GB914048A - Improvements in water tube boilers for nuclear power plants - Google Patents

Abstract

914,048. Water-tube steam boilers. HUET, A. March 31, 1959 [May 5, 1958], No. 10850/59. Class 123 (2). In a water-tube steam boiler the steam generating section comprises three coils 17... 19 of helical tubes which form three cylinders coaxial with a casing a traversed in a downward direction by heating fluid and which increase in crosssectional area from the inner coil 17 to the outer coil 19, each cylinder comprising several, e.g. four, as shown, series of four helical tubes connected in parallel between corresponding upper and lower rings of symmetricallyarranged headers. The lower and upper headers such as 11-13 and 14- 16 are connected respectively to the cylindrical tubes 1, 2, 3 of the economizer and, by tantially arranged tubes, to a central steam and water drum 20 having a separator S<SP>1</SP> and an axial down-pipe 21 leading, at its lower end, to radially extending pipes 23 fitted into the lower headers. Each pipe 23 extends into each header of a corresponding set of headers 11-13, as shown in Fig. 3, and has outlets 24 flanked by deflectors 25 at levels corresponding to the inlets 3 from the economizer. The windings, which are the same for each cylinder, can vary in pitch and direction from one cylinder to another and can also be opposite to those adapted for the economizer tubes, moreover the spacings between the cylinders can vary from one to the next. The tubes in each cylinder may be contiguous or variously spaced, finned or smooth, and have various shapes such as e.g. lenticular. Specifications 822,417 and 823,904 are referred to.