Study of a non-isothermal, non-isobaric consolidated reactive bed for chemisorption icemakers

Kinetic, heat and mass transfer in a consolidated reactive bed for sorption icemakers were studied with an analogical model that was experimentally validated. The bed was made from expanded graphite impregnated with calcium chloride, and the coefficients of the model were assessed by minimizing the sum of the squared deviations between the observed and simulated data, for several operation conditions normally employed in the ice making process. The average error in calculated global conversion during the synthesis phase ranged from 0.012 to 0.041, depending on the experimental conditions. The average error for the simulated temperature was smaller than 1.3 °C, and the average error for the pressure close to the wall of the reactor was smaller than 50 mbar. Simulation results showed that a specific cooling power higher than 1250 W/kg of salt can be achieved with a bed of 10 mm thickness operating with an evaporation temperature of −15 °C and a heat sink temperature of 25 °C; however if the thickness of the bed is increased to 20 mm, the evaporation temperature should be at least −10 °C to produce similar results.