ADJUSTABLE FLOW CONTROL ELEMENTS FOR BALANCING PULVERIZED COAL FLOW AT COAL PIPE SPLITTER JUNCTIONS

摘要

An adjustable device installed at the inlet of conventional junctions/splitters (116) for on-line control of the distribution of coal among the outlet pipes is herein disclosed. The device includes a plurality of flow control elements (60) each positioned upstream of a plurality of flow channels in the riffler (50) for directing coal flow to the outlet pipes. Each flow control element preferably comprises a rounded convex edge leading to straight tapered sides (Fig. 9). The surfaces of the sides may be roughened or textured (63) for promoting turbulent boundary layers (Fig. 9). In addition, conventional fixed or variable orifices may be used in combination with the flow control elements for balancing primary air flow rates. The device allows fine-adjustment control of coal flow rates when used in combination with the slotted riffler, yet it has negligible effect on the distribution of primary air. The combination of the riffler assembly and the coal flow control elements (60) results in closely balanced coal flow. Balanced coal flow is imperative to the optimization of the operation of pulverized coal boiler systems (i.e. reduced pollutant emissions, improved combustion efficiency).