吸油插板式隔油池

本文介绍了一种简易高效的隔油池 ,它用具有吸油和隔油双重作用的“板” ,来取代普通隔油池中的隔油墙(板 ) ,使原来不易上浮到水面的细小油珠也能被除去 ,从而提高了油水分离效率。吸油板式隔油池处理工厂一般含油废水比普通隔油池占用土地面积小、制作简单、投资省、效果好。监测结果表明 ,处理后水的油份浓工符合国家排放标准 (油≤ 10mg L)     

膜电除尘器-静电除尘新技术

膜电除尘器是将炭纤维或硅纤维编织膜作为集尘极的新式电除尘器,它克服了传统电除尘器存在的一些缺点,进一步提高了除尘效率,降低了电除尘器的造价,同时能去除粉尘中的酸性盐.介绍了膜电除尘器的结构、特点及除尘性能,并指出了进一步研究的方向.     

A numerical model for drying of spherical object in an indirect type solar dryer and estimating the drying time at different moisture level and air temperature

A numerical model for simultaneous heat and mass transfer was developed for solar drying of spherical objects and the object considered is green peas. Solar collector outlet temperature is assumed as drying chamber temperature and justified through energy balance equations. Assumptions are imposed on heat and mass transfer governing equations without losing the physics of the problem. Discretization is performed by finite difference method with implicit scheme. To generalize, the governing equation and boundary conditions are non-dimensionalized. The set of finite difference equations was solved by Tridiagonal Matrix Algorithm and a computer code in MATLAB was developed to solve them. The drying curves showed two stages of drying, initial, and secondary drying stage. At all drying temperatures and drying time, the center moisture was maximum and it was minimum at the boundary. A percentage of 85.67 surface moisture content and 25.33% center moisture was eliminated in the first 1 hr at 348 K. The product should be dried up to 7.45, 4.74, and 3.74 hr at air drying temperatures of 318, 333, and 348 K respectively, to maintain 10% of the product’s initial moisture content. The result is compared with the experimental result from literature and they are found to be in good agreement.     

A non-destructive single plate method for measurement of thermal resistance of polymer sheets and fabrics

Measurement of thermal resistance of polymer sheets and fibrous layers is important in various applications including those within the engineering, ergonomics, clothing design and personal protective equipment fields. Standard methods for measurement of thermal resistance of plain materials are generally time consuming, expensive and often require the sample to be cut. Moreover, the temperature difference between the surfaces of both plates surrounding the sample must be known, as well as the sample thickness. This article describes a new measuring device named the Thermoscope. The Thermoscope is not limited by the aforementioned requirements and is able to evaluate the thermal resistance of polymer sheets and textiles by touching the sample on one surface alone. Simultaneously, the other surface is kept in thermal contact with the supporting base. The accuracy of this device was compared with the Alambeta thermal insulation tester. Effects of various base materials on measurement precision were also studied.     

Analysis of floc morphology in a continuous-flow flocculation and sedimentation reactor

The floc morphology was investigated in a continuous-flow reactor, in order to understand the evolution of flocs in practical flocculation and sedimentation processes in water utilities. Kaolin-humic acid suspension was used as the test water, and polyaluminum chloride was chosen as the coagulant. An in-situ recognition system was applied to analyze the floc size, boundary fractal dimension, and eccentricity ratios. Particle numbers and turbidity were also determined in the sedimentation stage. At a coagulant dose of 1 mg/L as Al, the average floc size increased from 62 to 78 μm and the boundary fractal dimension was around 1.14, suggesting that flocs were compact and continuously grew during the entire flocculation process. However, with the dose increased to 5 mg/L, the average floc size decreased and stabilized at around 65 μm, with the fractal dimension of 1.20. It can be concluded that the excess coagulant doses resulted in the formation of chain-shaped, lower density, and more branched structure flocs, thereby restricting flocs' further growth in the subsequent flocculation. Floc morphology analysis suggested that charge neutralization dominated in the initial flocculation stage, then the bridge and sweep mechanisms were dominant in the subsequent flocculation. In addition, compared with the traditional inclined plate settler, a novel V-shaped plate settler introduced in this study had an advantage in small size floc(less than 5 μm) removal. The V-shaped region could promote aggregate restructuring and re-flocculation; therefore, the V-shaped plate settler provides an alternative method for sedimentation.     

某型飞机机翼下壁板整体油箱端5肋结构选型疲劳寿命研究

目的研究某型飞机机翼下壁板整体油箱端5肋结构的选型疲劳寿命。方法在结构选型设计时初步确定长桁连续和长桁断开两种结构形式的基础上,采用静力试验与疲劳试验方法对这两种结构模拟件进行对比试验验证。结果两种结构模拟件的静破坏载荷分别为588.20 k N和587.97 k N,与设计预计破坏载荷(590k N)高度一致。在相同的等幅载荷谱下,长桁连续结构的中值疲劳寿命和95%置信度与95%可靠度下的疲劳寿命分别约为长桁断开结构的1.7倍和4倍。长桁连续结构的疲劳分散性明显小于长桁断开结构。长桁连续结构的疲劳断口主要呈现脆性穿晶疲劳断裂特征;而长桁断开疲劳断口则呈现出韧窝型断裂和解理断裂的混合型穿晶疲劳断裂特征。疲劳断口微观形貌表明,长桁断开结构在疲劳过程中产生了塑性变形,这就从微观机理上解释了长桁连续结构的疲劳性能优于长桁断开结构的原因。结论在结构质量相近的情况下,长桁连续结构明显优于长桁断开结构。     

胶粘剂对芳纶无纬布防弹性能的影响

通过物理共混的方法,将固化剂及消泡剂加入到丙烯酸酯胶粘剂中,从而改善丙烯酸酯胶粘剂织造的无纬布表面粘手及不平整的问题,并利用电子拉力实验机对无纬布进行力学性能测试。研究表明：固化剂的添加可明显提高布样的粘结强度,并且布样的表面不粘手;消泡剂的添加能够明显改善布样的表观质量,布样表面平整、无气泡;添加固化剂可提高布样的力学性能,同时还可提高了材料的防弹性能,子弹穿透层数减少,布样的平均凹陷明显降低,减少了对人体的二次钝伤。     

港口煤翻车机房粉尘污染捕集的设计与应用

对煤翻车机房煤尘的污染现状进行了实际测量与数据分析,得到煤尘上扬的数学模型,设计了翻车机房扬尘的捕集系统,并对系统内各个装置的功能进行了分析。采用吹、吸互补并利用导流板的捕尘方式,使无序飞扬的粉尘变成了有序的流动,该方法解决了大区域、复杂工况环境捕集粉尘的问题。     

采用筛板塔吹脱模拟处理四氯乙烯污染地下水

利用自主设计的筛板塔装置模拟吹脱四氯乙烯(PCE)污染废水,综合考察了影响吹脱的各因素(气液体积比、初始浓度和筛板数等),同时对吹脱工艺条件进行了优化,并建立了吹脱模型.研究表明:25.68mg/L PCE废水经吹脱后出水浓度降至0.62mg/L,去除率可达97.59%;气液比对废水的吹脱效果影响很大, 且最佳气液比在200左右;PCE初始浓度对去除率的影响并不明显;采用4层塔板时PCE去除效果较好;实验数据很好地遵从一级衰变模型;吨水吹脱成本约为0.31元,可作为后续生化处理的预处理工艺.     

无损检测用X光底片伪缺陷的产生及防止方法

X光底片作为直接反映缺陷形状、大小、数量的媒介,它的质量好坏对于无损检测人员作出正确分析判断是极其重要的。总结了X光底片上伪缺陷产生的原因,并提出了相应的防止方法。