Case Study 1: Nucleonic gauges provide accurate and reliable alarm solutions

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Volume 5 Edition 2 Take Control of Your Process Using Tracerco s Fixed Density Measurement Technology Tracerco has been supplying nucleonic process measurement instrumentation to control a range of

1 Volume 5 Edition 2 Take Control of Your Process Using Tracerco s Fixed Density Measurement Technology Tracerco has been supplying nucleonic process measurement instrumentation to control a range of industrial process system levels, interfaces and material densities for over 50 years. Tracerco s range of nuclear gauges provide continuous non-contact measurement of single or multi-phase process mixtures, foams or solids. Each gauge is custom designed and fitted to a vessel, pipe or process to provide operators with critical information in applications such as: Bottom liquid level measurement in vacuum columns Presence, velocity, volume and frequency of liquid or gas slugs to minimise unforeseen process upsets or shutdowns Oil in water or water in oil breakthrough at low levels in two phase separators Foam detection above a liquid level in a wide range of reactors Liquid level and presence of carry over or vapour carry under within separation vessels that can cause issues downstream Solids build-up on vessel or pipe walls to establish its severity Measurement of slurry concentrations or solids build-up in vessels or transfer pipelines Density Gauge Applications The TRACERCO Density Gauge consists of a small radioactive source housed within a shielded container and a sensitive detector. The detector is housed in a flameproof enclosure and is suitable for use in most hazardous areas. Due to Tracerco s development of ultrasensitive detection technology the size of radioactive source required is minimised and has been shown to be the smallest used in industry. Both the source and detector are mounted externally to the vessel or piping giving an advantage as its use is not affected by any adverse conditions that can be found in a number of industrial process systems including high pressure, temperature, corrosive liquids and abrasive solids. Variation in the detected radiation intensity due to small changes in density allows the accurate and effective measurement of process contents in real-time. The following two case studies illustrate how effective density measurement can help with solving process problems. Case Study 1: Nucleonic gauges provide accurate and reliable alarm solutions A Gulf Coast Plant was interested in performing level checks on their batch vertical reactor at specific times during the batch process. The process had a tendency to foam that could lead to carry over. Due to production demands, their goal was to run the level as high as possible without getting liquid carry over. TRACERCO Diagnostics Tower Scans had been performed on two different occasions to gain a better understanding of the hydraulic condition in the reactor and determine the effectiveness of an anti-foam additive. The first series of scans performed at normal batch conditions showed a considerable amount of foaming during the distillation step. The level of foam rose nearly 1m above the base liquid height, exceeding the top tangent line elevation. Addition of anti-foam proved to be very effective and completely eliminated the foam early in the distillation (continued on page 2) INSIDE THIS ISSUE Take Control of Your Process 1 TRACERCO Density Gauge TRACERCO Diagnostics Tower Scans 3 Confirms Need to Repair Damaged Packing TRACERCO Diagnostics Helium Leak 5 Study of a Combustion Air Pre-Heater Delivers Results the Plant Was Hoping For 1 tracerco@tracerco.com

Take Control (Continued from page 1) step. However, foaming would re-occur when reactor temperatures reached their set-points, but not with the same severity as seen when no anti-foam was used.

The foam level was nearly 1m above the base liquid height, exceeding the top tangent line elevation by approximately 150mm.

Project Solution: A solution was proposed to allow the customer to determine the liquid/foam interface spanning 1.5m from the top tangent line down.

2 Take Control (Continued from page 1) step. However, foaming would re-occur when reactor temperatures reached their set-points, but not with the same severity as seen when no anti-foam was used. Three months later a second series of scans were performed with the batch size increased by 4% (Figure 1). Again the scans showed a considerable amount of foaming during the distillation step. The foam level was nearly 1m above the base liquid height, exceeding the top tangent line elevation by approximately 150mm. Addition of anti-foam again proved to be very effective at supressing the foam; however, foaming still occurred when reactor temperatures increased. Project Solution: A solution was proposed to allow the customer to determine the liquid/foam interface spanning 1.5m from the top tangent line down. A TRACERCO Level Gauge was installed to measure the average liquid / froth height. A TRACERCO Density Gauge was configured to share the same source but provide a high alarm set-point when a specific density of foam was present at a location just below the upper tangent line (Figure 2). This critical piece of information would alarm through the DCS in the event that foam was building, allowing time to add anti-foam before a carry over event occurred. Figure 2 A TRACERCO Density Gauge was installed to provide a high alarm set-point when a specific density of foam was present at a location just below the upper tangent line. Case Study 2: TRACERCO Density Gauge used to monitor vent line Tracerco was contacted to assist a US based customer with finding a solution to a troublesome problem. Their slurry pre-mix tank was experiencing build-up in the overhead vent system. The vent system was installed with inspection ports to view the process but these ports were obstructed with dust making it difficult to see what was going on inside. The vessel design used a center shaft with 3 impeller blades to pre-mix lime dust with liquid before the mixture was introduced into a reactor. The problem was excessive lime dust being carried out through the overhead vent system and plugging filters. Questions posed included; Does Tracerco have a way to see or detect evidence of lime dust in the pre-mix tank vapour space above the liquid level or in the overhead vapour outlet line? And, if so, at what point during the batch is the lime being carried out of the vessel? Project Overview: To provide the answers to these questions Tracerco set up a portable temporary TRACERCO Density Gauge on the overhead vent line. The test was carried out to determine if the vapour space density change due to the lime dust was measurable and if so, when did the lime dust form during normal batch operation. Tracerco s density gauge system was externally mounted to a vertical 101mm vent pipe from the pre-mix tank causing no interruption to operations and allowing it to cope with the harsh process conditions. Calibration data was obtained using the empty pipe as a reference. Two sets of surveys were taken one month apart. The first survey (Figure 3, page 6) indicated relative density variations throughout the survey between 0 and 6.8 kg/m 3 but did not show any consistent or stable response. There also appeared to be some form of cyclic pattern occurring in 8 to 10 minute intervals. This suggested that this vent line location had some form of dense material passing through regardless of the batch phase/ time. Also the data indicated that the 101mm line had higher density material left in the pipe once the batch was completed as the radiation intensity did not return to empty pipe status the residual coating within the line was 1.6 to 2.4 kg/m 3 density increase from the empty pipe. Figure 1 Thee months later with the batch size increased by 4% scan results showed a considerable amount of foaming during the distillation step. Addition of anti-foam proved to be effective; however, foaming still occurred when reactor temperatures increased. Results of a follow-up survey conducted a month later (Figure 4, page 6) showed similar results. The relative density through the vent line varied between 0 and 5.6 kg/m 3 during the entire batch cycle. The count rate was not stable as it oscillated in a cyclic pattern of 9 to 12 minute duration. At completion of the batch the vent line had a residual density ranging from 0.8 to 1.6 kg/m 3. (continued on page 6) 2

TRACERCO Diagnostics Tower Scans Confirms Need to Repair Damaged Packing By Lowell Pless, Tracerco Business Development Mgr Distillation Applications TRACERCO Diagnostics Tower Scans of packed beds

hydraulic problems before entering the tower. Figure 5 Due to the small diameter the column was scanned in a + pattern from tangent to tangent.

3 TRACERCO Diagnostics Tower Scans Confirms Need to Repair Damaged Packing By Lowell Pless, Tracerco Business Development Mgr Distillation Applications TRACERCO Diagnostics Tower Scans of packed beds are often used as part of a maintenance programme to periodically monitor fouling, evaluate the quality of liquid phase distribution, detect fouled or crushed packing, and to identify any other hydraulic problems before entering the tower. Figure 5 Due to the small diameter the column was scanned in a + pattern from tangent to tangent. Damage to packed beds in columns can be detected by noting the discrepancies in bed heights as detected from scans versus their reference heights as specified by drawings and/or gross differences in bed density from top to bottom of the packed bed. Recently a customer contacted Tracerco regarding an HF Stripper in an Alkylation Unit. The Stripper had been experiencing less than expected performance. A Tracerco crew performed an abbreviated TRACERCO Diagnostics Tower Scan to determine column performance and verify the integrity of the 3 packed beds. Typical scans performed on a packed bed are a series of four conventional column scans in a 2 x 2 orthogonal grid orientation. Due to the small 60cm diameter, this column was scanned in a + pattern from tangent to tangent as shown in Figure 5. The scans revealed that the top and middle packed beds appeared to be in place, operating without any process degrading conditions and exhibiting good liquid distribution. This was evident by the homogeneous density pattern with both scan lines overlaying each other (Figure 6). Damaged Packing Detected By comparing reference drawings provided by the customer to the scan results, a discrepancy was evident that could only be explained if the bottom bed was missing approximately 2.5m of packing material. The bottom bed showed an abnormal profile with a region of low density at the top of the bed. This low density measured the same as clear vapour even though there was supposed to be packing in this area. Furthermore, there was a small area of very dense packing at the bottom of the bed. This dense region at the bottom of the bed was reminiscent of liquid hold-up due to crushed packing. Above the bottom bed, in an area of the tower that should have been open space, a large absorption indicating some dense material was seen in the close-up in Figure 7. There was no indication of internal features in this area of the Stripper and no external features causing interference had been noted during the scans. One explanation, which would corroborate the other finding was the possibility of displaced packing material. Scan Results Verified After Entry Into The Column A few months later with the assistance of the scan results management decided to change out the packing in the column. Upon entering the Stripper inspectors found damage to the bottom bed that closely matched the scan results. Figure 8 shows what the upper part of the bottom bed looked like upon entering the tower. Tracerco scan results indicated a mass where there should not have been one and a void under it where there should have been packing. As illustrated in Figure 8 a piece of grating was bent and holding a pocket of packing in place. When the grating was pulled out, the packing fell several feet. Figure 9 is a photo of the grating in good condition as it should appear. Figure 6 Scans revealed the top and middle packed beds appeared to be in place and indicated that the bottom bed was missing approximately 2.5m of packing material. The TRACERCO Diagnostics Tower Scan results allowed the customer to provide verification that repairs to the column were needed, prepare equipment and schedule field services for the necessary repairs in advance minimizing downtime. Scan results were able to pinpoint the area of concern and focus repairs to the part of the Stripper that was damaged. (continued on page 4) 3

Damaged Packing (Continued from page 3) Figure 7 Scans of the top and middle beds appeared to be in place, operating without any process degrading conditions and exhibiting good liquid distribution.

crushed packing. Figure 8 Photo of damaged packing in the column bottom bed at the location indicated by scan results. Figure 9 Illustrates how the grating should appear in good condition.

The TRACERCO LevelFinderPlus provides operators with accurate and repeatable level measurement even in the presence of deposit build-up and vapour density fluctuations.

4 Damaged Packing (Continued from page 3) Figure 7 Scans of the top and middle beds appeared to be in place, operating without any process degrading conditions and exhibiting good liquid distribution. The bottom bed showed an abnormal profile with a region of low density at the top of the bed and a small area of very dense packing at the bottom of the bed reminiscent of liquid hold-up due to crushed packing. Figure 8 Photo of damaged packing in the column bottom bed at the location indicated by scan results. Figure 9 Illustrates how the grating should appear in good condition. Product Announcement - TRACERCO LevelFinderPlus Tracerco s patented technology is a breakthrough in level measurement. The TRACERCO LevelFinderPlus provides operators with accurate and repeatable level measurement even in the presence of deposit build-up and vapour density fluctuations. The instrument is unaffected by temperature and process conditions and is able to detect and monitor solid deposition. This instrument has no moving parts and does not have contact with the process giving it the ability to deliver consistent and repeatable level measurements regardless of process conditions. Tracerco s local service and support teams can assist with source delivery, storage, license regulations and commissioning resulting in a rapid installation process. This complete design to source disposal project management provides full radiological protection and advisory services including license application from our local bases. If you are looking to reduce unplanned shutdowns and improve product quality contact a Tracerco representative to schedule an onsite presentation to learn more about Tracerco s instrumentation products, training and support services. 4

5 TRACERCO Diagnostics Helium Leak Study of a Combustion Air Pre-Heater Delivers Results the Plant Was Hoping For By Dave Ferguson Business Dev. Manager Tracer Technology Tracerco provides scanning and leak test pre-turnaround inspection services that are used to assist with planning the scope of turnarounds and reducing cost over-runs. Results can be used in advance of a turnaround to identify damaged equipment and other process problems without having to shutdown the equipment for internal inspections. These results will fully prepare turnaround planners with the knowledge they need for critical path decisions that must be made prior to shutdown. A North American refinery contacted Tracerco to perform a pre-turnaround helium leak study of the combustion air pre-heater. Helium gas was used to detect the presence of any leaks within the system. A highly sensitive Mass Spectrometer is used by Tracerco to analyse the sample stream for the injected helium. The mass spectrometer registers the presence of the helium as it passes the sample point. Inspection Technique A pulse of helium was injected into the combustion air line downstream of the exchanger at injection point 1 (Figure 10). A slip stream of flue gas from the stack was continuously analysed by the mass spec. A pulse of helium was detected 105 seconds after the injection. The injection equipment was moved to the second injection point, which was upstream of the exchanger. Since the furnace flue gas pressure was lower than the combustion air pressure, any leak of helium through the exchanger and into the flue gas flow would exit the stack very quickly. The residence time for the second injection was 110 seconds. Great News The response times indicated there was no leak present in the exchanger at the time the injections took place. Had there been a leak, it was expected that the helium gas would have made a short circuit through the exchanger, triggering an early response on the analyser followed by another response on the analyser with the remainder of the helium gas exiting the furnace stack. The largest payoff from the TRACERCO Diagnostics Helium Leak Study results from the case study above was finding that there was not a leak so the plant could expect a reduced inspection scope during their turnaround window and remove the exchanger from their scope of equipment to be tested. This type of reduction in their inspection scope provided a savings of greater than $500,000. Figure 10 Orientation of helium sample points monitored by a highly sensitive mass spectrometer to determine the presence of helium. Strategic use of Tracerco s pre-turnaround helium leak testing services helps operating units assess the need of inspecting equipment in addition to helping turnaround groups plan for equipment, materials and labor. Since the test was performed, the exchanger in question was moved down the priority ladder and allowed operations to focus on other priorities. The practice of scheduling pre-turnaround TRACERCO Diagnostics Helium leak studies provides a dual value: to the operations/reliability engineers who manage the risk of failure and determine the timing of repair windows and to the turnaround groups who organise the expected scope of repair. If you would like to learn more about Tracerco s pre-turnaround services, helium, chemical or isotope tracers for heat exchanger inspections please contact a technical advisor to arrange an onsite presentation. Benefits of a TRACERCO Diagnostics Helium Leak Study Ultra-sensitive technique compared to hydro-testing or hand held helium leak methods Can detect leaks in systems that may partially reseal when taken offline due to metal contraction Able to pinpoint leaks in individual exchanger tubes allowing fast repair and vessel turnaround Un-reactive with any contaminants remaining in an exchanger under test For water sensitive processes a nonwetting technique that eliminates the requirement to dry before returning to service 5

Take Control (Continued from page 2) Project Solution: Measurements provided by the TRACERCO Density Gauge allowed the customer to determine the amount of solid material carry over.

This service includes providing round-the-clock support, training, and maintenance and optimisation expertise for all our products to ensure that the performance of your systems remains the best

6 Take Control (Continued from page 2) Project Solution: Measurements provided by the TRACERCO Density Gauge allowed the customer to determine the amount of solid material carry over. Instrumentation Commissioning, Site Services and Training A full and comprehensive range of radiation in-house support service s are provided by Tracerco for our customers worldwide. This service includes providing round-the-clock support, training, and maintenance and optimisation expertise for all our products to ensure that the performance of your systems remains the best possible. Our service and support team includes a network of nucleonic instrumentation engineers, radiation protection consultants and process diagnostic experts. Tracerco instruments training includes a comprehensive training course tailored to provide delegates with the essential knowledge and understanding that will enable them to operate and maintain a complete range of Tracerco level, density and interface nucleonic measurement systems, along with The TRACERCO Profiler. Each course can be tailored to the instruments installed onsite, with emphasis on a specific area of interest. Figure 3 Results of the first survey indicated relative density variations throughout the survey between 0 and 6.8 kg/m 3 but did not show any consistent or stable response. The Entire Instrument Package If you are spending valuable time pulling samples to measure what is happening inside your process and would like to learn more about how Tracerco s density, level and interface gauges can help free up your time then please contact a Tracerco technical advisor in your area to schedule an onsite presentation. Figure 4 Follow-up surveys conducted one month later showed similar results. The relative density throughout the vent line varied between 0 and 5.6 kg/m 3 during the entire batch cycle. At completion of the batch the vent line had a residual density ranging from 0.8 to 1.6 kg/m 3. Billingham, UK Tel: +44 (0) Aberdeen, UK Tel: +44 (0) Brussels, Belgium Tel: +32 (0) Villefontaine, France Tel: +33 (0) Oldenburg, Germany Tel: Milan, Italy Tel: Alblasserdam, The Netherlands Tel: +31 (0) Bergen, Norway Tel: Perth, Australia Tel: +61 (0) Rio de Janerio, RJ, Brasil Tel: Kuala Lumpur, Malaysia Tel: Baku, Azerbaijan Tel: Singapore Tel: Shanghai, China Tel: Beijing, China Tel: /5 Abu Dhabi, United Arab Emirates Tel: XM1043/0/0 6 tracerco@tracerco.com

Drilling Efficiency Utilizing Coriolis Flow Technology

Session 12: Drilling Efficiency Utilizing Coriolis Flow Technology Clement Cabanayan Emerson Process Management Abstract Continuous, accurate and reliable measurement of drilling fluid volumes and densities