Patent ID: 7874082
Filing Date: 2011-01-25
Classification: F26B,Y02P

Abstract:
1. A method for drying bulk material in connection with a pulp or paper production process and for cooling waste water of the pulp or paper production process, the method comprising: (a) providing a walled enclosure defining a drying space and including a bulk material inlet for introducing bulk material to be dried into the drying space, a bulk material outlet for discharging dried bulk material from the drying space and a gas discharge connector for discharging drying gas from the drying space, (b) positioning at least one drying conveyor within the drying space so that the bulk material conveyed to the drying space through the bulk material inlet is deposited onto one end of the conveyor and the dried material is discharged through the bulk material outlet from an opposite end of the conveyor, (c) positioning a heat exchanger within the walled enclosure so that drying gas to be heated is introduced from outside the drying space and heated drying gas from the heat exchanger is discharged into the drying space, (d) conveying bulk material to be dried through the bulk material inlet and onto the one end of the at least one drying conveyor located in the drying space, (e) introducing a drying gas from a blower positioned outside the enclosure to the heat exchanger located within the drying space, (f) bringing heated waste water from the pulp or paper production process into heat exchange relationship with the drying gas introduced into the drying space by the blower to heat the drying gas and discharging the heated drying gas into the drying space of the enclosure while simultaneously cooling the waste water, (g) conducting the heated drying gas through the at least one drying conveyor conveying the bulk material to be dried and thereafter discharging the drying gas that has passed through the at least one drying conveyor from the drying space through a gas discharge connector; and (e) discharging dried bulk material from the drying space.