The Design and Operation of a New Clapboard-Type Internal Circulating Fluidized-Bed Gasifier

The design and operation of a new clapboard-type Internal Circulating Fluidized-Bed gasifier is introduced in this paper. By setting clapboard in the middle of gasifier, bed layer in gasifier is divided into two regions that have different fluidization velocity, the incompletely reacted fuel or carbon in the high velocity region flows to the low velocity region companying with bed medium, and gasification reaction takes place in this region; still incompletely reacted fuel or carbon returns to the high velocity region in the bottom of gasifier, then gasification reaction further occurs. By this way, internal circulation in the gasifier was formed, gasification reaction time and efficiency increased. The experimental results indicate that gas yield (1.6 ∼ 1.9Nm3/kg fuel), gas heat values (5340kJ/Nm3 for wood chip fuel and 4880kJ/m3 for rice husk), and gasification efficiency (70%) can be obtained using this kind of gasifier in the optimal operational temperature range of 790∼850°C.