GB920836A - Improvements in and relating to tubular heat exchangers - Google Patents

Abstract

920,836. Tubular heat exchangers. HEAD, WRIGHTSON & CO. Ltd. Aug. 30, 1960 [Sept. 4, 1959], No. 30341/59. Class 64 (3). A standard coil unit for a heat exchanger has an inner and outer shell comprising a series of tube lengths which are of circular formation and are arranged concentrically one within the other, each tube length being an incomplete circle so that when arranged with their open ends in alignment provide a gap or gaps extending towards the centre to facilitate access thereto. The heat exchanger may comprise a plurality of such coils superimposed one above the other. The tubes may be plain or finned. In the form shown each coil is formed of four pairs of circular tube lengths 1 to 8 enclosed between a central core 9 and an outer shell 10. The coil is provided with a segmental opening 11 facilitating access to the half-circle reverse bend connections 12 and also to the inlet and outlet connections 13. With the above arrangement the flow path through the coil alternates clockwise and anticlockwise, and a gas path through the heat exchanger is bounded by baffle plates 14, 14<SP>1</SP> between which i.e. on the space 11, there is no gas flow. Baffling around the outer periphery may also be provided as at 15. In Fig. 2, the outer tube 1 is connected to the inner tube 8 by means of reverse bends 16, the tube 2 with the tube 7 and so on to provide a four start coil having four inlet and outlet connections 13. Two segmental openings 11 can also be provided. In another embodiment (Fig. 3, not shown) pipe connections extend across the segmental opening 11. Another embodiment (Fig. 4, not shown) has the pipes 5 to 8 on one side of the opening 11 connected to the tubes 4 to 7 on the other side. Other forms of coil providing multiple flow paths are described.