Patent Application
20230383754
Pumps commonly used to pump molten metal include transfer pumps. Moreover, a transfer pump can transfer molten metal out of one furnace and into another furnace, into a ladle, or into a mold, as examples.
An exemplary transfer pump is illustrated in U.S. Pat. No. 5,716,195, the disclosure of which is herein incorporated by reference. The transfer pump described in the referenced patent includes a base, a shaft receiving sleeve, and a riser. Rotation of the impeller within the base forces molten metal up the riser for delivery outside of the furnace.
A further exemplary transfer pump is illustrated in U.S. Pat. No. 9,506,346, the disclosure of which is herein incorporated by reference. The transfer pump described in the referenced patent operates by rotation of an impeller/shaft assembly within an elongated tube. The impeller rotation results is a vortex of molten metal within the elongated tube that rises therein for discharge at a top end.
The present disclosure is directed to a molten metal transfer pump that advantageously provides a low-pressure discharge of molten metal using few but robust pump components. Low-pressure discharge can reduce dross formation
Various details of the present disclosure are hereinafter summarized to provide a basic understanding. This summary is not an extensive overview of the disclosure and is neither intended to identify certain elements of the disclosure, nor to delineate scope thereof. Rather, the primary purpose of this summary is to present some concepts of the disclosure in a simplified form prior to the more detailed description that is presented hereinafter.
According to a first embodiment, a pump for transferring molten metal is provided. The pump includes a motor, a base having an impeller chamber, a shaft connected to the motor at one end and impeller connected to the other end of the shaft. The shaft rotates the impeller within the impeller chamber. A riser is disposed on an upper surface of the base. The riser assembly has a first open end facing the base. The base includes a shaft opening and an outlet opening in the upper surface. The first open end of the riser is dimensioned to encompass the shaft opening and the outlet opening.
According to another embodiment, a molten metal pump is provided. The pump includes an elongated tube having a bottom end and a top end. The bottom end is disposed on an upper surface of a pump base. A shaft is disposed within the elongated tube and a centrifugal impeller is rotatable by the shaft. The impeller is disposed in a pumping chamber defined by the pump base. The pumping chamber has a diameter and the elongated tube has a diameter. The elongated tube diameter is greater than the pumping chamber diameter. The pump base includes a passage in the upper surface providing fluid communication between the pumping chamber and the elongated tube. The diameter of the passage is less than the diameter of the pumping chamber.
According to a further embodiment, a molten metal pump is provided. The pump includes a body defining an elongated chamber. The elongated chamber is configured to receive a shaft and impeller assembly. The body is comprised of a refractory material. The elongated chamber includes an open top through which the shaft passes and a bottom opening residing on a top surface of a base defining a pumping chamber. The impeller is disposed in the pumping chamber. The pumping chamber includes a bearing interfacing with the impeller. The base defining the pumping chamber includes a passage in an upper surface. The passage is in fluid communication with the elongated chamber and the pumping chamber. The base has a circumference and the body has a circumference, wherein the base defining the pumping chamber circumference can be slightly larger than the body, or the same circumference as the body, or smaller than the circumference of the body. In the embodiment where the base defining the pumping chamber has a smaller O.D. circumference than the I.D. of the body, the base defining the pumping chamber can be inserted within the walls of the body. Optionally, a bottom portion of the body can form a portion of the pumping chamber, such as the inlet and/or the sidewalls.
According to an additional embodiment, a method for transferring molten metal from a vessel is provided. The method comprises disposing a molten metal pump in a bath of molten metal. The pump includes a refractory material body defining an elongated chamber. The elongated chamber is configured to receive a shaft and impeller assembly through an open top and position the impeller in a base. The base defines a pumping chamber including a passage in an upper surface in fluid communication with the elongated chamber. Rotation of the impeller forces molten metal through the passage and into the elongated chamber such that the molten metal rises in the elongated chamber without creation of a substantial vortex to a level such that molten metal is selectively discharged from the pump via a discharge channel.
The following is a brief description of the drawings, which are presented for the purposes of illustrating the exemplary embodiments disclosed herein and not for the purposes of limiting the same.
A more complete understanding of the components, processes and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments.
Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.
The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
As used herein, the terms about, generally and substantially are intended to encompass structural or numerical modifications which do not significantly affect the purpose of the element or number modified by such term.
As used in the specification and in the claims, the term “comprising” may include the embodiments “consisting of” and “consisting essentially of.” The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients/steps and permit the presence of other ingredients/steps. However, such description should be construed as also describing compositions or processes as “consisting of” and “consisting essentially of” the enumerated ingredients/steps, which allows the presence of only the named ingredients/steps, along with any impurities that might result therefrom, and excludes other ingredients/steps.
With reference to
The pumping chamber base 12 can be formed of a graphite material. The riser body 14 can be formed of a ceramic material or of reinforced fiberglass fabric disposed in a ceramic matrix.
The riser body 14 is secured to the bonded particle filter cage 18 forming a portion of the pumping chamber base 12. The attachment can be via interference fit or cement or both.
A shaft 20 and impeller 22 assembly extends between the motor 16 and the pumping chamber base 12. Shaft 20 passes through riser chamber 23 defined by riser body 14. The impeller 22 is disposed within a pumping chamber 24 defined by the pumping chamber base 12. The pumping chamber 24 can be either a voluted chamber or a non-volute chamber. Impeller 22 is a bottom inlet configuration such that rotation of the shaft 20 and impeller 22 assembly by the motor 16 draws molten metal into the pumping chamber 24 through a bottom surface 27 with radial discharge.
Pumping chamber base 12 includes a passage 26 in top surface 30 of the pumping chamber base 12 creating fluid communication between the pumping chamber 24 and the riser chamber 23. In operation, molten metal is drawn from an external environment into the impeller 22 and radially discharged into the pumping chamber 24. The molten metal passes through passage 26 and flows into the riser chamber 23. Molten metal passing into riser chamber 23 causes a gradual rise of molten metal within the riser chamber until a controlled flow of metal enters outlet channel 28. Advantageously, the rise of molten metal in the riser chamber 23 is gentle such that vortexing and turbulence can be avoided. This allows the ingestion of potentially reactive gasses to be avoided.
It is noted that the various components including the riser body, bonded particle filter cage, and pumping chamber base can function cooperatively to form the toality of the base. For example, it is contemplated that the riser body at its lower end can form a portion of the pumping chamber side or bottom walls.
Turning now to
Although circular and elliptical shaped pumping chambers and riser bodies have been illustrated, it is noted that the shape of these elements is not limited. Moreover, square or rectangular shapes are also contemplated. In certain embodiments, it may be desirable that the pumping chamber base shape and the riser body shape be complimentary. It may also be desirable that the pumping chamber base be only slightly larger, or the same, or smaller in cross-sectional area than the riser at their interface.
With reference to
The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
To aid the Patent Office and any readers of this application and any resulting patent in interpreting the claims appended hereto, applicants do not intend any of the appended claims or claim elements to invoke 35 U.S.C. 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/052403 | 9/28/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63087685 | Oct 2020 | US |
