Valve system

Abstract

A valve system for monitoring and controlling a flow of a fluid additive into a main fluid line is disclosed. The system includes a pump that provides a constant flow of the additive from a fluid reservoir through a supply conduit into the main fluid line. A portion of the fluid additive may be diverted into one or more return conduits leading back to the reservoir by opening a solenoid actuated valve in the return conduit. Flow meters are employed to detect the flow rates of the fluids in the supply conduit and the main fluid line. The flow meters provide signals to a control system, which are effective to control the operation of the solenoid actuated valves to maintain a desired flow of the additive into the main fluid line.

1 . A method of monitoring and controlling a flow of a fluid additive into a main fluid line comprising the steps of:
 providing a source of the fluid additive in fluid communication with the main fluid line;   causing the fluid additive to flow from the source of the fluid additive into the main fluid line;   monitoring a flow rate of the fluid additive into the main fluid conduit;   monitoring a flow rate of a fluid in the main fluid line; and   diverting a selected amount of the fluid additive into a return line in fluid communication with the source of the fluid additive to maintain a desired flow rate of the fluid additive into the main fluid line.   
     
     
         2 . The method of  claim 1  including the steps of providing a control system for diverting the selected amount of the fluid additive into the return line and inputting into the control system the desired flow rate of the fluid additive. 
     
     
         3 . The method of  claim 1  including the step of inputting a desired ratio of the fluid additive to the primary fluid in the main fluid line. 
     
     
         4 . The method of  claim 1 , including the step of providing a valve system for monitoring and controlling the flow of the fluid additive into the main fluid line. 
     
     
         5 . The method of  claim 4 , wherein the source of the fluid additive is a fluid reservoir adapted to contain the fluid additive. 
     
     
         6 . The method of  claim 5 , wherein the valve system further includes a supply conduit providing fluid communication between the reservoir and the main fluid line. 
     
     
         7 . The method of  claim 6 , wherein the valve system further includes a pump adapted to cause a continuous and uninterrupted flow of the fluid additive from the reservoir through the supply conduit to the main fluid line. 
     
     
         8 . The method of  claim 7 , wherein the valve system further includes a first valve to selectively prevent the flow of the fluid additive into the main fluid line, the first valve disposed along the supply conduit and being normally opened. 
     
     
         9 . The method of  claim 8 , wherein the valve system further includes the return line providing fluid communication between the supply conduit and the reservoir, the return line including an orifice restriction. 
     
     
         10 . The method of  claim 9 , wherein the valve system further includes a second valve to selectively prevent the flow of fluid additive through the return line, the second valve disposed along the return line and being normally closed, the orifice restriction disposed between the supply conduit and the second valve. 
     
     
         11 . The method of  claim 10 , wherein the valve system further includes a first flow meter disposed in the supply conduit adapted to detect the flow rate of the fluid additive into the main fluid line. 
     
     
         12 . The method of  claim 11 , wherein the valve system further includes a second flow meter disposed in the main fluid line adapted to detect the flow rate of the fluid in the main fluid line. 
     
     
         13 . The method of  claim 12 , wherein the valve system further includes means for controlling the pump, the first valve, and the second valve, wherein a signal from the first flow meter and a signal from the second flow meter are effective to control an operation of the pump, the first valve, and the second valve to maintain the desired flow rate of the fluid additive into the main fluid line.