Parametric evaluation of dynamic multistage centrifugal humidifier

Evaporative cooling is a passive cooling technique, which is energy efficient, sustainable, and environmentally friendly. The present work deals with the design and construction of a three-stage rotating centrifugal humidifier test rig equipped with a UV filter. Experiments are conducted varying the air velocity and the motor shaft speed. Overall cumulative performances such as DBT ratio, RH ratio, humidification effectiveness, coefficient of performance, and evaporation rate are determined with respect to Reynold's number and stage wise. Measurements of CO₂, Total Volatile Organic Compounds (TVOCs) and formaldehyde are performed at the exit air from the filter. Results showed maximum evaporation rate, humidification effectiveness, and coefficient of performance equal to 0.82 g s⁻¹, 88.74%, and 6.14, respectively. The cumulative performance improved for consecutive stages, but stagewise analysis indicated that the first stage gave a maximum performance. Exiting air quality after filtration is improved by 33%, which meets the most exigent standards in terms of the target pollutants.