MOLTEN METAL TRANSFER AND DEGASSING SYSTEM

• US 20130306687A1
• Filed: 03/15/2013
• Published: 11/21/2013
• Est. Priority Date: 06/21/2007
• Status: Active Grant

• Current Assignee: Molten Metal Equipment Innovations Incorporated (Molten)
• Original Assignee: Molten Metal Equipment Innovations Incorporated (Molten)
• Inventors: Cooper, Paul V., Fontana, Vincent D.
• Granted Patent: US 9,643,247 B2
• Time in Patent Office: Days
• US Class Current: 222/594
• CPC Class Codes: B22D 37/00 Controlling or regulating the pouring of molten metal from a casting melt-holding vessel B22D11/18, B22D39/00, B22D41/00 take precedence
• CPC Class Codes: B22D 39/00 Equipment for supplying molten metal in rations
• CPC Class Codes: B22D 41/00 Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like B22D39/00, B22D43/00 take precedence
• CPC Class Codes: B22D 7/00 Casting ingots, e.g. from ferrous metalsequipment for conveying molten metal B22D35/00
• CPC Class Codes: C22B 21/0084 melting and handling molten aluminium C22B21/02, C22B21/04 and C22B21/06 take precedence
• CPC Class Codes: C22B 21/064 using inert or reactive gases C22B21/066 and C22B21/068 take precedence
• CPC Class Codes: F27D 27/005 Pumps
• CPC Class Codes: F27D 3/14 Charging or discharging liquid or molten material

Abstract

Aspects of the invention include a transfer chamber constructed inside of or next to a vessel used to retain and degas molten metal. The transfer chamber is in fluid communication with the vessel so molten metal from the vessel is pulled through the vessel by the pump as it is degassed. This helps maintain a generally constant flow of molten metal through the degassing vessel. Other aspects relate to a system and method for efficiently performing maintenance on components positioned in a vessel.

Claims

1. A system for transferring molten metal out of a vessel, the system comprising:

(a) a vessel, the vessel having an inlet, a cavity and including a transfer chamber having an opening in communication with the cavity, the transfer chamber including an uptake section above the opening;

(b) one or more degassers between the inlet and the transfer chamber;

(c) an outlet in communication with the uptake section and above the opening; and

(d) a molten metal pump having a motor, a drive shaft connected to the pump and extending into the uptake section, the drive shaft connected to a rotor, wherein the rotor is configured to move molten metal upward into the uptake section, where it exits the outlet.

2. The system of claim 1 wherein the molten metal pump does not include a pump housing connected to a superstructure.

3. The system of claim 1 wherein the pump does not include support posts.

4. The system of claim 1 wherein the rotor comprises one or more rotor blades, and each blade includes:

(a) a first portion having (i) a leading edge with a thickness of 1/8″

or greater, (ii) a first upper surface angled to direct molten metal upwards, and (iii) a first bottom surface with an angle equal to or less than the angle of the first upper surface as measured from a vertical axis; and

(b) a second portion integrally formed with the first portion, the second portion having (i) a second upper surface angled to direct molten metal upwards, the angle of the second upper surface being greater than the angle of the first upper surface as measured from the vertical axis, and (ii) a second bottom surface, the second bottom surface having an angle greater than the angle of the first bottom surface as measured from the vertical axis.

5. The system of claim 1 wherein the rotor comprises one or more blades and each blade is vertically oriented and straight.

6. The system of claim 1 wherein the vessel is comprised of refractory material.

7. The system of claim 1 wherein the vessel has an inner bottom surface and the inner bottom surface is angled downwards towards the opening.

8. The system of claim 1 wherein the rotor has a diameter and is positioned in the transfer chamber and the portion of the transfer chamber in which the rotor is positioned in is circular and has a diameter of 1/4″

or less than the diameter of the rotor.

9. The system of claim 1 wherein the opening has a diameter of 1/32″

-1⅛

″

of the diameter of the rotor.

10. The system of claim 1 wherein the transfer chamber has a first section having a first cross-sectional area and a second section having a second cross-sectional area, the second section adjacent the opening and for reviewing the rotor, and the second cross-sectional area being smaller than the first cross-sectional area.

11. The system of claim 10 that has a third section having a third cross-sectional area, the third section being between the first section and the second section, and the third cross-sectional area being smaller than the first cross-sectional area, but larger than the second cross-sectional area.

12. The system of claim 10 wherein the rotor is positioned at least partially in the second section.

13. The system of claim 10 wherein the rotor is positioned at least partially in the second section.

14. The system of claim 10 that further includes a superstructure for supporting the motor.

15. The system of claim 1 that includes one or more brackets for supporting the pump above the vessel.

16. The system of claim 15 wherein the vessel has a first side wall and a second side wall opposite the first side wall and the bracket comprises two metal beams that extend from the first side wall to the second side wall, and each bracket is connected to the first side wall, the second side wall and the superstructure.

17. The system of claim 1 that further includes a first tap-out opening in communication with the vessel cavity, the first tap-out opening being positioned lower than the rotor.

18. The system of claim 17 that includes a second tap-out opening on a side of the vessel opposite the side that includes the first tap-out opening.

19. The system of claim 18 that further includes a wall dividing the vessel into a first section that retains the transfer chamber and a second section that retains the one or more degassers, the wall having an opening that keeps the first section and second section in fluid communication.

20. The system of claim 1 wherein there is a plurality of degassers.

21. The system of claim 20 that has three degassers.

22. The system of claim 20 wherein each at least two degassers are separated by a dividing wall wherein each dividing wall has one or more openings for allowing molten metal to pass through.

23. The system of claim 20 that includes at least one heating element between two of the plurality of the degassers.

24. The system of claim 1 that includes a heating element between at least one degasser and the pump.

25. The system of claim 23 that includes a heating element between at least one degasser and the pump.

26. The system of claim 1 wherein the inlet and outlet are on the same side of the vessel.

27. The system of claim 1 wherein the transfer chamber has a bottom that includes an opening in communication with the cavity, a first section having a first cross-sectional area and a second section above the first section, the second section having a second cross-sectional area that is greater than the first cross-sectional area, and an outlet in fluid communication with the second section and leading out of the transfer conduit;

wherein the first section is configured to receive a molten metal pump rotor.

28. The system of claim 27 wherein the transfer chamber is comprised of refractory material.

29. The system of claim 27 wherein the transfer chamber is generally cylindrical.

30. The system of claim 27 wherein the outlet is a launder extending from the second section.

31. The system of claim 30 wherein the launder is between 6″

and 6′

in length.

32. The system of claim 30 wherein the launder is formed at a horizontal angle of one or more of the group selected from:

0°

, an angle tilting backwards towards the second section of between 1° and

3°

, an angle tilting backwards towards the second section of between 1° and

10°

.

33. The system of claim 27 wherein there is a wall that separates the cavity from the transfer chamber and a channel is formed in the bottom of the wall and allows molten metal to pass from the cavity to the opening.

34. The system of claim 27 wherein the molten metal pump includes a motor, a platform on which the motor rests, a shaft having a first end connected to the motor and a second end connected to a rotor, wherein at least part of the shaft is positioned in the second section and the rotor is positioned in the first section.

35. The system of claim 34 wherein the vessel has an upper perimeter, and the transfer chamber has an upper perimeter, and the platform of the molten metal pump is supported by at least the upper perimeter of the transfer chamber in order to support the pump.

36. The system of claim 35 wherein the platform of the molten metal pump also rests on at least the upper perimeter of the vessel.

37. The system of claim 34 wherein the transfer chamber includes a first wall having a first outer surface and a second wall having a second outer surface, and one side of the platform includes a first centering bracket and the opposite side of the platform includes a second centering bracket;

the first centering bracket being juxtaposed the first outer surface and the second centering bracket being juxtaposed the second outer surface to help center the shaft and rotor in the transfer conduit.

38. The system of claim 34 wherein the rotor has a plurality of blades.

39. The system of claim 38 wherein each blade is flat.

40. The system of claim 38 wherein each blade is a dual-flow blade, with a first, angled portion that moves molten metal upward and a second portion that moves molten metal outward.

41. The system of claim 1 wherein the vessel includes a top and one or more access doors covering at least part of the top in order to keep heat in.

42. A system for transferring molten metal out of a vessel, the system comprising:

(a) the vessel having an inlet, a cavity and including a transfer chamber having an opening in communication with the cavity, the transfer chamber being separated from the cavity by a dividing wall to create a second chamber opposite the cavity;

(b) one or more degassers between the inlet and the transfer chamber;

(c) an outlet in communication with the second chamber; and

(d) a molten metal pump having a superstructure, a pump base including a pump chamber and a tangential discharge, a motor positioned on the superstructure, a rotor positioned in the pump chamber, and a drive shaft connecting the motor to the rotor;

wherein the pump pumps molten metal from the cavity past the dividing wall into the second chamber raising the level of molten metal in the second chamber until it flows out of the second chamber and into the outlet.

43. The method of claim 42 wherein the pumping is not continuous.

44. The method of claim 42 wherein the pumping is performed by a circulation pump.

45. The method of claim 42 wherein the pumping is performed by a gas-release pump.

46. The method of claim 42 further comprising the step of measuring an amount of molten metal within one or more of a launder, a ladle, and an ingot mold.

47. The method of claim 46 further comprising the step of adjusting the speed of the molten metal pump in response to the measured amount.

48. The system of claim 42 wherein the molten metal pump has a base configured to be received partially in an opening of the dividing wall, wherein at least part of the dividing wall has a height H1 and the opening is positioned entirely below height H1, the pump being one of either a circulation pump and a gas-release pump.

49. The system of claim 42 wherein the dividing wall has an opening to permit molten metal to be pumped from the first chamber through the opening and into the second chamber.

50. The system of claim 42 wherein the drive shaft is comprised of a motor shaft coupled to a rotor shaft by a coupling, the rotor shaft being connected to the rotor.