METHOD AND APPARATUS FOR SUPPLY OF LOW-BTU GAS TO AN ENGINE GENERATOR

Abstract

A carburetion system and method for adapting a low-Btu gas source with a low-Btu gas consumer. Pressure-based air-gas mixers geometrically appropriate for the carburetion system and method. The carburetion system comprises a low-Btu gas inlet, a gas outlet, a zero-pressure regulator, and at least one pressure-based air-gas mixer capable of maintaining a volumetric air to low-Btu gas ratio of no more than about 2:1. The method comprises diverting a low-Btu gas to a gas outlet when the gas consumer is off. The method further comprises, during operation of the consumer, diverting low-Btu gas to a zero-pressure regulator in order to balance low-Btu gas pressure with air pressure, passing low-Btu gas to at least one pressure-based air-gas mixer capable of maintaining a volumetric air to low-Btu gas ratio of no more than about 2:1, mixing the low-Btu gas with air in the at least one pressure-based air-gas mixer to form an air-gas mixture, and sending the air-gas mixture to the consumer. A venturi air-gas mixer comprising at least one venturi gas intake and at least one venturi air intake wherein the at least one venturi gas intake has a cross-sectional area at least equal to the cross-sectional area of the at least one venturi air intake whereby the venturi air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of no more than about 1:1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

FIG. 1 is a schematic of an embodiment according to the present disclosure of a low-Btu gas carburetion system comprising a venturi air-gas mixer;

FIG. 2 is a schematic of an embodiment of a suitable venturi air-gas mixer;

FIG. 3 is a schematic of an embodiment according to the present disclosure of a low-Btu gas carburetion system comprising a series of diaphragm air-gas mixers; and

FIG. 4 is a schematic of a diaphragm air-gas mixer 322 of the embodiment of FIG. 3.

Claims

1. A carburetion system for low-Btu gas comprising: a low-Btu gas inlet;a gas outlet;a zero-pressure regulator; andat least one pressure-based air-gas mixer capable of maintaining a volumetric air-to-gas ratio of no more than about 2:1.

2. The carburetion system of claim 1, wherein the gas outlet comprises a flare device.

3. The carburetion system of claim 1, wherein the zero-pressure regulator is coupled to a load control valve.

4. The carburetion system of claim 1 further comprising a low-Btu gas source.

5. The carburetion system of claim 4, wherein the low-Btu gas source is a continuous gas source.

6. The carburetion system of claim 4, wherein the low-Btu gas source is a biomass gasifier.

7. The carburetion system of claim 4, wherein the low-Btu gas source is a gas producing oil well.

8. The carburetion system of claim 1 comprising a plurality of air-gas mixers.

9. The carburetion system of claim 8, wherein the plurality of air-gas mixers are connected in series.

10. The carburetion system of claim 1, wherein the at least one pressure-based air-gas mixer comprises a venturi mixer.

11. The carburetion system of claim 10, wherein the venturi mixer comprises at least one venturi gas intake and at least one venturi air intake.

12. The carburetion system of claim 10, wherein the venturi mixer comprises a plurality of venturi gas intakes.

13. The carburetion system of claim 11, wherein the at least one venturi gas mixer comprises a cross-sectional area at least equal to the cross-sectional area of the at least one venturi air intake.

14. The carburetion system of claim 1, wherein the air-gas mixer comprises a diaphragm mixer.

15. The carburetion system of claim 1 wherein the at least one pressure-based air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of from about 1:1 to about 2:1.

16. The carburetion system of claim 15 wherein the at least one pressure-based air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of about 1:1.

17. The carburetion system of claim 1, wherein the carburetion system is coupled to a consumer.

18. The carburetion system of claim 17 wherein the consumer is capable of being operated intermittently.

19. The carburetion system of claim 17 wherein the consumer is an engine generator.

20. The carburetion system of claim 19, wherein the engine generator is selected from the group consisting of gas turbines, microturbines, and piston engines.

21. A method of adapting a low-Btu gas source with a consumer comprising: when the consumer is off: diverting a low-Btu gas to a gas outlet; andwhen the consumer is on: diverting the low-Btu gas to a zero-pressure regulator to balance gas pressure with air pressure; passing the low-Btu gas to at least one pressure-based air-gas mixer, wherein the at least one pressure-based air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of no more than about 2:1; mixing the low-Btu gas with air in the at least one pressure-based air-gas mixer to form an air-gas mixture; and sending the air-gas mixture to the consumer.

22. The method of claim 21 wherein the low-Btu gas source is continuous.

23. The method of claim 21 wherein the consumer is an engine generator.

24. The method of claim 21 wherein the at least one pressure-based air-gas mixer comprises a venturi mixer.

25. The method of claim 21 wherein the at least one pressure-based air-gas mixer comprises a diaphragm mixer.

26. The method of claim 21 wherein passing the low-Btu gas to at least one pressure-based air-gas mixer comprises passing the low-Btu gas through a plurality of air-gas mixers.

27. The method of claim 26 wherein the low-Btu gas is supplied to the plurality of air-gas mixers in parallel and air is supplied to the plurality of air-gas mixers in series.

28. The method of claim 26 wherein the plurality of air-gas mixers are in series.

29. The method of claim 28, wherein the plurality of air-gas mixers comprise diaphragm mixers.

30. The method of claim 21 wherein the at least one pressure-based air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of from about 1:1 to about 2:1.

31. The method of claim 21 wherein the at least one pressure-based air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of about 1:1.

32. A venturi air-gas mixer comprising at least one venturi gas intake and at least one venturi air intake wherein the at least one venturi gas intake has a cross-sectional area at least equal to the cross-sectional area of the at least one venturi air intake whereby the venturi air-gas mixer is capable of maintaining a volumetric air-to-gas ratio of about 1:1.