... precompetitive research that has broad industry support. Research Cooperative research Pulp and Paper Digesters Recovery Boiler Composite tubes Suction Rolls Alloys Duplex Stainless Steels FRP Corrosion Inspection INTRODUCTION The invention of the Tomlinson recovery boiler in the early 1930's, which...

...Carbon steel scraper arms can also experience extensive pitting corrosion during muriatic acid cleaning of the digester. Corrosion can occur even in inhibited acid cleaning solutions especially if the temperature is above 120°F (50°C). Poor circulation during acid cleaning can result in more...

...Stainless steels are highly resistant to corrosion in most alkaline pulping liquors. One notable exception is batch digesters where the corrosion of stainless steel cladding and weld overlays can be very rapid ¹⁰ . There is also some field experience with corrosion and stress corrosion...

...alkaline pulping liquors corrosion testing digesters quality assurance welding white liquor INTRODUCTION The superior corrosion resistance of duplex stainless steels in kraft digester liquors compared with other materials of construction (carbon steel, austenitic stainless steels, nickel-base...

... salts and H₂S. Some of the significant corrosion problems that exist in the pulp and paper industry are the following: Continuous digester pitting and stress corrosion cracking Abstract A large number of corrosion problems prevail in the pulp and paper mills owing to high alkalinity...

... be poisoned so that nascent hydrogen can diffuse into the metal rather than recombining on the metal surface. FAILURES DUE TO EAC Failure of a Continuous Digester due to SCC Chloride SCC in stainless steels is typically branched in cross section ( Figure 2 ). The cracks are most often transgranular but can...

...AP of batch digesters helps the natural passivation process that occurs during a batch cook. Passivation without AP may take 1 hour. With AP passivation is typically accomplished within minutes. AP has been used in many batch digesters in Scandinavia but has yet to be tried in North America. Weld...

...Abstract The numerous mechanisms of corrosion and cracking in kraft batch and continuous digesters are reviewed. For carbon steel these include stress corrosion cracking, general corrosion thinning, pitting corrosion, and preferential attack of welds and weld buildup, and erosion-corrosion...

... been reported, although these are very limited in number: one digester, one calorifier, two pulp storage towers, and two bleach plant filter washers, of a total of more than 700 identified installations. duplex stainless steel pulp digesters calorifiers impregnation vessels oxygen reactors pulp...

... stainless steel black liquor carbon steel corrosion testing digesters duplex stainless steel flash tanks green liquor pulp and paper storage tanks white liquor INTRODUCTION The stainless steel specimens were all provided in the cold rolled form (3 mm thick). The stainless steels were cut...

...IGA was discovered in the stainless steel cladding of a kraft continuous digester a year after it went into service in 1989. The IGA was most pronounced behind the cooking and extraction screens. Subsequent annual inspections showed the corrosion to be proceeding at a rate that, if continued, could...