The research compares the efficiency of particle removal from exhaust of ritual money burning by an electrostatic precipitator (ESP) and a bag-house filter (BH), both have a capacity of around 30-35 Am3/min. A stainless steel chamber of 0.6 m in diameter and 1.0 m in height was used for the ritual money burning. Combustion gas from the chamber was cooled to 300-400oC by mixing with a certain proportion of ambient air and further cooled to around 100-130oC by a fin tube gas cooler before entering either to the ESP or the BH.
Results indicate that TSP in the influent gas could be reduced from 6-392 (average 83) to 1-143 (average 22) mg/Nm3 by the ESP with gas velocities of 5-10 cm/s at 100-120 oC through the spacing between collecting plates. TSP emission factors of 0.0295-9.94 (average ± standard deviation = 1.81±2.25) and 0.031-3.36 (average ± standard deviation = 0.27±0.26) g/(kg combusted ritual money), respectively, were obtained before and after the ESP filtration. Although the ESP had an initial TSP removal of 80-99%, the performance dropped in a few operation hours because of a fouling of the plate surfaces by the collected fume dusts. Cleaning of the plate surfaces helped in the recovery of the performance, however, it dropped after a few cycles of collection and cleaning.
Results from BH tests indicate that TSP in the influent gas to it could be reduced from 9-182 (average 72) to 0-12 (average 2.0) mg/Nm3 with the gas flow through the filter cloth with a velocity of 3.3 cm/s at 120-130 oC which resulted in an initial pressure drop of around 100 mmAq. It was observed that some fine dusts would escape from the cloth fiber spaces when the backwash pulse was operated. It is recommended that the backwash cycle should be minimized and trigged after the gas pressure drop over the cloth reaches up to 300 mmAq. TSP emission factors of 0.0176-1.64 (average ± standard deviation = 0.52±0.33) and 0-0.491 (average ± standard deviation = 0.02±0.05) g/(kg combusted ritual money), respectively, were obtained before and after the BH filtration. BH filtration is recommended for the TSP control in the ritual money buring.
XRD(X-Ray Diffraction) examination of a bottom ash sample indicates that the ash has an elemental composition of O, Na, Al, and Si of 49.9, 11.8, 23.8, and 15.1%, respectively. SEM(Scanning Electron Microscope) analysis indicates that the collected fly ash and the bottom ash have particle sizes of 20-110 (mostly 45-60 nm) and 50-300 (average 250) nm, respectively.