Ventilation gas management systems and processes
View Patent ↗A ventilation gas management system and process for an enclosure adapted to contain fluid supply vessel(s) and through which ventilation gas is flowed to provide safe operation in the event of leakage of fluid from a vessel. Ventilation gas flow is modulated to accommodate various hazard levels associated with the deployment and operation of such enclosure containing fluid supply vessel(s), e.g., a gas box or gas cabinet in a semiconductor manufacturing facility, thereby achieving reduction in ventilation gas requirements otherwise required for such deployment and operation.
1. A ventilation gas management system for an enclosure containing a fluid supply vessel and flow circuitry coupled thereto and adapted for flow of ventilation gas through the enclosure, said system comprising:
a flow modulator arranged to control ventilation gas flow through the enclosure;
a monitoring assembly adapted to (i) monitor a characteristic of said fluid supply vessel, enclosure, or fluid in or dispensed from said fluid supply vessel, that affects a level of hazard or risk associated with leakage of fluid from said fluid supply vessel or associated flow circuitry in said enclosure, and (ii) output a monitoring signal correlative of the monitored characteristic; and
a controller arranged to receive said monitoring signal from said monitoring assembly, and to responsively adjust the flow modulator based on fluid inventory in the fluid supply vessel during dispensing of fluid therefrom, in relation to the level of hazard or risk associated with leakage of fluid from said fluid supply vessel in said enclosure.
2. The system of claim 1 , wherein the monitored characteristic comprises at least one characteristic selected from the group consisting of: fluid inventory in the fluid supply vessel; fluid pressure in the fluid supply vessel; fluid pressure in a gas delivery manifold downstream of the fluid supply vessel; strain in a wall of the fluid supply vessel; weight of the fluid supply vessel containing said fluid; physical adsorbent characteristic of a physical adsorbent disposed in an interior volume of the fluid supply vessel; temperature of the fluid supply vessel; temperature in the enclosure; cumulative volume of fluid dispensed from said fluid supply vessel; duration of fluid dispensing from said fluid supply vessel; flow rate of fluid dispensed from said fluid supply vessel; ambient conditions in said enclosure; fluid conditions in said fluid supply vessel; open or closed character of an access structure of the enclosure; and an alarm condition associated with the fluid supply vessel, flow circuitry, enclosure and/or process consuming the dispensed fluid.
3. The system of claim 1 , wherein the controller is arranged to responsively adjust the flow modulator to reduce flow of ventilation gas through the enclosure during dispensing of fluid from the fluid supply vessel, so that ventilation gas flow through the enclosure is progressively reduced as fluid inventory decreases during said dispensing of fluid.
4. The ventilation gas management system of claim 1 , as adapted for management of ventilation gas flow wherein the enclosure is compartmented to provide a separate sub-enclosure for each of multiple fluid supply vessels, and wherein the ventilation gas management system is arranged to manage ventilation gas flow through each sub-enclosure.
5. The system of claim 1 , as operably deployed with a gas box of an ion implanter in a semiconductor manufacturing facility, to modulate flow of ventilation gas through the gas box.
6. The system of claim 5 , wherein the gas box contains a sorbent-based fluid supply vessel.
7. The system of claim 6 , wherein the sorbent-based fluid supply vessel contains fluid selected from the group consisting of hydride gases, halide gases, gaseous organometallic compounds, silane, diborane, germane, ammonia, phosphine, arsine, stibine, hydrogen sulfide, hydrogen selenide, hydrogen telluride, boron trifluoride, B 2 F 4 , tungsten hexafluoride, chlorine, hydrogen chloride, hydrogen bromide, hydrogen iodide, and hydrogen fluoride.
8. The system of claim 6 , wherein fluid is stored in said fluid supply vessel at sub-atmospheric pressure.
9. The system of claim 5 , wherein the gas box contains an internally pressure-regulated fluid supply vessel.
10. The system of claim 9 , wherein the internally pressure-regulated fluid supply vessel contains fluid selected from the group consisting of hydride gases, halide gases, gaseous organometallic compounds, silane, diborane, germane, ammonia, phosphine, arsine, stibine, hydrogen sulfide, hydrogen selenide, hydrogen telluride, boron trifluoride, B 2 F 4 , tungsten hexafluoride, chlorine, hydrogen chloride, hydrogen bromide, hydrogen iodide, and hydrogen fluoride.
11. A method of supplying gas from a fluid source in an enclosure through which ventilation gas is flowed, said method comprising monitoring a characteristic of said fluid source, enclosure, or fluid in or dispensed from said fluid source, that affects a level of hazard or risk associated with leakage of fluid from said fluid source or associated flow circuitry in said enclosure, and in response to said monitoring, adjusting flow of ventilation gas through the enclosure based on fluid inventory in the fluid source during dispensing of fluid therefrom, in relation to the level of hazard or risk associated with leakage of fluid from said fluid source in said enclosure.
12. The method of claim 11 , wherein the monitored characteristic comprises at least one characteristic selected from the group consisting of: fluid inventory in the fluid source; fluid pressure in the fluid source; fluid pressure in a gas delivery manifold downstream of the fluid supply vessel; strain in a wall of the fluid source; weight of the fluid source containing said fluid; physical adsorbent characteristic of a physical adsorbent disposed in an interior volume of the fluid source; temperature of the fluid source; temperature in the enclosure; cumulative volume of fluid dispensed from said fluid source; duration of fluid dispensing from said fluid source; flow rate of fluid dispensed from said fluid source; ambient conditions in said enclosure; fluid conditions in said fluid source; open or closed character of an access structure of the enclosure; and an alarm condition associated with the fluid source, flow circuitry, and/or enclosure.
13. The method of claim 11 , wherein the monitored characteristic comprises pressure fluid dispensed from said fluid source.
14. The method of claim 11 , wherein said adjusting comprises modulating a flow control device selected from the group consisting of: flow control valves; dampers; variable-size restricted flow orifice devices; mass flow controllers; variable speed pumps; and variable speed blowers.
15. The method of claim 11 , wherein said adjusting comprises acquiring data in a data acquisition module that is positioned outside the enclosure and is operatively coupled with at least one sensor in the enclosure for said monitoring.
16. The method of claim 11 , wherein said adjusting reduces flow of ventilation gas through the enclosure upon dispensing of fluid from the fluid source under non-alarm conditions and closed character of an access structure of the enclosure, and increases flow of ventilation gas through the enclosure upon occurrence of an alarm condition associated with the fluid supply vessel, flow circuitry, enclosure and/or process consuming the dispensed fluid, or upon the opening of the access structure of the enclosure.
17. The method of claim 11 , wherein said adjusting reduces flow of ventilation gas through the enclosure during dispensing of fluid from the fluid source, so that ventilation gas flow through the enclosure is progressively reduced as fluid inventory decreases during said dispensing of fluid.
18. The method of claim 11 , wherein the enclosure is compartmented to provide a separate sub-enclosure for each of multiple fluid sources, said method comprising carrying out said monitoring and adjusting flow of ventilation gas for each sub-enclosure.
19. The method of claim 11 , as conducted in a semiconductor manufacturing facility comprising a gas box of an ion implanter as said enclosure, to modulate flow of ventilation gas through the gas box.
20. The method of claim 19 , wherein the gas box contains a sorbent-based fluid supply vessel as said fluid source.
21. The method of claim 20 , wherein the sorbent-based fluid supply vessel contains an activated carbon adsorbent.
22. The method of claim 20 , wherein the sorbent-based fluid supply vessel contains fluid selected from the group consisting of hydride gases, halide gases, gaseous organometallic compounds, silane, diborane, germane, ammonia, phosphine, arsine, stibine, hydrogen sulfide, hydrogen selenide, hydrogen telluride, boron trifluoride, B 2 F 4 , tungsten hexafluoride, chlorine, hydrogen chloride, hydrogen bromide, hydrogen iodide, and hydrogen fluoride.
23. The method of claim 20 , wherein fluid is stored in said fluid supply vessel at sub-atmospheric pressure.
24. The method of claim 19 , wherein the gas box contains an internally pressure-regulated fluid supply vessel.
25. The method of claim 24 , wherein the internally pressure-regulated fluid supply vessel contains fluid selected from the group consisting of hydride gases, halide gases, gaseous organometallic compounds, silane, diborane, germane, ammonia, phosphine, arsine, stibine, hydrogen sulfide, hydrogen selenide, hydrogen telluride, boron trifluoride, B 2 F 4 , tungsten hexafluoride, chlorine, hydrogen chloride, hydrogen bromide, hydrogen iodide, and hydrogen fluoride.