GB799274A - Improvements in and relating to steam generators - Google Patents

Abstract

799,274. Water-tube boilers. ROSSI, G. Jan. 24, 1955 [Jan. 26, 1954]. No. 2082/55. Class 123(2) A water-tube boiler comprises a steam and water drum B from the bottom of which extend the downcomer limbs of a number of tube loops A, the loops being arranged in side-by-side relationship and together forming the boundary surface of a combustion chamber equipped with a burner C, the riser limbs of the tubes reentering the drum at about its horizontal diameter. A feed water pipe 2 discharges water downwardly into the downcomer limbs and this, together with the fact that the riser limbs are of greater length than the downcomer limbs and thus receive more heat, ensures a positive water circulation in a predetermined direction as shown by the arrows X as soon as the boiler is started. In a modification, Fig. 10, the drum B is replaced by four interconnected collector headers D<1> from two of which tube loops 12 extend to encircle the combustion chamber E<1> whilst a further series of loops 13 extend from the other headers D' around the loops 12 to form a return pass F<1> around the chamber E<1> for the combustion gases therefrom. In further modifications, the uneven heat absorption rate of the downcomer and riser limbs of the tube loops is achieved by disposing the burners C nearer to the risers, by screening the downcomers with refractory material or by further increasing the heat absorbing surface of the risers by having a single downcomer branching into several riser tubes of smaller diameter or by making the risers of sinuous form.