未脱墨废人民币纸浆配抄瓦楞原纸

为增加造纸工业的纤维原料来源并充分利用废人民币纸,本文对未脱墨废人民币纸浆配抄瓦楞原纸进行了初步的研究。采用5%氢氧化钠和硫酸溶液对废人民币纸进行化学预处理,再经PFI磨机械疏解后得到未脱墨的废人民币纸浆。采用纤维形态分析仪对未脱墨废人民币纸浆的纤维长度、宽度及其分布进行了分析检测。通过在废新闻纸浆中配加不同比例的未脱墨废人民币纸浆考查瓦楞原纸的质量指标,并对不同的纸浆配比进行分析。结果表明,废人民币纸浆的纤维长度在机械疏解过程中损失较多,只相当于草类原料化学浆的纤维长度。抄造定量为120 g/m2的瓦楞原纸,当废人民币纸浆配比增加时,瓦楞原纸的裂断长和环压指数均下降,废人民币纸浆的配抄比例控制在40%左右时,可以满足D级瓦楞原纸对裂断长和环压指数的要求。虽然废人民币纸浆的成纸强度较低而导致瓦楞原纸的强度指标下降,然而由于其原料价格较低,有利于降低瓦楞原纸的生产成本。     

Investigation of effective dimensionless numbers on initiation of instability in combustion of moisty organic dust简

In this work, the effect of various effective dimensionless numbers and moisture contents on initiation of instability in combustion of moisty organic dust is calculated. To have reliable model, effect of thermal radiation is taken into account. One- dimensional flame structure is divided into three zones： preheat zone, reaction zone and post-flame zone. To investigate pulsating characteristics of flame, governing equations are rewritten in dimensionless space-time （（, r/, ~） coordinates. By solving these newly achieved governing equations and combining them, which is completely discussed in body of article, a new expression is obtained. By solving this equation, it is possible to predict initiation of instability in organic dust flame. According to the obtained results by increasing Lewis number, threshold of instability happens sooner. On the other hand, pulsating is postponed by increasing Damk6hler number, pyrolysis temperature or moisture content. Also, by considering thermal radiation effect, burning velocity predicted by our model is closer to experimental results.     

Kinetics study of leaching arsenic from Ni-Mo ore roasting in dust mixture of hydrochloric and sulfuric acids

The kinetics of leaching arsenic from Ni-Mo ore roasting dust was investigated. The effects including leaching temperature, particle size of the smelter dust, stirring speed, the coefficient β（the molar ratio of sodium chlorate to arsenic in the smelter dust） and the initial H＋ concentration on leaching arsenic were studied. The results indicate that the leaching of arsenic increases sharply with the decrease of particle size. The orders of reaction with respect to H＋ concentration and particle size are determinted to be 1.136 and 1.806, respectively. The leaching of arsenic reaches 99% under experimental conditions, the apparent activation energy is determined to be 11.157 kJ/mol, which is consistent with the values of activation energy for diffusion model The kinetics equation of leaching arsenic from the roasting dust could be expressed by a semi-empirical equation as 1-2/3η （1 -η）^2/3 = k0（c[H＋]）^1.136ro^-1.806 exp[（-11157 /RT）t].     

Effects of expanding zone parameters of vacuum dust suction mouth on flow simulation results

Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth, the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics （CFD） software, Fluent. The effects of the expanding zone parameters on flow simulation were analyzed. The results show that simulation effects depend on threshold values of the expanding zone parameters of the dust suction mouth, and the threshold values of the expanding zone can be obtained according to the different structures of the vacuum dust suction mouth and be selected as the geometric parameters in calculating, and also corners of the expanding zone make unobvious difference in calculation accuracy and in computational efficiency compared with no corner. The simulation results provide practical guidance to the flow simulation on the dust suction mouth.     

提高湿法烟气脱硫喷淋塔脱硫和除尘效率的探讨

分析了现代大型喷淋塔为提高脱硫与除尘效率在设计上所作的改进及存在的问题。通过一个曾经设计过的喷淋塔实例,结合烟气和吸收液两相逆向流动和两相间的化工传质过程,剖析了喷淋层覆盖率的实质,提出弱效喷淋覆盖和多重喷淋覆盖对喷淋塔脱硫和除尘效率的影响,给出喷淋覆盖率的选择、喷淋层和喷嘴布置的设计方法,对改善烟气脱硫和除尘效率均有明显效果。     

矸石山风蚀扬尘起尘风速确定研究

利用实测空气颗粒物数据和颗粒物体源扩散模式推导扬尘实际排放强度,根据扬尘实际排放强度突变比例确定不同地区矸石山风蚀扬尘起尘风速。     

Reinforcing effect of nanocrystalline cellulose and office waste paper fibers on mechanical and thermal properties of poly (lactic acid) composites

Nanocrystalline cellulose (NCC) was prepared from office waste paper (OWP) by sulfuric acid hydrolysis method in this paper and it was used to prepare a series of poly (lactic acid) PLA/NCC composites by using a dissolution method in solvent N, N-dimethylformamide solution. The results indicated that with the addition of only 3 wt% NCC, the composites exhibited outstanding mechanical property. The tensile, bending and impact properties of the PLA/3NCC composite were improved by 8.2%, 13.1%, and 35.9% than those of pure PLA, respectively. On this basis, office waste paper fibers (OWF) were also used as a physical blended filler to enhance PLA/NCC composites to reduce the preparation cost of PLA composites and the perfect PLA/NCC/OWF sample was easily manufactured by melting–blending and injection molding. According to the crystallization and melting performance table, both NCC and OWF can act as nucleating agent to promote the crystallization properties on composites, while the blends did not have positive effect on thermal stability. Furthermore, the water absorption and degradation properties of PLA composites were also studied. This work not only provided a novel idea for the utilization of office waste paper but also successfully produced environment friendly composites with favorable mechanical properties and crystallization performance.     

露天铝土矿山粉尘治理措施

介绍了露天矿山铝土生产流程、产尘源及产尘设备。针对各产尘源的治理进行了分步分析。提出了治理措施。从而有效降低了铝土露天矿山生产过程中外排及岗位粉尘浓度。     

换流变阀侧干式套管表带触指失效过程分析

在超、特高压电力系统中,换流变压器阀侧干式套管作为换流变压器连接换流阀的关键设备,其安全运行直接关系到电力系统的可靠性。近年来,国内外发生多起由于电接触失效而导致的套管过热和放电故障,因此有必要对套管载流连接结构的失效机理开展研究分析。该文以±500kV换流变阀侧套管的过热故障为例,计算分析套管在实际运行电流下表带触指的摩擦行程,采用扫描电镜(scanning electron microscope, SEM)和能量色散光谱仪(energy dispersive spectrometer,EDS)对表带触指失效前后的表面和断面进行形貌分析和成分分析,提出表带触指在套管内的劣化机理。研究发现:铜导杆接触区域没有镀银是缩短触指寿命的主要原因,长期的机械磨损和SF6气体分解产物对触指的腐蚀是导致触指劣化的重要因素,相关结论可为套管电连接设计、选型和过热型故障分析提供理论依据。     

汽车车轴制动毂挡尘盖冲压成形工艺与模具设计

通过对局部不对称盒形结构的汽车车轴制动毂挡尘盖的工艺分析,提出了采用浮动式多点成形模来进行拉深成形,并对产品试制过程中出现的起皱、破裂等现象进行了理论分析及实验研究.