Electromagnetic priming of molten metal filters

Patent metadata

Field	Value
Publication number	US-12059643-B2
Application number	US-201917278615-A
Country	US
Kind code	B2
Filing date	Sep 20, 2019
Priority date	Sep 21, 2018
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

According to one aspect of the present disclosure, a method of priming a ceramic filter element for removal of solid inclusions from liquid metal is provided. The filter element is contained in a filter box and at least two separate inductors are placed on opposed sides of the filter element. The method includes the steps of a) applying an excitation current to the inductors, b) adding sufficient liquid metal to cover an upstream side of the filter element, c) allowing the current induced in the liquid metal by the inductors to create Lorentz forces which press upon and stir the liquid metal such that the liquid metal is forced into the ceramic filter element, hence priming the filter element, and d) discontinuing the excitation current once a predetermined degree of priming has been obtained.

First claim

The invention claimed is:

1. A method of priming a filter element, said filter element configured for removal of solid inclusions from liquid metal, wherein said filter element is contained in a box or launder and at least two inductors are placed symmetrically on opposed sides of the filter element, each of said inductors receiving electrical power independent from the other, said method comprises: a) applying an adjustable AC or pulsed DC excitation current to the at least two inductors, b) adding liquid metal to cover an upstream side of the filter element, c) allowing the currents induced in the liquid metal by the inductors creating a variable magnetic field to create Lorentz forces which stir the liquid metal such that the liquid metal is forced into the filter element, priming the filter element, and d) discontinuing the excitation current once a predetermined degree of priming has been obtained.

2. The method of claim 1 wherein only two separate inductor coils on opposed sides of the filter element are employed.

3. The method of claim 1 wherein molten metal can be directed to flow either upwardly or downwardly through the filter element.

4. The method of claim 3 wherein said coil includes at least two turns of a wire forming said coil either above or below a plane of a top or bottom surface of the filter element.

5. The method of claim 1 wherein said coils include electromagnetic shielding.

6. The method of claim 1 wherein said filter element is conductive.

7. The method of claim 1 wherein said coils are connected in series or in parallel and phase adjusted to complement one another.

8. The method of claim 1 wherein said filter comprises one of an open well structure, a bed filter structure, and/or a sieving geometry.

9. The method of claim 8 wherein the filter element is comprised of silica bonded alumina or zirconia, SiC, graphite, phosphate bonded alumina, silica bonded titanium dioxide, mullite, spinel zirconium dioxide, graphene coated material.

10. The method of claim 1 wherein the filter element is comprised of at least one tube filter.

11. The method of claim 1 wherein the filter element comprises a bonded particle filter.

12. The method of claim 1 wherein coils have multiple coil geometrics.

13. The method of claim 1 wherein the pulsed DC is variable and switching.

14. A method of filtering molten metal comprising inserting a filter between a launder upper section and a launder lower section and priming said filter using two separate plate inductors placed at the long sides of the filter.

15. The method of claim 1 wherein the sides of the filter box including a metal inlet and a metal outlet do not include inductors.

16. The method of claim 1 wherein the inductors are used in combination to perform inductive heating prior to priming.

17. A method of filtering molten metal wherein a filter is oriented vertically and separate inductors are disposed on at least two sides of the filter.

18. The method of claim 17 wherein said vertical filter is disposed in a launder.

19. The method of claim 17 wherein multiple vertical filters are dispersed in a filter box.

Assignees

• Pyrotek Inc

Inventors

• Fritzsch Robert

Classifications

• B01D39/00

  Filtering material for liquid or gaseous fluids · CPC title

• Y02P10/25

  Process efficiency · CPC title

• C22B9/023

  By filtering (filtration of aluminium C22B21/066) · CPC title

• C22B9/003

  by induction · CPC title

• B01D37/02 Primary

  Precoating the filter medium; Addition of filter aids to the liquid being filtered {(devices for feeding reagents C02F1/685 and sub-groups; filter aids)} · CPC title