An experimental investigation and design of flow-conditioning devices for orifice metering

Abstract

The problems associated with the use of flow conditioners usually relate to their ability to remove swirl and produce a fully developed mean velocity and turbulence profiles. In the present research, the mechanism for both swirl reduction and profile correction was suspected to be related to the action occurring within the turbulent mixing zone, which occurs within the first few diameters downstream of the flow straightener. A flow-conditioner device, which consists of a graded perforated plate with upstream vanes and short downstream tabs mounted on the plate has been designed, and demonstrated a good performance in terms of removing swirl and producing a fully developed flow within a short distance downstream of the flow conditioner. Furthermore, the flow conditioner produces good quality results in conjunction with an orifice plate meter. The vaned plate created a self-stabilizing mechanism for the time velocity profile and turbulence structure with respect to the axial position. Furthermore, the deviation on the discharge coefficient was low at around >0.2 per cent. Also the Zanker conditioner performs at its best when using the same design concept as the vaned plate (honeycomb followed by a perforated plate).