Petrochemical cracker

Abstract

The invention relates to a petrochemical cracker having piping comprising a portion wherein the centerline of the portion follows a substantially helical path, wherein the amplitude of the helix is less than or equal to one half of the internal diameter of the piping. When fluid flows in such piping, it is made to swirl. This provides a number of advantages, such as improved in-plane mixing of the fluid, enhanced uniformity of residence time, and so on.

1 . A petrochemical cracker comprising a cracking furnace, a quench tower, a cracked gas compressor, and a helical piping portion for fluid flow therealong, the helical piping portion having an internal diameter (D 1 ) and a centerline ( 40 ) which follows a substantially helical path, the helical centerline having an amplitude (A) and a helix angle, wherein the amplitude of the helical centerline ( 40 ) is less than or equal to one half of the internal diameter of the helical piping portion so as to provide a line of sight along the lumen of the piping portion. 
     
     
         2 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion has a plurality of turns of the helix. 
     
     
         3 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion has a varying amplitude and/or a varying helix angle along its length. 
     
     
         4 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion has substantially the same amplitude and helix angle along its length. 
     
     
         5 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion extends along the entire length of the piping. 
     
     
         6 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion only extends along part of the piping. 
     
     
         7 . A petrochemical cracker as claimed in  claim 1 , wherein the axis ( 30 ) of helical rotation is a straight line. 
     
     
         8 . A petrochemical cracker as claimed in  claim 1 , wherein the axis of helical rotation is curved. 
     
     
         9 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion has a substantially circular cross-section. 
     
     
         10 . A petrochemical cracker as claimed in  claim 1 , wherein the amplitude of the helix is less than or equal to 0.4 of the internal diameter (D I ) of the piping portion. 
     
     
         11 . A petrochemical cracker as claimed in  claim 1 , wherein the angle of the helix is less than or equal to 15°. 
     
     
         12 . A petrochemical cracker as claimed in  claim 1 , wherein the piping portion has an inner surface with no grooves or ribs. 
     
     
         13 . A petrochemical cracker comprising a cracking furnace, a quench tower, a cracked gas compressor, and a helical piping portion for fluid flow therealong, the helical piping portion having an internal diameter (D I ) and a centre line ( 40 ) which follows a substantially helical path, the helical centre line having an amplitude (A) and a helix angle, wherein the amplitude of the helical centre line is less than or equal to one half of the internal diameter of the helical piping portion so as to provide a line of sight along the lumen of the piping portion, and wherein the helix angle of the helical centre line is less than or equal to 15°. 
     
     
         14 . A petrochemical cracker comprising a cracking furnace, a quench tower, and a cracked gas compressor, the petrochemical cracker comprising piping having a helical piping portion between the cracking furnace, through the quench tower, to the cracked gas compressor, the helical piping portion having an internal diameter and a centre line which follows a substantially helical path, the helical centre line having an amplitude and a helix angle, wherein the amplitude of the helical centre line is less than or equal to one half of the internal diameter of the helical piping portion so as to provide a line of sight along the lumen of the piping portion.