Abstract: A tunnel freezer uses carbon dioxide snow to directly contact product carried on a conveyor belt passing through the freezer. Fans are provided above and below the upper conveyor belt run carrying the product, with the fans above and below having downwardly directed exhaust. Trough-shaped deflector plates are provided adjacent the lower fans to circulate a flow adjacent the underneath surface of the upper conveyor belt run. Preferably, circulation adjacent the upper conveyor belt run is generally parallel to the upper conveyor belt run, and turning vanes are provided to deflect the flow upwardly through the upper conveyor belt run. Freezers may be provided with one or more cooling zones arranged in series along the path of conveyor belt travel.

Abstract: Substantially uniform distribution of developer in a cascade assembly for xerographic reproduction apparatus is effected as the developer slides down an inclined cascade baffle onto which the developer is dumped by a succession of buckets which elevate the developer from a sump in the cascade chamber. From the cascade baffle the developer is cascaded substantially uniformly onto a perimeter sector of the electrostatic image carrying drum of the associated apparatus. Uniform developer distribution is attained on the cascade baffle by means of an array of distribution projections.Toner dust is effectively screened from the image-free areas of the image carrying drum. This is accomplished by efficiently blocking access of the dust to the drum by the position of an effective dust baffle between the developer supply and the drum in the area where the unused developer drops into the developer sump after the developing cascade.