Abstract An apparatus for spray drying milk in which drying hot air is blown against a spray of milk sprayed from a nozzle disposed in the upper portion of a drying tower, and at the same time cooled air is introduced into the drying tower so as to surround the flow of hot air so that the portions of the inner walls of the tower which would otherwise be overheated are covered with a layer of cooled air. Further, a first spray of milk in the form of a generally diverging conical sheet is provided in the tower, and simultaneously a second spray is applied to the first spray from its outside in such a manner that the particles of the second spray impinge upon the particles of the first spray at a transient position between a constant-rate drying period and a falling rate drying period of the particles of the first spray, whereby the particles of the second spray are combined with those of the first spray.
In the spray drying apparatus of claim 1, the atomizer means being arranged to provide a first spray of the liquid medium containing a solid in the form of a generally conical sheet; and means mounted in the upper drying tower part for applying a second spray of fine particles of the solid to the conical surface of the first spray, the second spray applying means being disposed to impinge the fine particles upon the first spray at a transient position between the constant rate drying period and the falling rate drying period of the first spray.
Claim 2
Dependent Claim
105 words
In the spray drying apparatus of claim 2, the second spray applying means comprising a vertically disposed coaxial feed tube having an upper end communicating with a source of the fine particles and a converging lower end defining an output aperture, the atomizer means comprising a coaxial pipe supplying the liquid medium and passing through the feed tube and having an end below the output aperture thereof, and a diverging baffle means connected to the pipe and defining a delivery channel for the fine particles with the converging lower end of the feed tube, the baffle means directing the fine particles to the transient position.
Claim 3
Dependent Claim
88 words
In the spray drying apparatus of claim 2, the second spray applying means comprising a plurality of circumferentially equidistantly spaced feed pipes each extending generally downwardly with a slight tilt angle inwardly relative to the vertical axis of the tower, the pipes having upper ends communicating with a source of the fine particles and being so arranged that the particles emitted from the pipes impinge upon the first spray at a transient position between the constant-rate drying period and the falling rate drying period of the first spray.