In order to fill cooling tanks comprising a compartment for receiving the products to be cooled and a separate coolant-receiving compartment, filling devices are used, with which devices liquid carbon dioxide is injected at an expansion nozzle into the coolant-receiving compartment in a liquefied state and once there is partially transformed into gaseous carbon dioxide and partially into solid carbon dioxide. The disadvantage of known filling devices is that the carbon dioxide exiting the expansion nozzle under high pressure is distributed very unevenly in the coolant-receiving compartment and also exerts a strong force effect which pushes the expansion nozzle out of the coolant-receiving compartment, thus making complex, mostly electrical retaining systems a prerequisite. According to the invention, a filling device is used comprising an expansion valve that is equipped with at least two nozzle heads, each of said nozzle heads having at least one nozzle opening. The nozzle openings are arranged such that the
