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Seminar Pendayagunaan Teknologi Nuklir 2017Badan Tenaga Nuklir N asional

Tangerang Selatan 21- 23 November 2017

IDENTIFICATION OF SCALING THICKNESS ON 48 INCHES PIPELINE USING GAMMA SCANNING TECHNIQUE

Wibisono, Bayu Azmi

Centerfor Isotopes and Radiation App/ication-BA TANJI. Raya Lebak Bu/us no 49, Jakarta 12440

lI'ibi@batan.go.id

~SENPATEN

ABSTRACT

IDENT/FICA nON OF SCALING THICKNESS ON 48 INCHES PIPE LINE USINGGAMMA SCANNING TECHNIQUE. Gas pipeline suspected consist of scale inside thewall. A cracking gas flowed from furnish to gasoline fractionation tower has a diameter48 inches and length 20 meters. Gamma scanning technique performed to diagnosescaling profile and thickness inside the pipe. A gamma source Cs-137 has an activity80 mCi and other equipment such as a gamma rate meter, Nal(T/) scintillationdetector, induction motor, and two gamma collimators which has a radius 5 mm and adeep 30mm, a computer designed for measuring objects with a radius of 150 em. Themeasurement method was scanned the pipe vertically and horizontally. Experimentresult observed scale thickness is 32-57 em in range. This experiment report is guideto maintain schedule for continuous productivity.

Keywords: Gamma, industry, nuclear, radiation, scaling, tomography.

ABSTRAK

IDENTIFIKASI KETEBALAN KERAK DI DALAM PIPA 48 INCH DENGAN TEKNIKGAMMA TOMOGRAFI. Pipa aliran fluida gas diduga mengalami penyumbatan padadinding dalam pipa disebabkan kerak didalamnya. Aliran cracking gas dari furnish ketower gasoline fraksinasi ini memiliki diameter dalam 48 inci dan panjang 20 meter.Teknik gama tomografi dilakukan untuk mendiagnosa tebal dan profile kerak didalampipa. Sumber gamma 80 mCi Cs-137 dan perfengkapan lainnya seperli gammaratemeter, detektor sintilasi Nal(TI), motor induksi dan kolimator gamma radius 5 mmdalam 30 mm, serta sebuah komputer didisain untuk pengukuran objek berdimensiradius 150 em. Metode pengukuran adalah dengan memindai pipa secara vertikaldan horizontal. Eksperimen berhasil mengidentifikasi tebal kerak antara 32-57 em.Laporan investigasi ini akan menentukan jadwal perbaikan yang diperfukan untukmempertahankan waktu produksi.

Keywords: Gamma, industri, nuklir, radiasi, scaling, tomografi.

INTRODUCTION

The measurement of phase fractions andphase distributions in full-scale industrialdevices operated under authentic

conditions is of highest interest for designers andoperators [1]. The ability to see the inside of anobject is very necessary in industrial processes todiagnose malfunctions or in order to increaseproduction. Gamma-ray has been widely used

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for industrial process diagnosis because it hashigh energy and does not need a radiationgenerator [2]. Gamma ray scanning is an onlineand completely non- destructive tool fortroubleshooting distillation columns and otherprocess unit [3]. This technique is also a fast,efficient, and cost-effective tool for betterunderstanding the dynamic processes that occurin industrial columns and examining the innerdetails of a distillation column [4]. In comparison

Wibisono, dkk.

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Senlinar Pendayagunaan Teknologi Nuklir 2017Badan Tenaga NukIir Nasional

Tangerang Selatan 21-23 November 2017 SENPATEN

2000 4000I (count)

to other non-destructive control techniques usedin practice, gamma-ray scanning provides, in realtime. the clearest vision of the productionconditions inside a reservoir of process [5].

Particles residue of gas cracking processwas found at BA-106 outline pipeline. Theseparticles are suspected of sticking to the innerwall along the pipe during operation. This pipelinehas not been inspected since 30 years ofoperation. This pipe has a diameter of 48 inchesand a length of 20 meters. The temperature ofthe gas flowing within it is 150°C so that the pipeis encased in insulation and jacket. The scaleinside the pipe will of course decrease the flowdue to the reduced effective diameter in the pipethus compressing the compressor work. Theresidual particles also become impurities in thenext process.

The management will identify the scaleprofile in the pipe to know the distribution of itsthickness along the pipe. Investigation is doneoff-line as it coincides with the timing of anothersegment maintenance.

The pipe line will be scanned at severalpositions vertically and/or horizontally. The scancurve results can represent the condition insidethe pipe .

METHODOLOGY

The investigation was conducted byshooting the gamma rays through the pipe. Thegamma rays interact with the pipe and scale.When mono-energetic gamma rays arecollimated into a narrow beam and allowed tostrike a detector after passing through onabsorber of variable thickness, the result shouldbe simple exponential attenuation of the gammarays as shown in Figure 1 [6]. The interaction ofgamma rays when interacting with the materialwill decrease its intensity exponentially followingequation (1) [6].

(1)

B= build factor

For practical application of formula (1) issimplified into (2) [7].- ---- - .. -"~--.- .--- ..... --

(2)

Where 10 is the initial intensity, x the length of thepassage, and IJ is the coefficient of absorption.

Wibisono, dkk.

fA.

Figure 1. The exponential transmission curve forgamma rays measured under "good geometry"

condition.

Cs-137 source was used in this work. Itsenergy is 662 keV which is sensitive todistinguish material density. The empty cylinderpipe will have a symmetrical and smooth intensityprofile when scanned from one side to the otheras shown in Figure 2.

p~e co

I -;:0' ~Sc

•.••.••••.••. 0. anproftle" .....~ ..···t. ,

----{ $Irnf!:try

....::::: L.............m 5· Jr ..........: ••••••

•••••••••• • ''';f~' Notmol

Figure 2. Vertical scan profiles of normal and scaledpipe.

The gamma scan technique wasperformed by scanning the cross section of thepipe by using a collected Cs-137 gammaradiation source as a transmitter and a pulsedNal(TI) detector as a receiver. The radiationsource emits radiation (pencil beam) and thedetector receives the gamma photons after it haspenetrated the object (pipe). [3]. Gamma detectoris connected to gamma counter Ludlum 2200 tosupply 1000V voltage. The gamma counter is setto calculate gamma ray intensity for threeseconds [8]. The radiation source and thedetector perform a translation scan at 10 mm per

. step. It was performed at-15- positions as shown ­in Figure 3. The detail of scanning position isshown in Table 1.

Gamma scan profiles can represent theinside of the pipe condition. The scale existenceis predicted using scan profiles. Anunsymmetrical scan profile indicates scaleexistence inside the pipe.

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Seminar Pendayagunaan Teknologi Nuklir 2017Badan Tenaga N uklir Nasional

Tangerang Selatan 21-23 Nov~~ber 2017

Figure 3. Gamma scanning position

~SENPATEN

Point A

-M\IO Horizontal scan ~.,;:

Table 1. Gamma scanning positions.

No

CodePosition (em)Sean line1

A 200Vert I Hor2

B 700Vertical3

C 1100Vertical4

D 1800Vertical5

E 2600Vertical6

F 3600Vert I Hor7

G 4300Vert I Hor8

H 5450Vert I Hor9

I 6600Vertical10

J 7600Vertical11

K 8450Vertical12

L 9500Vert I Hor13

M 10500Vertical14

N 11100Vertical15

0 11450Vertical

There are only five positions that can bescanned vertically and horizontally, the rest canonly scanned vertically. This is due to fieldconditions around the pipeline. There are someobstacles such as other units, its support, ladder,and so on.

RESULT AND DISCUSSION

The scale at point A is identified usingvertical and horizontal scan profiles. Thehorizontal scan shows low intensity at position100-150 cm. The same condition is alsohappened in the position of 30-50 cm. Theintensity of the vertical scan position of 20-40 emand 100-140 cm looks low relative to 70-100 cm.Scale profile prediction on point A is shown inFigure 4.I.. J:, __--·~·....-r ....

4••• _.___-."

~.,(....•f' ~• j

Point AVertikal scan

.- •..- ¢"'" ....._ •..)

Figure 4. Scale profile prediction on point A.The vertical and horizontal scans plotted

to the pipe image to predict the abnormality In the same way, the scales prediction at point B-inside the pipeline. As mentioned before, un~er a is shown in figure 5. The scale profiles of point

-·normal pipe conditions (without scal~).t~e pipe ---A F, G, H, and L were built from-vertically-andprofile will be symmetrical as .sh~wn In FI~ure 2. horizontally scan, whereas the other points wereThe asymmetry scan profile indicates eXistence predicted using vertically scan data.of foreign material inside the pipe.

216 Wibisono, dkk.

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Seminar Pendayagunaan Teknologi Nuklir 2017Badan Tenaga Nuklir Nasional

Tangerang Selatan 21-23 November 2017

Figure5. Scaleprofile predictionof 15 scanningpoints.

The scale profiles are considered asrepresentation of the segments along the pipelineso that it can be assumed the profile along thepipeline in three dimensional visualization imageas shown in Figure 6. Gamma tomography

technique is important as a complementary datato get the cross-section visualization of scaleprofile inside the pipeline.

Figure 6. Three dimensionalscaleprofile predictionin the pipeline

CONCLUSSION

. Gamma' scanning-- technique -is- able to­identify existence of scale inside the pipeline.Experiment result observed scale thickness is 32­57 cm in range. Gamma tomography technique isimportant as a complementary data to get thecross-section visualization of scale profile insidethe pipeline.

Wibisono,dkk.

ACKNOWLEDGEMENT

. ~".. _T.heauthOJS would like to acknowledge PTChandra Asri Petrochemical Tbk. and CIRA­BATAN who have been continuously encouragingthe realization of the application of nucleartechnology in the field of industry. This support isvery useful to add experience, discourse, andchallenges in the field. Thank you also to theteam and the field manager Ir. Zulkifli Lubis.

217

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REFERENCES

[1] A. Bieberle, D. Hoppe, and U. Hampel,"Process diagnostics and non-destructivetesting using high-resolution gamma-raytomography," 2010 IEEE Int. Cont.Imaging Syst. Tech. 1ST 2010 - Proc., pp.261-265, 2010.

[2] J. S. Charlton, Radioisotope Techniquesfor Problem-solving in Industrial ProcessPlants. Leonard Hill, 1986.

[3] H. Shahabinejad and S. A. H. Feghhi,"Design, optimization and performance ofsource and detector colli- mators forgamma-ray scanning of a lab-scaledistillation column," Appl. Radiat. Isot., vol.99, pp. 25-34, 2015.

[4] P. A. Vasquez, F. E. Costa, W. A. P.Calvo, M. M. H. A. and P. A. Va,"Development of a scintillator detectorsystem for g -ray scan measurements ofindustrial distillation columns," Nucl.Instruments Methods Phys. Res., vol. 537,pp. 458-461, 2005.

[5] K. Laraki, R. Alami, R. C. EI, A. Bensitel,and L. EI Badri, "An expert system forimproving the gamma-ray scanningtechnique," vol. 578, pp. 340-344, 2007.

[6] Glenn F. Knoll, Radiation Detection andMeasurement, 2nd ed. John Wiley &Sons, Ltd, 2010.

[7] S. Sugiharto, "On-line Diagnosing onTrayed Column of Etylene Plant UsingGamma Ray Scanning," Atom Indones.,vol. 38, no. 3, pp. 138-146,2012.

[8] Ludlum Measurements, "Ludlum Model2200 Scaler Ratemeter," 2005.

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