Claims
- 1. A molten metal supply system, comprising:
a molten metal supply source; a plurality of molten metal injectors, each comprising:
an injector housing configured to contain molten metal and in fluid communication with the molten metal supply source; and a piston reciprocally operable within the housing, with the piston movable through a return stroke allowing molten metal to be received into the housing from the molten metal supply source and a displacement stroke for displacing the molten metal from the housing to a downstream process, and with the piston having a pistonhead for displacing the molten metal from the housing; and a gas supply source in fluid communication with the housing of each of the injectors through respective gas control valves, wherein during the return stroke of the piston for each of the injectors a space is formed between the pistonhead and the molten metal and the corresponding gas control valve is operable to fill the space with gas from the gas supply source, and wherein during the displacement stroke of the piston for each of the injectors the corresponding gas control valve is operable to prevent venting of gas from the gas filled space such that the gas in the gas filled space is compressed between the pistonhead and the molten metal received into the housing and displaces the molten metal from the housing ahead of the pistonhead.
- 2. The system of claim 1, further including a control unit connected to each of the injectors and configured to individually actuate the injectors such that the pistons move substantially serially through their return and displacement strokes thereby providing a substantially constant molten metal flow and pressure to the downstream process.
- 3. The system of claim 2, wherein the control unit is configured to control the injectors such that at least one of the pistons moves through its displacement stroke while the remaining pistons move through their return strokes to provide the substantially constant molten metal flow and pressure to the downstream process.
- 4. The system of claim 3, wherein the piston of each of the injectors includes a piston rod having a first end and a second end, and wherein the first end is connected to the pistonhead and the second end is connected to an actuator for driving the piston through the return and displacement strokes.
- 5. The system of claim 4, wherein the control unit is connected to the actuator and the gas control valve of each of the injectors for controlling the operation of the actuator and the gas control valve.
- 6. The system of claim 4, further including an annular pressure seal positioned about the piston rod of each of the injectors and providing a substantially gas tight seal between the piston rod and the housing for each of the injectors.
- 7. The system of claim 6, further including a cooling water jacket positioned about the housing of each of the injectors and located substantially coincident with the pressure seal for cooling the pressure seal.
- 8. The system of claim 4, wherein the first end of the piston rod of each of the injectors is connected to the pistonhead by a thermal insulation barrier.
- 9. The system of claim 4, wherein the piston rod of each of the injectors defines a central bore, and wherein the central bore is in fluid communication with a cooling water inlet and outlet for supplying cooling water to the central bore.
- 10. The system of claim 1, wherein the molten metal supply source contains a metal selected from the group consisting of aluminum, magnesium, copper, bronze, iron, and alloys thereof.
- 11. The system of claim 1, wherein the gas supply source is a gas selected from the group consisting of helium, nitrogen, argon, compressed air, and carbon dioxide.
- 12. The system of claim 1, wherein each of the injectors further includes a floating thermal insulation barrier located between the pistonhead and the molten metal received into the housing.
- 13. The system of claim 1, wherein each of the injectors further includes an intake/injection port connected to the housing for injecting the molten metal displaced from the housing to the downstream process.
- 14. The system of claim 13, further including an outlet manifold in fluid communication with the intake/injection port of each of the injectors to receive the molten metal displaced from the injectors.
- 15. The system of claim 14, further including a check valve located in the intake/injection port of each of the injectors, and wherein the molten metal supply source is in fluid communication with the housing of each of the injectors through the check valve located in the intake/injection port.
- 16. The system of claim 15, further including a second check valve located in the intake/injection port of each of the injectors and configured to allow the displacement of molten metal from the housing of each of the injectors to the outlet manifold.
- 17. A molten metal supply system, comprising:
a molten metal supply source; a plurality of molten metal injectors, each comprising:
an injector housing configured to contain molten metal and in fluid communication with the molten metal supply source; and a piston reciprocally operable within the housing, with the piston movable through a return stroke allowing molten metal to be received into the housing from the molten metal supply source and a displacement stroke for displacing the molten metal from the housing to a downstream process, and with the piston having a pistonhead for displacing the molten metal from the housing; and a liquid chamber positioned above and in fluid communication with the housing of each of the injectors, with the liquid chamber containing a liquid chemically resistive to the molten metal contained in the molten metal supply source, wherein the liquid chamber is in fluid communication with the housing of each of the injectors such that during the return and displacement strokes of the piston within the housing liquid from the liquid chamber is located about the pistonhead and between the molten metal received into the housing and the liquid chamber.
- 18. The system of claim 17, further including a control unit connected to each of the injectors and configured to individually actuate the injectors such that the pistons move substantially serially through their return and displacement strokes thereby providing a substantially constant molten metal flow and pressure to the downstream process.
- 19. The system of claim 18, wherein the control unit is configured to control the injectors such that at least one of the pistons moves through its displacement stroke while the remaining pistons move through their return strokes to provide the substantially constant molten metal flow and pressure to the downstream process.
- 20. The system of claim 19, wherein the piston of each of the injectors includes a piston rod having a first end and a second end, and wherein the first end is connected to the pistonhead and the second end is connected to an actuator for driving the piston through the return and displacement strokes.
- 21. The system of claim 20, wherein the control unit is connected to the actuator of each of the injectors for controlling the operation of the actuator.
- 22. The system of claim 17, wherein the molten metal supply source contains a metal selected from the group consisting of aluminum, magnesium, copper, bronze, iron, and alloys thereof.
- 23. The system of claim 17, wherein the molten metal supply source comprises molten aluminum or aluminum alloy and the liquid in the liquid chamber comprises boron oxide.
- 24. The system of claim 17, wherein the liquid chamber is positioned directly on top of the housings of the injectors and the piston of each of the injectors is reciprocally operable such that during the return stroke of the piston the pistonhead retracts at least partially upward into the liquid chamber.
- 25. The system of claim 17, wherein each of the injectors further includes an intake/injection port connected to the housing for injecting the molten metal displaced from the housing to the downstream process.
- 26. The system of claim 25, further including an outlet manifold in fluid communication with the intake/injection port of each of the injectors to receive the molten metal displaced from the injectors.
- 27. The system of claim 26, further including a check valve located in the intake/injection port of each of the injectors, and wherein the molten metal supply source is in fluid communication with the housing of each of the injectors through the check valve located in the intake/injection port.
- 28. The system of claim 27, further including a second check valve located in the intake/injection port of each of the injectors and configured to allow the displacement of molten metal from the housings of the injectors to the outlet manifold.
- 29. A method of operating a molten metal supply system to supply molten metal to a downstream process at substantially constant molten metal flow rates and pressures, with the system comprising:
a molten metal supply source; a plurality of injectors, each comprising an injector housing configured to contain molten metal and in fluid communication with the molten metal supply source; and a piston reciprocally operable within the housing, with the piston movable through a return stroke and a displacement stroke, and with the piston having a pistonhead located within the housing; and a gas supply source in fluid communication with the housing of each of the injectors, the method comprising the steps of:
serially actuating the injectors to move the pistons through their return and displacement strokes at different times thereby providing substantially constant molten metal flow rate and pressure to the downstream process; forming a space between the pistonhead and molten metal received into the housing during each respective return stroke of the pistons; filling the space with gas from the gas supply source during each respective return stroke of the pistons; and compressing the gas in the gas filled space formed between the pistonhead and the molten metal received into the housing of each of the injectors during each respective downstroke of the pistons to displace the molten metal from the housings of the injectors in advance of the compressed gas in the gas filled space.
- 30. The method of claim 29, wherein at least one of the pistons moves through its displacement stroke while the remaining pistons move through their return strokes to provide the substantially constant molten metal flow and pressure to the downstream process.
- 31. The method of claim 29, further comprising the step of venting the compressed gas in the gas filled space to atmospheric pressure approximately when the pistons respectively reach the end of their displacement strokes.
- 32. The method of claim 29, further comprising the step of respectively moving the pistons through a partial return stroke in their respective housings after the step of compressing the gas in the gas filled space to partially relieve the pressure in the compressed gas filled space.
- 33. The method of claim 32, further comprising the step of respectively venting the gas in the gas filled space to atmospheric pressure when the pistons are respectively located at the end of the partial return stroke in the housings.
- 34. The method of claim 33, further comprising the step of respectively returning the pistons substantially to the end of their displacement strokes in the housings.
- 35. A method of operating a molten metal supply system to supply molten metal to a downstream process at substantially constant molten metal flow rates and pressures, with the system comprising:
a molten metal supply source; a plurality of injectors, each comprising a housing configured to contain molten metal and in fluid communication with the molten metal supply source; and a piston reciprocally operable within the housing, with the piston movable through a return stroke and a displacement stroke, and with the piston having a pistonhead for displacing the molten metal from the housing; and a liquid chamber located above and in fluid communication with the housing of each of the injectors, and containing a liquid chemically resistive to the molten metal contained in the molten metal supply source, the method comprising the steps of:
serially actuating the injectors to move the pistons through their return and displacement strokes at different times thereby providing substantially constant molten metal flow rate and pressure to the downstream process; and supplying liquid from the liquid chamber around the pistonhead and between the molten metal received into the housing and the liquid chamber of each of the injectors during the respective return and displacement strokes of the pistons, wherein at least one of the pistons moves through its displacement stroke while the remaining pistons move through their return strokes to provide the substantially constant molten metal flow rate and pressure to the downstream process.
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. application Ser. No. 09/957,846 entitled “Injector for Continuous Pressure Molten Metal Supply System” filed Sep. 21, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60284952 |
Apr 2001 |
US |
Divisions (1)
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Number |
Date |
Country |
Parent |
10014649 |
Dec 2001 |
US |
Child |
10323149 |
Dec 2002 |
US |
Continuation in Parts (1)
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Number |
Date |
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Parent |
09957846 |
Sep 2001 |
US |
Child |
10014649 |
Dec 2001 |
US |