Patent ID: 6038988
Filing Date: 2000-03-21
Classification: F23G,F23L,F23M

Abstract:
A method of incinerating waste material in a waste incinerator having a combustion chamber with different zones disposed between opposite side walls of the chamber, and a grate on which waste the material is moved through said combustion chamber and through which primary air is supplied from below grate to the waste material for combustion of the waste material in said zones to form hot combustion gases which are conducted both above the waste material on the grate in parallel flow with the movement of the waste material on said grate and below installation components disposed above the grate and which gases are then conducted above the installation components to a discharge opening in counter-current flow to the flow of said combustion gases above the grate, said method comprising the steps of:maintaining, in a first zone of the combustion chamber above the grate, an average temperature of less than 900.degree. C.,maintaining, in a second zone adjacent said first zone, an average temperature of about 1000.degree. C.,maintaining, in a third zone adjacent said second zone, an average temperature which is between 950.degree. C. and 860.degree. C., and is thus lower than that in said second zonemaintaining, in a fourth zone adjacent said third zone, a temperature of between 860.degree. C. with 680.degree. C.,admitting primary air from below said grate to said first, second, third and fourth zones through said grate in a controlled manner such that the combustion in said first and second zones is under-stoichiometric,admitting additional combustion air through the side walls to said first and second zones below said installation components and above said grate, said additional air being heated before entering said combustion chamber to a temperature corresponding to about the temperature in the respective zone of the combustion chamber to which said additional air is admitted, said waste material on said grate being burned by said combustion air and forming combustion gases which are conducted above said grate in the same direction as said waste material is moved on said grate around said installation components and then conducted above said installation components in a counter-current flow to the movement of said waste material being burned on said grate, while no additional air is supplied to the counter-current exhaust gas flow above said installation components.