旋流除尘器尺寸参数与除尘粒径关系的研究

通过对除尘器内烟尘粒子的受力及运动分析，求出了除尘器内烟尘粒子滞留及沉降时间，从而导出了除尘临界粒径与除尘器尺寸、速度参数的关系式，为合理设计除尘器结构从而获得满意除尘效果提供了理论参考。     

旋流除尘器尺寸参数与除尘粒径关系的研究

通过对除尘器内烟尘粒子的受力及运动分析，求出了除尘器内烟尘粒子滞留及沉降时间，从而导出了除尘临界粒径与除尘器尺寸、速度参数的关系式，为合理设计除尘器结构从而获得满意除尘效果提供了理论参考。     

铝电解烟气净化系统中菱形袋式除尘器的改进

菱形袋式除尘器是铝电解烟气净化系统中的重要设备。根据实际运行情况，对菱形袋式除尘器进行了改进，取消了除尘器下部的沸腾床，实际效果很好，不仅取得了良好的环境效益还取得了较好的经济效益和社会效益。     

烟气旋风除尘器的改进

针对旋风除尘器的工作特点设计了双联旋风除尘器，使其在处理同样的风量时，除尘效率更高，内壁磨损更少，运行也更加可靠。     

冲天炉高效旋流除尘器设计

运用流体力学理论，结合试验研究，对冲天炉旋流除尘器的结构进行了系统分析，设计的旋流除尘器简单、可靠、不占地面面积、使用方便，除尘效率９２％以上。     

冲天炉高效旋流除尘器设计

运用流体力学理论，结合试验研究，对冲天炉旋流除尘器的结构进行了系统分析，设计的旋流除尘器简单、可靠、不占地面面积、使用方便，除尘效率９２％以上。     

冲天炉水幕除尘器的改进

对冲天炉水幕除尘器结构进行了技术改造，使除尘器达到了烟气流的全截面滤尘，可有效地净化冲天炉烟尘．减少对环境的污染。     

反吹风除尘器和脉冲除尘器之浅议

比较了脉冲除尘器和反吹风除尘器的优劣,以及在国内的应用过程。通过对脉冲除尘器主要影响参数的论述,得出在铝电解烟气净化中,脉冲袋式除尘器的性能优于反吹风除尘器的性能。     

氢氧化铝焙烧炉耐高温烟气金属电袋复合除尘器应用

由于氢氧化铝焙烧炉烟气固有的高温、高压、高湿、高浓度等特点，常规静电除尘器难以满足铝工业烟气排放限值的要求。传统的纤维布袋除尘器或纤维布袋电袋复合除尘器虽然除尘效率高，但无法满足高温烟气的要求。本文根据氢氧化铝焙烧炉高温烟气的特点及电除尘器的应用现状，提出采用耐高温金属滤袋与原有电除尘器相结合的电袋复合除尘器，既有效地降低了除尘后系统烟气颗粒物的含量，达到超低排放标准，又回收了烟气中夹带的氧化铝，是稳定可靠的烟气治理技术。本文以某公司氢氧化铝焙烧炉为例，详细分析了电除尘器改耐高温烟气金属电袋复合除尘器的相关设计计算、流场分析以及应用效果。     

气箱脉冲袋除尘器在铝电解含氟烟气干法净化中的应用

本文介绍了气箱脉冲袋除尘器在铝电解烟气净化工程上的成功应用。实践结果表明。在保证净化效果的前提下，采用改进型气箱脉冲袋除尘器作为净化设备．可使其一次投资、能耗、年维修费与其他型式布袋除尘器相比均有所降低。为铝电解烟气净化工程扩大了除尘器的选择范围。     

环境保护与冲天炉烟尘治理

介绍了铸造大气污染的特性和污染物排放限值,认为采用上吸排风罩和顶板微负压补风吸风系统、余热利用式双极水气热交换冷却烟气、普温袋式除尘技术以及正压脱硫技术,可有效降低冲天炉烟尘的排放量.     

PROTOOL6.0在袋式除尘自动控制系统中的应用

以一成套的袋式除尘机组为例,提出了应用PROTOOL6.0软件设计袋式除尘自动控制系统的方法,详细介绍了系统的设计、PROTOOL6.0软件通信的原理及配置,实现了控制、维护与技术管理的集成.     

Coke formation in metal dusting experiments

Selected samples of carbonaceous deposit from metal dusting corrosion have been investigated. The morphology and the internal structure were examined by light microscopy, environmental scanning electron microscopy, and energy-dispersive analysis of X-rays. Alternating structures within the carbonaceous deposits have been observed, which suggest that metal dusting is an oscillatory corrosion process. The results are discussed in the light of reported examples of oscillatory high-temperature reactions. Nonequilibrium phases have been observed, and it is speculated on their origin and influence on metal dusting. The localized character of this corrosion type is emphasized. Conclusions about the influence of oxygen in the mechanism of metal dusting are given, leading to the idea of alternating carburizing and oxidizing conditions occurring in the metal dusting process.     

一种电子束熔炼炉用高真空插板阀

介绍了一种用于电子束熔炼炉加料系统的高真空插板阀.该型插板阀采用独特的充气气囊密封结构,通过一个气动控制回路巧妙实现了对气囊充气放气的操作,是一种工作可靠、满足低泄漏率密封要求的高真空环境插板阀.同时对该型插板阀常见故障进行了分析并给出了处理措施.     

Using sonic cleaning to improve dry scrubber operation

At Noranda Aluminum, implementation of sonic cleaning has allowed the company to improve the efficiency and reliability of its shaker dust collector operation. Using this method of bag cleaning permits the use of a more efficient bag fabric and eliminates bag failures caused by abrasion of the bag at the tube sheet thimble. Bag life has increased substantially as has the efficiency of the scrubber operation. Time requirements for production personnel have been reduced as constant cleaning of the tube sheets has been eliminated. This system has become stable and reliable.     

Metal Dusting-Mechanisms and Preventions

Metal dusting attacks iron, low and high alloy steels and nickel-or cobalt-base alloys by disintegrating bulk metals and alloys into metal particles in a coke deposit. It occurs in strongly carburising gas atmospheres (carbon activity aC>1) at elevated temperatures (400℃～1000℃). This phenomenon has been studied for decades, but the detailed mechanism is still not well understood. Current methods of protection against metal dusting are either directed to the process conditions-temperature and gas composition-or to the development of a dense adherent oxide layer on the surface of the alloy by selective oxidation. However, metal dusting still occurs by carbon dissolving in the base metal via defects in the oxide scale. The research work at UNSW is aimed at determining the detailed mechanism of metal dusting of both ferritic and austenitic alloys, in particular the microprocesses of graphite deposition, nanoparticle formation and underlying metal destruction. This work was carried out using surface observation, cross-section analysis by focused ion beam and electron microscopic examination of coke deposits at different stages of the reaction. It was found that surface orientation affected carbon deposition and metal dusting at the initial stage of the reaction. Metal dusting occurred only when graphite grew into the metal interior where the volume expansion is responsible for metal disintegration and dusting. It was also found that the metal dusting process could be significantly changed by alterations in alloy chemistry. Germanium was found to affect the iron dusting process by destabilising Fe<,3>C but increasing the rate of carbon deposition and dusting, which questions the role of cementite in ferritic alloy dusting. Whilst adding copper to iron did not change the carburisation kinetics, cementite formation and coke morphology, copper alloying reduced nickel and nickel-base alloy dusting rates significantly. Application of these fundamental results to the dusting behaviour of engineering alloys is discussed.     

The influence of Metal Dusting on gas reactions

Gas composition analysis measurements have been performed in the outlet gas stream of a laboratory metal dusting test furnace in order to study the influence of metal dusting on gas reactions. This analysis has shown that carbon deposition is associated with metal dusting, i.e. the material most severely attacked by metal dusting, catalyses the formation of carbon to the largest extent. Also, metal dusting has not been seen to influence the methanation reactions. A kinetic model has been used to interpret the obtained data with respect to the catalytic activity of several high temperature materials showing that the catalytic activity of the material can vary by orders of magnitude for different reactions.     

Solid-state phase stabilities of relevance to metal dusting in coal gasifier environments

Thermochemical calculations involving some typical mixed-gas environments and temperatures of gasifiers were used to examine iron-based phase stabilities to assess the potential for metal dusting in coal gasification systems. The results indicated that Fe₃C is only stable under conditions when certain reactions are suppressed and that FeO and Fe_0.877S tend to form instead of the carbide. Assuming Fe₃C is a necessary step in the metal dusting of steels, there are therefore numerous coal gasification systems where this type of carbon-related degradation will not occur, particularly under conditions associated with higher oxygen and sulfur activities.     

Role of alloying elements in steels on metal dusting

Metal dusting of Fe-Ni-Cr alloys has been observed in industrial processes in strongly carburizing atmospheres at temperatures from 450°C to 800°C. At temperatures below 650°C the alloys are generally not able to form dense, well adherent oxide layers in spite of relatively high Cr-contents, therefore, metal dusting can take place. Already a lot of experimental work has been done to elucidate the mechanism and to compare the resistance against metal dusting for high alloy steels [1]. The intention of this study was to obtain additional information concerning the role of alloying elements and the effects of carbide precipitates in austenitic high alloy steels such as Alloy 800. The susceptibility to metal dusting was determined by measuring the metal loss under metal dusting conditions of Fe-20%Cr-32%Ni alloys modified with additions of different carbide formers (W, Mo, Nb) or oxide formers (Si, Al). The samples were exposed at 600°C in a CO-H₂-H₂O-gas mixture for repeated periods up to 500 – 1500 h. The attack by the oxidizing and carburizing atmosphere leads to the precipitation of internal carbides and metal dusting and more or less to formation of an oxide layer. In comparison to the undoped material, the addition of carbide formers retards the initiation of metal dusting attack. The additions of Si and Al seem to prevent metal dusting under the given laboratory conditions. When carbides are present at the metal surface, they affect the initial oxide growth and have a negative effect on the protectivity of scales. Very striking is the effect of Ce, this rare earth element is generally known to favour Cr-oxide formation and to improve the adherence of the oxide layer [2], but in the case of metal dusting it clearly enhances metal dusting and metal wastage.     

Ni-Cr/BN混合粉末在石墨舟中烧结时的碳化和粉化行为

采用扫描电镜、X射线衍射、差示热分析(DTA)等方法对Ni-Cr／BN混合粉末在1250℃烧结时发生的碳化和粉化行为进行了分析,借用Grabke的模型探讨了这种现象产生的原因和机理,并进行了碳化动力学的讨论,提出了预防产生这种现象的措施。