木制品企业粉尘爆炸灾害与防治

分析了木制品企业发生粉尘爆炸的潜在危险性，以某木制品企业的一起木材粉尘爆炸事故为例，对事故发生的过程和原因进行了仔细分析，在此基础上从预防和防护两个方面提出了防止类似系统发生火灾及粉尘爆炸事故的措施。     

一种火炸药爆炸火球计算方法

介绍一种火炸药爆炸火球直径及温度持续时间的计算方法，可以为火炸药产生企业为防止事故发生时人员伤亡而采取必要的防护措施提供科学依据。     

油库静电危险性分析及防护

油库静电事故造成的破坏性很大,影响面也很广,其中以爆炸及火灾事故引起的后果最为严重.加强静电防护对油库安全运行是非常重要的,为防止静电引起火灾爆炸而采取的安全防护措施,对防止其他静电危害也同样有效.     

浅析煤气发生炉事故引起的一些思索

通过1台煤气发生炉爆炸事故的原因分析，提出运行中的安全防护措施．     

浅谈粉尘爆炸及预防对策

叙述了粉尘发生爆炸的条件，影响粉尘爆炸的因素及爆炸特征，从理论上和技术措施两方面提出了粉尘爆炸的预防对策，对防止和减少粉尘爆炸事故有一定的意义。     

电动机的火灾危险和防火措施

电动机是常用的电气设备之一．也是机械设备中的主要动力源．对机电系统的安全运行起主要作用、为防止电机发生重大爆炸和火灾事故．可针对起火原因，采取防火措施。     

浅谈企业个体防护用品的应用

<正>防止职业危害的措施主要有技术措施和个体防护措施。当不能采取技术措施或采取的技术措施不能完全消除生产过程中的危险和有害因素或达不到国家标准和有关规定时,最常见的防护措施是佩戴适合的个体防护用品,职工在作业过程中使用的个体防护用品则是预防和控制职业病危害的最后一道防线。科学配置、合理维护个体防护用品,切实加强其使用     

一种火炸药爆炸火球计算方法

介绍一种火炸药爆炸火球直径及温度持续时间的计算方法,可以为火炸药产生企业为防止事故发生时人员伤亡而采取必要的防护措施提供科学依据。     

专业劳动防护鞋安全性能及选用浅析

<正>劳动者在生产、建设、运输、服务、勘探或科学研究中,往往会由于作业环境条件恶劣或因脚的防护装备缺乏、存在缺陷等原因造成触电、静电感应、爆炸、烧伤、冻伤、腐蚀、打击、坠落、绞辗和刺割等急、慢性危害或工伤事故,严重的甚至危及生命。国家早已制定了劳动保护法规,采取各种劳动卫生和安全技术措施,来改善劳动条件,预防职业病发生。而穿用个人防护鞋就是措施之一。虽说这只是一种预防性的辅助措施,但当劳动条件差,危害因素大或集体防护措施起不到防护作用时,防护鞋即变身为主要的防护措施。本文围绕防护鞋的方方面面作一大概阐述,试     

常用防火防爆技术简介

防火防爆是企业安全生产中主要的安全防范技术措施。从理论上讲,防止火灾爆炸事故发生须防止和限制可燃可爆系统的形成;当燃烧爆炸物质不可避免地出现时,要尽可能地消除和或隔离各类点火源;阻止和限制火灾爆炸的蔓延扩展,尽量降低火灾爆炸事故造成的损失。但是在实践中,往往需要采取多方面的措施,以提高生产过程的安全程度,甚至还应考虑其他辅助措施,以便在发生火灾爆炸事故时减少危害程度,将损失降到最低。     

Collecting representative dust samples: A comparison of various sampling methods in underground coal mines

Former methods used in the U.S. to assess hazardous and explosible coal dust date back to the 1950s. As mining technologies advanced, so too have the hazards. Given the results of the recent coal dust particle size survey and full-scale experimental mine explosion tests, the National Institute for Occupational Safety and Health (NIOSH) recommended a new minimum standard, in the absence of background methane, of 80% total incombustible content (TIC) be required in the intake airways of bituminous coal mines, replacing the previous 65% TIC requirement. Most important to monitoring and maintaining the 80% TIC is the ability to effectively collect and analyze representative dust samples that would likely disperse and participate in dust explosion propagation. Research has shown that dust suspended on elevated surfaces is usually finer, more reactive, and more readily dispersible while floor deposits of dust are generally coarser and more difficult to disperse given the same blast of air. The roof, rib, and floor portions of the dust samples were collected and analyzed for incombustible content separately and the results were compared to a band sample of the roof, rib, and floor components. Results indicate that the roof and rib dust samples should be kept separate from floor dust samples and considered individually for analyses. The various experimental collection methods are detailed along with preferred sampling approaches that improve the detectability of potentially hazardous accumulations of explosible dust.     

爆炸事故及预防

为了促进我国的爆炸安全研究工作更深入发展,本文列出了利用爆炸激波管技术测定氢气、汽油、铝粉等可爆性物质的爆炸特性。研究表明:这些可爆性物质在一定条件都能形成破坏力极大的爆轰现象。实验确定了氢、汽油和氧混合物的可爆(轰)极限、可燃性极限、混合物临界初始压力等爆炸临界条件。控制可爆性物质的初始条件不超过其爆炸临界条件,能够防止爆轰或爆燃现象发生;添加不参加反应的物质(如氩气、氮气、水蒸汽等)能够使已达到爆炸条件的混合物阻爆。本文的数据可供有关部门参考。     

爆炸焊接的安全评估和安全防护措施

根据爆炸焊接的装药特点,对爆炸焊接炸药的使用、爆炸产生的地震波、毒气、噪音等的安全性进行了分析,给出了定量的计算公式,同时还针对不同的爆破危害,提出了相应的安全防护措施     

Does your facility have a dust problem: Methods for evaluating dust explosion hazards

The hazards of dust explosions prevailing in plants are dependent on a large variety of factors that include process parameters, such as pressure, temperature and flow characteristics, as well as equipment properties, such as geometry layout, the presence of moving elements, dust explosion characteristics and mitigating measures. A good dust explosion risk assessment is a thorough method involving the identification of all hazards, their probability of occurrence and the severity of potential consequences. The consequences of dust explosions are described as consequences for personnel and equipment, taking into account consequences of both primary and secondary events.While certain standards cover all the basic elements of explosion prevention and protection, systematic risk assessments and area classifications are obligatory in Europe, as required by EU ATEX and Seveso II directives. In the United States, NFPA 654 requires that the design of the fire and explosion safety provisions shall be based on a process hazard analysis of the facility, process, and the associated fire or explosion hazards. In this paper, we will demonstrate how applying such techniques as SCRAM (short-cut risk analysis method) can help identify potentially hazardous conditions and provide valuable assistance in reducing high-risk areas. The likelihood of a dust explosion is based on the ignition probability and the probability of flammable dust clouds arising. While all possible ignition sources are reviewed, the most important ones include open flames, mechanical sparks, hot surfaces, electric equipment, smoldering combustion (self-ignition) and electrostatic sparks and discharges. The probability of dust clouds arising is closely related to both process and dust dispersion properties.Factors determining the consequences of dust explosions include how frequently personnel are present, the equipment strength, implemented consequence-reducing measures and housekeeping, as risk assessment techniques demonstrate the importance of good housekeeping especially due to the enormous consequences of secondary dust explosions (despite their relatively low probability). The ignitibility and explosibility of the potential dust clouds also play a crucial role in determining the overall risk.Classes describe both the likelihood of dust explosions and their consequences, ranging from low probabilities and limited local damage, to high probability of occurrence and catastrophic damage. Acceptance criteria are determined based on the likelihood and consequence of the events. The risk assessment techniques also allow for choosing adequate risk reducing measures: both preventive and protective. Techniques for mitigating identified explosions risks include the following: bursting disks and quenching tubes, explosion suppression systems, explosion isolating systems, inerting techniques and temperature control. Advanced CFD tools (DESC) can be used to not only assess dust explosion hazards, but also provide valuable insight into protective measures, including suppression and venting.     

A review on hybrid mixture explosions: Safety parameters,explosion regimes and criteria,flame characteristics

The hybrid mixture of combustible dusts and flammable gases/vapours widely exist in various industries, including mining, petrochemical, metallurgical, textile and pharmaceutical. It may pose a higher explosion risk than gas/vapor or dust/mist explosions since the hybrid explosions can still be initiated even though both the gas and the dust concentration are lower than their lower explosion limit (LEL) values. Understanding the explosion threat of hybrid mixtures not only contributes to the inherent safety and sustainability of industrial process design, but promotes the efficiency of loss prevention and mitigation. To date, however, there is no test standard with reliable explosion criteria available to determine the safety parameters of all types of hybrid mixture explosions, nor the flame propagation and quenching mechanism or theoretical explanation behind these parameters. This review presents a state-of-the-art overview of the comprehensive understanding of hybrid mixture explosions mainly in an experimental study level; thereby, the main limitations and challenges to be faced are explored. The discussed main contents include the experimental measurement for the safety parameters of hybrid mixtures (i.e., explosion sensitivity and severity parameters) via typical test apparatuses, explosion regime and criterion of hybrid mixtures, the detailed flame propagation/quenching characteristics behind the explosion severities/sensitivities of hybrid mixtures. This work aims to summarize the essential basics of experimental studies, and to provide the perspectives based on the current research gaps to understand the explosion hazards of hybrid mixtures in-depth.     

Lower explosion limit of hybrid mixtures of burnable gas and dust

Hybrid mixtures – mixtures of burnable dusts and burnable gases – pose special problems to industries, as their combined Lower Explosion Limit (LEL) can lie below the LEL of the single substances. Different mathematical relations have been proposed by various authors in literature to predict the Lower Explosion Limit of hybrid mixtures (LEL_hybrid). The aim of this work is to prove the validity or limitations of these formulas for various combinations of dusts and gases. The experiments were executed in a standard 20 L vessel apparatus used for dust explosion testing. Permanent spark with an ignition energy of 10 J was used as ignition source. The results obtained so far show that, there are some combinations of dust and gas where the proposed mathematical formulas to predict the lower explosible limits of hybrid mixtures are not safe enough.     

浅谈提高爆炸容器使用安全性的技术措施

针对爆炸容器工作时 ,产生的爆炸冲击波、破片、有害气体、振动及噪声等危害因素 ,简述了国内外使用爆炸容器时 ,采取的一些相关安全技术措施 ;提出了将结构健康监测技术应用于爆炸容器寿命安全评估的构想     

EVA树脂粉尘/甲烷/空气杂混物爆炸特性

在20 L爆炸实验装置中,开展了3种不同中值粒径的EVA树脂粉尘/甲烷/空气所组成的杂混物爆炸特性研究,探究了甲烷浓度对粉尘爆炸下限、最大爆炸压力的影响。结果表明,尽管添加的甲烷气体浓度低于爆炸下限,仍使得粉尘爆炸下限得以降低,粒径较大的EVA III粉尘,当甲烷体积分数为1%时,爆炸下限降低约25%;粒径较小的EVA I粉尘,当混入甲烷体积分数为4%时,爆炸下限则降低80%;甲烷体积分数每增加1%,可燃粉尘最大爆炸压力上升约10%,但对于粒径较小的EVA I粉尘,当甲烷体积分数为4%时,最大爆炸压力的上升呈现突变趋势,上升近50%。     

Hybrid H2/Al dust explosions in Siwek sphere

Explosion indices and explosion behaviour of Al dust/H₂/air mixtures were studied using standard 20 l sphere. The study was motivated by an explosion hazard occurring at some accidental scenarios considered now in ITER design (International Thermonuclear Experimental Reactor). During Loss-of-Vacuum or Loss-of-Coolant Accidents (LOCA/LOVA) it is possible to form inside the ITER vacuum vessel an explosible atmosphere containing fine Be or W dusts and hydrogen. To approach the Be/H₂ explosion problem, Be dust is substituted in this study by aluminium, because of high toxicity of Be dusts. The tested dust concentrations were 100, 200, 400, 800, and 1200 g/m3; hydrogen concentrations varied from 8 to 20 vol. % with 2% step. The mixtures were ignited by a weak electric spark. Pressure evolutions were recorded during the mixture explosions. In addition, the gaseous compositions of the combustion products were measured by a quadruple mass-spectrometer. The dust was involved in the explosion process at all hydrogen and dust concentrations even at the combination ‘8%/100 g/m3’. In all the other tests the explosion overpressures and the pressure rise rates were noticeably higher than those relevant to pure H₂/air mixtures and pure Al dust/air mixtures. At lower hybrid fuel concentrations the mixture exploded in two steps: first hydrogen explosion followed by a clearly separated Al dust explosion. With rising concentrations, the two-phase explosion regime transits to a single-phase regime where the two fuel components exploded together as a single fuel. In this regime both the hybrid explosion pressures and pressure rise rates are higher than either H₂ or Al ones. The two fuels compete for the oxygen; the higher the dust concentration, the more part of O2 it consumes (and the more H₂ remains in the combustion products). The test results are used to support DUST3D CFD code developed at KIT to model LOCA or LOVA scenarios in ITER.     

Classification of dispersibility for combustible dust based on Hausner ratio

Mixing of combustible dust and oxidant is one of five essential prerequisites in the dust explosion pentagon, requiring that particles originally in mutual contact within the deposits be separated and suspended in the air. However, dust dispersion never proceeds with 100% efficiency, with inevitable particle agglomeration, and an inherent trend toward settling out of suspension. Dispersibility is defined to describe the ease of dispersion of a dust and the tendency of the particulate matter to remain airborne once a dust cloud has been formed. Pioneers made contributions to classify dust dispersibility by introducing dustiness group (DG), dustability index (DI), NIOSH dispersion chamber and in-situ particle size analysis. Issues remained including the difficulty in comparing results from different methods, as well as the availability of some high-tech testing apparatus.This study aims to provide a quick and universal testing method to estimate the dispersion property of combustible dust. A new dispersibility classification was developed based on dimensionless numbers Hausner ratio and Archimedes number. Four dispersibility classes (DCs) were proposed from one to four, with a larger number meaning better dispersibility. Results for more than a dozen dust samples and mixtures thereof showed the new method is useful in dust explosion research. The consistency in classifying dust dispersion properties between the DC method and previous methods was good. Changes in DC well explained our earlier findings on suppressant enhanced explosion parameter (SEEP) phenomenon attributed to the improvement in dust dispersibility. Hausner ratio and Archimedes number, as easily measured parameters, can be quite advantageous to assess dust dispersibility, permitting a proper risk assessment for the formation of explosible dust clouds.