利用VOF(volume of fluid)方法对海水淡化中空离心式喷嘴的气液两相流动进行了数值模拟,并将模拟结果与实验数据进行了对比,两者吻合良好。对喷嘴出口扩散角和出口直径等结构参数进行了比较分析,得出结论:喷嘴出口扩散角越大,喷淋液锥...利用VOF(volume of fluid)方法对海水淡化中空离心式喷嘴的气液两相流动进行了数值模拟,并将模拟结果与实验数据进行了对比,两者吻合良好。对喷嘴出口扩散角和出口直径等结构参数进行了比较分析,得出结论:喷嘴出口扩散角越大,喷淋液锥角度也越大,但出口扩散角度并不是越大越好,实际应用中存在一个最优值;喷嘴出口扩散角会影响到空气心吸气气流的速度大小;喷嘴中心轴线处空气心直径随着喷嘴出口直径的减小而变小,该处速度曲线有两个跃动,第一个跃动发生在刚进入喷嘴的位置(z=0.05m),第二个跃动发生在喷嘴出口收缩段至出口扩张段(0.02～0.04m);喷嘴出口直径越小,对喷嘴内接近出口处液体的加速作用越明显,出口截面上的径向速度越大。展开更多
Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano b...Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.展开更多
文摘利用VOF(volume of fluid)方法对海水淡化中空离心式喷嘴的气液两相流动进行了数值模拟,并将模拟结果与实验数据进行了对比,两者吻合良好。对喷嘴出口扩散角和出口直径等结构参数进行了比较分析,得出结论:喷嘴出口扩散角越大,喷淋液锥角度也越大,但出口扩散角度并不是越大越好,实际应用中存在一个最优值;喷嘴出口扩散角会影响到空气心吸气气流的速度大小;喷嘴中心轴线处空气心直径随着喷嘴出口直径的减小而变小,该处速度曲线有两个跃动,第一个跃动发生在刚进入喷嘴的位置(z=0.05m),第二个跃动发生在喷嘴出口收缩段至出口扩张段(0.02～0.04m);喷嘴出口直径越小,对喷嘴内接近出口处液体的加速作用越明显,出口截面上的径向速度越大。
基金West Virginia State Coal and Energy Research Bureau(WVCERB)the Department of Mining Engineering,West Virginia University
文摘Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.
