Optimization of a Developed Multi-Cyclone Using Response Surface Methodology (RSM) to Control Fine Particulate Emission

Abstract

The effects of increasing volumetric air flow rate and inlet particulate loading on overall collection efficiency of MR-deDuster; a developed multi-cyclone system was investigated using various segregated sizes of palm oil mill boiler fly ash. The operating conditions of the fabricated pilot plant scale of the unit were predicted theoretically and screened experimentally. Increasing volumetric air flow rate theoretically will increase the overall collection efficiency, yet the experimental results during screening stage demonstrated contradict finding when the increment of volumetric air flow rate caused the overall collection efficiency to be decreased for a constant particulate loading. Subsequently, the optimization work was done to determine the optimum operating conditions of the system using Response Surface Method (RSM) with Box-Behnken design. The parallel arrangement of multi-cyclone units proved the ability of the system to uniformly disseminate the gas flow with high volume of gas carrier. Nevertheless, excessive pressure drops between each unit of multi-cyclone due to high volumetric air flow rate should be avoided as such condition may lower the overall collection efficiency by allowing dust re-entrainment from the hopper to circulate between the cyclones. Through statistical analysis of variance (ANOVA), validation and verification studies, it is suggested that the developed pilot scale multi-cyclone unit would be able to meet the targeted limit of 150 mg/m3 for solid fuel burning equipment industry in Malaysia by operating with optimized volumetric air flow rate of 0.27 m3/s, and maximum inlet particulate loading rate and size of 2 g/m3 and 1000 μm respectively.