Apparatus and method for filtering metals

Abstract

The present application relates to an apparatus and method for filtering metals, for filtering molten metals such as aluminum or aluminum alloys, comprising at least one ceramic foam filter or any other type of filter medium, such as a porous tube or aluminum balls, disposed in a container for the molten metal. A vibrator vibrates at least one of the filter, container, or metal, and can be used to induce priming, filtering, and / or draining of the filter. The vibrator can be retrofitted to an existing filtration system and can be adjustable in frequency and amplitude. The vibration can be continuous or produced in a single vibration over a given period of time.

Description

[0001] Case information

[0002] This application is a divisional application of the invention patent application with application number 201710401629.0 filed on May 31, 2017 and invention name “Device and method for filtering metals”.

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 343,489, filed May 31, 2016, entitled “Apparatus and Methods For Filtering Metals,” which is incorporated herein by reference in its entirety. Technical Field

[0005] The present invention relates to the filtration of aluminum metal in a molten state, and more particularly to filtration through a porous filter such as a ceramic filter. Background Art

[0006] Ceramic filters (e.g., ceramic foam filters (CCF)) are known for filtering or removing contaminants from molten metals (e.g., aluminum metals and alloys). The use of such filters has associated limitations and challenges, such as initiating the flow of molten metal through the filter by removing air from the internal pores / channels in the filter (priming). Known methods for accomplishing this task include preheating the filter, forming a sufficient head of molten metal above the filter to apply pressure to push the molten metal through the filter, applying negative pressure to the downstream side of the filter by applying a vacuum to the downstream side, and agitating the molten metal against the filter / driving the molten metal through the filter with an electromagnetic field that has a hydrodynamic effect on the molten metal. Nonetheless, these known methods, alternative methods, and apparatus for promoting the flow of metal through the filter are still desirable. Summary of the invention

[0007] The disclosed subject matter relates to a filtering device having a container for molten metal, a filter element within the container, and a vibrator; the container having an inlet through which metal can enter the container and an outlet through which metal can leave the container; the filter element being located between the inlet and the outlet, the filter being capable of allowing molten metal to pass therethrough; and the vibrator being capable of inducing vibrations in the metal.

[0008] In another embodiment, the vibrator contacts the surface of the container.

[0009] In another embodiment, the vibrator has a driven element that contacts the metal.

[0010] In another embodiment, the driven element is immersed in the metal.

[0011] In another embodiment, the device has an arm extending between the vibrator and the driven element.

[0012] In another embodiment, the arm is L-shaped.

[0013] In another embodiment, further comprising a support for the container, and wherein the arm is attached to the support.

[0014] In another embodiment, at least one elastic element is further included, the at least one elastic element being interposed between the arm and the support so as to enable the arm to vibrate at least partially independently of the support under the influence of the vibrator.

[0015] In another embodiment, the vibrator is at least one of electrically driven, pneumatically driven, or hydraulically driven.

[0016] In another embodiment, the vibrator generates a force in a direction between 45° and 90° relative to the direction of metal flow.

[0017] In another embodiment, the vibrator is mounted on an outer surface of the container proximate the filter element.

[0018] In another embodiment, a controller for the vibrator is also included, the controller being capable of adjusting the vibrator in at least one of frequency and amplitude.

[0019] In another embodiment, a container has an inner liner and an outer shell, the inner liner receiving the metal.

[0020] In another embodiment, at least one elastic member is interposed between the liner and the outer shell.

[0021] In another embodiment, at least one resilient member at least partially decouples vibrations of the liner from the shell.

[0022] In another embodiment, the filter is a ceramic foam filter.

[0023] In another embodiment, the filter has greater than 50 pores per inch.

[0024] In another embodiment, the filter has greater than 60 pores per inch.

[0025] In another embodiment, the filter may be a bed filter, a porous tube, or any known filter media for molten metals.

[0026] In another embodiment, the molten metal includes aluminum.

[0027] In another embodiment, the driven element is at least partially covered by a refractory material.

[0028] In another embodiment, at least one additional vibrator is further included, and the vibrator and the additional vibrator are operable independently or simultaneously and may operate at the same frequency or at different frequencies.

[0029] In another embodiment, a method of pouring a filter having pores for filtering molten metal, the filter being disposed in a reservoir, the method comprising the steps of: pouring molten metal into the reservoir, onto the filter; and vibrating at least one of the molten metal, the filter, or the reservoir to induce the molten metal to enter the pores of the filter, thereby displacing air present in the filter.

[0030] In another embodiment, a method of emptying a filter having pores containing molten metal includes the steps of vibrating the filter containing the molten metal to induce metal in the pores of the filter to flow out.

[0031] In another embodiment, further comprising the step of draining the filter of molten metal, and during at least a portion of the draining step, simultaneously vibrating at least one of the molten metal, the filter, or the reservoir to induce metal in the pores of the filter to flow out. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] For a more complete understanding of the present disclosure, reference is made to the following detailed description of exemplary embodiments which are explained in conjunction with the accompanying drawings.

[0033] Figure 1 is a perspective view of a filtering device according to an embodiment of the present disclosure.

[0034] Figure 2 for Figure 1 A plan view of the device.

[0035] Figure 3 The image is taken along the section line 2-2 and seen in the direction of the arrow. Figure 1 and Figure 2 A partial cross-sectional view of the device.

[0036] Figure 4 Schematic diagram of a filtering device according to an optional embodiment of the present disclosure.

[0037] Figure 5 Schematic diagram of a filtering device according to another optional embodiment of the present disclosure.

[0038] Figure 6 Schematic diagram of a filtering device according to another optional embodiment of the present disclosure.

[0039] Figure 7Schematic diagram of a filtering device according to another optional embodiment of the present disclosure.

[0040] Figure 8 Schematic diagram of a filtering device according to another optional embodiment of the present disclosure.

[0041] Fig. 9 Schematic diagram of a filtering device according to another optional embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] In the processing of metals, it may be preferred to remove certain contaminants and inclusions. For example, in the case of aluminum and aluminum alloys, it may be desirable to remove oxides, borides, carbides, nitrides and spinels of aluminum and magnesium to promote purer metal products for various reasons. This contaminant removal has been performed by a porous ceramic filter (e.g., a ceramic foam filter (CFF)), through which the molten metal flow passes. As for the filter, generally speaking, the smaller the pore size and the greater the thickness of the filter, the more effective the filtration process is in removing contaminants, but the more restrictive the filter flow is. When used to filter liquid metal, the ceramic filter exhibits a requirement to be perfused, that is, the flow through the filter is induced by removing the air present in the filter pores by the liquid metal. Because the method for promoting the flow of metal through the ceramic filter includes preheating the filter, the initial metal flow is not solidified when contacting the filter and forming a sufficient molten metal height (head) above the filter to push the metal through the filter. Typically, because there are restrictions on the metal head, the metal head can be formed in a given metal processing facility, so alternative methods and equipment have been used. For example, a low pressure may be created on the downstream side of the filter by a vacuum device, as disclosed, for example, in U.S. Pat. No. 7,666,248, which is incorporated herein by reference in its entirety. In another approach, an induction coil may be used to generate a Lorentz force that acts on the metal and promotes the flow of the metal through the filter, as disclosed in Canadian Patent Document No. CA 2,871,245, which is incorporated herein by reference in its entirety.

[0043] The present disclosure recognizes that a vibrating mechanism may also be used to facilitate passage of molten metal through a filter. More specifically, a mechanically powered, electrically powered, electromechanically powered, air powered, and / or hydraulically powered mechanism may be used to create vibrations of a filter, containment / container (through which the molten metal passes) near the filter and / or molten metal to facilitate flow of metal through the filter. The vibration may have the properties of a wave (e.g., a compression wave / pressure wave), such as a sound wave of ultrasonic frequency in one embodiment, which is transmitted through the metal from a transducer / vibrator that acts on a filter, a container / conduit in communication with or adjacent to the filter, or the molten metal. To this end, the use of a vibrating mechanism may allow the molten metal to pass through a filter that is finer than the filters commonly used. For example, in many conventional metal purification systems, filters with more than 50 pores per inch (PPI) are unavailable. According to the present disclosure, filters with more than 50 PPI or finer, such as filters with 50 PPI to 80 PPI, may be used.

[0044] The vibration mechanism / filtration technique according to the present disclosure can be used to promote filling at the beginning of casting to utilize the entire surface of the filter, for example, to promote the removal of metal and / or captured contaminants from the filter during filtration and / or after the filtration of a batch of molten metal is completed. In the latter application, the removal of metal and contaminants from the filter can extend the service life of the filter (e.g., a bed filter), and the technique can be used to extend the life and flush the contents to continue with a refreshed bed. The amount of heating that would otherwise be required to reform the molten metal flow through the filter in a subsequent filtration run can also be reduced. It should be understood that the vibration mechanism and method of the present disclosure can be used independently of known methods and equipment for filling the filter and promoting the flow of metal through the filter. Alternatively, the vibration method of the present disclosure can be used in combination with known methods. For example, the vibration device can be used independently of or in combination with a vacuum or magnetic induction assisted filtration promoter.

[0045] Figures 1 to 3A filter device 10 according to one embodiment of the present disclosure is shown, and the filter device 10 has a container 12 for molten metal M, which is included in its internal cavity 12C. In the illustrated embodiment, the container has four tapered walls 12W forming a funnel shape. The container 12 is held to a support frame 14 by a mounting plate 12P, which is attached to the container 12 and clamped by a clamp 16 (e.g., in the form of a clamping vise), which is fastened to a support beam 14B of the frame 14. Alternatively, the container can be fastened to the frame 14 by bolts or other types of fasteners. The frame 14 has wheels 18, thereby allowing the device 10 to move by rolling. The frame 14 has a lower portion 14L supporting the container 12 and a vertical support 14V having a plate 20, and the plate 20 has a slot 20S. The vibrator assembly 22 is characterized in that a vibrator 24 is attached to an arm 26, and the arm 26 is attached with a driven plate 28 at one end. There are a large number of different types of vibrators available, such as those driven by air, hydraulic or electric energy. These types of industrial vibrators are commercially available from, for example, VIBCO, Rhode Island, Wyoming, RI, USA. In one example, VIBCO model SCR-100 provides about 1825 impacts / minute for an operating air pressure of 60 to 80 psi, generating 2105 pounds of force / impact. In another example, the vibrator may be a pneumatic hammer drill, such as a pneumatic hammer drill commercially available from Dewalt, producing vibrations at an amplitude of 2000 pounds / impact and a frequency of 1500 impacts / minute. In yet another example, an air-driven vibrator (such as Martin P Series P4S pneumatic piston vibrator (www.martin-eng.com) from Martin Engineering, Neponset, IL) may be used. In this example, air pressure is converted into vibration frequency and force amplitude.

[0046] In the illustrated embodiment, the arm 26 has a horizontal extension 26H and a vertical extension 26V, wherein the horizontal extension 26H provides a selected relative horizontal position of the vibrator assembly 22 relative to the container 12, for example, allowing the driven plate 28 to be centered in the center of the container 12; and the vertical extension 26V allows the driven plate 28 to extend downward until the container 12 has reached a selected height. Figure 3As shown, the horizontal extension 26H is attached to the mounting plate 30 at one end, and one or more elastic mounting assemblies 32 (e.g., elastomer or spring mounting member) are attached to the mounting plate 30. The elastic mounting assembly 32 has an elastic element 32R and an axis 32S attached to the mounting plate 30 at one end, and the axis 32S extends through the elastic element 32R, through the slot 20S and is pivotally attached to the handle portion 32H with a cam element 32C. This type of handle 32H is commercially available from, for example, McMaster Carr of Elmhurst, Illinois, USA. When in a gripping position (wherein the handle portion 32H is pressed downward), the mounting assembly 32 grips the plate 20 in a given adjustable position so that the vibrator assembly 22 can be located at a selected height relative to the container 12 and relative to the height (head) H of the molten metal M therein. The elastic element 32R provides freedom of movement and decouples the vibratory motion induced by the vibrator 24 from the support frame 14. The vibration induced by the vibrator 24 is transmitted along the arm 26 to the driven plate 28 and the molten metal M, which is poured into the container 12, for example to a height (head level) H, as schematically shown by the dotted line. As can be appreciated, the head level H can change dynamically as the molten metal flows through the device 10, as determined by changes in inflow and outflow. The driven plate 28 can be located at any given depth within the molten metal, ranging from a surface contact at the top surface of the molten metal M metal to a depth where it is close to the bottom of the container 12.

[0047] like Figure 3As shown, the vessel 12 has a metal shell 12S (e.g., made of steel) and a refractory lining 12R (e.g., made of ceramic (e.g., N-14—N-17, as mentioned on the website pyrotek-inc.com), alumina, or any refractory material used for storage tank construction for molten aluminum or other metals). The refractory lining 12R can be a coating applied to the shell 12S or can be made as a separate plug-in that is inserted into the shell 12S after being separately formed. A filter 34 (e.g., made of ceramic foam) (CCF) is located at the bottom of the vessel 12, and the molten metal M poured into the vessel 12 can pass through the filter 34 to remove contents and contaminants. The filter can be a commercially available type, such as a 30 PPI to 80 PPI CCF filter purchased from Selee (selee.com). In one example, the molten metal can be aluminum or an aluminum alloy. The filter 34 is contained in a filter housing 36, which has an outer metal shell 36S (e.g., made of steel) and an inner refractory lining 36R. The refractory lining 36R may taper inwardly in the discharge direction to receive the filter 34 having a complementary taper, thereby allowing the filter 34 to be placed and retained within the filter housing 36 (the filter 34 does not pass through the filter housing 36). The filter housing 36 may be provided with a flange 36F that allows clamping to the flange 12F on the vessel 12 by a clamping mechanism (such as the clamp device 16). In this way, the device 10 can be assembled and disassembled for inspection and maintenance.

[0048] In operation, the vibrator assembly 22 may be placed at a selected height and secured in place by the clamp assembly 32 before or after the molten metal M is introduced into the vessel 12. Figure 3 As shown, in one approach, the vibrator assembly 22 can be positioned so that the driven plate 28 is below the surface of the metal M, as shown by the dashed line marked H and the schematic diagram of the driven plate 28 shown in dashed lines. As noted above, the driven plate 28 can be located at the top surface (line H) of the molten metal M. When actuated, the vibrator 24 induces vibrations (having motion components in the up and down directions) of the driven plate 28, as shown by the up and down arrows. The vibrations of the driven plate 28 generate a compression / tension wave W in the molten metal M. The wave W advances through the metal M in a downward direction toward the filter 34, thereby inducing the molten metal M to move through the filter 34. In addition to the wave W, a wave having a component in the side-to-side direction is also generated, as shown in FIG. Figure 324, and the wave propagation in the arm 26 is directed to the vibrator 24. As indicated by the double-ended arrow S in FIG. 24 , the wave strikes the container 12, thereby causing it to move. In addition to moving the molten metal M, the wave W transmitted through the metal M strikes the housing 12 and the filter 34, thereby inducing responsive motion thereof in various directions. The relative amplitude of the wave propagation in any given direction will depend on the vibrator 24, the material, the manufacturing technique used to prepare the arm 26, and many other factors. For example, a vibrator 24 utilizing a spinning mass with an eccentric mass distribution will generate a circular wave pattern, while a vibrator 24 utilizing a linear oscillating mass will produce a wave with more linear components.

[0049] The above-described apparatus 10 may be used to induce filling of the filter 34 at the beginning of a run, or to induce removal of metal and / or debris from the filter 34 at the end of a run. The vibrator 24 may be operated continuously during operation to increase the flow rate of the molten metal M. In one embodiment, the frequency of the vibration and / or the amplitude of the vibration may be controlled by the controller 38 ( Figure 1 ) can be adjusted by a digital electronic controller or an analog device (such as a rheostat for an electronic vibrator or a valve for an air or hydraulic vibrator) to adapt to the requirements of a specific operation (e.g., priming, cleaning of the filter), or to adapt to other variable parameters encountered in the filtering operation. For example, as the filter 34 becomes more blocked due to debris during the filtering process, the frequency and amplitude of the vibration can increase. The optimal vibration parameters can be recorded and used for various metals and alloys, as well as for various levels of contamination and for different types of contaminants in the metal M. When placed in the container 12 with a selected degree of insertion, the driven plate 28 can have a size that allows the molten metal M to flow appropriately between its outer periphery and the refractory lining 12R of the container 12. In an alternative form, the driven plate 28 and / or portions of the vertical portion 26V of the arm 26 can be coated with a refractory material to make them more heat resistant and to prevent undesirable heat transfer from the metal M to the vibrator assembly 22. For the vibrator 24', an alternative mounting location is shown in dotted lines, that is, on the side wall 12S adjacent to the filter 34. As shown, the vibrator 24' is oriented at an angle A relative to the horizontal reference line HR. The force vector F originating from the vibrator 24' is at an angle A, such as 45°, relative to the reference line HR. The force vector F bisects the right angle between the reference line HR and the vertical orientation direction of the metal flow, and is therefore also set at 45° relative to the direction of the metal flow. Other mounting positions and orientations may be utilized.

[0050] Figure 4A filter device 110 according to another embodiment of the present disclosure is shown, and the filter device 110 has a container 112, and the container 112 has an outer shell 112S (e.g., steel) and a refractory lining 112R. A filter 134 (such as a ceramic filter (CCF)) is located in the refractory lining 112R to filter the molten metal (not shown) passing therethrough. One or more elastic elements 140A, 140B, 140C (such as springs) are inserted between the refractory lining 112R and the shell 112S, thereby allowing the refractory lining 112R to move independently of the shell 112S. One or more vibrators 124A, 124B, 124C of the type described above are assembled to the shell 112S, so that when in operation, the vibrators 124A, 124B, 124C induce vibrations of a selected frequency and amplitude of the shell 112S. In an alternative embodiment, the vibrations are conducted to the refractory lining 112R through the elastic elements 140A, 140B, 140C. The elastic elements 140A-140C are schematically described as springs, but may be elastomeric members. In another embodiment, the vibrators are mechanically coupled to the refractory liner 112R so that they impart vibrations directly to the refractory liner 112R, which is suspended in the shell 112S by the elastic elements 140A, 140B, 140C. The coupling L extending between the vibrator 124A and the refractory liner schematically illustrates the mechanical connection. The elastic elements 140A, 140B, 140C allow the refractory liner 112R to move (vibrate) independently of the shell 112S and independently of the structure supporting or coupling the shell 112S. The vibrators 124A, 124B, 124C may be of the same type and set to deliver vibrations of the same frequency and amplitude, or they may be of different types and may be set to deliver vibrations of different frequencies and amplitudes. The vibrators 124A, 124B, 124C may be powered by a common energy source, such as a common pressurized air circuit or an electrical supply circuit, or may be powered by independent sources, which may be of the same type or of different types, such as electrical or pressurized air. The vibrators 124A, 124B, 124C may be operated simultaneously in subgroups or individually in sequence, as appropriate for the operating phase of the filter device 110, such as filling, filtering, or draining.

[0051] Figure 5A filter device 210 according to another embodiment of the present disclosure is shown, and the filter device 210 has a container 212, and the container 212 has an outer shell 212S (e.g., steel) and a refractory lining 212R. A filter 234 (such as a ceramic filter (CCF)) is located within the refractory lining 212R to filter the molten metal (not shown) passing therethrough. One or more vibrators 224A, 224B, 224C of the type described above are assembled to the shell 212S, so that when in operation, the vibrators 224A, 224B, 224C induce vibrations of a selected frequency and amplitude of the shell 212S. Because the shell 212S contacts the refractory lining 212R and the filter 234 contacts the refractory lining 212R, the vibrations are conducted to the refractory lining 212R and the filter 234. In addition, when the container 212 contains molten metal (not shown), the vibrations of the refractory lining 212R and the filter 234 are also imparted to the molten metal. It should be understood that the vibrators 24, 124A-C and 224A-C can be adjustable in frequency and amplitude so that the vibrators can be adjusted to have maximum efficiency based on specific component parameters (such as mass, density, flexibility, etc.) that are set in the movement of the shell 12, 112, 212, refractory lining 12R, 112R, 212R and the metal contained therein.

[0052] Figure 5 It is also shown that the vibration force line V can be oriented at any given angle A, B, etc. relative to the reference orientation R. In the illustrated case, the reference orientation R is parallel to the wall of the housing 212S and perpendicular to the filter 234 at an angle A of about 90°. As shown by angle B, the vibrator 224A can be repositioned / installed to generate vibration forces along the dotted line V', which is at an angle of about 45° relative to the reference orientation R. In this way, if the filter device 10, 110, 210, the vibration force V can be oriented at any given angle relative to a given reference orientation, then the vibrator 24, 124, 224A-224C can be installed on any given surface. As will be described below, the force V oriented at 45° relative to the metal flow through the filter 34, 134, 234 provides good results in the test of the filter device 10, 110, 210. Other reference orientations and force V angles can be selected based on the shape of the filter device and other factors.

[0053] It should be further understood that although embodiments utilizing a refractory lining (e.g., 12R) have been described above, vessels made of a heat-resistant metal (such as steel or cast iron) may also be used to form a vessel without a refractory lining that receives the molten metal and conducts it through a ceramic filter included therein.

[0054] Figure 6A filtering device 310 with a container 312 is shown, which may or may not utilize an outer shell and a refractory lining. In the illustrated embodiment, the filtering device 310 utilizes only a refractory element 312R. A pair of spaced filters 334A and 334B bridging the hollow portion defined by the refractory lining 312R are positioned to sequentially filter the molten metal M flowing through the device 310 as indicated by the arrows. A vibrator 324A is attached to the refractory element 312R, and induces vibrations in the refractory element 312R, the filters 334A and 334B, and the metal M to facilitate the flow through the filters 334A and 334B and the device 310. The filters 334A and 334B may have the same thickness and porosity or may have different thicknesses or porosities. In one embodiment, the filter 334A (e.g., 50 PPI) has a coarser porosity than the filter 334B (e.g., 60 PPI). Optionally, a vibrator 324B (such as Figure 1 Vibrator 24A) may be used in place of or in combination with vibrator 324A.

[0055] Figure 7A filtering device 410 is shown having a container 412 in which a filtering structure 450 has been installed. The container 412 may be in the form of a tank or channel made of a refractory material (such as N-14-N-17) or any other industrial material for containing molten metal; the tank or channel conducts the molten metal M by gravity as it flows from one filter to another. The filtering structure 450 interrupts the flow of the molten metal M, thereby dividing the container 412 into three chambers 412C1 (upstream), 412C2 (midstream), and 412C3 (downstream). A pair of filters 434A and 434B are respectively received in passages 450A, 450B in a sealing manner to filter the molten metal M as it flows through the chambers 412C1, 412C2, and 412C3, thereby sequentially filtering the molten metal M flowing through the device 410. In one embodiment, a vibrator 424A having an arm 424VA and a follower plate 428A acts on the molten metal in the chamber 412C1 to induce vibrations in the metal M, the container 412, the filter 434A, and the filter structure 450 to increase the metal flow through the filter 434A and the device 410. The vibration induced by the vibrator 424A may be sufficient to promote the flow through the filter 434B. In an alternative form, the vibrator 424B and / or the vibrator 424C acting on the container 412 may be used sequentially or simultaneously to improve the flow through the filters 434A, 434B and the device 410. The filters 434A, 434B may have the same thickness and porosity or may have different thicknesses or porosities. In one embodiment, the filter 434A (e.g., 50 PPI) has larger pores than the filter 434B (e.g., 60 PPI), so that the filter 434A conducts a first level of filtration of larger particles and the filter 434B conducts a second level of filtration of smaller particles carried in the metal M.

[0056] Figure 8A filtering device 510 is shown having two containers 512A, 512B, each container having filters 534A and 534B therein, respectively, and joined at a joint 512J. In another alternative form, the containers 512A, 512B may be integrated into a continuous slot or channel through which the molten metal stream M passes. The containers 512A, 512B may be in the form of a tank or channel made of a refractory material (such as, N-14-N-17) or other types of materials used in the molten metal industry; with the tank or channel conducting the molten metal M by gravity as the molten metal M flows from one filter to another. The filters 534A and 534B are respectively received in the containers 512A, 512B in a sealing manner to filter the molten metal M as the molten metal M flows therethrough, thereby sequentially filtering the molten metal M flowing through the device 510. Vibrators 524A, 524B act on containers 512A, 512B, filters 534A, 534B, and the metal M contained therein to increase the flow of metal through filters 534A, 534B and device 510. In an alternative form, one or more vibrators 524C (like vibrators 424A and 424B) can be used to act directly on the metal M in containers 512A, 512B to improve the flow through filters 534A, 534B and device 510. Filters 534A, 534B may have the same thickness and porosity or may have different thicknesses or porosities.

[0057] Fig. 9Shown is a filter device 610 with two containers 612A, 612B, each container having ceramic filters 634A and 634B therein respectively.Container 612A, 612B is supplied with molten metal stream M by conduit 660, and conduit 660 is split into parallel paths 660A, 660B.After passing through container 612A, 612B and filter 634A and 634B, a pair of conduit paths 660C and 660D are rejoined at conduit 660R to allow metal M to pass through for the processing of the next stage.In an alternative form, conduit 660, 660A etc. can be a passage or groove made of refractory material.Along with molten metal M flowing through it, filter 634A and 634B are respectively received in container 612A, 612B sealingly to filter molten metal M. Vibrators 624A, 624B act on containers 612A, 612B, filters 634A, 634B and the metal contained therein to increase the flow of metal through filters 634A, 634B and device 610. In an alternative form, one or more vibrators 624C (like vibrators 424A and 424B) can be used to act directly on conduits 660, 660A, 660B, etc. and metal M in containers 612A, 612B to improve flow through filters 634A, 634B and device 610. Filters 634A, 634B may have the same thickness and porosity or may have different thicknesses or porosities. Figures 1 to 9 The vibrators (e.g., 324B, 424A, 524C, 624C, etc.) can be oriented to produce a vibratory force in a selected direction, for example, at a 45° angle relative to the filter 34, 134, 234, 334A, etc. and / or in the direction of metal flow.

[0058] Experimental testing

[0059] Laboratory scale

[0060] The apparatus and method described above were tested under the parameters listed in Table 1 below. More specifically, the filter device 10 (such as the filter device 10 having a vibrator 24 or 24') Figures 1 to 3 ) was used to filter molten aluminum using the parameters noted in Table 1.

[0061]

[0062]

[0063] Table 1

[0064] As can be understood from the table above, there is a correlation between the pouring time, whether vibration is utilized, and the device utilized. More specifically, keeping other parameters the same (i.e., ppi, alloy, temperature, preheating of the filter, etc.), varying the presence of vibration and the type of vibrator, a series of tests showed that: 1) without vibration, the pouring time was 22 seconds; 2) with vibration from a pneumatic hammer drill, the pouring time was 14 seconds; 3) with vibration from a Vibco vibrator, the pouring time was 20 seconds; and 4) with vibration from another air vibrator, the pouring time was 20 seconds. This testing showed that vibration promoted faster pouring, and that a pneumatic hammer drill was the most effective vibrator.

[0065] As can be understood from Table 1, the weight of the filter (g / cm 2 ), filter preheating and whether vibration is used. The filter is weighed after use, and the weight includes the weight of the filter itself plus the weight of any residual metal retained in the filter. The greater the weight, the better the effect, and the weight indicates the area / volume of the filter used. In the poorly used area of ​​the filter, small cross-sectional areas or channels through the filter will guide the metal through the filter. Because the metal flow is distributed throughout the filter, more efficient filtering conditions utilize more parts of the filter to allow the metal to pass through, resulting in greater throughput and better filtering results. Keeping other parameters the same (ppi, alloy, temperature, filter preheating, etc.), changing the filter preheating and changing the vibration level between vibration and no vibration will give the following results: 1) Filter cooling, no vibration: 1594g / cm 2 ; 2) Filter cooling, vibration: 1854g / cm 2 ; 3) Filter preheating, no vibration: 1960g / cm 2 ; 4) Filter preheating, vibration: 2162g / cm 2 This testing showed that vibration promoted better distribution of metal flow through the filter regardless of whether preheat was applied relative to vibration.

[0066] As can be understood from Table 1, there is a correlation between the temperature of the metal, the presence of vibration, and the infusion time, i.e., the higher the temperature and the presence of vibration, the shorter the infusion time. Keeping other parameters the same (ppi, alloy, etc.), varying the temperature of the metal and varying the vibration level between with and without vibration gives the following results: 1) Metal temperature 720C, no vibration, then infusion time: 21 seconds; 2) Metal temperature 720 and above, no vibration, then infusion time: 12 seconds; 3) Metal temperature 710C, filter preheated, with vibration, then infusion time: 12 seconds; 4) Metal temperature 710C, filter cooled, with vibration, then infusion time: 17 seconds. This test shows that vibration promotes better distribution of metal flow through the filter regardless of whether preheat is applied relative to vibration.

[0067] Tests have revealed that the weight of the filter (when expressed in g / cm 2 More specifically, keeping other parameters the same (i.e., ppi, alloy, temperature, filter preheating, etc.), changing the orientation of the vibrator 24' ( Figure 3 ) to change the angle A of the vibration force F between 45°, 90° and vertical (at or in line with 0 / 180°) relative to the metal flow. A series of tests showed that: 1) The vibration weight from the pneumatic hammer drill at a 45° angle is: 2111 g / cm 2 ; 2) With vibration from a pneumatic hammer drill at a 90° angle, weight: 1750g / cm 2 ; 3) With vertical pneumatic hammer drill vibration, weight: 1738g / cm 2 ; and 4) no vibration, weight is 1886g / cm 2 The test showed that the vibration of the pneumatic hammer drill was most effective at an angle of 45°, with 90° and vertical orientations having a negative effect.

[0068] Testing has revealed that there is a correlation between infusion time and the location and orientation of the vibration source. More specifically, keeping other parameters the same (ie, ppi, alloy, temperature, filter preheating, etc.), changing the orientation of the vibrator 24' ( Figure 3 ) to vary the angle of the vibration force between 45°, 90° and vertical relative to the metal flow and the presence of vibration (which varied between with and without vibration), showing: 1) without vibration, the pouring time was 30 seconds; 2) with vibration from a pneumatic hammer drill at a 45° angle, the pouring time was: 14 seconds; 3) with vibration from a pneumatic hammer drill at a 90° angle, the pouring time was: 13 seconds; and 4) with vibration from a vertical pneumatic hammer drill, the pouring time was: 20 seconds. This test shows that vibration promotes faster pouring and is most effective when the pneumatic hammer drill is at an angle between 45° and 90°.

[0069] The above test was repeated by varying the ppi value of the filter between 30 ppi and 40 ppi and the filter was weighed. The test revealed: 1) A 30 ppi filter without vibration, the weight was found to be 1147 g / cm 2 ; 2) A 30 ppi filter with vibration from a pneumatic vibrator at a 45° angle relative to the direction of the metal flow, yielding a weight of 1626 g / cm 2 ; 3) 30ppi filter with vibration from vertical wind hammer vibrator, the weight obtained is 1032g / cm 2 ; 4) A 40ppi filter with vibration from a wind hammer vibrator at a 45° angle, yielding a weight of 1273g / cm 2; 5) A 40ppi filter with vibration from a wind hammer vibrator at a 90° angle, yielding a weight of 780g / cm 2 ; and 6) a 40 ppi filter with vibration from a vertical wind hammer vibrator, yielding a weight of 1152 g / cm 2 The foregoing tests indicate that an orientation of 45° is optimal for 30ppi and 40ppi filters.

[0070] Extending the above test to a 50 ppi filter yields the following results: 1) A 50 ppi filter without vibrations has a weight of 1642 g / cm 2 ; 2) A 50 ppi filter with vibration from a pneumatic vibrator at a 45° angle relative to the direction of the metal flow, yielding a weight of 1837 g / cm 2 ; 3) A 50ppi filter with vibration from a wind hammer vibrator at a 90° angle, yielding a weight of 1670g / cm 2 ; 4) 50ppi filter with vibration from vertical wind hammer vibrator, the weight obtained is 1518g / cm 2 The above tests show that an orientation of 45° is optimal for a 50 ppi filter.

[0071] The tests revealed that vibration had a positive effect on the metal impregnation of the filter, obtaining an increase of 5% to 13% (depending on the filter). The 30ppi and 60ppi filters with vibration had an increase of more than 10% in metal impregnation. This beneficial effect was enhanced when the filter was preheated, showing an improvement of 13% in metal impregnation for the 50-60ppi filters and 24% in metal impregnation for the 30ppi filter.

[0072] With all other factors being the same, the following results were obtained for various filter sizes with and without vibration: 1) 30ppi, no vibration, the resulting filter weight was: 1651g; 2) 30ppi, with vibration, the resulting filter weight was: 1823g; 3) 50ppi, no vibration, the resulting filter weight was: 2076g; 4) 50ppi, with vibration, the resulting filter weight was: 2175g; 5) 60ppi, no vibration, the resulting filter weight was: 2027g; and 6) 60ppi, with vibration, the resulting filter weight was: 2289g.

[0073] With all other factors being equal, the following results were obtained for various filter sizes taking into account the orientation of the vibration force: 1) 30 ppi, no vibration, the filter weight was: 1709 g; 2) 30 ppi, with vibration using a pneumatic hammer drill at an angle of 45° to the direction of the metal flow, the filter weight was: 2126 g; 3) 50 ppi, no vibration, the filter weight was: 2076 g; 4) 50 ppi, with vibration using a pneumatic hammer drill at an angle of 45°, the filter weight was: 2337 g; 5) 60 ppi, no vibration, the filter weight was: 2027 g; and 6) 60 ppi, with vibration using a pneumatic hammer drill at an angle of 45°, the filter weight was: 2289 g.

[0074] Beneficial effects on priming time were also observed using vibration of the filter. More specifically, preheating a 30 ppi filter resulted in a priming time of 30 seconds without vibration and 15 seconds with vibration. Preheating a 40 ppi filter took 13 seconds to prime with vibration. Preheating a 50 ppi filter resulted in a priming time of 60 seconds without vibration and 18 seconds with vibration. Preheating a 60 ppi filter resulted in a priming time of 20 seconds without vibration and 16 seconds with vibration. In each case, filter impregnation and priming times were improved by vibration. For a given filter (preheated, 30 ppi), the priming time was 30 seconds; when vibrated by a pneumatic hammer drill at a 45° angle to the direction of metal flow, the same filter showed a priming time of 14 seconds; when vibrated by a pneumatic hammer drill at a 90° angle to the metal flow, the priming time was 13 seconds; and when vibrated by a pneumatic hammer drill with a vertical orientation (i.e., in the same direction as the metal flow), the priming time was 20 seconds.

[0075] The cast alloys were also tested to determine metal cleanliness using LiMCA (Liquid Metal Cleanliness Analyzer) and PoDFA (Porous Disk Filter Analysis) from ABB Group (new.abb.com), and it was determined that vibration, which aids filtration, did not interfere with metal cleanliness even though other parameters such as pour time, resulting filter weight, ability to use finer filters and remove more inclusions were improved.

[0076] Actual scale testing

[0077] The full-scale tests were conducted at a casting facility that produces C17N ingots, pure alloys (1050 type) used, for example, in photolithography applications, C42Z (5042) with 3.5% Mg, and C52Z (5352) with 2.5% Mg. C52Z and C42Z can be used for can applications. The cast alloys were tested to determine metal cleanliness using LiMCA and PoDFA.

[0078] A minimum of two castings were made for each alloy to produce an ingot of 330 inches (minimum) length. A maximum of three ingots could be cast at one time, which is consistent with the maximum flow rate (333-417 Kg / min) specified by the filter supplier for a 60 or 70 ppi filter (which is 23 inches by 23 inches). Only 60 ppi and 70 ppi filters were used. LiMCA measurements were performed on four castings. PoDFA was used at the 2000 mm and 4000 mm castings before and after the dual CFF filter. After the CFF with a specific tube, LiMCA was continuously used during casting to minimize the effects of chlorides and bubbles at the furnace outlet. The vibration of the filter started before the molten metal encountered the filter and stopped before casting a 50 mm ingot. A temperature difference of about 100°C between the bottom of the filter and the top of the filter facilitated filtration. The heating of the filter was performed with gas burners below and on the top of the filter. After the filter, a laser was used at the furnace outlet to determine the metal head loss during casting. A pneumatic piston vibrator (i.e., Martin P Series P4S vibrator from Martin Engineering, Neponset, IL (www.martin-eng.com)) was used as the vibrator. The vibrating system was operated at 60-80 psi, producing approximately 1825 impacts per minute at a force of 2105 lbs. The molten alloy was subjected to TAC (aluminum in crucible treatment) to remove Na and Ca and alkali metals. The filter weight was recorded.

[0079] The amount of time the vibrator was operated was varied to compensate for filter temperature variations to avoid casting stops due to filter clogging prior to casting a 50 mm ingot. The vibrating force was ramped during the start-up process to cover all forces in the optimal direction G. Forces and corresponding pressures that would cause resonance of the filter assembly were avoided. Resonance was observed at 30-40 psi. In this test, maximum infusion was achieved with 70 psi air pressure to the vibrator.

[0080] The results of the actual scale tests showed results equivalent to those of the laboratory scale tests, where 18% more metal was added to the filter for the 60 ppi and 70 ppi filters due to the application of vibration according to the present disclosure. For example, the standard casting process without vibration gave 57.75 g / cm 2 When vibration was applied, the filter showed an average value of 68.08 g / cm 2The weights were averaged, which corresponds to an 18% weight increase. Comparison of the total weight of the preheated filters shows the following results: 1) 30 ppi, no vibration: 1709 g; 2) 30 ppi, vibration with a vibrator at a 45° angle: 2126 g; 3) 50 ppi, no vibration: 2076 g; 4) 50 ppi, vibration with a vibrator at a 45° angle: 2337 g; 5) 60 ppi, no vibration: 2027 g; 6) 60 ppi, vibration with a vibrator at a 45° angle: 2289 g.

[0081] The aforementioned vibration techniques and equipment have been explained independently, but each and all can be used in combination. That is, more than one type of vibrator 24 can be used on a single filter device 10 and can be operated simultaneously or sequentially. According to the present disclosure, a vibrator (such as, for example, vibrator 24, 124A) can be retrofitted to an existing conduit or container to improve the filtration of a ceramic filter. It should be understood that the embodiments described herein are exemplary only, and those skilled in the art can make many variations and modifications without departing from the spirit and scope of the claimed subject matter. For example, although the embodiments described above have been related to the filtration of aluminum and its alloys, other metals and alloys may be suitable for filtration using the teachings of the present disclosure, such as mold casting or iron casting. Although the CCF ceramic filter is described above as a filter medium, other types of filters can be used to perform the apparatus and methods disclosed in the present application, such as bed filtration or porous tube filtration. Although the vibrator described above can be used to generate continuous vibrations within a given time period, the vibrator can also be used to generate a single vibration, thereby generating a vibration wave passing through at least one of the molten metal, container or filter. All such variations and modifications are intended to be included within the scope of the present disclosure.

Claims

1. A filtering device, It is characterized in that include: A vessel for molten metal, wherein the vessel comprises an outer shell and an inner liner separate from and spaced apart from the outer shell, the inner liner defining a molten metal filter chamber, the inner liner having an inlet through which the molten metal can enter the vessel and an outlet through which the molten metal can exit the vessel; a ceramic foam filter located in the molten metal filter chamber and at least partially in physical contact with the liner, the ceramic foam filter having a pore density of at least 40 PPI; a vibrator in mechanical communication with the liner, wherein the vibrator is configured to induce vibrations in the molten metal via vibrations of the liner; and At least one elastic member is interposed between the inner liner and the outer shell, wherein the at least one elastic member at least partially isolates vibrations of the inner liner from the outer shell.

2. The device according to claim 1, It is characterized in that The vibrator does not contact the molten metal.

3. The device according to claim 1, It is characterized in that The vibrator is mounted on the outer surface of the container, close to the ceramic foam filter.

4. The device according to claim 1, It is characterized in that The vibrator is at least one of electrically driven, pneumatically driven or hydraulically driven.

5. The device according to claim 1, It is characterized in that The vibrator generates a force in a direction between 45° and 90° relative to the direction of metal flow.

6. The device according to claim 1, It is characterized in that The vibrator is mounted close to the ceramic foam filter, and wherein the vibrator does not directly contact the ceramic foam filter.

7. The device according to claim 1, It is characterized in that Also included is a controller for the vibrator, the controller being capable of adjusting the vibrator in at least one of frequency and amplitude.

8. The device according to claim 1, It is characterized in that The ceramic foam filter has more than 60 pores per inch.

9. The device according to claim 1, It is characterized in that The molten metal includes aluminum.

10. A filtering device, It is characterized in that include: A vessel for molten metal, wherein the vessel comprises an outer shell and an inner liner separate from the outer shell, the inner liner defining a molten metal filter chamber, the inner liner having an inlet through which the molten metal can enter the vessel and an outlet through which the molten metal can exit the vessel; a ceramic foam filter within the vessel, the ceramic foam filter being located in the molten metal filter chamber and in at least partial physical contact with the liner, the ceramic foam filter being capable of allowing molten metal to pass therethrough and comprising a pore density of at least 40 PPI; a vibrator connected to the container; as well as A driven plate, the driven plate being in physical communication with the vibrator via the active arm, wherein the vibrator is configured to drive the driven plate, wherein when the driven plate is immersed in the molten metal, vibration is introduced into the molten metal via the movement of the driven plate, wherein the active arm extends between the vibrator and the driven plate, and The active arm extends through the outer shell and the inner liner into the molten metal filter chamber.

11. The device according to claim 10, It is characterized in that Also included is a controller for the vibrator, the controller being capable of adjusting the vibrator in at least one of frequency and amplitude.

12. The device according to claim 10, It is characterized in that The vibrator is mounted on the outer wall of the container.

13. The device according to claim 10, It is characterized in that The longitudinal axis of the follower plate extends at an angle between 45° and 90° relative to the longitudinal axis of the ceramic foam filter.

14. The device according to claim 10, It is characterized in that The follower plate is at least partially covered by a refractory material.

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