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 SMARTGard HVTS was chosen for this on-site...
SMARTGard®: 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...