回转窑在医废焚烧工程应用中的参数优化

以规模3 t/h的某医疗废物焚烧生产线为依托,优化分析了回转窑焚烧装置核心控制参数（窑头温度、供风量及窑转速）,考察了不同负荷、回转窑转动模式及进料方式对焚烧效果的影响,结果表明：窑头温度升高,有利于提高焚烧效果,是影响焚烧效果最重要的工艺参数;75%负荷时最佳工况是窑头温度850℃、窑转速0.09 r/min、供风量7 000 Nmc/h;连续反转的回转窑转动模式和恒流量的连续进料技术,有助于保持良好焚烧工况,炉渣热灼减率分别达到2.6%和2.3%。     

医疗垃圾热解焚烧实验研究

医疗垃圾是一种对环境危害极大的危险废弃物.用一种固定炉排炉热解焚烧系统,对广州市部分医院的医疗垃圾进行了热解焚烧及尾气净化试验,并对焚烧工况、烟气中主要的污染物含量及灰渣的灼减率进行分析.分析结果表明:稳定运行时炉膛平均温度在850℃左右,二燃室平均温度在1000℃以上;尾气中CO、NOx、HCl和SO2浓度分别为:71mg/m3、125 mg/m3、27.8 mg/m3和21 mg/m3,灰渣的灼减率为2.7%.均远远低于标准限值.     

医疗垃圾热解焚烧实验研究

医疗垃圾是一种对环境危害极大的危险废弃物。用一种固定炉排炉热解焚烧系统，对广州市部分医院的医疗垃圾进行了热解焚烧及尾气净化试验，并对焚烧工况、烟气中主要的污染物含量及灰渣的灼减率进行分析。分析结果表明：稳定运行时炉膛平均温度在850℃左右，二燃室平均温度在1000℃以上；尾气中CO、NOx，HCI和SO2浓度分别为：71mg／m^3、125mg／m^3、27．8mg／m^3和21mg／m^3，灰渣的灼减率为2．7％。均远远低于标准限值。     

医疗废物回转窑焚烧线中二恶英的生成

通过采集医疗废物回转窑焚烧生产线不同部位的烟气的二恶英样品,研究了医废焚烧过程二恶英在焚烧线200~600℃区间不同烟道断面烟气中分布变化情况。研究结果表明,医疗废物焚烧后烟气中二恶英的发生浓度要高于一般的生活垃圾焚烧烟气的浓度,大致在5~23.3 ng TEQ/m3的范围,锅炉出口到脱酸塔入口段的管道和设备为烟气中二恶英重新合成的高发区域,医废焚烧烟气中二恶英(TEQ)主要是以气态污染物的形态存在。     

城市下水污泥焚烧过程中二次污染物排放特性的试验研究

在0.15 MWt循环流化床燃烧试验台上进行了城市下水污泥与煤的混烧试验,分析了烟气中的二次污染物排放特性.分析结果表明,利用循环流化床焚烧城市下水污泥时,添加辅助燃料(如煤)及改变焚烧条件,不仅可以达到稳定燃烧的目的,而且有利于抑制焚烧中二次污染物(如CO及二恶英等有机污染物)的生成.分析了焚烧污泥污染物的排放特性,为采用焚烧方式处理城市下水污泥提供了基础性试验数据.     

城市下水污泥焚烧过程中二次污染物排放特性的试验研究

在0．15MWt循环流化床燃烧试验台上进行了城市下水污泥与煤的混烧试验，分析了烟气中的二次污染物排放特性。分析结果表明，利用循环流化床焚烧城市下水污泥时，添加辅助燃料（如煤）及改变焚烧条件，不仅可以达到稳定燃烧的目的，而且有利于抑制焚烧中二次污染物（如CO及二恶英等有机污染物）的生成。分析了焚烧污泥污染物的排放特性。为采用焚烧方式处理城市下水污泥提供了基础性试验数据。     

循环流化床锅炉掺烧危废渣蜡对灰渣污染特征的影响

煤制油技术产生的易蓄热自燃的渣蜡属于危险废物,处置不当会带来较大的环境影响和环境风险。通过与燃料煤混合燃烧的利用方式处理渣蜡可降低处理成本,同时减少能源浪费。按燃料煤与渣蜡30∶1的比例混合,通过循环流化床 (CFB) 锅炉掺烧,对其热能进行利用,并研究其对CFB锅炉运行和灰渣特征的影响。结果表明,混合后的掺烧燃料组分变化差异较大,部分重金属含量有所增高;掺烧实验开始阶段锅炉的运行负荷和炉膛的出口温度出现明显上升,而工况稳定后,波动不大;相比燃料煤,掺烧产生的粉煤灰和炉渣的热灼减率无明显差异,二恶英类持久性有机污染物贡献均以OCDD为主导,但重金属铬、锰和铜含量稍有增加,主要受渣蜡中重金属迁移和难挥发影响。本研究结果可为通过循环流化床 (CFB) 锅炉掺烧发电的方式对渣蜡进行合理的资源化利用提供参考。     

油田油泥与煤在流化床中的混烧

基于小型流化床焚烧实验平台,通过含油污泥与煤混合燃烧,分析气体污染物排放浓度以及灰渣特性。含油污泥与煤混烧后NOx、SO2的排放浓度均低于危险废物焚烧排放标准。根据灰渣中组分分析,煤中碱金属化合物能抑制SO2的排放。渣样的浸出毒性均在标准范围内,灰样的浸出毒性高于渣样,主要因为飞灰中更容易富集挥发和易溶形态的重金属。基于小试实验的结果,油泥在小型流化床上的燃烧不充分导致了CO排放浓度较高,且灰的灼减率较高,因此,在后续中试以及示范工程中,应保证油泥的充分燃烧,为灰渣的综合利用提供理论基础。     

固体回收燃料焚烧技术的研究现状及发展方向

固体回收燃料(SRF)是由城市生活垃圾(MSW)经机械生物处理(MBT)而得,具有高热值、低氯和含汞的特点,是继垃圾衍生燃料(RDF)之后的一种新型燃料。目前SRF焚烧技术在国内外已有一定的基础研究,但仍需要向大规模、高参数(高蒸汽温度和压力)、稳定运行方向发展。从垃圾焚烧现状入手,简述了国外SRF焚烧和共处置技术的研究现状,同时回顾了国内对MSW和RDF焚烧技术的相关研究,分析了SRF焚烧和共处置时污染物排放的规律,以及SRF对共处置锅炉运行工况的影响。最后指出了实现SRF焚烧技术的大规模、高参数工业应用必须研究的3个方面,包括:SRF的分类方法和燃烧模型,烟气净化系统的改进,SRF焚烧对锅炉腐蚀、结渣和积灰生长的影响。     

回转窑式纯氧熔融焚烧垃圾技术研究

生活垃圾安全无害化处理是目前迫切需要解决的问题,直接气化熔融焚烧垃圾技术以降低二恶英排放方面巨大优势得到广泛关注,在此基础上提出纯氧熔融焚烧垃圾技术,几乎可以实现所有二次污染物近零排放。以350 t/d回转窑垃圾焚烧炉为例,对纯氧代替空气应用在回转窑上熔融焚烧垃圾系统进行了详细热力计算及分析。结果表明,纯氧熔融焚烧垃圾系统的锅炉效率可达90.56%,回转窑熔融焚烧系统还可以在垃圾焚烧后灰渣达到熔融温度的条件下,保持该系统热量平衡,稳定燃烧。并参考回转窑设计标准对该纯氧熔融焚烧城市生活垃圾的回转窑参数进行确定。     

3-D Flow Modeling of a Hazardous Waste Incinerator

A three-dimensional flow model of a hazardous waste incinerator kiln and vertical secondary combustion chamber arrangement was constructed to evaluate critical system parameters. The chamber wall configuration, location and arrangement of burners, and the positioning of the outlet duct were examined to determine the critical secondary combustion chamber gas residence time and mixing of the combustion flows. The scale model consisted of the rotary kiln as a primary combustion chamber, the secondary combustion chamber, two burners, and the exhaust ducting. Flue gas velocities in the model inlets and outlet were maintained to provide a Reynolds numbers equal to the full size unit. Patterns of smoke which were injected into the model inlets were viewed to evaluate flow mixing. Slow motion playback of video tape was used to determine the minimum residence time of flow in the high temperature combustion zone. The results of the model study were used to complete the engineering of a waste incineration system.     

基于催化陶瓷纤维滤管的一体化烟气净化工艺处理危废焚烧烟气的中试示范工程

实现烟气多污染物一体化净化成为危废焚烧烟气治理领域的新趋势。提出了基于催化陶瓷纤维滤管的危废焚烧烟气一体化处理工艺,并依托江苏某危险废物焚烧厂建设了中试示范工程,以考察该工艺的处理效果。结果表明：该工程可实现对危废焚烧烟气进行除尘、脱酸、脱硝及降解二恶英等处理的集约、高效运行;其关键技术为催化陶瓷纤维管的应用;运行成本较传统工艺降低了约30%,且具有处理效率更高、占地面积更小、投资和运行费用更低等优点。本示范工程可为现役危废焚烧烟气净化工程的改造及新建项目实现深度净化提供参考。     

Field Testing and Computer Modeling of an Oxygen Combustion System at the EPA Mobile Incinerator

The LINDE® Oxygen Combustion System has been demonstrated successfully at the EPA Denney Farm site as part of the modified EPA mobile incinerator. This paper describes the field testing results and computer modeling of the LINDE system. The oxygen system enables the EPA unit to incinerate dioxin and PCB contaminated soil at a consistent rate of 4000 lb/h—200 percent of the original maximum capacity. The pure oxygen combustion system improved the thermal efficiency of the incinerator by over 60 percent and reduced the flue gas volume dramatically. Therefore, the dust carryover problem was mitigated. The destruction and removal efficiencies of hazardous wastes exceeded EPA requirements.

The design of the proprietary burner allows the use of up to 100 percent oxygen in place of air for incineration with improvements over conventional oxy-fuel burners. As a result, the temperature distributions in the rotary kiln are uniform and NO_x emissions are low.

The oxygen combustion system, controlled by a programmable controller, provided much better response and flexibility than conventional air based systems. The system generated a stable flame and responsed well to the transient conditions of the rotary kiln. Kiln puff occurrence was virtually eliminated in the operation of the mobile incinerator.

A computer model of the incinerator was developed and used for the process design of the LINDE system. The model predicted the test results reasonably well. This model can be a useful tool in the design and operation of rotary kiln incineration systems.     

A Comparison of In situ Vitrification and Rotary Kiln Incineration for Soils Treatment

In the hazardous waste community, the term “thermal destruction” is a catchallphrase that broadly refers to high temperature destruction of hazardous contaminants. Included in the thermal destruction category are treatment technologies such as rotary kiln incineration, fiuidized bed incineration, infrared thermal treatment, wet air oxidation, pyrolytic incineration, and vitrification. Among them, conventional rotary kiln incineration, a disposal method for many years, is the most well established, and often serves as a barometer to gauge the relative success of similar technologies. Public sentiment on environmental issues and increasingly stringent environmental regulations has, over time, spurred design and development of innovative thermal treatment processes directed toward reducing harmful emissions and residuals that may require further treatment or disposal. In situ vitrification (ISV), a technology that combines heat and immobiliztion, is one such innovative and relatively new technology.

This paper presents a comparison of ISV and rotary kiln incineration for soils treatment in the areas of process performance, process residuals, process limitations, applicable or relevant and appropriate (ARAJRs) regulations, criteria and limitations, and costs.     

A comparison of in situ vitrification and rotary kiln incineration for soils treatment.

In the hazardous waste community, the term "thermal destruction" is a catchall phrase that broadly refers to high temperature destruction of hazardous contaminants. Included in the thermal destruction category are treatment technologies such as rotary kiln incineration, fluidized bed incineration, infrared thermal treatment, wet air oxidation, pyrolytic incineration, and vitrification. Among them, conventional rotary kiln incineration, a disposal method for many years, is the most well established, and often serves as a barometer to gauge the relative success of similar technologies. Public sentiment on environmental issues and increasingly stringent environmental regulations has, over time, spurred design and development of innovative thermal treatment processes directed toward reducing harmful emissions and residuals that may require further treatment or disposal. In situ vitrification (ISV), a technology that combines heat and immobilization, is one such innovative and relatively new technology. This paper presents a comparison of ISV and rotary kiln incineration for soils treatment in the areas of process performance, process residuals, process limitations, applicable or relevant and appropriate (ARARs) regulations, criteria and limitations, and costs.     

水泥窑协同处置村镇生活垃圾

针对位于新型干法水泥厂附近且生活垃圾收运较为困难的村镇,提出了一种利用新型干法水泥窑协同处置垃圾的简易模式。实验将预处理后的村镇生活垃圾定量喂入水泥窑系统中,并对比了掺烧20、50和80 t村镇生活垃圾前后,水泥熟料品质、窑系统工况以及污染物排放的情况。结果表明:实验期间在80 t范围内,生活垃圾的掺烧使水泥熟料抗压强度最多降低3 MPa,但仍符合国家标准;对水泥窑衬结皮和窑工况稳定性基本没有影响;同时对水泥窑系统污染物排放量无负面影响,烟气中二恶英的含量为0.004 0 ng TEQ/m3,远远低于国家标准。     

Performance of High-temperature Slagging Rotary Kiln Incinerator

A high-temperature, slagging rotary kiln hazardous waste incineration system with modern combustion, heat recovery and air pollution control equipment was put in operation at PPG Coating and Resin Plant in Circleville, Ohio in the latter part of 1987. New design solutions contributed to the overall high performance of the system. The system employs European and American feed, combustion, heat recovery and stack emission control technologies. Performance of the system is analyzed in detail covering topics such as feed methods, equipment selection, destruction and removal efficiencies, fate of the metals, and financial information.     

炉排式垃圾焚烧炉参数敏感性分析与燃用高热值垃圾运行优化的数值模拟

针对垃圾热值提高造成的炉排式垃圾焚烧炉受热面超温问题,采用计算流体力学(CFD)方法模拟焚烧炉内垃圾焚烧过程,并将模拟结果与Morris敏感性分析方法结合,考察一次风温度、过量空气系数、干燥段风量占比和垃圾停留时间4个输入参数改变对垃圾着火位置和下炉膛最高烟气温度2个输出参数的敏感性,以评估各参数对炉内垃圾焚烧的影响,得到更为有效的运行参数调整方案。结果表明,垃圾停留时间是最敏感的控制参数,一次风温度和炉排配风比例也是较敏感的参数。在此基础上,对某1 000 t·d⁻¹焚烧炉燃用高热值垃圾运行优化开展模拟分析发现,缩短垃圾停留时间和调整炉排配风比例使着火点位置接近基准垃圾工况,使烟道前侧壁面附近温度降低93 K;进一步调整后墙二次风入射角至水平,可显著降低进料口壁面附近温度,且烟气温度、氧气和未燃气体的体积分数均满足国家排放标准。本研究结果可为炉排式垃圾焚烧炉燃用高热值垃圾的运行优化提供参考。