Abstract: Disclosed is an apparatus and method for cooling a product in a vacuum chamber which utilizes a door mounted in an opening portion of a vacuum tumbler chamber, a mechanism mounted on the door for injecting a coolant fluid into the tumbler chamber, a mechanism for rotating the tumbler chamber relative to the door and a vacuum mechanism for exhausting the coolant fluid from the tumbler chamber. The process includes the method of cooling a product in a vacuum chamber and which includes the steps of depositing the products in the vacuum chamber, subjecting the chamber to a vacuum, rotating the chamber, applying a coolant fluid to the products in the chamber; and exhausting the coolant fluid from the chamber by vacuum.

Abstract: For producing and holding CO.sub.2 snow, first and second cylindrical horns connected to an open ended vertical discharge duct to form a generally Y-shaped continuous expansion chamber. First and second nozzles axially positioned at the tops of the snow horns have tangential fluid discharge passages which are mutually oppositely oriented to produce oppositely oriented spiral flows of CO.sub.2 snow within the snow horns. The two oppositely oriented spiral flows meet in a mixing region where their spiral components are cancelled, leaving only a vertical component of motion so that the snow is discharged through the vertical discharge duct by gravity. The discharged snow can be stored in a snow receiving container without blowing or wastage.