GB992298A - Vertical marine steam generator with integral superheater - Google Patents

Abstract

992,298. Vertical steam boilers; superheaters. FOSTER WHEELER Ltd. April 24, 1964 [May 1, 1963], No. 17204/63. Addition to 929,682. Heading F4A. The vertical steam boiler described in the parent Specification is modified in that the vertical bundle of U- tubes instead of being connected to a pair of headers or to a tube plate is connected to a single header subdivided into an inlet and an outlet compartment by an internal partition. In the form shown, an upright casing 10 contains within its lower portion a bundle of inverted U- tubes consisting of two outer banks such as 26 between which is located a middle bank 24, the ends of the tubes being connected to a horizontally disposed header 50 divided internally by a partition 52 into a heating medium inlet chamber 54 and outlet chamber 58. A cylindrical baffle 18 surrounds the outer banks to provide an annular downcomer space 20 into which feedwater is directed from a pipe 16 and an inner riser space 22 wherein steam is generated as the ascending water column passes over the outer banks, steam-water mixture flowing into separators 23 whence water returns to the downcomer space whilst steam flows through driers 34 into an upper space 35. The middle tube bundle is enclosed by spaced inner and outer coaxial baffles 38, 30, the lower end of the inner baffle terminating at a distance above the header 50 whilst its upper end is continued as an extension 48 forming a steam outlet pipe. The lower end of the outer baffle 30 is welded to the header 50 whilst its upper end is continued as an extension 42 leading into the steam space 35. Steam from the space 35 flows downwardly in the annular space between baffles 38, 30 and rises in contact with the bundle 24 becoming superheated and discharges to the point of use through the extension pipe 48.