Rupture disc alarm system

• US RE34,308 E
• Filed: 01/11/1991
• Issued: 07/13/1993
• Est. Priority Date: 01/25/1980
• Status: Expired due to Term

• Current Assignee: Continental Disc Corporation (TSL Engineered Products LLC)
• Original Assignee: Continental Disc Corporation (TSL Engineered Products LLC)
• Inventors: Thompson, Leonard K., Corbett, William H.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US07/640,290
• Time in Patent Office: 914 Days
• Field of Search: 340/679, 340/550, 340/590, 340/548, 340/591, 340/592, 340/595-598, 340/610, 340/626, 340/665, 340/668, 340/500, 340/501, 340/506, 340/532, 340/537, 200/61.08, 200/61.18, 200/61.23, 200/61.25, 200/61.86, 200/81 R, 200/83 R, 73/725, 73/726, 137/67, 137/68.1, 137/70, 137/71, 137/554, 220/89.1, 220/89.2, 220/89.4
• US Class Current: 340/679
• CPC Class Codes: F16K 17/1606 of the reverse-buckling-type F16K17/1633 takes precedence
• CPC Class Codes: F16K 37/0041 for measuring valve parameters F16K37/0033 takes precedence
• CPC Class Codes: Y10T 137/1632 Destructible element
• CPC Class Codes: Y10T 137/1684 With alarm or indicator
• CPC Class Codes: Y10T 137/1692 Rupture disc
• CPC Class Codes: Y10T 137/1737 Reverse buckling
• CPC Class Codes: Y10T 137/1759 Knife or cutter causes disc to break
• CPC Class Codes: Y10T 137/8242 Electrical

Abstract

A monitor system for sensing the failure of a rupture disc and activating an alarm in response to such a failure. The system also senses potential failure of a rupture disc. The system includes a failsafe signal carrying loop which is broken when the rupture disc fails, thereby interrupting the signal. The system also includes a signal sensor which recognizes a signal interruption or substantial modification in the signal and initiates and cooperates with an alarm device to provide notice to an operator or a safety device that the rupture disc has failed.

Claims

1. A monitoring system for detecting alterations in a deformable member of a rupture disc assembly;

said system comprising;

(a) .Iadd.a deformable member capable of withstanding a predetermined minimum amount of fluid pressure and blocking the flow of fluid through a conduit, said deformable member deforming upon the application of pressure and rupturing when said predetermined minimum amount of pressure is applied;

.Iaddend.

(.Iadd.b.Iaddend.) generating means for producing a signal;

(.[.b.]. .Iadd.c.Iaddend.) signal carrying means in touching relationship and positioned on said deformable member and transmitting said signal therethrough when said member is not deformed;

.Iadd.said signal carrying means being flexible and formed of a material with characteristics that will allow it to flex when the deformable member flexes and break when the deformable member ruptures without affecting the predetermined amount of pressure necessary to rupture the deformable member;

.Iaddend.said carrying means having a modifiable transmission capacity and being sensitive to alterations in said deformable member such that the carrying means transmitted signal is modified when alterations occur in said deformable member;

(.[.c.]. .Iadd.d.Iaddend.) sensor means cooperating with said generating means and said carrying means for detecting said transmitted signal;

said sensor means having the capacity to determine when said transmitted signal has been modified a predetermined amount and triggering a response at a location remote from said deformable member indicating that said signal has been modified said predetermined amount; and

(.[.d.]. .Iadd.e.Iaddend.) alarm means remote from said deformable member and being triggered by said sensor means upon said transmitted signal being modified said predetermined amount;

(.[.e.]. .Iadd.f.Iaddend.) whereby said alarm means is activated whenever said deformable member is altered a sufficient amount to modify said transmitted signal said predetermined amount.

2. The system according to claim 1 wherein:

(a) said signal is electrical; and

(b) said signal carrying means comprises an electrical circuit.

3. The system according to claim 1 wherein:

(a) said signal is a light beam; and

(b) said signal carrying means comprises a light transmitting optical fiber.

4. The system according to claim 1, 2 or 3 wherein:

(a) said deformable member is rupture disc seal; and

(b) said carrying means is physically attached to said seal in such a manner that when said seal ruptures, then said carrying means is broken thereby interrupting and thus modifying said transmitted signal.

5. The system according to claim 4 wherein:

(a) said seal deforms by stretching before rupture thereof; and

(b) said carrying means deforms with said seal and has the capacity to modify the signal transmitted thereby in substantive proportion to the stretching of said seal;

(c) whereby when said seal is stretched a prespecified amount then said signal is modified said predetermined amount such that said alarm means is activated.

6. The system according to claim 5 wherein:

(a) said carrying means comprises an electrical current carrying wire being attached to said seal to stretch therewith and having a varying resistance related to the cross-sectional area thereof;

the cross-sectional area of said wiring varying in proportion to the stretching of said seal.

7. The system according to claim 3 wherein:

(a) said alarm is activated whenever said signal is modified by means external to said system; and

(b) said alarm is activated whenever said sensor fails to function;

whereby said system is failsafe.

8. A rupture disc assembly for relief of excessive fluid pressure in at least one direction in processing equipment and for triggering an alarm located remotely from said assembly when such relief occurs;

said assembly comprising;

(a) a rupturable seal positioned to operably block flow of fluid through a conduit communicating with the processing equipment during normal operating conditions;

said seal rupturing and allowing flow of fluid during conditions of excessive fluid pressure in the processing equipment;

(b) support means securing said seal prior to rupture thereof in said conduit;

(c) generating means developing a signal comprising a reference level of energy;

(d) carrying means cooperating with said generating means to transmit said signal;

said carrying means being positioned in touching relationship with respect to and extending along said seal and being physically altered by a change in condition in said seal thereby modifying said signal;

.Iadd.said carrying means being flexible and formed of a material with characteristics that will allow it to break when the rupturable seal ruptures without affecting the predetermined amount of pressure necessary to rupture the rupturable seal;

.Iaddend.

(e) sensor means cooperating with said generating means and said carrying means and monitoring said signal after transmission by said carrying means, said sensor means detecting a change in the transmitted signal and producing a response to such a change; and

(f) alarm means remote from said seal and cooperating with said sensor means and being activated by said response after a predetermined level of change in the transmitted signal;

(g) whereby when the condition of said seal changes a sufficient amount to produce said predetermined level of change in the transmitted signal, said alarm is activated.

9. The assembly, according to claim 8 wherein:

(a) said generating means comprises an electrical power supply;

(b) said signal is electrical; and

(c) said carrying means comprises an electrical circuit.

10. The assembly according to claim 9 wherein:

(a) said seal is stretchable to a predetermined limit before rupturing;

(b) a portion of said circuit is attached to said seal such that said circuit is stretched whenever said seal is stretched; and

(c) said circuit modifies the signal being transmitted thereby upon stretching.

11. The assembly according to claim 10 wherein:

(a) stretching of said circuit decreases the cross section thereof, thereby changing the electrical resistance thereof.

12. The assembly according to claim 9 wherein:

(a) said electrical circuit includes an electrical supply being in the nature of not more than approximately 6 volts D.C. and not more than approximately 0.1M amperes;

whereby

(b) said electrical circuit is generally intrinsically safe for use in conjunction with explosive fluids in said conduit.

13. The assembly according to claim 8 wherein:

(a) said sensor means produces a continuous impulse upon reception of the signal transmitted by said carrying means unless said predetermined level of change has occurred in said transmitted signal and sends said impulse to said alarm means;

said impulse being stopped by mechanical and electrical failures of said sensor means;

said alarm means being maintained is a non-activated state when receiving said impulse and being in an activated state when not receiving said impulse;

whereby said alarm means is activated when said sensor means fails and when said signal is modified said predetermined level of change, such that said system is substantially failsafe.

14. In combination:

(a) a rupture disc seal .[.having.]. .Iadd.assembly comprising, a rupture disc including an outer edge and being capable of withstanding a predetermined minimum amount of pressure, and further including .Iaddend.opposed sides for blocking flow of fluid through a passageway until a differential pressure between said sides exceeds a predetermined level whereupon said seal ruptures;

.Iadd.said seal assembly including means for engaging the outer edge of the disc and holding the disc in place;

.Iaddend.and

(b) a conduit having a pathway .[.adapted.]. .Iadd.means comprising a breakable, electrically-conductive material .Iaddend.for transmitting a signal from one end thereof to an opposite end thereof;

said conduit being fixedly attached to said .Iadd.rupture disc .Iaddend.seal .Iadd.assembly at least in the vicinity of the edge of said seal assembly, said pathway means being flexible and formed of a material with characteristics that will allow it to break without affecting the predetermined amount of pressure necessary to rupture the rupture disc, said pathway means including a length of said breakable, electrically-conductive material extending in close proximity across at least a substantial portion of one side of said rupture disc, .Iaddend.such that .Iadd.when .Iaddend.said .[.pathway is.]. .Iadd.rupture disc is ruptured the electrically conductive material would be .Iaddend.broken and .Iadd.the pathway means would be .Iaddend.incapable of transmitting a signal .[.when said seal ruptures.].;

said conduit also being adapted to communicate with alarm means such that when said pathway .Iadd.means .Iaddend.is unbroken said signal is transmitted to said alarm means and when said pathway .Iadd.means .Iaddend.is broken said signal is not transmitted to said alarm means thereby activating said alarm means.

15. The combination according to claim 14 including:

(a) generating means for producing a signal and delivering said signal to said conduit one end;

(b) sensor means for receiving a transmitted signal from said conduit opposite end, sensing an interruption of said signal, and producing a response to such an interruption; and

(c) alarm means being triggered by said response. .Iadd.

16. The combination in claim 14, wherein the conduit is fixedly attached to the rupture disc seal assembly on opposite portions of the edge of the disc. .Iaddend. .Iadd.

17. The combination of claim 14, wherein the rupture disc has a convex side and the pathway means transmits a signal across said convex side. .Iaddend. .Iadd.18. The combination of claim 14, wherein the rupture disc has a concave side and the pathway means transmits a signal across said concave side. .Iaddend. .Iadd.19. The combination of claim 14, wherein said length of said breakable, electrically-conductive material extends across said side of the rupture disc in direct contact with said side.

18. Iaddend. .Iadd.20. The combination of claim 14, wherein said length of said breakable, electrically-conductive material is formed of metal foil. .Iaddend. .Iadd.21. The combination of claim 14, wherein said length of said breakable, electrically-conductive material is generally U-shaped.

19. Iaddend. .Iadd.22. The combination of claim 14, and further including insulating means for insulating said length of said breakable, electrically-conductive material from the rupture disc. .Iaddend.