泥沙输移的理论研探

本文通过对泥沙颗粒在水中的受力情况分析，从理论上导出了描述推移质运动的数学表达式．在此基础上，又导得了挟沙水流的底部含沙量，从而使泥沙运动的扩散方程能够方便地运用到工程实际问题之中．     

快速流化床内探头设置方向对传热系数测量结果的影响

本文在一高8m,直径186mm 的快速流化床中采用小型电加热探头测定了床层与换热面之间的局部传热系数,实验中通过将探头向上和向下设置考察了探头设置方向对局部传热系数的影响,实验表明探头在床中的设置方向不同将对传热系数的测定值产生一定的影响:另外在同一床层浓度下,操作气速和固体循环速率的变化将对传热系数产生直接的影响     

SORPTION EQUILIBRIUM OF COPPER BY PARTIALLY-COAGULATED CALCIUM ALGINATE GEL

The sorption equilibrium of dissolved copper by spherical partially-coagulated gels of calcium alginate was investigated in this work. The gels were formed by dispensing a viscous algin (food grade sodium alginate from kelp) solution with a multi-tip dispenser into 0.05 M CaCl₂ solution in a loop fluidized bed reactor. The resultant semi-rigid spherical gels were then transferred to another reactor operated batch wise to absorb dissolved copper at low concentrations (10-40 ppm). When the concentration of the inert neutral salt NaNO₃, added to the reactor fluid was 0.01 M, the amount of copper absorbed was found to be substantially higher than that at 0.1 MNaN0₃. The conventional Langmuir's model based on the concentration of copper in solution yielded different values of conditional stability constant at different ionic strengths in the reactor fluid. However, by defining the copper-binding stability constant on the basis of copper activity in the gel phase with the competition from calcium for metal binding sites taken into account, a unique copper-binding stability constant and a unique calcium-binding stability constant were obtained. The numerical procedure for estimating the activity of copper in the gel fluid was modified from Jang et al. Water Research, 1990, in press).     

Fundamental investigation of plug conveying of cohesionless particles in a vertical pipe (pressure drop and friction of a stationary plug)

A stationary packed bed of cohesionless particles is set up in a vertical pipe for the fundamental study of plug conveying. The effect of flow acceleration or deceleration on the pressure drop of the plug is investigated first. It is found that the pressure drop increases due to the flow acceleration and vice versa. Next, the following three kinds of experiments were made for the study of friction characteristics: 1. Friction between the plug and moving wall without air flow, 2. Friction between the plug and wall with downward air flow, 3. Friction between the plug and wall with upward air flow. The results are compared with the theory established in powder mechanics. The state of stress being of the active or passive case is discussed. Finally the problem of particles raining down from the back of the plug is studied. It is shown that the air velocity necessary to support the particles can be calculated based on a simple analysis of pressure distribution around the particles.     

旋转填料床强化Fenton试剂处理DNT废水实验研究

采用旋转填料床强化Fenton试剂处理DNT废水,确定了最佳工艺条件:Fe2+投加量为0.07mol/L,H2O2的投加量为0.53mol/L,pH值为1,温度为40℃,反应时间为5h,旋转填料床转速为1 500r·min-1;该条件下处理DNT废水,COD去除率达到98.57％,硝基化合物去除率达到97.64％,BOD/COD为0.62,后续处理可采用一般生化法;并对该最佳工艺条件进行放大化研究,为该法的工业化应用奠定基础.     

适于自动绕簧机的床用钢丝生产工艺

选用优质盘条,按含碳量分组投料,经铅浴处理后拉制成所需的床用弹簧钢丝,通条性能均匀,线盘平整度好。这样的钢丝在自动绕簧机上绕制性能好,材料消耗低,生产效率高,绕制弹簧的质量好     

三峡水库变动回水区铜锣峡河段演变研究

三峡水库铜锣峡河段泥沙模型进行了正常蓄水位160m,170m,175m及180m方案的浑水试验;该河段分别处于各种方案的变动回水区上、中、下段位置。文中综合分析了这些试验成果,认为变动回水区内各河段悬移质泥沙淤积量的多少,主要取决于汛期壅水高度,因此优化三峡水库调度是解决变动回水区航道、港口泥沙问题的重要手段之一。建库后卵石推移质主要淤积在回水末端附近和变动回水区上段,应针对不同河段特点实施整治工程。     

立堵截流规律再探讨

本文从龙口下游水力条件出发，探讨下游水深、河床糙率以及抛料堆积体对立堵规律的影响。最后又介绍了龙口平均流速的理论计算方法。     

关于沉沙池计算中的水流挟沙力

一度流超饱和输沙法是考虑了超饱和输沙特点的泥沙沉降计算方法．沉沙池内水流挟沙力是一定水力和床沙组成条件下水流挟带床沙质的能力．从已建沉沙池沉降标准、池内设计水流水力以及床沙组成条件来看，沉沙池运行前期、中期水流挟沙力一般都很小．用一度流趋饱和输沙法计算沉沙池沉降率时可不考虑水流换沙力的影响．均匀流条件下，用不考虑挟沙力和考虑挟沙力的一度流超饱和输沙法分别计算沉沙池的沉降率，二者相对误差取决于挟沙力与进口含沙量之比，该比值小于0．2时，相对误差小于20％．沉沙池内挟沙力与进口含沙量之比小于0.2时，用一度流趋饱和输沙法计算沉沙池的沉降率，可不考虑水流挟沙力的影响．     

那吉水利枢纽坝基第三系软岩工程地质特性评价

通过大量的勘探和试验工作，分析那吉水利枢纽坝基第三系软岩的工程地质特性，并参照国内外类似工程的经验，对软岩地基进行评价，最后提出初步处理措施。