Rotork’s recent acquisition of K-Tork International Inc. has supplied Ash Hopper (AH Series) damper drives to the Entergy Corp.’s White Bluff Generating Station in Redfield, Arkansas to replace cylinder actuators that were proving to be unreliable. The units were installed in 2006 and after five years of operation a recent inspection has confirmed that the Type K products have solved a major maintenance problem at the plant.
The White Bluff Generating Station historically purchased 40-50 pneumatic cylinder actuators per year to operate their ash hopper rotary gates under routine maintenance budgets to replace failing cylinders. In 2006, the coal-fired power plant installed 136 Type K ‘AH Series’ damper drives to replace the poorly performing cylinder actuators.
The units were fitted with a high-cycle “no-play” linkage kit that eliminates hysteresis to adapt the TK-2 rotary drives to the existing ash hopper equipment. After five years in service, there have been no failures. By EPA mandate, ash particulate must be contained and cannot simply accumulate in piles on the ground in the way that coal piles are kept.
The pneumatic conveyors that operate under the precipitators collect the ash and push it with compressed air into collection bins, where it is sold as an ingredient for dry wall production or used in concrete mixes for civil construction. When a conveyor bank is in operation, the Type K damper drives cycle every 90-120 seconds 24/7. Together with the Type K Representative, Boiler Valve and Equipment Company, K-Tork hopes to complete the Ash Hopper retrofit in 2012.