Flow through type drying apparatus

Abstract

.Iadd.Apparatus for method of vacuum freeze-drying frozen granular material in spaced, substantially vertical product beds is provided by vertical cell units designed for this purpose. Sublimed water vapors are conveyed from the product beds to the condensing area by open spaces between said product beds. The open spaces contain heating means for supplying heat of sublimation to the frozen material within the product beds..Iaddend.

I claim: 
     
       1. A product flow through drying apparatus comprising a regular parallelepiped housing, upper and lower ends of said housing having selectively movable portions so that products to be dried may be inserted into the housing from an upper end and removed from a lower end, an open ended container within said housing and supported thereby, said container being adapted to receive a product at its upper end and permit discharge of the product through its lower end, opposite sides of said container having apertures providing open communication between the interior of said container and the interior of said housing, heating panels juxtaposed to the apertured sides of said container for radiantly heating product within said container, said heating panels being disposed in spaced apart relation between the apertured opposite sides and the adjacent side walls of the housing, and means coupled to said housing for reducing the pressure within said housing and said container, said last-mentioned means including conduit means communicating with the interior of said housing through a wall perpendicular to the said adjacent walls, said conduit means being positioned on said perpendicular wall so as to be aligned in communication with the open space between said heater panels and said apertured sides of said container. 
     
     
       2. A drying apparatus in accordance with claim 1 wherein the movable portions of the ends of said housing constitute the entire top and bottom walls of said housing. 
     
     
       3. A drying apparatus in accordance with claim 1 wherein the upper end of said container is spaced from the top wall of said housing so that the upper end of said container is in open communication with the interior of said housing. 
     
     
       4. A drying apparatus in accordance with claim 1 including means pivotably mounting said top and bottom walls on said housing, and latch means for selectively retaining said bottom wall in a closed disposition. 
     
     
       5. Apparatus in accordance with claim 1 wherein the apertures in the sides of said container are elongated, integral lip portions of said container sides extending inwardly from the upper edge of the elongated apertures, whereby said lip portions assist in preventing a product being dried from flowing freely out of the container by way of the aperture. 
     
     
       6. A product flow through drying apparatus comprising a regular parallelepiped housing, a selectively operable top wall means on said housing for providing for the selective introduction of a product into said housing, a selectively operable bottom wall means on said housing providing for the selective discharge of a product from said housing, first and second spaced container within said housing, said containers being adapted to receive a product at the upper end and permit discharge of the product through the lower end, said containers being rectangular in transverse section and spaced from the side walls of said housing, each container having apertures in a pair of opposite sides, said containers being disposed side by side within said housing, means on said housing side wall for supporting each container so that the lowermost edge is juxtaposed to the bottom wall means whereby a product in said container will be supported by said bottom wall, the upper edges of said containers being spaced from the top wall means for said housing so that each container is in open communication with the interior of said housing, said bottom wall means having a movable portion at least as large as the combined cross-sectional area of said containers, each container being open at the upper and lower ends thereof, a heating panel juxtaposed adjacent apertured sides of said containers for radiantly heating a product within said containers, and an additional panel being juxtaposed to the opposite apertured side of each of said containers whereby three heater panels are within said housing, and means for selectively reducing the pressure within said housing, said means for selectively reducing the pressure within said housing including at least three conduits communicating with said housing through walls perpendicular to the apertured sides of said containers at points generally aligned with the open space between said heater panels and said apertured sides. 
     
     
       7. Apparatus is accordance with claim 6 wherein said apertures in the sides of each container are elongated, integral lip portions of the container sides extending inwardly from the upper edge of the elongated apertures, whereby said lip portions assist in preventing a product being dried from flowing freely out of the containers by way of the apertures. .Iadd. 8. Apparatus for bulk freeze-drying of heat-sensitive material which has been frozen into a granular particle form comprising a series of aligned and substantially vertical product cells separated by open spaces having substantially the same height and length as said cells, said cells having opposed walls of relatively large surface area in relation to the thickness of said cells, said walls being permeable to free passage of water vapor into said open spaces; means for sealing said product walls from atmosphere; vacuum means for lowering the pressure in the open spaces adjacent to each product retaining wall to assure sublimation into said spaces; means for applying heat to provide heat of sublimation; means for removal of water vapor; and means for discharging said product from the vertical product beds by the force of gravity. .Iaddend..Iadd. 9. The apparatus of claim 8 wherein the vertical cells are in the form of elongated, substantially rectangular product retaining cells; the walls of said cells having a sufficient number of openings therein for free passage of water vapor to the open spaces. .Iaddend.