The prediction of a three-dimensional oil-fired industrial-type furnace is described. The gas-phase combustion-related properties are calculated by means of time-averaged Eulerian conservation equations, in addition to the k-epsilon turbulence model. The droplets and cenospheres balance equations are solved in Lagrangian fashion, with a stochastic approach for turbulent dispersion. The different phases are coupled through mass, momentum and energy exchange processes, assuming negligible influence of local discontinuities induced by the non-gaseous phase. The turbulent-diffusion flame is modelled by means of a clipped-Gaussian pdf to account for fluctuations of scalar properties. Chemistry is assumed to be fast. Radiation is modelled by the discrete transfer method. Oil combustion particulate, namely soot formed during gas-phase reactions, and cenospheres formed by the liquid-phase pyrolysis, may contribute to fouling, heat-transfer and emissions. Soot was modelled by solution of its Eulerian transport equation. In this work a Lagrangian model to predict formation, oxidation and spatial distribution of cenospheres is used. Soot is found to form in the fuel-rich edges of the flame; because of its fast oxidation, it contributes significantly to radiation only. On the other hand cenospheres, because of their structure and size, contribute significantly to fouling and emissions.