HXD运行参数与工作段气流初始温度相关性的回归分析

HXD叶丝在线膨胀系统工作段气流初始温度设定值合理与否,与叶丝出料含水率及整个干燥系统运行参数的稳定关系密切。通过分别改变不同工艺参数进行试验,并对试验数据进行回归分析,得出了工作段气流初始温度与进料含水率、物料流量、工艺气流流量、蒸气喷射量等参数的相关方程。利用该方程可以计算出能保证HXD正常运行的参数组合,使其在较短时间内达到叶丝出料含水率的稳定,提高了加工质量。     

HXD气流干燥对卷烟综合质量的影响

对比分析了隧道式燃油烘丝机(HXD)气流干燥与CO2膨胀2种生产方式及HXD气流干燥叶丝不同掺配比例对配方烟丝质量和卷烟综合质量的影响.结果表明:掺配HXD气流干燥处理的膨胀叶丝能提高配方烟丝的整丝率,降低碎丝率,叶丝结构较合理,弹性较好;在实验牌号卷烟中,2种生产方式生产的膨胀叶丝掺配比例相同时,HXD气流膨胀叶丝卷烟感官质量较好,最佳掺配比例为15%.     

纸浆的气流干燥技术

商品浆厂要将纸浆进行干燥，以便贮存和运输。气流干燥是常用的干燥方法之一。它广泛用于纸浆特别是高得率纸浆如CTMP的干燥。和砂浆机干燥纸浆相比，这种方法具有以下优点：投资省、能耗低、占地面积小、操作简便，干燥后的纸浆易于解离。下面就这种纸浆干燥技术介绍如下：1纸浆气流干燥的Xi艺过程气流干燥纸浆的工艺过程如图1所示。围1纸浆气流干燥过程经过洗选漂后的浆料，利用洗涤浓缩设备进行初步脱水后，再通过挤浆机进一步脱除纸浆内的水分、纸浆干度达42～48％。为了增加纸浆的比表面积，加强纸浆与热空气的热量交换，出挤浆机后…     

烘房气流运动的初步探讨

<正> 从事挂面生产的同志都知道,挂面制作工艺最关键的工序是烘房干燥,而干燥的机理在于湿热传递,即是湿热空气把热量传递给面条带走面条的水份;湿面条吸热蒸发出水份。这些过程离不开循环气流,离不开风扇,到底有什么规律?我们做了两组试验。试图寻求点滴答案。试验前状况:班产4吨的挂面生产线,隧道式烘房、中温中速,通过散热管散热,中间设地下风管排湿。烘道长40米,五排面,设置风扇二十八台,风扇直径1400毫米,扇叶呈曲面,扇叶边缘离烘房侧壁400毫米,转速     

滚筒-气流式烘丝机的设计应用

由于气流式和滚筒式烘丝机存在烘后叶丝含水率波动大、叶丝结团和"干头干尾"等问题,结合两种烘丝机的技术优势,设计了滚筒-气流式烘丝机。该设备主要由进出料气锁、干燥滚筒、燃烧炉、主工艺风机等组成,采用气流烘丝原理,即利用含一定量蒸汽的热风在滚筒内与叶丝均匀接触,进行热量对流交换,完成叶丝脱水干燥。通过调节烘丝温度、烘丝时间、水流量和排潮量,实现对烘后叶丝含水率的精确控制。应用效果表明:①烘后叶丝含水率均匀、稳定,含水率偏差±0.5%,填充值≥4.3 cm3/g,烟丝颜色、形态好,保持了烟草本香。②设备工艺参数调节范围宽,满足了中式卷烟分组加工和精细化加工需求。③设备结构简单,滚筒筒体不会出现泄漏问题,减少了设备维护工作量,降低了工人劳动强度和设备维修成本。     

白肋烟烘焙关键工艺参数设置与加工质量

为研究白肋烟烘焙过程中干燥气流温度与干燥终端含水率之间的关系,选择确定适宜的热风风量和排潮风门开度、铺叶厚度、烘焙时间等配套参数,进行了白肋烟叶组不同干燥模式、干燥气流温度及干燥终端含水率等关键工艺参数与烘焙处理后白肋烟物理指标和感官质量的关系研究。结果表明,在试验范围内,采用“先高后低”的干燥气流温度模式,选择130℃、130℃、110℃、110℃的干燥气流温度和4%～6%干燥终端含水率的参数设置,最适于F白肋烟叶组感官质量的改善。     

HXD在线膨胀工艺参数和膨胀率与卷烟质量的关系

为进一步提高叶丝的在线膨胀效果,对不同等级的烤烟型卷烟叶丝在HXD上的膨胀效果进行了试验。结果表明:①提高HXD进料含水率和工艺气流的干燥温度,可提高叶丝的膨胀率;②当叶丝的进料含水率为22%时,经HXD膨胀后叶丝的膨胀率以及卷烟的物理指标、烟气指标等与滚筒式烘丝机处理后的结果基本一致;③在试验范围内,提高喷射蒸气的流量,可提高叶丝的膨胀率;④提高进料含水率和工艺气流的热风温度,可使卷烟在吸阻和硬度不变的情况下降低单支重量;⑤随着进料含水率和工艺气流干燥温度的提高,卷烟烟气焦油呈下降趋势,而烟碱和CO下降趋势不明显;⑥高档卷烟配方不宜采用HXD进行膨胀干燥;采用HXD进行膨胀干燥时,中档卷烟和低档卷烟的进料含水率宜分别控制在24%和28%左右。     

气流干燥在制丝生产中的应用研究进展

综述了近年来国内烟丝气流干燥技术在工艺优化、设备改造及研发上的进展和气流干燥对烟丝物理特性、感官质量及化学成分的影响,并与传统的滚筒烘丝工艺进行了对比。开发适合中式卷烟的烟丝气流干燥系统是今后研究的重要方向。     

葡萄低温气流膨化干燥工艺研究

以葡萄为原料,研究了其低温气流膨化干燥工艺。用单因素试验分析了预干燥含水率、膨化温度、抽空温度、抽空时间、停滞时间和膨化压力差对葡萄低温气流膨化干燥产品的影响。在此基础上,用响应面法对原料预干燥含水率、膨化温度、抽空温度进行了优化,推导出了描述3个指标的二次回归模型。确定了葡萄低温气流膨化干燥工艺条件为:预干燥含水率22.55%,膨化温度为83.45℃,抽空温度为68.38℃,抽空时间120min,停滞时间5min,膨化压力差0.2MPa。     

气流换向干燥设备设计

为了有效地保证物料的干燥质量 ,扩大干燥设备的适应范围 ,设计了气流换向干燥设备。介绍了设备的结构、工作原理以及主要参数的设计计算。该设备与控制系统相结合 ,采用“小参数热风渗流、气流换向深层干燥、间接加热”的干燥工艺可提高谷物的干燥品质、减轻劳动强度以及实现干燥过程的自动化     

粮食干燥机废气回收工艺技术研究与实践

根据植物性杂质与粉尘等废气的特性,结合粮食干燥机的特点,采用全封闭结构、负压粉尘杂质集中分离回收工艺,改变露天开放式的干燥作业方式,实现植物性杂质和粉尘的有序排放。经过生产验证,植物性杂质和粉尘回收率可达90%,能耗降低3%以上,既解决了废气排放超标等环境污染问题,还能将回收的废料加工成为生物质颗粒变废为宝,同时减少干燥机热量散失,提高干燥热效率。     

印染企业节能技改项目的监测分析

湿布定形、使用回收余热的溴化锂热水空调以及车间废水热能回收是印染企业实施的三大节能技术改造项目。现场监测分析表明,采用湿布定形可减少一道烘干工序,一年可节省2 200.7吨标煤;以用热设备的蒸汽冷凝水和高温外排废气的余热资源制取热水,再驱动溴化锂制冷机组,单台机组每年可节约1 045.4吨标煤;采用板式热交换器回收车间废水余热,每年可节约标煤8 291.5吨,还可减少燃煤锅气对环境的影响。     

批式循环粮食干燥机板式换热器优化设计

基于前人研究得出的高效小型批式粮食干燥工艺,将批式循环粮食干燥机用列管式换热器设计为板式换热器,以更易得到的100℃高温蒸汽代替800℃烟气,将板式换热器采用更为高效的材料,最后在保证换热效率不变的情况下利用matlab优化工具箱优化换热器的尺寸。研究表明:改善之后的换热器具有更高的换热效率,减少了换热器占地面积以及材料的浪费。     

浆纱设备能耗分析与节能措施探讨

探讨浆纱过程中的节能措施。分析了当前浆纱设备的电能消耗和蒸汽消耗情况,论述了蒸汽压力、烘房排风状态和烘筒冷凝水排风状态与烘燥效率的关系,总结了浆纱过程中的节能措施,指出浆纱中的烘燥过程为浆纱设备的节能减排重点,适当提高蒸汽压力、改善烘房排风状态和烘筒冷凝水排放状态有助于提高烘燥效率;采用高压上浆工艺、充分利用好烘筒冷凝水、选择适宜的冷凝水疏水阀、合理安排浆纱生产及加强浆纱操作和浆纱机状态管理都具有节能效果。认为:重视浆纱设备节能,树立节能意识才能保证达到良好的节能效果。     

升温型吸收式热泵在纸机干燥部的应用探讨

为解决纸机干燥部冷凝水系统末段存在冷凝水排出温度较高、吨纸蒸汽消耗大等问题,本课题提出应用升温型吸收式热泵（adsorption heat transformer, AHT）作为冷凝水系统余热回收设备。该设备可利用中间品位的余热与低温热源的热势差作为驱动,制取品位高于中间余热的热量,从而提高余热的利用率。本文在分析纸机干燥部蒸汽冷凝水系统热力系统现状及升温型吸收式热泵工作原理的基础上,给出了一种基于升温型吸收式热泵的多段供汽热力系统流程。通过LabVIEW仿真计算结果表明,应用升温型吸收式热泵的纸机干燥部蒸汽冷凝水系统具有更好的节能效果。     

IMPINGEMENT DRYING OF POTATO CHIPS

The effect of superheated steam temperature (115, 130, and 145C) and convective heat transfer coefficient (100 and 160 W/m²C) on the drying rate and product quality attributes (shrinkage, density, porosity, color, texture, and nutrition loss) of potato chips was investigated. Furthermore, potato chips dried by impinging superheated steam (130 and 145C, h = 100 W/m²C) were compared to air dried (same conditions), commercial, and fried potato chips. Temperature and convective heat transfer coefficient had a significant effect on the drying rate during superheated steam impingement drying. Potato chips dried at higher drying temperature and convective heat transfer coefficient showed less shrinkage, lower bulk density, higher porosity, and darker color when compared to chips dried at lower temperatures and convective heat transfer coefficients. They were also less hard and had a lower vitamin C content. A higher rate of evaporation during the falling rate period was obtained when superheated steam drying was compared to air impingement drying. Potato chips produced using superheated steam impingement drying showed more shrinkage, higher bulk density, lower porosity, and lighter color than chips dried with air under the same temperature and with the same convective heat transfer coefficient (130, and 145C, h = 100 W/m²C). Moreover, superheated steam‐dried potato chips retained more vitamin C during the drying process.     

制浆造纸业蒸汽价格及能源优化利用的探讨

制浆造纸业,如何确定其自备电厂蒸汽价格历来都有争议,不同的蒸汽价格直接影响余热回收或其他节能措施的经济效益,会对决策层在选择使用能源种类、节能技术等问题上犯难,有时还会造成决策错误。本文介绍了一种计算新增或节降蒸汽的使用成本或价格的方法,指出了纸厂常用的低压或中压蒸汽的价格水平,并以此为依据对气罩余热回收的经济效益做了分析,同时还根据能源梯级利用的原则,对制冷、热风干燥、热风干燥的余热回收、污泥干化、靴压改造及蒸汽箱的应用等过程的能源使用进行了探讨。     

LQJ系列废气余热回收装置在定型机上的应用

LQJ定型机余热回收装置可以解决定型机废气排放过程中的余热回收,该回收装置利用螺旋管作换热器,废气走管程,所交换的新鲜风走壳程,而且管程内壁经过特殊防粘处理,便于系统的自动清洗。该装置具有不堵塞、换热效率不下降等功能。经过客户一年使用的情况来看,系统运行状况良好。     

Effect of superheated steam drying on properties of foodstuffs and kinetic modeling

Conventional hot air drying is an energy intensive technique which consumes around 15–25% of national industrial energy in most of the countries. It also often results in unacceptable product quality, nutrient degradation and non-uniform drying. Using air as a drying media leads to oxidation and combustion reaction and releases undesirable components creating environmental issues. Drying operation also needs continuous improvements to reduce energy consumption and preserve quality. Superheated steam drying (SSD) is an innovative drying technology, utilizing heated steam beyond its boiling point as a drying medium in a dryer to remove excess water from the material. Researchers on comparing conventional and SSD claimed that SSD supports product, environment, and energy saving benefits as well as it overcomes many constraints of hot air and other conventional drying techniques. This review will provide comprehensive detail about the effect of SSD on different properties (texture, microstructure, color, nutrient retention, shrinkage) of foodstuffs. Mathematical modeling and simulation of the SSD process as well as product characteristics undertaken by researchers are also compiled briefly in this article.Industrial relevanceSSD offers many advantages over hot air drying which includes low net energy consumption, utilization of exhaust steam, no oxidative reactions and no hazardous gas, dust, dirt emission into environment. Kinetic modeling may prove to be useful for optimization and designing of the process.     

Nucleation mode particles with a nonvolatile core in the exhaust of a heavy duty diesel vehicle

The characteristics of the nucleation mode particles of a Euro IV heavy-duty diesel vehicle exhaust were studied. The NOx and PM emissions of the vehicle were controlled through the use of cooled EGR and high-pressure fuel injection techniques; no exhaust gas after-treatment was used. Particle measurements were performed in vehicle laboratory and on road. Nucleation mode dominated the particle number size distribution in all the tested driving conditions. According to the on-road measurements, the nucleation mode was already formed after 0.7 s residence time in the atmosphere and no significant changes were observed for longer residence times. The nucleation mode was insensitive to the fuel sulfur content, dilution air temperature, and relative humidity. An increase in the dilution ratio decreased the size of the nucleation mode particles. This behavior was observed to be linked to the total hydrocarbon concentration in the diluted sample. In volatility measurements, the nucleation mode particles were observed to have a nonvolatile core with volatile species condensed on it. The results indicate that the nucleation mode particles have a nonvolatile core formed before the dilution process. The core particles have grown because of the condensation of semivolatile material, mainly hydrocarbons, during the dilution.