Experimental investigation of the mixing behaviour of pumpable ice slurries and ice pigs in pipe flows

As part of an extensive programme on the development of a novel pigging technique using crushed ice, work has been undertaken to investigate the propensity of fluids to mix in ducts when pumped. Experimental work suggests that the 'ice pig' will tend to hold together, be self-healing, and maintain its identity under most flow conditions. The crushed ice making up the pig will tend to form a sharp interface between itself and the fluid following it. Any water resulting from melting ice will tend to be transported to the front of the pig, thus ensuring that the back of the pig will maintain its sharp interface. A simple theoretical model is proposed that is in qualitative agreement with the experimental results. Both experimental data and the proposed model are consistent with the literature. The importance of the self-healing properties of the ice pig is briefly explored.