Optimization Design of Airlift Loop Reactor for Hydrothermal Oxidation of Sludge
1.Sichuan Provincial Key Laboratory of Clean Combustion and Flue Gas Purification, Chengdu 611731, China;
2.Dongfang Boiler Group Company Limited, Chengdu 611731, China
Abstract Airlift loop reactor is a kind of gas-liquid reaction apparatus, which is very suitable for sludge hydrothermal oxidation. The experimental research and computational simulation of airlift loop reactor were carried out in this article. A 0.1 m3/h cold model experimental apparatus was built and several experiments focusing on type and number of nozzles, height-to-diameter ratio (H/D), cross-sectional area ratio of the downcomer to the riser (Ad/Ar) and particles deposition were studied. By using computational fluid dynamics (CFD) simulation and software of Design Expert, the structure of reactor was optimized. The results indicated that the reactor with annular nozzle (annular intake), H/D ratio in 10 and Ad/Ar ratio in 0.333 had superior performance. Most of the particles were suspended when the superficial gas velocity reached 0.0070 m/s and fewer were deposited with higher superficial gas velocity. The error between calculated value of CFD and experimental value was less than 10%. After optimization by Design Expert software, the gas holdup in riser increased by 9%.
