ES296590A1 - Improvements in or relating to steam generators - Google Patents

Abstract

A steam generator comprises a horizontal cylindrical vessel 1 through which extends a cylindrical furnace tube 6, having transverse corrugations 7 at its central portion to permit expansion, surrounded by smoke tubes 8 which are interconnected at one end of the vessel by an annular smoke box 9 whilst at the other end the upper tubes are connected to the furnace outlet by a flue 10 and the bottom tubes are connected to an outlet 12 leading to a chimney (not shown). A steam and water drum 2 having a safety valve 19 and steam off-take tubes 17 is located above the vessel 1. Steam and water pass from the vessel into the drum through vertical radial riser pipes 3 capped by deflectors 5 which separate steam and water the latter returning to the vessel through laterally disposed downcomers 4 having discharge cocks 20 at their lowest point. A feed water supply pipe 21, Fig. 2 (not shown) is laterally disposed on the vessel and both the vessel and drum may have manholes 22 suitably located. A sight hole provided in the outer vertical wall of the flue 10 is formed by a tube 13 having an end plate 14 and an axle 15, Fig. 3 (not shown) on which pivots a sector-shaped transparent panel 16 of sufficient area to allow one part to be cleaned whilst the other covers the sight hole. The panel can then be pivoted to bring the cleaned portion over the hole and to allow the portion originally covering the hole to be cleaned. In another embodiment the furnace tube is formed by a helical tube coil having contacting turns welded together, preheated air is supplied to the furnace and water from the drum is circulated at a rate which may be varied, through the tube by a pump which discharges into the steam space of the drum. The flow through the smoke tubes may be controlled or accelerated in any known manner for example by placing accelerating bars in the tubes.