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In this study the enhancement effect of adsorption mass transfer by acoustic wave is investigated to understand how the acoustic wave influences the adsorption performance. The experimental data were obtained to show the behavior of silica-gel adsorption with/without acoustic field. The experimental results showed the adsorption speed with acoustic wave became higher than that without acoustic wave although the equilibrium adsorption amount was kept to be the same. From the viewpoint of acoustic wave conditions, the adsorption speed was increased with increasing the velocity amplitude, while the pressure amplitude had no effect on the enhancement. The maximum adsorption speed attained five times as high as the case without acoustic wave when the velocity amplitude was 1.35 m/s. Background air flow velocity is also an influential factor. The experimental results support that the non-dimensional ratio of the velocity amplitude to the background flow velocity is essential to describe the enhancement effect. Based on the observed data, an empirical formula was estimated to express the relationship between the enhancement effect and the non-dimensional velocity amplitude. The liner regression showed the good agreement and gave the critical non-dimensional velocity amplitude of 1.9 over which acoustic wave is effective to amplify the mass transfer rate of adsorption. [ABSTRACT FROM AUTHOR]

There have been performed experimental measurements of effective thermal conductivity of silica-gel for a stagnant cylindrical fixed bed under transient and steady state conditions in the presence of dry air at different pressures and for different amounts of adsorbed water. The Bauer-Schlünder and Kunii-Smith models have been used to identify the thermal solid conductivity of silica gel pellets from measurements of the conductivity in an adsorbent bed. Sorption rates of water vapor in silica gel were measured using a single-step thermal method by monitoring the sample surface temperature by infrared detection. In order to obtain the mass diffusivity it is necessary to match the numerical solution of the mathematical model to the experimental data. [ABSTRACT FROM AUTHOR]