Drying of Xanthan Gum Using a Two-Dimensional Spouted Fluidized Bed (2DSFB) with Inert Particles: Performance and Rheological Considerations

Abstract

Xanthan commercial gum was dried using a two-dimensional spouted fluidized bed dryer (2DSFB) with inert particles under different conditions of temperature, suspension feed rate, and air flow in the spout and annulus. Performance characteristics of drying processing, flow characteristics of the bed, and influence of the drying variables on rheological behavior of product were evaluated. The results indicated that xanthan suspension can be dried out in a spout-fluidized bed without several damages in its rheological behavior. In addition, the lower feed rate was the main factor to decrease viscosity and elastic character of xanthan, which was associated to a depolimerization caused by shearing for an extended processing time.

Keywords:

• Drying
• Rheology
• Spouted bed
• Xanthan

Notes

T = Drying temperature; R = Xanthan solution feed rate; S = percentage of air volumetric feed rate into the spout and α is the axial condition.

The position x and y in cm (S = spout, A = annulus). Γ = Dimensionless drying time.