Contribution of Various Loads to the Convex Shape of Rock Wool Insulation Slabs during Production

Abstract

Rock wool insulation slabs are produced in special curing ovens, where molten rock wool fibres coated with binder are compressed between two slat conveyors and blown with hot air for vitrification. Often, the cross-section of the final slabs is slightly convex, which is undesirable. The degree of convexity depends on the deformation of the steel crossbars of the slat conveyors, which are subjected to combined pressure and nonlinear temperature loadings. Due to this complex loading state, it is difficult to determine the contribution of individual load to the total deformation. The main aim of the study was to determine these contributions. Temperature and stress measurements of the crossbars were performed during rock wool production. Upon collecting these measurements, a finite element (FE) model of a crossbar was established for the identification of the pressure loading acting on the crossbars, and finally for determination of their deformations. As a main result of the study, an inverse problem-based methodology for the identification of the deflection of a structure due to unknown temperature and pressure loadings was established and applied on the specific case. The deviations between the deformations of the FE crossbars and the final shape of the rock wool slabs were below 10%, which validates the novel methodology.