A Major component of the Boiler

Superheater are of Two Type
1. Convective type
2. Radiant type

Convective super heater gives maximum of 80ºC of Superheat while, Radiant Superheat can give 150-300ºC Superheat. Former is more prone to thermal failure & rarely used in ‘flue gas boiler’.

I’ll discuss the convective type super heater.
The basic criterion for the design are
1. Degree of superheat required
2. Steam Dryness available at inlet of super heater
3. Heat duty available.
4. Maximum pressure drop allowed in the system.
5. Flue gas maximum temperature.
6. Type of heat exchanger configuration flow, Cross/Parallel/counter etc.
Flue gas maximum temperature is required to select the MOC of the super heater tubes

for Heat duty following equation shall be validated
M Cp DT = m. (Unit enthalpy of steam)
M = Mass of flue gas
cp = Heat capacity of the flue gas
DT = Temp. drop across super heater
m = mass of Steam


Comments (1)

  1. Jana


    Dear Mr Sumit waghmare,
    I am happy to see your blog.I am working for a boiler concern in south India, i would like to know the correlations used for the design of superheaters, reheaters, economisers, why because we normally run in software developed by in-house company.. i would like to know the manual calculation for the above mentioned.
    mail me to jana.murali@rediffmail.com

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