Two Phase Flow in Chimneys - The Origin and Transport of Moisture and Particles in the Chimney Flue
J. Sipek & P. Snop
CICIND REPORT Vol. 12, No. 2, 1996
Order No: CR-002
The paper deals with the mechanisms of origin and transport of fluid and solid particles in a chimney flue. It defines conditions for vapour condensation on the flue wall from gas-vapour flow; the mechanism of droplet separation and atomisation of films and their transport. For the typical case of the inlet part of the flue, the results of viscous flow computations are given and the aspects of complicated velocity fields in two-phase flow are discussed. These computations involved a program capable of solving three-dimensional turbulent isothermic non-compressible flow problems.
Zones of high pressure were shown to occur adjacent to the flue wall under certain conditions. These can lead to localised situations of positive pressure, with the attendant problems of outward leakage of flue gas through brickwork.