GB230941A - Improvements in or relating to furnaces - Google Patents

Abstract

230,941. Smallwood, A. Dec. 29, 1923. Gaseous-fuel furnaces.-In a tunnel furnace having a number of independently controllable heating-zones gas is supplied to each zone from a separate manifold i through a number of combustion shafts h, to each of which heated air is supplied in regulable quantities. The furnace shown has four heating - zones in addition to entrance and cooling sections, and on each side of each zone is a gas manifold i in dampered communication with a lower distributing-flue j supplied from a main k. From each manifold upcast passages or shafts h lead to the lower part of the tunnel, and into each passage a supply of air, regulatable by a damper at s<1>, is delivered from one or other of the flues n, m, n<1>, m<1>. The supplies of heating-gases through the shafts h may be controlled by dampers manipulated through openings h<1>. Preferably two pairs of independently controllable waste gas outlets are provided at the entrance end of the tunnel, and these lead to an underground flue p' adjacent which is the air inlet flue o. The air supply may also be heated in flues around the cooling- zone of the tunnel. The ports through which the heating-gases are delivered are so constructed that in the first of the heating-zones the gases flow more or less horizontally into the tunnel, as indicated at the left hand part of Fig. 5, and in the subsequent zones the direction of delivery approaches nearer to the vertical, as shown at the right.