Patent ID: 6047649
Filing Date: 2000-04-11
Classification: F23G,F23M

Abstract:
A method for circulating cooling medium of a recovery boiler wherein said recovery boiler comprises a furnace limited by wall tubes and substantially horizontal floor tubes, said method comprising the steps of:circulating cooling medium in said wall tubes and said floor tubes;supplying combustion air to said recovery boiler;supplying black liquor to said recovery boiler;forming a smelt layer on the floor of said boiler composed of said floor tubes due to combustion of said black liquor;causing longitudinal flow in at least some of the floor tubes at least on a section of their length for mixing a liquid phase and a steam phase of said cooling medium, andusing rifled floor tubes at least in some of the floor tubes constituting the floor of the recovery boiler, at least on a section of their length, to create a spiral longitudinal flow in the floor tubes for mixing said liquid phase and said steam phase.