Friction stir welding of tube-to-tubesheets for thermoplastic shell and tube heat exchangers

Recently, there is a real demand for thermoplastic shell-and-tube heat exchangers because of their antifouling and chemically inert properties. A novel non-conventional joining technique is developed for creating efficient thermoplastic tube-to-tubesheet joints (TTJs) using the friction stir welding (FSW) process. The carbon black reinforced high-density polyethylene sheet and tube materials are used. A highly ductile joint with a maximum strength of 517 N (42 % greater than adhesives), and a maximum leak path of 3 mm (77 % of remaining tubesheet thickness) was achieved using FSW. The proposed technique was found promising and reliable for developing TTJs for thermoplastic shell-and-tube heat exchangers.