Apparatus and process for drying a moist material dispersed or dispersible in a stream of drying gas
AssigneeNiro A/S
InventorsPoul Rasmus Andersen, Ove Emil Hansen
Life of this patent
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Abstract
In an apparatus for drying a moist material in a stream of drying gas the residence time is increased by inserting one or more perforated plates, above which fluidized particle layers are created, and through which a portion of the drying gas and material to be dried are passed, whereas the remaining part of the drying gas and material is by-passed said perforated plates. Improved drying capacity, heat economy and operational flexibility and decreased risk for heat damage of the material to be dried are obtained.
Claims36
An apparatus for drying a moist material dispersed or dispersible in a stream of drying gas, comprising;
- a housing;
- supplying means in the lower part of said housing for drying gas and material to be dried, said supplying means having at least one common inlet opening for supplying drying gas entraining the moist material, wherein in the housing above said supplying means at least one substantially horizontal perforated plate, the perforations of which are dimensioned to allow an upward passage of a portion of the drying gas with entrained material therethrough sufficient to maintain a fluidized particle layer on the upper side of said plate when operating the apparatus, the periphery of said plate substantially being in sealing contact with the housing;
- for each perforated plate at least one by-pass means from a location below the plate to a location above the plate for passage of that portion of the drying gas with entrained material which has not passed through said perforations;
- and in the upper part of the housing above said at least one perforated plate, outlet means for discharging the drying gas entraining the material with reduced moisture content.
A process for drying a moist material comprising;
- feeding a supplying means in a lower part of a housing with drying gas and material to be dried;
- conducting a stream of drying gas entraining material having reduced moisture content from an outlet means in an upper part of the housing to a particle collector device;
- conducting recovered particles from said particle collector device to a means for introducing particulate material above the gas distribution plate;
- conducting a partial stream of drying gas freed from particulate material from said particle collector device to the means for introducing fluidizing gas below the gas distribution plate, thereby forming a fluidized layer using the spent drying gas as fluidizing gas for further utilization of the drying capacity thereof;
- and recovering of a dried particulate material from said fluidized layer.
An apparatus for drying a moist material dispersed or dispersible in a stream of drying gas, comprising;
- a housing;
- supplying means in the lower part of said housing for drying gas and material to be dried, said supplying means comprising at least one inlet opening for drying gas and at least one inlet for moist material to be entrained in the drying gas after introduction into said housing;
- wherein in the housing above said supplying means at least one substantially horizontal perforated plate, the perforations of which are dimensioned to allow an upward passage of a portion of the drying gas with entrained material therethrough sufficient to maintain a fluidized particle layer on the upper side of said plate when operating the apparatus, the periphery of said plate substantially being in sealing contact with the housing;
- for each perforated plate at least one by-pass means from a location below the plate to a location above the plate for passage of that portion of the drying gas with entrained material which has not passed through said perforations;
- and in the upper part of the housing above said at least one perforated plate, outlet means for discharging the drying gas entraining the material with reduced moisture content.
Dependencies are inferred from the claim text.