蓄热式高温带压蒸汽发生器设计

介绍了自制蓄热式高温带压蒸汽发生器的工作原理及运行过程，对炉体结构进行了设计计算，设计并计算了保温层的厚度，通过部分热态实验，验证了高温带压蒸汽发生器设计的合理性和系统运行的可靠性。试验结果表明，经过高温带压蒸汽发生器蓄热室的换热，可以生产出压力在0.2～0.4 MPa、温度在650℃以上的高温过热水蒸气。从而说明系统的整体设计能满足要求。     

喷钙脱硫灰在高温条件下的稳定性研究

对喷钙脱硫灰在高温条件下的稳定性进行了研究，通过对不同CaSO3,CaO含量的脱硫灰在不同气氛下CaO3的分解规律来考察其稳定定性。结果表明，温度和灰中CaO对脱硫灰的稳定性有直接影响。CaO3的分解率随温度的升高而升高，随CaO含量的增多而降低；气氛中含有氧气对其稳定性有重要作用，氧气能使其生成性能稳定的CaSO4，因此，高温利用脱硫灰时，在1150℃以下，空气中仅有极微量的SO2放出，不会对环境造成危害。     

废旧晶体硅光伏组件的回收利用

为应对光伏产业的快速发展而产生的废旧光伏组件高效低污染回收利用的问题,对不同气氛下光伏封装材料及背板材料的热失重行为及其产物进行了实验分析;并利用高温箱式炉对晶体硅组件进行热处理回收研究。考察了热处理温度、升温速率以及有无背板对硅晶片回收的影响。结果表明,封装材料和背板材料在空气气氛下均存在2个失重阶段,且最终失重温度为500℃左右。通过高温热处理,能够完全去除背板和封装材料,且能回收完整的表面玻璃。预先去除背板的光伏电池在热处理后的硅晶片完整性明显比未去除背板的光伏组件好。以20℃·min~(-1)的升温速率加热至480℃,得到了高完整性的回收硅晶片。     

蓄热式热氧化器的改进与应用

为了解决城市周边小企业挥发性有机物空气污染问题,研发了一种新型多蓄热室旋转换向蓄热式热氧化器,对现有蓄热式热氧化器内不合理的流通截面积分配比例进行了改进,并在北京市郊某工厂建设了处理能力3 000 m3/h的应用示范装置.应用情况表明,新型蓄热式热氧化器对VOC的处理效率可达96%,同时比常规热力焚烧炉节能70%以上....     

基于Fluent的甲苯蓄热燃烧过程的数值模拟

利用Fluent软件对甲苯在蜂窝陶瓷蓄热体中的蓄热燃烧过程进行数值模拟研究,确定模拟计算所需的网格精度,并计算分析蓄热体孔道直径、燃烧温度、甲苯入口浓度、人口流速对甲苯转化率的影响.结果表明,在较高入口流速条件下,蓄热体孔道直径对甲苯转化率影响较大.随着燃烧温度的升高、甲苯入口浓度和人口流速的降低,甲苯转化率会增大.当...     

大尺寸大孔径TiO2/SiO2光催化剂的制备及甲醛去除研究

以大孔径SiO2为载体，通过钛酸丁酯溶液的浸渍、原位水解以及高温煅烧制备出大尺寸、大孔径的TiO2/SiO2光催化剂。利用自制空气净化装置对室内甲醛的清除进行研究，分别考察了TiO2的百分含量、紫外光光强、温度、湿度和空气流量等不同条件下TiO2/SiO2光催化剂对除去甲醛效率的影响。结果表明，反应温度从10～50℃依...     

水热条件下绿矾稳定垃圾焚烧飞灰的研究

研究了饱和温度为200 ℃的水热条件下绿矾对垃圾焚烧飞灰中重金属的稳定效果,并与常温常压下的稳定效果进行了对比.研究结果表明,高温水热条件有利于Pb特别是Cr(Ⅵ)的稳定,对Cd的稳定无明显影响,同时绿矾的用量大为降低,降低了药剂的成本.     

初始温度对人粪便好氧堆肥过程的影响

温度是好氧堆肥过程中需要控制的一个重要因素。不同的初始温度直接影响了堆肥过程中微生物活性及有机物的降解。为了研究初始温度对粪便好氧堆肥过程的影响,采用序批式好氧堆肥反应器,以新鲜锯末为载体,控制含水率在55%~60%的范围左右并强制通风的好氧条件下,进行了初始温度分别为25、35、45和55℃,20 d为一个周期好氧堆肥实验,研究了不同初始温度条件下堆肥过程有机物降解、氮的迁移转化及种子发芽指数的变化。结果表明,初始的高温度会抑制堆肥反应的进行,但初始温度越高,水解效果越显著;初始的高温有利于COD的去除,最终COD的去除率分别为88.2%、89.3%、92.0%和89.9%。初始高温对种子发芽率有抑制作用,同时延迟了堆肥的腐熟期。     

冶金高炉高温熔融处理垃圾飞灰

为了探讨冶金高炉处理垃圾飞灰的可能性,将一定量的垃圾飞灰作为造球原料通过快凝水泥固化制备冷固飞灰球团,模拟高炉温度、气氛条件对飞灰球团进行高温冶金性能实验研究,并采用X射线衍射仪对飞灰球团中物相变化进行了研究。结果表明:在造球原料里配入5%左右的飞灰通过水泥固化造出的球团能达到入炉要求;配入10%飞灰球团的高炉炉料的高温冶金性能变化不大,且能够保持高炉内的工作环境相对稳定,符合当前冶炼要求的炉内工程条件;在高温下飞灰中的重金属能有效还原固封,二恶英能有效分解,为垃圾飞灰的资源化处理开辟了新的途径。     

CO_2高温活化活性炭材料对苯酚的吸附行为研究

以CO2为活化气体,在高温条件下对国产椰壳活性炭进行活化。研究了活化前后的活性炭在不同温度和pH等条件下对水溶液中苯酚的吸附行为。结果表明,活性炭经活化后,微孔体积和中孔体积增加,吸附容量明显提高;苯酚在活性炭上的吸附符合Freundlich吸附等温方程和准二级反应动力学方程;在一定范围内降低温度有利于吸附的进行;在pH为2～8时,吸附效果较好;在pH9时,吸附效率明显降低。     

Formation and removal of PCDD/Fs in a municipal waste incinerator during different operating periods

The PCDD/F concentrations and removal efficiencies achieved with air pollution control devices (APCDs) during different operating periods (start-up, normal operation, and shut-down) at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS), and selective catalytic reduction system (SCR) as APCDs. The sampling results indicate that the PCDD/F concentrations at the EP inlet during start-up period were 15 times higher than that measured during normal operation period. The PCDD/F concentration observed at shut-down period was close to that measured at normal operation period. The CO concentration was between 400 and 1000 ppm during start-up period, which was about 50 times higher compared with the normal operation. Hence, combustion condition significantly affected the PCDD/F formation concentration during the waste incineration process. In addition, the distributions of the PCDD/F congeners were similar at different operating periods. During the normal operation and shut-down periods, the EP decreases the PCDD/F concentration (based on TEQ) by 18.4-48.6%, while the removal efficiency of PCDD/Fs achieved with SCR system reaches 99.3-99.6%. Nevertheless, the PCDD/F removal efficiency achieved with SCR was only 42% during the 19-h start-up period due to the low SCR operating temperature (195 degrees C).     

Evaluation of trickle-bed air biofilter performance under periodic stressed operating conditions as a function of styrene loading

Trickle-bed air biofilters (TBABs) are suitable for treating volatile organic compounds (VOCs) at a significantly high practical loading because of their controlled environmental conditions. The application of TBAB for treating styrene-contaminated air under periodic backwashing and cyclical nonuse periods at a styrene loading of 0.64-3.17 kg chemical oxygen demand (COD)/m3 x day was the main focus of this study. Consistent long-term efficient performance of TBAB strongly depended on biomass control. A periodic in situ upflow with nutrient solution under media fluidization, that is, backwashing, was approached in this study. Two different nonuse periods were employed to simulate a shutdown for equipment repair or during weekends and holidays. The first is a starvation period without styrene loading, and the second is a stagnant period, which reflects no flow passing through the biofilter. For styrene loadings up to 1.9 kg COD/m3 x day, removal efficiencies consistently above 99% were achieved by conducting a coordinated biomass control strategy, that is, backwashing for 1 hr once per week. Under cyclical nonuse periods for styrene loadings up to 1.27 kg COD/m3 x day, stable long-term performance of the biofilter was maintained at more than 99% removal without employing backwashing. No substantial impact of nonuse periods on the biofilter performance was revealed. However, a coordinated biomass control by backwashing subsequently was unavoidable for attaining consistently high removal efficiency at a styrene loading of 3.17 kg COD/m3 x day. As styrene loading was increased, reacclimation of the biofilter to reach the 99% removal efficiency following backwashing or the nonuse periods was delayed. After the non-use periods, the response of the biofilter was a strong function of the biomass in the bed. No significant difference between the effects of the two different nonuse periods on TBAB performance was observed during the study period.     

生物滴滤器净化低浓度甲苯废气的非稳态工况研究

生物法处理大气污染物时,经常会遇到条件波动或污染物间歇排放等非稳态工况。在不同非稳态条件下,考察了甲苯废气间歇排放对生物滴滤器净化性能的影响。实验方案分3种情况:无甲苯废气排放、无循环液供应或同时没有甲苯废气和循环液的供应。间歇排放时间从2~47 d不等。结果表明,不管何种形式的停运或故障,甲苯净化能力4 d以内基本不下降;停运时间超过5 d,则甲苯去除能力严重下降,仅为原来的1/3~1/2;停运时间在10 d以内,24 h内即可恢复,47 d的长期停运,3 d内也可恢复净化能力。     

流化床中污泥干燥特性

以湿污泥为原料在气固流动流化床干燥器内进行了污泥干燥特性的实验研究,考察流化风速、送风温度、联合干燥热量配比的变化对干燥强度、干燥热效率及平均传热系数的影响。实验结果表明,流化床污泥干燥最佳流化风速为1.48 m/s左右;随着流化风温的升高,干燥强度和干燥热效率逐渐增大,但增幅减小;单独的加热管干燥和流化风干燥的干燥热效率均较低,分别为33%和45%左右。在相同总输入热量下,随着内置加热管输入热量的比重越来越大,干燥热效率、干燥强度和平均传热系数均先增大后减小。     

生活垃圾高温空气气化处理的低污染特性分析

本文介绍了高温空气气化城市生活垃圾的工作原理及过程 ,分析了城市生活垃圾高温气化反应机理。通过对高温空气 /蒸汽发生器、高温气化炉及湿式除尘器等关键部件的分析发现 ,采用高温空气气化系统可实现城市生活垃圾低污染处理     

压力溶气气浮工艺中溶气效率测定方法述评

气浮工艺中溶气效率高低直接影响到回流水量的大小 ,即决定着运行费用的高低。对气浮工艺设计者和运营者来讲 ,达到并维持较高溶气效率是优先考虑的问题 ,而对新型气浮设备研发者而言 ,了解并确定其在不同工况下的溶气效率也是至关重要的。就已有溶气效率的测定方法进行了分类介绍与评价。     

Waste burning and heat recovery characteristics of a mass burn incineration system

An experimental investigation on waste combustion characteristics of a mass burn incinerator is conducted in this study. Three different charging modes, including operator manipulation, periodic feeding, and temperature control, are taken into consideration. The results indicate that the burning characteristics in the combustion chambers are closely related to the operating modes. For the operator manipulation where the wastes are sent into the incinerator in two short periods, the entire temperature distribution of the primary combustion chamber can be partitioned into two parts, thereby yielding waste group combustion. Temperature oscillations in both the primary and secondary combustion chambers are characterized for the periodic feeding. However, because of the shorter charging period and smaller amount of waste, the burning interaction between the two chambers is initially weak and becomes notable in the final stage. When temperature control is performed, the burning oscillation of the primary combustion chamber is further amplified so the combustion interaction is drastic. These exhibitions are mainly caused by the competition between endothermic and exothermic reactions. The instantaneous heat exchange efficiency of the cyclone heat recovery system (CHRS) installed in the incineration system is also evaluated to obtain details of energy recovery behaviors. As a result, the efficiency tends to decrease linearly with increasing temperature of hot flue gas. This arises from the fact that heat loss from the gas to the environment is increased when the temperature of the former is higher, even though the temperature gradient across the cyclone is enlarged.     

Characteristic Study of Ambient Air Total Gaseous Mercury (TGM) Concentrations During Rainy and Non-Rainy Periods at a Traffic Site in Taiwan

This investigation studied the concentrations of ambient air total gaseous mercury (TGM) during the rainy periods at the Hung-Kuang traffic sampling site in central Taiwan from May 26 to June 16, 2014. The results were compared with those of a previous study for ambient air TGM during non-rainy daytime and nighttime periods at the Hung-Kuang traffic sampling site, which was conducted during March 21 to July 20, 2012. The observed mean concentration of ambient air TGM was 1.16 ng/m³ during the rainy periods at the Hung-Kuang traffic sampling site. The mean ambient air TGM concentrations were higher in the non-rainy sampling period in daytime than in the rainy sampling period from this study. The mean ratio of non-rainy sampling period in daytime to that of rainy sampling period for ambient air TGM were 3.15. Furthermore, the mean ambient air TGM concentrations were higher in the non-rainy sampling period in nighttime in than in the rainy sampling period for this study. The mean rations for non-rainy sampling period in nighttime to that of the rainy sampling period for ambient air TGM were 2.70. The results obtained in this study also revealed that the ambient air TGM concentrations during the rainy period had the lowest concentrations when compared with the other sampling sites in other world regions.     

Validation of a flow-through sampler for pesticides and polybrominated diphenyl ethers in air

At locations without access to the electrical grid, a flow-through sampler (FTS) collects large volumes of air for the analysis of semi-volatile organic compounds (SVOCs). To test its performance under field conditions, an FTS and a traditional pumped high volume air sampler, both using polyurethane foam (PUF) as sampling medium, were co-deployed at the campus of the University of Toronto Scarborough from August 2006 to June 2007. Polybrominated diphenyl ethers (PBDEs) and various pesticides were quantified in the samples taken by both samplers to test the FTS's applicability to relatively non-volatile and slightly polar SVOCs. Air concentrations in samples taken with the FTS over five 2-week periods compare favourably with the average of the concentrations in several 24-h active high volume samples taken during the same period. In particular, time trends, temperature dependence relationships, and isomer ratios show a reasonable agreement between the two sampling techniques. An empirical linear solvation energy relationship for predicting the apparent theoretical plate number of the PUF assembly used in the FTS illustrates the effect of chemical properties, as well as temperature and wind speed, on sampling efficiency. In the absence of electrical power, the FTS can collect SVOCs from large air volumes as reliably and quantitatively as traditional HiVol samplers, although without separating gas and particle phase.     

大尺寸大孔径TiO_2/SiO_2光催化剂的制备及甲醛去除研究

以大孔径SiO2为载体,通过钛酸丁酯溶液的浸渍、原位水解以及高温煅烧制备出大尺寸、大孔径的TiO2/SiO2光催化剂。利用自制空气净化装置对室内甲醛的清除进行研究,分别考察了TiO2的百分含量、紫外光光强、温度、湿度和空气流量等不同条件下TiO2/SiO2光催化剂对除去甲醛效率的影响。结果表明,反应温度从10～50℃依次升高,去除率逐渐下降。在相对湿度为50%,TiO2负载率为55.6%,流量为8 m3/h时,甲醛的最佳除去率达96.5%;经过7周时间的考察,发现TiO2/SiO2光催化剂的催化活性没有明显的下降。