Mobile filling station

Abstract

The present invention relates generally to a compact, mobile filling station for filling cylinders. The compact modular filling station is capable of filling cylinders with fluids at high pressures and at high gas flow rates to achieve a rapid fill rates as measured in volume of fluid per time per filling system area using a controlled temperature filling process.

What is claimed is: 
     
         1 . A compact, mobile filling station for filling cylinders with fluids comprising:
 a portable skid containing at least two filling systems designed to fill cylinders affixed thereto,   the filling system comprising filling equipment in fluid communication with a fluid source and cylinders to be filled and capable of pressurizing and filling the cylinders with fluid at fast flow rates, and   wherein the physical configuration of the filling equipment is in close approximation such that the filling station has a capacity to fill cylinders at an average rate of at least 80 scfh per sq. foot of skid.   
     
     
         2 . The filling station of  claim 1  wherein the fluid is a cryogenic fluid or mixture of fluids. 
     
     
         3 . The filling station of  claim 2  wherein the fluid is selected from oxygen, nitrogen, argon, helium, carbon dioxide, hydrogen, methane, natural gas and mixtures of two or more thereof 
     
     
         4 . The filling station of  claim 3  wherein the filling equipment includes at least one cryogenic reciprocating pump, vaporizer; vacuum pump; and fill head connected in by a network of piping and valves for venting, evacuating and filling cylinders on a skid with an area of not more than about 72 ft 2 . 
     
     
         5 . The filling station of  claim 4  wherein the skid is made from a welded tubular steel structure and all major equipment is affixed to the floor of the skid on solid rubber blocks on a rod and pinion assembly. 
     
     
         6 . The filling station of  claim 5  wherein the skid has self propelled hydraulic lifts for raising it onto a flat bed for transport. 
     
     
         7 . The filling station of  claim 4  wherein the piping path lengths between the vaporizer and the cryogenic pump and between the vaporizer and the fill head are each less than 9 feet. 
     
     
         8 . The filling station of  claim 1  having a dedicated control system that will fill the cylinders in accordance with a predetermined recipe at maximum rate of flow. 
     
     
         9 . The filling station of  claim 8  wherein the control system collects all filling data and stores such data on a local server which can communicate with a remote receiver and which can receive instruction for filling operations. 
     
     
         10 . The filling station of  claim 1  wherein the filling equipment includes a vacuum valve sized to have minimum flow area opening with an equivalent hydraulic diameter in the range of 10% to 60% of that of the cylinder neck bore. 
     
     
         11 . A process for filling a cylinder with cryogenic fluid in a filling system comprising:
 pumping a cryogenic liquid at an initial rate to an elevated pressure within the range of from 800 to 10,000 psia to produce elevated pressure cryogenic liquid;   vaporizing a first portion of the elevated pressure cryogenic liquid to produce elevated pressure gas;   mixing a second portion of the elevated pressure cryogenic liquid with the elevated pressure gas and vaporizing the second portion of the elevated pressure cryogenic liquid by direct heat exchange with the elevated pressure gas to produce a controlled temperature elevated pressure gas having a temperature of higher than −40° F. (−40° C.);   passing the controlled temperature elevated pressure gas into the cylinder to form a filled gas; and varying the cryogenic liquid pumping initial rate based on the temperature rise to limit the temperature of filled gas to not more than 120° F.   
     
     
         12 . The process of  claim 11  wherein the first portion of the elevated pressure cryogenic liquid passes through a vaporizer to produce an elevated pressure gas and the second portion of the elevated pressure cryogenic liquid is mixed directly with the elevated pressure gas to form a controlled temperature elevated pressure gas ready for filling into the cylinders. 
     
     
         13 . The process of  claim 12  wherein and the second portion of the elevated pressure cryogenic liquid is vaporized by direct heat exchange with the elevated pressure gas to produce a temperature of the controlled temperature elevated pressure gas of between −31° F. to 14° F. 
     
     
         14 . The process of  claim 13  wherein the controlled temperature elevated pressure gas is passed into the cylinders at a rate of 200 to 1000 psi per minute. 
     
     
         15 . The process of  claim 14  wherein the final pressure of the gas within the cylinder is within the range of 1000 to 3500 psia and the temperature is within the range of 59° F. to 120° F.