Level gauging system for long narrow nozzles

• US 9,304,029 B2
• Filed: 03/31/2014
• Issued: 04/05/2016
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: Rosemount Tank Radar AB (Emerson Electric Company)
• Original Assignee: Rosemount Tank Radar AB (Emerson Electric Company)
• Inventors: Guzman, Oscar, Rikhter, Ilya
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): JENKINS, JERMAINE L
• Application Number:
  US14/230,574
• Publication Number:
  US 20150276461A1
• Time in Patent Office: 736 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01F 23/241 for discrete levels
• CPC Class Codes: G01F 23/261 for discrete levels
• CPC Class Codes: G01F 23/265 for discrete levels
• CPC Class Codes: G01F 23/282 for discrete levels G01F23/284, G01F23/296 take precedence
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• CPC Class Codes: G01F 23/2961 for discrete levels G01F23/2962 - G01F23/2968 take precedence

Abstract

A gauging installation for a tank with a long narrow nozzle providing access to an interior of the tank. The gauging system includes a GWR level gauge with a probe, and a first rigid extension member providing an interior probe mounting position at the end of the nozzle. The probe is configured to guide an electromagnetic transmit signal from a transceiver towards the product inside the tank, and to return the electromagnetic echo signal resulting from a reflection of the electromagnetic transmit signal by a surface of the product. A microwave transmission line connects the transceiver and the probe.

With this design the beginning of the probe of the GWR level gauge will be located at the lower end of the nozzle, i.e. at the upper interior of the tank.

Claims

1. A gauging installation mounted in a tank for holding liquids, comprising:

a nozzle providing access to an interior of said tank, said nozzle having a tank end connected to an opening in a tank wall, and a distal end at a distance from said tank, said distance being greater than 0.5 meter, and

a gauging system including;

a tank seal arranged in said distal end of said nozzle and configured to separate a tank interior from a tank exterior;

a first rigid extension member extending from said tank seal and providing an interior probe mounting position located proximal to said tank end of said nozzle;

a guided wave radar level gauge for measurement of a distance to a surface of a product in said tank, said guided wave radar level gauge including;

a transceiver configured to transmit an electromagnetic transmit signal and to receive an electromagnetic echo signal;

processing circuitry connected to said transceiver and configured to determine said distance based on a relationship between said electromagnetic transmit signal and said electromagnetic echo signal;

a probe mounted in said probe mounting position and extending into said tank, said probe configured to guide said electromagnetic transmit signal from said transceiver towards said product inside said tank, and to return said electromagnetic echo signal resulting from a reflection of said electromagnetic transmit signal by a surface of said product;

a microwave transmission line having a first end connected to said transceiver; and

a probe sealing arrangement providing a sealed connection of said probe to a second end of said transmission line.

2. The gauging installation according to claim 1, wherein said distance is greater than 1 m.

3. The gauging installation according to claim 1, wherein an inner diameter of said nozzle is less than 4 inches.

4. The gauging installation according to claim 1, further comprising at least one support element, wherein said at least one support element is arranged to keep at least a predetermined distance between said rigid extension member and an inner wall of said nozzle.

5. The gauging installation according to claim 1, further comprising a level switch, functionally independent from said guided wave radar level gauge and arranged to determine when said surface exceeds a predetermined filling level.

6. The gauging installation according to claim 5, wherein said level switch comprises;

a surface detector arranged in the tank interior and configured to detect said surface, and provide a measurement signal indicative of said surface;

a control unit arranged in the tank exterior and configured to receive said measurement signal and, based on said measurement signal, determine if said surface has exceeded a predetermined filling level;

an electrical connection line having a first end connected to said control unit, and

a detector sealing arrangement providing a sealed connection of said surface detector to a second end of said electrical connection line.

7. The gauging installation according to claim 6, wherein said surface detector is mounted in the probe mounting position.

8. The gauging installation according to claim 7, wherein the first rigid extension member is tubular, and wherein said electrical connection line is arranged inside said first rigid, tubular extension member.

9. The gauging installation according to claim 6, further comprising:

a second rigid extension member extending from said tank seal to provide an interior detector mounting position, wherein said surface detector being mounted in said interior detector mounting position.

10. The gauging installation according to claim 9, wherein said detector mounting position is located below the probe mounting position.

11. The gauging installation according to claim 9, wherein the detector mounting position is located above the probe mounting position.

12. The gauging installation according to claim 9, further comprising at least one support element arranged between said first and second rigid extension members to ensure at least a predetermined distance between said first and second rigid extension members.

13. The gauging installation according to claim 9, wherein the second rigid extension member is tubular, and wherein said electrical connection line is arranged inside said second rigid, tubular extension member.

14. The gauging installation according to claim 6, wherein said transceiver, said processing circuitry and said control unit are housed in one single electronics unit.

15. The gauging installation according to claim 1, wherein the first rigid extension member is tubular, and wherein said transmission line is arranged inside said first rigid, tubular extension member.

16. The gauging installation according to claim 1, wherein the microwave transmission line has an impedance matching an impedance of said transceiver.

17. The gauging installation according to claim 1, further comprising a temperature sensor, arranged to detect a temperature in a position along said first extension member.

18. A gauging system, intended to be mounted in a tank nozzle having a length of at least 0.5 meter, said gauging system comprising:

a tank seal configured to be mounted in an upper opening of said nozzle, said tank seal configured to separate a tank interior from a tank exterior;

a first rigid extension member extending from said tank seal and providing an interior probe mounting position at a distance from said tank seal, said first extension member having a length of at least 0.5 meter;

a guided wave radar level gauge for measurement of a distance to a surface of a product in said tank, said guided wave radar level gauge including;

a transceiver configured to transmit an electromagnetic transmit signal and to receive an electromagnetic echo signal;

processing circuitry connected to said transceiver and configured to determine said distance based on a relationship between said electromagnetic transmit signal and said electromagnetic echo signal;

a probe mounted in said probe mounting position and configured to guide said electromagnetic transmit signal from said transceiver towards said product inside said tank, and to return said electromagnetic echo signal resulting from a reflection of said electromagnetic transmit signal by a surface of said product;

a microwave transmission line having a first end connected to said transceiver; and

a probe sealing arrangement providing a sealed connection of said probe to a second end of said transmission line.

19. The gauging system according to claim 18, wherein said first rigid extension member has a length of at least 1 meter.

20. The gauging system according to claim 18, further comprising at least one support element, wherein said at least one support element is adapted to keep at least a predetermined distance between said first rigid extension member and an inner wall of said nozzle, when said gauging system is mounted in said nozzle.

21. The gauging system according to claim 18, further comprising a level switch, functionally independent from said guided wave radar level gauge and arranged to determine when said surface exceeds a predetermined filling level.

22. The gauging system according to claim 21, wherein said level switch comprises;

a surface detector arranged in the tank interior and configured to detect said surface, and provide a measurement signal indicative of said surface;

a control unit arranged in the tank exterior and configured to receive said measurement signal and, based on said measurement signal, determine if said surface has exceeded a predetermined filling level; and

an electrical connection line having a first end connected to said control unit, and

a detector sealing arrangement providing a sealed connection of said surface detector to a second end of said electrical connection line.

23. The gauging system according to claim 22, wherein said surface detector is mounted in said probe mounting position.

24. The gauging system according to claim 23, wherein the first rigid extension member is tubular, and wherein said electrical connection line is arranged inside said first rigid, tubular extension member.

25. The gauging system according to claim 22, further comprising:

a second rigid extension member extending from said tank seal to provide an interior detector mounting position, wherein said surface detector is mounted in said interior detector mounting position.

26. The gauging system according to claim 25, wherein the second rigid extension member is shorter than the first rigid extension member.

27. The gauging system according to claim 25, wherein the second rigid extension member is longer than the first rigid extension member.

28. The gauging system according to claim 25, further comprising at least one support element arranged between said first and second rigid extension members to ensure at least a predetermined distance between said first and second rigid extension members.

29. The gauging system according to claim 25, wherein the second rigid extension member is tubular, and wherein said electrical connection line is arranged inside said second rigid, tubular extension member.

30. The gauging system according to claim 22, wherein said transceiver, said processing circuitry and said control unit are housed in one single electronics unit.

31. The gauging system according to claim 18, wherein the first rigid extension member is tubular, and wherein said transmission line is arranged inside said first rigid, tubular extension member.

32. The gauging system according to claim 18, wherein the microwave transmission line has an impedance matching an impedance of said transceiver.

33. The gauging system according to claim 18, further comprising a temperature sensor, arranged to detect a temperature in a position along said first extension member.

34. A method for measuring a distance to a surface of a product in a tank, said tank having a nozzle with a tank end connected to an opening in a tank wall, and a distal end, wherein a distance between said tank end and said distal end is greater than 0.5 m, said method comprising the steps of:

feeding an electromagnetic transmit signal from a transceiver through a tank seal mounted in the distal end of said nozzle;

guiding said electromagnetic transmit signal along a microwave transmission line from said tank seal to a probe mounted in a probe mounting position proximal to said tank end of said nozzle;

feeding said electromagnetic transmit signal through a probe sealing arrangement to said probe extending into the tank,

guiding said electromagnetic transmit signal along said probe,

returning an electromagnetic echo signal resulting from a reflection of said electromagnetic transmit signal by a surface of said product;

receiving said electromagnetic echo signal in said transceiver; and

determining said distance based on a relationship between said electromagnetic transmit signal and said electromagnetic echo signal.

35. The method according to claim 34, further comprising the steps of:

detecting said surface;

providing a measurement signal in response to said detecting;

guiding said measurement signal along an electrical connection line extending through the nozzle to a control unit; and

determining, based on said measurement signal, if said surface has exceeded a predetermined filling level surface.