Coke drum crack repairs

Thompsons structural repair technology is the best available. The ideal solution is a repair or upgrade that can be. During the cycle, the process temperature varies from 150 0 f to 900 0 f. A coke drum is a type of pressure vessel that uses heat and pressure to refine complex hydrocarbons into lighter, more useful, products, such as gasoline, diesel, and jet fuel. Depending upon the overall coke drum cycle being used, a coke drum may fill in 16 to 24 hours. Jagged cracking in the heataffected zone of weld overlay on. This fractionator tower has a reservoir in the bottom where the fresh feed is. Coking unit repair at citgo lemont refinery youtube. This alarm was out of service and bypassed for the twelve months prior to the incident. The industry recognises that the shorter and more severe the cycle, the sooner and more pronounced the bulging and cracking will appear. A decision by the refinery management team was made to complete longterm repairs to the coke drum support structure that would return it to its original operating capacity. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke delayed coking is one of the unit processes used in many oil refineries. Drum repair and restoration services kentville drums. A coke drum skirt to minimize the stresses experienced by the coke drum and the supporting structure of the coke drum is described.

The 4 drums were approximately 28 in diameter x 100 tall. Nooter construction is an industry leader in coke drum repair and replacement. Keep cracks at bay using thompsons structural repair technology to keep your drum rotating longer. Hes coke drum engineering houston engineering solutions. Introduction to actual field repair for skirt attachment portion in. Ports are spaced according to the depth of the material being repaired and are filled via lowpressure injection and then capped from the bottomup, creating the best opportunity for a continuous, permanent repair of the whole crack or spall. This leads to coke drums experiencing significant downtime throughout their useful life to make needed repairs or partial shell replacements.

Coke drum design and fabrication issues pressure vessels. Figure 3 is a polar plot of the coke drum data from figure 2 at an. Jagged cracking in the heataffected zone of weld overlay. It is then charged to the product fractionator for separation into naphtha, diesel oils, and heavy gas oils for further processing in the. Repair existing cracks to keep your drum rotating and producing right now drum shell. Figure 2 shows a typical bulge map of a coke drum, where the entire vessel is shown in a rolled out view. Repair cracks in foundations, concrete floors, and driveways. These failures are typically aligned with the circumferential welds, with similar failures appearing in vertical plate seamless vessels designs as well. It is a problem that has plagued refineries for decades. Coke drum design services stress engineering services, inc. T5a20 coke drum life improvement a combined approach. Bulge repair of coke drum utilizing temperbead refinery in canada 8 coke drums bulge repair of coke drum utilizing basic data material. As shown in figure 1, a colour palette is used to visually display coke drum radius, much like an ultrasonic cscan. Coke drums have been studied by a number of refining and engineering companies.

The drum operates at about 50 psi but this pressure varies during the cycle. Just like chips in your windshield will eventually propagate into a full crack, high stress on a point weakness in a dryer drum could propagate into a lifethreatening drum crack. Breaking the repair cycle to petroleum coke chute wear. To illustrate this, figure 1 is a photo that was taken from a coke drum shell replacement project, illustrating the severity of the distortion. Successful reversal of deterioration in an old set of coke. Enhancing infrastructure coke drum engineered repair and. Azz specialty welding has provided advanced repair options to address the more prevalent coke drum failures for decades. Coke drums api survey of 54 drums 61% bulging 97% circumferential cracking 78% skirt cracking cracking occurs within 5 to 7 years why are they cracking andor bulging operating on shorter cycles running different feedstocks werent designed for low cycle fatigue or compressive strength of coke. Mo plate that was recovered from a retired drum that was in operation for 20 years and inconel 625 weld overlay. The cracked lighter product rises to the top of the drum and is drawn off. Assessment, mitigation, management and extension of coke drum. Custom designed mechanical welding and machining solutions. Result were intended as a guide to rank bulges for inspection priority as a. In addition to bulging and cracking, localized crack repair and emergent.

Finding better ways to repair cracks in coke drums. Stress engineering services is pleased to announce the 2016 coke drum reliability workshop to be held february 1617, 2016. Citgo lemont refinery, a large petroleum refinery in the united states, planned a future installation of new coke drums. Cia inspection premiere coke drum inspection service. Bulge repair of coke drum utilizing temperbead refinery in canada bulge severity and growth customer used stress engineerings bif t ltbl itfth bif internal cracking likelihood bulge repair of coke drum utilizing bif to evaluate bulge severity of the drum surface. This document is intended to provide a template and act as a checklist for items to be included whether the coke drum s be shop fabricated, field fabricated, new or replacement. From complete replacement to the replacement of drum sections, nooter. Due to the metallurgy of modern coke drums, repairs require sophisticated weld procedures and care must be taken to follow the procedures or the crack condition can reoccur. After filling, the coke is cooled by a steam strip and a water quench and then it is removed from the drum. Coke drum services brochure stress engineering services.

Figure 2 outlines the typical features of flaws found in the clad restoration weld of coke drums. From beverage dispensers to streamlined racks to technology to keep customers connected, the cocacola company has the right equipment to boost sales. The reliability of coke drums has become a central theme to many refineries worldwide as high value products are recovered from refinery residuum. Cracked brick and mortar joints on the exterior of your home are unsightly and the open up your home to pretty nasty damage like water penetration and mold. In the last decade, us petroleum coke production has been steadily increasing. Coke drums operate mostly in pairs to permit the continuous operation of the delayed coking unit. Coke drums are an integral part of coker units and serve as the final step in the cracking process.

Assessment, mitigation, management and extension of coke. Long story short, weld overlay can have a 10x increase in the fatigue life of the coke drum. But, before the installation could be completed, structural repairs to the. The entire cycle lasts between 2448 hours as shown in figure 2. After the blade drill has bored through the coke bed, high pressure water jets from the base of the stem are used to cut and dismantle the coke from the drum, allowing it to fall through the lower opening into a pit, or rail car. Bottom deheading device weight to be supported by drum table top. Brick restoration specializes in undetectable masonry crack repairs but we know that some people are diyers at heart and want to try their hand at masonry crack. Coke drum cracking assessment industry standard api 5791 asme ffs1 contains elaborate rules for the assessment of cracks in pressure equipment. For support skirt crack repairs, azz specialty welding utilizes proprietary welding processes to replace the critical welds and, in some cases, install new sections of skirt, also without requirement for post weld heat treatment.

Jan 10, 2011 shargay, cathleen, singh, anil, munsterman, tim, and antalffy, les. Assessment, mitigation, management and extension of coke drum life through equipment health monitoring systems and on line inspection abstract. Assessing the structural integrity and remaining life of coke. Breaking the repair cycle to petroleum coke chute wear plates. The main function of these units is to boil the residual oil feed to the thermal cracking temperature in order to produce gas oil and petroleum coke. For best results and longer life, a hand drum should be evaluated by a professional before attempting any sort of home repairs to its shell or to the natural animal skin drum head. Assessing the structural integrity and remaining life of. The overhead vapors from the coke drums flow to a fractionator, usually called a combination tower.

Whether you need new headsskins on djembes, congas, bongos, a piece of hardware repaired, or complex jobs like rewrapping drums and cutting bearing edges, just drums has the tools and expertise to get the job done right. It first outlines the potential damage mechanisms resulting from coke drum operation, which are primarily thermal fatigue and bulging and also embrittlement, sulfidation and erosion. As the drum ages, cracks occur more frequently, repairs become more common, and eventually the drum needs to be replaced because the. The 4 drum drill tower structure was removed in one piece to facilitate the replacement of the 4 drums that set inside the structure. Api 80% of all coke drums in operation are experiencing cracking. Cracks on skirt attachment welds in coke drum fabricated in 1979 installed in a coker plant in japan were completely repaired by the team of. From complete replacement to the replacement of drum sections, nooter construction has pioneered many of the industry solutions used today. The purpose of this workshop is to provide updates on the latest coke drum technology and to continue to discuss and develop best practices in key areas to improve coke drum reliability, performance and safety. Delayed coke drums are operated under severe conditions of cyclic heating and forced. We draw on our extensive design, testing, analysis, measuring, and monitoring capabilities, along with our vast industry experience, to solve problems that improve plant integrity, safety, and. Prevent future cracks and flexing so you dont have to keep spending your maintenance budget on fixing the same thing over and over installation of internal andor external drum structural enhancers rings or rats. This approach has been implemented in over 100 coke drums throughout the world with flawless performance. Our focus is always on longterm reliability to build longterm customer relationships. Deheading device bottom andor top supports are not to be welded to the drum shell or heads.

Since 1993, ciai has performed nearly site inspections of coke drums of all sizes and metallurgy. Tungsten inert gas tig welding, is an arc welding process that uses a. Crack repairs houston wheel repair can easily weld cracked rims by high quality aluminum welding. As the drum ages, cracks occur more frequently, repairs become more common, and eventually the drum needs to. Prior to filling, the drum is preheated with overhead vapor gas from its twin drum. Coke drum reliability workshop nondestructive testing. E 2 corporate headquarters e g industry 20600 chagrin. A delayed coker is a type of coker whose process consists of heating a residual oil feed to its thermal cracking temperature in a furnace with multiple parallel passes. Figure 2 shows the process inlet temperature in a drum. Delayed coking operation is described along with the ever present desire by owners to shorten cycle times to maximize unit throughput. Mar 16, 2016 the 4 drum drill tower structure was removed in one piece to facilitate the replacement of the 4 drums that set inside the structure. In 2012 at a refinery in the chicago suburbs, a six 6 drum delayed petroleum coking unit required significant repairs to the coke drum support structure. This coke drum has been in service since 1967, and repairs with weld overlay were conducted on the coke shell in 2011 when weld overlay bands were installed for strengthening the circumferential seams in the lower sections sections 2, 3, 4, and 5 of the coke drum. Ae can also be an essential tool to monitor crack growth when shutdown is not preferred but cracks.

Figure 2 coke drum shell bulging petroleum coke produced by the delayed coking method has been commercially manufactured for more than 70 years. Structural repairs using automated weld overlay ipeia 2015 samman et al. Our unique process consists of installing a highly engineered weld metal overlay to the existing vessel to modify the structure of the vessel to mitigate bulging and cracking caused by the low cycle fatigue mechanisms to which the vessels are exposed. Coking cycles, from fill start to fill start, last between 24 and 48 hours. Mechanical testing, metallurgical examinations, nondestructive evaluations. In place valve seat repair via machining and welding services. Ta to retro fit 4 four coke drums to accept new delta valves coke drum material. But, since coke drums are exposed to spatially and temporallyvariable thermomechanical loads that cannot be accurately defined or predicted, a standard deterministic assessment of a coke drum crack. Coke drum repair troubleshooting, us lloyds register. If a crack is discovered usually at the welds, the coke drum needs to be taken out of service and repaired typically while the other drum is still in operation. One of the most common failure mechanisms of a coke drum shell is the bulging and cracking of the cylindrical pressure boundary.

Repairs are carried out by either drilling or mounting injection ports into the affected area. In delayed coking, coke drums are operated in pairs where only one drum is filled at a time. After the first drum is full of the solidified coke, the hot mixture from the furnace is switched to the second drum. New drum fabrication conventional design new drum with vertical plate technique 1. The solid coke is deposited and remains in the coke drum in a porous structure that allows flow through the pores. Unfortunately, conventional repair practices may take the unit out of service for too long or the repair life is too short. Replacement sections are easily subassembled to allow retrofitting of existing coke drums. Depending on the operating parameters, type of coke produced, feedstock and other variables, the cycle time of a given unit can be from as little.

Proceedings of the asme 2010 pressure vessels and piping divisionkpvp conference. This may not be permanent because all surface repairs will eventually get loose or crack. Coke drum repaircoke drum repair refining community. Ranging from 20m to 29m one of the cokers was experiencing. This document is intended to provide a template and act as a checklist for items to be included whether the coke drums be shop fabricated, field fabricated, new or replacement. The purpose of this meeting is to provide updates on the. The skirt includes one circumferential horizontal plate attached to the coke drum, and the circumferential horizontal plate is slidingly sandwiched between a lower supporting plate that supports the weight of the drum through the circumferential horizontal plate. An alternative foundation repair method is to excavate and patch the crack on the exterior. Below is an open art refinery delayed coker unit dcu coke drum specification. Today, azz specialty welding is the largest provider in the industry of structural repairs for coke drums. Comparison of stress and strain methods for bulging assessment of coke drums pvp 2014. In that case, consult a professional drum repair technician to see if a full replacement of the drum head is a better option. Crack repair and stitching resin injection twistfix. Cia inspection ciai is the premiere coke drum inspection service in the world and the only firm completely dedicated to the inspection of coke drums.