Patent ID: 8529323

Claim:
A method of reducing a draft effect of a flue duct upon an upstream exhaust gas cleaning system, including the steps of: extending a downwardly open first flue duct, having a second flue duct disposed thereon for connection to an upstream exhaust gas cleaning system, into a vat so as, with the aid of a liquid that has collected in the vat, to form a liquid barrier that is adapted to close off a flue gas end of said first flue duct relative to the environment; relieving the upstream exhaust gas cleaning system from the draft effect of the first flue duct by lowering the level of the liquid in the vat below an edge of the first flue duct to expose at least a portion of a cross-section of the first flue duct; using a trough as the vat, wherein the trough is associated with a lower edge of said flue draft, and wherein the trough outwardly delimits a discharge plate; adjusting a depth of immersion of said first flue duct into the trough by vertically positioning the trough.