Thermodynamic Analysis of a Diesel Exhaust Wet Scrubber

A wet scrubber is an air pollution removal device that eliminates particulate matter and acid gases from a diesel engine. The exhaust gas enters the scrubber beneath the liquid surface, causing a reduction in gas temperature and increases the relative humidity of the scrubber outlet. In this study, a wet scrubber was investigated experimentally based on a transient heat loss and steady-state heating process. A transient heat loss experiments were performed to estimate the heat loss from the scrubber surface. The steady-state heating process was investigated separately with various inlet gas temperatures and flow rates. The experimental results confirmed that the scrubber effectively reduces the inlet gas temperature from 650 oC to about 50oC. However, the outlet gas relative humidity increased due to the high liquid evaporation rate. A thermodynamic analysis estimated the outlet gas relative humidity and compares it with the measured values. The contribution of this study is: heat loss estimation methodology and relative humidity calculations.