GB590603A - Improvements in or relating to waste heat or surplus heat boilers - Google Patents

Abstract

590,603. Water-tube steam boilers. LEWIS, W. Y. July 18, 1944, No. 13716. [Class 123 (ii)] A surplus heat steam boiler comprises a horizontal drum a from the lower surface of which depend a plurality of water tubes, in two banks e, b, between which and around hot gases are caused to flow in a direction parallel to the axis of the drum, from left to right as seen in Fig. 1. The tube bank b, or latent heat section, are single closed-end or double-legged U-tubes provided with inner feed tubes c leading from a trough or floor q fitted within and extended across the drum, whereas those of the bank e, or sensible heat section, are double-legged tubes in series relationship with the legs of each tube opening into adjacent closed compartments f formed in the drum by transverse segmental plates g. A sloping tray k with side walls n, Fig. 2, is mounted above the compartments f, and a steam and water chamber s, defined by side and end plates t, 11 and a cover u, above the floor q. The arrangement is such that feed water, supplied to the drum at h and led to the extreme right-hand compartment f, passes through said compartments f and tubes e in succession to the other extreme compartment i, from whence it flows through an opening j in the tray k and down the tray for discharge into the drum a proper at m. It then passes to above the floor q and into the tubes c. partly through openings 10 in the side plates 11 of the chamber s, and returns through the tubes b to the space below the floor q where it is directed by a duct r to the chamber s, the cover u of the latter being provided with a steam outlet opening w above the normal water level x. Superheated elements may be fitted at the gas inlet end of the boiler, that is to the left of the first row of tubes b, Fig. 1, and the drum a is preferably provided with blow-down outlets o, z.