GB1434530A - Pressure relief arrangements for combustion chamber equipment employed in air heaters for space heating purposes - Google Patents

Abstract

1434530 Vent or relief valves; preventing explosions; outlets to chimneys COLT INTERNATIONAL Ltd 1 Feb 1974 [12 Dec 1972] 57372/72 Headings F4B and F4W A pressure relief arrangement for fuel fired space heating equipment comprises a pressure relief door closing an opening between the combustion chamber and a pressure relief chamber leading to the heater flue, and a second pressure relief door closes an opening leading from the chamber to the exterior of the space to be heated. The pressure relief chamber is connected at 7 to the outlet from the heat exchanger of the space heater and is mounted on the combustion chamber by flanges 6 so that an outlet from the combustion chamber is normally closed by relief valve 9. A spigot is provided for the connection of a flue 33, alternative flue connections being closed by cups 34, Fig. IV. A spigot of larger diameter is connected to a pressure relief pipe 42 normally closed by a valve 30 outside the building. An alternative large diameter spigot 32 forms a flue sump. The pressure relief chamber may be arranged with the pressure relief door from the combustion chamber at the side of the flue gas outlet from the heat exchanger, and the flue 33 may be connected to the pressure relief box by a T 46, one branch of which forms a flue sump 32<SP>1</SP> outside the space to be heated. The pressure relief valve 9 within the chamber, Fig. 1, is hinged about an axis at angle of about 45 degrees to the horizontal, so that it can be normally biased to a closed position by a weight, but the hinge cannot become blocked by debris. A strap on the hinge prevents the valve opening beyond the vertical. Minor pressure surges or explosions in the combustion chamber cause gases to be vented direct to the pressure relief chamber and the flue, bypassing the heat exchanger, while major explosions are vented to the outside of the space to be heated.