Pulp & Paper

Stop BLRB, Digester and Flash Tank Corrosion

IGS provides solutions to address operators’ problems within many of the critical boilers and pressure vessels used in the pulp and paper manufacturing process worldwide. We install corrosion and erosion resistant alloy barriers to protect mission-critical equipment at pulp and paper mills using proven HVTS on-site alloy cladding.


Corrosion Protection for Black Liquor Recovery Boiler (BLRB) Tubes

Common areas where our technology mitigates BLRB carbon steel boiler tube corrosion from high-temperature sulfidation attack with our thermal spray Cladding Systems are:

  • WaterWall Tubes
  • Nose Arch Tubes
  • Superheater Tubes

At IGS, we couple our technical expertise and application experience together to ensure our customers receive long-term, durable and measurable solutions, which increase their Recovery Boiler Reliability from a corrosion mitigation perspective. Our execution teams understand the dynamics of working in an outage environment and we recognize our customer’s need to meet their critical path maintenance schedules. IGS strives to deliver HVTS Metalspray® Cladding Systems on time, with the highest quality and safety standards in the industry.

Corrosion Prevention in Black Liquor Evaporators

Many LTV- and plate-type evaporators were manufactured out of carbon steel.  These units often see corrosion later in life due to increased solids content or temperature.  Some units just make it past their useable life.  Stopping the corrosion is a way to eliminate costly shell replacement. The IGS HVTS cladding systems are effective at extending asset life for 10-15 years.

Typical focus areas on plate type units are carbon steel to stainless steel welds where there is a heat-affected zone.  Also, areas in the lower head are more susceptible to corrosion. All areas in contact with liquor are more likely to corrode.  A good ultrasonic thickness testing program is important for determining which areas may need a protective barrier to stop further metal wastage or loss.

On the photo you can see IGS HVTS Cladding in the Lower Part and Corroded Carbon Steel in the Top Part of the Evaporator.


How to Stop Digester and Flash Tank Stress Corrosion Cracking

Digester vessel wall degradation due to corrosion, stress corrosion cracking, and erosion has always been a costly and repetitive maintenance challenge for pulp mills. Stress corrosion cracking (SCC) is the growth of crack formation in a corrosive environment. It can lead to unexpected sudden failure of normally ductile metals subjected to tensile stress, especially at the elevated temperatures characteristic for digesters and Flash tanks. To prevent SCC, we apply a Di-Arc 360  coating that provides a barrier between the process environment and the HAZ found in the welds. A major advantage is that thermal spray processes do not alter the digester substrate or induce any thermal stress, so the threat of application-induced cracking is eliminated. It has been effective in preventing SCC when applied over the HAZ at the weld seams or the weld overlay edges at the carbon steel interface.

We utilize our core technology, Di-Arc 360, to install corrosion-resistant alloy claddings in the field, mitigating corrosion in digester process environments since the early 1990’s. Our Di-Arc 360 cladding systems utilize known corrosion resistant alloys to provide a true protection barrier on the carbon steel and circular weld surfaces. The cladding typically lasts 7-14 years depending on the aggressiveness of the vessel environment. With IGS technology, there is no risk of weld dilution with iron so the installed cladding is inherently more corrosion resistant than weld overlay.

How We Execute Kraft Mill Corrosion protection Projects

Inspection and understanding the current wastage rates is the key. Knowing the substrate and fuel type allows IGS to custom design the material and application needed to solve the problem. We prepare the substrate to ensure the application quality of our thermal spray claddings. We mobilize on-site equipment specially designed for field application and advanced patented technology that enables the maximum bonding of materials.

Being a global company, we do not rely on increasing our pool of technicians with part-time help in the spring and fall and then reduce our pool of technicians in the winter and summer. It is always outage season somewhere, so we can maintain a strong experienced workforce year around. Call us now – we are glad to help.

IGS field experience

IGS has over forty years of experience in the Pulp & Paper Industry. Over the past 40 years, we have provided our HVTS Cladding Services and Technologies to many of the leading kraft mills around the globe. Our team of full-time experienced project managers, superintendents, foremen, safety managers, and HVTS technicians ensure that we are always ready to deliver high-quality on-site high velocity thermal spray cladding applications.

Free Consultation with IGS Subject Matter Expert

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