發(fā)布時(shí)間：2018-05-18 03:13

  本文選題：納米材料 + 旋轉(zhuǎn)液膜反應(yīng)器�。� 參考：《北京化工大學(xué)》2015年碩士論文

【摘要】：旋轉(zhuǎn)液膜反應(yīng)器是一類以沉淀法制備硫酸鋇等納米材料的微反應(yīng)器,它由兩同軸等高的圓臺(tái)構(gòu)成,兩圓臺(tái)間充滿不可壓縮的粘性反應(yīng)液。在制備納米材料的過(guò)程中,反應(yīng)液的加入量(體積流量)是一個(gè)恰當(dāng)?shù)闹?這個(gè)量稱為臨界流量。納米材料的制備過(guò)程均在臨界流量下進(jìn)行,臨界流量只能通過(guò)實(shí)驗(yàn)測(cè)得。本文建立了旋轉(zhuǎn)液膜反應(yīng)器內(nèi)流體運(yùn)動(dòng)的數(shù)學(xué)模型,并結(jié)合N-S方程和適當(dāng)?shù)倪吔鐥l件,對(duì)臨界流量進(jìn)行了數(shù)值求解,并研究了臨界流量隨不同因素的變化規(guī)律。本文首先對(duì)實(shí)驗(yàn)中參數(shù)下的臨界流量進(jìn)行了數(shù)值模擬,臨界流量的數(shù)值結(jié)果與實(shí)驗(yàn)結(jié)果吻合良好,驗(yàn)證了求解臨界流量方法的可靠性,然后我們研究了其他參數(shù)的改變對(duì)臨界流量的影響。研究結(jié)果表明,在小雷諾數(shù)時(shí),臨界流量Q與反應(yīng)液的運(yùn)動(dòng)粘性系數(shù)成反比,即Q∝1/y；與反應(yīng)器轉(zhuǎn)子的轉(zhuǎn)速Ω成二次關(guān)系,即Q-a*Ω2+b;在內(nèi)定-外轉(zhuǎn)情況下,臨界流量隨轉(zhuǎn)子的變化關(guān)系也為二次函數(shù),且同樣的轉(zhuǎn)速,內(nèi)定-外轉(zhuǎn)下的流量要略大于內(nèi)轉(zhuǎn)-外定下的流量。研究還表明,在忽略重力影響時(shí),轉(zhuǎn)子轉(zhuǎn)速和運(yùn)動(dòng)粘性系數(shù)對(duì)臨界流量的影響可統(tǒng)一到無(wú)量綱的雷諾數(shù)上,且無(wú)量綱的臨界流量與雷諾數(shù)呈線性關(guān)系,即Q'-k*Re。研究還發(fā)現(xiàn),改變反應(yīng)器的夾縫寬度比改變轉(zhuǎn)子轉(zhuǎn)速對(duì)臨界流量的影響更大。最后,對(duì)不同傾斜角的反應(yīng)器的臨界流量進(jìn)行了數(shù)值模擬,結(jié)果表明隨著傾斜角的增大,臨界流量先增大后減小,存在流量最大的臨界傾斜角。研究還表明,臨界傾斜角不隨流體的運(yùn)動(dòng)粘性系數(shù)而變化,但隨轉(zhuǎn)子的轉(zhuǎn)速而變化,此結(jié)論也證實(shí)了實(shí)驗(yàn)中設(shè)計(jì)的圓臺(tái)傾斜角的合理性。
[Abstract]:The rotating liquid membrane reactor is a kind of micro reactor which can prepare nanometer materials such as barium sulfate by precipitation method. It is composed of two coaxial and high circular platforms, and the two tables are filled with incompressible viscous reaction fluid. In the preparation of nanomaterials, the amount of reactant (volume flow) is an appropriate value, which is called critical flow rate. The preparation process of nanomaterials is carried out under the critical flow rate, which can only be measured by experiments. In this paper, a mathematical model of fluid motion in a rotating liquid-membrane reactor is established. Combining N-S equation and appropriate boundary conditions, the critical flow rate is numerically solved, and the variation of critical flow rate with different factors is studied. In this paper, the numerical simulation of the critical flow rate under the experimental parameters is carried out. The numerical results of the critical flow rate are in good agreement with the experimental results, and the reliability of the method is verified. Then we study the influence of other parameters on the critical flow rate. The results show that at small Reynolds number, the critical flow rate Q is inversely proportional to the viscosity coefficient of the reaction fluid, that is, Q 鈭，

本文編號(hào)：1904108