Coal, Emissions

Coal abrasionis tough business

Issue 5 and Volume 100.

Coal abrasionis tough business

Abrasion wear on coal handling equipment can add significantly to the total cost of the equipment. A tougher, longer-lasting finish can greatly increase the value of such equipment. Balancing the need for durability with a requirement to keep purchasing costs low can create a long, difficult search for the right piece of equipment.

Van Den Bos Inc., Paw Paw, Mich., an industrial fabricator that manufacturers a wide range of equipment, including coal buckets used in coal-fired electricity generating plants, has found a tough answer to this riddle.

Steel considerations

Because Van Den Bos` products are subject to heavy abrasion, sliding friction and corrosion, they used to require frequent replacement.

Then Van Den Bos began specifying Nitronic 30 stainless steel for all its coal buckets in 1991. Jerry Van Den Bos, president, said he and his customers have been “very pleased with the performance characteristics,” of the stainless steel, which is engineered by Armco Inc., Pittsburgh, Pa.

Material costs in such applications must include consideration of maintenance, downtime and replacement costs associated with the material`s performance. Such costs, if overlooked, can wreak havoc with production time and budgets. Engineers at Van Den Bos have found that over the life of a typical piece of equipment made from standard carbon steel, costs are almost three times less when the same equipment is made from Nitronic 30, despite a lower initial cost.

It is the chemical makeup that allows Nitronic 30 to endure a higher degree of abrasion and corrosion than other stainless steels and materials. Nitronic 30 is self-polishing for improved sliding, making it well suited to high-friction applications like coal chutes. The material is also impact resistant in heavy-duty applications, such as truck bedliners and conveying equipment.

Van Den Bos reports that Nitronic 30 linings last twice as long as traditional steels used in the same applications.

Detroit Stoker, Monroe, Mich.-based designer and manufacturer of material handling systems for power plants, has started using Nitronic 30 in its chutes, hoppers and conical distributors.

This coal-handling equipment is particularly prone to wet, fine coal dust buildup, which, when coupled with a 24-hour-a-day sliding friction environment, can lead to serious abrasion and corrosion problems.

Equipment replacement can contribute significantly to cost in these items as chutes built with low-cost carbon steel must be replaced every five to seven years. Tougher grades like Type 304 stainless require replacement every 10 years or so.

Detroit Stoker reports that with Nitronic 30, no liners are needed in its conical distributors. Projected lifetime of these distributors is 20 years. The endurance can save on maintenance costs and limit the downtime associated with replacement of worn chutes.

Circle 136