Batch scales

    Stoker boiler fuel measurement

    Stock® Batch Scales are designed for measuring coal usage into stoker boilers. They are primarily used to feed multiple stokers through transition chutework such as the Stock® Conical® Distributor. Batch scales are typically mounted underneath each bunker outlet for gravity feed on to an internal feed belt that conveys coal from the inlet to a weigh hopper. The weigh hopper is suspended by dual load cells.

    During the load cycle, the belt runs to fill the weigh hopper. The strain gauge load cells sense the weight and send a signal to the controller. The controller compares the measured weight with the pre-selected weight, compensates for dribble, and turns off the belt drive at precisely the right moment. During each cycle, in the short time between the hopper dump and the start of the belt drive, the system measures the tare weight to ensure the most accurate measurement possible. Even if material sticks to the hopper, the system will make the necessary compensation and give an indication of abnormal conditions.

    The microprocessor control displays the total weight delivered, the actual batch weight delivered. The rate of material feed and the material density are available.

    Summary of Benefits

    • Improves fuel accountability with increased scale accuracy plus electronic measuring and indicating devices.
    • Increases reliability by using a pneumatic gate latching system plus other mechanical design improvements.
    • Reduces downtime by indicating faults and required corrective action.
    • Replaces existing scales directly.
    • Accuracy of +/- 0.25%.