Systems and methods for transferring and delivering a liquid chemical from a source to an end use station

Abstract

Provided is a system for transferring and delivering a liquid chemical from a source to an end use station. The system includes: (a) a pressure vessel connected to a liquid chemical source by a delivery conduit, the pressure vessel having an internal surface; (b) a non-mechanical means of transferring the liquid chemical from the source through the delivery conduit to the pressure vessel; (c) a flexible liquid metering device disposed within the pressure vessel, the metering device having an interior and an interior surface and an exterior and an exterior surface; (d) a space adapted to receive the liquid chemical, the space being defined by at least a portion of the metering device external surface and at least a portion of the pressure vessel interior surface, or by at least a portion of the metering device internal surface; and (e) a pressurized gas conduit connected to a pressurized gas source for delivering the pressurized gas into the pressure vessel so as to contact the other of the interior or exterior surface of the metering device that defines the space, whereby the liquid chemical is forced out of the pressure vessel by the metering device to an end use station. Also provided is a method of transferring and delivering a liquid chemical from a source to an end use station. The invention has particular applicability to the semiconductor manufacturing industry for the distribution of ultrapure liquid chemicals to end use stations.

What is claimed is:  
     
         1 . A system for transferring and delivering a liquid chemical from a source to an end use station, comprising: 
 (a) a pressure vessel connected to a liquid chemical source by a delivery conduit, the pressure vessel having an internal surface;    (b) a non-mechanical means of transferring the liquid chemical from the source through the delivery conduit to the pressure vessel;    (c) a flexible liquid metering device disposed within the pressure vessel, the metering device having an interior and an interior surface and an exterior and an exterior surface;    (d) a space adapted to receive the liquid chemical, the space being defined by at least a portion of the metering device external surface and at least a portion of the pressure vessel interior surface, or by at least a portion of the metering device internal surface; and    (e) a pressurized gas conduit connected to a pressurized gas source for delivering the pressurized gas into the pressure vessel so as to contact the other of the interior or exterior surface of the metering device that defines the space, whereby the liquid chemical is forced out of the pressure vessel by the metering device to an end use station.    
     
     
         2 . The system according to  claim 1 , wherein the pressurized gas conduit is connected to deliver the pressurized gas into the pressure vessel so as to contact the interior surface of the metering device.  
     
     
         3 . The system according to  claim 1 , wherein the non-mechanical means of transferring the liquid chemical comprises a gravity feed structure, and wherein the liquid chemical source is contained in a container at an elevated height with respect to the pressure vessel.  
     
     
         3 . The system according to  claim 1 , wherein the non-mechanical means of transferring the liquid chemical source comprises means for pressurizing the liquid chemical source with a pressurized gas.  
     
     
         4 . The system according to  claim 3 , wherein the pressurized gas is an inert gas.  
     
     
         5 . The system according to  claim 3 , wherein the pressurized gas is a reactive gas.  
     
     
         6 . The system according to  claim 1 , wherein a plurality of pressure vessels connected in parallel is used.  
     
     
         7 . The system according to  claim 1 , wherein the metering device is a balloon.  
     
     
         8 . The system according to  claim 7 , wherein the balloon is constructed of a material selected from the group consisting of TEFLON, polypropylene and polyethylene.  
     
     
         9 . The system according to  claim 1 , wherein the metering device is a bellows.  
     
     
         10 . The system according to  claim 9 , wherein the bellows is constructed of a material selected from the group consisting of polypropylene, polyethylene, TEFLON and stainless steel.  
     
     
         11 . The system according to  claim 1 , further comprising: 
 a first isolation valve in the pressurized gas conduit;    a vent conduit with a second isolation valve connected to a vent system at one end, and to an upper portion of the pressure vessel at another end; and    a connecting conduit with a third isolation valve connected to the pressurized gas conduit and the vent conduit.    
     
     
         12 . A method of transferring and delivering a liquid chemical from a source to an end use station, comprising: 
 (a) transferring by non-mechanical means a liquid chemical from a source to a pressure vessel through a delivery conduit, wherein the pressure vessel has an interior surface;    (b) providing a flexible liquid metering device disposed within the pressure vessel, the metering device having an interior and an interior surface and an exterior and an exterior surface; the liquid chemical occupying at least a portion of the space being defined by at least a portion of the metering device external surface and at least a portion of the pressure vessel interior surface, or by at least a portion of the metering device internal surface; and    (c) delivering a pressurized gas into the pressure vessel so as to contact the other of the interior or exterior surface of the metering device that defines the space, whereby the liquid chemical is forced out of the pressure vessel by the metering device to an end use station.    
     
     
         13 . The method according to  claim 12 , wherein the pressurized gas is delivered into the pressure vessel so as to contact the interior surface of the metering device.  
     
     
         14 . The method according to  claim 12 , wherein the non-mechanical means of transferring the liquid chemical source comprises means for pressurizing the liquid chemical source with a pressurized gas.  
     
     
         15 . The method according to  claim 14 , wherein the pressurized gas is an inert gas.  
     
     
         16 . The method according to  claim 14 , wherein the pressurized gas is a reactive gas.  
     
     
         17 . The method according to  claim 12 , wherein a plurality of pressure vessels connected in parallel is used.  
     
     
         18 . The method according to  claim 12 , wherein the metering device is a balloon.  
     
     
         19 . The method according to  claim 18 , wherein the balloon is constructed of a material selected from the group consisting of TEFLON, polypropylene and polyethylene.  
     
     
         20 . The method according to  claim 12 , wherein the metering device is a bellows.  
     
     
         21 . The method according to  claim 20 , wherein the bellows is constructed of a material selected from the group consisting of polypropylene, polyethylene, TEFLON and stainless steel.