Abstract: A hot spot detection system for a rotary regenerative preheater has a linear rail system positionable between the central portion and the casing of the air preheater. The rail assembly has a pair of rails with a carriage movably mounted to each rail. The drive assembly has a motor and sprocket drive mountable to the exterior of the casing for driving the chain to which each carriage is affixed, to move the carriages in a linear reciprocating motion. On each carriage is a sensor assembly for detecting hot spots on the rotor of the air preheater.

Abstract: A rotary regenerative air preheater has bypass seals located at the top and bottom of one side of each sector of heat exchange baskets located at the top and bottom of the adjacent diaphragm and sealing the gap between that one side of the baskets and the diaphragm. The bypass seals are metal strips extending along the radial length of the diaphragm with a main body portion attached to the diaphragm and a bent leg portion extending outwardly to engage the baskets. The bypass seals are notched to fit over the stay plates and are attached over the radial seals to hold the radial seals in position.