Fuente: WIPO "rice" 21,704. Rice, B. W., and McFarlin, F. J. Oct. 30. Water-tube boilers.-One or more circles of vertical tubes, or "circulating mediums or manifolds" surround a central "standpipe or drum" the upper part of which forms a steam drum, each tube being connected at top and bottom to the drum by radial connecting-tubes. In the arrangement shown in Figs. 1 and 2, each circle of vertical tubes 2 is arranged as a continuous serpentine, and the radial connecting-tubes 6 and 7, Fig. 2, are connected to the U-shaped connecting-pieces 3, 3. Water is introduced at 4, and steam is led away at 5. Figs. 5 and 6 show a modified arrangement, in which each circle of tubes 2 is connected to annular chambers or "unifying conveyers" 9, 10, which are connected to the central stand-pipe by radial tubes 6, 7. Such a boiler is arranged vertically in a furnace setting as shown in Fig. 1.