GB1299061A - Once through vapour generator with division wall - Google Patents

Abstract

1299061 Once through vapour generators FOSTER WHEELER CORP 2 Jan 1970 [23 Jan 1969] 258/70 Heading F4A A once-through vapour generator A comprises a radiantly heated furnace enclosure 8 formed by vertical tube walls 14, 16, 18, 20, containing at least one division wall 52, the walls being connected by headers 60, 62, 68, 70, 74, 76 so that fluid flows through the division wall to first and second passes in at least the lower portion of the furnace walls formed from the front and rear walls 14, 16, and the side walls 18, 20 respectively. The rear wall is divided into tubular exit screens 24, 28 through which furnace gases pass to a vestibule D and convection or heat recovery area E, and a tubular roof 22 extends across both the furnace and convection areas. The convection area is divided by a partition wall 32 into front and rear gas passes 38, 40. The rear pass contains an economizer 46 and a primary super heater 42; the front pass contains a reheater 44. A radiant planten superheater 48 is located in the furnace, and a finishing super heater 30 is provided between the screens 24, 28. The furnace is coal fired by burners F supplied by air heated in a heater I in the flue system. To prevent fractures of the tube walls due to large temperature differences between adjacent tubes, corner panels 82, 84, 86, 88, Fig. 4 and Fig. 3 (not shown), form a buffer circuit supplied by a combination of portions of the flows to the first and second passes. In a second embodiment, Figs. 7, 8 (not shown), the first and second passes occupy the lower part of the furnace walls and a third flow pass is provided by the upper portion of the side and front walls, and the exit screens may also be included in this pass