Abstract: A system and method for detecting hot spots in a rotary regenerative air preheater which compensates for normal variations in the temperature of the incoming hot gas stream or incoming cold air stream. Alarm conditions are based on calculations relating to the average and maximum outlet gas or outlet air over a period of time compared to the air and gas inlet temperature. The alarm is triggered if the maximum values deviate from the time averaged values more than a selected percentage.

Abstract: A catalytic regenerative oxidizer (18) comprises a closed casing (24) having upper and lower ends, an input port (20) at the lower end and an output port (22) at the upper end. The casing contains a plurality of stacked layers or beds, including upper (34), lower (32), and central beds (40) of silica gravel or the like. Two catalyst layers (36, 38) are provided in the stack, one between the lower and central gravel beds, and the other between the upper and central gravel beds. A heating element (42) is situated in the central bed, for maintaining at least one of the catalyst layers at an activation temperature in the range of about 500-1000 deg.F. The catalyst layers are formed by a multiplicity of ceramic pellets on which is deposited a catalyst material, such as precious metal. The contaminated gas stream enters the casing through the lower port and passes vertically through the stacked beds and layers.