宽间距长芒刺静电除尘技术的应用

宽间距长芒刺静电除尘技术是国家“九五”科技攻关课题所取得的成果之一。由于采用宽间距、长芒刺放电极结构和极板涂敷特种防腐涂层 ,降低金属材料消耗的同时 ,降低了宽间距电除尘器电压工作范围 ,避免了使用超高压电源所致的绝缘难题 ,大大减少了静电除尘器的初期投资。笔者将该成果应用于某水泥厂生料磨系统 ,现场使用效果表明 ,该除尘技术不仅可有效改善作业环境 ,且工作电流、电压稳定 ,收尘效率高 ,设备阻力低 ,运转稳定可靠。     

Test methodology for determining the incendiary nature and electrostatic discharge characteristics of plastic surfaces

This experimental study was originally designed to quantify the electrostatic characteristics of offshore grade fiberglass reinforced plastic (FRP) pipes [Dastidar, A. G., Dahn, C. J., Cole, B. W., & Lo, K. H. (2005a). Electrostatic characteristics of FRP pipes. In Fourth international conference on composite materials for offshore operation, Houston, TX, Oct 4–6, 2005]. Discharge energies were measured from the sample surfaces for each test condition after an aggressive corona charging of up to −40 kV. While the measured values of total discharge energy were relatively high for some samples, the energy in the first peak was significantly lower. The first peak energy is thought to be the most significant measure in establishing the potential for incendive events.

To further quantify the incendive potential of discharges from FRP pipes, a unique test method was developed [Dastidar, A. G., Dahn, C. J., Cole, B. W., & Lo, K. H., (2005b). Incendiary nature and electrostatic discharge characteristics of FRP pipes. In Fourth international conference on composite materials for offshore operation, Houston, TX, Oct 4–6, 2005]. The methodology has been expanded to include other FRP components. This paper describes the test method and the test results obtained for testing several FRP structures and materials (pipes, grill work, railing etc.). The significance of the experimental results to industry is also discussed.     

燃煤电厂烟气降温过程中多环芳烃分布特征

分别以燃用褐煤与烟煤无烟煤的2个电厂为例,研究2个电厂烟气降温过程中多环芳烃的分布及转化特征。研究表明,萘、菲、苯并[a]蒽和苯并[a]芘4种多环芳烃在烟气降温过程中呈过渡分子状态,在适当的条件下,存在相互转化的可能性;萘、菲、苯并[a]蒽和苯并[a]芘在不同的电厂随飞灰粒径变化所表现出来的吸附特性不同,颗粒的粒度影响多环芳烃的形成与吸附。在烟气降温过程中飞灰表面吸附的萘、菲、苯并[a]蒽和苯并[a]芘含量随着飞灰粒径的变小呈现出逐渐增加的趋势。     

带电细水雾的灭火实验研究

利用静电感应原理,设计了使细水雾强制带电的感应荷电装置,进行了带电细水雾的灭火实验研究。为研究带电细水雾的灭火效率,在受限空间内,采用小尺度实验方法,通过改变电压的极性和大小、针-环状电极的半径及其距伞罩电极之间的距离,分析对灭火时间和热电偶温度变化的影响。结果表明:带电细水雾比普通细水雾能更迅速地降低火焰温度、熄灭火焰,荷负电的细水雾比荷正电的细水雾具有更好的抑制效果,随着电压的增大、针-环状电极半径及两电极间距的减小,灭火效能提高,熄灭时间减少。     

提高电除尘器除尘效率措施的研究进展

电除尘器在粉尘治理领域发挥着极其重要的作用.简要介绍了影响电除尘器除尘效率的主要因素.综述了近年来提高电除尘器效率措施的研究进展.着重介绍了几种新型电除尘器的除尘机制及除尘试验结果,评论了其除尘性能和应用前景,并对进一步的研究方向提出了看法.     

隧道电除尘器的应用及其安装计算

介绍了电除尘器在公路长隧道中的应用，对隧道电除尘器在隧道中的安装位置和台数进行了公式推导，并给出了应用实例。     

Brilliant red X-3B uptake by a novel polycyclodextrin-modified magnetic cationic hydrogel: Performance, kinetics and mechanism

A novel polycyclodextrin-modified magnetic cationic hydrogel (PCD-MCH) was developed and its performance, kinetics and mechanism for the removal of reactive brilliant red X-3B (X-3B) were studied. The results showed that the zeta-potential of PCD-MCH was 32.8 to 16.7 mV at pH 3.0–10.5. The maximum X-3B adsorption capacity of PCD-MCH was 2792.3 mg/g. The adsorption kinetics could be well-described by the Weber–Morris model and the homogeneous surface diffusion model (HSDM). Diffusion stages corresponding to surface or film diffusion, intra-particle or wide mesopore diffusion, and narrow mesopore/micropore diffusion occurred at 0–120, 120–480 and 480–1200 min, respectively. The latter two diffusion stages were rate-controlling for X-3B adsorption kinetics. At the initial X-3B concentration of 600 mg/L, the diffusion coefficient (D_s) and external mass transfer coefficient in the liquid phase (k_F) were 3 × 10^?11 cm²/min and 4.68 × 10^?6 cm/min, respectively. X-3B approaching the center of PCD-MCH particles could be observed at 360 min. At the end of the third diffusion stage, the C_p at q/q_e = 0 was 45.20 mg/L, which was close to the homogeneous C_p value of 46 mg/L along the radius of PCD-MCH particles. At pH 3.0–10.0, PCD-MCH showed stable X-3B adsorption capacities. After five regeneration-reuse cycles, the residual adsorption capacity of regenerated PCD-MCH was higher than 892.7 mg/g. The corresponding adsorption mechanism was identified as involving electrostatic interactions, cyclodextrin cavities and hydrogen bonds, of which cyclodextrin cavities showed prominent capture performance towards dye molecules through the formation of inclusion complexes.     

新型电除尘器控制与节能技术

普通电除尘器的控制采用固定的火花频率控制方式以及低压控制,不能随工况变化而改变,所以能耗大,效果差。新型电除尘器控制器采用火花电平跟踪、间隙供电、降功率振打等技术,有利于提高电除尘器收尘效率,降低粉尘排放,大幅度降低电能消耗。通过对某发电机组电除尘器40台高压控制柜进行控制技术及节能改造,证明新型电除尘器控制技术在保证效率的基础上可节电60﹪左右。     

Electrostatic ignition of sensitive flammable mixtures: Is charge generation due to bubble bursting in aqueous solutions a credible hazard?

Experiments have been conducted to gain insight into the credibility of sparging aqueous solutions as an electrostatic ignition hazard for sensitive hydrogen/air or fuel/oxygen mixtures (Minimum Ignition Energies of ∼0.017 mJ and ∼0.002 mJ, respectively, compared to ∼0.25 mJ for hydrocarbon/air mixtures). Tests performed in a 0.5 m³ ullage produced electric field strengths between 125 and 560 V m⁻¹ for air flows of 5–60 l min⁻¹, respectively, comprised of 2–4 mm diameter bubbles. Field strength can be related to the space charge and fitting to an exponential accumulation curve enabled the charge generation rate from the air flows to be estimated. This was observed to be directly proportional to the air flow and its magnitude was consistent with literature data for bubble bursts. The charge accumulation observed at laboratory scale would not be a cause for concern. On the basis of a simple model, the charge accumulation in a 27 m³ ullage was predicted for a range of air flows. It is apparent from such calculations that ignition of hydrocarbon/air mixtures would not be expected. However, it would seem possible that field strengths might be sufficient to cause a risk of incendive spark or corona discharges in moderately sized vessels with sensitive flammable mixtures.     

KJF-01型室内空气净化器的实验研究

将高压静电场除尘杀菌、活性炭吸附光催化分解等技术集成一体 , 开发高效空气净化技术和空气净化器,并进行污染物净化实验。结果表明,该集成技术对空气中颗粒物、二甲苯和甲醛等污染物均具有很高的净化效率;气态污染物净化时,初期以活性炭吸附为主,后期以光催化分解为主;活性炭吸附具有选择性,吸附二甲苯速度比甲醛快。