Wet gas measure by tapered tube variable area ring orifice

Great difficulties exist in wet gas flow measuring by means of standard orifice plate since the rangeability can only reach 3:1, with serious pressure loss plus liquid aggregation near the upstream orifice plate. Therefore, it is necessary to improve the structure of the standard orifice plate. This paper presents a sort of tapered tube variable area ring orifice device for wet gas measure, which is designed structurally by combination of a tapered tube, an inner circle-shaped movable baffle, a precision spring and a displacement sensor. Accordingly, a wet gas flow equation is shown that features the substitution of displacement for pressure difference. The rangeability can be as large as 15:1 in the case that the area ratio of the variable flow path is designed to be 5:1. The hydromechanical numerical simulation results indicate that both rate field and pressure field inside the device are stable and the pressure loss is one-third of the standard orifice plate. Further, the problems of liquid aggregation and pressure ducts block are avoided.H