still be liquid when the pellets 132 reach the end of the trough 125 the conveyor belt 135 is located below the trough 125 to collect the at least partially frozen pellets 132 the conveyor belt 135 is adapted to collect the pellets 132 on the conveyor belt 135 but allow the cooling medium 117 to pass through an exemplary material for the conveyor belt 135 is a metal screen the cooling medium 117 is collected by a fluid collection apparatus 119 and returned to the storage tank 110 in another embodiment the length of the trough 125 may be selected to ensure that the pellets 132 are completely frozen by the time the pellets 132 reach the end of the trough 125 in another embodiment the cooling medium may be any suitable cryogenic fluid known to a person of ordinary skill in the art the pellet freezing process in the trough 125 vaporizes some of the cooling medium 117 to produce a vaporized cooling medium 118 the trough 125 and the conveyor belt 135 may be encased by a heat insulating casing 140 in such a way that the vaporized cooling medium 118 are drawn off above the conveyor belt 135 in parallel flow with the transport direction of the pellets 132 in one embodiment the vaporized cooling medium 118 is drawn off by an exhaust gas fan 145 installed above the end of the conveyor belt 135 in this respect the direction of flow of the gaseous cooling medium 118 corresponds to the transport direction of the pellets 132 on the conveyor belt 135 thus the flow of gaseous cooling medium 118 may continue to remove energy from the pellets 132 during transport.