Heat Transfer Studies on Freeze Concentration of Salt Brines in a Liquid Solid Fluidized Bed Heat Exchanger Available to Purchase

Fluidized bed freeze concentration is a technology in which liquid solutions can be concentrated within a fluidized bed heat exchanger by preferential freezing of water out of the solution. Water forms an ice layer on the heat exchanger wall from where it is removed by the action of the fluidized bed on it. A double pipe fluidized bed heat exchanger was constructed which included a bed of 4×4 mm 304 stainless steel solid cylinders. Salt solutions (0–9.4 wt%) were used in the process to form ice, which could successfully be removed by the particles with bed porosity of 0.81–0.83. Freeze concentration effects were observed with continuous freezing point depression in these experiments. Coolants used in experiments were 34% ethylene glycol solution and a potassium formate solution. The respective overall heat transfer coefficients were ∼600 W/m²K with ethylene glycol and ∼1000 W/m²K with potassium formate solution (Tyfoxit).