陕甘宁中部气田集气站低温脱水工艺探讨

中部气田开发初期，井口压力较高，在节流降压的同时，节流后天然气温度降低，天然气中部分饱和水凝析出来，天然气露点降低。本文运用这一原理，研究利用天然气原始压力能，实现节流降温在集气站所采用的工艺流程，给出了在节流降温过程中，不形成水化物所需的甲醇注入量的计算方法。     

NGS型高效深锥浓缩机的应用

本介绍了ＮＧＳ型高效深锥浓缩机的结构、工作原理、主要技术参数、高效化措施和试验结果。试验表明，该设备对铁、银、铜、硫、金产品和尾矿浓缩，单位处理能力达１８０￣１５００ｋｇ／ｍ＾２·ｈ，底流浓度达４０％￣７０％，溢流水浊度小于５００ｐｐｍ，被认为是固液分离的高效率脱水设备。     

冰铜INBA粒化和脱水法在祥光铜业的应用

介绍了冰铜INBA粒化和脱水法在祥光铜业工程中应用的工艺过程,阐述了该工艺中水的闭路循环设计,并就主要设备进行了说明。     

Hydraulic Performance of Geosynthetic Clay Liners in a Landfill Final Cover

Percolation from a landfill final cover containing a geosynthetic clay liner (GCL) as the hydraulic barrier is described. The GCL was covered with 760?mm of vegetated silty sand and underlain with two gravel-filled lysimeters to monitor percolation from the base of the cover. Higher than anticipated percolation rates were recorded in both lysimeters within 4–15?months after installation of the GCL. The GCL was subsequently replaced with a GCL laminated with a polyethylene geofilm on one surface (a “composite” GCL). The composite GCL was installed in two ways, with the geofilm oriented upwards or downwards. Low percolation rates (2.6–4.1?mm/year) have been transmitted from the composite GCL for more than 5?years regardless of the orientation of the geofilm. Samples of the conventional GCL that were exhumed from the cover ultimately had hydraulic conductivities on the order of 5×10?5?cm/s. These high hydraulic conductivities apparently were caused by exchange of Ca and Mg for Na on the bentonite combined with dehydration. The overlying and underlying soils likely were the source of the Ca and Mg involved in the exchange. Column experiments and numerical modeling indicated that plant roots and hydraulic anomalies caused by the lysimeters were not responsible for the high hydraulic conductivity of the GCL. Despite reports by others, the findings of this study indicate that a surface layer 760?mm thick is unlikely to protect conventional GCLs from damage caused by cation exchange and dehydration. Accordingly, GCLs should be used in final covers with caution unless if cation exchange and dehydration can be prevented or another barrier layer is present (geomembrane or geofilm).     

基坑降排水施工技术在颍上船闸工程的应用

通过轻型井点降水施工在沙颍河颍上船闸工程中的实际应用,阐述轻型井点降水施工方法和工艺特点,以供今后类似工程参考.     

Evaluation of flocculation characteristics of kaolinite dispersion system using guar gum: A green flocculant

This paper reports the systematic investigation on the flocculation, sedimentation and consolidation characteristics of kaolinite using guar gum as a green flocculant. In-situ flocculation behavior of kaolinite at various pH, guar gum dosages, and ionic strength were studied using a light scattering technique. The effect of these parameters on the settling rate, solid consolidation, and supernatant liquid clarity was recorded. The morphology of kaolinite and flocculated kaolinite aggregates were analyzed using FESEM. The morphology studies suggest that it is poorly crystalline with multiple steps on edge, broken edge; laminar with high aspect ratio and have rough basal surface. The complex irregularity on the basal surface and the presence of multiple steps in the edges, broken edges(hydroxyl groups) have facilitated the guar gum adsorption. The isoelectric point of kaolinite is pH 3.96. The p H, ionic strength and flocculant dosage have a significant effect on the kaolinite settling rate. The guar gum has exhibited excellent turbidity removal efficiency at pH 5. The turbidity removal is inefficient at pH 10. However, guar gum has shown high turbidity removal with 80% transmission at pH 10 in the presence of a KNO_3 electrolyte.     

Separation technologies for sludge dewatering

Particles in sludge feeds interact strongly one with another to prevent settling and offer a significant resistance to filtration and compression. This leads to the need for dewatering forces to be compressive ones applied directly to the networked solid phase; sometimes shear forces can be an assist dewatering. Designs of filtration equipment most suitable for sludge dewatering have evolved to meet the intrinsic characteristics of sludges, the most important of which are their compressibility and fine particle sizes, which lead to cakes with extraordinarily high solids contents close to the filter medium. Hence, the membrane plate press, the belt filter and the decanter centrifuge have become most widely accepted machines for sludge dewatering. Filter presses tend to yield a drier solids discharge, but the level of dryness depends on the sludge properties. The same feed properties dictate the need for chemical pre-treatment to ensure the highest rates of dewatering and best clarity of filtrate, and correct choice of filter cloth is also crucial in these respects.     

福建九龙江流域给水厂污泥脱水性能的试验研究

根据九龙江流域给水厂污泥的颗粒性质,进行絮凝、污泥比阻和过滤试验,研究污泥的脱水性能。试验结果表明,适当投加聚丙烯酰胺可以降低污泥比阻,改善脱水性能。其中阴离子型聚丙烯酰胺对该地区水厂污泥的调理效果较好,PAM投加范围以低于0.5‰为佳,不仅可以降低运行成本,而且在改善污泥的脱水性能及上清液水质的回用效果上,均可以达到最佳的状态。     

In depth characterisation of hydrocyclones: Ascertaining the effect of geometry and operating conditions on their performance

Hydrocyclones are used for densification of waste streams prior to drying or for classification of solid and liquids in two-phase streams. They are becoming popular in industrial units due to their simplicity, low energy consumption and high versatility. However, the effect of geometry and operating conditions on the cut diameter and solid recovery efficiency have been independently studied, and therefore there are no studies approaching the influence of all the parameters simultaneously. Thus, a detailed experimental study was conducted to ascertain the effect of the hydrocyclone body (diameter and angle) and the vortex finder and spigot size and shape, as well as operating conditions (inlet pressure and solid concentration) on the separation efficiency curve, cut diameter, solid and volume recovery and the main features of the outlet streams. It has been proven that separation efficiency and outlet stream composition are sensitive to both the geometry of the hydrocyclone and the operating parameters. Therefore, knowledge of their influence is essential for the design of industrial units where liquid reutilisation is a major concern.     

永平铜矿凹陷露天排水方案选择

本文简要地介绍了永平铜矿凹陷露天排水设计,通过对排水方案的分析比较,提出了技术上可行和经济上合理的排水方案.