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电凝交理论及在除尘应用中的新进展 总被引:3,自引:0,他引:3
向晓东 《建筑热能通风空调》1994,13(4):28-31,42
在交变电场中强化荷电微粒的电换并被认为是收集亚队米烟尘的一种新方法而引起空气净化领域的关注。为使除尘工业者对电凝并研究发展现状有更深入的了解,本文较为系统地阐述了电凝并的基本原理,讨论了荷电微粒在交变电场中的凝并行为,最后重点介绍了Loffler和Gutsch关于感应荷电和偶极荷电亚微米粒子在交变电场中凝并的理论研究结果以及Watanaabe所研制的交流电凝并型电除尘成功地应用于收集亚微尘烟尘的新成果。 相似文献
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静电增强布袋除尘器的实验研究及其应用 总被引:4,自引:0,他引:4
实验表明,粉尘预荷电技术能有效提高纤维过滤器性能,尤以双极不对称荷电方式为最佳。在实验研究成果基础上设计成的静电增强布袋除尘机组,通过工业性实验,除生效率和设备阻力等性能指标显著提高。 相似文献
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为了探究外部高温对不同荷电状态锂离子电池热失控特性的影响,将三种荷电状态的18650 型锂离子电池分别热处理至80、100 ℃,在常温下静置24 h 后通过热流道加热线圈使其热失控并分析电池的温度、电压等特征参数。研究表明,同一热处理温度下,锂离子电池荷电状态越高其热失控现象越剧烈,热失控温度越高,电压下降时间越早。同一荷电状态下,热处理至80 ℃的锂离子电池热失控现象更剧烈,热失控温度更高,电压下降时间却更晚。试验结论可为锂离子电池的安全运输、存储及应用提供理论依据。 相似文献
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利用异极性荷电粉尘在电场中的凝并聚集成大颗粒物从而提高净化效率这一理论基础,设计一种新型电凝并静电增强型过滤装置,通过电离区针尖,凝并区结构及系统优化等一系列措施提高凝并效果,降低功率、臭氧发生量、风阻等不利因素,最终设计出一款体积小、净化效率高的新型电凝并静电增强过滤装置。 相似文献
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为定量研究空运锂电池热失控危险性并为其批量运输提供理论指导,对不同荷电状态和负压环境下的锂电池开展热失控试验,确定锂电池在不同条件下热失控释放气体的释放特性。利用GC-MS 确定不同荷电状态及负压环境下气体组分,并利用气相色谱仪确定不同条件下锂离子电池热失控释放气体各组分的含量。试验结果表明,在锂电池发生初爆时,不同荷电状态对热失控释放气体量有显著影响,荷电状态在10%及以下时热失控释放气体量较多并且初爆温度较高。不同荷电状态对生成气体中组成成分影响较小,对组分含量影响较大。热失控释放气体量随着负压程度的增加而增大。 相似文献
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研制了一种以金属拉伐尔管为阳极,管喉部装针状放电阴极的粉尘预荷电装置。由于含湿空气通过该装置的电晕放电场时急剧膨胀,产生大量的带电冰气溶胶。实验测定了用于产生带电冰气溶胶的有效电流和冰气溶胶对粉尘预荷电的效果。并探讨了将这项技术用于除尘实践的可能性。 相似文献
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王能勤 《建筑热能通风空调》1990,9(4):38-41
电颢粒层除尘装置是由沸腾颗粒除尘器的沉降室内安装预荷电装置和尘气分流装置组成,单级、干法、高效和低阻收集沸腾锅炉排出的烟尘.经20t/沸腾锅炉应用表明:单级除尘器阻力600—800Pa;当入口粉尘浓度42.27g/Nm~3,排出口粉尘浓度179·66mg/hNm~3,.净化效率达99.52%,为沸腾炉除尘提供一条可行之路. 相似文献
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《Planning》2015,(11)
为研究液滴变形对荷电水雾吸附细颗粒物的影响,通过对三维空间中液滴周围细颗粒物的运动方程量纲为1化,获得影响细颗粒物运动的主要参数——斯托克斯数(Stk)和库仑数(Kc),在考虑液滴变形对电场影响的基础上,建立了静电力和气动力共同作用下不同变形状态的荷电液滴周围细颗粒物运动的数值模型,通过追踪三维空间中细颗粒物的运动轨迹来描述荷电单液滴的除尘过程。结果表明:Stk的增大能促进惯性碰撞沉积,而Kc的增大能促进静电沉积;液滴变形为长椭球且它的长轴与气流运动方向平行时,会削弱惯性碰撞沉积,但对静电沉积有一定促进作用,而长轴与气流运动方向垂直时,情况则完全相反;液滴变形率越大,不同角度下液滴变形对沉积的影响作用越强。 相似文献
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The effect of polydisperse water droplet size distribution on the burning behavior and extinction condition of counterflow spray diffusion flame was investigated experimentally in this study. N-heptane as liquid fuel spray and nitrogen as a carrier gas were introduced from the lower duct while water spray and oxidizer consisting of oxygen and nitrogen was issued from the upper duct. The burning behavior of spray flame for different fuel droplet size with and without water spray was observed and the extinction condition of counterflow spray diffusion flame was characterized by oxygen concentration at extinction. The results show that the minimum value of oxygen concentration at extinction for counterflow spray diffusion flame with water spray is similar to the extinction condition without water spray for higher mean droplet diameter of water. The minimum value of oxygen concentration at extinction shifts to the smaller fuel droplet size when decreasing the water droplet size. For fuel droplet size higher than 48 μm, the optimum of water droplet size for suppressing counterflow spray diffusion flame was smaller than gaseous flame. The explanation of optimum water droplet size based on the coupled effect of Stokes number and vaporization Damköhler number can be used for prediction of the effectiveness of water droplet on the suppression of counterflow spray diffusion flame. 相似文献
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The present article aims at developing simple realistic models in order to describe the gaseous removal process of SO(2) by absorption with and without chemical reaction in spray towers. Effects of droplet size, droplet velocity, superficial gas velocity, liquid flow rate and tower height on the performance of such a system are theoretically predicted. Model calculations bring out some very interesting facets of gas scrubbing as functions of droplet diameter and velocity. Four distinct regimes, viz. droplet lean, dense droplet, rigid droplet and droplet inertia controlling regimes, are found important in spray scrubbing process. Model calculation also elucidates the existence of rigid droplet (sphere) for a distinct droplet size at a specific droplet velocity. Theoretical considerations reveal that best performance can be achieved in the droplet inertia-controlling regime. Effect of turbulence on scrubbing is also considered for modeling. The model development and experimental data are limited to use of water-soluble alkaline scrubbing. However, the predicted values agree reasonably well with the available experimental data at lower gas and liquid flow rates for relatively smaller droplets. Models can also be applied to any gas-liquid spray absorption process subject to the assumptions and conditions necessary to describe the specific physico-chemical hydrodynamics of the system. However, incorporation of various droplet interactions can further refine the models for better prediction of removal efficiency. 相似文献
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针对城镇集中供热锅炉房的特点,提出使用钙基脱硫剂的双液位喷射鼓泡烟气脱硫除尘装置。介绍了双液位喷射鼓泡烟气脱硫除尘装置的脱硫机理,实验分析了脱硫剂pH值对脱硫效率的影响、冲击管出口烟气流速对烟气压力降的影响,探讨了该脱硫装置的工业应用。使用钙基为脱硫剂的双液位喷射鼓泡烟气脱硫除尘装置,可减缓设备结垢,降低脱硫除尘成本,实现脱硫产物随灰渣一同处理。 相似文献
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Evaluation on speciation and removal efficiencies of mercury from municipal solid waste incinerators in Taiwan 总被引:2,自引:0,他引:2
Two large-scale municipal solid waste incinerators (MWIs) located in Taiwan were selected for conducting flue gas sampling to determine the chemical speciation of mercury by both USEPA Method 29 and Ontario Hydro Method (OHM). In addition, the emission characteristics and removal efficiencies of mercury were evaluated via isokinetic sampling of flue gas upstream and downstream of APCDs. Results indicated that the average removal efficiencies of Hg for MWI-A and MWI-B were 29.56 and 44.70%, respectively. In terms of mercury speciation by USEPA Method 29 and Ontario Hydro Method (OHM), oxidized mercury (Hg2+), in the flue gas was predominant at the inlet of APCD for both incinerators. Less than 30% of mercury in the flue gas existed in the elemental form (Hg0) at APCD inlet. Mercury emitted from the stack also predominated as a form of Hg2+ in MWI-A. Approximately 90% of total mercury emission from the stack existed in the form of Hg2+ for MWI-A. Due to the higher removal efficiency of soluble mercury (Hg2+) in wet scrubber, less total Hg was actually emitted from MWI-B than MWI-A. Regarding the removal efficiency of Hg0 in the flue gas, the APCDs of MWI-A (DSI + FF) had a higher removal efficiency than that of MWI-B (ESP + WS) possibly due to the reduction of Hg2+ which occurred in the wet scrubber. 相似文献
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锅炉烟气脱硫除尘系统改造与存在问题分析 总被引:2,自引:1,他引:1
为保证烟气排放达标,将锅炉原除尘系统改造成脱硫除尘系统。内容包括:缩小文丘里除尘器喉管尺寸,以提高烟气流速;在水膜除尘器内部增设3层旋流板和1层除雾板;改造脱硫除尘液系统,使用 pH 值为8~10的脱硫除尘液(NaOH 溶液);增设脱硫除尘液 pH 值计反馈自控装置。经过改造后,烟气的烟尘、SO_2含量符合要求。对改造后烟气带水等问题进行了分析,提出解决方法。 相似文献
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大功率雾状水消防装备--涡喷消防车 总被引:2,自引:2,他引:2
利用喷射功率达4000kW的航空涡轮喷气发动机产生的大流量、高流速气体射流,与大流量的水射流混合,形成高流速“气体一水雾两相射流”的涡喷消防车,使雾状水的喷射距离大幅度增加,将大流量水雾射流或轻水泡沫微珠射流沿水平方向快速射入火焰中。分析了涡喷消防车的工作原理及雾状水消防车喷射功率大、控制火势能力强、灭火速度快的特点。 相似文献
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Partitioning of PCDD/F (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran) congeners between gaseous and particulate phases and removal efficiencies of the existing air pollution control devices (APCDs) for PCDD/Fs at two large-scale municipal waste incinerators (MWIs) in Taiwan are evaluated via stack sampling and analysis. Two MWIs investigated are equipped with activated carbon injection (ACI) and selective catalytic reduction system (SCR) as major PCDD/F control devices, respectively. The average PCDD/F concentrations of stack gases are 2.35 and 1.49 ng/N m(3), and the international toxic equivalent quantity (TEQ) are 0.17 and 0.043 ng TEQ/N m(3) in MWI-A and MWI-B, respectively. The average removal efficiency of PCDD/Fs achieved with ACI+BF (bag filters) reaches 95% (MWI-A) while that achieved with the WS (wet scrubber)+SCR system reaches 99% (MWI-B). The results obtained on gas/particulate partitioning in flue gases indicate that particulate-phase PCDD/Fs accounted for 27.7% and 24.7% of the total PCDD/F concentrations at the outlets of cyclone (CY) and electrostatic precipitator (EP) for MWI-A and MWI-B, respectively. But the gas/particulate partitioning in flue gas after PCDD/Fs control devices is quite different in two MWIs. This study also indicates that total 2,3,7,8-substituted PCDD/F discharges are 142.3 microg TEQ/ton waste for MWI-A and 98.6 microg TEQ/ton waste for MWI-B, respectively. 相似文献