Filling machine, in particular for filling a container with a pasteurized liquid

Abstract

A filling machine for filling a container with a liquid having a gas line, a liquid supply line connectable to a liquid tank and at least one filling device. The filling device having an inlet communicating with the liquid supply line, a lower outlet and a gas port communicating with the gas line. A differential pressure sensor is connected to the gas line and the liquid supply line to determine a feedback value defined by the pressure difference between the lines. The gas line communicates with a gas tank that is separated from the liquid supply line and connected to a pressurized gas source. The gas tank is also connected to a discharge opening via valves controlled by an electronic control unit that brings the pressure difference between the liquid supply line and the gas line to a set-point corresponding to the feedback value.

The claimed invention is:  
     
         1 . A filling machine for filling a container with a pasteurized liquid, comprising:
 a gas line;   a liquid supply line connectable to a liquid tank;   at least one filling device including:
 an inlet communicating with the liquid supply line to receive a liquid stored in the liquid tank, 
 a lower outlet for supplying the liquid into a container during filling, and 
 a gas port communicating with the gas line and defining a gas outlet for permitting gas flow from the container towards the gas line during filling; 
   a pressure sensor connected to the gas line and to the liquid supply line to determine a feedback value defined by the pressure difference between the liquid supply line and the gas line;   an electronic control unit configured to adjust the pressure difference between the liquid supply line and the gas line to a set-point in response to the feedback value;   a gas tank that communicates with the gas line and is separated from the liquid supply line;   a first valve controlling communication between the gas tank and a pressurized gas source, wherein the first valve is operable by the electronic control unit to open the first valve to increase pressure inside the gas tank; and   a second valve controlling communication between the gas tank and a discharge opening, wherein the second valve is operable by the electronic control unit to open the second valve to discharge gas from the gas tank when the feedback value is lower than the set-point.   
     
     
         2 . The filling machine of  claim 1 , wherein the electronic control unit is configured to open the first valve to pressurize the gas tank when the feedback value becomes higher than the set-point. 
     
     
         3 . The filling machine of  claim 1 , wherein the gas tank is external and positioned apart from the filling device. 
     
     
         4 . The filling machine of  claim 3 , further comprising a filling station having a conveyor and a plurality of the filling devices positioned on the conveyor;
 wherein the gas tank is external and positioned apart from the filling station.   
     
     
         5 . The filling machine of  claim 4 , wherein the gas line comprises a pipe connecting the gas tank to the filling station and having a length of less than about 10 meters. 
     
     
         6 . The filling machine according to  claim 1 , wherein the pressure sensor is connected to the gas line is positioned between the gas tank and the filling device. 
     
     
         7 . The filling machine according to  claim 1 , wherein the gas port also defines a gas inlet for pressurizing the container with gas from the gas line before filling.