Abstract:RESUMOTeste de Impacto do Martelo aplicado na Deteccão de Incrustação em Tubulações A detecção da incrustação em sistemas de dutosé um problema persistente e requer uma demanda pertinente para as indústrias químicas, petrolíferas, alimentícias e farmacêuticas. A incrustaçãoé um processo de deposicão de materiais sólidos dissolvidos orgânicos e outros materiais pesados nos fluidos transportados ou em suspensão sobre as superfícies das paredes internas em sistemas de transporte de fluidos. Este trabalho apresent… Show more
“…The relationship between pipe thickness and the natural frequency evaluated using experimental values, theory, and FEM analysis is shown in Figure 6. The red lines are theoretical values obtained from Equation (9). The black markers are values obtained from finite-element simulations, the settings of which are given in Section 4.1.…”
Section: Dependence Of Natural Frequency On Pipe Thicknessmentioning
confidence: 99%
“…However, the leakage field is small, and the inspection target (piping) requires magnetization with a permanent magnet or yoke, and that requirement makes the inspection equipment larger. Another method for inspecting piping is the hammer test (HT), in which the pipe is struck directly, and the resulting vibration is analyzed [ 9 , 10 ]. The HT has a relatively low resolution, but it is speedy and simple.…”
A new nondestructive inspection method, the magnetic hammer test (MHT), which uses a compact and highly sensitive tunnel magnetoresistance (TMR) sensor, is proposed. This method complements the magnetic flux leakage method and eliminates the issues of the hammer test. It can therefore detect weak magnetic fields generated by the natural vibration of a pipe with a high signal-to-noise ratio. In this study, several steel pipes with different wall thicknesses were measured using a TMR sensor to demonstrate the superiority of MHT. The results of the measurement show that wall thickness can be evaluated with the accuracy of several tens of microns from the change in the natural vibration frequency of the specimen pipe. The pipes were also inspected underwater using a waterproofed TMR sensor, which demonstrated an accuracy of less than 100 μm. The validity of these results was by simulating the shielding of magnetic fields and vibration of the pipes with the finite element method (FEM) analysis. The proposed noncontact, fast, and accurate method for thickness testing of long-distance pipes will contribute to unmanned, manpower-saving nondestructive testing (NDT) in the future.
“…The relationship between pipe thickness and the natural frequency evaluated using experimental values, theory, and FEM analysis is shown in Figure 6. The red lines are theoretical values obtained from Equation (9). The black markers are values obtained from finite-element simulations, the settings of which are given in Section 4.1.…”
Section: Dependence Of Natural Frequency On Pipe Thicknessmentioning
confidence: 99%
“…However, the leakage field is small, and the inspection target (piping) requires magnetization with a permanent magnet or yoke, and that requirement makes the inspection equipment larger. Another method for inspecting piping is the hammer test (HT), in which the pipe is struck directly, and the resulting vibration is analyzed [ 9 , 10 ]. The HT has a relatively low resolution, but it is speedy and simple.…”
A new nondestructive inspection method, the magnetic hammer test (MHT), which uses a compact and highly sensitive tunnel magnetoresistance (TMR) sensor, is proposed. This method complements the magnetic flux leakage method and eliminates the issues of the hammer test. It can therefore detect weak magnetic fields generated by the natural vibration of a pipe with a high signal-to-noise ratio. In this study, several steel pipes with different wall thicknesses were measured using a TMR sensor to demonstrate the superiority of MHT. The results of the measurement show that wall thickness can be evaluated with the accuracy of several tens of microns from the change in the natural vibration frequency of the specimen pipe. The pipes were also inspected underwater using a waterproofed TMR sensor, which demonstrated an accuracy of less than 100 μm. The validity of these results was by simulating the shielding of magnetic fields and vibration of the pipes with the finite element method (FEM) analysis. The proposed noncontact, fast, and accurate method for thickness testing of long-distance pipes will contribute to unmanned, manpower-saving nondestructive testing (NDT) in the future.
“…Silva [7], [8] presented preliminary research results of vibrational hammer excitation for easy to use external noninvasive, non-destructive fouling detection in pipelines. The proposed method could detect the inner pipe layer formation, and thickness estimation of the adsorbed material.…”
This paper has addressed the common monitoring problems in petrochemical companies, which are caused by fouling and clogging in the circulating water heat exchangers, and has introduced techniques to monitor the heat exchanger's wall vibrations for early failure detection. Due to the difficulties encountered in simulation caused by the large number of tubes inside the heat exchanger, such monitoring methods are discussed by studying the fouling of a fluid-conveying pipeline. ANSYS was used to establish the normal and fouling models of a fluid-conveying pipeline so as to analyze the changing rules of various parameters that are influenced by different inlet velocities. These parameters include flow velocity, direction, pipeline wall load, wall displacement, and the acceleration of fluid domain in a fluid-conveying pipeline. It is shown that, as the inlet velocity and fouling severity continuously increase, the wall load and the vibration acceleration increase as well, leading variations in wall vibration signals. This paper conducts extensive experiments by using straight pipes to compare the results from simulation with those from the normal fluid-conveying pipelines under the same working conditions. By such comparison, the efficacy of the simulation model has been demonstrated.INDEX TERMS Fluid-conveying pipelines, fouling impact, vibration characteristics, vibration signals.
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