The Vibratory Ash Extractor (VAX) recently unveiled by United Conveyor Corp. is designed to improve operational efficiencies for dry bottom ash – handling at plants whose operators want to transition away from wet systems. Suitable for pulverized bituminous and subbituminous coal boilers, the VAX can also be retrofitted for lignite-fired boilers. To minimize forced boiler outages and improve boiler efficiency, the extractor has no exposed moving parts in the boiler flue gas environment. It incorporates a vibratory conveyer trough that can resist large slag falls and absorb clinker impact, reducing stress to the bin capturing the bottom ash. Coil springs absorb impact and transmit the vibrating motion to the steel pan, eliminating the need for tensioning devices or secondary conveyors to remove fine particles.
The VAX conveyor vibration velocity controller automatically compensates for load fluctuations and cooling airflow capacity. Controlled forced air over the entire surface of ash particles creates intensive cooling — from 1,800F to 500F — and ensures uniform bed temperatures to enhance the oxidation of residual carbon in falling ash. The air space above the VAX contains the dust cloud, reducing loss of radiation energy when compared to wet bottom ash systems. (www.unitedconveyor.com)