Ice Slurry Formation Using The Cold Energy of Liquefied Natural Gas

This research work investigates the method of forming ice slurry in sea water by direct contact cooling of cryogenic liquid. Liquid nitrogen, acting as refrigerant, is withdrawn from a low-pressurized tank (22 psig) and directly injected into a pool of sea water through two injecting ports. Sea water is cooled until the freezing point as liquid nitrogen evaporates by absorbing heat. Subsequent cooling produces ice slurry which is defined as suspended ice particles in aqueous solution. The slurries are generated in an insulated vertical column stainless steel cylinder that has been fitted with a motorized stirrer. The stirrer ensures turbulence mixing and prevents ice agglomerations and blockages at the cryogenic inlet ports. The reported data in this study are obtained by varying the refrigerant flow rates (100, 200 and 300 Lpm) and sea water volumes in the generator (10 and 20 litres). A simulation on the sea water solution temperature is performed using the lumped model to validate the experimental results which incorporate heat leak to the ambient. It is found that the model can predict the solution temperature within reasonable accuracy.