Patent GB-190120906-A (GB)
Title: Improvements in Smoke-consuming Apparatus for Boiler Furnaces.
Inventor: BLOXAM ARTHUR GEORGE
Filed: 1901-10-18
Granted: 1902-04-03
Abstract: 20,906. Bloxam, A. G., [Ganz & Co.]. Oct. 18. Smoke-consuming.-Relates to apparatus for the regulated supply of air over the fire for secondary combustion, and for the control of flue dampers, the apparatus being operated by the movements of the fire-door and controlled by a dashpot. According to the arrangement shown in Figs. 1 and 2, the fire-door hinge pin, which is fast to the door, carries a double arm 4, shown separately in Figs. 9 and 10, on which are pivoted two fingers 5 and 6, made in one piece but in different planes. Mounted beside the door is a cylinder 16 to which compressed fluid is admitted, to depress its piston, by a valve operated by the lever 8, and from which it escapes through an adjustable valve 17. The piston-rod is connected by a chain 33 to the flue damper 2 ; it also carries a rod 7 arranged parallel to the lever 8. The fire-door is fitted below with an air-admission flap 14 operated by a sliding wedge cam 13 connected by the lever 11 and link 10 to the rod 7. The parts being in the position shown, on opening the fire-door, the finger 5 is deflected by the rod 7 as shown in Fig. 9, and turns the finger 6 so that it escapes the lever 8 ; the finger 5 finally escapes the rod 7. On closing the fire-door, the finger 5 is retained by the rod 7, so that the finger 6 is moved to the left, as shown in Fig. 10, and shifts the lever 8, thus opening the valve of the cylinder 16. The piston is thus depressed, the damper 2 opened, and the air-admission flap 14 opened by the wedge 13 ; the descent of the bars 7 also liberates the finger 5. After the door is shut, the damper 2 and flap 14 close gradually under the weight of the damper, the contents of the cylinder 16 being gradually expelled through the adjustable valve 17. The rate of closure of the flap 14 may be varied by the substitution of wedge pieces of different form, for the plain wedge piece 13, and the rate of closure of the damper 2 may be similarly regulated by employing a scroll pulley instead of a plain pulley. Figs. 5 and 6 show a modification in which the supply of steam to a draught-inducing injector is controlled simultaneously with the admission of air through openings in the door. The door hinge carries a tappet sleeve 41, operating a loose tappet sleeve 23 on which are mounted a face-cam 13 and an eccentric 22. The face-cam operates lower flaps 14 in the fire-door by means of the roller 20. The eccentric 22 operates the valve 21 controlling the supply of steam to the injector 18. The rotation of the sleeve 23 is communicated by a rack and pinion 25 to the piston 28 of a dash-pot. On opening the fire-door, the cam and eccentric are turned, and the valve 21 is opened. On closing the door, the cam and eccentric are left behind, being retained by the dash-pot ; and the roller 20, riding up the incline of the cam, opens the louvres 14. The piston of the dash-pot, being pressed by the spring 36, acts by means of the rack and pinion 25 to bring the cam and eccentric back gradually to their original position, allowing the valve 21 and the louvres 14 to close. In a modification of the valve 21, it is arranged to control also the supply of steam to a chimney draught inducer. The application to locomotive and marine boilers is mentioned.