Modular Shell-and-Tube Heat Exchanger Apparatuses and Molds and Methods for Forming Such Apparatuses

Abstract

Modular tubing apparatuses for use in a shell-and-tube heat exchanger are described. Multiple apparatuses may be connected in series to form a high density, small tube diameter, long length tube apparatus assembly. Casting molds for forming modular tubing apparatuses are likewise described, including methods for casting such apparatuses.

What is claimed is: 
     
         1 . A modular tube apparatus for a heat exchanger, the apparatus comprising:
 a connecting plate;   a plurality of tubes extending from a bottom surface of the connecting plate, wherein each tube of the plurality of tubes comprises a distal open end and a hollow portion extending from the distal open end to the connecting plate;   a plurality of receiving cups, wherein each receiving cup of the plurality of receiving cups is recessed into a top surface of the connecting plate to a depth partially through the connecting plate and disposed opposite a respective tube of the plurality of tubes, and wherein each receiving cup of the plurality of receiving cups defines an internal contour that conforms to an outer contour of the distal open end of the respective tube of the plurality of tubes;   a first plurality of fluid paths inside the connecting plate, wherein each fluid path of the first plurality of fluid paths extends from each receiving cup of the plurality of receiving cups to the hollow portion of each respective tube of the plurality of tubes; and   a second plurality of fluid paths through the connecting plate, wherein each fluid path of the second plurality of fluid paths extends from the top surface of the connecting plate to the bottom surface of the connecting plate.   
     
     
         2 . The apparatus of  claim 1 , wherein the apparatus is formed as a unitary body. 
     
     
         3 . The apparatus of  claim 2 , wherein the unitary body comprises a cast material. 
     
     
         4 . The apparatus of  claim 3 , wherein the cast material comprises a metal. 
     
     
         5 . The apparatus of  claim 1 , wherein each tube of the plurality of tubes is substantially cylindrical. 
     
     
         6 . The apparatus of  claim 1 , wherein proximate to each receiving cup of the plurality of receiving cups, the connecting plate is thicker than the depth of the respective receiving cup. 
     
     
         7 . The apparatus of  claim 1 , wherein a surface of the internal contour of each receiving cup of the plurality of receiving cups is configured to form a fluid seal with a surface of the outer contour of the distal open end of the respective tube of the plurality of tubes. 
     
     
         8 . The apparatus of  claim 7 , wherein the fluid seal is formed with a brazing material. 
     
     
         9 . The apparatus of  claim 7 , wherein the internal contour is substantially cylindrical, wherein the surface of the internal contour is an internal circumferential surface, wherein the outer contour is substantially cylindrical, wherein the surface of the outer contour is an outer circumferential surface, and wherein the internal circumferential surface is configured to form a fluid seal with the outer circumferential surface. 
     
     
         10 . The apparatus of  1 , wherein a ratio of a length of each tube of the plurality of tubes to an outside width of the distal open end of each tube of the plurality tubes is at least 50:1. 
     
     
         11 . The apparatus of  1 , wherein a ratio of a length of each tube of the plurality of tubes to an outside width of the distal open end of each tube of the plurality tubes is at least 100:1. 
     
     
         12 . The apparatus of  claim 1 , wherein each tube of the plurality of tubes is parallel to each other tube of the plurality of tubes. 
     
     
         13 . The apparatus of  claim 1  further comprising a fillet at the interface between each tube of the plurality of tubes and the bottom surface of the connecting plate. 
     
     
         14 . The apparatus of  claim 1  further comprising a chamfer at the interface between each tube of the plurality of tubes and the bottom surface of the connecting plate. 
     
     
         15 . A mold assembly comprising:
 a bottom mold portion comprising:
 a bottom block comprising a top surface, and 
 a plurality of cavities in the bottom block extending downwardly from the top surface to a first depth; 
   a top mold portion comprising:
 a top plate positioned opposite and at a first distance from the top surface of the bottom block, 
 a first plurality of protrusions extending downwardly from the top plate to a length less than the first distance, wherein each protrusion of the first plurality of protrusions is disposed opposite a respective cavity of the plurality of cavities, and wherein each protrusion of the first plurality of protrusions defines an outer contour that conforms to an internal contour at a base of the respective cavity, 
 a plurality of cores extending downwardly from each protrusion of the first plurality of protrusions, wherein each core of the plurality of cores is disposed within and extends to the first depth of the respective cavity of the plurality of cavities, and 
 a second plurality of protrusions extending downwardly from the top plate, wherein each protrusion of the second plurality of protrusions forms a seal at the top surface of the bottom block; and 
   a middle mold portion comprising a wall that forms a seal between the top plate and the bottom block around the periphery of a void space between the top plate and the bottom block.   
     
     
         16 . The mold assembly of  claim 15 , wherein each cavity of the plurality of cavities comprises a locating receptacle at the first depth, wherein each respective core of the plurality of cores comprises a locating pin at a bottom end of the core; wherein each locating receptacle and each respective locating pin are configured to register the bottom end of each core of the plurality of cores at a fixed position within the respective cavity. 
     
     
         17 . The mold assembly of  claim 16 , wherein the locating receptacle comprises a cone, and wherein the locating pin comprises a cone. 
     
     
         18 . The mold assembly of  claim 15 , wherein each cavity of the plurality of cavities is substantially cylindrical. 
     
     
         19 . The mold assembly of  claim 15 , wherein each core of the plurality of cores is substantially cylindrical. 
     
     
         20 . The mold assembly of  claim 15 , wherein each core of the plurality of cores is parallel to each other core of the plurality of cores. 
     
     
         21 . The mold assembly of  claim 15 , wherein each cavity of the plurality of cavities in the bottom block comprises a chamfer at the top surface of the bottom block. 
     
     
         22 . The mold assembly of  claim 15 , wherein each cavity of the plurality of cavities in the bottom block comprises a convex fillet at the top surface of the bottom block. 
     
     
         23 . The mold assembly of  claim 15 , wherein a ratio of the first depth to a bottom width of each cavity of the plurality of cavities in the bottom block is at least 50:1. 
     
     
         24 . The mold assembly of  claim 15 , wherein a ratio of the first depth to a bottom width of each cavity of the plurality of cavities in the bottom block is at least 100:1 
     
     
         25 . The mold assembly of  claim 15 , wherein the middle mold portion is integral with the top mold portion. 
     
     
         26 . The mold assembly of  claim 15 , wherein the middle mold portion is integral with the bottom mold portion. 
     
     
         27 . A method of forming a modular tube apparatus comprising the steps of:
 providing a bottom mold portion, wherein the bottom mold portion comprises: a bottom block comprising a top surface, and a plurality of cavities in the bottom block extending downwardly from the top surface to a first depth;   providing a top mold portion, wherein the top mold portion comprises: a top plate positioned opposite and at a first distance from the top surface of the bottom block, a first plurality of protrusions extending downwardly from the top plate to a length less than the first distance, wherein each protrusion of the first plurality of protrusions is disposed opposite a respective cavity of the plurality of cavities, and wherein each protrusion of the first plurality of protrusions defines an outer contour that conforms to an internal contour at a base of the respective cavity, a plurality of cores extending downwardly from each protrusion of the first plurality of protrusions, wherein each core of the plurality of cores is disposed within and extends to the first depth of the respective cavity of the plurality of cavities, and a second plurality of protrusions extending downwardly from the top plate, wherein each protrusion of the second plurality of protrusions forms a seal at the top surface of the bottom block;   providing a middle mold portion, wherein the middle mold portion comprises: a wall that forms a seal between the top plate and the bottom block around the periphery of a void space between the top plate and the bottom block;   
       coupling the top mold portion, the middle mold portion, and the bottom mold portion to form a mold chamber;
 infiltrating the mold chamber with a molten material; and 
 decoupling and removing the top mold portion.