防止炸药装药和皮带输送药卷时发生传爆和殉爆的防范措施探讨

文章通过对三种工业炸药（乳化炸药、膨化硝铵炸药、改性铵油炸药）的径向殉爆距离的测试,提出了一种防止装药与包装工序皮带输送药卷发生传爆和殉爆的安全装置,并对影响殉爆距离的一些因素进行了讨论,对提高工业炸药装药与包装工序皮带输送药卷的本质安全条件,具有重要的现实意义。     

基于试验的工业雷管传输皮带殉爆距离的安全评价

由于目前对于殉爆问题没有从理论上精确地定量描述这种复杂现象的模型,因此针对工业雷管生产线中传输皮带上雷管殉爆的问题,采用升降试验的方法分别确定了100发DDNP起爆药纸壳雷管、100发DDNP起爆药铝壳雷管、100发无起爆药纸壳雷管和100发无起爆药矿用纸壳雷管殉爆安全距离,对试验方法选择的合理性进行了分析评价,对试验条件下得出的结果用于指导工业雷管生产线中传输皮带上雷管摆放的合理性进行了分析。结果表明,文章得出的雷管发生殉爆概率为0．01％时的距离值可以用于确定工业雷管生产线传输皮带上雷管之间的殉爆安全距离。对于工业雷管生产线中存在的殉爆安全问题,采用试验的方法进行评价是合理的,得出结论在工业雷管生产线实际生产过程中有推广应用价值,对提高工业雷管生产线安全性有指导意义。     

某弹药库设计方案的安全分析

对某弹药库的设计方案进行了安全分析,得到了弹药爆炸时的空气冲击波、振动、飞石等作用的安全距离及相邻库房殉爆的可能性.给出了对原设计方案的改进意见和改进后的安全距离.     

炸药的殉爆与殉爆安全距离

什么是炸药的殉爆 炸药A爆炸后,能够引起与其相距一定距离的炸药B爆炸,这种现象叫做炸药的殉爆(如图1所示)。先发生爆炸的炸药A称为主爆药,引起殉爆的炸药B称为从爆药。能引起从爆药百分之百殉爆的两炸药之间的最大距离L叫做殉爆距离;而百分之百不能引起从爆药殉爆的两炸药之间的最小距离R叫做最小不殉爆距离,或叫殉爆安全距离。殉爆安全距离大于殉爆距离。 主爆药爆炸后,其爆炸能量通过介质传递给从爆药。由于下列原因,可能引起从爆药殉爆: (1)主爆药的爆轰产物直接冲击从爆药。从爆药在炽热爆轰气团和冲击波的作用下达到起爆条件,于是…     

轻质隔爆材料的实验研究

对数十种材料的隔爆性能进行了研究。用上下法分别求出不同材料的雷管径向殉爆以及轴向殉爆的半爆距离Ｌ５０。针对材料密度小，隔爆效果好的要求，定义了一个既考虑材料密度又考虑其隔爆性能的优化参数，并以此作为判据，对实验材料进行了优选     

安装电子监控系统提高生产本质安全

一、安装电子监控系统的必要性 工业炸药包括胶状乳化炸药、粉状乳化炸药、铵梯炸药、铵梯油炸药、膨化硝铵炸药、改性铵油炸药等.工业炸药生产通常是流水线作业,物料按照工艺流程,从上道工序向下道工序流动,在途物料多,涉及人员多,特别是装药、包装工序在岗人员更多,少则十几人,多则几十人.炸药在生产过程中往往因人的不安全行为、物的不安全状态、管理上的缺陷、环境不良等因素或各种因素的同时存在,引发炸药燃烧、爆炸事故.一旦某个工序发生爆炸事故,与之相邻的工序有可能受到强大的爆炸冲击波的作用发生殉爆,甚至引发生产线整体爆炸,造成重、特大爆炸事故.     

ISO包装标准保护儿童免于受到日常用品的伤害

最近,新的ISO 13127:2012《包装–防儿童开启的包装–可再封闭的防儿童包装系统机械试验方法》标准发布实施。该新的ISO日常用品包装标准将有助于防止儿童的死亡和伤害。每天都会有儿童因为他们吞咽药品、家居清洁品或者一些DIY产品而导致死亡或生病,ISO13127:2012标准将帮助设计师和制造商确保儿童不能打开具有潜在危险的产品,从而减少这类悲剧的发生。     

爆炸危险品运输中的安全问题

由于爆炸危险品属于高能量、亚稳态的物质，自身具有爆炸性和殉爆性，其运输中的安全问题显得尤为重要。为了有效预防和减少爆炸危险品运输中事故的发生，本文运用事故致因理论中的“三圆环理论”，对爆炸危险品运输中容易引发事故的因素进行了分析，并提出了具体的防范措施。     

电气设备污闪事故的分析及对策

对电气设备的污闪及防污闪措施进行了初步探讨和分析,着重介绍了单组分RTV电力防污闪涂料的性能,为污染地区的电气设备防污闪安全运行提供一种对策可行性的选择.     

浅析周界防入侵安全技术

本文分析确定了周界安防的基本概念,阐述了周界安防在安全防范工程中的地位与作用,分析了周界防入侵安全技术在安防行业的重要性。着重对周界入侵行为和实体防护的防入侵技术进行了分析与探索,针对防范重点对象介绍了基本的防入侵技术和方法。最后对周界防入侵安全技术的应用特点和前景作了简要的总结.     

初始温度和初始压力对气体爆轰参数影响的研究

利用已有的气体爆炸模型和包含初始压力、初始温度的气体爆轰参数的计算公式,从理论上研究初始压力和初始温度对气体爆轰参数的影响情况。使用VisualBasic语言编写计算程序,将计算值与文献值进行对比,具有较好的一致性。以甲烷-空气混合物为例,计算在98000Pa,280～400K及298K,0.1～0.5MPa的气体爆轰参数。计算结果表明,初始压力一定,混合物的爆轰压随初始温度的升高而减小,爆轰波速增大;初始温度一定,混合物的爆轰压随初始压力的增大而增大,爆轰波速基本不变;在初始温度和初始压力两个影响因素中,初始压力对混合物爆轰参数的影响明显大于初始温度。     

Propagation Characteristics of Gas Explosion in Linked Vessels Based on DDT Criteria

To study the occurrence conditions and propagation characteristics of deflagration to detonation transition (DDT) in linked vessels, two typical linked vessels were investigated in this study. The DDT of the methane–air mixture under different pipe lengths and inner diameters was studied. Results showed that the CJ detonation pressure of the methane–air mixture was 1.86 MPa, and the CJ detonation velocity was 1987.4 m/s. Compared with a single pipe, the induced distance of DDT is relatively short in the linked vessels. With the increase in pipeline length, DDT is more likely to occur. Under the same pipe diameter, the DDT induction distance in the vessel–pipe–vessel structure is shorter than that in the vessel–pipe structure. With the increase in pipeline diameter, the length of the pipe required to form the DDT is reduced. For linked vessels in which detonation formed, four stages, namely, slow combustion, deflagration, deflagration to detonation, and stable detonation, occurred in the vessels. Moreover, for a pipe diameter of 60 mm and a length of 8 m, overdriven detonation occurred in the vessel–pipe–vessel structure.     

Influence of non-reactive particle cloud on heterogeneous detonation propagation

An interaction of a detonation wave propagating in the cellular detonation mode with a cloud of inert particles is investigated numerically. The analysis of results allows the regimes of propagation of the heterogeneous plane Chapman–Jouguet and cellular detonations and their suppression to be identified. The influence of various parameters of the inert cloud is demonstrated. The critical length of the cloud sufficient for detonation suppression is determined. It is shown that the disperse composition and the nonuniform distribution of particles in the cloud are important parameters affecting the detonation propagation mode.     

Regimes and critical conditions of detonation propagation in expanding channels in gas suspensions of ultrafine aluminum particles

Under study are the regimes of detonation propagation in channels with linear expansion filled with monodisperse mixtures of oxygen and ultrafine aluminum particles of various loading; the methods of numerical simulations are used. The detonation combustion of submicron aluminum particles is described within the semi-empirical model of reduced kinetics with due regard to the transition from the diffusion-limited regime of combustion to the kinetic one. Waves of both planar and developed cellular detonation are considered as initial conditions. The characteristics of the main flow regimes are obtained and described: the subcritical (detonation failure), critical (detonation failure in some part of the channel) and supercritical (continuous detonation propagation). The maps of flow regimes in suspensions of 200-nm – 400-nm particles are presented in the plane of parameters: the channel width, expansion angle. The obtained critical conditions are similar to those observed in the gas detonation. The critical channel width linearly depends on the expansion angle up to a first critical value (35°–38°). Behind the second critical value (50°), the channel width is independent on the expansion angle. Between these values, there is an interval of nonmonotonicity similar to the detonation of micro-sized suspensions of aluminum particles. The effect of particle loading on the critical conditions in poor mixtures appears in the form of a sharp increase in the critical channel width, if the mass concentration falls below 0.25.     

Numerical simulation of propane detonation in medium and large scale geometries

A modelling strategy has been developed for consequence analysis of medium and large scale gaseous detonation. The model is based on the solution of Euler equations with one-step chemistry. The Van Leer flux limited method which is a total variation diminishing scheme is used for shock capturing. Preliminary calculations were firstly conducted for small domains with fine grids which resolve the wave, relatively coarse grids which have less than 10 grids across the wave and coarse grids in which the minimum grid size is larger than the wave thickness to ensure that the reaction scheme has been properly tuned to capture the correct detonation pressure, temperature and velocity in the resolutions used in the different cases. The model was firstly tested against a medium scale detonation test in a shock tube with U-bends. Reasonably good agreement is achieved on detonation pressure and mean shock wave velocities at different measuring segments of the tube. Following the validation, the detonation of a hypothetical planar propane-air cloud is simulated. The predictions uncovered some interesting features of such large scale detonation phenomena which are of significance in the safety context, especially for accidental investigations. The findings from the present analysis are in line with the forensic evidence on damages in some historic accidents and challenges previous analysis of a major accident in which forensic evidence suggested localised detonation but was considered as the consequence of fire storms by the investigation team.     

High resolution numerical simulation of methane explosion in bend ducts

In this paper we developed a parallel code, adopting a fifth-order weighted essentially non-oscillatory (WENO) scheme with a third-order TVD Runge-Kutta time stepping method for the two-dimensional reactive Euler equations, to investigate the propagation process of methane explosion in bend ducts. In the simulations, an inverse Lax-Wendroff procedure is adopted to construct a high order boundary in order to treat the complex boundaries. The numerical results show that when the bend angle is 30° and 45°, it cannot inhibit the propagation of the detonation wave; while when the angle reaches 60° and 75°, the detonation wave finally attenuates to the shock wave. It indicates that the propagation of the detonation wave can be inhibited. Furthermore, the temperature and the pressure at the entrance of the bend are low. When the angle arrives at 90°, the detonation wave evolves into cellular detonation when it passes through the bend. When the angle is larger than 90°, the detonation wave dramatically attenuates at the diffracting point, and later some hot spots can be formed, which can ignite the combustible gas nearby. Thus the second explosion occurs and finally the detonation is formed. When the angle is larger than or equal to 90°, the temperature and the pressure at the entrance of the bend is too high that the rescue efforts in the methane explosion accidents will encounter great difficulties. Hence, the laneway with 60° and 75° bend can inhibit the propagation of the detonation wave, and the temperature and the pressure at the entrance of the bend is not too high as well. All the results above can provide an important basis for the design and optimization of the mine laneway.     

Detonation flows in aluminium particle gas suspensions,inhomogeneous in concentrations

A physical and mathematical model of the reduced kinetics is presented describing heterogeneous detonation in suspensions non-uniform in particle concentration. The model is based on the heterogeneous media approaches, semi-empirical laws of ignition and combustion, and data on the dependence of the detonation velocity on particle concentration. Formation of suboxides and incomplete combustion of aluminum are taken into account integrally. The dependence of the heat release of chemical reactions and the fraction of unburnt particles on the initial composition is determined from the solution of the stationary problem of the structure of the detonation wave. In the calculations of unsteady detonation flows, it is supposed to solve an additional equation for the spatial distribution of initial concentrations. The problems of initiation and development of cellular detonation in flat channels in suspensions of micron-sized aluminum particles are studied. Dependences of the cell size on particle concentration in uniform suspensions are determined. The flow patterns of cellular structures, the forms of the leading front, and the propagation velocities in channels with longitudinal or transversal gradients of particle concentration are analyzed.