Design of a new external plugging device with permanent magnetic positioning and adaptive airbag

With the development of the process industry, the leakage accidents of hazardous chemical materials are frequent in the process of storage and transportation, and the quick and effective disposal of the leakage points is of vital importance. It is difficult to plug the leakage in the complex curved surface areas of welds on large pipelines and storage tanks. To solve this problem, a quick plugging device was developed based on the fast positioning of permanent magnetic mechanism, combined with the adaptive airbag and diversion and pressure relief channel. Thus, the adaptive emergency plugging of the leakage point on the complex curved surface of the large curvature radius is realized. The finite element models were established for the flexible airbag plugging method and the conventional top pressure plugging method respectively, to perform simulation analysis on the pressure distribution at the plugging contact area around the leakage point of welds on the large storage tank while two methods were used. It is shown that when the flexible airbag plugging method is used for emergency plugging, an ideal contact area with uniform pressure is formed around the leakage point, so as to reduce effectively the stress concentration caused by the local deformation of the rubber when the conventional top pressure plugging method is adopted. It is demonstrated that the flexible airbag plugging method is better in adaptive performance to curved surface plugging and higher in the stability and reliability of emergency plugging.