DEMECH has entered into technical collaboration with Hitachi Power Europe GmbH (HPE), Germany; to manufacture Gravimetric Coal Feeders. This gives Demech the unique advantage to supply Gravimetric Coal Feeders using the proven and reliable designs of Hitachi Power Europe GmbH.
The major function of Gravimetric Coal Feeders is to continuously feed the specified quantity of raw coal from the overhead bunkers to the coal pulveriser. However, it is used for any solid fuel feeding to boilers. The feeder also reports the total fuel consumption for a specified period which helps in calculating and controlling cost of power production.
- Gravimetric Coal Feeder is a belt conveyor which measures the amount of coal, in terms of weight, being conveyed / fed to the pulveriser.
- The feed rate is computed from load cell signal and belt speed signal collected from the load cells strategically mounted below the belt and the hollow shaft sensor mounted on the tail pulley of the belt conveyor in the weigh controller.
- The control and instrumentation features are achieved by combination of weigh controller, VFD and PLC-HMI housed in local & remote control panel.
DEMECH gravimetric coal feeders offer the following advantages –
- The most prominent feature of Demech feeders is the load cell mounting arrangement which is bottom supported, pivot mounted cantilever frame. This arrangement makes it possible to use only one load cell for accurate load measurement unlike the side suspended two load cell arrangement.
- This arrangement provides rigidity, easy alignment, protection against vibration & impact and has no effect of lateral forces due to the belt motion.
- This also makes it possible to have low tension on the belt thereby increasing the life of the belt. Due to low belt tension, the feeder does not have the weigh down roller and the tail end roller also act as tensioning roller with external tensioning arrangement.
- The belt has a unique continuous side wall with no cuts or opening which virtually eliminates coal spillage and does not allow any seepage of water to underside of belt.
- The skirt liners cover the side walls from inside with their gap so adjusted to avoid any lodging of bigger coal particles between them.
- The crowned drive pulley helps in centering the belt with addition of bottom V-guide further protects against belt slippage.
- The motors are direct shaft mounted eliminating alignment activity.