CaCO_3悬浮液热压过滤干燥实验研究

碳化法生产所得超细CaCO3浆体需经机械过滤和二级热力干燥才能得到粉体产品,工艺复杂,能耗较大。为简化传统生产工艺,采用热压过滤干燥固液分离技术进行超细CaCO3悬浮液的脱水干化研究。通过对热压过滤干燥固液分离技术的原理分析和理论研究,设计小型热压过滤干燥装置,并确定影响CaCO3热压干燥效果的主要因素为滤饼厚度、热压干燥温度和热压干燥时间。设计正交试验,以滤饼含水率为考察指标,结果表明:影响滤饼含水率的显著因素是浆体填料高度(决定滤饼厚度)和热压干燥时间,浆体填料高度为40 mm,热压干燥温度为150℃,热压过滤时间为15 min和热压干燥时间为30 min时,所得滤饼水分最低,质量分数为15.67%。热压干燥过程中部分水分以液态形式脱除,与传统热力干燥相比节能约73%。     

溶胶法制白炭黑工艺研究

以水玻璃和硫酸为原料,工艺过程中首先制备硅溶胶作为母液,继续反应完成白炭黑的合成过程,反应pH值为9.0～10.5。所得固体悬浮液经酸化、过滤、洗涤、干燥和粉碎得到白炭黑产品。该方法工艺过程简单,易于操作,所得产品质量稳定,性能优良。     

热压过滤完善选煤工艺

论述了热压过滤干燥脱水机具有过滤与干燥的双重作用、脱水效率高等特点;分析了干燥压滤机内脱水峰面的形成和移动过程,以及物料中液体饱和度与时间的关系;介绍了热压过滤干燥工艺系统与装备,并通过应用实例说明其完善选煤工艺的意义。     

泡沫过滤

<正> BASF AG公司发明了一种过滤设备,用于悬浮液中悬浮物的分离。这种设备主要由过滤元件和挤压滚筒构成。过滤元件为环状,以泡沫聚氨酯为材质。悬浮液经过过滤元件过滤和滚筒挤压处理,达到分离悬浮液     

活性硅酸钙过滤分离工艺实验研究

由于活性硅酸钙在加压过滤后得到的滤饼含水率高达66％左右,加重了后续干燥工段的负荷,耗能较高,影响了生产效率.本文在测定活性硅酸钙基本物性的基础上,确定活性硅酸钙是一种高孔隙率、蜂窝状结构、粒径较小的轻质材料;通过实验确定了加压工艺条件;采用添加表面活性剂的预处理技术,研究了添加阳离子表面活性剂FL02的适宜添加量以及滤液循环使用的方法.研究结果表明,在加压过滤之前,向质量分数为10％的活性硅酸钙悬浮液中加入表面活性剂FL02(初次添加量占悬浮液质量的0.5％,后续的4～5次添加量占悬浮液质量的0.15％),混合均匀后,在0.35 MPa的操作压力下,得到的滤饼含水率了降低至54％左右.研究结果为工业应用提供了参考依据.     

喷雾干燥器的设计计算

噴雾干燥是将溶液或悬浮液等分散成細粒后用气态载热(載湿)体使其迅速干燥的过程。因此噴雾干燥特別适用于处理对热敏感的物质,同时还可縮短工艺过程、省去过滤、离心、沉降、研磨等操作;且可以控制成品的松密度、顆粒大小,及获得高度的溶解性。大型喷雾干燥的脫水能力可达每小时几千公斤。因此工业上的应用日益广泛。諸如奶粉、蛋粉、蛋白腖、骨胶、咖啡、生物制品、药物、維生素、抗菌素、酵母,甚至某种菌类芽胞等的干燥,以及許多要求极細分散度的产品如氫氧化鋁、紙張填料、高岭土、化装品用碳酸鈣等都有采用。还有一些极細顆粒的悬浮液,过滤困难,也可經噴雾干燥直接获得干物料。甚至可能获得保持原来直徑的顆粒,以滿足对极微顆粒的要求。在     

电厂烟气脱硫中石膏过滤过程的可行性试验研究

对电厂湿法烟气脱硫中产生石膏悬浮液进行了真空过滤的可行性研究。主要包括石膏悬浮液在真空过滤过程中过滤性能的试验、过滤介质的选择,影响石膏滤饼湿含量的因素,石膏悬浮液过滤过程操作参数的确定,并在1m2橡胶带式真空过滤机样机上进行了小型工业试验。     

滤布的过滤性能试验研究

以4种常用工业滤布为过滤介质,分别进行了透过空气、清洁水和酞氰蓝染料悬浮液的渗透性试验,测得了滤布的透气阻力、透水阻力和透过悬浮液的过滤介质阻力,并推出了它们之间的关系。通过悬浮液的过滤试验,提出了一种理论预测滤布的颗粒截留能力的方法。     

浅谈过滤洗涤干燥机的应用

介绍了过滤洗涤干燥机的结构和特点,论述了该机过滤、洗涤、干燥和灭菌工艺的原理,并分析了该机的优缺点。     

万华化学集团开发出聚酰亚胺制备新方法

正万华化学集团股份有限公司开发出一种聚酰亚胺制备新方法,包括以下步骤:二元伯胺溶解于弱水溶性溶剂中,逐渐加入有机酸酐发生缩聚反应生成聚酰胺酸;然后升温回流,聚酰胺酸发生脱水反应得到半亚胺化的聚酰亚胺悬浮液;过滤悬浮液得到半亚胺化的聚酰亚胺固体,干燥后得到聚酰亚胺粉末产品;或     

结构陶瓷部件的压滤成型工艺

本文简要介绍了结构陶瓷部件的压滤成型工艺原理，浆料体系及性能、成型压力参数、模型材料及模型结构和坯体干燥等，讨论了影响压滤成型及成型体均匀性的一些因素，并介绍了一种提高压滤成型坯体均匀性的同步超声波辅助压滤成型。     

Steam Dewatering of Filter Cakes in a Vertical Filter Press

Steam dewatering of filter cakes is recognized as a competitive alternative to conventional air drying and thermally assisted mechanical dewatering (TAMD). The main benefit of cake dewatering with high-pressure steam is that mechanical and thermal dewatering can be efficiently performed in a single process step. The target of this study was to determine the potential of a steam-dewatering technique for two industrial mineral suspensions. The first mineral, kaolin, was very difficult to dewater using conventional mechanical dewatering techniques, whereas the second one, ground calcium carbonate (GCC), represented only moderate resistance to filtration. The secondary objective was to compare the filterability of the original kaolin slurry with the same slurry treated with a coagulant (aluminum sulphate, Al₂(SO₄)₃ · 16H₂O). Four different kinds of experiments were performed: tests without any kind of cake dewatering, tests with air drying, tests with steam drying, and tests with both coagulation and steam drying. The obtained results show that steam dewatering is an efficient technique for achieving lower cake-moisture contents. Also, the positive influence of coagulation on the filtration capacity was found to be considerable in the case of kaolin. An approximate energy balance was created for the steam-drying process and the determined energy efficiencies were compared with those obtainable with an ideal thermal drier. The main conclusion from these comparisons is that steam drying can be effectively used instead of traditional thermal drying if the large energy losses can be reduced by proper insulation and heat recovery systems.     

Pressure filtration assisted gel casting in translucent alumina ceramics fabrication

High density and homogeneous green body is important for fabricating transparent ceramics. Inspired by the improved samples’ homogeneity in slip casting, we introduced low pressure filtration to gel casting to further increase the relative density and homogeneity of the green body and to shorten the drying time. The effect of pressure filtration on drying characteristics, bulk density and porosity of the pre-sintered bodies, and the microstructure and optical transmittance of the resultant ceramics were intensively investigated. The results showed that pressure filtration can reduce the drying time by 27.3%, improve the density of the pre-sintered bodies and reduce the residual pores of the sintered ceramics. The in-line transmittance of the translucent alumina prepared by the pressure filtration assisted gel casting was 32.7% at 600?nm with a thickness of 1?mm, which is about 6% higher than that without pressure filtration. In principle, this process can be applied to fabricate any other high-performance ceramic.     

有机合成中以弱碱性盐作催化剂产生的废盐渣的回收利用研究

有机合成以弱碱性盐作催化剂产生的废盐渣经灼烧、溶解、反应、过滤、蒸馏、结晶、过滤、干燥等处理后,制得合格的无机盐类产品,变废为宝,实现良好的经济效益和社会效益。     

1，2-戊二醇生产过程水解中和方法的改进

以 1,2 环氧戊烷的甲酸溶液和氢氧化钙为起始原料 ,通过中和、水解、过滤干燥、浓缩、萃取、过滤干燥、浓缩、精馏 ,得到高纯度、高收率的 1,2 戊二醇和甲酸钙。 1,2 戊二醇的总收率 92 8% ,含量 99 5 % ;甲酸钙的收率 95 % ,含量≥ 98%。此法反应条件温和 ,操作简便 ,适合工业化生产。     

Experimental and computational design tools for industrial drying processes: Challenges in process-limit prediction

The coating and drying of inks and slurries are important steps to manufacture a plethora of products. Drying processes, particularly, comprise energy-intensive steps that affect product cost and quality. Prior work has highlighted failures of various multicomponent diffusivity models to conserve mass in dryer modeling and challenges in predicting process limits given variability in published values of key thermodynamic parameters. Herein, we develop a computational model and benchtop drying experiments to investigate these concerns for drying polymer-laden coatings. Model predictions of process limits in a single-zone drying oven demonstrate that published variability in Flory–Huggins parameter yields large variations in predicted operating temperatures above which blistering occurs. This indicates that caution should be exercised when choosing approaches to obtain or predict the Flory–Huggins parameter, and that both benchtop drying experiments and a set of additional experiments, such as sorption experiments, are needed to fully characterize and optimize a given drying process.     

食品低温干燥新技术

简要介绍了低温干燥技术的特点 ;重点阐明了低温干燥法之一———吸附干燥法的工作原理、干燥空气处理系统的流程、干燥过程的影响因素等 ,并以胡萝卜干燥实验为例 ,对比说明了低温吸附干燥法用于食品干燥的干燥效果。     

草菇,菠萝的冷冻干燥过程及影响因素分析

从草菇、菠萝做冷冻干燥试验所得的冻干曲线和冻干时间,用分子运动论的观点分析了温度、压力等因素对冷干燥过程的影响。