可调式跌水网格混合器设计参数对水头损失的影响

Effect of design parameters of adjustable head fall grid mixer on head loss

通过中试试验,研究可调式跌水网格混合器的主要设计参数对水头损失的影响。试验结果表明:影响水头损失的各因素由主到次为网格间距、调节高度和网孔大小,且网格间距对水头损失的影响呈显著性;水头损失随调节高度、网格间距和层数的增加而变大,随网格开孔率的减小而略有增加;设置多层网格和较大的网格间距可使水流形成良好的湍流结构,在混合过程中形成涡旋串级,产生高比率、高强度的微涡旋;由试验数据可拟合出摩擦系数和雷诺数的关系,得到水头损失公式,进而为设备选型和工艺设计提供参数。

The effect of main design parameters of adjustable head fall grid mixer on head loss was studied with a pilot test, the results showed that： the influencing factors on head loss were listed in the following descending order of importance ： the space between grids, the height that water dropped from the bellouth and the dimension of grid. The space between grid layers influenced the head loss prominently; the head loss increased with the increasing of the height which water dropped from the bellmouth, the space between grids and the layers, meanwhile it also increased a little when the hole-rate of grid decreasing; the test also indicated that the setting of muhiplayer grid and wider space between grids could benefit the forming of turbulent structure, and the vortex cascade could formed in the mixing process which brought tiny vortex with high ratio, high intensity; based on the test data, head loss equation could be determined by fitting the relationship between friction coefficient and Reynolds number, which would supply parameters for equipment selection and process design.