GB706729A - Improvements in tubulous vapour generating and superheating units - Google Patents

Abstract

706,729. Water-tube steam boilers; attemperating. BABCOCK & WILCOX, Ltd. Nov. 7, 1951 [Nov. 10, 1950], No. 26061/51. Classes 123(2) and 123(3) A steam boiler comprises a combustion chamber 50 which is lined with steamgenerating wall tubes 51a, 52a, 53a and, at its upper end, opens into a gas pass 79 which extends laterally above an arch 73 projecting from the side 52 of the chamber 50 towards the opposite side 51 and houses - a superheater 93, 94, the arch 73 defining a space 109 which is screened from the combustion chamber and serves to locate an attemperator 103. The attemperator is in the form of a drum 104 which is connected in the circulatory circuit of some of the rear wall tubes 52a whereby water is caused to pass through the drum in contact with two banks of U-tubes 105, one at each end of the drum, through which steam is adapted to flow in its passage from the outlet header 96 of the superheater section 93 to the inlet header 98 of the superheater section 94, a by-pass connection 108, with valve 107, being provided between the superheated steam pipes 102, 106 leading to and from said drum. Fig. 2 shows the rear wall tubes 52a relatively to the drum 104, every fourth one 52b being connected to the bottom thereof: the remaining tubes 52c are extended along the underside of the arch 73, whereupon one tube 52d of every three is further extended upwardly across the entrance of the gas pass 79, and, as regards the other two tubes 52e, one 52f is connected to the said drum and the other 52g continues along the upper side of the arch 73, and then through the rear of the pass 79 to the steam-andwater drum 55, in alignment with tubes 111, 112 which have their lower ends connected to the drum 104 and constitute risers therefrom. The drum 104 is also provided at each end with additional risers 114 arranged in a row in alignment with the corresponding side wall tubes 53a. A modification is described in which the combustion chamber is divided bv a tube wall into two separately-fired sections and the primary superheater section 93 is located in a flue or gas pass 80 parallel with the combustion chamber. Specification 696,047, [Group XII], and U.S.A. Specification 2,633,831 are referred to.