弧形抄板的结构与应用

弧形抄板在８０年代后期,已在建材行业推广,主要用在烘干机、冷却机等设备上。１９９６年鲁北化工总厂在改造３ｍ烘干机时,应用了弧形抄板,紧接着在３ｍ造粒机中进行了试验性使用。由于该抄板在打疤时较困难,故主要用在干燥段,老河口化肥厂等在同规格造粒机的干燥段采用了这种抄板,效果很好。弧形抄板为焊接结构（见图１）,基本部分为圆弧状,两端为直线段。在其两侧焊有筋板,加固与筒体的整体性,并使抄板成为一个斗子,以便抄起更多的物料充实料幕。弧形抄板的功能在于改善物料的抄扬形式,提高热能利用率或冷却效率。目前,…     

硝酸磷肥回转滚筒干燥机抄板改造

介绍硝酸磷肥干燥机抄板的改造情况。拆除若干组损坏频繁的十字抄板,代之以升举抄板,改造后设备故障率降低,连续运行时间延长,企业效益提高。     

转筒干燥器抄板的数值模拟

采用离散单元法研究转筒干燥器抄板形式及转筒转速对颗粒混合程度的影响。抄板形式和转筒干燥器转速在不同程度上影响颗粒的混合。相同转速下,转筒干燥器内设组合抄板时混合较优。     

基于Rocky DEM的松散润叶筒内抄板作用的模拟与优化

为深入研究松散润叶筒内叶片在抄板上的掉落过程,提升叶片的耐加工性,利用三维建模软件建立松散润叶筒三维模型,通过Rocky 2021 R2离散元仿真软件创建薄片柔性叶片进行数值模拟,对叶片在松散润叶筒内抄板上的运动进行可视化计算。根据抄板上叶片的持料量百分比曲线和落料速率曲线,将叶片的掉落过程分为两个阶段。结果表明：片状颗粒的受力区别于刚性球体间的点对点接触受力,叶片形状不可忽略;松散润叶筒转速为15 r/min时,叶片在筒体底部分布较少,筒体上半部分分布较多;抄板安装角度为80°时,板上持料量增多,抄板倾角较合理,增温增湿效果最优;松散润叶筒倾角对叶片在抄板上掉落的轴向速度影响显著。通过仿真得出叶片在抄板上掉落过程的优化参数,有助于松散润叶过程调控,指导实际工业生产。     

螺旋折流板与弓形折流板换热器的性能比较

针对螺旋折流板换热器的折流板的角度提出了一些改进措施。在自行设计的换热原理试验台上,5#柴油走壳程,水走管程,分别对12°,18°的单螺旋和18°的双螺旋折流板和弓形折流板换热器的阻力和传热性能进行了试验研究。试验结果表明,螺旋折流板阻力只有弓形的30%,此外,在同样的压降下,螺旋折流板传热效率也提高10%。     

石棉乳液抄取板的生产改进及污水处理技术

以改性苯丙乳液代替丁腈胶乳作为抄取板用胶,改进了石棉乳液抄取板的生产.采用气泡漂浮、过滤、回用的处理方法,使污水回用率达85%,节约了成本,减少了环境污染.     

复合肥干燥机防粘壁技术

介绍复合肥干燥机防粘壁的技术:干燥机外部安装振动锤打击振动防止结壁及振动锤的制造、安装、布点方法;调整干燥机内部抄板适度的密度、高度和角度;处理好原料、配方与工艺操作的关系。综合实施各项技术可有效解决复合肥干燥机的粘壁问题,使全年设备开工天数提高30天左右,并可提高产品质量、产量,节约原料、燃料、电能消耗。     

滚筒流化床造粒机的改进

针对大颗粒硝酸盐、硝基复合肥产品生产中滚筒流化床造粒机存在的抄板脱落、料帘分布不均、物料易结疤、喷嘴易堵塞、卸料不方便等问题,采取壳体与内部部件焊接连接,改进抄板安装角度,改进流化床分风网板与水平面夹角及喷嘴结构,调节返料比,增加卸料板等改进措施。改进后,提高了造粒产品的质量和产量,效果良好。     

自身返碱重灰煅烧炉的抄板改造

我公司为了提升重灰煅烧炉产能，将螺旋管由原设计的"三根返碱一根出碱",改为了"两出碱，两返碱",由此带来螺旋倒碱管堵塞、炉头泄漏、下游设备腐蚀等问题。出现问题的主要原因是原设计中炉头抄板较短，推送能力不够。通过更改炉头抄板尺寸、增加一排炉头抄板等措施，达到了预期效果。     

干燥机十字抄板组的改造

分析干燥机十字抄板组的损坏原因,并通过计算确定技术改造方案,使十字抄板组的损坏问题得到解决。     

直热式转筒干燥过程物料停留时间理论推导

为了对物料在直热式转筒干燥机内理想扬料板作用下停留时间进行计算研究,根据扬料板作用下的物料在转筒内撒落分布均匀状态,建立了理想扬料板的截面方程,采用建立的理想扬料板的截面方程,导出了随着转筒转动到不同位置的扬料板持料量,在此基础上,分析物料在直热式转筒干燥机内的实际运动情况,建立转筒内物料运动的数学模型,导出物料在转筒内的停留时间,对现有停留时间计算方法进行了修正。研究为扬料板作用下直热式转筒干燥过程物料停留时间的计算提供一种参考。     

The movement of solids through flighted rotating drums. Part i: Model formulation

A rotating drum with lifting flights is an important piece of industrial equipment used to contact granular solids with a gas stream. Applications include the drying of materials such as wood chips, coal, grain, and metallurgical ores, the cooling of fertilizer pellets and more recently the combustion of coked oil sand. A new mathematical model for a rotating drum with lifting flights that predicts the residence time of particles is proposed. Particle motion is considered in both the airborne phase and the dense phase. Moreover, the holdup and the axial flow rate of particles in the two phases are determined separately. Overall, the model is more flexible than previous models. The drum may be inclined or horizontal with cocurrent or countercurrent flow, may have any type of lifting flights and may be underloaded or overloaded.     

干熄焦提升机安装方式的优化

干熄焦施工场地狭窄,大吨位吊车难以靠近站位,合理选择吊车,既可以节约吊装成本,又可以解决吊装场地狭窄等问题,缩短吊装时间。     

FLIGHT DESIGN I N ROTARY DRYERS

ABSTRACT

The effectiveness of the rotary drum drying process depends primarily on the contact between the cascading particles and the drying gases within the drum. This paper considers first the factors which contribute to the cascade pattern and which influence the design of the lifting flights which distribute the particles in the top half of the drum. A generalised calculation design procedure for flights is developed and described in detail for the case of Equal Horizontal Distribution (EHD) flights. It is reasoned that the EHD flights, which have an equal distribution of particles across the horizontal diameter of the rotary drum dryer, give the optimum distribution in the context of the heat and mass transfer operations of the rotary drying process. An industrial design which approximates the optimum flight design is suggested.     

Effect of Gravity on the Macroscopic Advancing Contact Angle of Sessile Drops

A series of experiments were conducted in a reduced gravity (near‐free‐fall) environment (g = 0) and on ground (g = 1) to study the effect of gravity on the advancing contact angles of sessile drops. The reduced net acceleration force was produced by parabolic flights. The ground experiments were conducted for various three‐phase contact‐line advancing rates whereas the reduced gravity experiments were conducted for only one advancing rate due to the short duration of reduced gravity. The experimental results show that for water sessile drops on Teflon‐coated silicon wafers, the advancing contact angle in the reduced gravity environment is less than that of the advancing contact angle in 1g (126°) by about 5° for the same three‐phase contact line advancing rates.     

FLIGHT DESIGN I N ROTARY DRYERS

The effectiveness of the rotary drum drying process depends primarily on the contact between the cascading particles and the drying gases within the drum. This paper considers first the factors which contribute to the cascade pattern and which influence the design of the lifting flights which distribute the particles in the top half of the drum. A generalised calculation design procedure for flights is developed and described in detail for the case of Equal Horizontal Distribution (EHD) flights. It is reasoned that the EHD flights, which have an equal distribution of particles across the horizontal diameter of the rotary drum dryer, give the optimum distribution in the context of the heat and mass transfer operations of the rotary drying process. An industrial design which approximates the optimum flight design is suggested.     

海洋结构物吊装索具配置研究

本文将对配扣的原理及影响配扣的相关因素进行分析研究．再利用EXCEL表格编制配扣计算公式为工程实例设计吊装索具,最后对在工程实践中出现的关于索具配置的相关问题进行梳理和总结。     

大型平台吊装施工与管理分析

本文阐释了大型平台吊装施工过程，并对其项目管理进行了系统分析，提出了施工中工程设计及管理中项目经理责任制的重要性，倡导技术与管理结合的项目运营理念。     

Fabrication of Polypropylene Super-Hydrophobic Surface Using PTFE-Coated-Sieves Template via Templating and Splitting Process

Super-hydrophobic Polypropylene surfaces were prepared employing combination method of replicating an artificial template and subsequent lifting off the master via a splitting way. The super-hydrophobic polypropylene surface, which was prepared using a 500-mesh PTFE-coated sieve, has gradient structures that microbumps with typical height and radius of approximately 20 µm and nano bundles on top of the bump surface. This surface exhibits the same self-cleaning property as the lotus leaf with water contact angle of 152.2 ± 2° and sliding angle less than 5°. The whole preparation process is simple, efficient, large-scale-prepare and environmentally friendly without organic solvents pollution.     

Degradation and life prediction of a natural rubber engine mount compound

To assess and predict the functional life of a natural rubber engine mount compound, the mechanical property changes were determined under accelerated aging conditions. The rubber was aged at temperatures ranging from 70 to 110°C for times ranging from 1 h to 5 weeks. Tensile and fatigue measurements were used to characterize the aging trends and mechanisms of the engine mount compound. With the time–temperature superposition approach, the activation energy was found to be about 98 kJ/mol for the elongation at break, 93 kJ/mol for the tensile strength, and 60 kJ/mol for the fatigue life. The tensile strength after aging for 13 weeks at 50°C was predicted to be 18.73 MPa, which was very close to the experimental value of 19.04 ± 2.25 MPa. With a 50% reduction in the tensile strength used as the failure criterion, it was predicted that the tensile strength of the engine mount compound would take 80 days to decrease by 50% at 70°C. At 23°C, it would last approximately 140 times (31 years) its lifetime at 70°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008