What is a condition in which the flames from a burner touch the tubes in the furnace?

Question

Quizplus · Accepted Answer

A) Incorrect. Hot spots areas within a radiant section furnace tube, or areas within a furnace firebox, that have been overheated due to flame impingement or some other cause.
B) Incorrect. Breech is the area below the stack where flue gases are collected past the last convection tubes.
C) Correct. Flame impingement is a condition in which the flames from a burner touch the tubes in the furnace.
D) Incorrect. Furnace purge is a method of using steam or air to remove combustibles from a furnace firebox prior to lighting the burner and startup.

What Is a Condition in Which the Flames from a Burner