Comparison of Combustion Behavior between Solid Porous Burners Installed the Porous Emitter and Non-Porous Emitter

The combustion behavior, i.e., temperature profile (T), exhaust gas (CO and NOx) and combustion efficiency (ηC), of solid porous burner installed porous emitter and non-porous emitter were compared. The stainless wire-net having PPI (Pores per inch) of 12 and thickness (HPE) of 3 layer was selected as porous emitter. A rice husk with humidity percentage in the range of 12 - 14% was solid fuel. A cylindrical porous burner was made of ASUS 304 and there was 100 mm-outer with 5 mm- thick. An alignment of porous burner was in the horizontal direction. The fuel was supplied and was burned on the center of the burner. The grate was constructed below the fuel to control the flow of rice husk. The above of combustion zone along the porous burner was able to install the porous media defined here as porous emitter. Three mass fuel rates (QF) consisting of 0.080, 0.096 and 0.116 kg/min were examined. Four volume flow rates of air (QA: 10, 15, 20 and 25 m3/hr) were conducted. From the study, the trend of T in both cases, namely the burner with installation of porous emitter and the burner with non-porous emitter, was raised as increasing QF but the maximum of T become at QA = 15 m3/hr. The level of CO was decreased as increasing QF and was minimum at QA = 15 m3/hr. The level of NOx was relative low as in the rage not over 50 ppm owing to the combustion temperature was not reached to 1300 K (Thermal NOx). For comparison, the T of installation of porous case was higher than the non-porous case and, also, the level of CO of porous case become lower. Thus, the ηC of porous case reached to 95-97% was greater than non-porous case.