Problem

India’s leading state government owned pulp and paper manufacturing plant located in southern India with an integrated power plant, sugar plant and its own forestation. Pulping mill is bagasse and eucalyptus tree raw meal based. The pulping mill and paper plant OEMs were Bauer Refiner and Andritz AG Pressafiners.

1. Pulping mill Breaker Bars suffered severe wear-corrosion
2. Pressafiner Screen Bars suffered wear-corrosion
3. The OEMs were charging high for replacement parts with long delivery period to supply the spares as long as 12 months
4. Materials for breaker bars and screen cage pressafiners were Cobalt Alloy 6 and lower cost solution 17-7 PH precipitation hardening stainless steel

Evaluation, Assessment, Recommendation And Solution(s)

ACME team visited the plant and made detailed evaluation of wear, corrosion and failures of the breaker bars and pressafiners.

ACMECAST successfully developed, manufactured and supplied Bauer Double Disc Refiner Spares when OEM declined to provide spares for its equipment siting old discontinued model as the reason and continuously suggested the Pulp and Paper Plant to replace with new Bauer Double Disk Refiners.

ACMECAST successfully reverse engineered breaker bars- main cage and manufactured them in Modified ASTM A 743 Grade CA-40 and CC-50 alloys, solution annealed and tempered martensite and bainite final microstructures.

ACMECAST also developed and supplied pressafiner screen bars based on old samples in ASTM A 743 CA-40 Modified alloy.

Result

Breaker bars main cage performed well and offered lower life cycle cost solution with 40% cost savings, faster delivery and import substitute solution to the plant.

The pressafiner screen bars were successfully developed after three iterations as those developed by us were from precision sand casting (ceramic coated) route rather than lost-wax investment casting process. The pressafiners were machined, and precision grinded to eventually achieve and maintain the same tolerances that had been obtained by precision grinding investment cast pressafiners bars. The performance of ACME Modified ASTM A 743 CA 40 alloy was better than 17-7PH alloy of OEM. Cobalt Alloy 6 as component metallurgy was not selected due to its high cost.

Many other import substitute replacement parts were developed and supplied to the pulp and paper plant, including Air-Injection Nozzles for CFBC Boilers at its power plant along with blow pipe assemblies. ACMECAST was recognized as most innovative vendor by the plant management and operational team towards saving foreign exchange currency and indigenously developing parts in high performance alloys. To our surprise we were approached by the OEM to supply the spares to them rather than their customer plants.