a method and system for preparing comestibles for frozen storage in which pressurized freezing air is utilized in conjunction with a substantially flat conveyance surface , both to aid in or contribute to the conveyance of the packages or containers as well as to effectuate the rapid freezing of the comestibles therein during the course of such conveyance through the system . in the preferred embodiment , the elongated conveyance deck is of space saving substantially helical form with successive descending turns underlying one another and with the space surrounded by the turns forming part of a plenum chamber into which pressurized freezing air is blown for admission into a laterally open plenum duct underlying the deck throughout its length . such elongated plenum duct is tapered transversely beneath the deck for uniform distribution of pressurized freezing air to the discharge apertures in the deck by means of a transversely inclined duct - forming panel cooperating with the deck . on its upper side the panel forms the plenum duct and on its lower side the panel cooperates with a surrounding enclosure common to the helical turns of the conveyance deck to form a collecting chamber from which air is withdrawn by the combined freezing and pressurizing means for recirculation continuingly as the containers or packages descend by increments progressively down the helical path of the deck . a partition with variable damper means separates the central plenum chamber and the surrounding collecting chamber and provides a variable bypass to regulate or vary the flow of air through such discharge apertures and maintain constant airflow through refrigerated evaporator coils so as to maintain efficient heat exchange operation thereof . with the comestibles packaged in the usual manner so as to afford air space within the packages for expansion of the comestibles upon freezing , this method of combined conveyance and freezing by use of the pressurized air flow greatly accelerates the freezing process and effects conveyance of the comestibles , appropriately retarded to maintain relative high - velocity flow of air sweeping the packages , without necessity for mechanical conveyance devices .