文献翻译-机械搅拌槽挡板的研究

英文翻译 Mechanical stirring chest back plate research Mechanical stirring chest reasonable structure including mixer choice, stirring chest structure as well as back plate structural style. Any placement the static part all constitutes the back plate beside in the stirring device trough. Thus the back plate may divide into two kinds: The most common back plate form is vertical installs Yu Caobi the component, namely wall back plate; Another kind is the special back plate, the shape, the position respectively different, is confident the back plate, the superficial back plate and so on, in the recuperator tube and the insertion trough under the liquid level vapor pipe, the air conduit and the inlet pipe and so on internal component also can play the back plate role. First, the back plate function back plate basic function, is changes the liquid rotary motion the vertical tilting motion, eliminates the whirlpool, simultaneously improves exerts the power the effective use factor. The back plate has limited the liquid tangential speed, increased axial and the radial velocity component, its purification is enable the mixer exhaust stream to have a wider mobile radius, the exhaust stream which mixer revolving produces, because of the trough wall and the back plate function, forms in the stirring chest the complex flow field, the flow pattern, the speed size and the direction and so on has because of the mixer impeller and the back plate mutual function the change, the mix effect obtains the remarkable enhancement. Second, the entire back plate condition power is the mixer characteristic parameter. Regarding specific mixer (impeller form and rotational speed invariable), the power increases along with the back plate coefficient increases. But when the back plate coefficient achieved when certain value, the power cannot further increase, but is the basic maintenance is constant. This time thrustplate coefficient is called the entire back plate condition, namely the agitation power achieves saturated. In the stirring chest actual design, according to the back plate width, quantity empirical stipulated that, usually uses vertical Yu Caobi 4 width bd is the D/12D/10 back plate (called generally it “standard back plate”) satisfies the entire back plate condition, this is because of the basis formula (1), under the entire back plate condition back plate size, quantity and the shape are by no means most superior. The suitable back plate condition provides the flow pattern can drive the entire trough the material movement, guarantees the intensive mixing; But excessively many back plates, namely the stirring chest the back plate, has reduced the overall to be mobile, and will mix the limitation in the partial region, will cause not the good mix performance. Third, the back plate to the power the influence in the non-back plate stirring chest, any type mixer, will all produce the tangential flow and the swirl. After establishes the back plate about, the tangential flow comes under the suppression or the hindrance, in the trough has the large scale movement which changes, the whirlpool elimination. The standard back plate contains the dual meanings: Power saturated and whirlpool elimination. But the standard back plate optimizes the structure by no means. 1st, agitation power computation in hydrometallurgy process, mixer impeller usually for propellor type, pusher type and turbine wheel type 2nd, the back plate structure to the power accurate number influence (1) theoretical analysis basis mixer power hydromechanics foundation analysis, the power accurate number physics significance is the friction coefficient. Speaking of the mixer impeller, under the full turbulent conditions, the form resistance is the resistance important constitution, thus the power accurate number is decided by the stirring chest geometry structure. The back plate gives the different impeller by the different influence (2) experiment analyzed the back plate to increase the mixer power consumption, simultaneously improved the mix effect. Regarding the different form paddle blade, the back plate influence is different. Under the same medium condition, the use different form paddle blade, in has in 4 kind of back plate structure small stirring chest to carry on the experiment (in experiment nd =4), obtains a group of power accurate number, see Table 1. Data may obtain the following structure by Table 1: The back plate coefficient pair process radial flow paddle blade (disc turbine wheel oar) affects in a big way, to simultaneously produces the radial flow and the axial flow paddle blade (flap turbine wheel oar) is next, the pair process axial flow paddle blade (propeller) affects slightly; Regarding identical type paddle blade, back plate coefficient enlargement, also causes the power accurate number the increase; When impeller form and back plate coefficient same, the back plate structure improvement, may change the power accurate number similarly, and in satisfies the power input under the condition to improve the medium the mix performance. In addition, further observes the experimental phenomenon also to be possible to discover that, the chart 1a narrow back plate structure, the medium center has produced the obvious whirlpool and the volume in the experiment attracts, has shown the small back plate although the power dissipation is small, has not achieved the elimination whirlpool actually the goal, but Figure 1 b, c, d back plate structure not this phenomenon occurrence. But at the back of the chart 1d standard back plate appeared the medium minor cycle, and as a result of the back plate hindrance, in this minor cycle medium is unable to be separated from the renewal, therefore forms the endless loop. Explained this kind of structure caused the partial mix not to be full; But chart 1b, at the back of c back plate although also has the minor cycle, but because the back plate leaves leeway the crevice, causes in the minor cycle the medium to carry off unceasingly by other direction liquid flow, the new medium may supplement unceasingly, its mix effect is extremely ideal. Fourth, the practical application back plate structure often receives the stirring chest trough body material the limit. The hydrometallurgy uses the agitation equipment internal material usually for the fine metal, the metal outer covering inside lining rubber, the metal outer covering inside lining rubber and the anti-corrosive brick, the coagulation outer covering inside lining glass fiber reinforced plastic or the rubber and the anti-corrosive brick and so on. Regarding the fine metal or the metal outer covering inside lining rubber stirring chest, the early time uses chart 1d much the back plate structure, recently for coordinates the mixer impeller pattern, chart 1b, the c back plate structure becomes the mainstream. In addition, also has conceived in the fine metal trough in vivo establishment mesh back plate or the grill back plate, on the one hand saves the material, on the other hand coordinates the impeller to change the medium flow pattern, enhances the agitation effect. But these all wait for unceasingly the experimental study. Speaking of the metal or the concrete outer covering inside lining anti-corrosive brick stirring chest, because the back plate brick must insert in turn the trough nogging, causes it to become a whole with the trough wall, avoids stirring in the process brick abscission, therefore and hollows out the structure to the wall not suitably to use generally, mostly continues to use chart 2the back plate structure, various refineries presently use overwhelming majority lining brick stirring chest for this kind of structure. But the Zhuzhou Refinery lining brick leaching vat and the purification trough are exceptions, because some overseas stirring device supplier proposed, it provides the mixer must under the specific back plate structure be able to achieve the anticipated agitation effect, namely the back plate must leave the bottom according to the basic size to the wall, therefore we to designed have made the change which as shown in Figure 2. Although this change has satisfied the agitation request, but invested many increases (each stirring chest stainless steel amount of use to increase near 2t). How therefore causes the mixer and the back plate structure in the lining brick stirring chest achieved a more perfect conjunction, is worth further studying. Therefore, regarding the agitation mix performance optimized request, causes the back plate to receive the attention in agitation flow field function, and enable the back plate form to tend to the diversification. In particular the multi-impellers, the poly-phase system, disperse, the solid in the gas aerosol and so on under the operating statuses, the back plate design has certain influence to the overall system performance, the standard back plate, the standard impeller structure can adapt the specific technological requirement not necessarily. In recent years appeared refers to the shape back plate, the oval cross section back plate, the concave shape back plate, half cauldron back plate as well as the reverse part back plate and so on, all aims at the different mix goal, satisfied its agitation request. Thus under the non-standard condition impeller, the back plate and affect mutually, becomes the agitation research the important constituent, and becomes the craft improvement one way. The specific agitation impeller and the specific form back plate design unifies, may give the more outstanding shop characteristics. 中文翻译 机械搅拌槽挡板的研究 机械搅拌槽的合理结构包括搅拌器的选择、搅拌槽结构以及挡板结构形式。任何安置于搅拌装置之外的槽内静止部件都构成挡板。因而挡板可分为两类：最常见的挡板形式是垂直安装于槽壁的构件，即壁挡板；另一类是特殊挡板，形状、位置各异，有底挡板、表面挡板等，换热管和插入槽内液面下的蒸气管、空气管和进料管等内部构件也能起到挡板作用。 一、挡板的作用 挡板的基本作用，是将液体的旋转运动改为垂直翻转运动，消除旋涡，同时改善所施加功率的有效利用率。挡板限制了液体的切向速度，增加了轴向和径向速度分量，其净化作用是使搅拌器排出流具有更宽的流动半径，搅拌器旋转所产生的排出流，因受槽壁和挡板的作用，在搅拌槽内形成复杂的流场，流型、速度大小和方向等均因搅拌器叶轮与挡板的相互作用而有所变化，混合效果得到显著加强。 二、全挡板条件 功率是搅拌器的特征参数。对于特定的搅拌器（叶轮形式和转速不变），功率随挡板系数的增大而增大。但当挡板系数达到一定数值时，功率不会进一步增大，而是基本保持恒定。此时的档板系数称为全挡板条件，即搅拌功率达到饱和。 在搅拌槽的实际设计中，按照挡板宽度、数量的经验性规定，通常采用垂直于槽壁的 4 块宽度 bd 为 D 12 D 10 的挡板（一般称之为 “标准挡板 ”）来满足全挡板条件，这是因为根据公式（ 1），全挡板条件下的挡板尺寸、数量和形状并非最优。适当的挡板条件所提供的流型能够带动全槽的物料运动，确保充分混合；而过多的挡板，即搅拌槽的过挡板化，将减少总体流动，并将混合局限在局部区域，导致不良的混合性能。 三、挡板对功率的影响 在无挡板的搅拌槽中，任何类型的搅拌器，都将产生切向流并形成旋涡。设置挡板后，切向流受到抑制或阻碍，槽内产生上下翻动的大幅度运动，旋涡消除。标准挡板包含双重含义：功率饱和与旋涡消除。但标准挡板并非优化结构。 1、搅拌功率的计算在湿法冶金过程中，搅拌器叶轮通常为桨式、推进式和涡轮式， 2、挡板结构对功率准数的影响（ 1）理论分析根据搅拌器功率的流体力学基础分析，功率准数的物理意义是阻力系数。对于搅拌器叶轮而言，在充分湍流状态下，形状阻力是阻力的重要构成，因而功率准数取决于搅拌槽的几何结构。 挡板给予不同的叶轮以不同的影响。 （ 2）实验分析挡板增加了搅拌器功率的消耗，同时改进了混合效果。对于不同形式的桨叶，挡板影响不同。 在相同介质条件下，使用不同形式的桨叶，在具有 4 种挡板结构的小型搅拌槽中进行实验（实验中 nd 4），得到一组功率准数，见表 1。由表 1 的数据可以得到如下结构： 挡板系数对产生径向流的