Perfectionnements aux chaudières tubulaires

摘要

870,735. Water-tube steam boilers; superheaters. BABCOCK & WILCOX Ltd. July 29, 1959 [Aug. 1, 1958], No. 24949/58. Classes 123(2) and 123(3) In a forced flow steam boiler of the kind having circuits connected in parallel for the flow of the working medium and an upright furnace chamber space lined by tube lengths of the circuits, equal heating of the circuits is ensured by dividing the furnaces space into a number of zones one above the other each occupied by a lining tube section, each section comprising horizontal tube lengths of the different circuits. The arrangement of tubes is shown diagrammatically in Fig. 1 wherein a furnace chamber 1 is lined with horizontal tubes 2, the lining comprising two sections 5A, 5B. Four circuits constituted by two pairs of tubes 3, 3' and 4, 41 are shown extending from a distribution header 6. The tubes 3, 31 enter the furnace chamber through a wall 7 and then pass is one direction around one half of the chamber as part of the lining section 5A to leave the chamber through the opposite wall 10. The tubes 3, 31 are then continued upwardly as tubes 8, 9 and re-enter the chamber through the wall 10 wherein they pass around one half of the chamber as part of the lining section 5B to leave through the wall 7. The tubes 4. 41 line the opposite halves of the chamber in both the sections 5A, 5B. The complete lining of tubes arranged in this manner may have any suitable number of circuits and sections. For example, in Fig. 3, not shown, the lining has 128 circuits and 14 sections. The tubes 2 of each section of the wall lining are welded together so that each section is rigid unit of box girder like form. Each section of the wall lining is supported by suspension from vertical buckstays 50. Fig. 4, gas tight expansion joints, Fig. 6, being provided between adjacent sections. The buckstays 50 which are supported against outward movement by horizontal buckstays 51' present rows of hinge-like connectors 53 to which are welded the upper tubes of respective sections, the sections thus being able to expand and contract independently of one another. The setting has an external gastight casing of metal plates 60, 61, whilst the tube bundles passing upwardly from one section to the next are packed around with insulation 62. The expansion gap 48, Fig. 6, between adjacent sections 41, 42 is sealed by a gastight expansion bellows 100 which is built in between adjacent positions of the insulating wall 63A...63D of the unit. In a modification a natural circulation boiler having a furnace lined with vertical generating tubes has a superposed radiation space lined with horizontal superheater tubes arranged as described above.