内循环厌氧反应器关键结构的研究

发布时间：2018-03-29 06:00

  本文选题：IC反应器　切入点：旋流布水　出处：《苏州大学》2017年硕士论文

【摘要】：内循环厌氧反应器(简称IC反应器)是在升流式厌氧污泥床UASB的基础上发展而来的一种高效厌氧生物反应器,是最具代表性的第三代厌氧反应器。在IC反应器的诸多部件中,对运行负荷与去除率有着显著影响的关键结构有布水系统、重渣排放和反应器循环系统,目前主要存在布水不均匀、容易出现死区、反应器钙化严重且重渣无法实现有效排放、循环量不足、反应器缓冲能力差、生物颗粒污泥流失严重等问题。因此,对IC反应器的关键结构进行优化,使反应器实现长期稳定高效的运行具有重要的理论与现实意义。(1)在对比分析各种布水系统的设计思想、结构形式和混合机理等研究现状的基础上,结合运用旋流布水和大阻力配水技术,设计出一套反应器梯度多层旋流布水系统。提高系统的布水均匀性,布水区域无死区,使污泥床处于流化状态以增强废水和颗粒污泥的混合度,有效强化传质和反应过程。(2)对反应器重渣形成机理进行研究,借鉴水力旋流除渣原理对反应器重渣分离与排放装置进行结构设计。在反应器污泥床底部设计一套倒锥型重渣水力旋流筛选装置,并在其底部设计一个圆柱形的集渣槽以使重渣得以有效收集后分离,最终成功实现重渣的排放并使排出重渣中灰分含量不低于80%,能根据反应器重渣含量随时进行排放。(3)综合运用厌氧颗粒污泥膨胀床和固体流态化技术,对IC反应器循环系统水力条件进行优化。通过调整反应器出水设计,在内循环系统的基础上增加一套功能上可以实现上部溢流出水,部分出水和洗出污泥循环回流至反应器的立管结构。由立管构成IC反应器的外部循环系统,提高了反应器的液面上升流速而且可以使其稳定在5~8m/h的中高负荷区间,出水颗粒污泥浓度≤5ml/L,保证了基质的混合强度和稳定运行能力。(4)制作出实验室规模的小试反应器装置以检测布水均匀性、重渣排放效果、流场形态和传质效果、COD去除率与运行稳定性等。小试装置运行状态表明:布水系统均匀性显著提高,布水区域无死区;重渣成功从反应器中得到筛选分离;反应器基质间传质明显。反应器运行综合评价体系项目中COD去除率达到80%,污泥负荷0.2kg COD/(kgVSS·d),容积负荷30kg COD/(m~3·d),出水VFA稳定在5mmol/L左右,说明反应器运行状况良好。最后,对原结构形式的IC反应器的关键结构进行了工程改造及应用,此工程是国内首次采用优化后的关键结构对原有反应器进行的改造。改造后反应器运行数据及红外热成像检测表明改造取得了预计效果:反应器布水均匀性得到改善;解决了原先存在的反应器钙化和重渣不能筛选排放的问题;温度场均衡分布区域占比达到90%以上;传质效果较好,反应器运行稳定高效,去除率较原设计值提高10个百分点。为IC厌氧反应器关键结构的研究、优化和应用提供了新的参考。
[Abstract]:Internal circulation anaerobic reactor (IC reactor) is a highly efficient anaerobic bioreactor based on upflow anaerobic sludge bed (UASB). It is the most representative third generation anaerobic reactor. Water distribution system, heavy slag discharge and reactor circulatory system are the key structures which have significant influence on operation load and removal rate. At present, there are mainly uneven distribution of water, easy to appear dead zone, serious calcification of reactor and no effective discharge of heavy slag. The critical structure of IC reactor is optimized, such as insufficient circulation, poor buffer capacity and serious loss of biological granular sludge. It is of great theoretical and practical significance to make the reactor run stably and efficiently for a long time. On the basis of comparing and analyzing the design ideas, structural forms and mixing mechanism of various water distribution systems, etc. Combined with the technology of swirl water distribution and large resistance water distribution, a reactor gradient multi-layer swirl water distribution system is designed. The uniformity of water distribution of the system is improved and there is no dead zone in the water distribution area. The sludge bed was fluidized to enhance the mixing degree of wastewater and granular sludge, and the mass transfer and reaction process were effectively enhanced. The formation mechanism of heavy slag in the reactor was studied. Based on the principle of hydrocyclone slag removal, the structure design of heavy slag separation and discharge device in reactor was carried out, and a set of inverted cone hydrocyclone screening device was designed at the bottom of sludge bed of reactor. At the bottom of it, a cylindrical slag-collecting groove is designed so that the heavy slag can be collected effectively and separated from each other. Finally, the discharge of heavy slag is realized successfully, and the ash content in the discharged heavy slag is not less than 80%, which can be discharged at any time according to the heavy slag content of the reactor.) the anaerobic granular sludge bulking bed and the solid fluidization technology can be used synthetically. The hydraulic conditions of IC reactor circulation system are optimized. By adjusting the reactor effluent design, a set of functions can be added to the inner circulation system to realize the upper overflow effluent. The external circulation system of IC reactor is composed of risers, which can increase the rising velocity of liquid level of the reactor and stabilize it in the middle and high load range of 5~8m/h. The effluent granular sludge concentration 鈮，

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