GB748047A - Vapour generating apparatus - Google Patents

Abstract

748,047. Vertical steam boilers ; heating boilers by hot gases or liquids. ILUNE, G. Nov. 24, 1953, No. 32632/53. Class 123(2). A steam generator which is heated by a heat transfer fluid circulating between the generator and a separate heating means comprises an outer bell-shaped casing 20 to the lower end of which is bolted a cylindrical skirt 17, the skirt being closed at its underside by a removable plate 15 to form a chamber 11 which is separated from the interior of the bell by a plate 10. A vertical, axially-mounted duct 1, sealed at its upper end by a dome plate 3, extends through plates 15, 10 to within a short distance of the top of bell 20, the top portion of the duct having apertures 8 from which a triple ring of tubes 9 extend downwardly to pass through plate 10 and open into chamber 11. Surrounding the tubes 9 is an inner bell 27 which is mounted for limited vertical movement as determined by stops 28, 36 at the top thereof. The inner bell has a ring of apertures 34 therethrough at a level immediately below the lowest working level of the generator, a gap 29 being left between plate 10 and the edge of the bell at its lowermost position. In operation, the heat transfer fluid flows upwardly through duct 1 then downwardly through tubes 9 into chamber 11 whence it is withdrawn for recirculation to the heater through ducts 13, 14. Feed water is supplied through a pipe 25 to the interior of bell 27 to maintain the normal working level of the generator. Steam liberated on the tubes 9 rises inside the bell 27 and causes an internal circulation of water which passes through apertures 34, downwardly in space 31 between the bells and returns into bell 27 through the gap 29. The steam collecting in the top of the bell 27 passes down through and is heated in tubes 4 mounted in duct 1, the tubes 4 discharging into an outlet chamber 5 whence the steam is withdrawn to its point of use.