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针对高固含量木质纤维素同步糖化与发酵生产燃料乙醇过程,研究了螺带型搅拌槽内层流流动条件下少量低粘低密度液体(a)加入大量高粘高密度主体液体(b)中的混合性能,考察了转速、两种液体体积比(V_a/V_b)、粘度比(μ_b/μ_a)、密度差等影响因素.结果表明,当V_a/V_b>1%时,异物性物系混合时间远高于相同物性液体混合时间,可延长2~5倍:V_a/V_b对混合时间影响最显著,V_a/V_b=0.2%~3.7%范围内,无量纲混合时间Nt_m随体积比增大先降低后升高存在一最小值;当V_a/V_b≥2%,单位主体液体密度之差Δρ/ρ_b>0.2时,Nt_m随着V_a/V_b,Δρ/ρ_o增加线性增大;Nt_m随着μ_b/μ_a增大而减小;加入相加在主体液体内所得混合时间比加在液体表面时短;V_a/V_b>2%时,混合工况可分为Re数控制区(桨叶控制)及Ri数控制区(重力控制).
Aiming at the process of simultaneous saccharification and fermentation of high-solids lignocellulose to produce fuel ethanol, a small amount of low-viscous low-density liquid (a) was added to a large amount of high-viscous high-density liquid (V_a / V_b), viscosity ratio (μ_b / μa), density difference and other factors were investigated.The results showed that when V_a / V_b> 1%, the mixture of foreign matter Time is much higher than that of liquid with the same physical properties, which can be prolonged by 2 ~ 5 times: V_a / V_b has the most significant influence on the mixing time, Vt / 0.2 ~ 3.7%, and the dimensionless mixing time Nt_m increases with volume ratio When V_a / V_b≥2%, the liquid density difference Δρ / ρ_b> 0.2, Nt_m increases linearly with V_a / V_b and Δρ / ρ_o; Nt_m increases with μ_b / μ_a increases and decreases; the mixing time added in the main liquid is shorter than that added to the liquid surface; V_a / V_b> 2%, the mixing conditions can be divided into Re number control area (blade control) and Ri Number of control zones (gravity control).