Process for producing an agglomerated powdery milk product
AssigneeA/S Niro Atomizer
InventorsJan Pisecky, Jens Krag, Ib H. Sorensen
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Abstract
An agglomerated powdery milk product is prepared by spraying a concentrate of milk or a fraction thereof into a stream of drying gas directed against the surface of a fluidized layer of already spray dried particles in a conical chamber, thereby obtaining a favorable interaction. Special parameters including temperatures, rates of streams of drying air and residence time are adjusted to obtain an extensively agglomerated product, high production capacity, improved heat economy, low heat damage of the product, and to make possible an easy spray drying of materials, which have hitherto been regarded as unsuitable for spray drying.
Claims15
A process for producing an agglomerated powdery milk product, comprising the steps of
- (a) atomizing a liquid derived from milk, in the upper part of a conical downward tapering drying chamber by means of a nozzle into a central downward stream of drying gas at 200.degree.-400.degree. C. to produce particles,
- (b) maintaining in the lower part of said drying chamber a layer of particles fluidized in an upward stream of gas having a velocity of 0.3-1.5 m/sec, whereby the temperature of said upward stream of gas is adjusted between 10.degree. and 150.degree. C. to maintain the temperature required of the fluidized particles for ensuring the agglomeration ability of said particles with respect to the particles produced in step (a), and wherein the amount of particles in the fluidized layer is adjusted corresponding to a pressure drop of 1.5-4.5 k Pas over the fluidized layer,
- (c) adjusting the amount of said liquid to the amount and drying capacity of the downward stream to ensure a moisture content of the particles reaching the fluidized layer between 2-16% and sufficient for agglomerating said particles by forming clusters thereof, but less than the moisture content which would cause formation of monogranules, and also to ensure that the downward gas stream still has a substantial drying capacity upon reaching the fluidized layer and sufficient kinetic energy for penetrating therein, thereby contributing to the drying process in the fluidized layer and promoting removal of particles and small agglomerates from the fluidized layer to the upper part of the drying chamber for agglomerate-forming contact with wet droplets and moist particles,
- (d) withdrawing a stream comprising the gas from said downward stream and the gas from said upward stream at a non-central location in the upper part of the drying chamber,
- (e) adjusting the amount of drying gas introduced as a central downward stream to be 2-4 times the amount of the upward stream of fluidizing gas, and
- (f) recovering agglomerated particles from said fluidized layer.
Dependencies are inferred from the claim text.