Taking a representative resid sample while avoiding safety risks related to personnel exposure to hot temperatures has historically been a challenge. Hence the large number of sampling devices and configurations used in the industry. This presentation will review strengths and weaknesses of various sampler designs as well as share learnings from a near-miss incident that occurred while taking a coker feed sample.

To be discussed:

• methods of quenching,
• how to minimize coke formation,
• and how to remove coke that forms.

This presentation will discuss the design of coke drum bottom head flanges for leak free operation and assembly best practice when bolting to an automatic bottom un-heading device (BUD). Coke drum bottom head flanges are unique in their behavior when compared to other refinery bolted flanged joints due to the various loadings seen through changes in pressure and temperatures, locally to the joint, over a typical drum cycle. Specific damage mechanisms must be accounted for at the design phase along with accurate assembly methods to avoid leakage. BUD joints are expected to remain leak free for years between valve maintenance. It is common practice for owner-operators to periodically re-tighten the joint after a specified number of drum cycles, usually undertaken on an "extended drum cycle" to allow sufficient time for maintenance crews to re-tighten the joint. Correct design and assembly can extend or eliminate these costly maintenance interventions.

In most refining conversion units such as delayed coker and others, unscheduled shutdowns, high maintenance, reduced heat transfer, higher fuel consumption and throughput reduction due to furnace and heat exchanger tube coking, fouling and corrosion is a widespread problem. TUBACOAT technology minimizes formation, deposition and plugging due to coke/carbon in addition to reduction in fouling, corrosion, and fuel usage. Use of TUBACOAT technology in these applications leads to longer runs, incremental life cycle for equipment, reliable operations, increased heat transfer, reduced fuel consumptions, reduced CO2 emissions and hence significant savings in OPEX and CAPEX.

In this presentation, results and case studies from two commercial field trials in North America and Asia, respectively, are shared showing the DCU online spalling performance and other improvements based on 12 months of operation using Tubacoat Technology. Results and comparison include improvement in online spalling frequency, time required to clean tubes during spalling and fouling rate for Tubacoat coated tubes and uncoated tubes, respectively.

Since many years Slide Valves are standard in the industry to open and close coke drums.

But there are still coker units which cannot install Valves, especially at the bottom of the drum. These coker units are mainly older coker with smaller drums.

20 years ago, at a mayor revamp, a coker unit with 4 x 17’ drums decided to install a semi-automatic bottom deheading system while installing electric operated valves at the top.

In the TAR 2023 the Bottom Deheading has been checked and overhauled to continue safe and satisfactory operation for the next periods of operation.

This presentation shows, how with Computer-Fluid-Dynamic (CFD) Calculations and Finite Element Analysis (FEA) heat and load distribution has been determined to check and upgrade the system.

The delayed coker unit is known for processing vacuum residue of the vacuum rerun unit to produce various high-quality products such as Heavy Coker Gas Oil (HCGO), Light Coker Gas Oil (LCGO), Kerosene, Naphtha, Refinery Fuel Gas (RFG), and coke. Non-standard feedstock, known as Low Sulfur Atmospheric Residue (LSAR), has been successfully processed in DCU-136 of the MAA Refinery in Kuwait. Processing LSAR required an implementation of a new jump-over line from Atmospheric Residue Desulphurization Units to the cold feed line of the delayed coker unit. The jump-over line was implemented using a hot-tapping procedure to avoid any unit disruption. The LSAR processing was initiated on December 2, 2023, during U-83 shutdown and sustained for 19 days, in which the hot VR was flowing around 180 ??3 /h??, while LSAR flow was maintained at 40 ??3 /h??. Product specifications were analyzed and found to be normal except for the Hardgrove Grindability Index of coke, in which it reflected higher values. Several actions were performed by operations and process departments to mitigate that issue. Additionally, an emergency shutdown of the cold VR unit has been overcome by replacing the cold feed with LSAR and maintaining normal unit throughput attesting the positive result of the executed project. All in all, LSAR processing in the DCU was completed successfully leading to increasing the throughput during the loss of cold feed and thus growing a profit equivalent to $9.5M USD.

This presentation outlines the progressive automation of an Eastern delayed coker hydraulic coke cutting system equipped with turntables rather than the standard drill stem drive type assembly. Initially, top and bottom deheading solutions were implemented, with a particular focus on a novel bottom deheading system utilizing a hydraulic car. The top deheading was enhanced using slide valves, addressing challenges associated with a squared drill stem guide. The final stage involved the development of a new electric-driven turntable system, including a completely redesigned Freefall Arrestor (FFA), culminating in a fully remote and automatic cutting process.

Since the advent of Delayed Coker Automated Unheading Valves, and unlike traditional centered bottom-feed entry, today’s side-feed configurations create nonsymmetric coke bed channeling primarily against one wall of the coke drum. This channeling causes accelerated thermal expansion and contraction on one side of the drum which can result in an increase in drum warping, bulging, and through-wall cracks, as well as decrease the fatigue life of the drum skirt and cone. Costly drum repairs and replacements are occurring far too early compared to typical drum life.  

Recent evidence shows that in some side feed configurations, the nonsymmetric heating can create four distinct quadrants in the lower transition cone segment where two cool and two hot regions reside 180° from one another.  The four-quadrant heating is attributed with a rise in occurrence of permanent thermal distortion in the coke drum flange and transition cone.  

This is a new and distinct failure mechanism for coke drums and is occurring as early as 5 years after a new coke drum installation.  

DeltaValve’s presentation will show the evolution of the bottom transition cone and flange geometry after automated unheading was introduced and the mechanics behind the complex loading of the unheading flanged joint.  This presentation shall also demonstrate the effects of feed configurations including single side feed, dual side feed and DeltaValve’s CenterFeed® injection device on flow channeling within the drum and provide evidence on how the DeltaValve CenterFeed offers significant benefits over all other drum feed systems, which ultimately leads to extended coke drum life.

Serpentine coils in Delayed Coker Heaters are challenging to both clean and inspect utilizing today’s latest technologies. Extensive fouling on the coils interior surface often warrants cleaning intervals of two years, or less, depending on online spalling capabilities. Mechanical decoking pigs are often utilized for cleaning, however there’s a wide variation of designs on the market and effectiveness of each. Mechanical decoking equipment operator experience, combined with supporting equipment such as pumps, valve systems, launcher/receivers, etc. play a significant role in terms of cleaning effectiveness.  Often refiners will employee Intelligent Pigging technology directly after the cleaning of the heater coils to (1) Verify coil cleanliness, (2) Detect/Quantify damage mechanisms and (3) Establish current coil condition to enable fitness for service and remaining life expectancy.  Both Mechanical Pigging and Intelligent Pigging processes depend heavily upon one another to ensure the success of each task. Proactive preplanning in advance of upcoming plant turnarounds can assist greatly in proper contractor/technology selection to ensure quality of outcome.  The discussion will also include how issues with data collection in these efforts trickle down to increasing error bands for remaining tube life and fitness for service calculations. Key takeaways from the discussion will be (1) critical planning steps (2) pitfalls of the equipment and what to check for (3) how planning and equipment impact cleaning effectiveness and data resolution.   

Coke drums stand as vital components in the refining process, enduring harsh operating conditions that subject them to mechanical stresses and thermal cycling. Among the critical areas prone to cracks are the skirt and knuckle joints, presenting significant challenges to Coke Drums Reliability. Over the past 25 years, Reliance has continuously refined its Maintenance & Inspection approach by leveraging technological advancements and lessons learned from experience to enhance operational efficiency and asset integrity. This paper delves into the experiences of the industry in managing the Coke Drums, focusing particularly on the challenges faced in skirt knuckle joints and the transformative journey of Reliance Industries Ltd. in addressing these challenges through inspection, repairs, modifications, and successful remediation strategies.

The installation of unheading systems in existing delayed coker units typically requires modifications on the bottom cone of the drums to adapt or make room for the new equipment.

This presentation will focus on why such spools are required, the different options available, the design criteria, and installation considerations.

Early engineering work is always recommended to confirm the feasibility and approach to the design of the spools further down the project execution path, while their design and fabrication should be considered potential candidates for the critical path of the schedule.

This presentation is about Automated Coke Cutting System and CenterFeed Device field experiences in the delayed coking unit at TUPRAS Izmit Refinery.

The delayed coker unit at Izmit Refinery has been in operation since 2015 and is designed for 18-hour cycles with four coke drums at 8200 Sm3/d feed capacity (AFW). The unit has had cycle time change from 18h-18h to 16h-16h cycle time and capacity increased to 8,700 Sm3/d.

In the past, the coke cutting system was manually operated three times per day and operators were faced with dust, coke, H2S, and system failures. With the addition of the automated coke cutting system, dust and coke emissions decreased, H2S exposure for operators was reduced, and system failures decreased. The additional benefit of extended equipment life was observed after the installation of automated system in 2017.

Even after many improvements were tried in DCU feed and operations, formation of hotspots and other operational problems continued. To improve safety in the unit and to eliminate the effects of hot spots on environment, the CenterFeed Device was installed in the first unit T/A in 2019. Since 2019, TUPRAS has gained many valuable CenterFeed Device operational experiences.

The focus of this presentation will be:

• The benefits of automated Coke Cutting System. (What TUPRAS faced before and after)
• TUPRAS’ experiences after the installation of the Coke Cutting System in 2017
• TUPRAS’ operational experience with the CenterFeed Device
• TUPRAS’ management of incidents impacting operations prior to the CenterFeed Injection Device installation vs. the operational improvements observed post installation

Coke drums experience failures in through-wall cracking throughout their operating life, resulting from low cycle fatigue. Coke drums are typically fabricated from high strength low alloy (HSLA) steels. This study was performed on 1-1/4CrMo base material using ER70S-B2L and Alloy 625 (ERNiCrMo-3) filler materials. Specimens were welded with the temperbead/controlled deposition welding technique. The weld processes used were Hot PulseTM GTAW, GMAW and SMAW. The fatigue performance, HAZ hardness and toughness of the weld samples was evaluated. The Hot PulseTM GTAW welds exhibited an order of magnitude improvement in fatigue performance when compared to the other weld processes using ER70S-B2L filler material. The Hot PulseTM GTAW welds also exhibited improved HAZ hardness and toughness when compared to the other weld processes. This presentation will introduce the Hot Pulse GTAWTM process, its features, and benefits and where it is applied in Coke drum repair welding. Comparative test results of the different weld processes for fatigue performance, HAZ tempering, and toughness will also be presented.

Every DCU is slightly different, so this forum gives participants the opportunity to ask questions and address issues within the group. Use the expertise in the room to “think tank” solutions to your unit’s issues.