Patent ID: 11913721
Assignee: ED-IPR APS
Field: Chemical engineering (Chemistry)
Classification: CPC F | IPC F

Claim 4:
5. A method of drying bulk particulate materials with an apparatus, said apparatus comprising:
a vessel defining a lower cylindrical part, having a lower cylindrical inner wall and defining a first cross-sectional area being perpendicular to the length of the lower cylindrical part and an upper cylindrical part defining a second cross-sectional area being perpendicular to the length of the upper cylindrical part,
an inner cylindrical part centrally located within said upper cylindrical part and said lower cylindrical part of said vessel for establishing a first fluid path from said upper cylindrical part to said lower cylindrical part within said inner cylindrical part and a second fluid path from said lower cylindrical part to said upper cylindrical part outside said inner cylindrical part,
a number of partitioning walls extending radially within said lower cylindrical part between said lower cylindrical part and said inner cylindrical part and defining in said lower cylindrical part an inlet chamber, an outlet chamber and a number of intermediate chambers located between said inlet chamber and said outlet chamber in a circumferential direction, said inlet chamber comprising an inlet,
said outlet chamber comprising an outlet, said inlet chamber and said intermediate chambers each defining a steam permeable bottom, said outlet chamber defining a non-steam permeable bottom, said steam permeable bottom of said inlet chamber being adapted to receive superheated steam from said impeller,
said steam permeable bottom is arranged for directing the flow of superheated steam in a number of directions towards said lower cylindrical inner wall, and in directions different from a radial direction of the steam permeable bottom, a heat exchanger located within said inner cylindrical part, and an impeller, wherein said steam permeable bottom comprises a plurality of perforations for guiding said superheated steam in a substantial vertical blowing direction and wherein an opening area of said louvers of said inlet chamber defines an area being 10% to 90% of a total opening area of all of said perforations and louvers of said steam permeable bottom of said inlet chamber,
said method comprising the steps of:

(a) maintaining within said vessel a superheated steam at a pressure equal to or larger than the ambient pressure surrounding the vessel,
(b) receiving moist bulk particulate material at said inlet,
(c) heating said steam within said heat exchanger,
(d) generating a flow of superheated steam along said first fluid path from said upper cylindrical part through said heat exchanger within said inner cylindrical part to said lower cylindrical part, and via said steam permeable bottom, directing the flow of superheated steam in a number of directions different from said radial direction, towards said lower cylindrical inner wall, and generally along said second fluid path from said lower cylindrical part to said upper cylindrical part outside said inner cylindrical part, by using said impeller, hereby increasing the velocity and whirling movement of the superheated steam, and
(e) ejecting dry bulk particulate material at said outlet.