Question 70Steam Plants - Assistant Engineer

The correct answer is B) protect the expansion joints. A corbel is a structural element used in boiler furnaces to help accommodate the thermal expansion of the furnace walls. As the furnace heats up and the walls expand, the corbel helps protect the expansion joints between the furnace sections, preventing leaks and structural damage. This is the primary function of a corbel in a boiler furnace. The other answer choices are incorrect because they do not accurately describe the main purpose of a corbel. Directing the flow of gases (A), reducing gas turbulence (C), and containing the furnace heat (D) are not the primary roles of a corbel in a boiler furnace design.