Transfer, Fluid Mechanics and Energy Analysis of an Industrial Roller Ironing Machine

In this study, energy, heat transfer, and fluid flow analyses were conducted for an industrial roller ironer, a system that has received limited attention in the scientific literature. These machines simultaneously dry and press flat textiles by conveying them between a rotating roller and a stationary heated chest. A high and uniform surface temperature is maintained via thermal oil circulation within the chest, enabling rapid moisture evaporation and fabric smoothing. This system is widely employed in industrial laundries for high-throughput ironing. Two operating conditions are considered, one with pre-dried fabric (faster ironing) and one without pre-drying (slower ironing), both requiring the same heat load. A single Conjugate Heat Transfer (CHT) CFD simulation was performed under this heat load to represent both scenarios. The simulations yielded the surface heat load and temperature distribution, revealing localized regions of low heat flux. These zones were attributed to complex three-dimensional flow separation occurring at the U-bends of the internal oil channels, which impair local heat transfer. Design modifications were proposed to mitigate these deficiencies. Overall, the analysis indicates uniform thermal performance across the ironing surface, with targeted areas for further improvement.