A Method for Measuring the Strength of Scale Deposits on Heat Transfer Surfaces

Abstract The technique of fluid dynamic gauging has been successfully applied to assess the adhesion characteristics of thin (< 1 mm) layers of calcium sulphate deposits serving as mimics of mineral scales often found on heat transfer surfaces. The shear strength of the scale layers increased on ageing; layers aged for more than 14 hours could not be removed by the gauging fluid flow. The shear stresses imposed by the gauging flow have been shown to be reliably estimated by an analytical result, provided that the flow rate is measured.