Engineer Utilizes Insulation-Performance Analyzing Tools

Maria T. O’Brien

December 1, 2004

In his work with insulation, this month’s Insulation Star meets his biggest challenges when determining the causes of hot surface temperatures on insulated equipment. The equipment his company insulates is usually very large, and when a client reports hot surface temperatures, outer lagging needs to be removed for inspections. The problem can be localized or caused by something such as missing draft barriers, often several floors below the detected problem area. When several problem areas are identified, it is typically not the same problem in all areas, and it is often an expensive and time-consuming process until all hot areas are remedied.

Douglas DeVault, principal engineer, has been with The Babcock & Wilcox Company for more than 20 years. He is involved with thermal insulation and also research and development of new technologies for improving boiler performance and emissions reduction in large electric utility coal-fired boilers. He is also his company’s product technical representative for refractory, insulation and lagging as well as structural heat transfer.

For DeVault, recent significant advances in the industry have come in the form of new tools for analyzing insulation performance.

"With the advancements in computer equipment, the calculation of cold face temperatures and required thickness are quickly at our fingertips. This is particularly true when evaluating a system that requires a three-dimensional heat transfer analysis, which tends to be a lot more complex than one-dimensional thermal calculations," said DeVault, who holds a degree in mechanical engineering with an emphasis on heat transfer.

Standard manuals for the equipment his company insulates inform designers and contractors how to install the insulation, as well as how much to use. It is DeVault’s responsibility to periodically review these standards and keep them current. He becomes involved in specific contracts only when there is something that the standards do not address or if problems come up on a specific job.

DeVault stays current with his knowledge of new insulation products and procedures and industry standards in part through customer and vendor contacts as well as magazine articles. However, his most valuable resources are the field service engineers and sales force, who are in constant contact with a large diverse number of people and insulated systems. New items are brought to DeVault’s attention for evaluation.

For DeVault, thermal insulation plays a key role in regard to the new ASME Power Test Code 4, the code that defines boiler test procedures for fuel efficiency.

"Under this new code the customer has the option of measuring surface temperatures and calculating heat loss from the boiler and related equipment. This is a different twist from the past when this heat loss was based on a published curve versus boiler capacity. The implications of the new code are the possibilities of missing performance guarantees if the insulation system does not perform as expected," he explained.

In regard to bettering the industry and solving insulation-related problems, DeVault’s wish list begins with a way to manufacture block insulation with a foolproof method of assuring that the blocks are butted together tightly when installed.

"Currently, an inspection is used after installation and this task is left to supervisors-on large boiler or environmental contracts, much can be missed," he said. This problem would be solved by block insulation manufactured in a way to ensure proper installation.