Careers 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 using both proven HVTS® on-site alloy cladding and automated weld overlay technologies, selecting the most appropriate solution based on the equipment, operating environment, and corrosion mechanism.
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 Protect Digesters and Flash Tanks from Corrosion, Stress Corrosion Cracking and Wall Loss
Digester vessel wall degradation due to corrosion, stress corrosion cracking (SCC), pitting, localized wall loss, and erosion has always been a costly maintenance challenge for pulp mills. Extraction and washing zones within continuous digesters are particularly susceptible to corrosion damage that can threaten vessel integrity and reduce equipment life if left untreated.
IGS provides both thermal spray cladding and automated weld overlay solutions for continuous digesters and flash tanks. Depending on the degradation mechanism, our engineers recommend the most effective repair strategy. Automated Stainless Steel 309LSi weld overlay restores corroded extraction and washing zones, repairs localized wall loss and gouging, and provides long-term corrosion protection during planned outages.
Where stress corrosion cracking is the primary concern, IGS utilizes its Di-Arc 360 thermal spray cladding technology. The coating provides a corrosion-resistant barrier over the heat-affected zone (HAZ) at weld seams without altering the digester substrate or inducing thermal stress, eliminating the risk of application-induced cracking. Because thermal spray cladding does not experience weld dilution with iron, it provides excellent corrosion resistance for SCC mitigation, while automated weld overlay is used where structural restoration and wall rebuild are required.
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. Depending on the application, this may include HVTS® alloy cladding or automated weld overlay systems installed during planned outages. 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
Over the past 40 years, we have provided our HVTS® Cladding Services and Technologies to many of the leading kraft mills around the globe. Today, IGS also supports pulp mills with automated weld overlay solutions for continuous digesters and other critical pressure vessels requiring corrosion restoration and long-term protection.
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.
Watch: How did this Pulp Mill Achieve a Dramatic Reduction in Forced Outages of its CFB Boiler?
This particular pulp and paper mill approached IGS due to experiencing a tremendous level of reliability issues. Since the application of IGS HVTS® cladding to critical areas of the CFB boiler, as part of our SMART Gard solution for counteracting boiler tube erosion and corrosion, the mill has seen a dramatic reduction in forced outages. This reduction is due to the superiority of IGS’s HVTS® cladding compared to previous cladding solutions from other providers.
Free consultation with an IGS Subject Matter Expert
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