新型布浆器的布浆机理及流动特性

在分析了方锥管布浆器的设计方法的基础上，利用方锥管布浆器不均匀的布浆特性，提出一种新型布浆器,把两个结构完全相同的方锥管布浆器对称地上下叠放在一起，由于两个方锥管布浆器的支管束的质量流量分布趋势相反，在混合室内形成互补的混合状态，使混合室出口支管束的质量流量分布更接近期望值，提高了布浆器的布浆性能。采用数值分析方法研究了新型布浆器内浆料的流动特性和布浆机理。结果表明，新型布浆器的浆料在混合室内进行了互补式的充分混合，有效地消除了方锥管支管束出浆的不均匀性。混合室支管束的质量流量分布趋势接近于理论曲线，降低了与期望值的偏差，布浆效果更好，证明了新型布浆器的布浆机理和结构设计是合理的。

Distributing mechanism and flow characteristic of a new pulp distributor

In order to distribute pulp more uniformly in the headbox,the design methods of the rectangular tapered distributor were analyzed.A new distributor was developed based on non-uniformity of pulp mass flow rate out of the manifold in the rectangular tapered distributor,which is designed by the Baines method or the methods derived from it.Then,the mechanism of pulp distribution in the new distributor was analyzed and the structure of the new distributor was designed.The new distributor was composed of two identical rectangular tapered heads,which were symmetrically put together one on the top of the other.The distribution trends of mass flow rate in manifold tubes of two rectangular tapered heads were just inverse.So the pulp out of manifold tubes was mixed complementarily in the mixing chamber and pulp distribution out of the mixing chamber was closer to the expected value than the old one.Finally the method of numerical simulation was adopted to research the flow characteristics of pulp in the new distributor.The results showed that pulp out of manifold tubes of two rectangular tapered heads was mixed complementarily and fully in the mixing chamber.The non-uniformity of pulp flow out of two rectangular tapered heads was effectively eliminated.So the trend of mass flow rate of pulp out of the mixed chamber was closer to the theoretical curve and expected value curve than that of the old model.In comparison of pulp distribution in models,the new model was obviously better than others and the deviation to expected value in the new model was minimum.For the new distributor,the analysis of distributing mechanism and the structure design were reasonable and the distribution of pulp was more uniform and satisfying.