Dual volute molten metal pump and selective outlet discriminating means

• US 4,786,230 A
• Filed: 11/22/1985
• Issued: 11/22/1988
• Est. Priority Date: 03/28/1984
• Status: Expired due to Term

• Current Assignee: Bruno H. Thut
• Original Assignee: Bruno H. Thut
• Inventors: Thut, Bruno H.
• Primary Examiner(s): Garrett, Robert E.
• Assistant Examiner(s): KWON, JOHN
• Application Number:
  US06/800,791
• Time in Patent Office: 1,096 Days
• Field of Search: 415/116, 415/117, 415/88, 415/98, 415/102, 415/103, 415/209, 415/182, 137/825, 137/832, 137/834
• US Class Current: 415/88
• CPC Class Codes: F04D 1/006 double suction pumps
• CPC Class Codes: F04D 29/506 especially adapted for liquid pumps
• CPC Class Codes: F04D 7/065 for liquid metal
• CPC Class Codes: Y10T 137/218 Means to regulate or vary operation of device
• CPC Class Codes: Y10T 137/2218 Means [e.g., valve] in control input

Abstract

This invention relates to improvements in molten metal pumps for the transfer of principally molten aluminum and zinc from specialized molten and holding furnaces through fluidics control means downstream of the pump to control the direction of flow of molten metals at 1200°-1600° temperatures. The molten metal pump is characterized by both upper and lower dual volute pumps driven by the same shaft, each having separated intake filtering adjacent the top and bottom of the pump unit. Separated and extended molten metal intake permit molten metal flow from a submerged environment through restricted peripheral ingress slots both about the top and bottom and into both top and bottom independent voluted pump impellers. The invention permits direct use of the novel pump with aluminum metal, whose oxide impurities settle and/or zinc metal whose oxide particles float, in the molten state without pump modification. Separate dual peripheral filter ingress zones lead into separated dual volute pumps removing hard particulates suspended in the melt, illustratively; spalled fire brick refractory chunks, scraps of unmelted metal and other foreign inclusions from causing excessive wear and tear or total destruction of the interior volutes and their related impellers of the pumps.

The combination of the so-improved pump in cooperation with the divergent stream transition control provides an improved portable of selectivity of one egress out of two diverging exit channels through molten metal flow control remote from the melt.

Claims

1. A submersible molten metal pump continuously operable at temperatures in excess of 750°

C. comprising a supporting planar base and top, a top horizontal plate substantially separately supported above, spaced apart from but parallel with planar base top;

said space defining a separated upper level filter means;

a corresponding planar plate bottom of said supporting base having a plurality of downwardly depending volume restricting spacer legs integral therewith, said spacer legs upon submersion of said pump interiorly of a melting/holding furnace thereby creating a separated lower liquid metal filter ingress means through said intake volume means;

interiorly of said supporting base a vertically separated pair of back-to-back volute impeller pumps operably and centrally affixed to a common vertical driven air-cooled shaft extending upwardly of and supported from within the interior of said base to a rigidly mounted air exposed shaft driving means, both of said upper and lower filter ingress intake volumes terminating in oppositely disposed, axially centered cup-like impeller receptacles integral with their respective volute impellers and rotatably interior of upper and lower fixed volute members creating thereby a common molten egress port downstream of said volute pumps discharging into a fluidics diverter valve integral and downstream of said dual volute pumps.

2. An ordered unitary non-metallic functionally cooperative assembly of a filter, pump and remotely controlled fluidics diverter valve operable when submersed in molten aluminum and/or zinc metals at temperatures in excess of 750°

C. which comprises a rectilinear box-like base housing unit, the base plate and two top plate elements being planar and parallel to one another;

said base supported on the flat floor of a melting furnace by a plurality of downwardly depending spacer button legs, which upon submersion in functional position and use establish a molten metal lower level ingress interiorly of said box housing and pump;

said dual planar to elements being likewise similarly spaced apart to severally function to filter both said lower level and said upper level ingress of molten metal interiorly of said pump housing;

said housing interiorly adapted to support a power drive upwardly extending elongated air-cooled vertical pump driven shaft centrally positioned above and within the pump section of said housing, said driven shaft within said housing driving a pair of back-to-back vertically adjacent volute impeller pumps operating in fixed and separate volute chambers within said housing;

filtered molten-metal ingress means through said two top elements comprising a multi-plate filter to remove particulates less dense than said melt and similar lower level ingress through the said restricted planar floor filter zone to remove particulates of greater density than said melt;

said diametrically opposed volute pumps driven by said common vertical shaft discharging continuous filtered and controlled molten metal streams into and through the common ingress port of a fluidics diverter valve provided with a selective downstream fluid control means comprising compressed gas ingress ports adapted to selectively impinge substantially inert gas under pressure directly upon said molten metal diverter valve power stream to redirect through fluidics principles molten metal stream flow downstream thereof through a predetermined one of said available channels of said fluidics diverter valve to a preselected downstream station, said gas ingress control means operable from a control point remote from said assembly.

3. A molten metal submersible fluidics operated dual directional non-metallic fluidics diverter valve and alternative flow direction remote control device operable at temperatures in excess of 750°

C. by which an upstream first entry conduit carrying a pre-filtered liquid molten metal downstream under a pre-established constant head and filtered flow rate originating from an integral upstream molten metal pump and co-submersible and integral therewith interiorly of a metal melting furnace exiting into said entry conduit as a particulate-free power stream is divergible into a preselected one of two alternate bifurcating downstream conduits by means of a transition piece of expanding internal volume thereby creating a fluidics control zone, said control zone transition piece bifurcated interiorly, downstream and centrally by fixed placement therein of a triangular shaped splitter element the apex of said triangle directed upstream determining a point of origin of a fluidics controlled diversion of direction of the original liquified metal power stream into a selected one of two bifurcated downstream conduits;

a pair of diametrically aligned, oppositely disposed compressed, essentially inert, gas inlet orifices within a zone of influence of the said pre-filtered first powered stream and conduit, adapted to provide controlled alternative inert gas flow under pressured ingress to within and egress from selected single ones of said orifices upon demand and pair of external gas conduits remotely operatively associated with a common source of said compressed inert gas providing a source injection of said gas through a preselected one of said inlet orifices to impact internally said molten metal power stream upstream of said transition piece effecting thereby a fluidics directional control upon said power stream as it passes into and through said fluidics diverter control device.

4. The non-metallic fluidics operated diverter valve and flow control apparatus assembly of claim 3, wherein the interior cross-section of all molten metal conduits downstream of the power entry conduit into said transition zone are ellipses whose major axes are substantially vertical to the horizonal plane of the base of said control assembly.

5. A molten metal submersible fluid flow control device functionally operable at temperatures in excess of 750°

C. upon a particulate-free source of molten metal;

said source further characterized by a relatively constant pressure head, flow rate and temperature comprising a single stream of fluidized metal entry through an ingress channel and dually divergent bifurcated egress channels spaced downstream thereof; and

intermediate said single controlled fluid metal stream ingress channel and egress channels, a fluidics controlled transition zone;

said fluidics controlled transition zone comprising oppositely disposed and inwardly directed dual inert gas control ports at and about said fluid entry ingress channel controlling transverse entry of compressed inert gas impingement on and from a selected port from a remote control point upon demand, said transition zone expanded in volume downstream of said ports to accommodate non-turbulent molten metal liquid entry and passage through the downstream end of said transition zone which comprises dual, bifurcated egress channels which channels initially diverge and separate at an acute angle forming thereby and interiorly thereof a divergent triangular splitter element the apex of which extends upstream into the said downstream expanded transition zone.

6. A remote controlled directionally selective non-metallic fluid flow control unit adapted to be submersed in molten metal liquid metal held within a melting furnace at temperatures at temperatures in excess of 750°

C., which comprises in ordered sequence;

a molten metal pump having an upper and lower melt ingress means, a lower pump intake adapted to remove suspended particulates more dense than said melt and an upper pump intake adapted to remove suspended particulates of less density than said melt;

a single vertical driven shaft driving a pair of oppositely disposed volute impeller pumps horizontally about, said shaft downstream of said dual filters but discharging the filtered melt therefrom downstream in a single coherent stream under relatively constant head and flow rate into the single melt ingress port of a fluidics diverter valve control means;

said fluidics control valve having oppositely disposed substantially inert gas injection control ports having egress into a directional transition control entry zone of increasing downstream volume characteristic of a fluidics diverter valve, said ports oppositely disposed about the single melt ingress port and immediately downstream of the melt entry into said valve;

said dual and oppositely disposed gas injection ports oriented to direct, from a remote control station, an impinging flow of pressurized gas through one preselected control port to activate said melt stream to flow into and through a preselected one of the two bifunctional diverting downstream channels characteristic of said fluidics diverter valve.