Liquid supply or drain pipe equipped with a leakage detector

• US 6,513,542 B1
• Filed: 08/08/2000
• Issued: 02/04/2003
• Est. Priority Date: 08/08/2000
• Status: Expired due to Term

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Hsieh, Tsung-Chi
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/634,495
• Time in Patent Office: 910 Days
• Field of Search: 137/312, 137/387, 137/392, 137/554, 137/557, 137/558, 137/613, 137/485, 137/486, 137/487.5, 340/604, 340/605, 340/606, 340/620, 340/608, 73/405.R, 73/46, 73/498
• US Class Current: 137/312
• CPC Class Codes: G01M 3/04 by detecting the presence of fluid at the leakage point
• CPC Class Codes: G01M 3/184 for valves
• CPC Class Codes: Y10T 137/5762 With leakage or drip collecting
• CPC Class Codes: Y10T 137/7759 Responsive to change in rate of fluid flow
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/8242 Electrical
• CPC Class Codes: Y10T 137/8326 Fluid pressure responsive indicator, recorder or alarm

Abstract

A liquid supply/drain conduit system that is equipped with an inner leakage detector and a liquid process tank that is equipped with such liquid supply/drain conduit system are disclosed. The liquid supply/drain conduit system includes a first conduit for feeding a liquid into an inlet of a first valve of the normal-closed type, a second conduit of T-shape that has a horizontal portion and a vertical portion, the horizontal portion of the second conduit flows a liquid from an outlet of the first valve into a reservoir tank. The second valve of the normal-open type has an inlet and an outlet, the inlet is situated in relation to the first valve in such a way that it receives through a vertical portion of the second conduit a leaked flow of liquid by gravity when the normal-closed first valve failed to close. A liquid detector is further provided for detecting a leaked flow of liquid through the second valve. The leakage detector may optionally include an alarm system to be activated when a leakage flow is detected. The leakage detector may further send a signal to a process controller for alerting a machine operator of the leakage status of the liquid supply/drain conduit system.

Claims

1. A liquid supply or drain conduit system equipped with a leakage detector comprising:

a first valve of the normal closed type having an inlet and an outlet,

a first conduit for feeding a liquid into said inlet of said first valve,

a second conduit of T-shape having a horizontal portion and a vertical portion, said horizontal portion of the second conduit being in fluid communication with said outlet of said first valve for flowing said liquid into a reservoir tank when said first valve is in an opened state,

a second valve of the normal-open type except when said first valve is in an opened state having an inlet and an outlet, said inlet of said second valve being in fluid communication with said outlet of said first valve and situated under said first valve in such a way that said inlet of said second valve receives through said vertical portion of said second conduit a leaked flow of liquid by gravity when said first valve is supposed to be in a closed state but failed to close, and

a leakage detector positioned under and in fluid communication with said outlet of the second valve for detecting a flow of liquid through said second valve, when said first valve is in a closed state and said second valve is in an opened state.

2. A liquid supply or drain conduit system equipped with a leakage detector according to claim 1, wherein said reservoir tank is a chemical process tank.

3. A liquid supply or drain conduit system equipped with a leakage detector according to claim 1, wherein said reservoir tank is a waste chemical collection tank.

4. A liquid supply or drain conduit system equipped with a leakage detector according to claim 1, wherein said leakage detector further comprises a liquid flow meter.

5. A liquid supply or drain conduit system equipped with a leakage detector according to claim 1, wherein said leakage detector further comprises an alarm to be activated when a liquid flows through said second valve.

6. A liquid supply or drain conduit system equipped with a leakage detector according to claim 1, wherein said leakage detector sends a signal to a micro-processor when a flow of liquid through said second valve is detected.

7. A liquid supply or drain conduit system equipped with a leakage detector according to claim 1, wherein said leakage detector sends a signal to a closed-loop control system for closing said first valve when a flow of liquid through said second valve is detected.

8. A liquid process tank equipped with a supply/drain system capable of detecting an inner leakage comprising:

a process tank for receiving a fresh liquid from a second conduit and for draining a used liquid to a third conduit,

a first valve of the normal-closed type having an inlet and an outlet,

a first conduit for feeding said fresh liquid into said inlet of said first valve, a second conduit being provided in a T-shape having a horizontal portion and a vertical portion, said horizontal portion being in fluid communication with said outlet of said first valve for flowing said fresh liquid from said outlet of said first valve into said process tank, when said first valve is in an open state,

a second valve of the normal-open type except when said first valve is in an open state having an in;

et and an outlet, said inlet of said second valve being in fluid communication with said outlet of said first valve and is situated under said first valve in such a way that it receives through said fresh liquid by gravity when said first valve is supposed to be in close state but failed to close,

a first leakage detector positioned under and in fluid communication with said outlet of said second valve, when said first valve is in a closed state and said second valve is in an open state,

a third conduit for draining said used liquid from said process tank into an inlet of a third valve,

a fourth conduit of T-shape having a horizontal portion and a vertical portion, said horizontal portion being in fluid communication with and receives said used liquid from said outlet of said third valve and delivers said used liquid to a used liquid collection tank,

a fourth valve of the normal-open type, except when said third valve is in an open state, having an inlet and an outlet, said inlet in fluid communication with said outlet of the third valve and is situated under said third valve in such a way that it receives through said vertical portion of said fourth conduit a leaked flow of said used liquid by gravity when said third valve is supposed to be in a closed state but failed to close, and

a second leakage detector positioned under and in fluid communication with said outlet of said fourth valve for detecting a flow of said used liquid through said fourth valve, when said third valve is in a closed state and said fourth valve is in an opened state.

9. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8 further comprising a micro-processor for receiving a signal from said first and said second leakage detector when a leakage is detected by either of said detectors.

10. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8 further comprising an alarm system to be activated by a signal received from either of said first or said second leakage detector.

11. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8, wherein said process tank is an etch tank.

12. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8, wherein said process tank is a photoresist liquid reservoir tank.

13. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8, wherein said process tank further comprises an outer overflow tank for receiving overflow from said process tank.

14. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8, wherein said process tank further comprises an outer overflow tank and a pump for pumping an overflow from said process tank back into said process tank.

15. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8, wherein said first valve is a supply valve and said third valve is a drain valve.

16. A liquid process tank equipped with a supply/drain system capable of detecting inner leakage according to claim 8, wherein said first and said second leakage detector further comprises a liquid flow meter for sensing a flow of liquid therethrough.