乙炔气瓶爆炸的原因分析11

An acetylene cylinder explosion:A most probable

cause analysis q

John W.H.Price *

Mechanical Engineering Department,Monash University,PO Box 197,Caulfield East,Vic.3145,Australia

Received 12July 2004;accepted 4April 2005

Available online 15September 2005

Abstract

This paper considers the explosion of an acetylene gas cylinder,which occurred in 1993in Sydney.The failure caused severe fragmentation of the cylinder and resulted in a fatality and property damage.This failure is outstanding in two respects:the violence of the failure which occurred and the fact that the explosion occurred where there were no appar-ent ignition sources present and several days,possibly weeks after filling.There is no other recorded failure of this type in the modern history of acetylene cylinder traffic.

The paper describes the failure and the circumstances surrounding it,examines the nature of the explosion which occurred and seeks an explanation of the events.Since there is no physical evidence remaining of how the failure occurred,the analysis concentrates on an evaluation of the most probable cause of the incident.

Ó2005Elsevier Ltd.All rights reserved.

Keywords:Acetylene cylinder;Explosion;Fragmentation;Most probable cause analysis

1.Introduction

1.1.The acetylene gas cylinder explosion

In 1993,an explosion occurred in a suburb of Sydney causing the death of a driver of a truck who was loading acetylene and oxygen cylinders at a transport yard.The force of the blast caused damage to build-ings and nearby equipments.Fragments were found up to 200m away [1].

1350-6307/$-see front matter Ó2005Elsevier Ltd.All rights reserved.doi:10.1016/j.engfailanal.2005.04.014

q

Paper presented at the First International Conference on Engineering Failure Analysis (Lisbon,Portugal,12–14July 2004).*Tel.:+61399032868;fax:+61399032766.

E-mail address:john.price@.au

.

Engineering Failure Analysis 13(2006)

705–715

/locate/engfailanal

During site investigations,it became evident that the explosion was related to the failure of a seamless carbon steel acetylene cylinder,which was being returned to a ship after delivery from thefilling plant three days earlier.The cylinder had fragmented violently,the fragments caused rupture of other acetylene and oxygen cylinders and were the cause of impact damage in the surrounding area.Following the incident, there werefires and pressure wave damage to surrounding buildings and equipments.Nearly200fragments of the cylinder were collected,but accounted for only about half the mass of the original vessel.

This paper discusses the phenomena involved in this kind of loading and proposes theoretical ap-proaches designed to extract information about the nature of the incident,which occurred in the cylinder.

1.2.The cylinder

The cylinder which exploded was one of a group of imported seamless steel cylinders,which are used on ships(see Fig.1).The cylinders have a design with an outside diameter of229mm and a cylindrical length of1.22m with a specified wall thickness of4.72mm minimum in the cylindrical section.The steel for man-ufacture has a specified yieldð^U yÞof235MPa,UTS411MPa and elongation of14%.Manufacture from correct alloys was confirmed on retrieved fragments.

The designfilling pressure for the cylinder is1.5MPa and its internal volume is about421.When full, the cylinder contains approximately16l of acetone,6.2kg of acetylene(depending on temperature)and 9.2kg of porous mass.Total mass content is about70kg.

The thin wall formula for a cylinder gives a minimum required thickness of0.71mm.The specified thick-ness of the cylinders is4.72and the actual thickness is6.1mm.A similar shaped cylinder is also in use for oxygen traffic,where the design pressure is typically15MPa.In oxygen service,the cylinder isfitted with a

different valve system though the cylinder itself always has a right hand screw

thread.

Fig.1.A cylinder of the type which failed.

706J.W.H.Price/Engineering Failure Analysis13(2006)705–715