GB405303A - Improvements in or relating to waste heat and dual fired steam generators or boilers - Google Patents

Abstract

405,303. Water-tube steam boilers ; water chambers in flues. GILL, H., The Hermitage, Old Fort Road, Shoreham-by-Sea. July 4, 1932, No. 18902. [Class 123 (ii).] Steam boilers or water heaters comprise outer and inner elements the outer element consisting of an annular water chamber surrounding an internal heating flue with curved or bent or thimble tubes mounted in the chamber inner wall and extending into the flue, and the inner element being either independent from the outer and fitted with water or fire-tubes or being connected with it to provide circulation between them in which case the water or fire tubes may be omitted. In the form shown in Fig. 5 in which gilled loop tubes f, p, are employed for the outer and inner elements a, m, a common circulation is maintained by pipes o, n at the lower and upper parts of the water space of the outer element. Modifications of the inner element include vertical water-tubes connecting headers from which the pipes n, o lead to the outer water space, and a vertical water cylinder with vertical fire-tubes. The heating flue may be of reversed type providing a central and annular passage formed by the inner element which comprises an annulus with inwardly and optionally outwardly extending loop tubes. Or the inner element may comprise a chamber with outwardly extending thimbles an annular baffle separating these from the outer element thimbles and providing a reversed flow for the gases. The inner and outer elements of the boiler shown in Fig. 24 are heated by oil burners and waste heat or exhaust gases respectively the gases discharging to atmosphere through conduits j<2>, j<1> passing through the outer element water space. Conduits j<1>, j<2>, may be co-axial. Gills which may be provided on the water-tubes may be arranged longitudinally or in planes normal to the tube or they may comprise a continuous helix. A less number of thicker fins are preferably provided on tubes nearest the gas inlet. The boiler elements may be arranged horizontally.