Fuel cell operated welder

• US 6,331,694 B1
• Filed: 12/08/1999
• Issued: 12/18/2001
• Est. Priority Date: 12/08/1999
• Status: Expired due to Term

• Current Assignee: Lincoln Global Incorporated (Lincoln Electric Holdings Incorporated)
• Original Assignee: Lincoln Global Incorporated (Lincoln Electric Holdings Incorporated)
• Inventors: Blankenship, George D.
• Primary Examiner(s): Shaw, Clifford C.
• Application Number:
  US09/457,156
• Time in Patent Office: 741 Days
• Field of Search: 219/130.1, 219/130.31, 219/130.32, 219/130.33, 219/130.5, 219/130.51, 219/137.PS, 219/74, 320/111, 429/22, 429/33, 429/37, 429/13
• US Class Current: 219/137.0PS
• CPC Class Codes: B23K 9/091 characterised by the circuits
• CPC Class Codes: B23K 9/1006 Power supply
• CPC Class Codes: B23K 9/1043 characterised by the electric circuit B23K9/1012 takes precedence
• CPC Class Codes: B23K 9/16 making use of shielding gas selection of media B23K35/38
• CPC Class Codes: B23K 9/325 Devices for supplying or evacuating shielding gas
• CPC Class Codes: H01M 8/00 Fuel cells; Manufacture thereof
• CPC Class Codes: Y10S 429/90 Fuel cell including means for power conditioning, e.g. Conversion to ac

Abstract

An electric arc welder powered by a plurality of liquid organic fuel cells. The fuel cells use a methanol/water mixture as the organic feed. The fuel cells produce carbon dioxide as a reactive product which is used an a shielding gas during the arc welding process. The fuel cells are stacked together to produce the desired arc voltage and current between an electrode and the workpiece. The arc welder includes a welding current to control the current wave shape through the electrode and to control or increase the voltage through the electrode.

Claims

1. An electric arc welding apparatus for forming a welding bead on a workpiece comprising an electric energy source, a welding circuit, an electrode and a shielding gas source, said electric energy source including a plurality of fuel cells that provide sufficient voltage and current to said welding circuit to cause an electric arc to form between said electrode and said workpiece, said fuel cell including an anode, a cathode, at least one solid polymer proton conductor membrane positioned between the anode and cathode, an organic liquid feed, and a mechanism to pass the organic feed past said anode, said shielding gas at least partially from a gas reaction product of said fuel cell.

2. The apparatus as defined in claim 1, wherein said fuel cell is selected from the group consisting of an indirect fuel cell, a direct fuel cell and combinations thereof.

3. The apparatus as defined in claim 2, wherein said fuel cell is a direct fuel cell.

4. The apparatus as defined in claim 1, wherein said organic feed includes a feed selected from a group consisting of methanol, formaldehyde, formic acid, dimethoxymethane, trimethoxymethane, trioxane and combinations thereof.

5. The apparatus as defined in claim 1, wherein said gas reaction product includes a gas selected from the group consisting carbon monoxide, carbon dioxide and combinations thereof.

6. The apparatus as defined in claim 1, wherein said anode includes a metal selected from the group consisting of platinum-ruthenium alloy, platinum-tin, platinum-iridium, platinum-osmium, platinum-rhenium, and mixtures thereof.

7. The apparatus as defined in claim 1, wherein said solid polymer proton conductor membrane includes a material selected from the group consisting of co-polymer of tetrafluoroethylene and perflourinated sulfonic acid, perflourinated sulfonic acid polymer, polyhydrocarbon sulfonic acid, and mixtures thereof.

8. The apparatus as defined in claim 1, wherein said solid polymer proton conductor membrane includes a catalyst, said catalyst including a material selected from the group consisting of Ir, Mo, Nb, Nu, Os, Pd, Pt, Re, Ru, RuO₂, Sn, SnO₂, Ti, W, WO₃, Zr, and combinations thereof.

9. The apparatus as defined in claim 1, including at least two solid polymer proton conductor membranes, one of said solid polymer proton conductor membranes having a different composition from another of said solid polymer proton conductor membranes.

10. The apparatus as defined in claim 1, wherein said cathode includes platinum.

11. The apparatus as defined in claim 1, wherein said welding circuit at least partially controls at least one welding parameter between said electrode and said workpiece, said welding parameter includes a parameter selected from the group consisting of voltage, current, energy, power, polarity and combinations thereof.

12. The apparatus as defined in claim 11, wherein said welding circuit includes a welding current circuit that supplies current to said electrode, said welding current circuit including a first circuit to create a transfer current and a second circuit to create a melting current, said second circuit supplying a sufficient amount of current to said electrode to form said weld bead on said workpiece.

13. The apparatus as defined in claim 12, wherein said second circuit directing a preselected amount of energy to said welding wire to melt a relatively constant volume of said electrode during each welding cycle.

14. The apparatus as defined in claim 12, wherein said second circuit reducing the amount of current to said electrode prior to molten metal on said electrode forming a short circuit with said workpiece.

15. The apparatus as defined in claim 14, wherein said second circuit creating a decaying current profile when said current is reduced.

16. The apparatus as defined in claim 12, wherein said first circuit directing a high current pulse at the end of a short circuit condition between said electrode and said workpiece and applying said pulse until just prior to a predicted termination of the short circuit condition.

17. The apparatus as defined in claim 12, wherein said first circuit reducing the amount of current to said welding wire prior to said molten metal on said electrode forming a short circuit condition with workpiece.

18. The apparatus as defined in claim 1, wherein said welding circuit boosts the voltage of said electric energy source.

19. The apparatus as defined in claim 1, wherein said welding circuit including a background current circuit which directs a background current though said electrode.

20. The apparatus as defined in claim 1, wherein said electrode is a consumable flux cored metal electrode.

21. An apparatus as defined in claim 20, wherein said flux cored electrode includes alloying components in the core to form a weld bead having a substantially similar composition as the composition of said workpiece.

22. The apparatus as defined in claim 1, wherein said welding circuit including a current polarity controller to control the polarity of at least a portion the current passing through said electrode.

23. The apparatus as defined in claim 22, wherein said welding circuit creates a series of small width current pulses constituting a welding cycle with a short circuit transfer portion and a plasma arc melting portion, said current pulses in said cycle each having a given electrical polarity, said polarity controller selecting the polarity of said pulses in said cycle between a first polarity being positive and a second polarity being negative.

24. The apparatus as defined in claim 22, wherein said polarity controller includes a decoder with a first condition for selecting one of said first or second polarity for a first number of consecutive welding cycles and a second condition for selecting the other of said polarity for a second number of consecutive cycles and a mechanism to alternate between said first and second conditions during a welding operation.

25. The apparatus as defined in claim 24, wherein said cycles each have a desired arc current and including a shunt to sense the actual arc current and an error amplifier to compare said actual arc current with said desired arc current to control the width of said current pulses.

26. The apparatus as defined in claim 22, wherein said polarity controller maintaining a positive polarity during at least a portion of said current passing through said electrode.

27. The apparatus as defined in claim 22, wherein said polarity controller maintaining a negative polarity during at least a portion of said current passing through said electrode.

28. The apparatus as defined in claim 22, wherein said polarity controller maintaining said current in a positive polarity for a first duration of time and maintaining the current in a negative polarity for a second duration of time.

29. The apparatus as defined in claim 28, wherein the time period of the sum of said first and second duration substantially the same during each welding cycle.

30. The apparatus as defined in claims 28, wherein said first duration greater than said second duration.

31. The apparatus as defined in claim 22, wherein said welding circuit includes a center tapped inductor with a first portion creating said first polarity and a second portion creating said second polarity, a first switch for connecting said first portion of said inductor between said electrode and said workpiece, a second switch for connecting said second portion of said inductor between said electrode and said workpiece, and a selector to close either said first switch or said second switch during a given weld cycle.

32. A method of electric arc welding to form a weld bead on a workpiece, said method comprising:

a) providing a metal electrode;

b) providing an electric energy source which produces a current, said electric energy source including a fuel cell, said fuel cell forms a gas product which can at least partially be used as a shielding gas;

c) providing a welding circuit;

d) supplying said current to said welding circuit to form an arc between said electrode and said workpiece; and

,

e) at least partially directing said gas product to said workpiece during the formation of said weld bead.

33. The method as defined in claim 32, wherein said welding circuit at least partially controlling the wave shape of said current to said electrode.

34. The method as defined in claim 32, wherein said electrode is a consumable flux cored metal electrode.

35. The method as defined in claim 32, wherein said welding circuit forming an electric wave to said electrode comprising a short circuit transfer portion and a controlled melting portion.

36. The method as defined in claim 35, wherein said controlled melting portion selected from the group consisting of applying a preselected amount of energy to the electrode or applying a preselected amount of power to said electrode.

37. The method as defined in claim 32, wherein welding circuit forming a background current, said background current having a high inductance component and a low level just above the level necessary to sustain an arc between said electrode and said workpiece throughout each welding cycle.

38. The method as defined in claim 32, wherein said welding circuit controls the polarity of the electric wave to said electrode.

39. The method as defined in claim 38, wherein said electric wave includes a series of small width current pulses each having a given electrical polarity.

40. The method as defined in claim 39, wherein the polarity of said electric wave is shifted between a first polarity and a second polarity during the welding cycle.

41. The method as defined in claim 38, wherein polarity of said electric wave is alternated as a function of the cumulative amount of energy applied to said electrode and said workpiece in one polarity and the cumulative amount of energy applied to said electrode and said workpiece in the other polarity.

42. The method as defined in claim 32, wherein said welding circuit boosts the voltage of said electric energy source.

43. The method as defined in claim 32, wherein said fuel cell is selected from the group consisting of an indirect fuel cell, a direct fuel cell and combinations thereof.

44. The method as defined in claim 32, wherein said fuel cell includes an organic feed.

45. The method as defined in claim 44, wherein said organic feed includes a feed selected from a group consisting of methanol, formaldehyde, formic acid, dimethoxymethane, trimethoxymethane, trioxane and combinations thereof.

46. The method as defined in claim 32, wherein said fuel cell includes a liquid feed.

47. The method as defined in claim 32, wherein said fuel cell includes an anode, a cathode and at least one solid polymer proton conductor membrane positioned between the anode and the cathode.

48. The method as defined in claim 32, wherein said fuel cell includes a plurality of stacked fuel cells.