Heat and Mass Transfer in Circulating Dessicant Air Dehumidifier.

Eldebsi, Ahmed Mahmoud Hasan; Ahmed, Ahmed Ramzi Abbas; Gad, Helmy El Sayed

doi:10.21608/bfemu.2020.99019

Heat and Mass Transfer in Circulating Dessicant Air Dehumidifier.

Document Type : Research Studies

Authors

¹ Damietta power plant, East Delta Electricity Production Co., Egypt

² Mechanical Power Engineering Department, University of Mansoura, Egypt

³ Prof. at Mechanical Power Engineering - Faculty of Engineering - Mansoura University

10.21608/bfemu.2020.99019

Abstract

In the present work, a novel circulating desiccant air dehumidifier is numerically and experimentally investigated. Experimental tests and numerical analysis are conducted to investigate the adsorption and desorption processes in fluidized and packed bed columns which are connected via two inclined tubes. The dehumidification process occurs in the packed bed and regeneration process is carried out in the fluidized bed. Silica gel is used as a working desiccant, and its flow rate is controlled using manual valves. The experimental setup is designed, constructed and described. Silica gel is transferred continuously by gravity to the fluidized bed and particles fluidization to the packed bed. A simulation computer code was developed to predict the performance of the system and analyze its sensitivity to the main operating parameters. Results show that when applying intercooling between the two columns a significant improvement in adsorption process is observed. A satisfactory regeneration rate is confirmed at a regeneration temperature of 90 ^oC. The adsorption and desorption rates are dependent on the initial humidity of air. It was found that circulation rate is optimal when the bottom valve opening is 30 %. In the proposed system, continuous processes of adsorption and desorption and steady state moisture transfer rate during these processes are achieved.

Keywords