Control of fluid conditions in bulk fluid distribution systems
AssigneeAir Liquide Electronics U.S. LP
InventorDavid Gerken
Life of this patent
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Abstract
An improved bulk fluid distribution for supplying process fluids to semiconductor process tools. The improved system having an alternating pressure vessel engine substantially eliminates pressure fluctuations in the bulk fluid supply line due to head losses from the changing weight of the fluid in the dispensing vessels. The system also enables flexible control of the flow conditions of the fluid in the fluid supply line.
Claims21
A method for controlling the pressure of a fluid in a bulk fluid distribution system having a first vessel and a second vessel for supplying the fluid to a supply line, an inert gas source for supplying an inert gas to the first and second vessels, a controller and a sensor positioned in the supply line comprising the steps of:
- receiving at the controller a control signal from the sensor;
- initiating a dispense cycle of the first vessel comprising the steps of:
- determining a first signal from the control signal and a change in head pressure of the fluid between a first level and a second level of the second vessel;
- applying a first pressure to the fluid in the first vessel based upon the first signal;
- and dispensing the fluid from a first level to a second level of the first vessel;
- and
- initiating a dispense cycle of the second vessel comprising the steps of:
- determining a second signal from the control signal and a change in head pressure between the first level and the second level of the first vessel;
- applying a second pressure to the fluid in the second vessel based upon the second signal;
- and dispensing the fluid from the first level to the second level of the second vessel.
A method for controlling the pressure of a fluid in a bulk fluid distribution system having a first vessel and a second vessel for supplying the fluid to a supply line, an inert gas source for supplying an inert gas to the first and second vessels, a controller and a sensor positioned in the supply line comprising the steps of:
- applying the inert gas to the fluid at a first level in the first vessel;
- dispensing the fluid in the first vessel from the first level to a second level of the first vessel;
- adjusting the inert gas pressure to the first vessel in response to a signal from the sensor in the supply line in order to maintain a predetermined fluid pressure in the supply line;
- applying the inert gas to the fluid at a first level in the second vessel;
- dispensing the fluid in the second vessel from the first level to a second level of the second vessel;
- and
- adjusting the inert gas pressure to the second vessel in response to a signal from the sensor in the supply line in order to maintain a predetermined pressure in the supply line;
- wherein the inert gas pressure supplied to the fluid at the first level of the first vessel is adjusted for a change in head pressure between the first and second levels of the second vessel and wherein the inert gas pressure supplied to the first level of the second vessel is adjusted for a head pressure between the first and second levels of the first vessel.
A method for controlling the pressure of a fluid in a bulk fluid distribution system having a supply line, a first vessel and a second vessel for supplying the fluid to the supply line, an inert gas source for supplying an inert gas to the first and second vessels, a controller and a sensor positioned in the supply line comprising the steps of:
- sending a control signal from the sensor to the controller;
- determining a first signal from the control signal and a change in the head pressure of the fluid between a first level and a second level of the second vessel;
- applying a first inert gas pressure to the first vessel based upon the first signal;
- dispensing the fluid from the first vessel to the supply line and;
- determining a second signal from the control signal and a change in the head pressure of the fluid between a first level and a second level of the first vessel;
- applying a second inert gas pressure to the second vessel based upon the second signal;
- and dispensing the fluid from the second vessel to the supply line.
Dependencies are inferred from the claim text.