On the effect of venting large vessels with mass inert panels

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• 作者：Hö ; chst ; Siegfried ; Leuckel ; Wolfgang
• 关键词：vented explosion ; vent panel inertia ; turbulence
• 刊名：Journal of Loss Prevention in the Process Industries
• 出版年：1998
• 出版时间：March, 1998
• 年：1998
• 卷：11
• 期：2
• 页码：89-97
• 全文大小：388 K

文摘

A numerical analysis indicated that in some situations venting by rather heavy venting devices such as panels or explosion doors will lead to substantial increase of the peak pressure in the considered enclosure compared to venting with burst disks or membranes of negligible mass. Vent sizing guidelines like the VDI 3673 consider a vent capability of explosion doors which has to be tested prior to their use. To study the effect of mass inertia of explosion doors or panels moved by translation, a set of experiments was carried out in a 50 m³ silo with a height to diameter ratio H/D=4. The experiments showed, however, partially unexpected results. The peak pressure p_red increased when changing membranes with inert devices (turbulent mixtures). When the mass of the devices was varied, no variation of p_red was detected, though it could be demonstrated that the time necessary for full opening of the vent increased with higher mass. When venting with inert devices (quiescent gas mixtures at the instant of ignition), there are even situations which led to lower explosion pressures compared with membrane venting. Panels moved by translation are faster than explosion doors, but the flow through the vent seems to be less disturbed during venting in the case of explosion doors. The effect of pressure generation and flame front propagation during a vented explosion is dominated by conditions other than the mass of the devices, especially with the turbulence level of the mixture at the instant of ignition.