超重力传质技术及其应用

超重力技术是利用强大的离心力场代替重力场来强化传质过程的,自上个世纪问世以来,在国内外受到广泛的重视,但大多仅限于应用基础研究,工业化应用报道不多。北京新特科技发展公司现已成功地将超重力技术应用于热敏性物质的脱臭、超细粉体的制备以及氢化过程中的加氢,并且已经建成工业示范性装置。本文重点介绍了超重力技术在超细碳酸钙生产中的应用。     

解氨剂-超重力法处理高浓度氨氮废水中试研究

介绍了超重力技术的基本原理,采用解氨剂协同超重力法处理高浓度氨氮废水并进行中试研究,重点考察了超重力因子、多级处理次数、进水氨氮初始浓度、解氨剂投加量等因素对脱氮效率的影响,得出在p H为11、温度40℃、气液比1 200、超重力因子460、解氨剂投加量为70 mg/L的实验条件下,单级处理脱氮率达到90.6%。相较于传统吹脱法,解氨剂-超重力法具有脱氮效率高、运行成本低、操作简单的特点,具有广阔的工业化应用前景。     

超重力强化折点氯化法处理低浓度氨氮废水

折点氯化法具有反应速度快、氨氮脱除率高等优点,广泛应用于氯碱等行业中,但反应过程中产生二氯胺致使废水中余氯浓度过高,无法满足离子膜法烧碱生产安全技术规定（HAB004—2002）。为解决这一问题,本文提出了超重力技术强化折点氯化法处理氨氮废水的新工艺,利用超重力技术强化传质的特点,实现次氯酸钠和氨氮的快速反应以及二氯胺的有效去除,研究了超重力因子（β）、氯氮比（Cl/N）、pH和液体流量Q_L等操作参数对氨氮脱除率和余氯的影响规律。研究结果表明,当Cl/N=11、β=30、pH=6~8和液体流量Q_L=80L/h时,氨氮去除率＞95%,余氯浓度＜1.5mg/L。与传统反应器相比,二氯胺去除效果明显,处理后的水中氨氮满足烧碱安全生产技术规定,此方法对于氯碱行业中低浓度氨氮的去除具有广阔的应用前景。     

气浮-生物接触氧化-臭氧氧化组合工艺处理冷轧碱性含油废水

为满足新的钢铁工业水污染物排放标准,应对新增、改造机组带来的废水量提升,某冷轧厂新建稀碱含油废水处理系统处理稀碱含油废水、平整废水和乳化液废水的预处理后出水。设计采用气浮-生物接触氧化-臭氧氧化组合工艺,出水满足GB 13456—2012《钢铁工业水污染物排放标准》表3要求。工程运行结果表明,新建稀碱含油废水处理系统出水水质满足设计要求,运行成本约为3元/m3。     

超重力-臭氧法处理TNT红水的试验研究

为提高O3氧化处理TNT红水的功效和利用率,节约水处理成本,将具有高效传质特性的旋转填料床用于研究O3氧化处理TNT红水的特性规律。考察了超重力因子卢、红水初始pH值和气液比等因素对红水COD去除率的影响。结果表明,β对COD去除率有萌显的影响,随着pH值的增大卢对COD去除率的影响增大,卢大于100后对COD去除率的影响不明显;COD去除率随气液比的增加呈先减小后增大的趋势,COD去除率随pH值的增大而升高,当pH值超过11时,COD去除率有所下降。通过试验证明了该方法在技术上是可行的,具有良好的应用前景。     

超重力强化臭氧高级氧化技术的研究进展

臭氧高级氧化技术因其绿色高效、适用性广、操作简便等优势,成为当前水处理领域前沿技术之一,但臭氧在传统反应器内普遍存在吸收效果差,臭氧利用率低等缺陷。旋转填料床（RPB）利用高速旋转的填料产生超重力场,将液体剪切破碎为细小的液膜、液丝或液滴,其较高的相界面积、不断更新的界面以及内部流体的强制湍动,加快了臭氧的传质与分解,该技术对于传质受限的臭氧高级氧化过程的强化有着突出的优势。本文简述了超重力强化臭氧氧化过程的原理,介绍了RPB与O₃、O₃/H₂O₂、O₃/Fenton、O₃/PS（过硫酸盐）、催化臭氧氧化等高级氧化法耦合应用处理有机废水的研究现状,并对超重力技术的优势及技术突破进行了述评,总结了超重力应用臭氧高级氧化技术的潜在经济效益和环境效益,提出功能化填料及大型RPB的开发需求,以期为超重力技术在废水处理领域的拓展应用提供理论基础和技术参考。     

铝炭微电解法处理碱性棕G模拟废水的研究

利用铝炭微电解法对碱性棕G模拟废水进行了处理,研究了铝炭比、进水pH值、曝气时间等因素对处理效果的影响,得到了最佳条件。结果表明,铝炭微电解法在铝炭比1∶1.5,曝气时间3.5 h,pH为8时,对碱性棕G模拟废水COD的去除率达到66.4%,同时经过铝炭反应后出水B/C增大,提高了可生化性。这为微电解法在碱性废水预处理中的应用奠定了基础。     

氨吹脱过程的传质模型

试验设计了一种新型的氨吹脱反应器,采用雾化喷头代替了传统的填料,废水经过加压雾化后与上升的气流逆向接触,通过增加接触面积达到提高去除率的目的.对气液传质过程作了合理假设,运用微分学等数学方法,得到氨吹脱过程的传质模型,讨论了模型中参数的影响因素,说明了去除率η随着pH和温度的提高、运行时间的延长、鼓风量的增大而增大,通过试验验证了使用这种新型的氨吹脱反应器来处理含高浓度氨氮的废水,在合适条件下,氨去除率高于85%.     

臭氧氧化法处理焦化废水的研究

本文研究了臭氧对焦化废水的处理,提出了臭氧氧化酚的机理。研究发现,对于COD值小于1000mg/L、酚含量小于500mg/L的焦化废水,臭氧氧化是很有效的。     

多级雾化旋转填料床的传质性能

以两级雾化超重力旋转床为例,用化学吸收法考察了超重力因子β、液体流量、气体流量等对体积传质系数kyα的影响。结果表明:多级雾化超重力旋转床的体积传质系数随气液流量的增加而增加,在β较小时,实验曲线的斜率较大,kyα随β的增加急剧增加;但是当β超过100后,曲线的斜率减小,kyα随β的增加缓慢增大。     

新型旋转填料床强化气膜控制传质过程

转子结构为相互嵌套填料环的新型旋转填料床是基于强化气膜控制传质过程的新型高效传质设备,可适用于受气膜控制的吸收、精馏和低浓度工业气体的净化等过程。分别以化学吸收体系CO2-NaOH和物理吸收体系NH3-H2O测定了不同气量、液气比和超重力因子条件下的有效比表面积a和气相体积传质系数kya,并由此得到气相传质系数ky,对其传质性能进行研究。实验结果表明：a、kya和ky均随着气量、液气比和超重力因子的增大而增大。通过对比可知,新型旋转填料床的气相体积传质系数在相近操作条件下是文献逆流旋转填料床的2倍。并对实验数据进行了回归,拟合出了a、kya和ky分别与气相雷诺数ReG、液相韦伯数WeL和伽利略数Ga之间的关联式。     

Dynamics of droplets and mass transfer in a rotating packed bed

To do further research on the mass‐transfer mechanism in rotating packed bed (RPB), dynamics of droplets in a RPB are studied by an analytical approach combined with a series of laboratory measurements. Based on the results of the fluid dynamics, mathematical models of mass‐transfer coefficient and mass‐transfer process in RPB are proposed, respectively. Mass‐transfer experiments in RPB are also carried out using ethanol–water solution. By comparison, the results of simulation agree well with that of the experiment, which demonstrate that both hydrodynamic model and mass‐transfer models can better describe the real conditions of RPB. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2705–2723, 2014     

旋转填料床中臭氧化处理染料废水的试验

研究了在旋转填料床中O3氧化处理染料废水。主要考察了超重力因子β、初始pH值和气液比等因素对脱色率的影响。试验结果表明,随着β的增大脱色率增大,β大于100后对脱色率增大不明显;脱色率随染料废水初始pH值增加呈先增大后略微下降的趋势;最佳初始pH值为10～11;气液比的增加有助于脱色率的提高。与传统O3气液反应设备相比,旋转填料床的高效传质特性可以提高O3的氧化功效和利用率,节约O3的消耗量。     

A three-zone mass transfer model for a rotating packed bed

A rotating packed bed (RPB) is recognized for its merits in chemical process intensification. In most studies of RPB mass transfer modeling, however, the effects of the end and cavity zones have not been taken into consideration, since it was very difficult to distinguish the end and bulk zones by hydrodynamics and mass transfer process. In this work, the radial thickness of the end zone was obtained by developing a probability method and imaging experiments to separate the end and bulk zones. A three-zone model, including end, bulk, and cavity zones, of the overall gas-side volumetric mass transfer coefficient (K_Ga)t was first established. Experiments of dissolved MEA chemisorption of CO₂ were carried out to validate the proposed three-zone mass transfer model. The results of the MEA-CO₂ absorption experiments showed that the experimentally obtained values of CO₂ absorption efficiency were in agreement within ±20% with the model predictions.     

旋转填充床内高黏介质脱挥过程的传质模型(英文)

A mass transfer model for devolatilization process of highly viscous media in rotating packed bed(RPB) was developed based on penetration theory and mass conservation.Before establishing the model,some mass transfer experiments of thin film were conducted in a designed diffusion cell including vacuum and feeding system. In this study,acetone was used as the volatile organic compound(VOC) and syrup as the highly viscous media.The thickness of thin film was changed by using different liquid distributor.It was found that bubbling played an important role in the devolatilization.The correlation of diffusion coefficient of acetone in highly viscous dilute solution was proposed.The relative error between predicted and experimental data was within the range of ± 30% for diffusion coefficient of acetone in syrup.A comparison of experimental data of RPB with model indicated that the relative error was within ± 30% for efficiency of acetone removal.     

不同填料旋转填料床废水气提效果研究

为了探索旋转填料床中不同填料对废水中丙烯腈去除率的影响,并为超重力气提丙烯腈废水工艺优选合适的填料提供参考,分别在装有填料A和填料B的旋转填料床中进行气提丙烯腈废水的实验。在相同的工艺条件下对比考察了填料A和B对丙烯腈去除率的影响。结果表明:在实验操作条件范围内,填料A和B的丙烯腈去除率均可达60%以上;更换高效的填料有助于丙烯腈去除率的提高,且气液比对丙烯腈去除率的增幅影响最为显著,超重力因子β次之;与填料A相比,仅考虑丙烯腈废水处理效果和处理成本,填料B更适用于超重力气提工艺中的旋转填料床。研究结果为选取适宜的旋转填料床填料以及超重力气提工艺的工业化应用提供一定依据。     

超重力旋转填充床氧解吸过程的数值模拟

基于旋转填充床流体流动的可视化结果,建立了超重力旋转填充床气液传质过程的数学模型,模拟氮气解吸水中溶解氧的传质过程。模拟结果表明,缩短液相停留时间、提高液相扩散系数都能增大液相传质分系数k_L;总体积传质系数K_La随超重力因子的增加而增大、随温度的上升而增大、随气相流率的增加略有下降、随液相流率的增加明显增大;空腔区传质贡献率随空腔区的增大而增大,随超重力因子的增大而减小;且短暂的停留时间是超重力旋转填充床对传质过程强化的本质原因。模型较好地符合文献的实验数据,误差在±16%以内。     

Experimental researches on mass and heat transfer in new typical cross-flow rotating packed bed

New typical cross-flow Rotating Packed Bed(RPB)called multi-pulverizing RPB was manufactured.There is enough void in multi-pulverizing RPB,where liquid easily flows and is repeatedly pulverized by light packing,which decreases the material consumed,lightens the weight,and compacts the structure.Mass and heat transfer property in the new type PRB were studied by two experimental models.In the mass transfer model,the axial fan pumping gas press is only 100 Pa,mass transfer coefficient and volumetric mass transfer coefficient are similar to countercurrent RPB,which are an order quantity lager than that in the conventional packed tower.In the heat transfer experiment,the axial fan pumping gas press is only 120 Pa;volumetric heatwhich especially suits the treatment of large gas flow and lower gas pressure drop.     

不同规整填料旋转床的传质性能对比

采用Na₂CO₃-H₂S为体系,利用规整丝网填料和新型塑料填料的错流旋转床为吸收设备,探究了两种填料床的传质性能,通过理论推导气液传质系数K_y和K_ya的表达式,考察了液量、气液比、超重力因子对脱硫率、K_y和K_ya的影响。实验结果表明:在相同条件下,规整丝网填料床的脱硫率略高于新型塑料填料床,约为3%～4%,但K_y、K_ya和压降分别是新型塑料填料床的0.25～0.5、0.8～0.9和0.3～0.5倍。通过文献对比分析,在相近工况条件下,新型塑料填料床的K_ya比散装丝网填料床提高了1.45倍。并对实验数据进行回归,拟合出K_y、K_ya与气相雷诺数Re_G、液相韦伯数We_L和伽利略数Ga之间的关联式。