Drying of liqueform materials

Claim 3

A method as claimed in claim 1 comprising the steps of forming the gas by mixing air and a combustible fuel and controlling the temperature in each drying zone independently by varying the air/fuel ratio in the gas supplied to the respective gas supply chambers.

Claim 4

A method as claimed in claim 1 comprising the step of heating the wall means to emit radiant heat.

Claim 5

A method as claimed in claim 1 comprising the step of varying the porosity of different sections of the wall means.

Claim 8

A method as claimed in claim 5, further comprising the step of heating the wall portions of the drying zone whereby to heat the drying gas.

Claim 9

A method as claimed in claim 6 wherein the wall means is heated by burning a combustible gas mixture in the pores of the wall, the combustion products being used to form at least a part of the drying gas.

Claim 10

A method as claimed in claim 6 in which the wall portions of at least some of the drying zones are heated such that the wall portions emit radiant heat.

Claim 11

A method as claimed in claim 8 wherein the wall is heated by burning a combustible gas mixture in the pores of the wall, the combustion products being used to form at least a part of the drying gas.

Claim 12

In a drying device means defining a vertical, cylindrical drying space having a substantially vertical axis, said means comprising a plurality of separate elements each said element including an inner porous annular wall, and an outer annular wall spaced from the inner wall to define therewith an annular chamber, said elements being stacked vertically in contiguous relationship with said inner annular walls collectively defining the drying space, annular transverse wall means axially separating each said chamber from the adjacent chamber, means feeding liqueform material to be dried axially into the upper end of the drying space, means feeding drying gas into each said chamber, said gas being distributed uniformly around each chamber, and passing through the inner porous wall into the drying space transversely to the axis thereof, separate gas control means associated with each chamber to permit control of the gas supply to each chamber independently, means defining an outlet for the drying gas at one end of the drying space and means defining a dried granular product outlet at the lower end of the drying space.

Claim 13

In a drying device means defining a vertical, cylindrical drying space having a substantially vertical axis, said means comprising a plurality of separate elements each said element including an inner porous annular wall, and an outer annular wall spaced from the inner wall to define therewith an annular chamber, said elements being stacked vertically in contiguous relationship with said inner annular walls collectively defining the drying space, annular transverse wall means axially separating each said chamber from the adjacent chamber, means feeding liqueform material to be dried axially into the upper end of the drying space, means feeding drying gas into each said chamber, said gas being distributed uniformly around each chamber, and passing through the inner porous wall into the drying space transversely to the axis thereof, separate gas control means associated with each chamber to permit control of the gas supply to each chamber independently, means defining an outlet for the drying gas at one end of the drying space and means defining a dried granular product outlet at the lower end of the drying space.

Claim 14

A drying device according to claim 10, wherein the gas is a mixture composed of air and fuel and said gas control means controls the air/fuel ratio.

Claim 15

A drying device according to claim 10, wherein porosities of the inner walls of the respective elements are different.

Claim 16

A drying device comprising wall means defining a cylindrical drying space, means dividing at least a major portion of the space into a plurality of axially distributed and substantially contiguous drying zones, said means comprising a plurality of separate, contiguous, annular gas supply chambers operative to feed gas into each drying zone transversely to its longitudinal axis with the gas being uniformly distributed around the wall means, separate control means controlling the gas supply to each chamber whereby to permit separate control of the temperature in each zone, means operative to feed material to be dried axially into the drying space, and means defining an outlet for the drying gas at least at one end portion of the drying space.

Claim 17

A drying device comprising wall means defining a cylindrical drying space, means dividing at least a major portion of the space into a plurality of axially distributed and substantially contiguous drying zones, said means comprising a plurality of separate, contiguous, annular gas supply chambers operative to feed gas into each drying zone transversely to its longitudinal axis with the gas being uniformly distributed around the wall means, separate control means controlling the gas supply to each chamber whereby to permit separate control of the temperature in each zone, means operative to feed material to be dried axially into the drying space, and means defining an outlet for the drying gas at least at one end portion of the drying space.

Claim 18

A device as claimed in claim 13 further comprising means operative to heat the wall meanS.

Claim 19

A device as claimed in claim 13 wherein at least part of the wall means is porous.

Claim 20

A device as claimed in claim 13 wherein the wall means comprises, a plurality of annular wall elements, each said wall element comprising, an inner wall portion, and means defining a gas supply chamber surrounding the inner wall portion, said gas supply chamber constituting said supply means.

Claim 21

A device as claimed in claim 16, further comprising separate control means for controlling the gas supply to each gas supply chamber.