下噴式環(huán)流反應(yīng)器流動(dòng)特性研究
發(fā)布時(shí)間：2018-08-17 16:09
【摘要】：下噴式環(huán)流反應(yīng)器(Reverse Jet Loop Reactor,簡稱RJLR)借助高速的射流和環(huán)流的相互作用,因而強(qiáng)化了流體的混合效果,提高了傳熱及傳質(zhì)速率,改善了反應(yīng)條件,是一種新型的高效多相反應(yīng)裝置�；谄浣Y(jié)構(gòu)簡單、投資廉價(jià)、無轉(zhuǎn)動(dòng)部件、密封性好及混合傳質(zhì)傳熱性能好、操作維修以及工業(yè)放大容易等優(yōu)點(diǎn),下噴式環(huán)流反應(yīng)器特別適合于液-液、氣-液及氣-液-固等多相反應(yīng)體系中。在化學(xué)化工、生物工程、環(huán)境保護(hù)等領(lǐng)域很快得到廣泛應(yīng)用,具有良好的發(fā)展前景。但由于研究者在研究方法、測試手段、研究內(nèi)容方面的不系統(tǒng),導(dǎo)致目前對(duì)該反應(yīng)器的放大設(shè)計(jì)和優(yōu)化缺乏依據(jù),對(duì)環(huán)流反應(yīng)器的操作規(guī)律更是缺乏研究。因此本文對(duì)下噴式環(huán)流反應(yīng)器的流動(dòng)特性進(jìn)行了研究,主要的研究內(nèi)容和結(jié)論如下：(1)空氣-水體系為研究對(duì)象,實(shí)驗(yàn)研究了下噴式環(huán)流反應(yīng)器的結(jié)構(gòu)參數(shù)及操作參數(shù)對(duì)氣含率ε、吸氣量QG的影響規(guī)律。實(shí)驗(yàn)結(jié)果表明,氣含率隨著表觀液速及表觀氣速的增加而增加；氣體吸入量隨著液體流量的增加和噴嘴位置的上升而增加。并根據(jù)實(shí)驗(yàn)結(jié)果回歸了氣含率的關(guān)聯(lián)式如下：(2)在空氣-水體系下,實(shí)驗(yàn)研究了下噴式環(huán)流反應(yīng)器的啟動(dòng)規(guī)律(環(huán)流啟動(dòng)的最小液體流量弛以及環(huán)流維持的最小液體流量QLd等)。實(shí)驗(yàn)結(jié)果表明,隨著噴嘴位置及導(dǎo)流筒直徑的升高,環(huán)流啟動(dòng)的最小液體流量QLu以及環(huán)流維持的最小液體流量QLd都不斷的升高。隨著導(dǎo)流筒位置的下降,QLu稍微升高,而QLd逐漸降低。在氣體流量較低時(shí)(QG1.5m3/h),隨著氣體流量的增加,Qu以及QLd迅速下降,而在氣體流量較高時(shí)(QG1.5m3/h),氣體流量的變化對(duì)QLu以及QLd影響不大。并利用實(shí)驗(yàn)數(shù)據(jù)對(duì)QLu以及QLd進(jìn)行了關(guān)聯(lián),關(guān)聯(lián)式如下：(3)將粒子圖像測速法(Particle Image Velocimetry,簡稱PIV)和計(jì)算流體動(dòng)力學(xué)(Computational Fluid Dynamics，簡稱CFD)相結(jié)合,研究下噴式環(huán)流反應(yīng)器內(nèi)部的速度場分布規(guī)律,并將速度的測量值與k-ε湍流模型模擬值進(jìn)行了對(duì)比。結(jié)果表明,導(dǎo)流筒內(nèi)速度呈拋物線分布,隨著噴嘴位置的下降,拋物線圖形越陡,環(huán)隙的速度先降低后升高；隨著噴嘴的速度升高時(shí),反應(yīng)器內(nèi)各位置的速度值均升高,實(shí)驗(yàn)和模擬的結(jié)果的一致,證明了模型的正確性。(4)將下噴式環(huán)流反應(yīng)器應(yīng)用于2,4-二硝基甲苯(2,4-dinitrotoluene,簡稱DNT)催化加氫合成2,4-甲苯二胺(2,4-tolylene diamine，簡稱TDA)反應(yīng),對(duì)反應(yīng)器的體積、循環(huán)量以及換熱進(jìn)行了設(shè)計(jì),并與相同反應(yīng)條件下的攪拌釜式反應(yīng)器進(jìn)行了比較。實(shí)驗(yàn)表明,采用下噴式環(huán)流反應(yīng)器的體積約為攪拌釜式反應(yīng)器的10%。同時(shí)模擬了反應(yīng)器的體積和換熱器的面積隨著循環(huán)比的變化規(guī)律,最后確定了反應(yīng)系統(tǒng)的循環(huán)比為80,換熱器面積為355m2。
[Abstract]:Reverse Jet Loop Reactor (RJLR) is a new type of multiphase reactor with high efficiency, which is characterized by its simple structure, low investment, no rotating parts and sealing. Down-jet loop reactor is especially suitable for liquid-liquid, gas-liquid and gas-liquid-solid systems. It has been widely used in chemical, biological engineering, environmental protection and other fields, and has a good development prospect. The unsystematic research methods, testing methods and research contents lead to the lack of basis for the scale-up design and optimization of the reactor, and the lack of research on the operating rules of the loop reactor. The experimental results show that the gas holdup increases with the increase of superficial liquid velocity and superficial gas velocity, and the gas suction increases with the increase of liquid flow rate and nozzle position. According to the experimental results, the correlation of gas holdup was regressed as follows: (2) In the air-water system, the start-up law of the downspout loop reactor (the minimum liquid flow relaxation and the minimum liquid flow QLd maintained by the circulation) was experimentally studied. The minimum liquid flow rate QLu and the minimum liquid flow rate QLd maintained by the circulating current both increase continuously. With the decrease of the position of the guide tube, QLu increases slightly, but QLd decreases gradually. At the lower gas flow rate (QG1.5m3/h), Qu and QLd decrease rapidly with the increase of gas flow rate, but at the higher gas flow rate (QG1.5m3/h), the change of gas flow rate is obvious. Qlu and QLd have little effect. The experimental data are used to correlate Qlu and QLd. The correlations are as follows: (3) The particle image velocimetry (PIV) and computational fluid dynamics (CFD) are combined to study the velocity field distribution in the downspout loop reactor. The measured velocity was compared with the simulated value of k-e turbulence model. The results show that the velocity in the draft tube is parabolic. With the decrease of the nozzle position, the parabolic figure becomes steeper, and the velocity in the annulus first decreases and then rises. (4) The downjet loop reactor was applied to the catalytic hydrogenation of 2,4-dinitrotoluene (DNT) to synthesize 2,4-tolylene diamine (TDA), and the reactor volume, circulating capacity and heat transfer were designed. The experimental results show that the volume of the down-jet loop reactor is about 10% of that of the stirred tank reactor. Simultaneously, the variation of the reactor volume and the area of the heat exchanger with the circulation ratio is simulated. Finally, the circulation ratio of the reaction system is 80 and the area of the heat exchanger is 355m2.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ052
本文編號(hào)：2188181
[Abstract]:Reverse Jet Loop Reactor (RJLR) is a new type of multiphase reactor with high efficiency, which is characterized by its simple structure, low investment, no rotating parts and sealing. Down-jet loop reactor is especially suitable for liquid-liquid, gas-liquid and gas-liquid-solid systems. It has been widely used in chemical, biological engineering, environmental protection and other fields, and has a good development prospect. The unsystematic research methods, testing methods and research contents lead to the lack of basis for the scale-up design and optimization of the reactor, and the lack of research on the operating rules of the loop reactor. The experimental results show that the gas holdup increases with the increase of superficial liquid velocity and superficial gas velocity, and the gas suction increases with the increase of liquid flow rate and nozzle position. According to the experimental results, the correlation of gas holdup was regressed as follows: (2) In the air-water system, the start-up law of the downspout loop reactor (the minimum liquid flow relaxation and the minimum liquid flow QLd maintained by the circulation) was experimentally studied. The minimum liquid flow rate QLu and the minimum liquid flow rate QLd maintained by the circulating current both increase continuously. With the decrease of the position of the guide tube, QLu increases slightly, but QLd decreases gradually. At the lower gas flow rate (QG1.5m3/h), Qu and QLd decrease rapidly with the increase of gas flow rate, but at the higher gas flow rate (QG1.5m3/h), the change of gas flow rate is obvious. Qlu and QLd have little effect. The experimental data are used to correlate Qlu and QLd. The correlations are as follows: (3) The particle image velocimetry (PIV) and computational fluid dynamics (CFD) are combined to study the velocity field distribution in the downspout loop reactor. The measured velocity was compared with the simulated value of k-e turbulence model. The results show that the velocity in the draft tube is parabolic. With the decrease of the nozzle position, the parabolic figure becomes steeper, and the velocity in the annulus first decreases and then rises. (4) The downjet loop reactor was applied to the catalytic hydrogenation of 2,4-dinitrotoluene (DNT) to synthesize 2,4-tolylene diamine (TDA), and the reactor volume, circulating capacity and heat transfer were designed. The experimental results show that the volume of the down-jet loop reactor is about 10% of that of the stirred tank reactor. Simultaneously, the variation of the reactor volume and the area of the heat exchanger with the circulation ratio is simulated. Finally, the circulation ratio of the reaction system is 80 and the area of the heat exchanger is 355m2.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ052
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 劉亞娟;張金利;;液固下噴自吸環(huán)流反應(yīng)器流體力學(xué)特性[J];化學(xué)工業(yè)與工程;2007年03期
2 閆少偉;范輝;于智慧;梁川;李忠;孟凡敬;;二硝基甲苯加氫制甲苯二胺催化劑的研究進(jìn)展[J];化工進(jìn)展;2013年02期
，本文編號(hào)：2188181
本文鏈接：http://sikaile.net/kejilunwen/huagong/2188181.html
最近更新
教材專著
