Patent Publication Number: US-2021180866-A1

Title: Modular gun assembly for melt furnaces

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of provisional application 62/948,997 filed on Dec. 17, 2019. The disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to electron beam furnaces, and particularly to electron beam gun assemblies for electron beam furnaces. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     An electron beam (EB) furnace uses one or more electron beams to melt material (e.g., scrap or virgin alloy material) and produce an ingot. Such a furnace typically has one or more EB guns mounted on or to apertures of a chamber lid attached to a chamber such that electron beam(s) generated by the EB gun(s) propagate through the apertures and melt material contained in the chamber during a melting campaign. One issue with EB furnace melting efficiency is downtime required to clean the chamber and/or chamber lid before another melting campaign can begin. 
     The present disclosure addresses issues related to downtime in EB furnace melting, among other issues related to melting and forming of alloy ingots. 
     SUMMARY 
     In one form of the present disclosure, an electron beam (EB) gun assembly for an EB furnace is provided. The EB gun assembly comprises an EB gun-frame assembly comprising a skeleton frame and at least one EB gun mounted to the skeleton frame, wherein the EB gun-frame assembly is configured to rigidly mount onto a first EB chamber lid and melt material in a first EB chamber and be removed and rigidly mount onto a second EB chamber lid and melt material in a second EB chamber. In some variations, the skeleton frame comprises at least one EB gun opening and the at least one EB gun extends through the at least one EB gun opening. 
     In at least one variation of the present disclosure, the EB gun assembly includes at least one mounting frame, the at least one EB gun is mounted to the at least one mounting frame and the at least one mounting frame is mounted to the skeleton frame. In some variations, the mounting frame comprises a nozzle opening and the at least one EB gun comprises a nozzle extending through the nozzle opening. In at least one variation, the mounting frame comprises a top plate having the nozzle opening and a floating plate movably attached to the top plate, and the nozzle of the at least one EB gun is mounted to the floating plate such that a position of the nozzle is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. 
     In some variations a collar is rigidly attached to the nozzle of the EB gun and is movably attached to the top plate of the mounting frame such that the position of the nozzle is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. In at least one variation a plurality of biasing members is positioned between the collar and the top plate such that the collar is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. Also a first alignment guide configured to receive a second alignment pin extending from at least one of the first EB furnace lid and the second EB furnace lid can be included such that the at least one EB gun is aligned with a lid gun aperture. 
     In some variations of the present disclosure, the at least one EB gun is a plurality of EB guns mounted to the skeleton frame. In such variations the EB gun assembly has a plurality of mounting frames, each of the plurality of EB guns is mounted to a mounting frame and each of the plurality of mounting frames is mounted to the skeleton frame. In at least one variation each of the plurality of mounting frames has a nozzle opening and each of the plurality of EB guns has a nozzle extending through the nozzle opening of a mounting frame. Each of the plurality of mounting frames includes a top plate with a nozzle opening and a floating plate movably attached to the top plate. The nozzle of each of the plurality of EB guns is mounted to the floating plate of a mounting frame such that a position of the nozzle of each of the plurality of EB guns is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. In some variations, each of the plurality of mounting frames includes a collar rigidly attached to the nozzle of the EB gun and movably attached to the top plate of the mounting frame such that the position of the nozzle of each of the plurality of EB guns is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. In at least one variation a plurality of biasing members is positioned between each collar and a top plate such that each collar is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. 
     In another form of the present disclosure, an electron beam (EB) furnace assembly is provided. The EB furnace assembly comprises a first EB furnace comprising a first EB chamber and a first EB chamber lid having a first set of EB gun apertures, a second EB furnace comprising a second EB chamber and a second EB chamber lid having a second set of EB gun apertures, and an EB gun-frame assembly. The EB gun-frame assembly comprises a skeleton frame and a plurality of EB guns mounted to the skeleton frame. The EB gun-frame assembly is configured to rigidly mount onto the first EB chamber lid with the plurality of EB guns mounted onto the first set of EB gun apertures and rigidly mount onto the second EB chamber lid with the plurality of EB guns mounted onto the second set of EB gun apertures such that the EB gun-frame assembly is interchangeable with the first and second EB chamber lids. 
     In some variations of the present disclosure, the EB gun assembly includes a plurality of mounting frames, the plurality of EB guns are securely mounted to the plurality of mounting frames, and the plurality of mounting frames are securely mounted to the skeleton frame. In at least one variation, each of the plurality of mounting frames has a top plate and a floating plate movable mounted to the top plate. Also, each of the plurality of EB guns is rigidly mounted to a floating plate such that the nozzle of the each of the plurality of EB guns is mounted to the floating plate of a mounting frame such that a position of each of the plurality of EB guns is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. In some variations each of the plurality of mounting frames includes a collar rigidly attached to a nozzle of an EB gun and the nozzle is movably attached to the top plate of the mounting frame such that the position of the nozzle of each of the plurality of EB guns is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. 
     In yet another form of the present disclosure, a method of melting material with an electron gun (EB) furnace assembly is provided. The method includes securely mounting an EB gun-frame assembly to a first EB chamber lid. The EB gun-frame assembly includes a skeleton frame and a plurality of EB guns securely mounted to the skeleton frame. The first EB chamber lid comprises a first set of EB gun apertures and the plurality of EB guns are mounted onto the first set of EB gun apertures. Material is melted in a first EB chamber using the plurality of EB guns when the first EB chamber lid and the EB gun-frame assembly are securely mounted to the first EB chamber. In some variations, the method includes removing the EB gun-frame assembly from the first EB chamber lid and securely mounting the EB gun-frame assembly to a second EB chamber lid that has a second set of EB gun apertures. The plurality of EB guns are mounted onto the second set of EB gun apertures and material is melted in a second EB chamber using the plurality of EB guns when the second EB chamber lid and the EB gun-frame assembly are securely mounted to the second EB chamber. 
     In some variations of the present disclosure the EB gun-frame assembly includes a plurality of mounting frames securely mounted to the skeleton frame and the plurality of EB guns securely mounted to the plurality of mounting frames. In at least one variation each of the plurality of mounting frames has a top plate and a floating plate movable mounted to the top plate, and each of the plurality of EB guns is rigidly mounted to a floating plate such that a position of each of the plurality of EB guns is movable after the EB gun-frame assembly is rigidly mounted to the first and second EB chamber lids. In some variations the method includes moving a position of at least one of the plurality of EB guns and securely mounting the at least one of the plurality of EB guns onto an EB gun aperture on the first EB chamber lid after the EB gun-frame assembly is rigidly mounted to the first EB chamber lid. In at least one variation a position of at least one of the plurality of EB guns is moved and securely mounted onto an EB gun aperture on the second EB chamber lid after the EB gun-frame assembly is rigidly mounted to the second EB chamber lid. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of chamber and a plurality of electron beam (EB) guns mounted on a chamber lid; 
         FIG. 2  is a perspective view of an EB gun assembly configured to attach or mount to a first chamber and a second chamber lid according to the teachings of the present disclosure; 
         FIG. 3  is a perspective view of a skeleton frame for the EB gun assembly in  FIG. 2 ; 
         FIG. 4  is the skeleton frame in  FIG. 3  with an EB gun mounted to the skeleton frame according to the teachings of the present disclosure; 
         FIG. 5A  is a perspective view of a mounting frame for the EB gun assembly according to the teachings of the present disclosure; 
         FIG. 5B  is a front view of the mounting frame in  FIG. 5A ; 
         FIG. 6  is front view of the mounting frame ion  FIG. 5B  with an EB gun mounted to the mounting frame; 
         FIG. 7  is an enlarged view of the EB gun assembly in  FIG. 2 ; 
         FIG. 8  is the EB gun assembly in  FIG. 7  mounted to a chamber lid according to the teachings of the present disclosure; and 
         FIG. 9  is the EB gun assembly and chamber lid in  FIG. 8  hanging from a support according to the teachings of the present disclosure. 
     
    
    
     The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     Referring to  FIG. 1 , an electron beam (EB) gun and lid assembly  20  is shown. The EB gun and lid assembly  20  comprises at least one EB gun  22  (also referred to herein simply as “EB guns”) and a lid  40 . The EB guns  22  each have a pair of EB gun ducts  24 ,  26  through which air can be withdrawn and exhaust gas can flow during operation of the EB guns  22  as described below. The EB guns  22  are attached and mounted to the lid  40  at EB gun apertures  44 , and the EB gun and lid assembly  20  couples to a chamber  60  with an interior  64 . In some variations of the present disclosure, clamps (not shown) are used to fasten and secure a lid flange  42  of the lid  40  to a chamber flange  62  of the chamber  60  such that an air or vacuum tight seal is provided between the lid  40  and chamber  60 . In some variations, one or more of the EB guns  22  are mounted to the lid  40  before the lid  40  is attached or coupled to the chamber  60 , while in other variations one or more of the EB guns  22  are mounted to the lid  40  after the lid  40  is attached or coupled to the chamber  60 . 
     Mounting the EB guns  22  to the EB gun apertures  44 , and coupling the EB gun and lid assembly  20  to the chamber  60 , aligns the EB guns  22  at desired angles relative to the interior  64 . And during operation of the EB guns  22 , a vacuum is pulled on the EB guns  22  (i.e., housings that contain the EB guns  22  (not labeled)) through the EB gun ducts  24 ,  26  and electron beams from the EB guns  22  propagate through EB gun apertures  44  and into chamber  60 . It should be understood that air is also withdrawn from the chamber  60  using vacuum pumps (not shown). The electron beams heat and melt a campaign of one or more batches of material to form liquid metal (not shown) in the interior  64  of the chamber  60  during a melting campaign and the liquid metal is allowed to cool within the chamber to form an ingot (not shown) before the lid  40  with the attached EB guns  22  is removed. 
     It should be understood that using such an EB gun and lid assembly  20  provides a clean and energy efficient process for producing commercial ingots, e.g., commercial titanium alloy ingots. However, it is desired to clean and/or refurbish the chamber  60  and the lid  40  before proceeding with a subsequent melting campaign, and such cleaning and/or refurbishing takes or occupies time during which use of the EB gun and lid assembly  20  for melting is prohibited. That is, the EB gun and lid assembly  20  cannot be used to melt material when the chamber  60  and the lid  40  are being cleaned and/or refurbished. 
     Referring now to  FIG. 2 , an EB gun assembly  80  according to the teachings of the present disclosure is shown. The EB gun assembly  80  comprises a skeleton frame  100  and EB guns  22  with mounted to the skeleton frame  100 . In some variations, each of the EB guns  22  has the pair of EB ducts  24 ,  26 . As depicted in  FIG. 2 , the skeleton frame  100  is configured to couple to a first lid  40   a  and a second lid  40   b  (collectively referred to herein as “lids  40   a ,  40   b ”), and the first lid  40   a  is configured to couple to a first chamber  60   a  and the second lid  40   b  is configured to couple to a second chamber  60   b . In some variations the first lid  40   a  is also configured to couple to the second chamber  60   b  and the second lid  40   b  is configured to couple to the first chamber  60   a . That is, the lids  40   a ,  40   b  are interchangeable with the first chamber  60   a  and the second chamber  60   b  (collectively referred to herein as “chambers  60   a ,  60   b ”). In at least one variation, one or both of the lids  40   a ,  40   b  can include a first alignment guide  41  that assists in alignment of the EB gun assembly  80  onto the lids  40   a ,  40   b  as described in more detail below. It should be understood that such a configuration allows or enables the EB gun assembly  80  to be removed from the first lid  40   a , e.g., after first melting campaign, and be attached to the second lid  40   b  for a second melting campaign in the second chamber  60   b . Such a configuration also allows or enables the first lid  40   a  to be cleaned and/or refurbished for another melting campaign in the first chamber  60   a  while or during the second melting campaign in the second chamber  60   b.    
     Referring now to  FIG. 3 , the skeleton frame  100  is shown and includes an outer ring  102 , a plurality of cross members  104 , and at least one mounting member  106 . The outer ring  102 , the plurality of cross members  104 , and the at least one mounting member  106  are rigidly attached to each other to form the skeleton frame  100  and to define a plurality of openings  110 . The openings  110  reduce the weight of the skeleton frame  100  and permit visual inspection, observation, and access to the lids  40   a ,  40   b . In some variations a deck  108  is included and attached to at least one cross member  104 . The deck  108  provides a platform for an individual to walk on and work from during installation or mounting of the EB guns  22  to the skeleton frame  100 , mounting of the EB gun assembly  80  to one of the lids  40   a ,  40   b , and/or melting of material in the chambers  60   a ,  60   b . In at least one variation a cover plate  112 , with or without a second alignment guide  101 , is included and extends between and is attached to one or more of the cross members  104 . 
     Referring to  FIG. 4 , in some variations the EB gun assembly  80  includes a mounting frame  120  configured to receive and hold one of the EB guns  22 . Particularly, and as discussed in greater detail below, the mounting frame  120  is rigidly attached to the skeleton frame  100  and can assist in aligning and rigidly mounting an EB gun  22  to an EG gun aperture  44 . In some variations of the present disclosure, the skeleton frame  100  also couples to and supports at least one of the EB ducts  24 ,  26 . 
     Referring to  FIGS. 5A and 5B , in some variations the mounting frame  120  includes a mounting plate  122 , a pair of side plates  124 , and a top plate  126 . The mounting plate  122 , pair of side plates  124 , and top plate  126  form a frame  121  configured to support an EB gun  22 . Also, the mounting plate  122  is configured to be rigidly attached to the mounting member  106  ( FIG. 3 ) of the skeleton frame  100  and the top plate  126  and floating plate  130  each have a gun aperture  132 . 
     In some variations of the present disclosure, a floating plate  130  is included and coupled to the top plate  126  with a plurality of rods  134  and floating springs  136 . For example, the plurality of rods  134  have an upper end (not labeled, +z direction) rigidly attached to the floating plate  130  and a plurality of floating springs  136  disposed between lower ends (not labeled, −z direction) of the rods  134  and the top plate  126  as shown in  FIG. 5B . Accordingly, the floating plate  130  has limited and biased movement relative to the top plate  126  and the frame  121 . That is, the rods  134  translate through the top plate  126 , and with the floating springs  136  disposed between lower ends of the rods  134  and the top plate  126 , the floating plate  130  is configured to move up/down (+/−z direction) and tilt (about z axis) when the mounting frame  120  is rigidly attached to the skeleton frame  100 . 
     In some variations, a collar  138  is included and coupled to the floating plate  130  such that both the floating plate  130  and the collar have limited and biased movement relative to the top plate  126 . It should be understood that the rods  134  can be threaded members and that commercially available fasteners (pins, nuts, washers, among others) affix the rods  134  to the floating springs  136  and floating plate  130 . 
     In at least one variation, the mounting frame  120  includes a brace  128  coupled to either the top plate  126  or the floating plate  130 . In variations where the brace  128  is coupled to top plate  126 , the brace  128  can be slidably coupled to and/or translate through the floating plate  130 . In the alternative, the top plate  126  can extend beyond (+y direction) the floating plate  130  such that the brace  128  is coupled to the top plate  126  but not the floating plate  130 . In variations where the brace  128  is coupled to the floating plate  130 , the brace  128  moves with the floating plate  130  and has limited movement relative to the top plate  126 . 
     Referring to  FIG. 6 , an EB gun  22  mounted to the mounting frame  120  is shown. The EB gun  22  includes a gun chamber  23  positioned on the floating plate  130  and a gun nozzle  25  with a mounting flange  27  disposed within the gun apertures  132  ( FIG. 5A ) of the top plate  126  and the floating plate  130 . In some variations a bottom surface (not labeled, −z direction) of the gun chamber  23  is rigidly attached to the floating plate  130  and/or the collar  138  is rigidly attached to the gun nozzle  25  such that the gun nozzle  25  has limited movement relative to the mounting frame  120 . Accordingly, when the mounting frame  120  is rigidly attached to the skeleton frame  100 , the gun nozzle  25  has limited movement relative to the skeleton frame  100 , and when the skeleton frame  100  is rigidly attached to the lids  40   a ,  40   b , the gun nozzle  23  has limited movement relative to the lids  40   a ,  40   b  and limited movement relative to an EB gun aperture  44 . Such limited movement by the gun nozzle  25  assists and enhances alignment and attachment of the gun nozzle  25  to a particular EB gun aperture  44 . 
     Referring to  FIG. 7  the EB gun assembly  80  with the plurality of EB guns  22  mounted to the skeleton frame  100  via a plurality frames  120  is shown. It should be understood that each of the mounting frames  120  includes a floating plate  130  movably attached to a top plate  126  as described above such that limited movement is provided to each of the gun nozzles  25  during alignment and attachment of the gun nozzles  25  to respective EB gun apertures  44 . 
     Referring to  FIG. 8 , the EB gun assembly  80  rigidly attached to the first lid  40   a  or second lid  40   b  is shown. Particularly, the skeleton frame  100  is rigidly attached to the first lid  40   a  or second lid  40   b  with a plurality of clamps  103  and each of the EB guns  22  is rigidly attached to a respective EB gun apertures  44 . In at least one variation, the mounting flange  27  of each gun nozzle  25  is bolted (not shown) to a respective gun aperture  44 . It should be understood that attaching each of the EB guns  22  to the EB gun apertures  44  is assisted and enhanced by the mounting frame  120 . For example, in some variations each of the EB guns  22  is mounted to a mounting frame  120  when the EB gun assembly  80  is moved into position and mounted to the first lid  40   a  or second lid  40   b . In at least one variation, the first alignment guide  41  and the second alignment guide  101  assist in positioning the skeleton frame  100  on the lid  40   a  or second lid  40   b . After the skeleton frame  100  is mounted to the first lid  40 , each of the gun nozzles  25  is aligned with a respective EB gun aperture  44 . Alignment of the gun nozzles  25  with the EB gun apertures  44  is assisted by the limited movement provided by the floating plate  130  relative to the top plate  126  and after each gun nozzle  25  is properly aligned, it is rigidly attached to a EB gun aperture  44  via the mounting flange  27 . After the EB guns  22  are rigidly attached to the EB gun apertures  44 , a vacuum is pulled on the first chamber  60   a  (i.e., air is evacuated from the first chamber  60   a ) and EB melting of material within the first chamber  60   a  begins (e.g., a first melt campaign is executed or performed). It should be understood that after the first melt campaign the EB gun assembly  80  rigidly is removed from the first lid  40   a  and the attached to the second lid  40   b  as described above with respect to the first lid  40   a  such that a second melt campaign within the second chamber  60   b  can proceed while the first lid  40   a  and the first chamber  60   a  are cleaned and/or refurbished. In addition, this cycle of attaching the EB gun assembly to a separate lid and executing a melt campaign in a separate chamber during cleaning and/or refurbishing or a previously used lid and chamber is repeated over and over such that productivity is enhanced and costs are reduced. 
     Referring now to  FIG. 9 , hanging of the EB gun assembly  80  from a support (not shown) using hangers  160  is shown. The support can include a support structure such as a ceiling, crane, frame, platform, rail, and wall, among others. The hangers  160  can include cables, chains, rods, struts, wire, or other appropriate fastening and fixturing assembles. In the alternative, or in addition to, the first lid  40   a , second lid  40   b , skeleton frame  100  and/or hangers  160  is supported by wheels (not shown). The wheels are supported by rails which enable the lids  40   a ,  40   b  and/or skeleton frame  100  to move between chambers, lids, and outside of the furnace station. 
     It should be understood from the teachings of the present disclosure that an EB gun assembly that reduces downtime for one or more EB guns is provided. The EB gun assembly includes a skeleton frame configured for the one or more EB guns to be securely attached to and yet provide limited movement to the one or more EB guns for alignment of EB gun apertures with a chamber lid. The EB gun assembly can be installed on and/or removed from a chamber lid in a time efficient manner. In addition, when a pair of chambers and a pair chamber lids are included, the EB gun assembly provides a melting campaign to proceed in one of the chambers while the other chamber and chamber lid are being cleaned or refurbished. The use of two chambers, two chamber lids, a skeleton frame, and the EB gun assembly according to the teachings of the present disclosure reduces changeover time (i.e., down time of the EB guns) by at least 20 hours when melting and forming commercial ingots weighing between about 15,000 to about 40,000 pounds. That is, the EB gun assembly with the skeleton frame reduces the complexity and time between melting campaigns. 
     The skeleton frame enables furnace operators to leave a chamber lid coupled to a chamber while venting the furnace, thereby reducing the introduction of furnace by-products (ash, dust, smoke, among others) into the melt shop during venting. The reduction of by-products introduced into the melt shop improves efficiency as melt shop equipment service life is improved since fewer furnace by-products interact with the manufacturing equipment. The skeleton frame also enables chamber lid cleaning, inspecting, and/or repairing to be performed outside of the furnace station (i.e., where melting of the ingot material occurs), thereby providing more room and easier access to the lid, and improving efficiency, productivity, and safety. Moreover, refurbishing activities do not impact the EB guns which increases EB gun reliability while reducing EB gun maintenance. 
     Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability. 
     As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” 
     The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.