Delamination of fiberglass reinforced plastics in flue gas environments

Fiberglass reinforced plastic, FRP, is an often-used material in corrosive environments such as flue gas ducts and stacks in incinerator. Flue gas ducts and other equipment may be exposed to changing operating conditions with rapid shifts between humid flue gases and dry and hot flue gases. The thermal shock that the material is exposed to, risks giving delamination with high maintenance costs as a result.

Tested as in actual operation

The test method developed by RISE and used in the test bed is in good agreement with the actual operation of a incinerator, with regard to temperature fluctuations, air velocity and humidity. Here, the same laminate structure can be used as in real constructions, it can be sample pieces taken from components that have been in operation or new pieces. The test bed can handle pipes up to 40 centimeters in diameter and 1.5 meters in length.

The test pieces are subjected to a simulated bypass operation, an operation that is linked to a negative material impact. In cycles, the air is circulated in the tube and varied between humid air of about 70 degrees and dry air up to 200 degrees. A heating takes about 3.5 minutes and about as fast as it goes for a cool down. During heating, the pipe is also subjected to an air velocity of up to 8 meters per second, in order to simulate the hot air flow that becomes in a stack.

Unique in Europe

RISE test bed is the only one in Europe that can simulate a bypass operation with such rapid changes and high temperatures combined with large test pieces. Here we can study in detail the impact that moisture, temperature and laminate build-up have on the life of the construction.

Through the test bed, RISE can:

• Contribute to a deeper understanding of the mechanisms that cause delamination damage in the material
• Contributes to the development of new FRP laminates, FRP with objection waistband and coated metals for this type of environment, with improved resistance to delamination
• Contribute knowledge of the life of the material to better anticipate maintenance needs
• Contribute to quality control for flue gas plants