شبیه‌سازی اثر تنش برشی امواج فراصوت هدایت شده در رسوب‌زدایی لوله 2 اینچ فولادی

Descaling in piping systems and heat exchangers is one of the key challenges faced by process industries. The use of high-power ultrasound as a novel, non-chemical, and cavitation-free method has attracted attention due to its ability to generate shear stresses and localized vibrations at the interface between the scale and the inner wall of the pipe.
In this study, a 2” diameter steel pipe, covered by scale layers of 0.5 mm and 1 mm thickness, is analyzed in the frequency range of 30–40 kHz using the finite element method. By extracting the L(0,1) mode followed by dispersion curve analysis, the appropriate wavelength and width of the holding fixture are determined. Then, a high-power ultrasonic transducer with a resonant frequency of 35.66 kHz is designed, and the assembly of the pipe, transducer, and holding fixture is analyzed in the frequency domain.
The results show that increasing the scale thickness causes a slight reduction in the resonant frequency and a significant decrease in the shear stress effect generated by high-power ultrasonic waves. Moreover, examining configurations with one, two, four, and six transducers around the pipe reveals that for a 0.5 mm scale layer and a single transducer, the maximum shear stress reaches approximately 7.6 MPa at a frequency of 33.35 kHz. Therefore, this method can be used to determine the threshold for detachment of scale from the pipe wall.