浅析入炉煤挥发份对CFB锅炉磨损的影响

CFB锅炉作为现今各大发电厂普遍使用的燃煤锅炉,因具有燃烧效率高、燃料适用范围广、排放物更环保等优点而备受青睐。但是在CFB锅炉的使用过程中,炉内磨损却无法避免,这也造成了CFB锅炉存在长周期运行时间偏短的问题,严重影响着系统的安全、经济、稳定运行。入炉煤干燥无灰基挥发份,是CFB锅炉燃煤的一个重要指标。同一台锅炉,若实际干燥无灰基挥发份与设计干燥无灰基挥发份偏差较大,将会对CFB锅炉的磨损有一定程度的影响。通过入炉煤干燥无灰基挥发份指标调整前后的数据对比,探讨其对CFB锅炉的磨损产生的影响,从而达到改善CFB锅炉磨损状况的目的。     

HRG接枝粉生产工艺

主要介绍了HRG接枝粉生产工艺,包括HRG胶乳的聚合生产工序和胶乳的凝聚、干燥工序。胶乳的稳定性是一个很重要的分析指标,它决定了胶乳是否能够进入凝聚、干燥系统。对后续工艺,主要描述了凝聚、干燥的方式和过程以及风送系统。HRG生产采用浓硫酸作为凝聚剂,胶乳破乳后形成大粒径颗粒,经脱酸过程由干燥器进行干燥形成HRG粉尘,再由风送系统最后输送到料仓供掺混工序使用。     

MBS胶乳凝聚方法研究进展

介绍了MBS树脂的凝聚原理和影响凝聚的因素.叙述了国内外MBS的凝聚方法和生产现状,凝聚操作条件对MBS粉体性能的影响,并对各种方法的操作条件和优缺点进行了对比.认为气体酸凝聚技术技术操作工艺简单,设备投资少,将现有的单釜凝聚装置稍加改进即可,所得树脂颗粒综合性能可以达到喷雾凝聚水平,适合我国中小企业采用.     

填充型粉末丁苯橡胶的开发

确定了超细碳酸钙填充型粉末丁苯橡胶（PSBR）的制备工艺，研究了影响凝聚粉末化效果的因素，结果表明，影响粉末化效果的主要因素是包覆剂用量、凝聚条件、搅拌转速，次要因素是凝聚温度、干燥方式。适宜的粉末化条件是包覆剂用量为10份，将凝聚剂加入m(胶）：m(水）=8.5:100的凝聚体系中，搅拌转速为400-500r/min(3L凝聚釜），凝聚温度不小于40℃，湿粉采用闪蒸干燥方式干燥。     

氯气干燥装置工艺条件的控制对操作结果的影响

本文分析了氯气干燥装置的工艺条件、物理数据及有关指标，分析了各种工艺因素对干燥塔操作结果的影响，具有实际的指导生产的意义。     

悬浮法聚氯乙烯树脂质量影响因素和牌号配方探究

本文主要介绍了悬浮法聚氯乙烯生产工艺中,影响聚氯乙烯产品质量的相关因素,其中原料指标、化学助剂（如引发剂和分散剂等）、聚合釜内搅拌、进料油比、反应转化率、反应温度和系统pH值、防粘釜技术、浆料汽提和干燥均匀性及温度等是质量的主要影响因素,各影响因素对不同产品参数造成影响,从而影响产品树脂的品质。所以要根据工艺原理、生产实际、操作影响等综合考虑,并根据季节变化等进行相应调整,才能找出生产高质量聚氯乙烯树脂的工艺方案。同时,对生产不同牌号树脂产品所应用的化学品配方和不同的工艺操作参数,进行技术探究。     

石灰乳法漂粉精收率低的原因探讨

针对漂粉精收率低的问题，找出其影响因素，从原料消石灰的质量入手；严格控制石灰浆的氯化过程；离心操作中掌握加料和出料的节奏；减少干燥和包装中的跑料等损失。在保证工艺指标下生产，取得了较高的收率。     

辅助凝聚剂对ABS装置凝聚和脱水系统的影响

在丙烯腈-丁二烯-苯乙烯共聚物生产装置中,凝聚干燥单元易出现凝聚颗粒形态不佳、结构松散、浆液水层浑浊、真空过滤机滤布堵塞、脱水机电流超限和湿粉料含水量高等问题,严重制约了装置的生产能力。在凝聚过程熟化阶段加入辅助凝聚剂,可显著改善凝聚效果。结果表明:加入的辅助凝聚剂占凝聚浆液中固体质量的1.0%~2.0%时,凝聚废水中化学需氧量减少近60%,悬浮物减少97%,湿粉料含水质量分数由23.6%~23.9%降至19.4%~20.1%;辅助凝聚剂的使用对凝聚、脱水、干燥等单元操作的长周期连续稳定运行和最终产品质量无不良影响。     

影响精己二酸质量的因素探讨

精己二酸中水分和硝酸盐的含量是影响产品质量的主要指标。对影响产品质量的因素进行了分析,通过调整粗精酸结晶器、粗精酸增稠器、粗精离心机、干燥流化床等设备的操作参数,达到了提升产品质量的目的。     

干燥过程中颗粒湿含量的检测

引言 干燥是流程工业中重要的单元操作,是众多产品生产的关键步骤,在医药化工、食品、矿产加工、农产品加工等领域都有涉及[1-4].干燥效果的好坏不仅决定了生产单元的能耗,还会对产品的性能、形态、质量等产生影响.研究干燥过程的目的在于控制过程参数(包括干燥时间、进出口温度、风速等),对物料进行适度干燥,以使产品的湿度、质量等指标达到要求.在过程参数的设定过程中,干燥时间的控制(或称为干燥终点的确定)是影响产品质量最为关键的环节之一.     

Reduction of the Volatile Matter Evolution Rate from a Plastic Pellet during Bubbling Fluidized Bed Pyrolysis by Using Porous Bed Material

Rapid volatile matter evolution from high‐volatile fuels such as wastes and biomass is one of problems associated with fluidized bed incinerators and gasifiers. When volatile matter evolves rapidly in the vicinity of the fuel feed point, the mixing of volatile matter with reactant gas is poor, and therefore, unreacted volatile matter is expected to be released from the reactor. In the present work, reduction of the volatile matter evolution rate was attempted by employing porous solids as bed materials instead of nonporous sand. The effect of bed material on the onset of devolatilization was measured by use of a bench‐scale bubbling fluidized bed reactor. Volatile matter capture by the porous solids (capacitance effect) and the heat transfer rate within the bed, both of which affect volatile matter evolution rate, were also measured. Four types of porous solids, both with and without capacitance effect, were employed as the bed material. By employing porous solids without capacitance effect, the contributions of reduced heat transfer rate and capacitance effect to the delay of volatile matter evolution can be evaluated separately. For porous bed materials with a moderate capacitance effect (volatile matter capture of up to 20 %), the delay of the onset of devolatilization, which was measured by detecting the flame combustion of the volatile matter, was explained by the lower heat transfer between the fuel and bed. However, for a porous particle with high capacitance effect (volatile matter capture of 30 %), the capacitance effect also affected the delay of the onset of the flame combustion.     

Modelling fluidized bed combustion of high-volatile solid fuels

A model of an atmospheric bubbling fluidized bed combustor operated with high-volatile solid fuel feedings is presented. It aims at the assessment of axial burning profiles along the reactor and of the associated temperature profiles, relevant to combustor performance and operability. The combustor is divided into three sections: the dense bed, the splashing region and the freeboard. Three combustible phases are considered: volatile matter, relatively large non-elutriable char particles and fine char particles of elutriable size. The model takes into account phenomena that assume particular importance with high-volatile solid fuels, namely fuel particle fragmentation and attrition in the bed and volatile matter segregation and postcombustion above the bed. An energy balance on the splashing zone is set up, taking into account volatile matter and elutriated fines postcombustion and radiative and convective heat fluxes to the bed and the freeboard.Results from calculations with a high-volatile biomass fuel indicate that combustion occurs to comparable extents in the bed and in the splashing region of the combustor. Due to volatile matter segregation with respect to the bed, a significant fraction of the heat is released into the splashing region of the combustor and this results in an increase of the temperature in this region. Extensive bed solids recirculation associated to solids ejection/falling back due to bubbles bursting at bed surface promotes thermal feedback from this region to the bed of as much as 80-90% of the heat released by afterburning of volatile matter and elutriated fines. Depending on the operating conditions a significant fraction of the volatile matter may burn in the freeboard or in the cyclone.     

煤磨碎性能与煤质特性的相关性研究

采用多元统计方法对煤质特性与可磨性HGI的相关性进行了研究.结果表明,水分和挥发分越高,HGI越低;灰分和固定碳含量越高,HGI越高.但HGI与煤质特性存在明显的非线性.国外文献提供的非线性预测方程不适合我国煤种.仅从煤的工业分析等化学组分出发,将其看作一种均匀的物质,不能科学地反映煤的可磨性.煤的显微组分、矿物质类型、颗粒大小和分布以及煤种的显微构造等物理参数是决定煤可磨性能的重要因素.     

香榧假种皮中主要化学组成的研究

研究了新鲜香榧假种皮中所含的挥发油、溶剂提取物、单宁物质、非单宁物质、木质素等主要化学组分及其含量。测定了新鲜原料中的挥发性精油的提取率及密度、折光率、比旋光度等物理化学性质。结果表明,新鲜的香榧假种皮精油提取得率按绝干物计算为 5.5%,提取精油后残渣用溶剂甲苯提取的收率为 19.7%。精油中主要含单萜类化合物,含量 74.66%;残渣甲苯提取物主要含二萜类物质,含量 78.22%;新鲜香榧假种皮中含有 1.8% 的单宁物质、 18.9% 的非单宁类物质、 20.1% 的木质素;水蒸气蒸馏残渣和溶剂抽提残渣中含木质素分别为 17.13% 和 17.16%。     

建筑涂料中毒性物质的控制措施

本文介绍建筑涂料中的主要污染物甲醛、重金属、挥发性有机物(VOC)及其毒性,并论述判断有毒物质毒性大小的常用指标,提出了减少建筑涂料对室内污染的对策。     

The fragmentation of coal particles during the coal combustion in a fluidized bed

This paper presents an experimental method for studying the fragmentation of coal particles during coal combustion in a fluidized bed and the quantitative fragmentation indexes of 10 typical Chinese coal ranks. The influences of a variety of factors such as the bed temperature, the size of coal particles, the coal rank and the fluidizing medium on the fragmentation index of coal particles are also studied. The research results show that the main reason for the fragmentation of coal particles is the primary fragmentation, and that the volatile matter can drastically influence the degree of fragmentation of coal particles.     

Correlation between the content of volatile matter and mineral matter in hard coals

If coal is heated to 900 °C, in the absence of air the organic coal substance and the associated mineral matter are decomposed. The analytically determined volatile-matter yield includes the volatile decomposition products of both the coal substance and the minerals. The correlation between mineral matter and ash and the volatile-matter yield is derived, and its accuracy shown by evaluation of test results. Methods are proposed for calculating a value for the volatile matter dmmf for coals of a particular mine. Various formulae for calculating the volatile matter of coals to dmmf basis are critically considered. Finally, a generally applicable equation for calculating dmmf volatile matter is derived which can be used for classification.     

炼焦精煤氧化性质的研究

测试了5种露天堆放的炼焦煤在不同时间的各指标变化情况,结果表明：高挥发分高粘结性的炼焦煤在氧化初期结焦性略有上升,然后逐步下降;中等及低挥发分的炼焦煤随着煤质的氧化其结焦性越来越差;煤的挥发分随堆放时间延长而下降,灰分则略有上升。     

基氏流动度指标特征分析

通过对炼焦煤基氏流动度指标、黏结性指标、镜质组反射率和挥发分等质量指标的研究,分析了不同煤种基氏流动度指标与其他黏结性指标和质量指标之间的关系,结果显示基氏流动度指标能够很好地反映炼焦煤的黏结特性,基氏流动度指标的最大流动度温度与炼焦煤变质程度呈现良好的相关性,可为炼焦煤质量的全面评价提供参考。     

DSC法测定煤的比热

本文采用差示扫描量热仪（ＤＳＣ）对１４种含有不同挥发分的中国煤，在２０～１７０℃范围内测定了煤的比热，并校正为干燥无灰基煤的比热。结果表明，煤的比热随温度的变化和挥发分含量的不同而变化，依此建立了煤的比热和温度及挥发分含量的数学关联式。用此模型可以估计中国煤在２０～１７０℃范围内比热的值，其误差小于１０％。