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期刊论文 5

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2021 1

2011 2

2009 1

2007 1

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固体颗粒 1

气升式搅拌 1

浆态床反应器 1

环流反应器 1

过程强化 1

鼓泡塔 1

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Investigation of bubble diameter and flow regime between water and dilute aqueous ethanol solutions in an airlift

Baharak SAJJADI, Mostafa Keshavarz MORAVEJI, Reza DAVARNEJAD

《化学科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 194-202 doi: 10.1007/s11705-010-1019-2

摘要: In this study, the effect of ethanol addition into pure water and its concentration on bubble diameter, gas hold-up and flow regimes were investigated in an airlift reactor. Air and water with ethanol (concentration ranging from 0%–1%, v/v) were as dispersed and continuous phases, respectively. Superficial gas velocity was considered as an effective parameter. Bubble size distribution was measured by photography and picture analysis at various concentrations of ethanol and various velocities of gas. Alcohol concentration enhancement caused bubble diameter to decrease. Furthermore, the bubbles diameter in pure water was nearly 4 times higher than that of ethanol with concentration of 1% (v/v) and also was 3.4 times higher than that of ethanol with concentration of 0.25% (v/v) at the highest aeration gas velocity inlet. For ethanol solutions in lower superficial gas velocity, a homogenous flow regime was observed. This trend continued to inlet gas velocity of about 0.4 cm/s. The transition flow regime occurred after this datum although in pure water, a homogenous flow regime was observed up to a superficial gas velocity of 0.7 cm/s. The gas hold-up in dilute ethanol solutions were more than (around 2 times) that of pure water and increased with increasing concentration of ethanol in those solutions.

关键词: airlift rector     bubble diameter     gas hold-up     flow regime     ethanol    

Flow characteristic and wastewater treatment performance of a pilot-scale airlift oxidation ditch

Hongtao PANG, Hanchang SHI, Huiming SHI,

《环境科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 470-476 doi: 10.1007/s11783-009-0143-z

摘要: A pilot-scale airlift oxidation ditch using bubble diffuser and baffle as aerator was operated in a wastewater treatment plant (WWTP) to investigate its flow characteristic and wastewater treatment performance. Compared with the conventional oxidation ditch process, effective depth and oxygen utilization efficiency of this new process was improved by underwater aeration. Furthermore, it had a reversed velocity distribution, which decreased from the bottom to the top on vertical section. Velocity measurement showed that a velocity over 0.2m/s at the bottom was sufficient to prevent sludge settlement during long term operation. Application of these concepts would save land area and energy consumption by about 25%―50% and 55%, respectively. In this new system, organic biodegradation and nitrification could be well achieved. Denitrification could occur steadily in the straight part by adjusting the airflow rate. An average TN removal rate of 63% was achieved with dissolved oxygen (DO) concentrations between 0.6mg/L and 1.5mg/L. The main pollutants in the effluent could meet the strictest discharge standard (COD<50mg/L, NH―N<5mg/L, and TN<15mg/L) in China now.

关键词: airlift oxidation ditch     flow characteristic     wastewater treatment    

Nitrifying and denitrifying bacteria in aerobic granules formed in sequencing batch airlift reactors

WANG Fang, YANG Fenglin, QI Aijiu

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 184-189 doi: 10.1007/s11783-007-0032-2

摘要: The purpose of this study was to investigate nitrifying bacteria and denitrifying bacteria isolated from aerobic granules. Aerobic granules were formed in an internal-circulate sequencing batch airlift reactor (SBAR) and biodegradation of NH3--N was analyzed in the reactor. Bacteria were isolated and determined from aerobic granules using selected media. The growth properties and morphology of bacteria colonies were observed by controlling aerobic or anaerobic conditions in the culture medium. It was found that bacteria in aerobic granules were diverse and some of them were facultative aerobes. The diversity of bacteria in aerobic granules was a premise of simultaneous nitrification and denitrification.

CFD simulation of the hydrodynamics in an internal air-lift reactor with two different configurations

Mona EBRAHIMIFAKHAR, Elmira MOHSENZADEH, Sadegh MORADI, Mostafa MORAVEJI, Mahmoud SALIMI

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 455-462 doi: 10.1007/s11705-011-1116-x

摘要: Computational fluid dynamics (CFD) was used to investigate the hydrodynamic parameters of two internal airlift bioreactors with different configurations. Both had a riser diameter of 0.1 m. The model was used to predict the effect of the reactor geometry on the reactor hydrodynamics. Water was utilized as the continuous phase and air in the form of bubbles was applied as the dispersed phase. A two-phase flow model provided by the bubbly flow application mode was employed in this project. In the liquid phase, the turbulence can be described using the - model. Simulated gas holdup and liquid circulation velocity results were compared with experimental data. The predictions of the simulation are in good agreement with the experimental data.

关键词: airlift reactor     gas holdup     liquid circulation velocity     bubbly flow     computational fluid dynamics (CFD)    

气升式浆态床反应器的过程强化 Review

耿淑君, 毛在砂, 黄青山, 杨超

《工程(英文)》 2021年 第7卷 第3期   页码 304-325 doi: 10.1016/j.eng.2021.03.002

摘要:

气升式浆态床反应器是一种重要的气-液-固多相反应器,包括鼓泡塔反应器和环流反应器。这些反应器具有剪切应力低、混合程度好、传质/传热能力强、成本低等优点,已被广泛应用于许多工业过程,尤其是生物发酵和能源化工领域。为了进一步提高浆态床反应器的性能(即混合和传质/传热性能)和满足工业应用要求(如温度控制、减少返混和产品分离等),浆态床反应器的过程强化至关重要。首先,本文回顾了这两种反应器在强化混合和传质/传热方面的最新研究进展。然后,总结了浆态床反应器在连续生产时混合与分离的过程强化方法,其中,由于具有高效率和低成本的优点,推荐采用将环流反应器内的定向流动与水力旋流器的简单固-液分离相结合的过程强化技术。接着,系统地讨论了浆态床反应器所面临的问题和挑战,包括流型判别、气体分布器设计、固体颗粒影响及其他问题。本文还介绍了应用计算流体力学对浆态床反应器进行数值模拟的研究进展,讨论了建模的难点。最后,对工业浆态床反应器的设计进行总结和展望。

关键词: 浆态床反应器     气升式搅拌     鼓泡塔     环流反应器     过程强化     固体颗粒    

标题 作者 时间 类型 操作

Investigation of bubble diameter and flow regime between water and dilute aqueous ethanol solutions in an airlift

Baharak SAJJADI, Mostafa Keshavarz MORAVEJI, Reza DAVARNEJAD

期刊论文

Flow characteristic and wastewater treatment performance of a pilot-scale airlift oxidation ditch

Hongtao PANG, Hanchang SHI, Huiming SHI,

期刊论文

Nitrifying and denitrifying bacteria in aerobic granules formed in sequencing batch airlift reactors

WANG Fang, YANG Fenglin, QI Aijiu

期刊论文

CFD simulation of the hydrodynamics in an internal air-lift reactor with two different configurations

Mona EBRAHIMIFAKHAR, Elmira MOHSENZADEH, Sadegh MORADI, Mostafa MORAVEJI, Mahmoud SALIMI

期刊论文

气升式浆态床反应器的过程强化

耿淑君, 毛在砂, 黄青山, 杨超

期刊论文