this water is not only sufficient to compensate the losses of a closed circuit but covers the needs of an open circuit for this purpose a sap press 52 is represented in fig5 which is fed with the beet heads and leafs 8a by means of a second conveyor belt 4 arranged after the cutting device preferably the sap press 52 is preceeded by a crushing device which in the present case is a staw cutting device 53 if a buffer tank is arranged after the sap press 52 the sap press may be operated immediately in the example represented the sap press is working continuously the sap press 52 is composed of a screw 54 diminishing in diameter in feeding direction being located in a strainer housing 55 which in turn is surrounded by a jacket 56 having a water outlet 57 at the small end of screw 54 is provided an interchangeable discharge nozzle being in the present case an apertured disk 58 this allows passing the solids to small pellets or the like which are directly fed to animals or easily dried and thus preserved in the example represented a bucket 59 is provided for receiving the solids and which may be emptied from time to time into a truck placed alongside the field if the filtering action of the strainer housing 55 is sufficient the outlet 57 may be connected to directly with a pump feeding the cleaning unit 6 in the example represented the water coming out of the sap press 52 is transferred to a filter.