Abstract: A video camera or other scanning device is employed to monitor the loading with articles to be frozen of an endless belt which passes through a freezing apparatus so as to freeze such articles typically by contact with liquid nitrogen or its cold vapor. The video camera is associated with electronic circuits that generate a signal representative of the belt loading and compare it with a signal representative of an optimum belt loading. If the difference between the signals is greater than a chosen threshold the belt speed is adjusted so as to reduce or eliminate the difference. By this means an improvement is made possible in the efficiency with which the liquid nitrogen is utilized.

Abstract: In a method of freezing a liquid such as cream, a continuous, pulsating stream of liquid is dispensed from nozzles onto a stream of liquified gas flowing along downwardly inclined channels provided by a trough. The liquid forms itself into discrete spheroidal bodies, a substantial number of which have a larger cross-sectional area than that defined by the outlet of each nozzle from which they are dispensed. The bodies are carried by the liquified gas along the channels and at least their peripheries are frozen by the time the bodies reach the downstream end of the channels. Freezing may be completed by gas cooling. The bodies are then separated from the liquified gas.