GB1231052A - - Google Patents

Abstract

1,231,052. Making tube banks; coiling helices. BABCOCK & WILCOX Ltd. 23 May, 1969 [24 May, 1968], No. 24998/68. Headings B3A and B3E. Apparatus for forming a coiled tube bank in which a cylindrical core 10 together with end flanges 12 are positioned between a headstock 2 and tailstock 4. A first layer of spacer bars 16 is secured to the flanges 12 and held in rigid abutment with the core 10 with steel strapping. A hoop 48 is welded to the spacer bars at the end intended to form the inlet of the bank, from which end coiling is started, and a split bush 50 bolted to the hoop. For a two-start initial tube layer the ends of two straight tubes are connected to split bushes 50 and positioned between a pair of guide rolls 22 and 24. Back-up shoes 44 are positioned with steel strapping between the spacer bars 16 and core 10. The core is then rotated so as to wind the tubes on to the spacer bars whilst at the same time retarding the pressure roller 24 to a speed appropriate to the coiling diameter, to overcome the effect of spring-back forces, and traversing the guide rollers to give the required pitch. As the coil forms along the core 10, the steel stripping is removed and the back-up shoes moved along the core. When the end of a tube is reached the machine is stopped, one of the tubes clamped to a spacer bar, and if a tube bend is required the location of the bend is marked and coiling continued for about 15 cms. beyond the mark. The tube is then cut and the procedure repeated for the other tube after which the tubes are bent 90 degrees to produce axially extending tube tails. The next layer of spacer bars 16 are then bolted to the end flanges and held in position of the initial layer using steel strapping and the procedure repeated. If it is required to have equal lengths of tube in each pass, the number of tubes in each layer are increased progressively.