GB335886A - Improved chimney top for the prevention of down draught - Google Patents

Abstract

335,886. Grieve, G. M. June 27, 1929. Chimney-tops.-A chimney-top comprises an inner rectangular tube A positioned over the chimneys and an outer tube B of round, square, octagonal, or other cross-section mounted eccentrically thereon, the inner tube being provided with exterior vertical partitions V, the space between the tubes being thus divided into vertical ducts 1 - - 5. Openings U arranged obliquely relative to the walls of the inner tube are provided at the bottom of the outer tube, and the partitions V are provided at the bottom with sloping portions adjacent the openings U, the total cross-section of the openings U and of the ducts being equal to that of the outlet of the tapered top T of the outer tube. The inner tube is provided with a cover F which rests upon the sloping top of the side walls G, H, the cover being provided at the bottom with a vertical piece Y carrying brackets K which coact with studs L on the walls G, H to limit the upward movement of the cover when a brush is passed through the tube. The wall I of the inner tube adjacent the duct 1 is provided with a top which slopes inwards and is provided with a vertical portion P, the space between the top of the portion P and the under side of the top of the cover F forming a vertical outlet R to the inner tube, which outlet is protected by the parts S of the walls G, H. In action, horizontal wind currents entering the openings U and striking the walls G, H, are diverted against the sloping portions at the bottom of the partitions V and are deflected up the ducts, whilst any currents entering the duct 1 are diverted by the wall I and leave the chimney by the adjacent opening U, thus creating a suction and preventing down-draught from entering the inner tube.