Gas-operated diaphragm dosing pump

Abstract

A diaphragm dosing pump with a gas-operated drive, in particular for adding in a dosed manner adjuvants into gas pipelines, for example a natural gas well, having a drive head for the diaphragm dosing pump, a drive rod moving back and forth in a cylinder chamber of the drive head, which carries a drive part separating the cylinder chamber into two chambers and is effectively connected to a piston rod of the diaphragm dosing pump. A feeding pipeline is connected to the cylinder chamber of the drive head for pressurized gas from the gas pipeline. A control valve is located between the gas feeding pipeline as well as an outlet for the relaxed gas to return to the gas pipeline. The arrangement is made such that the drive head of the diaphragm dosing pump is embodied as a simple operating gas drive such that only the pressure stroke side of the drive head is connected via the control valve to the pressurized gas feeding pipeline while the suction stroke side of the drive head is connected at all times to the gas outlet and that on the suction stroke side of the drive head a spring is provided, which acts upon the drive part in the direction of the suction stroke.

1 . In combination, a diaphragm dosing pump and a gas-operated drive for dosing adjuvants into gas pipelines of a natural gas well, said combination comprising 
 a drive head of the gas operated drive, said drive head having a cylinder chamber,    a drive rod movable back and forth in the cylinder chamber of the drive head,    a drive part separating the cylinder chamber into a pressure stroke side chamber and a suction stroke side chamber, said drive part being connected to a piston rod of the diaphragm dosing pump by the drive rod,    a feeding pipeline connected at one end to the pressure stroke side chamber of the cylinder chamber of the drive head, and    a control valve connected at the other end of the feeding pipeline, the control valve being movable for controlling flow of gas from the feeding pipeline and the cylinder chamber of the drive head to a gas pipeline,    the drive head being alternatingly connected via the control valve to the feeding pipeline and the pressure stroke side chamber of the drive head and to the suction stroke side chamber of the drive head by a gas outlet from the suction stroke side chamber, and    a spring in the suction stroke side chamber of the drive head being biased in a direction of the pressure stroke side chamber.    
     
     
         2 . The combination according to  claim 1 , wherein the control valve is open for performing a pressure stroke of the drive head by connection with the feeding pipeline.  
     
     
         3 . The combination according to  claim 1 , wherein control of the control valve occurs mechanically via a rod operated via axial movement of at least one of the piston rod of the diaphragm dosing pump and the drive rod of the drive head.  
     
     
         4 . The combination according to  claim 1 , wherein the diaphragm dosing pump operated by the gas-operated drive is a hydraulically operating diaphragm pump, with the piston rod in a connection with the drive rod of the drive head.  
     
     
         5 . The combination according to  claim 1 , wherein the drive head is a diaphragm drive, and the drive part is a diaphragm member.  
     
     
         6 . The combination according to  claim 5 , wherein the diaphragm member is a single diaphragm.  
     
     
         7 . The combination according to  claim 5 , wherein the diaphragm member is a dual diaphragm.  
     
     
         8 . The combination according to  claim 5 , wherein the diaphragm member is a rolling diaphragm.  
     
     
         9 . The combination according to  claim 1 , wherein the drive head is a piston drive, and the drive part is a piston.  
     
     
         10 . A method for controlling a gas operated drive of a diaphragm dosing pump, said method comprising the steps of 
 moving a drive part, on one hand, during a pressure stroke by impinging a pressure stroke side chamber of a drive head with pressurized gas and, on the other hand, during a suction stroke by impinging a suction stroke side chamber of the drive head with a spring force.    
     
     
         11 . The method according to  claim 10 , wherein the pressure stroke of the drive part is introduced by opening a connection between the pressure stroke side chamber of the drive head and a first location of a pressurized gas feeding pipeline.  
     
     
         12 . The method according to  claim 11 , wherein the suction stroke of the drive part is introduced by closing the connection between the pressurized gas feeding pipeline and the pressure stroke side chamber of the drive head by a spring force as well as by a connection between a suction stroke side chamber and a second location of the pressurized gas feeding pipeline with a lower pressure than said first location.