NOTE: The sponsor of this content may contact you with more information on this topic. Click here to opt-out from sharing your email address with this sponsor. (This link will not unsubscribe you from any other BIC email list).
Hot spots in primary reformers represent a challenging and potentially costly maintenance issue for processing plants. These localized areas of excessive temperature not only threaten structural integrity and operational continuity but can also lead to substantial economic losses through forced shutdowns. Learn common causes of hot spots, inspection methods and how to fix a hot spot on a live fired heater, with recent case studies.
Understanding the challenge of hot spots on primary reformers
Managing hot spots in primary reformers
A typical hot spot on a reformer shell
Primary reformers are critical components in chemical and petrochemical processes, where maintaining optimal temperature distribution is essential for both operational efficiency and equipment longevity. Hot spots typically manifest in reformers because the refractory lining has become compromised. Refractory linings are insulating and minimize heat loss, making them essential to retaining the high-temperature environment.
Refractory maintenance and repairs are typically undertaken during planned shutdowns. If refractory failure results in an unplanned shutdown, it can cost plants more than $1m/day in lost production.
Common causes of hot spots
The two most common root causes of hot spots are often refractory anchor failure or premature aging of the refractory itself due to localized flame impingement from burner operations.
1. Refractory anchor failure
Refractory anchor failure often occurs due to corrosion of the welded joint between the anchor and the external steel shell of the fired heater. This failure mechanism typically involves:
- Hot flue gases penetrating through the refractory lining
- Condensation of these gases upon reaching the cooler shell
- Rapid oxidation or corrosion of the weakest point, which is usually the weld
Once the anchor support is compromised, individual refractory components such as bricks or modules can fall away, exposing the metal shell. This creates a domino effect, leading to the failure of adjacent refractory lining.
2. Flame impingement
Unless specifically designed, flame impingement may cause localized areas of premature failure of the refractory, leading to loss of insulation and hot spot formation.
Consequences of hot spots
Hot spots can trigger interconnected problems that severely impact operational efficiency, structural integrity and equipment longevity.
How to inspect primary reformers for damage
Often the first sign of refractory failure is a hot spot on the external steel shell since direct observation of the problem area is not possible. Integrated Global Services (IGS) has designed and developed a Cetek® Lancescope™ fired heater inspection tool. It allows the undertaking of a high-temperature furnace inspection to determine the scope of the problem, often avoiding an expensive shutdown of the heater.
The hot inspection system uses a state-of-the-art digital camera system, which provides clear, detailed images of problem areas up to 3000°F (1650°C). The furnace inspection system can be inserted into openings as small as 3” (7.62cm) and reach up to 20 ft (6m). In applications below 1000°F (540°C), the heater inspection system provides illumination via a high-temperature light source for optimum clarity.
The benefits of performing a hot inspection include:
- Performed while the unit is in operation
- Provides insight into production availability
- Identifies damage in early stages
- Allows for a planned repair schedule
- Reduces maintenance costs
- Minimizes repair downtime
- Maximizes production
How to fix a hot spot on a live fired heater
Preventative maintenance is always recommended, however, if a hot spot does occur, there are several options to consider. One option is to interrupt production to take the asset offline and carry out conventional repairs. Alternatively, the furnace can continue to run at reduced performance until the next planned turnaround. However, this could exacerbate any existing damage.
Alternatively, an online refractory repair service is offered by Hot-tek™, where there is no need to bring the heater off-line and production will not be interrupted or capacity limited.
A team of refractory technicians can be mobilized at short notice and the repair involves creating minimal access point openings to insert specially designed components and repair material, delivering a semi-permanent repair lasting at least until the next turnaround.
Case study 1: Live repair solution in Qatar
Fertilizer plant overview
Asset owner:
Leading fertilizer manufacturer in Qatar
Operations:
Six trains in ammonia and urea production
Managing hot spots in primary reformers
Repairing a hot spot on a live fired heater
Challenge:
Hot spot identified in Ammonia train 3, necessitating urgent repair
A leading fertilizer manufacturer in Qatar recently faced a critical hot spot issue in their third ammonia production train's reformer duct area. The situation was particularly challenging as initial repair attempts had failed. The original repair strategy of welding a patch plate proved insufficient, with subsequent cracking occurring at the interface between the substrate and the new alloy plate.
Evaluation of available options
The plant could repair the hot spot offline by isolating the train, but that option would prove costly. The plant would have faced a minimum two-week shutdown.
The economic impact of avoiding such a shutdown is substantial. Another alternative would be to repair the hot spot on a live reformer during its normal operation. Such repair requires expertise and equipment not typically possessed by general contractors.
As a result, the plant reached out to IGS, an efficiency and reliability solutions provider. The implementation of Hot-Tek™ Hot Refractory Repair (HRR) technology enabled repairs to be completed during normal operations, eliminating the need for a costly shutdown. The repair was executed over nine shifts while maintaining full production capacity.
Plant manager feedback
The plant manager said:
“The entire plant management witnessed the installation process, appreciating the innovative approach that averted a potential shutdown. We even hosted a small celebration at the end of the project.”
Key outcomes included:
- Successful repair without operational interruption
- Extension of the maintenance window by one year
- Improved refractory performance post-repair
- Significant cost savings through shutdown avoidance
Case study 2: Internal refractory repair on a live small modular reactor
Plant overview
This project took place at a major U.S. fertilizer manufacturer producing a diverse range of products including:
- Anhydrous ammonia
- Urea and urea blends
- Ammonium nitrate solution
- Phosphate and potash
- Ammonium polyphosphate
- Sulfur-based products
The challenge
The plant faced a critical maintenance challenge when a significant hot spot developed on their ammonia reformer's external steel shell at a former manway location.
Refractory maintenance and repairs are typically undertaken during planned shutdowns. If this refractory failure resulted in an unplanned shutdown, it could have cost the plant more than $1m/day in lost production.
Other challenges included:
- Operating conditions included bridgewall temperatures of approximately 1850°F
- Complete failure of 7-inch refractory lining
- Visible steel distortion due to excessive temperatures
Initial hot spot repair attempt
The plant personnel attempted to repair this area on their own by installing a steel box over the affected area and filling it with castable refractory.
This temporary solution failed within two weeks, highlighting the need for a more robust approach. Facing the prospect of an expensive emergency shutdown, plant management sought expertise from IGS.
Live small modular reactor repair solution implementation
IGS deployed its proprietary Hot-tek HRR service, which enabled repairs during normal operations. The repair process involved several steps:
- Creation of access points under negative pressure
- Installation of protective refractory to shield workers from radiant heat
- Installation of hot refractory baskets flush with existing refractory
- Management of structural hazards, including careful handling of an exposed structural beam
Key technical achievements
The project was successfully completed in three days, maintaining full operational capacity throughout the repair.
The solution resulted in reduced temperature in the primary repair area from over 536°F to under 100°F.
IGS successfully addressed a second identified hot spot, bringing temperatures down from over 500°F to 70°F.
Case study 3: Live heater maintenance saves methanol complex $30 million
Located in the Kingdom of Saudi Arabia, the largest methanol producing complex in the world had hot spot issues in two separate furnaces.
Localized refractory failure leads to hot spots. In this case some hot spots on the external shell reached temperatures of 915°C. These hot spots present a health and safety hazard, energy wastage, poor performance and even complete fired heater shutdown.
Hot-tek repair on live heater
Over 80 hot spots have been safely repaired on live heater units, 3 and 5, back-to-back, over the course of one month.
$30 million savings
The only viable alternative to the Hot-tek solution would be to shut down the heaters and repair them offline.
Unit 5 produces $2.3 million of methanol per day. Conventional repairs would have taken 8 days to complete.
Unit 3 produces $1.2 million of methanol per day. Conventional repairs would have taken 10 days to complete.
Eliminating the need for shutdown and any loss of production has saved the complex $30 million.
Revolutionizing reformer maintenance
Managing hot spots in primary reformers remains a time-sensitive challenge for processing plants. These areas not only pose immediate risks to operational safety and equipment integrity but can also result in substantial financial losses if not addressed promptly and effectively. While traditional approaches to hot spot repair often require downtime, potentially resulting in millions of dollars in lost production, there are solutions available to repair hot spots online.
Advanced technologies such as HRR enables plants to conduct repairs while maintaining normal operations, effectively eliminating the need for costly shutdowns. The case studies presented in this article demonstrate the substantial economic benefits of this approach, with some facilities saving upwards of $30 million by avoiding production interruptions.
The future of primary reformer maintenance lies in these modern technologies and methodologies that prioritize both operational continuity and equipment integrity. Plants that adopt such solutions position themselves to achieve greater operational efficiency, reduced maintenance costs and improved long-term reliability of their critical equipment.
To access exclusive Hot-tek offers in February & March 2025, visit integratedglobal.com.
