Extended perturbation series analysis and improvement applied to a porous catalyst slab

In this paper techniques available for the analysis and improvement of extended regular perturbation series are applied to an example problem of chemical reaction inside a porous catalyst slab of infinite length. The techniques used include the extraction of singularity, Euler transformation, Pade approximants, Shanks transformation, Levin transformations and series reversion. The example illustrates the utility of these techniques in improving the convergence of regular perturbation series.

In general, the Pade approximants given the best results for the present problem.     

大型磷酸二铵装置工艺改进及操作控制优化

针对大型磷酸二铵(DAP)装置使用低质原料出现的系统堵塞、旋风除尘器除尘效率下降、产品着色效果不佳等问题,给出工艺改进的方法。分析各种工艺控制指标对生产的影响,提出改善产品外观质量的措施。通过工艺改进及操作控制指标的优化,解决系统存在的问题,运行周期得到延长。该成果对大型磷酸二铵装置的技术改造、操作优化及生产管理等有良好的指导、借鉴意义。     

提高脱硝装置产能的工艺优化措施及效果分析

介绍潍坊亚星化学股份有限公司提高脱硝装置产能的工艺优化措施,并分析了优化后的效果。     

GK255生产线开放式炼胶机过胶方式的改进GK255 production line for improvement of the open rubber mixing machines gluing method 金森,岳锋,李洪全

本文简要介绍了一种新型开炼机过胶方式。在原有开炼机翻胶装置上进行改进,通过自动控制替代传统的人工操作,改进成本低,结构简单,从技术上规范了操作步骤,不仅保证了工艺流程,而且大大减少了操作工劳动量。     

图版法判别碳酸盐岩洞穴储层有效性

塔中地区下奥陶统碳酸盐岩地层发育岩溶洞穴,充填作用强弱不等,洞穴的有效性受到严重影响。针对此问题,根据既有资料建立了不同类型洞穴储层的交会图版,对洞穴储层进行有效性评价,从而为生产测试提供指导,极大地提高了经济效益。该方法在塔中地区取得了良好的效果。     

Process synthesis,design and analysis using a process-group contribution method

This paper describes the development and application of a process-group contribution method to model, simulate and synthesize chemical processes. Process flowsheets are generated in the same way as atoms or groups of atoms are combined to form molecules in computer aided molecular design (CAMD) techniques. The fundamental pillars of this framework are the definition and use of functional process-groups (building blocks) representing a wide range of process operations, flowsheet connectivity rules to join the process-groups to generate all the feasible flowsheet alternatives and flowsheet property models like energy consumption, atom efficiency, environmental impact to evaluate the performance of the generated alternatives. In this way, a list of feasible flowsheets are quickly generated, screened and selected for further analysis. Since the flowsheet is synthesized and the operations in the flowsheet designed through predictive models to match a set of design targets, optimal solution of a given synthesis problem is guaranteed.     

An improvement on the quraishi-fahidy method of dimensional analysis

An improvement on the Quraishi-Fahidy method of dimensional analysis is given which is based on the systematic use of basic matrix algebra. This allows the construction of dimensionless groups to be carried out on the computer using standard matrix algebra software, a procedure which would be most effective when the constitutive matrix is very large. While this is not generally the case with many physical systems, the method illustrates the direct application of matrix algebra to an engineering problem.     

3MW背压式汽轮机运行故障分析及改进措施

针对3 MW背压式汽轮机运行中出现的复速级叶片断裂和前汽封体变形开裂等故障进行了原因分析,并确定了解决措施。通过方案措施的实施,解决了存在的问题,发电量增加了3%。     

提高PVC糊树脂产量的工艺改进

介绍了乳液种子聚合工艺的特点,列举了提高PVC糊树脂产量的改进措施及实施后的效果。     

油泥砂流化焚烧处理系统与运行分析

提出一种采用异密度循环流化床燃烧技术处理油泥砂的方法。该方法能以较低的运行成本对油泥砂进行资源化洁净利用,降低石油开采成本,实现危险污染物的无害化、减量化、规模化、资源化处理,解决环境污染问题。结合工程实际,详细介绍了流化床焚烧处理的工艺流程、技术特点和1台145t／d流化床焚烧锅炉的设计参数和运行特点。     

Hydrodynamic and mass transfer efficiency of ceramic foam packing applied to distillation

In addition to a high void volume and specific area, solid foams possess other properties (low density, good thermal, mechanical, electrical, and acoustical behaviour) that make them attractive for applications such as heat exchangers and reformers. Applications using foams as catalysts or structured catalyst supports have demonstrated higher performance than classical catalysts. Several studies have explored the hydrodynamic behaviour of foams in monophasic and countercurrent systems and have reported very low pressure drops. This paper describes the application of ceramic foam to distillation. The β-SiC foam contains 5 pores per inch (PPI) with a 91% void volume and a surface area of 640 m²/m³. Performance parameters including pressure drop for the dry and wet packing, flooding behaviour, and dynamic liquid hold-up were measured in a column of 150 mm internal diameter. The mass transfer efficiency in terms of the height equivalent to theoretical plate (HETP) was determined by total reflux experiments using a mixture of n-heptane and cyclohexane at atmospheric pressure. The experimental results were used to develop a set of correlations describing pressure drop and liquid hold-up in terms of a dimensionless number. The hydrodynamic performance and mass transfer efficiency were compared with classical packing materials used in distillation.     

Nitrogen-use efficiency and economic efficiency of slow-release N fertilisers applied to irrigated turfs in a Mediterranean environment

The effect of three fertilisers that delay the bioavailability of nitrogen (N) in the soil was compared with ammonium nitrate and a zero N control in two irrigated turfs in NE Portugal. The fertilisers used were: Floranid permanent 16-7-15 (slow-release, IBDU/Isodur fertiliser); Basacote plus 9M 16-8-12 (controlled-release fertiliser, copolymer ethylene acrylic); Nitroteck 20-8-10 (stabilized fertiliser, dicyandiamide as nitrification inhibitor + coating with polyterpene) and Nitrolusal (ammonium nitrate, 20.5% N), applied all at a rate of 120 kg N ha⁻¹. Nitrolusal was split into two fractions of 60 kg N ha⁻¹. Phosphorus (P) and potassium (K) rates were balanced among treatments by using superphosphate (18% P₂O₅) and potassium chloride (60% K₂O). The turf dry matter (DM) yield and N concentration in dry material were determined from several cuts of biomass throughout the growing season. Based on DM yield, N concentration in dry material and fertilisation costs, indices of N use efficiency and economic efficiency were estimated. Soil nitrate levels were monitored by using anion exchange membranes inserted directly into the soil. Basacote gave significantly lower DM yields than the other fertilised treatments. The apparent N recovery of Basacote was also the lowest. The results showed that Basacote released less N than that required for an adequate plant growth in the beginning of the growing season, hampered the flush of spring growth. Furthermore, the release period of this Basacote formulation, in the environmental conditions of these experiments, seemed to be longer than the length of the growing season. Nitroteck and Floranid yielded similar or even higher DM and apparent N recovery values than did Nitrolusal. The indices of economic efficiency ordered the fertilisers as Nitroteck > Nitrolusal > Floranid > Basacote or Nitrolusal > Nitroteck > Floranid > Basacote, if the costs of P and K fertilisers used to balance the P and K rates in the experimental design were, respectively, taken or not taken into account.     

Effect of digested sewage sludge on the efficiency of N-fertilizer applied to barley

Enhanced microbial activity following sewage sludge land application may affect soil N cycling and, therefore, plant available N. We studied the effect of anaerobically treated sewage sludge on N-fertilizer efficiency and on some aspects of the soil N cycling. Field plots (3 m × 9 m) sown with barley (Hordeum vulgare L.) in November were amended with a) sludge (80 mg ha-¹) and ammonium nitrate (150 kg N ha-¹), b) ammonium nitrate (150 kg ha-¹) only, c) or left unamended. Monthly soil samples were taken from 0 to 20-and 20 to 50-cm depths to determine soil inorganic N (NH₄ ⁺, NO₃-). Denitrification in the upper 20-cm horizon was estimated by measuring N₂O+N₂ emission from undisturbed soil samples by the acetylene-inhibition technique. Crop yield parameters were analysed before harvesting, and grain production was recorded. With respect to the control, the yield increase for the N-fertilizer treatment was 85% and 45% for the sludge + N-fertilizer treatment. The decrease of N-fertilizer efficiency in sludge amended plots was presumably due to a decrease in spring plant available N. Presumably, microbial immobilisation and denitrification in organic amended treatments were responsible for the decrease in N-fertilizer efficiency. This revised version was published online in August 2006 with corrections to the Cover Date.     

基于测试数据的蔗渣锅炉能量分析及能效提升措施

目前蔗渣锅炉存在服役年限较长、燃烧不充分、效率低下、燃料浪费严重以及污染物排放高等问题,对其原因分析欠缺大量现场数据。为了解决这一问题,本文对121台蔗渣锅炉进行能效测试,得出锅炉热效率达到标准限定值和目标值的数量分别仅占51.24%和0.83%;热损失最大的排烟热损失达10%,其中所含水分的热损失占到将近1/4;二氧化碳排放量平均值达到131.54kg/GJ。深入分析各影响因素与热效率的关系,得出了主要影响因素为烟气温度、过量空气系数和飞灰含碳量。并针对这些因素提出了能效提升措施。若能效均能达到限定值或目标值,每年的蔗渣消耗量将分别减少157kt或568kt,二氧化碳排放量将分别减少160kt或522kt,其他污染物排放同样会减少,推及到全国的蔗渣锅炉,节能减排潜力更巨大。     

废水处理中的复极性固定床电解槽技术

复极性固定床电解槽（bipolar packed bed cell,BPBC)是在三维电极原理基础上发展起来的新型电化学工程技术，其在治理含氰及重金属废水、有机废水和印染废水方面具有良好的处理效果。介绍了BPBC的电化学特性，综述了国内外BPBC废水处理技术应用现状及其机理研究的概况。同时，提出了该技术目前存在的问题，并对其进一步的深入研究作了展望。     

Statistical key variable analysis and model-based control for the improvement of thermal efficiency of a multi-fuel boiler

Burning multi-fuel, including gases, liquid fuels and coal, whose flow rates and heating values vary all the time, a typical boiler in the steel and iron plant poses a challenge to achieving optimal operation. The present study proposes to develop an adaptive data-driven thermal efficiency estimator of multi-fuel boilers based on statistical identification of key variables. With the available on-line efficiency model, the model-based controller is hence readily applicable to improve the boiler efficiency. Real operation data taken from two industrial boilers are used to verify the effectiveness of the proposed method. The first half part of data serves to develop statistical models while the second half part serves to be simulated as virtual plants. The application of the proposed methods improved 1.94% of the thermal efficiency of a boiler burning multi-gas and 0.73% of a boiler burning coal and multi-gas in the virtual plant simulations.     

Process parameters analysis of direct laser sintering and post treatment of porcelain components using Taguchi's method

The effects of laser sintering parameters (laser power, scan speed and hatching space) and post sintering process (heating rate, sintering temperature and holding time) on the physical and mechanical properties of porcelain components have been investigated. The study has been carried out using the Taguchi's method for the experimental design. In the laser sintering process, lower laser energy density and higher hatching space will increase the final mechanical properties of the porcelain components. A stress relief principle has been put forward to explain the different influence of the factors. The appropriate laser sintering parameters are attained in this paper: laser power 50 W; scan speed 85 mm/s; and hatching space 0.6 mm. Sintering temperature has been determined to be the most important factor in the post sintering process. Appropriate sintering temperature for the laser sintered porcelain bodies is in the range of 1425–1475 °C regarding the mechanical properties of the porcelain components. The maximum bending strength, 34.0 ± 4.9 MPa, is reached.     

Fate and efficiency of sulfur fertilizer applied to food crops in West Africa

Increased food production in West Africa must be linked to increased fertilizer use. However, the increased use of the high analysis sulfur-free materials currently available in the region will lead to increased incidence of sulfur (S) deficiency. In order to determine the S fertilizer requirements of major cereal crops, and compare the fate and efficiency of alternative S sources, experiments were conducted at six sites in semiarid and subhumid West Africa from 1985–1988. Sulfur fertilizers increased grain yields from 10% to 65% (200 to 2000 kg/ha) in 14 out of 20 site-years (at 5 out of 6 sites). Maximum response was generally obtained with only 5–10 kg S/ha. Both powdered (–60 mesh S⁰) and granular (S⁰-fortified TSP) elemental S sources were usually as effective as sulfate sources (gypsum or SSP). The residual effectiveness of S⁰, however, was superior to that of sulfate at most sites. Sulfur-35 balances demonstrated substantial leaching and low crop recovery (5%–10% of S applied) of fertilizer S. Up to 50% of the applied S was lost from sulfate sources, whereas <20% was lost from S⁰ sources. Although S⁰ sources were at least as effective as sulfate sources, the low S rates required suggest that S deficiencies in the region can be corrected at relatively low cost with sulfate-containing fertilizers, provided they can be supplied at more appropriate nutrient ratios.     

极限碳酸盐硬度法评定阻垢剂的阻垢性能

着重介绍了极限碳酸盐硬度法及其在阻垢剂评价筛选中的应用,并对PAPEMP,HPMA(水溶出)．HPMA(油溶出),T-225,HEDP,PBTCA,HPAA等阻垢剂的阻垢性能进行了评定。由实验的结果来看．极限碳酸盐硬度法简便、快捷、重现性好,可信度高。     

Periodic operation applied to the kinetic study of CO2 methanation

Periodic operation was applied to the CO₂ methanation reaction at 383 K on 2% Ru/TiO₂. A continuous feed recycle reactor combined with a diffuse reflectance infrared cell and a mass spectrometer allowed to follow simultaneously the gas phase CO₂ and CH₄ as well as the adsorbed species (CO)_a and (formate)_a. Experiments consisting of periodic variations of CO₂ in the hydrogen feed showed response curves with maxima/minima shifted in time in the sequence CO₂, (formate)_a → (CO)_a → CH₄. Similar delays measured for the (CO)_a formation and hydrogenation indicate that both of these processes are limiting the overall reaction rate. A kinetic model was proposed and verified under periodic conditions. The main experimental trends, which are pronounced time lags between CO₂, (CO)_a and CH₄, could be described satisfactorily.