Transdutor a fibra ótica para monitoração de vazão em tubulações industriais

Abstract

Fluid flow monitoring is essential in industrial processes. Volumetric flow measurement methods are not feasible in some applications, such as in environments subject to explosions or subject to intense electromagnetic fields. The present work shows the development of an optical fiber transducer for flow measurement in industrial pipes. The force created by the displacing fluid results in the tubular cantilever deformation, within which are adhered four optical fibers, two as a sensor element using Fiber Bragg Grating and two to ensure the optimal geometrical positioning of FBGs. The flow rate is obtained by monitoring the two wavelengths difference of each FBG, which also corrects the cross sensitivity trouble of sensor temperature and strain. Furthermore, the use of clamps adds another strong point to the sensor as it allows easy installation and maintenance on industrial pipes. Static and dynamic tests were performed for transducer calibration and validation. The highest sensitivity in Transducer 1 dynamic calibration is 14,7 pm⁄mh³ ± 2,9 pm(t95% = 2,0) and Transducer 2, 19,2 pm⁄mh³ ± 4,5 pm(t95% = 2,0). For the static calibration the Transducer 1 highest sensitivity is 2,34 nm⁄N ± 31 pm(t95% = 2,1) and Transducer 2, 3,2 nm⁄N ± 35 pm(t95% = 2,1). The difference in sensitivity between the transducers is due to the rotation to the probe of Transducer 1 during the drying period of the epoxy adhesive.The transducer was able to measure flow rate in the range of 0,5 m³⁄h to 6,0 m³⁄h. Furthermore, the gas-liquid flow. There are several advantages of using optical fibers such as flow rate sensors and the development of robust devices allows them to be used in an aggressive industrial environments.