The Circulation of Water and Steam in Water-Tube Boilers, and the Rational Simplification of Boiler Design

Abstract

The authors stress the need for a sound theory of circulation in water-tube boilers, to enable weight and space to be saved and efficiency and reliability to be increased. They establish, as a standard of excellence with which other boilers may be compared, a simple boiler consisting of a single drum and a single U-tube. The paper consists of three parts. Part I describes the nature of the change from water to steam; in part II the flow in the simple U-tube boiler is calculated; and in part III the features of various departures from the standard U-tube, met with in practice, are discussed. An improved type of tube, approaching very nearly to the standard U-tube, is evolved, allowing much simplification of boiler design, with the advantages of excellent circulation, high gas speeds, and higher heat transmission rates. Other rational simplifications and improvements are also rendered possible, which enable substantial reductions to be made in the cost of manufacturing, installing, and maintaining boilers of any pressure and capacity, for any service, ashore or afloat. The MS. of this paper was received at the Institution on 10th November 1938. The paper was presented for discussion at an Extra General Meeting of the Institution on 1st March 1940.