含WC纳米微粒的镍基复合镀层的滑动磨损机理研究

本文通过对含WC纳米微粒的镍基复合镀层在干摩擦滑动磨损条件下，磨损失重、施加载荷、滑动距离、镀层种类之间的正交实验及对磨损表面的显微分析及形貌观察，发现在不同的磨损条件下，复合镀层的磨损表面的显微形貌有很大的不同。实践证明，在不同的干摩擦磨损条件下，可能发生粘着磨损，也可能发生犁削磨损，或两者同时发生。     

机械立窑零部件主要失效形式及原因

机械立窑零部件主要失效形式及原因一、磨损：磨损导致的机械失效占８５—９０％，这种磨损可分为有润滑条件下的磨损和无润滑条件下的磨损。一般来说有润滑条件下的磨损速度较慢，但如果保养不好这种磨损也可能转变为无润滑磨损，如润滑油用完、密封条件不好，杂质混入润...     

循环流化床脱硫塔磨损处理措施及防治

近年来，循环流化床半干法脱硫工艺逐渐成为工业烟气治理的主流工艺，然而脱硫工艺、结构设计、质量控制存在一定的不足，脱硫塔本体极易出现磨损。塔体磨损主要表现在文丘里磨损、锥形段磨损、直管段磨损，为根治磨损，最终需要对文丘里进行更换。通过分析文丘里更换的实施步骤，总结日常运行过程中预防磨损的维护检修要点，确保循环流化床脱硫系统的稳定可靠运行。     

基于离散元法双螺杆挤出机磨损特性分析

双螺杆挤出机在生产过程中经常会出现螺杆磨损等问题，严重影响了螺杆的使用寿命和聚合物加工的品质。本文采用离散单元法（DEM），结合Archard磨损模型，对同向啮合双螺杆挤出机螺杆磨损进行数值模拟，分析螺杆转速和填充率等因素对双螺杆挤出机磨损特性的影响规律。结果表明，螺杆磨损主要发生在螺棱的顶部区域以及进料口处，在物料进入机筒入口处会发生严重的挤压磨损；随着螺杆转速和填充率的增加，螺杆的磨损程度不断增大；料槽后方输送段的螺杆主要产生横向切削磨损，切向累积能量是导致磨损的关键因素。     

抽油机井杆管磨损深度计算方法研究

本文系统讨论了抽油机井杆管磨损形式，根据杆管磨损的截面的几何关系，分别建立斜井狗腿度导致的磨损段、末端失稳螺旋屈曲磨损段以及旋转油管情况下的杆管磨损深度和磨损截面积之间关系的理论方法，建立抽油机井杆管摩擦磨损计算模型，可以在已知抽油机井侧向载荷分布的基础上计算不同时间的杆管磨损深度和截面积，为判断油管磨漏、杆柱接箍剩余截面积等提供依据。应用该模型编制的成果软件在我国油田对比分析20井次，证实其计算的磨损是比较可靠的。     

电机用电刷磨损机理的几点探索

分析了有色电刷，黑色电刷在相同条件下磨损机理的变化，分析了不同材质电刷在某些试验参数相同的条件下，磨损差别较明显的原因。研究了正负电刷磨损规律不同的磨损机理及电气性能与机械性能磨损机理。     

超高分子量聚乙烯摩擦磨损特性

用磨损试验机对超高分子量聚乙烯（UHMWPE）进行滑动磨损试验，考察了对磨钢轮的粗糙度，对磨时间及载荷对磨损及摩擦系数的影响。结果表明，UHMWPE具有较好的耐磨性，与45^#钢轮对磨时其磨损量很小，但其耐硬质的SiC颗粒磨损的性能不佳；UHMWPE在跑合期及加速磨损期摩擦系数较大，而在稳定磨损阶段则较低；载荷的加大会增大UHMWPE的摩擦系数。     

氧化锆陶瓷的摩擦磨损性能

研究了ＺｒＯ２砂同工况条件下的摩擦磨损特性。运用扫描电镜，Ｘ射线衍射技术等来观察和分析磨损前后摩擦副的表面形貌、截面特征、磨悄形状及其相组成，从而分析磨损的机制。实验结果表明：干摩擦磨损和加水润滑的摩擦磨损主要机制是粘着磨损和疲劳磨损机制，并随着工况的     

干摩擦及水润滑下氧化锆-氧化铝层状复合陶瓷的摩擦学行为

研究了氧化锆氧化铝三层结构层状复合陶瓷在干摩擦和水润滑下的摩擦学性能和磨损机制，并比较了氧化锆-氧化铝单层陶瓷在相同条件下的摩擦学性能。结果表明：相同条件下，层状陶瓷的摩擦系数和磨损率均低于单层陶瓷，根本原因在于层状陶瓷表面的压应力导致的韧性提高和磨损表面剪切应力的降低。水润滑可以有效地降低复合陶瓷的摩擦磨损，主要原因是由于水引起主导磨损机制发生变化，由干摩擦时的磨粒磨损和粘着磨损转变为摩擦化学磨损和疲劳磨损。     

硫酸焙烧熄灭器输送螺旋的失效分析及选材探讨

根据螺旋叶片磨损失效的特征，对叶片的运行工况、磨损条件、磨损机理和对磨损的主要因素作详细分析，推导出在特定磨损条件下对叶片材质的具体要求，从而合理选材。     

热电厂锅炉给水泵平衡套密封改进

针对热电厂锅炉给水泵出口段及平衡机构汽蚀腐蚀现象,分析故障产生原因,在总结检修处理方案的基础上,通过对平衡套密封结构进行改造,采取多级复合密封,彻底解决泄漏引起的汽蚀腐蚀问题。     

对磷酸二铵生产工艺一些问题的认识

阐述生产磷酸二铵 (DAP)的不同工艺 ,其热平衡、水平衡、氨平衡与中和度控制的不同情况对装置生产带来的影响。认为槽式工艺、双管工艺和混合工艺较易解决热平衡问题 ,产品水分易达标 ,氨损失小 ,生产运行稳定 ;单管工艺生产 DAP系统的热平衡、产品水分达标 ,稳定运行难度均较大 ,氨损失大。提出在建设磷铵装置时要重视选定合适的工艺。     

A population balance approach to describing bulk attrition

Attrition arising from mechanical damage during processing has been studied in annular shear cells, these having the ability to vary readily the testing stress and shear strain. A population balance approach has been deployed to analyse the evolution of the size distribution with strain which bases its arguments on the kinetic theory of grinding. This incorporates the ideas of a selection function and a breakage function. The extent of attrition is determined in terms of three parameters, one related to the selection function, one to the breakage function, and additionally one which allows for the balance of fracture and abrasion. The product size distribution of the Gaudin-Schuhmann form is consistent with experimental findings from annular shear cells. Whatever reasonable physical assumptions are made about the form of the selection and breakage functions, and of the balance between fracture and abrasion, particle size distributions of the same form arise. From comparisons with several materials, the index in the breakage function is consistent with the particle fracture pattern observed experimentally.     

木糖结晶动力学模型

<正>木糖(D-xylose)是一种新型的甜味剂.其生产原料为农业植物纤维废料,如玉米芯、甘蔗渣、棉子壳、甘蔗髓、稻壳等.中国是农业大国,木糖的原料极其丰富,生产木糖是一个具有较高附加值的二次资源利用项目.国内已有数家企业投入生产,但许多技术问题尚未解决,制约了经济效益,其中结晶工序也是瓶颈之一.本文作为木糖生产新工艺的重要环节,研究了木糖连续冷却结晶过程,并根据结晶动力学的粒数衡算理论(Population Balance)及其连续稳态的动力学测定方法,探索了木糖的结晶动力学模型.国内外迄今尚无这方面的报道.1 粒数衡算理论     

石灰炉热工参数在线监测与节能

根据炉内热平衡和物料平衡原理，建立石灰炉炉内反应与传热过程数学物理模型以及石灰煅烧分解率的在线监测模型，运用计算机仿真研究各操作参数对石灰石煅烧过程的影响，提出改善技术经济指标的措施，实现石灰炉运行的集中监控与自动控制，达到石友炉高效稳定运行、增产降耗的目标。     

Identification of the grinding mechanisms and their origin in a stirred ball mill using population balances

The objective of this work was to understand the origin of the stresses and the nature of the grinding mechanisms in a high-shear ball mill. The ball mill used was a Dynomill and the grinding media consisted of zirconium oxide beads. The ground powder was a poorly water soluble product. The particle size distribution was analyzed with laser diffraction.A population balance model enabled to calculate the breakage function from the experimental data. The breaking parameters were used to determine the grinding mechanism at different grinding conditions. The grinding mechanism depends on the orientation and intensity of the forces applied on the particles. The grinding mechanisms were determined from the grinding experiments and correlated to the movement of the grinding media in the grinding chamber and the applied mechanical stresses.The observed grinding mechanisms are cleavage and some fracture for coarse particles , cleavage and abrasion for intermediate particles and cleavage for fine particles (smaller than ).The grinding mechanisms are related to the movement of the grinding media in the grinding chamber. Cleavage and abrasion of particles are the result of compression forces and shear in the centrifuged packed bed of grinding beads. The grinding mechanism does not change when changing the operating conditions and the packed bed of media is similar in the studied ranges of operating conditions.     

Experimental and model investigation on the mass balance of a dry circulating fluidized bed for flue gas desulfurization system

A moderate temperature dry circulating fluidized bed flue gas desulfurization (CFB-FGD) process was developed using rapidly hydrated sorbent. This technique has the advantages of low cost, no water consumption, and a valuable dry product CaSO₄. To keep the system operation stable, a mass balance model, based on cell model considering flow state, particle abrasion, particle residence time, particle segregation and desulfurization processes, was built to predict the system state and optimize the operating condition. Experimental studies were conducted on a pilot-scale CFB-FGD system with rapidly hydrated sorbent made from CFB circulating ash and lime (circulating ash sorbent) or coal fly ash and lime (coal fly ash sorbent). Calculated results were compared with experimental results and the relative error was less than 10%. The results indicated that feed sorbent mass, feed sorbent size, superficial gas velocity, particle abrasion coefficient and cyclone efficiency had significant influence on the mass balance of CFB system. The circulating ash sorbent was better than the coal fly ash sorbent, for providing higher desulfurization efficiency and being better for the CFB-FGD system to achieve mass balance.     

重油催化装置干气纯度的软测量

以吸收塔系物料平衡,相平衡分析计算为基础,建立干气纯度的预测模型,为干气纯度的控制提供更为可靠的控制依据。     

年产1000万吨赖氨酸发酵工艺设计

赖氨酸作为人体必须氨基酸之一,在食品工业、医药工业和饲料工业上有着广泛的应用。由于发酵法工艺简单,生产周期短,本文选择以发酵法进行赖氨酸的工艺设计。针对该工艺进行了物料衡算和热量衡算,经过该工艺生产工艺设计可以得到较高产率和纯度的赖氨酸。     

总焓平衡法在合成氨系统热量平衡中的应用

从实用的角度介绍了合成氨气体焓的计算方法，并对采用元素平衡和能量平衡方程的总焓平衡来作热量衡算的方法进行了讨论。