A Multicomponent Distributed Parameter Model for Spray Drying: Model Development and Validation with Experiments

作者：Wang Shuosi^*; Langrish Tim; Adhikari Benu

来源：Drying Technology, 2013, 31(13-14): 1513-1524.

DOI：10.1080/07373937.2013.813533

• Distributed parameters
• Drop drying
• Model
• Multicomponent
• Protein

A distributed-parameter model was developed based on previous work to simulate the spray-drying process for droplets, including the diffusion and solubility of multiple components (sugars and proteins), and was extended to estimate the water activity of a multicomponent solution and to account for the surface activity of the protein. The ordinary differential equation (ODE) solver for ordinary differential equations was altered to specify the time step for the simulation. Regridding was also carried out routinely to counter the numerical problem of thinning layers. This model was then validated with drop-drying experiments that measured the rate of drying of solution droplets using having 4mg initial mass and 1-10% (w/w) initial solid concentration at 65 and 90 degrees C. The effect of air velocity past the droplets was maintained at 0.5-1m/s. Lactose and sodium caseinate were used as a model sugar and model protein and their mixtures were used as models of sugar-protein mixtures. It was found that solubility did not contribute significantly to the component segregation process and that the diffusion-convection mechanism of the solvent in solid matrix, as well as the surface activity of casein, both contributed to the accumulation of casein on the product surfaces.

• 出版日期2013-10-26