Gas dissolution reduces the release of methane to the atmosphere from subsea sources. Being able to predict and assess the methane flux to the atmosphere requires knowledge on gas dissolution and mass transfer. This can be obtained by studying the size evolution of bubbles rising in water. New data of bubble size evolution have been obtained by releasing, tracking, and filming methane bubbles with an ROV in the Trondheimsfjord from depths varying between 100 and 300 m. Released bubbles had an initial diameter between 5 and 7 mm and were tracked until they reached a diameter of roughly 2 mm. The new data were compared against theory, applying established correlations for the mass transfer coefficient. There was an inconsistency between experiment and theory. Thus, new correlations for the mass transfer are proposed. The new correlations are consistent with both the new experiments and previously published experiments. They indicate that the conditions in the ocean can be labeled as partly contaminated with respect to mass transfer.

Furnace tapping is a critical operation on pyrometallurgical furnaces known for unpredictable performance in many cases. A reduced order mathematical model capable of predicting tapping rates of both slag and metal is presented. The model accounts for separate liquid phases and particle bed resistance to flow. The model is compared for consistency against results from both a water-model experiment and computational fluid dynamics simulations. The model is applied to study drainage from a typical ferro-manganese furnace. The model results show that particle bed conditions in the immediate vicinity of the tap-hole strongly influence tapping rates and that the slag/metal interface deformation due to suction pressure near to the tap-hole is significant and must be accounted for in such models.

During sawing of silicon wafers for the photovoltaic industry, the variations in temperature will influence the process performance and surface quality of the wafers. To investigate the significance of this effect, the temperature field and heat transfer have been studied experimentally and computationally. Among others, it is found that the temperature typically can increase from 30 °C at the inlet to 65 °C at the outlet of the sawing channel. It is also shown that viscous dissipation is by far the most significant heating source in the process.