操作状态下板式塔自振频率的影响因素

Influential Factors on the Natural Vibration Frequency of the Tray Column Under Operating State

操作状态下的板式塔发生自振时,板上操作介质产生额外偏心惯性力矩,影响塔体的自振频率。通过对偏心惯性力矩的分析,得到了操作状态下板式塔自振频率的影响因素。对四个板式塔的计算表明,塔板直径大的板式塔应该考虑偏心惯性力矩。直径为2.4m的板式塔,塔板直径增加一倍,塔体一阶自振频率也相应增加一倍。板上介质液面高度增加,塔体自振频率增大。液面高度增加一倍,四个板式塔的一阶和八阶自振频率最大增加分别13.2%和16.2%。板上介质密度增加使塔体的各阶自振频率减小,长径比为13.5的板式塔,介质密度增加一倍,塔体自振频率减小50%。对结构相同的板式塔,操作介质密度对高阶自振频率的影响大于低阶自振频率。

When the tray column under operating state occurs natural vibration,the operating liquid on the tray will generate additional eccentric inertia moment that affects the natural frequency of the column.The factors affecting the natural frequency of the tray column under operating conditions are obtained by analyzing the eccentric inertia moment. The calculation of the four tray columns shows that the tray column with large tray diameter should consider the eccentric moment of inertia. The tray column with a diameter of 2.4 m doubles the diameter of the tray and the first-order natural frequency of the column is doubled accordingly.The natural vibration frequency of the tray column increases with the increase of the liquid level of the medium on the tray.The first and eighth natural frequencies of four tray columns increased by 13.2% and 16.2% respectively when the liquid level height doubled.The increase in liquid density on the plate reduces the natural frequency of each step of the column.The density of the tray column with a length to diameter ratio of 13.5 is doubled,and the natural vibration frequency of the tower is reduced by 50%.The operating medium density of the same plate tower has a greater influence on the highorder natural frequency than the low-order natural frequency.