Superheater, also known as steam superheater, is generally installed in the outlet position of the furnace, its role is to lead the saturated steam in the drum (generally contains 2% of the water) under the condition of constant pressure, and then heated to the specified overheating temperature, in order to meet the needs of the production process.

The function of the superheater tube is to absorb heat. The seamless boiler steel tube or heat-resistant alloy steel tube is bent into a snake shape, and both ends are welded to the inlet and outlet containers respectively.

The outer diameter of the pipe is generally 30 ~ 60 mm.The most common type of superheater is the serpentine tube.It has a relatively dense tube set, arranged in the flue gas temperature of 450 ~ 1000℃, by the transverse and longitudinal erosion of flue gas.The flue gas mainly transfers heat to the pipe by convection, and some radiation absorbs heat.Screen type superheater consists of a plurality of tube screen, arranged in the upper part of the furnace or the outlet, belongs to the radiation or semi-radiation superheater.The former absorbs the radiant heat of the furnace flame, while the latter absorbs part of the convective heat.In the power station boiler above 10 mpa, generally both screen type and serpentine tube type superheater are used to increase heat absorption.The wall superheater applied to the inner wall of the furnace is the radiant superheater, which is seldom used.Wall type superheater is used in large capacity power station boiler to form the wall of the furnace roof and convection flue, and the insulation material is applied outside to form the light furnace wall.

Differences