GB1048622A - Improvements in heat-exchangers - Google Patents

Abstract

1,048,622. Concentric tube heat-exchangers; hot water boilers. P. LECLERCQ. May 10, 1963 [May 11, 1962; Feb. 25, 1963], No. 18530/63. Headings F4A and F4S. A heat-exchanger comprises a plurality of coaxial cylinders O, adjacent pairs of which enclose annular spaces 1-11, at either end of which are fluid-distribution chambers each divided into first and second chambers containing inlet and outlet ports, such that a heating fluid flows through alternate annular spaces and a fluid to be heated flows through the other spaces. In the embodiment shown in Fig. 1, the cylinders O engage with circular grooves 12 provided in two perforate plates 13 and 14. Externally of these plates are cylinders 15, 16 which similarly engage the plates 13, 14 and also endplates 17, 18; the lower part of the latter containing fluid inlets 19, 20 and the upper part, fluid outlets 21, 22. Opposite the inlets 19, 20 are fixed deflectors 45, 46 on the partitions 13, 14 respectively. The spaces between the plates 13 and 17, and 14 and 18 constitute the distribution chambers. The cylinders 15, 16 are circumferentially interrupted, alternate annular spaces being blocked from the inlet 19 and outlet 21; and the other annular spaces being blocked from the inlet 20 and the outlet 22 by radial partitions 23, 24 (Fig. 2, not shown). The annular spaces contain helical dividers 49, 50. The cylinders 0 have annular rings 60 welded to them (Fig. 4, not shown) which provide a seating for packings 61 between these rings and ridges 13a on the plate 13. Sealing is similarly effected with the plate 14 and between the cylinders 15, 16 and plates 13, 17 and 14, 18, respectively. The end plates are constrained towards one another by means of a tie-rod 36 and nuts 37, 38, 39. A frusto-conical cap 106 may be placed between the end plates and the outer nut (Fig. 3, not shown). The invention may be used as a vertical boiler (Fig. 5, not shown). The burner is positioned at the top of the central cylinder down which the combustion gases pass to a smoke box 204, lined with refractory material or water-jacketed, from which gases are deflected upwards through alternate spaces. The water inlet being at the lower end of the boiler, both the water and the exhaust gas outlets are positioned in the upper distribution chamber. The single connecting rod is replaced in this embodiment by four rods passing through the innermost annular space through which water flows. In another embodiment (Fig. 6, not shown) the longitudinal dimension of the coaxial cylinders increases towards the axis of the heat-exchanger, the ends of the cylinders abutting on to a frusto-conical shaped plate 63 comprising rings 64-68 which contain vents 71-75 respectively. The vents provide passages for the fluids between the inlets and outlets and the annular spaces, adjacent vents being offset 180 degrees on opposite sides of two radial partitions 76-77 (Fig. 8, not shown). Sealing between the cylinders and the frusto-conical plate 63 is effected in similar manner to that described above.