Development of an organizational framework for studying dust explosion phenomena

To develop a predictive dust explosion model or theory many considerations of the interaction between several complex multiscale processes are required. Due to practical considerations only some of the processes may be fully resolved, while the rest must be approximated or neglected. The current study focuses on constructing an organizational framework for dust explosion model development. The framework is organized based on progression of the explosion in time and geometric scale of the important features. Suggested methodologies are given to investigate the small-scale features and develop feed-forward approximations for predictive models at the larger system-scale. The concepts developed through constructing the organizational framework are applied to closed volume dust explosion testing and classification of several sources of experimental variance for this system is given.     

高压闷罐与普通敝口容器消解土壤的对比实验研究

土壤（底质）环境样品的消解直接关系到测定结果的好坏，通过对比实验证明，高压闷罐法消解土壤（底质）比普通法具有消解完全，精密度和准确度高，重现性好等优点。     

三种典型的污泥发电工艺

污泥发电是城市污水处理厂进行污泥合理开发利用的技术措施之一,是污泥实行减量化、稳定化、无害化、资源化的良好方法,本文介绍了3种典型的污泥发电工艺：污泥焚烧发电;污泥厌氧消化产生沼气、通过燃气轮机组发电;污泥厌氧消化产生沼气、进而通过改质制造氢气,经燃料电池发电。对污泥合理利用的规范化、科学化有一定的借鉴意义。     

沈阳市污水处理厂污泥处置现状及对策

目前沈阳市日处理市政污水能力为130万m^3／d,日产污泥约700t／d,污泥问题已经日益严重。通过对沈阳市污水处理厂污泥处置必要性、现状、污泥特征的分析,对沈阳市污泥处置的发展方向提出了思路及对策。     

Experimental investigation on spontaneous ignition caused by pressurized hydrogen suddenly release into an S-shaped tube

An experimental investigation on the effects of continuous semicircular curved structure on spontaneous ignition during pressurized hydrogen suddenly release was conducted. An S-shaped tube with 700 mm in length and 10 mm in diameter was used in our experiments, and a straight tube with the same configuration was adopted for comparison. The results show that the continuously generated rarefaction waves and reflected shock waves make the pressure curves in the S-shaped tube more complicated. Meanwhile, the mean velocity and intensity of the leading shock wave undergo considerable attenuation when it propagates in the S-shaped structure. By comparing with the straight tube, the minimum critical pressure condition for spontaneous ignition in the S-shaped tube is slightly difficult to reach, but the difference is not huge. Nevertheless, the S-shaped structure can effectively promote hydrogen-air mixing and make combustion more intense. A secondary overpressure peak detected by the pressure transducer near the nozzle occurs in the spontaneous ignition cases and no such pressure increase is caught in the non-ignition cases. The transition from spontaneous combustion flame to a jet flame at the nozzle and the complete out-tube jet flame development process are captured and discussed.     

COD测定仪法测定不同水样COD消解时间的差异性

通过实验证实COD测定仪法具有较好的精密度和准确性,与标准回流法的分析结果比较,相对误差为-3.37%~1.41%,具有替代标准回流法的可行性。由于水样性质不同,所需最佳消解时间不同,通过比较不同消解时间下COD测定的结果,得到COD测定仪法测定水中COD所需的最佳消解时间分别为:工业废水60 min,生活污水和地表水90 min。     

End-of-life flows of multiple cycle consumer products

Explicit expressions for the end-of-life flows (EOL) of single and multiple cycle products (MCPs) are presented, including deterministic and stochastic EOL exit. The expressions are given in terms of the physical parameters (maximum lifetime, T, annual cycling frequency, f, number of cycles, N, and early discard or usage loss). EOL flows are also obtained for hi-tech products, which are rapidly renewed and thus may not attain steady state (e.g. electronic products, passenger cars). A ten-step recursive procedure for obtaining the dynamic EOL flow evolution is proposed. Applications of the EOL expressions and the ten-step procedure are given for electric household appliances, industrial machinery, tyres, vehicles and buildings, both for deterministic and stochastic EOL exit, (normal, Weibull and uniform exit distributions). The effect of the physical parameters and the stochastic characteristics on the EOL flow is investigated in the examples: it is shown that the EOL flow profile is determined primarily by the early discard dynamics; it also depends strongly on longevity and cycling frequency: higher lifetime or early discard/loss imply lower dynamic and steady state EOL flows. The stochastic exit shapes the overall EOL dynamic profile: Under symmetric EOL exit distribution, as the variance of the distribution increases (uniform to normal to deterministic) the initial EOL flow rise becomes steeper but the steady state or maximum EOL flow level is lower. The steepest EOL flow profile, featuring the highest steady state or maximum level, as well, corresponds to skew, earlier shifted EOL exit (e.g. Weibull). Since the EOL flow of returned products consists the sink of the reuse/remanufacturing cycle (sink to recycle) the results may be used in closed loop product lifecycle management operations for scheduling and sizing reverse manufacturing and for planning recycle logistics. Decoupling and quantification of both the full age EOL and of the early discard flows is useful, the latter being the target of enacted legislation aiming at increasing reuse.     

Management of treated pulp and paper mill effluent to achieve zero discharge

Pulp and paper mills are one of the major effluent generating industries in the world. In most cases, mill effluent (treated or raw) is discharged back into a river, creek, stream or other water body; resulting in negative environmental impacts, as well as social concerns, among the downstream users. Pulp and paper mill effluent management, which could result in zero discharge into downstream water bodies, would present the best management option to address socio-environmental concerns. This paper presents such an effort aimed at closing the water cycle by using treated effluent from the mill to irrigate forage and fodder crops for producing animals feed. The treated effluent is delivered from the mill through gravity into a winter storage dam of 490ML capacity. For irrigation applications on 110ha of farmland, which is 42% of the total farmland, the water is pumped from the winter storage dam to five individual paddocks with Centre Pivot (CP) irrigators and one rectangular paddock with a Soft Hose Travelling (SHT) irrigator. From October 2001 to June 2006, a total of 2651mm of wastewater was applied at the farm. The impact assessment results, obtained from field monitoring, investigations and analysis, indicated that the closed water cycle effluent management strategy described had resulted in a lessening of the impact on water resources usually associated with paper mills. However, social attitudes to the use of crops that have been irrigated with recycled waters and the resulting impact on market value of the produce may still be a major consideration.     

荧光废水中COD_(Cr)闭管与开管消解测定方法研究

通过考察6个实验室中,标准溶液和标准样品的试验分析数据,得出闭管法较开管法具有更优的准确度、精密度和氧化能力,其闭管法的最佳氧化浓度(并非检测限)在150～850mg/L;结合水样的监测数据,研究了两种快速测定方法的优缺点和适用性,得出两种方法均普遍适合工业废水监测,其中闭管法在测定中、高浓度荧光废水时,结果更准确、更环保,而开管法适用于相对低浓度的废水测定;总结归纳了CODCr监测分析过程中影响准确性的因素及需要注意的问题。     

一种封闭式选煤车间的设计

近年来,随着国家对煤炭行业控制环境污染的条件越来越严格,为了更有效的治理煤场环境污染,改善煤场周边地区环境质量,根据国内已建成的大型封闭厂房的设计经验,提出一种封闭式煤炭风选车间,车间采用轻型门式钢架结构设计,常规经济柱距6m,抗风柱柱距7．5m,室内净高10m。工程长度90m,跨度35m,屋盖系统采用钢桁架结构体系,单层压型彩色钢板封闭。封闭车间同时配套通风除尘系统,有效降低煤尘量。