The hotdisc is a simple combustion device, integrated with the pre-heater and calciner systems. This device manufactured by large FL Smidth, has a large, moving hearth furnace which consists of a annular, refractory-lined combustion chamber with a stationary casing, a roof, and a central post. The bottom of the combustion chamber is a horizontal, refractory lined rotary disc. It also consists of a wall upon which scraper segments are mounted. The wall, itself, divides the annular combustion chamber between the waste feed inlet and the residual ash outlet. It is equipped with a slewing ring which rests on a support and carries the rotary disc. The slewing ring is toothed on the inside and driven by two geared motors with frequency drive. The support for the central post, slewing ring and casing rest is from a common bottom frame. The two outer supports are provided with openings to enable access for maintenance and inspection. There are also openings in the central post to draw in ambient cooling air from below the rotary disc by means of natural draught. The control of the temperature of the outlet gases from the hotdisc into the riser duct – approximately 1050?C – by addition of materials from the second lowermost cyclone. The control takes place by operating the gate dividing the materials between the hotdisc and the calciner. The waste feed rate to the hotdisc is kept constant and the temperature in the bottom cyclone is controlled by adjusting the feed rate of the fuel, usually coal, to the calciner.
Contact: FL Smidth Inc Tel: +1-610 264-6011, 800-523-9482 Fax: +1-610-264-6170 Email: info-us@flsmidth.com Website: www.flsmidth.com