Centrifugal atomisation of liquid or melts using a rotating cup is an efficient process that is widely used in many industrial processes, which range from chemical reactors to powder production in metallurgy. The theoretical prediction of liquid drop or particle size is desirable for the design of atomisers and operating parameters. In this paper, film disintegration by centrifugal atomisation using a rotating cup was analysed based on wave theory. Two mathematical models were proposed to predict the maximum unstable growth rate, wave length, film length, break-up time and drop size for the rotating cup at high and low Weber number respectively. The film break-up length and drop size were calculated numerically and agreed with the experimental results very well in film disintegration. In addition, the effects of the atomisation parameters in the film disintegration were discussed. The mathematical models are able to accurately predict the atomisation parameters.

The object of this study was to explore the effects of basicity (CaO/SiO 2 ratio), MgO and Al 2 O 3 on viscosity and melting temperature of molten slag in the process of coal gasification with blast furnace (BF) slag as heat carrier to recover the waste heat. The results showed that the viscosity and melting temperature of BF slag decreased first and then increased with CaO/SiO 2 ratio increasing, and the suitable CaO/SiO 2 ratio was 1.10-1.20. Both viscosity and melting temperature increased with the increasing of MgO and Al 2 O 3 in the slag, which should be lower than 8.22 and 11.00%, respectively. What is more, the viscosity estimation model for molten BF slag was established according to the Urbain model and experimental data of slag viscosity. In the model, the activation energy was calculated using slag compositions based on the redefine of material types in the slag, and the temperature was described by the Weymann-Frenkel equation. The viscosity of BF slag system estimated by proposed viscosity estimation model (modified Urbain model) fitted well with the experimental data and the mean deviation was about 17.98%.