Artigo de peri??dico
Tomographic 2-D gamma scanning for industrial process troubleshooting
Registro en:
0955-5986
62
10.1016/j.flowmeasinst.2017.09.004
aguardando
51.163
66.75
Autor
HARAGUCHI, MARCIO I.
CALVO, WILSON A.P.
KIM, HAE Y.
Resumen
Gamma scanning is a nuclear inspection technique widely used to troubleshoot industrial equipments in refineries
and petrochemicals plants such as distillation columns and reactors. In this technique, a sealed radiation
source and detector move along the equipment, and the intensity readouts generate the density profile of the
equipment. Although many improvements have been introduced in recent years, the result of gamma scan still
consists of a simple 1-D density plot. In this work, we present the tomographic gamma scanning that, using
image reconstruction techniques, shows the result as a 2-D image of density distribution. Clearly, an image
reveals more features of the equipment than a 1-D graph and many problems that could not be troubleshooted
using the conventional technique can now be solved with this imaging technique. We use ART (Algebraic
Reconstruction Technique) intercalated with total variation minimization filter. The use of total variation
minimization leads to compressive sensing tomography, allowing to obtain good quality reconstruction from few
irradiation data. We simulated the reconstruction of different density distributions. We applied the new technique
to data obtained by irradiating with gamma rays phantoms that emulate industrial equipments. Finally, we
present the result obtained by applying the innovative technique to real operating distillation column. It seems
that the new technique has identified a problem in this equipment that is very difficult to detect using conventional
gamma scan. Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) CNPq: 163088/2014-4