GB586523A - Improvements in or relating to air heating apparatus - Google Patents

Abstract

586,523. Air heating furnaces. SUTTON, B. W., and AMENT, C. J. June 5, 1944, No. 10769. [Class 64 (i)] In an air heater comprising a furnace chamber 1 upon which is mounted a heat-exchanging element 2 through which flow air to be heated and combustion gases from the furnace, the combustion gases pass from the furnace chamber 1 through an opening 9 in a firebrick arch 8 into a space 10 between the arch 8 and the upper lining 11 of the furnace chamber, and thence pass through an outlet 4 situated adjacent to the hot air outlet from the heat exchanging element 2 and through the element 2 in counter current to the air flow to an outlet 26, 13 adjacent to the cold air inlet 12. The heat exchanger 2 comprises a casing containing parallel plates forming passages through alternate ones of which air is forced by a fan 5. A by-pass passage is provided on each side of the set of plates, these passages being controlled by dampers linked to a single control lever. An additional outlet 14 for hot gases may be provided in the roof 11, to prevent condensation of moisture from the air entering the heat exchanger 2. The relative sizes of the openings 4, 14 may be made variable by a horizontally slidable element between them. Secondary air for combustion is heated in pipes 16 at the sides of the furnace and, after mixing with cold air in the box 18, enters the furnace through openings 19. The pipes 16 may be supplied with air from the fan 5. Primary and secondary combustion air may be thermostatically controlled. The firebars are V-shaped, with one arm longer than the other. A fuel hopper at one or each side of the furnace has an outlet extending the length of the furnace.