Case Studies

Thermal Spray Stops Alloy T24 Fireside Corrosion in Supercritical Boiler

This Power Plant provides steam to nearby industrial facilities using sustainable biomass (such as SBP, GGL, FSC, and PEFC) and industrial by-products (such as bio-propane) to generate power and heat.
SUPERCRITICAL BOILER The boiler has five rows of six burners on two sides. These burners are fed with coal, bio-propane, wood, and MBM (Meat and Bone Meal) – animal residue foam injected into the boiler. MBM is very erosive, so...
A SUPER ALLOY T24 BOILER The unique feature of this boiler is that it is one of the first boilers manufactured with alloy T24. T24 material is a novel superalloy, designed for strength at high temperatures that does not require...
ALLOY T24 WELDING ISSUES Welding this superalloy is difficult, especially without annealing or post-weld heat treatment. Non-alloy steel, a material used to produce typical boiler tubes, PH 265GH, is the easiest material to weld. The superheater material, 10CrMo9-10, is known...
As a result, these first boilers manufactured with T24 suffered many leaks after just a few hundred hours of operation. Welding experts from VGA and other parties involved helped them find the solution, enabling them to erect such supercritical boilers...
TESTING HVTS SUPERALLOY PROTECTION As the plant continued having multiple stoppages due to tube leaks, in 2019, they decided to apply a protective cladding onto a test area to evaluate its performance. IGS HVTS was chosen for this on-site job....
IGS HVTS – High-Velocity Thermal Spray HVTS cladding was also applied onto superheater hanging tubes facing soot blowers. Test areas were installed onto various locations of tube bundles as an alternative to thick metal protection shields.
A LEAK OCCURRED DURING HVTS TESTING After installing the trial HVTS application in August 2019, another forced unexpected shutdown due to a tube leak occurred in December that year. Although initially it was suspected to be in the IGS clad...
QUALITY INSPECTION PROGRAMME UT Quality inspected HVTS cladding and unprotected tubes. They performed tube scanning using a PEC Scan, Pulsed Eddy Current scanning, that delivers specific tube thickness mapping. This inspection was conducted in 2019 and again in 2021. By...
INSPECTION DISCREPANCIES AND RESULTS When comparing inspection results between 2019 and 2021, the inspection company immediately noticed that some areas appeared to have gained thickness. Cyril Narjoz, IGS Boiler Reliability Expert, commented:
“You need to keep in mind that first of all, you never read the same point two years later, it’s impossible. Even when you do the reading on the same spot, during the same inspection or the day later, you...
The inspection results were matched with the positioning of the HVTS cladded area. It was a challenge because it didn’t match the red area or the colored area of the thinning. Moreover, to make it a little more complicated, in...
“Nevertheless, what we can see in the area where we applied the HVTS the cladding, there’s much less thinning. And above the area, we have this red zone where we can notice up to nearly one millimeter per year loss...
FUTURE-PROOFING THE BOILER Initially, prior to evaluating the readings, the plant had commissioned IGS to expand their HVTS cladding scope to protect a 35 m² surface area finishing the band and protecting a band below. However, after evaluating the readings...
HVTS APPLICATION IN 2021 The expanded scope was completed in record time by IGS utilizing additional operational resources to speed up the process, with work proceeding simultaneously on several levels. Plant representative said: “We really appreciated IGS’ flexibility during the...
SUPERHEATER TUBES This project’s second exciting part included the hanging superheater tube bundle with steam at 320 bar / 5400C. These tubes face the soot blowers that are operated at regular intervals to clean deposits of the tube surfaces. Welded...
Cyril Narjoz commented: “Cladding supplied by a different vendor was also applied and tested in a similar area and performed well.  The key difference is – these other tests were sprayed in the workshop before being installed in the boiler....
CONCLUSION As T24 material is extremely challenging to weld. One of the major benefits of the IGS HVTS solution is that no welding is involved in its application. Since HVTS is not welded, it does not generate any alteration to...

Efficiency Increases in Catalytic Reformer

Process Overview

Catalytic reforming converts low-octane, straight-run naphtha fractions, particularly heavy naphtha into a high-octane, low-sulfur reformate, which is a major blending product for gasoline/petrol.

The process is endothermic and is carried out by feeding a naphtha and hydrogen mixture to a furnace, where it is heated in a series of fired heaters to the desired temperature, 450° to 520°C (840° to 965°F), before passing through a series of reactors.

Thermal Inefficiencies In a high temperature environment, steel alloy process tubes will oxidize and scale will develop. This oxidation scale layer acts as an insulator and will lead to a decrease in heat transfer as the scale increases in thickness....
Ceramic Coatings Cetek’s ceramic coatings for process tubes prevent oxidation and scale formation for approximately two turnarounds. This thin-film coating maintains the process tube in a like-new condition, maximizing conductive heat transfer to the process and increasing radiant section efficiency....

Coating Refractory Lining

The Emissivity of typical refractory linings in fired heaters ranges from 0.45-0.65. When radiant energy encounters these refractory linings, much of the energy is reflected back and is absorbed into the flue gas and carried out of the radiant section, into the convection section and out the stack, with the majority never reaching the process.

High emissivity coatings for refractory surfaces increase surface emissivity to 0.92, a near black body. Radiant energy is absorbed by the high emissivity lining and reradiated across a broad spectrum. The reradiated energy is able to penetrate the flue gas and be absorbed by the process, increasing radiant section efficiency.

Heater Evaluation at a Refinery A refinery reported that excessive process tube scale on their catalytic reformer was creating a limitation and contacted Cetek, the pre-eminent global turnkey provider of ceramic high-emissivity coatings, for an inspection and recommendation. Cetek visited...
Post Application Report After the catalytic reformer was returned to service and conditions in the heaters were similar to the pre-evaluation conditions, a fired heater study was completed to measure the actual benefits of the ceramic coatings. The actual increase...
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Twice as Good and Twice as Fast: Reliable Boiler Tube Protection

Åmotfors Energi Åmotfors Energi has one of Sweden’s most modern thermal power plants. The plant was completed and commissioned in 2010. The power plant’s production capacity is 180,000,000 kWh per year. The heat and energy produced is mainly used by...
PROBLEM After discovering metal wastage in 2014 and having to replace a panel section in 2016, engineers decided to protect new panels with thermal spray cladding. SOLUTION Integrated Global Services (IGS) proposed a high velocity thermal spray (HVTS) alloy cladding...
Boiler Metal Wastage In summer 2014 corrosion was identified on the unprotected boiler tubes, above the weld overlay section. New panels were installed to replace corroded sections, needing cost-effective protection, which would also be faster to apply than weld overlay....
2020 Inspection Spot check inspection of the boiler in 2020 on both high velocity alloy cladding applications showed no reduction of metal thickness. Svante Amberg, Åmotfors Energi boiler engineer, commented: “We are pleased with the service provided by IGS. Reliability...
Routine Boiler Inspections IGS have certified inspectors who are able to evaluate the performance of any boiler tube protection, highlighting areas of improvement and advising on a suitable solution for erosion and corrosion issues. Soren Stutin, IGS boiler expert in...

Improving Radiant Efficiency in Catalytic Reformers

PROBLEM

Optimizing the operation of Catalytic Reforming Units is critical as these fired heaters consume large amounts of energy to provide the required heat for the process.

SOLUTION

Cetek partnered with PTTGC, Thailand, for a ceramic coating application in their CCR Platforming Heaters. Upon completion of the successful field application, once back in service, the results exceeded expectations and provided an excellent projected ROI over the lifetime of the coating.

Catalytic Reformer The unit of this study is a 27,900 BPD, 4-cell catalytic reformer located in Rayong, Thailand. Each heater has wicket style radiant tube configuration. The metallurgy of the radiant tubes is ASTM A335 P9; 9%Cr, 1%Mo. The refractory...
    PTTGC Catalytic Reformer
   
Tube Scale Formation The sample IR inspection image shown in Fig.1 provides an insight into the degree of scale formation and the surface temperature of the scale. As evident in the image, heavy scale presence was hindering heat transfer within...
Results of Cetek IR Evaluation The result of the Cetek evaluation was a recommendation that ceramic coatings should be considered for both tubes and refractory surfaces in all four cells. The calculated benefit showed that the improvement in radiant heat...
Application Any coating application requires strict attention to surface preparation and protection of areas of the fired heaters where necessary. The 9%Cr process tubes were grit blasted with a proprietary surface profile, required by the ceramic coating. In order to...
 
Conclusion The application of ceramic coatings in this heater proved exceptionally beneficial to PTTGC. Whether utilizing the fuel savings or production increase benefit, the payback to PTTGC was superbly quick. The approximate 11% benefit is in line with historical Cetek...
Results of the Application IR thermography analysis from before (left) and after (right) the application is shown below. The heavy scale present before is evident. Clean surfaces are observed one year after the coating application. This was calculated to provide...

Reliable Boiler Protection Supported By Long-Term EPRI Study

EPRI Study In the mid 2000s, a US power utility owner and EPRI performed a long-term study to determine if thermal spray technology would protect the sidewall tubes (adjacent to burner levels) from thinning caused by reduced sulfidizing atmospheres. A...
PROBLEM The boiler was experiencing tube wall thickness wastage caused by operating the boiler in a reducing atmosphere (low NOₓ burners)which results in sulfidation corrosion. This boiler is the newest of the 1300 mw units but experienced very similar corrosion...
SOLUTION During the Fall of 2019, the plant was in a major planned outage. A full furnace scaffold was installed for boiler maintenance and a tube assessment was performed. During the inspection, new wastage was discovered on the upper front...

Rapid Response To Address The Boiler Damage Zone

Scheduled Shutdown

The unit was in a scheduled outage in October 2019, at which time the fireside of the tubes in the boiler were inspected by robotic UT. Wastage was discovered on both sidewalls above the existing field applied overlay, rear wall slope and burners, and front wall slope and burners. The type of damage is typical for opposed wall fired pulverized coal boilers operating in a reducing atmosphere with low NOₓ burners.

Rapid Response

IGS was contracted to install 5450 EPRI Proven HVTS Alloy Cladding over the damage zones. IGS offered a rapid response and addressed the areas during the week of November 4, 2019. The IGS solution is a rather fast application – a total of 2,000 square foot of boiler tubing was protected with HVTS in 5 short days.

Safety First

The project was executed in accordance with the IGS Safety Program. Safety is, and always will be Integrated Global Services’ first and highest priority. Our Management Team is dedicated to becoming the industry leader in Health and Safety while our excellent safety record bears witness to this fact. A continuous improvement process is utilized that enables all levels of personnel to take part in identifying and fixing hazards associated within the workplace. This is marked by our Safety Committee that involves members of all areas and levels of IGS.

Quality

IGS Thermal Spray projects are performed in accordance with the IGS quality control standards which have been developed in to meet customer requirements. All site work will be executed in accordance to the accepted Quality Control Plan (ITP/QCP) and accompanying method statement. The final project QC package will be issued along with this report.

Blasting Away the Snowman

The Snowman Problem A cement plant in the Midwest has reported major buildup issues in their cooler, known as the “snowman”. A snowman is caused when clinker pouring out of the kiln does not move down through the cooler on...

Cementing a New Standard of Cleaning in a Sticky Situation

PROBLEM Sticky material fell into the chute in large chunks, blocking the chute. Oftentimes, the plant was forced to stop production and clean this chute every 5 hours. An average of 900 tons of production was lost per day equating...
Problem | The Failed Trio A cement plant in the Caribbean was experiencing issues in their raw material chute. Buildup occurred in the entire chute, but the principal problem was near the top. Sticky material fell into the chute in...
Evaluating Alternatives Jeff Shelton, IGS air cannon innovations pioneer, has commented: “Little has changed in the air cannon market over the last two decades, in terms of design of the cannon and its components. All the while, cement industry has...
EXPERT OPINION Chris Landers, IGS air cannon expert, has commented: “For air cannons to solve buildup issues they must be applied correctly. The air cannons in this application were not applied correctly in our opinion. We felt there were issues...
Smooth Solution Following a through evaluation and multiple consultations with IGS technical experts, a solution was identified and installed. A three-port multiplier with high velocity nozzles was fitted. The high velocity nozzle produces a high energy ball of air, moving...
Smooth SolutionIGS Big Blue Air Cannon installation – manual cleaning is no longer necessary.
Cementing a New Standard of Cleaning Efficiency and innovation are major drivers in the current climate. Cement plant managers, therefore, look for vendors who are able to fortify their resources by taking traditional systems and enhancing them for better performance....

Cutting Costs with Retrofits & Keeping Air Cannons from Retiring

PROBLEM Several cannon suppliers made the decision to no longer supply spare parts for their high-performance air cannons. This has coincided with the roll out of the next generation of air cannons.   SOLUTION IGS has developed a simple retrofit...
CUSTOMER Roanoke Cement Company LLC purchased 12 IGS retrofit kits in early 2019. Roanoke Cement is recognized for its clean manufacturing practices, energy efficiency practices, resource conservation and its outstanding safety record. Roanoke Cement is an Energy Star® Partner and the...
Is Replacement Necessary? Many air cannons that have been successful solving buildup problems do not require replacement and only call for the replacement of a few spare parts. However, recently, several cannon suppliers made the decision to no longer supply...
Inexpensive Retrofit Solution IGS has developed a simple retrofit kit that easily replaces the internal components allowing plants to keep their existing air cannons operating. The cost of a retrofit typically comes at a fraction of the cost of the...
IGS Retrofit   Inside Behind Piston
Inexpensive Retrofit Solution IGS made several improvements to the internals of traditional air cannons. First, the manufacture of construction was upgraded to coated carbon steel from aluminum. IGS experience with aluminum in this application is that the material is too...
Installation of New Components in Action Roanoke Cement purchased 12 IGS retrofit kits in early 2019. The kits were installed on existing air cannons within the plant. Some of the cannons were still firing while others had not been operational...
Renergia Perlen waste to energy plant in Switzerland

HVTS Stops Alloy 625 Weld Overlay Corrosion in a WtE Boiler

Stopping Fireside Corrosion in WtE Boiler A waste to energy boiler was experiencing fireside corrosion. Shop applied Alloy 625 weld overlay was showing signs of premature accelerated degradation. IGS was contracted to apply an HVTS cladding on top of the weld overlay...
Renergia Perlen The Renergia waste incineration plant is a joint effort of all waste disposal associations from Central Switzerland and Perlen Papier AG. Renergia Zentralschweiz AG is responsible for more than just recycling waste from Central Switzerland. It supplies Perlen...

WTE Boiler Fireside Corrosion of Alloy 625 Weld Overlay Cladding

The Hitachi Zosen Inova (HZI) furnace installed at Renergia is an inclined moving grate four-pass waste to energy boiler with an external economizer. The boiler’s thermal capacity is 47MW with the steam flow of 58 t/h and steam pressure of 41 Bar at 410°C.

Alloy 625 weld overlay was shop-applied on the fireside water wall panels to protect the WtE boiler tubes from fireside corrosion. After months of operation, an inspection revealed accelerated degradation of the Alloy 625 just above the grate.

Several solutions were considered to manage the boiler tube metal wastage and improve reliability and lifetime of the water walls, including replacement, field applied weld overlay and thermal spray.

Evaluation of Alternatives The replacement of affected water wall sections with new tubes would have been time-consuming and expensive, considering the estimated frequency of replacement of 5 years or less. Like-for-like weld overlay repair is an intensive and time-consuming solution....
HVTS Application IGS HVTS application took place in 2017 on a 20m2 area located on the left membrane wall at the very low furnace of the moving grate WtE boiler above the refractory. The plant also had a thermal spray (TS)...
Weld Overlay Protection: Inspection and Results Markus Benz, head of maintenance at Renergia Zentralschweiz AG, commented: “IGS has been selected in November 2017 to apply ~20m² of their IGS material using their HVTS technology. They mobilized efficiently and performed within the...
2020 Inspection and Results The latest inspection in 2020 has confirmed that HVTS IGS5470 is performing in line with expectations and is protecting weld overlay areas from further corrosion.