A shell-and-tube heat exchanger with helical baffles

Abstract

A shell-and-tube heat exchanger with helical baffles wherein the shell (1) includes inside an outer continuous helical baffle (8) to support the tubes (4) of the outer bundle of tubes (2), and an integrated inner discontinuous helical baffle (23) to support the tubes (4) of the inner bundle of tubes (22). The outer continuous helical baffle (8) is formed of many main flat segments (11) and many intermediate flat segments (14) or (16). The inner discontinuous helical baffle (23) is formed of flat segments (25). The flat segments (25) with the intermediate flat segments (14) or (16) form together common flat segments (27) or (27A). The heat exchanger according to the present invention solves the problem of optimal continuous helical flow characterized by highly efficient heat transfer.

1 .- 8 . (canceled) 
     
     
         9 . A shell-and-tube heat exchanger comprising:
 a main enclosure with an inlet nozzle, an outlet nozzle, and covers defined on opposing side of the enclosure;   a central pipe defined in an interior of the enclosure;   at least one outer tube passing around the central pipe;   an outer helical baffle defined by flat segments and intermediate segments comprising a continuous helical baffle; and   a second helical baffle defined in the central pipe.   
     
     
         10 . The shell-and-tube heat exchanger of  claim 9  wherein said covers defined on opposing side of the enclosure are tubesheets. 
     
     
         11 . The shell-and-tube heat exchanger of  claim 9  wherein said outer helical baffle comprises:
 multiple main flat segments, each segment having a shape of an isosceles triangle whose base comprises a convex arc and facing an inner surface of the heat exchanger and an apex of the triangle is located on a circle of a diameter equal to an outside diameter of the central pipe; and 
 multiple intermediate flat segments in shape of an isosceles triangle whose base has shape of a concave arc facing an X-X axis of the heat exchanger; 
 wherein said main flat segments and intermediate flat segments alternately adjoin each other along length of their legs and are arranged in relation to each other at an alternating angle a lesser than 180 degrees. 
 
     
     
         12 . The shell-and-tube heat exchanger of  claim 11  wherein said outer helical baffle further comprises:
 multiple common flat segments, where each the flat segment of an inner discontinuous helical baffle has an area larger than an area of a flat geometric figure similar to an isosceles triangle whose base has a shape of a convex arc congruent with the concave arc of the intermediate flat segment of the shape of an isosceles triangle or with the concave arc of the intermediate flat segment of the shape of an isosceles trapezium whereas an apex of this triangle is on the X-X axis of the heat exchanger, and where a projection of said geometric figure on a plane perpendicular to the X-X axis corresponds to ¼ or ⅙ of cross-sectional area of a central flow contained in a circle of a diameter equal to the diameter of the central flow. 
 
     
     
         13 . The shell-and-tube heat exchanger of  claim 9  wherein said outer helical baffle comprises:
 multiple main flat segments, each segment having a shape of an isosceles triangle whose base comprises a convex arc and facing an inner surface of the heat exchanger and an apex of the triangle is located on a circle of a diameter equal to an outside diameter of the central pipe; 
 multiple intermediate flat segments in shape of an isosceles trapezium whose one base has the shape of a convex arc facing an inner surface of the heat exchanger and other base has shape of a concave arc facing a X-X axis of the heat exchanger; 
 wherein the main flat segments together with the intermediate flat segments in the shape of an isosceles trapezium alternately adjoin each other along length of their legs and are arranged in relation to each other at an alternating angle a lesser than 180 degrees; and 
 at every other main flat segment or every other intermediate flat segment of the shape of an isosceles trapezium are mutually parallel, while the intermediate flat segments are positioned at an angle b lesser than 90 degrees in relation to the X-X axis of the heat exchanger, whereas an inner discontinuous helical baffle is formed of many flat segments whose one side has the shape of a convex arc congruent with the concave arc of the intermediate flat segment of the shape of a concave arc of the intermediate flat segment in the shape of an isosceles trapezium, and which form together with the intermediate flat segments of the outer continuous helical baffle. 
 
     
     
         14 . The shell-and-tube heat exchanger of  claim 11  wherein said outer helical baffle further comprises:
 multiple common flat segments, where each the flat segment of an inner discontinuous helical baffle has an area larger than an area of a flat geometric figure similar to an isosceles triangle whose base has a shape of a convex arc congruent with the concave arc of the intermediate flat segment of the shape of an isosceles triangle or with the concave arc of the intermediate flat segment of the shape of an isosceles trapezium whereas an apex of this triangle is on the X-X axis of the heat exchanger, and where a projection of said geometric figure on a plane perpendicular to the X-X axis corresponds to ¼ or ⅙ of cross-sectional area of a central flow contained in a circle of a diameter equal to the diameter of the central flow. 
 
     
     
         15 . The heat exchanger of  claim 11  wherein said flat segments of an inner discontinuous helical baffle have an area F larger than an area S of a flat geometric figure in order to accommodate all tube holes located within the flat geometric figure and at least all complete boundary tube holes located at an edge of the flat geometric figure and arranged in accordance with layout of an inner bundle of tubes. 
     
     
         16 . The shell-and-tube heat exchanger according to  claim 11  wherein:
 the main flat segments together with the intermediate flat segments form couples of segments, which consecutively repeated n-fold form one full pitch P of the outer continuous helical baffle along the X-X axis of the heat exchanger, where n=4 or 6. 
 
     
     
         17 . The shell-and-tube heat exchanger according to  claim 11  wherein:
 the main flat segments together with flat segments form couples of segments, which consecutively repeated n-fold form one full pitch P of the outer continuous helical baffle integrated with an inner discontinuous helical baffle, where n=4 or 6. 
 
     
     
         18 . The shell-and-tube heat exchanger according to  claim 13  wherein:
 the angle b ranges from 30° to 75°, whereas the angle α is within the range from 120° to 170°. 
 
     
     
         19 . The shell-and-tube heat exchanger according to  claim 11  wherein:
 each couple of the flat segments is cut out from a single plate sheet and bent at the a angle along the legs of the main flat segments. 
 
     
     
         20 . The shell-and-tube heat exchanger according to  claim 13  wherein:
 the convex arcs of the intermediate flat segments in the shape of an isosceles trapezium, where these segments are located at the b angle in relation to the X-X axis of the heat exchanger, as well as the convex arcs of the main flat segments are fragments of an ellipse and all these arcs in a projection on a plane perpendicular to the X-X axis form a circle of a diameter lesser by 2 to 20 mm than an inside diameter of the enclosure, and concurrently the concave arcs of the intermediate flat segments of the shape of an isosceles triangle or the concave arcs of the intermediate flat segments of the shape of an isosceles trapezium are fragments of such an ellipse which in a projection on a plane perpendicular to the X-X axis creates a circle of a diameter equal to the outside diameter of the central pipe or the diameter of a central flow.