Venturi design for metering solids flow in gas-solids suspensions

The utility of venturimeters to meter the flow rate of gas-solid suspensions was investigated. The data show that the pessure drop between the pipe and throat varies linearly with solids mass flow rate at a given gas mass flow rate. The slope of this curve, which is related to the pressure ratio parameter, provides a measure of sensitivity of venturimeter to loading (solids/gas mass flow ratio). The optimum geometry consisted of a flow nozzle configuration with an extended throat section. The performance was considerably improved over the conventional venturi. An annular venturi geometry with two approach angles was tested. It performed equivalently to a conventional venturi, but could be located as close as five diameters to an upstream elbow with no deterioration in performance. Also, the data show that venturi performance is unaffected by orientation of venturi (horizontal or vertical). The effect of particle size distribution is not easily quantified. The total head loss measurements showed that there were no excessive head losses associated with gas-solids flow in a venturimeter.