The natural phenomena of the density difference between a hot and cold air column that creates a natural flow through a chimney is called the Chimney effect.
The gas temperature inside the flue gas stack is around 140 ° C. The outside ambient air temperature is around say 30° C. Consider this as two air columns connected at the bottom. The high density and heavier cold air will be always pushing the low density and lighter hot gases up. This causes the natural flow of gases up the flue gas stack. This pressure difference that pushes the hot gas up the flue gas stack or the chimney is the 'chimney or stack effect'.
Depending on the height it can be gentle draught or heavy suction. This is the chimney or stack effect.
In numerical terms this can be represented as
Chimney effect = 353 x Chimney Height x [1/ Stack gas temperature – 1/ Ambient Temperature]
Where:
Chimney effect is in mm of water column.
Chimney height is in mteres.
Temperatures are in ° Kelvin.
No comments:
Post a Comment