大型储罐声发射在线检测越来越得到石化行业的认可, 然而对于不同类型的储罐, 罐底声发射信号采集方法基本相同, 并未考虑储罐的结构差异。提出采用护卫传感器对拱顶储罐底板的腐蚀声发射信号进行采集的方法。通过在罐壁上布置两组传感器, 其中一组接收来自罐顶液滴撞击液面产生的声发射信号, 即护卫传感器, 另一组接收来自罐底的声发射信号, 并应用特定的方法有效地滤除拱顶滴液产生的干扰声信号。现场试验结果表明, 该方法能有效滤除拱顶储罐罐顶滴液产生的干扰噪声, 为后续的数据分析与处理提供了可靠的原始数据。

In-service inspection of large above-storage tanks with acoustic emission technique is accepted by petrochemical industries more and more. But the way of acoustic emission signal acquisition is nearly same for different type storage tanks while their structure differences are neglected. The way that the guard sensors are used to help acquire the corrosion acoustic emission signals from the floor of the fixed roof tank is presented. Tow group sensors are placed around the tank shell in acoustic emission inspection for the fixed roof tank. One group is used to collect the noise signals from fixed roof when liquid drops fall to the surface of tank content, i.e. guard sensor, the other group is used to collect the acoustic emission signal from the floor. A special method is adopted to filter the signals by liquid drops. In order to evaluate the performance of the method, an in-service field inspection is practiced on product oil fixed roof tank. The result of the experience shows that our method can filter the noise signals by liquid drops and provide reliable original data for acoustic emission signal processing.