Steam Superheaters


Superheaters are essentially a bank of tubes, in the exhaust gas duct after the boiler, used to heat the steam above the saturation temperature. The saturated steam enters the inlet header from piping connected to the steam drum. In a superheater, the saturated steam flows from the saturated header through the superheater elements into the superheater outlet header.
Marine boiler superheater design requires a sensible balancing of economic and practical factors. There must be a sufficiently large temperature difference between the combustion gas passing over the superheater surface and the steam within the surface to result in a superheater of economic proportions. At the same time, there are practical limitations on superheater metal temperatures, and provision must be made to arrange superheater elements to resist slag accumulation.