Summary: | 碩士 === 國立中央大學 === 環境工程研究所 === 87 === Two municipal solid waste incinerators(MWIs)equipped with different air pollution control device (APCD) were selected for conducting flue gas sampling to determine the particle size distribution and heavy metal concentrations on particles with different sizes by U.S. EPA Method 5 and Andersen Mark III Cascade Impactor. MWI-A is equipped with cyclone, dry lime scrubbing system with fabric filter while MWI-B is equipped with electrostatic precipitators (ESP) followed by wet scrubbers for removing air contaminants in flue gas. Results indicated that particulate and heavy metal for the APCD inlet of MWI-A and MWI-B have bimodal form on mass conc. versus particle sizes. Concentrations of particulate matter at the inlet of APCD for both incinerators (MWI-A and MWI-B) were 2,965 and 3,094 mg/Nm3, respectively. The particulate matter removal efficiencies of two MWIs were higher than 99.5%. Emission factors of particulate matter were 12.01 and 37.76 g/ton-waste at MWI-A and MWI-B, respectively. Based on the mass concentrations and emission rate at each location, the mass percentage of carbon and chlorine element in MSW was estimated by back calculation method. Carbon content of municipal solid waste was 27.67% and 21.74% while chlorine content was 0.53 and 0.72% for MWI-A and MWI-B, respectively. The average HCl concentrations in front of APCD were 265 and 232 ppm at MWI-A and MWI-B, respectively. HCl concentrations of stack were 30 and 15 ppm and HCl removal efficiency were 88.8% and 93.5% for MWI-A and MWI-B, respectively. The results of energy balance calculation indicate that the rate of energy input are 17,500,000 kcal/hr based on the LHV value of 1,800 kcal/kg for one incinerating unit at MWI-B. Energy distribution analysis demonstrates that heat loss of incinerator, boiler absorption amount, heat loss of APCD and heat emission from stack are 3.74%, 68.12%, 11.55% and 15.42% of total energy input, respectively.
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