入炉污泥含水率对污泥干化焚烧工艺影响研究

以上海某污水处理厂为例,通过理论计算和工程设计分析,研究了入炉污泥含水率(质量分数)对污泥干化焚烧工艺的影响.结果表明,随着干化程度的提高,对干燥机处理能力的要求提高,对干燥机型式的选择余地缩小,对焚烧炉、余热锅炉等设备的要求也将提高,对设备材质、系统安装、运行管理的要求也将相应提高.随着污泥干化程度的降低,进料量和烟气量增大,导致焚烧和烟气处理设备体积庞大.由于污泥泥质特性随时间变化大,在污泥热值整体偏低的地区,采用60%入炉污泥含水率存在一定的风险.污泥入炉含水率对污泥焚烧处理工程中的工艺选择及布置影响较大,工程设计中不应简单照搬国内外类似工程,而应根据当地污泥泥质特性、热值、辅助热源等实际情况,合理选择入炉污泥含水率.     

污泥干化及焚烧净化系统的调试

石洞口污水处理厂污泥处置工程项目,是国内第一套利用干化与焚烧相结合的方法处理污水处理厂脱水机出来的活性污泥的项目,介绍该项日污泥干化及焚烧净化系统的调试内容.     

热电厂污泥干化焚烧综合利用分析

污泥处理处置的目标是实现污泥减量化、稳定化和无害化,鼓励回收和利用污泥中的能源和资源。文中介绍了污泥经干化后用于热电厂循环流化床锅炉焚烧的工艺技术特点、节能减排效果等,该项目的投运,对发展循环经济和构建生态文明意义重大。     

污泥干化焚烧工艺系统分析

随着我国城市化进程的加快,污水处理率逐年提高,污水处理厂的脱水污泥产量也急剧增加,国内一些城市开始脱水污泥处理.目前在我国脱水污泥处理中采取的方法主要以填埋、农用和焚烧为主,而现阶段干化焚烧的无害化处理方式已逐渐被认可.     

上海市竹园污泥干化焚烧系统的能量平衡分析

结合上海市竹园污泥处理工程,根据竹园污泥干化焚烧工程的设计方案,研究了污泥干化焚烧系统的能量平衡模型。根据所建立模型的计算结果,上海竹园污泥处理工程焚烧系统可产生47×106kJ的能量,而干化机所需的能量约为57.2×106kJ,焚烧系统产生的能量不足以提供污泥干化系统所需的全部能量。     

一种污泥联合干化处置工艺介绍

目前国内污泥干化处置技术不同技术流派分别实现落地应用.应用较为广泛的常温深度脱水技术和间接式热干化技术均存在一定的缺点.本文通过污泥常温深度脱水和间接式热干化工艺的紧密结合,研发污泥联合干化处置系统,为大幅降低污泥处置运营成本,实现污泥减量化、无害化、稳定化、资源化处理的最佳途径提供一种选择.     

深度脱水污泥输送系统问题研究

污泥处理处置是我国建设无废城市最关注的问题之一。其中燃煤耦合污泥发电是目前国内主流的污泥处理工艺,主要是利用电厂内低品位蒸汽对含水率为60%～80%的污泥干化至含水率为30%～40%后与燃煤掺烧处理。无论采用何种技术对污泥进行处理处置,都不可避免地需要对污泥进行输送,选择合适的污泥输送技术及输送工艺系统的合理设计对于整个污泥处理系统的稳定运行至关重要。本文通过某燃煤电厂污泥输送系统的设计选型及运行情况进行分析,以期为同类项目的设计提供参考。     

污泥独立干化焚烧系统关键参数节能优化

本文以某污泥独立干化焚烧项目为研究对象,对该系统中不同污泥外热(干化机)及内热(焚烧炉内干化)的比例进行热平衡计算,并结合安全、物料输送等方面进行综合分析.研究发现:系统外部所需蒸汽量随热干化机污泥出口含水率升高而降低.提高热干化机出口污泥含水率,有助于污泥独立干化项目节省蒸汽,但同时需要考虑焚烧炉入炉污泥允许最高含水率及污泥输送粘度等问题.     

湿污泥循环流化床干化焚烧一体化研究

为高效处理污泥并回收热量,提出湿污泥干化焚烧一体化工艺.在0.15 MW循环流化床试验台上对湿污泥干化焚烧一体化工艺进行验证性试验.利用循环流化床焚烧产生的热灰在外置式流化床干化器内对湿污泥先进行干化,再送回炉膛燃烧,结果表明通过调节湿污泥给料速率、循环热灰调节阀开度和辅助给煤量可以实现焚烧炉内温度和干化器内料层温度的运行稳定,干化后污泥颗粒粒径分布比较均匀,水分在20%左右,焚烧后烟气排放在环境允许的范围内.     

污泥脱水干化技术研究

目前,污水处理厂在国内已得到广泛应用,由此带来的污泥处置作为一个急需处理的问题出现在人们面前。多年的重水轻泥思想使得目前污泥处置问题尤为严重,业界都在探讨污泥解决之道。污泥处置方法中都必须要先经过脱水和干化,目前污泥脱水技术绝大部分只能将污泥含水率降到80%左右,进一步的脱水则需要污泥干化技术,前者在中国已经很成熟,但还有进一步发展空间,而后者在中国还处在起步和发展阶段。     

市政污泥干燥焚烧联合运行分析

依据深圳宝安区污泥处理工程中的技术数据,对污泥流化床低温干燥、流化床高温焚烧系统进行能量平衡计算,对污泥含水率及其影响进行分析,得出本系统的理论工作参数,流化床干燥器入口的污泥含水率应尽量降低到70%～80%;干燥器出口的污泥含水率为10%～20%,最大不宜超过30%.为达到系统的能量平衡,可采取降低湿污泥的含水率和添加辅助燃料的措施.     

利用太阳能进行市政污泥干化处理和生物能源回收

通过太阳能干化处理,使原来20%～30%DS脱水污泥的体积或重量大幅度下降,从而降低后处理费用。处理工艺为:将市政污泥放置在暖房内,然后通过污泥翻抛机进行全自动翻泥运输。输出的产品是无臭味颗粒干泥,既可作为农肥施用,也可作为生物能源物质进行焚烧。太阳能干化处理只需少量辅助电能,操作费用极低。     

Graphical determination of drying process and moisture transfer parameters for solids drying

In this paper a simple graphical method is proposed to determine the drying moisture transfer parameters such as moisture diffusivity and moisture transfer coefficient for solid products. Once the lag factor and the drying coefficient are obtained from the experimental moisture content data, the proposed graphical method can be used to estimate the drying moisture transfer parameters in a quick and efficient manner. Drying time can also be easily determined for a solid whose drying process parameters are known. Two illustrative examples are given to highlight the importance of the topic and validate the use of the present methodology for practical drying applications.     

Experimental comparison of open sun drying and solar drying based on evacuated tube collector

In this article, an experimental comparison between open sun and solar drying is done. The thermal performance of evacuated tube based solar dryer is investigated with drying characteristics of Phyllanthus Emblica (Anvla), Aloe Vera, Aegle Marmelos (Bel) and leaves of Azadirachta Indica (Neem), Aegle Marmelos (Bel) and Psidium Guajava (Guava). In this setup, an evacuated tube collector, shell and tube heat exchanger and drying chamber are used. It was found that the maximum temperature difference between hot air and ambient air is 35.4°C and maximum efficiency of the setup is calculated as 55%. The average drying rate of Phyllanthus Emblica (Anvla), Aloe Vera and Aegle Marmelos (Bel) is measured as 0.46?g/min, 0.44?g/min, and 0.39?g/min respectively which are higher than that of Open Sun Drying. The leaves of Azadirachta Indica (Neem), Aegle Marmelos (Bel) and Psidium Guajava (Guava) also get dried with faster rates of 0.18?g/min, 0.17?g/min, and 0.14?g/min respectively.     

规模化猪场厌氧消化污泥脱水工艺研究

规模化猪场厌氧消化污泥堆肥是消化污泥处置的最重要途径之一,而作为污泥堆肥的重要预处理环节,消化污泥脱水却一直是道难题,文章就如何选择合理的污泥脱水工艺展开深入探讨.研究表明,规模化猪场消化污泥具有相对密度小、比阻大、有机养分含量高等特点,运用机械方法脱水不但费用高,而且技术上难度大,还会破坏消化污泥原本的有机养分组成,降低其堆肥后的农用的价值;和机械脱水方法相比,自然脱水方法在经济上具有明显的优势,而且技术上也可行.最后,文章认为污泥干化床工艺是自然脱水方法中较为理想的厌氧消化污泥脱水工艺.     

Application of a thermally assisted mechanical dewatering process to biomass

Thermally assisted mechanical dewatering (TAMD) is a new process for energy-efficient liquid/solids separation which enhances conventional-device efficiency. The main idea of this process is to supply a flow of heat in mechanical dewatering processes to favour the reduction of the liquid content. This is not a new idea but the proposed combination, especially the chosen operating conditions (T < 100 °C and P < 3000 kPa) constitutes an original approach and a significant energy saving since the liquid is kept in liquid state. Response surface methodology was used to evaluate the effects of the processing parameters of TAMD on the final dry solids content, which is a fundamental dewatering parameter and an excellent indicator of the extent of TAMD. In this study, a two-factor central composite design was used to establish the optimum conditions for the TAMD of alfalfa biomass. Experiments were carried out on a laboratory compression cell. Experiments showed that the dewatering enhancement results only from thermal effects. With a moderate heat supply (T_piston = 80 °C), the dry solid content of the press cake can reach 66%, compared to 36% at ambient temperature. A significant regression model, describing changes on final dry solids content with respect to independent variables, was established with determination coefficient, R², greater than 88%. With an energy consumption of less than 150 kWh/m³, the use of the TAMD process before a thermal drying process leads to an energy saving of at least 30% on the overall separation chain.     

硫对垃圾焚烧过程中二恶英生成的抑制作用

二恶英是环境中的痕量剧毒有机污染物,具有强烈的致癌、致畸、致突变性,对人类健康极具危害。垃圾焚烧过程排放的二恶英是近现代环境中二恶英的重要来源,如何有效地抑制垃圾焚烧过程中二恶英的生成具有着深远的意义,目前国内外学者对垃圾焚烧过程中二恶英的生成、排放和控制机理进行了多方面的研究。综述分析了硫对垃圾焚烧过程二恶英生成的抑制作用,并分析了煤和垃圾混烧过程中煤中硫对二恶英生成的抑制机理,并结合我国国情,提出了采用煤和垃圾混烧可以有效抑制垃圾焚烧过程的二恶英排放的建议。     

Modeling of a convective-infrared kiwifruit drying process

This paper aims to evaluate the experimental performance of a convective-infrared system with heat recovery (CIRHR) at different drying temperatures (40, 45, 50 and 55 °C) and 0.5 m/s air velocity and also to discuss and predict the performance of system on energy consumption and drying kinetics of sliced kiwifruit using artificial neural networks (ANNs). The energy efficiency values were obtained between 2.85% and 32.17%. The ANN model was used to predict the energy consumption of the system and moisture content of the kiwifruit. The back-propagation learning algorithm with Levenberg–Marquardt (LM) and Fermi transfer function were used in the network. The coefficient of determination (R²), the root means square error (RMSE) and the mean absolute percentage error (MAPE) were calculated as 0.99, 0.001 and 0.34, respectively. It can be concluded that predicted values are in good agreement with experimental results.