Investigating measurements of fine particle (PM2.5) emissions from the cooking of meals and mitigating exposure using a cooker hood

There is growing awareness that indoor exposure to particulate matter with diameter ≤ 2.5 μm (PM_2.5) is associated with an increased risk of adverse health effects. Cooking is a key indoor source of PM_2.5 and an activity conducted daily in most homes. Population scale models can predict occupant exposures to PM_2.5, but these predictions are sensitive to the emission rates used. Reported emission rates are highly variable and are typically for the cooking of single ingredients and not full meals. Accordingly, there is a need to assess PM_2.5 emissions from the cooking of complete meals. Mean PM_2.5 emission rates and source strengths were measured for four complete meals. Temporal PM_2.5 concentrations and particle size distributions were recorded using an optical particle counter (OPC), and gravimetric sampling was used to determine calibration factors. Mean emission rates and source strengths varied between 0.54—3.7 mg/min and 15—68 mg, respectively, with 95% confidence. Using a cooker hood (apparent capture efficiency > 90%) and frying in non‐stick pans were found to significantly reduce emissions. OPC calibration factors varied between 1.5 and 5.0 showing that a single value cannot be used for all meals and that gravimetric sampling is necessary when measuring PM_2.5 concentrations in kitchens.     

Surface Profile Optimization of Yankee Dryer Based on Finite Element Analysis

The deformation and stress distribution of cast iron Yankee dryer caused by outside linear load， inside steam pressure and self-gravity were calculated by numerical simulation with ANSYS software. The deformation curve of the linear load area was obtained and compared with the deformation in the actual working process. The surface profile of dryer was optimized and the deformation and stress of the optimized dryer were calculated and compared with the that of before optimization. In this paper， the method of the surface profile optimization of Yankee dryer was presented．     

操作窗口对排风柜污染物控制效果影响的实验研究

为提升排风柜的控污能力,在排风柜性能测试实验台上,采用示踪气体测试法和正交试验法,研究了操作窗口竖直开度、水平开度、面风速和操作窗口位置对排风柜前呼吸区污染物控制效果的影响。极差分析和方差分析结果表明:各因素对呼吸区污染物控制效果影响的强弱顺序依次为竖直开度、水平开度、面风速、操作窗口位置;操作窗口水平开度、竖直开度增大,排风柜对呼吸区的污染物控制效果减弱;面风速增大,控制效果增强;水平开度与竖直开度对控制浓度的影响存在较大的相关性,这2个因素对控制浓度的影响仅在另一因素达到一定水平后才能体现。     

冶金矿山企业的噪声现状及其治理措施

我国钢铁联合企业中的黑色冶金矿山企业 ,从采矿、选矿到烧结各环节的生产过程中 ,都存在着较严重的噪声污染。其噪声源既有机械噪声、空气动力噪声 ,又有电磁噪声 ,比较广泛的分布在车间内。而且多数是超标噪声 ,对环境及生产工人的健康带来一定影响。现对选矿厂、烧结厂的噪声现状做了系统分析 ,并提出了相应的治理措施。     

局部排风罩的优化设计方法

本文用三维紊流正交数值模似，定量分析了各种因素对控制风速的影响，得到了最佳几何尺寸的计算公式和相应的νｘ计算图表。初步应用表明，达到同样的通风效果，若采用优化几何尺寸，系统风量平均可减少数％，节电达３０％左右。     

爆发点测试仪排风装置设计

在爆发点测试实验中,伍德合金加热、炸药爆炸后会产生有毒、有害气体,如果不及时将这些气体排出实验室,将会对实验人员的身体健康产生危害。这就需要在爆发点测试仪上设计排风装置。设计的排风装置由排风罩、通风管道和轴流风机组成,并由排风罩计算出的排风量和通风管道计算出的风压选出风机型号。     

对《喇叭罩拉伸冲压工艺与模具设计》一文的探讨

针对《喇叭罩拉伸冲压工艺与模具设计》（2011年第10期）一文，指出了该论文中工艺计算和模具结构存在的不足之处，并提出了改进措施，对同类零件的工艺计算和模具设计提供了借鉴。     

气浮/双重过滤联用工艺在河口水厂的应用

针对河口水厂常规脉冲沉淀池和虹吸滤池改造为气浮-移动罩滤池-翻板滤池的实践,介绍了主要构筑物的设计参数和滤池施工要求,以及运行中需要注意的问题.改造后的处理工艺运行良好,出水浊度<0.2 NTU,为平原水库水的处理和水厂的运行提供了参考.     

基于多目标满意度的车身轻量化方案优选

为实现车身不同轻量化方案的有效优选,提出了一种基于多目标满意度决策机理的车身轻量化方案优选方法。该方法以不同方案对应性能分析数据为基础,以质量减轻、成本降低和性能改善为目标,估测各目标对方案优选的权重,建立车身轻量化方案优选的多目标优化。基于多目标满意度决策机理,对不同方案进行综合评价,得到的综合满意度最大的方案经验证合格即为优选的轻量化方案。以车身发动机罩板为例,验证了所提方案的有效性。     

再循环自净型排风柜对室内环境影响的研究

本文用数值模拟的方法对再循环自净型排风柜的性能进行分析,当排风柜面风速一定时,改变排风柜出口处污染物浓度来分析经排风柜过滤后的空气携带污染物在房间里的速度场及浓度分布;并且模拟了房间内增加全面通风量及不同的换气次数对速度场及浓度分布的影响。