Method and apparatus for drying pulp
AssigneeMetso Paper, Inc.
InventorsPaavo Sairanen, Olli Huhtala
Life of this patent
Estimating the term…
Abstract
A fiber containing pulp, such as chemical pulp, mechanical pulp, thermomechanical pulp, TMP, de-inked water, or fiber containing sludge, is dried in an effective and efficient manner. The wet pulp is first dewatered mechanically, such as by using a drum or screw press. Then dewatered pulp is passed to a dryer. The dryer has first and second apertured cylindrical surfaces defining a gap between them, and drying gas is blown through one of the apertured surfaces, then through a pulp layer moving in the drying gap between the cylindrical surfaces, and then through the apertures in the other cylindrical surface, to evaporate water from the pulp and dry it to a dry matter content of over 80%, preferably about 85-90%.
Claims31
A method for drying a wet pulp, comprising:
- (a) mechanically dewatering the wet pulp;
- and then
- (b) passing the pulp through a drying gap defined by first and second apertured cylindrical surfaces by pushing the pulp along the surfaces, and while simultaneously blowing drying gas through one of the apertured cylindrical surfaces, through the pulp in the gap to evaporate water from the pulp and through the apertures in the other cylindrical surface.
Apparatus for drying a fiber containing pulp, comprising:
- a mechanical dewaterer which dewaters wet pulp, and having a discharge;
- and
- a dryer operatively connected to the discharge of the mechanical dewaterer, said dryer comprising first and second apertured cylindrical surfaces defining a gap between them, means for conveying pulp along the first or second cylindrical surfaces in the gap, and means for blowing drying gas through one apertured cylindrical surface, through the pulp in the gap, and through apertures in the other cylindrical surface.
A method for drying wet fiber-containing pulp, comprising:
- mechanically dewatering the wet pulp with a drum or screw press;
- passing the pulp through a dryer, in which drying gas is blown through a layer of the pulp in order to evaporate water from the pulp, wherein the pulp is passed through the dryer in a drying space limited by a first and a second cylindrical surface provided with respective apertures, the pulp being pushed forward along the first or the second surface by screw means.
A device for drying fiber-containing pulp comprising:
- a mechanical dewaterer comprising a drum or screw press for dewatering the wet pulp;
- and
- a dryer in which water is evaporated form the pulp by blowing drying gas through a layer of the pulp, wherein the dryer comprises:
- a first and a second cylindrical surface provided with respective apertures, the surfaces being fitted to form a drying space between them, and
- screw means for conveying the pulp layer forward along the first or second surface in the drying space.
Dependencies are inferred from the claim text.