RADIOTRACER APPLICATIONS IN INDUSTRY AND ENVIRONMENT

Transcription

1 ID: B11-03 RADIOTRACER APPLICATIONS IN INDUSTRY AND ENVIRONMENT H.J.Pant Isotope and Radiation Application Division Bhabha Atomic Research Centre, Mumbai, India

2 COMMONLY CARRIED OUT RADIOTRACER APPLICATIONS IN INDUSTRY AND ENVIRONMENT Leak detection in heat exchangers and buried pipelines Flow rate measurement Mixing time measurement Residence time distribution measurement Sediment transport investigations in ports Effluent dispersion in coastal waters Wear/corrosion rate measurements (TLA Technique) Characterization and management of oil fields Radioactive particle tracking technique Adsorption studies

3 Counts / 2 Seconds Counts / 2 Seconds Leak Detection in a Welded Plate Heat Exchanger (Alfa Laval Packinox reactor feed/effluent heat) exchanger Feed out D6 Effluent in D D2 - E1 Feed Inlet D3- E1 Feed outlet D4 - E1 Eflluent Outlet 2000 HE1 HE Leak Peak of E Time (s) Radiotracer injection D2 D4 D7 Effluent out D D5 - E2 Feed Inlet D6- E2 Feed outlet D7 - E2 Effluent Outlet D Leak Peak of E-2 Radiotracer: Br-82 as paradibromobenzene Time (s) Both the heat exchangers were found to be leaking. The leak rate was estimated to be about 0.8% and 0.6% in exchanger E1 and E2 respectively.

4 Flow rate measurements in large diameter Thermal Power Plant) Pipeline: Dia. 3.6 m Installed flow meter Vertical turbine pumps

5 Schematic diagram and experimental setup Radiotracer: Iodine-131 as KI (half life: 8 days, gamma energy: 365 kev) Activity: mci Radiotracer injection vessel Q Q 2 Q C 1 C

6 Results of flow rate measurements Experiment 1 (Unit-2, P2A) Sample No. Q 1 (ml/min) C 1 (Counts/2 Mins.) C 2 (Counts/2 Mins.) Q 2 (m 3 /s) Mean Q 2 (m 3 /s) S x S x S x Experiment 2 (Unit-2, P2A+P2B) S x S x S x Experiment 3 (Unit-1, P1A) S x S x S x Experiment 4 (Unit-1, P1A+P1B) S x S x S x

7 Mixing Study in a Thermal Stratification Test Facility (Mixing of water to hot layer of water)

8 Thermal Stratification Test Facility

9 Experimental setup for Run1-5 (Front side monitoring) Experimental for Run 7 (lateral side monitoring) Technium-99m as sodium pertechnatate (0.5-1mCi/test) Experimental setup for Run 6 (Front side monitoring)

10 Radiotracer concentration (Counts / 20s) Radiotracer concentration (Counts / 20s) Radiotracer concentration (Counts / 20s) Run 2: Cold water, circulation only in lower section D2-Level-1 D3-Level-1 D4-Level-2 D5-Level-2 D6-Level-3 D7-Level-3 D8-Level-4 D9-Level Mixing time~17 Min Time (Sec) The radiotracer study confirmed existence of the thermocline formed during normal operation. Run 5: Only cold water and no circulation (Diffussion) D2-Level-1(Cold layer) D3-Level-1(Cold layer) D4-Level-2(Cold layer) D5-Level-2(Cold layer) D6-Level-3(Cold layer) D7-Level-3( Cold layer) D8-Level-4( Cold layer) D9-Level-4(Cold layer) Mixing time~2.8 h Time (Sec) Condition Run 4:Cold water circulation D2-Level-1(Cold layer) in lower section and hot water D3-Level-1(Cold layer) circulation in upper section D4-Level-2(Cold layer) D5-Level-2(Cold layer) D6-Level-3(Hot layer) D7-Level-3(Hot layer) D8-Level-4(Hot layer) D9-Level-4(Hot layer) Time (Sec) Cold water with circulation in bottom and top section Circulation of cold (bottom) and hot (top) layers (Normal operating condition) Mixing time: ~15 hours The thermocline was effective to reduce the transport rate of radiotracer from the cold water layer to the hot water layer Cold water without any circulation (Diffusion) Mixing time 0.5 h 15 h 1.7 h (bottom) 2.8 h (Top)

11 Residence Time Distribution Measurements in an Industrial Visbreaker in a Refinery Production of more gaseous product, suspecting backmixing D o C Gas + Gasoline Visbreaker Data acquisition system Feed Radiotracer injection Point D1 Fractionator CW Heater ( o C) Visbreaker residue Radiotracer: Br-82 as pdbb, Activity: 5 mci/test

12 Normalised tracer concentration (s -1 ) Normalised tracer concentration (s -1 ) RTD Analysis Q RUN 1 Experimental MRT 57 min. Model simulated ( T min. Axially dispersed Plug flow component (Bypassed fraction) N N Tanks with stagnant volume (Back mixed fraction) Time(s) Backmixing RUN 4 Experimental MRT 48 min. Model simulated ( T min. Q 1, 1 Q 2, Q Backmixing Block diagram of the model used Time (min)

13 Run No. T ( o C ) P (Kg /cm 2 ) Results of RTD investigation Q (m 3 /h) (min.) (min.) Plug flow component p (min.) Pe Q p Model Parameters Tank in series with stagnant volume exchange component a (min.) m (min.) N K Q bm Total MRT T (min.) T: temperature in the visbreaker unit, P: pressure in the visbreaker unit, Q: feed rate at inlet of the visbreaker, : theoretical mean residence time, : Experimentalmean residence time, p : MRT in plug flow component, Pe: Peleclet number, a : MRT in main stream (Tank in series with exchange component), m : time constant for exchange between two volumes, N: Tank number, K: relative volume of stagnant zone with respect to active zone, Q 1 : Flow fraction in the bypass stream (plug flow component), Q 2 : Flow fraction in main stream (Tank in series exchange with stagnant zone), T: Overall model mean residence time

14 Half-life:77.3 days, Gamma energies: Mev (100%), Mev (67) Useful irradiation thickness: 240 m Yield: 2 x 104 Bq A -1 h -1 m -1 Cross section at 13 Mev: 392 mb Relative remnant activity Investigation of Anti-wear Performance of Automobile Lubricants Using TLA Technique Wear process can be prolonged by efficient selection of lubricant Thin layer activation analysis (TLA) offers a sensitive and rapid method to quantify wear rate of automobile parts 1.0 Calibration curve Ion beam irradiation 0.8 Vacuum Metal Faraday chamber Target cup Proton beam Aluminium Window Aluminium Collimator 56 Fe(p,n) 56 Co Current meter Thickness loss ( m)

15 Wear rate (nm/minute) Thickness loss ( m) L1 L2 L3 L Time (minute) Wear depth versus time plot for L1-L4 at 30 KgF load and 200 rpm speed L1, 30 KgF L1, 40 KgF L4, 30 KgF L4, 40 KgF Speed (rpm) Wear rate versus speed plot for L1 and L4 at different loads Wear measurements of disc gears were studied in presence of four different lubricants (L1, L2, L3, L4) L4 was identified: having best anti-wear behavior for all the load and rotation speeds considered

16 Radioactive Particle Tracking Technique in a Bioreactor Objective: Assessment of mixing of Media elements Reactor volume: 630 L Water in Air out Water out 1260 mm 796 mm 796 mm Air in r z Front View Side View Radioactive Particle, Sc-46, 1 mci

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18 Implementation of RPT in a Bioreactor Calibration device Radiotracer particle (Scandium-46 glass particle Activity~1 mci) Tracer particle Calibration rod for vertical positioning Detectors used: 22, Data acquired for 15 days at each conditions at an interval of 20 ms, Experiments conducted at four different conditions RFB reactor

19 Occurrences of Tracer Particle along Axis Air 11.5 m 3 /h water 7.76 m 3 /day G 1 L 1 G 2 L 1 Air 12.5 m 3 /h water 7.76 m 3 /day Air 11.5 m 3 /h water 10 m 3 /day G 1 L 2 Air 12.5 m 3 /h water 10 m 3 /day G 2 L 2

20 G 1 L 1 Trace of Particle Movement in axial Direction Air 11.5 m 3 /h water 7.76 m 3 /day Air 12.5 m 3 /h water 7.76 m 3 /day G 2 L 1 G 1 L 2 Air 11.5 m 3 /h water 10 m 3 /day G 2 L 2 Air 12.5 m 3 /h water 10 m 3 /day

21 Conclusions from RPT Study At low flows, media tends to spend more time at the inlet and less at exit. At higher flow rates, movement is more uniform and relative times spent at inlet and exit are comparable. Media tend to recirculate along the inner walls of the reactor About 30% volume of the reactor was underutilized (dead). Flow of media particles was tracked and characterize. The movement of media particle with respect to time and space helped to visualize the flow pattern of media particles. The results of the RPT investigation helped Engineers to improve the design of the bioreactor and hence its efficiency.

22 IAEA/RCA/RTC On Radioactive Particle Tracking Technique for Investigating Process Hydrodynamics October 17-21, 2011, New Delhi India Thank You