System and method for joining tubes to sheets in a tubular heat transfer system

Abstract

A system and method for expanding, joining or securing a plurality of tubes by electromagnetic expansion to a plurality of sheets in a tubular heat transfer system. The system and method involve the automatic sensing and positioning of a electromagnetic coil in operative relationship with at least a portion of a tube and an inner wall of a sheet and then energizing the electromagnetic coil to expand the portion of the tube to engage the inner wall of the sheet, thereby securing the tube thereto. A tubular heat transfer system tube expander and method are also shown.

What is claimed is:  
     
         1 - 20 . (Cancelled)  
     
     
         21 . A method for securing a plurality of conductive tubes to a plurality of plates to provide a tube bundle in a tubular heat transfer system, each of said plurality of plates having a plurality of inner walls defining a plurality of apertures, respectively, said method comprising the steps of: 
 situating said plurality of conductive tubes in said plurality of apertures. respectively, and magnetically increasing a diameter of a portion of at least one of said plurality of conductive tubes into engagement with at least one of said plurality of inner walls, thereby securing said at least one of said plurality of conductive tubes to said at least one of said plurality of inner walls;    situating a coil inside said at least one of said plurality of conductive tubes: energizing said coil to perform said increasing step; and    sensing said surrounding member and energizing said coil when said coil is positioned in operative relationship with said surrounding member.    
     
     
         22 . A method for securing a conductive tube to at least one surrounding member of a tubular heat transfer system, said method comprising the steps of: 
 inserting a coil into said conductive tube until said coil is positioned in operative relationship with said conductive tube and said at least one surrounding member;    energizing said coil to expand a portion of the conductive tube to engage said at least one surrounding member, thereby securing said conductive tube to said at least one surrounding member;    said energizing step further comprising the steps of:    providing a capacitor discharge bank that provides a predetermined capacitance:    charging said capacitor discharge bank with a predetermined voltage:    discharging said capacitor discharge bank to energize said coil to perform said energizing step;    wherein said conductive tube comprises a conductive tube dimension and said surrounding member comprises an inner wall comprising an inner wall dimension, said method further comprising the steps of:    selecting said predetermined capacitance and said predetermined charge voltage in response to at least said conductive tube dimension and said inner wall dimension; and sensing a next position of said plurality of positions and performing said energizing step at said next position.    
     
     
         23 - 26 . (Cancelled)  
     
     
         27 . A method for enlarging a first portion and a second portion of a conductive tube for use in a tubular heat transfer system, said method comprising the steps of: 
 moving a coil to a first position in operative relationship with said first portion of said conductive tube;    energizing said coil to enlarge magnetically said first portion of said conductive tube at said first position;    moving said coil to the second position in operative relationship with said second portion of said conductive tube;    energizing said coil to enlarge magnetically said second portion of said conductive tube at said second position; and    sensing said first position before said first energizing step; sensing said second position after said first energizing step, but before said second energizing step.    
     
     
         28 . A method for enlarging a first portion and a second portion of a conductive tube for use in a tubular heat transfer system, said method comprising the steps of: 
 moving a coil to a first position in operative relationship with said first portion of said conductive tube;    energizing said coil to enlarge magnetically said first portion of said conductive tube at said first position;    moving said coil to the second position in operative relationship with said second portion of said conductive tube;    energizing said coil to enlarge magnetically said second portion of said conductive tube at said second position;    inserting said conductive tube in a first surrounding member located at said first position and a second surrounding member located at said second position;    performing said first energizing step to secure said first portion of said conductive tube to said first surrounding member;    performing said second energizing step to secure said second portion of said conductive tube to said second surrounding member; and    sensing a position of said first surrounding member before said first moving step; and    sensing a position of said second surrounding member before said second moving step and after said first energizing step.    
     
     
         29 - 40 . (Cancelled)  
     
     
         41 . A method for assembling a tubular heat transfer system having a housing, said method comprising the steps of: 
 (a) providing a plurality of sheets, each of said plurality of sheets comprising a plurality of inner walls defining a plurality of apertures, respectively    (b) positioning a plurality of conductive tubes into said plurality of apertures, respectively;    (c) inserting a coil into a first conductive tube of said plurality of conductive tubes;    (d) moving said coil to a first position in said first conductive tube; said first position corresponding to where a first inner wall of said plurality of inner walls and said coil become substantially aligned;    (e) energizing said coil to enlarge magnetically said first portion of said first conductive tube adjacent the first inner wall to secure said first portion of said first conductive tube to said first inner wall;    (f) moving a second coil to a next position in said first conductive tube; said second position corresponding to where said a second inner wall of a second sheet and said coil become substantially aligned;    (g) energizing said coil to enlarge magnetically said second portion of said first conductive tube adjacent the second inner wall to secure said second portion of said first conductive tube to said second inner wall; and    (h) repeating said steps (f) and (g) until each of said plurality of conductive tubes is secured to said plurality of sheets; and    sensing said first position before performing said step (e).    
     
     
         42 . A method for assembling a tubular heat transfer system having a housing, said method comprising the steps of: 
 (a) providing a plurality of sheets, each of said plurality of sheets comprising a plurality of inner walls defining a plurality of apertures, respectively;    (b) positioning a plurality of conductive tubes into said plurality of apertures, respectively;    (c) inserting a coil into a first conductive tube of said plurality of conductive tubes;    (d) moving said coil to a first position in said first conductive tube; said first position corresponding to where a first inner wall of said plurality of inner walls and said coil become substantially aligned;    (e) energizing said coil to enlarge magnetically said first portion of said first conductive tube adjacent the first inner wall to secure said first portion of said first conductive tube to said first inner wall;    (f) moving a second coil to a next position in said first conductive tube; said second position corresponding to where said a second inner wall of a second sheet and said coil become substantially aligned;    (g) energizing said coil to enlarge magnetically said second portion of said first conductive tube adjacent the second inner wall to secure said second portion of said first conductive tube to said second inner wall; and    (h) repeating said steps (f) and (g) until each of said plurality of conductive tubes is secured to said plurality of sheets; and    sensing said second position before performing said step (g).    
     
     
         43 - 92 . (Cancelled).  
     
     
         93 . An expander assembly comprising: 
 an expander for magnetically enhancing at least a portion of a tube into a surrounding member; and    a sensor connected with the expander for sensing a position of the surrounding member as the expander is moved through the tube.    
     
     
         94 . The expander assembly as recited in  claim 93  wherein said expander assembly comprises: 
 a cable having a first mount and a second mount for detachably coupling to said direct drive expander;  
 a sensor associated with the mount for sensing said surrounding member.  
 
     
     
         95 . The expander assembly as recited in  claim 94  wherein said cable comprises a sensor core for coupling said sensor to a controller.  
     
     
         96 . The expander assembly as recited in  claim 93  wherein said sensor is a Hall effect sensor.  
     
     
         97 . The expander assembly as recited in  claim 94  wherein said cable is extruded and comprises a sensor bundle, a first conductor and a second conductor, said first and second conductors conductively coupling said coil to said circuit.  
     
     
         98 . The expander assembly as recited in  claim 93  wherein said expander assembly comprises a sensor for sensing the surrounding member as the direct drive expander is moved through the tube.  
     
     
         99 . The expander assembly as recited in  claim 93  wherein said surrounding member is a sheet.  
     
     
         100 . The expander assembly as recited in  claim 93  wherein said expander is a coil.  
     
     
         101 . The expander assembly as recited in  claim 100  wherein said coil is a solenoid.