高层综合楼排烟系统设计分析与计算校核

高层综合楼功能复杂,人员密集,火灾危险性大,而火灾中烟气的毒害和窒息作用是致人死亡的最主要原因。因此,对该类建筑进行必要的排烟设计,既可以保证人员疏散安全,也有利于进行消防扑救。以某高层综合楼的排烟设计为例,对其排烟系统设计进行分析,重点对其排烟风机的排烟量进行计算校核,并提出了在排烟系统设计时应注意的问题,为设计人员及消防设计审核人员提供参考。     

Effect of molecular properties on the photocatalytic degradation rates of dichlorophenols and dichloroanilines in aqueous TiO2 suspensions

The kinetics of the photocatalytic degradation of 10 different dichlorophenols and dichloroanilines have been investigated experimentally and theoretically. With the intention of finding certain molecular indices in order to determine the degradation rates of aromatic pollutants, geometry optimizations of the compounds have been performed with the semiempirical PM3 method. The molecular orbital calculations have been carried out by an SCF method using the RHF formalism. The correlations between the apparent first-order rate constants and the calculated molecular properties of the compounds have been examined. Four different structure–activity relationships have been developed expressing the logarithms of the rate constants in terms of the Hammett constants, electron densities of the substituents, the coefficients and the energies of the highest occupied molecular orbitals HOMO, and 1-octanol/water partition coefficients log?K _OW.     

塔式起重机金属结构的振动模态校核与非接触测量

塔式起重机的结构特点和使用要求决定了它不可避免产生振动。详细介绍了使用有限元法求解塔机的振动模态的步骤。使用非接触法测量塔机的振动频率,给出塔机振动的架构、算法设计、数据结果及处理。试验证实,使用有限元法可以对塔机的金属结构振动进行有效分析和计算,与非接触法测量的结果接近,误差在15%以内。通过对非接触测量的结果分析可以得到塔机金属结构不同部件间刚度强弱的关系。     

储油罐机械清洗技术实践与探讨

本文以长庆油田咸阳末站2#、4#储油罐为例,系统介绍了机械清洗技术在储油罐清罐方面对安全环保工作的现实意义,对同类企业开展储油罐清洗作业提供了很好的借鉴。     

混凝沉淀-两段接触氧化法处理制革废水工程实践

采用混凝沉淀-两段接触氧化法处理制革区综合制革废水,经过半年多稳定运行,系统COD去除率达到96%,硫化物去除率达到99.5%,处理后出水的各项指标完全达到了国家《污水综合排放标准》(GB8978-1996)制革行业废水二级标准。对废水处理系统的工艺作了简单介绍,对系统调试、运行结果进行了分析与总结。     

岩石掘进机(TBM)穿越板岩和碳酸盐岩接触带引发的环境工程地质问题分析

在穿越隔水板岩和透水碳酸盐岩间接触带时,隧道施工将遇到一系列工程地质问题,这对地质条件适应性较传统钻爆法差的TBM掘进来说尤为突出。结合TBM施工的云南上公山隧道工程,通过对该接触带工程地质条件评价和问题分析,讨论了该洞段的泥石流、库水位下降、泉水断流等一系列环境工程地质问题的发生机理。     

印染废水处理工艺工程实例

介绍了改良型水解酸化+生物接触氧化工艺处理印染废水的工程实例,处理后水中的COD、BOD5浓度均低于GB 8978—1996《污水综合排放标准》中的一级标准。该工艺运行费用低、管理简单方便、易于操作、去除色度效果好、无二次污染、投资规模小。     

水解酸化-多级接触氧化工艺处理大蒜废水

介绍了水解酸化-多级接触氧化工艺在处理大蒜废水中的应用。运行结果表明:进水ρ(COD)=800~1 000 mg/L,ρ(BOD5)=300~500 mg/L,ρ(SS)=200~300 mg/L,时,出水ρ(COD)、ρ(BOD5)、ρ(SS)分别为56,19,22 mg/L。系统出水达到GB8978-96《污水综合排放标准》一级排放标准。     

Field experiment on biological contact oxidation process to treat polluted river water in the Dianchi Lake watershed

In this study two types of biological contact oxidation processes (BCOP), a step-feed (SBCOP) unit and an inter-recycle (IBCOP) unit, were designed to investigate the treatment of heavily polluted river water. The Daqing River, which is the largest pollutant contributor to the Dianchi Lake, one of the most eutrophic freshwater lakes in China, was taken for the case study. It was found that the SBCOP had higher adaptability and better performance in the reduction of COD, TN, and TP, which made it applicable for the treatment of polluted river water entering the Dianchi Lake. Nitrification rate was observed to be greatly affected by the influent temperature. During each season, the nitrification in the SBCOP was higher than that in the IBCOP. TN removal efficiency in the SBCOP was higher than that in the IBCOP during the winter and spring but poorer during the summer, possibly due to the inhibition of denitrification by higher dissolved oxygen level in the summer. Moreover, symbiotic algaebacteria growth may be conducive to the removal of pollutants.     

基于ADAMS的机械式内割刀切割失效影响研究

割刀常因振动而折断刀片,造成切割设备失效,影响施工安全。为降低ND-J114型号机械式内割刀的事故率提高割刀使用寿命,采用多体动力学的方法,利用ADAMS软件对其切削套管的过程进行动态模拟,在不同钻压和转速情况下,对割刀切削力和角加速度的变化规律进行分析,从割刀振动的角度出发,通过降低割刀的振动来降低刀片折断的风险。分析结果表明:割刀在切削套管的过程中最优钻压为4 800 N,割刀运转平稳;切削力的大小跟钻压近似于成正比关系;割刀最优转速为29 r/min,割刀运转平稳;切割转速在10~30 r/min时,切割效果较好,切割设备越不易折断;转速对切削力大小的影响较小。