GB918246A - Improvements in or relating to tubulous vapour generators - Google Patents

Abstract

918,246. Vertical steam boilers. BABCOCK & WILCOX Ltd. March 27, 1961 [March 28, 1960], No. 10880/60. Class 123 (2). In a tubulous vapour generator comprising an upright pressure vessel having a cylindrical wall 1, heating fluid, for example the coolant from a liquid-cooled nuclear reactor, enters an inner chamber 10 of circular cross-section through an opening 7 and passes through annularly disposed apertures 13 in a tube plate 9 to a bank 17 of nested tubes of inverted U-shape, the axes of the tubes in each nest lying in upright radial planes, and then via a similar set of apertures 14 to an outer chamber 11 which lies around the inner chamber being separated from it by a wall 12. The fluid discharges from the chamber 11 through an opening 8 for return to the reactor. Liquid, for example feedwater, to be evaporated entering through an aperture 31 passes downwardly in an annular space 23 which lies between the wall of the vessel and a cylindrical baffle 22 enclosing the tube bank. Liquid and vapour mixture rises within the baffle to a cylindrical section 20 and passes through openings 28 to a ring of cyclone separators 24 which discharge liquid below the normal liquid level 25 into the downcomer space 23 and vapour upwardly through the scrubber 29 to a vapour outlet 3. In a modification, Fig. 3 (not shown) the axes of the tubes meet the plate at the points of intersection of an equilateral triangular lattice framework.