Analysis And Research On Explosion Accident Of Pressure Vessels With Quick-Opening Gate

Pressure vessel with quick-opening door is one common kind of the pressure vessel, whose safe operation relates to safety of people’s life and property. Accounting for one quarter of domestic explosion accident on pressure vessel, the current situation on security of quick-open-door pressure vessel is not optimistic. In order to enhance the safety of pressure vessel operation, this essay analyzes and researches into explosion accident of quick-open-door pressure vessel.An investigation on quick-open-door pressure vessel was made, in which its security situation was analyzed. The explosion accident data was collected. The cause was analyzed from an aspect of structure and interlock device on typical quick-open-door structure (tooth-locked and parallel structure). The result shows that during practical operation, the safety interlock failure, faulty operation, and safety interlock without installation happen frequently. Under these circumstances, explosion accidents are mainly caused by increasing pressure due to low gear engagement degree, and gate opening due to residual pressure. Furthermore, clamping and tooth-lock structure are the main type of structure among explosion accident.Referring to increasing pressure due to low gear engagement degree, in this article, two test vessels are simulated and analyzed in an experiment where finite element analysis is used to discuss the supporting capability of low gear engagement. The result shows that with decrease of gear engagement, the capability declines and descent rate accelerates as gear engagement degree reaches to a certain value. Besides, stress is centralized, and fatigue endurance of equipment is shortened. In former case, pressures increase as a result of low engagement degree. Once capability of equipment is overloaded, the quick-opening closure would be unveiled. In the latter case, the latch might be broken. Both would lead to explosion.Concerning the gate opening due to residual pressure, explosion consequences of two vessels are tested when covers are unveiled resulting from different residual pressure (0.01-0.08MPa). A law is concluded that the lifting height of gate closure changes linearly with residual pressure. Corresponding numerical value is analyzed on simulation. The result shows that for1#and2#test vessel, the energy affecting on gate cover accounts for1%to2%of total explosive energy when residual pressure causes explosion. If residual pressure can be controlled below0.02MPa, the gate opens safely.Based on research above, precaution measures and requirements about typical quick-opening pressure vessel are proposed in this essay, from the aspects of design, manufacture, installation, operation, management, and inspection etc.