GB245562A - Improvements in water tube boilers - Google Patents

Abstract

245,562. Burkhardt, G. Nov. 26, 1924. Water-tube boilers.-In a water-tube boiler, an upper drum is connected to a lower drum by a number of curved tubes some of which lie in planes inclined to the others, so that the hot gases flow lengthwise along the tubes and the streams are caused to intersect. The banks of tubes 3, 4, Fig. 1, connecting the drums 1, 2 are bent in circular arcs which intersect at points 5, 6, 7. 8, so that the tubes can be inserted through holes at these points. The tubes in each bank are in two series, a, b, Fig. 2, the planes of which are inclined on opposite sides of a plane at right angles to the two drums. The hot gases flowing longitudinally through each bank of tubes are thus divided into streams which are caused to intersect twice. The main deflection of the gases is produced by plates 17<1>. The tubes may alternatively be of S or zig-zag shape, so that a number of crossings of the streams of gases are obtained. In a modification. Fig. 5, the lower drum may be replaced by a header 24, preferably of circular cross-section. The diameter of the descending tubes may be less than that of the ascending tubes, or the number of tubes may be less. In another modification. there may be two upper drums and two pairs of intersecting banks of tubes, so that the weakening of each drum by the tube holes is decreased. In another modification, Fig. 7, upper and lower headers 23, 24, may be employed instead of drums, and an upper drum 28 outside the setting mav be connected by tubes 25, 26, 27 to the upper header, for the upward passage of steam, while smaller tubes 29 are provided for the passage of water. The upper headers may be provided with semi-circular troughs 39, Fig. 13, to convey the water across from the tubes 38 without interference from the rising steam bubbles. The headers 23, 24, Fig. 7, are protected from the hot gases by shields 32, 33.