Question

Calculate the mass of Flue gases flowing the Chimney

when the draught produced is equal to 1.9 cm of

water. Temperature of Flue gases is 2900 C and

ambient temperature is 200 C. The flue gases formed

per kg of fuel burnt are 23 kg. Neglect the losses and

take the diameter of the chimney as 1.8 m​

Answer 1

Draught and chimney

1. UNIT-II Draught And Chimney

2. Content  Introduction to draught system  Functions & Classification of Draughts  Introduction to natural draught  Estimate the height & diameter of chimney with Numericals.  Condition for maximum discharge through a chimney  Efficiency of chimney  Advantages and Limitations of chimney or natural draught  Boiler Performance: Equivalent Evaporation and Boiler Efficiency with Numericals. PramodKathamore

3. Draught  Draught is defined as “the pressure difference (between absolute gas pressure at any point in a gas flow passage and the atmospheric air outside the boiler) required to maintain flow of air and exhaust gases through the boiler setting.”  Function of draught:  To supply required quantity of air to the boiler furnace for the combustion of fuel.  To remove exhaust gases from the boiler passage to maintain flow of air and gases.  Tocreate pressure difference against pressure losses in the flow passage.  To discharge the exhaust gases such that they will not be objectionable or injurious to the surroundings. PramodKathamore