Patent GB-236322-A (GB)
Title: Improvements in and relating to steam generators
IPC: F22B17/10
Filed: 1924-04-25
Abstract: 236,322. Hawley, C. G. April 25, 1924. Water-tube boilers.-A watertube boiler comprises a vertically extended bank of inclined flame dividing and radiant heat absorbing tubes of minor exten,t, in which the tubes in the same horizontal rows are widely spaced, and two or more vertical rows of which terminate in a common header carrying above these tubes a vertically and horizontally extended bank of closely spaced convected heat absorbing tubes of major extent, all the vertical rows of tubes being parallel and placed in communication by wall formmg headers. Four interconnected units are placed over the grate, each unit comprising front and rear headers 3, 4, Figs. 1 and 2, a large upper group of convected heat absorbing tubes 5 and two or more widely spaced rows of radiant heat absorbing tubes 6 forming flame passages 16. The front header may have a partition about a third of the height from the top, and the whole boiler may be set with the tubes at a slight angle to the horizontal. The headers have corner top and bottom brackets for the attachment to the walls. The steam drum 2 and mud-drum 9 are connected in common to the four units, the drum 2 being provided with baffle plates 2<11>. The brick side walls are covered by metal plates, and the spaces 17 between the sets of upper tubes are provided with rows of baffles 18. The upper rows of tubes may be replaced by a large drum-like tube,. At the sides, angle beams are attached to the front and rear headers and rest in the brickwork. Vertical or horizontal baffles may be employed between the tubes. In a modification, the front header 32<1>, Fig. 15, is bent, and the rear header is in two parts 37, 38 connected by tubes 39 whereby the upper bank of tubes 34<1> is horizontal and a superheater unit 40 is placed in the space between the two banks. The front header may be in two parts instead of one bent member, and the top bank may be slightly inclined to the horizontal but to a lesser extent than the lower bank. The arrangement can be modified to include an inclined front header 50. Fig. 23, and two-part vertical rear header 51, tubes being curved, or straight with curved ends. the lower bank 53 being on a greater angle than the upper bank 52. The units are wider and two only are used over each grate, the headers being connected by curved tubes 54. A number of thimbles 59 are placed between the parts of the rear header and carry the loops of the superheater. The headers are supported on girders 60, 60<1>. The generator may be constructed with vertical headers 61, 62, Fig. 45, each unit carrying a longitudinal steam drum 65 which is coupled to the adjacent drum by steam and water pipes. The lowest row of tubes 63<11> of the upper bank is bent and placed under a baffle 68, the superheater 81' being accommodated beneath these tubes. The bottom row 63' of the lower bank is also bent under two baffles 66, 66<1>. The front headers are suspended from the beam 74 and the rear header brackets 8<x> rest on beams on the floor 73. The steam pipe 79 passes down the. side of the boiler clear of the tube ends. The protecting walls 83, 84 for the bottoms of the header are supported on boxes 84<1>, 84<11> which supply air to vertical pipes 85, 85<1> enclosed in the walls. The construction may be simplified by omitting the top steam drums. When installed in ships the headers are supported on beams and secured also at the top to deck beams. The outer longitudinal drums are also provided with side downcomers placed in the side walls. By closing the top and fitting a baffle between the banks, it is possible to lead off the gases to the stack from the space between the banks. In place of the flat headers, which are preferably of the kind described in Specification 236,320, circular sectioned headers may be used. Specification 218,492 also is referred to.