Patent ID: 8764937

Claim:
An apparatus for converting a paper residue into a mineral product, the apparatus comprising: a fluidized bed device, including: an air box; a distribution plate positioned above said air box and configured for an evenly distributed supply of at least a combustion air to a bed material positioned above said distribution plate and to a paper residue introduced into said fluidized bed device; and a control system configured for controlling an amount of said bed material above said distribution plate and a particle size of said bed material, said control system being arranged to monitor and maintain a process parameter within a predefined range, said process parameter being related to an amount of said combustion air, said control system being at least one of: 1) arranged to control a temperature of said combustion air in said air box within a range of said process parameter selected at a predefined target value (′ target ) of said temperature plus and minus 25° C., said predefined target value (′ target ) of said temperature of said combustion air in said air box being expressed in centigrade is defined as follows: ′ target =−500*calorific value+1400 wherein said calorific value is expressed in Megajoules per kilogram (MJ/kg) and relates to said paper residue including any additional matter introduced into said fluidized bed device; 2) arranged to control said amount of combustion air supplied to said air box at a predefined target value target, (Q target ) plus and minus 15% for each square meter area of said distribution plate, wherein said target value (Q target ) of said combustion air supplied to said air box for each square meter of said distribution plate is defined as follows: Q target =4.35*organic fraction wherein said organic fraction relates to a percentage of an organic material forming part of the paper residue introduced into said fluidized bed device; and 3) said control system is configured such that said target value of said amount of combustion air supplied to said air box for each square meter area of said distribution plate is set at a level of 1.7 cubic meters per second (m 3 /s) for each square meter are of said distribution plate.