GB908501A - Improvements in steam generating units - Google Patents

Abstract

908,501. Water-tube steam boilers; reheaters; superheaters. COMBUSTION ENGINEERING Inc. Jan. 29, 1959 [April 11, 1958; April 15, 1958], No. 3267/59. Class 123 (3). In a high-capacity steam-generating unit serially connected low- and high-temperature reheater sections 30, 32 comprising respectively vertical banks of internested tubes 35 and rows of tubular panels 48 which are laterally spaced between the side walls 42, 44 and 50, 52 respectively of a vertical down pass 20 and a furnace chamber 10 of the generator a horizontally arranged outlet header 36 for the lowtemperature reheater section 30 is internally partitioned by a baffle 60 which reverses the steam flow from one side of the unit to the other before it enters an inlet header 38 for the tube banks 48 of the high-temperature reheat section to offset the effect of variation in heat absorption transversely of the combustion stream. The steam to be reheated enters a header 34 and the banks of internested tubes 35 nearest the side walls 42, 44 respectively of the down pass 20 communicate with separate chambers 76, 78 in the header 36. The chambers 76, 78 are formed by tack welding the upper edge and the lower edges of the oppositely bent lower half portions 66, 68 of the baffle 60 to the internal surface of the header 36 and securing intermediate and end sector-shaped plates 70 and 72, 74 to the baffle 60. The chambers 76, 78 communicate respectively with large vertical conduits 47, 46, which are disposed at opposite ends of the header to reverse the flows of steam, and lead to a header 38 for the hightemperature reheater banks 48. Groups of laterally spaced tubes 58 supply steam from the header 38 to stub headers 59 for each row of high-temperature reheat panels 40 which have an outlet header 56. In a modification the lowtemperature reheat section of a construction generally similar to that shown in Fig. 1, is located at the top of the pass 20 and is connected to the high-temperature reheat section by a single header which is arranged above the roof of the unit and incorporates a baffle having a half-twist to effectively divide the header into two chambers. The high-temperature reheat panels are spaced across a horizontal gas pass laterally adjacent pairs of panels being connected to common inlet and outlet headers.