A patch of shell that shows up hot on a thermal camera, shell scanner or temperature crayon because refractory has worn, spalled or fallen out behind it. On rotary kilns operators fight hot spots with shell cooling fans and by building coating; on ladles and furnaces they gun repair or pull the vessel. Every hot spot is logged and watched, because the next stage is a red spot or a breakout.
Scanner shows a hot spot at 28 metres, 380 C and rising, put the fans on it and watch it every hour.
Also heard as
- hotspot
- shell hot spot
Related terms
Red spot
Shell area glowing visibly red from lining loss, the signal to take a kiln or vessel out of service.
Breakout
Escape of molten metal or slag through a failed lining and shell, the most dangerous refractory failure.
Coating
Layer of clinker that sticks to the burning zone brick in a cement kiln and shields it from heat and wear.
Hot face
Surface of a refractory lining exposed to the furnace interior, as opposed to the cold face against the shell.
Same word, different worlds
Localized area of active corrosion on a pipeline, or the targeted anodes installed to protect just that spot.
Nuclear Safety & Radiation ProtectionA small spot on piping or equipment with a much higher dose rate than its surroundings.
Lighting & Color ScienceA distractingly bright patch in a beam or on a lit surface, brighter than its surroundings.
Photonics & LasersA small region of a beam with much higher intensity than the rest, a common cause of optic damage.