内返料内分级喷浆造粒干燥机的返料分级机理研究 Ⅵ.悬浮式螺旋进…

本文研究内返料内分级喷浆造粒干燥机中悬浮式螺旋进料口的有效返料系数。推导出有效返料系数的计算式，讨论了螺旋进料口和悬浮高度、转筒半径和装载系数对有效返流系数的影响。     

内返料喷浆造粒干燥技术概述

内返料喷浆造粒干燥机集造粒、干燥、分级与破碎为一体 ,并广泛应用于化肥生产中。主要介绍了内返料喷浆造粒技术及其在国内外的发展过程     

内返料内分级喷浆造粒干燥机的返料分级机理研究Ⅵ．悬浮式螺旋进料口的有效返料系数的理论分析

本文研究内返料内分级喷浆造粒干燥机中悬浮式螺旋进料口的有效返料系数。推导出有效返料系数的计算式，讨论了螺旋进料口的悬浮高度、转筒半径和装载系数对有效返料系数的影响。     

磷复肥喷浆造粒内返料技术研究与应用

探讨了磷复肥喷浆造粒干燥机内返料数量与质量对造粒的影响，提出返料量计算式，为返料螺旋设计提供理论依据。     

内返料喷浆造粒干燥机分级返料研究

设计磷铵用全内返料喷浆造粒干燥机的关键是返料螺旋的确定,返料的前提是颗粒在回转圆筒内充分有效的分级。本文通过理论分析与简单的几何变换得到了返料螺旋口高度的计算公式,实验验证并得到修正系数。该公式为返料螺旋的确定提供依据     

全内返料喷浆造粒干燥机研究进展

全内返料喷浆造粒干燥机是集喷浆、造粒、返料、分级、破碎于一体的高效设备,具有结构紧凑、单机生产能力大、单位能耗低、适应性强、工艺成熟等优点,在磷复肥等领域获得广泛应用。本文介绍了全内返料喷浆造粒干燥机研究进展及成果。     

内返料内分级喷浆造粒干燥机返料流量研究

研究内返料内分级喷浆造粒于燥机的返料流量．通过分析粉料与螺旋通道进料口的相对运动揭示粉料进入螺旋通道的机理．利用积分法建立了返料流量的计算模型．返料流量等于螺旋通道进料口在单位时间内平均穿越的料层体积与有效返料系数之积讨论了有效返料系数的控制变量及其受装载系数的影响．     

内返料内分级喷浆造粒干燥机的返料分级机理研究：V.料幕分析

本文研究内返料内分级喷浆造粒干燥机的料幕特性。推导料幕密度的计算式和抄板最大撒料角的计算式，并认为料幕密度与物料性能有关。分析径向倾斜抄板对料幕的影响，讨论抄板高角的合理性。     

内返料内分级喷浆造粒干燥机的返料分级系统的设计

简述了内返料内分级喷浆造粒干燥机的工作原理,归纳了返料分级过程的数学模型,提出了返料分级系统的设计方法,讨论了返料螺旋通道进料口的改进措施。     

内返料内分级喷浆造粒干燥机的返料分级机理研究Ⅶ．悬浮式螺旋进料口的内分级效率分析

本文建立了内返料内分级喷浆造粒干燥机悬浮式螺旋进料口的内分级效率的计算模型，认为转筒半径、粉料容积分布函数对内分级效率没有影响，推荐返料螺旋进料口相似放大宜采用的４个参量。     

磷复肥“三内技术”研究与开发(五)

介绍磷复肥喷浆造粒“三内技术”中的料幕特性的研究 ,探讨物料量、料幕密度与扬料板之间的关系 ,提出扬料板计算为升举式扬料板设计提供理论依据。     

3万吨／年“料浆法”磷铵装置技术改造方案探讨

用分析投资效益的方法比较了增加我国磷铵产量的三种方式,得出了“改造现有小磷铵装置增产磷铵具有最佳效益”的结论。并在分析３ 万吨／年料浆法磷铵装置的潜力和薄弱环节的基础上,提出了扩能为６ 万吨／年磷铵的具体技改方案     

CUSUM‐type testing for changing parameters in a spatial autoregressive model for stock returns

The article suggests a CUSUM‐type test for time‐varying parameters in a recently proposed spatial autoregressive model for stock returns and derives its asymptotic null distribution as well as local power properties. As can be seen from Euro Stoxx 50 returns, a combination of spatial modelling and change point tests might allow for superior risk forecasts in portfolio management.     

Activating solution gas drive as an extra oil production mechanism after carbonated water injection

Enhanced oil recovery (EOR) methods are mostly based on different phenomena taking place at the interfaces between fluid–fluid and rock–fluid phases. Over the last decade, carbonated water injection (CWI) has been considered as one of the multi-objective EOR techniques to store CO₂ in the hydrocarbon bearing formations as well as improving oil recovery efficiency. During CWI process, as the reservoir pressure declines, the dissolved CO₂ in the oil phase evolves and gas nucleation phenomenon would occur. As a result, it can lead to oil saturation restoration and subsequently, oil displacement due to the hysteresis effect. At this condition, CO₂ would act as in-situ dissolved gas into the oil phase, and play the role of an artificial solution gas drive (SGD).In this study, the effect of SGD as an extra oil recovery mechanism after secondary and tertiary CWI (SCWI-TCWI) modes has been experimentally investigated in carbonate rocks using coreflood tests. The depressurization tests resulted in more than 25% and 18% of original oil in place (OOIP) because of the SGD after SCWI and TCWI tests, respectively. From the ultimate enhanced oil recovery point of view, the efficiency of SGD was observed to be more than one-third of that of CWI itself. Furthermore, the pressure drop data revealed that the system pressure depends more on the oil production pattern than water production.     

Activating solution gas drive as an extra oil production mechanism after carbonated water injection

Enhanced oil recovery (EOR) methods are mostly based on different phenomena taking place at the interfaces between fluid-fluid and rock-fluid phases. Over the last decade, carbonated water injection (CWI) has been considered as one of the multi-objective EOR techniques to store CO₂ in the hydrocarbon bearing formations as well as improving oil recovery efficiency. During CWI process, as the reservoir pressure declines, the dissolved CO₂ in the oil phase evolves and gas nucleation phenomenon would occur. As a result, it can lead to oil saturation restoration and subsequently, oil displacement due to the hysteresis effect. At this condition, CO₂ would act as insitu dissolved gas into the oil phase, and play the role of an artificial solution gas drive (SGD).In this study, the effect of SGD as an extra oil recovery mechanism after secondary and tertiary CWI (SCWI-TCWI) modes has been experimentally investigated in carbonate rocks using coreflood tests. The depressurization tests resulted in more than 25% and 18% of original oil in place (OOIP) because of the SGD after SCWI and TCWI tests, respectively. From the ultimate enhanced oil recovery point of view, the efficiency of SGD was observed to be more than one-third of that of CWI itself. Furthermore, the pressure drop data revealed that the system pressure depends more on the oil production pattern than water production.     

积极采取措施努力促进以我为主发展现代煤化工

煤化工是煤炭的深加工产业。现代煤化工属于技术密集型和资金密集型产业。坚持科学发展观,认真转变增长方式,实现现代煤化工的可持续发展,对推动我国石油替代战略的实施和化学工业的结构调整至关重要。坚持一体化、基地化、大型化、现代化,发展现代煤化工首先要从战略的高度,认识提高自主创新能力,开发具有自主知识产权核心技术的重要性,正确处理引进、消化、吸收、创新的关系,充分发挥国内工程设计单位的作用,积极推进重大装备国产化,并充分考虑环境、资源、效益等诸多因素。     

基于随机前沿面的全球石化行业技术效率相关研究

采用随机前沿面生产函数法,考察1989—1999年全球石化行业及典型企业的技术效率,进行企业国际竞争力的比较,发现全球石化行业发展所经历的3个不同规模效应变化的阶段:规模报酬递减—规模报酬不变—规模报酬递增。这个结论与全球石化行业实际经历的3个典型阶段完全吻合,说明全球石化行业正处于不断发展中,而不是衰退趋势。同时研究中还发现,新的管理技术在行业和企业的发展中已经起到引擎作用,领先公司引导了整个行业发展轨迹。     

Efficient estimation and particle filter for max‐stable processes

Extreme values are often correlated over time, for example, in a financial time series, and these values carry various risks. Max‐stable processes such as maxima of moving maxima (M3) processes have been recently considered in the literature to describe time‐dependent dynamics, which have been difficult to estimate. This article first proposes a feasible and efficient Bayesian estimation method for nonlinear and non‐Gaussian state space models based on these processes and describes a Markov chain Monte Carlo algorithm where the sampling efficiency is improved by the normal mixture sampler. Furthermore, a unique particle filter that adapts to extreme observations is proposed and shown to be highly accurate in comparison with other well‐known filters. Our proposed algorithms were applied to daily minima of high‐frequency stock return data, and a model comparison was conducted using marginal likelihoods to investigate the time‐dependent dynamics in extreme stock returns for financial risk management.     

Aerosol diffusion battery: The retrieval of particle size distribution with the help of analytical formulas

A new algorithm is proposed for the determination of aerosol particle size distribution from a set of screen diffusion battery penetrations. The idea is to determine the size spectra of the fractions of particles separated by the sections of diffusion battery, so the total size distribution is the sum of the spectra of fractions. The spectrum of each fraction is approximated by the lognormal function, which is defined by two parameters: the standard geometric deviation (SGD) and geometric mean diameter. The SGD value is chosen to be 1.35 for each fraction. The geometric mean diameters of fractions are calculated from the diffusion battery penetrations. For this purpose, analytical formulas are derived to link the mean single-fiber collection efficiency for each fraction with the experimentally measured penetrations. Then the mean diameters of fractions are calculated from the collection efficiencies using the fan model filtration theory. To achieve a better size resolution, numerical approach is proposed to calculate the particle size spectrum using the analytical solution as an initial approximation. The validity of the analytical and numerical solutions is investigated by comparing them with the spectra determined by means of transmission electron microscopy and gravity settling. For this purpose, the aerosol is generated using the evaporation-nucleation technique, Collison-type nebulizer, and hot-wire bulb generator. It is found that the analytical solution demonstrates a good sizing accuracy but relatively poor size resolution, while the numerical approach results in both good sizing accuracy and good size resolution for the two-mode aerosol.

Copyright © 2018 American Association for Aerosol Research