GB607818A - Improvements in or relating to underfed mechanical stokers - Google Patents

Abstract

607,818. Furnaces. WARD, F. H. ALLMAN-. Feb. 12,1946, No. 4356. [Class 51(i)] In an underfeed stoker wherein the grate or retort is divided, each section is supplied by an independent worm and a feeder delivers fuel from a hopper, or hoppers, to the worms. As shown in plan in Fig. 1, hoppers 1, 2 are provided with shaker feeders 3, 4 e.g. as shown in Specification 556,720, [Group XXX], delivering fuel into the casings 5, 6 of worms 7, 8 which are driven by a motor 11 through belting 14, 15 and reduction gearing 16, 17. A fan 13 on the shaft 12, supplies air to a trunking 18 which is branched to blow the two fires. In a modification, a single hopper feeds both worms by means of a double-ended shaker feeder, two air trunks flanking the worm casings are provided, and the two fans are carried on a transverse shaft driven through a belt from a motor and connected through reduction gearing to the worm shafts. In another arrangement, the worms each with its flanking air trunk are each driven by a separate motor, and two hoppers which are staggered longitudinally of the worms to reduce overall width, supply the worm casings by separate single ended shaker feeders. Alternatively the .hoppers may be arranged in the same transverse line with longitudinally offset feeders. Fuel feeding may be thermostatically controlled as described in Specification 556,720, or each section may be controlled by its own thermostat. Fig. 9 shows two shaker feeders 32, 33 operated by a common crank disc 34 having a pin 35 which rocks a lever 36 pivoted at 37 and formed with arcuate parts 38, 39 slidably engaging the counterbalanced connecting-rods 40, 41. The strokes of the feeders are thus independently variable. A main thermostat 44 is coupled by chains 42, 43 to the rods 40, 41, the pulleys 45, 46 being positioned by thermostats 47, 48 each responding to one section of the retort. Chains 49, 50 attached to the thermostats 47, 48 pass over pulleys 51, 52 and are secured to the thermostat 44. The pulleys 51, 52 are'connected to dampers 53, 54 in the air trunkings so that both air and fuel supplies are automatically controlled.