Hot slag and ash fall into the zone with water filling. The reclaimer serves for cooling and dust-free transportation of the slag and ash mixture from the discharge hopper under the boiler into the crusher and then into the canalization channel; in connection with the steel hopper it is sealed perfectly, thus preventing the penetration of false air into the boiler from the boiler house. The slag reclaimer is usually situated at the level of ±0.0 m. It comprises the welded bath, driving station with the front drive shaft and the drive itself, tensioning station with the rear take-up shaft and the discharge chain. The centre reclaimer, i.e. the bath under the boiler hopper, can either be anchored to the base or mobile, on traveling wheels. The reversing chain under the bath is accessible after removing the side covers, even in operation.
The straight part of the bath is made up of several welded parts, with the sides and bottom reinforced with flat steel and rolled sections. The bath width is 1400 mm, length as needed and the bath is ended by connecting flanges for screwing together with a driving and reversing station. The bath frame is made of U100 and U120 sections and is fitted with brackets. The bath and the frame are connected by means of screws. Cleaning and inspection doors are installed in the sides of the bath to make the reclaimer interior as well as the boiler combustion chamber accessible. The bath bottom and the sloping haunch of the bottom of the driving station are lined with abrasion-resistant metal.
The water depth in the bath is approximately 500 mm and due to sufficient dipping of the steel hopper it reliably ensures tightness of the bottom of the combustion chamber. The minimum water level in the bath is ensured by the water supply flowing above the bath. The maximum water level is regulated by a side spillway located on the bath side. Water overflowing through the spillway flows through the DN 100 tube into the canalization channel. Above the batch bottom, the DN 100 discharge spout with the gate valve is located, the release of which may drain all the water content in the reclaimer. The rear side of the bath is ended by a flange connecting it with the tensioning station. The connection is secured with a seal weld.
The driving station, the bottom of which slopes 30° from the horizontal plane, is connected to the front side of the bath. The end of the sloped bottom consists of a spillway for reclaimed slag and water residue to the crusher, which is located under the driving station. The bearing housings, where the bearings and driving shaft are housed, are screwed to the side walls. Two chain wheels driving the discharge chain with a scraper-type extractor are guided on the shaft by springs. The inspection door, which may also be used to release the blocked crusher rotor, is located on the side wall in the area above the crusher. The whole upper part of the driving station above the working area is protected by a cover. The flange electric motor with a frequency converter and with a single-speed planetary gearbox slipped over the driving shaft is installed on the structure of the driving station. The reclaimer is equipped with the automatic lubrication of all bearings. The tensioning (reversing) station is connected to the rear of the bath by means of screwed flanges. The bottom behind the guide pulleys is raised at an angle of 30° from the horizontal plane. The rear take-up shaft is also housed in bearings and two chain wheels with slip are mounted on them, thus balancing the possible different lengths of both discharge chains. The respective bearing boxes are displaceably mounted in the guides screwed to the upper flanges of the tensioning station. The tensioning device with springs used to set the tensioning force of the chain is connected to each bearing box. The drive chains may also be tensioned automatically by means of a pressure air cylinder. Four guide pulleys are overhung on the side walls of the tensioning station. For better visual check of the condition of the discharge chain, the rear side of the tensioning station is closed with a cover made of perforated sheet metal. The console, with two sensors for the discharge chain run indication is placed between the upper and lower covers of the rear panel of the tensioning station. The slag reclaimer is equipped with two discharge chains with 22x86 links, which are made of 21MnNiMoCr material. The free ends of both chains are connected by VHV22x86 coupling links. Scrapers taking the slag towards the driving station are attached on chains, which must not become twisted during mounting, by means of KFB 22x86 clamps. The scrapers are attached to the chains on every 9th link. The transverse distance between the chains is 1,224 mm. The chain in the working area is trailed by scrapers over the friction metal of the bottom and returns under the bath on the lower guide paths. The chain at the bottom of the reclaimer is guided and held by guide pulleys. The discharge chain is protected with detachable covers over the total length of the bath. The water distribution system for the reclaimer and for cooling the steel hopper is connected to the current water supply, DN 100. Water is distributed through the DN 80 tube. All rinsing pipes ended in a nozzle and the appropriate gate valves (ball valves). The bath is filled with water through the rinsing nozzles of the guide pulleys. The water spillway is guided on the side of the bath out of the overflow vessel through the DN 125 tube and led to the canalization channel. The DN 80 drainpipe with the appropriate gate valve leads out of the bottom of the bath under the overflow vessel and it is also led to the canalization channel.
Location of the slag reclaimer under the boiler hopper