Abstract：Burner design and flow rate control strongly impact combustion stability, SiO2 generation, soot quality, and key flue gas components. This paper presents a numerical study of SiO2 soot synthesis by the CVD method with octamethylcyclotetra-siloxane (also called ‘OMCTS’ or ‘D4’) as the precursor. The study investigates the effects of various feeding modes and D4 and oxygen mass flow rates on the SiO2 generation efficiency and the distribution of key components on the surface. The SiO2 generation rate and deposition uniformity can be significantly improved by using the multi-point feeding mode which increases the SiO2 generation rate and reduces the OH concentration even with similar D4 inlet velocities. Proper control of the oxygen flow rate relative to the D4 mass flow rate improves the SiO2 generation rate, but also increases the OH concentration. The multi-point feeding mode with the same D4 mass flow rate can reduce the D4 inlet velocity with then reduces the deposition efficiency some. Multi-point feeding with the proper increased D4 flow rate and flame temperature control improves the SiO2 generation rate and deposition efficiency.
[1] 聂兰舰, 宋学富, 向在奎, 等. 一种间接合成石英玻璃的方法及其专用设备以及一种石英玻璃:102583977A. 2012-07-18.NIE L J, SONG X F, XIANG Z K, et al. A method of indirect synthesis of silica glass and its special equipment and a kind of silica glass:102583977A. 2012-07-18. (in Chinese) [2] DOBBINS M, MCLAY R E. Method of making fused silica by decomposing siloxanes:US5043002. 1991-08-27. [3] BRIESEN H, FUHRMANN A, PRATSINIS S E. The effect of precursor in flame synthesis of SiO2[J]. Chemical Engineering Science, 1998, 53(24):4105-4112. [4] 聂兰舰, 王玉芬, 向在奎, 等. 石英玻璃的制备方法:106277750A. 2017-01-04.NIE L J, WANG Y F, XIANG Z K, et al. Method of making silica glass:106277750A. 2017-01-04. (in Chinese) [5] 张国君, 李得军, 王巍, 等. 一种石英玻璃燃烧器:206799423U. 2017-12-26.ZHANG G J, LI D J, WANG W, et al. A silica glass burner:206799423U. 2017-12-26. (in Chinese) [6] 黄若杰, 王巍, 刘志龙, 等. 高速合成石英玻璃生产用多点下料燃烧器:207760219U. 2018-08-24.HUANG R J, WANG W, LIU Z L, et al. Multi-point feeding burner for high-speed synthetic silica glass production:207760219U. 2018-08-24. (in Chinese) [7] LAUNDER B E, SPALDING D B, Lectures in mathermatical models of turbulence[M]. London:Academic Press, 1972. [8] CHEN J, HUANG Z Y, ZHENG L L. Detailed OMCTS/H2/O2 chemical kinetics mechanism and its application in the fused silica glass synthesis[J]. Journal of Non-Crystalline Solids, 2018, 481:33-40. [9] CHUI E H, RAITHBY G D. Computation of radiant heat transfer on a non-orthogonal mesh using the finite-volume method[J]. Numerical Heat Transfer, Part B:Fundamentals, 1993, 23(3):269-288. [10] HUANG Z Y, HUANG Y S, ZHENG L L, et al. Effects of precursors on silica particle generation in CVD synthesis for fused silica glass[J]. Journal of Non-Crystalline Solids, 2018, 499:86-94. [11] 黄泽宇, 黄耀松, 陈靖, 等. 入口条件对D4合成石英玻璃的影响[J]. 燃烧科学与技术, 2018, 24(6):477-486.HUANG Z Y, HUANG Y S, CHEN J, et al. Effects of entrance conditions on fused silica glass synthesis using D4[J]. Journal of Combustion Science and Technology, 2018, 24(6):477-486. (in Chinese)
2020, Vol. 60 
