裂解气洗涤塔简体化学爆炸剖析

针对某合成气装置洗涤塔筒体爆炸的重大事故。计算了裂解气的理论爆炸极限、最大爆炸压力及筒体材料的爆炸压力。分析了爆炸前后的筒体材料的化学成分及金相组织，得出了爆炸事故的原因。提出了以人为本强化管理、加大安全投入、增设监控和紧急事故放空装置等防范措施。     

液氮容器爆炸原因分析

简单介绍了一起YDZ-100型液氮容器罐爆炸事故的事故经过,经过检测,认定液氮容器的爆炸原因为内筒体液氮泄漏到夹层中并在短时间内迅速汽化,从而导致夹层空间压力升高,压力升高至一定极限致容器外筒体发生爆炸。针对液氮容器的爆炸原因,从液氮的理化特性、贮存使用和注意事项等方面阐述了安全使用的基本知识。     

高压甲铵洗涤器防爆筒体破裂原因分析及预防措施

介绍了尿素装置高压甲铵洗涤器的结构及工作原理,阐述了2起高压甲铵洗涤器筒体破裂事故的经过并详细分析了事故原因。为了防止开停车阶段和其他非正常生产状态下高压甲铵洗涤器筒体破裂事故的发生,提出了相应的防范措施。     

科技简讯

MQY型球磨机的改进MQY型球磨机是新型气化炉装置中煤浆制备工序的核心设备。为了防止筒体的磨损,在其内壁固定了耐磨橡胶;其电机和筒体的轴承均为静压滑动轴承,在轴瓦的内壁衬有巴氏合金。根据多年来电机及筒体发生的烧瓦事故及橡胶压条存在的缺陷,认真分析了原因,并进行了有效     

MQY型球磨机的改进

MQY型球磨机是新型气化炉装置中煤浆制备工序的核心设备。为了防止筒体的磨损，在其内壁固定了耐磨橡胶；其电机和筒体的轴承均为静压滑动轴承，在轴瓦的内壁衬有巴氏合金。根据多年来电机及筒体发生的烧瓦事故及橡胶压条存在的缺陷，认真分析了原因，并进行了有效的改进。     

二甲苯塔水压试验泄漏原因分析

针对某石化厂二甲苯塔水压试验时发生泄漏，出现筒体母材开裂和支撑圈断裂的现象，从设备的材料、设计和试压三方面来寻找原因。通过材料的理化试验排除了材料的原因；通过强度计算和强度校核排除了设计上的原因；通过分析支撑圈断裂和筒体母材塑性变形时的应力水平，推算出当时塔内所受的试验压力至少达到设计要求试验压力的2倍，从而确定了试压时超压是二甲苯塔发生泄漏的主要原因。针对这次事故，对大型设备水压试验提出了几点建议。     

苯酐生产反应器的火灾、爆炸危险性分析与评价

分析了反应器火灾爆炸事故发生的原因，对火灾爆炸产生的温度、压力及引起冲击波作定量的分析，提出了针对性的防火防爆措施和技术，对反应器泄压装置合理设计具有一定实用指导意义．     

HDPE干燥机滚圈连接方式的改进分析

对扬子石化低压高密度聚乙烯装置C线的M-3302干燥机滚圈与筒体及驱动齿圈与筒体连接方式和结构进行了优化设计,并从各自的材料上进行了改进和优化,提高了干燥机的装配精度,极大地提高了运转平稳性、可靠性,延长了检修周期。     

一起压力容器爆炸事故的剖析

简述了一起压力容器爆炸事故的经过和严重后果,并从技术角度对爆炸的原因、爆炸时的压力及爆炸断裂拉力走向进行理论分析和计算,提出了预防类似事故的对策,对预防压力容器爆炸以及调查、分析压力容器爆炸事故原因具有一定的指导意义。     

ф800 mm氨合成塔外壳的损坏分析

1事故概述　氨合成塔是化肥企业合成氨高压系统的关键设备.某化肥企业合成氨生产能力为60 kt/a,在生产中1台φ800 mm氨合成塔筒体泄放孔出现合成气泄漏着火事故,因及时发现,所以紧急降压停车,未造成爆炸事故.     

Explosion hazard analysis in partially confined area

A fuel gas leak in a partially confined area creates a flammable atmosphere and gives rise to an explosion, which is one of the most common accidents in a chemical plant. Observations from accidents suggest that some explosions are caused by a quantity of fuel significantly less than the lower explosion limit (LEL) amount required to fill the whole confined area, which is attributed to inhomogeneous mixing of leaked gas. The minimum amount of leaked gas for explosion is highly dependent on the mixing degree in the area. This paper presents a method for analyzing the explosion hazard in partially confined area with very small amount of leaked gas. Based on explosion limit concentration, the Gaussian distribution model is used to estimate the minimum amount of leak which yields a specified explosion pressure. The method will help in analyzing hazards to develop new safe devices as well as for investigating accidents.     

Explosion characteristics of nano-aluminum powder-air mixtures in 20 L spherical vessels

Using 20 L spherical explosion vessel, the explosion characteristics of nano-aluminum powders with different sizes were investigated. Compared with micro-scale aluminum powders explosion, nano-powders explosion processes and mechanisms were analyzed based on the auxiliary analysis of scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The results show that the maximum explosion pressure and maximum rate of pressure rise mainly depended on the dust concentrations. With the increasing of dust concentration, the maximum explosion pressure increases gradually to the maximum when the dust concentrations below 1000 g/m³ and then the maximum explosion pressure decreased especially for the dust concentrations higher about 1250 g/m³. At the same time, the trends of maximum rate of pressure rise performed the similar rules with the dust concentrations. For the selected nano-powders, particle size change seems no obvious explosion differences. However, for micro-sized aluminum powders, explosion characteristic presents decreased change rules with the particle size increase. At the same time, the lower explosion concentration limits of aluminum powders explosion were measured and presented. Research result may have important implications for nano-sized aluminum powders utilization and safety operation.     

CFD Analysis of Dust Explosion Relief System in the Counter-Current Industrial Spray Drying Tower

The aim of the paper was to evaluate the performance of venting devices in an industrial counter-current spray tower during dust explosion using a CFD model and EN14491:2006 standard. Three-dimensional CFD simulations of dust explosion in the spray tower for six different configurations of safety vents located at the top and side walls of the dryer were carried out. In the calculations, in which dust was replaced with a flammable gas-air mixture, the following parameters of dust explosion were analyzed: reaction progress, maximum and average gas temperature, gas velocity, and pressure. Reduced pressures calculated according to EN 14991:2006 standard are close to maximum pressure obtained from CFD simulations for all analyzed spatial configurations of the safety vents, which proves that the CFD model can be used both to design explosion mitigation systems and to describe the mechanism of explosion propagation in the drying chamber. Results of the calculations allowed us to evaluate the performance of analyzed venting devices, to determine the spatial configuration and parameters of venting devices that should be installed to minimize damages of the dryer construction.     

Coal dust/air explosions in a large-scale tube

Coal dust/air mixture explosions under weak ignition conditions have been studied in a horizontal experimental tube of diameter 199 mm and length 29.6 m. The experimental tube is closed at one end and open at the downstream end. An array of 40 equally spaced dust dispersion units was used to disperse coal dust particles into the experimental tube. The coal dust/air mixture was ignited by an electric spark. A constant-temperature hot-wire anemometer was used to measure the gas velocity during the dispersion process. Kistler piezoelectric pressure sensors were used to measure the propagation of the pressure wave during the explosion process. The maximum overpressure of the coal dust explosion under the weak ignition conditions in the tube was 70 kPa and the propagation velocity of the pressure wave along the tube was approximately 370 m/s. The minimum concentration for obtaining a coal dust explosion that propagated along the tube was 120 g/m³. The suppressing effects on the coal dust explosion of two different kinds of suppressing agents have been studied.     

Flammability studies of benzene and methanol with various vapor mixing ratios at 150°C

Both benzene and methanol are important raw materials in petrochemical industries worldwide. However, with increased demand in the past few years, the fire and explosion hazards from both benzene and methanol under abnormal conditions have increased rapidly with the demand. This study investigated the flammability characteristics of a binary solution for the mixture of benzene and methanol at various vapor-mixing ratios (100/0, 75/25, 50/50, 25/75, 0/100 vol%) under 150°C, 760 and 1,520 mmHg by using a 20 Liter Spherical Explosion Vessel. Such work leads to specific safety-related property parameters, including upper explosion limit (UEL), lower explosion limit (LEL), minimum oxygen concentration (MOC), maximum explosion pressure (P _max ), maximum rate of explosion pressure rise (dP/dt) _max , and gas or vapor explosion constant (K _g ). Along with the results which show that the UEL, P_max, and K_g all increased with the pressure and oxygen concentration, a triangular flammability diagram was also established. This all serves to elucidate the potential hazards when vapors of different flammable chemicals are mixed. This paper was presented at the 2004 Korea/Japan/Taiwan Chemical Engineering Conference held at Busan, Korea between November 3 and 4, 2004.     

二氧化碳气瓶爆炸事故分析与强度计算

对一起气瓶爆炸事故进行了详细的分析,并对气瓶进行了检验和检测,得出了气瓶发生爆炸的主要原因和次要原因。     

高温乙二醇在不同水和氮气含量下爆炸极限的测定

爆炸极限不是固定不变的,它随温度、压力、含氧量、氮气含量等因素的变化而变化。利用自制爆炸容器,在高温下(260℃),改变氮气和水蒸气含量,测定乙二醇的爆炸极限,通过分析得出随着氮气和水蒸气含量的增加,乙二醇的爆炸极限不断缩小,达到一定值时,该体系不再爆炸,而进入安全区域。而水比氮气具有更加好的压缩乙二醇爆炸极限的作用。     

连通容器内预混气体泄爆过程

对甲烷-空气预混气体在连通容器内的泄爆过程进行了实验研究,与密闭容器爆炸过程进行了比较,研究了连通容器泄爆过程中压力的变化规律,分析了气体浓度和泄爆方式对连通容器泄爆过程的影响。结果表明,连通容器泄爆过程中,压力最大值通常出现在管道末端,由于震荡在球形容器内产生真空压力;与略低于化学计量比浓度相比,甲烷体积浓度略高于化学计量比浓度时,连通容器内爆炸压力增加,这种情况与单个密闭容器气体爆炸相同;两个泄爆口泄爆能较好地降低连通容器内最高爆炸压力,而仅采用一个泄爆口泄爆并不能显著降低容器内的最大爆炸压力。研究结论为工程上连通容器的泄爆安全设计提供重要参考。     

低碳钢压力容器爆破压力公式的修正

在大量Q2 35 A和 2 0R等低碳钢类容器爆破试验的基础上 ,在对低碳钢类压力容器的爆破压力进行统计分析后 ,对原有的爆破压力估算公式———Faupel公式进行了修正 ,得到更符合实验值的计算公式 ,并对其他不同直径的低碳钢类压力容器进行验证 ,具有一定的通用性