(1. 中南大學 能源科學與工程學院，長沙 410083；
2. 中南大學 流程工業(yè)節(jié)能湖南省重點實驗室，長沙 410083)
摘 要: 為提高中心桶內固含濃度在60~70 g/L范圍內料漿的體積分數，以正交試驗和數值模擬的方法對沉降槽中心桶的5個結構參數進行數值仿真試驗。設計一個5因素5水平的L25(55)正交試驗方案，采用仿真軟件FLUENT對不同結構參數組合的沉降槽進行數值模擬計算，分析沉降槽中心桶的結構參數對中心桶內固含分布的影響規(guī)律，用極差分析和方差分析法對計算結果進行數理統(tǒng)計分析，得出5個因素對試驗指標影響的主次順序和顯著性，從而得到中心桶結構參數的優(yōu)化組合。結果表明：中心桶內固含分布的主要影響因素是進料射流管的直徑，沉降槽中心桶的最佳組合結構參數為中心桶直徑為3 m，中心桶深度為5 m、射流管直徑d1、d2和d3分別為0.8、0.48和0.36 m，環(huán)形擋流板離進料管下沿高度為0.22 m，喉嘴距為0.18 m；優(yōu)化工況下，中心桶內處于最佳絮凝固含濃度范圍內的料漿體積所占中心桶體積的體積分數變?yōu)榛A工況的4.8倍，顯著地提高沉降槽的絮凝沉降效率。
關鍵字: 沉降槽；中心桶；正交試驗；赤泥；絮凝；數值模擬
（1. School of Energy Science and Engineering, Central South University, Changsha 410083, China;
2. Hunan Key Laboratory of Energy Conservation in Process Industry, Central South University,
Changsha 410083, China）
Abstract:In order to improve the volume fraction of liquid with solid concentration of 60-70 g/L in the feedwell, a orthogonal experiment was proposed through a L25(55)orthogonal program to investigate the feedwell’s performance under five different structural factors. Numerical simulation as well as customed criteria was used to conduct the experiment and evaluate the results. The effects of structure parameters on solid concentration distribution in the feedwell were analyzed, further more, the range analysis and variance analysis were also used to analyze the experiment results. The primary and secondary order sequence of the five factors and their significant effects on design index are obtained, and then, the optimal combination of the feedwell structural parameter was received. The type of the jet pipe is the primary factor, and the optimal combination of the feedwell structural parameters is diameter of 3 m, depth of 5 m, the jet pipe diameter d1, d2 and d3, respectively, of 0.8, 0.48 and 0.36 m, the annular baffle 0.22 m below the feed pipe, throat nozzle distance of 0.18 m. Under the optimal condition, the volume fraction of the best solid concentration can be increased by 4.8 times compared with that of the base case, which significantly improves the efficiency and process of the thickener.
Key words: thickener; feedwell; orthogonal test; red mud; flocculation; numerical simulation
