Hot ash and slag no problem for tough conveyor components
29 October 2020 | Web Article Number: ME202020929
BMG’s power transmission range encompasses German-made Heko conveyor components including round link chains and components for submerged chain conveyors.
“We recommend the use of submerged chain conveyors for our customers who work with coal, wood, refuse and scrubber sludge, to effectively collect, cool and drain bottom ash from a boiler discharge. These conveyors, which are fitted with secure releases, are designed to handle bottom ash efficiently and safely,” said Carlo Beukes, Business Unit Manager, Power Transmission Division, BMG
Submerged chain conveyors are often installed for the transportation of slag granulated material, ash made of stone and brown coal firing, as well as metallurgical process residue or waste ash. Fluid slag or hot ash from melt firing is filled in a vessel with water for cooling and then transported via a chain conveyor from the vessel to an ash bunker.
“Heko chain strands are highly wear-resistant, case hardened and manufactured with low tolerances. Chain sprockets and chain rollers, with replaceable segments of teeth, are sealed for safe use under water.”
Beukes added that Heko’s pocket teeth chain wheels, with toothed rims, are manufactured from special alloy steels and designed for extended service life.
Chain contact surfaces are machined and the sides are chamfered to ensure a positive contact with the chain and a good lead into the wheel. Chain contact surfaces are hardened for long service life.
Pocket toothed chain wheels are supplied for use with special attachments - vertical shackle to DIN or TS-shackle and lift-in scraper bars. Replaceable rims have the advantage that the hub can be left in place during refurbishment, which saves maintenance time and reduces costs. Purchasing costs for replacements are also lower compared to the investment in completely new wheels.
Dimensions for existing installations are tailored to suit every specific application.
Heko support idling wheels and snub wheels are alternative solutions to guide rails for horizontal and inclined conveyors. The use of wheels reduces friction and thus power requirements.
Heko chain systems with attachments can be supplied pre-assembled (with the chain as endless round strands), thus eliminating the need for on-site assembly. Plug-in scraper attachments type SMO, enable fast connection to endless chain strands with chain locks, making reversible conveying possible.
Also in BMG’s range are round link chains, which have been developed by Heko for bucket elevators and chain conveyors. “These components are suitable for use in various sectors, including mining and quarrying, cement, chemical and incinerating plants, paper production, food and beverage, as well as artificial manure and general machine industries,” Beukes said.
The chains are manufactured from durable materials, including manganese, chrome-nickel and fine grain chrome-nickel alloy steels. Computer-controlled heat-treatment processes are employed to produce tempered or case-hardened chains.
Beukes said advantages of case-hardening include a high breaking load, resulting from a tough, fine grain core and high wear-resistance, from a minimum surface hardness of 800 HV. In addition to six standard hardening depths, BMG also offers Heko products with hardening depths to suit specific requirements.
The Heko range comprises round steel chains, bucket and scraper attachments, chain wheels, buckets and shafts, as well as complete return and tensioning units. Heat-resistant ring kiln chains for rotary kilns also form part of the range.
BMG’s national branch network offers a technical advisory service on correct chain selection, which Beukes said is a critical factor in power transmission systems.