干燥器法测定甲醛释放量的不确定度评定

依据GB/T 17657-1999《人造板及饰面人造板理化性能试验方法》中干燥器法测定甲醛释放量,对装饰单板贴面人造板中甲醛释放量的检测过程进行研究,分析了检测过程的不确定度来源,确定了人造板甲醛释放量的测量结果不确定度,提出了干燥器法甲醛释放量检测不确定度的评定方法。     

人造板家具甲醛释放量检测干燥器法研究与分析

实验通过干燥器法对不同使用功能的人造板类家具的甲醛释放情况进行了检测,以确定不同种类人造板类家具甲醛释放量之间的关系。干燥器实验结果显示,当人造板家具生产所使用板材相同的情况下,干燥器法检测的数值基本上相同,从而得出结论,干燥器法不能反映不同种类家具甲醛释放状况。同时,实验结果还说明了GB18584-2001《室内装饰装修材料木家具中有害物质限量》还存在很多需要进一步完善和改进的地方。     

气候箱法测定人造板甲醛释放量不确定度评定

采用1 m3气候箱法对人造板进行甲醛释放量测定,对测定过程的不确定度进行量化和评定,结果表明,引入不确定度的因素按引入不确定度大小排序依次为:采气过程,标准曲线绘制过程,标准物质,气候箱内部环境,重复性测定过程,分光光度计;其余影响因素对不确定度贡献较小。     

干燥器法中甲醛释放，扩散和吸收的规律

以家具产品质量标准中检测甲醛释放量的干燥器法为研究对象,分别对甲醛从板中释放,甲醛在空气中扩散和甲醛被水吸收三个过程进行深入研究。根据经典的气体传质理论,我们分别介绍了这三个过程中甲醛气体传质的数学模型。通过数学关系的分析,我们发现板材本身,环境温度和湿度,甲醛在空气中扩散效率和被水吸收程度对检测结果有不同程度的影响,针对这些影响,我们从原理上提出了初步的改进建议。     

人造板甲醛释放量检测方法探究

因甲醛的危害程度较大,因此针对人造板中甲醛的释放量的检测方法越来越受到社会各界关注。对人造板甲醛释放量的几种国内外常见的检测方法进行研究,如干燥器法、气候箱法、穿孔萃取法,提高检测效率和检测准确性。     

人造板甲醛释放量干燥器法测定的干扰及对结果的影响的探讨

本文讨论了干燥器法溅定甲醛释放量的一些主要干抗因素。分析了测定时污染分析环境对显色剂、吸收剂的污染，造成对结果的误差，以及干燥器的密封性及样品稳定期对结果的影响。     

中密度纤维板粉末涂料涂装工艺研究

近年来,用粉末涂料涂装热敏性材质研究已经逐渐成为行业研究的重点,低温固化粉末涂料和UV固化粉末涂料已开始应用于中密度纤维板(MDF)的涂装.研究了低温固化粉末涂料及其应用于MDF上的涂装工艺,重点介绍了不同加热方式对MDF含水率、粉末上粉量等的影响.     

书刊印刷产品中甲醛释放量的测定

利用真空干燥器法,建立了乙酰丙酮显色法测定书籍中甲醛释放量的分析方法。研究表明,甲醛释放量的线性方程为y=7.3108x-0.0764,R2=0.9969,RSD=0.296%,该方法操作快捷,结果稳定,能实现无损化检测,具有良好的再现性,可满足检测需要。     

防冻剂产品氨释放量控制

近几年来,经过多方面地的努力,防冻剂产品氨释放量得到了有效的控制,相关投诉越来越少。那么,我们是不是可以认为此项工作已高枕无忧万事大吉了呢?其实不然,本人作为一名3C认证的审查员,就防冻剂产品氨释放量控制的问题,谈谈自己的看法,供大家探讨。     

浅析国内外人造板甲醛释放量干燥器法的异同

现今,我国人造板生产量已成为世界第一人造板生产大国。人造板是利用木材和胶粘剂为主要原料,通过一定的生产工艺加工而成的不同种类的板材,现代建筑家庭装修中经常会使用大量的人造板,但是人造板中往往含有甲醛,甲醛对人体健康的影响日益引起国家和人们的关注,而甲醛释放量作为人造板一项重要评价指标,文章针对当前我国、美国、日本等国内外广泛使用的甲醛释放量干燥器法测试方法进行分析。     

铁炭微电解-混凝沉淀预处理密度纤维板热磨废水

研究了铁炭微电解-混凝沉淀对于密度纤维板热磨废水的预处理效果。通过试验,得出处理该废水的组合工艺最佳条件为:调节废水初始pH值为3.0,进行铁炭微电解反应60min,然后调节pH值为8.5,进行混凝沉淀60min。在进水COD的质量浓度为5183mg/L,色度为500倍时,经组合工艺处理后,COD去除率可达92%以上,脱色率达99%以上,且出水生化性好。     

Reducing ammonia emission from poultry manure composting via struvite formation

Composting can provide a viable alternative for poultry manure management in the Fraser Valley of British Columbia, Canada. However, it has a high potential for ammonia emission because of the high nitrogen content of poultry litter. The objective of this study was to reduce ammonia emission by precipitating ammonia into struvite before it can volatilize from the composting matrix. Nitrogen transformation occurs during composting, but struvite formation can help to conserve nitrogen, and does not allow a large amount of nitrogen to be released into the environment as ammonia or nitrate, because ammonium‐nitrogen becomes bound in struvite. It would also be possible to remove phosphorus from the manure. A laboratory‐scale experiment was conducted to examine the feasibility of struvite formation during poultry manure composting. Magnesium and phosphate salts were supplemented to create favorable conditions to form struvite. Results indicated that ammonia emission was reduced by 40% to 84%, while the nitrogen retention in compost was enhanced. The struvite formed in compost was confirmed by means of X‐ray diffraction; and scanning electron microscopy with energy dispersive X‐ray spectroscopy. Copyright © 2007 Society of Chemical Industry     

A simplified model on vertical density profile and shrinkage ratio of virgin and charred medium density fibreboard

This work is part of a wider scope of research on developing comprehensive pyrolysis model for medium density fibreboard (MDF) in fires. A simplified model is developed to predict the vertical density profile of virgin MDF. The model shows that vertical density profile can be reproduced using a second order conic curve. Several sets of experimental data are used to validate the model with promising results that are presented. Further investigation shows that the density difference between surface and core densities tends to maintain constant within a range of 300 to 450 kg/m³. Moreover, the model can predict the mean density with an error less than 30 kg/m³. Typical MDF panels were experimentally charred using thermogravimetric analysis and cone calorimetry to investigate the shrinkage and density of char. The actual char density is measured as 330 kg/m³ with a uniform density distribution along the char layer thickness. A model is developed to predict the shrinkage ratios. The restraining effect caused by surface deformation will lead to different vertical and horizontal shrinkage ratios. The volume reductions at vertical and horizontal directions are experimentally measured as 40% and 20% for the two tested MDF panels, which is comparable with the model predictions. Copyright © 2013 John Wiley & Sons, Ltd.     

直流舱测定材料VOC散发关键参数的浓度轨迹法

室内及车内环境中材料散发的挥发性有机化合物(VOC)是造成空气品质低劣的重要因素之一, 显著影响着人们的舒适度和身体健康。材料VOC散发特性由3个关键参数表征:初始可散发浓度C₀、扩散系数D_m和分配系数K。测定上述散发关键参数是研究材料VOC散发规律进而预测人体暴露和健康风险的基础。基于目前应用最广泛的直流舱中材料VOC的散发过程, 提出了同时测定C₀和D_m的浓度轨迹法。该方法通过预设K值, 然后对环境舱浓度的对数进行线性拟合, 根据斜率和截距获得关键参数C₀和D_m。敏感性分析表明, 不同的K值对测定的C₀和D_m值影响很小。通过对文献中的直流舱散发实验数据进行处理, 结果表明该测定方法具有较高的精度。     

空气重介质流化床流化特性及密度梯度分布研究

为实现物料的有效分选,以磁铁矿粉和玻璃微粉为混合加重质,研究了混合加重质的流化特性及空气重介质流化床床层密度梯度分布情况。结果表明:空气重介质流化床形成了均匀稳定的流化状态,当流化气速大于7.10 cm/s后,床层压降基本维持在510 Pa,床层密度基本不变,为1.71~1.74 g/cm3。当流化气速为7.95 cm/s时,流化床内气泡直径为15~25 mm,且分布均匀,流化床各层平均密度从上至下依次为1.72、1.74、1.74、1.74、1.73 g/cm3。流化床上部区域,超微细玻璃微粉被气流带到床层表面,使表面床层密度较小;流化床底部区域,气体分布相对均匀,并未形成大气泡,使该区域流化床床层平均密度偏小;而床层大部分区域床层平均密度均为1.74 g/cm3,比较稳定。因此,当流化气速为7.95 cm/s时,流化床内并未形成明显的分层和分级现象,说明加重质混合比较均匀,为空气重介质流化床分选物料创造良好条件。     

耐火材料真密度试验方法的研究

简述了耐火材料真密度试验的测试原理及测试过程,通过实际测试数据,说明影响真密度测试的主要因素是试样粒度,容器内的真空度及所用试液和环境温度。     

中小氮肥合成氨生产系统操作条件优化

针对国内中小氮肥企业合成氨生产系统的设备条件和技术水平,以提高氨净值为目标,将整体优化问题进行合理有效的分解,采用广义预测控制算法实现氨合成塔热点温度自动调节,以保证在线优化调节的稳定;抽取单向优化因素进行卡边操作,最终实现合成氨生产操作条件的自适应在线操作优化,氨净值提高0. 4％,系统压力降低1. 2 MPa,实现节能降耗,说明了该方案的有效性。     

蒸氨法氨回收工艺及装置简介

农药厂IDAN法草甘磷在碱解反应中产生大量的含氨气体,采用中压蒸氨工艺回收氨。介绍了低压解吸蒸氨工艺和中压蒸氨工艺各自的特点,阐述了中压蒸氨工艺流程、产品质量、消耗指标、工艺指标、主要设备,介绍了生产成本、收益情况,并进行了分析。     

Modern concept of acoustic emission (AE) coupled with electrochemical measurements for monitoring the elastomer-coated carbon steel damage in phosphoric acid medium

Elastomer coatings (rubber) are industrially used to protect phosphoric acid storage tanks against corrosion. Rubber constitutes a barrier against the penetration of H₃PO₄ to metallic surface. Coatings damage induces both acid infiltration and steel corrosion. In this concept, acoustic emission (AE) monitoring technique could be used for the detection of coatings damage as well as for steel corrosion under the coating. In the present work AE was coupled to electrochemical measurements (EM) for rubber damage evaluation and steel corrosion on three types of steels (XC48, E20 and A60) at room temperature in concentrated phosphoric acid (30% P₂O₅) contaminated by Cl⁻, F⁻, SO₄²⁻. Electrochemical behaviour of steels was studied and characterized by potentiodynamic curves and polarization resistance measurement. A good correlation between acoustic emission and polarization resistance or corrosion potential measurements was found during stages of coatings damage and steels corrosion. The majority of AE activity recorded during experiments is related to hydrogen bubbles release. The release of hydrogen bubbles gives rise to two populations of signals: one impulsive and another one resonant.