Sludge accumulated inside a fluid-flowing pipe used in a chemical or semiconductor processing factory should be periodically removed to avoid flow blockage that increases undesirable pressure inside the pipe. Accordingly, it is common practice to periodically dismantle a pipe system, clean up the accumulate sludge, and reassemble. Therefore, an accurate estimation of sludge accumulation in the pipe is important to minimize the halting time of a chemical process using the system. Considering the lack of a practically efficient, non-invasive method to estimate the severity of sludge accumulation without interrupting the on-going chemical process, we propose an ultrasonic, non-invasive, real-time inspection method using a pair of ultrasonic wedge transducers installed circumferentially on the outer wall of a pipe at the same axial coordinate. To detect lowly accumulated sludge, an ultrasonic wave path from a transmitting transducer via a test pipe with accumulated sludge to a receiving transducer is carefully designed. The severity of sludge accumulation can then be determined by the amplitude of the longitudinal wave picked up by another transducer installed on the other side of the wall. We performed a series of experiments with steel and PVC pipes that are partially filled with water and sludge of different heights. The experimental results confirmed the effectiveness and practical viability of the proposed inspection method.

化学或半导体加工厂使用的流体流动管道内积聚的污泥应定期清除，以避免流动阻塞，从而增加管道内不希望的压力。因此，通常的做法是定期拆除管道系统，清理积聚的污泥，然后重新组装。因此，准确估计管道中的污泥堆积对于最大限度地减少使用该系统的化学过程的停止时间很重要。考虑到缺乏一种实用的、非侵入性的方法来估计污泥堆积的严重程度而不中断正在进行的化学过程，我们提出了一种使用安装的一对超声波楔形换能器的超声波、非侵入性、实时检测方法在同一轴向坐标的管道外壁圆周上。为了检测低沉积污泥，精心设计了从发射换能器通过带有沉积污泥的试管到接收换能器的超声波路径。然后可以通过安装在墙另一侧的另一个传感器拾取的纵波的幅度来确定污泥堆积的严重程度。我们对部分填充有不同高度的水和污泥的钢和 PVC 管道进行了一系列实验。实验结果证实了所提出的检测方法的有效性和实际可行性。然后可以通过安装在墙另一侧的另一个传感器拾取的纵波的幅度来确定污泥堆积的严重程度。我们对部分填充有不同高度的水和污泥的钢和 PVC 管道进行了一系列实验。实验结果证实了所提出的检测方法的有效性和实际可行性。然后可以通过安装在墙另一侧的另一个传感器拾取的纵波的幅度来确定污泥堆积的严重程度。我们对部分填充有不同高度的水和污泥的钢和 PVC 管道进行了一系列实验。实验结果证实了所提出的检测方法的有效性和实际可行性。