Abstract:
A method for recycling rail is provided wherein the rail is heated, and then slit into two pieces. The two pieces are passed through a single mill pass line such that each piece of the rail is deformed to have a generally uniform shape.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application is a continuation of U.S. patent application Ser. No. 10/635,948, filed on Aug. 7, 2003, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND  
       [0002]     The present disclosure relates generally to recycling worn rail, and more particularly to a process for recycling rail which reduces the amount of resources needed to recycle the rail while maintaining or improving the quality of the recycled rail and reducing the need to scrap portions of the rail.  
         [0003]     It is common practice to recycle worn rail, such as worn railroad rail, into a variety of products such as t-post, rebar, angles, etc. by subjecting the rail to rolling operations. Rolling operations generally include heating of the rail to a plastic state and deforming of the rail into a generally uniform shape having a reduced cross-sectional area relative to the original worn rail.  
         [0004]     As can be appreciated, rail typically does not take an easily workable shape such as a square, circle, or rectangle. Rather, most rail takes a unitary T-like shape to include a lower portion, a web portion, and an upper portion. Recycling such rail can be problematic due to the formation of structurally-deficient laps or seams that result from rolling rail having difficult geometric orientations. As such, it is often necessary to divide the rail into workable sections in a process known as slitting.  
         [0005]     In the past, slitting has involved forming multiple slits in the rail to separate the lower portion, the web portion, and the upper portion of the rail prior to rolling. Oftentimes, the web portion of the rail will include holes or other attachment means to accommodate laying of the rail. Thus, the portions of the rail that include these holes need to be scrapped prior to the remainder of the rail undergoing deformation processes because deformation of porous portions of rail can lead to a structurally deficient finished product.  
         [0006]     After scrapping the unusable portion of the rail, the lower, upper, and web portions of the rail are passed down separate deformation lines, often referred to as mill pass lines, during which each portion is subjected to rolling operations. Thus, multiple mill pass lines are required in order to accommodate passage of the lower, upper, and web portions of the rail during such rolling operations. Each mill pass line requires a considerable amount of equipment including mill stands, conveyors, guiding systems, cooling beds, finishing shears, bundling systems, etc. Furthermore, each mill pass line requires employees to supervise the rolling operations. As can be appreciated, the cost of running multiple mill pass lines during the recycling of worn rail can be economically burdensome due to the amount of equipment and number of employees needed for such operations.  
         [0007]     Therefore, what is needed is a rail recycling process that reduces the number of mill pass lines while maintaining or improving the quality of the recycled rail and reducing the need to scrap portions of the rail.  
       SUMMARY  
       [0008]     A method for recycling rail is provided in which the rail is heated and then slit to separate the rail into a first piece and a second piece. The first and second pieces of the rail are then deformed.  
         [0009]     In another embodiment, a method for recycling rail in a single mill pass line is provided in which the rail to be recycled includes a lower portion, an upper portion, and a web portion linking the lower portion and the upper portion. The rail is heated and then slit across the web portion of the rail to separate the rail into a first piece and a second piece. The first and second pieces of the rail are then deformed by being passed through at least one reduction pass. Deformation of the first and second pieces of the rail causes the first and second pieces to have a generally uniform shape.  
         [0010]     In yet another embodiment, a method for reducing structural defects in recycled rail is provided in which the rail to be recycled includes holes formed therein. The rail is slit across the holes to separate the rail into a first piece and a second piece. Slitting across the holes defines partial holes in each of the first and second pieces. The first and second pieces of the rail are then deformed by being passed through at least one reduction pass. Deformation of the first and second pieces of the rail eliminates the partial holes of the first and second pieces. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a block diagram depicting a rail recycling process according to one embodiment of the present disclosure.  
         [0012]      FIG. 2   a  is a schematic perspective view of a whole rail to be deformed according to the process depicted in  FIG. 1 .  
         [0013]      FIG. 2   b  is a schematic perspective view of the rail of  FIG. 2   a  after having undergone a slitting process.  
         [0014]      FIG. 3  is a schematic side view of the rail of  FIG. 2   a.    
         [0015]      FIG. 4  is a schematic view of the rail of  FIG. 2   a  after having undergone a first reduction pass.  
         [0016]      FIG. 5   a  is a schematic view of a flange of the rail of  FIG. 2   a  after having undergone a second reduction pass.  
         [0017]      FIG. 5   b  is a schematic view of a head of the rail of  FIG. 2   a  after having undergone a second reduction pass.  
         [0018]      FIG. 6   a  is a schematic view of the flange of the rail of  FIG. 2   a  after having undergone a third reduction pass.  
         [0019]      FIG. 6   b  is a schematic view of the head of the rail of  FIG. 2   a  after having undergone a third reduction pass.  
         [0020]      FIG. 7   a  is a schematic view of the flange of the rail of  FIG. 2   a  after having undergone a fourth reduction pass.  
         [0021]      FIG. 7   b  is a schematic view of the head of the rail of  FIG. 2   a  after having undergone a fourth reduction pass. 
     
    
     DETAILED DESCRIPTION  
       [0022]     Referring to  FIG. 1 , a process for recycling whole rail according to one embodiment of the present disclosure is generally referred to by reference numeral  10 . It is understood that whole rail is a term of art used to describe raw material for rolling mill operations. A substantial amount of the process  10  may be carried out in a single mill pass line as will be described.  FIGS. 2   a - 3  depict a worn railroad rail  20  to be recycled in the rail recycling process  10 . However, use of the railroad rail  20  is for sake of example only and various other types of whole rail are contemplated for use with the rail recycling process  10 .  
         [0023]     The railroad rail  20  is of conventional design, and as such, includes a lower portion  22 , an upper portion  24 , and a web portion  26  linking the lower and upper portions. In one embodiment, and with specific reference to  FIG. 2   a,  the rail  20  includes at least one hole  27  formed laterally through the web portion  26 . Such holes are common in railroad rail as they facilitate mounting of the rail  20  during formation of a track for a railroad, and thus there are typically a plurality of such holes adjacent each end of a rail, as shown in  FIG. 2   a.  As an example, the hole  27  and the like corresponding holes may receive a clamping element  28  to connect the rail  20  with an adjacent rail  29 .  
         [0024]     Referring back to  FIG. 1 , the rail  20  is first inserted into a furnace in which the rail is heated to facilitate deforming of the rail. In one embodiment, the rail  20  is heated to a plastic state. The rail  20  is then discharged from the furnace and enters a first reduction pass entry guiding system, which aligns and centers the rail for entry into a first reduction pass.  
         [0025]     It is understood that the term “entry guiding system” (hereinafter “EGS”) is a term of art in the industry, which generally defines an entry system having conventional guiding components such as entry guides and guide boxes for delivering rail to a reduction pass used in rolling operations. Furthermore, it is understood that the term “reduction pass” is also a term of art in the industry, which generally defines conventional deformation components such as a pair of cast iron cylinders, or rolls, which rotate in opposite directions to deform rail. Since the components of the entry guiding system and the reduction pass are conventional, they are not shown, nor will they be described, in detail.  
         [0026]     Referring to  FIG. 4 , deformation and slitting of the rail  20  takes place in the first reduction pass such that the rail is separated into two pieces—a head  30  (comprising the upper portion  24  and partial web portion  26  of the rail in  FIG. 3 ) and a flange  32  (comprising the lower portion  22  and partial web portion  26  of the rail in  FIG. 3 ). In one embodiment, and with additional reference to  FIG. 2   b,  slitting of the rail  20  takes place across the hole  27  and any like corresponding holes and is accomplished via a single set of slitting knives (not shown) associated with the first reduction pass. Slitting across the hole  27  is advantageous as it creates a partial hole P in each of the head  30  and the flange  32 , which reduces the probability of forming structurally deficient seams in the head and the flange as will be described. The term “partial hole” is a general term, which describes the result of splitting the hole  27 , and is therefore not limited to any specific size or orientation.  
         [0027]     Referring again to  FIG. 1 , in one embodiment, the rail  20  exits the first reduction pass still intact and enters a first reduction pass delivery guiding system where the head  30  is separated from the flange  32 . It is understood that the term “delivery guiding system” (hereinafter “DGS”) is a term of art in the industry, which generally defines a delivery system having conventional delivery components such as delivery guides and guide boxes to extract rail from a reduction pass and deliver it to the next element of the mill pass line. Since the components of the delivery guiding system are conventional, they are not shown, nor will they be described, in detail.  
         [0028]     The head  30  and the flange  32  then enter a pinch roll EGS while simultaneously remaining in the first reduction pass DGS. The pinch roll EGS delivers the head  30  and the flange  32  to a pair of pinch rolls, which generally apply pressure to the head  30  and the flange  32  such that the head and the flange are pulled in a direction away from the first reduction pass, thereby removing the head and the flange from the first reduction pass DGS. The head  30  and the flange  32  then exit the pinch rolls and enter a pinch roll DGS for aligning the head and flange onto a conveyor line (not shown).  
         [0029]     The conveyor line delivers the head  30  and the flange  32  to separate second reduction pass EGSs. While on the conveyor line, the head  30  and the flange  32  may be rotated substantially 90° for insertion into the head second reduction pass EGS and flange second reduction pass EGS, respectively. In one embodiment, the rotation of the head  30  and the flange  32  is accomplished via a plurality of conveyor rollers (not shown), which rotate the head and the flange in stages, such as can be accomplished via usage of a “turn up” conveyor line. It is understood that in no-twist mills, no rotation is necessary. Upon entry into their respective second reduction pass EGSs, the head  30  and the flange  32  are guided, in turn, into a second reduction pass.  
         [0030]     The flange  32  then enters the second reduction pass in which further deformation of the flange takes place. In particular and referring to  FIG. 5   a,  the web portion  26  of the flange  32  is edged back into the lower portion  22  such that the flange  32  begins to take a generally uniform shape. The flange  32  then exits the second reduction pass and enters a flange second reduction pass DGS where it is held from further advancement via a stop (not shown).  
         [0031]     Upon exiting of the flange  32  from the second reduction pass, the head  30  enters the second reduction pass. In particular and referring to  FIG. 5   b,  the web portion  26  of the head  30  is edged back into the upper portion  24  such that the head  30  begins to take a generally uniform shape. The head  30  then exits the second reduction pass and enters a head second reduction pass DGS.  
         [0032]     At this point, the flange  32  remains in the flange second reduction pass DGS via the stop, and the head  30  proceeds to enter a head third reduction pass EGS, which aligns the head for entry into a third reduction pass. Referring to  FIG. 6   b,  the third reduction pass deforms the head  30  to further the process of deforming the head into a generally uniform shape. The head  30  then exits the third reduction pass and enters a head third reduction pass DGS ( FIG. 1 ).  
         [0033]     Upon exiting of the head  30  from the third reduction pass, the flange  32  enters a flange third reduction pass EGS, which aligns the flange for entry into the third reduction pass. Referring to  FIG. 6   a,  the third reduction pass deforms the flange  32  to further the process of deforming the flange into a generally uniform shape. The flange  32  then exits the third reduction pass and enters a flange third reduction pass DGS ( FIG. 1 ).  
         [0034]     Simultaneously with the deformation of the flange  32  in the third reduction pass, the head  30  enters a fourth reduction pass EGS, which aligns the head for entry into a fourth reduction pass. Referring to  FIG. 7   b,  upon entry into the fourth reduction pass, the head  30  is again deformed to further the process of deforming the head into a generally uniform shape. The head then exits the fourth reduction pass and enters a fourth reduction pass DGS ( FIG. 1 ).  
         [0035]     Upon exiting of the head  30  from the fourth reduction pass, the flange  32  enters a flange fourth reduction pass EGS, which aligns the flange for entry into the fourth reduction pass. Referring to  FIG. 7   a,  the fourth reduction pass deforms the flange  32  to further the process of deforming the flange into a generally uniform shape. The flange  32  then exits the fourth reduction pass and enters a flange fourth reduction pass DGS ( FIG. 1 ).  
         [0036]     As illustrated in  FIGS. 7   a  and  7   b,  upon exiting the fourth reduction pass, the head  30  and the flange  32  have substantially the same generally uniform shape. Additionally, the head  30  and the flange  32  have a reduced cross-sectional area relative to the cross-sectional area of the head and the flange prior to undergoing the above-described deformation process. The head  30  and the flange  32  may then be rolled into a variety of desired finished products by passing through additional reduction passes and associated EGSs and DGSs.  
         [0037]     The benefits of the above-described process are multifold. First, by slitting the rail  20  along the web  26 , two pieces of the rail—the head  30  and the flange  32 —require deforming rather than three pieces of rail as results from conventional multi-slitting processes that require separating the lower portion, the upper portion, and the web portion. By only having to deform two pieces of the rail  20 , the above-described process  10  enjoys the advantage of requiring only one mill pass line for recycling of the rail. Thus, the rail recycling process  10  reduces the amount of equipment and number of employees needed to recycle rail.  
         [0038]     Furthermore, slitting of the rail along the web  26  is advantageous in recycling the rail  20  into a structurally-sound, substantially seam-free finished product. By slitting the rail  20  across the hole  27  formed through the web portion  26 , the formation of structurally deficient seams is effectively avoided. Moreover, the portion of the rail  20  containing the hole  27  no longer needs to be scrapped. Thus, the above-described process increases the amount of rail that can be recycled, which reduces the amount of waste otherwise associated with the recycling of rail.  
         [0039]     Although only a few exemplary embodiments of this disclosure have been described in detail above, those skilled in the art will readily appreciate that many other modifications are possible without materially departing from the novel teachings and advantages of the disclosure. For instance, the sequence in which the head  30  and the flange  32  pass through the reduction passes may vary. Furthermore, the number of reduction passes is variable depending on the desired amount of deformation and the desired finished product.  
         [0040]     Moreover, the specific arrangement and structure of the EGSs, reduction passes, and DGSs is not critical to the above-described process. For example, although the reduction passes were described as a pair of rolls, the reduction passes may alternatively employ presses for deforming of the rail  20 . Thus, the EGSs, reduction passes, and DGSs may be arranged in any manner and may include any structure that provides for deforming of the rail  20  in a single mill pass line.  
         [0041]     Furthermore, use of the pinch rolls are optional and it is contemplated that the rail  20  may be recycled according to the present disclosure without such pinch rolls. Still further, transportation of the rail  20  through the mill pass line depicted in  FIG. 1  is not limited to a specific arrangement. Moreover, the above-described process can be used in a no-twist mill without departing from the spirit of the disclosure. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.