Shock elimination for filling system

Abstract

A product fill system and method uses a mode valve. The mode valve is a shuttle valve that allows the shock tube to communicate with the filler valve during a fill operation corresponding to fill mode of the mode valve. If the filler valve is shut off, any overpressure can pass through the mode valve and be absorbed by the shock tube. The mode valve can be switched into a clean mode in which the shock tube is connected more directly in the circuit between the upstream side of the mode valve and the filler valve. In other words, the shock tube is on a side circuit of the main circuit used for product feeding during the fill operation. However, during the clean operation, the shock tube is in the circuit such that cleaning material travels completely throughout the shock tube. The method of the present invention involves the use of the product fill system so as to accommodate cleaning without disassembly of parts.

What is claimed is:  
     
         1 . A product fill system comprising: 
 a source of product supplied along in a circuit;    a filler valve at a fill end of the circuit such that product flows in a path from the source through the filler valve during a fill operation;    a shock tube in communication with the circuit, but off the path; and a mode valve connected to the circuit and wherein the shock tube is connected to the path via the mode valve; and wherein the mode valve has at least two modes: 
 a fill mode in which any overpressure caused by shut off of the filler valve will travel through the mode valve into the shock tube; and  
 a clean mode in which passage of cleaning material from upstream of the mode valve on the path is directed from the mode valve through a first end of the shock tube and out a second end of the shock tube towards the filler valve by way of the mode valve.  
   
     
     
         2 . The product fill system of  claim 1  wherein the mode valve has first, second, third, and fourth ports.  
     
     
         3 . The product fill system of  claim 2  wherein the mode valve, when disposed in the fill mode, has communication between the first, second, and third ports and the fourth port is not in communication with other ports.  
     
     
         4 . The product fill system of  claim 3  wherein the mode valve, when disposed in the clean mode, has communication between the first and fourth ports and separate communication between the second and third ports.  
     
     
         5 . The product fill system of  claim 4  wherein the mode valve, when disposed in the clean mode, is operable to pass cleaning material from the third port to the second port.  
     
     
         6 . The product fill system of  claim 5  further comprising a shock tube valve between the mode valve and the first end of the shock tube, the shock tube valve being closed when the mode valve is in the fill mode and being open when the mode valve is in the clean mode.  
     
     
         7 . The product fill system of  claim 1  wherein, with the mode valve in fill mode, any overpressure caused by shut off of the filler valve will travel through the mode valve to enter the second end of shock tube.  
     
     
         8 . A product fill system comprising: 
 a source of product supplied along in a circuit;    a filler valve at a fill end of the circuit such that product flows in a path from the source through the filler valve during a fill operation;    a shock tube in communication with the circuit, but off the path, the shock tube having first and second ends; and a mode valve connected to the circuit and wherein the shock tube is connected to the path via the mode valve; and wherein the mode valve has at least two modes: 
 a fill mode in which any overpressure caused by shut off of the filler valve will travel through the mode valve into the second end of the shock tube; and  
 a clean mode in which passage of cleaning material from upstream of the mode valve on the path is directed from the mode valve through the first end of the shock tube and out the second end of the shock tube towards the filler valve.  
   
     
     
         9 . The product fill system of  claim 8  wherein, in the clean mode, the mode valve directs cleaning material from the second end of the shock tube towards the filler valve via the mode valve.  
     
     
         10 . The product fill system of  claim 8  wherein the mode valve has first, second, third, and fourth ports.  
     
     
         11 . The product fill system of  claim 10  wherein the mode valve, when disposed in the fill mode, has communication between the first, second, and third ports and the fourth port is not in communication with other ports.  
     
     
         12 . The product fill system of  claim 10  wherein the mode valve, when disposed in the clean mode, has communication between the first and fourth ports and separate communication between the second and third ports.  
     
     
         13 . The product fill system of  claim 4  wherein the mode valve, when disposed in the clean mode, is operable to pass cleaning material from the third port to the second port.  
     
     
         14 . The product fill system of  claim 13  further comprising a shock tube valve between the mode valve and the first end of the shock tube, the shock tube valve being closed when the mode valve is in the fill mode and being open when the mode valve is in the clean mode.  
     
     
         15 . The product fill system of  claim 14  wherein, with the mode valve in fill mode, any overpressure caused by shut off of the filler valve will travel through the mode valve to enter the second end of shock tube.  
     
     
         16 . The product fill system of  claim 8  further comprising a shock tube valve between the mode valve and the first end of the shock tube, the shock tube valve being closed when the mode valve is in the fill mode and being open when the mode valve is in the clean mode.  
     
     
         17 . The product fill system of  claim 8  wherein, with the mode valve in fill mode, any overpressure caused by shut off of the filler valve will travel through the mode valve to enter the second end of shock tube.  
     
     
         18 . A method of using a product fill system having a product source, a filler valve connected to the product source by a circuit and from which product is dispensed, and a shock tube to absorb overpressure from shutting of the filler valve, the shock tube having first and second ends, the steps comprising: 
 using a mode valve to dispose the system in a fill mode in which the product goes from the product source through the mode valve to the filler valve and in which any overpressure from the closing of the filler valve passes through the mode valve and enters the second end of the shock tube; and    switching the mode valve into a clean mode such that cleaning material passes from the circuit upstream of the mode valve through the mode valve to the first end of the shock tube and out the second end of the shock tube..    
     
     
         19 . The method of  claim 18  wherein, with the mode valve in fill mode, any overpressure caused by shut off of the filler valve will travel through the mode valve to enter the second end of shock tube.  
     
     
         20 . The method of  claim 19  wherein the mode valve has first, second, third, and fourth ports and wherein the switching of the mode valve into clean mode allows communication between the first and fourth ports and separate communication between the second and third ports.