GB884015A - Improvements in vapour generators - Google Patents

Abstract

884,015. Forced flow steam boilers; superheaters. BABCOCK & WILCOX Ltd. July 28, 1960 [July 30, 1959], No. 26226/59. Classes 123(2) and 123(3) In a forced-flow tubulous boiler having a furnace chamber or gas pass lined with horizontal tube sections extending one above the other each section, comprising, e.g. tube sets 2, 4, has externally heated input and output groups of working medium connector tubes such as 1A-1F and 3A-3F which extend upwardly and downwardly respectively for connection to the corresponding tubes 2A, 2F and 4A, 4F of the sets 2, 4. A connector 6, welded to the groups of connector tubes and having a central blow-down access aperture 5, is tied by plates 7, 8 respectively to the cranked portions 9, 10 of the connector tube groups 1A-1F and 3A-3F, the adjacent ends of the tube sets being shaped to screen the connector 6 from the furnace chamber or gas pass and define an aperture 11 in the furnace wall axially aligned with the passage 5. The vertical limbs such as 1F<SP>1</SP>, 3F<SP>1</SP> of the connectors, Fig. 1, may be bent to follow the sloping sides of the connector. The connector tube groups are enclosed by a casing 13 which is connected to a skin casing 14 for the wall tubes by flexible sealing strips 15 and has a centrally apertured closure plate 18 secured to its outer face and to the connector 6, the casing 13, 14 being covered with a layer of heat insulating material 20. In a modification, Fig. 3, upwardly extending groups 31, 32 of connector tubes for sections 33, 34 are connected to downwardly extending connector groups 35, 36 for sections 37, 38 by tension plates 41, 42 which extend past the tube lengths 40 of an intermediate section and embrace respective tubes 43, 44 which carry aperture defining plates 45, 46 at their inner ends and are welded to the tension plates 41, 42 and to the enclosing casing. An access aperture need only be provided at one location in which case the tube lengths at the location are contiguously arranged at their extremities. Specifications 870,735 and 877,116 are referred to.