煤泥二次浮选、精煤泥两段回收流程在梗阳选煤厂的应用

根据生产系统检测的数据,分析并评述了梗阳选煤厂煤泥二次浮选、精煤泥两段回收流程中粒度控制、煤泥粗选、粗精煤泥脱水回收、煤泥部分精选四个主要作业的效果;该流程整体工艺分选指标效果好,能有效回收煤炭资源,解决浮选精煤灰分普遍偏高的问题。     

“2+2”模式重介质选煤系统煤泥及煤泥水处理首创工艺技术

"2+2"模式重介质选煤系统煤泥两级浮选、精煤泥两段脱水、尾煤泥水两段浓缩两段回收首创工艺技术,在多座选煤厂的应用结果表明,该工艺可解决我国炼焦煤选煤厂长期存在的以浮选精煤为主的精煤泥灰分、水分偏高的难题,可实现煤泥全部厂内回收、洗水闭路循环。     

浮选精煤两段脱水新工艺

分析了沉降过滤式离心脱水机单段脱水回收精煤泥工艺的缺点;详述了沉降过滤式离心脱水机和压滤机组合而成的精煤泥两段脱水新工艺。该工艺增加了离心机入料中的粗精煤泥量,减少了煤泥循环量,可使最终精煤水分降到10%,适用于以重介质旋流器为主选设备的选煤厂;新工艺的基建投资费用低,动力消耗少,劳动效率高,设备运行稳定、可靠。     

白庄矿选煤厂煤泥浮选可行性研究

针对白庄矿选煤厂煤泥量大、发热量高,因缺少煤泥浮选环节,导致洗煤效益较低的实际情况,对煤泥进行了粒度分析和不同浮选工艺试验;研究表明,在相同药剂制度下,两段射流微泡浮选机在降低精煤灰分和提高精煤产率方面优势明显;采用该浮选工艺后预计年增收益(税前)2 020.82万元。     

两段浓缩、两段回收模式的煤泥水流程

介绍了选煤厂通常采用的单段浓缩、单段回收模式的煤泥水处理流程存在的局限性,阐述了两段浓缩、两段回收模式煤泥水处理流程中四个作业的主要作用及工艺要求,根据多年的设计经验和选煤厂生产实践,对煤泥水浓缩及粗、细煤泥脱水回收设备的选型提出了看法和建议。     

尾煤泥两段浓缩、两段回收工艺在田陈矿选煤厂的应用

针对田陈煤矿选煤厂尾煤泥中大于0.045 mm粒级含量较高的特点,采用两段浓缩、两段脱水回收工艺流程进行改造;将粗尾煤泥和细尾煤泥根据各自特征分别由沉降过滤式离心脱水机和压滤机回收,实现了煤泥全部厂内回收、洗水闭路循环、工业废水零排放,循环水浓度低至0.3 g/L。     

三产品重介旋流器—煤泥两段直接浮选工艺的应用

辛置选煤厂应用脱泥有压三产品重介旋流器—煤泥两段直接浮选工艺对一车间进行了技术改造,生产实践证明,该工艺在分选极难选、易泥化炼焦煤时,具有分选精度较高、技术指标先进的良好效果。     

尾煤泥两段浓缩、两段回收工艺在梗阳选煤厂的应用

介绍了尾煤泥两段浓缩、两段回收工艺在梗阳选煤厂的应用情况,分析了二段斜管浓缩机和压滤机的工艺性能指标以及该工艺实现清水选煤、尾煤二段回收、弧形筛截粗除杂的三个特点。     

沉降过滤式离心脱水机在煤泥二次浮选、精煤泥两段回收系统中的工艺效果

在设有煤泥二次浮选、精煤泥两段回收生产系统的5座选煤厂中,对沉降过滤式离心脱水机进行了工业性试验,并计算出各项工艺指标,分析表明,该设备脱泥、降灰和脱水的工艺效果良好。     

分级浓缩浮选工艺探讨

针对选煤厂目前使用的浮选工艺分选精度低、高灰细泥污染严重的问题,提出了分级浓缩浮选工艺;采用分级旋流器组将煤泥分级,粗颗粒用浮选机分选,细颗粒经浓缩后用浮选柱浮选;提高了煤泥的浮选精度和精煤产率,增加了企业经济效益。     

新型两段式气化炉的数值分析

对一种新型两段式水煤浆气化炉的气化效率进行了数值计算和分析。模型中将水煤浆的气化过程分为水分蒸发、煤热解、气相反应和气固异相反应等子模型。气相反应速率需同时考虑湍流混合和化学反应机理,气固反应的速率采用未反应缩芯模型。运用可实现k-ε模型描述气相湍流流动,随机轨道模型追踪水煤浆颗粒的运动。以中试多喷嘴水煤浆气化炉为建模基础,验证了该水煤浆气化模型的准确性。模拟计算得出新型两段炉的有效气组分含量为85.91%,冷煤气效率为76.42%。     

Improving the post-experiment properties of stein's two-stage procedure

We show that the properties of stein's(1945) two-stage test conditional on an observed ancillary stastistic are such that one may be concerned aboutt its performance in particular individual experiments. We present a new two-stage t-test which has preferable conditional properties under the null hypothesis and we describe a group sequential Stein-based test with appealing properties under null and alternative hypotheses.Study of our new two-stage test reveals a surprising feature of Stein's original procedure which illustrates how the requirements of conditional acceptability and admissibility may come into conflict.     

Φ3.6m两段炉煤气站模拟设计

根据设计依据中原料煤和所需煤气参数,经过计算和对气化、净化以及脱硫工艺的分析,确定采用5台Φ3.6 m两段炉为气源,经除尘、除焦油、脱硫得到净化煤气后,送往用气点。核算分析表明,煤气站气化炉选型合理,工艺路线确定合适,净化煤气等参数满足用气点要求,模拟设计达到设计要求。     

两段炉内的压降以及速度分布

化学热回收两段组合式气化炉有效地提高了高温合成气的显热回收。为进一步了解该新型两段炉内气体的流动规律,在自行搭建的冷模实验装置上,考察了该组合式两段炉内的二段床层压降以及速度分布情况。研究表明,采用Montiller经验公式能够准确预测二段固定床的床层压降,当气体达到二段床层表面时,将产生一个冲击区。拟合得到单喷嘴顶喷的轴向速度衰减公式以及四喷嘴撞击后的向下径向射流速度衰减公式。轴向速度的径向分布中,中心气速最大并且衰减最快,采用四喷嘴对喷的形式达到管流区所需的轴向距离较单喷嘴顶喷小1.8D。     

两段法处理高浓度含砷废水的工艺研究

通过正交试验研究了用石灰、有机捕集沉淀剂(DTCR)两段法处理高浓度含砷废水的工艺条件，并与常规法比较了处理效果和处理费用。结果表明：用两段法处理后的废水可达标排放；污泥量大大减少，易脱水，含水率低，降低了后处理的难度和费用；污泥稳定，不产生二次污染。该法具有显著的社会效益和生态效益。     

A two-stage preparation of mesophase pitch from the vacuum residue of FCC decant oil

The preparation of mesophase pitch as a precursor for the high-performance carbon fiber from a vacuum residue of FCC-decant oil (FCC-DOVR) was studied, applying a two-stage heat treatment to improve the pitch yield as well as its liquid crystal properties. The present two-stage preparation consisted of the pressurized heat treatment (1–5 MP) of the first stage at 430–480°C and the successive heat treatment under 13–260 Pa at 430°C. Such a two-stage preparation increased the yield of the spinnable mesophase pitch of 100% domain texture with lower softening point to 45% from 22% by the single-stage one from the same feedstock. Spinning properties of the mesophase pitch were excellent to allow smooth spinning for longer than 15 min and random orientation of mesogen molecules in the tranverse section of the fiber perpendicular to the fiber axis. The chemistry of the two-stage preparation for the higher yield and better properties as the fiber precursor is briefly discussed.     

两级低压引射器的结构设计与数值分析

引射器是目前家用燃气热水器、壁挂炉中燃烧器的重要组成部件，承担着两种以上介质相互引射及其混合的关键任务。首先对燃气燃烧器用的两级引射器进行了结构设计和优化，并对设计出的两种两级引射器进行了二维、稳态的数值模拟，探究了两级引射器内燃气和空气进行动量及质量交换的混合过程，采用质量引射系数和出口甲烷质量分数标准差系数来分别表征引射器的引射性能和混合性能，研究了引射器结构参数和运行参数对引射器性能的影响。研究表明，两种两级引射器均可以引射超过化学当量比的空气，第一级引射器混合段的长度存在最优值使引射器质量引射系数达到最大，当引射器其他参数相同时，优化后的两级引射器在不同背压下引射性能均有提升，在不同背压下混合性能有所降低，背压越高引射性能提升程度越大，混合性能降低程度越小。     

CO2跨临界双级压缩制冷循环的热力学分析

Two-stage vapor compression refrigeration cycle was accomplished with an intercooler.The state of the refrigerant vapor leaving the intercooler affects the system performance.The thermodynamic analysis of the trans-critical two-stage refrigeration cycle using CO₂ as the refrigerant was made with a condensing temperature of 35℃.When the intercooler operated at about the geometric mean of the evaporating and condensing pressures,compared with the single stage cycle,the coefficient of performance（COP）of the two-stage cycle was improved.As the degree of superheating of the CO₂ vapor leaving the intercooler increased,the COP of the two-stage system decreased.     

Combustion characteristics of a two-stage swirl-flow fluidized bed combustor

In order to investigate the combustion characteristics of a two-stage swirl-flow fluidized bed combustor, combustion experiments of low-grade anthracite coal were performed. Experimental parameters were the fluidizing air velocity, coal feed rates, bed temperature, stoichiometric air ratio, swirl nozzle diameter and rotational diameter. The experimental results showed that, due to the swirl flow, the elutriation rates of fines were lower than those of the single-stage fluidized bed combustor. The combustible contents of the ash in the outflow streams were also reduced. Therefore, the combustion efficiency of the two-stage swirl-flow fluidized bed combustor was 20% greater than that of the single-stage fluidized bed combustor under the same operating conditions.