40 kt/a硫铁矿制酸装置技术改造

江苏恒盛化肥有限公司磷铵厂原有40kt／a硫酸生产装置一套。采用文一泡一电半封闭稀酸洗净化，一转一吸流程。该装置虽经多次改造，产量能达到60kt／a（直烧硫磺），但仍不能满足本厂磷铵、硫基复合肥生产的需要，且一转一吸流程尾气排放不能达到环保的要求。为此，2005年初公司决定投资300万元进行扩产并改一转一吸为两转两吸，改造后采用硫铁矿制酸，产量达80kt／a，尾气SO2要求达标排放，净化污水实现封闭循环，蒸汽产量达6．5t／h，主要改造内容如下。     

40 kt/a硫铁矿制酸装置扩能改造实践

从节省投资、降低消耗考虑,介绍了一转一吸流程的40kt／a硫铁矿制酸装置扩能改造为80kt／a、两转两吸流程。在焙烧、净化、干吸各工序的改造措施,实现了稀酸封闭循环、污水零排放、尾气达标排放。     

铅锌烧结机烟气两转两吸制酸装置的设计与试生产总结

对铅锌烧结机烟气制酸装置的转化和干吸系统进行改造。新建一套160kt/a转化系统代替原两套系统，改一转一吸流程为两转两吸流程，采用高温吸收工艺。4个月的试生产实践证明，装置运行良好，能够保持自然平衡，尾气排放达到设计标准。     

40kt/a硫铁矿制酸装置改造成硫磺制酸装置

分析了两转两吸制醋工艺的40kt/a硫铁矿制酸装置改造成硫磺制酸装置的规模、工艺技术方案、设备利用方式以及改造所需的投资。建议采用“3+2”五段转化、98％H_2SO_4的硫酸干燥技术,改造后的硫磺制酸装置规模在80～100kt/a较佳。     

云铜公司硫酸四系统简介

介绍150kt/a冶炼烟气制酸装置的工艺流程、主要设备及生产运行情况。装置彩和ⅤⅣⅠⅢⅡ“3＋2”5段转化工艺，在气ψ（SO2）大于5％的情况下可以维持自热平衡，转化经达99．2％。烟气二氧化硫浓度偏低时采用一转一吸工艺，转化经达98．7％。     

浓硫酸冷却器及其循环水冷却系统的改造

随着我公司硫酸市场的开拓和内部用酸量的增加，我厂决定对已停车一年多的20kt/a硫铁矿制酸一系列进行“二改四”扩产改造。改造分两期进行；一期工程对转化、干吸工序进行改造，将一转一吸工艺改成两转两吸工艺；二期工程对焙烧、净化工序进行改造。现将浓硫酸冷却系统的改造介绍如下。     

副产高浓度亚硫酸氢铵装置的扩产改造

在采用一转一吸加二段氨酸法尾吸工艺的硫铁矿制酸装置中，用第一段尾吸母液吸收风机出口的高浓度二氧化硫[φ(SO2)约8％]，生产高浓度亚硫酸氢铵，设计产量为5kt／a。通过增大进亚硫酸氢铵吸收塔二氧化硫管径、减小亚硫酸氢铵吸收塔筛板开孔率及孔径、降低吸收液温度、优化操作控制指标等措施，使生产能力增加到16．5kt／a，经济效益及环保效益可观。     

合成氨装置扩能改造总结

合成氨厂分2期对2套合成氨装置进行配套扩能改造,以新老系统转化工序实施“并联换热式转化”工艺为重点,在不改变原外加热式箱式一段炉转化工艺的前提下,采用并联换热式转化工艺,使转化工序的生产能力达到160kt／a,为合成氨生产装置能力由96．5kt／a扩能改造到160kt／a奠定了坚实基础,并为联碱厂由285kt／a扩能改造到450kt／a提供了强有力的支撑。     

40 kt/a硫酸系统的挖潜改造

介绍40kt/a硫铁矿制酸装置的挖潜改造。装置原采用文-泡-电水洗净化、一转一吸工艺，技术经济指标差，环境污染严重。通过将工艺原料改为固体颗粒硫磺及更新设备，装置生产能力达60kt/a以上，改进了技术经济指标，减轻了环境污染。     

60kt／a硫铁矿制酸装置扩建改造的设计特点

介绍一套小型硫铁矿制酸装置扩建改造的设计特点。装置产能由60kt／a增加到80kt／a,净化工序由水洗净化工艺改为稀酸洗净化工艺。净化工序使用了下段为泡沫板、上段为填料床的组合式洗涤设备泡填塔,具有投资省和效率高的优点。预期改造投资回收期为4．5年,经济效益和环境效益良好。     

Extraction into a flow of a fluid with a velocity gradient

Unsteady extraction from a system of semi-infinite capillaries to the flow of a fluid with a linear velocity gradient is studied. An assumption that the diffusion in the flow is a quasi-steady-state process is taken to obtain a linear equation for the local mass flux from the pore space, which involves fractional derivatives with respect to time and flow coordinate. Limiting solutions for the total diffusion flux at small and large times that cover the entire time interval are found.     

Electrolytes: From a Thorn Comes a Rose,and from a Rose,a Thorn

In this article we take a stroll through the metaphorical rose garden, part of the flower garden, that is electrochemical storage systems. We take a closer look at batteries as the center‐pieces – the roses – and especially at the system component of batteries, the electrolyte and its development, throughout history. Just as a rose can only develop its unique beauty when taken good care of and provided with clean water and suitable nutrients, a battery cell cannot function without its electrolyte; the seemingly trivial component that has to juggle a multitude of requirements in order to make batteries truly bloom.     

Propagation of a burning front over a condensed material from a focus

Measured propagation speeds are given for the combustion front in a blind gap in a condensed substance, which are related to gap height and mean pressure. The front may propagate monotonically, which is characteristic of relatively high pressures and wide gaps, or as a result of additional burning foci arising at a certain distance from the main front. At low pressures and particularly with small gap heights, the front propagates in an unstable fashion over the surface.Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 4, pp. 49–53, July–August, 1992.     

Mesomorphic transitions in a mixture of a flexible and a semi-rigid polymer

Phase studies on a mixture of two polymers are presented, one of which is mesomorphic. We have systematically examined the influence of the molecular weight of the flexible polymer (including the oligomers) and of the semi-flexible polymer. In addition to the effect of the molecular weight, specific interactions are important for compatibility and formation of a homogeneous mesomorphic phase. The nature of this phase is demonstrated to be cholesteric and the pitch is determined.     

When is a Beam a Plate?

Formulas associated with simple beam or plate theories are used extensively in structural design, to determine You's modulus, and to determine fracture strength of brittle nonmetallic materials. The question may arise as to whether the proper ratio of beam-width-to-beam-depth is such that the bent structural element can be considered as a beam and, if not, what is the correction factor that should be used with the simple beam formula. These questions are answered for a range of structural metallic and brittle nonmetallic materials.     

Laminar flow deformation of a droplet adhering to a wall in a channel

We study the deformation of oil droplets of varying viscosity adhering to a solid, rigid wall in a rectangular channel induced by a pressure-driven, laminar flow of water. Our experimental investigation involves the systematic study of the effects of initial droplet volume, flow rate and viscosity ratio on the various modes of droplet motion and deformation; this is performed via direct visualisation of the flow in a glass cell using a high-speed camera. Our results are used to construct flow maps that delineate the critical conditions for droplet ‘sliding’, ‘crawling’ and detachment from the channel wall as a function of system parameters. Comparisons of our experimental results with numerical predictions obtained using a procedure based on the diffuse-interface method yield reasonably good agreement for certain flow regimes.     

Detonation of a Column of a Chemically Active Bubbly Medium in a Liquid

The problem of a detonation wave propagating in a cylindrical column of a chemically active bubbly medium screened by a liquid from the tube walls is formulated and numerically solved within the framework of the Iordanskii–Kogarko two-phase model with allowance for energy dissipation due to acoustic radiation of bubbles. The wave structure of the reaction zone and the detonation velocity of the bubbly medium column are calculated. It is found that the self-sustaining wave can propagate with a velocity greater than the velocity of one-dimensional bubble detonation by a factor of 1.5–2.5.