Patent GB-190225833-A (GB)
Title: Improvements in Apparatus for Consuming Smoke in Furnaces.
Inventor: COTTON ROBERT
Filed: 1902-11-24
Granted: 1903-11-24
Abstract: 25,833. Cotton, R., Todd, H., and Blizzard, A. E. Nov. 24. Air supply, heating and regulating; smoke-consuming.- Relates to airheaters for heating air for secondary combustion, and to automatic arrangements in connection with the furnace door for controlling the supply of air. One form of heater A is shown in Figs. 1 and 2 applied to a boiler furnace. It consists of a pair of slabs of refractory material placed behind the grate and inclined towards each other to form an arch. Air passages B are formed in the slabs, communicating with a cast-iron box D, the bottom of which E acts as an air valve or door. The air is heated in the passages, and delivered, as shown by arrows, to mix with and consume the smoke passing between and over the slabs. The valve E may be operated by hand, or automatically by the opening and closing of the furnace door. The Provisional Specification describes also a modified arrangement working '' alternately " as a regenerator, in which similar slabs, without air passages, are employed. Fig. 1 shows also another form of heater and air distributer at the front of the furnace, consisting of a vertical plate F, fixed a few inches from the door, and provided with nozzles for the purpose of heating and delivering the air which enters through an air valve H in the fire-door. The outside edge of the plate fills the boiler flue. Another flat blank plate G is fixed to the fire-door in front of the plate F, preventing access of air to the furnace except through the nozzles. This latter arrrangemeut is not claimed. Fig. 3 shows the automatic arrangement for opening and closing the doors E, H. A lever I, mounted on the fire-door and connected by links and levers to the door H, rests against an arm J<1> fixed to the rod J. This rod is coupled to the air valve E of the heater A. A chain I, adjustably connected to the rod J by a loose collar T<1> and screw T<2>, passes round a pulley T<3>, through a pipe, round another guide-pulley, and thence through the pipe S ; it is then joined to the piston in the cylinder N. A valve P admits air to the cylinder, the amount being regulated by a cock O. A spring R, regulated by a set-screw Q, tends to press the valve down. One end of a chain K is fixed to the fire-door, and the other to a chain-wheel L turning with the corresponding guide-pulley of the chain T. When the furnace door is opened, the chain K become slack and lets the rack M fall; the cylinder N also falls, and turns the chain-wheel L, lapping up the chain K. When the door is shut, the chain pulls the rack and cylinder up, and, since the air cannot enter fast enough at the top, the piston is also pulled up and the chain T pulled, thereby opening the valve E. Figs. 5 and 6 show the invention applied to furnaces for ovens or kilns, Fig. 5 being a longitudinal vertical section and Fig. 6 a cross-sectional elevation. The heater is arranged in the crown of the furnace, and delivers heated air to mix with the furnace gases as they pass in the kiln. The heater is made in three parts, on the lowest of which ribs 2 are formed, to support the two upper parts and to form air spaces with them. These top parts carry ribs, to support the roof of the furnace and to form passages 4 for a part of the furnace gases. Air enters the heater at the holes 5, and the amount entering is regulated automatically or by hand. The Provisional Specification describes the furnace as having a small secondary door for levelling or stirring the fire. Both this and the large door may be used to work the automatic air supply.